From e36d23a85ebff914d74bb541558c2b6082b78edb Mon Sep 17 00:00:00 2001
From: dan miller
Date: Sat, 20 Oct 2007 02:49:29 +0000
Subject: sqlite source (unix build) added to libraries

---
 libraries/sqlite/unix/sqlite-3.5.1/mkopcodeh.awk | 127 +++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 libraries/sqlite/unix/sqlite-3.5.1/mkopcodeh.awk

(limited to 'libraries/sqlite/unix/sqlite-3.5.1/mkopcodeh.awk')

diff --git a/libraries/sqlite/unix/sqlite-3.5.1/mkopcodeh.awk b/libraries/sqlite/unix/sqlite-3.5.1/mkopcodeh.awk
new file mode 100644
index 0000000..c0874b1
--- /dev/null
+++ b/libraries/sqlite/unix/sqlite-3.5.1/mkopcodeh.awk
@@ -0,0 +1,127 @@
+#!/usr/bin/awk -f
+#
+# Generate the file opcodes.h.
+#
+# This AWK script scans a concatenation of the parse.h output file from the
+# parser and the vdbe.c source file in order to generate the opcodes numbers
+# for all opcodes.  
+#
+# The lines of the vdbe.c that we are interested in are of the form:
+#
+#       case OP_aaaa:      /* same as TK_bbbbb */
+#
+# The TK_ comment is optional.  If it is present, then the value assigned to
+# the OP_ is the same as the TK_ value.  If missing, the OP_ value is assigned
+# a small integer that is different from every other OP_ value.
+#
+# We go to the trouble of making some OP_ values the same as TK_ values
+# as an optimization.  During parsing, things like expression operators
+# are coded with TK_ values such as TK_ADD, TK_DIVIDE, and so forth.  Later
+# during code generation, we need to generate corresponding opcodes like
+# OP_Add and OP_Divide.  By making TK_ADD==OP_Add and TK_DIVIDE==OP_Divide,
+# code to translate from one to the other is avoided.  This makes the
+# code generator run (infinitesimally) faster and more importantly it makes
+# the library footprint smaller.
+#
+# This script also scans for lines of the form:
+#
+#       case OP_aaaa:       /* no-push */
+#
+# When the no-push comment is found on an opcode, it means that that
+# opcode does not leave a result on the stack.  By identifying which
+# opcodes leave results on the stack it is possible to determine a
+# much smaller upper bound on the size of the stack.  This allows
+# a smaller stack to be allocated, which is important to embedded
+# systems with limited memory space.  This script generates a series
+# of "NOPUSH_MASK" defines that contain bitmaps of opcodes that leave
+# results on the stack.  The NOPUSH_MASK defines are used in vdbeaux.c
+# to help determine the maximum stack size.
+#
+
+
+# Remember the TK_ values from the parse.h file
+/^#define TK_/ {
+  tk[$2] = $3
+}
+
+# Scan for "case OP_aaaa:" lines in the vdbe.c file
+/^case OP_/ {
+  name = $2
+  sub(/:/,"",name)
+  sub("\r","",name)
+  op[name] = -1
+  for(i=3; i<NF; i++){
+    if($i=="same" && $(i+1)=="as"){
+      sym = $(i+2)
+      sub(/,/,"",sym)
+      op[name] = tk[sym]
+      used[op[name]] = 1
+      sameas[op[name]] = sym
+    }
+    if($i=="no-push"){
+      nopush[name] = 1
+    }
+  }
+}
+
+# Assign numbers to all opcodes and output the result.
+END {
+  cnt = 0
+  max = 0
+  print "/* Automatically generated.  Do not edit */"
+  print "/* See the mkopcodeh.awk script for details */"
+  for(name in op){
+    if( op[name]<0 ){
+      cnt++
+      while( used[cnt] ) cnt++
+      op[name] = cnt
+    }
+    used[op[name]] = 1;
+    if( op[name]>max ) max = op[name]
+    printf "#define %-25s %15d", name, op[name]
+    if( sameas[op[name]] ) {
+      printf "   /* same as %-12s*/", sameas[op[name]]
+    } 
+    printf "\n"
+
+  }
+  seenUnused = 0;
+  for(i=1; i<max; i++){
+    if( !used[i] ){
+      if( !seenUnused ){
+        printf "\n/* The following opcode values are never used */\n"
+        seenUnused = 1
+      }
+      printf "#define %-25s %15d\n", sprintf( "OP_NotUsed_%-3d", i ), i
+    }
+  }
+
+  # Generate the 10 16-bit bitmasks used by function opcodeUsesStack()
+  # in vdbeaux.c. See comments in that function for details.
+  # 
+  nopush[0] = 0              # 0..15
+  nopush[1] = 0              # 16..31
+  nopush[2] = 0              # 32..47
+  nopush[3] = 0              # 48..63
+  nopush[4] = 0              # 64..79
+  nopush[5] = 0              # 80..95
+  nopush[6] = 0              # 96..111
+  nopush[7] = 0              # 112..127
+  nopush[8] = 0              # 128..143
+  nopush[9] = 0              # 144..159
+  for(name in op){
+    if( nopush[name] ){
+      n = op[name]
+      j = n%16
+      i = ((n - j)/16)
+      nopush[i] = nopush[i] + (2^j)
+    }
+  }
+  printf "\n"
+  print "/* Opcodes that are guaranteed to never push a value onto the stack"
+  print "** contain a 1 their corresponding position of the following mask"
+  print "** set.  See the opcodeNoPush() function in vdbeaux.c  */"
+  for(i=0; i<10; i++){
+    printf "#define NOPUSH_MASK_%d 0x%04x\n", i, nopush[i]
+  }
+}
-- 
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