Make sure get_sha1 does not accept ambiguous sha1 prefix (again).
[git/gitweb.git] / diff.c
blob7d06b035ae8b6a53f10a7f94251a24d911baa509
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"
12 static const char *diff_opts = "-pu";
14 static int use_size_cache;
16 static const char *external_diff(void)
18 static const char *external_diff_cmd = NULL;
19 static int done_preparing = 0;
20 const char *env_diff_opts;
22 if (done_preparing)
23 return external_diff_cmd;
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:
31 * GIT_DIFF_OPTS="-c";
33 external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
35 /* In case external diff fails... */
36 env_diff_opts = getenv("GIT_DIFF_OPTS");
37 if (env_diff_opts) diff_opts = env_diff_opts;
39 done_preparing = 1;
40 return external_diff_cmd;
43 #define TEMPFILE_PATH_LEN 50
45 static struct diff_tempfile {
46 const char *name; /* filename external diff should read from */
47 char hex[41];
48 char mode[10];
49 char tmp_path[TEMPFILE_PATH_LEN];
50 } diff_temp[2];
52 static int count_lines(const char *filename)
54 FILE *in;
55 int count, ch, completely_empty = 1, nl_just_seen = 0;
56 in = fopen(filename, "r");
57 count = 0;
58 while ((ch = fgetc(in)) != EOF)
59 if (ch == '\n') {
60 count++;
61 nl_just_seen = 1;
62 completely_empty = 0;
64 else {
65 nl_just_seen = 0;
66 completely_empty = 0;
68 fclose(in);
69 if (completely_empty)
70 return 0;
71 if (!nl_just_seen)
72 count++; /* no trailing newline */
73 return count;
76 static void print_line_count(int count)
78 switch (count) {
79 case 0:
80 printf("0,0");
81 break;
82 case 1:
83 printf("1");
84 break;
85 default:
86 printf("1,%d", count);
87 break;
91 static void copy_file(int prefix, const char *filename)
93 FILE *in;
94 int ch, nl_just_seen = 1;
95 in = fopen(filename, "r");
96 while ((ch = fgetc(in)) != EOF) {
97 if (nl_just_seen)
98 putchar(prefix);
99 putchar(ch);
100 if (ch == '\n')
101 nl_just_seen = 1;
102 else
103 nl_just_seen = 0;
105 fclose(in);
106 if (!nl_just_seen)
107 printf("\n\\ No newline at end of file\n");
110 static void emit_rewrite_diff(const char *name_a,
111 const char *name_b,
112 struct diff_tempfile *temp)
114 /* Use temp[i].name as input, name_a and name_b as labels */
115 int lc_a, lc_b;
116 lc_a = count_lines(temp[0].name);
117 lc_b = count_lines(temp[1].name);
118 printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
119 print_line_count(lc_a);
120 printf(" +");
121 print_line_count(lc_b);
122 printf(" @@\n");
123 if (lc_a)
124 copy_file('-', temp[0].name);
125 if (lc_b)
126 copy_file('+', temp[1].name);
129 static void builtin_diff(const char *name_a,
130 const char *name_b,
131 struct diff_tempfile *temp,
132 const char *xfrm_msg,
133 int complete_rewrite)
135 int i, next_at, cmd_size;
136 const char *const diff_cmd = "diff -L%s%s -L%s%s";
137 const char *const diff_arg = "%s %s||:"; /* "||:" is to return 0 */
138 const char *input_name_sq[2];
139 const char *path0[2];
140 const char *path1[2];
141 const char *name_sq[2];
142 char *cmd;
144 name_sq[0] = sq_quote(name_a);
145 name_sq[1] = sq_quote(name_b);
147 /* diff_cmd and diff_arg have 6 %s in total which makes
148 * the sum of these strings 12 bytes larger than required.
149 * we use 2 spaces around diff-opts, and we need to count
150 * terminating NUL, so we subtract 9 here.
