Merge branch 'maint'
[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
20 static char blame_usage[] =
21 "git-blame [-c] [-l] [-t] [-f] [-n] [-p] [-L n,m] [-S <revs-file>] [-M] [-C] [-C] [--contents <filename>] [--incremental] [commit] [--] file\n"
22 "  -c, --compatibility Use the same output mode as git-annotate (Default: off)\n"
23 "  -b                  Show blank SHA-1 for boundary commits (Default: off)\n"
24 "  -l, --long          Show long commit SHA1 (Default: off)\n"
25 "  --root              Do not treat root commits as boundaries (Default: off)\n"
26 "  -t, --time          Show raw timestamp (Default: off)\n"
27 "  -f, --show-name     Show original filename (Default: auto)\n"
28 "  -n, --show-number   Show original linenumber (Default: off)\n"
29 "  -p, --porcelain     Show in a format designed for machine consumption\n"
30 "  -L n,m              Process only line range n,m, counting from 1\n"
31 "  -M, -C              Find line movements within and across files\n"
32 "  --incremental       Show blame entries as we find them, incrementally\n"
33 "  --contents file     Use <file>'s contents as the final image\n"
34 "  -S revs-file        Use revisions from revs-file instead of calling git-rev-list\n";
35
36 static int longest_file;
37 static int longest_author;
38 static int max_orig_digits;
39 static int max_digits;
40 static int max_score_digits;
41 static int show_root;
42 static int blank_boundary;
43 static int incremental;
44 static int cmd_is_annotate;
45
46 #ifndef DEBUG
47 #define DEBUG 0
48 #endif
49
50 /* stats */
51 static int num_read_blob;
52 static int num_get_patch;
53 static int num_commits;
54
55 #define PICKAXE_BLAME_MOVE              01
56 #define PICKAXE_BLAME_COPY              02
57 #define PICKAXE_BLAME_COPY_HARDER       04
58
59 /*
60  * blame for a blame_entry with score lower than these thresholds
61  * is not passed to the parent using move/copy logic.
62  */
63 static unsigned blame_move_score;
64 static unsigned blame_copy_score;
65 #define BLAME_DEFAULT_MOVE_SCORE        20
66 #define BLAME_DEFAULT_COPY_SCORE        40
67
68 /* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
69 #define METAINFO_SHOWN          (1u<<12)
70 #define MORE_THAN_ONE_PATH      (1u<<13)
71
72 /*
73  * One blob in a commit that is being suspected
74  */
75 struct origin {
76         int refcnt;
77         struct commit *commit;
78         mmfile_t file;
79         unsigned char blob_sha1[20];
80         char path[FLEX_ARRAY];
81 };
82
83 /*
84  * Given an origin, prepare mmfile_t structure to be used by the
85  * diff machinery
86  */
87 static char *fill_origin_blob(struct origin *o, mmfile_t *file)
88 {
89         if (!o->file.ptr) {
90                 enum object_type type;
91                 num_read_blob++;
92                 file->ptr = read_sha1_file(o->blob_sha1, &type,
93                                            (unsigned long *)(&(file->size)));
94                 o->file = *file;
95         }
96         else
97                 *file = o->file;
98         return file->ptr;
99 }
100
101 /*
102  * Origin is refcounted and usually we keep the blob contents to be
103  * reused.
104  */
105 static inline struct origin *origin_incref(struct origin *o)
106 {
107         if (o)
108                 o->refcnt++;
109         return o;
110 }
111
112 static void origin_decref(struct origin *o)
113 {
114         if (o && --o->refcnt <= 0) {
115                 if (o->file.ptr)
116                         free(o->file.ptr);
117                 memset(o, 0, sizeof(*o));
118                 free(o);
119         }
120 }
121
122 /*
123  * Each group of lines is described by a blame_entry; it can be split
124  * as we pass blame to the parents.  They form a linked list in the
125  * scoreboard structure, sorted by the target line number.
126  */
127 struct blame_entry {
128         struct blame_entry *prev;
129         struct blame_entry *next;
130
131         /* the first line of this group in the final image;
132          * internally all line numbers are 0 based.
133          */
134         int lno;
135
136         /* how many lines this group has */
137         int num_lines;
138
139         /* the commit that introduced this group into the final image */
140         struct origin *suspect;
141
142         /* true if the suspect is truly guilty; false while we have not
143          * checked if the group came from one of its parents.
144          */
145         char guilty;
146
147         /* the line number of the first line of this group in the
148          * suspect's file; internally all line numbers are 0 based.
149          */
150         int s_lno;
151
152         /* how significant this entry is -- cached to avoid
153          * scanning the lines over and over.
154          */
155         unsigned score;
156 };
157
158 /*
159  * The current state of the blame assignment.
160  */
161 struct scoreboard {
162         /* the final commit (i.e. where we started digging from) */
163         struct commit *final;
164
165         const char *path;
166
167         /*
168          * The contents in the final image.
169          * Used by many functions to obtain contents of the nth line,
170          * indexed with scoreboard.lineno[blame_entry.lno].
171          */
172         const char *final_buf;
173         unsigned long final_buf_size;
174
175         /* linked list of blames */
176         struct blame_entry *ent;
177
178         /* look-up a line in the final buffer */
179         int num_lines;
180         int *lineno;
181 };
182
183 static int cmp_suspect(struct origin *a, struct origin *b)
184 {
185         int cmp = hashcmp(a->commit->object.sha1, b->commit->object.sha1);
186         if (cmp)
187                 return cmp;
188         return strcmp(a->path, b->path);
189 }
190
191 #define cmp_suspect(a, b) ( ((a)==(b)) ? 0 : cmp_suspect(a,b) )
192
193 static void sanity_check_refcnt(struct scoreboard *);
194
195 /*
196  * If two blame entries that are next to each other came from
197  * contiguous lines in the same origin (i.e. <commit, path> pair),
198  * merge them together.
199  */
200 static void coalesce(struct scoreboard *sb)
201 {
202         struct blame_entry *ent, *next;
203
204         for (ent = sb->ent; ent && (next = ent->next); ent = next) {
205                 if (!cmp_suspect(ent->suspect, next->suspect) &&
206                     ent->guilty == next->guilty &&
207                     ent->s_lno + ent->num_lines == next->s_lno) {
208                         ent->num_lines += next->num_lines;
209                         ent->next = next->next;
210                         if (ent->next)
211                                 ent->next->prev = ent;
212                         origin_decref(next->suspect);
213                         free(next);
214                         ent->score = 0;
215                         next = ent; /* again */
216                 }
217         }
218
219         if (DEBUG) /* sanity */
220                 sanity_check_refcnt(sb);
221 }
222
223 /*
224  * Given a commit and a path in it, create a new origin structure.
225  * The callers that add blame to the scoreboard should use
226  * get_origin() to obtain shared, refcounted copy instead of calling
227  * this function directly.
228  */
229 static struct origin *make_origin(struct commit *commit, const char *path)
230 {
231         struct origin *o;
232         o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
233         o->commit = commit;
234         o->refcnt = 1;
235         strcpy(o->path, path);
236         return o;
237 }
238
239 /*
240  * Locate an existing origin or create a new one.
241  */
242 static struct origin *get_origin(struct scoreboard *sb,
243                                  struct commit *commit,
244                                  const char *path)
245 {
246         struct blame_entry *e;
247
248         for (e = sb->ent; e; e = e->next) {
249                 if (e->suspect->commit == commit &&
250                     !strcmp(e->suspect->path, path))
251                         return origin_incref(e->suspect);
252         }
253         return make_origin(commit, path);
254 }
255
256 /*
257  * Fill the blob_sha1 field of an origin if it hasn't, so that later
258  * call to fill_origin_blob() can use it to locate the data.  blob_sha1
259  * for an origin is also used to pass the blame for the entire file to
260  * the parent to detect the case where a child's blob is identical to
261  * that of its parent's.
262  */
263 static int fill_blob_sha1(struct origin *origin)
264 {
265         unsigned mode;
266
267         if (!is_null_sha1(origin->blob_sha1))
268                 return 0;
269         if (get_tree_entry(origin->commit->object.sha1,
270                            origin->path,
271                            origin->blob_sha1, &mode))
272                 goto error_out;
273         if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
274                 goto error_out;
275         return 0;
276  error_out:
277         hashclr(origin->blob_sha1);
278         return -1;
279 }
280
281 /*
282  * We have an origin -- check if the same path exists in the
283  * parent and return an origin structure to represent it.
284  */
285 static struct origin *find_origin(struct scoreboard *sb,
286                                   struct commit *parent,
287                                   struct origin *origin)
288 {
289         struct origin *porigin = NULL;
290         struct diff_options diff_opts;
291         const char *paths[2];
292
293         if (parent->util) {
294                 /*
295                  * Each commit object can cache one origin in that
296                  * commit.  This is a freestanding copy of origin and
297                  * not refcounted.
298                  */
299                 struct origin *cached = parent->util;
300                 if (!strcmp(cached->path, origin->path)) {
301                         /*
302                          * The same path between origin and its parent
303                          * without renaming -- the most common case.
304                          */
305                         porigin = get_origin(sb, parent, cached->path);
306
307                         /*
308                          * If the origin was newly created (i.e. get_origin
309                          * would call make_origin if none is found in the
310                          * scoreboard), it does not know the blob_sha1,
311                          * so copy it.  Otherwise porigin was in the
312                          * scoreboard and already knows blob_sha1.
