git-unpack-objects: start parsing the actual packed data
[git/git.git] / diff.c
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 "diff.h"
9 #include "diffcore.h"
10
11 static const char *diff_opts = "-pu";
12 static unsigned char null_sha1[20] = { 0, };
13
14 static int reverse_diff;
15 static int use_size_cache;
16
17 static const char *external_diff(void)
18 {
19 static const char *external_diff_cmd = NULL;
20 static int done_preparing = 0;
21
22 if (done_preparing)
23 return external_diff_cmd;
24
25 /*
26 * Default values above are meant to match the
27 * Linux kernel development style. Examples of
28 * alternative styles you can specify via environment
29 * variables are:
30 *
31 * GIT_DIFF_OPTS="-c";
32 */
33 if (gitenv("GIT_EXTERNAL_DIFF"))
34 external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
35
36 /* In case external diff fails... */
37 diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
38
39 done_preparing = 1;
40 return external_diff_cmd;
41 }
42
43 /* Help to copy the thing properly quoted for the shell safety.
44 * any single quote is replaced with '\'', and the caller is
45 * expected to enclose the result within a single quote pair.
46 *
47 * E.g.
48 * original sq_expand result
49 * name ==> name ==> 'name'
50 * a b ==> a b ==> 'a b'
51 * a'b ==> a'\''b ==> 'a'\''b'
52 */
53 static char *sq_expand(const char *src)
54 {
55 static char *buf = NULL;
56 int cnt, c;
57 const char *cp;
58 char *bp;
59
60 /* count bytes needed to store the quoted string. */
61 for (cnt = 1, cp = src; *cp; cnt++, cp++)
62 if (*cp == '\'')
63 cnt += 3;
64
65 buf = xmalloc(cnt);
66 bp = buf;
67 while ((c = *src++)) {
68 if (c != '\'')
69 *bp++ = c;
70 else {
71 bp = strcpy(bp, "'\\''");
72 bp += 4;
73 }
74 }
75 *bp = 0;
76 return buf;
77 }
78
79 static struct diff_tempfile {
80 const char *name; /* filename external diff should read from */
81 char hex[41];
82 char mode[10];
83 char tmp_path[50];
84 } diff_temp[2];
85
86 static int count_lines(const char *filename)
87 {
88 FILE *in;
89 int count, ch, completely_empty = 1, nl_just_seen = 0;
90 in = fopen(filename, "r");
91 count = 0;
92 while ((ch = fgetc(in)) != EOF)
93 if (ch == '\n') {
94 count++;
95 nl_just_seen = 1;
96 completely_empty = 0;
97 }
98 else {
99 nl_just_seen = 0;
100 completely_empty = 0;
101 }
102 fclose(in);
103 if (completely_empty)
104 return 0;
105 if (!nl_just_seen)
106 count++; /* no trailing newline */
107 return count;
108 }
109
110 static void print_line_count(int count)
111 {
112 switch (count) {
113 case 0:
114 printf("0,0");
115 break;
116 case 1:
117 printf("1");
118 break;
119 default:
120 printf("1,%d", count);
121 break;
122 }
123 }
124
125 static void copy_file(int prefix, const char *filename)
126 {
127 FILE *in;
128 int ch, nl_just_seen = 1;
129 in = fopen(filename, "r");
130 while ((ch = fgetc(in)) != EOF) {
131 if (nl_just_seen)
132 putchar(prefix);
133 putchar(ch);
134 if (ch == '\n')
135 nl_just_seen = 1;
136 else
137 nl_just_seen = 0;
138 }
139 fclose(in);
140 if (!nl_just_seen)
141 printf("\n\\ No newline at end of file\n");
142 }
143
144 static void emit_rewrite_diff(const char *name_a,
145 const char *name_b,
146 struct diff_tempfile *temp)
147 {
148 /* Use temp[i].name as input, name_a and name_b as labels */
149 int lc_a, lc_b;
150 lc_a = count_lines(temp[0].name);
151 lc_b = count_lines(temp[1].name);
152 printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
153 print_line_count(lc_a);
154 printf(" +");
155 print_line_count(lc_b);
156 printf(" @@\n");
157 if (lc_a)
158 copy_file('-', temp[0].name);
159 if (lc_b)
160 copy_file('+', temp[1].name);
161 }
162
163 static void builtin_diff(const char *name_a,
164 const char *name_b,
165 struct diff_tempfile *temp,
166 const char *xfrm_msg,
167 int complete_rewrite)
168 {
169 int i, next_at, cmd_size;
170 const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
171 const char *diff_arg = "'%s' '%s'||:"; /* "||:" is to return 0 */
172 const char *input_name_sq[2];
173 const char *path0[2];
174 const char *path1[2];
175 const char *name_sq[2];
176 char *cmd;
177
178 name_sq[0] = sq_expand(name_a);
179 name_sq[1] = sq_expand(name_b);
180
181 /* diff_cmd and diff_arg have 6 %s in total which makes
182 * the sum of these strings 12 bytes larger than required.