152 cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
153 strlen(diff_arg) - 9);
154 for (i = 0; i < 2; i++) {
155 input_name_sq[i] = sq_quote(temp[i].name);
156 if (!strcmp(temp[i].name, "/dev/null")) {
157 path0[i] = "/dev/null";
158 path1[i] = "";
159 } else {
160 path0[i] = i ? "b/" : "a/";
161 path1[i] = name_sq[i];
163 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
164 strlen(input_name_sq[i]));
167 cmd = xmalloc(cmd_size);
169 next_at = 0;
170 next_at += snprintf(cmd+next_at, cmd_size-next_at,
171 diff_cmd,
172 path0[0], path1[0], path0[1], path1[1]);
173 next_at += snprintf(cmd+next_at, cmd_size-next_at,
174 " %s ", diff_opts);
175 next_at += snprintf(cmd+next_at, cmd_size-next_at,
176 diff_arg, input_name_sq[0], input_name_sq[1]);
178 printf("diff --git a/%s b/%s\n", name_a, name_b);
179 if (!path1[0][0]) {
180 printf("new file mode %s\n", temp[1].mode);
181 if (xfrm_msg && xfrm_msg[0])
182 puts(xfrm_msg);
184 else if (!path1[1][0]) {
185 printf("deleted file mode %s\n", temp[0].mode);
186 if (xfrm_msg && xfrm_msg[0])
187 puts(xfrm_msg);
189 else {
190 if (strcmp(temp[0].mode, temp[1].mode)) {
191 printf("old mode %s\n", temp[0].mode);
192 printf("new mode %s\n", temp[1].mode);
194 if (xfrm_msg && xfrm_msg[0])
195 puts(xfrm_msg);
196 if (strncmp(temp[0].mode, temp[1].mode, 3))
197 /* we do not run diff between different kind
198 * of objects.
200 exit(0);
201 if (complete_rewrite) {
202 fflush(NULL);
203 emit_rewrite_diff(name_a, name_b, temp);
204 exit(0);
207 fflush(NULL);
208 execlp("/bin/sh","sh", "-c", cmd, NULL);
211 struct diff_filespec *alloc_filespec(const char *path)
213 int namelen = strlen(path);
214 struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
216 memset(spec, 0, sizeof(*spec));
217 spec->path = (char *)(spec + 1);
218 memcpy(spec->path, path, namelen+1);
219 return spec;
222 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
223 unsigned short mode)
225 if (mode) {
226 spec->mode = DIFF_FILE_CANON_MODE(mode);
227 memcpy(spec->sha1, sha1, 20);
228 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
233 * Given a name and sha1 pair, if the dircache tells us the file in
234 * the work tree has that object contents, return true, so that
235 * prepare_temp_file() does not have to inflate and extract.
237 static int work_tree_matches(const char *name, const unsigned char *sha1)
239 struct cache_entry *ce;
240 struct stat st;
241 int pos, len;
243 /* We do not read the cache ourselves here, because the
244 * benchmark with my previous version that always reads cache
245 * shows that it makes things worse for diff-tree comparing
246 * two linux-2.6 kernel trees in an already checked out work
247 * tree. This is because most diff-tree comparisons deal with
248 * only a small number of files, while reading the cache is
249 * expensive for a large project, and its cost outweighs the
250 * savings we get by not inflating the object to a temporary
251 * file. Practically, this code only helps when we are used
252 * by diff-cache --cached, which does read the cache before
253 * calling us.
255 if (!active_cache)
256 return 0;
258 len = strlen(name);
259 pos = cache_name_pos(name, len);
260 if (pos < 0)
261 return 0;
262 ce = active_cache[pos];
263 if ((lstat(name, &st) < 0) ||
264 !S_ISREG(st.st_mode) || /* careful! */
265 ce_match_stat(ce, &st) ||
266 memcmp(sha1, ce->sha1, 20))
267 return 0;
268 /* we return 1 only when we can stat, it is a regular file,
269 * stat information matches, and sha1 recorded in the cache
270 * matches. I.e. we know the file in the work tree really is
271 * the same as the <name, sha1> pair.
273 return 1;
276 static struct sha1_size_cache {
277 unsigned char sha1[20];
278 unsigned long size;
279 } **sha1_size_cache;
280 static int sha1_size_cache_nr, sha1_size_cache_alloc;
282 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
283 int find_only,
284 unsigned long size)
286 int first, last;
287 struct sha1_size_cache *e;
289 first = 0;
290 last = sha1_size_cache_nr;
291 while (last > first) {
292 int cmp, next = (last + first) >> 1;
293 e = sha1_size_cache[next];
294 cmp = memcmp(e->sha1, sha1, 20);
295 if (!cmp)
296 return e;
297 if (cmp < 0) {
298 last = next;
299 continue;
301 first = next+1;
303 /* not found */
304 if (find_only)
305 return NULL;
306 /* insert to make it at "first" */
307 if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
308 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
309 sha1_size_cache = xrealloc(sha1_size_cache,
310 sha1_size_cache_alloc *
311 sizeof(*sha1_size_cache));
313 sha1_size_cache_nr++;
314 if (first < sha1_size_cache_nr)
315 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
316 (sha1_size_cache_nr - first - 1) *
317 sizeof(*sha1_size_cache));
318 e = xmalloc(sizeof(struct sha1_size_cache));
319 sha1_size_cache[first] = e;
320 memcpy(e->sha1, sha1, 20);
321 e->size = size;
322 return e;
326 * While doing rename detection and pickaxe operation, we may need to
327 * grab the data for the blob (or file) for our own in-core comparison.
