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1.5 ! millert 1: /* $OpenBSD: compile.c,v 1.4 1997/11/14 03:59:25 deraadt Exp $ */
1.2 deraadt 2:
1.1 deraadt 3: /*-
4: * Copyright (c) 1992 Diomidis Spinellis.
5: * Copyright (c) 1992, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * This code is derived from software contributed to Berkeley by
9: * Diomidis Spinellis of Imperial College, University of London.
10: *
11: * Redistribution and use in source and binary forms, with or without
12: * modification, are permitted provided that the following conditions
13: * are met:
14: * 1. Redistributions of source code must retain the above copyright
15: * notice, this list of conditions and the following disclaimer.
16: * 2. Redistributions in binary form must reproduce the above copyright
17: * notice, this list of conditions and the following disclaimer in the
18: * documentation and/or other materials provided with the distribution.
19: * 3. All advertising materials mentioning features or use of this software
20: * must display the following acknowledgement:
21: * This product includes software developed by the University of
22: * California, Berkeley and its contributors.
23: * 4. Neither the name of the University nor the names of its contributors
24: * may be used to endorse or promote products derived from this software
25: * without specific prior written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37: * SUCH DAMAGE.
38: */
39:
40: #ifndef lint
41: /* from: static char sccsid[] = "@(#)compile.c 8.1 (Berkeley) 6/6/93"; */
1.5 ! millert 42: static char *rcsid = "$OpenBSD: compile.c,v 1.4 1997/11/14 03:59:25 deraadt Exp $";
1.1 deraadt 43: #endif /* not lint */
44:
45: #include <sys/types.h>
46: #include <sys/stat.h>
47:
48: #include <ctype.h>
49: #include <errno.h>
50: #include <fcntl.h>
51: #include <limits.h>
52: #include <regex.h>
53: #include <stdio.h>
54: #include <stdlib.h>
55: #include <string.h>
56:
57: #include "defs.h"
58: #include "extern.h"
59:
60: #define LHSZ 128
61: #define LHMASK (LHSZ - 1)
62: static struct labhash {
63: struct labhash *lh_next;
64: u_int lh_hash;
65: struct s_command *lh_cmd;
66: int lh_ref;
67: } *labels[LHSZ];
68:
69: static char *compile_addr __P((char *, struct s_addr *));
70: static char *compile_ccl __P((char **, char *));
71: static char *compile_delimited __P((char *, char *));
72: static char *compile_flags __P((char *, struct s_subst *));
73: static char *compile_re __P((char *, regex_t **));
74: static char *compile_subst __P((char *, struct s_subst *));
75: static char *compile_text __P((void));
76: static char *compile_tr __P((char *, char **));
77: static struct s_command
78: **compile_stream __P((struct s_command **));
79: static char *duptoeol __P((char *, char *));
80: static void enterlabel __P((struct s_command *));
81: static struct s_command
82: *findlabel __P((char *));
83: static void fixuplabel __P((struct s_command *, struct s_command *));
84: static void uselabel __P((void));
85:
86: /*
87: * Command specification. This is used to drive the command parser.
88: */
89: struct s_format {
90: char code; /* Command code */
91: int naddr; /* Number of address args */
92: enum e_args args; /* Argument type */
93: };
94:
95: static struct s_format cmd_fmts[] = {
96: {'{', 2, GROUP},
97: {'}', 0, ENDGROUP},
98: {'a', 1, TEXT},
99: {'b', 2, BRANCH},
100: {'c', 2, TEXT},
101: {'d', 2, EMPTY},
102: {'D', 2, EMPTY},
103: {'g', 2, EMPTY},
104: {'G', 2, EMPTY},
105: {'h', 2, EMPTY},
106: {'H', 2, EMPTY},
107: {'i', 1, TEXT},
108: {'l', 2, EMPTY},
109: {'n', 2, EMPTY},
110: {'N', 2, EMPTY},
111: {'p', 2, EMPTY},
112: {'P', 2, EMPTY},
113: {'q', 1, EMPTY},
114: {'r', 1, RFILE},
115: {'s', 2, SUBST},
116: {'t', 2, BRANCH},
117: {'w', 2, WFILE},
118: {'x', 2, EMPTY},
119: {'y', 2, TR},
120: {'!', 2, NONSEL},
121: {':', 0, LABEL},
122: {'#', 0, COMMENT},
123: {'=', 1, EMPTY},
124: {'\0', 0, COMMENT},
125: };
126:
127: /* The compiled program. */
128: struct s_command *prog;
129:
130: /*
131: * Compile the program into prog.
