/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using OpenSim.Region.ScriptEngine.Shared.ScriptBase;
using OpenSim.Region.ScriptEngine.XMREngine;
using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.Serialization;
using System.Text;
using System.Threading;

using LSL_Float = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLFloat;
using LSL_Integer = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLInteger;
using LSL_Key = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLString;
using LSL_List = OpenSim.Region.ScriptEngine.Shared.LSL_Types.list;
using LSL_Rotation = OpenSim.Region.ScriptEngine.Shared.LSL_Types.Quaternion;
using LSL_String = OpenSim.Region.ScriptEngine.Shared.LSL_Types.LSLString;
using LSL_Vector = OpenSim.Region.ScriptEngine.Shared.LSL_Types.Vector3;

/**
 * @brief translate a reduced script token into corresponding CIL code.
 * The single script token contains a tokenized and textured version of the whole script file.
 */

namespace OpenSim.Region.ScriptEngine.XMREngine
{
    public interface IScriptCodeGen
    {
        ScriptMyILGen ilGen { get; } // the output instruction stream
        void ErrorMsg (Token token, string message);
        void PushDefaultValue (TokenType type);
        void PushXMRInst (); 
    }

    public class ScriptCodeGen : IScriptCodeGen
    {
        private static readonly bool DEBUG_STACKCAPRES = false;
        private static readonly bool DEBUG_TRYSTMT = false;

        public static readonly string OBJECT_CODE_MAGIC = "XMRObjectCode";
        public static int COMPILED_VERSION_VALUE = 20;  // incremented when compiler changes for compatibility testing

        public static readonly int CALL_FRAME_MEMUSE = 64;
        public static readonly int STRING_LEN_TO_MEMUSE = 2;

        public static Type xmrInstSuperType = null;  // typeof whatever is actually malloc'd for script instances
                                                     // - must inherit from XMRInstAbstract

        /*
         * Static tables that there only needs to be one copy of for all.
         */
        private static VarDict legalEventHandlers = CreateLegalEventHandlers ();
        private static CompValu[]      zeroCompValus = new CompValu[0];
        private static TokenType[]     zeroArgs      = new TokenType[0];
        private static TokenTypeBool   tokenTypeBool = new TokenTypeBool   (null);
        private static TokenTypeExc    tokenTypeExc  = new TokenTypeExc    (null);
        private static TokenTypeFloat  tokenTypeFlt  = new TokenTypeFloat  (null);
        private static TokenTypeInt    tokenTypeInt  = new TokenTypeInt    (null);
        private static TokenTypeObject tokenTypeObj  = new TokenTypeObject (null);
        private static TokenTypeRot    tokenTypeRot  = new TokenTypeRot    (null);
        private static TokenTypeStr    tokenTypeStr  = new TokenTypeStr    (null);
        private static TokenTypeVec    tokenTypeVec  = new TokenTypeVec    (null);
        private static Type[] instanceTypeArg = new Type[] { typeof (XMRInstAbstract) };
        private static string[] instanceNameArg = new string[] { "$xmrthis" };

        private static ConstructorInfo lslFloatConstructorInfo = typeof (LSL_Float).GetConstructor (new Type[] { typeof (double) });
        private static ConstructorInfo lslIntegerConstructorInfo = typeof (LSL_Integer).GetConstructor (new Type[] { typeof (int) });
        private static ConstructorInfo lslListConstructorInfo = typeof (LSL_List).GetConstructor (new Type[] { typeof (object[]) });
        public  static ConstructorInfo lslRotationConstructorInfo = typeof (LSL_Rotation).GetConstructor (new Type[] { typeof (double), typeof (double), typeof (double), typeof (double) });
        private static ConstructorInfo lslStringConstructorInfo = typeof (LSL_String).GetConstructor (new Type[] { typeof (string) });
        public  static ConstructorInfo lslVectorConstructorInfo = typeof (LSL_Vector).GetConstructor (new Type[] { typeof (double), typeof (double), typeof (double) });
        private static ConstructorInfo scriptBadCallNoExceptionConstructorInfo = typeof (ScriptBadCallNoException).GetConstructor (new Type[] { typeof (int) });
        private static ConstructorInfo scriptChangeStateExceptionConstructorInfo = typeof (ScriptChangeStateException).GetConstructor (new Type[] { typeof (int) });
        private static ConstructorInfo scriptRestoreCatchExceptionConstructorInfo = typeof (ScriptRestoreCatchException).GetConstructor (new Type[] { typeof (Exception) });
        private static ConstructorInfo scriptUndefinedStateExceptionConstructorInfo = typeof (ScriptUndefinedStateException).GetConstructor (new Type[] { typeof (string) });
        private static ConstructorInfo sdtClassConstructorInfo = typeof (XMRSDTypeClObj).GetConstructor (new Type[] { typeof (XMRInstAbstract), typeof (int) });
        private static ConstructorInfo xmrArrayConstructorInfo = typeof (XMR_Array).GetConstructor (new Type[] { typeof (XMRInstAbstract) });
        private static FieldInfo callModeFieldInfo       = typeof (XMRInstAbstract).GetField ("callMode");
        private static FieldInfo doGblInitFieldInfo      = typeof (XMRInstAbstract).GetField ("doGblInit");
        private static FieldInfo ehArgsFieldInfo         = typeof (XMRInstAbstract).GetField ("ehArgs");
        private static FieldInfo rotationXFieldInfo      = typeof (LSL_Rotation).GetField ("x");
        private static FieldInfo rotationYFieldInfo      = typeof (LSL_Rotation).GetField ("y");
        private static FieldInfo rotationZFieldInfo      = typeof (LSL_Rotation).GetField ("z");
        private static FieldInfo rotationSFieldInfo      = typeof (LSL_Rotation).GetField ("s");
        private static FieldInfo sdtXMRInstFieldInfo     = typeof (XMRSDTypeClObj).GetField ("xmrInst");
        private static FieldInfo vectorXFieldInfo        = typeof (LSL_Vector).GetField ("x");
        private static FieldInfo vectorYFieldInfo        = typeof (LSL_Vector).GetField ("y");
        private static FieldInfo vectorZFieldInfo        = typeof (LSL_Vector).GetField ("z");

        private static MethodInfo arrayClearMethodInfo   = typeof (XMR_Array).GetMethod ("__pub_clear", new Type[] { });
        private static MethodInfo arrayCountMethodInfo   = typeof (XMR_Array).GetMethod ("__pub_count", new Type[] { });
        private static MethodInfo arrayIndexMethodInfo   = typeof (XMR_Array).GetMethod ("__pub_index", new Type[] { typeof (int) });
        private static MethodInfo arrayValueMethodInfo   = typeof (XMR_Array).GetMethod ("__pub_value", new Type[] { typeof (int) });
        private static MethodInfo checkRunStackMethInfo  = typeof (XMRInstAbstract).GetMethod ("CheckRunStack", new Type[] { });
        private static MethodInfo checkRunQuickMethInfo  = typeof (XMRInstAbstract).GetMethod ("CheckRunQuick", new Type[] { });
        private static MethodInfo ehArgUnwrapFloat       = GetStaticMethod (typeof (TypeCast), "EHArgUnwrapFloat",    new Type[] { typeof (object) });
        private static MethodInfo ehArgUnwrapInteger     = GetStaticMethod (typeof (TypeCast), "EHArgUnwrapInteger",  new Type[] { typeof (object) });
        private static MethodInfo ehArgUnwrapRotation    = GetStaticMethod (typeof (TypeCast), "EHArgUnwrapRotation", new Type[] { typeof (object) });
        private static MethodInfo ehArgUnwrapString      = GetStaticMethod (typeof (TypeCast), "EHArgUnwrapString",   new Type[] { typeof (object) });
        private static MethodInfo ehArgUnwrapVector      = GetStaticMethod (typeof (TypeCast), "EHArgUnwrapVector",   new Type[] { typeof (object) });
        private static MethodInfo xmrArrPubIndexMethod   = typeof (XMR_Array).GetMethod ("__pub_index", new Type[] { typeof (int) });
        private static MethodInfo xmrArrPubValueMethod   = typeof (XMR_Array).GetMethod ("__pub_value", new Type[] { typeof (int) });
        private static MethodInfo captureStackFrameMethodInfo = typeof (XMRInstAbstract).GetMethod ("CaptureStackFrame", new Type[] { typeof (string), typeof (int), typeof (int) });
        private static MethodInfo restoreStackFrameMethodInfo = typeof (XMRInstAbstract).GetMethod ("RestoreStackFrame", new Type[] { typeof (string), typeof (int).MakeByRefType () });
        private static MethodInfo stringCompareMethodInfo     = GetStaticMethod (typeof (String), "Compare", new Type[] { typeof (string), typeof (string), typeof (StringComparison) });
        private static MethodInfo stringConcat2MethodInfo     = GetStaticMethod (typeof (String), "Concat", new Type[] { typeof (string), typeof (string) });
        private static MethodInfo stringConcat3MethodInfo     = GetStaticMethod (typeof (String), "Concat", new Type[] { typeof (string), typeof (string), typeof (string) });
        private static MethodInfo stringConcat4MethodInfo     = GetStaticMethod (typeof (String), "Concat", new Type[] { typeof (string), typeof (string), typeof (string), typeof (string) });
        private static MethodInfo lslRotationNegateMethodInfo = GetStaticMethod (typeof (ScriptCodeGen), 
                                                                                 "LSLRotationNegate", 
                                                                                 new Type[] { typeof (LSL_Rotation) });
        private static MethodInfo lslVectorNegateMethodInfo = GetStaticMethod (typeof (ScriptCodeGen), 
                                                                               "LSLVectorNegate", 
                                                                               new Type[] { typeof (LSL_Vector) });
        private static MethodInfo scriptRestoreCatchExceptionUnwrap = GetStaticMethod (typeof (ScriptRestoreCatchException), "Unwrap", new Type[] { typeof (Exception) });
        private static MethodInfo thrownExceptionWrapMethodInfo  = GetStaticMethod (typeof (ScriptThrownException), "Wrap", new Type[] { typeof (object) });

        private static MethodInfo catchExcToStrMethodInfo = GetStaticMethod (typeof (ScriptCodeGen),
                                                                             "CatchExcToStr",
                                                                             new Type[] { typeof (Exception) });

        private static MethodInfo consoleWriteMethodInfo      = GetStaticMethod (typeof (ScriptCodeGen), "ConsoleWrite",   new Type[] { typeof (object) });
        public static void ConsoleWrite (object o)
        {
            if (o == null) o = "<<null>>";
            Console.Write (o.ToString ());
        }

        public static bool CodeGen (TokenScript tokenScript, BinaryWriter objFileWriter, string sourceHash)
        {
            /*
             * Run compiler such that it has a 'this' context for convenience.
             */
            ScriptCodeGen scg = new ScriptCodeGen (tokenScript, objFileWriter, sourceHash);

            /*
             * Return pointer to resultant script object code.
             */
            return !scg.youveAnError;
        }

        /*
         * There is one set of these variables for each script being compiled.
         */
        private bool mightGetHere = false;
        private bool youveAnError = false;
        private BreakContTarg curBreakTarg = null;
        private BreakContTarg curContTarg  = null;
        private int lastErrorLine = 0;
        private int nStates = 0;
        private string sourceHash;
        private string lastErrorFile = "";
        private string[] stateNames;
        private XMRInstArSizes glblSizes = new XMRInstArSizes ();
        private Token errorMessageToken = null;
        private TokenDeclVar curDeclFunc = null;
        private TokenStmtBlock curStmtBlock = null;
        private BinaryWriter objFileWriter = null;
        private TokenScript tokenScript = null;
        public  int tempCompValuNum = 0;
        private TokenDeclSDTypeClass currentSDTClass = null;

        private Dictionary<string, int> stateIndices = null;

        // These get cleared at beginning of every function definition
        private ScriptMyLocal instancePointer;   // holds XMRInstanceSuperType pointer
        private ScriptMyLabel retLabel  = null;  // where to jump to exit function
        private ScriptMyLocal retValue  = null;
        private ScriptMyLocal actCallNo = null;  // for the active try/catch/finally stack or the big one outside them all
        private LinkedList<CallLabel> actCallLabels = new LinkedList<CallLabel> ();  // for the active try/catch/finally stack or the big one outside them all
        private LinkedList<CallLabel> allCallLabels = new LinkedList<CallLabel> ();  // this holds each and every one for all stacks in total
        public  CallLabel openCallLabel = null;  // only one call label can be open at a time
                                                 // - the call label is open from the time of CallPre() until corresponding CallPost()
                                                 // - so no non-trivial pushes/pops etc allowed between a CallPre() and a CallPost()

        private ScriptMyILGen _ilGen;
        public ScriptMyILGen ilGen { get { return _ilGen; } }

        private ScriptCodeGen (TokenScript tokenScript, BinaryWriter objFileWriter, string sourceHash)
        {
            this.tokenScript   = tokenScript;
            this.objFileWriter = objFileWriter;
            this.sourceHash    = sourceHash;

            try {
                PerformCompilation ();
            } catch {
                // if we've an error, just punt on any exception
                // it's probably just a null reference from something
                // not being filled in etc.
                if (!youveAnError) throw;
            } finally {
                objFileWriter = null;
            }
        }

        /**
         * @brief Convert 'tokenScript' to 'objFileWriter' format.
         *   'tokenScript' is a parsed/reduced abstract syntax tree of the script source file
         *   'objFileWriter' is a serialized form of the CIL code that we generate
         */
        private void PerformCompilation ()
        {
            /*
             * errorMessageToken is used only when the given token doesn't have a
             * output delegate associated with it such as for backend API functions
             * that only have one copy for the whole system.  It is kept up-to-date
             * approximately but is rarely needed so going to assume it doesn't have 
             * to be exact.
             */
            errorMessageToken = tokenScript;

            /*
             * Set up dictionary to translate state names to their index number.
             */
            stateIndices = new Dictionary<string, int> ();

            /*
             * Assign each state its own unique index.
             * The default state gets 0.
             */
            nStates = 0;
            tokenScript.defaultState.body.index = nStates ++;
            stateIndices.Add ("default", 0);
            foreach (KeyValuePair<string, TokenDeclState> kvp in tokenScript.states) {
                TokenDeclState declState = kvp.Value;
                declState.body.index = nStates ++;
                stateIndices.Add (declState.name.val, declState.body.index);
            }

            /*
             * Make up an array that translates state indices to state name strings.
             */
            stateNames = new string[nStates];
            stateNames[0] = "default";
            foreach (KeyValuePair<string, TokenDeclState> kvp in tokenScript.states) {
                TokenDeclState declState = kvp.Value;
                stateNames[declState.body.index] = declState.name.val;
            }

            /*
             * Make sure we have delegates for all script-defined functions and methods,
             * creating anonymous ones if needed.  Note that this includes all property 
             * getter and setter methods.
             */
            foreach (TokenDeclVar declFunc in tokenScript.variablesStack) {
                if (declFunc.retType != null) {
                    declFunc.GetDelType ();
                }
            }
            while (true) {
                bool itIsAGoodDayToDie = true;
                try {
                    foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                        itIsAGoodDayToDie = false;
                        if (sdType is TokenDeclSDTypeClass) {
                            TokenDeclSDTypeClass sdtClass = (TokenDeclSDTypeClass)sdType;
                            foreach (TokenDeclVar declFunc in sdtClass.members) {
                                if (declFunc.retType != null) {
                                    declFunc.GetDelType ();
                                    if (declFunc.funcNameSig.val.StartsWith ("$ctor(")) {
                                        // this is for the "$new()" static method that we create below.
                                        // See GenerateStmtNewobj() etc.
                                        new TokenTypeSDTypeDelegate (declFunc, sdtClass.MakeRefToken (declFunc), 
                                                declFunc.argDecl.types, tokenScript);
                                    }
                                }
                            }
                        }
                        if (sdType is TokenDeclSDTypeInterface) {
                            TokenDeclSDTypeInterface sdtIFace = (TokenDeclSDTypeInterface)sdType;
                            foreach (TokenDeclVar declFunc in sdtIFace.methsNProps) {
                                if (declFunc.retType != null) {
                                    declFunc.GetDelType ();
                                }
                            }
                        }
                        itIsAGoodDayToDie = true;
                    }
                    break;
                } catch (InvalidOperationException) {
                    if (!itIsAGoodDayToDie) throw;
                    // fetching the delegate created an anonymous entry in tokenScript.sdSrcTypesValues
                    // which made the foreach statement puque, so start over...
                }
            }

            /*
             * No more types can be defined or we won't be able to write them to the object file.
             */
            tokenScript.sdSrcTypesSeal ();

            /*
             * Assign all global variables a slot in its corresponding XMRInstance.gbl<Type>s[] array.
             * Global variables are simply elements of those arrays at runtime, thus we don't need to create
             * an unique class for each script, we can just use XMRInstance as is for all.
             */
            foreach (TokenDeclVar declVar in tokenScript.variablesStack) {

                /*
                 * Omit 'constant' variables as they are coded inline so don't need a slot.
                 */
                if (declVar.constant) continue;

                /*
                 * Do functions later.
                 */
                if (declVar.retType != null) continue;

                /*
                 * Create entry in the value array for the variable or property.
                 */
                declVar.location = new CompValuGlobalVar (declVar, glblSizes);
            }

            /*
             * Likewise for any static fields in script-defined classes.
             * They can be referenced anywhere by <typename>.<fieldname>, see 
             * GenerateFromLValSField().
             */
            foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                if (!(sdType is TokenDeclSDTypeClass)) continue;
                TokenDeclSDTypeClass sdtClass = (TokenDeclSDTypeClass)sdType;

                foreach (TokenDeclVar declVar in sdtClass.members) {

                    /*
                     * Omit 'constant' variables as they are coded inline so don't need a slot.
                     */
                    if (declVar.constant) continue;

                    /*
                     * Do methods later.
                     */
                    if (declVar.retType != null) continue;

                    /*
                     * Ignore non-static fields for now.
                     * They get assigned below.
                     */
                    if ((declVar.sdtFlags & ScriptReduce.SDT_STATIC) == 0) continue;

                    /*
                     * Create entry in the value array for the static field or static property.
                     */
                    declVar.location = new CompValuGlobalVar (declVar, glblSizes);
                }
            }

            /*
             * Assign slots for all interface method prototypes.
             * These indices are used to index the array of delegates that holds a class' implementation of an 
             * interface.
             * Properties do not get a slot because they aren't called as such.  But their corresponding
             * <name>$get() and <name>$set(<type>) methods are in the table and they each get a slot.
             */
            foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                if (!(sdType is TokenDeclSDTypeInterface)) continue;
                TokenDeclSDTypeInterface sdtIFace = (TokenDeclSDTypeInterface)sdType;
                int vti = 0;
                foreach (TokenDeclVar im in sdtIFace.methsNProps) {
                    if ((im.getProp == null) && (im.setProp == null)) {
                        im.vTableIndex = vti ++;
                    }
                }
            }

            /*
             * Assign slots for all instance fields and virtual methods of script-defined classes.
             */
            int maxExtends = tokenScript.sdSrcTypesCount;
            bool didOne;
            do {
                didOne = false;
                foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                    if (!(sdType is TokenDeclSDTypeClass)) continue;
                    TokenDeclSDTypeClass sdtClass = (TokenDeclSDTypeClass)sdType;
                    if (sdtClass.slotsAssigned) continue;

                    /*
                     * If this class extends another, the extended class has to already 
                     * be set up, because our slots add on to the end of the extended class.
                     */
                    TokenDeclSDTypeClass extends = sdtClass.extends;
                    if (extends != null) {
                        if (!extends.slotsAssigned) continue;
                        sdtClass.instSizes     = extends.instSizes;
                        sdtClass.numVirtFuncs  = extends.numVirtFuncs;
                        sdtClass.numInterfaces = extends.numInterfaces;

                        int n = maxExtends;
                        for (TokenDeclSDTypeClass ex = extends; ex != null; ex = ex.extends) {
                            if (-- n < 0) break;
                        }
                        if (n < 0) {
                            ErrorMsg (sdtClass, "loop in extended classes");
                            sdtClass.slotsAssigned = true;
                            continue;
                        }
                    }

                    /*
                     * Extended class's slots all assigned, assign our instance fields 
                     * slots in the XMRSDTypeClObj arrays.
                     */
                    foreach (TokenDeclVar declVar in sdtClass.members) {
                        if (declVar.retType != null) continue;
                        if (declVar.constant) continue;
                        if ((declVar.sdtFlags & ScriptReduce.SDT_STATIC) != 0) continue;
                        if ((declVar.getProp == null) && (declVar.setProp == null)) {
                            declVar.type.AssignVarSlot (declVar, sdtClass.instSizes);
                        }
                    }

                    /*
                     * ... and assign virtual method vtable slots.
                     *
                     *                   - : error if any overridden method, doesn't need a slot
                     *            abstract : error if any overridden method, alloc new slot but leave it empty
                     *                 new : ignore any overridden method, doesn't need a slot
                     *        new abstract : ignore any overridden method, alloc new slot but leave it empty
                     *            override : must have overridden abstract/virtual, use old slot
                     *   override abstract : must have overridden abstract, use old slot but it is still empty
                     *              static : error if any overridden method, doesn't need a slot
                     *          static new : ignore any overridden method, doesn't need a slot
                     *             virtual : error if any overridden method, alloc new slot and fill it in
                     *         virtual new : ignore any overridden method, alloc new slot and fill it in
                     */
                    foreach (TokenDeclVar declFunc in sdtClass.members) {
                        if (declFunc.retType == null) continue;
                        curDeclFunc = declFunc;

                        /*
                         * See if there is a method in an extended class that this method overshadows.
                         * If so, check for various conflicts.
                         * In any case, SDT_NEW on our method means to ignore any overshadowed method.
                         */
                        string declLongName = sdtClass.longName.val + "." + declFunc.funcNameSig.val;
                        uint declFlags = declFunc.sdtFlags;
                        TokenDeclVar overridden = null;
                        if ((declFlags & ScriptReduce.SDT_NEW) == 0) {
                            for (TokenDeclSDTypeClass sdtd = extends; sdtd != null; sdtd = sdtd.extends) {
                                overridden = FindExactWithRet (sdtd.members, declFunc.name, declFunc.retType, declFunc.argDecl.types);
                                if (overridden != null) break;
                            }
                        }
                        if (overridden != null) do {
                            string overLongName = overridden.sdtClass.longName.val;
                            uint overFlags = overridden.sdtFlags;

                            /*
                             * See if overridden method allows itself to be overridden.
                             */
                            if ((overFlags & ScriptReduce.SDT_ABSTRACT) != 0) {
                                if ((declFlags & (ScriptReduce.SDT_ABSTRACT | ScriptReduce.SDT_OVERRIDE)) == 0) {
                                    ErrorMsg (declFunc, declLongName + " overshadows abstract " + overLongName + " but is not marked abstract, new or override");
                                    break;
                                }
                            } else if ((overFlags & ScriptReduce.SDT_FINAL) != 0) {
                                ErrorMsg (declFunc, declLongName + " overshadows final " + overLongName + " but is not marked new");
                            } else if ((overFlags & (ScriptReduce.SDT_OVERRIDE | ScriptReduce.SDT_VIRTUAL)) != 0) {
                                if ((declFlags & (ScriptReduce.SDT_NEW | ScriptReduce.SDT_OVERRIDE)) == 0) {
                                    ErrorMsg (declFunc, declLongName + " overshadows virtual " + overLongName + " but is not marked new or override");
                                    break;
                                }
                            } else {
                                ErrorMsg (declFunc, declLongName + " overshadows non-virtual " + overLongName + " but is not marked new");
                                break;
                            }

                            /*
                             * See if our method is capable of overriding the other method.
                             */
                            if ((declFlags & ScriptReduce.SDT_ABSTRACT) != 0) {
                                if ((overFlags & ScriptReduce.SDT_ABSTRACT) == 0) {
                                    ErrorMsg (declFunc, declLongName + " abstract overshadows non-abstract " + overLongName + " but is not marked new");
                                    break;
                                }
                            } else if ((declFlags & ScriptReduce.SDT_OVERRIDE) != 0) {
                                if ((overFlags & (ScriptReduce.SDT_ABSTRACT | ScriptReduce.SDT_OVERRIDE | ScriptReduce.SDT_VIRTUAL)) == 0) {
                                    ErrorMsg (declFunc, declLongName + " override overshadows non-abstract/non-virtual " + overLongName);
                                    break;
                                }
                            } else {
                                ErrorMsg (declFunc, declLongName + " overshadows " + overLongName + " but is not marked new");
                                break;
                            }
                        } while (false);

                        /*
                         * Now we can assign it a vtable slot if it needs one (ie, it is virtual).
                         */
                        declFunc.vTableIndex = -1;
                        if (overridden != null) {
                            declFunc.vTableIndex = overridden.vTableIndex;
                        } else if ((declFlags & ScriptReduce.SDT_OVERRIDE) != 0) {
                            ErrorMsg (declFunc, declLongName + " marked override but nothing matching found that it overrides");
                        }
                        if ((declFlags & (ScriptReduce.SDT_ABSTRACT | ScriptReduce.SDT_VIRTUAL)) != 0) {
                            declFunc.vTableIndex = sdtClass.numVirtFuncs ++;
                        }
                    }
                    curDeclFunc = null;

                    /*
                     * ... and assign implemented interface slots.
                     * Note that our implementations of a given interface is completely independent of any 
                     * rootward class's implementation of that same interface.
                     */
                    int nIFaces        = sdtClass.numInterfaces + sdtClass.implements.Count;
                    sdtClass.iFaces    = new TokenDeclSDTypeInterface[nIFaces];
                    sdtClass.iImplFunc = new TokenDeclVar[nIFaces][];
                    for (int i = 0; i < sdtClass.numInterfaces; i ++) {
                        sdtClass.iFaces[i]    = extends.iFaces[i];
                        sdtClass.iImplFunc[i] = extends.iImplFunc[i];
                    }

                    foreach (TokenDeclSDTypeInterface intf in sdtClass.implements) {
                        int i = sdtClass.numInterfaces ++;
                        sdtClass.iFaces[i] = intf;
                        sdtClass.intfIndices.Add (intf.longName.val, i);
                        int nMeths = 0;
                        foreach (TokenDeclVar m in intf.methsNProps) {
                            if ((m.getProp == null) && (m.setProp == null)) nMeths ++;
                        }
                        sdtClass.iImplFunc[i] = new TokenDeclVar[nMeths];
                    }

                    foreach (TokenDeclVar classMeth in sdtClass.members) {
                        if (classMeth.retType == null) continue;
                        curDeclFunc = classMeth;
                        for (TokenIntfImpl intfImpl = classMeth.implements; intfImpl != null; intfImpl = (TokenIntfImpl)intfImpl.nextToken) {

                            /*
                             * One of the class methods implements an interface method.
                             * Try to find the interface method that is implemented and verify its signature.
                             */
                            TokenDeclSDTypeInterface intfType = intfImpl.intfType.decl;
                            TokenDeclVar intfMeth = FindExactWithRet (intfType.methsNProps, intfImpl.methName, classMeth.retType, classMeth.argDecl.types);
                            if (intfMeth == null) {
                                ErrorMsg (intfImpl, "interface does not define method " + intfImpl.methName.val + classMeth.argDecl.GetArgSig ());
                                continue;
                            }

                            /*
                             * See if this class was declared to implement that interface.
                             */
                            bool found = false;
                            foreach (TokenDeclSDTypeInterface intf in sdtClass.implements) {
                                if (intf == intfType) {
                                    found = true;
                                    break;
                                }
                            }
                            if (!found) {
                                ErrorMsg (intfImpl, "class not declared to implement " + intfType.longName.val);
                                continue;
                            }

                            /*
                             * Get index in iFaces[] and iImplFunc[] arrays.
                             * Start scanning from the end in case one of our rootward classes also implements the interface.
                             * We should always be successful because we know by now that this class implements the interface.
                             */
                            int i;
                            for (i = sdtClass.numInterfaces; -- i >= 0;) {
                                if (sdtClass.iFaces[i] == intfType) break;
                            }

                            /*
                             * Now remember which of the class methods implements that interface method.
                             */
                            int j = intfMeth.vTableIndex;
                            if (sdtClass.iImplFunc[i][j] != null) {
                                ErrorMsg (intfImpl, "also implemented by " + sdtClass.iImplFunc[i][j].funcNameSig.val);
                                continue;
                            }
                            sdtClass.iImplFunc[i][j] = classMeth;
                        }
                    }
                    curDeclFunc = null;

                    /*
                     * Now make sure this class implements all methods for all declared interfaces.
                     */
                    for (int i = sdtClass.numInterfaces - sdtClass.implements.Count; i < sdtClass.numInterfaces; i ++) {
                        TokenDeclVar[] implementations = sdtClass.iImplFunc[i];
                        for (int j = implementations.Length; -- j >= 0;) {
                            if (implementations[j] == null) {
                                TokenDeclSDTypeInterface intf = sdtClass.iFaces[i];
                                TokenDeclVar meth = null;
                                foreach (TokenDeclVar im in intf.methsNProps) {
                                    if (im.vTableIndex == j) {
                                        meth = im;
                                        break;
                                    }
                                }
                                ErrorMsg (sdtClass, "does not implement " + intf.longName.val + "." + meth.funcNameSig.val);
                            }
                        }
                    }

                    /*
                     * All slots for this class have been assigned.
                     */
                    sdtClass.slotsAssigned = true;
                    didOne = true;
                }
            } while (didOne);

            /*
             * Compute final values for all variables/fields declared as 'constant'.
             * Note that there may be forward references.
             */
            do {
                didOne = false;
                foreach (TokenDeclVar tdv in tokenScript.variablesStack) {
                    if (tdv.constant && !(tdv.init is TokenRValConst)) {
                        tdv.init = tdv.init.TryComputeConstant (LookupInitConstants, ref didOne);
                    }
                }
                foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                    if (!(sdType is TokenDeclSDTypeClass)) continue;
                    currentSDTClass = (TokenDeclSDTypeClass)sdType;
                    foreach (TokenDeclVar tdv in currentSDTClass.members) {
                        if (tdv.constant && !(tdv.init is TokenRValConst)) {
                            tdv.init = tdv.init.TryComputeConstant (LookupInitConstants, ref didOne);
                        }
                    }
                }
                currentSDTClass = null;
            } while (didOne);

