#!/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] = 0+$3 } # Scan for "case OP_aaaa:" lines in the vdbe.c file /^case OP_/ { name = $2 sub(/:/,"",name) sub("\r","",name) op[name] = -1 jump[name] = 0 out2_prerelease[name] = 0 in1[name] = 0 in2[name] = 0 in3[name] = 0 out3[name] = 0 for(i=3; i<NF; i++){ if($i=="same" && $(i+1)=="as"){ sym = $(i+2) sub(/,/,"",sym) op[name] = tk[sym] used[op[name]] = 1 sameas[op[name]] = sym } 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=="out3"){ out3[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 */" op["OP_Noop"] = -1; op["OP_Explain"] = -1; 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 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++) bv[i] = 0; for(name in op){ x = op[name] a0 = a1 = a2 = a3 = a4 = a5 = a6 = a7 = 0 # a8 = a9 = a10 = a11 = a12 = a13 = a14 = a15 = 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( out3[name] ) a5 = 32; # bv[x] = a0+a1+a2+a3+a4+a5+a6+a7+a8+a9+a10+a11+a12+a13+a14+a15; bv[x] = 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_OUT3 0x0020 /* 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 "}" }