Merge branch 'jx/t5411-unique-filenames'
[git] / range-diff.c
1 #include "cache.h"
2 #include "range-diff.h"
3 #include "string-list.h"
4 #include "run-command.h"
5 #include "strvec.h"
6 #include "hashmap.h"
7 #include "xdiff-interface.h"
8 #include "linear-assignment.h"
9 #include "diffcore.h"
10 #include "commit.h"
11 #include "pretty.h"
12 #include "userdiff.h"
13 #include "apply.h"
14 #include "revision.h"
15
16 struct patch_util {
17         /* For the search for an exact match */
18         struct hashmap_entry e;
19         const char *diff, *patch;
20
21         int i, shown;
22         int diffsize;
23         size_t diff_offset;
24         /* the index of the matching item in the other branch, or -1 */
25         int matching;
26         struct object_id oid;
27 };
28
29 static size_t find_end_of_line(char *buffer, unsigned long size)
30 {
31         char *eol = memchr(buffer, '\n', size);
32
33         if (!eol)
34                 return size;
35
36         *eol = '\0';
37         return eol + 1 - buffer;
38 }
39
40 /*
41  * Reads the patches into a string list, with the `util` field being populated
42  * as struct object_id (will need to be free()d).
43  */
44 static int read_patches(const char *range, struct string_list *list,
45                         const struct strvec *other_arg)
46 {
47         struct child_process cp = CHILD_PROCESS_INIT;
48         struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
49         struct patch_util *util = NULL;
50         int in_header = 1;
51         char *line, *current_filename = NULL;
52         int offset, len;
53         size_t size;
54
55         strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
56                      "--reverse", "--date-order", "--decorate=no",
57                      "--no-prefix",
58                      /*
59                       * Choose indicators that are not used anywhere
60                       * else in diffs, but still look reasonable
61                       * (e.g. will not be confusing when debugging)
62                       */
63                      "--output-indicator-new=>",
64                      "--output-indicator-old=<",
65                      "--output-indicator-context=#",
66                      "--no-abbrev-commit",
67                      "--pretty=medium",
68                      "--notes",
69                      NULL);
70         if (other_arg)
71                 strvec_pushv(&cp.args, other_arg->v);
72         strvec_push(&cp.args, range);
73         cp.out = -1;
74         cp.no_stdin = 1;
75         cp.git_cmd = 1;
76
77         if (start_command(&cp))
78                 return error_errno(_("could not start `log`"));
79         if (strbuf_read(&contents, cp.out, 0) < 0) {
80                 error_errno(_("could not read `log` output"));
81                 finish_command(&cp);
82                 return -1;
83         }
84         if (finish_command(&cp))
85                 return -1;
86
87         line = contents.buf;
88         size = contents.len;
89         for (offset = 0; size > 0; offset += len, size -= len, line += len) {
90                 const char *p;
91
92                 len = find_end_of_line(line, size);
93                 line[len - 1] = '\0';
94                 if (skip_prefix(line, "commit ", &p)) {
95                         if (util) {
96                                 string_list_append(list, buf.buf)->util = util;
97                                 strbuf_reset(&buf);
98                         }
99                         util = xcalloc(sizeof(*util), 1);
100                         if (get_oid(p, &util->oid)) {
101                                 error(_("could not parse commit '%s'"), p);
102                                 free(util);
103                                 free(current_filename);
104                                 string_list_clear(list, 1);
105                                 strbuf_release(&buf);
106                                 strbuf_release(&contents);
107                                 return -1;
108                         }
109                         util->matching = -1;
110                         in_header = 1;
111                         continue;
112                 }
113
114                 if (!util) {
115                         error(_("could not parse first line of `log` output: "
116                                 "did not start with 'commit ': '%s'"),
117                               line);
118                         free(current_filename);
119                         string_list_clear(list, 1);
120                         strbuf_release(&buf);
121                         strbuf_release(&contents);
