rebase: reinstate --no-keep-empty
[git/debian.git] / range-diff.c
blobf745567cf6719665cdfd23145335380f36e0c54b
1 #include "cache.h"
2 #include "range-diff.h"
3 #include "string-list.h"
4 #include "run-command.h"
5 #include "argv-array.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"
15 struct patch_util {
16 /* For the search for an exact match */
17 struct hashmap_entry e;
18 const char *diff, *patch;
20 int i, shown;
21 int diffsize;
22 size_t diff_offset;
23 /* the index of the matching item in the other branch, or -1 */
24 int matching;
25 struct object_id oid;
28 static size_t find_end_of_line(char *buffer, unsigned long size)
30 char *eol = memchr(buffer, '\n', size);
32 if (!eol)
33 return size;
35 *eol = '\0';
36 return eol + 1 - buffer;
40 * Reads the patches into a string list, with the `util` field being populated
41 * as struct object_id (will need to be free()d).
43 static int read_patches(const char *range, struct string_list *list,
44 const struct argv_array *other_arg)
46 struct child_process cp = CHILD_PROCESS_INIT;
47 struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
48 struct patch_util *util = NULL;
49 int in_header = 1;
50 char *line, *current_filename = NULL;
51 int offset, len;
52 size_t size;
54 argv_array_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
55 "--reverse", "--date-order", "--decorate=no",
56 "--no-prefix",
58 * Choose indicators that are not used anywhere
59 * else in diffs, but still look reasonable
60 * (e.g. will not be confusing when debugging)
62 "--output-indicator-new=>",
63 "--output-indicator-old=<",
64 "--output-indicator-context=#",
65 "--no-abbrev-commit",
66 NULL);
67 if (other_arg)
68 argv_array_pushv(&cp.args, other_arg->argv);
69 argv_array_push(&cp.args, range);
70 cp.out = -1;
71 cp.no_stdin = 1;
72 cp.git_cmd = 1;
74 if (start_command(&cp))
75 return error_errno(_("could not start `log`"));
76 if (strbuf_read(&contents, cp.out, 0) < 0) {
77 error_errno(_("could not read `log` output"));
78 finish_command(&cp);
79 return -1;
82 line = contents.buf;
83 size = contents.len;
84 for (offset = 0; size > 0; offset += len, size -= len, line += len) {
85 const char *p;
87 len = find_end_of_line(line, size);
88 line[len - 1] = '\0';
89 if (skip_prefix(line, "commit ", &p)) {
90 if (util) {
91 string_list_append(list, buf.buf)->util = util;
92 strbuf_reset(&buf);
94 util = xcalloc(sizeof(*util), 1);
95 if (get_oid(p, &util->oid)) {
96 error(_("could not parse commit '%s'"), p);
97 free(util);
98 string_list_clear(list, 1);
99 strbuf_release(&buf);
100 strbuf_release(&contents);
101 finish_command(&cp);
102 return -1;
104 util->matching = -1;
105 in_header = 1;
106 continue;
109 if (starts_with(line, "diff --git")) {
110 struct patch patch = { 0 };
111 struct strbuf root = STRBUF_INIT;
112 int linenr = 0;
114 in_header = 0;
115 strbuf_addch(&buf, '\n');
116 if (!util->diff_offset)
117 util->diff_offset = buf.len;
118 line[len - 1] = '\n';
119 len = parse_git_diff_header(&root, &linenr, 0, line,
120 len, size, &patch);
121 if (len < 0)
122 die(_("could not parse git header '%.*s'"), (int)len, line);
123 strbuf_addstr(&buf, " ## ");
124 if (patch.is_new > 0)
125 strbuf_addf(&buf, "%s (new)", patch.new_name);
126 else if (patch.is_delete > 0)
127 strbuf_addf(&buf, "%s (deleted)", patch.old_name);
128 else if (patch.is_rename)
129 strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
130 else
131 strbuf_addstr(&buf, patch.new_name);
133 free(current_filename);
134 if (patch.is_delete > 0)
135 current_filename = xstrdup(patch.old_name);
