Implement limited context matching in git-apply.
[git.git] / rev-list.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "tag.h"
4 #include "commit.h"
5 #include "tree.h"
6 #include "blob.h"
7 #include "tree-walk.h"
8 #include "revision.h"
9
10 /* bits #0-6 in revision.h */
11
12 #define COUNTED         (1u<<7)
13
14 static const char rev_list_usage[] =
15 "git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
16 "  limiting output:\n"
17 "    --max-count=nr\n"
18 "    --max-age=epoch\n"
19 "    --min-age=epoch\n"
20 "    --sparse\n"
21 "    --no-merges\n"
22 "    --remove-empty\n"
23 "    --all\n"
24 "  ordering output:\n"
25 "    --topo-order\n"
26 "    --date-order\n"
27 "  formatting output:\n"
28 "    --parents\n"
29 "    --objects | --objects-edge\n"
30 "    --unpacked\n"
31 "    --header | --pretty\n"
32 "    --abbrev=nr | --no-abbrev\n"
33 "    --abbrev-commit\n"
34 "  special purpose:\n"
35 "    --bisect"
36 ;
37
38 struct rev_info revs;
39
40 static int bisect_list = 0;
41 static int verbose_header = 0;
42 static int abbrev = DEFAULT_ABBREV;
43 static int abbrev_commit = 0;
44 static int show_timestamp = 0;
45 static int hdr_termination = 0;
46 static const char *commit_prefix = "";
47 static enum cmit_fmt commit_format = CMIT_FMT_RAW;
48
49 static void show_commit(struct commit *commit)
50 {
51         if (show_timestamp)
52                 printf("%lu ", commit->date);
53         if (commit_prefix[0])
54                 fputs(commit_prefix, stdout);
55         if (commit->object.flags & BOUNDARY)
56                 putchar('-');
57         if (abbrev_commit && abbrev)
58                 fputs(find_unique_abbrev(commit->object.sha1, abbrev), stdout);
59         else
60                 fputs(sha1_to_hex(commit->object.sha1), stdout);
61         if (revs.parents) {
62                 struct commit_list *parents = commit->parents;
63                 while (parents) {
64                         struct object *o = &(parents->item->object);
65                         parents = parents->next;
66                         if (o->flags & TMP_MARK)
67                                 continue;
68                         printf(" %s", sha1_to_hex(o->sha1));
69                         o->flags |= TMP_MARK;
70                 }
71                 /* TMP_MARK is a general purpose flag that can
72                  * be used locally, but the user should clean
73                  * things up after it is done with them.
74                  */
75                 for (parents = commit->parents;
76                      parents;
77                      parents = parents->next)
78                         parents->item->object.flags &= ~TMP_MARK;
79         }
80         if (commit_format == CMIT_FMT_ONELINE)
81                 putchar(' ');
82         else
83                 putchar('\n');
84
85         if (verbose_header) {
86                 static char pretty_header[16384];
87                 pretty_print_commit(commit_format, commit, ~0, pretty_header, sizeof(pretty_header), abbrev);
88                 printf("%s%c", pretty_header, hdr_termination);
89         }
90         fflush(stdout);
91 }
92
93 static struct object_list **process_blob(struct blob *blob,
94                                          struct object_list **p,
95                                          struct name_path *path,
96                                          const char *name)
97 {
98         struct object *obj = &blob->object;
99
100         if (!revs.blob_objects)
101                 return p;
102         if (obj->flags & (UNINTERESTING | SEEN))
103                 return p;
104         obj->flags |= SEEN;
105         return add_object(obj, p, path, name);
106 }
107
108 static struct object_list **process_tree(struct tree *tree,
109                                          struct object_list **p,
110                                          struct name_path *path,
111                                          const char *name)
112 {
113         struct object *obj = &tree->object;
114         struct tree_entry_list *entry;
115         struct name_path me;
116
117         if (!revs.tree_objects)
118                 return p;
119         if (obj->flags & (UNINTERESTING | SEEN))
120                 return p;
121         if (parse_tree(tree) < 0)
122                 die("bad tree object %s", sha1_to_hex(obj->sha1));
123         obj->flags |= SEEN;
124         p = add_object(obj, p, path, name);
125         me.up = path;
126         me.elem = name;
127         me.elem_len = strlen(name);
128         entry = tree->entries;
129         tree->entries = NULL;
130         while (entry) {
131                 struct tree_entry_list *next = entry->next;
132                 if (entry->directory)