            /*
             * Now we should be able to assign all those constants their type and location.
             */
            foreach (TokenDeclVar tdv in tokenScript.variablesStack) {
                if (tdv.constant) {
                    if (tdv.init is TokenRValConst) {
                        TokenRValConst rvc = (TokenRValConst)tdv.init;
                        tdv.type = rvc.tokType;
                        tdv.location = rvc.GetCompValu ();
                    } else {
                        ErrorMsg (tdv, "value is not constant");
                    }
                }
            }
            foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                if (!(sdType is TokenDeclSDTypeClass)) continue;
                currentSDTClass = (TokenDeclSDTypeClass)sdType;
                foreach (TokenDeclVar tdv in currentSDTClass.members) {
                    if (tdv.constant) {
                        if (tdv.init is TokenRValConst) {
                            TokenRValConst rvc = (TokenRValConst)tdv.init;
                            tdv.type = rvc.tokType;
                            tdv.location = rvc.GetCompValu ();
                        } else {
                            ErrorMsg (tdv, "value is not constant");
                        }
                    }
                }
            }
            currentSDTClass = null;

            /*
             * For all classes that define all the methods needed for the class, ie, they aren't abstract,
             * define a static class.$new() method with same args as the $ctor(s).  This will allow the
             * class to be instantiated via the new operator.
             */
            foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                if (!(sdType is TokenDeclSDTypeClass)) continue;
                TokenDeclSDTypeClass sdtClass = (TokenDeclSDTypeClass)sdType;

                /*
                 * See if the class as it stands would be able to fill every slot of its vtable.
                 */
                bool[] filled = new bool[sdtClass.numVirtFuncs];
                int numFilled = 0;
                for (TokenDeclSDTypeClass sdtc = sdtClass; sdtc != null; sdtc = sdtc.extends) {
                    foreach (TokenDeclVar tdf in sdtc.members) {
                        if ((tdf.retType != null) && (tdf.vTableIndex >= 0) && ((tdf.sdtFlags & ScriptReduce.SDT_ABSTRACT) == 0)) {
                            if (!filled[tdf.vTableIndex]) {
                                filled[tdf.vTableIndex] = true;
                                numFilled ++;
                            }
                        }
                    }
                }

                /*
                 * If so, define a static class.$new() method for every constructor defined for the class.
                 * Give it the same access (private/protected/public) as the script declared for the constructor.
                 * Note that the reducer made sure there is at least a default constructor for every class.
                 */
                if (numFilled >= sdtClass.numVirtFuncs) {
                    List<TokenDeclVar> newobjDeclFuncs = new List<TokenDeclVar> ();
                    foreach (TokenDeclVar ctorDeclFunc in sdtClass.members) {
                        if ((ctorDeclFunc.funcNameSig != null) && ctorDeclFunc.funcNameSig.val.StartsWith ("$ctor(")) {
                            TokenDeclVar newobjDeclFunc = DefineNewobjFunc (ctorDeclFunc);
                            newobjDeclFuncs.Add (newobjDeclFunc);
                        }
                    }
                    foreach (TokenDeclVar newobjDeclFunc in newobjDeclFuncs) {
                        sdtClass.members.AddEntry (newobjDeclFunc);
                    }
                }
            }

            /*
             * Write fixed portion of object file.
             */
            objFileWriter.Write (OBJECT_CODE_MAGIC.ToCharArray ());
            objFileWriter.Write (COMPILED_VERSION_VALUE);
            objFileWriter.Write (sourceHash);
            objFileWriter.Write (tokenScript.expiryDays);
            glblSizes.WriteToFile (objFileWriter);

            objFileWriter.Write (nStates);
            for (int i = 0; i < nStates; i ++) {
                objFileWriter.Write (stateNames[i]);
            }

            /*
             * For debugging, we also write out global variable array slot assignments.
             */
            foreach (TokenDeclVar declVar in tokenScript.variablesStack) {
                if (declVar.retType == null) {
                    WriteOutGblAssignment ("", declVar);
                }
            }
            foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                if (!(sdType is TokenDeclSDTypeClass)) continue;
                TokenDeclSDTypeClass sdtClass = (TokenDeclSDTypeClass)sdType;
                foreach (TokenDeclVar declVar in sdtClass.members) {
                    if ((declVar.sdtFlags & ScriptReduce.SDT_STATIC) != 0) {
                        WriteOutGblAssignment (sdtClass.longName.val + ".", declVar);
                    }
                }
            }
            objFileWriter.Write ("");

            /*
             * Write out script-defined types.
             */
            foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                objFileWriter.Write (sdType.longName.val);
                sdType.WriteToFile (objFileWriter);
            }
            objFileWriter.Write ("");

            /*
             * Output function headers then bodies.
             * Do all headers first in case bodies do forward references.
             * Do both global functions, script-defined class static methods and 
             * script-defined instance methods, as we handle the differences
             * during compilation of the functions/methods themselves.
             */
            for (int pass = 0; pass < 2; pass ++) {
                foreach (TokenDeclVar declFunc in tokenScript.variablesStack) {
                    if (declFunc.retType != null) {
                        if (pass == 0) GenerateMethodHeader (declFunc);
                                  else GenerateMethodBody   (declFunc);
                    }
                }
                foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                    if (sdType is TokenDeclSDTypeClass) {
                        TokenDeclSDTypeClass sdtClass = (TokenDeclSDTypeClass)sdType;
                        foreach (TokenDeclVar declFunc in sdtClass.members) {
                            if ((declFunc.retType != null) && ((declFunc.sdtFlags & ScriptReduce.SDT_ABSTRACT) == 0)) {
                                if (pass == 0) GenerateMethodHeader (declFunc);
                                          else GenerateMethodBody   (declFunc);
                            }
                        }
                    }
                }
            }

            /*
             * Output default state event handler functions.
             * Each event handler is a private static method named 'default <eventname>'.
             * Splice in a default state_entry() handler if none defined so we can init global vars.
             */
            TokenDeclVar defaultStateEntry = null;
            for (defaultStateEntry = tokenScript.defaultState.body.eventFuncs;
                 defaultStateEntry != null;
                 defaultStateEntry = (TokenDeclVar)defaultStateEntry.nextToken) {
                if (defaultStateEntry.funcNameSig.val == "state_entry()") break;
            }
            if (defaultStateEntry == null) {
                defaultStateEntry               = new TokenDeclVar   (tokenScript.defaultState.body, null, tokenScript);
                defaultStateEntry.name          = new TokenName      (tokenScript.defaultState.body, "state_entry");
                defaultStateEntry.retType       = new TokenTypeVoid  (tokenScript.defaultState.body);
                defaultStateEntry.argDecl       = new TokenArgDecl   (tokenScript.defaultState.body);
                defaultStateEntry.body          = new TokenStmtBlock (tokenScript.defaultState.body);
                defaultStateEntry.body.function = defaultStateEntry;

                defaultStateEntry.nextToken = tokenScript.defaultState.body.eventFuncs;
                tokenScript.defaultState.body.eventFuncs = defaultStateEntry;
            }
            GenerateStateEventHandlers ("default", tokenScript.defaultState.body);

            /*
             * Output script-defined state event handler methods.
             * Each event handler is a private static method named <statename> <eventname>
             */
            foreach (KeyValuePair<string, TokenDeclState> kvp in tokenScript.states) {
                TokenDeclState declState = kvp.Value;
                GenerateStateEventHandlers (declState.name.val, declState.body);
            }

            ScriptObjWriter.TheEnd (objFileWriter);
        }

        /**
         * @brief Write out what slot was assigned for a global or sdtclass static variable.
         *        Constants, functions, instance fields, methods, properties do not have slots in the global variables arrays.
         */
        private void WriteOutGblAssignment (string pfx, TokenDeclVar declVar)
        {
            if (!declVar.constant && (declVar.retType == null) && (declVar.getProp == null) && (declVar.setProp == null)) {
                objFileWriter.Write (pfx + declVar.name.val);    // string
                objFileWriter.Write (declVar.vTableArray.Name);  // string
                objFileWriter.Write (declVar.vTableIndex);       // int
            }
        }

        /**
         * @brief generate event handler code
         * Writes out a function definition for each state handler
         * named <statename> <eventname>
         *
         * However, each has just 'XMRInstance __sw' as its single argument
         * and each of its user-visible argments is extracted from __sw.ehArgs[].
         *
         * So we end up generating something like this:
         *
         *   private static void <statename> <eventname>(XMRInstance __sw)
         *   {
         *      <typeArg0> <nameArg0> = (<typeArg0>)__sw.ehArgs[0];
         *      <typeArg1> <nameArg1> = (<typeArg1>)__sw.ehArgs[1];
         *
         *      ... script code ...
         *   }
         *
         * The continuations code assumes there will be no references to ehArgs[]
         * after the first call to CheckRun() as CheckRun() makes no attempt to
         * serialize the ehArgs[] array, as doing so would be redundant.  Any values
         * from ehArgs[] that are being used will be in local stack variables and
         * thus preserved that way.
         */
        private void GenerateStateEventHandlers (string statename, TokenStateBody body)
        {
            Dictionary<string,TokenDeclVar> statehandlers = new Dictionary<string,TokenDeclVar> ();
            for (Token t = body.eventFuncs; t != null; t = t.nextToken) {
                TokenDeclVar tdv = (TokenDeclVar)t;
                string eventname = tdv.GetSimpleName ();
                if (statehandlers.ContainsKey (eventname)) {
                    ErrorMsg (tdv, "event handler " + eventname + " already defined for state " + statename);
                } else {
                    statehandlers.Add (eventname, tdv);
                    GenerateEventHandler (statename, tdv);
                }
            }
        }

        private void GenerateEventHandler (string statename, TokenDeclVar declFunc)
        {
            string eventname = declFunc.GetSimpleName ();
            TokenArgDecl argDecl = declFunc.argDecl;

            /*
             * Make sure event handler name is valid and that number and type of arguments is correct.
             * Apparently some scripts exist with fewer than correct number of args in their declaration 
             * so allow for that.  It is ok because the handlers are called with the arguments in an
             * object[] array, and we just won't access the missing argments in the vector.  But the 
             * specified types must match one of the prototypes in legalEventHandlers.
             */
            TokenDeclVar protoDeclFunc = legalEventHandlers.FindExact (eventname, argDecl.types);
            if (protoDeclFunc == null) {
                ErrorMsg (declFunc, "unknown event handler " + eventname + argDecl.GetArgSig ());
                return;
            }

            /*
             * Output function header.
             * They just have the XMRInstAbstract pointer as the one argument.
             */
            string functionName = statename + " " + eventname;
            _ilGen = new ScriptObjWriter (tokenScript, 
                                          functionName,
                                          typeof (void),
                                          instanceTypeArg,
                                          instanceNameArg,
                                          objFileWriter);
            StartFunctionBody (declFunc);

            /*
             * Create a temp to hold XMRInstanceSuperType version of arg 0.
             */
            instancePointer = ilGen.DeclareLocal (xmrInstSuperType, "__xmrinst");
            ilGen.Emit (declFunc, OpCodes.Ldarg_0);
            ilGen.Emit (declFunc, OpCodes.Castclass, xmrInstSuperType);
            ilGen.Emit (declFunc, OpCodes.Stloc, instancePointer);

            /*
             * Output args as variable definitions and initialize each from __sw.ehArgs[].
             * If the script writer goofed, the typecast will complain.
             */
            int nArgs = argDecl.vars.Length;
            for (int i = 0; i < nArgs; i ++) {

                /*
                 * Say that the argument variable is going to be located in a local var.
                 */
                TokenDeclVar argVar = argDecl.vars[i];
                TokenType argTokType = argVar.type;
                CompValuLocalVar local = new CompValuLocalVar (argTokType, argVar.name.val, this);
                argVar.location = local;

                /*
                 * Copy from the ehArgs[i] element to the temp var.
                 * Cast as needed, there is a lot of craziness like OpenMetaverse.Quaternion.
                 */
                local.PopPre (this, argVar.name);
                PushXMRInst ();                                          // instance
                ilGen.Emit (declFunc, OpCodes.Ldfld, ehArgsFieldInfo);   // instance.ehArgs (array of objects)
                ilGen.Emit (declFunc, OpCodes.Ldc_I4, i);                // array index = i
                ilGen.Emit (declFunc, OpCodes.Ldelem, typeof (object));  // select the argument we want
                TokenType stkTokType = tokenTypeObj;                     // stack has a type 'object' on it now
                Type argSysType = argTokType.ToSysType ();               // this is the type the script expects
                if (argSysType == typeof (double)) {                // LSL_Float/double -> double
                    ilGen.Emit (declFunc, OpCodes.Call, ehArgUnwrapFloat);
                    stkTokType = tokenTypeFlt;                       // stack has a type 'double' on it now
                }
                if (argSysType == typeof (int)) {                        // LSL_Integer/int -> int
                    ilGen.Emit (declFunc, OpCodes.Call, ehArgUnwrapInteger);
                    stkTokType = tokenTypeInt;                       // stack has a type 'int' on it now
                }
                if (argSysType == typeof (LSL_List)) {                   // LSL_List -> LSL_List
                    TypeCast.CastTopOfStack (this, argVar.name, stkTokType, argTokType, true);
                    stkTokType = argTokType;                         // stack has a type 'LSL_List' on it now
                }
                if (argSysType == typeof (LSL_Rotation)) {               // OpenMetaverse.Quaternion/LSL_Rotation -> LSL_Rotation
                    ilGen.Emit (declFunc, OpCodes.Call, ehArgUnwrapRotation);
                    stkTokType = tokenTypeRot;                       // stack has a type 'LSL_Rotation' on it now
                }
                if (argSysType == typeof (string)) {                     // LSL_Key/LSL_String/string -> string
                    ilGen.Emit (declFunc, OpCodes.Call, ehArgUnwrapString);
                    stkTokType = tokenTypeStr;                       // stack has a type 'string' on it now
                }
                if (argSysType == typeof (LSL_Vector)) {                 // OpenMetaverse.Vector3/LSL_Vector -> LSL_Vector
                    ilGen.Emit (declFunc, OpCodes.Call, ehArgUnwrapVector);
                    stkTokType = tokenTypeVec;                       // stack has a type 'LSL_Vector' on it now
                }
                local.PopPost (this, argVar.name, stkTokType);           // pop stack type into argtype
            }

            /*
             * Output code for the statements and clean up.
             */
            GenerateFuncBody ();
        }

        /**
         * @brief generate header for an arbitrary script-defined global function.
         * @param declFunc = function being defined
         */
        private void GenerateMethodHeader (TokenDeclVar declFunc)
        {
            curDeclFunc = declFunc;

            /*
             * Make up array of all argument types as seen by the code generator.
             * We splice in XMRInstanceSuperType or XMRSDTypeClObj for the first 
             * arg as the function itself is static, followed by script-visible
             * arg types.
             */
            TokenArgDecl argDecl = declFunc.argDecl;
            int nArgs = argDecl.vars.Length;
            Type[] argTypes = new Type[nArgs+1];
            string[] argNames = new string[nArgs+1];
            if (IsSDTInstMethod ()) {
                argTypes[0] = typeof (XMRSDTypeClObj);
                argNames[0] = "$sdtthis";
            } else {
                argTypes[0] = xmrInstSuperType;
                argNames[0] = "$xmrthis";
            }
            for (int i = 0; i < nArgs; i ++) {
                argTypes[i+1] = argDecl.vars[i].type.ToSysType ();
                argNames[i+1] = argDecl.vars[i].name.val;
            }

            /*
             * Set up entrypoint.
             */
            string objCodeName = declFunc.GetObjCodeName ();
            declFunc.ilGen = new ScriptObjWriter (tokenScript, 
                                                  objCodeName,
                                                  declFunc.retType.ToSysType (),
                                                  argTypes,
                                                  argNames,
                                                  objFileWriter);

            /*
             * This says how to generate a call to the function and to get a delegate.
             */
            declFunc.location = new CompValuGlobalMeth (declFunc);

            curDeclFunc = null;
        }

        /**
         * @brief generate code for an arbitrary script-defined function.
         * @param name = name of the function
         * @param argDecl = argument declarations
         * @param body = function's code body
         */
        private void GenerateMethodBody (TokenDeclVar declFunc)
        {
            /*
             * Set up code generator for the function's contents.
             */
            _ilGen = declFunc.ilGen;
            StartFunctionBody (declFunc);

            /*
             * Create a temp to hold XMRInstanceSuperType version of arg 0.
             * For most functions, arg 0 is already XMRInstanceSuperType.
             * But for script-defined class instance methods, arg 0 holds
             * the XMRSDTypeClObj pointer and so we read the XMRInstAbstract
             * pointer from its XMRSDTypeClObj.xmrInst field then cast it to
             * XMRInstanceSuperType.
             */
            if (IsSDTInstMethod ()) {
                instancePointer = ilGen.DeclareLocal (xmrInstSuperType, "__xmrinst");
                ilGen.Emit (declFunc, OpCodes.Ldarg_0);
                ilGen.Emit (declFunc, OpCodes.Ldfld, sdtXMRInstFieldInfo);
                ilGen.Emit (declFunc, OpCodes.Castclass, xmrInstSuperType);
                ilGen.Emit (declFunc, OpCodes.Stloc, instancePointer);
            }

            /*
             * Define location of all script-level arguments so script body can access them.
             * The argument indices need to have +1 added to them because XMRInstance or 
             * XMRSDTypeClObj is spliced in at arg 0.
             */
            TokenArgDecl argDecl = declFunc.argDecl;
            int nArgs = argDecl.vars.Length;
            for (int i = 0; i < nArgs; i ++) {
                TokenDeclVar argVar = argDecl.vars[i];
                argVar.location = new CompValuArg (argVar.type, i + 1);
            }

            /*
             * Output code for the statements and clean up.
             */
            GenerateFuncBody ();
        }

        private void StartFunctionBody (TokenDeclVar declFunc)
        {
            /*
             * Start current function being processed.
             * Set 'mightGetHere' as the code at the top is always executed.
             */
            instancePointer = null;
            mightGetHere    = true;
            curBreakTarg    = null;
            curContTarg     = null;
            curDeclFunc     = declFunc;

            /*
             * Start generating code.
             */
            ((ScriptObjWriter)ilGen).BegMethod ();
        }

        /**
         * @brief Define function for a script-defined type's <typename>.$new(<argsig>) method.
         *        See GenerateStmtNewobj() for more info.
         */
        private TokenDeclVar DefineNewobjFunc (TokenDeclVar ctorDeclFunc)
        {
            /*
             * Set up 'static classname $new(params-same-as-ctor) { }'.
             */
            TokenDeclVar newobjDeclFunc = new TokenDeclVar (ctorDeclFunc, null, tokenScript);
            newobjDeclFunc.name         = new TokenName (newobjDeclFunc, "$new");
            newobjDeclFunc.retType      = ctorDeclFunc.sdtClass.MakeRefToken (newobjDeclFunc);
            newobjDeclFunc.argDecl      = ctorDeclFunc.argDecl;
            newobjDeclFunc.sdtClass     = ctorDeclFunc.sdtClass;
            newobjDeclFunc.sdtFlags     = ScriptReduce.SDT_STATIC | ctorDeclFunc.sdtFlags;

            /*
             * Declare local variable named '$objptr' in a frame just under 
             * what the '$new(...)' function's arguments are declared in.
             */
            TokenDeclVar objptrVar = new TokenDeclVar (newobjDeclFunc, newobjDeclFunc, tokenScript);
            objptrVar.type         = newobjDeclFunc.retType;
            objptrVar.name         = new TokenName (newobjDeclFunc, "$objptr");
            VarDict newFrame       = new VarDict (false);
            newFrame.outerVarDict  = ctorDeclFunc.argDecl.varDict;
            newFrame.AddEntry (objptrVar);

            /*
             * Set up '$objptr.$ctor'
             */
            TokenLValName objptrLValName  = new TokenLValName (objptrVar.name, newFrame);
                                                                                   // ref a var by giving its name
            TokenLValIField objptrDotCtor = new TokenLValIField (newobjDeclFunc);  // an instance member reference
            objptrDotCtor.baseRVal        = objptrLValName;                        // '$objptr'
            objptrDotCtor.fieldName       = ctorDeclFunc.name;                     // '.' '$ctor'

            /*
             * Set up '$objptr.$ctor(arglist)' call for use in the '$new(...)' body.
             * Copy the arglist from the constructor declaration so triviality 
             * processing will pick the correct overloaded constructor.
             */
            TokenRValCall callCtorRVal = new TokenRValCall (newobjDeclFunc);   // doing a call of some sort
            callCtorRVal.meth          = objptrDotCtor;                        // calling $objptr.$ctor()
            TokenDeclVar[] argList     = newobjDeclFunc.argDecl.vars;          // get args $new() was declared with
            callCtorRVal.nArgs         = argList.Length;                       // ...that is nArgs we are passing to $objptr.$ctor()
            for (int i = argList.Length; -- i >= 0;) {
                TokenDeclVar arg          = argList[i];                    // find out about one of the args
                TokenLValName argLValName = new TokenLValName (arg.name, ctorDeclFunc.argDecl.varDict);
                                                                           // pass arg of that name to $objptr.$ctor()
                argLValName.nextToken     = callCtorRVal.args;             // link to list of args passed to $objptr.$ctor()
                callCtorRVal.args         = argLValName;
            }

            /*
             * Set up a funky call to the constructor for the code body.
             * This will let code generator know there is some craziness.
             * See GenerateStmtNewobj().
             *
             * This is in essence:
             *    {
             *        classname $objptr = newobj (classname);
             *        $objptr.$ctor (...);
             *        return $objptr;
             *    }
             */
            TokenStmtNewobj newobjStmtBody = new TokenStmtNewobj (ctorDeclFunc);
            newobjStmtBody.objptrVar       = objptrVar;
            newobjStmtBody.rValCall        = callCtorRVal;
            TokenStmtBlock newobjBody      = new TokenStmtBlock (ctorDeclFunc);
            newobjBody.statements          = newobjStmtBody;

            /*
             * Link that code as the body of the function.
             */
            newobjDeclFunc.body = newobjBody;

            /*
             * Say the function calls '$objptr.$ctor(arglist)' so we will inherit ctor's triviality.
             */
            newobjDeclFunc.unknownTrivialityCalls.AddLast (callCtorRVal);
            return newobjDeclFunc;
        }

        private class TokenStmtNewobj : TokenStmt {
            public TokenDeclVar objptrVar;
            public TokenRValCall rValCall;
            public TokenStmtNewobj (Token original) : base (original) { }
        }

        /**
         * @brief Output function body (either event handler or script-defined method).
         */
        private void GenerateFuncBody ()
        {
            /*
             * We want to know if the function's code is trivial, ie,
             * if it doesn't have anything that might be an infinite 
             * loop and that is doesn't call anything that might have 
             * an infinite loop.  If it is, we don't need any CheckRun()
             * stuff or any of the frame save/restore stuff.
             */
            bool isTrivial = curDeclFunc.IsFuncTrivial (this);

            /*
             * Clear list of all call labels.
             * A call label is inserted just before every call that can possibly
             * call CheckRun(), including any direct calls to CheckRun().
             * Then, when restoring stack, we can just switch to this label to
             * resume at the correct spot.
             */
            actCallLabels.Clear ();
            allCallLabels.Clear ();
            openCallLabel = null;

            /*
             * Alloc stack space for local vars.
             */
            AllocLocalVarStackSpace ();

            /*
             * Any return statements inside function body jump to this label
             * after putting return value in __retval.
             */
            retLabel = ilGen.DefineLabel ("__retlbl");
            retValue = null;
            if (!(curDeclFunc.retType is TokenTypeVoid)) {
                retValue = ilGen.DeclareLocal (curDeclFunc.retType.ToSysType (), "__retval");
            }

            /*
             * Output:
             *    int __mainCallNo = -1;
             *    try {
             *        if (instance.callMode != CallMode_NORMAL) goto __cmRestore;
             */
            actCallNo = null;
            ScriptMyLabel cmRestore = null;
            if (!isTrivial) {
                actCallNo = ilGen.DeclareLocal (typeof (int), "__mainCallNo");
                SetCallNo (curDeclFunc, actCallNo, -1);
                cmRestore = ilGen.DefineLabel ("__cmRestore");
                ilGen.BeginExceptionBlock ();
                PushXMRInst ();
                ilGen.Emit (curDeclFunc, OpCodes.Ldfld, ScriptCodeGen.callModeFieldInfo);
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, XMRInstAbstract.CallMode_NORMAL);
                ilGen.Emit (curDeclFunc, OpCodes.Bne_Un, cmRestore);
            }

            /*
             * Splice in the code optimizer for the body of the function.
             */
            ScriptCollector collector = new ScriptCollector ((ScriptObjWriter)ilGen);
            _ilGen = collector;

            /*
             * If this is the default state_entry() handler, output code to set all global
             * variables to their initial values.  Note that every script must have a
             * default state_entry() handler, we provide one if the script doesn't explicitly
             * define one.
             */
            string methname = ilGen.methName;
            if (methname == "default state_entry") {

                // if (!doGblInit) goto skipGblInit;
                ScriptMyLabel skipGblInitLabel = ilGen.DefineLabel ("__skipGblInit");
                PushXMRInst ();                                  // instance
                ilGen.Emit (curDeclFunc, OpCodes.Ldfld, doGblInitFieldInfo);  // instance.doGblInit
                ilGen.Emit (curDeclFunc, OpCodes.Brfalse, skipGblInitLabel);

                // $globalvarinit();
                TokenDeclVar gviFunc = tokenScript.globalVarInit;
                if (gviFunc.body.statements != null) {
                    gviFunc.location.CallPre  (this, gviFunc);
                    gviFunc.location.CallPost (this, gviFunc);
                }

                // various $staticfieldinit();
                foreach (TokenDeclSDType sdType in tokenScript.sdSrcTypesValues) {
                    if (sdType is TokenDeclSDTypeClass) {
                        TokenDeclVar sfiFunc = ((TokenDeclSDTypeClass)sdType).staticFieldInit;
                        if ((sfiFunc != null) && (sfiFunc.body.statements != null)) {
                            sfiFunc.location.CallPre  (this, sfiFunc);
                            sfiFunc.location.CallPost (this, sfiFunc);
                        }
                    }
                }

                // doGblInit = 0;
                PushXMRInst ();                                  // instance
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4_0);
                ilGen.Emit (curDeclFunc, OpCodes.Stfld, doGblInitFieldInfo);  // instance.doGblInit

                //skipGblInit:
                ilGen.MarkLabel (skipGblInitLabel);
            }

            /*
             * If this is a script-defined type constructor, call the base constructor and call
             * this class's $instfieldinit() method to initialize instance fields.
             */
            if ((curDeclFunc.sdtClass != null) && curDeclFunc.funcNameSig.val.StartsWith ("$ctor(")) {
                if (curDeclFunc.baseCtorCall != null) {
                    GenerateFromRValCall (curDeclFunc.baseCtorCall);
                }
                TokenDeclVar ifiFunc = ((TokenDeclSDTypeClass)curDeclFunc.sdtClass).instFieldInit;
                if (ifiFunc.body.statements != null) {
                    CompValu thisCompValu = new CompValuArg (ifiFunc.sdtClass.MakeRefToken (ifiFunc), 0);
                    CompValu ifiFuncLocn  = new CompValuInstMember (ifiFunc, thisCompValu, true);
                    ifiFuncLocn.CallPre  (this, ifiFunc);
                    ifiFuncLocn.CallPost (this, ifiFunc);
                }
            }

            /*
             * See if time to suspend in case they are doing a loop with recursion.
             */
            if (!isTrivial) EmitCallCheckRun (curDeclFunc, true);

            /*
             * Output code body.
             */
            GenerateStmtBlock (curDeclFunc.body);

            /*
             * If code falls through to this point, means they are missing 
             * a return statement.  And that is legal only if the function 
             * returns 'void'.
             */
            if (mightGetHere) {
                if (!(curDeclFunc.retType is TokenTypeVoid)) {
                    ErrorMsg (curDeclFunc.body, "missing final return statement");
                }
                ilGen.Emit (curDeclFunc, OpCodes.Leave, retLabel);
            }

            /*
             * End of the code to be optimized.
             * Do optimizations then write it all out to object file.
             * After this, all code gets written directly to object file.
             * Optimization must be completed before we scan the allCallLabels
             * list below to look for active locals and temps.
             */
            collector.Optimize ();
            _ilGen = collector.WriteOutAll ();
            collector = null;

            /*
             * Output code to restore stack frame from stream.
             * It jumps back to the call labels within the function body.
             */
            List<ScriptMyLocal> activeTemps = null;
            if (!isTrivial) {

                /*
                 * Build list of locals and temps active at all the call labels.
                 */
                activeTemps = new List<ScriptMyLocal> ();
                foreach (CallLabel cl in allCallLabels) {
                    foreach (ScriptMyLocal lcl in cl.callLabel.whereAmI.localsReadBeforeWritten) {
                        if (!activeTemps.Contains (lcl)) {
                            activeTemps.Add (lcl);
                        }
                    }
                }

                /*
                 * Output code to restore the args, locals and temps then jump to
                 * the call label that we were interrupted at.
                 */
                ilGen.MarkLabel (cmRestore);
                GenerateFrameRestoreCode (activeTemps);
            }

            /*
             * Output epilog that saves stack frame state if CallMode_SAVE.
             *
             *   finally {
             *      if (instance.callMode != CallMode_SAVE) goto __endFin;
             *      GenerateFrameCaptureCode();
             *   __endFin:
             *   }
             */
            ScriptMyLabel endFin = null;
            if (!isTrivial) {
                ilGen.BeginFinallyBlock ();
                endFin = ilGen.DefineLabel ("__endFin");
                PushXMRInst ();
                ilGen.Emit (curDeclFunc, OpCodes.Ldfld, callModeFieldInfo);
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, XMRInstAbstract.CallMode_SAVE);
                ilGen.Emit (curDeclFunc, OpCodes.Bne_Un, endFin);
                GenerateFrameCaptureCode (activeTemps);
                ilGen.MarkLabel (endFin);
                ilGen.Emit (curDeclFunc, OpCodes.Endfinally);
                ilGen.EndExceptionBlock ();
            }

            /*
             * Output the 'real' return opcode.
             */
            ilGen.MarkLabel (retLabel);
            if (!(curDeclFunc.retType is TokenTypeVoid)) {
                ilGen.Emit (curDeclFunc, OpCodes.Ldloc, retValue);
            }
            ilGen.Emit (curDeclFunc, OpCodes.Ret);
            retLabel = null;
            retValue = null;

            /*
             * No more instructions for this method.
             */
            ((ScriptObjWriter)ilGen).EndMethod ();
            _ilGen = null;

            /*
             * Not generating function code any more.
             */
            curBreakTarg = null;
            curContTarg  = null;
            curDeclFunc  = null;
        }

        /**
         * @brief Allocate stack space for all local variables, regardless of
         *        which { } statement block they are actually defined in.
         */
        private void AllocLocalVarStackSpace ()
        {
            foreach (TokenDeclVar localVar in curDeclFunc.localVars) {

