xref: /netbsd/usr.bin/patch/patch.c (revision ebbaadf3)
1 /*
2  * $OpenBSD: patch.c,v 1.45 2007/04/18 21:52:24 sobrado Exp $
3  * $DragonFly: src/usr.bin/patch/patch.c,v 1.10 2008/08/10 23:39:56 joerg Exp $
4  * $NetBSD: patch.c,v 1.34 2023/06/16 11:27:00 wiz Exp $
5  */
6 
7 /*
8  * patch - a program to apply diffs to original files
9  *
10  * Copyright 1986, Larry Wall
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following condition is met:
14  * 1. Redistributions of source code must retain the above copyright notice,
15  * this condition and the following disclaimer.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
24  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
30  * behaviour
31  */
32 
33 #include <sys/cdefs.h>
34 __RCSID("$NetBSD: patch.c,v 1.34 2023/06/16 11:27:00 wiz Exp $");
35 
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 
39 #include <ctype.h>
40 #include <getopt.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <string.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 
47 #include "common.h"
48 #include "util.h"
49 #include "pch.h"
50 #include "inp.h"
51 #include "backupfile.h"
52 #include "pathnames.h"
53 
54 mode_t		filemode = 0644;
55 
56 char		*buf;			/* general purpose buffer */
57 size_t		bufsz;			/* general purpose buffer size */
58 
59 bool		using_plan_a = true;	/* try to keep everything in memory */
60 bool		out_of_mem = false;	/* ran out of memory in plan a */
61 
62 #define MAXFILEC 2
63 
64 char		*filearg[MAXFILEC];
65 bool		ok_to_create_file = false;
66 char		*outname = NULL;
67 char		*origprae = NULL;
68 char		*TMPOUTNAME;
69 char		*TMPINNAME;
70 char		*TMPREJNAME;
71 char		*TMPPATNAME;
72 bool		toutkeep = false;
73 bool		trejkeep = false;
74 bool		warn_on_invalid_line;
75 bool		last_line_missing_eol;
76 
77 #ifdef DEBUGGING
78 int		debug = 0;
79 #endif
80 
81 bool		force = false;
82 bool		batch = false;
83 bool		verbose = true;
84 bool		reverse = false;
85 bool		noreverse = false;
86 bool		skip_rest_of_patch = false;
87 int		strippath = 957;
88 bool		canonicalize = false;
89 bool		check_only = false;
90 int		diff_type = 0;
91 char		*revision = NULL;	/* prerequisite revision, if any */
92 LINENUM		input_lines = 0;	/* how long is input file in lines */
93 int		posix = 0;		/* strict POSIX mode? */
94 int		backup_if_mismatch = -1;/* create backup file when patch doesn't apply cleanly */
95 
96 static void	reinitialize_almost_everything(void);
97 static void	get_some_switches(void);
98 static LINENUM	locate_hunk(LINENUM);
99 static void	abort_context_hunk(void);
100 static void	rej_line(int, LINENUM);
101 static void	abort_hunk(void);
102 static void	apply_hunk(LINENUM);
103 static void	init_output(const char *);
104 static void	init_reject(const char *);
105 static void	copy_till(LINENUM, bool);
106 static bool	spew_output(void);
107 static void	dump_line(LINENUM, bool);
108 static bool	patch_match(LINENUM, LINENUM, LINENUM);
109 static bool	similar(const char *, const char *, int);
110 __dead static void	usage(void);
111 
112 /* true if -E was specified on command line.  */
113 static bool	remove_empty_files = false;
114 
115 /* true if -R was specified on command line.  */
116 static bool	reverse_flag_specified = false;
117 
118 /* buffer holding the name of the rejected patch file. */
119 static char	rejname[PATH_MAX];
120 
121 /* buffer for stderr */
122 static char	serrbuf[BUFSIZ];
123 
124 /* how many input lines have been irretractibly output */
125 static LINENUM	last_frozen_line = 0;
126 
127 static int	Argc;		/* guess */
128 static char	**Argv;
129 static int	Argc_last;	/* for restarting plan_b */
130 static char	**Argv_last;
131 
132 static FILE	*ofp = NULL;	/* output file pointer */
