Code

git-apply: creatign empty files is nonfatal
[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"
11 static const char *diff_opts = "-pu";
12 static unsigned char null_sha1[20] = { 0, };
14 static int reverse_diff;
15 static int use_size_cache;
17 static const char *external_diff(void)
18 {
19         static const char *external_diff_cmd = NULL;
20         static int done_preparing = 0;
22         if (done_preparing)
23                 return external_diff_cmd;
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");
36         /* In case external diff fails... */
37         diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
39         done_preparing = 1;
40         return external_diff_cmd;
41 }
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;
60         /* count bytes needed to store the quoted string. */
61         for (cnt = 1, cp = src; *cp; cnt++, cp++)
62                 if (*cp == '\'')
63                         cnt += 3;
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 }
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];
86 static void builtin_diff(const char *name_a,
87                          const char *name_b,
88                          struct diff_tempfile *temp,
89                          const char *xfrm_msg)
90 {
91         int i, next_at, cmd_size;
92         const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
93         const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
94         const char *input_name_sq[2];
95         const char *path0[2];
96         const char *path1[2];
97         const char *name_sq[2];
98         char *cmd;
100         name_sq[0] = sq_expand(name_a);
101         name_sq[1] = sq_expand(name_b);
103         /* diff_cmd and diff_arg have 6 %s in total which makes
104          * the sum of these strings 12 bytes larger than required.
105          * we use 2 spaces around diff-opts, and we need to count
106          * terminating NUL, so we subtract 9 here.
107          */
108         cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
109                         strlen(diff_arg) - 9);
110         for (i = 0; i < 2; i++) {
111                 input_name_sq[i] = sq_expand(temp[i].name);
112                 if (!strcmp(temp[i].name, "/dev/null")) {
113                         path0[i] = "/dev/null";
114                         path1[i] = "";
115                 } else {
116                         path0[i] = i ? "b/" : "a/";
117                         path1[i] = name_sq[i];
118                 }
119                 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
120                              strlen(input_name_sq[i]));
121         }
123         cmd = xmalloc(cmd_size);
125         next_at = 0;
126         next_at += snprintf(cmd+next_at, cmd_size-next_at,
127                             diff_cmd,
128                             path0[0], path1[0], path0[1], path1[1]);
129         next_at += snprintf(cmd+next_at, cmd_size-next_at,
130                             " %s ", diff_opts);
131         next_at += snprintf(cmd+next_at, cmd_size-next_at,
132                             diff_arg, input_name_sq[0], input_name_sq[1]);
134         printf("diff --git a/%s b/%s\n", name_a, name_b);
135         if (!path1[0][0]) {
136                 printf("new file mode %s\n", temp[1].mode);
137                 if (xfrm_msg && xfrm_msg[0])
138                         puts(xfrm_msg);
139         }
140         else if (!path1[1][0]) {
141                 printf("deleted file mode %s\n", temp[0].mode);
142                 if (xfrm_msg && xfrm_msg[0])
143                         puts(xfrm_msg);
144         }
145         else {
146                 if (strcmp(temp[0].mode, temp[1].mode)) {
147                         printf("old mode %s\n", temp[0].mode);
148                         printf("new mode %s\n", temp[1].mode);
149                 }
150                 if (xfrm_msg && xfrm_msg[0])
151                         puts(xfrm_msg);
153                 if (strncmp(temp[0].mode, temp[1].mode, 3))
154                         /* we do not run diff between different kind
155                          * of objects.
156                          */
157                         exit(0);
158         }
159         fflush(NULL);
160         execlp("/bin/sh","sh", "-c", cmd, NULL);
163 struct diff_filespec *alloc_filespec(const char *path)
165         int namelen = strlen(path);
166         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
167         spec->path = (char *)(spec + 1);
168         strcpy(spec->path, path);
169         spec->should_free = spec->should_munmap = 0;
170         spec->xfrm_flags = 0;
171         spec->size = 0;
172         spec->data = NULL;
173         spec->mode = 0;
174         memset(spec->sha1, 0, 20);
175         return spec;
178 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
179                    unsigned short mode)
181         if (mode) {
182                 spec->mode = DIFF_FILE_CANON_MODE(mode);
183                 memcpy(spec->sha1, sha1, 20);
184                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
185         }
188 /*
189  * Given a name and sha1 pair, if the dircache tells us the file in
190  * the work tree has that object contents, return true, so that
191  * prepare_temp_file() does not have to inflate and extract.
