[PATCH] Documentation: update recommended workflow when working with others.
[git.git] / diff-tree.c
1 #include <ctype.h>
2 #include "cache.h"
3 #include "diff.h"
4 #include "commit.h"
5
6 static int show_root_diff = 0;
7 static int verbose_header = 0;
8 static int ignore_merges = 1;
9 static int recursive = 0;
10 static int show_tree_entry_in_recursive = 0;
11 static int read_stdin = 0;
12 static int diff_output_format = DIFF_FORMAT_RAW;
13 static int diff_line_termination = '\n';
14 static int detect_rename = 0;
15 static int find_copies_harder = 0;
16 static int diff_setup_opt = 0;
17 static int diff_score_opt = 0;
18 static const char *pickaxe = NULL;
19 static int pickaxe_opts = 0;
20 static int diff_break_opt = -1;
21 static const char *orderfile = NULL;
22 static const char *diff_filter = NULL;
23 static const char *header = NULL;
24 static const char *header_prefix = "";
25 static enum cmit_fmt commit_format = CMIT_FMT_RAW;
26
27 // What paths are we interested in?
28 static int nr_paths = 0;
29 static const char **paths = NULL;
30 static int *pathlens = NULL;
31
32 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
33
34 static void update_tree_entry(void **bufp, unsigned long *sizep)
35 {
36         void *buf = *bufp;
37         unsigned long size = *sizep;
38         int len = strlen(buf) + 1 + 20;
39
40         if (size < len)
41                 die("corrupt tree file");
42         *bufp = buf + len;
43         *sizep = size - len;
44 }
45
46 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
47 {
48         int len = strlen(tree)+1;
49         const unsigned char *sha1 = tree + len;
50         const char *path = strchr(tree, ' ');
51         unsigned int mode;
52
53         if (!path || size < len + 20 || sscanf(tree, "%o", &mode) != 1)
54                 die("corrupt tree file");
55         *pathp = path+1;
56         *modep = DIFF_FILE_CANON_MODE(mode);
57         return sha1;
58 }
59
60 static char *malloc_base(const char *base, const char *path, int pathlen)
61 {
62         int baselen = strlen(base);
63         char *newbase = xmalloc(baselen + pathlen + 2);
64         memcpy(newbase, base, baselen);
65         memcpy(newbase + baselen, path, pathlen);
66         memcpy(newbase + baselen + pathlen, "/", 2);
67         return newbase;
68 }
69
70 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
71 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);
72
73 /* A file entry went away or appeared */
74 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
75 {
76         unsigned mode;
77         const char *path;
78         const unsigned char *sha1 = extract(tree, size, &path, &mode);
79
80         if (recursive && S_ISDIR(mode)) {
81                 char type[20];
82                 unsigned long size;
83                 char *newbase = malloc_base(base, path, strlen(path));
84                 void *tree;
85
86                 tree = read_sha1_file(sha1, type, &size);
87                 if (!tree || strcmp(type, "tree"))
88                         die("corrupt tree sha %s", sha1_to_hex(sha1));
89
90                 show_tree(prefix, tree, size, newbase);
91
92                 free(tree);
93                 free(newbase);
94                 return;
95         }
96
97         diff_addremove(prefix[0], mode, sha1, base, path);
98 }
99
100 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
101 {
102         unsigned mode1, mode2;
103         const char *path1, *path2;
104         const unsigned char *sha1, *sha2;
105         int cmp, pathlen1, pathlen2;
106
107         sha1 = extract(tree1, size1, &path1, &mode1);
108         sha2 = extract(tree2, size2, &path2, &mode2);
109
110         pathlen1 = strlen(path1);
111         pathlen2 = strlen(path2);
112         cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
113         if (cmp < 0) {
114                 show_file("-", tree1, size1, base);
115                 return -1;
116         }
117         if (cmp > 0) {
118                 show_file("+", tree2, size2, base);
119                 return 1;
120         }
121         if (!find_copies_harder && !memcmp(sha1, sha2, 20) && mode1 == mode2)
122                 return 0;
123
124         /*
125          * If the filemode has changed to/from a directory from/to a regular
126          * file, we need to consider it a remove and an add.
