4.3BSD - /usr/src/ucb/pascal/src/yylex.c

   1: /*
   2:  * Copyright (c) 1980 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)yylex.c	5.1 (Berkeley) 6/5/85";
   9: #endif not lint
  10: 
  11: #include "whoami.h"
  12: #include "0.h"
  13: #include "tree_ty.h"    /* must be included for yy.h */
  14: #include "yy.h"
  15: 
  16: /*
  17:  * Scanner
  18:  */
  19: int yylacnt;
  20: 
  21: #define YYLASIZ 10
  22: 
  23: struct  yytok Yla[YYLASIZ];
  24: 
  25: unyylex(y)
  26:     struct yytok *y;
  27: {
  28: 
  29:     if (yylacnt == YYLASIZ)
  30:         panic("unyylex");
  31:     copy((char *) &Yla[yylacnt], (char *) y, sizeof Yla[0]);
  32:     yylacnt++;
  33: 
  34: }
  35: 
  36: yylex()
  37: {
  38:     register c;
  39:     register int **ip;
  40:     register char *cp;
  41:     int f;
  42:     char delim;
  43: 
  44:     if (yylacnt != 0) {
  45:         yylacnt--;
  46:         copy((char *) &Y, (char *) &Yla[yylacnt], sizeof Y);
  47:         return (yychar);
  48:     }
  49:     if (c = yysavc)
  50:         yysavc = 0;
  51:     else
  52:         c = readch();
  53: #ifdef PXP
  54:     yytokcnt++;
  55: #endif
  56: 
  57: next:
  58:     /*
  59: 	 * skip white space
  60: 	 */
  61: #ifdef PXP
  62:     yywhcnt = 0;
  63: #endif
  64:     while (c == ' ' || c == '\t') {
  65: #ifdef PXP
  66:         if (c == '\t')
  67:             yywhcnt++;
  68:         yywhcnt++;
  69: #endif
  70:         c = readch();
  71:     }
  72:     yyecol = yycol;
  73:     yyeline = yyline;
  74:     yyefile = filename;
  75:     yyeseqid = yyseqid;
  76:     yyseekp = yylinpt;
  77:     cp = token;
  78:     yylval = yyline;
  79:     switch (c) {
  80:         case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
  81:         case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
  82:         case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
  83:         case 'v': case 'w': case 'x': case 'y': case 'z':
  84:         case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
  85:         case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N':
  86:         case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
  87:         case 'V': case 'W': case 'X': case 'Y': case 'Z':
  88:             do {
  89:                 *cp++ = c;
  90:                 c = readch();
  91:             } while (alph(c) || digit(c));
  92:             *cp = 0;
  93:             if (opt('s'))
  94:                 for (cp = token; *cp; cp++)
  95:                     if (*cp >= 'A' && *cp <= 'Z') {
  96:                         *cp |= ' ';
  97:                     }
  98:             yysavc = c;
  99:             ip = (int **) hash((char *) 0, 1);
 100:             if (*ip < (int *) yykey || *ip >= (int *) lastkey) {
 101:                 yylval = (int) *ip;
 102:                 return (YID);
 103:             }
 104:             yylval = yyline;
 105:             /*
 106: 			 * For keywords
 107: 			 * the lexical token
 108: 			 * is magically retrieved
 109: 			 * from the keyword table.
 110: 			 */
 111:             return ((*ip)[1]);
 112:         case '0': case '1': case '2': case '3': case '4':
 113:         case '5': case '6': case '7': case '8': case '9':
 114:             f = 0;
 115:             do {
 116:                 *cp++ = c;
 117:                 c = readch();
 118:             } while (digit(c));
 119:             if (c == 'b' || c == 'B') {
 120:                 /*
 121: 				 * nonstandard - octal constants
 122: 				 */
 123:                 if (opt('s')) {
 124:                     standard();
 125:                     yerror("Octal constants are non-standard");
 126:                 }
 127:                 *cp = 0;
 128:                 yylval = copystr(token);
 129:                 return (YBINT);
 130:             }
 131:             if (c == '.') {
 132:                 c = readch();
 133:                 if (c == '.') {
 134:                     *cp = 0;
 135:                     yysavc = YDOTDOT;
 136:                     yylval = copystr(token);
 137:                     return (YINT);
 138:                 }
 139: infpnumb:
 140:                 f++;
 141:                 *cp++ = '.';
 142:                 if (!digit(c)) {
 143:                     yyset();
 144:                     recovered();
 145:                     yerror("Digits required after decimal point");
 146:                     *cp++ = '0';
 147:                 } else
 148:                     while (digit(c)) {
 149:                         *cp++ = c;
 150:                         c = readch();
 151:                     }
 152:             }
 153:             if (c == 'e' || c == 'E') {
 154:                 f++;
 155:                 *cp++ = c;
 156:                 if ((c = yysavc) == 0)
 157:                     c = readch();
 158:                 if (c == '+' || c == '-') {
 159:                     *cp++ = c;
 160:                     c = readch();
 161:                 }
 162:                 if (!digit(c)) {
 163:                     yyset();
 164:                     yerror("Digits required in exponent");
 165:                     *cp++ = '0';
 166:                 } else
 167:                     while (digit(c)) {
 168:                         *cp++ = c;
 169:                         c = readch();
 170:                     }
 171:             }
 172:             *cp = 0;
 173:             yysavc = c;
 174:             yylval = copystr(token);
