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cpp/eval.c
520 строк
10 KB
David Hanson
Fixed the bug that forbid the use of predefined macros in #if and #ifdef.
27 апр 1995, 18:50
27 апр 1995, 18:50
2c28739
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#include <stdlib.h> #include <string.h> #include "cpp.h" #define NSTAK 32 #define SGN 0 #define UNS 1 #define UND 2 #define UNSMARK 0x1000 struct value { long val; int type; }; /* conversion types */ #define RELAT 1 #define ARITH 2 #define LOGIC 3 #define SPCL 4 #define SHIFT 5 #define UNARY 6 /* operator priority, arity, and conversion type, indexed by tokentype */ struct pri { char pri; char arity; char ctype; } priority[] = { { 0, 0, 0 }, /* END */ { 0, 0, 0 }, /* UNCLASS */ { 0, 0, 0 }, /* NAME */ { 0, 0, 0 }, /* NUMBER */ { 0, 0, 0 }, /* STRING */ { 0, 0, 0 }, /* CCON */ { 0, 0, 0 }, /* NL */ { 0, 0, 0 }, /* WS */ { 0, 0, 0 }, /* DSHARP */ { 11, 2, RELAT }, /* EQ */ { 11, 2, RELAT }, /* NEQ */ { 12, 2, RELAT }, /* LEQ */ { 12, 2, RELAT }, /* GEQ */ { 13, 2, SHIFT }, /* LSH */ { 13, 2, SHIFT }, /* RSH */ { 7, 2, LOGIC }, /* LAND */ { 6, 2, LOGIC }, /* LOR */ { 0, 0, 0 }, /* PPLUS */ { 0, 0, 0 }, /* MMINUS */ { 0, 0, 0 }, /* ARROW */ { 0, 0, 0 }, /* SBRA */ { 0, 0, 0 }, /* SKET */ { 3, 0, 0 }, /* LP */ { 3, 0, 0 }, /* RP */ { 0, 0, 0 }, /* DOT */ { 10, 2, ARITH }, /* AND */ { 15, 2, ARITH }, /* STAR */ { 14, 2, ARITH }, /* PLUS */ { 14, 2, ARITH }, /* MINUS */ { 16, 1, UNARY }, /* TILDE */ { 16, 1, UNARY }, /* NOT */ { 15, 2, ARITH }, /* SLASH */ { 15, 2, ARITH }, /* PCT */ { 12, 2, RELAT }, /* LT */ { 12, 2, RELAT }, /* GT */ { 9, 2, ARITH }, /* CIRC */ { 8, 2, ARITH }, /* OR */ { 5, 2, SPCL }, /* QUEST */ { 5, 2, SPCL }, /* COLON */ { 0, 0, 0 }, /* ASGN */ { 4, 2, 0 }, /* COMMA */ { 0, 0, 0 }, /* SHARP */ { 0, 0, 0 }, /* SEMIC */ { 0, 0, 0 }, /* CBRA */ { 0, 0, 0 }, /* CKET */ { 0, 0, 0 }, /* ASPLUS */ { 0, 0, 0 }, /* ASMINUS */ { 0, 0, 0 }, /* ASSTAR */ { 0, 0, 0 }, /* ASSLASH */ { 0, 0, 0 }, /* ASPCT */ { 0, 0, 0 }, /* ASCIRC */ { 0, 0, 0 }, /* ASLSH */ { 0, 0, 0 }, /* ASRSH */ { 0, 0, 0 }, /* ASOR */ { 0, 0, 0 }, /* ASAND */ { 0, 0, 0 }, /* ELLIPS */ { 0, 0, 0 }, /* DSHARP1 */ { 0, 0, 0 }, /* NAME1 */ { 16, 1, UNARY }, /* DEFINED */ { 16, 0, UNARY }, /* UMINUS */ }; int evalop(struct pri); struct value tokval(Token *); struct value vals[NSTAK], *vp; enum toktype ops[NSTAK], *op; /* * Evaluate an #if #elif #ifdef #ifndef line. trp->tp points to the keyword. */ long eval(Tokenrow *trp, int kw) { Token *tp; Nlist *np; int ntok, rand; trp->tp++; if (kw==KIFDEF || kw==KIFNDEF) { if (trp->lp - trp->bp != 4 || trp->tp->type!