313                          */
314                         if (porigin->refcnt == 1)
315                                 hashcpy(porigin->blob_sha1, cached->blob_sha1);
316                         return porigin;
317                 }
318                 /* otherwise it was not very useful; free it */
319                 free(parent->util);
320                 parent->util = NULL;
321         }
322
323         /* See if the origin->path is different between parent
324          * and origin first.  Most of the time they are the
325          * same and diff-tree is fairly efficient about this.
326          */
327         diff_setup(&diff_opts);
328         diff_opts.recursive = 1;
329         diff_opts.detect_rename = 0;
330         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
331         paths[0] = origin->path;
332         paths[1] = NULL;
333
334         diff_tree_setup_paths(paths, &diff_opts);
335         if (diff_setup_done(&diff_opts) < 0)
336                 die("diff-setup");
337
338         if (is_null_sha1(origin->commit->object.sha1))
339                 do_diff_cache(parent->tree->object.sha1, &diff_opts);
340         else
341                 diff_tree_sha1(parent->tree->object.sha1,
342                                origin->commit->tree->object.sha1,
343                                "", &diff_opts);
344         diffcore_std(&diff_opts);
345
346         /* It is either one entry that says "modified", or "created",
347          * or nothing.
348          */
349         if (!diff_queued_diff.nr) {
350                 /* The path is the same as parent */
351                 porigin = get_origin(sb, parent, origin->path);
352                 hashcpy(porigin->blob_sha1, origin->blob_sha1);
353         }
354         else if (diff_queued_diff.nr != 1)
355                 die("internal error in blame::find_origin");
356         else {
357                 struct diff_filepair *p = diff_queued_diff.queue[0];
358                 switch (p->status) {
359                 default:
360                         die("internal error in blame::find_origin (%c)",
361                             p->status);
362                 case 'M':
363                         porigin = get_origin(sb, parent, origin->path);
364                         hashcpy(porigin->blob_sha1, p->one->sha1);
365                         break;
366                 case 'A':
367                 case 'T':
368                         /* Did not exist in parent, or type changed */
369                         break;
370                 }
371         }
372         diff_flush(&diff_opts);
373         if (porigin) {
374                 /*
375                  * Create a freestanding copy that is not part of
376                  * the refcounted origin found in the scoreboard, and
377                  * cache it in the commit.
378                  */
379                 struct origin *cached;
380
381                 cached = make_origin(porigin->commit, porigin->path);
382                 hashcpy(cached->blob_sha1, porigin->blob_sha1);
383                 parent->util = cached;
384         }
385         return porigin;
386 }
387
388 /*
389  * We have an origin -- find the path that corresponds to it in its
390  * parent and return an origin structure to represent it.
391  */
392 static struct origin *find_rename(struct scoreboard *sb,
393                                   struct commit *parent,
394                                   struct origin *origin)
395 {
396         struct origin *porigin = NULL;
397         struct diff_options diff_opts;
398         int i;
399         const char *paths[2];
400
401         diff_setup(&diff_opts);
402         diff_opts.recursive = 1;
403         diff_opts.detect_rename = DIFF_DETECT_RENAME;
404         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
405         diff_opts.single_follow = origin->path;
406         paths[0] = NULL;
407         diff_tree_setup_paths(paths, &diff_opts);
408         if (diff_setup_done(&diff_opts) < 0)
409                 die("diff-setup");
410
411         if (is_null_sha1(origin->commit->object.sha1))
412                 do_diff_cache(parent->tree->object.sha1, &diff_opts);
413         else
414                 diff_tree_sha1(parent->tree->object.sha1,
415                                origin->commit->tree->object.sha1,
416                                "", &diff_opts);
417         diffcore_std(&diff_opts);
418
419         for (i = 0; i < diff_queued_diff.nr; i++) {
420                 struct diff_filepair *p = diff_queued_diff.queue[i];
421                 if ((p->status == 'R' || p->status == 'C') &&
422                     !strcmp(p->two->path, origin->path)) {
423                         porigin = get_origin(sb, parent, p->one->path);
424                         hashcpy(porigin->blob_sha1, p->one->sha1);
425                         break;
426                 }
427         }
428         diff_flush(&diff_opts);
429         return porigin;
430 }
431
432 /*
433  * Parsing of patch chunks...
434  */
435 struct chunk {
436         /* line number in postimage; up to but not including this
437          * line is the same as preimage
438          */
439         int same;
440
441         /* preimage line number after this chunk */
442         int p_next;
443
444         /* postimage line number after this chunk */
445         int t_next;
446 };
447
448 struct patch {
449         struct chunk *chunks;
450         int num;
451 };
452
453 struct blame_diff_state {
454         struct xdiff_emit_state xm;
455         struct patch *ret;
456         unsigned hunk_post_context;
457         unsigned hunk_in_pre_context : 1;
458 };
459
460 static void process_u_diff(void *state_, char *line, unsigned long len)
461 {
462         struct blame_diff_state *state = state_;
463         struct chunk *chunk;
464         int off1, off2, len1, len2, num;
465
466         num = state->ret->num;
467         if (len < 4 || line[0] != '@' || line[1] != '@') {
468                 if (state->hunk_in_pre_context && line[0] == ' ')
469                         state->ret->chunks[num - 1].same++;
470                 else {
471                         state->hunk_in_pre_context = 0;
472                         if (line[0] == ' ')
473                                 state->hunk_post_context++;
474                         else
475                                 state->hunk_post_context = 0;
476                 }
477                 return;
478         }
479
480         if (num && state->hunk_post_context) {
481                 chunk = &state->ret->chunks[num - 1];
482                 chunk->p_next -= state->hunk_post_context;
483                 chunk->t_next -= state->hunk_post_context;
484         }
485         state->ret->num = ++num;
486         state->ret->chunks = xrealloc(state->ret->chunks,
487                                       sizeof(struct chunk) * num);
488         chunk = &state->ret->chunks[num - 1];
489         if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) {
490                 state->ret->num--;
491                 return;
492         }
493
494         /* Line numbers in patch output are one based. */
495         off1--;
496         off2--;
497
498         chunk->same = len2 ? off2 : (off2 + 1);
499
500         chunk->p_next = off1 + (len1 ? len1 : 1);
501         chunk->t_next = chunk->same + len2;
502         state->hunk_in_pre_context = 1;
503         state->hunk_post_context = 0;
504 }
505
506 static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o,
507                                     int context)
508 {
509         struct blame_diff_state state;
510         xpparam_t xpp;
511         xdemitconf_t xecfg;
512         xdemitcb_t ecb;
513
514         xpp.flags = XDF_NEED_MINIMAL;
515         xecfg.ctxlen = context;
516         xecfg.flags = 0;
517         ecb.outf = xdiff_outf;
518         ecb.priv = &state;
519         memset(&state, 0, sizeof(state));
520         state.xm.consume = process_u_diff;
521         state.ret = xmalloc(sizeof(struct patch));
522         state.ret->chunks = NULL;
523         state.ret->num = 0;
524
525         xdl_diff(file_p, file_o, &xpp, &xecfg, &ecb);
526
527         if (state.ret->num) {
528                 struct chunk *chunk;
529                 chunk = &state.ret->chunks[state.ret->num - 1];
530                 chunk->p_next -= state.hunk_post_context;
531                 chunk->t_next -= state.hunk_post_context;
532         }
533         return state.ret;
534 }
535
536 /*
537  * Run diff between two origins and grab the patch output, so that
538  * we can pass blame for lines origin is currently suspected for
539  * to its parent.
540  */
541 static struct patch *get_patch(struct origin *parent, struct origin *origin)
542 {
543         mmfile_t file_p, file_o;
544         struct patch *patch;
545
546         fill_origin_blob(parent, &file_p);
547         fill_origin_blob(origin, &file_o);
548         if (!file_p.ptr || !file_o.ptr)
549                 return NULL;
550         patch = compare_buffer(&file_p, &file_o, 0);
551         num_get_patch++;
552         return patch;
553 }
554
555 static void free_patch(struct patch *p)
556 {
557         free(p->chunks);
558         free(p);
559 }
560
561 /*
562  * Link in a new blame entry to the scoreboard.  Entries that cover the
563  * same line range have been removed from the scoreboard previously.
564  */
565 static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
566 {
567         struct blame_entry *ent, *prev = NULL;
568
569         origin_incref(e->suspect);
570
571         for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
572                 prev = ent;
573
574         /* prev, if not NULL, is the last one that is below e */
575         e->prev = prev;
576         if (prev) {
577                 e->next = prev->next;
578                 prev->next = e;
579         }
580         else {
581                 e->next = sb->ent;
582                 sb->ent = e;
583         }
584         if (e->next)
585                 e->next->prev = e;
586 }
587
588 /*
589  * src typically is on-stack; we want to copy the information in it to
590  * an malloced blame_entry that is already on the linked list of the
591  * scoreboard.  The origin of dst loses a refcnt while the origin of src
592  * gains one.
593  */
594 static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
595 {
596         struct blame_entry *p, *n;
597
598         p = dst->prev;
599         n = dst->next;
600         origin_incref(src->suspect);
601         origin_decref(dst->suspect);
602         memcpy(dst, src, sizeof(*src));
603         dst->prev = p;
604         dst->next = n;
605         dst->score = 0;
606 }
607
608 static const char *nth_line(struct scoreboard *sb, int lno)
609 {
610         return sb->final_buf + sb->lineno[lno];
611 }
612
613 /*
614  * It is known that lines between tlno to same came from parent, and e
615  * has an overlap with that range.  it also is known that parent's
616  * line plno corresponds to e's line tlno.
