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Update documentation for C-style quoting.
[git/jnareb-git/bp-gitweb.git] / diff.c
blob823c8d0aabe7d68a6dd0c4b3311ecff64710ea6e
1 /*
2 * Copyright (C) 2005 Junio C Hamano
3 */
4 #include <sys/types.h>
5 #include <sys/wait.h>
6 #include <signal.h>
7 #include "cache.h"
8 #include "quote.h"
9 #include "diff.h"
10 #include "diffcore.h"
11
12 static const char *diff_opts = "-pu";
13
14 static int use_size_cache;
15
16 static char *quote_one(const char *str)
17 {
18 int needlen;
19 char *xp;
20
21 if (!str)
22 return NULL;
23 needlen = quote_c_style(str, NULL, NULL, 0);
24 if (!needlen)
25 return strdup(str);
26 xp = xmalloc(needlen + 1);
27 quote_c_style(str, xp, NULL, 0);
28 return xp;
29 }
30
31 static char *quote_two(const char *one, const char *two)
32 {
33 int need_one = quote_c_style(one, NULL, NULL, 1);
34 int need_two = quote_c_style(two, NULL, NULL, 1);
35 char *xp;
36
37 if (need_one + need_two) {
38 if (!need_one) need_one = strlen(one);
39 if (!need_two) need_one = strlen(two);
40
41 xp = xmalloc(need_one + need_two + 3);
42 xp[0] = '"';
43 quote_c_style(one, xp + 1, NULL, 1);
44 quote_c_style(two, xp + need_one + 1, NULL, 1);
45 strcpy(xp + need_one + need_two + 1, "\"");
46 return xp;
47 }
48 need_one = strlen(one);
49 need_two = strlen(two);
50 xp = xmalloc(need_one + need_two + 1);
51 strcpy(xp, one);
52 strcpy(xp + need_one, two);
53 return xp;
54 }
55
56 static const char *external_diff(void)
57 {
58 static const char *external_diff_cmd = NULL;
59 static int done_preparing = 0;
60 const char *env_diff_opts;
61
62 if (done_preparing)
63 return external_diff_cmd;
64
65 /*
66 * Default values above are meant to match the
67 * Linux kernel development style. Examples of
68 * alternative styles you can specify via environment
69 * variables are:
70 *
71 * GIT_DIFF_OPTS="-c";
72 */
73 external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
74
75 /* In case external diff fails... */
76 env_diff_opts = getenv("GIT_DIFF_OPTS");
77 if (env_diff_opts) diff_opts = env_diff_opts;
78
79 done_preparing = 1;
80 return external_diff_cmd;
81 }
82
83 #define TEMPFILE_PATH_LEN 50
84
85 static struct diff_tempfile {
86 const char *name; /* filename external diff should read from */
87 char hex[41];
88 char mode[10];
89 char tmp_path[TEMPFILE_PATH_LEN];
90 } diff_temp[2];
91
92 static int count_lines(const char *filename)
93 {
94 FILE *in;
95 int count, ch, completely_empty = 1, nl_just_seen = 0;
96 in = fopen(filename, "r");
97 count = 0;
98 while ((ch = fgetc(in)) != EOF)
99 if (ch == '\n') {
100 count++;
101 nl_just_seen = 1;
102 completely_empty = 0;
103 }
104 else {
105 nl_just_seen = 0;
106 completely_empty = 0;
107 }
108 fclose(in);
109 if (completely_empty)
110 return 0;
111 if (!nl_just_seen)
112 count++; /* no trailing newline */
113 return count;
114 }
115
116 static void print_line_count(int count)
117 {
118 switch (count) {
119 case 0:
120 printf("0,0");
121 break;
122 case 1:
123 printf("1");
124 break;
125 default:
126 printf("1,%d", count);
127 break;
128 }
129 }
130
131 static void copy_file(int prefix, const char *filename)
132 {
133 FILE *in;
134 int ch, nl_just_seen = 1;
135 in = fopen(filename, "r");
136 while ((ch = fgetc(in)) != EOF) {
137 if (nl_just_seen)
138 putchar(prefix);
139 putchar(ch);
140 if (ch == '\n')
141 nl_just_seen = 1;
142 else
143 nl_just_seen = 0;
144 }
145 fclose(in);
146 if (!nl_just_seen)
147 printf("\n\\ No newline at end of file\n");
148 }
149
150 static void emit_rewrite_diff(const char *name_a,
151 const char *name_b,
152 struct diff_tempfile *temp)
153 {
154 /* Use temp[i].name as input, name_a and name_b as labels */
155 int lc_a, lc_b;
156 lc_a = count_lines(temp[0].name);
157 lc_b = count_lines(temp[1].name);
158 printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
159 print_line_count(lc_a);
160 printf(" +");
161 print_line_count(lc_b);
162 printf(" @@\n");
163 if (lc_a)
164 copy_file('-', temp[0].name);
165 if (lc_b)
166 copy_file('+', temp[1].name);
167 }
168
169 static void builtin_diff(const char *name_a,
170 const char *name_b,
171 struct diff_tempfile *temp,
172 const char *xfrm_msg,
173 int complete_rewrite)
174 {
175 int i, next_at, cmd_size;
176 const char *const diff_cmd = "diff -L%s -L%s";
177 const char *const diff_arg = "%s %s||:"; /* "||:" is to return 0 */
178 const char *input_name_sq[2];
179 const char *label_path[2];
180 char *cmd;
181
182 /* diff_cmd and diff_arg have 4 %s in total which makes
183 * the sum of these strings 8 bytes larger than required.