133                         p = process_tree(entry->item.tree, p, &me, entry->name);
134                 else
135                         p = process_blob(entry->item.blob, p, &me, entry->name);
136                 free(entry);
137                 entry = next;
138         }
139         return p;
140 }
141
142 static void show_commit_list(struct rev_info *revs)
143 {
144         struct commit *commit;
145         struct object_list *objects = NULL, **p = &objects, *pending;
146
147         while ((commit = get_revision(revs)) != NULL) {
148                 p = process_tree(commit->tree, p, NULL, "");
149                 show_commit(commit);
150         }
151         for (pending = revs->pending_objects; pending; pending = pending->next) {
152                 struct object *obj = pending->item;
153                 const char *name = pending->name;
154                 if (obj->flags & (UNINTERESTING | SEEN))
155                         continue;
156                 if (obj->type == tag_type) {
157                         obj->flags |= SEEN;
158                         p = add_object(obj, p, NULL, name);
159                         continue;
160                 }
161                 if (obj->type == tree_type) {
162                         p = process_tree((struct tree *)obj, p, NULL, name);
163                         continue;
164                 }
165                 if (obj->type == blob_type) {
166                         p = process_blob((struct blob *)obj, p, NULL, name);
167                         continue;
168                 }
169                 die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
170         }
171         while (objects) {
172                 /* An object with name "foo\n0000000..." can be used to
173                  * confuse downstream git-pack-objects very badly.
174                  */
175                 const char *ep = strchr(objects->name, '\n');
176                 if (ep) {
177                         printf("%s %.*s\n", sha1_to_hex(objects->item->sha1),
178                                (int) (ep - objects->name),
179                                objects->name);
180                 }
181                 else
182                         printf("%s %s\n", sha1_to_hex(objects->item->sha1), objects->name);
183                 objects = objects->next;
184         }
185 }
186
187 /*
188  * This is a truly stupid algorithm, but it's only
189  * used for bisection, and we just don't care enough.
190  *
191  * We care just barely enough to avoid recursing for
192  * non-merge entries.
193  */
194 static int count_distance(struct commit_list *entry)
195 {
196         int nr = 0;
197
198         while (entry) {
199                 struct commit *commit = entry->item;
200                 struct commit_list *p;
201
202                 if (commit->object.flags & (UNINTERESTING | COUNTED))
203                         break;
204                 if (!revs.prune_fn || (commit->object.flags & TREECHANGE))
205                         nr++;
206                 commit->object.flags |= COUNTED;
207                 p = commit->parents;
208                 entry = p;
209                 if (p) {
210                         p = p->next;
211                         while (p) {
212                                 nr += count_distance(p);
213                                 p = p->next;
214                         }
215                 }
216         }
217
218         return nr;
219 }
220
221 static void clear_distance(struct commit_list *list)
222 {
223         while (list) {
224                 struct commit *commit = list->item;
225                 commit->object.flags &= ~COUNTED;
226                 list = list->next;
227         }
228 }
229
230 static struct commit_list *find_bisection(struct commit_list *list)
231 {
232         int nr, closest;
233         struct commit_list *p, *best;
234
235         nr = 0;
236         p = list;
237         while (p) {
238                 if (!revs.prune_fn || (p->item->object.flags & TREECHANGE))
239                         nr++;
240                 p = p->next;
241         }
242         closest = 0;
243         best = list;
244
245         for (p = list; p; p = p->next) {
246                 int distance;
247
248                 if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
249                         continue;
250
251                 distance = count_distance(p);
252                 clear_distance(list);
253                 if (nr - distance < distance)
254                         distance = nr - distance;
255                 if (distance > closest) {
256                         best = p;
257                         closest = distance;
258                 }
259         }