133 static FILE	*rejfp = NULL;	/* reject file pointer */
134 
135 static int	filec = 0;	/* how many file arguments? */
136 static LINENUM	last_offset = 0;
137 static LINENUM	maxfuzz = 2;
138 
139 /* patch using ifdef, ifndef, etc. */
140 static bool		do_defines = false;
141 /* #ifdef xyzzy */
142 static char		if_defined[128];
143 /* #ifndef xyzzy */
144 static char		not_defined[128];
145 /* #else */
146 static const char	else_defined[] = "#else\n";
147 /* #endif xyzzy */
148 static char		end_defined[128];
149 
150 
151 /* Apply a set of diffs as appropriate. */
152 
153 int
main(int argc,char * argv[])154 main(int argc, char *argv[])
155 {
156 	int	error = 0, hunk, failed, i, fd;
157 	LINENUM	where = 0, newwhere, fuzz, mymaxfuzz;
158 	const	char *tmpdir;
159 	char	*v;
160 
161 	bufsz = INITLINELEN;
162 	if ((buf = malloc(bufsz)) == NULL)
163 		pfatal("allocating input buffer");
164 	buf[0] = '\0';
165 
166 	setbuf(stderr, serrbuf);
167 	for (i = 0; i < MAXFILEC; i++)
168 		filearg[i] = NULL;
169 
170 	/* Cons up the names of the temporary files.  */
171 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
172 		tmpdir = _PATH_TMP;
173 	for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
174 		;
175 	i++;
176 	if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
177 		fatal("cannot allocate memory");
178 	if ((fd = mkstemp(TMPOUTNAME)) < 0)
179 		pfatal("can't create %s", TMPOUTNAME);
180 	close(fd);
181 
182 	if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
183 		fatal("cannot allocate memory");
184 	if ((fd = mkstemp(TMPINNAME)) < 0)
185 		pfatal("can't create %s", TMPINNAME);
186 	close(fd);
187 
188 	if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
189 		fatal("cannot allocate memory");
190 	if ((fd = mkstemp(TMPREJNAME)) < 0)
191 		pfatal("can't create %s", TMPREJNAME);
192 	close(fd);
193 
194 	if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
195 		fatal("cannot allocate memory");
196 	if ((fd = mkstemp(TMPPATNAME)) < 0)
197 		pfatal("can't create %s", TMPPATNAME);
198 	close(fd);
199 
200 	v = getenv("SIMPLE_BACKUP_SUFFIX");
201 	if (v)
202 		simple_backup_suffix = v;
203 	else
204 		simple_backup_suffix = ORIGEXT;
205 
206 	if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
207 		v = getenv("VERSION_CONTROL");
208 	if (v != NULL)
209 		backup_type = get_version(v);
210 
211 	/* parse switches */
212 	Argc = argc;
213 	Argv = argv;
214 	get_some_switches();
215 
216 	if (backup_type == undefined)
217 		backup_type = posix ? none : numbered_existing;
218 
219 	/* make sure we clean up /tmp in case of disaster */
220 	set_signals(0);
221 
222 	for (open_patch_file(filearg[1]); there_is_another_patch();
223 	    reinitialize_almost_everything()) {
224 		/* for each patch in patch file */
225 
226 		warn_on_invalid_line = true;
227 
228 		if (outname == NULL)
229 			outname = savestr(filearg[0]);
230 
231 		/* for ed script just up and do it and exit */
232 		if (diff_type == ED_DIFF) {
233 			do_ed_script();
234 			continue;
235 		}
236 		/* initialize the patched file */
237 		if (!skip_rest_of_patch)
238 			init_output(TMPOUTNAME);
239 
240 		/* initialize reject file */
241 		init_reject(TMPREJNAME);
242 
243 		/* find out where all the lines are */
244 		if (!skip_rest_of_patch)
245 			scan_input(filearg[0]);
246 
247 		/* from here on, open no standard i/o files, because malloc */
248 		/* might misfire and we can't catch it easily */
249 
250 		/* apply each hunk of patch */
251 		hunk = 0;
252 		failed = 0;
253 		out_of_mem = false;
254 		while (another_hunk()) {
255 			hunk++;
256 			fuzz = 0;
257 			mymaxfuzz = pch_context();
258 			if (maxfuzz < mymaxfuzz)
259 				mymaxfuzz = maxfuzz;
260 			if (!skip_rest_of_patch) {