192  */
193 static int work_tree_matches(const char *name, const unsigned char *sha1)
195         struct cache_entry *ce;
196         struct stat st;
197         int pos, len;
199         /* We do not read the cache ourselves here, because the
200          * benchmark with my previous version that always reads cache
201          * shows that it makes things worse for diff-tree comparing
202          * two linux-2.6 kernel trees in an already checked out work
203          * tree.  This is because most diff-tree comparisons deal with
204          * only a small number of files, while reading the cache is
205          * expensive for a large project, and its cost outweighs the
206          * savings we get by not inflating the object to a temporary
207          * file.  Practically, this code only helps when we are used
208          * by diff-cache --cached, which does read the cache before
209          * calling us.
210          */
211         if (!active_cache)
212                 return 0;
214         len = strlen(name);
215         pos = cache_name_pos(name, len);
216         if (pos < 0)
217                 return 0;
218         ce = active_cache[pos];
219         if ((lstat(name, &st) < 0) ||
220             !S_ISREG(st.st_mode) || /* careful! */
221             ce_match_stat(ce, &st) ||
222             memcmp(sha1, ce->sha1, 20))
223                 return 0;
224         /* we return 1 only when we can stat, it is a regular file,
225          * stat information matches, and sha1 recorded in the cache
226          * matches.  I.e. we know the file in the work tree really is
227          * the same as the <name, sha1> pair.
228          */
229         return 1;
232 static struct sha1_size_cache {
233         unsigned char sha1[20];
234         unsigned long size;
235 } **sha1_size_cache;
236 static int sha1_size_cache_nr, sha1_size_cache_alloc;
238 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
239                                                  int find_only,
240                                                  unsigned long size)
242         int first, last;
243         struct sha1_size_cache *e;
245         first = 0;
246         last = sha1_size_cache_nr;
247         while (last > first) {
248                 int cmp, next = (last + first) >> 1;
249                 e = sha1_size_cache[next];
250                 cmp = memcmp(e->sha1, sha1, 20);
251                 if (!cmp)
252                         return e;
253                 if (cmp < 0) {
254                         last = next;
255                         continue;
256                 }
257                 first = next+1;
258         }
259         /* not found */
260         if (find_only)
261                 return NULL;
262         /* insert to make it at "first" */
263         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
264                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
265                 sha1_size_cache = xrealloc(sha1_size_cache,
266                                            sha1_size_cache_alloc *
267                                            sizeof(*sha1_size_cache));
268         }
269         sha1_size_cache_nr++;
270         if (first < sha1_size_cache_nr)
271                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
272                         (sha1_size_cache_nr - first - 1) *
273                         sizeof(*sha1_size_cache));
274         e = xmalloc(sizeof(struct sha1_size_cache));
275         sha1_size_cache[first] = e;
276         memcpy(e->sha1, sha1, 20);
277         e->size = size;
278         return e;
281 /*
282  * While doing rename detection and pickaxe operation, we may need to
283  * grab the data for the blob (or file) for our own in-core comparison.
284  * diff_filespec has data and size fields for this purpose.