122                         return -1;
123                 }
124
125                 if (starts_with(line, "diff --git")) {
126                         struct patch patch = { 0 };
127                         struct strbuf root = STRBUF_INIT;
128                         int linenr = 0;
129                         int orig_len;
130
131                         in_header = 0;
132                         strbuf_addch(&buf, '\n');
133                         if (!util->diff_offset)
134                                 util->diff_offset = buf.len;
135                         line[len - 1] = '\n';
136                         orig_len = len;
137                         len = parse_git_diff_header(&root, &linenr, 0, line,
138                                                     len, size, &patch);
139                         if (len < 0) {
140                                 error(_("could not parse git header '%.*s'"),
141                                       orig_len, line);
142                                 free(util);
143                                 free(current_filename);
144                                 string_list_clear(list, 1);
145                                 strbuf_release(&buf);
146                                 strbuf_release(&contents);
147                                 return -1;
148                         }
149                         strbuf_addstr(&buf, " ## ");
150                         if (patch.is_new > 0)
151                                 strbuf_addf(&buf, "%s (new)", patch.new_name);
152                         else if (patch.is_delete > 0)
153                                 strbuf_addf(&buf, "%s (deleted)", patch.old_name);
154                         else if (patch.is_rename)
155                                 strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
156                         else
157                                 strbuf_addstr(&buf, patch.new_name);
158
159                         free(current_filename);
160                         if (patch.is_delete > 0)
161                                 current_filename = xstrdup(patch.old_name);
162                         else
163                                 current_filename = xstrdup(patch.new_name);
164
165                         if (patch.new_mode && patch.old_mode &&
166                             patch.old_mode != patch.new_mode)
167                                 strbuf_addf(&buf, " (mode change %06o => %06o)",
168                                             patch.old_mode, patch.new_mode);
169
170                         strbuf_addstr(&buf, " ##");
171                 } else if (in_header) {
172                         if (starts_with(line, "Author: ")) {
173                                 strbuf_addstr(&buf, " ## Metadata ##\n");
174                                 strbuf_addstr(&buf, line);
175                                 strbuf_addstr(&buf, "\n\n");
176                                 strbuf_addstr(&buf, " ## Commit message ##\n");
177                         } else if (starts_with(line, "Notes") &&
178                                    line[strlen(line) - 1] == ':') {
179                                 strbuf_addstr(&buf, "\n\n");
180                                 /* strip the trailing colon */
181                                 strbuf_addf(&buf, " ## %.*s ##\n",
182                                             (int)(strlen(line) - 1), line);
183                         } else if (starts_with(line, "    ")) {
184                                 p = line + len - 2;
185                                 while (isspace(*p) && p >= line)
186                                         p--;
187                                 strbuf_add(&buf, line, p - line + 1);
188                                 strbuf_addch(&buf, '\n');
189                         }
190                         continue;
191                 } else if (skip_prefix(line, "@@ ", &p)) {
192                         p = strstr(p, "@@");
193                         strbuf_addstr(&buf, "@@");
194                         if (current_filename && p[2])
195                                 strbuf_addf(&buf, " %s:", current_filename);
196                         if (p)
197                                 strbuf_addstr(&buf, p + 2);
198                 } else if (!line[0])
199                         /*
200                          * A completely blank (not ' \n', which is context)
201                          * line is not valid in a diff.  We skip it
202                          * silently, because this neatly handles the blank
203                          * separator line between commits in git-log
204                          * output.