184 * we use 2 spaces around diff-opts, and we need to count
185 * terminating NUL; we used to subtract 5 here, but we do not
186 * care about small leaks in this subprocess that is about
187 * to exec "diff" anymore.
188 */
189 cmd_size = (strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg)
190 + 128);
191
192 for (i = 0; i < 2; i++) {
193 input_name_sq[i] = sq_quote(temp[i].name);
194 if (!strcmp(temp[i].name, "/dev/null"))
195 label_path[i] = "/dev/null";
196 else if (!i)
197 label_path[i] = sq_quote(quote_two("a/", name_a));
198 else
199 label_path[i] = sq_quote(quote_two("b/", name_b));
200 cmd_size += (strlen(label_path[i]) + strlen(input_name_sq[i]));
201 }
202
203 cmd = xmalloc(cmd_size);
204
205 next_at = 0;
206 next_at += snprintf(cmd+next_at, cmd_size-next_at,
207 diff_cmd, label_path[0], label_path[1]);
208 next_at += snprintf(cmd+next_at, cmd_size-next_at,
209 " %s ", diff_opts);
210 next_at += snprintf(cmd+next_at, cmd_size-next_at,
211 diff_arg, input_name_sq[0], input_name_sq[1]);
212
213 printf("diff --git %s %s\n",
214 quote_two("a/", name_a), quote_two("b/", name_b));
215 if (label_path[0][0] == '/') {
216 /* dev/null */
217 printf("new file mode %s\n", temp[1].mode);
218 if (xfrm_msg && xfrm_msg[0])
219 puts(xfrm_msg);
220 }
221 else if (label_path[1][0] == '/') {
222 printf("deleted file mode %s\n", temp[0].mode);
223 if (xfrm_msg && xfrm_msg[0])
224 puts(xfrm_msg);
225 }
226 else {
227 if (strcmp(temp[0].mode, temp[1].mode)) {
228 printf("old mode %s\n", temp[0].mode);
229 printf("new mode %s\n", temp[1].mode);
230 }
231 if (xfrm_msg && xfrm_msg[0])
232 puts(xfrm_msg);
233 if (strncmp(temp[0].mode, temp[1].mode, 3))
234 /* we do not run diff between different kind
235 * of objects.
236 */
237 exit(0);
238 if (complete_rewrite) {
239 fflush(NULL);
240 emit_rewrite_diff(name_a, name_b, temp);
241 exit(0);
242 }
243 }
244 fflush(NULL);
245 execlp("/bin/sh","sh", "-c", cmd, NULL);
246 }
247
248 struct diff_filespec *alloc_filespec(const char *path)
249 {
250 int namelen = strlen(path);
251 struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
252
253 memset(spec, 0, sizeof(*spec));
254 spec->path = (char *)(spec + 1);
255 memcpy(spec->path, path, namelen+1);
256 return spec;
257 }
258
259 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
260 unsigned short mode)
261 {
262 if (mode) {
263 spec->mode = DIFF_FILE_CANON_MODE(mode);
264 memcpy(spec->sha1, sha1, 20);
265 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
266 }
267 }
268
269 /*
270 * Given a name and sha1 pair, if the dircache tells us the file in
271 * the work tree has that object contents, return true, so that
272 * prepare_temp_file() does not have to inflate and extract.
273 */
274 static int work_tree_matches(const char *name, const unsigned char *sha1)
275 {
276 struct cache_entry *ce;
277 struct stat st;
278 int pos, len;
279
280 /* We do not read the cache ourselves here, because the
281 * benchmark with my previous version that always reads cache
282 * shows that it makes things worse for diff-tree comparing
283 * two linux-2.6 kernel trees in an already checked out work
284 * tree. This is because most diff-tree comparisons deal with
285 * only a small number of files, while reading the cache is
286 * expensive for a large project, and its cost outweighs the
287 * savings we get by not inflating the object to a temporary
288 * file. Practically, this code only helps when we are used
289 * by diff-cache --cached, which does read the cache before
290 * calling us.
291 */
292 if (!active_cache)
293 return 0;
294
295 len = strlen(name);
296 pos = cache_name_pos(name, len);
297 if (pos < 0)
298 return 0;
299 ce = active_cache[pos];
300 if ((lstat(name, &st) < 0) ||
301 !S_ISREG(st.st_mode) || /* careful! */
302 ce_match_stat(ce, &st) ||
303 memcmp(sha1, ce->sha1, 20))
304 return 0;
305 /* we return 1 only when we can stat, it is a regular file,
306 * stat information matches, and sha1 recorded in the cache
307 * matches. I.e. we know the file in the work tree really is
308 * the same as the <name, sha1> pair.