285  */
286 int diff_populate_filespec(struct diff_filespec *s, int size_only)
288         int err = 0;
289         if (!DIFF_FILE_VALID(s))
290                 die("internal error: asking to populate invalid file.");
291         if (S_ISDIR(s->mode))
292                 return -1;
294         if (!use_size_cache)
295                 size_only = 0;
297         if (s->data)
298                 return err;
299         if (!s->sha1_valid ||
300             work_tree_matches(s->path, s->sha1)) {
301                 struct stat st;
302                 int fd;
303                 if (lstat(s->path, &st) < 0) {
304                         if (errno == ENOENT) {
305                         err_empty:
306                                 err = -1;
307                         empty:
308                                 s->data = "";
309                                 s->size = 0;
310                                 return err;
311                         }
312                 }
313                 s->size = st.st_size;
314                 if (!s->size)
315                         goto empty;
316                 if (size_only)
317                         return 0;
318                 if (S_ISLNK(st.st_mode)) {
319                         int ret;
320                         s->data = xmalloc(s->size);
321                         s->should_free = 1;
322                         ret = readlink(s->path, s->data, s->size);
323                         if (ret < 0) {
324                                 free(s->data);
325                                 goto err_empty;
326                         }
327                         return 0;
328                 }
329                 fd = open(s->path, O_RDONLY);
330                 if (fd < 0)
331                         goto err_empty;
332                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
333                 s->should_munmap = 1;
334                 close(fd);
335         }
336         else {
337                 char type[20];
338                 struct sha1_size_cache *e;
340                 if (size_only) {
341                         e = locate_size_cache(s->sha1, 1, 0);
342                         if (e) {
343                                 s->size = e->size;
344                                 return 0;
345                         }
346                         if (!sha1_file_size(s->sha1, &s->size))
347                                 locate_size_cache(s->sha1, 0, s->size);
348                 }
349                 else {
350                         s->data = read_sha1_file(s->sha1, type, &s->size);
351                         s->should_free = 1;
352                 }
353         }
354         return 0;
357 void diff_free_filespec_data(struct diff_filespec *s)
359         if (s->should_free)
360                 free(s->data);
361         else if (s->should_munmap)
362                 munmap(s->data, s->size);
363         s->should_free = s->should_munmap = 0;
364         s->data = NULL;
367 static void prep_temp_blob(struct diff_tempfile *temp,
368                            void *blob,
369                            unsigned long size,
370                            unsigned char *sha1,
371                            int mode)
373         int fd;
375         strcpy(temp->tmp_path, ".diff_XXXXXX");
376         fd = mkstemp(temp->tmp_path);
377         if (fd < 0)
378                 die("unable to create temp-file");
379         if (write(fd, blob, size) != size)
380                 die("unable to write temp-file");
381         close(fd);
382         temp->name = temp->tmp_path;
383         strcpy(temp->hex, sha1_to_hex(sha1));
384         temp->hex[40] = 0;
385         sprintf(temp->mode, "%06o", mode);
388 static void prepare_temp_file(const char *name,
389                               struct diff_tempfile *temp,
390                               struct diff_filespec *one)
392         if (!DIFF_FILE_VALID(one)) {
393         not_a_valid_file:
394                 /* A '-' entry produces this for file-2, and
395                  * a '+' entry produces this for file-1.
396                  */
397                 temp->name = "/dev/null";
398                 strcpy(temp->hex, ".");
399                 strcpy(temp->mode, ".");
400                 return;
401         }
403         if (!one->sha1_valid ||
404             work_tree_matches(name, one->sha1)) {
405                 struct stat st;
406                 if (lstat(name, &st) < 0) {
407                         if (errno == ENOENT)
408                                 goto not_a_valid_file;
409                         die("stat(%s): %s", name, strerror(errno));
410                 }
411                 if (S_ISLNK(st.st_mode)) {
412                         int ret;
413                         char *buf, buf_[1024];
414                         buf = ((sizeof(buf_) < st.st_size) ?
415                                xmalloc(st.st_size) : buf_);
416                         ret = readlink(name, buf, st.st_size);
417                         if (ret < 0)
418                                 die("readlink(%s)", name);
419                         prep_temp_blob(temp, buf, st.st_size,
420                                        (one->sha1_valid ?
421                                         one->sha1 : null_sha1),
422                                        (one->sha1_valid ?
