#!/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 # tk[x] holds the numeric value for TK symbol X
}
# Find "/* Opcode: " lines in the vdbe.c file. Each one introduces
# a new opcode. Remember which parameters are used.
/^.. Opcode: / {
currentOp = "OP_" $3
m = 0
for(i=4; i<=NF; i++){
x = $i
if( x=="P1" ) m += 1
if( x=="P2" ) m += 2
if( x=="P3" ) m += 4
if( x=="P4" ) m += 8
if( x=="P5" ) m += 16
}
paramused[currentOp] = m
}
# Find "** Synopsis: " lines that follow Opcode:
/^.. Synopsis: / {
if( currentOp ){
x = $3
for(i=4; i<=NF; i++){
x = x " " $i
}
synopsis[currentOp] = x
}
}
# Scan for "case OP_aaaa:" lines in the vdbe.c file
/^case OP_/ {
name = $2
sub(/:/,"",name)
sub("\r","",name)
op[name] = -1 # op[x] holds the numeric value for OP symbol x
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