132: * Initialise appends.
133: */
134: void
135: compile()
136: {
137: *compile_stream(&prog) = NULL;
138: fixuplabel(prog, NULL);
139: uselabel();
140: appends = xmalloc(sizeof(struct s_appends) * appendnum);
141: match = xmalloc((maxnsub + 1) * sizeof(regmatch_t));
142: }
143:
144: #define EATSPACE() do { \
145: if (p) \
146: while (*p && isascii(*p) && isspace(*p)) \
147: p++; \
148: } while (0)
149:
150: static struct s_command **
151: compile_stream(link)
152: struct s_command **link;
153: {
154: register char *p;
155: static char lbuf[_POSIX2_LINE_MAX + 1]; /* To save stack */
156: struct s_command *cmd, *cmd2, *stack;
157: struct s_format *fp;
158: int naddr; /* Number of addresses */
159:
160: stack = 0;
161: for (;;) {
162: if ((p = cu_fgets(lbuf, sizeof(lbuf))) == NULL) {
163: if (stack != 0)
164: err(COMPILE, "unexpected EOF (pending }'s)");
165: return (link);
166: }
167:
168: semicolon: EATSPACE();
169: if (p && (*p == '#' || *p == '\0'))
170: continue;
171: *link = cmd = xmalloc(sizeof(struct s_command));
172: link = &cmd->next;
173: cmd->nonsel = cmd->inrange = 0;
174: /* First parse the addresses */
175: naddr = 0;
176:
177: /* Valid characters to start an address */
178: #define addrchar(c) (strchr("0123456789/\\$", (c)))
179: if (addrchar(*p)) {
180: naddr++;
181: cmd->a1 = xmalloc(sizeof(struct s_addr));
182: p = compile_addr(p, cmd->a1);
183: EATSPACE(); /* EXTENSION */
184: if (*p == ',') {
185: p++;
186: EATSPACE(); /* EXTENSION */
187: naddr++;
188: cmd->a2 = xmalloc(sizeof(struct s_addr));
189: p = compile_addr(p, cmd->a2);
190: EATSPACE();
191: } else
192: cmd->a2 = 0;
193: } else
194: cmd->a1 = cmd->a2 = 0;
195:
196: nonsel: /* Now parse the command */
197: if (!*p)
198: err(COMPILE, "command expected");
199: cmd->code = *p;
200: for (fp = cmd_fmts; fp->code; fp++)
201: if (fp->code == *p)
202: break;
203: if (!fp->code)
204: err(COMPILE, "invalid command code %c", *p);
205: if (naddr > fp->naddr)
206: err(COMPILE,
207: "command %c expects up to %d address(es), found %d", *p, fp->naddr, naddr);
208: switch (fp->args) {
209: case NONSEL: /* ! */
210: p++;
211: EATSPACE();
212: cmd->nonsel = ! cmd->nonsel;
213: goto nonsel;
214: case GROUP: /* { */
215: p++;
216: EATSPACE();
217: cmd->next = stack;
218: stack = cmd;
219: link = &cmd->u.c;
220: if (*p)
221: goto semicolon;
222: break;
223: case ENDGROUP:
224: /*
225: * Short-circuit command processing, since end of
226: * group is really just a noop.