423                                         one->mode : S_IFLNK));
424                 }
425                 else {
426                         /* we can borrow from the file in the work tree */
427                         temp->name = name;
428                         if (!one->sha1_valid)
429                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
430                         else
431                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
432                         /* Even though we may sometimes borrow the
433                          * contents from the work tree, we always want
434                          * one->mode.  mode is trustworthy even when
435                          * !(one->sha1_valid), as long as
436                          * DIFF_FILE_VALID(one).
437                          */
438                         sprintf(temp->mode, "%06o", one->mode);
439                 }
440                 return;
441         }
442         else {
443                 if (diff_populate_filespec(one, 0))
444                         die("cannot read data blob for %s", one->path);
445                 prep_temp_blob(temp, one->data, one->size,
446                                one->sha1, one->mode);
447         }
450 static void remove_tempfile(void)
452         int i;
454         for (i = 0; i < 2; i++)
455                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
456                         unlink(diff_temp[i].name);
457                         diff_temp[i].name = NULL;
458                 }
461 static void remove_tempfile_on_signal(int signo)
463         remove_tempfile();
466 /* An external diff command takes:
467  *
468  * diff-cmd name infile1 infile1-sha1 infile1-mode \
469  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
470  *
471  */
472 static void run_external_diff(const char *pgm,
473                               const char *name,
474                               const char *other,
475                               struct diff_filespec *one,
476                               struct diff_filespec *two,
477                               const char *xfrm_msg)
479         struct diff_tempfile *temp = diff_temp;
480         pid_t pid;
481         int status;
482         static int atexit_asked = 0;
484         if (one && two) {
485                 prepare_temp_file(name, &temp[0], one);
486                 prepare_temp_file(other ? : name, &temp[1], two);
487                 if (! atexit_asked &&
488                     (temp[0].name == temp[0].tmp_path ||
489                      temp[1].name == temp[1].tmp_path)) {
490                         atexit_asked = 1;
491                         atexit(remove_tempfile);
492                 }
493                 signal(SIGINT, remove_tempfile_on_signal);
494         }
496         fflush(NULL);
497         pid = fork();
498         if (pid < 0)
499                 die("unable to fork");
500         if (!pid) {
501                 if (pgm) {
502                         if (one && two) {
503                                 const char *exec_arg[10];
504                                 const char **arg = &exec_arg[0];
505                                 *arg++ = pgm;
506                                 *arg++ = name;
507                                 *arg++ = temp[0].name;
508                                 *arg++ = temp[0].hex;
509                                 *arg++ = temp[0].mode;
510                                 *arg++ = temp[1].name;
511                                 *arg++ = temp[1].hex;
512                                 *arg++ = temp[1].mode;
513                                 if (other) {
514                                         *arg++ = other;
515                                         *arg++ = xfrm_msg;
516                                 }
517                                 *arg = NULL;
518                                 execvp(pgm, (char *const*) exec_arg);
519                         }
520                         else
521                                 execlp(pgm, pgm, name, NULL);
522                 }
523                 /*
524                  * otherwise we use the built-in one.
525                  */
526                 if (one && two)
527                         builtin_diff(name, other ? : name, temp, xfrm_msg);
528                 else
529                         printf("* Unmerged path %s\n", name);
530                 exit(0);
531         }
532         if (waitpid(pid, &status, 0) < 0 ||
533             !WIFEXITED(status) || WEXITSTATUS(status)) {
534                 /* Earlier we did not check the exit status because
535                  * diff exits non-zero if files are different, and
536                  * we are not interested in knowing that.  It was a
537                  * mistake which made it harder to quit a diff-*
538                  * session that uses the git-apply-patch-script as
539                  * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
540                  * should also exit non-zero only when it wants to
541                  * abort the entire diff-* session.
542                  */
543                 remove_tempfile();
544                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
545                 exit(1);
546         }
547         remove_tempfile();
550 static void run_diff(const char *name,
551                      const char *other,
552                      struct diff_filespec *one,
553                      struct diff_filespec *two,
554                      const char *xfrm_msg)
556         const char *pgm = external_diff();
557         if (!pgm &&
558             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
559             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
560                 /* a filepair that changes between file and symlink
561                  * needs to be split into deletion and creation.