                /*
                 * Skip all 'constant' vars as they were handled by the reducer.
                 */
                if (localVar.constant) continue;

                /*
                 * Get a stack location for the local variable.
                 */
                localVar.location = new CompValuLocalVar (localVar.type, localVar.name.val, this);
            }
        }

        /**
         * @brief Generate code to write all arguments and locals to the capture stack frame.
         *        This includes temp variables.
         *        We only need to save what is active at the point of callLabels through because 
         *        those are the only points we will jump to on restore.  This saves us from saving 
         *        all the little temp vars we create.
         * @param activeTemps = list of locals and temps that we care about, ie, which
         *                      ones get restored by GenerateFrameRestoreCode().
         */
        private void GenerateFrameCaptureCode (List<ScriptMyLocal> activeTemps)
        {
            /*
             * Compute total number of slots we need to save stuff.
             * Assume we need to save all call arguments.
             */
            int nSaves = curDeclFunc.argDecl.vars.Length + activeTemps.Count;

            /*
             * Output code to allocate a stack frame object with an object array.
             * This also pushes the stack frame object on the instance.stackFrames list.
             * It returns a pointer to the object array it allocated.
             */
            PushXMRInst ();
            ilGen.Emit (curDeclFunc, OpCodes.Ldstr, ilGen.methName);
            GetCallNo (curDeclFunc, actCallNo);
            ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, nSaves);
            ilGen.Emit (curDeclFunc, OpCodes.Call, captureStackFrameMethodInfo);

            if (DEBUG_STACKCAPRES) {
                ilGen.Emit (curDeclFunc, OpCodes.Ldstr, ilGen.methName + "*: capture mainCallNo=");
                ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (curDeclFunc, OpCodes.Ldloc, actCallNo);
                ilGen.Emit (curDeclFunc, OpCodes.Box, typeof (int));
                ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
            }

            /*
             * Copy arg values to object array, boxing as needed.
             */
            int i = 0;
            foreach (TokenDeclVar argVar in curDeclFunc.argDecl.varDict) {
                ilGen.Emit (curDeclFunc, OpCodes.Dup);
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, i);
                argVar.location.PushVal (this, argVar.name, tokenTypeObj);
                if (DEBUG_STACKCAPRES) {
                    ilGen.Emit (curDeclFunc, OpCodes.Ldstr, "\n    arg:" + argVar.name.val + "=");
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                    ilGen.Emit (curDeclFunc, OpCodes.Dup);
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                }
                ilGen.Emit (curDeclFunc, OpCodes.Stelem_Ref);
                i ++;
            }

            /*
             * Copy local and temp values to object array, boxing as needed.
             */
            foreach (ScriptMyLocal lcl in activeTemps) {
                ilGen.Emit (curDeclFunc, OpCodes.Dup);
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, i ++);
                ilGen.Emit (curDeclFunc, OpCodes.Ldloc, lcl);
                Type t = lcl.type;
                if (t == typeof (HeapTrackerList)) {
                    t = HeapTrackerList.GenPush (curDeclFunc, ilGen);
                }
                if (t == typeof (HeapTrackerObject)) {
                    t = HeapTrackerObject.GenPush (curDeclFunc, ilGen);
                }
                if (t == typeof(HeapTrackerString)) {
                    t = HeapTrackerString.GenPush (curDeclFunc, ilGen);
                }
                if (t.IsValueType) {
                    ilGen.Emit (curDeclFunc, OpCodes.Box, t);
                }
                if (DEBUG_STACKCAPRES) {
                    ilGen.Emit (curDeclFunc, OpCodes.Ldstr, "\n    lcl:" + lcl.name + "=");
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                    ilGen.Emit (curDeclFunc, OpCodes.Dup);
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                }
                ilGen.Emit (curDeclFunc, OpCodes.Stelem_Ref);
            }
            if (DEBUG_STACKCAPRES) {
                ilGen.Emit (curDeclFunc, OpCodes.Ldstr, "\n");
                ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
            }

            ilGen.Emit (curDeclFunc, OpCodes.Pop);
        }

        /**
         * @brief Generate code to restore all arguments and locals from the restore stack frame.
         *        This includes temp variables.
         */
        private void GenerateFrameRestoreCode (List<ScriptMyLocal> activeTemps)
        {
            ScriptMyLocal objArray = ilGen.DeclareLocal (typeof (object[]), "__restObjArray");

            /*
             * Output code to pop stack frame from instance.stackFrames.
             * It returns a pointer to the object array that contains values to be restored.
             */
            PushXMRInst ();
            ilGen.Emit (curDeclFunc, OpCodes.Ldstr, ilGen.methName);
            ilGen.Emit (curDeclFunc, OpCodes.Ldloca, actCallNo);  // __mainCallNo
            ilGen.Emit (curDeclFunc, OpCodes.Call, restoreStackFrameMethodInfo);
            ilGen.Emit (curDeclFunc, OpCodes.Stloc, objArray);
            if (DEBUG_STACKCAPRES) {
                ilGen.Emit (curDeclFunc, OpCodes.Ldstr, ilGen.methName + "*: restore mainCallNo=");
                ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (curDeclFunc, OpCodes.Ldloc, actCallNo);
                ilGen.Emit (curDeclFunc, OpCodes.Box, typeof (int));
                ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
            }

            /*
             * Restore argument values from object array, unboxing as needed.
             * Although the caller has restored them to what it called us with, it's possible that this 
             * function has modified them since, so we need to do our own restore.
             */
            int i = 0;
            foreach (TokenDeclVar argVar in curDeclFunc.argDecl.varDict) {
                CompValu argLoc = argVar.location;
                argLoc.PopPre (this, argVar.name);
                ilGen.Emit (curDeclFunc, OpCodes.Ldloc, objArray);
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, i);
                ilGen.Emit (curDeclFunc, OpCodes.Ldelem_Ref);
                if (DEBUG_STACKCAPRES) {
                    ilGen.Emit (curDeclFunc, OpCodes.Ldstr, "\n    arg:" + argVar.name.val + "=");
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                    ilGen.Emit (curDeclFunc, OpCodes.Dup);
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                }
                TypeCast.CastTopOfStack (this, argVar.name, tokenTypeObj, argLoc.type, true);
                argLoc.PopPost (this, argVar.name);
                i ++;
            }

            /*
             * Restore local and temp values from object array, unboxing as needed.
             */
            foreach (ScriptMyLocal lcl in activeTemps) {
                Type t = lcl.type;
                Type u = t;
                if (t == typeof (HeapTrackerList))   u = typeof (LSL_List);
                if (t == typeof (HeapTrackerObject)) u = typeof (object);
                if (t == typeof (HeapTrackerString)) u = typeof (string);
                if (u != t) {
                    ilGen.Emit (curDeclFunc, OpCodes.Ldloc, lcl);
                }
                ilGen.Emit (curDeclFunc, OpCodes.Ldloc, objArray);
                ilGen.Emit (curDeclFunc, OpCodes.Ldc_I4, i ++);
                ilGen.Emit (curDeclFunc, OpCodes.Ldelem_Ref);
                if (DEBUG_STACKCAPRES) {
                    ilGen.Emit (curDeclFunc, OpCodes.Ldstr, "\n    lcl:" + lcl.name + "=");
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                    ilGen.Emit (curDeclFunc, OpCodes.Dup);
                    ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
                }
                if (u.IsValueType) {
                    ilGen.Emit (curDeclFunc, OpCodes.Unbox_Any, u);
                } else if (u != typeof (object)) {
                    ilGen.Emit (curDeclFunc, OpCodes.Castclass, u);
                }
                if (u != t) {
                    if (t == typeof (HeapTrackerList))   HeapTrackerList.GenPop   (curDeclFunc, ilGen);
                    if (t == typeof (HeapTrackerObject)) HeapTrackerObject.GenPop (curDeclFunc, ilGen);
                    if (t == typeof (HeapTrackerString)) HeapTrackerString.GenPop (curDeclFunc, ilGen);
                } else {
                    ilGen.Emit (curDeclFunc, OpCodes.Stloc, lcl);
                }
            }
            if (DEBUG_STACKCAPRES) {
                ilGen.Emit (curDeclFunc, OpCodes.Ldstr, "\n");
                ilGen.Emit (curDeclFunc, OpCodes.Call, consoleWriteMethodInfo);
            }

            OutputCallNoSwitchStmt ();
        }

        /**
         * @brief Output a switch statement with a case for each possible 
         *        value of whatever callNo is currently active, either 
         *        __mainCallNo or one of the try/catch/finally's callNos.
         *
         *   switch (callNo) {
         *      case 0: goto __call_0;
         *      case 1: goto __call_1;
         *      ...
         *   }
         *   throw new ScriptBadCallNoException (callNo);
         */
        private void OutputCallNoSwitchStmt ()
        {
            ScriptMyLabel[] callLabels = new ScriptMyLabel[actCallLabels.Count];
            foreach (CallLabel cl in actCallLabels) {
                callLabels[cl.index] = cl.callLabel;
            }
            GetCallNo (curDeclFunc, actCallNo);
            ilGen.Emit (curDeclFunc, OpCodes.Switch, callLabels);

            GetCallNo (curDeclFunc, actCallNo);
            ilGen.Emit (curDeclFunc, OpCodes.Newobj, scriptBadCallNoExceptionConstructorInfo);
            ilGen.Emit (curDeclFunc, OpCodes.Throw);
        }

        /**
         * @brief There is one of these per call that can possibly call CheckRun(),
         *        including direct calls to CheckRun().
         *        They mark points that the stack capture/restore code will save & restore to.
         *        All object-code level local vars active at the call label's point will 
         *        be saved & restored.
         *
         *            callNo = 5;
         *        __call_5:
         *            push call arguments from temps
         *            call SomethingThatCallsCheckRun()
         *
         *        If SomethingThatCallsCheckRun() actually calls CheckRun(), our restore code
         *        will restore our args, locals & temps, then jump to __call_5, which will then 
         *        call SomethingThatCallsCheckRun() again, which will restore its stuff likewise.
         *        When eventually the actual CheckRun() call is restored, it will turn off restore 
         *        mode (by changing callMode from CallMode_RESTORE to CallMode_NORMAL) and return, 
         *        allowing the code to run normally from that point.
         */
        public class CallLabel {
            public int           index;       // sequential integer, starting at 0, within actCallLabels
                                              // - used for the switch statement
            public ScriptMyLabel callLabel;   // the actual label token

            public CallLabel (ScriptCodeGen scg, Token errorAt)
            {
                if (scg.openCallLabel != null) throw new Exception ("call label already open");

                if (!scg.curDeclFunc.IsFuncTrivial (scg)) {
                    this.index = scg.actCallLabels.Count;
                    string name = "__call_" + index + "_" + scg.allCallLabels.Count;

                    /*
                     * Make sure eval stack is empty because the frame capture/restore 
                     * code expects such (restore switch stmt has an empty stack).
                     */
                    int depth = ((ScriptCollector)scg.ilGen).stackDepth.Count;
                    if (depth > 0) {
                        // maybe need to call Trivialize()
                        throw new Exception ("call label stack depth " + depth + " at " + errorAt.SrcLoc);
                    }

                    /*
                     * Eval stack is empty so the restore code can handle it.
                     */
                    this.index = scg.actCallLabels.Count;
                    scg.actCallLabels.AddLast (this);
                    scg.allCallLabels.AddLast (this);
                    this.callLabel = scg.ilGen.DefineLabel (name);
                    scg.SetCallNo (errorAt, scg.actCallNo, this.index);
                    scg.ilGen.MarkLabel (this.callLabel);
                }

                scg.openCallLabel = this;
            }
        };

        /**
         * @brief generate code for an arbitrary statement.
         */
        private void GenerateStmt (TokenStmt stmt)
        {
            errorMessageToken = stmt;
            if (stmt is TokenDeclVar)       { GenerateDeclVar       ((TokenDeclVar)stmt);       return; }
            if (stmt is TokenStmtBlock)     { GenerateStmtBlock     ((TokenStmtBlock)stmt);     return; }
            if (stmt is TokenStmtBreak)     { GenerateStmtBreak     ((TokenStmtBreak)stmt);     return; }
            if (stmt is TokenStmtCont)      { GenerateStmtCont      ((TokenStmtCont)stmt);      return; }
            if (stmt is TokenStmtDo)        { GenerateStmtDo        ((TokenStmtDo)stmt);        return; }
            if (stmt is TokenStmtFor)       { GenerateStmtFor       ((TokenStmtFor)stmt);       return; }
            if (stmt is TokenStmtForEach)   { GenerateStmtForEach   ((TokenStmtForEach)stmt);   return; }
            if (stmt is TokenStmtIf)        { GenerateStmtIf        ((TokenStmtIf)stmt);        return; }
            if (stmt is TokenStmtJump)      { GenerateStmtJump      ((TokenStmtJump)stmt);      return; }
            if (stmt is TokenStmtLabel)     { GenerateStmtLabel     ((TokenStmtLabel)stmt);     return; }
            if (stmt is TokenStmtNewobj)    { GenerateStmtNewobj    ((TokenStmtNewobj)stmt);    return; }
            if (stmt is TokenStmtNull)      {                                                   return; }
            if (stmt is TokenStmtRet)       { GenerateStmtRet       ((TokenStmtRet)stmt);       return; }
            if (stmt is TokenStmtRVal)      { GenerateStmtRVal      ((TokenStmtRVal)stmt);      return; }
            if (stmt is TokenStmtState)     { GenerateStmtState     ((TokenStmtState)stmt);     return; }
            if (stmt is TokenStmtSwitch)    { GenerateStmtSwitch    ((TokenStmtSwitch)stmt);    return; }
            if (stmt is TokenStmtThrow)     { GenerateStmtThrow     ((TokenStmtThrow)stmt);     return; }
            if (stmt is TokenStmtTry)       { GenerateStmtTry       ((TokenStmtTry)stmt);       return; }
            if (stmt is TokenStmtVarIniDef) { GenerateStmtVarIniDef ((TokenStmtVarIniDef)stmt); return; }
            if (stmt is TokenStmtWhile)     { GenerateStmtWhile     ((TokenStmtWhile)stmt);     return; }
            throw new Exception ("unknown TokenStmt type " + stmt.GetType ().ToString ());
        }

        /**
         * @brief generate statement block (ie, with braces)
         */
        private void GenerateStmtBlock (TokenStmtBlock stmtBlock)
        {
            if (!mightGetHere) return;

            /*
             * Push new current statement block pointer for anyone who cares.
             */
            TokenStmtBlock oldStmtBlock = curStmtBlock;
            curStmtBlock = stmtBlock;

            /*
             * Output the statements that make up the block.
             */
            for (Token t = stmtBlock.statements; t != null; t = t.nextToken) {
                GenerateStmt ((TokenStmt)t);
            }

            /*
             * Pop the current statement block.
             */
            curStmtBlock = oldStmtBlock;
        }

        /**
         * @brief output code for a 'break' statement
         */
        private void GenerateStmtBreak (TokenStmtBreak breakStmt)
        {
            if (!mightGetHere) return;

            /*
             * Make sure we are in a breakable situation.
             */
            if (curBreakTarg == null) {
                ErrorMsg (breakStmt, "not in a breakable situation");
                return;
            }

            /*
             * Tell anyone who cares that the break target was actually used.
             */
            curBreakTarg.used = true;

            /*
             * Output the instructions.
             */
            EmitJumpCode (curBreakTarg.label, curBreakTarg.block, breakStmt);
        }

        /**
         * @brief output code for a 'continue' statement
         */
        private void GenerateStmtCont (TokenStmtCont contStmt)
        {
            if (!mightGetHere) return;

            /*
             * Make sure we are in a contable situation.
             */
            if (curContTarg == null) {
                ErrorMsg (contStmt, "not in a continueable situation");
                return;
            }

            /*
             * Tell anyone who cares that the continue target was actually used.
             */
            curContTarg.used = true;

            /*
             * Output the instructions.
             */
            EmitJumpCode (curContTarg.label, curContTarg.block, contStmt);
        }

        /**
         * @brief output code for a 'do' statement
         */
        private void GenerateStmtDo (TokenStmtDo doStmt)
        {
            if (!mightGetHere) return;

            BreakContTarg oldBreakTarg = curBreakTarg;
            BreakContTarg oldContTarg  = curContTarg;
            ScriptMyLabel loopLabel    = ilGen.DefineLabel ("doloop_" + doStmt.Unique);

            curBreakTarg = new BreakContTarg (this, "dobreak_" + doStmt.Unique);
            curContTarg  = new BreakContTarg (this, "docont_"  + doStmt.Unique);

            ilGen.MarkLabel (loopLabel);
            GenerateStmt (doStmt.bodyStmt);
            if (curContTarg.used) {
                ilGen.MarkLabel (curContTarg.label);
                mightGetHere = true;
            }

            if (mightGetHere) {
                EmitCallCheckRun (doStmt, false);
                CompValu testRVal = GenerateFromRVal (doStmt.testRVal);
                if (IsConstBoolExprTrue (testRVal)) {

                    /*
                     * Unconditional looping, unconditional branch and
                     * say we never fall through to next statement.
                     */
                    ilGen.Emit (doStmt, OpCodes.Br, loopLabel);
                    mightGetHere = false;
                } else {

                    /*
                     * Conditional looping, test and brach back to top of loop.
                     */
                    testRVal.PushVal (this, doStmt.testRVal, tokenTypeBool);
                    ilGen.Emit (doStmt, OpCodes.Brtrue, loopLabel);
                }
            }

            /*
             * If 'break' statement was used, output target label.
             * And assume that since a 'break' statement was used, it's possible for the code to get here.
             */
            if (curBreakTarg.used) {
                ilGen.MarkLabel (curBreakTarg.label);
                mightGetHere = true;
            }

            curBreakTarg = oldBreakTarg;
            curContTarg  = oldContTarg;
        }

        /**
         * @brief output code for a 'for' statement
         */
        private void GenerateStmtFor (TokenStmtFor forStmt)
        {
            if (!mightGetHere) return;

            BreakContTarg oldBreakTarg = curBreakTarg;
            BreakContTarg oldContTarg  = curContTarg;
            ScriptMyLabel loopLabel    = ilGen.DefineLabel ("forloop_" + forStmt.Unique);

            curBreakTarg = new BreakContTarg (this, "forbreak_" + forStmt.Unique);
            curContTarg  = new BreakContTarg (this, "forcont_"  + forStmt.Unique);

            if (forStmt.initStmt != null) {
                GenerateStmt (forStmt.initStmt);
            }
            ilGen.MarkLabel (loopLabel);

            /*
             * See if we have a test expression that is other than a constant TRUE.
             * If so, test it and conditionally branch to end if false.
             */
            if (forStmt.testRVal != null) {
                CompValu testRVal = GenerateFromRVal (forStmt.testRVal);
                if (!IsConstBoolExprTrue (testRVal)) {
                    testRVal.PushVal (this, forStmt.testRVal, tokenTypeBool);
                    ilGen.Emit (forStmt, OpCodes.Brfalse, curBreakTarg.label);
                    curBreakTarg.used = true;
                }
            }

            /*
             * Output loop body.
             */
            GenerateStmt (forStmt.bodyStmt);

            /*
             * Here's where a 'continue' statement jumps to.
             */
            if (curContTarg.used) {
                ilGen.MarkLabel (curContTarg.label);
                mightGetHere = true;
            }

            if (mightGetHere) {

                /*
                 * After checking for excessive CPU time, output increment statement, if any.
                 */
                EmitCallCheckRun (forStmt, false);
                if (forStmt.incrRVal != null) {
                    GenerateFromRVal (forStmt.incrRVal);
                }

                /*
                 * Unconditional branch back to beginning of loop.
                 */
                ilGen.Emit (forStmt, OpCodes.Br, loopLabel);
            }

            /*
             * If test needs label, output label for it to jump to.
             * Otherwise, clear mightGetHere as we know loop never
             * falls out the bottom.
             */
            mightGetHere = curBreakTarg.used;
            if (mightGetHere) {
                ilGen.MarkLabel (curBreakTarg.label);
            }

            curBreakTarg = oldBreakTarg;
            curContTarg  = oldContTarg;
        }

        private void GenerateStmtForEach (TokenStmtForEach forEachStmt)
        {
            if (!mightGetHere) return;

            BreakContTarg oldBreakTarg = curBreakTarg;
            BreakContTarg oldContTarg  = curContTarg;
            CompValu      keyLVal      = null;
            CompValu      valLVal      = null;
            CompValu      arrayRVal    = GenerateFromRVal (forEachStmt.arrayRVal);

            if (forEachStmt.keyLVal != null) {
                keyLVal = GenerateFromLVal (forEachStmt.keyLVal);
                if (!(keyLVal.type is TokenTypeObject)) {
                    ErrorMsg (forEachStmt.arrayRVal, "must be object");
                }
            }
            if (forEachStmt.valLVal != null) {
                valLVal = GenerateFromLVal (forEachStmt.valLVal);
                if (!(valLVal.type is TokenTypeObject)) {
                    ErrorMsg (forEachStmt.arrayRVal, "must be object");
                }
            }
            if (!(arrayRVal.type is TokenTypeArray)) {
                ErrorMsg (forEachStmt.arrayRVal, "must be an array");
            }

            curBreakTarg = new BreakContTarg (this, "foreachbreak_" + forEachStmt.Unique);
            curContTarg  = new BreakContTarg (this, "foreachcont_"  + forEachStmt.Unique);

            CompValuTemp indexVar = new CompValuTemp (new TokenTypeInt (forEachStmt), this);
            ScriptMyLabel loopLabel = ilGen.DefineLabel ("foreachloop_" + forEachStmt.Unique);

            // indexVar = 0
            ilGen.Emit (forEachStmt, OpCodes.Ldc_I4_0);
            indexVar.Pop (this, forEachStmt);

            ilGen.MarkLabel (loopLabel);

            // key = array.__pub_index (indexVar);
            // if (key == null) goto curBreakTarg;
            if (keyLVal != null) {
                keyLVal.PopPre (this, forEachStmt.keyLVal);
                arrayRVal.PushVal (this, forEachStmt.arrayRVal);
                indexVar.PushVal (this, forEachStmt);
                ilGen.Emit (forEachStmt, OpCodes.Call, xmrArrPubIndexMethod);
                keyLVal.PopPost (this, forEachStmt.keyLVal);
                keyLVal.PushVal (this, forEachStmt.keyLVal);
                ilGen.Emit (forEachStmt, OpCodes.Brfalse, curBreakTarg.label);
                curBreakTarg.used = true;
            }

            // val = array._pub_value (indexVar);
            // if (val == null) goto curBreakTarg;
            if (valLVal != null) {
                valLVal.PopPre (this, forEachStmt.valLVal);
                arrayRVal.PushVal (this, forEachStmt.arrayRVal);
                indexVar.PushVal (this, forEachStmt);
                ilGen.Emit (forEachStmt, OpCodes.Call, xmrArrPubValueMethod);
                valLVal.PopPost (this, forEachStmt.valLVal);
                if (keyLVal == null) {
                    valLVal.PushVal (this, forEachStmt.valLVal);
                    ilGen.Emit (forEachStmt, OpCodes.Brfalse, curBreakTarg.label);
                    curBreakTarg.used = true;
                }
            }

            // indexVar ++;
            indexVar.PushVal (this, forEachStmt);
            ilGen.Emit (forEachStmt, OpCodes.Ldc_I4_1);
            ilGen.Emit (forEachStmt, OpCodes.Add);
            indexVar.Pop (this, forEachStmt);

            // body statement
            GenerateStmt (forEachStmt.bodyStmt);

            // continue label
            if (curContTarg.used) {
                ilGen.MarkLabel (curContTarg.label);
                mightGetHere = true;
            }

            // call CheckRun()
            if (mightGetHere) {
                EmitCallCheckRun (forEachStmt, false);
                ilGen.Emit (forEachStmt, OpCodes.Br, loopLabel);
            }

            // break label
            ilGen.MarkLabel (curBreakTarg.label);
            mightGetHere = true;

            curBreakTarg = oldBreakTarg;
            curContTarg  = oldContTarg;
        }

        /**
         * @brief output code for an 'if' statement
         * Braces are necessary because what may be one statement for trueStmt or elseStmt in
         * the script may translate to more than one statement in the resultant C# code.
         */
        private void GenerateStmtIf (TokenStmtIf ifStmt)
        {
            if (!mightGetHere) return;

            bool constVal;

            /*
             * Test condition and see if constant test expression.
             */
            CompValu testRVal = GenerateFromRVal (ifStmt.testRVal);
            if (IsConstBoolExpr (testRVal, out constVal)) {

                /*
                 * Constant, output just either the true or else part.
                 */
                if (constVal) {
                    GenerateStmt (ifStmt.trueStmt);
                } else if (ifStmt.elseStmt != null) {
                    GenerateStmt (ifStmt.elseStmt);
                }
            } else if (ifStmt.elseStmt == null) {

                /*
                 * This is an 'if' statement without an 'else' clause.
                 */
                testRVal.PushVal (this, ifStmt.testRVal, tokenTypeBool);
                ScriptMyLabel doneLabel = ilGen.DefineLabel ("ifdone_" + ifStmt.Unique);
                ilGen.Emit (ifStmt, OpCodes.Brfalse, doneLabel);  // brfalse doneLabel
                GenerateStmt (ifStmt.trueStmt);                   // generate true body code
                ilGen.MarkLabel (doneLabel);
                mightGetHere = true;                              // there's always a possibility of getting here
            } else {

                /*
                 * This is an 'if' statement with an 'else' clause.
                 */
                testRVal.PushVal (this, ifStmt.testRVal, tokenTypeBool);
                ScriptMyLabel elseLabel = ilGen.DefineLabel ("ifelse_" + ifStmt.Unique);
                ilGen.Emit (ifStmt, OpCodes.Brfalse, elseLabel);  // brfalse elseLabel
                GenerateStmt (ifStmt.trueStmt);                   // generate true body code
                bool trueMightGetHere = mightGetHere;             // save whether or not true falls through
                ScriptMyLabel doneLabel = ilGen.DefineLabel ("ifdone_" + ifStmt.Unique);
                ilGen.Emit (ifStmt, OpCodes.Br, doneLabel);       // branch to done
                ilGen.MarkLabel (elseLabel);                      // beginning of else code
                mightGetHere = true;                              // the top of the else might be executed
                GenerateStmt (ifStmt.elseStmt);                   // output else code
                ilGen.MarkLabel (doneLabel);                      // where end of true clause code branches to
                mightGetHere |= trueMightGetHere;                 // gets this far if either true or else falls through
            }
        }

        /**
         * @brief output code for a 'jump' statement
         */
        private void GenerateStmtJump (TokenStmtJump jumpStmt)
        {
            if (!mightGetHere) return;

            /*
             * Make sure the target label is defined somewhere in the function.
             */
            TokenStmtLabel stmtLabel;
            if (!curDeclFunc.labels.TryGetValue (jumpStmt.label.val, out stmtLabel)) {
                ErrorMsg (jumpStmt, "undefined label " + jumpStmt.label.val);
                return;
            }
            if (!stmtLabel.labelTagged) {
                stmtLabel.labelStruct = ilGen.DefineLabel ("jump_" + stmtLabel.name.val);
                stmtLabel.labelTagged = true;
            }

            /*
             * Emit instructions to do the jump.
             */
            EmitJumpCode (stmtLabel.labelStruct, stmtLabel.block, jumpStmt);
        }

        /**
         * @brief Emit code to jump to a label
         * @param target = label being jumped to
         * @param targetsBlock = { ... } the label is defined in
         */
        private void EmitJumpCode (ScriptMyLabel target, TokenStmtBlock targetsBlock, Token errorAt)
        {
            /*
             * Jumps never fall through.
             */
            mightGetHere = false;

            /*
             * Find which block the target label is in.  Must be in this or an outer block,
             * no laterals allowed.  And if we exit a try/catch block, use Leave instead of Br.
             *
             *    jump lateral;
             *    {
             *        @lateral;
             *    }
             */
            bool useLeave = false;
            TokenStmtBlock stmtBlock;
            Stack<TokenStmtTry> finallyBlocksCalled = new Stack<TokenStmtTry> ();
            for (stmtBlock = curStmtBlock; stmtBlock != targetsBlock; stmtBlock = stmtBlock.outerStmtBlock) {
                if (stmtBlock == null) {
                    ErrorMsg (errorAt, "no lateral jumps allowed");
                    return;
                }
                if (stmtBlock.isFinally) {
                    ErrorMsg (errorAt, "cannot jump out of finally");
                    return;
                }
                if (stmtBlock.isTry || stmtBlock.isCatch) useLeave = true;
                if ((stmtBlock.tryStmt != null) && (stmtBlock.tryStmt.finallyStmt != null)) {
                    finallyBlocksCalled.Push (stmtBlock.tryStmt);
                }
            }

            /*
             * If popping through more than one finally block, we have to break it down for the stack 
             * capture and restore code, one finally block at a time.
             *
             *     try {
             *         try {
             *             try {
             *                 jump exit;
             *             } finally {
             *                 llOwnerSay ("exiting inner");
             *             }
             *         } finally {
             *             llOwnerSay ("exiting middle");
             *         }
             *     } finally {
             *         llOwnerSay ("exiting outer");
             *     }
             *   @exit;
             *
             *     try {
             *         try {
             *             try {
             *                 jump intr2_exit;         <<< gets its own tryNo call label so inner try knows where to restore to
             *             } finally {
             *                 llOwnerSay ("exiting inner");
             *             }
             *             jump outtry2;
             *           @intr2_exit; jump intr1_exit;  <<< gets its own tryNo call label so middle try knows where to restore to
             *           @outtry2;
             *         } finally {
             *             llOwnerSay ("exiting middle");
             *         }
             *         jump outtry1;
             *       @intr1_exit: jump exit;            <<< gets its own tryNo call label so outer try knows where to restore to
             *       @outtry1;
             *     } finally {
             *         llOwnerSay ("exiting outer");
             *     }
             *   @exit;
             */
            int level = 0;
            while (finallyBlocksCalled.Count > 1) {
                TokenStmtTry finallyBlock = finallyBlocksCalled.Pop ();
                string intername = "intr" + (++ level) + "_" + target.name;
                IntermediateLeave iLeave;
                if (!finallyBlock.iLeaves.TryGetValue (intername, out iLeave)) {
                    iLeave = new IntermediateLeave ();
                    iLeave.jumpIntoLabel = ilGen.DefineLabel (intername);
                    iLeave.jumpAwayLabel = target;
                    finallyBlock.iLeaves.Add (intername, iLeave);
                }
                target = iLeave.jumpIntoLabel;
            }