=NAME) { error(ERROR, "Syntax error in #ifdef/#ifndef"); return 0; } np = lookup(trp->tp, 0); return (kw==KIFDEF) == (np && np->flag&(ISDEFINED|ISMAC)); } ntok = trp->tp - trp->bp; kwdefined->val = KDEFINED; /* activate special meaning of defined */ expandrow(trp, "<if>"); kwdefined->val = NAME; vp = vals; op = ops; *op++ = END; for (rand=0, tp = trp->bp+ntok; tp < trp->lp; tp++) { switch(tp->type) { case WS: case NL: continue; /* nilary */ case NAME: case NAME1: case NUMBER: case CCON: case STRING: if (rand) goto syntax; *vp++ = tokval(tp); rand = 1; continue; /* unary */ case DEFINED: case TILDE: case NOT: if (rand) goto syntax; *op++ = tp->type; continue; /* unary-binary */ case PLUS: case MINUS: case STAR: case AND: if (rand==0) { if (tp->type==MINUS) *op++ = UMINUS; if (tp->type==STAR || tp->type==AND) { error(ERROR, "Illegal operator * or & in #if/#elsif"); return 0; } continue; } /* flow through */ /* plain binary */ case EQ: case NEQ: case LEQ: case GEQ: case LSH: case RSH: case LAND: case LOR: case SLASH: case PCT: case LT: case GT: case CIRC: case OR: case QUEST: case COLON: case COMMA: if (rand==0) goto syntax; if (evalop(priority[tp->type])!=0) return 0; *op++ = tp->type; rand = 0; continue; case LP: if (rand) goto syntax; *op++ = LP; continue; case RP: if (!rand) goto syntax; if (evalop(priority[RP])!=0) return 0; if (op<=ops || op[-1]!=LP) { goto syntax; } op--; continue; default: error(ERROR,"Bad operator (%t) in #if/#elsif", tp); return 0; } } if (rand==0) goto syntax; if (evalop(priority[END])!=0) return 0; if (op!=&ops[1] || vp!=&vals[1]) { error(ERROR, "Botch in #if/#elsif"); return 0; } if (vals[0].type==UND) error(ERROR, "Undefined expression value"); return vals[0].val; syntax: error(ERROR, "Syntax error in #if/#elsif"); return 0; } int evalop(struct pri pri) { struct value v1, v2; long rv1, rv2; int rtype, oper; rv2=0; rtype=0; while (pri.pri < priority[op[-1]].pri) { oper = *--op; if (priority[oper].arity==2) { v2 = *--vp; rv2 = v2.val; } v1 = *--vp; rv1 = v1.val; /*lint -e574 -e644 */ switch (priority[oper].ctype) { case 0: default: error(WARNING, "Syntax error in #if/#endif"); return 1; case ARITH: case RELAT: if (v1.type==UNS || v2.type==UNS) rtype = UNS; else rtype = SGN; if (v1.type==UND || v2.type==UND) rtype = UND; if (priority[oper].ctype==RELAT && rtype==UNS) { oper |= UNSMARK; rtype = SGN; } break; case SHIFT: if (v1.type==UND || v2.type==UND) rtype = UND; else rtype = v1.type; if (rtype==UNS) oper |= UNSMARK; break; case UNARY: rtype = v1.type; break; case LOGIC: case SPCL: break; } switch (oper) { case EQ: case EQ|UNSMARK: rv1 = rv1==rv2; break; case NEQ: case NEQ|UNSMARK: rv1 = rv1!=rv2; break; case LEQ: rv1 = rv1<=rv2; break; case GEQ: rv1 = rv1>=rv2; break; case LT: rv1 = rv1<rv2; break; case GT: rv1 = rv1>rv2; break; case LEQ|UNSMARK: rv1 = (unsigned long)rv1<=rv2; break; case GEQ|UNSMARK: rv1 = (unsigned long)rv1>=rv2; break; case LT|UNSMARK: rv1 = (unsigned long)rv1<rv2; break; case GT|UNSMARK: rv1 = (unsigned long)rv1>rv2; break; case LSH: rv1 <<= rv2; break; case LSH|UNSMARK: rv1 = (unsigned long)rv1<<rv2; break; case RSH: rv1 >>= rv2; break; case RSH|UNSMARK: rv1 = (unsigned long)rv1>>rv2; break; case LAND: rtype = UND; if (v1.type==UND) break; if (rv1!=0) { if (v2.type==UND) break; rv1 = rv2!