Introduce advise() to print hints
[git] / builtin / rev-list.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "diff.h"
4 #include "revision.h"
5 #include "list-objects.h"
6 #include "builtin.h"
7 #include "log-tree.h"
8 #include "graph.h"
9 #include "bisect.h"
10
11 static const char rev_list_usage[] =
12 "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
13 "  limiting output:\n"
14 "    --max-count=nr\n"
15 "    --max-age=epoch\n"
16 "    --min-age=epoch\n"
17 "    --sparse\n"
18 "    --no-merges\n"
19 "    --remove-empty\n"
20 "    --all\n"
21 "    --branches\n"
22 "    --tags\n"
23 "    --remotes\n"
24 "    --stdin\n"
25 "    --quiet\n"
26 "  ordering output:\n"
27 "    --topo-order\n"
28 "    --date-order\n"
29 "    --reverse\n"
30 "  formatting output:\n"
31 "    --parents\n"
32 "    --children\n"
33 "    --objects | --objects-edge\n"
34 "    --unpacked\n"
35 "    --header | --pretty\n"
36 "    --abbrev=nr | --no-abbrev\n"
37 "    --abbrev-commit\n"
38 "    --left-right\n"
39 "  special purpose:\n"
40 "    --bisect\n"
41 "    --bisect-vars\n"
42 "    --bisect-all"
43 ;
44
45 static void finish_commit(struct commit *commit, void *data);
46 static void show_commit(struct commit *commit, void *data)
47 {
48         struct rev_list_info *info = data;
49         struct rev_info *revs = info->revs;
50
51         graph_show_commit(revs->graph);
52
53         if (revs->count) {
54                 if (commit->object.flags & SYMMETRIC_LEFT)
55                         revs->count_left++;
56                 else
57                         revs->count_right++;
58                 finish_commit(commit, data);
59                 return;
60         }
61
62         if (info->show_timestamp)
63                 printf("%lu ", commit->date);
64         if (info->header_prefix)
65                 fputs(info->header_prefix, stdout);
66
67         if (!revs->graph) {
68                 if (commit->object.flags & BOUNDARY)
69                         putchar('-');
70                 else if (commit->object.flags & UNINTERESTING)
71                         putchar('^');
72                 else if (revs->left_right) {
73                         if (commit->object.flags & SYMMETRIC_LEFT)
74                                 putchar('<');
75                         else
76                                 putchar('>');
77                 }
78         }
79         if (revs->abbrev_commit && revs->abbrev)
80                 fputs(find_unique_abbrev(commit->object.sha1, revs->abbrev),
81                       stdout);
82         else
83                 fputs(sha1_to_hex(commit->object.sha1), stdout);
84         if (revs->print_parents) {
85                 struct commit_list *parents = commit->parents;
86                 while (parents) {
87                         printf(" %s", sha1_to_hex(parents->item->object.sha1));
88                         parents = parents->next;
89                 }
90         }
91         if (revs->children.name) {
92                 struct commit_list *children;
93
94                 children = lookup_decoration(&revs->children, &commit->object);
95                 while (children) {
96                         printf(" %s", sha1_to_hex(children->item->object.sha1));
97                         children = children->next;
98                 }
99         }
100         show_decorations(revs, commit);
101         if (revs->commit_format == CMIT_FMT_ONELINE)
102                 putchar(' ');
103         else
104                 putchar('\n');
105
106         if (revs->verbose_header && commit->buffer) {
107                 struct strbuf buf = STRBUF_INIT;
108                 struct pretty_print_context ctx = {0};
109                 ctx.abbrev = revs->abbrev;
110                 ctx.date_mode = revs->date_mode;
111                 pretty_print_commit(revs->commit_format, commit, &buf, &ctx);
112                 if (revs->graph) {
113                         if (buf.len) {
114                                 if (revs->commit_format != CMIT_FMT_ONELINE)
115                                         graph_show_oneline(revs->graph);
116
117                                 graph_show_commit_msg(revs->graph, &buf);
118
119                                 /*
120                                  * Add a newline after the commit message.
121                                  *
122                                  * Usually, this newline produces a blank
123                                  * padding line between entries, in which case
124                                  * we need to add graph padding on this line.
125                                  *
126                                  * However, the commit message may not end in a
127                                  * newline.  In this case the newline simply
128                                  * ends the last line of the commit message,
129                                  * and we don't need any graph output.  (This
130                                  * always happens with CMIT_FMT_ONELINE, and it
131                                  * happens with CMIT_FMT_USERFORMAT when the
132                                  * format doesn't explicitly end in a newline.)