261 				do {
262 					where = locate_hunk(fuzz);
263 					if (hunk == 1 && where == 0 && !force) {
264 						/* dwim for reversed patch? */
265 						if (!pch_swap()) {
266 							if (fuzz == 0)
267 								say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
268 							continue;
269 						}
270 						reverse = !reverse;
271 						/* try again */
272 						where = locate_hunk(fuzz);
273 						if (where == 0) {
274 							/* didn't find it swapped */
275 							if (!pch_swap())
276 								/* put it back to normal */
277 								fatal("lost hunk on alloc error!\n");
278 							reverse = !reverse;
279 						} else if (noreverse) {
280 							if (!pch_swap())
281 								/* put it back to normal */
282 								fatal("lost hunk on alloc error!\n");
283 							reverse = !reverse;
284 							say("Ignoring previously applied (or reversed) patch.\n");
285 							skip_rest_of_patch = true;
286 						} else if (batch) {
287 							if (verbose)
288 								say("%seversed (or %spreviously applied) patch detected!  %s -R.",
289 								    reverse ? "R" : "Unr",
290 								    reverse ? "" : "not ",
291 								    reverse ? "Assuming" : "Ignoring");
292 						} else {
293 							ask("%seversed (or %spreviously applied) patch detected!  %s -R? [y] ",
294 							    reverse ? "R" : "Unr",
295 							    reverse ? "" : "not ",
296 							    reverse ? "Assume" : "Ignore");
297 							if (*buf == 'n') {
298 								ask("Apply anyway? [n] ");
299 								if (*buf != 'y')
300 									skip_rest_of_patch = true;
301 								where = 0;
302 								reverse = !reverse;
303 								if (!pch_swap())
304 									/* put it back to normal */
305 									fatal("lost hunk on alloc error!\n");
306 							}
307 						}
308 					}
309 				} while (!skip_rest_of_patch && where == 0 &&
310 				    ++fuzz <= mymaxfuzz);
311 
312 				if (skip_rest_of_patch) {	/* just got decided */
313 					if (ferror(ofp) || fclose(ofp)) {
314 						say("Error writing %s\n",
315 						    TMPOUTNAME);
316 						error = 1;
317 					}
318 					ofp = NULL;
319 				}
320 			}
321 			newwhere = pch_newfirst() + last_offset;
322 			if (skip_rest_of_patch) {
323 				abort_hunk();
324 				failed++;
325 				if (verbose)
326 					say("Hunk #%d ignored at %ld.\n",
327 					    hunk, newwhere);
328 			} else if (where == 0) {
329 				abort_hunk();
330 				failed++;
331 				if (verbose)
332 					say("Hunk #%d failed at %ld.\n",
333 					    hunk, newwhere);
334 			} else {
335 				apply_hunk(where);
336 				if (verbose) {
337 					say("Hunk #%d succeeded at %ld",
338 					    hunk, newwhere);
339 					if (fuzz != 0)
340 						say(" with fuzz %ld", fuzz);
341 					if (last_offset)
342 						say(" (offset %ld line%s)",
343 						    last_offset,
344 						    last_offset == 1L ? "" : "s");
345 					say(".\n");
346 				}
347 			}
348 		}
349 
350 		if (out_of_mem && using_plan_a) {
351 			Argc = Argc_last;
352 			Argv = Argv_last;
353 			say("\n\nRan out of memory using Plan A--trying again...\n\n");
354 			if (ofp)
355 				fclose(ofp);
356 			ofp = NULL;
357 			if (rejfp)
358 				fclose(rejfp);
359 			rejfp = NULL;
360 			continue;
361 		}
362 		if (hunk == 0)
363 			fatal("Internal error: hunk should not be 0\n");
364 
365 		/* finish spewing out the new file */
366 		if (!skip_rest_of_patch && !spew_output()) {
367 			say("Can't write %s\n", TMPOUTNAME);
368 			error = 1;
369 		}
370 
371 		/* and put the output where desired */
372 		ignore_signals();
373 		if (!skip_rest_of_patch) {
374 			struct stat	statbuf;
375 			char	*realout = outname;
376 
377 			if (!check_only) {
378 				/* handle --backup-if-mismatch */
379 				enum backup_type saved = backup_type;
380 				if (failed > 0 && backup_if_mismatch > 0 && backup_type == none)
