Add mailmap.file as configurational option for mailmap location
[git] / builtin-blame.c
1 /*
2  * Pickaxe
3  *
4  * Copyright (c) 2006, Junio C Hamano
5  */
6
7 #include "cache.h"
8 #include "builtin.h"
9 #include "blob.h"
10 #include "commit.h"
11 #include "tag.h"
12 #include "tree-walk.h"
13 #include "diff.h"
14 #include "diffcore.h"
15 #include "revision.h"
16 #include "quote.h"
17 #include "xdiff-interface.h"
18 #include "cache-tree.h"
19 #include "string-list.h"
20 #include "mailmap.h"
21 #include "parse-options.h"
22
23 static char blame_usage[] = "git blame [options] [rev-opts] [rev] [--] file";
24
25 static const char *blame_opt_usage[] = {
26         blame_usage,
27         "",
28         "[rev-opts] are documented in git-rev-list(1)",
29         NULL
30 };
31
32 static int longest_file;
33 static int longest_author;
34 static int max_orig_digits;
35 static int max_digits;
36 static int max_score_digits;
37 static int show_root;
38 static int reverse;
39 static int blank_boundary;
40 static int incremental;
41 static int xdl_opts = XDF_NEED_MINIMAL;
42 static struct string_list mailmap;
43
44 #ifndef DEBUG
45 #define DEBUG 0
46 #endif
47
48 /* stats */
49 static int num_read_blob;
50 static int num_get_patch;
51 static int num_commits;
52
53 #define PICKAXE_BLAME_MOVE              01
54 #define PICKAXE_BLAME_COPY              02
55 #define PICKAXE_BLAME_COPY_HARDER       04
56 #define PICKAXE_BLAME_COPY_HARDEST      010
57
58 /*
59  * blame for a blame_entry with score lower than these thresholds
60  * is not passed to the parent using move/copy logic.
61  */
62 static unsigned blame_move_score;
63 static unsigned blame_copy_score;
64 #define BLAME_DEFAULT_MOVE_SCORE        20
65 #define BLAME_DEFAULT_COPY_SCORE        40
66
67 /* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
68 #define METAINFO_SHOWN          (1u<<12)
69 #define MORE_THAN_ONE_PATH      (1u<<13)
70
71 /*
72  * One blob in a commit that is being suspected
73  */
74 struct origin {
75         int refcnt;
76         struct commit *commit;
77         mmfile_t file;
78         unsigned char blob_sha1[20];
79         char path[FLEX_ARRAY];
80 };
81
82 /*
83  * Given an origin, prepare mmfile_t structure to be used by the
84  * diff machinery
85  */
86 static void fill_origin_blob(struct origin *o, mmfile_t *file)
87 {
88         if (!o->file.ptr) {
89                 enum object_type type;
90                 num_read_blob++;
91                 file->ptr = read_sha1_file(o->blob_sha1, &type,
92                                            (unsigned long *)(&(file->size)));
93                 if (!file->ptr)
94                         die("Cannot read blob %s for path %s",
95                             sha1_to_hex(o->blob_sha1),
96                             o->path);
97                 o->file = *file;
98         }
99         else
100                 *file = o->file;
101 }
102
103 /*
104  * Origin is refcounted and usually we keep the blob contents to be
105  * reused.
106  */
107 static inline struct origin *origin_incref(struct origin *o)
108 {
109         if (o)
110                 o->refcnt++;
111         return o;
112 }
113
114 static void origin_decref(struct origin *o)
115 {
116         if (o && --o->refcnt <= 0) {
117                 free(o->file.ptr);
118                 free(o);
119         }
120 }
121
122 static void drop_origin_blob(struct origin *o)
123 {
124         if (o->file.ptr) {
125                 free(o->file.ptr);
126                 o->file.ptr = NULL;
127         }
128 }
129
130 /*
131  * Each group of lines is described by a blame_entry; it can be split
132  * as we pass blame to the parents.  They form a linked list in the
133  * scoreboard structure, sorted by the target line number.
134  */
135 struct blame_entry {
136         struct blame_entry *prev;
137         struct blame_entry *next;
138
139         /* the first line of this group in the final image;
140          * internally all line numbers are 0 based.
141          */
142         int lno;
143
144         /* how many lines this group has */
145         int num_lines;
146
147         /* the commit that introduced this group into the final image */
148         struct origin *suspect;
149
150         /* true if the suspect is truly guilty; false while we have not
151          * checked if the group came from one of its parents.
152          */
153         char guilty;
154
155         /* true if the entry has been scanned for copies in the current parent
156          */
157         char scanned;
158
159         /* the line number of the first line of this group in the
160          * suspect's file; internally all line numbers are 0 based.
161          */
162         int s_lno;
163
164         /* how significant this entry is -- cached to avoid
165          * scanning the lines over and over.
166          */
167         unsigned score;
168 };
169
170 /*
171  * The current state of the blame assignment.
172  */
173 struct scoreboard {
174         /* the final commit (i.e. where we started digging from) */
175         struct commit *final;
176         struct rev_info *revs;
177         const char *path;
178
179         /*
180          * The contents in the final image.
181          * Used by many functions to obtain contents of the nth line,
182          * indexed with scoreboard.lineno[blame_entry.lno].
183          */
184         const char *final_buf;
185         unsigned long final_buf_size;
186
187         /* linked list of blames */
188         struct blame_entry *ent;
189
190         /* look-up a line in the final buffer */
191         int num_lines;
192         int *lineno;
193 };
194
195 static inline int same_suspect(struct origin *a, struct origin *b)
196 {
197         if (a == b)
198                 return 1;
199         if (a->commit != b->commit)
200                 return 0;
201         return !strcmp(a->path, b->path);
202 }
203
204 static void sanity_check_refcnt(struct scoreboard *);
205
206 /*
207  * If two blame entries that are next to each other came from
208  * contiguous lines in the same origin (i.e. <commit, path> pair),
209  * merge them together.
210  */
211 static void coalesce(struct scoreboard *sb)
212 {
213         struct blame_entry *ent, *next;
214
215         for (ent = sb->ent; ent && (next = ent->next); ent = next) {
216                 if (same_suspect(ent->suspect, next->suspect) &&
217                     ent->guilty == next->guilty &&
218                     ent->s_lno + ent->num_lines == next->s_lno) {
219                         ent->num_lines += next->num_lines;
220                         ent->next = next->next;
221                         if (ent->next)
222                                 ent->next->prev = ent;
223                         origin_decref(next->suspect);
224                         free(next);
225                         ent->score = 0;
226                         next = ent; /* again */
227                 }
228         }
229
230         if (DEBUG) /* sanity */
231                 sanity_check_refcnt(sb);
232 }
233
234 /*
235  * Given a commit and a path in it, create a new origin structure.
236  * The callers that add blame to the scoreboard should use
237  * get_origin() to obtain shared, refcounted copy instead of calling
238  * this function directly.
239  */
240 static struct origin *make_origin(struct commit *commit, const char *path)
241 {
242         struct origin *o;
243         o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
244         o->commit = commit;
245         o->refcnt = 1;
246         strcpy(o->path, path);
247         return o;
248 }
249
250 /*
251  * Locate an existing origin or create a new one.
252  */
253 static struct origin *get_origin(struct scoreboard *sb,
254                                  struct commit *commit,
255                                  const char *path)
256 {
257         struct blame_entry *e;
258
259         for (e = sb->ent; e; e = e->next) {
260                 if (e->suspect->commit == commit &&
261                     !strcmp(e->suspect->path, path))
262                         return origin_incref(e->suspect);
263         }
264         return make_origin(commit, path);
265 }
266
267 /*
268  * Fill the blob_sha1 field of an origin if it hasn't, so that later
269  * call to fill_origin_blob() can use it to locate the data.  blob_sha1
270  * for an origin is also used to pass the blame for the entire file to
271  * the parent to detect the case where a child's blob is identical to
272  * that of its parent's.
273  */
274 static int fill_blob_sha1(struct origin *origin)
275 {
276         unsigned mode;
277
278         if (!is_null_sha1(origin->blob_sha1))
279                 return 0;
280         if (get_tree_entry(origin->commit->object.sha1,
281                            origin->path,
282                            origin->blob_sha1, &mode))
283                 goto error_out;
284         if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
285                 goto error_out;
286         return 0;
287  error_out:
288         hashclr(origin->blob_sha1);
289         return -1;
290 }
291
292 /*
293  * We have an origin -- check if the same path exists in the
294  * parent and return an origin structure to represent it.
295  */
296 static struct origin *find_origin(struct scoreboard *sb,
297                                   struct commit *parent,
298                                   struct origin *origin)
299 {
300         struct origin *porigin = NULL;
301         struct diff_options diff_opts;
302         const char *paths[2];
303
304         if (parent->util) {
305                 /*
306                  * Each commit object can cache one origin in that
307                  * commit.  This is a freestanding copy of origin and
308                  * not refcounted.
309                  */
310                 struct origin *cached = parent->util;
311                 if (!strcmp(cached->path, origin->path)) {
312                         /*
313                          * The same path between origin and its parent
314                          * without renaming -- the most common case.
315                          */
316                         porigin = get_origin(sb, parent, cached->path);
317
318                         /*
319                          * If the origin was newly created (i.e. get_origin
320                          * would call make_origin if none is found in the
321                          * scoreboard), it does not know the blob_sha1,
322                          * so copy it.  Otherwise porigin was in the
323                          * scoreboard and already knows blob_sha1.
324                          */
325                         if (porigin->refcnt == 1)
326                                 hashcpy(porigin->blob_sha1, cached->blob_sha1);
327                         return porigin;
328                 }
329                 /* otherwise it was not very useful; free it */
330                 free(parent->util);
331                 parent->util = NULL;
332         }
333
334         /* See if the origin->path is different between parent
335          * and origin first.  Most of the time they are the
336          * same and diff-tree is fairly efficient about this.
337          */
338         diff_setup(&diff_opts);
339         DIFF_OPT_SET(&diff_opts, RECURSIVE);
340         diff_opts.detect_rename = 0;
341         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
342         paths[0] = origin->path;
343         paths[1] = NULL;
344
345         diff_tree_setup_paths(paths, &diff_opts);
346         if (diff_setup_done(&diff_opts) < 0)
347                 die("diff-setup");
348
349         if (is_null_sha1(origin->commit->object.sha1))
350                 do_diff_cache(parent->tree->object.sha1, &diff_opts);
351         else
352                 diff_tree_sha1(parent->tree->object.sha1,
353                                origin->commit->tree->object.sha1,
354                                "", &diff_opts);
355         diffcore_std(&diff_opts);
356
357         /* It is either one entry that says "modified", or "created",
358          * or nothing.
