#!/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:       /* jump, in1, in2, in3, out2-prerelease, out3 */
#
# When such comments are found on an opcode, it means that certain
# properties apply to that opcode.  Set corresponding flags using the
# OPFLG_INITIALIZER macro.
#


# Remember the TK_ values from the parse.h file
/^#define TK_/ {
  tk[$2] = 0+$3
}

# Scan for "case OP_aaaa:" lines in the vdbe.c file
/^case OP_/ {
  name = $2
  sub(/:/,"",name)
  sub("\r","",name)
  op[name] = -1
  jump[name] = 0
  out2_prerelease[name] = 0
  in1[name] = 0
  in2[name] = 0
  in3[name] = 0
  out2[name] = 0
  out3[name] = 0
  for(i=3; i