309 */
310 return 1;
311 }
312
313 static struct sha1_size_cache {
314 unsigned char sha1[20];
315 unsigned long size;
316 } **sha1_size_cache;
317 static int sha1_size_cache_nr, sha1_size_cache_alloc;
318
319 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
320 int find_only,
321 unsigned long size)
322 {
323 int first, last;
324 struct sha1_size_cache *e;
325
326 first = 0;
327 last = sha1_size_cache_nr;
328 while (last > first) {
329 int cmp, next = (last + first) >> 1;
330 e = sha1_size_cache[next];
331 cmp = memcmp(e->sha1, sha1, 20);
332 if (!cmp)
333 return e;
334 if (cmp < 0) {
335 last = next;
336 continue;
337 }
338 first = next+1;
339 }
340 /* not found */
341 if (find_only)
342 return NULL;
343 /* insert to make it at "first" */
344 if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
345 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
346 sha1_size_cache = xrealloc(sha1_size_cache,
347 sha1_size_cache_alloc *
348 sizeof(*sha1_size_cache));
349 }
350 sha1_size_cache_nr++;
351 if (first < sha1_size_cache_nr)
352 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
353 (sha1_size_cache_nr - first - 1) *
354 sizeof(*sha1_size_cache));
355 e = xmalloc(sizeof(struct sha1_size_cache));
356 sha1_size_cache[first] = e;
357 memcpy(e->sha1, sha1, 20);
358 e->size = size;
359 return e;
360 }
361
362 /*
363 * While doing rename detection and pickaxe operation, we may need to
364 * grab the data for the blob (or file) for our own in-core comparison.
365 * diff_filespec has data and size fields for this purpose.
366 */
367 int diff_populate_filespec(struct diff_filespec *s, int size_only)
368 {
369 int err = 0;
370 if (!DIFF_FILE_VALID(s))
371 die("internal error: asking to populate invalid file.");
372 if (S_ISDIR(s->mode))
373 return -1;
374
375 if (!use_size_cache)
376 size_only = 0;
377
378 if (s->data)
379 return err;
380 if (!s->sha1_valid ||
381 work_tree_matches(s->path, s->sha1)) {
382 struct stat st;
383 int fd;
384 if (lstat(s->path, &st) < 0) {
385 if (errno == ENOENT) {
386 err_empty:
387 err = -1;
388 empty:
389 s->data = "";
390 s->size = 0;
391 return err;
392 }
393 }
394 s->size = st.st_size;
395 if (!s->size)
396 goto empty;
397 if (size_only)
398 return 0;
399 if (S_ISLNK(st.st_mode)) {
400 int ret;
401 s->data = xmalloc(s->size);
402 s->should_free = 1;
403 ret = readlink(s->path, s->data, s->size);
404 if (ret < 0) {
405 free(s->data);
406 goto err_empty;
407 }
408 return 0;
409 }
410 fd = open(s->path, O_RDONLY);
411 if (fd < 0)
412 goto err_empty;
413 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
414 close(fd);
415 if (s->data == MAP_FAILED)
416 goto err_empty;
417 s->should_munmap = 1;
418 }
419 else {
420 char type[20];
421 struct sha1_size_cache *e;
422
423 if (size_only) {
424 e = locate_size_cache(s->sha1, 1, 0);
425 if (e) {
426 s->size = e->size;
427 return 0;
428 }
429 if (!sha1_object_info(s->sha1, type, &s->size))
430 locate_size_cache(s->sha1, 0, s->size);
431 }
432 else {
433 s->data = read_sha1_file(s->sha1, type, &s->size);
434 s->should_free = 1;
435 }
436 }
437 return 0;
438 }
439
440 void diff_free_filespec_data(struct diff_filespec *s)
441 {
442 if (s->should_free)
443 free(s->data);
444 else if (s->should_munmap)
445 munmap(s->data, s->size);
446 s->should_free = s->should_munmap = 0;
447 s->data = NULL;
448 }
449
450 static void prep_temp_blob(struct diff_tempfile *temp,
451 void *blob,
452 unsigned long size,
453 const unsigned char *sha1,
454 int mode)
455 {
456 int fd;
457
458 fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
459 if (fd < 0)
460 die("unable to create temp-file");
461 if (write(fd, blob, size) != size)
462 die("unable to write temp-file");
463 close(fd);
464 temp->name = temp->tmp_path;
465 strcpy(temp->hex, sha1_to_hex(sha1));
466 temp->hex[40] = 0;
467 sprintf(temp->mode, "%06o", mode);
468 }
469
470 static void prepare_temp_file(const char *name,
471 struct diff_tempfile *temp,
472 struct diff_filespec *one)
473 {
474 if (!DIFF_FILE_VALID(one)) {
475 not_a_valid_file:
476 /* A '-' entry produces this for file-2, and
477 * a '+' entry produces this for file-1.
478 */
479 temp->name = "/dev/null";
480 strcpy(temp->hex, ".");
481 strcpy(temp->mode, ".");
482 return;
483 }
484
485 if (!one->sha1_valid ||
486 work_tree_matches(name, one->sha1)) {
487 struct stat st;
488 if (lstat(name, &st) < 0) {
489 if (errno == ENOENT)
490 goto not_a_valid_file;
491 die("stat(%s): %s", name, strerror(errno));
492 }
493 if (S_ISLNK(st.st_mode)) {
494 int ret;
495 char *buf, buf_[1024];
496 buf = ((sizeof(buf_) < st.st_size) ?
497 xmalloc(st.st_size) : buf_);
498 ret = readlink(name, buf, st.st_size);
499 if (ret < 0)
500 die("readlink(%s)", name);
501 prep_temp_blob(temp, buf, st.st_size,
502 (one->sha1_valid ?
503 one->sha1 : null_sha1),
504 (one->sha1_valid ?
