projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| a1dba6e0 RH |
1 | #ifndef lint |
| 2 | static char sccsid[] = "@(#)yylex.c 1.1 %G%"; | |
| 3 | #endif lint | |
| 4 | ||
| 5 | #define isid(a) ((fastab+COFF)[a]&IB) | |
| 6 | #define IB 1 | |
| 7 | /* #if '\377' < 0 it would be nice if this worked properly!!!!! */ | |
| 8 | #if pdp11 | vax | |
| 9 | #define COFF 128 | |
| 10 | #else | |
| 11 | #define COFF 0 | |
| 12 | #endif | |
| 13 | ||
| 14 | yylex() { | |
| 15 | static int ifdef=0; | |
| 16 | static char *op2[]={"||", "&&" , ">>", "<<", ">=", "<=", "!=", "=="}; | |
| 17 | static int val2[]={OROR, ANDAND, RS, LS, GE, LE, NE, EQ}; | |
| 18 | static char *opc="b\bt\tn\nf\fr\r\\\\"; | |
| 19 | extern char fastab[]; | |
| 20 | extern char *outp,*inp,*newp; extern int flslvl; | |
| 21 | register char savc, *s; char *skipbl(); int val; | |
| 22 | register char **p2; | |
| 23 | struct symtab { | |
| 24 | char *name; | |
| 25 | char *value; | |
| 26 | } *sp, *lookup(); | |
| 27 | ||
| 28 | for (;;) { | |
| 29 | newp=skipbl(newp); | |
| 30 | if (*inp=='\n') return(stop); /* end of #if */ | |
| 31 | savc= *newp; *newp='\0'; | |
| 32 | for (p2=op2+8; --p2>=op2; ) /* check 2-char ops */ | |
| 33 | if (0==strcmp(*p2,inp)) {val=val2[p2-op2]; goto ret;} | |
| 34 | s="+-*/%<>&^|?:!~(),"; /* check 1-char ops */ | |
| 35 | while (*s) if (*s++== *inp) {val= *--s; goto ret;} | |
| 36 | if (*inp<='9' && *inp>='0') {/* a number */ | |
| 37 | if (*inp=='0') yylval= (inp[1]=='x' || inp[1]=='X') ? | |
| 38 | tobinary(inp+2,16) : tobinary(inp+1,8); | |
| 39 | else yylval=tobinary(inp,10); | |
| 40 | val=number; | |
| 41 | } else if (isid(*inp)) { | |
| 42 | if (0==strcmp(inp,"defined")) {ifdef=1; ++flslvl; val=DEFINED;} | |
| 43 | else { | |
| 44 | sp=lookup(inp,-1); if (ifdef!=0) {ifdef=0; --flslvl;} | |
| 45 | yylval= (sp->value==0) ? 0 : 1; | |
| 46 | val=number; | |
| 47 | } | |
| 48 | } else if (*inp=='\'') {/* character constant */ | |
| 49 | val=number; | |
| 50 | if (inp[1]=='\\') {/* escaped */ | |
| 51 | char c; if (newp[-1]=='\'') newp[-1]='\0'; | |
| 52 | s=opc; | |
| 53 | while (*s) if (*s++!=inp[2]) ++s; else {yylval= *s; goto ret;} | |
| 54 | if (inp[2]<='9' && inp[2]>='0') yylval=c=tobinary(inp+2,8); | |
| 55 | else yylval=inp[2]; | |
| 56 | } else yylval=inp[1]; | |
| 57 | } else if (0==strcmp("\\\n",inp)) {*newp=savc; continue;} | |
| 58 | else { | |
| 59 | *newp=savc; pperror("Illegal character %c in preprocessor if", *inp); | |
| 60 | continue; | |
| 61 | } | |
| 62 | ret: | |
| 63 | *newp=savc; outp=inp=newp; return(val); | |
| 64 | } | |
| 65 | } | |
| 66 | ||
| 67 | tobinary(st, b) char *st; { | |
| 68 | int n, c, t; | |
| 69 | char *s; | |
| 70 | n=0; | |
| 71 | s=st; | |
| 72 | while (c = *s++) { | |
| 73 | switch(c) { | |
| 74 | case '0': case '1': case '2': case '3': case '4': | |
| 75 | case '5': case '6': case '7': case '8': case '9': | |
| 76 | t = c-'0'; break; | |
| 77 | case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': | |
| 78 | t = c-'a'; if (b>10) break; | |
| 79 | case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': | |
| 80 | t = c - 'A'; if (b>10) break; | |
| 81 | default: | |
| 82 | t = -1; | |
| 83 | if ( c=='l' || c=='L') if (*s=='\0') break; | |
| 84 | pperror("Illegal number %s", st); | |
| 85 | } | |
| 86 | if (t<0) break; | |
| 87 | n = n*b+t; | |
| 88 | } | |
| 89 | return(n); | |
| 90 | } |