617  *
618  *                <---- e ----->
619  *                   <------>
620  *                   <------------>
621  *             <------------>
622  *             <------------------>
623  *
624  * Split e into potentially three parts; before this chunk, the chunk
625  * to be blamed for the parent, and after that portion.
626  */
627 static void split_overlap(struct blame_entry *split,
628                           struct blame_entry *e,
629                           int tlno, int plno, int same,
630                           struct origin *parent)
631 {
632         int chunk_end_lno;
633         memset(split, 0, sizeof(struct blame_entry [3]));
634
635         if (e->s_lno < tlno) {
636                 /* there is a pre-chunk part not blamed on parent */
637                 split[0].suspect = origin_incref(e->suspect);
638                 split[0].lno = e->lno;
639                 split[0].s_lno = e->s_lno;
640                 split[0].num_lines = tlno - e->s_lno;
641                 split[1].lno = e->lno + tlno - e->s_lno;
642                 split[1].s_lno = plno;
643         }
644         else {
645                 split[1].lno = e->lno;
646                 split[1].s_lno = plno + (e->s_lno - tlno);
647         }
648
649         if (same < e->s_lno + e->num_lines) {
650                 /* there is a post-chunk part not blamed on parent */
651                 split[2].suspect = origin_incref(e->suspect);
652                 split[2].lno = e->lno + (same - e->s_lno);
653                 split[2].s_lno = e->s_lno + (same - e->s_lno);
654                 split[2].num_lines = e->s_lno + e->num_lines - same;
655                 chunk_end_lno = split[2].lno;
656         }
657         else
658                 chunk_end_lno = e->lno + e->num_lines;
659         split[1].num_lines = chunk_end_lno - split[1].lno;
660
661         /*
662          * if it turns out there is nothing to blame the parent for,
663          * forget about the splitting.  !split[1].suspect signals this.
664          */
665         if (split[1].num_lines < 1)
666                 return;
667         split[1].suspect = origin_incref(parent);
668 }
669
670 /*
671  * split_overlap() divided an existing blame e into up to three parts
672  * in split.  Adjust the linked list of blames in the scoreboard to
673  * reflect the split.
674  */
675 static void split_blame(struct scoreboard *sb,
676                         struct blame_entry *split,
677                         struct blame_entry *e)
678 {
679         struct blame_entry *new_entry;
680
681         if (split[0].suspect && split[2].suspect) {
682                 /* The first part (reuse storage for the existing entry e) */
683                 dup_entry(e, &split[0]);
684
685                 /* The last part -- me */
686                 new_entry = xmalloc(sizeof(*new_entry));
687                 memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
688                 add_blame_entry(sb, new_entry);
689
690                 /* ... and the middle part -- parent */
691                 new_entry = xmalloc(sizeof(*new_entry));
692                 memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
693                 add_blame_entry(sb, new_entry);
694         }
695         else if (!split[0].suspect && !split[2].suspect)
696                 /*
697                  * The parent covers the entire area; reuse storage for
698                  * e and replace it with the parent.
699                  */
700                 dup_entry(e, &split[1]);
701         else if (split[0].suspect) {
702                 /* me and then parent */
703                 dup_entry(e, &split[0]);
704
705                 new_entry = xmalloc(sizeof(*new_entry));
706                 memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
707                 add_blame_entry(sb, new_entry);
708         }
709         else {
710                 /* parent and then me */
711                 dup_entry(e, &split[1]);
712
713                 new_entry = xmalloc(sizeof(*new_entry));
714                 memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
715                 add_blame_entry(sb, new_entry);
716         }
717
718         if (DEBUG) { /* sanity */
719                 struct blame_entry *ent;
720                 int lno = sb->ent->lno, corrupt = 0;
721
722                 for (ent = sb->ent; ent; ent = ent->next) {
723                         if (lno != ent->lno)
724                                 corrupt = 1;
725                         if (ent->s_lno < 0)
726                                 corrupt = 1;
727                         lno += ent->num_lines;
728                 }
729                 if (corrupt) {
730                         lno = sb->ent->lno;
731                         for (ent = sb->ent; ent; ent = ent->next) {
732                                 printf("L %8d l %8d n %8d\n",
733                                        lno, ent->lno, ent->num_lines);
734                                 lno = ent->lno + ent->num_lines;
735                         }
736                         die("oops");
737                 }
738         }
739 }
740
741 /*
742  * After splitting the blame, the origins used by the
743  * on-stack blame_entry should lose one refcnt each.
744  */
745 static void decref_split(struct blame_entry *split)
746 {
747         int i;
748
749         for (i = 0; i < 3; i++)
750                 origin_decref(split[i].suspect);
751 }
752
753 /*
754  * Helper for blame_chunk().  blame_entry e is known to overlap with
755  * the patch hunk; split it and pass blame to the parent.
756  */
757 static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
758                           int tlno, int plno, int same,
759                           struct origin *parent)
760 {
761         struct blame_entry split[3];
762
763         split_overlap(split, e, tlno, plno, same, parent);
764         if (split[1].suspect)
765                 split_blame(sb, split, e);
766         decref_split(split);
767 }
768
769 /*
770  * Find the line number of the last line the target is suspected for.
771  */
772 static int find_last_in_target(struct scoreboard *sb, struct origin *target)
773 {
774         struct blame_entry *e;
775         int last_in_target = -1;
776
777         for (e = sb->ent; e; e = e->next) {
778                 if (e->guilty || cmp_suspect(e->suspect, target))
779                         continue;
780                 if (last_in_target < e->s_lno + e->num_lines)
781                         last_in_target = e->s_lno + e->num_lines;
782         }
783         return last_in_target;
784 }
785
786 /*
787  * Process one hunk from the patch between the current suspect for
788  * blame_entry e and its parent.  Find and split the overlap, and
789  * pass blame to the overlapping part to the parent.
790  */
791 static void blame_chunk(struct scoreboard *sb,
792                         int tlno, int plno, int same,
793                         struct origin *target, struct origin *parent)
794 {
795         struct blame_entry *e;
796
797         for (e = sb->ent; e; e = e->next) {
798                 if (e->guilty || cmp_suspect(e->suspect, target))
799                         continue;
800                 if (same <= e->s_lno)
801                         continue;
802                 if (tlno < e->s_lno + e->num_lines)
803                         blame_overlap(sb, e, tlno, plno, same, parent);
804         }
805 }
806
807 /*
808  * We are looking at the origin 'target' and aiming to pass blame
809  * for the lines it is suspected to its parent.  Run diff to find
810  * which lines came from parent and pass blame for them.
811  */
812 static int pass_blame_to_parent(struct scoreboard *sb,
813                                 struct origin *target,
814                                 struct origin *parent)
815 {
816         int i, last_in_target, plno, tlno;
817         struct patch *patch;
818
819         last_in_target = find_last_in_target(sb, target);
820         if (last_in_target < 0)
821                 return 1; /* nothing remains for this target */
822
823         patch = get_patch(parent, target);
824         plno = tlno = 0;
825         for (i = 0; i < patch->num; i++) {
826                 struct chunk *chunk = &patch->chunks[i];
827
828                 blame_chunk(sb, tlno, plno, chunk->same, target, parent);
829                 plno = chunk->p_next;
830                 tlno = chunk->t_next;
831         }
832         /* The rest (i.e. anything after tlno) are the same as the parent */
833         blame_chunk(sb, tlno, plno, last_in_target, target, parent);
834
835         free_patch(patch);
836         return 0;
837 }
838
839 /*
840  * The lines in blame_entry after splitting blames many times can become
841  * very small and trivial, and at some point it becomes pointless to
842  * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
843  * ordinary C program, and it is not worth to say it was copied from
844  * totally unrelated file in the parent.
845  *
846  * Compute how trivial the lines in the blame_entry are.
847  */
848 static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
849 {
850         unsigned score;
851         const char *cp, *ep;
852
853         if (e->score)
854                 return e->score;
855
856         score = 1;
857         cp = nth_line(sb, e->lno);
858         ep = nth_line(sb, e->lno + e->num_lines);
859         while (cp < ep) {
860                 unsigned ch = *((unsigned char *)cp);
861                 if (isalnum(ch))
862                         score++;
863                 cp++;
864         }
865         e->score = score;
866         return score;
867 }
868
869 /*
870  * best_so_far[] and this[] are both a split of an existing blame_entry
871  * that passes blame to the parent.  Maintain best_so_far the best split
872  * so far, by comparing this and best_so_far and copying this into
873  * bst_so_far as needed.
874  */
875 static void copy_split_if_better(struct scoreboard *sb,
876                                  struct blame_entry *best_so_far,
877                                  struct blame_entry *this)
878 {
879         int i;
880
881         if (!this[1].suspect)
882                 return;
883         if (best_so_far[1].suspect) {
884                 if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
885                         return;
886         }
887
888         for (i = 0; i < 3; i++)
889                 origin_incref(this[i].suspect);
890         decref_split(best_so_far);
891         memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
892 }
893
894 /*
895  * Find the lines from parent that are the same as ent so that
896  * we can pass blames to it.  file_p has the blob contents for
897  * the parent.
898  */
899 static void find_copy_in_blob(struct scoreboard *sb,
900                               struct blame_entry *ent,
901                               struct origin *parent,
902                               struct blame_entry *split,
903                               mmfile_t *file_p)
904 {
905         const char *cp;
906         int cnt;
907         mmfile_t file_o;
908         struct patch *patch;
909         int i, plno, tlno;
910
911         /*
912          * Prepare mmfile that contains only the lines in ent.