 175:             if (f)
 176:                 return (YNUMB);
 177:             return (YINT);
 178:         case '"':
 179:         case '`':
 180:         case '#':
 181:             if (!any(bufp + 1, c))
 182:                 goto illch;
 183:             if (!dquote) {
 184:                 recovered();
 185:                 dquote++;
 186:                 yerror("Character/string delimiter is '");
 187:             }
 188:         case '\'':
 189:             delim = c;
 190:             do {
 191:                 do {
 192:                     c = readch();
 193:                     if (c == '\n') {
 194:                         yerror("Unmatched %c for string", (char *) delim);
 195:                         if (cp == token)
 196:                             *cp++ = ' ', cp++;
 197:                         break;
 198:                     }
 199:                     *cp++ = c;
 200:                 } while (c != delim);
 201:                 c = readch();
 202:             } while (c == delim);
 203:             *--cp = 0;
 204:             if (cp == token) {
 205:                 yerror("Null string not allowed");
 206:                 *cp++ = ' ';
 207:                 *cp++ = 0;
 208:             }
 209:             yysavc = c;
 210:             yylval = copystr(token);
 211:             return (YSTRING);
 212:         case '.':
 213:             c = readch();
 214:             if (c == '.')
 215:                 return (YDOTDOT);
 216:             if (digit(c)) {
 217:                 recovered();
 218:                 yerror("Digits required before decimal point");
 219:                 *cp++ = '0';
 220:                 goto infpnumb;
 221:             }
 222:             yysavc = c;
 223:             return ('.');
 224:         case '{':
 225:             /*
 226: 			 * { ... } comment
 227: 			 */
 228: #ifdef PXP
 229:             getcm(c);
 230: #endif
 231: #ifdef PI
 232:             c = options();
 233:             while (c != '}') {
 234:                 if (c <= 0)
 235:                     goto nonterm;
 236:                 if (c == '{') {
 237:                     warning();
 238:                     yyset();
 239:                     yerror("{ in a { ... } comment");
 240:                 }
 241:                 c = readch();
 242:             }
 243: #endif
 244:             c = readch();
 245:             goto next;
 246:         case '(':
 247:             if ((c = readch()) == '*') {
 248:                 /*
 249: 				 * (* ... *) comment
 250: 				 */
 251: #ifdef PXP
 252:                 getcm(c);
 253:                 c = readch();
 254:                 goto next;
 255: #endif
 256: #ifdef PI
 257:                 c = options();
 258:                 for (;;) {
 259:                     if (c < 0) {
 260: nonterm:
 261:                         yerror("Comment does not terminate - QUIT");
 262:                         pexit(ERRS);
 263:                     }
 264:                     if (c == '(' && (c = readch()) == '*') {
 265:                         warning();
 266:                         yyset();
 267:                         yerror("(* in a (* ... *) comment");
 268:                     }
 269:                     if (c == '*') {
 270:                         if ((c = readch()) != ')')
 271:                             continue;
 272:                         c = readch();
 273:                         goto next;
 274:                     }
 275:                     c = readch();
 276:                 }
 277: #endif
 278:             }
 279:             yysavc = c;
 280:             c = '(';
 281:         case ';':
 282:         case ',':
 283:         case ':':
 284:         case '=':
 285:         case '*':
 286:         case '+':
 287:         case '/':
 288:         case '-':
 289:         case ')':
 290:         case '[':
 291:         case ']':
 292:         case '<':
 293:         case '>':
 294:         case '^':
 295:             return (c);
 296:         case '~':
 297:         case '|':
 298:         case '&':
 299:             if ( opt('s') ) {
 300:                 yyset();
 301:                 standard();
 302:                 yerror("%c is non-standard", (char *) c);
 303:             }
 304:             return c;
 305:         default:
 306:             switch (c) {
 307:                 case YDOTDOT:
 308:                     return (c);
 309:                 case '\n':
 310:                     c = readch();
 311: #ifdef PXP
 312:                     yytokcnt++;
 313: #endif
 314:                     goto next;
 315:                 case '\f':
 316:                     c = readch();
 317:                     goto next;
 318:             }
 319:             if (c <= 0)
 320:                 return (YEOF);
 321: illch:
 322:             do
 323:                 yysavc = readch();
 324:             while (yysavc == c);
 325:             yylval = c;
 326:             return (YILLCH);
 327:     }
 328: }
 329: 
 330: yyset()
 331: {
 332: 
 333:     yyecol = yycol;
 334:     yyeline = yyline;
 335:     yyefile = filename;
 336:     yyseekp = yylinpt;
 337: }
 338: 
 339: /*
 340:  * Setuflg trims the current
 341:  * input line to at most 72 chars
 342:  * for the u option.
 343:  */
 344: setuflg()
 345: {
 346: 
 347:     if (charbuf[71] != '\n') {
 348:         charbuf[72] = '\n';
 349:         charbuf[73] = 0;
 350:     }
 351: }

Defined functions

Defined variables

Defined macros