505 one->mode : S_IFLNK));
506 }
507 else {
508 /* we can borrow from the file in the work tree */
509 temp->name = name;
510 if (!one->sha1_valid)
511 strcpy(temp->hex, sha1_to_hex(null_sha1));
512 else
513 strcpy(temp->hex, sha1_to_hex(one->sha1));
514 /* Even though we may sometimes borrow the
515 * contents from the work tree, we always want
516 * one->mode. mode is trustworthy even when
517 * !(one->sha1_valid), as long as
518 * DIFF_FILE_VALID(one).
519 */
520 sprintf(temp->mode, "%06o", one->mode);
521 }
522 return;
523 }
524 else {
525 if (diff_populate_filespec(one, 0))
526 die("cannot read data blob for %s", one->path);
527 prep_temp_blob(temp, one->data, one->size,
528 one->sha1, one->mode);
529 }
530 }
531
532 static void remove_tempfile(void)
533 {
534 int i;
535
536 for (i = 0; i < 2; i++)
537 if (diff_temp[i].name == diff_temp[i].tmp_path) {
538 unlink(diff_temp[i].name);
539 diff_temp[i].name = NULL;
540 }
541 }
542
543 static void remove_tempfile_on_signal(int signo)
544 {
545 remove_tempfile();
546 }
547
548 /* An external diff command takes:
549 *
550 * diff-cmd name infile1 infile1-sha1 infile1-mode \
551 * infile2 infile2-sha1 infile2-mode [ rename-to ]
552 *
553 */
554 static void run_external_diff(const char *pgm,
555 const char *name,
556 const char *other,
557 struct diff_filespec *one,
558 struct diff_filespec *two,
559 const char *xfrm_msg,
560 int complete_rewrite)
561 {
562 struct diff_tempfile *temp = diff_temp;
563 pid_t pid;
564 int status;
565 static int atexit_asked = 0;
566 const char *othername;
567
568 othername = (other? other : name);
569 if (one && two) {
570 prepare_temp_file(name, &temp[0], one);
571 prepare_temp_file(othername, &temp[1], two);
572 if (! atexit_asked &&
573 (temp[0].name == temp[0].tmp_path ||
574 temp[1].name == temp[1].tmp_path)) {
575 atexit_asked = 1;
576 atexit(remove_tempfile);
577 }
578 signal(SIGINT, remove_tempfile_on_signal);
579 }
580
581 fflush(NULL);
582 pid = fork();
583 if (pid < 0)
584 die("unable to fork");
585 if (!pid) {
586 if (pgm) {
587 if (one && two) {
588 const char *exec_arg[10];
589 const char **arg = &exec_arg[0];
590 *arg++ = pgm;
591 *arg++ = name;
592 *arg++ = temp[0].name;
593 *arg++ = temp[0].hex;
594 *arg++ = temp[0].mode;
595 *arg++ = temp[1].name;
596 *arg++ = temp[1].hex;
597 *arg++ = temp[1].mode;
598 if (other) {
599 *arg++ = other;
600 *arg++ = xfrm_msg;
601 }
602 *arg = NULL;
603 execvp(pgm, (char *const*) exec_arg);
604 }
605 else
606 execlp(pgm, pgm, name, NULL);
607 }
608 /*
609 * otherwise we use the built-in one.
610 */
611 if (one && two)
612 builtin_diff(name, othername, temp, xfrm_msg,
613 complete_rewrite);
614 else
615 printf("* Unmerged path %s\n", name);
616 exit(0);
617 }
618 if (waitpid(pid, &status, 0) < 0 ||
619 !WIFEXITED(status) || WEXITSTATUS(status)) {
620 /* Earlier we did not check the exit status because
621 * diff exits non-zero if files are different, and
622 * we are not interested in knowing that. It was a
623 * mistake which made it harder to quit a diff-*
624 * session that uses the git-apply-patch-script as
625 * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
626 * should also exit non-zero only when it wants to
627 * abort the entire diff-* session.