328 * diff_filespec has data and size fields for this purpose.
330 int diff_populate_filespec(struct diff_filespec *s, int size_only)
332 int err = 0;
333 if (!DIFF_FILE_VALID(s))
334 die("internal error: asking to populate invalid file.");
335 if (S_ISDIR(s->mode))
336 return -1;
338 if (!use_size_cache)
339 size_only = 0;
341 if (s->data)
342 return err;
343 if (!s->sha1_valid ||
344 work_tree_matches(s->path, s->sha1)) {
345 struct stat st;
346 int fd;
347 if (lstat(s->path, &st) < 0) {
348 if (errno == ENOENT) {
349 err_empty:
350 err = -1;
351 empty:
352 s->data = "";
353 s->size = 0;
354 return err;
357 s->size = st.st_size;
358 if (!s->size)
359 goto empty;
360 if (size_only)
361 return 0;
362 if (S_ISLNK(st.st_mode)) {
363 int ret;
364 s->data = xmalloc(s->size);
365 s->should_free = 1;
366 ret = readlink(s->path, s->data, s->size);
367 if (ret < 0) {
368 free(s->data);
369 goto err_empty;
371 return 0;
373 fd = open(s->path, O_RDONLY);
374 if (fd < 0)
375 goto err_empty;
376 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
377 close(fd);
378 if (s->data == MAP_FAILED)
379 goto err_empty;
380 s->should_munmap = 1;
382 else {
383 char type[20];
384 struct sha1_size_cache *e;
386 if (size_only) {
387 e = locate_size_cache(s->sha1, 1, 0);
388 if (e) {
389 s->size = e->size;
390 return 0;
392 if (!sha1_object_info(s->sha1, type, &s->size))
393 locate_size_cache(s->sha1, 0, s->size);
395 else {
396 s->data = read_sha1_file(s->sha1, type, &s->size);
397 s->should_free = 1;
400 return 0;
403 void diff_free_filespec_data(struct diff_filespec *s)
405 if (s->should_free)
406 free(s->data);
407 else if (s->should_munmap)
408 munmap(s->data, s->size);
409 s->should_free = s->should_munmap = 0;
410 s->data = NULL;
413 static void prep_temp_blob(struct diff_tempfile *temp,
414 void *blob,
415 unsigned long size,
416 const unsigned char *sha1,
417 int mode)
419 int fd;
421 fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
422 if (fd < 0)
423 die("unable to create temp-file");
424 if (write(fd, blob, size) != size)
425 die("unable to write temp-file");
426 close(fd);
427 temp->name = temp->tmp_path;
428 strcpy(temp->hex, sha1_to_hex(sha1));
429 temp->hex[40] = 0;
430 sprintf(temp->mode, "%06o", mode);
433 static void prepare_temp_file(const char *name,
434 struct diff_tempfile *temp,
435 struct diff_filespec *one)
437 if (!DIFF_FILE_VALID(one)) {
438 not_a_valid_file:
439 /* A '-' entry produces this for file-2, and
440 * a '+' entry produces this for file-1.
442 temp->name = "/dev/null";
443 strcpy(temp->hex, ".");
444 strcpy(temp->mode, ".");
445 return;
448 if (!one->sha1_valid ||
449 work_tree_matches(name, one->sha1)) {
450 struct stat st;
451 if (lstat(name, &st) < 0) {
452 if (errno == ENOENT)
453 goto not_a_valid_file;
454 die("stat(%s): %s", name, strerror(errno));
456 if (S_ISLNK(st.st_mode)) {
457 int ret;
458 char *buf, buf_[1024];
459 buf = ((sizeof(buf_) < st.st_size) ?
460 xmalloc(st.st_size) : buf_);
461 ret = readlink(name, buf, st.st_size);
462 if (ret < 0)
463 die("readlink(%s)", name);
464 prep_temp_blob(temp, buf, st.st_size,
465 (one->sha1_valid ?
466 one->sha1 : null_sha1),
467 (one->sha1_valid ?
468 one->mode : S_IFLNK));
470 else {
471 /* we can borrow from the file in the work tree */
472 temp->name = name;
473 if (!one->sha1_valid)
474 strcpy(temp->hex, sha1_to_hex(null_sha1));
475 else
476 strcpy(temp->hex, sha1_to_hex(one->sha1));
477 /* Even though we may sometimes borrow the
478 * contents from the work tree, we always want
479 * one->mode. mode is trustworthy even when
480 * !(one->sha1_valid), as long as
481 * DIFF_FILE_VALID(one).
