1*7980Srrh #ifndef lint 2*7980Srrh static char sccsid[] = "@(#)yylex.c 1.1 08/30/82"; 3*7980Srrh #endif lint 4*7980Srrh 5*7980Srrh #define isid(a) ((fastab+COFF)[a]&IB) 6*7980Srrh #define IB 1 7*7980Srrh /* #if '\377' < 0 it would be nice if this worked properly!!!!! */ 8*7980Srrh #if pdp11 | vax 9*7980Srrh #define COFF 128 10*7980Srrh #else 11*7980Srrh #define COFF 0 12*7980Srrh #endif 13*7980Srrh 14*7980Srrh yylex() { 15*7980Srrh static int ifdef=0; 16*7980Srrh static char *op2[]={"||", "&&" , ">>", "<<", ">=", "<=", "!=", "=="}; 17*7980Srrh static int val2[]={OROR, ANDAND, RS, LS, GE, LE, NE, EQ}; 18*7980Srrh static char *opc="b\bt\tn\nf\fr\r\\\\"; 19*7980Srrh extern char fastab[]; 20*7980Srrh extern char *outp,*inp,*newp; extern int flslvl; 21*7980Srrh register char savc, *s; char *skipbl(); int val; 22*7980Srrh register char **p2; 23*7980Srrh struct symtab { 24*7980Srrh char *name; 25*7980Srrh char *value; 26*7980Srrh } *sp, *lookup(); 27*7980Srrh 28*7980Srrh for (;;) { 29*7980Srrh newp=skipbl(newp); 30*7980Srrh if (*inp=='\n') return(stop); /* end of #if */ 31*7980Srrh savc= *newp; *newp='\0'; 32*7980Srrh for (p2=op2+8; --p2>=op2; ) /* check 2-char ops */ 33*7980Srrh if (0==strcmp(*p2,inp)) {val=val2[p2-op2]; goto ret;} 34*7980Srrh s="+-*/%<>&^|?:!~(),"; /* check 1-char ops */ 35*7980Srrh while (*s) if (*s++== *inp) {val= *--s; goto ret;} 36*7980Srrh if (*inp<='9' && *inp>='0') {/* a number */ 37*7980Srrh if (*inp=='0') yylval= (inp[1]=='x' || inp[1]=='X') ? 38*7980Srrh tobinary(inp+2,16) : tobinary(inp+1,8); 39*7980Srrh else yylval=tobinary(inp,10); 40*7980Srrh val=number; 41*7980Srrh } else if (isid(*inp)) { 42*7980Srrh if (0==strcmp(inp,"defined")) {ifdef=1; ++flslvl; val=DEFINED;} 43*7980Srrh else { 44*7980Srrh sp=lookup(inp,-1); if (ifdef!=0) {ifdef=0; --flslvl;} 45*7980Srrh yylval= (sp->value==0) ? 0 : 1; 46*7980Srrh val=number; 47*7980Srrh } 48*7980Srrh } else if (*inp=='\'') {/* character constant */ 49*7980Srrh val=number; 50*7980Srrh if (inp[1]=='\\') {/* escaped */ 51*7980Srrh char c; if (newp[-1]=='\'') newp[-1]='\0'; 52*7980Srrh s=opc; 53*7980Srrh while (*s) if (*s++!=inp[2]) ++s; else {yylval= *s; goto ret;} 54*7980Srrh if (inp[2]<='9' && inp[2]>='0') yylval=c=tobinary(inp+2,8); 55*7980Srrh else yylval=inp[2]; 56*7980Srrh } else yylval=inp[1]; 57*7980Srrh } else if (0==strcmp("\\\n",inp)) {*newp=savc; continue;} 58*7980Srrh else { 59*7980Srrh *newp=savc; pperror("Illegal character %c in preprocessor if", *inp); 60*7980Srrh continue; 61*7980Srrh } 62*7980Srrh ret: 63*7980Srrh *newp=savc; outp=inp=newp; return(val); 64*7980Srrh } 65*7980Srrh } 66*7980Srrh 67*7980Srrh tobinary(st, b) char *st; { 68*7980Srrh int n, c, t; 69*7980Srrh char *s; 70*7980Srrh n=0; 71*7980Srrh s=st; 72*7980Srrh while (c = *s++) { 73*7980Srrh switch(c) { 74*7980Srrh case '0': case '1': case '2': case '3': case '4': 75*7980Srrh case '5': case '6': case '7': case '8': case '9': 76*7980Srrh t = c-'0'; break; 77*7980Srrh case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': 78*7980Srrh t = c-'a'; if (b>10) break; 79*7980Srrh case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': 80*7980Srrh t = c - 'A'; if (b>10) break; 81*7980Srrh default: 82*7980Srrh t = -1; 83*7980Srrh if ( c=='l' || c=='L') if (*s=='\0') break; 84*7980Srrh pperror("Illegal number %s", st); 85*7980Srrh } 86*7980Srrh if (t<0) break; 87*7980Srrh n = n*b+t; 88*7980Srrh } 89*7980Srrh return(n); 90*7980Srrh } 91