359          */
360         if (!diff_queued_diff.nr) {
361                 /* The path is the same as parent */
362                 porigin = get_origin(sb, parent, origin->path);
363                 hashcpy(porigin->blob_sha1, origin->blob_sha1);
364         }
365         else if (diff_queued_diff.nr != 1)
366                 die("internal error in blame::find_origin");
367         else {
368                 struct diff_filepair *p = diff_queued_diff.queue[0];
369                 switch (p->status) {
370                 default:
371                         die("internal error in blame::find_origin (%c)",
372                             p->status);
373                 case 'M':
374                         porigin = get_origin(sb, parent, origin->path);
375                         hashcpy(porigin->blob_sha1, p->one->sha1);
376                         break;
377                 case 'A':
378                 case 'T':
379                         /* Did not exist in parent, or type changed */
380                         break;
381                 }
382         }
383         diff_flush(&diff_opts);
384         diff_tree_release_paths(&diff_opts);
385         if (porigin) {
386                 /*
387                  * Create a freestanding copy that is not part of
388                  * the refcounted origin found in the scoreboard, and
389                  * cache it in the commit.
390                  */
391                 struct origin *cached;
392
393                 cached = make_origin(porigin->commit, porigin->path);
394                 hashcpy(cached->blob_sha1, porigin->blob_sha1);
395                 parent->util = cached;
396         }
397         return porigin;
398 }
399
400 /*
401  * We have an origin -- find the path that corresponds to it in its
402  * parent and return an origin structure to represent it.
403  */
404 static struct origin *find_rename(struct scoreboard *sb,
405                                   struct commit *parent,
406                                   struct origin *origin)
407 {
408         struct origin *porigin = NULL;
409         struct diff_options diff_opts;
410         int i;
411         const char *paths[2];
412
413         diff_setup(&diff_opts);
414         DIFF_OPT_SET(&diff_opts, RECURSIVE);
415         diff_opts.detect_rename = DIFF_DETECT_RENAME;
416         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
417         diff_opts.single_follow = origin->path;
418         paths[0] = NULL;
419         diff_tree_setup_paths(paths, &diff_opts);
420         if (diff_setup_done(&diff_opts) < 0)
421                 die("diff-setup");
422
423         if (is_null_sha1(origin->commit->object.sha1))
424                 do_diff_cache(parent->tree->object.sha1, &diff_opts);
425         else
426                 diff_tree_sha1(parent->tree->object.sha1,
427                                origin->commit->tree->object.sha1,
428                                "", &diff_opts);
429         diffcore_std(&diff_opts);
430
431         for (i = 0; i < diff_queued_diff.nr; i++) {
432                 struct diff_filepair *p = diff_queued_diff.queue[i];
433                 if ((p->status == 'R' || p->status == 'C') &&
434                     !strcmp(p->two->path, origin->path)) {
435                         porigin = get_origin(sb, parent, p->one->path);
436                         hashcpy(porigin->blob_sha1, p->one->sha1);
437                         break;
438                 }
439         }
440         diff_flush(&diff_opts);
441         diff_tree_release_paths(&diff_opts);
442         return porigin;
443 }
444
445 /*
446  * Link in a new blame entry to the scoreboard.  Entries that cover the
447  * same line range have been removed from the scoreboard previously.
448  */
449 static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
450 {
451         struct blame_entry *ent, *prev = NULL;
452
453         origin_incref(e->suspect);
454
455         for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
456                 prev = ent;
457
458         /* prev, if not NULL, is the last one that is below e */
459         e->prev = prev;
460         if (prev) {
461                 e->next = prev->next;
462                 prev->next = e;
463         }
464         else {
465                 e->next = sb->ent;
466                 sb->ent = e;
467         }
468         if (e->next)
469                 e->next->prev = e;
470 }
471
472 /*
473  * src typically is on-stack; we want to copy the information in it to
474  * a malloced blame_entry that is already on the linked list of the
475  * scoreboard.  The origin of dst loses a refcnt while the origin of src
476  * gains one.
477  */
478 static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
479 {
480         struct blame_entry *p, *n;
481
482         p = dst->prev;
483         n = dst->next;
484         origin_incref(src->suspect);
485         origin_decref(dst->suspect);
486         memcpy(dst, src, sizeof(*src));
487         dst->prev = p;
488         dst->next = n;
489         dst->score = 0;
490 }
491
492 static const char *nth_line(struct scoreboard *sb, int lno)
493 {
494         return sb->final_buf + sb->lineno[lno];
495 }
496
497 /*
498  * It is known that lines between tlno to same came from parent, and e
499  * has an overlap with that range.  it also is known that parent's
500  * line plno corresponds to e's line tlno.
501  *
502  *                <---- e ----->
503  *                   <------>
504  *                   <------------>
505  *             <------------>
506  *             <------------------>
507  *
508  * Split e into potentially three parts; before this chunk, the chunk
509  * to be blamed for the parent, and after that portion.
510  */
511 static void split_overlap(struct blame_entry *split,
512                           struct blame_entry *e,
513                           int tlno, int plno, int same,
514                           struct origin *parent)
515 {
516         int chunk_end_lno;
517         memset(split, 0, sizeof(struct blame_entry [3]));
518
519         if (e->s_lno < tlno) {
520                 /* there is a pre-chunk part not blamed on parent */
521                 split[0].suspect = origin_incref(e->suspect);
522                 split[0].lno = e->lno;
523                 split[0].s_lno = e->s_lno;
524                 split[0].num_lines = tlno - e->s_lno;
525                 split[1].lno = e->lno + tlno - e->s_lno;
526                 split[1].s_lno = plno;
527         }
528         else {
529                 split[1].lno = e->lno;
530                 split[1].s_lno = plno + (e->s_lno - tlno);
531         }
532
533         if (same < e->s_lno + e->num_lines) {
534                 /* there is a post-chunk part not blamed on parent */
535                 split[2].suspect = origin_incref(e->suspect);
536                 split[2].lno = e->lno + (same - e->s_lno);
537                 split[2].s_lno = e->s_lno + (same - e->s_lno);
538                 split[2].num_lines = e->s_lno + e->num_lines - same;
539                 chunk_end_lno = split[2].lno;
540         }
541         else
542                 chunk_end_lno = e->lno + e->num_lines;
543         split[1].num_lines = chunk_end_lno - split[1].lno;
544
545         /*
546          * if it turns out there is nothing to blame the parent for,
547          * forget about the splitting.  !split[1].suspect signals this.
548          */
549         if (split[1].num_lines < 1)
550                 return;
551         split[1].suspect = origin_incref(parent);
552 }
553
554 /*
555  * split_overlap() divided an existing blame e into up to three parts
556  * in split.  Adjust the linked list of blames in the scoreboard to
557  * reflect the split.
558  */
559 static void split_blame(struct scoreboard *sb,
560                         struct blame_entry *split,
561                         struct blame_entry *e)
562 {
563         struct blame_entry *new_entry;
564
565         if (split[0].suspect && split[2].suspect) {
566                 /* The first part (reuse storage for the existing entry e) */
567                 dup_entry(e, &split[0]);
568
569                 /* The last part -- me */
570                 new_entry = xmalloc(sizeof(*new_entry));
571                 memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
572                 add_blame_entry(sb, new_entry);
573
574                 /* ... and the middle part -- parent */
575                 new_entry = xmalloc(sizeof(*new_entry));
576                 memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
577                 add_blame_entry(sb, new_entry);
578         }
579         else if (!split[0].suspect && !split[2].suspect)
580                 /*
581                  * The parent covers the entire area; reuse storage for
582                  * e and replace it with the parent.
583                  */
584                 dup_entry(e, &split[1]);
585         else if (split[0].suspect) {
586                 /* me and then parent */
587                 dup_entry(e, &split[0]);
588
589                 new_entry = xmalloc(sizeof(*new_entry));
590                 memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
591                 add_blame_entry(sb, new_entry);
592         }
593         else {
594                 /* parent and then me */
595                 dup_entry(e, &split[1]);
596
597                 new_entry = xmalloc(sizeof(*new_entry));
598                 memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
599                 add_blame_entry(sb, new_entry);
600         }
601
602         if (DEBUG) { /* sanity */
603                 struct blame_entry *ent;
604                 int lno = sb->ent->lno, corrupt = 0;
605
606                 for (ent = sb->ent; ent; ent = ent->next) {
607                         if (lno != ent->lno)
608                                 corrupt = 1;
609                         if (ent->s_lno < 0)
610                                 corrupt = 1;
611                         lno += ent->num_lines;
612                 }
613                 if (corrupt) {
614                         lno = sb->ent->lno;
615                         for (ent = sb->ent; ent; ent = ent->next) {
616                                 printf("L %8d l %8d n %8d\n",
617                                        lno, ent->lno, ent->num_lines);
618                                 lno = ent->lno + ent->num_lines;
619                         }
620                         die("oops");
621                 }
622         }
623 }
624
625 /*
626  * After splitting the blame, the origins used by the
627  * on-stack blame_entry should lose one refcnt each.
628  */
629 static void decref_split(struct blame_entry *split)
630 {
631         int i;
632
633         for (i = 0; i < 3; i++)
634                 origin_decref(split[i].suspect);
635 }
636
637 /*
638  * Helper for blame_chunk().  blame_entry e is known to overlap with
639  * the patch hunk; split it and pass blame to the parent.
640  */
641 static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
642                           int tlno, int plno, int same,
643                           struct origin *parent)
644 {
645         struct blame_entry split[3];
646
647         split_overlap(split, e, tlno, plno, same, parent);
648         if (split[1].suspect)
649                 split_blame(sb, split, e);
650         decref_split(split);
651 }
652
653 /*
654  * Find the line number of the last line the target is suspected for.