913          */
914         cp = nth_line(sb, ent->lno);
915         file_o.ptr = (char*) cp;
916         cnt = ent->num_lines;
917
918         while (cnt && cp < sb->final_buf + sb->final_buf_size) {
919                 if (*cp++ == '\n')
920                         cnt--;
921         }
922         file_o.size = cp - file_o.ptr;
923
924         patch = compare_buffer(file_p, &file_o, 1);
925
926         memset(split, 0, sizeof(struct blame_entry [3]));
927         plno = tlno = 0;
928         for (i = 0; i < patch->num; i++) {
929                 struct chunk *chunk = &patch->chunks[i];
930
931                 /* tlno to chunk->same are the same as ent */
932                 if (ent->num_lines <= tlno)
933                         break;
934                 if (tlno < chunk->same) {
935                         struct blame_entry this[3];
936                         split_overlap(this, ent,
937                                       tlno + ent->s_lno, plno,
938                                       chunk->same + ent->s_lno,
939                                       parent);
940                         copy_split_if_better(sb, split, this);
941                         decref_split(this);
942                 }
943                 plno = chunk->p_next;
944                 tlno = chunk->t_next;
945         }
946         free_patch(patch);
947 }
948
949 /*
950  * See if lines currently target is suspected for can be attributed to
951  * parent.
952  */
953 static int find_move_in_parent(struct scoreboard *sb,
954                                struct origin *target,
955                                struct origin *parent)
956 {
957         int last_in_target, made_progress;
958         struct blame_entry *e, split[3];
959         mmfile_t file_p;
960
961         last_in_target = find_last_in_target(sb, target);
962         if (last_in_target < 0)
963                 return 1; /* nothing remains for this target */
964
965         fill_origin_blob(parent, &file_p);
966         if (!file_p.ptr)
967                 return 0;
968
969         made_progress = 1;
970         while (made_progress) {
971                 made_progress = 0;
972                 for (e = sb->ent; e; e = e->next) {
973                         if (e->guilty || cmp_suspect(e->suspect, target))
974                                 continue;
975                         find_copy_in_blob(sb, e, parent, split, &file_p);
976                         if (split[1].suspect &&
977                             blame_move_score < ent_score(sb, &split[1])) {
978                                 split_blame(sb, split, e);
979                                 made_progress = 1;
980                         }
981                         decref_split(split);
982                 }
983         }
984         return 0;
985 }
986
987 struct blame_list {
988         struct blame_entry *ent;
989         struct blame_entry split[3];
990 };
991
992 /*
993  * Count the number of entries the target is suspected for,
994  * and prepare a list of entry and the best split.
995  */
996 static struct blame_list *setup_blame_list(struct scoreboard *sb,
997                                            struct origin *target,
998                                            int *num_ents_p)
999 {
1000         struct blame_entry *e;
1001         int num_ents, i;
1002         struct blame_list *blame_list = NULL;
1003
1004         for (e = sb->ent, num_ents = 0; e; e = e->next)
1005                 if (!e->guilty && !cmp_suspect(e->suspect, target))
1006                         num_ents++;
1007         if (num_ents) {
1008                 blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1009                 for (e = sb->ent, i = 0; e; e = e->next)
1010                         if (!e->guilty && !cmp_suspect(e->suspect, target))
1011                                 blame_list[i++].ent = e;
1012         }
1013         *num_ents_p = num_ents;
1014         return blame_list;
1015 }
1016
1017 /*
1018  * For lines target is suspected for, see if we can find code movement
1019  * across file boundary from the parent commit.  porigin is the path
1020  * in the parent we already tried.
1021  */
1022 static int find_copy_in_parent(struct scoreboard *sb,
1023                                struct origin *target,
1024                                struct commit *parent,
1025                                struct origin *porigin,
1026                                int opt)
1027 {
1028         struct diff_options diff_opts;
1029         const char *paths[1];
1030         int i, j;
1031         int retval;
1032         struct blame_list *blame_list;
1033         int num_ents;
1034
1035         blame_list = setup_blame_list(sb, target, &num_ents);
1036         if (!blame_list)
1037                 return 1; /* nothing remains for this target */
1038
1039         diff_setup(&diff_opts);
1040         diff_opts.recursive = 1;
1041         diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1042
1043         paths[0] = NULL;
1044         diff_tree_setup_paths(paths, &diff_opts);
1045         if (diff_setup_done(&diff_opts) < 0)
1046                 die("diff-setup");
1047
1048         /* Try "find copies harder" on new path if requested;
1049          * we do not want to use diffcore_rename() actually to
1050          * match things up; find_copies_harder is set only to
1051          * force diff_tree_sha1() to feed all filepairs to diff_queue,
1052          * and this code needs to be after diff_setup_done(), which
1053          * usually makes find-copies-harder imply copy detection.
1054          */
1055         if ((opt & PICKAXE_BLAME_COPY_HARDER) &&
1056             (!porigin || strcmp(target->path, porigin->path)))
1057                 diff_opts.find_copies_harder = 1;
1058
1059         if (is_null_sha1(target->commit->object.sha1))
1060                 do_diff_cache(parent->tree->object.sha1, &diff_opts);
1061         else
1062                 diff_tree_sha1(parent->tree->object.sha1,
1063                                target->commit->tree->object.sha1,
1064                                "", &diff_opts);
1065
1066         if (!diff_opts.find_copies_harder)
1067                 diffcore_std(&diff_opts);
1068
1069         retval = 0;
1070         while (1) {
1071                 int made_progress = 0;
1072
1073                 for (i = 0; i < diff_queued_diff.nr; i++) {
1074                         struct diff_filepair *p = diff_queued_diff.queue[i];
1075                         struct origin *norigin;
1076                         mmfile_t file_p;
1077                         struct blame_entry this[3];
1078
1079                         if (!DIFF_FILE_VALID(p->one))
1080                                 continue; /* does not exist in parent */
1081                         if (porigin && !strcmp(p->one->path, porigin->path))
1082                                 /* find_move already dealt with this path */
1083                                 continue;
1084
1085                         norigin = get_origin(sb, parent, p->one->path);
1086                         hashcpy(norigin->blob_sha1, p->one->sha1);
1087                         fill_origin_blob(norigin, &file_p);
1088                         if (!file_p.ptr)
1089                                 continue;
1090
1091                         for (j = 0; j < num_ents; j++) {
1092                                 find_copy_in_blob(sb, blame_list[j].ent,
1093                                                   norigin, this, &file_p);
1094                                 copy_split_if_better(sb, blame_list[j].split,
1095                                                      this);
1096                                 decref_split(this);
1097                         }
1098                         origin_decref(norigin);
1099                 }
1100
1101                 for (j = 0; j < num_ents; j++) {
1102                         struct blame_entry *split = blame_list[j].split;
1103                         if (split[1].suspect &&
1104                             blame_copy_score < ent_score(sb, &split[1])) {
1105                                 split_blame(sb, split, blame_list[j].ent);
1106                                 made_progress = 1;
1107                         }
1108                         decref_split(split);
1109                 }
1110                 free(blame_list);
1111
1112                 if (!made_progress)
1113                         break;
1114                 blame_list = setup_blame_list(sb, target, &num_ents);
1115                 if (!blame_list) {
1116                         retval = 1;
1117                         break;
1118                 }
1119         }
1120         diff_flush(&diff_opts);
1121
1122         return retval;
1123 }
1124
1125 /*
1126  * The blobs of origin and porigin exactly match, so everything
1127  * origin is suspected for can be blamed on the parent.
1128  */
1129 static void pass_whole_blame(struct scoreboard *sb,
1130                              struct origin *origin, struct origin *porigin)
1131 {
1132         struct blame_entry *e;
1133
1134         if (!porigin->file.ptr && origin->file.ptr) {
1135                 /* Steal its file */
1136                 porigin->file = origin->file;
1137                 origin->file.ptr = NULL;
1138         }
1139         for (e = sb->ent; e; e = e->next) {
1140                 if (cmp_suspect(e->suspect, origin))
1141                         continue;
1142                 origin_incref(porigin);
1143                 origin_decref(e->suspect);
1144                 e->suspect = porigin;
1145         }
1146 }
1147
1148 #define MAXPARENT 16
1149
1150 static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1151 {
1152         int i, pass;
1153         struct commit *commit = origin->commit;
1154         struct commit_list *parent;
1155         struct origin *parent_origin[MAXPARENT], *porigin;
1156
1157         memset(parent_origin, 0, sizeof(parent_origin));
1158
1159         /* The first pass looks for unrenamed path to optimize for
1160          * common cases, then we look for renames in the second pass.
1161          */
1162         for (pass = 0; pass < 2; pass++) {
1163                 struct origin *(*find)(struct scoreboard *,
1164                                        struct commit *, struct origin *);
1165                 find = pass ? find_rename : find_origin;
1166
1167                 for (i = 0, parent = commit->parents;
1168                      i < MAXPARENT && parent;
1169                      parent = parent->next, i++) {
1170                         struct commit *p = parent->item;
1171                         int j, same;
1172
1173                         if (parent_origin[i])
1174                                 continue;
1175                         if (parse_commit(p))
1176                                 continue;
1177                         porigin = find(sb, p, origin);
1178                         if (!porigin)
1179                                 continue;
1180                         if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1181                                 pass_whole_blame(sb, origin, porigin);
1182                                 origin_decref(porigin);
1183                                 goto finish;
1184                         }
1185                         for (j = same = 0; j < i; j++)
1186                                 if (parent_origin[j] &&
1187                                     !hashcmp(parent_origin[j]->blob_sha1,
1188                                              porigin->blob_sha1)) {
1189                                         same = 1;
1190                                         break;
1191                                 }
1192                         if (!same)
1193                                 parent_origin[i] = porigin;
1194                         else
1195                                 origin_decref(porigin);
1196                 }
1197         }
1198
1199         num_commits++;
1200         for (i = 0, parent = commit->parents;
1201              i < MAXPARENT && parent;
1202              parent = parent->next, i++) {
1203                 struct origin *porigin = parent_origin[i];
1204                 if (!porigin)
1205                         continue;
1206                 if (pass_blame_to_parent(sb, origin, porigin))
1207                         goto finish;
1208         }
1209
1210         /*
1211          * Optionally find moves in parents' files.