            /*
             * Finally output the branch/leave opcode.
             * If using Leave, prefix with a call label in case the corresponding finally block
             * calls CheckRun() and that CheckRun() captures the stack, it will have a point to 
             * restore to that will properly jump back into the finally block.
             */
            if (useLeave) {
                new CallLabel (this, errorAt);
                ilGen.Emit (errorAt, OpCodes.Leave, target);
                openCallLabel = null;
            } else {
                ilGen.Emit (errorAt, OpCodes.Br, target);
            }
        }

        /**
         * @brief output code for a jump target label statement.
         * If there are any backward jumps to the label, do a CheckRun() also.
         */
        private void GenerateStmtLabel (TokenStmtLabel labelStmt)
        {
            if (!labelStmt.labelTagged) {
                labelStmt.labelStruct = ilGen.DefineLabel ("jump_" + labelStmt.name.val);
                labelStmt.labelTagged = true;
            }
            ilGen.MarkLabel (labelStmt.labelStruct);
            if (labelStmt.hasBkwdRefs) {
                EmitCallCheckRun (labelStmt, false);
            }

            /*
             * We are going to say that the label falls through.
             * It would be nice if we could analyze all referencing
             * goto's to see if all of them are not used but we are
             * going to assume that if the script writer put a label
             * somewhere, it is probably going to be used.
             */
            mightGetHere = true;
        }

        /**
         * @brief Generate code for a script-defined type's <typename>.$new(<argsig>) method.
         *        It is used to malloc the object and initialize it.
         *        It is defined as a script-defined type static method, so the object level
         *        method gets the XMRInstance pointer passed as arg 0, and the method is 
         *        supposed to return the allocated and constructed XMRSDTypeClObj
         *        object pointer.
         */
        private void GenerateStmtNewobj (TokenStmtNewobj newobjStmt)
        {
            /*
             * First off, malloc a new empty XMRSDTypeClObj object
             * then call the XMRSDTypeClObj()-level constructor.
             * Store the result in local var $objptr.
             */
            newobjStmt.objptrVar.location.PopPre (this, newobjStmt);
            ilGen.Emit (newobjStmt, OpCodes.Ldarg_0);
            ilGen.Emit (newobjStmt, OpCodes.Ldc_I4, curDeclFunc.sdtClass.sdTypeIndex);
            ilGen.Emit (newobjStmt, OpCodes.Newobj, sdtClassConstructorInfo);
            newobjStmt.objptrVar.location.PopPost (this, newobjStmt);

            /*
             * Now call the script-level constructor.
             * Pass the object pointer in $objptr as it's 'this' argument.
             * The rest of the args are the script-visible args and are just copied from $new() call.
             */
            GenerateFromRValCall (newobjStmt.rValCall);

            /*
             * Put object pointer in retval so it gets returned to caller.
             */
            newobjStmt.objptrVar.location.PushVal (this, newobjStmt);
            ilGen.Emit (newobjStmt, OpCodes.Stloc, retValue);

            /*
             * Exit the function like a return statement.
             * And thus we don't fall through.
             */
            ilGen.Emit (newobjStmt, OpCodes.Leave, retLabel);
            mightGetHere = false;
        }

        /**
         * @brief output code for a return statement.
         * @param retStmt = return statement token, including return value if any
         */
        private void GenerateStmtRet (TokenStmtRet retStmt)
        {
            if (!mightGetHere) return;

            for (TokenStmtBlock stmtBlock = curStmtBlock; stmtBlock != null; stmtBlock = stmtBlock.outerStmtBlock) {
                if (stmtBlock.isFinally) {
                    ErrorMsg (retStmt, "cannot return out of finally");
                    return;
                }
            }

            if (curDeclFunc.retType is TokenTypeVoid) {
                if (retStmt.rVal != null) {
                    ErrorMsg (retStmt, "function returns void, no value allowed");
                    return;
                }
            } else {
                if (retStmt.rVal == null) {
                    ErrorMsg (retStmt, "function requires return value type " + curDeclFunc.retType.ToString ());
                    return;
                }
                CompValu rVal = GenerateFromRVal (retStmt.rVal);
                rVal.PushVal (this, retStmt.rVal, curDeclFunc.retType);
                ilGen.Emit (retStmt, OpCodes.Stloc, retValue);
            }

            /*
             * Use a OpCodes.Leave instruction to break out of any try { } blocks.
             * All Leave's inside script-defined try { } need call labels (see GenerateStmtTry()).
             */
            bool brokeOutOfTry = false;
            for (TokenStmtBlock stmtBlock = curStmtBlock; stmtBlock != null; stmtBlock = stmtBlock.outerStmtBlock) {
                if (stmtBlock.isTry) {
                    brokeOutOfTry = true;
                    break;
                }
            }
            if (brokeOutOfTry) new CallLabel (this, retStmt);
            ilGen.Emit (retStmt, OpCodes.Leave, retLabel);
            if (brokeOutOfTry) openCallLabel = null;

            /*
             * 'return' statements never fall through.
             */
            mightGetHere = false;
        }

        /**
         * @brief the statement is just an expression, most likely an assignment or a ++ or -- thing.
         */
        private void GenerateStmtRVal (TokenStmtRVal rValStmt)
        {
            if (!mightGetHere) return;

            GenerateFromRVal (rValStmt.rVal);
        }

        /**
         * @brief generate code for a 'state' statement that transitions state.
         * It sets the new state by throwing a ScriptChangeStateException.
         */
        private void GenerateStmtState (TokenStmtState stateStmt)
        {
            if (!mightGetHere) return;

            int index = 0;  // 'default' state

            /*
             * Set new state value by throwing an exception.
             * These exceptions aren't catchable by script-level try { } catch { }.
             */
            if ((stateStmt.state != null) && !stateIndices.TryGetValue (stateStmt.state.val, out index)) {
                // The moron XEngine compiles scripts that reference undefined states.
                // So rather than produce a compile-time error, we'll throw an exception at runtime.
                // ErrorMsg (stateStmt, "undefined state " + stateStmt.state.val);

                // throw new UndefinedStateException (stateStmt.state.val);
                ilGen.Emit (stateStmt, OpCodes.Ldstr, stateStmt.state.val);
                ilGen.Emit (stateStmt, OpCodes.Newobj, scriptUndefinedStateExceptionConstructorInfo);
            } else {
                ilGen.Emit (stateStmt, OpCodes.Ldc_I4, index);  // new state's index
                ilGen.Emit (stateStmt, OpCodes.Newobj, scriptChangeStateExceptionConstructorInfo);
            }
            ilGen.Emit (stateStmt, OpCodes.Throw);

            /*
             * 'state' statements never fall through.
             */
            mightGetHere = false;
        }

        /**
         * @brief output code for a 'switch' statement
         */
        private void GenerateStmtSwitch (TokenStmtSwitch switchStmt)
        {
            if (!mightGetHere) return;

            /*
             * Output code to calculate index.
             */
            CompValu testRVal = GenerateFromRVal (switchStmt.testRVal);

            /*
             * Generate code based on string or integer index.
             */
            if ((testRVal.type is TokenTypeKey) || (testRVal.type is TokenTypeStr)) {
                GenerateStmtSwitchStr (testRVal, switchStmt);
            } else {
                GenerateStmtSwitchInt (testRVal, switchStmt);
            }
        }

        private void GenerateStmtSwitchInt (CompValu testRVal, TokenStmtSwitch switchStmt)
        {
            testRVal.PushVal (this, switchStmt.testRVal, tokenTypeInt);

            BreakContTarg   oldBreakTarg = curBreakTarg;
            ScriptMyLabel   defaultLabel = null;
            TokenSwitchCase sortedCases  = null;
            TokenSwitchCase defaultCase  = null;

            curBreakTarg = new BreakContTarg (this, "switchbreak_" + switchStmt.Unique);

            /*
             * Build list of cases sorted by ascending values.
             * There should not be any overlapping of values.
             */
            for (TokenSwitchCase thisCase = switchStmt.cases; thisCase != null; thisCase = thisCase.nextCase) {
                thisCase.label = ilGen.DefineLabel ("case_" + thisCase.Unique);

                /*
                 * The default case if any, goes in its own separate slot.
                 */
                if (thisCase.rVal1 == null) {
                    if (defaultCase != null) {
                        ErrorMsg (thisCase, "only one default case allowed");
                        ErrorMsg (defaultCase, "...prior default case");
                        return;
                    }
                    defaultCase  = thisCase;
                    defaultLabel = thisCase.label;
                    continue;
                }

                /*
                 * Evaluate case operands, they must be compile-time integer constants.
                 */
                CompValu rVal = GenerateFromRVal (thisCase.rVal1);
                if (!IsConstIntExpr (rVal, out thisCase.val1)) {
                    ErrorMsg (thisCase.rVal1, "must be compile-time char or integer constant");
                    return;
                }
                thisCase.val2 = thisCase.val1;
                if (thisCase.rVal2 != null) {
                    rVal = GenerateFromRVal (thisCase.rVal2);
                    if (!IsConstIntExpr (rVal, out thisCase.val2)) {
                        ErrorMsg (thisCase.rVal2, "must be compile-time char or integer constant");
                        return;
                    }
                }
                if (thisCase.val2 < thisCase.val1) {
                    ErrorMsg (thisCase.rVal2, "must be .ge. first value for the case");
                    return;
                }

                /*
                 * Insert into list, sorted by value.
                 * Note that both limits are inclusive.
                 */
                TokenSwitchCase lastCase = null;
                TokenSwitchCase nextCase;
                for (nextCase = sortedCases; nextCase != null; nextCase = nextCase.nextSortedCase) {
                    if (nextCase.val1 >  thisCase.val2) break;
                    if (nextCase.val2 >= thisCase.val1) {
                        ErrorMsg (thisCase, "value used by previous case");
                        ErrorMsg (nextCase, "...previous case");
                        return;
                    }
                    lastCase = nextCase;
                }
                thisCase.nextSortedCase = nextCase;
                if (lastCase == null) {
                    sortedCases = thisCase;
                } else {
                    lastCase.nextSortedCase = thisCase;
                }
            }

            if (defaultLabel == null) {
                defaultLabel = ilGen.DefineLabel ("default_" + switchStmt.Unique);
            }

            /*
             * Output code to jump to the case statement's labels based on integer index on stack.
             * Note that each case still has the integer index on stack when jumped to.
             */
            int offset = 0;
            for (TokenSwitchCase thisCase = sortedCases; thisCase != null;) {

                /*
                 * Scan through list of cases to find the maximum number of cases who's numvalues-to-case ratio
                 * is from 0.5 to 2.0.  If such a group is found, use a CIL switch for them.  If not, just use a
                 * compare-and-branch for the current case.
                 */
                int numCases  = 0;
                int numFound  = 0;
                int lowValue  = thisCase.val1;
                int numValues = 0;
                for (TokenSwitchCase scanCase = thisCase; scanCase != null; scanCase = scanCase.nextSortedCase) {
                    int nVals = scanCase.val2 - thisCase.val1 + 1;
                    double ratio = (double)nVals / (double)(++ numCases);
                    if ((ratio >= 0.5) && (ratio <= 2.0)) {
                        numFound  = numCases;
                        numValues = nVals;
                    }
                }
                if (numFound > 1) {

                    /*
                     * There is a group of case's, starting with thisCase, that fall within our criteria, ie, 
                     * that have a nice density of meaningful jumps.
                     *
                     * So first generate an array of jumps to the default label (explicit or implicit).
                     */
                    ScriptMyLabel[] labels = new ScriptMyLabel[numValues];
                    for (int i = 0; i < numValues; i ++) {
                        labels[i] = defaultLabel;
                    }

                    /*
                     * Next, for each case in that group, fill in the corresponding array entries to jump to
                     * that case's label.
                     */
                    do {
                        for (int i = thisCase.val1; i <= thisCase.val2; i ++) {
                            labels[i-lowValue] = thisCase.label;
                        }
                        thisCase = thisCase.nextSortedCase;
                    } while (-- numFound > 0);

                    /*
                     * Subtract the low value and do the computed jump.
                     * The OpCodes.Switch falls through if out of range (unsigned compare).
                     */
                    if (offset != lowValue) {
                        ilGen.Emit (switchStmt, OpCodes.Ldc_I4, lowValue - offset);
                        ilGen.Emit (switchStmt, OpCodes.Sub);
                        offset = lowValue;
                    }
                    ilGen.Emit (switchStmt, OpCodes.Dup);
                    ilGen.Emit (switchStmt, OpCodes.Switch, labels);
                } else {

                    /*
                     * It's not economical to do with a computed jump, so output a subtract/compare/branch
                     * for thisCase.
                     */
                    if (lowValue == thisCase.val2) {
                        ilGen.Emit (switchStmt, OpCodes.Dup);
                        ilGen.Emit (switchStmt, OpCodes.Ldc_I4, lowValue - offset);
                        ilGen.Emit (switchStmt, OpCodes.Beq, thisCase.label);
                    } else {
                        if (offset != lowValue) {
                            ilGen.Emit (switchStmt, OpCodes.Ldc_I4, lowValue - offset);
                            ilGen.Emit (switchStmt, OpCodes.Sub);
                            offset = lowValue;
                        }
                        ilGen.Emit (switchStmt, OpCodes.Dup);
                        ilGen.Emit (switchStmt, OpCodes.Ldc_I4, thisCase.val2 - offset);
                        ilGen.Emit (switchStmt, OpCodes.Ble_Un, thisCase.label);
                    }
                    thisCase = thisCase.nextSortedCase;
                }
            }
            ilGen.Emit (switchStmt, OpCodes.Br, defaultLabel);

            /*
             * Output code for the cases themselves, in the order given by the programmer, 
             * so they fall through as programmer wants.  This includes the default case, if any.
             *
             * Each label is jumped to with the index still on the stack.  So pop it off in case
             * the case body does a goto outside the switch or a return.  If the case body might
             * fall through to the next case or the bottom of the switch, push a zero so the stack
             * matches in all cases.
             */
            for (TokenSwitchCase thisCase = switchStmt.cases; thisCase != null; thisCase = thisCase.nextCase) {
                ilGen.MarkLabel (thisCase.label);   // the branch comes here
                ilGen.Emit (thisCase, OpCodes.Pop); // pop the integer index off stack
                mightGetHere = true;            // it's possible to get here
                for (TokenStmt stmt = thisCase.stmts; stmt != null; stmt = (TokenStmt)(stmt.nextToken)) {
                    GenerateStmt (stmt);        // output the case/explicit default body
                }
                if (mightGetHere) {
                    ilGen.Emit (thisCase, OpCodes.Ldc_I4_0);
                                    // in case we fall through, push a dummy integer index
                }
            }

            /*
             * If no explicit default case, output the default label here.
             */
            if (defaultCase == null) {
                ilGen.MarkLabel (defaultLabel);
                mightGetHere = true;
            }

            /*
             * If the last case of the switch falls through out the bottom,
             * we have to pop the index still on the stack.
             */
            if (mightGetHere) {
                ilGen.Emit (switchStmt, OpCodes.Pop);
            }

            /*
             * Output the 'break' statement target label.
             * Note that the integer index is not on the stack at this point.
             */
            if (curBreakTarg.used) {
                ilGen.MarkLabel (curBreakTarg.label);
                mightGetHere = true;
            }

            curBreakTarg = oldBreakTarg;
        }

        private void GenerateStmtSwitchStr (CompValu testRVal, TokenStmtSwitch switchStmt)
        {
            BreakContTarg   oldBreakTarg = curBreakTarg;
            ScriptMyLabel   defaultLabel = null;
            TokenSwitchCase caseTreeTop  = null;
            TokenSwitchCase defaultCase  = null;

            curBreakTarg = new BreakContTarg (this, "switchbreak_" + switchStmt.Unique);

            /*
             * Make sure value is in a temp so we don't compute it more than once.
             */
            if (!(testRVal is CompValuTemp)) {
                CompValuTemp temp = new CompValuTemp (testRVal.type, this);
                testRVal.PushVal (this, switchStmt);
                temp.Pop (this, switchStmt);
                testRVal = temp;
            }

            /*
             * Build tree of cases.
             * There should not be any overlapping of values.
             */
            for (TokenSwitchCase thisCase = switchStmt.cases; thisCase != null; thisCase = thisCase.nextCase) {
                thisCase.label = ilGen.DefineLabel ("case");

                /*
                 * The default case if any, goes in its own separate slot.
                 */
                if (thisCase.rVal1 == null) {
                    if (defaultCase != null) {
                        ErrorMsg (thisCase, "only one default case allowed");
                        ErrorMsg (defaultCase, "...prior default case");
                        return;
                    }
                    defaultCase  = thisCase;
                    defaultLabel = thisCase.label;
                    continue;
                }

                /*
                 * Evaluate case operands, they must be compile-time string constants.
                 */
                CompValu rVal = GenerateFromRVal (thisCase.rVal1);
                if (!IsConstStrExpr (rVal, out thisCase.str1)) {
                    ErrorMsg (thisCase.rVal1, "must be compile-time string constant");
                    continue;
                }
                thisCase.str2 = thisCase.str1;
                if (thisCase.rVal2 != null) {
                    rVal = GenerateFromRVal (thisCase.rVal2);
                    if (!IsConstStrExpr (rVal, out thisCase.str2)) {
                        ErrorMsg (thisCase.rVal2, "must be compile-time string constant");
                        continue;
                    }
                }
                if (String.Compare (thisCase.str2, thisCase.str1, StringComparison.Ordinal) < 0) {
                    ErrorMsg (thisCase.rVal2, "must be .ge. first value for the case");
                    continue;
                }

                /*
                 * Insert into list, sorted by value.
                 * Note that both limits are inclusive.
                 */
                caseTreeTop = InsertCaseInTree (caseTreeTop, thisCase);
            }

            /*
             * Balance tree so we end up generating code that does O(log2 n) comparisons.
             */
            caseTreeTop = BalanceTree (caseTreeTop);

            /*
             * Output compare and branch instructions in a tree-like fashion so we do O(log2 n) comparisons.
             */
            if (defaultLabel == null) {
                defaultLabel = ilGen.DefineLabel ("default");
            }
            OutputStrCase (testRVal, caseTreeTop, defaultLabel);

            /*
             * Output code for the cases themselves, in the order given by the programmer, 
             * so they fall through as programmer wants.  This includes the default case, if any.
             */
            for (TokenSwitchCase thisCase = switchStmt.cases; thisCase != null; thisCase = thisCase.nextCase) {
                ilGen.MarkLabel (thisCase.label);   // the branch comes here
                mightGetHere = true;            // it's possible to get here
                for (TokenStmt stmt = thisCase.stmts; stmt != null; stmt = (TokenStmt)(stmt.nextToken)) {
                    GenerateStmt (stmt);        // output the case/explicit default body
                }
            }

            /*
             * If no explicit default case, output the default label here.
             */
            if (defaultCase == null) {
                ilGen.MarkLabel (defaultLabel);
                mightGetHere = true;
            }

            /*
             * Output the 'break' statement target label.
             */
            if (curBreakTarg.used) {
                ilGen.MarkLabel (curBreakTarg.label);
                mightGetHere = true;
            }

            curBreakTarg = oldBreakTarg;
        }

        /**
         * @brief Insert a case in a tree of cases
         * @param r = root of existing cases to insert into
         * @param n = new case being inserted
         * @returns new root with new case inserted
         */
        private TokenSwitchCase InsertCaseInTree (TokenSwitchCase r, TokenSwitchCase n)
        {
            if (r == null) return n;

            TokenSwitchCase t = r;
            while (true) {
                if (String.Compare (n.str2, t.str1, StringComparison.Ordinal) < 0) {
                    if (t.lowerCase == null) {
                        t.lowerCase = n;
                        break;
                    }
                    t = t.lowerCase;
                    continue;
                }
                if (String.Compare (n.str1, t.str2, StringComparison.Ordinal) > 0) {
                    if (t.higherCase == null) {
                        t.higherCase = n;
                        break;
                    }
                    t = t.higherCase;
                    continue;
                }
                ErrorMsg (n, "duplicate case");
                ErrorMsg (r, "...duplicate of");
                break;
            }
            return r;
        }

        /**
         * @brief Balance a tree so left & right halves contain same number within +-1
         * @param r = root of tree to balance
         * @returns new root
         */
        private static TokenSwitchCase BalanceTree (TokenSwitchCase r)
        {
            if (r == null) return r;

            int lc = CountTree (r.lowerCase);
            int hc = CountTree (r.higherCase);
            TokenSwitchCase n, x;

            /*
             * If lower side is heavy, move highest nodes from lower side to 
             * higher side until balanced.
             */
            while (lc > hc + 1) {
                x = ExtractHighest (r.lowerCase, out n);
                n.lowerCase  = x;
                n.higherCase = r;
                r.lowerCase  = null;
                r = n;
                lc --;
                hc ++;
            }

            /*
             * If higher side is heavy, move lowest nodes from higher side to 
             * lower side until balanced.
             */
            while (hc > lc + 1) {
                x = ExtractLowest (r.higherCase, out n);
                n.higherCase = x;
                n.lowerCase  = r;
                r.higherCase = null;
                r = n;
                lc ++;
                hc --;
            }

            /*
             * Now balance each side because they can be lopsided individually.
             */
            r.lowerCase  = BalanceTree (r.lowerCase);
            r.higherCase = BalanceTree (r.higherCase);
            return r;
        }

        /**
         * @brief Get number of nodes in a tree
         * @param n = root of tree to count
         * @returns number of nodes including root
         */
        private static int CountTree (TokenSwitchCase n)
        {
            if (n == null) return 0;
            return 1 + CountTree (n.lowerCase) + CountTree (n.higherCase);
        }

        // Extract highest node from a tree
        // @param r = root of tree to extract highest from
        // @returns new root after node has been extracted
        //          n = node that was extracted from tree
        private static TokenSwitchCase ExtractHighest (TokenSwitchCase r, out TokenSwitchCase n)
        {
            if (r.higherCase == null) {
                n = r;
                return r.lowerCase;
            }
            r.higherCase = ExtractHighest (r.higherCase, out n);
            return r;
        }

        // Extract lowest node from a tree
        // @param r = root of tree to extract lowest from
        // @returns new root after node has been extracted
        //          n = node that was extracted from tree
        private static TokenSwitchCase ExtractLowest (TokenSwitchCase r, out TokenSwitchCase n)
        {
            if (r.lowerCase == null) {
                n = r;
                return r.higherCase;
            }
            r.lowerCase = ExtractLowest (r.lowerCase, out n);
            return r;
        }

        /**
         * Output code for string-style case of a switch/case to jump to the script code associated with the case.
         * @param testRVal = value being switched on
         * @param thisCase = case that the code is being output for
         * @param defaultLabel = where the default clause is (or past all cases if none)
         * Note:
         *   Outputs code for this case and the lowerCase and higherCases if any.
         *   If no lowerCase or higherCase, outputs a br to defaultLabel so this code never falls through.
         */
        private void OutputStrCase (CompValu testRVal, TokenSwitchCase thisCase, ScriptMyLabel defaultLabel)
        {
            /*
             * If nothing lower on tree and there is a single case value, 
             * just do one compare for equality.
             */
            if ((thisCase.lowerCase == null) && (thisCase.higherCase == null) && (thisCase.str1 == thisCase.str2)) {
                testRVal.PushVal (this, thisCase, tokenTypeStr);
                ilGen.Emit (thisCase, OpCodes.Ldstr,   thisCase.str1);
                ilGen.Emit (thisCase, OpCodes.Ldc_I4,  (int)StringComparison.Ordinal);
                ilGen.Emit (thisCase, OpCodes.Call,    stringCompareMethodInfo);
                ilGen.Emit (thisCase, OpCodes.Brfalse, thisCase.label);
                ilGen.Emit (thisCase, OpCodes.Br,      defaultLabel);
                return;
            }

            /*
             * Determine where to jump if switch value is lower than lower case value.
             */
            ScriptMyLabel lowerLabel = defaultLabel;
            if (thisCase.lowerCase != null) {
                lowerLabel = ilGen.DefineLabel ("lower");
            }

            /*
             * If single case value, put comparison result in this temp.
             */
            CompValuTemp cmpv1 = null;
            if (thisCase.str1 == thisCase.str2) {
                cmpv1 = new CompValuTemp (tokenTypeInt, this);
            }

            /*
             * If switch value .lt. lower case value, jump to lower label.
             * Maybe save comparison result in a temp.
             */
            testRVal.PushVal (this, thisCase, tokenTypeStr);
            ilGen.Emit (thisCase, OpCodes.Ldstr,  thisCase.str1);
            ilGen.Emit (thisCase, OpCodes.Ldc_I4, (int)StringComparison.Ordinal);
            ilGen.Emit (thisCase, OpCodes.Call,   stringCompareMethodInfo);
            if (cmpv1 != null) {
                ilGen.Emit (thisCase, OpCodes.Dup);
                cmpv1.Pop (this, thisCase);
            }
            ilGen.Emit (thisCase, OpCodes.Ldc_I4_0);
            ilGen.Emit (thisCase, OpCodes.Blt,    lowerLabel);

            /*
             * If switch value .le. higher case value, jump to case code.
             * Maybe get comparison from the temp.
             */
            if (cmpv1 == null) {
                testRVal.PushVal (this, thisCase, tokenTypeStr);
                ilGen.Emit (thisCase, OpCodes.Ldstr,  thisCase.str2);
                ilGen.Emit (thisCase, OpCodes.Ldc_I4, (int)StringComparison.Ordinal);
                ilGen.Emit (thisCase, OpCodes.Call,   stringCompareMethodInfo);
            } else {
                cmpv1.PushVal (this, thisCase);
            }
            ilGen.Emit (thisCase, OpCodes.Ldc_I4_0);
            ilGen.Emit (thisCase, OpCodes.Ble,    thisCase.label);

            /*
             * Output code for higher comparison if any.
             */
            if (thisCase.higherCase == null) {
                ilGen.Emit (thisCase, OpCodes.Br, defaultLabel);
            } else {
                OutputStrCase (testRVal, thisCase.higherCase, defaultLabel);
            }

            /*
             * Output code for lower comparison if any.
             */
            if (thisCase.lowerCase != null) {
                ilGen.MarkLabel (lowerLabel);
                OutputStrCase (testRVal, thisCase.lowerCase, defaultLabel);
            }
        }

        /**
         * @brief output code for a throw statement.
         * @param throwStmt = throw statement token, including value to be thrown
         */
        private void GenerateStmtThrow (TokenStmtThrow throwStmt)
        {
            if (!mightGetHere) return;

            /*
             * 'throw' statements never fall through.
             */
            mightGetHere = false;

            /*
             * Output code for either a throw or a rethrow.
             */
            if (throwStmt.rVal == null) {
                for (TokenStmtBlock blk = curStmtBlock; blk != null; blk = blk.outerStmtBlock) {
                    if (curStmtBlock.isCatch) {
                        ilGen.Emit (throwStmt, OpCodes.Rethrow);
                        return;
                    }
                }
                ErrorMsg (throwStmt, "rethrow allowed only in catch clause");
            } else {
                CompValu rVal = GenerateFromRVal (throwStmt.rVal);
                rVal.PushVal (this, throwStmt.rVal, tokenTypeObj);
                ilGen.Emit (throwStmt, OpCodes.Call, thrownExceptionWrapMethodInfo);
                ilGen.Emit (throwStmt, OpCodes.Throw);
            }
        }

        /**
         * @brief output code for a try/catch/finally block
         */
        private void GenerateStmtTry (TokenStmtTry tryStmt)
        {
            if (!mightGetHere) return;

            /*
             * Reducer should make sure we have exactly one of catch or finally.
             */
            if ((tryStmt.catchStmt == null) && (tryStmt.finallyStmt == null)) {
                throw new Exception ("must have a catch or a finally on try");
            }
            if ((tryStmt.catchStmt != null) && (tryStmt.finallyStmt != null)) {
                throw new Exception ("can't have both catch and finally on same try");
            }

            /*
             * Stack the call labels.
             * Try blocks have their own series of call labels.
             */
            ScriptMyLocal saveCallNo = actCallNo;
            LinkedList<CallLabel> saveCallLabels = actCallLabels;

            /*
             * Generate code for either try { } catch { } or try { } finally { }.
             */
            if (tryStmt.catchStmt   != null) GenerateStmtTryCatch   (tryStmt);
            if (tryStmt.finallyStmt != null) GenerateStmtTryFinally (tryStmt);

            /*
             * Restore call labels.
             */
            actCallNo     = saveCallNo;
            actCallLabels = saveCallLabels;
        }


        /**
         * @brief output code for a try/catch block
         *
         *      int    __tryCallNo = -1;                                   // call number within try { } subblock
         *      int    __catCallNo = -1;                                   // call number within catch { } subblock
         *      Exception __catThrown = null;                              // caught exception
         *    <oldCallLabel>:                                              // the outside world jumps here to restore us no matter ...
         *      try {                                                      // ... where we actually were inside of try/catch
         *          if (__tryCallNo >= 0) goto tryCallSw;                  // maybe go do restore
         *          <try body using __tryCallNo>                           // execute script-defined code
         *                                                                 // ...stack capture WILL run catch { } subblock
         *          leave tryEnd;                                          // exits
         *        tryThrow:<tryCallLabel>:
         *          throw new ScriptRestoreCatchException(__catThrown);    // catch { } was running, jump to its beginning
         *        tryCallSw:                                               // restoring...
         *          switch (__tryCallNo) back up into <try body>           // not catching, jump back inside try
         *      } catch (Exception exc) {
         *          exc = ScriptRestoreCatchException.Unwrap(exc);         // unwrap possible ScriptRestoreCatchException
         *          if (exc == null) goto catchRetro;                      // rethrow if IXMRUncatchable (eg, StackCaptureException)
         *          __catThrown = exc;                                     // save what was thrown so restoring try { } will throw it again
         *          catchVar = exc;                                        // set up script-visible variable
         *          __tryCallNo = tryThrow:<tryCallLabel>
         *          if (__catCallNo >= 0) goto catchCallSw;                // if restoring, go check below
         *          <catch body using __catCallNo>                         // normal, execute script-defined code
         *          leave tryEnd;                                          // all done, exit catch { }
         *        catchRetro:
         *          rethrow;
         *        catchCallSw:
         *          switch (__catCallNo) back up into <catch body>         // restart catch { } code wherever it was
         *      }
         *    tryEnd:
         */
        private void GenerateStmtTryCatch (TokenStmtTry tryStmt)
        {
            CompValuTemp tryCallNo = new CompValuTemp (tokenTypeInt, this);
            CompValuTemp catCallNo = new CompValuTemp (tokenTypeInt, this);
            CompValuTemp catThrown = new CompValuTemp (tokenTypeExc, this);

            ScriptMyLabel tryCallSw   = ilGen.DefineLabel ("__tryCallSw_"   + tryStmt.Unique);
            ScriptMyLabel catchRetro  = ilGen.DefineLabel ("__catchRetro_"  + tryStmt.Unique);
            ScriptMyLabel catchCallSw = ilGen.DefineLabel ("__catchCallSw_" + tryStmt.Unique);
            ScriptMyLabel tryEnd      = ilGen.DefineLabel ("__tryEnd_"      + tryStmt.Unique);

            SetCallNo (tryStmt, tryCallNo, -1);
            SetCallNo (tryStmt, catCallNo, -1);
            ilGen.Emit (tryStmt, OpCodes.Ldnull);
            catThrown.Pop (this, tryStmt);

            new CallLabel (this, tryStmt);              //   <oldcalllabel>:
            ilGen.BeginExceptionBlock ();               //     try {
            openCallLabel = null;
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "enter try*: " + tryStmt.line + " callMode=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                PushXMRInst ();
                ilGen.Emit (tryStmt, OpCodes.Ldfld, callModeFieldInfo);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " tryCallNo=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                tryCallNo.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " catThrown.IsNull=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                catThrown.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Ldnull);
                ilGen.Emit (tryStmt, OpCodes.Ceq);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " catCallNo=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                catCallNo.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
            }

            GetCallNo (tryStmt, tryCallNo);             //         if (__tryCallNo >= 0) goto tryCallSw;
            ilGen.Emit (tryStmt, OpCodes.Ldc_I4_0);
            ilGen.Emit (tryStmt, OpCodes.Bge, tryCallSw);

            actCallNo = tryCallNo.localBuilder;                     // set up __tryCallNo for call labels
            actCallLabels = new LinkedList<CallLabel> ();

            GenerateStmtBlock (tryStmt.tryStmt);            // output the try block statement subblock

            bool tryBlockFallsOutBottom = mightGetHere;
            if (tryBlockFallsOutBottom) {
                new CallLabel (this, tryStmt);          //       <tryCallLabel>:
                ilGen.Emit (tryStmt, OpCodes.Leave, tryEnd);    //         leave tryEnd;
                openCallLabel = null;
            }

            CallLabel tryThrow = new CallLabel (this, tryStmt); //       tryThrow:<tryCallLabel>:
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "tryThrow*: " + tryStmt.line + " catThrown=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                catThrown.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
            }
            catThrown.PushVal (this, tryStmt);          //         throw new ScriptRestoreCatchException (__catThrown);
            ilGen.Emit (tryStmt, OpCodes.Newobj, scriptRestoreCatchExceptionConstructorInfo);
            ilGen.Emit (tryStmt, OpCodes.Throw);
            openCallLabel = null;

            ilGen.MarkLabel (tryCallSw);                //       tryCallSw:
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "tryCallSw*: " + tryStmt.line + " tryCallNo=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                tryCallNo.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
            }
            OutputCallNoSwitchStmt ();              //         switch (tryCallNo) ...