628 */
629 remove_tempfile();
630 fprintf(stderr, "external diff died, stopping at %s.\n", name);
631 exit(1);
632 }
633 remove_tempfile();
634 }
635
636 static void diff_fill_sha1_info(struct diff_filespec *one)
637 {
638 if (DIFF_FILE_VALID(one)) {
639 if (!one->sha1_valid) {
640 struct stat st;
641 if (stat(one->path, &st) < 0)
642 die("stat %s", one->path);
643 if (index_path(one->sha1, one->path, &st, 0))
644 die("cannot hash %s\n", one->path);
645 }
646 }
647 else
648 memset(one->sha1, 0, 20);
649 }
650
651 static void run_diff(struct diff_filepair *p)
652 {
653 const char *pgm = external_diff();
654 char msg[PATH_MAX*2+300], *xfrm_msg;
655 struct diff_filespec *one;
656 struct diff_filespec *two;
657 const char *name;
658 const char *other;
659 char *name_munged, *other_munged;
660 int complete_rewrite = 0;
661 int len;
662
663 if (DIFF_PAIR_UNMERGED(p)) {
664 /* unmerged */
665 run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
666 0);
667 return;
668 }
669
670 name = p->one->path;
671 other = (strcmp(name, p->two->path) ? p->two->path : NULL);
672 name_munged = quote_one(name);
673 other_munged = quote_one(other);
674 one = p->one; two = p->two;
675
676 diff_fill_sha1_info(one);
677 diff_fill_sha1_info(two);
678
679 len = 0;
680 switch (p->status) {
681 case DIFF_STATUS_COPIED:
682 len += snprintf(msg + len, sizeof(msg) - len,
683 "similarity index %d%%\n"
684 "copy from %s\n"
685 "copy to %s\n",
686 (int)(0.5 + p->score * 100.0/MAX_SCORE),
687 name_munged, other_munged);
688 break;
689 case DIFF_STATUS_RENAMED:
690 len += snprintf(msg + len, sizeof(msg) - len,
691 "similarity index %d%%\n"
692 "rename from %s\n"
693 "rename to %s\n",
694 (int)(0.5 + p->score * 100.0/MAX_SCORE),
695 name_munged, other_munged);
696 break;
697 case DIFF_STATUS_MODIFIED:
698 if (p->score) {
699 len += snprintf(msg + len, sizeof(msg) - len,
700 "dissimilarity index %d%%\n",
701 (int)(0.5 + p->score *
702 100.0/MAX_SCORE));
703 complete_rewrite = 1;
704 break;
705 }
706 /* fallthru */
707 default:
708 /* nothing */
709 ;
710 }
711
712 if (memcmp(one->sha1, two->sha1, 20)) {
713 char one_sha1[41];
714 memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
715
716 len += snprintf(msg + len, sizeof(msg) - len,
717 "index %.7s..%.7s", one_sha1,
718 sha1_to_hex(two->sha1));
719 if (one->mode == two->mode)
720 len += snprintf(msg + len, sizeof(msg) - len,
721 " %06o", one->mode);
722 len += snprintf(msg + len, sizeof(msg) - len, "\n");
723 }
724
725 if (len)
726 msg[--len] = 0;
727 xfrm_msg = len ? msg : NULL;
728
729 if (!pgm &&
730 DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
731 (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
732 /* a filepair that changes between file and symlink
733 * needs to be split into deletion and creation.
734 */
735 struct diff_filespec *null = alloc_filespec(two->path);
736 run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
737 free(null);
738 null = alloc_filespec(one->path);
739 run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
740 free(null);
741 }
742 else
743 run_external_diff(pgm, name, other, one, two, xfrm_msg,
744 complete_rewrite);
745
746 free(name_munged);
747 free(other_munged);
748 }
749
750 void diff_setup(struct diff_options *options)
751 {
752 memset(options, 0, sizeof(*options));
753 options->output_format = DIFF_FORMAT_RAW;
754 options->line_termination = '\n';
755 options->break_opt = -1;
756 options->rename_limit = -1;
757 }
758
759 int diff_setup_done(struct diff_options *options)
760 {
761 if ((options->find_copies_harder || 0 <= options->rename_limit) &&
762 options->detect_rename != DIFF_DETECT_COPY)
763 return -1;
764 if (options->setup & DIFF_SETUP_USE_CACHE) {
765 if (!active_cache)
766 /* read-cache does not die even when it fails
767 * so it is safe for us to do this here. Also
768 * it does not smudge active_cache or active_nr
769 * when it fails, so we do not have to worry about
770 * cleaning it up oufselves either.
771 */
772 read_cache();
773 }
774 if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
775 use_size_cache = 1;
776
777 return 0;
778 }
779
780 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
781 {
782 const char *arg = av[0];
783 if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
784 options->output_format = DIFF_FORMAT_PATCH;
785 else if (!strcmp(arg, "-z"))
786 options->line_termination = 0;
787 else if (!strncmp(arg, "-l", 2))
788 options->rename_limit = strtoul(arg+2, NULL, 10);
789 else if (!strcmp(arg, "--name-only"))
790 options->output_format = DIFF_FORMAT_NAME;
791 else if (!strcmp(arg, "--name-status"))
792 options->output_format = DIFF_FORMAT_NAME_STATUS;
793 else if (!strcmp(arg, "-R"))
794 options->reverse_diff = 1;
795 else if (!strncmp(arg, "-S", 2))
796 options->pickaxe = arg + 2;
797 else if (!strcmp(arg, "-s"))
798 options->output_format = DIFF_FORMAT_NO_OUTPUT;
799 else if (!strncmp(arg, "-O", 2))
800 options->orderfile = arg + 2;
801 else if (!strncmp(arg, "--diff-filter=", 14))
802 options->filter = arg + 14;
803 else if (!strcmp(arg, "--pickaxe-all"))
804 options->pickaxe_opts = DIFF_PICKAXE_ALL;
805 else if (!strncmp(arg, "-B", 2)) {
806 if ((options->break_opt =
807 diff_scoreopt_parse(arg)) == -1)
808 return -1;
809 }
810 else if (!strncmp(arg, "-M", 2)) {
811 if ((options->rename_score =
812 diff_scoreopt_parse(arg)) == -1)
813 return -1;
814 options->detect_rename = DIFF_DETECT_RENAME;
815 }
816 else if (!strncmp(arg, "-C", 2)) {
817 if ((options->rename_score =
818 diff_scoreopt_parse(arg)) == -1)
819 return -1;
820 options->detect_rename = DIFF_DETECT_COPY;
821 }
822 else if (!strcmp(arg, "--find-copies-harder"))
823 options->find_copies_harder = 1;
824 else
825 return 0;
826 return 1;
827 }
828
829 static int parse_num(const char **cp_p)
830 {
831 int num, scale, ch, cnt;
832 const char *cp = *cp_p;
833
834 cnt = num = 0;
835 scale = 1;
836 while ('0' <= (ch = *cp) && ch <= '9') {
837 if (cnt++ < 5) {
838 /* We simply ignore more than 5 digits precision. */
839 scale *= 10;
840 num = num * 10 + ch - '0';
841 }
842 cp++;
843 }
844 *cp_p = cp;
845
846 /* user says num divided by scale and we say internally that
847 * is MAX_SCORE * num / scale.