655  */
656 static int find_last_in_target(struct scoreboard *sb, struct origin *target)
657 {
658         struct blame_entry *e;
659         int last_in_target = -1;
660
661         for (e = sb->ent; e; e = e->next) {
662                 if (e->guilty || !same_suspect(e->suspect, target))
663                         continue;
664                 if (last_in_target < e->s_lno + e->num_lines)
665                         last_in_target = e->s_lno + e->num_lines;
666         }
667         return last_in_target;
668 }
669
670 /*
671  * Process one hunk from the patch between the current suspect for
672  * blame_entry e and its parent.  Find and split the overlap, and
673  * pass blame to the overlapping part to the parent.
674  */
675 static void blame_chunk(struct scoreboard *sb,
676                         int tlno, int plno, int same,
677                         struct origin *target, struct origin *parent)
678 {
679         struct blame_entry *e;
680
681         for (e = sb->ent; e; e = e->next) {
682                 if (e->guilty || !same_suspect(e->suspect, target))
683                         continue;
684                 if (same <= e->s_lno)
685                         continue;
686                 if (tlno < e->s_lno + e->num_lines)
687                         blame_overlap(sb, e, tlno, plno, same, parent);
688         }
689 }
690
691 struct blame_chunk_cb_data {
692         struct scoreboard *sb;
693         struct origin *target;
694         struct origin *parent;
695         long plno;
696         long tlno;
697 };
698
699 static void blame_chunk_cb(void *data, long same, long p_next, long t_next)
700 {
701         struct blame_chunk_cb_data *d = data;
702         blame_chunk(d->sb, d->tlno, d->plno, same, d->target, d->parent);
703         d->plno = p_next;
704         d->tlno = t_next;
705 }
706
707 /*
708  * We are looking at the origin 'target' and aiming to pass blame
709  * for the lines it is suspected to its parent.  Run diff to find
710  * which lines came from parent and pass blame for them.
711  */
712 static int pass_blame_to_parent(struct scoreboard *sb,
713                                 struct origin *target,
714                                 struct origin *parent)
715 {
716         int last_in_target;
717         mmfile_t file_p, file_o;
718         struct blame_chunk_cb_data d = { sb, target, parent, 0, 0 };
719         xpparam_t xpp;
720         xdemitconf_t xecfg;
721
722         last_in_target = find_last_in_target(sb, target);
723         if (last_in_target < 0)
724                 return 1; /* nothing remains for this target */
725
726         fill_origin_blob(parent, &file_p);
727         fill_origin_blob(target, &file_o);
728         num_get_patch++;
729
730         memset(&xpp, 0, sizeof(xpp));
731         xpp.flags = xdl_opts;
732         memset(&xecfg, 0, sizeof(xecfg));
733         xecfg.ctxlen = 0;
734         xdi_diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, &xpp, &xecfg);
735         /* The rest (i.e. anything after tlno) are the same as the parent */
736         blame_chunk(sb, d.tlno, d.plno, last_in_target, target, parent);
737
738         return 0;
739 }
740
741 /*
742  * The lines in blame_entry after splitting blames many times can become
743  * very small and trivial, and at some point it becomes pointless to
744  * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
745  * ordinary C program, and it is not worth to say it was copied from
746  * totally unrelated file in the parent.
747  *
748  * Compute how trivial the lines in the blame_entry are.
749  */
750 static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
751 {
752         unsigned score;
753         const char *cp, *ep;
754
755         if (e->score)
756                 return e->score;
757
758         score = 1;
759         cp = nth_line(sb, e->lno);
760         ep = nth_line(sb, e->lno + e->num_lines);
761         while (cp < ep) {
762                 unsigned ch = *((unsigned char *)cp);
763                 if (isalnum(ch))
764                         score++;
765                 cp++;
766         }
767         e->score = score;
768         return score;
769 }
770
771 /*
772  * best_so_far[] and this[] are both a split of an existing blame_entry
773  * that passes blame to the parent.  Maintain best_so_far the best split
774  * so far, by comparing this and best_so_far and copying this into
775  * bst_so_far as needed.
776  */
777 static void copy_split_if_better(struct scoreboard *sb,
778                                  struct blame_entry *best_so_far,
779                                  struct blame_entry *this)
780 {
781         int i;
782
783         if (!this[1].suspect)
784                 return;
785         if (best_so_far[1].suspect) {
786                 if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
787                         return;
788         }
789
790         for (i = 0; i < 3; i++)
791                 origin_incref(this[i].suspect);
792         decref_split(best_so_far);
793         memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
794 }
795
796 /*
797  * We are looking at a part of the final image represented by
798  * ent (tlno and same are offset by ent->s_lno).
799  * tlno is where we are looking at in the final image.
800  * up to (but not including) same match preimage.
801  * plno is where we are looking at in the preimage.
802  *
803  * <-------------- final image ---------------------->
804  *       <------ent------>
805  *         ^tlno ^same
806  *    <---------preimage----->
807  *         ^plno
808  *
809  * All line numbers are 0-based.
810  */
811 static void handle_split(struct scoreboard *sb,
812                          struct blame_entry *ent,
813                          int tlno, int plno, int same,
814                          struct origin *parent,
815                          struct blame_entry *split)
816 {
817         if (ent->num_lines <= tlno)
818                 return;
819         if (tlno < same) {
820                 struct blame_entry this[3];
821                 tlno += ent->s_lno;
822                 same += ent->s_lno;
823                 split_overlap(this, ent, tlno, plno, same, parent);
824                 copy_split_if_better(sb, split, this);
825                 decref_split(this);
826         }
827 }
828
829 struct handle_split_cb_data {
830         struct scoreboard *sb;
831         struct blame_entry *ent;
832         struct origin *parent;
833         struct blame_entry *split;
834         long plno;
835         long tlno;
836 };
837
838 static void handle_split_cb(void *data, long same, long p_next, long t_next)
839 {
840         struct handle_split_cb_data *d = data;
841         handle_split(d->sb, d->ent, d->tlno, d->plno, same, d->parent, d->split);
842         d->plno = p_next;
843         d->tlno = t_next;
844 }
845
846 /*
847  * Find the lines from parent that are the same as ent so that
848  * we can pass blames to it.  file_p has the blob contents for
849  * the parent.
850  */
851 static void find_copy_in_blob(struct scoreboard *sb,
852                               struct blame_entry *ent,
853                               struct origin *parent,
854                               struct blame_entry *split,
855                               mmfile_t *file_p)
856 {
857         const char *cp;
858         int cnt;
859         mmfile_t file_o;
860         struct handle_split_cb_data d = { sb, ent, parent, split, 0, 0 };
861         xpparam_t xpp;
862         xdemitconf_t xecfg;
863
864         /*
865          * Prepare mmfile that contains only the lines in ent.
866          */
867         cp = nth_line(sb, ent->lno);
868         file_o.ptr = (char*) cp;
869         cnt = ent->num_lines;
870
871         while (cnt && cp < sb->final_buf + sb->final_buf_size) {
872                 if (*cp++ == '\n')
873                         cnt--;
874         }
875         file_o.size = cp - file_o.ptr;
876
877         /*
878          * file_o is a part of final image we are annotating.
879          * file_p partially may match that image.
880          */
881         memset(&xpp, 0, sizeof(xpp));
882         xpp.flags = xdl_opts;
883         memset(&xecfg, 0, sizeof(xecfg));
884         xecfg.ctxlen = 1;
885         memset(split, 0, sizeof(struct blame_entry [3]));
886         xdi_diff_hunks(file_p, &file_o, handle_split_cb, &d, &xpp, &xecfg);
887         /* remainder, if any, all match the preimage */
888         handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
889 }
890
891 /*
892  * See if lines currently target is suspected for can be attributed to
893  * parent.
894  */
895 static int find_move_in_parent(struct scoreboard *sb,
896                                struct origin *target,
897                                struct origin *parent)
898 {
899         int last_in_target, made_progress;
900         struct blame_entry *e, split[3];
901         mmfile_t file_p;
902
903         last_in_target = find_last_in_target(sb, target);
904         if (last_in_target < 0)
905                 return 1; /* nothing remains for this target */
906
907         fill_origin_blob(parent, &file_p);
908         if (!file_p.ptr)
909                 return 0;
910
911         made_progress = 1;
912         while (made_progress) {
913                 made_progress = 0;
914                 for (e = sb->ent; e; e = e->next) {
915                         if (e->guilty || !same_suspect(e->suspect, target) ||
916                             ent_score(sb, e) < blame_move_score)
917                                 continue;
918                         find_copy_in_blob(sb, e, parent, split, &file_p);
919                         if (split[1].suspect &&
920                             blame_move_score < ent_score(sb, &split[1])) {
921                                 split_blame(sb, split, e);
922                                 made_progress = 1;
923                         }
924                         decref_split(split);
925                 }
926         }
927         return 0;
928 }
929
930 struct blame_list {
931         struct blame_entry *ent;
932         struct blame_entry split[3];
933 };
934
935 /*
936  * Count the number of entries the target is suspected for,
937  * and prepare a list of entry and the best split.
938  */
939 static struct blame_list *setup_blame_list(struct scoreboard *sb,
940                                            struct origin *target,
941                                            int min_score,
942                                            int *num_ents_p)
943 {
944         struct blame_entry *e;
945         int num_ents, i;
946         struct blame_list *blame_list = NULL;
947
948         for (e = sb->ent, num_ents = 0; e; e = e->next)
949                 if (!e->scanned && !e->guilty &&
950                     same_suspect(e->suspect, target) &&
951                     min_score < ent_score(sb, e))
952                         num_ents++;
953         if (num_ents) {
954                 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
955                 for (e = sb->ent, i = 0; e; e = e->next)
956                         if (!e->scanned && !e->guilty &&
957                             same_suspect(e->suspect, target) &&
958                             min_score < ent_score(sb, e))
959                                 blame_list[i++].ent = e;
960         }
961         *num_ents_p = num_ents;
962         return blame_list;
963 }
964
965 /*
966  * Reset the scanned status on all entries.
967  */
968 static void reset_scanned_flag(struct scoreboard *sb)
969 {
970         struct blame_entry *e;
971         for (e = sb->ent; e; e = e->next)
972                 e->scanned = 0;
973 }
974
975 /*
976  * For lines target is suspected for, see if we can find code movement
977  * across file boundary from the parent commit.  porigin is the path
978  * in the parent we already tried.