136 else
137 current_filename = xstrdup(patch.new_name);
139 if (patch.new_mode && patch.old_mode &&
140 patch.old_mode != patch.new_mode)
141 strbuf_addf(&buf, " (mode change %06o => %06o)",
142 patch.old_mode, patch.new_mode);
144 strbuf_addstr(&buf, " ##");
145 } else if (in_header) {
146 if (starts_with(line, "Author: ")) {
147 strbuf_addstr(&buf, " ## Metadata ##\n");
148 strbuf_addstr(&buf, line);
149 strbuf_addstr(&buf, "\n\n");
150 strbuf_addstr(&buf, " ## Commit message ##\n");
151 } else if (starts_with(line, "Notes") &&
152 line[strlen(line) - 1] == ':') {
153 strbuf_addstr(&buf, "\n\n");
154 /* strip the trailing colon */
155 strbuf_addf(&buf, " ## %.*s ##\n",
156 (int)(strlen(line) - 1), line);
157 } else if (starts_with(line, " ")) {
158 p = line + len - 2;
159 while (isspace(*p) && p >= line)
160 p--;
161 strbuf_add(&buf, line, p - line + 1);
162 strbuf_addch(&buf, '\n');
164 continue;
165 } else if (skip_prefix(line, "@@ ", &p)) {
166 p = strstr(p, "@@");
167 strbuf_addstr(&buf, "@@");
168 if (current_filename && p[2])
169 strbuf_addf(&buf, " %s:", current_filename);
170 if (p)
171 strbuf_addstr(&buf, p + 2);
172 } else if (!line[0])
174 * A completely blank (not ' \n', which is context)
175 * line is not valid in a diff. We skip it
176 * silently, because this neatly handles the blank
177 * separator line between commits in git-log
178 * output.
180 continue;
181 else if (line[0] == '>') {
182 strbuf_addch(&buf, '+');
183 strbuf_addstr(&buf, line + 1);
184 } else if (line[0] == '<') {
185 strbuf_addch(&buf, '-');
186 strbuf_addstr(&buf, line + 1);
187 } else if (line[0] == '#') {
188 strbuf_addch(&buf, ' ');
189 strbuf_addstr(&buf, line + 1);
190 } else {
191 strbuf_addch(&buf, ' ');
192 strbuf_addstr(&buf, line);
195 strbuf_addch(&buf, '\n');
196 util->diffsize++;
198 strbuf_release(&contents);
200 if (util)
201 string_list_append(list, buf.buf)->util = util;
202 strbuf_release(&buf);
203 free(current_filename);
205 if (finish_command(&cp))
206 return -1;
208 return 0;
211 static int patch_util_cmp(const void *dummy, const struct patch_util *a,
212 const struct patch_util *b, const char *keydata)
214 return strcmp(a->diff, keydata ? keydata : b->diff);
217 static void find_exact_matches(struct string_list *a, struct string_list *b)
219 struct hashmap map;
220 int i;
222 hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
224 /* First, add the patches of a to a hash map */
225 for (i = 0; i < a->nr; i++) {
226 struct patch_util *util = a->items[i].util;
228 util->i = i;
229 util->patch = a->items[i].string;
230 util->diff = util->patch + util->diff_offset;
231 hashmap_entry_init(&util->e, strhash(util->diff));
232 hashmap_add(&map, &util->e);
235 /* Now try to find exact matches in b */
236 for (i = 0; i < b->nr; i++) {
237 struct patch_util *util = b->items[i].util, *other;
239 util->i = i;
240 util->patch = b->items[i].string;
241 util->diff = util->patch + util->diff_offset;
242 hashmap_entry_init(&util->e, strhash(util->diff));
243 other = hashmap_remove_entry(&map, util, e, NULL);
244 if (other) {
245 if (other->matching >= 0)
246 BUG("already assigned!");
248 other->matching = i;
249 util->matching = other->i;
253 hashmap_free(&map);
256 static void diffsize_consume(void *data, char *line, unsigned long len)
258 (*(int *)data)++;
261 static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
262 const char *funcline, long funclen)
264 diffsize_consume(data, NULL, 0);
267 static int diffsize(const char *a, const char *b)
269 xpparam_t pp = { 0 };