205                          */
206                         continue;
207                 else if (line[0] == '>') {
208                         strbuf_addch(&buf, '+');
209                         strbuf_addstr(&buf, line + 1);
210                 } else if (line[0] == '<') {
211                         strbuf_addch(&buf, '-');
212                         strbuf_addstr(&buf, line + 1);
213                 } else if (line[0] == '#') {
214                         strbuf_addch(&buf, ' ');
215                         strbuf_addstr(&buf, line + 1);
216                 } else {
217                         strbuf_addch(&buf, ' ');
218                         strbuf_addstr(&buf, line);
219                 }
220
221                 strbuf_addch(&buf, '\n');
222                 util->diffsize++;
223         }
224         strbuf_release(&contents);
225
226         if (util)
227                 string_list_append(list, buf.buf)->util = util;
228         strbuf_release(&buf);
229         free(current_filename);
230
231         return 0;
232 }
233
234 static int patch_util_cmp(const void *dummy, const struct patch_util *a,
235                           const struct patch_util *b, const char *keydata)
236 {
237         return strcmp(a->diff, keydata ? keydata : b->diff);
238 }
239
240 static void find_exact_matches(struct string_list *a, struct string_list *b)
241 {
242         struct hashmap map = HASHMAP_INIT((hashmap_cmp_fn)patch_util_cmp, NULL);
243         int i;
244
245         /* First, add the patches of a to a hash map */
246         for (i = 0; i < a->nr; i++) {
247                 struct patch_util *util = a->items[i].util;
248
249                 util->i = i;
250                 util->patch = a->items[i].string;
251                 util->diff = util->patch + util->diff_offset;
252                 hashmap_entry_init(&util->e, strhash(util->diff));
253                 hashmap_add(&map, &util->e);
254         }
255
256         /* Now try to find exact matches in b */
257         for (i = 0; i < b->nr; i++) {
258                 struct patch_util *util = b->items[i].util, *other;
259
260                 util->i = i;
261                 util->patch = b->items[i].string;
262                 util->diff = util->patch + util->diff_offset;
263                 hashmap_entry_init(&util->e, strhash(util->diff));
264                 other = hashmap_remove_entry(&map, util, e, NULL);
265                 if (other) {
266                         if (other->matching >= 0)
267                                 BUG("already assigned!");
268
269                         other->matching = i;
270                         util->matching = other->i;
271                 }
272         }
273
274         hashmap_clear(&map);
275 }
276
277 static void diffsize_consume(void *data, char *line, unsigned long len)
278 {
279         (*(int *)data)++;
280 }
281
282 static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
283                           const char *funcline, long funclen)
284 {
285         diffsize_consume(data, NULL, 0);
286 }
287
288 static int diffsize(const char *a, const char *b)
289 {
290         xpparam_t pp = { 0 };
291         xdemitconf_t cfg = { 0 };
292         mmfile_t mf1, mf2;
293         int count = 0;
294
295         mf1.ptr = (char *)a;
296         mf1.size = strlen(a);
297         mf2.ptr = (char *)b;
298         mf2.size = strlen(b);
299
300         cfg.ctxlen = 3;
301         if (!xdi_diff_outf(&mf1, &mf2,
302                            diffsize_hunk, diffsize_consume, &count,
303                            &pp, &cfg))
304                 return count;
305
306         error(_("failed to generate diff"));
307         return COST_MAX;
308 }
309
310 static void get_correspondences(struct string_list *a, struct string_list *b,
311                                 int creation_factor)
312 {
313         int n = a->nr + b->nr;
314         int *cost, c, *a2b, *b2a;
315         int i, j;
316
317         ALLOC_ARRAY(cost, st_mult(n, n));
318         ALLOC_ARRAY(a2b, n);
319         ALLOC_ARRAY(b2a, n);
320
321         for (i = 0; i < a->nr; i++) {
322                 struct patch_util *a_util = a->items[i].util;
323
324                 for (j = 0; j < b->nr; j++) {
325                         struct patch_util *b_util = b->items[j].util;
326
327                         if (a_util->matching == j)
328                                 c = 0;
329                         else if (a_util->matching < 0 && b_util->matching < 0)
330                                 c = diffsize(a_util->diff, b_util->diff);
331                         else
332                                 c = COST_MAX;
333                         cost[i + n * j] = c;
334                 }
335
336                 c = a_util->matching < 0 ?
337                         a_util->diffsize * creation_factor / 100 : COST_MAX;
338                 for (j = b->nr; j < n; j++)
339                         cost[i + n * j] = c;
340         }
341
342         for (j = 0; j < b->nr; j++) {
343                 struct patch_util *util = b->items[j].util;
344
345                 c = util->matching < 0 ?