979  */
980 static int find_copy_in_parent(struct scoreboard *sb,
981                                struct origin *target,
982                                struct commit *parent,
983                                struct origin *porigin,
984                                int opt)
985 {
986         struct diff_options diff_opts;
987         const char *paths[1];
988         int i, j;
989         int retval;
990         struct blame_list *blame_list;
991         int num_ents;
992
993         blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
994         if (!blame_list)
995                 return 1; /* nothing remains for this target */
996
997         diff_setup(&diff_opts);
998         DIFF_OPT_SET(&diff_opts, RECURSIVE);
999         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1000
1001         paths[0] = NULL;
1002         diff_tree_setup_paths(paths, &diff_opts);
1003         if (diff_setup_done(&diff_opts) < 0)
1004                 die("diff-setup");
1005
1006         /* Try "find copies harder" on new path if requested;
1007          * we do not want to use diffcore_rename() actually to
1008          * match things up; find_copies_harder is set only to
1009          * force diff_tree_sha1() to feed all filepairs to diff_queue,
1010          * and this code needs to be after diff_setup_done(), which
1011          * usually makes find-copies-harder imply copy detection.
1012          */
1013         if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1014             || ((opt & PICKAXE_BLAME_COPY_HARDER)
1015                 && (!porigin || strcmp(target->path, porigin->path))))
1016                 DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
1017
1018         if (is_null_sha1(target->commit->object.sha1))
1019                 do_diff_cache(parent->tree->object.sha1, &diff_opts);
1020         else
1021                 diff_tree_sha1(parent->tree->object.sha1,
1022                                target->commit->tree->object.sha1,
1023                                "", &diff_opts);
1024
1025         if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
1026                 diffcore_std(&diff_opts);
1027
1028         retval = 0;
1029         while (1) {
1030                 int made_progress = 0;
1031
1032                 for (i = 0; i < diff_queued_diff.nr; i++) {
1033                         struct diff_filepair *p = diff_queued_diff.queue[i];
1034                         struct origin *norigin;
1035                         mmfile_t file_p;
1036                         struct blame_entry this[3];
1037
1038                         if (!DIFF_FILE_VALID(p->one))
1039                                 continue; /* does not exist in parent */
1040                         if (S_ISGITLINK(p->one->mode))
1041                                 continue; /* ignore git links */
1042                         if (porigin && !strcmp(p->one->path, porigin->path))
1043                                 /* find_move already dealt with this path */
1044                                 continue;
1045
1046                         norigin = get_origin(sb, parent, p->one->path);
1047                         hashcpy(norigin->blob_sha1, p->one->sha1);
1048                         fill_origin_blob(norigin, &file_p);
1049                         if (!file_p.ptr)
1050                                 continue;
1051
1052                         for (j = 0; j < num_ents; j++) {
1053                                 find_copy_in_blob(sb, blame_list[j].ent,
1054                                                   norigin, this, &file_p);
1055                                 copy_split_if_better(sb, blame_list[j].split,
1056                                                      this);
1057                                 decref_split(this);
1058                         }
1059                         origin_decref(norigin);
1060                 }
1061
1062                 for (j = 0; j < num_ents; j++) {
1063                         struct blame_entry *split = blame_list[j].split;
1064                         if (split[1].suspect &&
1065                             blame_copy_score < ent_score(sb, &split[1])) {
1066                                 split_blame(sb, split, blame_list[j].ent);
1067                                 made_progress = 1;
1068                         }
1069                         else
1070                                 blame_list[j].ent->scanned = 1;
1071                         decref_split(split);
1072                 }
1073                 free(blame_list);
1074
1075                 if (!made_progress)
1076                         break;
1077                 blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
1078                 if (!blame_list) {
1079                         retval = 1;
1080                         break;
1081                 }
1082         }
1083         reset_scanned_flag(sb);
1084         diff_flush(&diff_opts);
1085         diff_tree_release_paths(&diff_opts);
1086         return retval;
1087 }
1088
1089 /*
1090  * The blobs of origin and porigin exactly match, so everything
1091  * origin is suspected for can be blamed on the parent.
1092  */
1093 static void pass_whole_blame(struct scoreboard *sb,
1094                              struct origin *origin, struct origin *porigin)
1095 {
1096         struct blame_entry *e;
1097
1098         if (!porigin->file.ptr && origin->file.ptr) {
1099                 /* Steal its file */
1100                 porigin->file = origin->file;
1101                 origin->file.ptr = NULL;
1102         }
1103         for (e = sb->ent; e; e = e->next) {
1104                 if (!same_suspect(e->suspect, origin))
1105                         continue;
1106                 origin_incref(porigin);
1107                 origin_decref(e->suspect);
1108                 e->suspect = porigin;
1109         }
1110 }
1111
1112 /*
1113  * We pass blame from the current commit to its parents.  We keep saying
1114  * "parent" (and "porigin"), but what we mean is to find scapegoat to
1115  * exonerate ourselves.
1116  */
1117 static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
1118 {
1119         if (!reverse)
1120                 return commit->parents;
1121         return lookup_decoration(&revs->children, &commit->object);
1122 }
1123
1124 static int num_scapegoats(struct rev_info *revs, struct commit *commit)
1125 {
1126         int cnt;
1127         struct commit_list *l = first_scapegoat(revs, commit);
1128         for (cnt = 0; l; l = l->next)
1129                 cnt++;
1130         return cnt;
1131 }
1132
1133 #define MAXSG 16
1134
1135 static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1136 {
1137         struct rev_info *revs = sb->revs;
1138         int i, pass, num_sg;
1139         struct commit *commit = origin->commit;
1140         struct commit_list *sg;
1141         struct origin *sg_buf[MAXSG];
1142         struct origin *porigin, **sg_origin = sg_buf;
1143
1144         num_sg = num_scapegoats(revs, commit);
1145         if (!num_sg)
1146                 goto finish;
1147         else if (num_sg < ARRAY_SIZE(sg_buf))
1148                 memset(sg_buf, 0, sizeof(sg_buf));
1149         else
1150                 sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1151
1152         /*
1153          * The first pass looks for unrenamed path to optimize for
1154          * common cases, then we look for renames in the second pass.
1155          */
1156         for (pass = 0; pass < 2; pass++) {
1157                 struct origin *(*find)(struct scoreboard *,
1158                                        struct commit *, struct origin *);
1159                 find = pass ? find_rename : find_origin;
1160
1161                 for (i = 0, sg = first_scapegoat(revs, commit);
1162                      i < num_sg && sg;
1163                      sg = sg->next, i++) {
1164                         struct commit *p = sg->item;
1165                         int j, same;
1166
1167                         if (sg_origin[i])
1168                                 continue;
1169                         if (parse_commit(p))
1170                                 continue;
1171                         porigin = find(sb, p, origin);
1172                         if (!porigin)
1173                                 continue;
1174                         if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1175                                 pass_whole_blame(sb, origin, porigin);
1176                                 origin_decref(porigin);
1177                                 goto finish;
1178                         }
1179                         for (j = same = 0; j < i; j++)
1180                                 if (sg_origin[j] &&
1181                                     !hashcmp(sg_origin[j]->blob_sha1,
1182                                              porigin->blob_sha1)) {
1183                                         same = 1;
1184                                         break;
1185                                 }
1186                         if (!same)
1187                                 sg_origin[i] = porigin;
1188                         else
1189                                 origin_decref(porigin);
1190                 }
1191         }
1192
1193         num_commits++;
1194         for (i = 0, sg = first_scapegoat(revs, commit);
1195              i < num_sg && sg;
1196              sg = sg->next, i++) {
1197                 struct origin *porigin = sg_origin[i];
1198                 if (!porigin)
1199                         continue;
1200                 if (pass_blame_to_parent(sb, origin, porigin))
1201                         goto finish;
1202         }
1203
1204         /*
1205          * Optionally find moves in parents' files.
1206          */
1207         if (opt & PICKAXE_BLAME_MOVE)
1208                 for (i = 0, sg = first_scapegoat(revs, commit);
1209                      i < num_sg && sg;
1210                      sg = sg->next, i++) {
1211                         struct origin *porigin = sg_origin[i];
1212                         if (!porigin)
1213                                 continue;
1214                         if (find_move_in_parent(sb, origin, porigin))
1215                                 goto finish;
1216                 }
1217
1218         /*
1219          * Optionally find copies from parents' files.
1220          */
1221         if (opt & PICKAXE_BLAME_COPY)
1222                 for (i = 0, sg = first_scapegoat(revs, commit);
1223                      i < num_sg && sg;
1224                      sg = sg->next, i++) {
1225                         struct origin *porigin = sg_origin[i];
1226                         if (find_copy_in_parent(sb, origin, sg->item,
1227                                                 porigin, opt))
1228                                 goto finish;
1229                 }
1230
1231  finish:
1232         for (i = 0; i < num_sg; i++) {
1233                 if (sg_origin[i]) {
1234                         drop_origin_blob(sg_origin[i]);
1235                         origin_decref(sg_origin[i]);
1236                 }
1237         }
1238         drop_origin_blob(origin);
1239         if (sg_buf != sg_origin)
1240                 free(sg_origin);
1241 }
1242
1243 /*
1244  * Information on commits, used for output.
1245  */
1246 struct commit_info
1247 {
1248         const char *author;
1249         const char *author_mail;
1250         unsigned long author_time;
1251         const char *author_tz;
1252
1253         /* filled only when asked for details */
1254         const char *committer;
1255         const char *committer_mail;
1256         unsigned long committer_time;
1257         const char *committer_tz;
1258
1259         const char *summary;
1260 };
1261
1262 /*
1263  * Parse author/committer line in the commit object buffer
1264  */
1265 static void get_ac_line(const char *inbuf, const char *what,
1266                         int bufsz, char *person, const char **mail,
1267                         unsigned long *time, const char **tz)
1268 {
1269         int len, tzlen, maillen;
1270         char *tmp, *endp, *timepos;
1271
1272         tmp = strstr(inbuf, what);
1273         if (!tmp)
1274                 goto error_out;
1275         tmp += strlen(what);
1276         endp = strchr(tmp, '\n');
1277         if (!endp)
1278                 len = strlen(tmp);
1279         else
1280                 len = endp - tmp;
1281         if (bufsz <= len) {
1282         error_out:
1283                 /* Ugh */
1284                 *mail = *tz = "(unknown)";
1285                 *time = 0;
1286                 return;
1287         }
1288         memcpy(person, tmp, len);
1289
1290         tmp = person;
1291         tmp += len;
1292         *tmp = 0;
1293         while (*tmp != ' ')
1294                 tmp--;
1295         *tz = tmp+1;
1296         tzlen = (person+len)-(tmp+1);
1297
1298         *tmp = 0;
1299         while (*tmp != ' ')
1300                 tmp--;
1301         *time = strtoul(tmp, NULL, 10);
1302         timepos = tmp;
1303
1304         *tmp = 0;
1305         while (*tmp != ' ')
1306                 tmp--;
1307         *mail = tmp + 1;
1308         *tmp = 0;
1309         maillen = timepos - tmp;
1310
1311         if (!mailmap.nr)
1312                 return;
1313
1314         /*
1315          * mailmap expansion may make the name longer.