183 * we use 2 spaces around diff-opts, and we need to count
184 * terminating NUL, so we subtract 9 here.
185 */
186 cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
187 strlen(diff_arg) - 9);
188 for (i = 0; i < 2; i++) {
189 input_name_sq[i] = sq_expand(temp[i].name);
190 if (!strcmp(temp[i].name, "/dev/null")) {
191 path0[i] = "/dev/null";
192 path1[i] = "";
193 } else {
194 path0[i] = i ? "b/" : "a/";
195 path1[i] = name_sq[i];
196 }
197 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
198 strlen(input_name_sq[i]));
199 }
200
201 cmd = xmalloc(cmd_size);
202
203 next_at = 0;
204 next_at += snprintf(cmd+next_at, cmd_size-next_at,
205 diff_cmd,
206 path0[0], path1[0], path0[1], path1[1]);
207 next_at += snprintf(cmd+next_at, cmd_size-next_at,
208 " %s ", diff_opts);
209 next_at += snprintf(cmd+next_at, cmd_size-next_at,
210 diff_arg, input_name_sq[0], input_name_sq[1]);
211
212 printf("diff --git a/%s b/%s\n", name_a, name_b);
213 if (!path1[0][0]) {
214 printf("new file mode %s\n", temp[1].mode);
215 if (xfrm_msg && xfrm_msg[0])
216 puts(xfrm_msg);
217 }
218 else if (!path1[1][0]) {
219 printf("deleted file mode %s\n", temp[0].mode);
220 if (xfrm_msg && xfrm_msg[0])
221 puts(xfrm_msg);
222 }
223 else {
224 if (strcmp(temp[0].mode, temp[1].mode)) {
225 printf("old mode %s\n", temp[0].mode);
226 printf("new mode %s\n", temp[1].mode);
227 }
228 if (xfrm_msg && xfrm_msg[0])
229 puts(xfrm_msg);
230 if (strncmp(temp[0].mode, temp[1].mode, 3))
231 /* we do not run diff between different kind
232 * of objects.
233 */
234 exit(0);
235 if (complete_rewrite) {
236 fflush(NULL);
237 emit_rewrite_diff(name_a, name_b, temp);
238 exit(0);
239 }
240 }
241 fflush(NULL);
242 execlp("/bin/sh","sh", "-c", cmd, NULL);
243 }
244
245 struct diff_filespec *alloc_filespec(const char *path)
246 {
247 int namelen = strlen(path);
248 struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
249 spec->path = (char *)(spec + 1);
250 strcpy(spec->path, path);
251 spec->should_free = spec->should_munmap = 0;
252 spec->xfrm_flags = 0;
253 spec->size = 0;
254 spec->data = NULL;
255 spec->mode = 0;
256 memset(spec->sha1, 0, 20);
257 return spec;
258 }
259
260 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
261 unsigned short mode)
262 {
263 if (mode) {
264 spec->mode = DIFF_FILE_CANON_MODE(mode);
265 memcpy(spec->sha1, sha1, 20);
266 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
267 }
268 }
269
270 /*
271 * Given a name and sha1 pair, if the dircache tells us the file in
272 * the work tree has that object contents, return true, so that
273 * prepare_temp_file() does not have to inflate and extract.
274 */
275 static int work_tree_matches(const char *name, const unsigned char *sha1)
276 {
277 struct cache_entry *ce;
278 struct stat st;
279 int pos, len;
280
281 /* We do not read the cache ourselves here, because the
282 * benchmark with my previous version that always reads cache
283 * shows that it makes things worse for diff-tree comparing
284 * two linux-2.6 kernel trees in an already checked out work
285 * tree. This is because most diff-tree comparisons deal with
286 * only a small number of files, while reading the cache is
287 * expensive for a large project, and its cost outweighs the
288 * savings we get by not inflating the object to a temporary
289 * file. Practically, this code only helps when we are used
290 * by diff-cache --cached, which does read the cache before
291 * calling us.