133                                  */
134                                 if (buf.len && buf.buf[buf.len - 1] == '\n')
135                                         graph_show_padding(revs->graph);
136                                 putchar('\n');
137                         } else {
138                                 /*
139                                  * If the message buffer is empty, just show
140                                  * the rest of the graph output for this
141                                  * commit.
142                                  */
143                                 if (graph_show_remainder(revs->graph))
144                                         putchar('\n');
145                                 if (revs->commit_format == CMIT_FMT_ONELINE)
146                                         putchar('\n');
147                         }
148                 } else {
149                         if (revs->commit_format != CMIT_FMT_USERFORMAT ||
150                             buf.len)
151                                 printf("%s%c", buf.buf, info->hdr_termination);
152                 }
153                 strbuf_release(&buf);
154         } else {
155                 if (graph_show_remainder(revs->graph))
156                         putchar('\n');
157         }
158         maybe_flush_or_die(stdout, "stdout");
159         finish_commit(commit, data);
160 }
161
162 static void finish_commit(struct commit *commit, void *data)
163 {
164         if (commit->parents) {
165                 free_commit_list(commit->parents);
166                 commit->parents = NULL;
167         }
168         free(commit->buffer);
169         commit->buffer = NULL;
170 }
171
172 static void finish_object(struct object *obj, const struct name_path *path, const char *name)
173 {
174         if (obj->type == OBJ_BLOB && !has_sha1_file(obj->sha1))
175                 die("missing blob object '%s'", sha1_to_hex(obj->sha1));
176 }
177
178 static void show_object(struct object *obj, const struct name_path *path, const char *component)
179 {
180         char *name = path_name(path, component);
181         /* An object with name "foo\n0000000..." can be used to
182          * confuse downstream "git pack-objects" very badly.
183          */
184         const char *ep = strchr(name, '\n');
185
186         finish_object(obj, path, name);
187         if (ep) {
188                 printf("%s %.*s\n", sha1_to_hex(obj->sha1),
189                        (int) (ep - name),
190                        name);
191         }
192         else
193                 printf("%s %s\n", sha1_to_hex(obj->sha1), name);
194         free(name);
195 }
196
197 static void show_edge(struct commit *commit)
198 {
199         printf("-%s\n", sha1_to_hex(commit->object.sha1));
200 }
201
202 static inline int log2i(int n)
203 {
204         int log2 = 0;
205
206         for (; n > 1; n >>= 1)
207                 log2++;
208
209         return log2;
210 }
211
212 static inline int exp2i(int n)
213 {
214         return 1 << n;
215 }
216
217 /*
218  * Estimate the number of bisect steps left (after the current step)
219  *
220  * For any x between 0 included and 2^n excluded, the probability for
221  * n - 1 steps left looks like:
222  *
223  * P(2^n + x) == (2^n - x) / (2^n + x)
224  *
225  * and P(2^n + x) < 0.5 means 2^n < 3x
226  */
227 int estimate_bisect_steps(int all)
228 {
229         int n, x, e;
230
231         if (all < 3)
232                 return 0;
233
234         n = log2i(all);
235         e = exp2i(n);
236         x = all - e;
237
238         return (e < 3 * x) ? n : n - 1;
239 }
240
241 void print_commit_list(struct commit_list *list,
242                        const char *format_cur,
243                        const char *format_last)
244 {
245         for ( ; list; list = list->next) {
246                 const char *format = list->next ? format_cur : format_last;
247                 printf(format, sha1_to_hex(list->item->object.sha1));
248         }
249 }
250
251 static void show_tried_revs(struct commit_list *tried)
252 {
253         printf("bisect_tried='");
254         print_commit_list(tried, "%s|", "%s");
255         printf("'\n");
256 }
257
258 static void print_var_str(const char *var, const char *val)
259 {
260         printf("%s='%s'\n", var, val);
261 }
262
263 static void print_var_int(const char *var, int val)
264 {
265         printf("%s=%d\n", var, val);
266 }
267
268 static int show_bisect_vars(struct rev_list_info *info, int reaches, int all)
269 {
270         int cnt, flags = info->bisect_show_flags;
271         char hex[41] = "";
272         struct commit_list *tried;
273         struct rev_info *revs = info->revs;
274
275         if (!revs->commits && !(flags & BISECT_SHOW_TRIED))
276                 return 1;
277
278         revs->commits = filter_skipped(revs->commits, &tried,
279                                        flags & BISECT_SHOW_ALL,
280                                        NULL, NULL);
281
282         /*
283          * revs->commits can reach "reaches" commits among
284          * "all" commits.  If it is good, then there are
285          * (all-reaches) commits left to be bisected.