=0; } else rv1 = 0; rtype = SGN; break; case LOR: rtype = UND; if (v1.type==UND) break; if (rv1==0) { if (v2.type==UND) break; rv1 = rv2!=0; } else rv1 = 1; rtype = SGN; break; case AND: rv1 &= rv2; break; case STAR: rv1 *= rv2; break; case PLUS: rv1 += rv2; break; case MINUS: rv1 -= rv2; break; case UMINUS: if (v1.type==UND) rtype = UND; rv1 = -rv1; break; case OR: rv1 |= rv2; break; case CIRC: rv1 ^= rv2; break; case TILDE: rv1 = ~rv1; break; case NOT: rv1 = !rv1; if (rtype!=UND) rtype = SGN; break; case SLASH: if (rv2==0) { rtype = UND; break; } if (rtype==UNS) rv1 /= (unsigned long)rv2; else rv1 /= rv2; break; case PCT: if (rv2==0) { rtype = UND; break; } if (rtype==UNS) rv1 %= (unsigned long)rv2; else rv1 %= rv2; break; case COLON: if (op[-1] != QUEST) error(ERROR, "Bad ?: in #if/endif"); else { op--; if ((--vp)->val==0) v1 = v2; rtype = v1.type; rv1 = v1.val; } break; case DEFINED: break; default: error(ERROR, "Eval botch (unknown operator)"); return 1; } /*lint +e574 +e644 */ v1.val = rv1; v1.type = rtype; *vp++ = v1; } return 0; } struct value tokval(Token *tp) { struct value v; Nlist *np; int i, base, c; unsigned long n; uchar *p; v.type = SGN; v.val = 0; switch (tp->type) { case NAME: v.val = 0; break; case NAME1: if ((np = lookup(tp, 0)) != NULL && np->flag&(ISDEFINED|ISMAC)) v.val = 1; break; case NUMBER: n = 0; base = 10; p = tp->t; c = p[tp->len]; p[tp->len] = '\0'; if (*p=='0') { base = 8; if (p[1]=='x' || p[1]=='X') { base = 16; p++; } p++; } for (;; p++) { if ((i = digit(*p)) < 0) break; if (i>=base) error(WARNING, "Bad digit in number %t", tp); n *= base; n += i; } if (n>=0x80000000 && base!=10) v.type = UNS; for (; *p; p++) { if (*p=='u' || *p=='U') v.type = UNS; else if (*p=='l' || *p=='L') ; else { error(ERROR, "Bad number %t in #if/#elsif", tp); break; } } v.val = n; tp->t[tp->len] = c; break; case CCON: n = 0; p = tp->t; if (*p=='L') { p += 1; error(WARNING, "Wide char constant value undefined"); } p += 1; if (*p=='\\') { p += 1; if ((i = digit(*p))>=0 && i<=7) { n = i; p += 1; if ((i = digit(*p))>=0 && i<=7) { p += 1; n <<= 3; n += i; if ((i = digit(*p))>=0 && i<=7) { p += 1; n <<= 3; n += i; } } } else if (*p=='x') { p += 1; while ((i = digit(*p))>=0 && i<=15) { p += 1; n <<= 4; n += i; } } else { static char cvcon[] = "b\bf\fn\nr\rt\tv\v''\"\"??\\\\"; for (i=0; i<sizeof(cvcon); i+=2) { if (*p == cvcon[i]) { n = cvcon[i+1]; break; } } p += 1; if (i>=sizeof(cvcon)) error(WARNING, "Undefined escape in character constant"); } } else if (*p=='\'') error(ERROR, "Empty character constant"); else n = *p++; if (*p!='\'') error(WARNING, "Multibyte character constant undefined"); else if (n>127) error(WARNING, "Character constant taken as not signed"); v.val = n; break; case STRING: error(ERROR, "String in #if/#elsif"); break; } return v; } int digit(int i) { if ('0'<=i && i<='9') i -= '0'; else if ('a'<=i && i<='f') i -= 'a'-10; else if ('A'<=i && i<='F') i -= 'A'-10; else i = -1; return i; }