1212          */
1213         if (opt & PICKAXE_BLAME_MOVE)
1214                 for (i = 0, parent = commit->parents;
1215                      i < MAXPARENT && parent;
1216                      parent = parent->next, i++) {
1217                         struct origin *porigin = parent_origin[i];
1218                         if (!porigin)
1219                                 continue;
1220                         if (find_move_in_parent(sb, origin, porigin))
1221                                 goto finish;
1222                 }
1223
1224         /*
1225          * Optionally find copies from parents' files.
1226          */
1227         if (opt & PICKAXE_BLAME_COPY)
1228                 for (i = 0, parent = commit->parents;
1229                      i < MAXPARENT && parent;
1230                      parent = parent->next, i++) {
1231                         struct origin *porigin = parent_origin[i];
1232                         if (find_copy_in_parent(sb, origin, parent->item,
1233                                                 porigin, opt))
1234                                 goto finish;
1235                 }
1236
1237  finish:
1238         for (i = 0; i < MAXPARENT; i++)
1239                 origin_decref(parent_origin[i]);
1240 }
1241
1242 /*
1243  * Information on commits, used for output.
1244  */
1245 struct commit_info
1246 {
1247         const char *author;
1248         const char *author_mail;
1249         unsigned long author_time;
1250         const char *author_tz;
1251
1252         /* filled only when asked for details */
1253         const char *committer;
1254         const char *committer_mail;
1255         unsigned long committer_time;
1256         const char *committer_tz;
1257
1258         const char *summary;
1259 };
1260
1261 /*
1262  * Parse author/committer line in the commit object buffer
1263  */
1264 static void get_ac_line(const char *inbuf, const char *what,
1265                         int bufsz, char *person, const char **mail,
1266                         unsigned long *time, const char **tz)
1267 {
1268         int len;
1269         char *tmp, *endp;
1270
1271         tmp = strstr(inbuf, what);
1272         if (!tmp)
1273                 goto error_out;
1274         tmp += strlen(what);
1275         endp = strchr(tmp, '\n');
1276         if (!endp)
1277                 len = strlen(tmp);
1278         else
1279                 len = endp - tmp;
1280         if (bufsz <= len) {
1281         error_out:
1282                 /* Ugh */
1283                 *mail = *tz = "(unknown)";
1284                 *time = 0;
1285                 return;
1286         }
1287         memcpy(person, tmp, len);
1288
1289         tmp = person;
1290         tmp += len;
1291         *tmp = 0;
1292         while (*tmp != ' ')
1293                 tmp--;
1294         *tz = tmp+1;
1295
1296         *tmp = 0;
1297         while (*tmp != ' ')
1298                 tmp--;
1299         *time = strtoul(tmp, NULL, 10);
1300
1301         *tmp = 0;
1302         while (*tmp != ' ')
1303                 tmp--;
1304         *mail = tmp + 1;
1305         *tmp = 0;
1306 }
1307
1308 static void get_commit_info(struct commit *commit,
1309                             struct commit_info *ret,
1310                             int detailed)
1311 {
1312         int len;
1313         char *tmp, *endp;
1314         static char author_buf[1024];
1315         static char committer_buf[1024];
1316         static char summary_buf[1024];
1317
1318         /*
1319          * We've operated without save_commit_buffer, so
1320          * we now need to populate them for output.
1321          */
1322         if (!commit->buffer) {
1323                 enum object_type type;
1324                 unsigned long size;
1325                 commit->buffer =
1326                         read_sha1_file(commit->object.sha1, &type, &size);
1327         }
1328         ret->author = author_buf;
1329         get_ac_line(commit->buffer, "\nauthor ",
1330                     sizeof(author_buf), author_buf, &ret->author_mail,
1331                     &ret->author_time, &ret->author_tz);
1332
1333         if (!detailed)
1334                 return;
1335
1336         ret->committer = committer_buf;
1337         get_ac_line(commit->buffer, "\ncommitter ",
1338                     sizeof(committer_buf), committer_buf, &ret->committer_mail,
1339                     &ret->committer_time, &ret->committer_tz);
1340
1341         ret->summary = summary_buf;
1342         tmp = strstr(commit->buffer, "\n\n");
1343         if (!tmp) {
1344         error_out:
1345                 sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1346                 return;
1347         }
1348         tmp += 2;
1349         endp = strchr(tmp, '\n');
1350         if (!endp)
1351                 endp = tmp + strlen(tmp);
1352         len = endp - tmp;
1353         if (len >= sizeof(summary_buf) || len == 0)
1354                 goto error_out;
1355         memcpy(summary_buf, tmp, len);
1356         summary_buf[len] = 0;
1357 }
1358
1359 /*
1360  * To allow LF and other nonportable characters in pathnames,
1361  * they are c-style quoted as needed.
1362  */
1363 static void write_filename_info(const char *path)
1364 {
1365         printf("filename ");
1366         write_name_quoted(NULL, 0, path, 1, stdout);
1367         putchar('\n');
1368 }
1369
1370 /*
1371  * The blame_entry is found to be guilty for the range.  Mark it
1372  * as such, and show it in incremental output.
1373  */
1374 static void found_guilty_entry(struct blame_entry *ent)
1375 {
1376         if (ent->guilty)
1377                 return;
1378         ent->guilty = 1;
1379         if (incremental) {
1380                 struct origin *suspect = ent->suspect;
1381
1382                 printf("%s %d %d %d\n",
1383                        sha1_to_hex(suspect->commit->object.sha1),
1384                        ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1385                 if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1386                         struct commit_info ci;
1387                         suspect->commit->object.flags |= METAINFO_SHOWN;
1388                         get_commit_info(suspect->commit, &ci, 1);
1389                         printf("author %s\n", ci.author);
1390                         printf("author-mail %s\n", ci.author_mail);
1391                         printf("author-time %lu\n", ci.author_time);
1392                         printf("author-tz %s\n", ci.author_tz);
1393                         printf("committer %s\n", ci.committer);
1394                         printf("committer-mail %s\n", ci.committer_mail);
1395                         printf("committer-time %lu\n", ci.committer_time);
1396                         printf("committer-tz %s\n", ci.committer_tz);
1397                         printf("summary %s\n", ci.summary);
1398                         if (suspect->commit->object.flags & UNINTERESTING)
1399                                 printf("boundary\n");
1400                 }
1401                 write_filename_info(suspect->path);
1402         }
1403 }
1404
1405 /*
1406  * The main loop -- while the scoreboard has lines whose true origin
1407  * is still unknown, pick one blame_entry, and allow its current
1408  * suspect to pass blames to its parents.
1409  */
1410 static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
1411 {
1412         while (1) {
1413                 struct blame_entry *ent;
1414                 struct commit *commit;
1415                 struct origin *suspect = NULL;
1416
1417                 /* find one suspect to break down */
1418                 for (ent = sb->ent; !suspect && ent; ent = ent->next)
1419                         if (!ent->guilty)
1420                                 suspect = ent->suspect;
1421                 if (!suspect)
1422                         return; /* all done */
1423
1424                 /*
1425                  * We will use this suspect later in the loop,
1426                  * so hold onto it in the meantime.