227: */
228: cmd->nonsel = 1;
229: if (stack == 0)
230: err(COMPILE, "unexpected }");
231: cmd2 = stack;
232: stack = cmd2->next;
233: cmd2->next = cmd;
234: /*FALLTHROUGH*/
235: case EMPTY: /* d D g G h H l n N p P q x = \0 */
236: p++;
237: EATSPACE();
238: if (*p == ';') {
239: p++;
240: link = &cmd->next;
241: goto semicolon;
242: }
243: if (*p)
244: err(COMPILE,
245: "extra characters at the end of %c command", cmd->code);
246: break;
247: case TEXT: /* a c i */
248: p++;
249: EATSPACE();
250: if (*p != '\\')
251: err(COMPILE,
252: "command %c expects \\ followed by text", cmd->code);
253: p++;
254: EATSPACE();
255: if (*p)
256: err(COMPILE,
257: "extra characters after \\ at the end of %c command", cmd->code);
258: cmd->t = compile_text();
259: break;
260: case COMMENT: /* \0 # */
261: break;
262: case WFILE: /* w */
263: p++;
264: EATSPACE();
265: if (*p == '\0')
266: err(COMPILE, "filename expected");
267: cmd->t = duptoeol(p, "w command");
268: if (aflag)
269: cmd->u.fd = -1;
270: else if ((cmd->u.fd = open(p,
271: O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
272: DEFFILEMODE)) == -1)
273: err(FATAL, "%s: %s\n", p, strerror(errno));
274: break;
275: case RFILE: /* r */
276: p++;
277: EATSPACE();
278: if (*p == '\0')
279: err(COMPILE, "filename expected");
280: else
281: cmd->t = duptoeol(p, "read command");
282: break;
283: case BRANCH: /* b t */
284: p++;
285: EATSPACE();
286: if (*p == '\0')
287: cmd->t = NULL;
288: else
289: cmd->t = duptoeol(p, "branch");
290: break;
291: case LABEL: /* : */
292: p++;
293: EATSPACE();
294: cmd->t = duptoeol(p, "label");
295: if (strlen(p) == 0)
296: err(COMPILE, "empty label");
297: enterlabel(cmd);
298: break;
299: case SUBST: /* s */
300: p++;
301: if (*p == '\0' || *p == '\\')
302: err(COMPILE,
303: "substitute pattern can not be delimited by newline or backslash");
304: cmd->u.s = xmalloc(sizeof(struct s_subst));
305: p = compile_re(p, &cmd->u.s->re);
306: if (p == NULL)
307: err(COMPILE, "unterminated substitute pattern");
308: --p;
309: p = compile_subst(p, cmd->u.s);
310: p = compile_flags(p, cmd->u.s);
311: EATSPACE();
312: if (*p == ';') {
313: p++;
314: link = &cmd->next;
315: goto semicolon;
316: }
317: break;
318: case TR: /* y */
319: p++;
320: p = compile_tr(p, (char **)&cmd->u.y);
321: EATSPACE();
322: if (*p == ';') {
323: p++;
324: link = &cmd->next;
325: goto semicolon;
326: }
327: if (*p)
328: err(COMPILE,
329: "extra text at the end of a transform command");
330: break;
331: }
332: }
333: }
334:
335: /*
336: * Get a delimited string. P points to the delimeter of the string; d points
337: * to a buffer area. Newline and delimiter escapes are processed; other
338: * escapes are ignored.
339: *
340: * Returns a pointer to the first character after the final delimiter or NULL
341: * in the case of a non-terminated string. The character array d is filled
342: * with the processed string.
343: */
344: static char *
345: compile_delimited(p, d)
346: char *p, *d;
347: {
348: char c;
349:
350: c = *p++;
351: if (c == '\0')
352: return (NULL);
353: else if (c == '\\')
354: err(COMPILE, "\\ can not be used as a string delimiter");
355: else if (c == '\n')
356: err(COMPILE, "newline can not be used as a string delimiter");
357: while (*p) {
358: if (*p == '[') {
359: if ((d = compile_ccl(&p, d)) == NULL)
360: err(COMPILE, "unbalanced brackets ([])");
361: continue;
362: } else if (*p == '\\' && p[1] == '[') {
363: *d++ = *p++;
364: } else if (*p == '\\' && p[1] == c)
365: p++;
366: else if (*p == '\\' && p[1] == 'n') {
367: *d++ = '\n';
368: p += 2;
369: continue;
370: } else if (*p == '\\' && p[1] == '\\')
371: *d++ = *p++;
372: else if (*p == c) {
373: *d = '\0';
374: return (p + 1);
375: }
376: *d++ = *p++;
377: }
378: return (NULL);
379: }
380:
381:
382: /* compile_ccl: expand a POSIX character class */
383: static char *
384: compile_ccl(sp, t)
385: char **sp;
386: char *t;
387: {
388: int c, d;
389: char *s = *sp;
390:
391: *t++ = *s++;
392: if (*s == '^')
393: *t++ = *s++;
394: if (*s == ']')
395: *t++ = *s++;
396: for (; *s && (*t = *s) != ']'; s++, t++)
397: if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '=')) {
398: *++t = *++s, t++, s++;
399: for (c = *s; (*t = *s) != ']' || c != d; s++, t++)
400: if ((c = *s) == '\0')
401: return NULL;
402: } else if (*s == '\\' && s[1] == 'n')
403: *t = '\n', s++;
404: return (*s == ']') ? *sp = ++s, ++t : NULL;
405: }
406:
407: /*
408: * Get a regular expression. P points to the delimiter of the regular
409: * expression; repp points to the address of a regexp pointer. Newline
410: * and delimiter escapes are processed; other escapes are ignored.