562                  */
563                 struct diff_filespec *null = alloc_filespec(two->path);
564                 run_external_diff(NULL, name, other, one, null, xfrm_msg);
565                 free(null);
566                 null = alloc_filespec(one->path);
567                 run_external_diff(NULL, name, other, null, two, xfrm_msg);
568                 free(null);
569         }
570         else
571                 run_external_diff(pgm, name, other, one, two, xfrm_msg);
574 void diff_setup(int flags)
576         if (flags & DIFF_SETUP_REVERSE)
577                 reverse_diff = 1;
578         if (flags & DIFF_SETUP_USE_CACHE) {
579                 if (!active_cache)
580                         /* read-cache does not die even when it fails
581                          * so it is safe for us to do this here.  Also
582                          * it does not smudge active_cache or active_nr
583                          * when it fails, so we do not have to worry about
584                          * cleaning it up oufselves either.
585                          */
586                         read_cache();
587         }
588         if (flags & DIFF_SETUP_USE_SIZE_CACHE)
589                 use_size_cache = 1;
590         
593 static int parse_num(const char **cp_p)
595         int num, scale, ch, cnt;
596         const char *cp = *cp_p;
598         cnt = num = 0;
599         scale = 1;
600         while ('0' <= (ch = *cp) && ch <= '9') {
601                 if (cnt++ < 5) {
602                         /* We simply ignore more than 5 digits precision. */
603                         scale *= 10;
604                         num = num * 10 + ch - '0';
605                 }
606                 *cp++;
607         }
608         *cp_p = cp;
610         /* user says num divided by scale and we say internally that
611          * is MAX_SCORE * num / scale.
612          */
613         return (MAX_SCORE * num / scale);
616 int diff_scoreopt_parse(const char *opt)
618         int opt1, opt2, cmd;
620         if (*opt++ != '-')
621                 return -1;
622         cmd = *opt++;
623         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
624                 return -1; /* that is not a -M, -C nor -B option */
626         opt1 = parse_num(&opt);
627         if (cmd != 'B')
628                 opt2 = 0;
629         else {
630                 if (*opt == 0)
631                         opt2 = 0;
632                 else if (*opt != '/')
633                         return -1; /* we expect -B80/99 or -B80 */
634                 else {
635                         opt++;
636                         opt2 = parse_num(&opt);
637                 }
638         }
639         if (*opt != 0)
640                 return -1;
641         return opt1 | (opt2 << 16);
644 struct diff_queue_struct diff_queued_diff;
646 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
648         if (queue->alloc <= queue->nr) {
649                 queue->alloc = alloc_nr(queue->alloc);
650                 queue->queue = xrealloc(queue->queue,
651                                         sizeof(dp) * queue->alloc);
652         }
653         queue->queue[queue->nr++] = dp;
656 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
657                                  struct diff_filespec *one,
658                                  struct diff_filespec *two)
660         struct diff_filepair *dp = xmalloc(sizeof(*dp));
661         dp->one = one;
662         dp->two = two;
663         dp->score = 0;
664         dp->source_stays = 0;
665         dp->broken_pair = 0;
666         diff_q(queue, dp);
667         return dp;
670 void diff_free_filepair(struct diff_filepair *p)
672         diff_free_filespec_data(p->one);
673         diff_free_filespec_data(p->two);
674         free(p);
677 static void diff_flush_raw(struct diff_filepair *p,
678                            int line_termination,
679                            int inter_name_termination)
681         int two_paths;
682         char status[10];
684         if (line_termination) {
685                 const char *err = "path %s cannot be expressed without -z";
686                 if (strchr(p->one->path, line_termination) ||
687                     strchr(p->one->path, inter_name_termination))
688                         die(err, p->one->path);
689                 if (strchr(p->two->path, line_termination) ||
690                     strchr(p->two->path, inter_name_termination))
691                         die(err, p->two->path);
692         }
694         switch (p->status) {
695         case 'C': case 'R':
696                 two_paths = 1;
697                 sprintf(status, "%c%03d", p->status,
698                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
699                 break;
700         case 'N': case 'D':