483 sprintf(temp->mode, "%06o", one->mode);
485 return;
487 else {
488 if (diff_populate_filespec(one, 0))
489 die("cannot read data blob for %s", one->path);
490 prep_temp_blob(temp, one->data, one->size,
491 one->sha1, one->mode);
495 static void remove_tempfile(void)
497 int i;
499 for (i = 0; i < 2; i++)
500 if (diff_temp[i].name == diff_temp[i].tmp_path) {
501 unlink(diff_temp[i].name);
502 diff_temp[i].name = NULL;
506 static void remove_tempfile_on_signal(int signo)
508 remove_tempfile();
511 /* An external diff command takes:
513 * diff-cmd name infile1 infile1-sha1 infile1-mode \
514 * infile2 infile2-sha1 infile2-mode [ rename-to ]
517 static void run_external_diff(const char *pgm,
518 const char *name,
519 const char *other,
520 struct diff_filespec *one,
521 struct diff_filespec *two,
522 const char *xfrm_msg,
523 int complete_rewrite)
525 struct diff_tempfile *temp = diff_temp;
526 pid_t pid;
527 int status;
528 static int atexit_asked = 0;
529 const char *othername;
531 othername = (other? other : name);
532 if (one && two) {
533 prepare_temp_file(name, &temp[0], one);
534 prepare_temp_file(othername, &temp[1], two);
535 if (! atexit_asked &&
536 (temp[0].name == temp[0].tmp_path ||
537 temp[1].name == temp[1].tmp_path)) {
538 atexit_asked = 1;
539 atexit(remove_tempfile);
541 signal(SIGINT, remove_tempfile_on_signal);
544 fflush(NULL);
545 pid = fork();
546 if (pid < 0)
547 die("unable to fork");
548 if (!pid) {
549 if (pgm) {
550 if (one && two) {
551 const char *exec_arg[10];
552 const char **arg = &exec_arg[0];
553 *arg++ = pgm;
554 *arg++ = name;
555 *arg++ = temp[0].name;
556 *arg++ = temp[0].hex;
557 *arg++ = temp[0].mode;
558 *arg++ = temp[1].name;
559 *arg++ = temp[1].hex;
560 *arg++ = temp[1].mode;
561 if (other) {
562 *arg++ = other;
563 *arg++ = xfrm_msg;
565 *arg = NULL;
566 execvp(pgm, (char *const*) exec_arg);
568 else
569 execlp(pgm, pgm, name, NULL);
572 * otherwise we use the built-in one.
574 if (one && two)
575 builtin_diff(name, othername, temp, xfrm_msg,
576 complete_rewrite);
577 else
578 printf("* Unmerged path %s\n", name);
579 exit(0);
581 if (waitpid(pid, &status, 0) < 0 ||
582 !WIFEXITED(status) || WEXITSTATUS(status)) {
583 /* Earlier we did not check the exit status because
584 * diff exits non-zero if files are different, and
585 * we are not interested in knowing that. It was a
586 * mistake which made it harder to quit a diff-*
587 * session that uses the git-apply-patch-script as
588 * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
589 * should also exit non-zero only when it wants to
590 * abort the entire diff-* session.
592 remove_tempfile();
593 fprintf(stderr, "external diff died, stopping at %s.\n", name);
594 exit(1);
596 remove_tempfile();
599 static void run_diff(struct diff_filepair *p)
601 const char *pgm = external_diff();
602 char msg_[PATH_MAX*2+200], *xfrm_msg;
603 struct diff_filespec *one;
604 struct diff_filespec *two;
605 const char *name;
606 const char *other;
607 int complete_rewrite = 0;
609 if (DIFF_PAIR_UNMERGED(p)) {
610 /* unmerged */
611 run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
613 return;
616 name = p->one->path;
617 other = (strcmp(name, p->two->path) ? p->two->path : NULL);
618 one = p->one; two = p->two;
619 switch (p->status) {
620 case DIFF_STATUS_COPIED:
621 sprintf(msg_,
622 "similarity index %d%%\n"
623 "copy from %s\n"
624 "copy to %s",
625 (int)(0.5 + p->score * 100.0/MAX_SCORE),
626 name, other);
627 xfrm_msg = msg_;
628 break;
629 case DIFF_STATUS_RENAMED:
630 sprintf(msg_,
631 "similarity index %d%%\n"
632 "rename from %s\n"
633 "rename to %s",
634 (int)(0.5 + p->score * 100.0/MAX_SCORE),
635 name, other);
636 xfrm_msg = msg_;
637 break;
638 case DIFF_STATUS_MODIFIED:
639 if (p->score) {
640 sprintf(msg_,
641 "dissimilarity index %d%%",
642 (int)(0.5 + p->score * 100.0/MAX_SCORE));
643 xfrm_msg = msg_;
644 complete_rewrite = 1;
645 break;
647 /* fallthru */
648 default:
649 xfrm_msg = NULL;
652 if (!pgm &&
653 DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
654 (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
655 /* a filepair that changes between file and symlink
656 * needs to be split into deletion and creation.