411: * Returns a pointer to the first character after the final delimiter
412: * or NULL in the case of a non terminated regular expression. The regexp
413: * pointer is set to the compiled regular expression.
414: * Cflags are passed to regcomp.
415: */
416: static char *
417: compile_re(p, repp)
418: char *p;
419: regex_t **repp;
420: {
421: int eval;
422: char re[_POSIX2_LINE_MAX + 1];
423:
424: p = compile_delimited(p, re);
425: if (p && strlen(re) == 0) {
426: *repp = NULL;
427: return (p);
428: }
429: *repp = xmalloc(sizeof(regex_t));
1.5 ! millert 430: if (p && (eval = regcomp(*repp, re, REG_EXTENDED)) != 0)
1.1 deraadt 431: err(COMPILE, "RE error: %s", strregerror(eval, *repp));
432: if (maxnsub < (*repp)->re_nsub)
433: maxnsub = (*repp)->re_nsub;
434: return (p);
435: }
436:
437: /*
438: * Compile the substitution string of a regular expression and set res to
439: * point to a saved copy of it. Nsub is the number of parenthesized regular
440: * expressions.
441: */
442: static char *
443: compile_subst(p, s)
444: char *p;
445: struct s_subst *s;
446: {
447: static char lbuf[_POSIX2_LINE_MAX + 1];
448: int asize, ref, size;
449: char c, *text, *op, *sp;
450:
451: c = *p++; /* Terminator character */
452: if (c == '\0')
453: return (NULL);
454:
455: s->maxbref = 0;
456: s->linenum = linenum;
457: asize = 2 * _POSIX2_LINE_MAX + 1;
458: text = xmalloc(asize);
459: size = 0;
460: do {
461: op = sp = text + size;
462: for (; *p; p++) {
463: if (*p == '\\') {
464: p++;
465: if (strchr("123456789", *p) != NULL) {
466: *sp++ = '\\';
467: ref = *p - '0';
468: if (s->re != NULL &&
469: ref > s->re->re_nsub)
470: err(COMPILE,
471: "\\%c not defined in the RE", *p);
472: if (s->maxbref < ref)
473: s->maxbref = ref;
474: } else if (*p == '&' || *p == '\\')
475: *sp++ = '\\';
476: } else if (*p == c) {
477: p++;
478: *sp++ = '\0';
479: size += sp - op;
480: s->new = xrealloc(text, size);
481: return (p);
482: } else if (*p == '\n') {
483: err(COMPILE,
484: "unescaped newline inside substitute pattern");
485: /* NOTREACHED */
486: }
487: *sp++ = *p;
488: }
489: size += sp - op;
490: if (asize - size < _POSIX2_LINE_MAX + 1) {
491: asize *= 2;
492: text = xmalloc(asize);
493: }
494: } while (cu_fgets(p = lbuf, sizeof(lbuf)));
495: err(COMPILE, "unterminated substitute in regular expression");
496: /* NOTREACHED */
497: }
498:
499: /*
500: * Compile the flags of the s command
501: */
502: static char *
503: compile_flags(p, s)
504: char *p;
505: struct s_subst *s;
506: {
507: int gn; /* True if we have seen g or n */
508: char wfile[_POSIX2_LINE_MAX + 1], *q;
509:
510: s->n = 1; /* Default */
511: s->p = 0;
512: s->wfile = NULL;
513: s->wfd = -1;
514: for (gn = 0;;) {
515: EATSPACE(); /* EXTENSION */
516: switch (*p) {
517: case 'g':
518: if (gn)
519: err(COMPILE,
520: "more than one number or 'g' in substitute flags");
521: gn = 1;
522: s->n = 0;
523: break;
524: case '\0':
525: case '\n':
526: case ';':
527: return (p);
528: case 'p':
529: s->p = 1;
530: break;
531: case '1': case '2': case '3':
532: case '4': case '5': case '6':
533: case '7': case '8': case '9':
534: if (gn)
535: err(COMPILE,
536: "more than one number or 'g' in substitute flags");
537: gn = 1;
538: /* XXX Check for overflow */
539: s->n = (int)strtol(p, &p, 10);
540: break;
541: case 'w':
542: p++;
543: #ifdef HISTORIC_PRACTICE
544: if (*p != ' ') {
545: err(WARNING, "space missing before w wfile");
546: return (p);
547: }
548: #endif
549: EATSPACE();
550: q = wfile;
551: while (*p) {
552: if (*p == '\n')
553: break;
554: *q++ = *p++;
555: }
556: *q = '\0';
557: if (q == wfile)
558: err(COMPILE, "no wfile specified");
559: s->wfile = strdup(wfile);
560: if (!aflag && (s->wfd = open(wfile,
561: O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
562: DEFFILEMODE)) == -1)
563: err(FATAL, "%s: %s\n", wfile, strerror(errno));
564: return (p);
565: default:
566: err(COMPILE,
567: "bad flag in substitute command: '%c'", *p);
568: break;
569: }
570: p++;
571: }
572: }
573:
574: /*
575: * Compile a translation set of strings into a lookup table.