1316          * make room by pushing stuff down.
1317          */
1318         tmp = person + bufsz - (tzlen + 1);
1319         memmove(tmp, *tz, tzlen);
1320         tmp[tzlen] = 0;
1321         *tz = tmp;
1322
1323         tmp = tmp - (maillen + 1);
1324         memmove(tmp, *mail, maillen);
1325         tmp[maillen] = 0;
1326         *mail = tmp;
1327
1328         /*
1329          * Now, convert e-mail using mailmap
1330          */
1331         map_email(&mailmap, tmp + 1, person, tmp-person-1);
1332 }
1333
1334 static void get_commit_info(struct commit *commit,
1335                             struct commit_info *ret,
1336                             int detailed)
1337 {
1338         int len;
1339         char *tmp, *endp, *reencoded, *message;
1340         static char author_buf[1024];
1341         static char committer_buf[1024];
1342         static char summary_buf[1024];
1343
1344         /*
1345          * We've operated without save_commit_buffer, so
1346          * we now need to populate them for output.
1347          */
1348         if (!commit->buffer) {
1349                 enum object_type type;
1350                 unsigned long size;
1351                 commit->buffer =
1352                         read_sha1_file(commit->object.sha1, &type, &size);
1353                 if (!commit->buffer)
1354                         die("Cannot read commit %s",
1355                             sha1_to_hex(commit->object.sha1));
1356         }
1357         reencoded = reencode_commit_message(commit, NULL);
1358         message   = reencoded ? reencoded : commit->buffer;
1359         ret->author = author_buf;
1360         get_ac_line(message, "\nauthor ",
1361                     sizeof(author_buf), author_buf, &ret->author_mail,
1362                     &ret->author_time, &ret->author_tz);
1363
1364         if (!detailed) {
1365                 free(reencoded);
1366                 return;
1367         }
1368
1369         ret->committer = committer_buf;
1370         get_ac_line(message, "\ncommitter ",
1371                     sizeof(committer_buf), committer_buf, &ret->committer_mail,
1372                     &ret->committer_time, &ret->committer_tz);
1373
1374         ret->summary = summary_buf;
1375         tmp = strstr(message, "\n\n");
1376         if (!tmp) {
1377         error_out:
1378                 sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1379                 free(reencoded);
1380                 return;
1381         }
1382         tmp += 2;
1383         endp = strchr(tmp, '\n');
1384         if (!endp)
1385                 endp = tmp + strlen(tmp);
1386         len = endp - tmp;
1387         if (len >= sizeof(summary_buf) || len == 0)
1388                 goto error_out;
1389         memcpy(summary_buf, tmp, len);
1390         summary_buf[len] = 0;
1391         free(reencoded);
1392 }
1393
1394 /*
1395  * To allow LF and other nonportable characters in pathnames,
1396  * they are c-style quoted as needed.
1397  */
1398 static void write_filename_info(const char *path)
1399 {
1400         printf("filename ");
1401         write_name_quoted(path, stdout, '\n');
1402 }
1403
1404 /*
1405  * The blame_entry is found to be guilty for the range.  Mark it
1406  * as such, and show it in incremental output.
1407  */
1408 static void found_guilty_entry(struct blame_entry *ent)
1409 {
1410         if (ent->guilty)
1411                 return;
1412         ent->guilty = 1;
1413         if (incremental) {
1414                 struct origin *suspect = ent->suspect;
1415
1416                 printf("%s %d %d %d\n",
1417                        sha1_to_hex(suspect->commit->object.sha1),
1418                        ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1419                 if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1420                         struct commit_info ci;
1421                         suspect->commit->object.flags |= METAINFO_SHOWN;
1422                         get_commit_info(suspect->commit, &ci, 1);
1423                         printf("author %s\n", ci.author);
1424                         printf("author-mail %s\n", ci.author_mail);
1425                         printf("author-time %lu\n", ci.author_time);
1426                         printf("author-tz %s\n", ci.author_tz);
1427                         printf("committer %s\n", ci.committer);
1428                         printf("committer-mail %s\n", ci.committer_mail);
1429                         printf("committer-time %lu\n", ci.committer_time);
1430                         printf("committer-tz %s\n", ci.committer_tz);
1431                         printf("summary %s\n", ci.summary);
1432                         if (suspect->commit->object.flags & UNINTERESTING)
1433                                 printf("boundary\n");
1434                 }
1435                 write_filename_info(suspect->path);
1436                 maybe_flush_or_die(stdout, "stdout");
1437         }
1438 }
1439
1440 /*
1441  * The main loop -- while the scoreboard has lines whose true origin
1442  * is still unknown, pick one blame_entry, and allow its current
1443  * suspect to pass blames to its parents.
1444  */
1445 static void assign_blame(struct scoreboard *sb, int opt)
1446 {
1447         struct rev_info *revs = sb->revs;
1448
1449         while (1) {
1450                 struct blame_entry *ent;
1451                 struct commit *commit;
1452                 struct origin *suspect = NULL;
1453
1454                 /* find one suspect to break down */
1455                 for (ent = sb->ent; !suspect && ent; ent = ent->next)
1456                         if (!ent->guilty)
1457                                 suspect = ent->suspect;
1458                 if (!suspect)
1459                         return; /* all done */
1460
1461                 /*
1462                  * We will use this suspect later in the loop,
1463                  * so hold onto it in the meantime.
1464                  */
1465                 origin_incref(suspect);
1466                 commit = suspect->commit;
1467                 if (!commit->object.parsed)
1468                         parse_commit(commit);
1469                 if (reverse ||
1470                     (!(commit->object.flags & UNINTERESTING) &&
1471                      !(revs->max_age != -1 && commit->date < revs->max_age)))
1472                         pass_blame(sb, suspect, opt);
1473                 else {
1474                         commit->object.flags |= UNINTERESTING;
1475                         if (commit->object.parsed)
1476                                 mark_parents_uninteresting(commit);
1477                 }
1478                 /* treat root commit as boundary */
1479                 if (!commit->parents && !show_root)
1480                         commit->object.flags |= UNINTERESTING;
1481
1482                 /* Take responsibility for the remaining entries */
1483                 for (ent = sb->ent; ent; ent = ent->next)
1484                         if (same_suspect(ent->suspect, suspect))
1485                                 found_guilty_entry(ent);
1486                 origin_decref(suspect);
1487
1488                 if (DEBUG) /* sanity */
1489                         sanity_check_refcnt(sb);
1490         }
1491 }
1492
1493 static const char *format_time(unsigned long time, const char *tz_str,
1494                                int show_raw_time)
1495 {
1496         static char time_buf[128];
1497         time_t t = time;
1498         int minutes, tz;
1499         struct tm *tm;
1500
1501         if (show_raw_time) {
1502                 sprintf(time_buf, "%lu %s", time, tz_str);
1503                 return time_buf;
1504         }
1505
1506         tz = atoi(tz_str);
1507         minutes = tz < 0 ? -tz : tz;
1508         minutes = (minutes / 100)*60 + (minutes % 100);
1509         minutes = tz < 0 ? -minutes : minutes;
1510         t = time + minutes * 60;
1511         tm = gmtime(&t);
1512
1513         strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1514         strcat(time_buf, tz_str);
1515         return time_buf;
1516 }
1517
1518 #define OUTPUT_ANNOTATE_COMPAT  001
1519 #define OUTPUT_LONG_OBJECT_NAME 002
1520 #define OUTPUT_RAW_TIMESTAMP    004
1521 #define OUTPUT_PORCELAIN        010
1522 #define OUTPUT_SHOW_NAME        020
1523 #define OUTPUT_SHOW_NUMBER      040
1524 #define OUTPUT_SHOW_SCORE      0100
1525 #define OUTPUT_NO_AUTHOR       0200
1526
1527 static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1528 {
1529         int cnt;
1530         const char *cp;
1531         struct origin *suspect = ent->suspect;
1532         char hex[41];
1533
1534         strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1535         printf("%s%c%d %d %d\n",
1536                hex,
1537                ent->guilty ? ' ' : '*', // purely for debugging
1538                ent->s_lno + 1,
1539                ent->lno + 1,
1540                ent->num_lines);
1541         if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1542                 struct commit_info ci;
1543                 suspect->commit->object.flags |= METAINFO_SHOWN;
1544                 get_commit_info(suspect->commit, &ci, 1);
1545                 printf("author %s\n", ci.author);
1546                 printf("author-mail %s\n", ci.author_mail);
1547                 printf("author-time %lu\n", ci.author_time);
1548                 printf("author-tz %s\n", ci.author_tz);
1549                 printf("committer %s\n", ci.committer);
1550                 printf("committer-mail %s\n", ci.committer_mail);
1551                 printf("committer-time %lu\n", ci.committer_time);
1552                 printf("committer-tz %s\n", ci.committer_tz);
1553                 write_filename_info(suspect->path);
1554                 printf("summary %s\n", ci.summary);
1555                 if (suspect->commit->object.flags & UNINTERESTING)
1556                         printf("boundary\n");
1557         }
1558         else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1559                 write_filename_info(suspect->path);
1560
1561         cp = nth_line(sb, ent->lno);
1562         for (cnt = 0; cnt < ent->num_lines; cnt++) {
1563                 char ch;
1564                 if (cnt)
1565                         printf("%s %d %d\n", hex,
1566                                ent->s_lno + 1 + cnt,
1567                                ent->lno + 1 + cnt);
1568                 putchar('\t');
1569                 do {
1570                         ch = *cp++;
1571                         putchar(ch);
1572                 } while (ch != '\n' &&
1573                          cp < sb->final_buf + sb->final_buf_size);
1574         }
1575 }
1576
1577 static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1578 {
1579         int cnt;
1580         const char *cp;
1581         struct origin *suspect = ent->suspect;
1582         struct commit_info ci;
1583         char hex[41];
1584         int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1585
1586         get_commit_info(suspect->commit, &ci, 1);
1587         strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1588
1589         cp = nth_line(sb, ent->lno);
1590         for (cnt = 0; cnt < ent->num_lines; cnt++) {
1591                 char ch;
1592                 int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1593
1594                 if (suspect->commit->object.flags & UNINTERESTING) {