292 */
293 if (!active_cache)
294 return 0;
295
296 len = strlen(name);
297 pos = cache_name_pos(name, len);
298 if (pos < 0)
299 return 0;
300 ce = active_cache[pos];
301 if ((lstat(name, &st) < 0) ||
302 !S_ISREG(st.st_mode) || /* careful! */
303 ce_match_stat(ce, &st) ||
304 memcmp(sha1, ce->sha1, 20))
305 return 0;
306 /* we return 1 only when we can stat, it is a regular file,
307 * stat information matches, and sha1 recorded in the cache
308 * matches. I.e. we know the file in the work tree really is
309 * the same as the <name, sha1> pair.
310 */
311 return 1;
312 }
313
314 static struct sha1_size_cache {
315 unsigned char sha1[20];
316 unsigned long size;
317 } **sha1_size_cache;
318 static int sha1_size_cache_nr, sha1_size_cache_alloc;
319
320 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
321 int find_only,
322 unsigned long size)
323 {
324 int first, last;
325 struct sha1_size_cache *e;
326
327 first = 0;
328 last = sha1_size_cache_nr;
329 while (last > first) {
330 int cmp, next = (last + first) >> 1;
331 e = sha1_size_cache[next];
332 cmp = memcmp(e->sha1, sha1, 20);
333 if (!cmp)
334 return e;
335 if (cmp < 0) {
336 last = next;
337 continue;
338 }
339 first = next+1;
340 }
341 /* not found */
342 if (find_only)
343 return NULL;
344 /* insert to make it at "first" */
345 if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
346 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
347 sha1_size_cache = xrealloc(sha1_size_cache,
348 sha1_size_cache_alloc *
349 sizeof(*sha1_size_cache));
350 }
351 sha1_size_cache_nr++;
352 if (first < sha1_size_cache_nr)
353 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
354 (sha1_size_cache_nr - first - 1) *
355 sizeof(*sha1_size_cache));
356 e = xmalloc(sizeof(struct sha1_size_cache));
357 sha1_size_cache[first] = e;
358 memcpy(e->sha1, sha1, 20);
359 e->size = size;
360 return e;
361 }
362
363 /*
364 * While doing rename detection and pickaxe operation, we may need to
365 * grab the data for the blob (or file) for our own in-core comparison.
366 * diff_filespec has data and size fields for this purpose.
367 */
368 int diff_populate_filespec(struct diff_filespec *s, int size_only)
369 {
370 int err = 0;
371 if (!DIFF_FILE_VALID(s))
372 die("internal error: asking to populate invalid file.");
373 if (S_ISDIR(s->mode))
374 return -1;
375
376 if (!use_size_cache)
377 size_only = 0;
378
379 if (s->data)
380 return err;
381 if (!s->sha1_valid ||
382 work_tree_matches(s->path, s->sha1)) {
383 struct stat st;
384 int fd;
385 if (lstat(s->path, &st) < 0) {
386 if (errno == ENOENT) {
387 err_empty:
388 err = -1;
389 empty:
390 s->data = "";
391 s->size = 0;
392 return err;
393 }
394 }
395 s->size = st.st_size;
396 if (!s->size)
397 goto empty;
398 if (size_only)
399 return 0;
400 if (S_ISLNK(st.st_mode)) {
401 int ret;
402 s->data = xmalloc(s->size);
403 s->should_free = 1;
404 ret = readlink(s->path, s->data, s->size);
405 if (ret < 0) {
406 free(s->data);
407 goto err_empty;
408 }
409 return 0;
410 }
411 fd = open(s->path, O_RDONLY);
412 if (fd < 0)
413 goto err_empty;
414 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
415 s->should_munmap = 1;
416 close(fd);
417 }
418 else {
419 char type[20];
420 struct sha1_size_cache *e;
421
422 if (size_only) {
423 e = locate_size_cache(s->sha1, 1, 0);
424 if (e) {
425 s->size = e->size;
426 return 0;
427 }
428 if (!sha1_file_size(s->sha1, &s->size))
429 locate_size_cache(s->sha1, 0, s->size);
430 }
431 else {
432 s->data = read_sha1_file(s->sha1, type, &s->size);
433 s->should_free = 1;
434 }
435 }
436 return 0;
437 }
438
439 void diff_free_filespec_data(struct diff_filespec *s)
440 {
441 if (s->should_free)
442 free(s->data);