701                 two_paths = 0;
702                 if (p->score)
703                         sprintf(status, "%c%03d", p->status,
704                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
705                 else {
706                         status[0] = p->status;
707                         status[1] = 0;
708                 }
709                 break;
710         default:
711                 two_paths = 0;
712                 status[0] = p->status;
713                 status[1] = 0;
714                 break;
715         }
716         printf(":%06o %06o %s ",
717                p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
718         printf("%s %s%c%s",
719                sha1_to_hex(p->two->sha1),
720                status,
721                inter_name_termination,
722                p->one->path);
723         if (two_paths)
724                 printf("%c%s", inter_name_termination, p->two->path);
725         putchar(line_termination);
728 int diff_unmodified_pair(struct diff_filepair *p)
730         /* This function is written stricter than necessary to support
731          * the currently implemented transformers, but the idea is to
732          * let transformers to produce diff_filepairs any way they want,
733          * and filter and clean them up here before producing the output.
734          */
735         struct diff_filespec *one, *two;
737         if (DIFF_PAIR_UNMERGED(p))
738                 return 0; /* unmerged is interesting */
740         one = p->one;
741         two = p->two;
743         /* deletion, addition, mode or type change
744          * and rename are all interesting.
745          */
746         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
747             DIFF_PAIR_MODE_CHANGED(p) ||
748             strcmp(one->path, two->path))
749                 return 0;
751         /* both are valid and point at the same path.  that is, we are
752          * dealing with a change.
753          */
754         if (one->sha1_valid && two->sha1_valid &&
755             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
756                 return 1; /* no change */
757         if (!one->sha1_valid && !two->sha1_valid)
758                 return 1; /* both look at the same file on the filesystem. */
759         return 0;
762 static void diff_flush_patch(struct diff_filepair *p)
764         const char *name, *other;
765         char msg_[PATH_MAX*2+200], *msg;
767         if (diff_unmodified_pair(p))
768                 return;
770         name = p->one->path;
771         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
772         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
773             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
774                 return; /* no tree diffs in patch format */ 
776         switch (p->status) {
777         case 'C':
778                 sprintf(msg_,
779                         "similarity index %d%%\n"
780                         "copy from %s\n"
781                         "copy to %s",
782                         (int)(0.5 + p->score * 100.0/MAX_SCORE),
783                         p->one->path, p->two->path);
784                 msg = msg_;
785                 break;
786         case 'R':
787                 sprintf(msg_,
788                         "similarity index %d%%\n"
789                         "rename from %s\n"
790                         "rename to %s",
791                         (int)(0.5 + p->score * 100.0/MAX_SCORE),
792                         p->one->path, p->two->path);
793                 msg = msg_;
794                 break;
795         case 'D': case 'N':
796                 if (DIFF_PAIR_BROKEN(p)) {
797                         sprintf(msg_,
798                                 "dissimilarity index %d%%",
799                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
800                         msg = msg_;
801                 }
802                 else
803                         msg = NULL;
804                 break;
805         default:
806                 msg = NULL;
807         }
809         if (DIFF_PAIR_UNMERGED(p))
810                 run_diff(name, NULL, NULL, NULL, NULL);
811         else
812                 run_diff(name, other, p->one, p->two, msg);
815 int diff_queue_is_empty(void)
817         struct diff_queue_struct *q = &diff_queued_diff;
818         int i;
819         for (i = 0; i < q->nr; i++)
820                 if (!diff_unmodified_pair(q->queue[i]))
821                         return 0;
822         return 1;
825 #if DIFF_DEBUG
826 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
828         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
829                 x, one ? : "",
830                 s->path,