346                         util->diffsize * creation_factor / 100 : COST_MAX;
347                 for (i = a->nr; i < n; i++)
348                         cost[i + n * j] = c;
349         }
350
351         for (i = a->nr; i < n; i++)
352                 for (j = b->nr; j < n; j++)
353                         cost[i + n * j] = 0;
354
355         compute_assignment(n, n, cost, a2b, b2a);
356
357         for (i = 0; i < a->nr; i++)
358                 if (a2b[i] >= 0 && a2b[i] < b->nr) {
359                         struct patch_util *a_util = a->items[i].util;
360                         struct patch_util *b_util = b->items[a2b[i]].util;
361
362                         a_util->matching = a2b[i];
363                         b_util->matching = i;
364                 }
365
366         free(cost);
367         free(a2b);
368         free(b2a);
369 }
370
371 static void output_pair_header(struct diff_options *diffopt,
372                                int patch_no_width,
373                                struct strbuf *buf,
374                                struct strbuf *dashes,
375                                struct patch_util *a_util,
376                                struct patch_util *b_util)
377 {
378         struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
379         struct commit *commit;
380         char status;
381         const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
382         const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
383         const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
384         const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
385         const char *color;
386
387         if (!dashes->len)
388                 strbuf_addchars(dashes, '-',
389                                 strlen(find_unique_abbrev(oid,
390                                                           DEFAULT_ABBREV)));
391
392         if (!b_util) {
393                 color = color_old;
394                 status = '<';
395         } else if (!a_util) {
396                 color = color_new;
397                 status = '>';
398         } else if (strcmp(a_util->patch, b_util->patch)) {
399                 color = color_commit;
400                 status = '!';
401         } else {
402                 color = color_commit;
403                 status = '=';
404         }
405
406         strbuf_reset(buf);
407         strbuf_addstr(buf, status == '!' ? color_old : color);
408         if (!a_util)
409                 strbuf_addf(buf, "%*s:  %s ", patch_no_width, "-", dashes->buf);
410         else
411                 strbuf_addf(buf, "%*d:  %s ", patch_no_width, a_util->i + 1,
412                             find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
413
414         if (status == '!')
415                 strbuf_addf(buf, "%s%s", color_reset, color);
416         strbuf_addch(buf, status);
417         if (status == '!')
418                 strbuf_addf(buf, "%s%s", color_reset, color_new);
419
420         if (!b_util)
421                 strbuf_addf(buf, " %*s:  %s", patch_no_width, "-", dashes->buf);
422         else
423                 strbuf_addf(buf, " %*d:  %s", patch_no_width, b_util->i + 1,
424                             find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
425
426         commit = lookup_commit_reference(the_repository, oid);
427         if (commit) {
428                 if (status == '!')
429                         strbuf_addf(buf, "%s%s", color_reset, color);
430
431                 strbuf_addch(buf, ' ');
432                 pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
433         }
434         strbuf_addf(buf, "%s\n", color_reset);
435
436         fwrite(buf->buf, buf->len, 1, diffopt->file);
437 }
438
439 static struct userdiff_driver section_headers = {
440         .funcname = { "^ ## (.*) ##$\n"
441                       "^.?@@ (.*)$", REG_EXTENDED }
442 };
443
444 static struct diff_filespec *get_filespec(const char *name, const char *p)
445 {
446         struct diff_filespec *spec = alloc_filespec(name);
447
448         fill_filespec(spec, &null_oid, 0, 0100644);
449         spec->data = (char *)p;
450         spec->size = strlen(p);
451         spec->should_munmap = 0;
452         spec->is_stdin = 1;
453         spec->driver = &section_headers;
454
455         return spec;
456 }
457
458 static void patch_diff(const char *a, const char *b,
459                        struct diff_options *diffopt)
460 {
461         diff_queue(&diff_queued_diff,
462                    get_filespec("a", a), get_filespec("b", b));
463
464         diffcore_std(diffopt);
465         diff_flush(diffopt);
466 }
467
468 static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
469 {
470         return data;
471 }
472
473 static void output(struct string_list *a, struct string_list *b,
474                    struct range_diff_options *range_diff_opts)
475 {
476         struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
477         int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
478         int i = 0, j = 0;
479         struct diff_options opts;
480         struct strbuf indent = STRBUF_INIT;
481
482         if (range_diff_opts->diffopt)
483                 memcpy(&opts, range_diff_opts->diffopt, sizeof(opts));
484         else
485                 diff_setup(&opts);
486
487         if (!opts.output_format)
488                 opts.output_format = DIFF_FORMAT_PATCH;
489         opts.flags.suppress_diff_headers = 1;
490         opts.flags.dual_color_diffed_diffs =
491                 range_diff_opts->dual_color;
492         opts.flags.suppress_hunk_header_line_count = 1;
493         opts.output_prefix = output_prefix_cb;
494         strbuf_addstr(&indent, "    ");
495         opts.output_prefix_data = &indent;
496         diff_setup_done(&opts);
497
498         /*
499          * We assume the user is really more interested in the second argument
500          * ("newer" version). To that end, we print the output in the order of
501          * the RHS (the `b` parameter). To put the LHS (the `a` parameter)
502          * commits that are no longer in the RHS into a good place, we place
503          * them once we have shown all of their predecessors in the LHS.