286          * On the other hand, if it is bad, then the set
287          * to bisect is "reaches".
288          * A bisect set of size N has (N-1) commits further
289          * to test, as we already know one bad one.
290          */
291         cnt = all - reaches;
292         if (cnt < reaches)
293                 cnt = reaches;
294
295         if (revs->commits)
296                 strcpy(hex, sha1_to_hex(revs->commits->item->object.sha1));
297
298         if (flags & BISECT_SHOW_ALL) {
299                 traverse_commit_list(revs, show_commit, show_object, info);
300                 printf("------\n");
301         }
302
303         if (flags & BISECT_SHOW_TRIED)
304                 show_tried_revs(tried);
305
306         print_var_str("bisect_rev", hex);
307         print_var_int("bisect_nr", cnt - 1);
308         print_var_int("bisect_good", all - reaches - 1);
309         print_var_int("bisect_bad", reaches - 1);
310         print_var_int("bisect_all", all);
311         print_var_int("bisect_steps", estimate_bisect_steps(all));
312
313         return 0;
314 }
315
316 int cmd_rev_list(int argc, const char **argv, const char *prefix)
317 {
318         struct rev_info revs;
319         struct rev_list_info info;
320         int i;
321         int bisect_list = 0;
322         int bisect_show_vars = 0;
323         int bisect_find_all = 0;
324         int quiet = 0;
325
326         git_config(git_default_config, NULL);
327         init_revisions(&revs, prefix);
328         revs.abbrev = DEFAULT_ABBREV;
329         revs.commit_format = CMIT_FMT_UNSPECIFIED;
330         argc = setup_revisions(argc, argv, &revs, NULL);
331
332         memset(&info, 0, sizeof(info));
333         info.revs = &revs;
334         if (revs.bisect)
335                 bisect_list = 1;
336
337         quiet = DIFF_OPT_TST(&revs.diffopt, QUICK);
338         for (i = 1 ; i < argc; i++) {
339                 const char *arg = argv[i];
340
341                 if (!strcmp(arg, "--header")) {
342                         revs.verbose_header = 1;
343                         continue;
344                 }
345                 if (!strcmp(arg, "--timestamp")) {
346                         info.show_timestamp = 1;
347                         continue;
348                 }
349                 if (!strcmp(arg, "--bisect")) {
350                         bisect_list = 1;
351                         continue;
352                 }
353                 if (!strcmp(arg, "--bisect-all")) {
354                         bisect_list = 1;
355                         bisect_find_all = 1;
356                         info.bisect_show_flags = BISECT_SHOW_ALL;
357                         revs.show_decorations = 1;
358                         continue;
359                 }
360                 if (!strcmp(arg, "--bisect-vars")) {
361                         bisect_list = 1;
362                         bisect_show_vars = 1;
363                         continue;
364                 }
365                 usage(rev_list_usage);
366
367         }
368         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
369                 /* The command line has a --pretty  */
370                 info.hdr_termination = '\n';
371                 if (revs.commit_format == CMIT_FMT_ONELINE)
372                         info.header_prefix = "";
373                 else
374                         info.header_prefix = "commit ";
375         }
376         else if (revs.verbose_header)
377                 /* Only --header was specified */
378                 revs.commit_format = CMIT_FMT_RAW;
379
380         if ((!revs.commits &&
381              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
382               !revs.pending.nr)) ||
383             revs.diff)
384                 usage(rev_list_usage);
385
386         save_commit_buffer = (revs.verbose_header ||
387                               revs.grep_filter.pattern_list ||
388                               revs.grep_filter.header_list);
389         if (bisect_list)
390                 revs.limited = 1;
391
392         if (prepare_revision_walk(&revs))
393                 die("revision walk setup failed");
394         if (revs.tree_objects)
395                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
396
397         if (bisect_list) {
398                 int reaches = reaches, all = all;
399
400                 revs.commits = find_bisection(revs.commits, &reaches, &all,
401                                               bisect_find_all);
402
403                 if (bisect_show_vars)
404                         return show_bisect_vars(&info, reaches, all);
405         }
406
407         traverse_commit_list(&revs,
408                              quiet ? finish_commit : show_commit,
409                              quiet ? finish_object : show_object,
410                              &info);
411
412         if (revs.count) {
413                 if (revs.left_right)
414                         printf("%d\t%d\n", revs.count_left, revs.count_right);
415                 else
416                         printf("%d\n", revs.count_left + revs.count_right);
417         }
418
419         return 0;
420 }