            CompValuLocalVar catchVarLocExc = null;
            CompValuTemp catchVarLocStr = null;

            if (tryStmt.catchVar.type.ToSysType () == typeof (Exception)) {
                catchVarLocExc = new CompValuLocalVar (tryStmt.catchVar.type, tryStmt.catchVar.name.val, this);
            } else if (tryStmt.catchVar.type.ToSysType () == typeof (String)) {
                catchVarLocStr = new CompValuTemp (tryStmt.catchVar.type, this);
            }

            ScriptMyLocal excLocal = ilGen.DeclareLocal (typeof (String), "catchstr_" + tryStmt.Unique);

            ilGen.BeginCatchBlock (typeof (Exception));     // start of the catch block that can catch any exception
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldstr, "enter catch*: " + tryStmt.line + " callMode=");
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
                PushXMRInst ();
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldfld, callModeFieldInfo);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldstr, " catCallNo=");
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
                catCallNo.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldstr, " exc=");
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Dup);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, consoleWriteMethodInfo);
            }
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, scriptRestoreCatchExceptionUnwrap);
                                        // exc = ScriptRestoreCatchException.Unwrap (exc);
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Dup);        // rethrow if IXMRUncatchable (eg, StackCaptureException)
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Brfalse, catchRetro);
            if (tryStmt.catchVar.type.ToSysType () == typeof (Exception)) {
                tryStmt.catchVar.location = catchVarLocExc;
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Dup);
                catThrown.Pop (this, tryStmt);              // store exception object in catThrown
                catchVarLocExc.Pop (this, tryStmt.catchVar.name);      // also store in script-visible variable
            } else if (tryStmt.catchVar.type.ToSysType () == typeof (String)) {
                tryStmt.catchVar.location = catchVarLocStr;
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Dup);
                catThrown.Pop (this, tryStmt);              // store exception object in catThrown
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Call, catchExcToStrMethodInfo);

                ilGen.Emit (tryStmt.catchStmt, OpCodes.Stloc, excLocal);
                catchVarLocStr.PopPre (this, tryStmt.catchVar.name);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldloc, excLocal);
                catchVarLocStr.PopPost (this, tryStmt.catchVar.name, tokenTypeStr);
            } else {
                throw new Exception ("bad catch var type " + tryStmt.catchVar.type.ToString ());
            }

            SetCallNo (tryStmt, tryCallNo, tryThrow.index);     // __tryCallNo = tryThrow so it knows to do 'throw catThrown' on restore

            GetCallNo (tryStmt, catCallNo);             // if (__catCallNo >= 0) goto catchCallSw;
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Ldc_I4_0);
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Bge, catchCallSw);

            actCallNo = catCallNo.localBuilder;                 // set up __catCallNo for call labels
            actCallLabels.Clear ();
            mightGetHere = true;                    // if we can get to the 'try' assume we can get to the 'catch'
            GenerateStmtBlock (tryStmt.catchStmt);          // output catch clause statement subblock

            if (mightGetHere) {
                new CallLabel (this, tryStmt.catchStmt);
                ilGen.Emit (tryStmt.catchStmt, OpCodes.Leave, tryEnd);
                openCallLabel = null;
            }

            ilGen.MarkLabel (catchRetro);               // not a script-visible exception, rethrow it
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Pop);
            ilGen.Emit (tryStmt.catchStmt, OpCodes.Rethrow);

            ilGen.MarkLabel (catchCallSw);
            OutputCallNoSwitchStmt ();              // restoring, jump back inside script-defined body

            ilGen.EndExceptionBlock ();
            ilGen.MarkLabel (tryEnd);

            mightGetHere |= tryBlockFallsOutBottom;         // also get here if try body falls out bottom
        }

        /**
         * @brief output code for a try/finally block
         *
         * This is such a mess because there is hidden state for the finally { } that we have to recreate.
         * The finally { } can be entered either via an exception being thrown in the try { } or a leave 
         * being executed in the try { } whose target is outside the try { } finally { }.
         *
         * For the thrown exception case, we slip in a try { } catch { } wrapper around the original try { }
         * body.  This will sense any thrown exception that would execute the finally { }.  Then we have our
         * try { } throw the exception on restore which gets the finally { } called and on its way again.
         *
         * For the leave case, we prefix all leave instructions with a call label and we explicitly chain
         * all leaves through each try { } that has an associated finally { } that the leave would unwind 
         * through.  This gets each try { } to simply jump to the correct leave instruction which immediately 
         * invokes the corresponding finally { } and then chains to the next leave instruction on out until 
         * it gets to its target.
         *
         *      int    __finCallNo = -1;                                     // call number within finally { } subblock
         *      int    __tryCallNo = -1;                                     // call number within try { } subblock
         *      Exception __catThrown = null;                                // caught exception
         *    <oldCallLabel>:                                                // the outside world jumps here to restore us no matter ...
         *      try {                                                        // ... where we actually were inside of try/finally
         *          try {
         *              if (__tryCallNo >= 0) goto tryCallSw;                // maybe go do restore
         *              <try body using __tryCallNo>                         // execute script-defined code
         *                                                                   // ...stack capture WILL run catch/finally { } subblock
         *              leave tryEnd;                                        // executes finally { } subblock and exits
         *            tryThrow:<tryCallLabel>:
         *              throw new ScriptRestoreCatchException(__catThrown);  // catch { } was running, jump to its beginning
         *            tryCallSw:                                             // restoring...
         *              switch (__tryCallNo) back up into <try body>         // jump back inside try, ...
         *                                                                   // ... maybe to a leave if we were doing finally { } subblock
         *          } catch (Exception exc) {                                // in case we're getting to finally { } via a thrown exception:
         *              exc = ScriptRestoreCatchException.Unwrap(exc);       // unwrap possible ScriptRestoreCatchException
         *              if (callMode == CallMode_SAVE) goto catchRetro;      // don't touch anything if capturing stack
         *              __catThrown = exc;                                   // save exception so try { } can throw it on restore
         *              __tryCallNo = tryThrow:<tryCallLabel>;               // tell try { } to throw it on restore
         *            catchRetro:
         *              rethrow;                                             // in any case, go on to finally { } subblock now
         *          }
         *      } finally {
         *          if (callMode == CallMode_SAVE) goto finEnd;              // don't touch anything if capturing stack
         *          if (__finCallNo >= 0) goto finCallSw;                    // maybe go do restore
         *          <finally body using __finCallNo>                         // normal, execute script-defined code
         *        finEnd:
         *          endfinally                                               // jump to leave/throw target or next outer finally { }
         *        finCallSw:
         *          switch (__finCallNo) back up into <finally body>         // restoring, restart finally { } code wherever it was
         *      }
         *    tryEnd:
         */
        private void GenerateStmtTryFinally (TokenStmtTry tryStmt)
        {
            CompValuTemp finCallNo = new CompValuTemp (tokenTypeInt, this);
            CompValuTemp tryCallNo = new CompValuTemp (tokenTypeInt, this);
            CompValuTemp catThrown = new CompValuTemp (tokenTypeExc, this);

            ScriptMyLabel tryCallSw   = ilGen.DefineLabel (       "__tryCallSw_"   + tryStmt.Unique);
            ScriptMyLabel catchRetro  = ilGen.DefineLabel (       "__catchRetro_"  + tryStmt.Unique);
            ScriptMyLabel finCallSw   = ilGen.DefineLabel (       "__finCallSw_"   + tryStmt.Unique);
            BreakContTarg finEnd      = new BreakContTarg (this, "__finEnd_"      + tryStmt.Unique);
            ScriptMyLabel tryEnd      = ilGen.DefineLabel (       "__tryEnd_"      + tryStmt.Unique);

            SetCallNo (tryStmt, finCallNo, -1);
            SetCallNo (tryStmt, tryCallNo, -1);
            ilGen.Emit (tryStmt, OpCodes.Ldnull);
            catThrown.Pop (this, tryStmt);

            new CallLabel (this, tryStmt);              //   <oldcalllabel>:
            ilGen.BeginExceptionBlock ();               //     try {
            ilGen.BeginExceptionBlock ();               //     try {
            openCallLabel = null;
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "enter try*: " + tryStmt.line + " callMode=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                PushXMRInst ();
                ilGen.Emit (tryStmt, OpCodes.Ldfld, callModeFieldInfo);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " tryCallNo=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                tryCallNo.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " finCallNo=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                finCallNo.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " catThrown.IsNull=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                catThrown.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Ldnull);
                ilGen.Emit (tryStmt, OpCodes.Ceq);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
            }

            GetCallNo (tryStmt, tryCallNo);             //         if (__tryCallNo >= 0) goto tryCallSw;
            ilGen.Emit (tryStmt, OpCodes.Ldc_I4_0);
            ilGen.Emit (tryStmt, OpCodes.Bge, tryCallSw);

            actCallNo = tryCallNo.localBuilder;                     // set up __tryCallNo for call labels
            actCallLabels = new LinkedList<CallLabel> ();

            GenerateStmtBlock (tryStmt.tryStmt);            // output the try block statement subblock

            if (mightGetHere) {
                new CallLabel (this, tryStmt);          //       <newCallLabel>:
                ilGen.Emit (tryStmt, OpCodes.Leave, tryEnd);    //         leave tryEnd;
                openCallLabel = null;
            }

            foreach (IntermediateLeave iLeave in tryStmt.iLeaves.Values) {
                ilGen.MarkLabel (iLeave.jumpIntoLabel);     //       intr2_exit:
                new CallLabel (this, tryStmt);          //         tryCallNo = n;
                ilGen.Emit (tryStmt, OpCodes.Leave, iLeave.jumpAwayLabel);  //    __callNo_n_: leave int1_exit;
                openCallLabel = null;
            }

            CallLabel tryThrow = new CallLabel (this, tryStmt); //       tryThrow:<tryCallLabel>:
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "tryThrow*: " + tryStmt.line + " catThrown=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                catThrown.PushVal (this, tryStmt);
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
            }
            catThrown.PushVal (this, tryStmt);          //         throw new ScriptRestoreCatchException (__catThrown);
            ilGen.Emit (tryStmt, OpCodes.Newobj, scriptRestoreCatchExceptionConstructorInfo);
            ilGen.Emit (tryStmt, OpCodes.Throw);
            openCallLabel = null;

            ilGen.MarkLabel (tryCallSw);                //       tryCallSw:
            OutputCallNoSwitchStmt ();              //         switch (tryCallNo) ...
                                        //     }

            ilGen.BeginCatchBlock (typeof (Exception));     // start of the catch block that can catch any exception
            if (DEBUG_TRYSTMT) {
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "enter catch*: " + tryStmt.line + " callMode=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                PushXMRInst ();
                ilGen.Emit (tryStmt, OpCodes.Ldfld, callModeFieldInfo);
                ilGen.Emit (tryStmt, OpCodes.Box, typeof (int));
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, " exc=");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Dup);
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
                ilGen.Emit (tryStmt, OpCodes.Ldstr, "\n");
                ilGen.Emit (tryStmt, OpCodes.Call, consoleWriteMethodInfo);
            }
            ilGen.Emit (tryStmt, OpCodes.Call, scriptRestoreCatchExceptionUnwrap);  // exc = ScriptRestoreCatchException.Unwrap (exc);
            PushXMRInst ();                     // if (callMode == CallMode_SAVE) goto catchRetro;
            ilGen.Emit (tryStmt, OpCodes.Ldfld, callModeFieldInfo);
            ilGen.Emit (tryStmt, OpCodes.Ldc_I4, XMRInstAbstract.CallMode_SAVE);
            ilGen.Emit (tryStmt, OpCodes.Beq, catchRetro);

            catThrown.Pop (this, tryStmt);              // __catThrown = exc;
            SetCallNo (tryStmt, tryCallNo, tryThrow.index);     // __tryCallNo = tryThrow:<tryCallLabel>;
            ilGen.Emit (tryStmt, OpCodes.Rethrow);

            ilGen.MarkLabel (catchRetro);               // catchRetro:
            ilGen.Emit (tryStmt, OpCodes.Pop);
            ilGen.Emit (tryStmt, OpCodes.Rethrow);          //    rethrow;

            ilGen.EndExceptionBlock ();             // }

            ilGen.BeginFinallyBlock ();             // start of the finally block

            PushXMRInst ();                     // if (callMode == CallMode_SAVE) goto finEnd;
            ilGen.Emit (tryStmt, OpCodes.Ldfld, callModeFieldInfo);
            ilGen.Emit (tryStmt, OpCodes.Ldc_I4, XMRInstAbstract.CallMode_SAVE);
            ilGen.Emit (tryStmt, OpCodes.Beq, finEnd.label);

            GetCallNo (tryStmt, finCallNo);             // if (__finCallNo >= 0) goto finCallSw;
            ilGen.Emit (tryStmt, OpCodes.Ldc_I4_0);
            ilGen.Emit (tryStmt, OpCodes.Bge, finCallSw);

            actCallNo = finCallNo.localBuilder;                 // set up __finCallNo for call labels
            actCallLabels.Clear ();
            mightGetHere = true;                    // if we can get to the 'try' assume we can get to the 'finally'
            GenerateStmtBlock (tryStmt.finallyStmt);        // output finally clause statement subblock

            ilGen.MarkLabel (finEnd.label);             // finEnd:
            ilGen.Emit (tryStmt, OpCodes.Endfinally);       //    return out to next finally { } or catch { } or leave target

            ilGen.MarkLabel (finCallSw);                // restore mode, switch (finCallNo) ...
            OutputCallNoSwitchStmt ();

            ilGen.EndExceptionBlock ();
            ilGen.MarkLabel (tryEnd);

            mightGetHere |= finEnd.used;                // get here if finally body falls through or has a break statement
        }

        /**
         * @brief Generate code to initialize a variable to its default value.
         */
        private void GenerateStmtVarIniDef (TokenStmtVarIniDef varIniDefStmt)
        {
            if (!mightGetHere) return;

            CompValu left = GenerateFromLVal (varIniDefStmt.var);
            left.PopPre (this, varIniDefStmt);
            PushDefaultValue (left.type);
            left.PopPost (this, varIniDefStmt);
        }

        /**
         * @brief generate code for a 'while' statement including the loop body.
         */
        private void GenerateStmtWhile (TokenStmtWhile whileStmt)
        {
            if (!mightGetHere) return;

            BreakContTarg oldBreakTarg = curBreakTarg;
            BreakContTarg oldContTarg  = curContTarg;
            ScriptMyLabel loopLabel    = ilGen.DefineLabel ("whileloop_" + whileStmt.Unique);

            curBreakTarg = new BreakContTarg (this, "whilebreak_" + whileStmt.Unique);
            curContTarg  = new BreakContTarg (this, "whilecont_"  + whileStmt.Unique);

            ilGen.MarkLabel (loopLabel);                                          // loop:
            CompValu testRVal = GenerateFromRVal (whileStmt.testRVal);            //   testRVal = while test expression
            if (!IsConstBoolExprTrue (testRVal)) {
                testRVal.PushVal (this, whileStmt.testRVal, tokenTypeBool);   //   if (!testRVal)
                ilGen.Emit (whileStmt, OpCodes.Brfalse, curBreakTarg.label);  //      goto break
                curBreakTarg.used = true;
            }
            GenerateStmt (whileStmt.bodyStmt);                                    //   while body statement
            if (curContTarg.used) {
                ilGen.MarkLabel (curContTarg.label);                          // cont:
                mightGetHere = true;
            }
            if (mightGetHere) {
                EmitCallCheckRun (whileStmt, false);                          //   __sw.CheckRun()
                ilGen.Emit (whileStmt, OpCodes.Br, loopLabel);                //   goto loop
            }
            mightGetHere = curBreakTarg.used;
            if (mightGetHere) {
                ilGen.MarkLabel (curBreakTarg.label);                         // done:
            }

            curBreakTarg = oldBreakTarg;
            curContTarg  = oldContTarg;
        }

        /**
         * @brief process a local variable declaration statement, possibly with initialization expression.
         *        Note that the function header processing allocated stack space (CompValuTemp) for the
         *        variable and now all we do is write its initialization value.
         */
        private void GenerateDeclVar (TokenDeclVar declVar)
        {
            /*
             * Script gave us an initialization value, so just store init value in var like an assignment statement.
             * If no init given, set it to its default value.
             */
            CompValu local = declVar.location;
            if (declVar.init != null) {
                CompValu rVal = GenerateFromRVal (declVar.init, local.GetArgTypes ());
                local.PopPre  (this, declVar);
                rVal.PushVal  (this, declVar.init, declVar.type);
                local.PopPost (this, declVar);
            } else {
                local.PopPre  (this, declVar);
                PushDefaultValue (declVar.type);
                local.PopPost (this, declVar);
            }
        }

        /**
         * @brief Get the type and location of an L-value (eg, variable)
         * @param lVal    = L-value expression to evaluate
         * @param argsig  = null: it's a field/property
         *                  else: select overload method that fits these arg types
         */
        private CompValu GenerateFromLVal (TokenLVal lVal)
        {
            return GenerateFromLVal (lVal, null);
        }
        private CompValu GenerateFromLVal (TokenLVal lVal, TokenType[] argsig)
        {
            if (lVal is TokenLValArEle)     return GenerateFromLValArEle     ((TokenLValArEle)lVal);
            if (lVal is TokenLValBaseField) return GenerateFromLValBaseField ((TokenLValBaseField)lVal, argsig);
            if (lVal is TokenLValIField)    return GenerateFromLValIField    ((TokenLValIField)lVal,    argsig);
            if (lVal is TokenLValName)      return GenerateFromLValName      ((TokenLValName)lVal,      argsig);
            if (lVal is TokenLValSField)    return GenerateFromLValSField    ((TokenLValSField)lVal,    argsig);
            throw new Exception ("bad lval class");
        }

        /**
         * @brief we have an L-value token that is an element within an array.
         * @returns a CompValu giving the type and location of the element of the array.
         */
        private CompValu GenerateFromLValArEle (TokenLValArEle lVal)
        {
            CompValu subCompValu;

            /*
             * Compute location of array itself.
             */
            CompValu baseCompValu = GenerateFromRVal (lVal.baseRVal);

            /*
             * Maybe it is a fixed array access.
             */
            string basetypestring = baseCompValu.type.ToString ();
            if (basetypestring.EndsWith ("]")) {
                TokenRVal subRVal = lVal.subRVal;
                int nSubs = 1;
                if (subRVal is TokenRValList) {
                    nSubs   = ((TokenRValList)subRVal).nItems;
                    subRVal = ((TokenRValList)subRVal).rVal;
                }

                int rank = basetypestring.IndexOf (']') - basetypestring.IndexOf ('[');
                if (nSubs != rank) {
                    ErrorMsg (lVal.baseRVal, "expect " + rank + " subscript" + ((rank == 1) ? "" : "s") + " but have " + nSubs);
                }
                CompValu[] subCompValus = new CompValu[rank];
                int i;
                for (i = 0; (subRVal != null) && (i < rank); i ++) {
                    subCompValus[i] = GenerateFromRVal (subRVal);
                    subRVal = (TokenRVal)subRVal.nextToken;
                }
                while (i < rank) subCompValus[i++] = new CompValuInteger (new TokenTypeInt (lVal.subRVal), 0);
                return new CompValuFixArEl (this, baseCompValu, subCompValus);
            }

            /*
             * Maybe it is accessing the $idxprop property of a script-defined class.
             */
            if (baseCompValu.type is TokenTypeSDTypeClass) {
                TokenName name = new TokenName (lVal, "$idxprop");
                TokenTypeSDTypeClass sdtType = (TokenTypeSDTypeClass)baseCompValu.type;
                TokenDeclSDTypeClass sdtDecl = sdtType.decl;
                TokenDeclVar idxProp = FindThisMember (sdtDecl, name, null);
                if (idxProp == null) {
                    ErrorMsg (lVal, "no index property in class " + sdtDecl.longName.val);
                    return new CompValuVoid (lVal);
                }
                if ((idxProp.sdtFlags & ScriptReduce.SDT_STATIC) != 0) {
                    ErrorMsg (lVal, "non-static reference to static member " + idxProp.name.val);
                    return new CompValuVoid (idxProp);
                }
                CheckAccess (idxProp, name);

                TokenType[] argTypes = IdxPropArgTypes (idxProp);
                CompValu[] compValus = IdxPropCompValus (lVal, argTypes.Length);
                return new CompValuIdxProp (idxProp, baseCompValu, argTypes, compValus);

            }

            /*
             * Maybe they are accessing $idxprop property of a script-defined interface.
             */
            if (baseCompValu.type is TokenTypeSDTypeInterface) {
                TokenName name = new TokenName (lVal, "$idxprop");
                TokenTypeSDTypeInterface sdtType = (TokenTypeSDTypeInterface)baseCompValu.type;
                TokenDeclVar idxProp = FindInterfaceMember (sdtType, name, null, ref baseCompValu);
                if (idxProp == null) {
                    ErrorMsg (lVal, "no index property defined for interface " + sdtType.decl.longName.val);
                    return baseCompValu;
                }

                TokenType[] argTypes = IdxPropArgTypes (idxProp);
                CompValu[] compValus = IdxPropCompValus (lVal, argTypes.Length);
                return new CompValuIdxProp (idxProp, baseCompValu, argTypes, compValus);
            }

            /*
             * Maybe it is extracting a character from a string.
             */
            if ((baseCompValu.type is TokenTypeKey) || (baseCompValu.type is TokenTypeStr)) {
                subCompValu = GenerateFromRVal (lVal.subRVal);
                return new CompValuStrChr (new TokenTypeChar (lVal), baseCompValu, subCompValu);
            }

            /*
             * Maybe it is extracting an element from a list.
             */
            if (baseCompValu.type is TokenTypeList) {
                subCompValu = GenerateFromRVal (lVal.subRVal);
                return new CompValuListEl (new TokenTypeObject (lVal), baseCompValu, subCompValu);
            }

            /*
             * Access should be to XMR_Array otherwise.
             */
            if (!(baseCompValu.type is TokenTypeArray)) {
                ErrorMsg (lVal, "taking subscript of non-array");
                return baseCompValu;
            }
            subCompValu = GenerateFromRVal (lVal.subRVal);
            return new CompValuArEle (new TokenTypeObject (lVal), baseCompValu, subCompValu);
        }

        /**
         * @brief Get number and type of arguments required by an index property.
         */
        private static TokenType[] IdxPropArgTypes (TokenDeclVar idxProp)
        {
            TokenType[] argTypes;
            if (idxProp.getProp != null) {
                int nArgs = idxProp.getProp.argDecl.varDict.Count;
                argTypes = new TokenType[nArgs];
                foreach (TokenDeclVar var in idxProp.getProp.argDecl.varDict) {
                    argTypes[var.vTableIndex] = var.type;
                }
            } else {
                int nArgs = idxProp.setProp.argDecl.varDict.Count - 1;
                argTypes = new TokenType[nArgs];
                foreach (TokenDeclVar var in idxProp.setProp.argDecl.varDict) {
                    if (var.vTableIndex < nArgs) {
                        argTypes[var.vTableIndex] = var.type;
                    }
                }
            }
            return argTypes;
        }

        /**
         * @brief Get number and computed value of index property arguments.
         * @param lVal = list of arguments
         * @param nArgs = number of arguments required
         * @returns null: argument count mismatch
         *          else: array of index property argument values
         */
        private CompValu[] IdxPropCompValus (TokenLValArEle lVal, int nArgs)
        {
            TokenRVal subRVal = lVal.subRVal;
            int nSubs = 1;
            if (subRVal is TokenRValList) {
                nSubs   = ((TokenRValList)subRVal).nItems;
                subRVal = ((TokenRValList)subRVal).rVal;
            }

            if (nSubs != nArgs) {
                ErrorMsg (lVal, "index property requires " + nArgs + " subscript(s)");
                return null;
            }

            CompValu[] subCompValus = new CompValu[nArgs];
            for (int i = 0; i < nArgs; i ++) {
                subCompValus[i] = GenerateFromRVal (subRVal);
                subRVal = (TokenRVal)subRVal.nextToken;
            }
            return subCompValus;
        }

        /**
         * @brief using 'base' within a script-defined instance method to refer to an instance field/method 
         *        of the class being extended.
         */
        private CompValu GenerateFromLValBaseField (TokenLValBaseField baseField, TokenType[] argsig)
        {
            string fieldName = baseField.fieldName.val;

            TokenDeclSDType sdtDecl = curDeclFunc.sdtClass;
            if ((sdtDecl == null) || ((curDeclFunc.sdtFlags & ScriptReduce.SDT_STATIC) != 0)) {
                ErrorMsg (baseField, "cannot use 'base' outside instance method body");
                return new CompValuVoid (baseField);
            }
            if (!IsSDTInstMethod ()) {
                ErrorMsg (baseField, "cannot access instance member of base class from static method");
                return new CompValuVoid (baseField);
            }

            TokenDeclVar declVar = FindThisMember (sdtDecl.extends, baseField.fieldName, argsig);
            if (declVar != null) {
                CheckAccess (declVar, baseField.fieldName);
                TokenType baseType = declVar.sdtClass.MakeRefToken (baseField);
                CompValu  basePtr  = new CompValuArg (baseType, 0);
                return AccessInstanceMember (declVar, basePtr, baseField, true);
            }

            ErrorMsg (baseField, "no member " + fieldName + ArgSigString (argsig) + " rootward of " + sdtDecl.longName.val);
            return new CompValuVoid (baseField);
        }

        /**
         * @brief We have an L-value token that is an instance field/method within a struct.
         * @returns a CompValu giving the type and location of the field/method in the struct.
         */
        private CompValu GenerateFromLValIField (TokenLValIField lVal, TokenType[] argsig)
        {
            CompValu baseRVal = GenerateFromRVal (lVal.baseRVal);
            string fieldName = lVal.fieldName.val + ArgSigString (argsig);

            /*
             * Maybe they are accessing an instance field, method or property of a script-defined class.
             */
            if (baseRVal.type is TokenTypeSDTypeClass) {
                TokenTypeSDTypeClass sdtType = (TokenTypeSDTypeClass)baseRVal.type;
                TokenDeclSDTypeClass sdtDecl = sdtType.decl;
                TokenDeclVar declVar = FindThisMember (sdtDecl, lVal.fieldName, argsig);
                if (declVar != null) {
                    CheckAccess (declVar, lVal.fieldName);
                    return AccessInstanceMember (declVar, baseRVal, lVal, false);
                }
                ErrorMsg (lVal.fieldName, "no member " + fieldName + " in class " + sdtDecl.longName.val);
                return new CompValuVoid (lVal.fieldName);
            }

            /*
             * Maybe they are accessing a method or property of a script-defined interface.
             */
            if (baseRVal.type is TokenTypeSDTypeInterface) {
                TokenTypeSDTypeInterface sdtType = (TokenTypeSDTypeInterface)baseRVal.type;
                TokenDeclVar declVar = FindInterfaceMember (sdtType, lVal.fieldName, argsig, ref baseRVal);
                if (declVar != null) {
                    return new CompValuIntfMember (declVar, baseRVal);
                }
                ErrorMsg (lVal.fieldName, "no member " + fieldName + " in interface " + sdtType.decl.longName.val);
                return new CompValuVoid (lVal.fieldName);
            }

            /*
             * Since we only have a few built-in types with fields, just pound them out.
             */
            if (baseRVal.type is TokenTypeArray) {

                // no arguments, no parentheses, just the field name, returning integer
                // but internally, it is a call to a method()
                if (fieldName == "count") {
                    return new CompValuIntInstROProp (tokenTypeInt, baseRVal, arrayCountMethodInfo);
                }

                // no arguments but with the parentheses, returning void
                if (fieldName == "clear()") {
                    return new CompValuIntInstMeth (XMR_Array.clearDelegate, baseRVal, arrayClearMethodInfo);
                }