1427                  */
1428                 origin_incref(suspect);
1429                 commit = suspect->commit;
1430                 if (!commit->object.parsed)
1431                         parse_commit(commit);
1432                 if (!(commit->object.flags & UNINTERESTING) &&
1433                     !(revs->max_age != -1 && commit->date < revs->max_age))
1434                         pass_blame(sb, suspect, opt);
1435                 else {
1436                         commit->object.flags |= UNINTERESTING;
1437                         if (commit->object.parsed)
1438                                 mark_parents_uninteresting(commit);
1439                 }
1440                 /* treat root commit as boundary */
1441                 if (!commit->parents && !show_root)
1442                         commit->object.flags |= UNINTERESTING;
1443
1444                 /* Take responsibility for the remaining entries */
1445                 for (ent = sb->ent; ent; ent = ent->next)
1446                         if (!cmp_suspect(ent->suspect, suspect))
1447                                 found_guilty_entry(ent);
1448                 origin_decref(suspect);
1449
1450                 if (DEBUG) /* sanity */
1451                         sanity_check_refcnt(sb);
1452         }
1453 }
1454
1455 static const char *format_time(unsigned long time, const char *tz_str,
1456                                int show_raw_time)
1457 {
1458         static char time_buf[128];
1459         time_t t = time;
1460         int minutes, tz;
1461         struct tm *tm;
1462
1463         if (show_raw_time) {
1464                 sprintf(time_buf, "%lu %s", time, tz_str);
1465                 return time_buf;
1466         }
1467
1468         tz = atoi(tz_str);
1469         minutes = tz < 0 ? -tz : tz;
1470         minutes = (minutes / 100)*60 + (minutes % 100);
1471         minutes = tz < 0 ? -minutes : minutes;
1472         t = time + minutes * 60;
1473         tm = gmtime(&t);
1474
1475         strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm);
1476         strcat(time_buf, tz_str);
1477         return time_buf;
1478 }
1479
1480 #define OUTPUT_ANNOTATE_COMPAT  001
1481 #define OUTPUT_LONG_OBJECT_NAME 002
1482 #define OUTPUT_RAW_TIMESTAMP    004
1483 #define OUTPUT_PORCELAIN        010
1484 #define OUTPUT_SHOW_NAME        020
1485 #define OUTPUT_SHOW_NUMBER      040
1486 #define OUTPUT_SHOW_SCORE      0100
1487
1488 static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
1489 {
1490         int cnt;
1491         const char *cp;
1492         struct origin *suspect = ent->suspect;
1493         char hex[41];
1494
1495         strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1496         printf("%s%c%d %d %d\n",
1497                hex,
1498                ent->guilty ? ' ' : '*', // purely for debugging
1499                ent->s_lno + 1,
1500                ent->lno + 1,
1501                ent->num_lines);
1502         if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1503                 struct commit_info ci;
1504                 suspect->commit->object.flags |= METAINFO_SHOWN;
1505                 get_commit_info(suspect->commit, &ci, 1);
1506                 printf("author %s\n", ci.author);
1507                 printf("author-mail %s\n", ci.author_mail);
1508                 printf("author-time %lu\n", ci.author_time);
1509                 printf("author-tz %s\n", ci.author_tz);
1510                 printf("committer %s\n", ci.committer);
1511                 printf("committer-mail %s\n", ci.committer_mail);
1512                 printf("committer-time %lu\n", ci.committer_time);
1513                 printf("committer-tz %s\n", ci.committer_tz);
1514                 write_filename_info(suspect->path);
1515                 printf("summary %s\n", ci.summary);
1516                 if (suspect->commit->object.flags & UNINTERESTING)
1517                         printf("boundary\n");
1518         }
1519         else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH)
1520                 write_filename_info(suspect->path);
1521
1522         cp = nth_line(sb, ent->lno);
1523         for (cnt = 0; cnt < ent->num_lines; cnt++) {
1524                 char ch;
1525                 if (cnt)
1526                         printf("%s %d %d\n", hex,
1527                                ent->s_lno + 1 + cnt,
1528                                ent->lno + 1 + cnt);
1529                 putchar('\t');
1530                 do {
1531                         ch = *cp++;
1532                         putchar(ch);
1533                 } while (ch != '\n' &&
1534                          cp < sb->final_buf + sb->final_buf_size);
1535         }
1536 }
1537
1538 static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1539 {
1540         int cnt;
1541         const char *cp;
1542         struct origin *suspect = ent->suspect;
1543         struct commit_info ci;
1544         char hex[41];
1545         int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1546
1547         get_commit_info(suspect->commit, &ci, 1);
1548         strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1549
1550         cp = nth_line(sb, ent->lno);
1551         for (cnt = 0; cnt < ent->num_lines; cnt++) {
1552                 char ch;
1553                 int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
1554
1555                 if (suspect->commit->object.flags & UNINTERESTING) {
1556                         if (blank_boundary)
1557                                 memset(hex, ' ', length);
1558                         else if (!cmd_is_annotate) {
1559                                 length--;
1560                                 putchar('^');
1561                         }
1562                 }
1563
1564                 printf("%.*s", length, hex);
1565                 if (opt & OUTPUT_ANNOTATE_COMPAT)
1566                         printf("\t(%10s\t%10s\t%d)", ci.author,
1567                                format_time(ci.author_time, ci.author_tz,
1568                                            show_raw_time),
1569                                ent->lno + 1 + cnt);
1570                 else {
1571                         if (opt & OUTPUT_SHOW_SCORE)
1572                                 printf(" %*d %02d",
1573                                        max_score_digits, ent->score,
1574                                        ent->suspect->refcnt);
1575                         if (opt & OUTPUT_SHOW_NAME)
1576                                 printf(" %-*.*s", longest_file, longest_file,
1577                                        suspect->path);
1578                         if (opt & OUTPUT_SHOW_NUMBER)
1579                                 printf(" %*d", max_orig_digits,
1580                                        ent->s_lno + 1 + cnt);
1581                         printf(" (%-*.*s %10s %*d) ",
1582                                longest_author, longest_author, ci.author,
1583                                format_time(ci.author_time, ci.author_tz,
1584                                            show_raw_time),
1585                                max_digits, ent->lno + 1 + cnt);
1586                 }
1587                 do {
1588                         ch = *cp++;
1589                         putchar(ch);
1590                 } while (ch != '\n' &&
1591                          cp < sb->final_buf + sb->final_buf_size);
1592         }
1593 }
1594
1595 static void output(struct scoreboard *sb, int option)
1596 {
1597         struct blame_entry *ent;
1598
1599         if (option & OUTPUT_PORCELAIN) {
1600                 for (ent = sb->ent; ent; ent = ent->next) {
1601                         struct blame_entry *oth;
1602                         struct origin *suspect = ent->suspect;
1603                         struct commit *commit = suspect->commit;
1604                         if (commit->object.flags & MORE_THAN_ONE_PATH)
1605                                 continue;
1606                         for (oth = ent->next; oth; oth = oth->next) {
1607                                 if ((oth->suspect->commit != commit) ||
1608                                     !strcmp(oth->suspect->path, suspect->path))
1609                                         continue;
1610                                 commit->object.flags |= MORE_THAN_ONE_PATH;
1611                                 break;
1612                         }
1613                 }
1614         }
1615
1616         for (ent = sb->ent; ent; ent = ent->next) {
1617                 if (option & OUTPUT_PORCELAIN)
1618                         emit_porcelain(sb, ent);
1619                 else {
1620                         emit_other(sb, ent, option);
1621                 }
1622         }
1623 }
1624
1625 /*
1626  * To allow quick access to the contents of nth line in the
1627  * final image, prepare an index in the scoreboard.
1628  */
1629 static int prepare_lines(struct scoreboard *sb)
1630 {
1631         const char *buf = sb->final_buf;
1632         unsigned long len = sb->final_buf_size;
1633         int num = 0, incomplete = 0, bol = 1;
1634
1635         if (len && buf[len-1] != '\n')
1636                 incomplete++; /* incomplete line at the end */
1637         while (len--) {
1638                 if (bol) {
1639                         sb->lineno = xrealloc(sb->lineno,
1640                                               sizeof(int* ) * (num + 1));
1641                         sb->lineno[num] = buf - sb->final_buf;
1642                         bol = 0;
1643                 }
1644                 if (*buf++ == '\n') {
1645                         num++;
1646                         bol = 1;
1647                 }
1648         }
1649         sb->lineno = xrealloc(sb->lineno,
1650                               sizeof(int* ) * (num + incomplete + 1));
1651         sb->lineno[num + incomplete] = buf - sb->final_buf;
1652         sb->num_lines = num + incomplete;
1653         return sb->num_lines;
1654 }
1655
1656 /*
1657  * Add phony grafts for use with -S; this is primarily to
1658  * support git-cvsserver that wants to give a linear history
1659  * to its clients.
1660  */
1661 static int read_ancestry(const char *graft_file)
1662 {
1663         FILE *fp = fopen(graft_file, "r");
1664         char buf[1024];
1665         if (!fp)
1666                 return -1;
1667         while (fgets(buf, sizeof(buf), fp)) {
1668                 /* The format is just "Commit Parent1 Parent2 ...\n" */
1669                 int len = strlen(buf);
1670                 struct commit_graft *graft = read_graft_line(buf, len);
1671                 if (graft)
1672                         register_commit_graft(graft, 0);
1673         }
1674         fclose(fp);
1675         return 0;
1676 }
1677
1678 /*
1679  * How many columns do we need to show line numbers in decimal?
1680  */
1681 static int lineno_width(int lines)
1682 {
1683         int i, width;
1684
1685         for (width = 1, i = 10; i <= lines + 1; width++)
1686                 i *= 10;
1687         return width;
1688 }
1689
1690 /*
1691  * How many columns do we need to show line numbers, authors,
1692  * and filenames?
1693  */
1694 static void find_alignment(struct scoreboard *sb, int *option)
1695 {
1696         int longest_src_lines = 0;
1697         int longest_dst_lines = 0;
1698         unsigned largest_score = 0;
1699         struct blame_entry *e;
1700
1701         for (e = sb->ent; e; e = e->next) {
1702                 struct origin *suspect = e->suspect;
1703                 struct commit_info ci;
1704                 int num;
1705
1706                 if (strcmp(suspect->path, sb->path))
1707                         *option |= OUTPUT_SHOW_NAME;
1708                 num = strlen(suspect->path);
1709                 if (longest_file < num)
1710                         longest_file = num;
1711                 if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1712                         suspect->commit->object.flags |= METAINFO_SHOWN;
1713                         get_commit_info(suspect->commit, &ci, 1);
1714                         num = strlen(ci.author);
1715                         if (longest_author < num)
1716                                 longest_author = num;
1717                 }
1718                 num = e->s_lno + e->num_lines;
1719                 if (longest_src_lines < num)
1720                         longest_src_lines = num;
1721                 num = e->lno + e->num_lines;
1722                 if (longest_dst_lines < num)
1723                         longest_dst_lines = num;
1724                 if (largest_score < ent_score(sb, e))
1725                         largest_score = ent_score(sb, e);
1726         }
1727         max_orig_digits = lineno_width(longest_src_lines);
1728         max_digits = lineno_width(longest_dst_lines);
1729         max_score_digits = lineno_width(largest_score);
1730 }
1731
1732 /*
1733  * For debugging -- origin is refcounted, and this asserts that
1734  * we do not underflow.