831                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
832                 s->mode,
833                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
834         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
835                 x, one ? : "",
836                 s->size, s->xfrm_flags);
839 void diff_debug_filepair(const struct diff_filepair *p, int i)
841         diff_debug_filespec(p->one, i, "one");
842         diff_debug_filespec(p->two, i, "two");
843         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
844                 p->score, p->status ? : '?',
845                 p->source_stays, p->broken_pair);
848 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
850         int i;
851         if (msg)
852                 fprintf(stderr, "%s\n", msg);
853         fprintf(stderr, "q->nr = %d\n", q->nr);
854         for (i = 0; i < q->nr; i++) {
855                 struct diff_filepair *p = q->queue[i];
856                 diff_debug_filepair(p, i);
857         }
859 #endif
861 static void diff_resolve_rename_copy(void)
863         int i, j;
864         struct diff_filepair *p, *pp;
865         struct diff_queue_struct *q = &diff_queued_diff;
867         diff_debug_queue("resolve-rename-copy", q);
869         for (i = 0; i < q->nr; i++) {
870                 p = q->queue[i];
871                 p->status = 0; /* undecided */
872                 if (DIFF_PAIR_UNMERGED(p))
873                         p->status = 'U';
874                 else if (!DIFF_FILE_VALID(p->one))
875                         p->status = 'N';
876                 else if (!DIFF_FILE_VALID(p->two))
877                         p->status = 'D';
878                 else if (DIFF_PAIR_TYPE_CHANGED(p))
879                         p->status = 'T';
881                 /* from this point on, we are dealing with a pair
882                  * whose both sides are valid and of the same type, i.e.
883                  * either in-place edit or rename/copy edit.
884                  */
885                 else if (DIFF_PAIR_RENAME(p)) {
886                         if (p->source_stays) {
887                                 p->status = 'C';
888                                 continue;
889                         }
890                         /* See if there is some other filepair that
891                          * copies from the same source as us.  If so
892                          * we are a copy.  Otherwise we are a rename.
893                          */
894                         for (j = i + 1; j < q->nr; j++) {
895                                 pp = q->queue[j];
896                                 if (strcmp(pp->one->path, p->one->path))
897                                         continue; /* not us */
898                                 if (!DIFF_PAIR_RENAME(pp))
899                                         continue; /* not a rename/copy */
900                                 /* pp is a rename/copy from the same source */
901                                 p->status = 'C';
902                                 break;
903                         }
904                         if (!p->status)
905                                 p->status = 'R';
906                 }
907                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
908                          p->one->mode != p->two->mode)
909                         p->status = 'M';
910                 else {
911                         /* This is a "no-change" entry and should not
912                          * happen anymore, but prepare for broken callers.
913                          */
914                         error("feeding unmodified %s to diffcore",
915                               p->one->path);
916                         p->status = 'X';
917                 }
918         }
919         diff_debug_queue("resolve-rename-copy done", q);
922 void diff_flush(int diff_output_style, int resolve_rename_copy)
924         struct diff_queue_struct *q = &diff_queued_diff;
925         int i;
926         int line_termination = '\n';
927         int inter_name_termination = '\t';
929         if (diff_output_style == DIFF_FORMAT_MACHINE)
930                 line_termination = inter_name_termination = 0;
931         if (resolve_rename_copy)
932                 diff_resolve_rename_copy();
934         for (i = 0; i < q->nr; i++) {
935                 struct diff_filepair *p = q->queue[i];
936                 if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
937                     (p->status == 'X'))
938                         continue;
939                 if (p->status == 0)
940                         die("internal error in diff-resolve-rename-copy");
941                 switch (diff_output_style) {
942                 case DIFF_FORMAT_PATCH:
943                         diff_flush_patch(p);