658 struct diff_filespec *null = alloc_filespec(two->path);
659 run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
660 free(null);
661 null = alloc_filespec(one->path);
662 run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
663 free(null);
665 else
666 run_external_diff(pgm, name, other, one, two, xfrm_msg,
667 complete_rewrite);
670 void diff_setup(struct diff_options *options)
672 memset(options, 0, sizeof(*options));
673 options->output_format = DIFF_FORMAT_RAW;
674 options->line_termination = '\n';
675 options->break_opt = -1;
676 options->rename_limit = -1;
679 int diff_setup_done(struct diff_options *options)
681 if ((options->find_copies_harder || 0 <= options->rename_limit) &&
682 options->detect_rename != DIFF_DETECT_COPY)
683 return -1;
684 if (options->setup & DIFF_SETUP_USE_CACHE) {
685 if (!active_cache)
686 /* read-cache does not die even when it fails
687 * so it is safe for us to do this here. Also
688 * it does not smudge active_cache or active_nr
689 * when it fails, so we do not have to worry about
690 * cleaning it up oufselves either.
692 read_cache();
694 if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
695 use_size_cache = 1;
697 return 0;
700 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
702 const char *arg = av[0];
703 if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
704 options->output_format = DIFF_FORMAT_PATCH;
705 else if (!strcmp(arg, "-z"))
706 options->line_termination = 0;
707 else if (!strncmp(arg, "-l", 2))
708 options->rename_limit = strtoul(arg+2, NULL, 10);
709 else if (!strcmp(arg, "--name-only"))
710 options->output_format = DIFF_FORMAT_NAME;
711 else if (!strcmp(arg, "--name-status"))
712 options->output_format = DIFF_FORMAT_NAME_STATUS;
713 else if (!strcmp(arg, "-R"))
714 options->reverse_diff = 1;
715 else if (!strncmp(arg, "-S", 2))
716 options->pickaxe = arg + 2;
717 else if (!strcmp(arg, "-s"))
718 options->output_format = DIFF_FORMAT_NO_OUTPUT;
719 else if (!strncmp(arg, "-O", 2))
720 options->orderfile = arg + 2;
721 else if (!strncmp(arg, "--diff-filter=", 14))
722 options->filter = arg + 14;
723 else if (!strcmp(arg, "--pickaxe-all"))
724 options->pickaxe_opts = DIFF_PICKAXE_ALL;
725 else if (!strncmp(arg, "-B", 2)) {
726 if ((options->break_opt =
727 diff_scoreopt_parse(arg)) == -1)
728 return -1;
730 else if (!strncmp(arg, "-M", 2)) {
731 if ((options->rename_score =
732 diff_scoreopt_parse(arg)) == -1)
733 return -1;
734 options->detect_rename = DIFF_DETECT_RENAME;
736 else if (!strncmp(arg, "-C", 2)) {
737 if ((options->rename_score =
738 diff_scoreopt_parse(arg)) == -1)
739 return -1;
740 options->detect_rename = DIFF_DETECT_COPY;
742 else if (!strcmp(arg, "--find-copies-harder"))
743 options->find_copies_harder = 1;
744 else
745 return 0;
746 return 1;
749 static int parse_num(const char **cp_p)
751 int num, scale, ch, cnt;
752 const char *cp = *cp_p;
754 cnt = num = 0;
755 scale = 1;
756 while ('0' <= (ch = *cp) && ch <= '9') {
757 if (cnt++ < 5) {
758 /* We simply ignore more than 5 digits precision. */
759 scale *= 10;
760 num = num * 10 + ch - '0';
762 cp++;
764 *cp_p = cp;
766 /* user says num divided by scale and we say internally that
767 * is MAX_SCORE * num / scale.