848 */
849 return (MAX_SCORE * num / scale);
850 }
851
852 int diff_scoreopt_parse(const char *opt)
853 {
854 int opt1, opt2, cmd;
855
856 if (*opt++ != '-')
857 return -1;
858 cmd = *opt++;
859 if (cmd != 'M' && cmd != 'C' && cmd != 'B')
860 return -1; /* that is not a -M, -C nor -B option */
861
862 opt1 = parse_num(&opt);
863 if (cmd != 'B')
864 opt2 = 0;
865 else {
866 if (*opt == 0)
867 opt2 = 0;
868 else if (*opt != '/')
869 return -1; /* we expect -B80/99 or -B80 */
870 else {
871 opt++;
872 opt2 = parse_num(&opt);
873 }
874 }
875 if (*opt != 0)
876 return -1;
877 return opt1 | (opt2 << 16);
878 }
879
880 struct diff_queue_struct diff_queued_diff;
881
882 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
883 {
884 if (queue->alloc <= queue->nr) {
885 queue->alloc = alloc_nr(queue->alloc);
886 queue->queue = xrealloc(queue->queue,
887 sizeof(dp) * queue->alloc);
888 }
889 queue->queue[queue->nr++] = dp;
890 }
891
892 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
893 struct diff_filespec *one,
894 struct diff_filespec *two)
895 {
896 struct diff_filepair *dp = xmalloc(sizeof(*dp));
897 dp->one = one;
898 dp->two = two;
899 dp->score = 0;
900 dp->status = 0;
901 dp->source_stays = 0;
902 dp->broken_pair = 0;
903 if (queue)
904 diff_q(queue, dp);
905 return dp;
906 }
907
908 void diff_free_filepair(struct diff_filepair *p)
909 {
910 diff_free_filespec_data(p->one);
911 diff_free_filespec_data(p->two);
912 free(p->one);
913 free(p->two);
914 free(p);
915 }
916
917 static void diff_flush_raw(struct diff_filepair *p,
918 int line_termination,
919 int inter_name_termination,
920 int output_format)
921 {
922 int two_paths;
923 char status[10];
924 const char *path_one, *path_two;
925
926 path_one = p->one->path;
927 path_two = p->two->path;
928 if (line_termination) {
929 path_one = quote_one(path_one);
930 path_two = quote_one(path_two);
931 }
932
933 if (p->score)
934 sprintf(status, "%c%03d", p->status,
935 (int)(0.5 + p->score * 100.0/MAX_SCORE));
936 else {
937 status[0] = p->status;
938 status[1] = 0;
939 }
940 switch (p->status) {
941 case DIFF_STATUS_COPIED:
942 case DIFF_STATUS_RENAMED:
943 two_paths = 1;
944 break;
945 case DIFF_STATUS_ADDED:
946 case DIFF_STATUS_DELETED:
947 two_paths = 0;
948 break;
949 default:
950 two_paths = 0;
951 break;
952 }
953 if (output_format != DIFF_FORMAT_NAME_STATUS) {
954 printf(":%06o %06o %s ",
955 p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
956 printf("%s ", sha1_to_hex(p->two->sha1));
957 }
958 printf("%s%c%s", status, inter_name_termination, path_one);
959 if (two_paths)
960 printf("%c%s", inter_name_termination, path_two);
961 putchar(line_termination);
962 if (path_one != p->one->path)
963 free((void*)path_one);
964 if (path_two != p->two->path)
965 free((void*)path_two);
966 }
967
968 static void diff_flush_name(struct diff_filepair *p,
969 int inter_name_termination,
970 int line_termination)
971 {
972 char *path = p->two->path;
973
974 if (line_termination)
975 path = quote_one(p->two->path);
976 else
977 path = p->two->path;
978 printf("%s%c", path, line_termination);
979 if (p->two->path != path)
980 free(path);
981 }
982
983 int diff_unmodified_pair(struct diff_filepair *p)
984 {
985 /* This function is written stricter than necessary to support
986 * the currently implemented transformers, but the idea is to
987 * let transformers to produce diff_filepairs any way they want,
988 * and filter and clean them up here before producing the output.
989 */
990 struct diff_filespec *one, *two;
991
992 if (DIFF_PAIR_UNMERGED(p))
993 return 0; /* unmerged is interesting */
994
995 one = p->one;
996 two = p->two;
997
998 /* deletion, addition, mode or type change
999 * and rename are all interesting.
1000 */
1001 if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1002 DIFF_PAIR_MODE_CHANGED(p) ||
1003 strcmp(one->path, two->path))
1004 return 0;
1005
1006 /* both are valid and point at the same path. that is, we are
1007 * dealing with a change.