127          */
128         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
129                 show_file("-", tree1, size1, base);
130                 show_file("+", tree2, size2, base);
131                 return 0;
132         }
133
134         if (recursive && S_ISDIR(mode1)) {
135                 int retval;
136                 char *newbase = malloc_base(base, path1, pathlen1);
137                 if (show_tree_entry_in_recursive)
138                         diff_change(mode1, mode2, sha1, sha2, base, path1);
139                 retval = diff_tree_sha1(sha1, sha2, newbase);
140                 free(newbase);
141                 return retval;
142         }
143
144         diff_change(mode1, mode2, sha1, sha2, base, path1);
145         return 0;
146 }
147
148 static int interesting(void *tree, unsigned long size, const char *base)
149 {
150         const char *path;
151         unsigned mode;
152         int i;
153         int baselen, pathlen;
154
155         if (!nr_paths)
156                 return 1;
157
158         (void)extract(tree, size, &path, &mode);
159
160         pathlen = strlen(path);
161         baselen = strlen(base);
162
163         for (i=0; i < nr_paths; i++) {
164                 const char *match = paths[i];
165                 int matchlen = pathlens[i];
166
167                 if (baselen >= matchlen) {
168                         /* If it doesn't match, move along... */
169                         if (strncmp(base, match, matchlen))
170                                 continue;
171
172                         /* The base is a subdirectory of a path which was specified. */
173                         return 1;
174                 }
175
176                 /* Does the base match? */
177                 if (strncmp(base, match, baselen))
178                         continue;
179
180                 match += baselen;
181                 matchlen -= baselen;
182
183                 if (pathlen > matchlen)
184                         continue;
185
186                 if (matchlen > pathlen) {
187                         if (match[pathlen] != '/')
188                                 continue;
189                         if (!S_ISDIR(mode))
190                                 continue;
191                 }
192
193                 if (strncmp(path, match, pathlen))
194                         continue;
195
196                 return 1;
197         }
198         return 0; /* No matches */
199 }
200
201 /* A whole sub-tree went away or appeared */
202 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
203 {
204         while (size) {
205                 if (interesting(tree, size, base))
206                         show_file(prefix, tree, size, base);
207                 update_tree_entry(&tree, &size);
208         }
209 }
210
211 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
212 {
213         while (size1 | size2) {
214                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
215                         update_tree_entry(&tree1, &size1);
216                         continue;
217                 }
218                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
219                         update_tree_entry(&tree2, &size2);
220                         continue;
221                 }
222                 if (!size1) {
223                         show_file("+", tree2, size2, base);
224                         update_tree_entry(&tree2, &size2);
225                         continue;
226                 }
227                 if (!size2) {
228                         show_file("-", tree1, size1, base);
229                         update_tree_entry(&tree1, &size1);
230                         continue;
231                 }
232                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
233                 case -1:
234                         update_tree_entry(&tree1, &size1);
235                         continue;
236                 case 0:
237                         update_tree_entry(&tree1, &size1);
238                         /* Fallthrough */
239                 case 1:
240                         update_tree_entry(&tree2, &size2);
241                         continue;
242                 }
243                 die("git-diff-tree: internal error");
244         }
245         return 0;
246 }
247
248 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
249 {
250         void *tree1, *tree2;
251         unsigned long size1, size2;
252         int retval;
253
254         tree1 = read_object_with_reference(old, "tree", &size1, NULL);
255         if (!tree1)
256                 die("unable to read source tree (%s)", sha1_to_hex(old));
257         tree2 = read_object_with_reference(new, "tree", &size2, NULL);
258         if (!tree2)
259                 die("unable to read destination tree (%s)", sha1_to_hex(new));
260         retval = diff_tree(tree1, size1, tree2, size2, base);
261         free(tree1);
262         free(tree2);
263         return retval;
264 }
265
266 static void call_diff_setup(void)
267 {
268         diff_setup(diff_setup_opt);
269 }
270
271 static int call_diff_flush(void)
272 {
273         diffcore_std(NULL,
274                      detect_rename, diff_score_opt,