443 else if (s->should_munmap)
444 munmap(s->data, s->size);
445 s->should_free = s->should_munmap = 0;
446 s->data = NULL;
447 }
448
449 static void prep_temp_blob(struct diff_tempfile *temp,
450 void *blob,
451 unsigned long size,
452 unsigned char *sha1,
453 int mode)
454 {
455 int fd;
456
457 strcpy(temp->tmp_path, ".diff_XXXXXX");
458 fd = mkstemp(temp->tmp_path);
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
567 if (one && two) {
568 prepare_temp_file(name, &temp[0], one);
569 prepare_temp_file(other ? : name, &temp[1], two);
570 if (! atexit_asked &&
571 (temp[0].name == temp[0].tmp_path ||
572 temp[1].name == temp[1].tmp_path)) {
573 atexit_asked = 1;
574 atexit(remove_tempfile);
575 }
576 signal(SIGINT, remove_tempfile_on_signal);
577 }
578
579 fflush(NULL);
580 pid = fork();
581 if (pid < 0)
582 die("unable to fork");
583 if (!pid) {
584 if (pgm) {
585 if (one && two) {
586 const char *exec_arg[10];
587 const char **arg = &exec_arg[0];
588 *arg++ = pgm;
589 *arg++ = name;
590 *arg++ = temp[0].name;
591 *arg++ = temp[0].hex;
592 *arg++ = temp[0].mode;
593 *arg++ = temp[1].name;
594 *arg++ = temp[1].hex;
595 *arg++ = temp[1].mode;
596 if (other) {
597 *arg++ = other;
598 *arg++ = xfrm_msg;
599 }
600 *arg = NULL;
601 execvp(pgm, (char *const*) exec_arg);
602 }
603 else
604 execlp(pgm, pgm, name, NULL);
605 }
606 /*
607 * otherwise we use the built-in one.
608 */
609 if (one && two)
610 builtin_diff(name, other ? : name, temp, xfrm_msg,
611 complete_rewrite);
612 else
613 printf("* Unmerged path %s\n", name);
614 exit(0);
615 }
616 if (waitpid(pid, &status, 0) < 0 ||
617 !WIFEXITED(status) || WEXITSTATUS(status)) {
618 /* Earlier we did not check the exit status because
619 * diff exits non-zero if files are different, and
620 * we are not interested in knowing that. It was a
621 * mistake which made it harder to quit a diff-*
622 * session that uses the git-apply-patch-script as
623 * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
624 * should also exit non-zero only when it wants to
625 * abort the entire diff-* session.
626 */
627 remove_tempfile();
628 fprintf(stderr, "external diff died, stopping at %s.\n", name);
629 exit(1);
630 }
631 remove_tempfile();
632 }
633
634 static void run_diff(struct diff_filepair *p)
635 {
636 const char *pgm = external_diff();
637 char msg_[PATH_MAX*2+200], *xfrm_msg;
638 struct diff_filespec *one;
639 struct diff_filespec *two;
640 const char *name;
641 const char *other;
642 int complete_rewrite = 0;
643
644 if (DIFF_PAIR_UNMERGED(p)) {
645 /* unmerged */
646 run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
647 0);
648 return;
649 }
650
651 name = p->one->path;
652 other = (strcmp(name, p->two->path) ? p->two->path : NULL);
653 one = p->one; two = p->two;
654 switch (p->status) {
655 case 'C':
656 sprintf(msg_,
657 "similarity index %d%%\n"
658 "copy from %s\n"
659 "copy to %s",
660 (int)(0.5 + p->score * 100.0/MAX_SCORE),
661 name, other);
662 xfrm_msg = msg_;
663 break;
664 case 'R':
665 sprintf(msg_,
666 "similarity index %d%%\n"
667 "rename from %s\n"
668 "rename to %s",
669 (int)(0.5 + p->score * 100.0/MAX_SCORE),
670 name, other);
671 xfrm_msg = msg_;
672 break;
673 case 'M':
674 if (p->score) {
675 sprintf(msg_,
676 "dissimilarity index %d%%",
677 (int)(0.5 + p->score * 100.0/MAX_SCORE));
678 xfrm_msg = msg_;
679 complete_rewrite = 1;
680 break;
681 }
682 /* fallthru */
683 default:
684 xfrm_msg = NULL;
685 }
686
687 if (!pgm &&
688 DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
689 (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
690 /* a filepair that changes between file and symlink
691 * needs to be split into deletion and creation.