381 					backup_type = simple;
382 				if (move_file(TMPOUTNAME, outname) < 0) {
383 					toutkeep = true;
384 					realout = TMPOUTNAME;
385 					chmod(TMPOUTNAME, filemode);
386 				} else
387 					chmod(outname, filemode);
388 				backup_type = saved;
389 
390 				if (remove_empty_files &&
391 				    stat(realout, &statbuf) == 0 &&
392 				    statbuf.st_size == 0) {
393 					if (verbose)
394 						say("Removing %s (empty after patching).\n",
395 						    realout);
396 					unlink(realout);
397 				}
398 			}
399 		}
400 		if (ferror(rejfp) || fclose(rejfp)) {
401 			say("Error writing %s\n", rejname);
402 			error = 1;
403 		}
404 		rejfp = NULL;
405 		if (failed) {
406 			error = 1;
407 			if (*rejname == '\0') {
408 				if (strlcpy(rejname, outname,
409 				    sizeof(rejname)) >= sizeof(rejname))
410 					fatal("filename %s is too long\n", outname);
411 				if (strlcat(rejname, REJEXT,
412 				    sizeof(rejname)) >= sizeof(rejname))
413 					fatal("filename %s is too long\n", outname);
414 			}
415 			if (skip_rest_of_patch) {
416 				say("%d out of %d hunks ignored--saving rejects to %s\n",
417 				    failed, hunk, rejname);
418 			} else {
419 				say("%d out of %d hunks FAILED -- saving rejects to %s\n",
420 				    failed, hunk, rejname);
421 			}
422 			if (!check_only && move_file(TMPREJNAME, rejname) < 0)
423 				trejkeep = true;
424 		}
425 		set_signals(1);
426 	}
427 	my_exit(error);
428 	/* NOTREACHED */
429 }
430 
431 /* Prepare to find the next patch to do in the patch file. */
432 
433 static void
reinitialize_almost_everything(void)434 reinitialize_almost_everything(void)
435 {
436 	re_patch();
437 	re_input();
438 
439 	input_lines = 0;
440 	last_frozen_line = 0;
441 
442 	filec = 0;
443 	if (!out_of_mem) {
444 		free(filearg[0]);
445 		filearg[0] = NULL;
446 	}
447 
448 	free(outname);
449 	outname = NULL;
450 
451 	last_offset = 0;
452 	diff_type = 0;
453 
454 	free(revision);
455 	revision = NULL;
456 
457 	reverse = reverse_flag_specified;
458 	skip_rest_of_patch = false;
459 
460 	get_some_switches();
461 }
462 
463 /* Process switches and filenames. */
464 
465 static void
get_some_switches(void)466 get_some_switches(void)
467 {
468 	const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
469 	static struct option longopts[] = {
470 		{"backup",		no_argument,		0,	'b'},
471 		{"backup-if-mismatch",	no_argument,		&backup_if_mismatch, 1},
472 		{"batch",		no_argument,		0,	't'},
473 		{"check",		no_argument,		0,	'C'},
474 		{"context",		no_argument,		0,	'c'},
475 		{"debug",		required_argument,	0,	'x'},
476 		{"directory",		required_argument,	0,	'd'},
477 		{"ed",			no_argument,		0,	'e'},
478 		{"force",		no_argument,		0,	'f'},
479 		{"forward",		no_argument,		0,	'N'},
480 		{"fuzz",		required_argument,	0,	'F'},
481 		{"ifdef",		required_argument,	0,	'D'},
482 		{"input",		required_argument,	0,	'i'},
483 		{"ignore-whitespace",	no_argument,		0,	'l'},
484 		{"no-backup-if-mismatch",	no_argument,	&backup_if_mismatch, 0},
485 		{"normal",		no_argument,		0,	'n'},
486 		{"output",		required_argument,	0,	'o'},
487 		{"prefix",		required_argument,	0,	'B'},
488 		{"quiet",		no_argument,		0,	's'},
489 		{"reject-file",		required_argument,	0,	'r'},
490 		{"remove-empty-files",	no_argument,		0,	'E'},
491 		{"reverse",		no_argument,		0,	'R'},
492 		{"silent",		no_argument,		0,	's'},
493 		{"strip",		required_argument,	0,	'p'},
494 		{"suffix",		required_argument,	0,	'z'},
495 		{"unified",		no_argument,		0,	'u'},
496 		{"version",		no_argument,		0,	'v'},
497 		{"version-control",	required_argument,	0,	'V'},
498 		{"posix",		no_argument,		&posix,	1},
499 		{NULL,			0,			0,	0}
500 	};
501 	int ch;
502 