275                      pickaxe, pickaxe_opts,
276                      diff_break_opt,
277                      orderfile,
278                      diff_filter);
279         if (diff_queue_is_empty()) {
280                 diff_flush(DIFF_FORMAT_NO_OUTPUT, diff_line_termination);
281                 return 0;
282         }
283         if (header) {
284                 printf("%s%c", header, diff_line_termination);
285                 header = NULL;
286         }
287         diff_flush(diff_output_format, diff_line_termination);
288         return 1;
289 }
290
291 static int diff_tree_sha1_top(const unsigned char *old,
292                               const unsigned char *new, const char *base)
293 {
294         int ret;
295
296         call_diff_setup();
297         ret = diff_tree_sha1(old, new, base);
298         call_diff_flush();
299         return ret;
300 }
301
302 static int diff_root_tree(const unsigned char *new, const char *base)
303 {
304         int retval;
305         void *tree;
306         unsigned long size;
307
308         call_diff_setup();
309         tree = read_object_with_reference(new, "tree", &size, NULL);
310         if (!tree)
311                 die("unable to read root tree (%s)", sha1_to_hex(new));
312         retval = diff_tree("", 0, tree, size, base);
313         free(tree);
314         call_diff_flush();
315         return retval;
316 }
317
318 static const char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
319 {
320         static char this_header[16384];
321         int offset;
322
323         if (!verbose_header)
324                 return commit;
325
326         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
327         offset += pretty_print_commit(commit_format, msg, len, this_header + offset, sizeof(this_header) - offset);
328         return this_header;
329 }
330
331 static int diff_tree_commit(const unsigned char *commit, const char *name)
332 {
333         unsigned long size, offset;
334         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
335
336         if (!buf)
337                 return -1;
338
339         if (!name) {
340                 static char commit_name[60];
341                 strcpy(commit_name, sha1_to_hex(commit));
342                 name = commit_name;
343         }
344
345         /* Root commit? */
346         if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
347                 header = generate_header(name, "root", buf, size);
348                 diff_root_tree(commit, "");
349         }
350
351         /* More than one parent? */
352         if (ignore_merges) {
353                 if (!memcmp(buf + 46 + 48, "parent ", 7))
354                         return 0;
355         }
356
357         offset = 46;
358         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
359                 unsigned char parent[20];
360                 if (get_sha1_hex(buf + offset + 7, parent))
361                         return -1;
362                 header = generate_header(name, sha1_to_hex(parent), buf, size);
363                 diff_tree_sha1_top(parent, commit, "");
364                 if (!header && verbose_header) {
365                         header_prefix = "\ndiff-tree ";
366                         /*
367                          * Don't print multiple merge entries if we
368                          * don't print the diffs.
369                          */
370                 }
371                 offset += 48;
372         }
373         return 0;
374 }
375
376 static int diff_tree_stdin(char *line)
377 {
378         int len = strlen(line);
379         unsigned char commit[20], parent[20];
380         static char this_header[1000];
381
382         if (!len || line[len-1] != '\n')
383                 return -1;
384         line[len-1] = 0;
385         if (get_sha1_hex(line, commit))
386                 return -1;
387         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
388                 line[40] = 0;
389                 line[81] = 0;
390                 sprintf(this_header, "%s (from %s)\n", line, line+41);
391                 header = this_header;
392                 return diff_tree_sha1_top(parent, commit, "");
393         }
394         line[40] = 0;
395         return diff_tree_commit(commit, line);
396 }
397
398 static char *diff_tree_usage =
399 "git-diff-tree [--stdin] [-m] [-s] [-v] [--pretty] [-t] "
400 "[<common diff options>] <tree-ish> <tree-ish>"
401 COMMON_DIFF_OPTIONS_HELP;
402
403 int main(int argc, const char **argv)
404 {
405         int nr_sha1;
406         char line[1000];
407         unsigned char sha1[2][20];
408
409         nr_sha1 = 0;
410         for (;;) {
411                 const char *arg;
412
413                 argv++;
414                 argc--;
415                 arg = *argv;
416                 if (!arg)
417                         break;
418
419                 if (*arg != '-') {
420                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
421                                 nr_sha1++;
422                                 continue;
423                         }
424                         break;
425                 }
426
427                 if (!strcmp(arg, "--")) {
428                         argv++;
429                         argc--;