                // single integer argument, returning an object
                if (fieldName == "index(integer)") {
                    return new CompValuIntInstMeth (XMR_Array.indexDelegate, baseRVal, arrayIndexMethodInfo);
                }
                if (fieldName == "value(integer)") {
                    return new CompValuIntInstMeth (XMR_Array.valueDelegate, baseRVal, arrayValueMethodInfo);
                }
            }
            if (baseRVal.type is TokenTypeRot) {
                FieldInfo fi = null;
                if (fieldName == "x") fi = rotationXFieldInfo;
                if (fieldName == "y") fi = rotationYFieldInfo;
                if (fieldName == "z") fi = rotationZFieldInfo;
                if (fieldName == "s") fi = rotationSFieldInfo;
                if (fi != null) {
                    return new CompValuField (new TokenTypeFloat (lVal), baseRVal, fi);
                }
            }
            if (baseRVal.type is TokenTypeVec) {
                FieldInfo fi = null;
                if (fieldName == "x") fi = vectorXFieldInfo;
                if (fieldName == "y") fi = vectorYFieldInfo;
                if (fieldName == "z") fi = vectorZFieldInfo;
                if (fi != null) {
                    return new CompValuField (new TokenTypeFloat (lVal), baseRVal, fi);
                }
            }

            ErrorMsg (lVal, "type " + baseRVal.type.ToString () + " does not define member " + fieldName);
            return baseRVal;
        }

        /**
         * @brief We have an L-value token that is a function, method or variable name.
         * @param lVal = name we are looking for
         * @param argsig = null: just look for name as a variable
         *                 else: look for name as a function/method being called with the given argument types
         *                       eg, "(string,integer,list)"
         * @returns a CompValu giving the type and location of the function, method or variable.
         */
        private CompValu GenerateFromLValName (TokenLValName lVal, TokenType[] argsig)
        {
            /*
             * Look in variable stack then look for built-in constants and functions.
             */
            TokenDeclVar var = FindNamedVar (lVal, argsig);
            if (var == null) {
                ErrorMsg (lVal, "undefined constant/function/variable " + lVal.name.val + ArgSigString (argsig));
                return new CompValuVoid (lVal);
            }

            /*
             * Maybe it has an implied 'this.' on the front.
             */
            if ((var.sdtClass != null) && ((var.sdtFlags & ScriptReduce.SDT_STATIC) == 0)) {

                if (!IsSDTInstMethod ()) {
                    ErrorMsg (lVal, "cannot access instance member of class from static method");
                    return new CompValuVoid (lVal);
                }

                /*
                 * Don't allow something such as:
                 *
                 *    class A {
                 *        integer I;
                 *        class B {
                 *            Print ()
                 *            {
                 *                llOwnerSay ("I=" + (string)I); <- access to I not allowed inside class B.
                 *                                                  explicit reference required as we don't
                 *                                                  have a valid reference to class A.
                 *            }
                 *        }
                 *    }
                 *
                 * But do allow something such as:
                 *
                 *    class A {
                 *        integer I;
                 *    }
                 *    class B : A {
                 *        Print ()
                 *        {
                 *            llOwnerSay ("I=" + (string)I);
                 *        }
                 *    }
                 */
                for (TokenDeclSDType c = curDeclFunc.sdtClass; c != var.sdtClass; c = c.extends) {
                    if (c == null) {
                        // our arg0 points to an instance of curDeclFunc.sdtClass, not var.sdtClass
                        ErrorMsg (lVal, "cannot access instance member of outer class with implied 'this'");
                        break;
                    }
                }

                CompValu thisCompValu = new CompValuArg (var.sdtClass.MakeRefToken (lVal), 0);
                return AccessInstanceMember (var, thisCompValu, lVal, false);
            }

            /*
             * It's a local variable, static field, global, constant, etc.
             */
            return var.location;
        }

        /**
         * @brief Access a script-defined type's instance member
         * @param declVar = which member (field,method,property) to access
         * @param basePtr = points to particular object instance
         * @param ignoreVirt = true: access declVar's method directly; else: maybe use vTable
         * @returns where the field/method/property is located
         */
        private CompValu AccessInstanceMember (TokenDeclVar declVar, CompValu basePtr, Token errorAt, bool ignoreVirt)
        {
            if ((declVar.sdtFlags & ScriptReduce.SDT_STATIC) != 0) {
                ErrorMsg (errorAt, "non-static reference to static member " + declVar.name.val);
                return new CompValuVoid (declVar);
            }
            return new CompValuInstMember (declVar, basePtr, ignoreVirt);
        }

        /**
         * @brief we have an L-value token that is a static member within a struct.
         * @returns a CompValu giving the type and location of the member in the struct.
         */
        private CompValu GenerateFromLValSField (TokenLValSField lVal, TokenType[] argsig)
        {
            TokenType stType = lVal.baseType;
            string fieldName = lVal.fieldName.val + ArgSigString (argsig);

            /*
             * Maybe they are accessing a static member of a script-defined class.
             */
            if (stType is TokenTypeSDTypeClass) {
                TokenTypeSDTypeClass sdtType = (TokenTypeSDTypeClass)stType;
                TokenDeclVar declVar = FindThisMember (sdtType.decl, lVal.fieldName, argsig);
                if (declVar != null) {
                    CheckAccess (declVar, lVal.fieldName);
                    if ((declVar.sdtFlags & ScriptReduce.SDT_STATIC) == 0) {
                        ErrorMsg (lVal.fieldName, "static reference to non-static member " + fieldName);
                        return new CompValuVoid (lVal.fieldName);
                    }
                    return declVar.location;
                }
            }

            ErrorMsg (lVal.fieldName, "no member " + fieldName + " in " + stType.ToString ());
            return new CompValuVoid (lVal.fieldName);
        }

        /**
         * @brief generate code from an RVal expression and return its type and where the result is stored.
         * For anything that has side-effects, statements are generated that perform the computation then
         * the result it put in a temp var and the temp var name is returned.
         * For anything without side-effects, they are returned as an equivalent sequence of Emits.
         * @param rVal = rVal token to be evaluated
         * @param argsig = null: not being used in an function/method context
         *                 else: string giving argument types, eg, "(string,integer,list,vector)"
         *                       that can be used to select among overloaded methods
         * @returns resultant type and location
         */
        private CompValu GenerateFromRVal (TokenRVal rVal)
        {
            return GenerateFromRVal (rVal, null);
        }
        private CompValu GenerateFromRVal (TokenRVal rVal, TokenType[] argsig)
        {
            errorMessageToken = rVal;

            /*
             * Maybe the expression can be converted to a constant.
             */
            bool didOne;
            do {
                didOne = false;
                rVal = rVal.TryComputeConstant (LookupBodyConstants, ref didOne);
            } while (didOne);

            /*
             * Generate code for the computation and return resulting type and location.
             */
            CompValu cVal = null;
            if (rVal is TokenRValAsnPost)   cVal = GenerateFromRValAsnPost   ((TokenRValAsnPost)rVal);
            if (rVal is TokenRValAsnPre)    cVal = GenerateFromRValAsnPre    ((TokenRValAsnPre)rVal);
            if (rVal is TokenRValCall)      cVal = GenerateFromRValCall      ((TokenRValCall)rVal);
            if (rVal is TokenRValCast)      cVal = GenerateFromRValCast      ((TokenRValCast)rVal);
            if (rVal is TokenRValCondExpr)  cVal = GenerateFromRValCondExpr  ((TokenRValCondExpr)rVal);
            if (rVal is TokenRValConst)     cVal = GenerateFromRValConst     ((TokenRValConst)rVal);
            if (rVal is TokenRValInitDef)   cVal = GenerateFromRValInitDef   ((TokenRValInitDef)rVal);
            if (rVal is TokenRValIsType)    cVal = GenerateFromRValIsType    ((TokenRValIsType)rVal);
            if (rVal is TokenRValList)      cVal = GenerateFromRValList      ((TokenRValList)rVal);
            if (rVal is TokenRValNewArIni)  cVal = GenerateFromRValNewArIni  ((TokenRValNewArIni)rVal);
            if (rVal is TokenRValOpBin)     cVal = GenerateFromRValOpBin     ((TokenRValOpBin)rVal);
            if (rVal is TokenRValOpUn)      cVal = GenerateFromRValOpUn      ((TokenRValOpUn)rVal);
            if (rVal is TokenRValParen)     cVal = GenerateFromRValParen     ((TokenRValParen)rVal);
            if (rVal is TokenRValRot)       cVal = GenerateFromRValRot       ((TokenRValRot)rVal);
            if (rVal is TokenRValThis)      cVal = GenerateFromRValThis      ((TokenRValThis)rVal);
            if (rVal is TokenRValUndef)     cVal = GenerateFromRValUndef     ((TokenRValUndef)rVal);
            if (rVal is TokenRValVec)       cVal = GenerateFromRValVec       ((TokenRValVec)rVal);
            if (rVal is TokenLVal)          cVal = GenerateFromLVal          ((TokenLVal)rVal, argsig);

            if (cVal == null) throw new Exception ("bad rval class " + rVal.GetType ().ToString ());

            /*
             * Sanity check.
             */
            if (!youveAnError) {
                if (cVal.type == null) throw new Exception ("cVal has no type " + cVal.GetType ());
                string cValType = cVal.type.ToString ();
                string rValType = rVal.GetRValType (this, argsig).ToString ();
                if (cValType == "bool") cValType = "integer";
                if (rValType == "bool") rValType = "integer";
                if (cValType != rValType) {
                    throw new Exception ("cVal.type " + cValType + " != rVal.type " + rValType +
                                         "  (" + rVal.GetType ().Name + " " + rVal.SrcLoc + ")");
                }
            }

            return cVal;
        }

        /**
         * @brief compute the result of a binary operator (eg, add, subtract, multiply, lessthan)
         * @param token = binary operator token, includes the left and right operands
         * @returns where the resultant R-value is as something that doesn't have side effects
         */
        private CompValu GenerateFromRValOpBin (TokenRValOpBin token)
        {
            CompValu left, right;
            string opcodeIndex = token.opcode.ToString ();

            /*
             * Comma operators are special, as they say to compute the left-hand value and 
             * discard it, then compute the right-hand argument and that is the result.
             */
            if (opcodeIndex == ",") {

                /*
                 * Compute left-hand operand but throw away result.
                 */
                GenerateFromRVal (token.rValLeft);

                /*
                 * Compute right-hand operand and that is the value of the expression.
                 */
                return GenerateFromRVal (token.rValRight);
            }

            /*
             * Simple overwriting assignments are their own special case,
             * as we want to cast the R-value to the type of the L-value.
             * And in the case of delegates, we want to use the arg signature
             * of the delegate to select which overloaded method to use.
             */
            if (opcodeIndex == "=") {
                if (!(token.rValLeft is TokenLVal)) {
                    ErrorMsg (token, "invalid L-value for =");
                    return GenerateFromRVal (token.rValLeft);
                }
                left  = GenerateFromLVal ((TokenLVal)token.rValLeft);
                right = Trivialize (GenerateFromRVal (token.rValRight, left.GetArgTypes ()), token.rValRight);
                left.PopPre (this, token.rValLeft);
                right.PushVal (this, token.rValRight, left.type);  // push (left.type)right
                left.PopPost (this, token.rValLeft);               // pop to left
                return left;
            }

            /*
             * There are String.Concat() methods available for 2, 3 and 4 operands.
             * So see if we have a string concat op and optimize if so.
             */
            if ((opcodeIndex == "+") || 
                ((opcodeIndex == "+=") && 
                 (token.rValLeft is TokenLVal) && 
                 (token.rValLeft.GetRValType (this, null) is TokenTypeStr))) {

                /*
                 * We are adding something.  Maybe it's a bunch of strings together.
                 */
                List<TokenRVal> scorvs = new List<TokenRVal> ();
                if (StringConcatOperands (token.rValLeft, token.rValRight, scorvs, token.opcode)) {

                    /*
                     * Evaluate all the operands, right-to-left on purpose per LSL scripting.
                     */
                    int i;
                    int n = scorvs.Count;
                    CompValu[] scocvs = new CompValu[n];
                    for (i = n; -- i >= 0;) {
                        scocvs[i] = GenerateFromRVal (scorvs[i]);
                        if (i > 0) scocvs[i] = Trivialize (scocvs[i], scorvs[i]);
                    }

                    /*
                     * Figure out where to put the result.
                     * A temp if '+', or back in original L-value if '+='.
                     */
                    CompValu retcv;
                    if (opcodeIndex == "+") {
                        retcv = new CompValuTemp (new TokenTypeStr (token.opcode), this);
                    } else {
                        retcv = GenerateFromLVal ((TokenLVal)token.rValLeft);
                    }
                    retcv.PopPre (this, token);

                    /*
                     * Call the String.Concat() methods, passing operands in left-to-right order.
                     * Force a cast to string (retcv.type) for each operand.
                     */
                    ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                    while (i + 3 < n) {
                        ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                        ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                        ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                        ilGen.Emit (scorvs[i], OpCodes.Call, stringConcat4MethodInfo);
                    }
                    if (i + 2 < n) {
                        ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                        ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                        ilGen.Emit (scorvs[i], OpCodes.Call, stringConcat3MethodInfo);
                    }
                    if (i + 1 < n) {
                        ++ i; scocvs[i].PushVal (this, scorvs[i], retcv.type);
                        ilGen.Emit (scorvs[i], OpCodes.Call, stringConcat2MethodInfo);
                    }

                    /*
                     * Put the result where we want it and return where we put it.
                     */
                    retcv.PopPost (this, token);
                    return retcv;
                }
            }

            /*
             * If "&&&", it is a short-circuiting AND.
             * Compute left-hand operand and if true, compute right-hand operand.
             */
            if (opcodeIndex == "&&&") {
                bool leftVal, rightVal;
                left = GenerateFromRVal (token.rValLeft);
                if (!IsConstBoolExpr (left, out leftVal)) {
                    ScriptMyLabel falseLabel = ilGen.DefineLabel ("ssandfalse");
                    left.PushVal (this, tokenTypeBool);
                    ilGen.Emit (token, OpCodes.Brfalse, falseLabel);
                    right = GenerateFromRVal (token.rValRight);
                    if (!IsConstBoolExpr (right, out rightVal)) {
                        right.PushVal (this, tokenTypeBool);
                        goto donessand;
                    }
                    if (!rightVal) {
                        ilGen.MarkLabel (falseLabel);
                        return new CompValuInteger (new TokenTypeInt (token.rValLeft), 0);
                    }
                    ilGen.Emit (token, OpCodes.Ldc_I4_1);
                donessand:
                    ScriptMyLabel doneLabel = ilGen.DefineLabel ("ssanddone");
                    ilGen.Emit (token, OpCodes.Br, doneLabel);
                    ilGen.MarkLabel (falseLabel);
                    ilGen.Emit (token, OpCodes.Ldc_I4_0);
                    ilGen.MarkLabel (doneLabel);
                    CompValuTemp retRVal = new CompValuTemp (new TokenTypeInt (token), this);
                    retRVal.Pop (this, token);
                    return retRVal;
                }

                if (!leftVal) {
                    return new CompValuInteger (new TokenTypeInt (token.rValLeft), 0);
                }

                right = GenerateFromRVal (token.rValRight);
                if (!IsConstBoolExpr (right, out rightVal)) {
                    right.PushVal (this, tokenTypeBool);
                    CompValuTemp retRVal = new CompValuTemp (new TokenTypeInt (token), this);
                    retRVal.Pop (this, token);
                    return retRVal;
                }
                return new CompValuInteger (new TokenTypeInt (token), rightVal ? 1 : 0);
            }

            /*
             * If "|||", it is a short-circuiting OR.
             * Compute left-hand operand and if false, compute right-hand operand.
             */
            if (opcodeIndex == "|||") {
                bool leftVal, rightVal;
                left = GenerateFromRVal (token.rValLeft);
                if (!IsConstBoolExpr (left, out leftVal)) {
                    ScriptMyLabel trueLabel = ilGen.DefineLabel ("ssortrue");
                    left.PushVal (this, tokenTypeBool);
                    ilGen.Emit (token, OpCodes.Brtrue, trueLabel);
                    right = GenerateFromRVal (token.rValRight);
                    if (!IsConstBoolExpr (right, out rightVal)) {
                        right.PushVal (this, tokenTypeBool);
                        goto donessor;
                    }
                    if (rightVal) {
                        ilGen.MarkLabel (trueLabel);
                        return new CompValuInteger (new TokenTypeInt (token.rValLeft), 1);
                    }
                    ilGen.Emit (token, OpCodes.Ldc_I4_0);
                donessor:
                    ScriptMyLabel doneLabel = ilGen.DefineLabel ("ssanddone");
                    ilGen.Emit (token, OpCodes.Br, doneLabel);
                    ilGen.MarkLabel (trueLabel);
                    ilGen.Emit (token, OpCodes.Ldc_I4_1);
                    ilGen.MarkLabel (doneLabel);
                    CompValuTemp retRVal = new CompValuTemp (new TokenTypeInt (token), this);
                    retRVal.Pop (this, token);
                    return retRVal;
                }

                if (leftVal) {
                    return new CompValuInteger (new TokenTypeInt (token.rValLeft), 1);
                }

                right = GenerateFromRVal (token.rValRight);
                if (!IsConstBoolExpr (right, out rightVal)) {
                    right.PushVal (this, tokenTypeBool);
                    CompValuTemp retRVal = new CompValuTemp (new TokenTypeInt (token), this);
                    retRVal.Pop (this, token);
                    return retRVal;
                }
                return new CompValuInteger (new TokenTypeInt (token), rightVal ? 1 : 0);
            }

            /*
             * Computation of some sort, compute right-hand operand value then left-hand value
             * because LSL is supposed to be right-to-left evaluation.
             */
            right = Trivialize (GenerateFromRVal (token.rValRight), token.rValRight);

            /*
             * If left is a script-defined class and there is a method with the operator's name,
             * convert this to a call to that method with the right value as its single parameter.
             * Except don't if the right value is 'undef' so they can always compare to undef.
             */
            TokenType leftType = token.rValLeft.GetRValType (this, null);
            if ((leftType is TokenTypeSDTypeClass) && !(right.type is TokenTypeUndef)) {
                TokenTypeSDTypeClass sdtType = (TokenTypeSDTypeClass)leftType;
                TokenDeclSDTypeClass sdtDecl = sdtType.decl;
                TokenType[] argsig = new TokenType[] { right.type };
                TokenName funcName = new TokenName (token.opcode, "$op" + opcodeIndex);
                TokenDeclVar declFunc = FindThisMember (sdtDecl, funcName, argsig);
                if (declFunc != null) {
                    CheckAccess (declFunc, funcName);
                    left = GenerateFromRVal (token.rValLeft);
                    CompValu method = AccessInstanceMember (declFunc, left, token, false);
                    CompValu[] argRVals = new CompValu[] { right };
                    return GenerateACall (method, argRVals, token);
                }
            }

            /*
             * Formulate key string for binOpStrings = (lefttype)(operator)(righttype)
             */
            string leftIndex = leftType.ToString ();
            string rightIndex = right.type.ToString ();
            string key = leftIndex + opcodeIndex + rightIndex;

            /*
             * If that key exists in table, then the operation is defined between those types
             * ... and it produces an R-value of type as given in the table.
             */
            BinOpStr binOpStr;
            if (BinOpStr.defined.TryGetValue (key, out binOpStr)) {

                /*
                 * If table contained an explicit assignment type like +=, output the statement without
                 * casting the L-value, then return the L-value as the resultant value.
                 *
                 * Make sure we don't include comparisons (such as ==, >=, etc).
                 * Nothing like +=, -=, %=, etc, generate a boolean, only the comparisons.
                 */
                if ((binOpStr.outtype != typeof (bool)) && opcodeIndex.EndsWith ("=") && (opcodeIndex != "!=")) {
                    if (!(token.rValLeft is TokenLVal)) {
                        ErrorMsg (token.rValLeft, "invalid L-value");
                        return GenerateFromRVal (token.rValLeft);
                    }
                    left = GenerateFromLVal ((TokenLVal)token.rValLeft);
                    binOpStr.emitBO (this, token, left, right, left);
                    return left;
                }

                /*
                 * It's of the form left binop right.
                 * Compute left, perform operation then put result in a temp.
                 */
                left = GenerateFromRVal (token.rValLeft);
                CompValu retRVal = new CompValuTemp (TokenType.FromSysType (token.opcode, binOpStr.outtype), this);
                binOpStr.emitBO (this, token, left, right, retRVal);
                return retRVal;
            }

            /*
             * Nothing in the table, check for comparing object pointers because of the myriad of types possible.
             * This will compare list pointers, null pointers, script-defined type pointers, array pointers, etc.
             * It will show equal iff the memory addresses are equal and that is good enough.
             */
            if (!leftType.ToSysType().IsValueType && !right.type.ToSysType().IsValueType && ((opcodeIndex == "==") || (opcodeIndex == "!="))) {
                CompValuTemp retRVal = new CompValuTemp (new TokenTypeInt (token), this);
                left = GenerateFromRVal (token.rValLeft);
                left.PushVal (this, token.rValLeft);
                right.PushVal (this, token.rValRight);
                ilGen.Emit (token, OpCodes.Ceq);
                if (opcodeIndex == "!=") {
                    ilGen.Emit (token, OpCodes.Ldc_I4_1);
                    ilGen.Emit (token, OpCodes.Xor);
                }
                retRVal.Pop (this, token);
                return retRVal;
            }

            /*
             * If the opcode ends with "=", it may be something like "+=".
             * So look up the key as if we didn't have the "=" to tell us if the operation is legal.
             * Also, the binary operation's output type must be the same as the L-value type.
             * Likewise, integer += float not allowed because result is float, but float += integer is ok.
             */
            if (opcodeIndex.EndsWith ("=")) {
                key = leftIndex + opcodeIndex.Substring (0, opcodeIndex.Length - 1) + rightIndex;
                if (BinOpStr.defined.TryGetValue (key, out binOpStr)) {
                    if (!(token.rValLeft is TokenLVal)) {
                        ErrorMsg (token, "invalid L-value for <op>=");
                        return GenerateFromRVal (token.rValLeft);
                    }
                    if (!binOpStr.rmwOK) {
                        ErrorMsg (token, "<op>= not allowed: " + leftIndex + " " + opcodeIndex + " " + rightIndex);
                        return new CompValuVoid (token);
                    }

                    /*
                     * Now we know for something like %= that left%right is legal for the types given.
                     */
                    left = GenerateFromLVal ((TokenLVal)token.rValLeft);
                    if (binOpStr.outtype == leftType.ToSysType ()) {
                        binOpStr.emitBO (this, token, left, right, left);
                    } else {
                        CompValu temp = new CompValuTemp (TokenType.FromSysType (token, binOpStr.outtype), this);
                        binOpStr.emitBO (this, token, left, right, temp);
                        left.PopPre (this, token);
                        temp.PushVal (this, token, leftType);
                        left.PopPost (this, token);
                    }
                    return left;
                }
            }

            /*
             * Can't find it, oh well.
             */
            ErrorMsg (token, "op not defined: " + leftIndex + " " + opcodeIndex + " " + rightIndex);
            return new CompValuVoid (token);
        }

        /**
         * @brief Queue the given operands to the end of the scos list.
         *        If it can be broken down into more string concat operands, do so.
         *        Otherwise, just push it as one operand.
         * @param leftRVal  = left-hand operand of a '+' operation
         * @param rightRVal = right-hand operand of a '+' operation
         * @param scos      = left-to-right list of operands for the string concat so far
         * @param addop     = the add operator token (either '+' or '+=')
         * @returns false: neither operand is a string, nothing added to scos
         *           true: scos = updated with leftRVal then rightRVal added onto the end, possibly broken down further
         */
        private bool StringConcatOperands (TokenRVal leftRVal, TokenRVal rightRVal, List<TokenRVal> scos, TokenKw addop)
        {
            /*
             * If neither operand is a string (eg, float+integer), then the result isn't going to be a string.
             */
            TokenType leftType  = leftRVal.GetRValType  (this, null);
            TokenType rightType = rightRVal.GetRValType (this, null);
            if (!(leftType is TokenTypeStr) && !(rightType is TokenTypeStr)) return false;

            /*
             * Also, list+string => list so reject that too.
             * Also, string+list => list so reject that too.
             */
            if (leftType  is TokenTypeList) return false;
            if (rightType is TokenTypeList) return false;

            /*
             * Append values to the end of the list in left-to-right order.
             * If value is formed from a something+something => string, 
             * push them as separate values, otherwise push as one value.
             */
            StringConcatOperand (leftType,  leftRVal,  scos);
            StringConcatOperand (rightType, rightRVal, scos);

            /*
             * Maybe constant strings can be concatted.
             */
            try {
                int len;
                while (((len = scos.Count) >= 2) && 
                       ((leftRVal  = scos[len-2]) is TokenRValConst) && 
                       ((rightRVal = scos[len-1]) is TokenRValConst)) {
                    object sum = addop.binOpConst (((TokenRValConst)leftRVal).val, 
                                                   ((TokenRValConst)rightRVal).val);
                    scos[len-2] = new TokenRValConst (addop, sum);
                    scos.RemoveAt (len - 1);
                }
            } catch {
            }

            /*
             * We pushed some string stuff.
             */
            return true;
        }

        /**
         * @brief Queue the given operand to the end of the scos list.
         *        If it can be broken down into more string concat operands, do so.
         *        Otherwise, just push it as one operand.
         * @param type = rVal's resultant type
         * @param rVal = operand to examine
         * @param scos = left-to-right list of operands for the string concat so far
         * @returns with scos = updated with rVal added onto the end, possibly broken down further
         */
        private void StringConcatOperand (TokenType type, TokenRVal rVal, List<TokenRVal> scos)
        {
            bool didOne;
            do {
                didOne = false;
                rVal   = rVal.TryComputeConstant (LookupBodyConstants, ref didOne);
            } while (didOne);

            if (!(type is TokenTypeStr)) goto pushasis;
            if (!(rVal is TokenRValOpBin)) goto pushasis;
            TokenRValOpBin rValOpBin = (TokenRValOpBin)rVal;
            if (!(rValOpBin.opcode is TokenKwAdd)) goto pushasis;
            if (StringConcatOperands (rValOpBin.rValLeft, rValOpBin.rValRight, scos, rValOpBin.opcode)) return;
            pushasis:
            scos.Add (rVal);
        }

        /**
         * @brief compute the result of an unary operator
         * @param token = unary operator token, includes the operand
         * @returns where the resultant R-value is
         */
        private CompValu GenerateFromRValOpUn (TokenRValOpUn token)
        {
            CompValu inRVal = GenerateFromRVal (token.rVal);

            /*
             * Script-defined types can define their own methods to handle unary operators.
             */
            if (inRVal.type is TokenTypeSDTypeClass) {
                TokenTypeSDTypeClass sdtType = (TokenTypeSDTypeClass)inRVal.type;
                TokenDeclSDTypeClass sdtDecl = sdtType.decl;
                TokenName funcName = new TokenName (token.opcode, "$op" + token.opcode.ToString ());
                TokenDeclVar declFunc = FindThisMember (sdtDecl, funcName, zeroArgs);
                if (declFunc != null) {
                    CheckAccess (declFunc, funcName);
                    CompValu method = AccessInstanceMember (declFunc, inRVal, token, false);
                    return GenerateACall (method, zeroCompValus, token);
                }
            }

            /*
             * Otherwise use the default.
             */
            return UnOpGenerate (inRVal, token.opcode);
        }

        /**
         * @brief postfix operator -- this returns the type and location of the resultant value
         */
        private CompValu GenerateFromRValAsnPost (TokenRValAsnPost asnPost)
        {
            CompValu lVal = GenerateFromLVal (asnPost.lVal);

            /*
             * Make up a temp to save original value in.
             */
            CompValuTemp result = new CompValuTemp (lVal.type, this);

            /*
             * Prepare to pop incremented value back into variable being incremented.
             */
            lVal.PopPre (this, asnPost.lVal);

            /*
             * Copy original value to temp and leave value on stack.
             */
            lVal.PushVal (this, asnPost.lVal);
            ilGen.Emit (asnPost.lVal, OpCodes.Dup);
            result.Pop (this, asnPost.lVal);

            /*
             * Perform the ++/--.
             */
            if ((lVal.type is TokenTypeChar) || (lVal.type is TokenTypeInt)) {
                ilGen.Emit (asnPost, OpCodes.Ldc_I4_1);
            } else if (lVal.type is TokenTypeFloat) {
                ilGen.Emit (asnPost, OpCodes.Ldc_R4, 1.0f);
            } else {
                lVal.PopPost (this, asnPost.lVal);
                ErrorMsg (asnPost, "invalid type for " + asnPost.postfix.ToString ());
                return lVal;
            }
            switch (asnPost.postfix.ToString ()) {
                case "++": {
                    ilGen.Emit (asnPost, OpCodes.Add);
                    break;
                }
                case "--": {
                    ilGen.Emit (asnPost, OpCodes.Sub);
                    break;
                }
                default: throw new Exception ("unknown asnPost op");
            }

            /*
             * Store new value in original variable.
             */
            lVal.PopPost (this, asnPost.lVal);

            return result;
        }

        /**
         * @brief prefix operator -- this returns the type and location of the resultant value
         */
        private CompValu GenerateFromRValAsnPre (TokenRValAsnPre asnPre)
        {
            CompValu lVal = GenerateFromLVal (asnPre.lVal);

            /*
             * Make up a temp to put result in.
             */
            CompValuTemp result = new CompValuTemp (lVal.type, this);

            /*
             * Prepare to pop incremented value back into variable being incremented.
             */
            lVal.PopPre (this, asnPre.lVal);

            /*
             * Push original value.
             */
            lVal.PushVal (this, asnPre.lVal);

            /*
             * Perform the ++/--.
             */
            if ((lVal.type is TokenTypeChar) || (lVal.type is TokenTypeInt)) {
                ilGen.Emit (asnPre, OpCodes.Ldc_I4_1);
            } else if (lVal.type is TokenTypeFloat) {
                ilGen.Emit (asnPre, OpCodes.Ldc_R4, 1.0f);
            } else {
                lVal.PopPost (this, asnPre.lVal);
                ErrorMsg (asnPre, "invalid type for " + asnPre.prefix.ToString ());
                return lVal;
            }
            switch (asnPre.prefix.ToString ()) {
                case "++": {
                    ilGen.Emit (asnPre, OpCodes.Add);
                    break;
                }
                case "--": {
                    ilGen.Emit (asnPre, OpCodes.Sub);
                    break;
                }
                default: throw new Exception ("unknown asnPre op");
            }

            /*
             * Store new value in temp variable, keeping new value on stack.
             */
            ilGen.Emit (asnPre.lVal, OpCodes.Dup);
            result.Pop (this, asnPre.lVal);