503 	rejname[0] = '\0';
504 	Argc_last = Argc;
505 	Argv_last = Argv;
506 	if (!Argc)
507 		return;
508 	optreset = optind = 1;
509 	while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
510 		switch (ch) {
511 		case 'b':
512 			if (backup_type == undefined)
513 				backup_type = numbered_existing;
514 			if (optarg == NULL)
515 				break;
516 			if (verbose)
517 				say("Warning, the ``-b suffix'' option has been"
518 				    " obsoleted by the -z option.\n");
519 			/* FALLTHROUGH */
520 		case 'z':
521 			/* must directly follow 'b' case for backwards compat */
522 			simple_backup_suffix = savestr(optarg);
523 			break;
524 		case 'B':
525 			origprae = savestr(optarg);
526 			break;
527 		case 'c':
528 			diff_type = CONTEXT_DIFF;
529 			break;
530 		case 'C':
531 			check_only = true;
532 			break;
533 		case 'd':
534 			if (chdir(optarg) < 0)
535 				pfatal("can't cd to %s", optarg);
536 			break;
537 		case 'D':
538 			do_defines = true;
539 			if (!isalpha((unsigned char)*optarg) && *optarg != '_')
540 				fatal("argument to -D is not an identifier\n");
541 			snprintf(if_defined, sizeof if_defined,
542 			    "#ifdef %s\n", optarg);
543 			snprintf(not_defined, sizeof not_defined,
544 			    "#ifndef %s\n", optarg);
545 			snprintf(end_defined, sizeof end_defined,
546 			    "#endif /* %s */\n", optarg);
547 			break;
548 		case 'e':
549 			diff_type = ED_DIFF;
550 			break;
551 		case 'E':
552 			remove_empty_files = true;
553 			break;
554 		case 'f':
555 			force = true;
556 			break;
557 		case 'F':
558 			maxfuzz = atoi(optarg);
559 			break;
560 		case 'i':
561 			if (++filec == MAXFILEC)
562 				fatal("too many file arguments\n");
563 			filearg[filec] = savestr(optarg);
564 			break;
565 		case 'l':
566 			canonicalize = true;
567 			break;
568 		case 'n':
569 			diff_type = NORMAL_DIFF;
570 			break;
571 		case 'N':
572 			noreverse = true;
573 			break;
574 		case 'o':
575 			outname = savestr(optarg);
576 			break;
577 		case 'p':
578 			strippath = atoi(optarg);
579 			break;
580 		case 'r':
581 			if (strlcpy(rejname, optarg,
582 			    sizeof(rejname)) >= sizeof(rejname))
583 				fatal("argument for -r is too long\n");
584 			break;
585 		case 'R':
586 			reverse = true;
587 			reverse_flag_specified = true;
588 			break;
589 		case 's':
590 			verbose = false;
591 			break;
592 		case 't':
593 			batch = true;
594 			break;
595 		case 'u':
596 			diff_type = UNI_DIFF;
597 			break;
598 		case 'v':
599 			version();
600 			break;
601 		case 'V':
602 			backup_type = get_version(optarg);
603 			break;
604 #ifdef DEBUGGING
605 		case 'x':
606 			debug = atoi(optarg);
607 			break;
608 #endif
609 		default:
610 			if (ch != '\0')
611 				usage();
612 			break;
613 		}
614 	}
615 	Argc -= optind;
616 	Argv += optind;
617 
618 	if (Argc > 0) {
619 		filearg[0] = savestr(*Argv++);
620 		Argc--;
621 		while (Argc > 0) {
622 			if (++filec == MAXFILEC)
623 				fatal("too many file arguments\n");
624 			filearg[filec] = savestr(*Argv++);
625 			Argc--;
626 		}
627 	}
628 
629 	if (getenv("POSIXLY_CORRECT") != NULL)
630 		posix = 1;
631 
632 	if (backup_if_mismatch == -1) {
633 		backup_if_mismatch = posix ? 0 : 1;
634 	}
635 }
636 
637 static void
usage(void)638 usage(void)
639 {
640 	fprintf(stderr,
641 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
642 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
643 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
644 "             [--backup-if-mismatch] [--no-backup-if-mismatch] [--posix]\n"
645 "             [origfile [patchfile]]\n"
646 "       patch <patchfile\n");
647 	my_exit(EXIT_FAILURE);
648 }
649 
650 /*
651  * Attempt to find the right place to apply this hunk of patch.