1008 */
1009 if (one->sha1_valid && two->sha1_valid &&
1010 !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1011 return 1; /* no change */
1012 if (!one->sha1_valid && !two->sha1_valid)
1013 return 1; /* both look at the same file on the filesystem. */
1014 return 0;
1015 }
1016
1017 static void diff_flush_patch(struct diff_filepair *p)
1018 {
1019 if (diff_unmodified_pair(p))
1020 return;
1021
1022 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1023 (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1024 return; /* no tree diffs in patch format */
1025
1026 run_diff(p);
1027 }
1028
1029 int diff_queue_is_empty(void)
1030 {
1031 struct diff_queue_struct *q = &diff_queued_diff;
1032 int i;
1033 for (i = 0; i < q->nr; i++)
1034 if (!diff_unmodified_pair(q->queue[i]))
1035 return 0;
1036 return 1;
1037 }
1038
1039 #if DIFF_DEBUG
1040 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1041 {
1042 fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1043 x, one ? one : "",
1044 s->path,
1045 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1046 s->mode,
1047 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1048 fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1049 x, one ? one : "",
1050 s->size, s->xfrm_flags);
1051 }
1052
1053 void diff_debug_filepair(const struct diff_filepair *p, int i)
1054 {
1055 diff_debug_filespec(p->one, i, "one");
1056 diff_debug_filespec(p->two, i, "two");
1057 fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1058 p->score, p->status ? p->status : '?',
1059 p->source_stays, p->broken_pair);
1060 }
1061
1062 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1063 {
1064 int i;
1065 if (msg)
1066 fprintf(stderr, "%s\n", msg);
1067 fprintf(stderr, "q->nr = %d\n", q->nr);
1068 for (i = 0; i < q->nr; i++) {
1069 struct diff_filepair *p = q->queue[i];
1070 diff_debug_filepair(p, i);
1071 }
1072 }
1073 #endif
1074
1075 static void diff_resolve_rename_copy(void)
1076 {
1077 int i, j;
1078 struct diff_filepair *p, *pp;
1079 struct diff_queue_struct *q = &diff_queued_diff;
1080
1081 diff_debug_queue("resolve-rename-copy", q);
1082
1083 for (i = 0; i < q->nr; i++) {
1084 p = q->queue[i];
1085 p->status = 0; /* undecided */
1086 if (DIFF_PAIR_UNMERGED(p))
1087 p->status = DIFF_STATUS_UNMERGED;
1088 else if (!DIFF_FILE_VALID(p->one))
1089 p->status = DIFF_STATUS_ADDED;
1090 else if (!DIFF_FILE_VALID(p->two))
1091 p->status = DIFF_STATUS_DELETED;
1092 else if (DIFF_PAIR_TYPE_CHANGED(p))
1093 p->status = DIFF_STATUS_TYPE_CHANGED;
1094
1095 /* from this point on, we are dealing with a pair
1096 * whose both sides are valid and of the same type, i.e.
1097 * either in-place edit or rename/copy edit.
1098 */
1099 else if (DIFF_PAIR_RENAME(p)) {
1100 if (p->source_stays) {
1101 p->status = DIFF_STATUS_COPIED;
1102 continue;
1103 }
1104 /* See if there is some other filepair that
1105 * copies from the same source as us. If so
1106 * we are a copy. Otherwise we are either a
1107 * copy if the path stays, or a rename if it
1108 * does not, but we already handled "stays" case.
1109 */
1110 for (j = i + 1; j < q->nr; j++) {
1111 pp = q->queue[j];
1112 if (strcmp(pp->one->path, p->one->path))
1113 continue; /* not us */
1114 if (!DIFF_PAIR_RENAME(pp))
1115 continue; /* not a rename/copy */
1116 /* pp is a rename/copy from the same source */
1117 p->status = DIFF_STATUS_COPIED;
1118 break;
1119 }
1120 if (!p->status)
1121 p->status = DIFF_STATUS_RENAMED;
1122 }
1123 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1124 p->one->mode != p->two->mode)
1125 p->status = DIFF_STATUS_MODIFIED;
1126 else {
1127 /* This is a "no-change" entry and should not
1128 * happen anymore, but prepare for broken callers.
1129 */
1130 error("feeding unmodified %s to diffcore",
1131 p->one->path);
1132 p->status = DIFF_STATUS_UNKNOWN;
1133 }
1134 }
1135 diff_debug_queue("resolve-rename-copy done", q);
1136 }
1137
1138 void diff_flush(struct diff_options *options)
1139 {
1140 struct diff_queue_struct *q = &diff_queued_diff;
1141 int i;
1142 int inter_name_termination = '\t';
1143 int diff_output_format = options->output_format;
1144 int line_termination = options->line_termination;
1145
1146 if (!line_termination)
1147 inter_name_termination = 0;
1148
1149 for (i = 0; i < q->nr; i++) {
1150 struct diff_filepair *p = q->queue[i];
1151 if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
1152 (p->status == DIFF_STATUS_UNKNOWN))
1153 continue;
1154 if (p->status == 0)
1155 die("internal error in diff-resolve-rename-copy");
1156 switch (diff_output_format) {
1157 case DIFF_FORMAT_PATCH:
1158 diff_flush_patch(p);
1159 break;
1160 case DIFF_FORMAT_RAW:
1161 case DIFF_FORMAT_NAME_STATUS:
1162 diff_flush_raw(p, line_termination,
1163 inter_name_termination,
1164 diff_output_format);
1165 break;
1166 case DIFF_FORMAT_NAME:
1167 diff_flush_name(p,
1168 inter_name_termination,
1169 line_termination);
1170 break;
1171 }
1172 diff_free_filepair(q->queue[i]);
1173 }
1174 free(q->queue);
1175 q->queue = NULL;
1176 q->nr = q->alloc = 0;
1177 }
1178
1179 static void diffcore_apply_filter(const char *filter)
1180 {
1181 int i;
1182 struct diff_queue_struct *q = &diff_queued_diff;
1183 struct diff_queue_struct outq;
1184 outq.queue = NULL;
1185 outq.nr = outq.alloc = 0;
1186
1187 if (!filter)
1188 return;
1189
1190 if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1191 int found;
1192 for (i = found = 0; !found && i < q->nr; i++) {
1193 struct diff_filepair *p = q->queue[i];
1194 if (((p->status == DIFF_STATUS_MODIFIED) &&
1195 ((p->score &&
1196 strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1197 (!p->score &&
1198 strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1199 ((p->status != DIFF_STATUS_MODIFIED) &&
1200 strchr(filter, p->status)))
1201 found++;
1202 }
1203 if (found)
1204 return;
1205
1206 /* otherwise we will clear the whole queue
1207 * by copying the empty outq at the end of this
1208 * function, but first clear the current entries
1209 * in the queue.