692 */
693 struct diff_filespec *null = alloc_filespec(two->path);
694 run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
695 free(null);
696 null = alloc_filespec(one->path);
697 run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
698 free(null);
699 }
700 else
701 run_external_diff(pgm, name, other, one, two, xfrm_msg,
702 complete_rewrite);
703 }
704
705 void diff_setup(int flags)
706 {
707 if (flags & DIFF_SETUP_REVERSE)
708 reverse_diff = 1;
709 if (flags & DIFF_SETUP_USE_CACHE) {
710 if (!active_cache)
711 /* read-cache does not die even when it fails
712 * so it is safe for us to do this here. Also
713 * it does not smudge active_cache or active_nr
714 * when it fails, so we do not have to worry about
715 * cleaning it up oufselves either.
716 */
717 read_cache();
718 }
719 if (flags & DIFF_SETUP_USE_SIZE_CACHE)
720 use_size_cache = 1;
721
722 }
723
724 static int parse_num(const char **cp_p)
725 {
726 int num, scale, ch, cnt;
727 const char *cp = *cp_p;
728
729 cnt = num = 0;
730 scale = 1;
731 while ('0' <= (ch = *cp) && ch <= '9') {
732 if (cnt++ < 5) {
733 /* We simply ignore more than 5 digits precision. */
734 scale *= 10;
735 num = num * 10 + ch - '0';
736 }
737 *cp++;
738 }
739 *cp_p = cp;
740
741 /* user says num divided by scale and we say internally that
742 * is MAX_SCORE * num / scale.
743 */
744 return (MAX_SCORE * num / scale);
745 }
746
747 int diff_scoreopt_parse(const char *opt)
748 {
749 int opt1, opt2, cmd;
750
751 if (*opt++ != '-')
752 return -1;
753 cmd = *opt++;
754 if (cmd != 'M' && cmd != 'C' && cmd != 'B')
755 return -1; /* that is not a -M, -C nor -B option */
756
757 opt1 = parse_num(&opt);
758 if (cmd != 'B')
759 opt2 = 0;
760 else {
761 if (*opt == 0)
762 opt2 = 0;
763 else if (*opt != '/')
764 return -1; /* we expect -B80/99 or -B80 */
765 else {
766 opt++;
767 opt2 = parse_num(&opt);
768 }
769 }
770 if (*opt != 0)
771 return -1;
772 return opt1 | (opt2 << 16);
773 }
774
775 struct diff_queue_struct diff_queued_diff;
776
777 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
778 {
779 if (queue->alloc <= queue->nr) {
780 queue->alloc = alloc_nr(queue->alloc);
781 queue->queue = xrealloc(queue->queue,
782 sizeof(dp) * queue->alloc);
783 }
784 queue->queue[queue->nr++] = dp;
785 }
786
787 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
788 struct diff_filespec *one,
789 struct diff_filespec *two)
790 {
791 struct diff_filepair *dp = xmalloc(sizeof(*dp));
792 dp->one = one;
793 dp->two = two;
794 dp->score = 0;
795 dp->status = 0;
796 dp->source_stays = 0;
797 dp->broken_pair = 0;
798 diff_q(queue, dp);
799 return dp;
800 }
801
802 void diff_free_filepair(struct diff_filepair *p)
803 {
804 diff_free_filespec_data(p->one);
805 diff_free_filespec_data(p->two);
806 free(p);
807 }
808
809 static void diff_flush_raw(struct diff_filepair *p,
810 int line_termination,
811 int inter_name_termination)
812 {
813 int two_paths;
814 char status[10];
815
816 if (line_termination) {
817 const char *err = "path %s cannot be expressed without -z";
818 if (strchr(p->one->path, line_termination) ||
819 strchr(p->one->path, inter_name_termination))
820 die(err, p->one->path);
821 if (strchr(p->two->path, line_termination) ||
822 strchr(p->two->path, inter_name_termination))
823 die(err, p->two->path);
824 }
825
826 if (p->score)
827 sprintf(status, "%c%03d", p->status,
828 (int)(0.5 + p->score * 100.0/MAX_SCORE));
829 else {
830 status[0] = p->status;
831 status[1] = 0;
832 }
833 switch (p->status) {
834 case 'C': case 'R':
835 two_paths = 1;
836 break;
837 case 'N': case 'D':
838 two_paths = 0;
839 break;
840 default:
841 two_paths = 0;
842 break;
843 }
844 printf(":%06o %06o %s ",
845 p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
846 printf("%s %s%c%s",
847 sha1_to_hex(p->two->sha1),
848 status,
849 inter_name_termination,
850 p->one->path);
851 if (two_paths)
852 printf("%c%s", inter_name_termination, p->two->path);
853 putchar(line_termination);
854 }
855
856 int diff_unmodified_pair(struct diff_filepair *p)
857 {
858 /* This function is written stricter than necessary to support
859 * the currently implemented transformers, but the idea is to
860 * let transformers to produce diff_filepairs any way they want,
861 * and filter and clean them up here before producing the output.