652  */
653 static LINENUM
locate_hunk(LINENUM fuzz)654 locate_hunk(LINENUM fuzz)
655 {
656 	LINENUM	first_guess = pch_first() + last_offset;
657 	LINENUM	offset;
658 	LINENUM	pat_lines = pch_ptrn_lines();
659 	LINENUM	max_pos_offset = input_lines - first_guess - pat_lines + 1;
660 	LINENUM	max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
661 
662 	if (pat_lines == 0) {		/* null range matches always */
663 		if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
664 		    || diff_type == NEW_CONTEXT_DIFF
665 		    || diff_type == UNI_DIFF)) {
666 			say("Empty context always matches.\n");
667 		}
668 		return (first_guess);
669 	}
670 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */
671 		max_neg_offset = first_guess - 1;
672 	if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
673 		return first_guess;
674 	for (offset = 1; ; offset++) {
675 		bool	check_after = (offset <= max_pos_offset);
676 		bool	check_before = (offset <= max_neg_offset);
677 
678 		if (check_after && patch_match(first_guess, offset, fuzz)) {
679 #ifdef DEBUGGING
680 			if (debug & 1)
681 				say("Offset changing from %ld to %ld\n",
682 				    last_offset, offset);
683 #endif
684 			last_offset = offset;
685 			return first_guess + offset;
686 		} else if (check_before && patch_match(first_guess, -offset, fuzz)) {
687 #ifdef DEBUGGING
688 			if (debug & 1)
689 				say("Offset changing from %ld to %ld\n",
690 				    last_offset, -offset);
691 #endif
692 			last_offset = -offset;
693 			return first_guess - offset;
694 		} else if (!check_before && !check_after)
695 			return 0;
696 	}
697 }
698 
699 /* We did not find the pattern, dump out the hunk so they can handle it. */
700 
701 static void
abort_context_hunk(void)702 abort_context_hunk(void)
703 {
704 	LINENUM	i;
705 	const LINENUM	pat_end = pch_end();
706 	/*
707 	 * add in last_offset to guess the same as the previous successful
708 	 * hunk
709 	 */
710 	const LINENUM	oldfirst = pch_first() + last_offset;
711 	const LINENUM	newfirst = pch_newfirst() + last_offset;
712 	const LINENUM	oldlast = oldfirst + pch_ptrn_lines() - 1;
713 	const LINENUM	newlast = newfirst + pch_repl_lines() - 1;
714 	const char	*stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
715 	const char	*minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
716 
717 	fprintf(rejfp, "***************\n");
718 	for (i = 0; i <= pat_end; i++) {
719 		switch (pch_char(i)) {
720 		case '*':
721 			if (oldlast < oldfirst)
722 				fprintf(rejfp, "*** 0%s\n", stars);
723 			else if (oldlast == oldfirst)
724 				fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
725 			else
726 				fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
727 				    oldlast, stars);
728 			break;
729 		case '=':
730 			if (newlast < newfirst)
731 				fprintf(rejfp, "--- 0%s\n", minuses);
732 			else if (newlast == newfirst)
733 				fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
734 			else
735 				fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
736 				    newlast, minuses);
737 			break;
738 		case '\n':
739 			fprintf(rejfp, "%s", pfetch(i));
740 			break;
741 		case ' ':
742 		case '-':
743 		case '+':
744 		case '!':
745 			fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
746 			break;
747 		default:
748 			fatal("fatal internal error in abort_context_hunk\n");
749 		}
750 	}
751 }
752 
753 static void
rej_line(int ch,LINENUM i)754 rej_line(int ch, LINENUM i)
755 {
756 	size_t len;
757 	const char *line = pfetch(i);
758 
759 	len = strlen(line);
760 
761 	fprintf(rejfp, "%c%s", ch, line);
762 	if (len == 0 || line[len-1] != '\n')
763 		fprintf(rejfp, "\n\\ No newline at end of file\n");
764 }
765 
766 static void
abort_hunk(void)767 abort_hunk(void)
768 {
769 	LINENUM		i, j, split;
770 	int		ch1, ch2;
771 	const LINENUM	pat_end = pch_end();
772 	const LINENUM	oldfirst = pch_first() + last_offset;
773 	const LINENUM	newfirst = pch_newfirst() + last_offset;
774 
775 	if (diff_type != UNI_DIFF) {
776 		abort_context_hunk();
777 		return;
778 	}
779 	split = -1;
780 	for (i = 0; i <= pat_end; i++) {
781 		if (pch_char(i) == '=') {
782 			split = i;
783 			break;
784 		}
785 	}
786 	if (split == -1) {
787 		fprintf(rejfp, "malformed hunk: no split found\n");
788 		return;
789 	}
790 	i = 0;
791 	j = split + 1;
792 	fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
