17980Srrh #ifndef lint
2*29876Ssam static char sccsid[] = "@(#)yylex.c 1.4 10/15/86";
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!!!!! */
8*29876Ssam #if pdp11 | vax | mc68000 | tahoe
97980Srrh #define COFF 128
107980Srrh #else
117980Srrh #define COFF 0
127980Srrh #endif
137980Srrh
yylex()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 (;;) {
2912978Ssam extern int passcom; /* this crap makes #if's work */
3012978Ssam int opt_passcom = passcom; /* even with -C option */
3112978Ssam passcom = 0; /* (else comments make syntax errs) */
327980Srrh newp=skipbl(newp);
3312978Ssam 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
tobinary(st,b)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':
8212978Ssam t = c-'a'+10; if (b>10) break;
837980Srrh case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
8412978Ssam 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