1210 */
1211 for (i = 0; i < q->nr; i++)
1212 diff_free_filepair(q->queue[i]);
1213 }
1214 else {
1215 /* Only the matching ones */
1216 for (i = 0; i < q->nr; i++) {
1217 struct diff_filepair *p = q->queue[i];
1218
1219 if (((p->status == DIFF_STATUS_MODIFIED) &&
1220 ((p->score &&
1221 strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1222 (!p->score &&
1223 strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1224 ((p->status != DIFF_STATUS_MODIFIED) &&
1225 strchr(filter, p->status)))
1226 diff_q(&outq, p);
1227 else
1228 diff_free_filepair(p);
1229 }
1230 }
1231 free(q->queue);
1232 *q = outq;
1233 }
1234
1235 void diffcore_std(struct diff_options *options)
1236 {
1237 if (options->paths && options->paths[0])
1238 diffcore_pathspec(options->paths);
1239 if (options->break_opt != -1)
1240 diffcore_break(options->break_opt);
1241 if (options->detect_rename)
1242 diffcore_rename(options);
1243 if (options->break_opt != -1)
1244 diffcore_merge_broken();
1245 if (options->pickaxe)
1246 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1247 if (options->orderfile)
1248 diffcore_order(options->orderfile);
1249 diff_resolve_rename_copy();
1250 diffcore_apply_filter(options->filter);
1251 }
1252
1253
1254 void diffcore_std_no_resolve(struct diff_options *options)
1255 {
1256 if (options->pickaxe)
1257 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1258 if (options->orderfile)
1259 diffcore_order(options->orderfile);
1260 diffcore_apply_filter(options->filter);
1261 }
1262
1263 void diff_addremove(struct diff_options *options,
1264 int addremove, unsigned mode,
1265 const unsigned char *sha1,
1266 const char *base, const char *path)
1267 {
1268 char concatpath[PATH_MAX];
1269 struct diff_filespec *one, *two;
1270
1271 /* This may look odd, but it is a preparation for
1272 * feeding "there are unchanged files which should
1273 * not produce diffs, but when you are doing copy
1274 * detection you would need them, so here they are"
1275 * entries to the diff-core. They will be prefixed
1276 * with something like '=' or '*' (I haven't decided
1277 * which but should not make any difference).
1278 * Feeding the same new and old to diff_change()
1279 * also has the same effect.
1280 * Before the final output happens, they are pruned after
1281 * merged into rename/copy pairs as appropriate.
1282 */
1283 if (options->reverse_diff)
1284 addremove = (addremove == '+' ? '-' :
1285 addremove == '-' ? '+' : addremove);
1286
1287 if (!path) path = "";
1288 sprintf(concatpath, "%s%s", base, path);
1289 one = alloc_filespec(concatpath);
1290 two = alloc_filespec(concatpath);
1291
1292 if (addremove != '+')
1293 fill_filespec(one, sha1, mode);
1294 if (addremove != '-')
1295 fill_filespec(two, sha1, mode);
1296
1297 diff_queue(&diff_queued_diff, one, two);
1298 }
1299
1300 void diff_change(struct diff_options *options,
1301 unsigned old_mode, unsigned new_mode,
1302 const unsigned char *old_sha1,
1303 const unsigned char *new_sha1,
1304 const char *base, const char *path)
1305 {
1306 char concatpath[PATH_MAX];
1307 struct diff_filespec *one, *two;
1308
1309 if (options->reverse_diff) {
1310 unsigned tmp;
1311 const unsigned char *tmp_c;
1312 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1313 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1314 }
1315 if (!path) path = "";
1316 sprintf(concatpath, "%s%s", base, path);
1317 one = alloc_filespec(concatpath);
1318 two = alloc_filespec(concatpath);
1319 fill_filespec(one, old_sha1, old_mode);
1320 fill_filespec(two, new_sha1, new_mode);
1321
1322 diff_queue(&diff_queued_diff, one, two);
1323 }
1324
1325 void diff_unmerge(struct diff_options *options,
1326 const char *path)
1327 {
1328 struct diff_filespec *one, *two;
1329 one = alloc_filespec(path);
1330 two = alloc_filespec(path);
1331 diff_queue(&diff_queued_diff, one, two);
1332 }