944                         break;
945                 case DIFF_FORMAT_HUMAN:
946                 case DIFF_FORMAT_MACHINE:
947                         diff_flush_raw(p, line_termination,
948                                        inter_name_termination);
949                         break;
950                 }
951         }
952         for (i = 0; i < q->nr; i++)
953                 diff_free_filepair(q->queue[i]);
954         free(q->queue);
955         q->queue = NULL;
956         q->nr = q->alloc = 0;
959 void diffcore_std(const char **paths,
960                   int detect_rename, int rename_score,
961                   const char *pickaxe, int pickaxe_opts,
962                   int break_opt,
963                   const char *orderfile)
965         if (paths && paths[0])
966                 diffcore_pathspec(paths);
967         if (break_opt != -1)
968                 diffcore_break(break_opt);
969         if (detect_rename)
970                 diffcore_rename(detect_rename, rename_score);
971         if (break_opt != -1)
972                 diffcore_merge_broken();
973         if (pickaxe)
974                 diffcore_pickaxe(pickaxe, pickaxe_opts);
975         if (orderfile)
976                 diffcore_order(orderfile);
979 void diff_addremove(int addremove, unsigned mode,
980                     const unsigned char *sha1,
981                     const char *base, const char *path)
983         char concatpath[PATH_MAX];
984         struct diff_filespec *one, *two;
986         /* This may look odd, but it is a preparation for
987          * feeding "there are unchanged files which should
988          * not produce diffs, but when you are doing copy
989          * detection you would need them, so here they are"
990          * entries to the diff-core.  They will be prefixed
991          * with something like '=' or '*' (I haven't decided
992          * which but should not make any difference).
993          * Feeding the same new and old to diff_change() 
994          * also has the same effect.
995          * Before the final output happens, they are pruned after
996          * merged into rename/copy pairs as appropriate.
997          */
998         if (reverse_diff)
999                 addremove = (addremove == '+' ? '-' :
1000                              addremove == '-' ? '+' : addremove);
1002         if (!path) path = "";
1003         sprintf(concatpath, "%s%s", base, path);
1004         one = alloc_filespec(concatpath);
1005         two = alloc_filespec(concatpath);
1007         if (addremove != '+')
1008                 fill_filespec(one, sha1, mode);
1009         if (addremove != '-')
1010                 fill_filespec(two, sha1, mode);
1012         diff_queue(&diff_queued_diff, one, two);
1015 void diff_helper_input(unsigned old_mode,
1016                        unsigned new_mode,
1017                        const unsigned char *old_sha1,
1018                        const unsigned char *new_sha1,
1019                        const char *old_path,
1020                        int status,
1021                        int score,
1022                        const char *new_path)
1024         struct diff_filespec *one, *two;
1025         struct diff_filepair *dp;
1027         one = alloc_filespec(old_path);
1028         two = alloc_filespec(new_path);
1029         if (old_mode)
1030                 fill_filespec(one, old_sha1, old_mode);
1031         if (new_mode)
1032                 fill_filespec(two, new_sha1, new_mode);
1033         dp = diff_queue(&diff_queued_diff, one, two);
1034         dp->score = score * MAX_SCORE / 100;
1035         dp->status = status;
1038 void diff_change(unsigned old_mode, unsigned new_mode,
1039                  const unsigned char *old_sha1,
1040                  const unsigned char *new_sha1,
1041                  const char *base, const char *path) 
1043         char concatpath[PATH_MAX];
1044         struct diff_filespec *one, *two;
1046         if (reverse_diff) {
1047                 unsigned tmp;
1048                 const unsigned char *tmp_c;
1049                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1050                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1051         }
1052         if (!path) path = "";
1053         sprintf(concatpath, "%s%s", base, path);
1054         one = alloc_filespec(concatpath);
1055         two = alloc_filespec(concatpath);
1056         fill_filespec(one, old_sha1, old_mode);
1057         fill_filespec(two, new_sha1, new_mode);
1059         diff_queue(&diff_queued_diff, one, two);
1062 void diff_unmerge(const char *path)
1064         struct diff_filespec *one, *two;
1065         one = alloc_filespec(path);
1066         two = alloc_filespec(path);
1067         diff_queue(&diff_queued_diff, one, two);