270 xdemitconf_t cfg = { 0 };
271 mmfile_t mf1, mf2;
272 int count = 0;
274 mf1.ptr = (char *)a;
275 mf1.size = strlen(a);
276 mf2.ptr = (char *)b;
277 mf2.size = strlen(b);
279 cfg.ctxlen = 3;
280 if (!xdi_diff_outf(&mf1, &mf2,
281 diffsize_hunk, diffsize_consume, &count,
282 &pp, &cfg))
283 return count;
285 error(_("failed to generate diff"));
286 return COST_MAX;
289 static void get_correspondences(struct string_list *a, struct string_list *b,
290 int creation_factor)
292 int n = a->nr + b->nr;
293 int *cost, c, *a2b, *b2a;
294 int i, j;
296 ALLOC_ARRAY(cost, st_mult(n, n));
297 ALLOC_ARRAY(a2b, n);
298 ALLOC_ARRAY(b2a, n);
300 for (i = 0; i < a->nr; i++) {
301 struct patch_util *a_util = a->items[i].util;
303 for (j = 0; j < b->nr; j++) {
304 struct patch_util *b_util = b->items[j].util;
306 if (a_util->matching == j)
307 c = 0;
308 else if (a_util->matching < 0 && b_util->matching < 0)
309 c = diffsize(a_util->diff, b_util->diff);
310 else
311 c = COST_MAX;
312 cost[i + n * j] = c;
315 c = a_util->matching < 0 ?
316 a_util->diffsize * creation_factor / 100 : COST_MAX;
317 for (j = b->nr; j < n; j++)
318 cost[i + n * j] = c;
321 for (j = 0; j < b->nr; j++) {
322 struct patch_util *util = b->items[j].util;
324 c = util->matching < 0 ?
325 util->diffsize * creation_factor / 100 : COST_MAX;
326 for (i = a->nr; i < n; i++)
327 cost[i + n * j] = c;
330 for (i = a->nr; i < n; i++)
331 for (j = b->nr; j < n; j++)
332 cost[i + n * j] = 0;
334 compute_assignment(n, n, cost, a2b, b2a);
336 for (i = 0; i < a->nr; i++)
337 if (a2b[i] >= 0 && a2b[i] < b->nr) {
338 struct patch_util *a_util = a->items[i].util;
339 struct patch_util *b_util = b->items[a2b[i]].util;
341 a_util->matching = a2b[i];
342 b_util->matching = i;
345 free(cost);
346 free(a2b);
347 free(b2a);
350 static void output_pair_header(struct diff_options *diffopt,
351 int patch_no_width,
352 struct strbuf *buf,
353 struct strbuf *dashes,
354 struct patch_util *a_util,
355 struct patch_util *b_util)
357 struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
358 struct commit *commit;
359 char status;
360 const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
361 const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
362 const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
363 const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
364 const char *color;
366 if (!dashes->len)
367 strbuf_addchars(dashes, '-',
368 strlen(find_unique_abbrev(oid,
369 DEFAULT_ABBREV)));
371 if (!b_util) {
372 color = color_old;
373 status = '<';
374 } else if (!a_util) {
375 color = color_new;
376 status = '>';
377 } else if (strcmp(a_util->patch, b_util->patch)) {
378 color = color_commit;
379 status = '!';
380 } else {
381 color = color_commit;
382 status = '=';
385 strbuf_reset(buf);
386 strbuf_addstr(buf, status == '!' ? color_old : color);
387 if (!a_util)
388 strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
389 else
390 strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
391 find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
393 if (status == '!')
394 strbuf_addf(buf, "%s%s", color_reset, color);
395 strbuf_addch(buf, status);
396 if (status == '!')
397 strbuf_addf(buf, "%s%s", color_reset, color_new);
399 if (!b_util)
400 strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
401 else
402 strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
403 find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
405 commit = lookup_commit_reference(the_repository, oid);
406 if (commit) {
407 if (status == '!')