504          */
505
506         while (i < a->nr || j < b->nr) {
507                 struct patch_util *a_util, *b_util;
508                 a_util = i < a->nr ? a->items[i].util : NULL;
509                 b_util = j < b->nr ? b->items[j].util : NULL;
510
511                 /* Skip all the already-shown commits from the LHS. */
512                 while (i < a->nr && a_util->shown)
513                         a_util = ++i < a->nr ? a->items[i].util : NULL;
514
515                 /* Show unmatched LHS commit whose predecessors were shown. */
516                 if (i < a->nr && a_util->matching < 0) {
517                         if (!range_diff_opts->right_only)
518                                 output_pair_header(&opts, patch_no_width,
519                                            &buf, &dashes, a_util, NULL);
520                         i++;
521                         continue;
522                 }
523
524                 /* Show unmatched RHS commits. */
525                 while (j < b->nr && b_util->matching < 0) {
526                         if (!range_diff_opts->left_only)
527                                 output_pair_header(&opts, patch_no_width,
528                                            &buf, &dashes, NULL, b_util);
529                         b_util = ++j < b->nr ? b->items[j].util : NULL;
530                 }
531
532                 /* Show matching LHS/RHS pair. */
533                 if (j < b->nr) {
534                         a_util = a->items[b_util->matching].util;
535                         output_pair_header(&opts, patch_no_width,
536                                            &buf, &dashes, a_util, b_util);
537                         if (!(opts.output_format & DIFF_FORMAT_NO_OUTPUT))
538                                 patch_diff(a->items[b_util->matching].string,
539                                            b->items[j].string, &opts);
540                         a_util->shown = 1;
541                         j++;
542                 }
543         }
544         strbuf_release(&buf);
545         strbuf_release(&dashes);
546         strbuf_release(&indent);
547 }
548
549 int show_range_diff(const char *range1, const char *range2,
550                     struct range_diff_options *range_diff_opts)
551 {
552         int res = 0;
553
554         struct string_list branch1 = STRING_LIST_INIT_DUP;
555         struct string_list branch2 = STRING_LIST_INIT_DUP;
556
557         if (range_diff_opts->left_only && range_diff_opts->right_only)
558                 res = error(_("--left-only and --right-only are mutually exclusive"));
559
560         if (!res && read_patches(range1, &branch1, range_diff_opts->other_arg))
561                 res = error(_("could not parse log for '%s'"), range1);
562         if (!res && read_patches(range2, &branch2, range_diff_opts->other_arg))
563                 res = error(_("could not parse log for '%s'"), range2);
564
565         if (!res) {
566                 find_exact_matches(&branch1, &branch2);
567                 get_correspondences(&branch1, &branch2,
568                                     range_diff_opts->creation_factor);
569                 output(&branch1, &branch2, range_diff_opts);
570         }
571
572         string_list_clear(&branch1, 1);
573         string_list_clear(&branch2, 1);
574
575         return res;
576 }
577
578 int is_range_diff_range(const char *arg)
579 {
580         char *copy = xstrdup(arg); /* setup_revisions() modifies it */
581         const char *argv[] = { "", copy, "--", NULL };
582         int i, positive = 0, negative = 0;
583         struct rev_info revs;
584
585         init_revisions(&revs, NULL);
586         if (setup_revisions(3, argv, &revs, NULL) == 1) {
587                 for (i = 0; i < revs.pending.nr; i++)
588                         if (revs.pending.objects[i].item->flags & UNINTERESTING)
589                                 negative++;
590                         else
591                                 positive++;
592                 for (i = 0; i < revs.pending.nr; i++) {
593                         struct object *obj = revs.pending.objects[i].item;
594
595                         if (obj->type == OBJ_COMMIT)
596                                 clear_commit_marks((struct commit *)obj,
597                                                    ALL_REV_FLAGS);
598                 }
599         }
600
601         free(copy);
602         object_array_clear(&revs.pending);
603         return negative > 0 && positive > 0;
604 }