793 	    pch_ptrn_lines() ? oldfirst : 0,
794 	    pch_ptrn_lines(), newfirst, pch_repl_lines());
795 	while (i < split || j <= pat_end) {
796 		ch1 = i < split ? pch_char(i) : -1;
797 		ch2 = j <= pat_end ? pch_char(j) : -1;
798 		if (ch1 == '-') {
799 			rej_line('-', i);
800 			i++;
801 		} else if (ch1 == ' ' && ch2 == ' ') {
802 			rej_line(' ', i);
803 			i++;
804 			j++;
805 		} else if (ch1 == '!' && ch2 == '!') {
806 			while (i < split && ch1 == '!') {
807 				rej_line('-', i);
808 				i++;
809 				ch1 = i < split ? pch_char(i) : -1;
810 			}
811 			while (j <= pat_end && ch2 == '!') {
812 				rej_line('+', j);
813 				j++;
814 				ch2 = j <= pat_end ? pch_char(j) : -1;
815 			}
816 		} else if (ch1 == '*') {
817 			i++;
818 		} else if (ch2 == '+' || ch2 == ' ') {
819 			rej_line(ch2, j);
820 			j++;
821 		} else {
822 			fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
823 			    i, split, j);
824 			rej_line(ch1, i);
825 			rej_line(ch2, j);
826 			return;
827 		}
828 	}
829 }
830 
831 /* We found where to apply it (we hope), so do it. */
832 
833 static void
apply_hunk(LINENUM where)834 apply_hunk(LINENUM where)
835 {
836 	LINENUM		old = 1;
837 	const LINENUM	lastline = pch_ptrn_lines();
838 	LINENUM		new = lastline + 1;
839 #define OUTSIDE 0
840 #define IN_IFNDEF 1
841 #define IN_IFDEF 2
842 #define IN_ELSE 3
843 	int		def_state = OUTSIDE;
844 	const LINENUM	pat_end = pch_end();
845 
846 	where--;
847 	while (pch_char(new) == '=' || pch_char(new) == '\n')
848 		new++;
849 
850 	while (old <= lastline) {
851 		if (pch_char(old) == '-') {
852 			copy_till(where + old - 1, false);
853 			if (do_defines) {
854 				if (def_state == OUTSIDE) {
855 					fputs(not_defined, ofp);
856 					def_state = IN_IFNDEF;
857 				} else if (def_state == IN_IFDEF) {
858 					fputs(else_defined, ofp);
859 					def_state = IN_ELSE;
860 				}
861 				fputs(pfetch(old), ofp);
862 			}
863 			last_frozen_line++;
864 			old++;
865 		} else if (new > pat_end) {
866 			break;
867 		} else if (pch_char(new) == '+') {
868 			copy_till(where + old - 1, false);
869 			if (do_defines) {
870 				if (def_state == IN_IFNDEF) {
871 					fputs(else_defined, ofp);
872 					def_state = IN_ELSE;
873 				} else if (def_state == OUTSIDE) {
874 					fputs(if_defined, ofp);
875 					def_state = IN_IFDEF;
876 				}
877 			}
878 			fputs(pfetch(new), ofp);
879 			new++;
880 		} else if (pch_char(new) != pch_char(old)) {
881 			say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
882 			    pch_hunk_beg() + old,
883 			    pch_hunk_beg() + new);
884 #ifdef DEBUGGING
885 			say("oldchar = '%c', newchar = '%c'\n",
886 			    pch_char(old), pch_char(new));
887 #endif
888 			my_exit(2);
889 		} else if (pch_char(new) == '!') {
890 			copy_till(where + old - 1, false);
891 			if (do_defines) {
892 				fputs(not_defined, ofp);
893 				def_state = IN_IFNDEF;
894 			}
895 			while (pch_char(old) == '!') {
896 				if (do_defines) {
897 					fputs(pfetch(old), ofp);
898 				}
899 				last_frozen_line++;
900 				old++;
901 			}
902 			if (do_defines) {
903 				fputs(else_defined, ofp);
904 				def_state = IN_ELSE;
905 			}
906 			while (pch_char(new) == '!') {
907 				fputs(pfetch(new), ofp);
908 				new++;
909 			}
910 		} else {
911 			if (pch_char(new) != ' ')
912 				fatal("Internal error: expected ' '\n");
913 			old++;
914 			new++;
915 			if (do_defines && def_state != OUTSIDE) {
916 				fputs(end_defined, ofp);
917 				def_state = OUTSIDE;
918 			}
919 		}
920 	}
921 	if (new <= pat_end && pch_char(new) == '+') {
922 		copy_till(where + old - 1, false);
923 		if (do_defines) {
924 			if (def_state == OUTSIDE) {
925 				fputs(if_defined, ofp);
926 				def_state = IN_IFDEF;
927 			} else if (def_state == IN_IFNDEF) {
928 				fputs(else_defined, ofp);
929 				def_state = IN_ELSE;
930 			}
931 		}
932 		while (new <= pat_end && pch_char(new) == '+') {
933 			fputs(pfetch(new), ofp);
934 			new++;
935 		}
936 	}
937 	if (do_defines && def_state != OUTSIDE) {
938 		fputs(end_defined, ofp);
939 	}
940 }
941 
942 /*
943  * Open the new file.
944  */
945 static void
init_output(const char * name)946 init_output(const char *name)
947 {
948 	ofp = fopen(name, "w");
949 	if (ofp == NULL)
950 		pfatal("can't create %s", name);
951 }
952 
953 /*
954  * Open a file to put hunks we can't locate.
