17980Srrh #ifndef lint 2*12978Ssam static char sccsid[] = "@(#)yylex.c 1.2 06/10/83"; 37980Srrh #endif lint 47980Srrh 57980Srrh #define isid(a) ((fastab+COFF)[a]&IB) 67980Srrh #define IB 1 77980Srrh /* #if '\377' < 0 it would be nice if this worked properly!!!!! */ 87980Srrh #if pdp11 | vax 97980Srrh #define COFF 128 107980Srrh #else 117980Srrh #define COFF 0 127980Srrh #endif 137980Srrh 147980Srrh yylex() { 157980Srrh static int ifdef=0; 167980Srrh static char *op2[]={"||", "&&" , ">>", "<<", ">=", "<=", "!=", "=="}; 177980Srrh static int val2[]={OROR, ANDAND, RS, LS, GE, LE, NE, EQ}; 187980Srrh static char *opc="b\bt\tn\nf\fr\r\\\\"; 197980Srrh extern char fastab[]; 207980Srrh extern char *outp,*inp,*newp; extern int flslvl; 217980Srrh register char savc, *s; char *skipbl(); int val; 227980Srrh register char **p2; 237980Srrh struct symtab { 247980Srrh char *name; 257980Srrh char *value; 267980Srrh } *sp, *lookup(); 277980Srrh 287980Srrh for (;;) { 29*12978Ssam extern int passcom; /* this crap makes #if's work */ 30*12978Ssam int opt_passcom = passcom; /* even with -C option */ 31*12978Ssam passcom = 0; /* (else comments make syntax errs) */ 327980Srrh newp=skipbl(newp); 33*12978Ssam passcom = opt_passcom; /* nb: lint uses -C so its useful! */ 347980Srrh if (*inp=='\n') return(stop); /* end of #if */ 357980Srrh savc= *newp; *newp='\0'; 367980Srrh for (p2=op2+8; --p2>=op2; ) /* check 2-char ops */ 377980Srrh if (0==strcmp(*p2,inp)) {val=val2[p2-op2]; goto ret;} 387980Srrh s="+-*/%<>&^|?:!~(),"; /* check 1-char ops */ 397980Srrh while (*s) if (*s++== *inp) {val= *--s; goto ret;} 407980Srrh if (*inp<='9' && *inp>='0') {/* a number */ 417980Srrh if (*inp=='0') yylval= (inp[1]=='x' || inp[1]=='X') ? 427980Srrh tobinary(inp+2,16) : tobinary(inp+1,8); 437980Srrh else yylval=tobinary(inp,10); 447980Srrh val=number; 457980Srrh } else if (isid(*inp)) { 467980Srrh if (0==strcmp(inp,"defined")) {ifdef=1; ++flslvl; val=DEFINED;} 477980Srrh else { 487980Srrh sp=lookup(inp,-1); if (ifdef!=0) {ifdef=0; --flslvl;} 497980Srrh yylval= (sp->value==0) ? 0 : 1; 507980Srrh val=number; 517980Srrh } 527980Srrh } else if (*inp=='\'') {/* character constant */ 537980Srrh val=number; 547980Srrh if (inp[1]=='\\') {/* escaped */ 557980Srrh char c; if (newp[-1]=='\'') newp[-1]='\0'; 567980Srrh s=opc; 577980Srrh while (*s) if (*s++!=inp[2]) ++s; else {yylval= *s; goto ret;} 587980Srrh if (inp[2]<='9' && inp[2]>='0') yylval=c=tobinary(inp+2,8); 597980Srrh else yylval=inp[2]; 607980Srrh } else yylval=inp[1]; 617980Srrh } else if (0==strcmp("\\\n",inp)) {*newp=savc; continue;} 627980Srrh else { 637980Srrh *newp=savc; pperror("Illegal character %c in preprocessor if", *inp); 647980Srrh continue; 657980Srrh } 667980Srrh ret: 677980Srrh *newp=savc; outp=inp=newp; return(val); 687980Srrh } 697980Srrh } 707980Srrh 717980Srrh tobinary(st, b) char *st; { 727980Srrh int n, c, t; 737980Srrh char *s; 747980Srrh n=0; 757980Srrh s=st; 767980Srrh while (c = *s++) { 777980Srrh switch(c) { 787980Srrh case '0': case '1': case '2': case '3': case '4': 797980Srrh case '5': case '6': case '7': case '8': case '9': 807980Srrh t = c-'0'; break; 817980Srrh case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': 82*12978Ssam t = c-'a'+10; if (b>10) break; 837980Srrh case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': 84*12978Ssam t = c - 'A'+10; if (b>10) break; 857980Srrh default: 867980Srrh t = -1; 877980Srrh if ( c=='l' || c=='L') if (*s=='\0') break; 887980Srrh pperror("Illegal number %s", st); 897980Srrh } 907980Srrh if (t<0) break; 917980Srrh n = n*b+t; 927980Srrh } 937980Srrh return(n); 947980Srrh } 95