260         if (best)
261                 best->next = NULL;
262         return best;
263 }
264
265 static void mark_edge_parents_uninteresting(struct commit *commit)
266 {
267         struct commit_list *parents;
268
269         for (parents = commit->parents; parents; parents = parents->next) {
270                 struct commit *parent = parents->item;
271                 if (!(parent->object.flags & UNINTERESTING))
272                         continue;
273                 mark_tree_uninteresting(parent->tree);
274                 if (revs.edge_hint && !(parent->object.flags & SHOWN)) {
275                         parent->object.flags |= SHOWN;
276                         printf("-%s\n", sha1_to_hex(parent->object.sha1));
277                 }
278         }
279 }
280
281 static void mark_edges_uninteresting(struct commit_list *list)
282 {
283         for ( ; list; list = list->next) {
284                 struct commit *commit = list->item;
285
286                 if (commit->object.flags & UNINTERESTING) {
287                         mark_tree_uninteresting(commit->tree);
288                         continue;
289                 }
290                 mark_edge_parents_uninteresting(commit);
291         }
292 }
293
294 int main(int argc, const char **argv)
295 {
296         struct commit_list *list;
297         int i;
298
299         argc = setup_revisions(argc, argv, &revs, NULL);
300
301         for (i = 1 ; i < argc; i++) {
302                 const char *arg = argv[i];
303
304                 /* accept -<digit>, like traditilnal "head" */
305                 if ((*arg == '-') && isdigit(arg[1])) {
306                         revs.max_count = atoi(arg + 1);
307                         continue;
308                 }
309                 if (!strcmp(arg, "-n")) {
310                         if (++i >= argc)
311                                 die("-n requires an argument");
312                         revs.max_count = atoi(argv[i]);
313                         continue;
314                 }
315                 if (!strncmp(arg,"-n",2)) {
316                         revs.max_count = atoi(arg + 2);
317                         continue;
318                 }
319                 if (!strcmp(arg, "--header")) {
320                         verbose_header = 1;
321                         continue;
322                 }
323                 if (!strcmp(arg, "--no-abbrev")) {
324                         abbrev = 0;
325                         continue;
326                 }
327                 if (!strcmp(arg, "--abbrev")) {
328                         abbrev = DEFAULT_ABBREV;
329                         continue;
330                 }
331                 if (!strcmp(arg, "--abbrev-commit")) {
332                         abbrev_commit = 1;
333                         continue;
334                 }
335                 if (!strncmp(arg, "--abbrev=", 9)) {
336                         abbrev = strtoul(arg + 9, NULL, 10);
337                         if (abbrev && abbrev < MINIMUM_ABBREV)
338                                 abbrev = MINIMUM_ABBREV;
339                         else if (40 < abbrev)
340                                 abbrev = 40;
341                         continue;
342                 }
343                 if (!strncmp(arg, "--pretty", 8)) {
344                         commit_format = get_commit_format(arg+8);
345                         verbose_header = 1;
346                         hdr_termination = '\n';
347                         if (commit_format == CMIT_FMT_ONELINE)
348                                 commit_prefix = "";
349                         else
350                                 commit_prefix = "commit ";
351                         continue;
352                 }
353                 if (!strcmp(arg, "--timestamp")) {
354                         show_timestamp = 1;
355                         continue;
356                 }
357                 if (!strcmp(arg, "--bisect")) {
358                         bisect_list = 1;
359                         continue;
360                 }
361                 usage(rev_list_usage);
362
363         }
364
365         list = revs.commits;
366
367         if (!list &&
368             (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) && !revs.pending_objects))
369                 usage(rev_list_usage);
370
371         save_commit_buffer = verbose_header;
372         track_object_refs = 0;
373
374         prepare_revision_walk(&revs);
375         if (revs.tree_objects)
376                 mark_edges_uninteresting(revs.commits);
377
378         if (bisect_list)
379                 revs.commits = find_bisection(revs.commits);
380
381         show_commit_list(&revs);
382
383         return 0;
384 }