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Diffstat (limited to 'third_party/sqlite/src/mkopcodeh.awk')
| -rwxr-xr-x | third_party/sqlite/src/mkopcodeh.awk | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/third_party/sqlite/src/mkopcodeh.awk b/third_party/sqlite/src/mkopcodeh.awk new file mode 100755 index 0000000..796a7af --- /dev/null +++ b/third_party/sqlite/src/mkopcodeh.awk @@ -0,0 +1,157 @@ +#!/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 "}" +} |