1735  */
1736 static void sanity_check_refcnt(struct scoreboard *sb)
1737 {
1738         int baa = 0;
1739         struct blame_entry *ent;
1740
1741         for (ent = sb->ent; ent; ent = ent->next) {
1742                 /* Nobody should have zero or negative refcnt */
1743                 if (ent->suspect->refcnt <= 0) {
1744                         fprintf(stderr, "%s in %s has negative refcnt %d\n",
1745                                 ent->suspect->path,
1746                                 sha1_to_hex(ent->suspect->commit->object.sha1),
1747                                 ent->suspect->refcnt);
1748                         baa = 1;
1749                 }
1750         }
1751         for (ent = sb->ent; ent; ent = ent->next) {
1752                 /* Mark the ones that haven't been checked */
1753                 if (0 < ent->suspect->refcnt)
1754                         ent->suspect->refcnt = -ent->suspect->refcnt;
1755         }
1756         for (ent = sb->ent; ent; ent = ent->next) {
1757                 /*
1758                  * ... then pick each and see if they have the the
1759                  * correct refcnt.
1760                  */
1761                 int found;
1762                 struct blame_entry *e;
1763                 struct origin *suspect = ent->suspect;
1764
1765                 if (0 < suspect->refcnt)
1766                         continue;
1767                 suspect->refcnt = -suspect->refcnt; /* Unmark */
1768                 for (found = 0, e = sb->ent; e; e = e->next) {
1769                         if (e->suspect != suspect)
1770                                 continue;
1771                         found++;
1772                 }
1773                 if (suspect->refcnt != found) {
1774                         fprintf(stderr, "%s in %s has refcnt %d, not %d\n",
1775                                 ent->suspect->path,
1776                                 sha1_to_hex(ent->suspect->commit->object.sha1),
1777                                 ent->suspect->refcnt, found);
1778                         baa = 2;
1779                 }
1780         }
1781         if (baa) {
1782                 int opt = 0160;
1783                 find_alignment(sb, &opt);
1784                 output(sb, opt);
1785                 die("Baa %d!", baa);
1786         }
1787 }
1788
1789 /*
1790  * Used for the command line parsing; check if the path exists
1791  * in the working tree.
1792  */
1793 static int has_path_in_work_tree(const char *path)
1794 {
1795         struct stat st;
1796         return !lstat(path, &st);
1797 }
1798
1799 static unsigned parse_score(const char *arg)
1800 {
1801         char *end;
1802         unsigned long score = strtoul(arg, &end, 10);
1803         if (*end)
1804                 return 0;
1805         return score;
1806 }
1807
1808 static const char *add_prefix(const char *prefix, const char *path)
1809 {
1810         if (!prefix || !prefix[0])
1811                 return path;
1812         return prefix_path(prefix, strlen(prefix), path);
1813 }
1814
1815 /*
1816  * Parsing of (comma separated) one item in the -L option
1817  */
1818 static const char *parse_loc(const char *spec,
1819                              struct scoreboard *sb, long lno,
1820                              long begin, long *ret)
1821 {
1822         char *term;
1823         const char *line;
1824         long num;
1825         int reg_error;
1826         regex_t regexp;
1827         regmatch_t match[1];
1828
1829         /* Allow "-L <something>,+20" to mean starting at <something>
1830          * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1831          * <something>.
1832          */
1833         if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1834                 num = strtol(spec + 1, &term, 10);
1835                 if (term != spec + 1) {
1836                         if (spec[0] == '-')
1837                                 num = 0 - num;
1838                         if (0 < num)
1839                                 *ret = begin + num - 2;
1840                         else if (!num)
1841                                 *ret = begin;
1842                         else
1843                                 *ret = begin + num;
1844                         return term;
1845                 }
1846                 return spec;
1847         }
1848         num = strtol(spec, &term, 10);
1849         if (term != spec) {
1850                 *ret = num;
1851                 return term;
1852         }
1853         if (spec[0] != '/')
1854                 return spec;
1855
1856         /* it could be a regexp of form /.../ */
1857         for (term = (char*) spec + 1; *term && *term != '/'; term++) {
1858                 if (*term == '\\')
1859                         term++;
1860         }
1861         if (*term != '/')
1862                 return spec;
1863
1864         /* try [spec+1 .. term-1] as regexp */
1865         *term = 0;
1866         begin--; /* input is in human terms */
1867         line = nth_line(sb, begin);
1868
1869         if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
1870             !(reg_error = regexec(&regexp, line, 1, match, 0))) {
1871                 const char *cp = line + match[0].rm_so;
1872                 const char *nline;
1873
1874                 while (begin++ < lno) {
1875                         nline = nth_line(sb, begin);
1876                         if (line <= cp && cp < nline)
1877                                 break;
1878                         line = nline;
1879                 }
1880                 *ret = begin;
1881                 regfree(&regexp);
1882                 *term++ = '/';
1883                 return term;
1884         }
1885         else {
1886                 char errbuf[1024];
1887                 regerror(reg_error, &regexp, errbuf, 1024);
1888                 die("-L parameter '%s': %s", spec + 1, errbuf);
1889         }
1890 }
1891
1892 /*
1893  * Parsing of -L option
1894  */
1895 static void prepare_blame_range(struct scoreboard *sb,
1896                                 const char *bottomtop,
1897                                 long lno,
1898                                 long *bottom, long *top)
1899 {
1900         const char *term;
1901
1902         term = parse_loc(bottomtop, sb, lno, 1, bottom);
1903         if (*term == ',') {
1904                 term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
1905                 if (*term)
1906                         usage(blame_usage);
1907         }
1908         if (*term)
1909                 usage(blame_usage);
1910 }
1911
1912 static int git_blame_config(const char *var, const char *value)
1913 {
1914         if (!strcmp(var, "blame.showroot")) {
1915                 show_root = git_config_bool(var, value);
1916                 return 0;
1917         }
1918         if (!strcmp(var, "blame.blankboundary")) {
1919                 blank_boundary = git_config_bool(var, value);
1920                 return 0;
1921         }
1922         return git_default_config(var, value);
1923 }
1924
1925 static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
1926 {
1927         struct commit *commit;
1928         struct origin *origin;
1929         unsigned char head_sha1[20];
1930         char *buf;
1931         const char *ident;
1932         int fd;
1933         time_t now;
1934         unsigned long fin_size;
1935         int size, len;
1936         struct cache_entry *ce;
1937         unsigned mode;
1938
1939         if (get_sha1("HEAD", head_sha1))
1940                 die("No such ref: HEAD");
1941
1942         time(&now);
1943         commit = xcalloc(1, sizeof(*commit));
1944         commit->parents = xcalloc(1, sizeof(*commit->parents));
1945         commit->parents->item = lookup_commit_reference(head_sha1);
1946         commit->object.parsed = 1;
1947         commit->date = now;
1948         commit->object.type = OBJ_COMMIT;
1949
1950         origin = make_origin(commit, path);
1951
1952         if (!contents_from || strcmp("-", contents_from)) {
1953                 struct stat st;
1954                 const char *read_from;
1955
1956                 if (contents_from) {
1957                         if (stat(contents_from, &st) < 0)
1958                                 die("Cannot stat %s", contents_from);
1959                         read_from = contents_from;
1960                 }
1961                 else {
1962                         if (lstat(path, &st) < 0)
1963                                 die("Cannot lstat %s", path);
1964                         read_from = path;
1965                 }
1966                 fin_size = xsize_t(st.st_size);
1967                 buf = xmalloc(fin_size+1);
1968                 mode = canon_mode(st.st_mode);
1969                 switch (st.st_mode & S_IFMT) {
1970                 case S_IFREG:
1971                         fd = open(read_from, O_RDONLY);
1972                         if (fd < 0)
1973                                 die("cannot open %s", read_from);
1974                         if (read_in_full(fd, buf, fin_size) != fin_size)
1975                                 die("cannot read %s", read_from);
1976                         break;
1977                 case S_IFLNK:
1978                         if (readlink(read_from, buf, fin_size+1) != fin_size)
1979                                 die("cannot readlink %s", read_from);
1980                         break;
1981                 default:
1982                         die("unsupported file type %s", read_from);
1983                 }
1984         }
1985         else {
1986                 /* Reading from stdin */
1987                 contents_from = "standard input";
1988                 buf = NULL;
1989                 fin_size = 0;
1990                 mode = 0;
1991                 while (1) {
1992                         ssize_t cnt = 8192;
1993                         buf = xrealloc(buf, fin_size + cnt);
1994                         cnt = xread(0, buf + fin_size, cnt);
1995                         if (cnt < 0)
1996                                 die("read error %s from stdin",
1997                                     strerror(errno));
1998                         if (!cnt)
1999                                 break;
2000                         fin_size += cnt;
2001                 }
2002                 buf = xrealloc(buf, fin_size + 1);
2003         }
2004         buf[fin_size] = 0;
2005         origin->file.ptr = buf;
2006         origin->file.size = fin_size;
2007         pretend_sha1_file(buf, fin_size, OBJ_BLOB, origin->blob_sha1);
2008         commit->util = origin;
2009
2010         /*
2011          * Read the current index, replace the path entry with
2012          * origin->blob_sha1 without mucking with its mode or type
2013          * bits; we are not going to write this index out -- we just
2014          * want to run "diff-index --cached".