769 return (MAX_SCORE * num / scale);
772 int diff_scoreopt_parse(const char *opt)
774 int opt1, opt2, cmd;
776 if (*opt++ != '-')
777 return -1;
778 cmd = *opt++;
779 if (cmd != 'M' && cmd != 'C' && cmd != 'B')
780 return -1; /* that is not a -M, -C nor -B option */
782 opt1 = parse_num(&opt);
783 if (cmd != 'B')
784 opt2 = 0;
785 else {
786 if (*opt == 0)
787 opt2 = 0;
788 else if (*opt != '/')
789 return -1; /* we expect -B80/99 or -B80 */
790 else {
791 opt++;
792 opt2 = parse_num(&opt);
795 if (*opt != 0)
796 return -1;
797 return opt1 | (opt2 << 16);
800 struct diff_queue_struct diff_queued_diff;
802 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
804 if (queue->alloc <= queue->nr) {
805 queue->alloc = alloc_nr(queue->alloc);
806 queue->queue = xrealloc(queue->queue,
807 sizeof(dp) * queue->alloc);
809 queue->queue[queue->nr++] = dp;
812 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
813 struct diff_filespec *one,
814 struct diff_filespec *two)
816 struct diff_filepair *dp = xmalloc(sizeof(*dp));
817 dp->one = one;
818 dp->two = two;
819 dp->score = 0;
820 dp->status = 0;
821 dp->source_stays = 0;
822 dp->broken_pair = 0;
823 if (queue)
824 diff_q(queue, dp);
825 return dp;
828 void diff_free_filepair(struct diff_filepair *p)
830 diff_free_filespec_data(p->one);
831 diff_free_filespec_data(p->two);
832 free(p->one);
833 free(p->two);
834 free(p);
837 static void diff_flush_raw(struct diff_filepair *p,
838 int line_termination,
839 int inter_name_termination,
840 int output_format)
842 int two_paths;
843 char status[10];
845 if (line_termination) {
846 const char *const err =
847 "path %s cannot be expressed without -z";
848 if (strchr(p->one->path, line_termination) ||
849 strchr(p->one->path, inter_name_termination))
850 die(err, p->one->path);
851 if (strchr(p->two->path, line_termination) ||
852 strchr(p->two->path, inter_name_termination))
853 die(err, p->two->path);
856 if (p->score)
857 sprintf(status, "%c%03d", p->status,
858 (int)(0.5 + p->score * 100.0/MAX_SCORE));
859 else {
860 status[0] = p->status;
861 status[1] = 0;
863 switch (p->status) {
864 case DIFF_STATUS_COPIED:
865 case DIFF_STATUS_RENAMED:
866 two_paths = 1;
867 break;
868 case DIFF_STATUS_ADDED:
869 case DIFF_STATUS_DELETED:
870 two_paths = 0;
871 break;
872 default:
873 two_paths = 0;
874 break;
876 if (output_format != DIFF_FORMAT_NAME_STATUS) {
877 printf(":%06o %06o %s ",
878 p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
879 printf("%s ", sha1_to_hex(p->two->sha1));
881 printf("%s%c%s",status, inter_name_termination, p->one->path);
882 if (two_paths)
883 printf("%c%s", inter_name_termination, p->two->path);
884 putchar(line_termination);
887 static void diff_flush_name(struct diff_filepair *p,
888 int line_termination)
890 printf("%s%c", p->two->path, line_termination);
893 int diff_unmodified_pair(struct diff_filepair *p)
895 /* This function is written stricter than necessary to support
896 * the currently implemented transformers, but the idea is to
897 * let transformers to produce diff_filepairs any way they want,
898 * and filter and clean them up here before producing the output.
900 struct diff_filespec *one, *two;
902 if (DIFF_PAIR_UNMERGED(p))
903 return 0; /* unmerged is interesting */
905 one = p->one;
906 two = p->two;
908 /* deletion, addition, mode or type change
909 * and rename are all interesting.
911 if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
912 DIFF_PAIR_MODE_CHANGED(p) ||
913 strcmp(one->path, two->path))
914 return 0;
916 /* both are valid and point at the same path. that is, we are
917 * dealing with a change.