862 */
863 struct diff_filespec *one, *two;
864
865 if (DIFF_PAIR_UNMERGED(p))
866 return 0; /* unmerged is interesting */
867
868 one = p->one;
869 two = p->two;
870
871 /* deletion, addition, mode or type change
872 * and rename are all interesting.
873 */
874 if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
875 DIFF_PAIR_MODE_CHANGED(p) ||
876 strcmp(one->path, two->path))
877 return 0;
878
879 /* both are valid and point at the same path. that is, we are
880 * dealing with a change.
881 */
882 if (one->sha1_valid && two->sha1_valid &&
883 !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
884 return 1; /* no change */
885 if (!one->sha1_valid && !two->sha1_valid)
886 return 1; /* both look at the same file on the filesystem. */
887 return 0;
888 }
889
890 static void diff_flush_patch(struct diff_filepair *p)
891 {
892 if (diff_unmodified_pair(p))
893 return;
894
895 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
896 (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
897 return; /* no tree diffs in patch format */
898
899 run_diff(p);
900 }
901
902 int diff_queue_is_empty(void)
903 {
904 struct diff_queue_struct *q = &diff_queued_diff;
905 int i;
906 for (i = 0; i < q->nr; i++)
907 if (!diff_unmodified_pair(q->queue[i]))
908 return 0;
909 return 1;
910 }
911
912 #if DIFF_DEBUG
913 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
914 {
915 fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
916 x, one ? : "",
917 s->path,
918 DIFF_FILE_VALID(s) ? "valid" : "invalid",
919 s->mode,
920 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
921 fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
922 x, one ? : "",
923 s->size, s->xfrm_flags);
924 }
925
926 void diff_debug_filepair(const struct diff_filepair *p, int i)
927 {
928 diff_debug_filespec(p->one, i, "one");
929 diff_debug_filespec(p->two, i, "two");
930 fprintf(stderr, "score %d, status %c stays %d broken %d\n",
931 p->score, p->status ? : '?',
932 p->source_stays, p->broken_pair);
933 }
934
935 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
936 {
937 int i;
938 if (msg)
939 fprintf(stderr, "%s\n", msg);
940 fprintf(stderr, "q->nr = %d\n", q->nr);
941 for (i = 0; i < q->nr; i++) {
942 struct diff_filepair *p = q->queue[i];
943 diff_debug_filepair(p, i);
944 }
945 }
946 #endif
947
948 static void diff_resolve_rename_copy(void)
949 {
950 int i, j;
951 struct diff_filepair *p, *pp;
952 struct diff_queue_struct *q = &diff_queued_diff;
953
954 diff_debug_queue("resolve-rename-copy", q);
955
956 for (i = 0; i < q->nr; i++) {
957 p = q->queue[i];
958 p->status = 0; /* undecided */
959 if (DIFF_PAIR_UNMERGED(p))
960 p->status = 'U';
961 else if (!DIFF_FILE_VALID(p->one))
962 p->status = 'N';
963 else if (!DIFF_FILE_VALID(p->two))
964 p->status = 'D';
965 else if (DIFF_PAIR_TYPE_CHANGED(p))
966 p->status = 'T';
967
968 /* from this point on, we are dealing with a pair
969 * whose both sides are valid and of the same type, i.e.
970 * either in-place edit or rename/copy edit.