1595                         if (blank_boundary)
1596                                 memset(hex, ' ', length);
1597                         else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
1598                                 length--;
1599                                 putchar('^');
1600                         }
1601                 }
1602
1603                 printf("%.*s", length, hex);
1604                 if (opt & OUTPUT_ANNOTATE_COMPAT)
1605                         printf("\t(%10s\t%10s\t%d)", ci.author,
1606                                format_time(ci.author_time, ci.author_tz,
1607                                            show_raw_time),
1608                                ent->lno + 1 + cnt);
1609                 else {
1610                         if (opt & OUTPUT_SHOW_SCORE)
1611                                 printf(" %*d %02d",
1612                                        max_score_digits, ent->score,
1613                                        ent->suspect->refcnt);
1614                         if (opt & OUTPUT_SHOW_NAME)
1615                                 printf(" %-*.*s", longest_file, longest_file,
1616                                        suspect->path);
1617                         if (opt & OUTPUT_SHOW_NUMBER)
1618                                 printf(" %*d", max_orig_digits,
1619                                        ent->s_lno + 1 + cnt);
1620
1621                         if (!(opt & OUTPUT_NO_AUTHOR))
1622                                 printf(" (%-*.*s %10s",
1623                                        longest_author, longest_author,
1624                                        ci.author,
1625                                        format_time(ci.author_time,
1626                                                    ci.author_tz,
1627                                                    show_raw_time));
1628                         printf(" %*d) ",
1629                                max_digits, ent->lno + 1 + cnt);
1630                 }
1631                 do {
1632                         ch = *cp++;
1633                         putchar(ch);
1634                 } while (ch != '\n' &&
1635                          cp < sb->final_buf + sb->final_buf_size);
1636         }
1637 }
1638
1639 static void output(struct scoreboard *sb, int option)
1640 {
1641         struct blame_entry *ent;
1642
1643         if (option & OUTPUT_PORCELAIN) {
1644                 for (ent = sb->ent; ent; ent = ent->next) {
1645                         struct blame_entry *oth;
1646                         struct origin *suspect = ent->suspect;
1647                         struct commit *commit = suspect->commit;
1648                         if (commit->object.flags & MORE_THAN_ONE_PATH)
1649                                 continue;
1650                         for (oth = ent->next; oth; oth = oth->next) {
1651                                 if ((oth->suspect->commit != commit) ||
1652                                     !strcmp(oth->suspect->path, suspect->path))
1653                                         continue;
1654                                 commit->object.flags |= MORE_THAN_ONE_PATH;
1655                                 break;
1656                         }
1657                 }
1658         }
1659
1660         for (ent = sb->ent; ent; ent = ent->next) {
1661                 if (option & OUTPUT_PORCELAIN)
1662                         emit_porcelain(sb, ent);
1663                 else {
1664                         emit_other(sb, ent, option);
1665                 }
1666         }
1667 }
1668
1669 /*
1670  * To allow quick access to the contents of nth line in the
1671  * final image, prepare an index in the scoreboard.
1672  */
1673 static int prepare_lines(struct scoreboard *sb)
1674 {
1675         const char *buf = sb->final_buf;
1676         unsigned long len = sb->final_buf_size;
1677         int num = 0, incomplete = 0, bol = 1;
1678
1679         if (len && buf[len-1] != '\n')
1680                 incomplete++; /* incomplete line at the end */
1681         while (len--) {
1682                 if (bol) {
1683                         sb->lineno = xrealloc(sb->lineno,
1684                                               sizeof(int* ) * (num + 1));
1685                         sb->lineno[num] = buf - sb->final_buf;
1686                         bol = 0;
1687                 }
1688                 if (*buf++ == '\n') {
1689                         num++;
1690                         bol = 1;
1691                 }
1692         }
1693         sb->lineno = xrealloc(sb->lineno,
1694                               sizeof(int* ) * (num + incomplete + 1));
1695         sb->lineno[num + incomplete] = buf - sb->final_buf;
1696         sb->num_lines = num + incomplete;
1697         return sb->num_lines;
1698 }
1699
1700 /*
1701  * Add phony grafts for use with -S; this is primarily to
1702  * support git's cvsserver that wants to give a linear history
1703  * to its clients.
1704  */
1705 static int read_ancestry(const char *graft_file)
1706 {
1707         FILE *fp = fopen(graft_file, "r");
1708         char buf[1024];
1709         if (!fp)
1710                 return -1;
1711         while (fgets(buf, sizeof(buf), fp)) {
1712                 /* The format is just "Commit Parent1 Parent2 ...\n" */
1713                 int len = strlen(buf);
1714                 struct commit_graft *graft = read_graft_line(buf, len);
1715                 if (graft)
1716                         register_commit_graft(graft, 0);
1717         }
1718         fclose(fp);
1719         return 0;
1720 }
1721
1722 /*
1723  * How many columns do we need to show line numbers in decimal?
1724  */
1725 static int lineno_width(int lines)
1726 {
1727         int i, width;
1728
1729         for (width = 1, i = 10; i <= lines + 1; width++)
1730                 i *= 10;
1731         return width;
1732 }
1733
1734 /*
1735  * How many columns do we need to show line numbers, authors,
1736  * and filenames?
1737  */
1738 static void find_alignment(struct scoreboard *sb, int *option)
1739 {
1740         int longest_src_lines = 0;
1741         int longest_dst_lines = 0;
1742         unsigned largest_score = 0;
1743         struct blame_entry *e;
1744
1745         for (e = sb->ent; e; e = e->next) {
1746                 struct origin *suspect = e->suspect;
1747                 struct commit_info ci;
1748                 int num;
1749
1750                 if (strcmp(suspect->path, sb->path))
1751                         *option |= OUTPUT_SHOW_NAME;
1752                 num = strlen(suspect->path);
1753                 if (longest_file < num)
1754                         longest_file = num;
1755                 if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1756                         suspect->commit->object.flags |= METAINFO_SHOWN;
1757                         get_commit_info(suspect->commit, &ci, 1);
1758                         num = strlen(ci.author);
1759                         if (longest_author < num)
1760                                 longest_author = num;
1761                 }
1762                 num = e->s_lno + e->num_lines;
1763                 if (longest_src_lines < num)
1764                         longest_src_lines = num;
1765                 num = e->lno + e->num_lines;
1766                 if (longest_dst_lines < num)
1767                         longest_dst_lines = num;
1768                 if (largest_score < ent_score(sb, e))
1769                         largest_score = ent_score(sb, e);
1770         }
1771         max_orig_digits = lineno_width(longest_src_lines);
1772         max_digits = lineno_width(longest_dst_lines);
1773         max_score_digits = lineno_width(largest_score);
1774 }
1775
1776 /*
1777  * For debugging -- origin is refcounted, and this asserts that
1778  * we do not underflow.
1779  */
1780 static void sanity_check_refcnt(struct scoreboard *sb)
1781 {
1782         int baa = 0;
1783         struct blame_entry *ent;
1784
1785         for (ent = sb->ent; ent; ent = ent->next) {
1786                 /* Nobody should have zero or negative refcnt */
1787                 if (ent->suspect->refcnt <= 0) {
1788                         fprintf(stderr, "%s in %s has negative refcnt %d\n",
1789                                 ent->suspect->path,
1790                                 sha1_to_hex(ent->suspect->commit->object.sha1),
1791                                 ent->suspect->refcnt);
1792                         baa = 1;
1793                 }
1794         }
1795         for (ent = sb->ent; ent; ent = ent->next) {
1796                 /* Mark the ones that haven't been checked */
1797                 if (0 < ent->suspect->refcnt)
1798                         ent->suspect->refcnt = -ent->suspect->refcnt;
1799         }
1800         for (ent = sb->ent; ent; ent = ent->next) {
1801                 /*
1802                  * ... then pick each and see if they have the the
1803                  * correct refcnt.
1804                  */
1805                 int found;
1806                 struct blame_entry *e;
1807                 struct origin *suspect = ent->suspect;
1808
1809                 if (0 < suspect->refcnt)
1810                         continue;
1811                 suspect->refcnt = -suspect->refcnt; /* Unmark */
1812                 for (found = 0, e = sb->ent; e; e = e->next) {
1813                         if (e->suspect != suspect)
1814                                 continue;
1815                         found++;
1816                 }
1817                 if (suspect->refcnt != found) {
1818                         fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1819                                 ent->suspect->path,
1820                                 sha1_to_hex(ent->suspect->commit->object.sha1),
1821                                 ent->suspect->refcnt, found);
1822                         baa = 2;
1823                 }
1824         }
1825         if (baa) {
1826                 int opt = 0160;
1827                 find_alignment(sb, &opt);
1828                 output(sb, opt);
1829                 die("Baa %d!", baa);
1830         }
1831 }
1832
1833 /*
1834  * Used for the command line parsing; check if the path exists
1835  * in the working tree.
1836  */
1837 static int has_string_in_work_tree(const char *path)
1838 {
1839         struct stat st;
1840         return !lstat(path, &st);
1841 }
1842
1843 static unsigned parse_score(const char *arg)
1844 {
1845         char *end;
1846         unsigned long score = strtoul(arg, &end, 10);
1847         if (*end)
1848                 return 0;
1849         return score;
1850 }
1851
1852 static const char *add_prefix(const char *prefix, const char *path)
1853 {
1854         return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
1855 }
1856
1857 /*
1858  * Parsing of (comma separated) one item in the -L option
1859  */
1860 static const char *parse_loc(const char *spec,
1861                              struct scoreboard *sb, long lno,
1862                              long begin, long *ret)
1863 {
1864         char *term;
1865         const char *line;
1866         long num;
1867         int reg_error;
1868         regex_t regexp;
1869         regmatch_t match[1];
1870
1871         /* Allow "-L <something>,+20" to mean starting at <something>
1872          * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1873          * <something>.