576: */
577: static char *
578: compile_tr(p, transtab)
579: char *p;
580: char **transtab;
581: {
582: int i;
583: char *lt, *op, *np;
584: char old[_POSIX2_LINE_MAX + 1];
585: char new[_POSIX2_LINE_MAX + 1];
586:
587: if (*p == '\0' || *p == '\\')
588: err(COMPILE,
589: "transform pattern can not be delimited by newline or backslash");
590: p = compile_delimited(p, old);
591: if (p == NULL) {
592: err(COMPILE, "unterminated transform source string");
593: return (NULL);
594: }
595: p = compile_delimited(--p, new);
596: if (p == NULL) {
597: err(COMPILE, "unterminated transform target string");
598: return (NULL);
599: }
600: EATSPACE();
601: if (strlen(new) != strlen(old)) {
602: err(COMPILE, "transform strings are not the same length");
603: return (NULL);
604: }
605: /* We assume characters are 8 bits */
606: lt = xmalloc(UCHAR_MAX);
607: for (i = 0; i <= UCHAR_MAX; i++)
608: lt[i] = (char)i;
609: for (op = old, np = new; *op; op++, np++)
610: lt[(u_char)*op] = *np;
611: *transtab = lt;
612: return (p);
613: }
614:
615: /*
616: * Compile the text following an a or i command.
617: */
618: static char *
619: compile_text()
620: {
1.4 deraadt 621: int asize, esc_nl, size;
1.1 deraadt 622: char *text, *p, *op, *s;
623: char lbuf[_POSIX2_LINE_MAX + 1];
624:
625: asize = 2 * _POSIX2_LINE_MAX + 1;
626: text = xmalloc(asize);
627: size = 0;
628: while (cu_fgets(lbuf, sizeof(lbuf))) {
629: op = s = text + size;
630: p = lbuf;
631: EATSPACE();
1.4 deraadt 632: for (esc_nl = 0; *p != '\0'; p++) {
633: if (*p == '\\' && p[1] != '\0' && *++p == '\n')
634: esc_nl = 1;
1.1 deraadt 635: *s++ = *p;
636: }
637: size += s - op;
1.4 deraadt 638: if (!esc_nl) {
1.1 deraadt 639: *s = '\0';
640: break;
641: }
642: if (asize - size < _POSIX2_LINE_MAX + 1) {
643: asize *= 2;
644: text = xmalloc(asize);
645: }
646: }
647: return (xrealloc(text, size + 1));
648: }
649:
650: /*
651: * Get an address and return a pointer to the first character after
652: * it. Fill the structure pointed to according to the address.