919 if (one->sha1_valid && two->sha1_valid &&
920 !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
921 return 1; /* no change */
922 if (!one->sha1_valid && !two->sha1_valid)
923 return 1; /* both look at the same file on the filesystem. */
924 return 0;
927 static void diff_flush_patch(struct diff_filepair *p)
929 if (diff_unmodified_pair(p))
930 return;
932 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
933 (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
934 return; /* no tree diffs in patch format */
936 run_diff(p);
939 int diff_queue_is_empty(void)
941 struct diff_queue_struct *q = &diff_queued_diff;
942 int i;
943 for (i = 0; i < q->nr; i++)
944 if (!diff_unmodified_pair(q->queue[i]))
945 return 0;
946 return 1;
949 #if DIFF_DEBUG
950 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
952 fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
953 x, one ? one : "",
954 s->path,
955 DIFF_FILE_VALID(s) ? "valid" : "invalid",
956 s->mode,
957 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
958 fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
959 x, one ? one : "",
960 s->size, s->xfrm_flags);
963 void diff_debug_filepair(const struct diff_filepair *p, int i)
965 diff_debug_filespec(p->one, i, "one");
966 diff_debug_filespec(p->two, i, "two");
967 fprintf(stderr, "score %d, status %c stays %d broken %d\n",
968 p->score, p->status ? p->status : '?',
969 p->source_stays, p->broken_pair);
972 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
974 int i;
975 if (msg)
976 fprintf(stderr, "%s\n", msg);
977 fprintf(stderr, "q->nr = %d\n", q->nr);
978 for (i = 0; i < q->nr; i++) {
979 struct diff_filepair *p = q->queue[i];
980 diff_debug_filepair(p, i);
983 #endif
985 static void diff_resolve_rename_copy(void)
987 int i, j;
988 struct diff_filepair *p, *pp;
989 struct diff_queue_struct *q = &diff_queued_diff;
991 diff_debug_queue("resolve-rename-copy", q);
993 for (i = 0; i < q->nr; i++) {
994 p = q->queue[i];
995 p->status = 0; /* undecided */
996 if (DIFF_PAIR_UNMERGED(p))
997 p->status = DIFF_STATUS_UNMERGED;
998 else if (!DIFF_FILE_VALID(p->one))
999 p->status = DIFF_STATUS_ADDED;
1000 else if (!DIFF_FILE_VALID(p->two))
1001 p->status = DIFF_STATUS_DELETED;
1002 else if (DIFF_PAIR_TYPE_CHANGED(p))
1003 p->status = DIFF_STATUS_TYPE_CHANGED;
1005 /* from this point on, we are dealing with a pair
1006 * whose both sides are valid and of the same type, i.e.
1007 * either in-place edit or rename/copy edit.
1009 else if (DIFF_PAIR_RENAME(p)) {
1010 if (p->source_stays) {
1011 p->status = DIFF_STATUS_COPIED;
1012 continue;
1014 /* See if there is some other filepair that
1015 * copies from the same source as us. If so
1016 * we are a copy. Otherwise we are either a
1017 * copy if the path stays, or a rename if it
1018 * does not, but we already handled "stays" case.
1020 for (j = i + 1; j < q->nr; j++) {
1021 pp = q->queue[j];
1022 if (strcmp(pp->one->path, p->one->path))
1023 continue; /* not us */
1024 if (!DIFF_PAIR_RENAME(pp))
1025 continue; /* not a rename/copy */
1026 /* pp is a rename/copy from the same source */
1027 p->status = DIFF_STATUS_COPIED;
1028 break;
1030 if (!p->status)
1031 p->status = DIFF_STATUS_RENAMED;
1033 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1034 p->one->mode != p->two->mode)
1035 p->status = DIFF_STATUS_MODIFIED;
1036 else {
1037 /* This is a "no-change" entry and should not
1038 * happen anymore, but prepare for broken callers.
1040 error("feeding unmodified %s to diffcore",
1041 p->one->path);
1042 p->status = DIFF_STATUS_UNKNOWN;
1045 diff_debug_queue("resolve-rename-copy done", q);
1048 void diff_flush(struct diff_options *options)
1050 struct diff_queue_struct *q = &diff_queued_diff;
1051 int i;
1052 int inter_name_termination = '\t';
1053 int diff_output_format = options->output_format;
1054 int line_termination = options->line_termination;
1056 if (!line_termination)
1057 inter_name_termination = 0;
1059 for (i = 0; i < q->nr; i++) {
1060 struct diff_filepair *p = q->queue[i];
1061 if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
1062 (p->status == DIFF_STATUS_UNKNOWN))
1063 continue;
1064 if (p->status == 0)
1065 die("internal error in diff-resolve-rename-copy");
1066 switch (diff_output_format) {
1067 case DIFF_FORMAT_PATCH:
1068 diff_flush_patch(p);
1069 break;
1070 case DIFF_FORMAT_RAW:
1071 case DIFF_FORMAT_NAME_STATUS:
1072 diff_flush_raw(p, line_termination,
1073 inter_name_termination,
1074 diff_output_format);
1075 break;
1076 case DIFF_FORMAT_NAME:
1077 diff_flush_name(p, line_termination);
1078 break;
1080 diff_free_filepair(q->queue[i]);
1082 free(q->queue);
1083 q->queue = NULL;
1084 q->nr = q->alloc = 0;
1087 static void diffcore_apply_filter(const char *filter)
1089 int i;
1090 struct diff_queue_struct *q = &diff_queued_diff;
1091 struct diff_queue_struct outq;
1092 outq.queue = NULL;
1093 outq.nr = outq.alloc = 0;
1095 if (!filter)
1096 return;
1098 if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1099 int found;
1100 for (i = found = 0; !found && i < q->nr; i++) {
1101 struct diff_filepair *p = q->queue[i];
1102 if (((p->status == DIFF_STATUS_MODIFIED) &&
1103 ((p->score &&
1104 strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1105 (!p->score &&
1106 strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1107 ((p->status != DIFF_STATUS_MODIFIED) &&
1108 strchr(filter, p->status)))
1109 found++;
1111 if (found)
1112 return;
1114 /* otherwise we will clear the whole queue
1115 * by copying the empty outq at the end of this
1116 * function, but first clear the current entries
1117 * in the queue.