408 strbuf_addf(buf, "%s%s", color_reset, color);
410 strbuf_addch(buf, ' ');
411 pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
413 strbuf_addf(buf, "%s\n", color_reset);
415 fwrite(buf->buf, buf->len, 1, diffopt->file);
418 static struct userdiff_driver section_headers = {
419 .funcname = { "^ ## (.*) ##$\n"
420 "^.?@@ (.*)$", REG_EXTENDED }
423 static struct diff_filespec *get_filespec(const char *name, const char *p)
425 struct diff_filespec *spec = alloc_filespec(name);
427 fill_filespec(spec, &null_oid, 0, 0100644);
428 spec->data = (char *)p;
429 spec->size = strlen(p);
430 spec->should_munmap = 0;
431 spec->is_stdin = 1;
432 spec->driver = &section_headers;
434 return spec;
437 static void patch_diff(const char *a, const char *b,
438 struct diff_options *diffopt)
440 diff_queue(&diff_queued_diff,
441 get_filespec("a", a), get_filespec("b", b));
443 diffcore_std(diffopt);
444 diff_flush(diffopt);
447 static void output(struct string_list *a, struct string_list *b,
448 struct diff_options *diffopt)
450 struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
451 int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
452 int i = 0, j = 0;
455 * We assume the user is really more interested in the second argument
456 * ("newer" version). To that end, we print the output in the order of
457 * the RHS (the `b` parameter). To put the LHS (the `a` parameter)
458 * commits that are no longer in the RHS into a good place, we place
459 * them once we have shown all of their predecessors in the LHS.
462 while (i < a->nr || j < b->nr) {
463 struct patch_util *a_util, *b_util;
464 a_util = i < a->nr ? a->items[i].util : NULL;
465 b_util = j < b->nr ? b->items[j].util : NULL;
467 /* Skip all the already-shown commits from the LHS. */
468 while (i < a->nr && a_util->shown)
469 a_util = ++i < a->nr ? a->items[i].util : NULL;
471 /* Show unmatched LHS commit whose predecessors were shown. */
472 if (i < a->nr && a_util->matching < 0) {
473 output_pair_header(diffopt, patch_no_width,
474 &buf, &dashes, a_util, NULL);
475 i++;
476 continue;
479 /* Show unmatched RHS commits. */
480 while (j < b->nr && b_util->matching < 0) {
481 output_pair_header(diffopt, patch_no_width,
482 &buf, &dashes, NULL, b_util);
483 b_util = ++j < b->nr ? b->items[j].util : NULL;
486 /* Show matching LHS/RHS pair. */
487 if (j < b->nr) {
488 a_util = a->items[b_util->matching].util;
489 output_pair_header(diffopt, patch_no_width,
490 &buf, &dashes, a_util, b_util);
491 if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
492 patch_diff(a->items[b_util->matching].string,
493 b->items[j].string, diffopt);
494 a_util->shown = 1;
495 j++;
498 strbuf_release(&buf);
499 strbuf_release(&dashes);
502 static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
504 return data;
507 int show_range_diff(const char *range1, const char *range2,
508 int creation_factor, int dual_color,
509 const struct diff_options *diffopt,
510 const struct argv_array *other_arg)
512 int res = 0;
514 struct string_list branch1 = STRING_LIST_INIT_DUP;
515 struct string_list branch2 = STRING_LIST_INIT_DUP;
517 if (read_patches(range1, &branch1, other_arg))
518 res = error(_("could not parse log for '%s'"), range1);
519 if (!res && read_patches(range2, &branch2, other_arg))
520 res = error(_("could not parse log for '%s'"), range2);
522 if (!res) {
523 struct diff_options opts;
524 struct strbuf indent = STRBUF_INIT;
526 if (diffopt)
527 memcpy(&opts, diffopt, sizeof(opts));
528 else
529 diff_setup(&opts);
531 if (!opts.output_format)
532 opts.output_format = DIFF_FORMAT_PATCH;
533 opts.flags.suppress_diff_headers = 1;
534 opts.flags.dual_color_diffed_diffs = dual_color;
535 opts.flags.suppress_hunk_header_line_count = 1;
536 opts.output_prefix = output_prefix_cb;
537 strbuf_addstr(&indent, " ");
538 opts.output_prefix_data = &indent;
539 diff_setup_done(&opts);
541 find_exact_matches(&branch1, &branch2);
542 get_correspondences(&branch1, &branch2, creation_factor);
543 output(&branch1, &branch2, &opts);
545 strbuf_release(&indent);
548 string_list_clear(&branch1, 1);
549 string_list_clear(&branch2, 1);
551 return res;