955  */
956 static void
init_reject(const char * name)957 init_reject(const char *name)
958 {
959 	rejfp = fopen(name, "w");
960 	if (rejfp == NULL)
961 		pfatal("can't create %s", name);
962 }
963 
964 /*
965  * Copy input file to output, up to wherever hunk is to be applied.
966  * If endoffile is true, treat the last line specially since it may
967  * lack a newline.
968  */
969 static void
copy_till(LINENUM lastline,bool endoffile)970 copy_till(LINENUM lastline, bool endoffile)
971 {
972 	if (last_frozen_line > lastline)
973 		fatal("misordered hunks! output would be garbled\n");
974 	while (last_frozen_line < lastline) {
975 		if (++last_frozen_line == lastline && endoffile)
976 			dump_line(last_frozen_line, !last_line_missing_eol);
977 		else
978 			dump_line(last_frozen_line, true);
979 	}
980 }
981 
982 /*
983  * Finish copying the input file to the output file.
984  */
985 static bool
spew_output(void)986 spew_output(void)
987 {
988 	int rv;
989 
990 #ifdef DEBUGGING
991 	if (debug & 256)
992 		say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
993 #endif
994 	if (input_lines)
995 		copy_till(input_lines, true);	/* dump remainder of file */
996 	rv = ferror(ofp) == 0 && fclose(ofp) == 0;
997 	ofp = NULL;
998 	return rv;
999 }
1000 
1001 /*
1002  * Copy one line from input to output.
1003  */
1004 static void
dump_line(LINENUM line,bool write_newline)1005 dump_line(LINENUM line, bool write_newline)
1006 {
1007 	char	*s;
1008 
1009 	s = ifetch(line, 0);
1010 	if (s == NULL)
1011 		return;
1012 	/* Note: string is not NUL terminated. */
1013 	for (; *s != '\n'; s++)
1014 		putc(*s, ofp);
1015 	if (write_newline)
1016 		putc('\n', ofp);
1017 }
1018 
1019 /*
1020  * Does the patch pattern match at line base+offset?
1021  */
1022 static bool
patch_match(LINENUM base,LINENUM offset,LINENUM fuzz)1023 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1024 {
1025 	LINENUM		pline = 1 + fuzz;
1026 	LINENUM		iline;
1027 	LINENUM		pat_lines = pch_ptrn_lines() - fuzz;
1028 	const char	*ilineptr;
1029 	const char	*plineptr;
1030 	short		plinelen;
1031 
1032 	for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1033 		ilineptr = ifetch(iline, offset >= 0);
1034 		if (ilineptr == NULL)
1035 			return false;
1036 		plineptr = pfetch(pline);
1037 		plinelen = pch_line_len(pline);
1038 		if (canonicalize) {
1039 			if (!similar(ilineptr, plineptr, plinelen))
1040 				return false;
1041 		} else if (strnNE(ilineptr, plineptr, plinelen))
1042 			return false;
1043 		if (iline == input_lines) {
1044 			/*
1045 			 * We are looking at the last line of the file.
1046 			 * If the file has no eol, the patch line should
1047 			 * not have one either and vice-versa. Note that
1048 			 * plinelen > 0.
1049 			 */
1050 			if (last_line_missing_eol) {
1051 				if (plineptr[plinelen - 1] == '\n')
1052 					return false;
1053 			} else {
1054 				if (plineptr[plinelen - 1] != '\n')
1055 					return false;
1056 			}
1057 		}
1058 	}
1059 	return true;
1060 }
1061 
1062 /*
1063  * Do two lines match with canonicalized white space?
1064  */
1065 static bool
similar(const char * a,const char * b,int len)1066 similar(const char *a, const char *b, int len)
1067 {
1068 	while (len) {
1069 		if (isspace((unsigned char)*b)) {	/* whitespace (or \n) to match? */
1070 			if (!isspace((unsigned char)*a))	/* no corresponding whitespace? */
1071 				return false;
1072 			while (len && isspace((unsigned char)*b) && *b != '\n')
1073 				b++, len--;	/* skip pattern whitespace */
1074 			while (isspace((unsigned char)*a) && *a != '\n')
1075 				a++;	/* skip target whitespace */
1076 			if (*a == '\n' || *b == '\n')
1077 				return (*a == *b);	/* should end in sync */
1078 		} else if (*a++ != *b++)	/* match non-whitespace chars */
1079 			return false;
1080 		else
1081 			len--;	/* probably not necessary */
1082 	}
1083 	return true;		/* actually, this is not reached */
1084 	/* since there is always a \n */
1085 }
1086