1874          */
1875         if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1876                 num = strtol(spec + 1, &term, 10);
1877                 if (term != spec + 1) {
1878                         if (spec[0] == '-')
1879                                 num = 0 - num;
1880                         if (0 < num)
1881                                 *ret = begin + num - 2;
1882                         else if (!num)
1883                                 *ret = begin;
1884                         else
1885                                 *ret = begin + num;
1886                         return term;
1887                 }
1888                 return spec;
1889         }
1890         num = strtol(spec, &term, 10);
1891         if (term != spec) {
1892                 *ret = num;
1893                 return term;
1894         }
1895         if (spec[0] != '/')
1896                 return spec;
1897
1898         /* it could be a regexp of form /.../ */
1899         for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1900                 if (*term == '\\')
1901                         term++;
1902         }
1903         if (*term != '/')
1904                 return spec;
1905
1906         /* try [spec+1 .. term-1] as regexp */
1907         *term = 0;
1908         begin--; /* input is in human terms */
1909         line = nth_line(sb, begin);
1910
1911         if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1912             !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1913                 const char *cp = line + match[0].rm_so;
1914                 const char *nline;
1915
1916                 while (begin++ < lno) {
1917                         nline = nth_line(sb, begin);
1918                         if (line <= cp && cp < nline)
1919                                 break;
1920                         line = nline;
1921                 }
1922                 *ret = begin;
1923                 regfree(&regexp);
1924                 *term++ = '/';
1925                 return term;
1926         }
1927         else {
1928                 char errbuf[1024];
1929                 regerror(reg_error, &regexp, errbuf, 1024);
1930                 die("-L parameter '%s': %s", spec + 1, errbuf);
1931         }
1932 }
1933
1934 /*
1935  * Parsing of -L option
1936  */
1937 static void prepare_blame_range(struct scoreboard *sb,
1938                                 const char *bottomtop,
1939                                 long lno,
1940                                 long *bottom, long *top)
1941 {
1942         const char *term;
1943
1944         term = parse_loc(bottomtop, sb, lno, 1, bottom);
1945         if (*term == ',') {
1946                 term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1947                 if (*term)
1948                         usage(blame_usage);
1949         }
1950         if (*term)
1951                 usage(blame_usage);
1952 }
1953
1954 static int git_blame_config(const char *var, const char *value, void *cb)
1955 {
1956         if (!strcmp(var, "blame.showroot")) {
1957                 show_root = git_config_bool(var, value);
1958                 return 0;
1959         }
1960         if (!strcmp(var, "blame.blankboundary")) {
1961                 blank_boundary = git_config_bool(var, value);
1962                 return 0;
1963         }
1964         return git_default_config(var, value, cb);
1965 }
1966
1967 /*
1968  * Prepare a dummy commit that represents the work tree (or staged) item.
1969  * Note that annotating work tree item never works in the reverse.
1970  */
1971 static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
1972 {
1973         struct commit *commit;
1974         struct origin *origin;
1975         unsigned char head_sha1[20];
1976         struct strbuf buf = STRBUF_INIT;
1977         const char *ident;
1978         time_t now;
1979         int size, len;
1980         struct cache_entry *ce;
1981         unsigned mode;
1982
1983         if (get_sha1("HEAD", head_sha1))
1984                 die("No such ref: HEAD");
1985
1986         time(&now);
1987         commit = xcalloc(1, sizeof(*commit));
1988         commit->parents = xcalloc(1, sizeof(*commit->parents));
1989         commit->parents->item = lookup_commit_reference(head_sha1);
1990         commit->object.parsed = 1;
1991         commit->date = now;
1992         commit->object.type = OBJ_COMMIT;
1993
1994         origin = make_origin(commit, path);
1995
1996         if (!contents_from || strcmp("-", contents_from)) {
1997                 struct stat st;
1998                 const char *read_from;
1999
2000                 if (contents_from) {
2001                         if (stat(contents_from, &st) < 0)
2002                                 die("Cannot stat %s", contents_from);
2003                         read_from = contents_from;
2004                 }
2005                 else {
2006                         if (lstat(path, &st) < 0)
2007                                 die("Cannot lstat %s", path);
2008                         read_from = path;
2009                 }
2010                 mode = canon_mode(st.st_mode);
2011                 switch (st.st_mode & S_IFMT) {
2012                 case S_IFREG:
2013                         if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
2014                                 die("cannot open or read %s", read_from);
2015                         break;
2016                 case S_IFLNK:
2017                         if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
2018                                 die("cannot readlink %s", read_from);
2019                         break;
2020                 default:
2021                         die("unsupported file type %s", read_from);
2022                 }
2023         }
2024         else {
2025                 /* Reading from stdin */
2026                 contents_from = "standard input";
2027                 mode = 0;
2028                 if (strbuf_read(&buf, 0, 0) < 0)
2029                         die("read error %s from stdin", strerror(errno));
2030         }
2031         convert_to_git(path, buf.buf, buf.len, &buf, 0);
2032         origin->file.ptr = buf.buf;
2033         origin->file.size = buf.len;
2034         pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
2035         commit->util = origin;
2036
2037         /*
2038          * Read the current index, replace the path entry with
2039          * origin->blob_sha1 without mucking with its mode or type
2040          * bits; we are not going to write this index out -- we just
2041          * want to run "diff-index --cached".
2042          */
2043         discard_cache();
2044         read_cache();
2045
2046         len = strlen(path);
2047         if (!mode) {
2048                 int pos = cache_name_pos(path, len);
2049                 if (0 <= pos)
2050                         mode = active_cache[pos]->ce_mode;
2051                 else
2052                         /* Let's not bother reading from HEAD tree */
2053                         mode = S_IFREG | 0644;
2054         }
2055         size = cache_entry_size(len);
2056         ce = xcalloc(1, size);
2057         hashcpy(ce->sha1, origin->blob_sha1);
2058         memcpy(ce->name, path, len);
2059         ce->ce_flags = create_ce_flags(len, 0);
2060         ce->ce_mode = create_ce_mode(mode);
2061         add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2062
2063         /*
2064          * We are not going to write this out, so this does not matter
2065          * right now, but someday we might optimize diff-index --cached
2066          * with cache-tree information.
2067          */
2068         cache_tree_invalidate_path(active_cache_tree, path);
2069
2070         commit->buffer = xmalloc(400);
2071         ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2072         snprintf(commit->buffer, 400,
2073                 "tree 0000000000000000000000000000000000000000\n"
2074                 "parent %s\n"
2075                 "author %s\n"
2076                 "committer %s\n\n"
2077                 "Version of %s from %s\n",
2078                 sha1_to_hex(head_sha1),
2079                 ident, ident, path, contents_from ? contents_from : path);
2080         return commit;
2081 }
2082
2083 static const char *prepare_final(struct scoreboard *sb)
2084 {
2085         int i;
2086         const char *final_commit_name = NULL;
2087         struct rev_info *revs = sb->revs;
2088
2089         /*
2090          * There must be one and only one positive commit in the
2091          * revs->pending array.
2092          */
2093         for (i = 0; i < revs->pending.nr; i++) {
2094                 struct object *obj = revs->pending.objects[i].item;
2095                 if (obj->flags & UNINTERESTING)
2096                         continue;
2097                 while (obj->type == OBJ_TAG)
2098                         obj = deref_tag(obj, NULL, 0);
2099                 if (obj->type != OBJ_COMMIT)
2100                         die("Non commit %s?", revs->pending.objects[i].name);
2101                 if (sb->final)
2102                         die("More than one commit to dig from %s and %s?",
2103                             revs->pending.objects[i].name,
2104                             final_commit_name);
2105                 sb->final = (struct commit *) obj;
2106                 final_commit_name = revs->pending.objects[i].name;
2107         }
2108         return final_commit_name;
2109 }
2110
2111 static const char *prepare_initial(struct scoreboard *sb)
2112 {
2113         int i;
2114         const char *final_commit_name = NULL;
2115         struct rev_info *revs = sb->revs;
2116
2117         /*
2118          * There must be one and only one negative commit, and it must be
2119          * the boundary.
