#!/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_ value 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 translation from one to the other is avoided. This makes the
# code generator run (infinitesimally) faster and more importantly it makes
# the total library smaller.
#
# 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 = $2
gsub(/:/,"",name)
gsub("\r","",name)
op[name] = -1
for(i=3; i<NF; i++){
if($i=="same" && $(i+1)=="as"){
sym = $(i+2)
sub(/,/,"",sym)
op[name] = tk[sym]
used[op[name]] = 1
sameas[op[name]] = sym
}
if($i=="stack"){
stack[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.
#
stack[0] = 0 # 0..15
stack[1] = 0 # 16..31
stack[2] = 0 # 32..47
stack[3] = 0 # 48..63
stack[4] = 0 # 64..79
stack[5] = 0 # 80..95
stack[6] = 0 # 96..111
stack[7] = 0 # 112..127
stack[8] = 0 # 128..143
stack[9] = 0 # 144..159
for(name in op){
if( stack[name] ){
n = op[name]
j = n%16
i = ((n - j)/16)
stack[i] = stack[i] + (2^j)
}
}
printf "\n"
for(i=0; i<10; i++){
printf "#define STACK_MASK_%d %d\n", i, stack[i]
}
}