1119 for (i = 0; i < q->nr; i++)
1120 diff_free_filepair(q->queue[i]);
1122 else {
1123 /* Only the matching ones */
1124 for (i = 0; i < q->nr; i++) {
1125 struct diff_filepair *p = q->queue[i];
1127 if (((p->status == DIFF_STATUS_MODIFIED) &&
1128 ((p->score &&
1129 strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1130 (!p->score &&
1131 strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1132 ((p->status != DIFF_STATUS_MODIFIED) &&
1133 strchr(filter, p->status)))
1134 diff_q(&outq, p);
1135 else
1136 diff_free_filepair(p);
1139 free(q->queue);
1140 *q = outq;
1143 void diffcore_std(struct diff_options *options)
1145 if (options->paths && options->paths[0])
1146 diffcore_pathspec(options->paths);
1147 if (options->break_opt != -1)
1148 diffcore_break(options->break_opt);
1149 if (options->detect_rename)
1150 diffcore_rename(options);
1151 if (options->break_opt != -1)
1152 diffcore_merge_broken();
1153 if (options->pickaxe)
1154 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1155 if (options->orderfile)
1156 diffcore_order(options->orderfile);
1157 diff_resolve_rename_copy();
1158 diffcore_apply_filter(options->filter);
1162 void diffcore_std_no_resolve(struct diff_options *options)
1164 if (options->pickaxe)
1165 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1166 if (options->orderfile)
1167 diffcore_order(options->orderfile);
1168 diffcore_apply_filter(options->filter);
1171 void diff_addremove(struct diff_options *options,
1172 int addremove, unsigned mode,
1173 const unsigned char *sha1,
1174 const char *base, const char *path)
1176 char concatpath[PATH_MAX];
1177 struct diff_filespec *one, *two;
1179 /* This may look odd, but it is a preparation for
1180 * feeding "there are unchanged files which should
1181 * not produce diffs, but when you are doing copy
1182 * detection you would need them, so here they are"
1183 * entries to the diff-core. They will be prefixed
1184 * with something like '=' or '*' (I haven't decided
1185 * which but should not make any difference).
1186 * Feeding the same new and old to diff_change()
1187 * also has the same effect.
1188 * Before the final output happens, they are pruned after
1189 * merged into rename/copy pairs as appropriate.
1191 if (options->reverse_diff)
1192 addremove = (addremove == '+' ? '-' :
1193 addremove == '-' ? '+' : addremove);
1195 if (!path) path = "";
1196 sprintf(concatpath, "%s%s", base, path);
1197 one = alloc_filespec(concatpath);
1198 two = alloc_filespec(concatpath);
1200 if (addremove != '+')
1201 fill_filespec(one, sha1, mode);
1202 if (addremove != '-')
1203 fill_filespec(two, sha1, mode);
1205 diff_queue(&diff_queued_diff, one, two);
1208 void diff_change(struct diff_options *options,
1209 unsigned old_mode, unsigned new_mode,
1210 const unsigned char *old_sha1,
1211 const unsigned char *new_sha1,
1212 const char *base, const char *path)
1214 char concatpath[PATH_MAX];
1215 struct diff_filespec *one, *two;
1217 if (options->reverse_diff) {
1218 unsigned tmp;
1219 const unsigned char *tmp_c;
1220 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1221 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1223 if (!path) path = "";
1224 sprintf(concatpath, "%s%s", base, path);
1225 one = alloc_filespec(concatpath);
1226 two = alloc_filespec(concatpath);
1227 fill_filespec(one, old_sha1, old_mode);
1228 fill_filespec(two, new_sha1, new_mode);
1230 diff_queue(&diff_queued_diff, one, two);
1233 void diff_unmerge(struct diff_options *options,
1234 const char *path)
1236 struct diff_filespec *one, *two;
1237 one = alloc_filespec(path);
1238 two = alloc_filespec(path);
1239 diff_queue(&diff_queued_diff, one, two);