            /*
             * Store new value in original variable.
             */
            lVal.PopPost (this, asnPre.lVal);

            return result;
        }

        /**
         * @brief Generate code that calls a function or object's method.
         * @returns where the call's return value is stored (a TokenTypeVoid if void)
         */
        private CompValu GenerateFromRValCall (TokenRValCall call)
        {
            CompValu method;
            CompValu[] argRVals;
            int i, nargs;
            TokenRVal arg;
            TokenType[] argTypes;

            /*
             * Compute the values of all the function's call arguments.
             * Save where the computation results are in the argRVals[] array.
             * Might as well build the argument signature from the argument types, too.
             */
            nargs = call.nArgs;
            argRVals = new CompValu[nargs];
            argTypes = new TokenType[nargs];
            if (nargs > 0) {
                i = 0;
                for (arg = call.args; arg != null; arg = (TokenRVal)arg.nextToken) {
                    argRVals[i] = GenerateFromRVal (arg);
                    argTypes[i] = argRVals[i].type;
                    i ++;
                }
            }

            /*
             * Get function/method's entrypoint that matches the call argument types.
             */
            method = GenerateFromRVal (call.meth, argTypes);
            if (method == null) return null;

            return GenerateACall (method, argRVals, call);
        }

        /**
         * @brief Generate call to a function/method.
         * @param method = function/method being called
         * @param argVRVals = its call parameters (zero length if none)
         * @param call = where in source code call is being made from (for error messages)
         * @returns type and location of return value (CompValuVoid if none)
         */
        private CompValu GenerateACall (CompValu method, CompValu[] argRVals, Token call)
        {
            CompValuTemp result;
            int i, nArgs;
            TokenType retType;
            TokenType[] argTypes;

            /*
             * Must be some kind of callable.
             */
            retType = method.GetRetType ();  // TokenTypeVoid if void; null means a variable
            if (retType == null) {
                ErrorMsg (call, "must be a delegate, function or method");
                return new CompValuVoid (call);
            }

            /*
             * Get a location for return value.
             */
            if (retType is TokenTypeVoid) {
                result = new CompValuVoid (call);
            } else {
                result = new CompValuTemp (retType, this);
            }

            /*
             * Make sure all arguments are trivial, ie, don't involve their own call labels.
             * For any that aren't, output code to calculate the arg and put in a temporary.
             */
            nArgs = argRVals.Length;
            for (i = 0; i < nArgs; i ++) {
                if (!argRVals[i].IsReadTrivial (this, call)) {
                    argRVals[i] = Trivialize (argRVals[i], call);
                }
            }

            /*
             * Inline functions know how to generate their own call.
             */
            if (method is CompValuInline) {
                CompValuInline inline = (CompValuInline)method;
                inline.declInline.CodeGen (this, call, result, argRVals);
                return result;
            }

            /*
             * Push whatever the function/method needs as a this argument, if anything.
             */
            method.CallPre (this, call);

            /*
             * Push the script-visible args, left-to-right.
             */
            argTypes = method.GetArgTypes ();
            for (i = 0; i < nArgs; i ++) {
                if (argTypes == null) {
                    argRVals[i].PushVal (this, call);
                } else {
                    argRVals[i].PushVal (this, call, argTypes[i]);
                }
            }

            /*
             * Now output call instruction.
             */
            method.CallPost (this, call);

            /*
             * Deal with the return value (if any), by putting it in 'result'.
             */
            result.Pop (this, call, retType);
            return result;
        }

        /**
         * @brief This is needed to avoid nesting call labels around non-trivial properties.
         *        It should be used for the second (and later) operands.
         *        Note that a 'call' is considered an operator, so all arguments of a call
         *        should be trivialized, but the method itself does not need to be.
         */
        public CompValu Trivialize (CompValu operand, Token errorAt)
        {
            if (operand.IsReadTrivial (this, errorAt)) return operand;
            CompValuTemp temp = new CompValuTemp (operand.type, this);
            operand.PushVal (this, errorAt);
            temp.Pop (this, errorAt);
            return temp;
        }

        /**
         * @brief Generate code that casts a value to a particular type.
         * @returns where the result of the conversion is stored.
         */
        private CompValu GenerateFromRValCast (TokenRValCast cast)
        {
            /*
             * If casting to a delegate type, use the argment signature 
             * of the delegate to help select the function/method, eg, 
             *    '(delegate string(integer))ToString'
             * will select 'string ToString(integer x)'
             * instaead of 'string ToString(float x)' or anything else
             */
            TokenType[] argsig = null;
            TokenType outType = cast.castTo;
            if (outType is TokenTypeSDTypeDelegate) {
                argsig = ((TokenTypeSDTypeDelegate)outType).decl.GetArgTypes ();
            }

            /*
             * Generate the value that is being cast.
             * If the value is already the requested type, just use it as is.
             */
            CompValu inRVal = GenerateFromRVal (cast.rVal, argsig);
            if (inRVal.type == outType) return inRVal;

            /*
             * Different type, generate casting code, putting the result in a temp of the output type.
             */
            CompValu outRVal = new CompValuTemp (outType, this);
            outRVal.PopPre (this, cast);
            inRVal.PushVal (this, cast, outType, true);
            outRVal.PopPost (this, cast);
            return outRVal;
        }

        /**
         * @brief Compute conditional expression value.
         * @returns type and location of computed value.
         */
        private CompValu GenerateFromRValCondExpr (TokenRValCondExpr rValCondExpr)
        {
            bool condVal;
            CompValu condValu = GenerateFromRVal (rValCondExpr.condExpr);
            if (IsConstBoolExpr (condValu, out condVal)) {
                return GenerateFromRVal (condVal ? rValCondExpr.trueExpr : rValCondExpr.falseExpr);
            }

            ScriptMyLabel falseLabel = ilGen.DefineLabel ("condexfalse");
            ScriptMyLabel doneLabel  = ilGen.DefineLabel ("condexdone");

            condValu.PushVal (this, rValCondExpr.condExpr, tokenTypeBool);
            ilGen.Emit (rValCondExpr, OpCodes.Brfalse, falseLabel);

            CompValu trueValu = GenerateFromRVal (rValCondExpr.trueExpr);
            trueValu.PushVal (this, rValCondExpr.trueExpr);
            ilGen.Emit (rValCondExpr, OpCodes.Br, doneLabel);

            ilGen.MarkLabel (falseLabel);
            CompValu falseValu = GenerateFromRVal (rValCondExpr.falseExpr);
            falseValu.PushVal (this, rValCondExpr.falseExpr);

            if (trueValu.type.GetType () != falseValu.type.GetType ()) {
                ErrorMsg (rValCondExpr, "? operands " + trueValu.type.ToString () + " : " +
                              falseValu.type.ToString () + " must be of same type");
            }

            ilGen.MarkLabel (doneLabel);
            CompValuTemp retRVal = new CompValuTemp (trueValu.type, this);
            retRVal.Pop (this, rValCondExpr);
            return retRVal;
        }

        /**
         * @brief Constant in the script somewhere
         * @returns where the constants value is stored
         */
        private CompValu GenerateFromRValConst (TokenRValConst rValConst)
        {
            switch (rValConst.type) {
                case TokenRValConstType.CHAR: {
                    return new CompValuChar (new TokenTypeChar (rValConst), (char)(rValConst.val));
                }
                case TokenRValConstType.FLOAT: {
                    return new CompValuFloat (new TokenTypeFloat (rValConst), (double)(rValConst.val));
                }
                case TokenRValConstType.INT: {
                    return new CompValuInteger (new TokenTypeInt (rValConst), (int)(rValConst.val));
                }
                case TokenRValConstType.KEY: {
                    return new CompValuString (new TokenTypeKey (rValConst), (string)(rValConst.val));
                }
                case TokenRValConstType.STRING: {
                    return new CompValuString (new TokenTypeStr (rValConst), (string)(rValConst.val));
                }
            }
            throw new Exception ("unknown constant type " + rValConst.val.GetType ());
        }

        /**
         * @brief generate a new list object
         * @param rValList = an rVal to create it from
         */
        private CompValu GenerateFromRValList (TokenRValList rValList)
        {
            /*
             * Compute all element values and remember where we put them.
             * Do it right-to-left as customary for LSL scripts.
             */
            int i = 0;
            TokenRVal lastRVal = null;
            for (TokenRVal val = rValList.rVal; val != null; val = (TokenRVal)val.nextToken) {
                i ++;
                val.prevToken = lastRVal;
                lastRVal = val;
            }
            CompValu[] vals = new CompValu[i];
            for (TokenRVal val = lastRVal; val != null; val = (TokenRVal)val.prevToken) {
                vals[--i] = GenerateFromRVal (val);
            }

            /*
             * This is the temp that will hold the created list.
             */
            CompValuTemp newList = new CompValuTemp (new TokenTypeList (rValList.rVal), this);

            /*
             * Create a temp object[] array to hold all the initial values.
             */
            ilGen.Emit (rValList, OpCodes.Ldc_I4, rValList.nItems);
            ilGen.Emit (rValList, OpCodes.Newarr, typeof (object));

            /*
             * Populate the array.
             */
            i = 0;
            for (TokenRVal val = rValList.rVal; val != null; val = (TokenRVal)val.nextToken) {

                /*
                 * Get pointer to temp array object.
                 */
                ilGen.Emit (rValList, OpCodes.Dup);

                /*
                 * Get index in that array.
                 */
                ilGen.Emit (rValList, OpCodes.Ldc_I4, i);

                /*
                 * Store initialization value in array location.
                 * However, floats and ints need to be converted to LSL_Float and LSL_Integer,
                 * or things like llSetPayPrice() will puque when they try to cast the elements
                 * to LSL_Float or LSL_Integer.  Likewise with string/LSL_String.
                 *
                 * Maybe it's already LSL-boxed so we don't do anything with it except make sure
                 * it is an object, not a struct.
                 */
                CompValu eRVal = vals[i++];
                eRVal.PushVal (this, val);
                if (eRVal.type.ToLSLWrapType () == null) {
                    if (eRVal.type is TokenTypeFloat) {
                        ilGen.Emit (val, OpCodes.Newobj, lslFloatConstructorInfo);
                        ilGen.Emit (val, OpCodes.Box, typeof (LSL_Float));
                    } else if (eRVal.type is TokenTypeInt) {
                        ilGen.Emit (val, OpCodes.Newobj, lslIntegerConstructorInfo);
                        ilGen.Emit (val, OpCodes.Box, typeof (LSL_Integer));
                    } else if ((eRVal.type is TokenTypeKey) || (eRVal.type is TokenTypeStr)) {
                        ilGen.Emit (val, OpCodes.Newobj, lslStringConstructorInfo);
                        ilGen.Emit (val, OpCodes.Box, typeof (LSL_String));
                    } else if (eRVal.type.ToSysType ().IsValueType) {
                        ilGen.Emit (val, OpCodes.Box, eRVal.type.ToSysType ());
                    }
                } else if (eRVal.type.ToLSLWrapType ().IsValueType) {

                    // Convert the LSL value structs to an object of the LSL-boxed type
                    ilGen.Emit (val, OpCodes.Box, eRVal.type.ToLSLWrapType ());
                }
                ilGen.Emit (val, OpCodes.Stelem, typeof (object));
            }

            /*
             * Create new list object from temp initial value array (whose ref is still on the stack).
             */
            ilGen.Emit (rValList, OpCodes.Newobj, lslListConstructorInfo);
            newList.Pop (this, rValList);
            return newList;
        }

        /**
         * @brief New array allocation with initializer expressions.
         */
        private CompValu GenerateFromRValNewArIni (TokenRValNewArIni rValNewArIni)
        {
            return MallocAndInitArray (rValNewArIni.arrayType, rValNewArIni.valueList);
        }

        /**
         * @brief Mallocate and initialize an array from its initialization list.
         * @param arrayType = type of the array to be allocated and initialized
         * @param values    = initialization value list used to size and initialize the array.
         * @returns memory location of the resultant initialized array.
         */
        private CompValu MallocAndInitArray (TokenType arrayType, TokenList values)
        {
            TokenDeclSDTypeClass arrayDecl = ((TokenTypeSDTypeClass)arrayType).decl;
            TokenType eleType = arrayDecl.arrayOfType;
            int rank = arrayDecl.arrayOfRank;

            // Get size of each of the dimensions by scanning the initialization value list
            int[] dimSizes = new int[rank];
            FillInDimSizes (dimSizes, 0, rank, values);

            // Figure out where the array's $new() method is
            TokenType[] newargsig = new TokenType[rank];
            for (int k = 0; k < rank; k ++) {
                newargsig[k] = tokenTypeInt;
            }
            TokenDeclVar newMeth = FindThisMember (arrayDecl, new TokenName (null, "$new"), newargsig);

            // Output a call to malloc the array with all default values
            //    array = ArrayType.$new (dimSizes[0], dimSizes[1], ...)
            CompValuTemp array = new CompValuTemp (arrayType, this);
            PushXMRInst ();
            for (int k = 0; k < rank; k ++) {
                ilGen.Emit (values, OpCodes.Ldc_I4, dimSizes[k]);
            }
            ilGen.Emit (values, OpCodes.Call, newMeth.ilGen);
            array.Pop (this, arrayType);

            // Figure out where the array's Set() method is
            TokenType[] setargsig = new TokenType[rank+1];
            for (int k = 0; k < rank; k ++) {
                setargsig[k] = tokenTypeInt;
            }
            setargsig[rank] = eleType;
            TokenDeclVar setMeth = FindThisMember (arrayDecl, new TokenName (null, "Set"), setargsig);

            // Fill in the array with the initializer values
            FillInInitVals (array, setMeth, dimSizes, 0, rank, values, eleType);

            // The array is our resultant value
            return array;
        }

        /**
         * @brief Compute an array's dimensions given its initialization value list
         * @param dimSizes = filled in with array's dimensions
         * @param dimNo    = what dimension the 'values' list applies to
         * @param rank     = total number of dimensions of the array
         * @param values   = list of values to initialize the array's 'dimNo' dimension with
         * @returns with dimSizes[dimNo..rank-1] filled in
         */
        private static void FillInDimSizes (int[] dimSizes, int dimNo, int rank, TokenList values)
        {
            // the size of a dimension is the largest number of initializer elements at this level
            // for dimNo 0, this is the number of elements in the top-level list
            if (dimSizes[dimNo] < values.tl.Count) dimSizes[dimNo] = values.tl.Count;

            // see if there is another dimension to calculate
            if (++ dimNo < rank) {

                // its size is the size of the largest initializer list at the next inner level
                foreach (Token val in values.tl) {
                    if (val is TokenList) {
                        TokenList subvals = (TokenList)val;
                        FillInDimSizes (dimSizes, dimNo, rank, subvals);
                    }
                }
            }
        }

        /**
         * @brief Output code to fill in array's initialization values
         * @param array      = array to be filled in
         * @param setMeth    = the array's Set() method
         * @param subscripts = holds subscripts being built
         * @param dimNo      = which dimension the 'values' are for
         * @param values     = list of initialization values for dimension 'dimNo'
         * @param rank       = number of dimensions of 'array'
         * @param values     = list of values to initialize the array's 'dimNo' dimension with
         * @param eleType    = the element's type
         * @returns with code emitted to initialize array's [subscripts[0], ..., subscripts[dimNo-1], *, *, ...]
         *                                                          dimNo and up completely filled ---^
         */
        private void FillInInitVals (CompValu array, TokenDeclVar setMeth, int[] subscripts, int dimNo, int rank, TokenList values, TokenType eleType)
        {
            subscripts[dimNo] = 0;
            foreach (Token val in values.tl) {
                CompValu initValue = null;

                /*
                 * If it is a sublist, process it.
                 *    If we don't have enough subscripts yet, hopefully that sublist will have enough.
                 *    If we already have enough subscripts, then that sublist can be for an element of this supposedly jagged array.
                 */
                if (val is TokenList) {
                    TokenList sublist = (TokenList)val;
                    if (dimNo + 1 < rank) {

                        /*
                         * We don't have enough subscripts yet, hopefully the sublist has the rest.
                         */
                        FillInInitVals (array, setMeth, subscripts, dimNo + 1, rank, sublist, eleType);
                    } else if ((eleType is TokenTypeSDTypeClass) && (((TokenTypeSDTypeClass)eleType).decl.arrayOfType == null)) {

                        /*
                         * If we aren't a jagged array either, we can't do anything with the sublist.
                         */
                        ErrorMsg (val, "too many brace levels");
                    } else {

                        /*
                         * We are a jagged array, so malloc a subarray and initialize it with the sublist.
                         * Then we can use that subarray to fill this array's element.
                         */
                        initValue = MallocAndInitArray (eleType, sublist);
                    }
                }

                /*
                 * If it is a value expression, then output code to compute the value.
                 */
                if (val is TokenRVal) {
                    if (dimNo + 1 < rank) {
                        ErrorMsg ((Token)val, "not enough brace levels");
                    } else {
                        initValue = GenerateFromRVal ((TokenRVal)val);
                    }
                }

                /*
                 * If there is an initValue, output "array.Set (subscript[0], subscript[1], ..., initValue)"
                 */
                if (initValue != null) {
                    array.PushVal (this, val);
                    for (int i = 0; i <= dimNo; i ++) {
                        ilGen.Emit (val, OpCodes.Ldc_I4, subscripts[i]);
                    }
                    initValue.PushVal (this, val, eleType);
                    ilGen.Emit (val, OpCodes.Call, setMeth.ilGen);
                }

                /*
                 * That subscript is processed one way or another, on to the next.
                 */
                subscripts[dimNo] ++;
            }
        }

        /**
         * @brief parenthesized expression
         * @returns type and location of the result of the computation.
         */
        private CompValu GenerateFromRValParen (TokenRValParen rValParen)
        {
            return GenerateFromRVal (rValParen.rVal);
        }

        /**
         * @brief create a rotation object from the x,y,z,w value expressions.
         */
        private CompValu GenerateFromRValRot (TokenRValRot rValRot)
        {
            CompValu xRVal, yRVal, zRVal, wRVal;

            xRVal = Trivialize (GenerateFromRVal (rValRot.xRVal), rValRot);
            yRVal = Trivialize (GenerateFromRVal (rValRot.yRVal), rValRot);
            zRVal = Trivialize (GenerateFromRVal (rValRot.zRVal), rValRot);
            wRVal = Trivialize (GenerateFromRVal (rValRot.wRVal), rValRot);
            return new CompValuRot (new TokenTypeRot (rValRot), xRVal, yRVal, zRVal, wRVal);
        }

        /**
         * @brief Using 'this' as a pointer to the current script-defined instance object.
         *        The value is located in arg #0 of the current instance method.
         */
        private CompValu GenerateFromRValThis (TokenRValThis zhis)
        {
            if (!IsSDTInstMethod ()) {
                ErrorMsg (zhis, "cannot access instance member of class from static method");
                return new CompValuVoid (zhis);
            }
            return new CompValuArg (curDeclFunc.sdtClass.MakeRefToken (zhis), 0);
        }

        /**
         * @brief 'undefined' constant.
         *        If this constant gets written to an array element, it will delete that element from the array.
         *        If the script retrieves an element by key that is not defined, it will get this value.
         *        This value can be stored in and retrieved from variables of type 'object' or script-defined classes.
         *        It is a runtime error to cast this value to any other type, eg, 
         *        we don't allow list or string variables to be null pointers.
         */
        private CompValu GenerateFromRValUndef (TokenRValUndef rValUndef)
        {
            return new CompValuNull (new TokenTypeUndef (rValUndef));
        }

        /**
         * @brief create a vector object from the x,y,z value expressions.
         */
        private CompValu GenerateFromRValVec (TokenRValVec rValVec)
        {
            CompValu xRVal, yRVal, zRVal;

            xRVal = Trivialize (GenerateFromRVal (rValVec.xRVal), rValVec);
            yRVal = Trivialize (GenerateFromRVal (rValVec.yRVal), rValVec);
            zRVal = Trivialize (GenerateFromRVal (rValVec.zRVal), rValVec);
            return new CompValuVec (new TokenTypeVec (rValVec), xRVal, yRVal, zRVal);
        }

        /**
         * @brief Generate code to get the default initialization value for a variable.
         */
        private CompValu GenerateFromRValInitDef (TokenRValInitDef rValInitDef)
        {
            TokenType type = rValInitDef.type;

            if (type is TokenTypeChar) {
                return new CompValuChar (type, (char)0);
            }
            if (type is TokenTypeRot) {
                CompValuFloat x = new CompValuFloat (type, ScriptBaseClass.ZERO_ROTATION.x);
                CompValuFloat y = new CompValuFloat (type, ScriptBaseClass.ZERO_ROTATION.y);
                CompValuFloat z = new CompValuFloat (type, ScriptBaseClass.ZERO_ROTATION.z);
                CompValuFloat s = new CompValuFloat (type, ScriptBaseClass.ZERO_ROTATION.s);
                return new CompValuRot (type, x, y, z, s);
            }
            if ((type is TokenTypeKey) || (type is TokenTypeStr)) {
                return new CompValuString (type, "");
            }
            if (type is TokenTypeVec) {
                CompValuFloat x = new CompValuFloat (type, ScriptBaseClass.ZERO_VECTOR.x);
                CompValuFloat y = new CompValuFloat (type, ScriptBaseClass.ZERO_VECTOR.y);
                CompValuFloat z = new CompValuFloat (type, ScriptBaseClass.ZERO_VECTOR.z);
                return new CompValuVec (type, x, y, z);
            }
            if (type is TokenTypeInt) {
                return new CompValuInteger (type, 0);
            }
            if (type is TokenTypeFloat) {
                return new CompValuFloat (type, 0);
            }
            if (type is TokenTypeVoid) {
                return new CompValuVoid (type);
            }

            /*
             * Default for 'object' type is 'undef'.
             * Likewise for script-defined classes and interfaces.
             */
            if ((type is TokenTypeObject) || (type is TokenTypeSDTypeClass) || (type is TokenTypeSDTypeDelegate) || 
                (type is TokenTypeSDTypeInterface) || (type is TokenTypeExc)) {
                return new CompValuNull (type);
            }

            /*
             * array and list
             */
            CompValuTemp temp = new CompValuTemp (type, this);
            PushDefaultValue (type);
            temp.Pop (this, rValInitDef, type);
            return temp;
        }

        /**
         * @brief Generate code to process an <rVal> is <type> expression, and produce a boolean value.
         */
        private CompValu GenerateFromRValIsType (TokenRValIsType rValIsType)
        {
            /*
             * Expression we want to know the type of.
             */
            CompValu val = GenerateFromRVal (rValIsType.rValExp);

            /*
             * Pass it in to top-level type expression decoder.
             */
            return GenerateFromTypeExp (val, rValIsType.typeExp);
        }

        /**
         * @brief See if the type of the given value matches the type expression.
         * @param val = where the value to be evaluated is stored
         * @param typeExp = script tokens representing type expression
         * @returns location where the boolean result is stored
         */
        private CompValu GenerateFromTypeExp (CompValu val, TokenTypeExp typeExp)
        {
            if (typeExp is TokenTypeExpBinOp) {
                CompValu left  = GenerateFromTypeExp (val, ((TokenTypeExpBinOp)typeExp).leftOp);
                CompValu right = GenerateFromTypeExp (val, ((TokenTypeExpBinOp)typeExp).rightOp);
                CompValuTemp result = new CompValuTemp (tokenTypeBool, this);
                Token op = ((TokenTypeExpBinOp)typeExp).binOp;
                left.PushVal (this, ((TokenTypeExpBinOp)typeExp).leftOp);
                right.PushVal (this, ((TokenTypeExpBinOp)typeExp).rightOp);
                if (op is TokenKwAnd) {
                    ilGen.Emit (typeExp, OpCodes.And);
                } else if (op is TokenKwOr) {
                    ilGen.Emit (typeExp, OpCodes.Or);
                } else {
                    throw new Exception ("unknown TokenTypeExpBinOp " + op.GetType ());
                }
                result.Pop (this, typeExp);
                return result;
            }
            if (typeExp is TokenTypeExpNot) {
                CompValu interm = GenerateFromTypeExp (val, ((TokenTypeExpNot)typeExp).typeExp);
                CompValuTemp result = new CompValuTemp (tokenTypeBool, this);
                interm.PushVal (this, ((TokenTypeExpNot)typeExp).typeExp, tokenTypeBool);
                ilGen.Emit (typeExp, OpCodes.Ldc_I4_1);
                ilGen.Emit (typeExp, OpCodes.Xor);
                result.Pop (this, typeExp);
                return result;
            }
            if (typeExp is TokenTypeExpPar) {
                return GenerateFromTypeExp (val, ((TokenTypeExpPar)typeExp).typeExp);
            }
            if (typeExp is TokenTypeExpType) {
                CompValuTemp result = new CompValuTemp (tokenTypeBool, this);
                val.PushVal (this, typeExp);
                ilGen.Emit (typeExp, OpCodes.Isinst, ((TokenTypeExpType)typeExp).typeToken.ToSysType ());
                ilGen.Emit (typeExp, OpCodes.Ldnull);
                ilGen.Emit (typeExp, OpCodes.Ceq);
                ilGen.Emit (typeExp, OpCodes.Ldc_I4_1);
                ilGen.Emit (typeExp, OpCodes.Xor);
                result.Pop (this, typeExp);
                return result;
            }
            if (typeExp is TokenTypeExpUndef) {
                CompValuTemp result = new CompValuTemp (tokenTypeBool, this);
                val.PushVal (this, typeExp);
                ilGen.Emit (typeExp, OpCodes.Ldnull);
                ilGen.Emit (typeExp, OpCodes.Ceq);
                result.Pop (this, typeExp);
                return result;
            }
            throw new Exception ("unknown TokenTypeExp type " + typeExp.GetType ());
        }

        /**
         * @brief Push the default (null) value for a particular variable
         * @param var = variable to get the default value for
         * @returns with value pushed on stack
         */
        public void PushVarDefaultValue (TokenDeclVar var)
        {
            PushDefaultValue (var.type);
        }
        public void PushDefaultValue (TokenType type)
        {
            if (type is TokenTypeArray) {
                PushXMRInst ();                // instance
                ilGen.Emit (type, OpCodes.Newobj, xmrArrayConstructorInfo);
                return;
            }
            if (type is TokenTypeChar) {
                ilGen.Emit (type, OpCodes.Ldc_I4_0);
                return;
            }
            if (type is TokenTypeList) {
                ilGen.Emit (type, OpCodes.Ldc_I4_0);
                ilGen.Emit (type, OpCodes.Newarr, typeof (object));
                ilGen.Emit (type, OpCodes.Newobj, lslListConstructorInfo);
                return;
            }
            if (type is TokenTypeRot) {
                // Mono is tOO stOOpid to allow: ilGen.Emit (OpCodes.Ldsfld, zeroRotationFieldInfo);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_ROTATION.x);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_ROTATION.y);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_ROTATION.z);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_ROTATION.s);
                ilGen.Emit (type, OpCodes.Newobj, lslRotationConstructorInfo);
                return;
            }
            if ((type is TokenTypeKey) || (type is TokenTypeStr)) {
                ilGen.Emit (type, OpCodes.Ldstr, "");
                return;
            }
            if (type is TokenTypeVec) {
                // Mono is tOO stOOpid to allow: ilGen.Emit (OpCodes.Ldsfld, zeroVectorFieldInfo);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_VECTOR.x);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_VECTOR.y);
                ilGen.Emit (type, OpCodes.Ldc_R8, ScriptBaseClass.ZERO_VECTOR.z);
                ilGen.Emit (type, OpCodes.Newobj, lslVectorConstructorInfo);
                return;
            }
            if (type is TokenTypeInt) {
                ilGen.Emit (type, OpCodes.Ldc_I4_0);
                return;
            }
            if (type is TokenTypeFloat) {
                ilGen.Emit (type, OpCodes.Ldc_R4, 0.0f);
                return;
            }

            /*
             * Default for 'object' type is 'undef'.
             * Likewise for script-defined classes and interfaces.
             */
            if ((type is TokenTypeObject) || (type is TokenTypeSDTypeClass) || (type is TokenTypeSDTypeInterface) || (type is TokenTypeExc)) {
                ilGen.Emit (type, OpCodes.Ldnull);
                return;
            }

            /*
             * Void is pushed as the default return value of a void function.
             * So just push nothing as expected of void functions.
             */
            if (type is TokenTypeVoid) {
                return;
            }

            /*
             * Default for 'delegate' type is 'undef'.
             */
            if (type is TokenTypeSDTypeDelegate) {
                ilGen.Emit (type, OpCodes.Ldnull);
                return;
            }

            throw new Exception ("unknown type " + type.GetType ().ToString ());
        }

        /**
         * @brief Determine if the expression has a constant boolean value
         *        and if so, if the value is true or false.
         * @param expr = expression to evaluate
         * @returns true: expression is contant and has boolean value true
         *         false: otherwise
         */
        private bool IsConstBoolExprTrue (CompValu expr)
        {
            bool constVal;
            return IsConstBoolExpr (expr, out constVal) && constVal;
        }

        private bool IsConstBoolExpr (CompValu expr, out bool constVal)
        {
            if (expr is CompValuChar) {
                constVal = ((CompValuChar)expr).x != 0;
                return true;
            }
            if (expr is CompValuFloat) {
                constVal = ((CompValuFloat)expr).x != (double)0;
                return true;
            }
            if (expr is CompValuInteger) {
                constVal = ((CompValuInteger)expr).x != 0;
                return true;
            }
            if (expr is CompValuString) {
                string s = ((CompValuString)expr).x;
                constVal = s != "";
                if (constVal && (expr.type is TokenTypeKey)) {
                    constVal = s != ScriptBaseClass.NULL_KEY;
                }
                return true;
            }

            constVal = false;
            return false;
        }

        /**
         * @brief Determine if the expression has a constant integer value
         *        and if so, return the integer value.
         * @param expr = expression to evaluate
         * @returns true: expression is contant and has integer value
         *         false: otherwise
         */
        private bool IsConstIntExpr (CompValu expr, out int constVal)
        {
            if (expr is CompValuChar) {
                constVal = (int)((CompValuChar)expr).x;
                return true;
            }
            if (expr is CompValuInteger) {
                constVal = ((CompValuInteger)expr).x;
                return true;
            }

            constVal = 0;
            return false;
        }

        /**
         * @brief Determine if the expression has a constant string value
         *        and if so, return the string value.
         * @param expr = expression to evaluate
         * @returns true: expression is contant and has string value
         *         false: otherwise
         */
        private bool IsConstStrExpr (CompValu expr, out string constVal)
        {
            if (expr is CompValuString) {
                constVal = ((CompValuString)expr).x;
                return true;
            }
            constVal = "";
            return false;
        }