971 */
972 else if (DIFF_PAIR_RENAME(p)) {
973 if (p->source_stays) {
974 p->status = 'C';
975 continue;
976 }
977 /* See if there is some other filepair that
978 * copies from the same source as us. If so
979 * we are a copy. Otherwise we are a rename.
980 */
981 for (j = i + 1; j < q->nr; j++) {
982 pp = q->queue[j];
983 if (strcmp(pp->one->path, p->one->path))
984 continue; /* not us */
985 if (!DIFF_PAIR_RENAME(pp))
986 continue; /* not a rename/copy */
987 /* pp is a rename/copy from the same source */
988 p->status = 'C';
989 break;
990 }
991 if (!p->status)
992 p->status = 'R';
993 }
994 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
995 p->one->mode != p->two->mode)
996 p->status = 'M';
997 else {
998 /* This is a "no-change" entry and should not
999 * happen anymore, but prepare for broken callers.
1000 */
1001 error("feeding unmodified %s to diffcore",
1002 p->one->path);
1003 p->status = 'X';
1004 }
1005 }
1006 diff_debug_queue("resolve-rename-copy done", q);
1007 }
1008
1009 void diff_flush(int diff_output_style)
1010 {
1011 struct diff_queue_struct *q = &diff_queued_diff;
1012 int i;
1013 int line_termination = '\n';
1014 int inter_name_termination = '\t';
1015
1016 if (diff_output_style == DIFF_FORMAT_MACHINE)
1017 line_termination = inter_name_termination = 0;
1018
1019 for (i = 0; i < q->nr; i++) {
1020 struct diff_filepair *p = q->queue[i];
1021 if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
1022 (p->status == 'X'))
1023 continue;
1024 if (p->status == 0)
1025 die("internal error in diff-resolve-rename-copy");
1026 switch (diff_output_style) {
1027 case DIFF_FORMAT_PATCH:
1028 diff_flush_patch(p);
1029 break;
1030 case DIFF_FORMAT_HUMAN:
1031 case DIFF_FORMAT_MACHINE:
1032 diff_flush_raw(p, line_termination,
1033 inter_name_termination);
1034 break;
1035 }
1036 }
1037 for (i = 0; i < q->nr; i++)
1038 diff_free_filepair(q->queue[i]);
1039 free(q->queue);
1040 q->queue = NULL;
1041 q->nr = q->alloc = 0;
1042 }
1043
1044 static void diffcore_apply_filter(const char *filter)
1045 {
1046 int i;
1047 struct diff_queue_struct *q = &diff_queued_diff;
1048 struct diff_queue_struct outq;
1049 outq.queue = NULL;
1050 outq.nr = outq.alloc = 0;
1051
1052 if (!filter)
1053 return;
1054
1055 if (strchr(filter, 'A')) {
1056 /* All-or-none */
1057 int found;
1058 for (i = found = 0; !found && i < q->nr; i++) {
1059 struct diff_filepair *p = q->queue[i];
1060 if (((p->status == 'M') &&
1061 ((p->score && strchr(filter, 'B')) ||
1062 (!p->score && strchr(filter, 'M')))) ||
1063 ((p->status != 'M') && strchr(filter, p->status)))
1064 found++;
1065 }
1066 if (found)
1067 return;
1068
1069 /* otherwise we will clear the whole queue
1070 * by copying the empty outq at the end of this
1071 * function, but first clear the current entries
1072 * in the queue.