2120          */
2121         for (i = 0; i < revs->pending.nr; i++) {
2122                 struct object *obj = revs->pending.objects[i].item;
2123                 if (!(obj->flags & UNINTERESTING))
2124                         continue;
2125                 while (obj->type == OBJ_TAG)
2126                         obj = deref_tag(obj, NULL, 0);
2127                 if (obj->type != OBJ_COMMIT)
2128                         die("Non commit %s?", revs->pending.objects[i].name);
2129                 if (sb->final)
2130                         die("More than one commit to dig down to %s and %s?",
2131                             revs->pending.objects[i].name,
2132                             final_commit_name);
2133                 sb->final = (struct commit *) obj;
2134                 final_commit_name = revs->pending.objects[i].name;
2135         }
2136         if (!final_commit_name)
2137                 die("No commit to dig down to?");
2138         return final_commit_name;
2139 }
2140
2141 static int blame_copy_callback(const struct option *option, const char *arg, int unset)
2142 {
2143         int *opt = option->value;
2144
2145         /*
2146          * -C enables copy from removed files;
2147          * -C -C enables copy from existing files, but only
2148          *       when blaming a new file;
2149          * -C -C -C enables copy from existing files for
2150          *          everybody
2151          */
2152         if (*opt & PICKAXE_BLAME_COPY_HARDER)
2153                 *opt |= PICKAXE_BLAME_COPY_HARDEST;
2154         if (*opt & PICKAXE_BLAME_COPY)
2155                 *opt |= PICKAXE_BLAME_COPY_HARDER;
2156         *opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2157
2158         if (arg)
2159                 blame_copy_score = parse_score(arg);
2160         return 0;
2161 }
2162
2163 static int blame_move_callback(const struct option *option, const char *arg, int unset)
2164 {
2165         int *opt = option->value;
2166
2167         *opt |= PICKAXE_BLAME_MOVE;
2168
2169         if (arg)
2170                 blame_move_score = parse_score(arg);
2171         return 0;
2172 }
2173
2174 static int blame_bottomtop_callback(const struct option *option, const char *arg, int unset)
2175 {
2176         const char **bottomtop = option->value;
2177         if (!arg)
2178                 return -1;
2179         if (*bottomtop)
2180                 die("More than one '-L n,m' option given");
2181         *bottomtop = arg;
2182         return 0;
2183 }
2184
2185 int cmd_blame(int argc, const char **argv, const char *prefix)
2186 {
2187         struct rev_info revs;
2188         const char *path;
2189         struct scoreboard sb;
2190         struct origin *o;
2191         struct blame_entry *ent;
2192         long dashdash_pos, bottom, top, lno;
2193         const char *final_commit_name = NULL;
2194         enum object_type type;
2195
2196         static const char *bottomtop = NULL;
2197         static int output_option = 0, opt = 0;
2198         static int show_stats = 0;
2199         static const char *revs_file = NULL;
2200         static const char *contents_from = NULL;
2201         static const struct option options[] = {
2202                 OPT_BOOLEAN(0, "incremental", &incremental, "Show blame entries as we find them, incrementally"),
2203                 OPT_BOOLEAN('b', NULL, &blank_boundary, "Show blank SHA-1 for boundary commits (Default: off)"),
2204                 OPT_BOOLEAN(0, "root", &show_root, "Do not treat root commits as boundaries (Default: off)"),
2205                 OPT_BOOLEAN(0, "show-stats", &show_stats, "Show work cost statistics"),
2206                 OPT_BIT(0, "score-debug", &output_option, "Show output score for blame entries", OUTPUT_SHOW_SCORE),
2207                 OPT_BIT('f', "show-name", &output_option, "Show original filename (Default: auto)", OUTPUT_SHOW_NAME),
2208                 OPT_BIT('n', "show-number", &output_option, "Show original linenumber (Default: off)", OUTPUT_SHOW_NUMBER),
2209                 OPT_BIT('p', "porcelain", &output_option, "Show in a format designed for machine consumption", OUTPUT_PORCELAIN),
2210                 OPT_BIT('c', NULL, &output_option, "Use the same output mode as git-annotate (Default: off)", OUTPUT_ANNOTATE_COMPAT),
2211                 OPT_BIT('t', NULL, &output_option, "Show raw timestamp (Default: off)", OUTPUT_RAW_TIMESTAMP),
2212                 OPT_BIT('l', NULL, &output_option, "Show long commit SHA1 (Default: off)", OUTPUT_LONG_OBJECT_NAME),
2213                 OPT_BIT('s', NULL, &output_option, "Suppress author name and timestamp (Default: off)", OUTPUT_NO_AUTHOR),
2214                 OPT_BIT('w', NULL, &xdl_opts, "Ignore whitespace differences", XDF_IGNORE_WHITESPACE),
2215                 OPT_STRING('S', NULL, &revs_file, "file", "Use revisions from <file> instead of calling git-rev-list"),
2216                 OPT_STRING(0, "contents", &contents_from, "file", "Use <file>'s contents as the final image"),
2217                 { OPTION_CALLBACK, 'C', NULL, &opt, "score", "Find line copies within and across files", PARSE_OPT_OPTARG, blame_copy_callback },
2218                 { OPTION_CALLBACK, 'M', NULL, &opt, "score", "Find line movements within and across files", PARSE_OPT_OPTARG, blame_move_callback },
2219                 OPT_CALLBACK('L', NULL, &bottomtop, "n,m", "Process only line range n,m, counting from 1", blame_bottomtop_callback),
2220                 OPT_END()
2221         };
2222
2223         struct parse_opt_ctx_t ctx;
2224         int cmd_is_annotate = !strcmp(argv[0], "annotate");
2225
2226         git_config(git_blame_config, NULL);
2227         init_revisions(&revs, NULL);
2228         save_commit_buffer = 0;
2229         dashdash_pos = 0;
2230
2231         parse_options_start(&ctx, argc, argv, PARSE_OPT_KEEP_DASHDASH |
2232                             PARSE_OPT_KEEP_ARGV0);
2233         for (;;) {
2234                 switch (parse_options_step(&ctx, options, blame_opt_usage)) {
2235                 case PARSE_OPT_HELP:
2236                         exit(129);
2237                 case PARSE_OPT_DONE:
2238                         if (ctx.argv[0])
2239                                 dashdash_pos = ctx.cpidx;
2240                         goto parse_done;
2241                 }
2242
2243                 if (!strcmp(ctx.argv[0], "--reverse")) {
2244                         ctx.argv[0] = "--children";
2245                         reverse = 1;
2246                 }
2247                 parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
2248         }
2249 parse_done:
2250         argc = parse_options_end(&ctx);
2251
2252         if (cmd_is_annotate)
2253                 output_option |= OUTPUT_ANNOTATE_COMPAT;
2254
2255         if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
2256                 opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
2257                         PICKAXE_BLAME_COPY_HARDER);
2258
2259         if (!blame_move_score)
2260                 blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2261         if (!blame_copy_score)
2262                 blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2263
2264         /*
2265          * We have collected options unknown to us in argv[1..unk]
2266          * which are to be passed to revision machinery if we are
2267          * going to do the "bottom" processing.
2268          *
2269          * The remaining are:
2270          *
2271          * (1) if dashdash_pos != 0, its either
2272          *     "blame [revisions] -- <path>" or
2273          *     "blame -- <path> <rev>"
2274          *
2275          * (2) otherwise, its one of the two:
2276          *     "blame [revisions] <path>"
2277          *     "blame <path> <rev>"
2278          *
2279          * Note that we must strip out <path> from the arguments: we do not
2280          * want the path pruning but we may want "bottom" processing.
2281          */
2282         if (dashdash_pos) {
2283                 switch (argc - dashdash_pos - 1) {
2284                 case 2: /* (1b) */
2285                         if (argc != 4)
2286                                 usage_with_options(blame_opt_usage, options);
2287                         /* reorder for the new way: <rev> -- <path> */
2288                         argv[1] = argv[3];
2289                         argv[3] = argv[2];
2290                         argv[2] = "--";
2291                         /* FALLTHROUGH */
2292                 case 1: /* (1a) */
2293                         path = add_prefix(prefix, argv[--argc]);
2294                         argv[argc] = NULL;
2295                         break;
2296                 default:
2297                         usage_with_options(blame_opt_usage, options);
2298                 }
2299         } else {
2300                 if (argc < 2)
2301                         usage_with_options(blame_opt_usage, options);
2302                 path = add_prefix(prefix, argv[argc - 1]);
2303                 if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
2304                         path = add_prefix(prefix, argv[1]);
2305                         argv[1] = argv[2];
2306                 }
2307                 argv[argc - 1] = "--";
2308
2309                 setup_work_tree();
2310                 if (!has_string_in_work_tree(path))
2311                         die("cannot stat path %s: %s", path, strerror(errno));
2312         }
2313
2314         setup_revisions(argc, argv, &revs, NULL);
2315         memset(&sb, 0, sizeof(sb));
2316
2317         sb.revs = &revs;
2318         if (!reverse)
2319                 final_commit_name = prepare_final(&sb);
2320         else if (contents_from)
2321                 die("--contents and --children do not blend well.");
2322         else
2323                 final_commit_name = prepare_initial(&sb);
2324
2325         if (!sb.final) {
2326                 /*
2327                  * "--not A B -- path" without anything positive;
2328                  * do not default to HEAD, but use the working tree
2329                  * or "--contents".
2330                  */
2331                 setup_work_tree();
2332                 sb.final = fake_working_tree_commit(path, contents_from);
2333                 add_pending_object(&revs, &(sb.final->object), ":");
2334         }
2335         else if (contents_from)
2336                 die("Cannot use --contents with final commit object name");
2337
2338         /*
2339          * If we have bottom, this will mark the ancestors of the
2340          * bottom commits we would reach while traversing as
2341          * uninteresting.
2342          */
2343         if (prepare_revision_walk(&revs))
2344                 die("revision walk setup failed");
2345
2346         if (is_null_sha1(sb.final->object.sha1)) {
2347                 char *buf;
2348                 o = sb.final->util;
2349                 buf = xmalloc(o->file.size + 1);
2350                 memcpy(buf, o->file.ptr, o->file.size + 1);
2351                 sb.final_buf = buf;
2352                 sb.final_buf_size = o->file.size;
2353         }
2354         else {
2355                 o = get_origin(&sb, sb.final, path);
2356                 if (fill_blob_sha1(o))
2357                         die("no such path %s in %s", path, final_commit_name);
2358
2359                 sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2360                                               &sb.final_buf_size);
2361                 if (!sb.final_buf)
2362                         die("Cannot read blob %s for path %s",
2363                             sha1_to_hex(o->blob_sha1),
2364                             path);
2365         }
2366         num_read_blob++;
2367         lno = prepare_lines(&sb);
2368
2369         bottom = top = 0;
2370         if (bottomtop)
2371                 prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2372         if (bottom && top && top < bottom) {
2373                 long tmp;
2374                 tmp = top; top = bottom; bottom = tmp;
2375         }
2376         if (bottom < 1)
2377                 bottom = 1;
2378         if (top < 1)
2379                 top = lno;
2380         bottom--;
2381         if (lno < top)
2382                 die("file %s has only %lu lines", path, lno);
2383
2384         ent = xcalloc(1, sizeof(*ent));
2385         ent->lno = bottom;
2386         ent->num_lines = top - bottom;
2387         ent->suspect = o;
2388         ent->s_lno = bottom;
2389
2390         sb.ent = ent;
2391         sb.path = path;
2392
2393         if (revs_file && read_ancestry(revs_file))
2394                 die("reading graft file %s failed: %s",
2395                     revs_file, strerror(errno));
2396
2397         read_mailmap(&mailmap, NULL);
2398
2399         if (!incremental)
2400                 setup_pager();
2401
2402         assign_blame(&sb, opt);
2403
2404         if (incremental)
2405                 return 0;
2406
2407         coalesce(&sb);
2408
2409         if (!(output_option & OUTPUT_PORCELAIN))
2410                 find_alignment(&sb, &output_option);
2411
2412         output(&sb, output_option);
2413         free((void *)sb.final_buf);
2414         for (ent = sb.ent; ent; ) {
2415                 struct blame_entry *e = ent->next;
2416                 free(ent);
2417                 ent = e;
2418         }
2419
2420         if (show_stats) {
2421                 printf("num read blob: %d\n", num_read_blob);
2422                 printf("num get patch: %d\n", num_get_patch);
2423                 printf("num commits: %d\n", num_commits);
2424         }
2425         return 0;
2426 }