653: */
654: static char *
655: compile_addr(p, a)
656: char *p;
657: struct s_addr *a;
658: {
659: char *end;
660:
661: switch (*p) {
662: case '\\': /* Context address */
663: ++p;
664: /* FALLTHROUGH */
665: case '/': /* Context address */
666: p = compile_re(p, &a->u.r);
667: if (p == NULL)
668: err(COMPILE, "unterminated regular expression");
669: a->type = AT_RE;
670: return (p);
671:
672: case '$': /* Last line */
673: a->type = AT_LAST;
674: return (p + 1);
675: /* Line number */
676: case '0': case '1': case '2': case '3': case '4':
677: case '5': case '6': case '7': case '8': case '9':
678: a->type = AT_LINE;
1.3 millert 679: a->u.l = strtoul(p, &end, 10);
1.1 deraadt 680: return (end);
681: default:
682: err(COMPILE, "expected context address");
683: return (NULL);
684: }
685: }
686:
687: /*
688: * duptoeol --
689: * Return a copy of all the characters up to \n or \0.
690: */
691: static char *
692: duptoeol(s, ctype)
693: register char *s;
694: char *ctype;
695: {
696: size_t len;
697: int ws;
698: char *start;
699:
700: ws = 0;
701: for (start = s; *s != '\0' && *s != '\n'; ++s)
702: ws = isspace(*s);
703: *s = '\0';
704: if (ws)
705: err(WARNING, "whitespace after %s", ctype);
706: len = s - start + 1;
707: return (memmove(xmalloc(len), start, len));
708: }
709:
710: /*
711: * Convert goto label names to addresses, and count a and r commands, in
712: * the given subset of the script. Free the memory used by labels in b
713: * and t commands (but not by :).
714: *
715: * TODO: Remove } nodes
716: */
717: static void
718: fixuplabel(cp, end)
719: struct s_command *cp, *end;
720: {
721:
722: for (; cp != end; cp = cp->next)
723: switch (cp->code) {
724: case 'a':
725: case 'r':
726: appendnum++;
727: break;
728: case 'b':
729: case 't':
730: /* Resolve branch target. */
731: if (cp->t == NULL) {
732: cp->u.c = NULL;
733: break;
734: }
735: if ((cp->u.c = findlabel(cp->t)) == NULL)
736: err(COMPILE2, "undefined label '%s'", cp->t);
737: free(cp->t);
738: break;
739: case '{':
740: /* Do interior commands. */
741: fixuplabel(cp->u.c, cp->next);
742: break;
743: }
744: }
745:
746: /*
747: * Associate the given command label for later lookup.
748: */
749: static void
750: enterlabel(cp)
751: struct s_command *cp;
752: {
753: register struct labhash **lhp, *lh;
754: register u_char *p;
755: register u_int h, c;
756:
757: for (h = 0, p = (u_char *)cp->t; (c = *p) != 0; p++)
758: h = (h << 5) + h + c;
759: lhp = &labels[h & LHMASK];
760: for (lh = *lhp; lh != NULL; lh = lh->lh_next)
761: if (lh->lh_hash == h && strcmp(cp->t, lh->lh_cmd->t) == 0)
762: err(COMPILE2, "duplicate label '%s'", cp->t);
763: lh = xmalloc(sizeof *lh);
764: lh->lh_next = *lhp;
765: lh->lh_hash = h;
766: lh->lh_cmd = cp;
767: lh->lh_ref = 0;
768: *lhp = lh;
769: }
770:
771: /*
772: * Find the label contained in the command l in the command linked
773: * list cp. L is excluded from the search. Return NULL if not found.
774: */
775: static struct s_command *
776: findlabel(name)
777: char *name;
778: {
779: register struct labhash *lh;
780: register u_char *p;
781: register u_int h, c;
782:
783: for (h = 0, p = (u_char *)name; (c = *p) != 0; p++)
784: h = (h << 5) + h + c;
785: for (lh = labels[h & LHMASK]; lh != NULL; lh = lh->lh_next) {
786: if (lh->lh_hash == h && strcmp(name, lh->lh_cmd->t) == 0) {
787: lh->lh_ref = 1;
788: return (lh->lh_cmd);
789: }
790: }
791: return (NULL);
792: }
793:
794: /*
795: * Warn about any unused labels. As a side effect, release the label hash
796: * table space.
797: */
798: static void
799: uselabel()
800: {
801: register struct labhash *lh, *next;
802: register int i;
803:
804: for (i = 0; i < LHSZ; i++) {
805: for (lh = labels[i]; lh != NULL; lh = next) {
806: next = lh->lh_next;
807: if (!lh->lh_ref)
808: err(WARNING, "unused label '%s'",
809: lh->lh_cmd->t);
810: free(lh);
811: }
812: }
813: }