        /**
         * @brief create table of legal event handler prototypes.
         *        This is used to make sure script's event handler declrations are valid.
         */
        private static VarDict CreateLegalEventHandlers ()
        {
            /*
             * Get handler prototypes with full argument lists.
             */
            VarDict leh = new InternalFuncDict (typeof (IEventHandlers), false);

            /*
             * We want the scripts to be able to declare their handlers with
             * fewer arguments than the full argument lists.  So define additional 
             * prototypes with fewer arguments.
             */
            TokenDeclVar[] fullArgProtos = new TokenDeclVar[leh.Count];
            int i = 0;
            foreach (TokenDeclVar fap in leh) fullArgProtos[i++] = fap;

            foreach (TokenDeclVar fap in fullArgProtos) {
                TokenArgDecl fal = fap.argDecl;
                int fullArgCount = fal.vars.Length;
                for (i = 0; i < fullArgCount; i ++) {
                    TokenArgDecl shortArgList = new TokenArgDecl (null);
                    for (int j = 0; j < i; j ++) {
                        TokenDeclVar var = fal.vars[j];
                        shortArgList.AddArg (var.type, var.name);
                    }
                    TokenDeclVar shortArgProto = new TokenDeclVar (null, null, null);
                    shortArgProto.name         = new TokenName (null, fap.GetSimpleName ());
                    shortArgProto.retType      = fap.retType;
                    shortArgProto.argDecl      = shortArgList;
                    leh.AddEntry (shortArgProto);
                }
            }

            return leh;
        }

        /**
         * @brief Emit a call to CheckRun(), (voluntary multitasking switch)
         */
        public void EmitCallCheckRun (Token errorAt, bool stack)
        {
            if (curDeclFunc.IsFuncTrivial (this)) throw new Exception (curDeclFunc.fullName + " is supposed to be trivial");
            new CallLabel (this, errorAt);                               // jump here when stack restored
            PushXMRInst ();                                              // instance
            ilGen.Emit (errorAt, OpCodes.Call, stack ? checkRunStackMethInfo : checkRunQuickMethInfo);
            openCallLabel = null;
        }

        /**
         * @brief Emit code to push a callNo var on the stack.
         */
        public void GetCallNo (Token errorAt, ScriptMyLocal callNoVar)
        {
            ilGen.Emit (errorAt, OpCodes.Ldloc, callNoVar);
            //ilGen.Emit (errorAt, OpCodes.Ldloca, callNoVar);
            //ilGen.Emit (errorAt, OpCodes.Volatile);
            //ilGen.Emit (errorAt, OpCodes.Ldind_I4);
        }
        public void GetCallNo (Token errorAt, CompValu callNoVar)
        {
            callNoVar.PushVal (this, errorAt);
            //callNoVar.PushRef (this, errorAt);
            //ilGen.Emit (errorAt, OpCodes.Volatile);
            //ilGen.Emit (errorAt, OpCodes.Ldind_I4);
        }

        /**
         * @brief Emit code to set a callNo var to a given constant.
         */
        public void SetCallNo (Token errorAt, ScriptMyLocal callNoVar, int val)
        {
            ilGen.Emit (errorAt, OpCodes.Ldc_I4, val);
            ilGen.Emit (errorAt, OpCodes.Stloc, callNoVar);
            //ilGen.Emit (errorAt, OpCodes.Ldloca, callNoVar);
            //ilGen.Emit (errorAt, OpCodes.Ldc_I4, val);
            //ilGen.Emit (errorAt, OpCodes.Volatile);
            //ilGen.Emit (errorAt, OpCodes.Stind_I4);
        }
        public void SetCallNo (Token errorAt, CompValu callNoVar, int val)
        {
            callNoVar.PopPre (this, errorAt);
            ilGen.Emit (errorAt, OpCodes.Ldc_I4, val);
            callNoVar.PopPost (this, errorAt);
            //callNoVar.PushRef (this, errorAt);
            //ilGen.Emit (errorAt, OpCodes.Ldc_I4, val);
            //ilGen.Emit (errorAt, OpCodes.Volatile);
            //ilGen.Emit (errorAt, OpCodes.Stind_I4);
        }

        /**
         * @brief handle a unary operator, such as -x.
         */
        private CompValu UnOpGenerate (CompValu inRVal, Token opcode)
        {
            /*
             * - Negate
             */
            if (opcode is TokenKwSub) {
                if (inRVal.type is TokenTypeFloat) {
                    CompValuTemp outRVal = new CompValuTemp (new TokenTypeFloat (opcode), this);
                    inRVal.PushVal (this, opcode, outRVal.type);  // push value to negate, make sure not LSL-boxed
                    ilGen.Emit (opcode, OpCodes.Neg);     // compute the negative
                    outRVal.Pop (this, opcode);           // pop into result
                    return outRVal;                       // tell caller where we put it
                }
                if (inRVal.type is TokenTypeInt) {
                    CompValuTemp outRVal = new CompValuTemp (new TokenTypeInt (opcode), this);
                    inRVal.PushVal (this, opcode, outRVal.type);  // push value to negate, make sure not LSL-boxed
                    ilGen.Emit (opcode, OpCodes.Neg);     // compute the negative
                    outRVal.Pop (this, opcode);           // pop into result
                    return outRVal;                       // tell caller where we put it
                }
                if (inRVal.type is TokenTypeRot) {
                    CompValuTemp outRVal = new CompValuTemp (inRVal.type, this);
                    inRVal.PushVal (this, opcode);        // push rotation, then call negate routine
                    ilGen.Emit (opcode, OpCodes.Call, lslRotationNegateMethodInfo);
                    outRVal.Pop (this, opcode);           // pop into result
                    return outRVal;                       // tell caller where we put it
                }
                if (inRVal.type is TokenTypeVec) {
                    CompValuTemp outRVal = new CompValuTemp (inRVal.type, this);
                    inRVal.PushVal (this, opcode);        // push vector, then call negate routine
                    ilGen.Emit (opcode, OpCodes.Call, lslVectorNegateMethodInfo);
                    outRVal.Pop (this, opcode);           // pop into result
                    return outRVal;                       // tell caller where we put it
                }
                ErrorMsg (opcode, "can't negate a " + inRVal.type.ToString ());
                return inRVal;
            }

            /*
             * ~ Complement (bitwise integer)
             */
            if (opcode is TokenKwTilde) {
                if (inRVal.type is TokenTypeInt) {
                    CompValuTemp outRVal = new CompValuTemp (new TokenTypeInt (opcode), this);
                    inRVal.PushVal (this, opcode, outRVal.type);  // push value to negate, make sure not LSL-boxed
                    ilGen.Emit (opcode, OpCodes.Not);     // compute the complement
                    outRVal.Pop (this, opcode);           // pop into result
                    return outRVal;                       // tell caller where we put it
                }
                ErrorMsg (opcode, "can't complement a " + inRVal.type.ToString ());
                return inRVal;
            }

            /*
             * ! Not (boolean)
             *
             * We stuff the 0/1 result in an int because I've seen x+!y in scripts
             * and we don't want to have to create tables to handle int+bool and
             * everything like that.
             */
            if (opcode is TokenKwExclam) {
                CompValuTemp outRVal = new CompValuTemp (new TokenTypeInt (opcode), this);
                inRVal.PushVal (this, opcode, tokenTypeBool);  // anything converts to boolean
                ilGen.Emit (opcode, OpCodes.Ldc_I4_1);         // then XOR with 1 to flip it
                ilGen.Emit (opcode, OpCodes.Xor);
                outRVal.Pop (this, opcode);                    // pop into result
                return outRVal;                                // tell caller where we put it
            }

            throw new Exception ("unhandled opcode " + opcode.ToString ());
        }

        /**
         * @brief This is called while trying to compute the value of constant initializers.
         *        It is passed a name and that name is looked up in the constant tables.
         */
        private TokenRVal LookupInitConstants (TokenRVal rVal, ref bool didOne)
        {
            /*
             * If it is a static field of a script-defined type, look it up and hopefully we find a constant there.
             */
            TokenDeclVar gblVar;
            if (rVal is TokenLValSField) {
                TokenLValSField lvsf = (TokenLValSField)rVal;
                if (lvsf.baseType is TokenTypeSDTypeClass) {
                    TokenDeclSDTypeClass sdtClass = ((TokenTypeSDTypeClass)lvsf.baseType).decl;
                    gblVar = sdtClass.members.FindExact (lvsf.fieldName.val, null);
                    if (gblVar != null) {
                        if (gblVar.constant && (gblVar.init is TokenRValConst)) {
                            didOne = true;
                            return gblVar.init;
                        }
                    }
                }
                return rVal;
            }

            /*
             * Only other thing we handle is stand-alone names.
             */
            if (!(rVal is TokenLValName)) return rVal;
            string name = ((TokenLValName)rVal).name.val;

            /*
             * If we are doing the initializations for a script-defined type,
             * look for the constant among the fields for that type.
             */
            if (currentSDTClass != null) {
                gblVar = currentSDTClass.members.FindExact (name, null);
                if (gblVar != null) {
                    if (gblVar.constant && (gblVar.init is TokenRValConst)) {
                        didOne = true;
                        return gblVar.init;
                    }
                    return rVal;
                }
            }

            /*
             * Look it up as a script-defined global variable.
             * Then if the variable is defined as a constant and has a constant value,
             * we are successful.  If it is defined as something else, return failure.
             */
            gblVar = tokenScript.variablesStack.FindExact (name, null);
            if (gblVar != null) {
                if (gblVar.constant && (gblVar.init is TokenRValConst)) {
                    didOne = true;
                    return gblVar.init;
                }
                return rVal;
            }

            /*
             * Maybe it is a built-in symbolic constant.
             */
            ScriptConst scriptConst = ScriptConst.Lookup (name);
            if (scriptConst != null) {
                rVal = CompValuConst2RValConst (scriptConst.rVal, rVal);
                if (rVal is TokenRValConst) {
                    didOne = true;
                    return rVal;
                }
            }

            /*
             * Don't know what it is, return failure.
             */
            return rVal;
        }

        /**
         * @brief This is called while trying to compute the value of constant expressions.
         *        It is passed a name and that name is looked up in the constant tables.
         */
        private TokenRVal LookupBodyConstants (TokenRVal rVal, ref bool didOne)
        {
            /*
             * If it is a static field of a script-defined type, look it up and hopefully we find a constant there.
             */
            TokenDeclVar gblVar;
            if (rVal is TokenLValSField) {
                TokenLValSField lvsf = (TokenLValSField)rVal;
                if (lvsf.baseType is TokenTypeSDTypeClass) {
                    TokenDeclSDTypeClass sdtClass = ((TokenTypeSDTypeClass)lvsf.baseType).decl;
                    gblVar = sdtClass.members.FindExact (lvsf.fieldName.val, null);
                    if ((gblVar != null) && gblVar.constant && (gblVar.init is TokenRValConst)) {
                        didOne = true;
                        return gblVar.init;
                    }
                }
                return rVal;
            }

            /*
             * Only other thing we handle is stand-alone names.
             */
            if (!(rVal is TokenLValName)) return rVal;
            string name = ((TokenLValName)rVal).name.val;

            /*
             * Scan through the variable stack and hopefully we find a constant there.
             * But we stop as soon as we get a match because that's what the script is referring to.
             */
            CompValu val;
            for (VarDict vars = ((TokenLValName)rVal).stack; vars != null; vars = vars.outerVarDict) {
                TokenDeclVar var = vars.FindExact (name, null);
                if (var != null) {
                    val = var.location;
                    goto foundit;
                }

                TokenDeclSDTypeClass baseClass = vars.thisClass;
                if (baseClass != null) {
                    while ((baseClass = baseClass.extends) != null) {
                        var = baseClass.members.FindExact (name, null);
                        if (var != null) {
                            val = var.location;
                            goto foundit;
                        }
                    }
                }
            }

            /*
             * Maybe it is a built-in symbolic constant.
             */
            ScriptConst scriptConst = ScriptConst.Lookup (name);
            if (scriptConst != null) {
                val = scriptConst.rVal;
                goto foundit;
            }

            /*
             * Don't know what it is, return failure.
             */
            return rVal;

            /*
             * Found a CompValu.  If it's a simple constant, then use it.
             * Otherwise tell caller we failed to simplify.
             */
        foundit:
            rVal = CompValuConst2RValConst (val, rVal);
            if (rVal is TokenRValConst) {
                didOne = true;
            }
            return rVal;
        }

        private static TokenRVal CompValuConst2RValConst (CompValu val, TokenRVal rVal)
        {
            if (val is CompValuChar)    rVal = new TokenRValConst (rVal, ((CompValuChar)val).x);
            if (val is CompValuFloat)   rVal = new TokenRValConst (rVal, ((CompValuFloat)val).x);
            if (val is CompValuInteger) rVal = new TokenRValConst (rVal, ((CompValuInteger)val).x);
            if (val is CompValuString)  rVal = new TokenRValConst (rVal, ((CompValuString)val).x);
            return rVal;
        }

        /**
         * @brief Generate code to push XMRInstanceSuperType pointer on stack.
         */
        public void PushXMRInst ()
        {
            if (instancePointer == null) {
                ilGen.Emit (null, OpCodes.Ldarg_0);
            } else {
                ilGen.Emit (null, OpCodes.Ldloc, instancePointer);
            }
        }

        /**
         * @returns true: Ldarg_0 gives XMRSDTypeClObj pointer
         *                - this is the case for instance methods
         *         false: Ldarg_0 gives XMR_Instance pointer
         *                - this is the case for both global functions and static methods
         */
        public bool IsSDTInstMethod ()
        {
            return (curDeclFunc.sdtClass != null) && 
                   ((curDeclFunc.sdtFlags & ScriptReduce.SDT_STATIC) == 0);
        }

        /**
         * @brief Look for a simply named function or variable (not a field or method)
         */
        public TokenDeclVar FindNamedVar (TokenLValName lValName, TokenType[] argsig)
        {
            /*
             * Look in variable stack for the given name.
             */
            for (VarDict vars = lValName.stack; vars != null; vars = vars.outerVarDict) {

                // first look for it possibly with an argument signature
                // so we pick the correct overloaded method
                TokenDeclVar var = FindSingleMember (vars, lValName.name, argsig);
                if (var != null) return var;

                // if that fails, try it without the argument signature.
                // delegates get entered like any other variable, ie, 
                // no signature on their name.
                if (argsig != null) {
                    var = FindSingleMember (vars, lValName.name, null);
                    if (var != null) return var;
                }

                // if this is the frame for some class members, try searching base class members too
                TokenDeclSDTypeClass baseClass = vars.thisClass;
                if (baseClass != null) {
                    while ((baseClass = baseClass.extends) != null) {
                        var = FindSingleMember (baseClass.members, lValName.name, argsig);
                        if (var != null) return var;
                        if (argsig != null) {
                            var = FindSingleMember (baseClass.members, lValName.name, null);
                            if (var != null) return var;
                        }
                    }
                }
            }

            /*
             * If not found, try one of the built-in constants or functions.
             */
            if (argsig == null) {
                ScriptConst scriptConst = ScriptConst.Lookup (lValName.name.val);
                if (scriptConst != null) {
                    TokenDeclVar var = new TokenDeclVar (lValName.name, null, tokenScript);
                    var.name     = lValName.name;
                    var.type     = scriptConst.rVal.type;
                    var.location = scriptConst.rVal;
                    return var;
                }
            } else {
                TokenDeclVar inline = FindSingleMember (TokenDeclInline.inlineFunctions, lValName.name, argsig);
                if (inline != null) return inline;
            }

            return null;
        }


        /**
         * @brief Find a member of an interface.
         * @param sdType = interface type
         * @param name = name of member to find
         * @param argsig = null: field/property; else: script-visible method argument types
         * @param baseRVal = pointer to interface object
         * @returns null: no such member
         *          else: pointer to member
         *                baseRVal = possibly modified to point to type-casted interface object
         */
        private TokenDeclVar FindInterfaceMember (TokenTypeSDTypeInterface sdtType, TokenName name, TokenType[] argsig, ref CompValu baseRVal)
        {
            TokenDeclSDTypeInterface sdtDecl = sdtType.decl;
            TokenDeclSDTypeInterface impl;
            TokenDeclVar declVar = sdtDecl.FindIFaceMember (this, name, argsig, out impl);
            if ((declVar != null) && (impl != sdtDecl)) {

                /*
                 * Accessing a method or propterty of another interface that the primary interface says it implements.
                 * In this case, we have to cast from the primary interface to that secondary interface.
                 *
                 * interface IEnumerable {
                 *     IEnumerator GetEnumerator ();
                 * }
                 * interface ICountable : IEnumerable {
                 *     integer GetCount ();
                 * }
                 * class List : ICountable {
                 *     public GetCount () : ICountable { ... }
                 *     public GetEnumerator () : IEnumerable { ... }
                 * }
                 *
                 *     ICountable aList = new List ();
                 *     IEnumerator anEnumer = aList.GetEnumerator ();   << we are here
                 *                                                      << baseRVal = aList
                 *                                                      << sdtDecl = ICountable
                 *                                                      << impl = IEnumerable
                 *                                                      << name = GetEnumerator
                 *                                                      << argsig = ()
                 * So we have to cast aList from ICountable to IEnumerable.
                 */

                // make type token for the secondary interface type
                TokenType subIntfType = impl.MakeRefToken (name);

                // make a temp variable of the secondary interface type
                CompValuTemp castBase = new CompValuTemp (subIntfType, this);

                // output code to cast from the primary interface to the secondary interface
                // this is 2 basic steps:
                // 1) cast from primary interface object -> class object
                //    ...gets it from interfaceObject.delegateArray[0].Target
                // 2) cast from class object -> secondary interface object
                //    ...gets it from classObject.sdtcITable[interfaceIndex]
                baseRVal.PushVal (this, name, subIntfType);

                // save result of casting in temp
                castBase.Pop (this, name);

                // return temp reference
                baseRVal = castBase;
            }

            return declVar;
        }

        /**
         * @brief Find a member of a script-defined type class.
         * @param sdtType = reference to class declaration
         * @param name = name of member to find
         * @param argsig = argument signature used to select among overloaded members
         * @returns null: no such member found
         *          else: the member found
         */
        public TokenDeclVar FindThisMember (TokenTypeSDTypeClass sdtType, TokenName name, TokenType[] argsig)
        {
            return FindThisMember (sdtType.decl, name, argsig);
        }
        public TokenDeclVar FindThisMember (TokenDeclSDTypeClass sdtDecl, TokenName name, TokenType[] argsig)
        {
            for (TokenDeclSDTypeClass sdtd = sdtDecl; sdtd != null; sdtd = sdtd.extends) {
                TokenDeclVar declVar = FindSingleMember (sdtd.members, name, argsig);
                if (declVar != null) return declVar;
            }
            return null;
        }

        /**
         * @brief Look for a single member that matches the given name and argument signature
         * @param where = which dictionary to look in
         * @param name = basic name of the field or method, eg, "Printable"
         * @param argsig = argument types the method is being called with, eg, "(string)"
         *                 or null to find a field
         * @returns null: no member found
         *          else: the member found
         */
        public TokenDeclVar FindSingleMember (VarDict where, TokenName name, TokenType[] argsig)
        {
            TokenDeclVar[] members = where.FindCallables (name.val, argsig);
            if (members == null) return null;
            if (members.Length > 1) {
                ErrorMsg (name, "more than one matching member");
                for (int i = 0; i < members.Length; i ++) {
                    ErrorMsg (members[i], "  " + members[i].argDecl.GetArgSig ());
                }
            }
            return members[0];
        }

        /**
         * @brief Find an exact function name and argument signature match.
         *        Also verify that the return value type is an exact match.
         * @param where = which method dictionary to look in
         * @param name = basic name of the method, eg, "Printable"
         * @param ret = expected return value type
         * @param argsig = argument types the method is being called with, eg, "(string)"
         * @returns null: no exact match found
         *          else: the matching function
         */
        private TokenDeclVar FindExactWithRet (VarDict where, TokenName name, TokenType ret, TokenType[] argsig)
        {
            TokenDeclVar func = where.FindExact (name.val, argsig);
            if ((func != null) && (func.retType.ToString () != ret.ToString ())) {
                ErrorMsg (name, "return type mismatch, have " + func.retType.ToString () + ", expect " + ret.ToString ());
            }
            if (func != null) CheckAccess (func, name);
            return func;
        }

        /**
         * @brief Check the private/protected/public access flags of a member.
         */
        private void CheckAccess (TokenDeclVar var, Token errorAt)
        {
            TokenDeclSDType nested;
            TokenDeclSDType definedBy  = var.sdtClass;
            TokenDeclSDType accessedBy = curDeclFunc.sdtClass;

            /*******************************\
             *  Check member-level access  *
            \*******************************/

            /*
             * Note that if accessedBy is null, ie, accessing from global function (or event handlers),
             * anything tagged as SDT_PRIVATE or SDT_PROTECTED will fail.
             */

            /*
             * Private means accessed by the class that defined the member or accessed by a nested class
             * of the class that defined the member.
             */
            if ((var.sdtFlags & ScriptReduce.SDT_PRIVATE) != 0) {
                for (nested = accessedBy; nested != null; nested = nested.outerSDType) {
                    if (nested == definedBy) goto acc1ok;
                }
                ErrorMsg (errorAt, "private member " + var.fullName + " cannot be accessed by " + curDeclFunc.fullName);
                return;
            }

            /*
             * Protected means:
             *   If being accessed by an inner class, the inner class has access to it if the inner class derives 
             *   from the declaring class.  It also has access to it if an outer class derives from the declaring 
             *   class.
             */
            if ((var.sdtFlags & ScriptReduce.SDT_PROTECTED) != 0) {
                for (nested = accessedBy; nested != null; nested = nested.outerSDType) {
                    for (TokenDeclSDType rootward = nested; rootward != null; rootward = rootward.extends) {
                        if (rootward == definedBy) goto acc1ok;
                    }
                }
                ErrorMsg (errorAt, "protected member " + var.fullName + " cannot be accessed by " + curDeclFunc.fullName);
                return;
            }
        acc1ok:

            /******************************\
             *  Check class-level access  *
            \******************************/

            /*
             * If being accessed by same or inner class than where defined, it is ok.
             *
             *      class DefiningClass {
             *          varBeingAccessed;
             *                         .
             *                         .
             *                         .
             *                  class AccessingClass {
             *                      functionDoingAccess() { }
             *                  }
             *                         .
             *                         .
             *                         .
             *      }
             */
            nested = accessedBy;
            while (true) {
                if (nested == definedBy) return;
                if (nested == null) break;
                nested = (TokenDeclSDTypeClass)nested.outerSDType;
            }

            /*
             * It is being accessed by an outer class than where defined, 
             * check for a 'private' or 'protected' class tag that blocks.
             */
            do {

                /*
                 * If the field's class is defined directly inside the accessing class,
                 * access is allowed regardless of class-level private or protected tags.
                 *
                 *      class AccessingClass {
                 *          functionDoingAccess() { }
                 *          class DefiningClass {
                 *              varBeingAccessed;
                 *          }
                 *      }
                 */
                if (definedBy.outerSDType == accessedBy) return;

                /*
                 * If the field's class is defined two or more levels inside the accessing class, 
                 * access is denied if the defining class is tagged private.
                 *
                 *      class AccessingClass {
                 *          functionDoingAccess() { }
                 *                         .
                 *                         .
                 *                         .
                 *                  class IntermediateClass {
                 *                      private class DefiningClass {
                 *                          varBeingAccessed;
                 *                      }
                 *                  }
                 *                         .
                 *                         .
                 *                         .
                 *      }
                 */
                if ((definedBy.accessLevel & ScriptReduce.SDT_PRIVATE) != 0) {
                    ErrorMsg (errorAt, "member " + var.fullName + " cannot be accessed by " + curDeclFunc.fullName + 
                                       " because of private class " + definedBy.longName.val);
                    return;
                }

                /*
                 * Likewise, if DefiningClass is tagged protected, the AccessingClass must derive from the
                 * IntermediateClass or access is denied.
                 */
                if ((definedBy.accessLevel & ScriptReduce.SDT_PROTECTED) != 0) {
                    for (TokenDeclSDType extends = accessedBy; extends != definedBy.outerSDType; extends = extends.extends) {
                        if (extends == null) {
                            ErrorMsg (errorAt, "member " + var.fullName + " cannot be accessed by " + curDeclFunc.fullName + 
                                               " because of protected class " + definedBy.longName.val);
                            return;
                        }
                    }
                }

                /*
                 * Check next outer level.
                 */
                definedBy = definedBy.outerSDType;
            } while (definedBy != null);
        }

        /**
         * @brief Convert a list of argument types to printable string, eg, "(list,string,float,integer)"
         *        If given a null, return "" indicating it is a field not a method
         */
        public static string ArgSigString (TokenType[] argsig)
        {
            if (argsig == null) return "";
            StringBuilder sb = new StringBuilder ("(");
            for (int i = 0; i < argsig.Length; i ++) {
                if (i > 0) sb.Append (",");
                sb.Append (argsig[i].ToString ());
            }
            sb.Append (")");
            return sb.ToString ();
        }

        /**
         * @brief output error message and remember that we did
         */
        public void ErrorMsg (Token token, string message)
        {
            if ((token == null) || (token.emsg == null)) token = errorMessageToken;
            if (!youveAnError || (token.file != lastErrorFile) || (token.line > lastErrorLine)) {
                token.ErrorMsg (message);
                youveAnError  = true;
                lastErrorFile = token.file;
                lastErrorLine = token.line;
            }
        }

        /**
         * @brief Find a private static method.
         * @param owner = class the method is part of
         * @param name = name of method to find
         * @param args = array of argument types
         * @returns pointer to method
         */
        public static MethodInfo GetStaticMethod (Type owner, string name, Type[] args)
        {
            MethodInfo mi = owner.GetMethod (name, BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic, null, args, null);
            if (mi == null) {
                throw new Exception ("undefined method " + owner.ToString () + "." + name);
            }
            return mi;
        }

        // http://wiki.secondlife.com/wiki/Rotation 'negate a rotation' says just negate .s component
        // but http://wiki.secondlife.com/wiki/LSL_Language_Test (lslangtest1.lsl) says negate all 4 values
        public static LSL_Rotation LSLRotationNegate (LSL_Rotation r) { return new LSL_Rotation (-r.x,-r.y,-r.z,-r.s); }
        public static LSL_Vector   LSLVectorNegate   (LSL_Vector v)   { return -v; }
        public static string       CatchExcToStr     (Exception exc)  { return exc.ToString(); }
        //public static void       ConsoleWrite      (string str)     { Console.Write(str); }

        /**
         * @brief Defines an internal label that is used as a target for 'break' and 'continue' statements.
         */
        private class BreakContTarg {
            public bool used;
            public ScriptMyLabel label;
            public TokenStmtBlock block;

            public BreakContTarg (ScriptCodeGen scg, string name) {
                used  = false;                         // assume it isn't referenced at all
                label = scg.ilGen.DefineLabel (name);  // label that the break/continue jumps to
                block = scg.curStmtBlock;              // { ... } that the break/continue label is in
            }
        }
    }

    /**
     * @brief Marker interface indicates an exception that can't be caught by a script-level try/catch.
     */
    public interface IXMRUncatchable { }

    /**
     * @brief Thrown by a script when it attempts to change to an undefined state.
     * These can be detected at compile time but the moron XEngine compiles
     * such things, so we compile them as runtime errors.
     */
    [SerializableAttribute]
    public class ScriptUndefinedStateException : Exception, ISerializable {
        public string stateName;
        public ScriptUndefinedStateException (string stateName) : base ("undefined state " + stateName) {
            this.stateName = stateName;
        }
        protected ScriptUndefinedStateException (SerializationInfo info, StreamingContext context) : base (info, context)
        { }
    }

    /**
     * @brief Created by a throw statement.
     */
    [SerializableAttribute]
    public class ScriptThrownException : Exception, ISerializable {
        public object thrown;

        /**
         * @brief Called by a throw statement to wrap the object in a unique
         *        tag that capable of capturing a stack trace.  Script can 
         *        unwrap it by calling xmrExceptionThrownValue().
         */
        public static Exception Wrap (object thrown)
        {
            return new ScriptThrownException (thrown);
        }
        private ScriptThrownException (object thrown) : base (thrown.ToString ())
        {
            this.thrown = thrown;
        }

        /**
         * @brief Used by serialization/deserialization.
         */
        protected ScriptThrownException (SerializationInfo info, StreamingContext context) : base (info, context)
        { }
    }

    /**
     * @brief Thrown by a script when it attempts to change to a defined state.
     */
    [SerializableAttribute]
    public class ScriptChangeStateException : Exception, ISerializable, IXMRUncatchable {
        public int newState;
        public ScriptChangeStateException (int newState) {
            this.newState = newState;
        }
        protected ScriptChangeStateException (SerializationInfo info, StreamingContext context) : base (info, context)
        { }
    }

    /**
     * @brief We are restoring to the body of a catch { } so we need to 
     *        wrap the original exception in an outer exception, so the 
     *        system won't try to refill the stack trace.
     *
     *        We don't mark this one serializable as it should never get 
     *        serialized out.  It only lives from the throw to the very 
     *        beginning of the catch handler where it is promptly unwrapped.
     *        No CheckRun() call can possibly intervene.
     */
    public class ScriptRestoreCatchException : Exception {

        // old code uses these
        private object e;
        public ScriptRestoreCatchException (object e) {
            this.e = e;
        }
        public static object Unwrap (object o)
        {
            if (o is IXMRUncatchable) return null;
            if (o is ScriptRestoreCatchException) return ((ScriptRestoreCatchException)o).e;
            return o;
        }

        // new code uses these
        private Exception ee;
        public ScriptRestoreCatchException (Exception ee) {
            this.ee = ee;
        }
        public static Exception Unwrap (Exception oo)
        {
            if (oo is IXMRUncatchable) return null;
            if (oo is ScriptRestoreCatchException) return ((ScriptRestoreCatchException)oo).ee;
            return oo;
        }
    }

    [SerializableAttribute]
    public class ScriptBadCallNoException : Exception {
        public ScriptBadCallNoException (int callNo) : base ("bad callNo " + callNo) { }
        protected ScriptBadCallNoException (SerializationInfo info, StreamingContext context) : base (info, context)
        { }
    }

    public class CVVMismatchException : Exception {
        public int oldcvv;
        public int newcvv;

        public CVVMismatchException (int oldcvv, int newcvv) : base ("object version is " + oldcvv.ToString () + 
                                                             " but accept only " + newcvv.ToString ())
        {
            this.oldcvv = oldcvv;
            this.newcvv = newcvv;
        }
    }
}