#!/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 = $2
sub(/:/,"",name)
sub("\r","",name)
op[name] = -1 # op[x] holds the numeric value for OP symbol x
jump[name] = 0
out2_prerelease[name] = 0
in1[name] = 0
in2[name] = 0
in3[name] = 0
out2[name] = 0
out3[name] = 0
for(i=3; i<NF; i++){
if($i=="same" && $(i+1)=="as"){
sym = $(i+2)
sub(/,/,"",sym)
val = tk[sym]
op[name] = val
used[val] = 1
sameas[val] = sym
def[val] = name
}
x = $i
sub(",","",x)
if(x=="jump"){
jump[name] = 1
}else if(x=="out2-prerelease"){
out2_prerelease[name] = 1
}else if(x=="in1"){
in1[name] = 1
}else if(x=="in2"){
in2[name] = 1
}else if(x=="in3"){
in3[name] = 1
}else if(x=="out2"){
out2[name] = 1
}else if(x=="out3"){
out3[name] = 1
}
}
order[n_op++] = name;
}
# 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 */"
op["OP_Noop"] = -1;
order[n_op++] = "OP_Noop";
op["OP_Explain"] = -1;
order[n_op++] = "OP_Explain";
# Assign small values to opcodes that are processed by resolveP2Values()
# to make code generation for the switch() statement smaller and faster.
for(i=0; i<n_op; i++){
name = order[i];
if( op[name]>=0 ) continue;
if( name=="OP_Function" \
|| name=="OP_AggStep" \
|| name=="OP_Transaction" \
|| name=="OP_AutoCommit" \
|| name=="OP_Savepoint" \
|| name=="OP_Checkpoint" \
|| name=="OP_Vacuum" \
|| name=="OP_JournalMode" \
|| name=="OP_VUpdate" \
|| name=="OP_VFilter" \
|| name=="OP_Next" \
|| name=="OP_SorterNext" \
|| name=="OP_Prev" \
){
cnt++
while( used[cnt] ) cnt++
op[name] = cnt
used[cnt] = 1
def[cnt] = name
}
}
# Generate the numeric values for opcodes
for(i=0; i<n_op; i++){
name = order[i];
if( op[name]<0 ){
cnt++
while( used[cnt] ) cnt++
op[name] = cnt
used[cnt] = 1
def[cnt] = name
}
}
max = cnt
for(i=1; i<=max; i++){
if( !used[i] ){
def[i] = "OP_NotUsed_" i
}
printf "#define %-16s %3d", def[i], i
com = ""
if( sameas[i] ){
com = "same as " sameas[i]
}
x = synopsis[def[i]]
if( x ){
if( com=="" ){
com = "synopsis: " x
} else {
com = com ", synopsis: " x
}
}
if( com!="" ){
printf " /* %-42s */", com
}
printf "\n"
}
# Generate the bitvectors:
#
# bit 0: jump
# bit 1: pushes a result onto stack
# bit 2: output to p1. release p1 before opcode runs
#
for(i=0; i<=max; i++){
name = def[i]
a0 = a1 = a2 = a3 = a4 = a5 = a6 = a7 = 0
if( jump[name] ) a0 = 1;
if( out2_prerelease[name] ) a1 = 2;
if( in1[name] ) a2 = 4;
if( in2[name] ) a3 = 8;
if( in3[name] ) a4 = 16;
if( out2[name] ) a5 = 32;
if( out3[name] ) a6 = 64;
bv[i] = a0+a1+a2+a3+a4+a5+a6+a7;
}
print "\n"
print "/* Properties such as \"out2\" or \"jump\" that are specified in"
print "** comments following the \"case\" for each opcode in the vdbe.c"
print "** are encoded into bitvectors as follows:"
print "*/"
print "#define OPFLG_JUMP 0x0001 /* jump: P2 holds jmp target */"
print "#define OPFLG_OUT2_PRERELEASE 0x0002 /* out2-prerelease: */"
print "#define OPFLG_IN1 0x0004 /* in1: P1 is an input */"
print "#define OPFLG_IN2 0x0008 /* in2: P2 is an input */"
print "#define OPFLG_IN3 0x0010 /* in3: P3 is an input */"
print "#define OPFLG_OUT2 0x0020 /* out2: P2 is an output */"
print "#define OPFLG_OUT3 0x0040 /* out3: P3 is an output */"
print "#define OPFLG_INITIALIZER {\\"
for(i=0; i<=max; i++){
if( i%8==0 ) printf("/* %3d */",i)
printf " 0x%02x,", bv[i]
if( i%8==7 ) printf("\\\n");
}
print "}"
if( 0 ){
print "\n/* Bitmask to indicate which fields (P1..P5) of each opcode are"
print "** actually used.\n*/"
print "#define OP_PARAM_USED_INITIALIZER {\\"
for(i=0; i<=max; i++){
if( i%8==0 ) printf("/* %3d */",i)
printf " 0x%02x,", paramused[def[i]]
if( i%8==7 ) printf("\\\n");
}
print "}"
}
}