1073 */
1074 for (i = 0; i < q->nr; i++)
1075 diff_free_filepair(q->queue[i]);
1076 }
1077 else {
1078 /* Only the matching ones */
1079 for (i = 0; i < q->nr; i++) {
1080 struct diff_filepair *p = q->queue[i];
1081 if (((p->status == 'M') &&
1082 ((p->score && strchr(filter, 'B')) ||
1083 (!p->score && strchr(filter, 'M')))) ||
1084 ((p->status != 'M') && strchr(filter, p->status)))
1085 diff_q(&outq, p);
1086 else
1087 diff_free_filepair(p);
1088 }
1089 }
1090 free(q->queue);
1091 *q = outq;
1092 }
1093
1094 void diffcore_std(const char **paths,
1095 int detect_rename, int rename_score,
1096 const char *pickaxe, int pickaxe_opts,
1097 int break_opt,
1098 const char *orderfile,
1099 const char *filter)
1100 {
1101 if (paths && paths[0])
1102 diffcore_pathspec(paths);
1103 if (break_opt != -1)
1104 diffcore_break(break_opt);
1105 if (detect_rename)
1106 diffcore_rename(detect_rename, rename_score);
1107 if (break_opt != -1)
1108 diffcore_merge_broken();
1109 if (pickaxe)
1110 diffcore_pickaxe(pickaxe, pickaxe_opts);
1111 if (orderfile)
1112 diffcore_order(orderfile);
1113 diff_resolve_rename_copy();
1114 diffcore_apply_filter(filter);
1115 }
1116
1117
1118 void diffcore_std_no_resolve(const char **paths,
1119 const char *pickaxe, int pickaxe_opts,
1120 const char *orderfile,
1121 const char *filter)
1122 {
1123 if (paths && paths[0])
1124 diffcore_pathspec(paths);
1125 if (pickaxe)
1126 diffcore_pickaxe(pickaxe, pickaxe_opts);
1127 if (orderfile)
1128 diffcore_order(orderfile);
1129 diffcore_apply_filter(filter);
1130 }
1131
1132 void diff_addremove(int addremove, unsigned mode,
1133 const unsigned char *sha1,
1134 const char *base, const char *path)
1135 {
1136 char concatpath[PATH_MAX];
1137 struct diff_filespec *one, *two;
1138
1139 /* This may look odd, but it is a preparation for
1140 * feeding "there are unchanged files which should
1141 * not produce diffs, but when you are doing copy
1142 * detection you would need them, so here they are"
1143 * entries to the diff-core. They will be prefixed
1144 * with something like '=' or '*' (I haven't decided
1145 * which but should not make any difference).
1146 * Feeding the same new and old to diff_change()
1147 * also has the same effect.
1148 * Before the final output happens, they are pruned after
1149 * merged into rename/copy pairs as appropriate.
1150 */
1151 if (reverse_diff)
1152 addremove = (addremove == '+' ? '-' :
1153 addremove == '-' ? '+' : addremove);
1154
1155 if (!path) path = "";
1156 sprintf(concatpath, "%s%s", base, path);
1157 one = alloc_filespec(concatpath);
1158 two = alloc_filespec(concatpath);
1159
1160 if (addremove != '+')
1161 fill_filespec(one, sha1, mode);
1162 if (addremove != '-')
1163 fill_filespec(two, sha1, mode);
1164
1165 diff_queue(&diff_queued_diff, one, two);
1166 }
1167
1168 void diff_helper_input(unsigned old_mode,
1169 unsigned new_mode,
1170 const unsigned char *old_sha1,
1171 const unsigned char *new_sha1,
1172 const char *old_path,
1173 int status,
1174 int score,
1175 const char *new_path)
1176 {
1177 struct diff_filespec *one, *two;
1178 struct diff_filepair *dp;
1179
1180 one = alloc_filespec(old_path);
1181 two = alloc_filespec(new_path);
1182 if (old_mode)
1183 fill_filespec(one, old_sha1, old_mode);
1184 if (new_mode)
1185 fill_filespec(two, new_sha1, new_mode);
1186 dp = diff_queue(&diff_queued_diff, one, two);
1187 dp->score = score * MAX_SCORE / 100;
1188 dp->status = status;
1189 }
1190
1191 void diff_change(unsigned old_mode, unsigned new_mode,
1192 const unsigned char *old_sha1,
1193 const unsigned char *new_sha1,
1194 const char *base, const char *path)
1195 {
1196 char concatpath[PATH_MAX];
1197 struct diff_filespec *one, *two;
1198
1199 if (reverse_diff) {
1200 unsigned tmp;
1201 const unsigned char *tmp_c;
1202 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1203 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1204 }
1205 if (!path) path = "";
1206 sprintf(concatpath, "%s%s", base, path);
1207 one = alloc_filespec(concatpath);
1208 two = alloc_filespec(concatpath);
1209 fill_filespec(one, old_sha1, old_mode);
1210 fill_filespec(two, new_sha1, new_mode);
1211
1212 diff_queue(&diff_queued_diff, one, two);
1213 }
1214
1215 void diff_unmerge(const char *path)
1216 {
1217 struct diff_filespec *one, *two;
1218 one = alloc_filespec(path);
1219 two = alloc_filespec(path);
1220 diff_queue(&diff_queued_diff, one, two);
1221 }