430                         break;
431                 }
432                 if (!strcmp(arg, "-r")) {
433                         recursive = 1;
434                         continue;
435                 }
436                 if (!strcmp(arg, "-t")) {
437                         recursive = show_tree_entry_in_recursive = 1;
438                         continue;
439                 }
440                 if (!strcmp(arg, "-R")) {
441                         diff_setup_opt |= DIFF_SETUP_REVERSE;
442                         continue;
443                 }
444                 if (!strcmp(arg, "-p") || !strcmp(arg, "-u")) {
445                         diff_output_format = DIFF_FORMAT_PATCH;
446                         recursive = 1;
447                         continue;
448                 }
449                 if (!strncmp(arg, "-S", 2)) {
450                         pickaxe = arg + 2;
451                         continue;
452                 }
453                 if (!strncmp(arg, "-O", 2)) {
454                         orderfile = arg + 2;
455                         continue;
456                 }
457                 if (!strncmp(arg, "--diff-filter=", 14)) {
458                         diff_filter = arg + 14;
459                         continue;
460                 }
461                 if (!strcmp(arg, "--pickaxe-all")) {
462                         pickaxe_opts = DIFF_PICKAXE_ALL;
463                         continue;
464                 }
465                 if (!strncmp(arg, "-M", 2)) {
466                         detect_rename = DIFF_DETECT_RENAME;
467                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
468                                 usage(diff_tree_usage);
469                         continue;
470                 }
471                 if (!strncmp(arg, "-C", 2)) {
472                         detect_rename = DIFF_DETECT_COPY;
473                         if ((diff_score_opt = diff_scoreopt_parse(arg)) == -1)
474                                 usage(diff_tree_usage);
475                         continue;
476                 }
477                 if (!strncmp(arg, "-B", 2)) {
478                         if ((diff_break_opt = diff_scoreopt_parse(arg)) == -1)
479                                 usage(diff_tree_usage);
480                         continue;
481                 }
482                 if (!strcmp(arg, "--find-copies-harder")) {
483                         find_copies_harder = 1;
484                         continue;
485                 }
486                 if (!strcmp(arg, "--name-only")) {
487                         diff_output_format = DIFF_FORMAT_NAME;
488                         continue;
489                 }
490                 if (!strcmp(arg, "-z")) {
491                         diff_line_termination = 0;
492                         continue;
493                 }
494                 if (!strcmp(arg, "-m")) {
495                         ignore_merges = 0;
496                         continue;
497                 }
498                 if (!strcmp(arg, "-s")) {
499                         diff_output_format = DIFF_FORMAT_NO_OUTPUT;
500                         continue;
501                 }
502                 if (!strcmp(arg, "-v")) {
503                         verbose_header = 1;
504                         header_prefix = "diff-tree ";
505                         continue;
506                 }
507                 if (!strncmp(arg, "--pretty", 8)) {
508                         verbose_header = 1;
509                         header_prefix = "diff-tree ";
510                         commit_format = get_commit_format(arg+8);
511                         continue;
512                 }
513                 if (!strcmp(arg, "--stdin")) {
514                         read_stdin = 1;
515                         continue;
516                 }
517                 if (!strcmp(arg, "--root")) {
518                         show_root_diff = 1;
519                         continue;
520                 }
521                 usage(diff_tree_usage);
522         }
523         if (find_copies_harder && detect_rename != DIFF_DETECT_COPY)
524                 usage(diff_tree_usage);
525
526         if (argc > 0) {
527                 int i;
528
529                 paths = argv;
530                 nr_paths = argc;
531                 pathlens = xmalloc(nr_paths * sizeof(int));
532                 for (i=0; i<nr_paths; i++)
533                         pathlens[i] = strlen(paths[i]);
534         }
535
536         switch (nr_sha1) {
537         case 0:
538                 if (!read_stdin)
539                         usage(diff_tree_usage);
540                 break;
541         case 1:
542                 diff_tree_commit(sha1[0], NULL);
543                 break;
544         case 2:
545                 diff_tree_sha1_top(sha1[0], sha1[1], "");
546                 break;
547         }
548
549         if (!read_stdin)
550                 return 0;
551
552         if (detect_rename)
553                 diff_setup_opt |= (DIFF_SETUP_USE_SIZE_CACHE |
554                                    DIFF_SETUP_USE_CACHE);
555         while (fgets(line, sizeof(line), stdin))
556                 diff_tree_stdin(line);
557
558         return 0;
559 }