2015          */
2016         discard_cache();
2017         read_cache();
2018
2019         len = strlen(path);
2020         if (!mode) {
2021                 int pos = cache_name_pos(path, len);
2022                 if (0 <= pos)
2023                         mode = ntohl(active_cache[pos]->ce_mode);
2024                 else
2025                         /* Let's not bother reading from HEAD tree */
2026                         mode = S_IFREG | 0644;
2027         }
2028         size = cache_entry_size(len);
2029         ce = xcalloc(1, size);
2030         hashcpy(ce->sha1, origin->blob_sha1);
2031         memcpy(ce->name, path, len);
2032         ce->ce_flags = create_ce_flags(len, 0);
2033         ce->ce_mode = create_ce_mode(mode);
2034         add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2035
2036         /*
2037          * We are not going to write this out, so this does not matter
2038          * right now, but someday we might optimize diff-index --cached
2039          * with cache-tree information.
2040          */
2041         cache_tree_invalidate_path(active_cache_tree, path);
2042
2043         commit->buffer = xmalloc(400);
2044         ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2045         sprintf(commit->buffer,
2046                 "tree 0000000000000000000000000000000000000000\n"
2047                 "parent %s\n"
2048                 "author %s\n"
2049                 "committer %s\n\n"
2050                 "Version of %s from %s\n",
2051                 sha1_to_hex(head_sha1),
2052                 ident, ident, path, contents_from ? contents_from : path);
2053         return commit;
2054 }
2055
2056 int cmd_blame(int argc, const char **argv, const char *prefix)
2057 {
2058         struct rev_info revs;
2059         const char *path;
2060         struct scoreboard sb;
2061         struct origin *o;
2062         struct blame_entry *ent;
2063         int i, seen_dashdash, unk, opt;
2064         long bottom, top, lno;
2065         int output_option = 0;
2066         int show_stats = 0;
2067         const char *revs_file = NULL;
2068         const char *final_commit_name = NULL;
2069         enum object_type type;
2070         const char *bottomtop = NULL;
2071         const char *contents_from = NULL;
2072
2073         cmd_is_annotate = !strcmp(argv[0], "annotate");
2074
2075         git_config(git_blame_config);
2076         save_commit_buffer = 0;
2077
2078         opt = 0;
2079         seen_dashdash = 0;
2080         for (unk = i = 1; i < argc; i++) {
2081                 const char *arg = argv[i];
2082                 if (*arg != '-')
2083                         break;
2084                 else if (!strcmp("-b", arg))
2085                         blank_boundary = 1;
2086                 else if (!strcmp("--root", arg))
2087                         show_root = 1;
2088                 else if (!strcmp(arg, "--show-stats"))
2089                         show_stats = 1;
2090                 else if (!strcmp("-c", arg))
2091                         output_option |= OUTPUT_ANNOTATE_COMPAT;
2092                 else if (!strcmp("-t", arg))
2093                         output_option |= OUTPUT_RAW_TIMESTAMP;
2094                 else if (!strcmp("-l", arg))
2095                         output_option |= OUTPUT_LONG_OBJECT_NAME;
2096                 else if (!strcmp("-S", arg) && ++i < argc)
2097                         revs_file = argv[i];
2098                 else if (!prefixcmp(arg, "-M")) {
2099                         opt |= PICKAXE_BLAME_MOVE;
2100                         blame_move_score = parse_score(arg+2);
2101                 }
2102                 else if (!prefixcmp(arg, "-C")) {
2103                         if (opt & PICKAXE_BLAME_COPY)
2104                                 opt |= PICKAXE_BLAME_COPY_HARDER;
2105                         opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2106                         blame_copy_score = parse_score(arg+2);
2107                 }
2108                 else if (!prefixcmp(arg, "-L")) {
2109                         if (!arg[2]) {
2110                                 if (++i >= argc)
2111                                         usage(blame_usage);
2112                                 arg = argv[i];
2113                         }
2114                         else
2115                                 arg += 2;
2116                         if (bottomtop)
2117                                 die("More than one '-L n,m' option given");
2118                         bottomtop = arg;
2119                 }
2120                 else if (!strcmp("--contents", arg)) {
2121                         if (++i >= argc)
2122                                 usage(blame_usage);
2123                         contents_from = argv[i];
2124                 }
2125                 else if (!strcmp("--incremental", arg))
2126                         incremental = 1;
2127                 else if (!strcmp("--score-debug", arg))
2128                         output_option |= OUTPUT_SHOW_SCORE;
2129                 else if (!strcmp("-f", arg) ||
2130                          !strcmp("--show-name", arg))
2131                         output_option |= OUTPUT_SHOW_NAME;
2132                 else if (!strcmp("-n", arg) ||
2133                          !strcmp("--show-number", arg))
2134                         output_option |= OUTPUT_SHOW_NUMBER;
2135                 else if (!strcmp("-p", arg) ||
2136                          !strcmp("--porcelain", arg))
2137                         output_option |= OUTPUT_PORCELAIN;
2138                 else if (!strcmp("--", arg)) {
2139                         seen_dashdash = 1;
2140                         i++;
2141                         break;
2142                 }
2143                 else
2144                         argv[unk++] = arg;
2145         }
2146
2147         if (!incremental)
2148                 setup_pager();
2149
2150         if (!blame_move_score)
2151                 blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2152         if (!blame_copy_score)
2153                 blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2154
2155         /*
2156          * We have collected options unknown to us in argv[1..unk]
2157          * which are to be passed to revision machinery if we are
2158          * going to do the "bottom" processing.
2159          *
2160          * The remaining are:
2161          *
2162          * (1) if seen_dashdash, its either
2163          *     "-options -- <path>" or
2164          *     "-options -- <path> <rev>".
2165          *     but the latter is allowed only if there is no
2166          *     options that we passed to revision machinery.
2167          *
2168          * (2) otherwise, we may have "--" somewhere later and
2169          *     might be looking at the first one of multiple 'rev'
2170          *     parameters (e.g. " master ^next ^maint -- path").
2171          *     See if there is a dashdash first, and give the
2172          *     arguments before that to revision machinery.
2173          *     After that there must be one 'path'.
2174          *
2175          * (3) otherwise, its one of the three:
2176          *     "-options <path> <rev>"
2177          *     "-options <rev> <path>"
2178          *     "-options <path>"
2179          *     but again the first one is allowed only if
2180          *     there is no options that we passed to revision
2181          *     machinery.
2182          */
2183
2184         if (seen_dashdash) {
2185                 /* (1) */
2186                 if (argc <= i)
2187                         usage(blame_usage);
2188                 path = add_prefix(prefix, argv[i]);
2189                 if (i + 1 == argc - 1) {
2190                         if (unk != 1)
2191                                 usage(blame_usage);
2192                         argv[unk++] = argv[i + 1];
2193                 }
2194                 else if (i + 1 != argc)
2195                         /* garbage at end */
2196                         usage(blame_usage);
2197         }
2198         else {
2199                 int j;
2200                 for (j = i; !seen_dashdash && j < argc; j++)
2201                         if (!strcmp(argv[j], "--"))
2202                                 seen_dashdash = j;
2203                 if (seen_dashdash) {
2204                         /* (2) */
2205                         if (seen_dashdash + 1 != argc - 1)
2206                                 usage(blame_usage);
2207                         path = add_prefix(prefix, argv[seen_dashdash + 1]);
2208                         for (j = i; j < seen_dashdash; j++)
2209                                 argv[unk++] = argv[j];
2210                 }
2211                 else {
2212                         /* (3) */
2213                         if (argc <= i)
2214                                 usage(blame_usage);
2215                         path = add_prefix(prefix, argv[i]);
2216                         if (i + 1 == argc - 1) {
2217                                 final_commit_name = argv[i + 1];
2218
2219                                 /* if (unk == 1) we could be getting
2220                                  * old-style
2221                                  */
2222                                 if (unk == 1 && !has_path_in_work_tree(path)) {
2223                                         path = add_prefix(prefix, argv[i + 1]);
2224                                         final_commit_name = argv[i];
2225                                 }
2226                         }
2227                         else if (i != argc - 1)
2228                                 usage(blame_usage); /* garbage at end */
2229
2230                         if (!has_path_in_work_tree(path))
2231                                 die("cannot stat path %s: %s",
2232                                     path, strerror(errno));
2233                 }
2234         }
2235
2236         if (final_commit_name)
2237                 argv[unk++] = final_commit_name;
2238
2239         /*
2240          * Now we got rev and path.  We do not want the path pruning
2241          * but we may want "bottom" processing.
2242          */
2243         argv[unk++] = "--"; /* terminate the rev name */
2244         argv[unk] = NULL;
2245
2246         init_revisions(&revs, NULL);
2247         setup_revisions(unk, argv, &revs, NULL);
2248         memset(&sb, 0, sizeof(sb));
2249
2250         /*
2251          * There must be one and only one positive commit in the
2252          * revs->pending array.
2253          */
2254         for (i = 0; i < revs.pending.nr; i++) {
2255                 struct object *obj = revs.pending.objects[i].item;
2256                 if (obj->flags & UNINTERESTING)
2257                         continue;
2258                 while (obj->type == OBJ_TAG)
2259                         obj = deref_tag(obj, NULL, 0);
2260                 if (obj->type != OBJ_COMMIT)
2261                         die("Non commit %s?",
2262                             revs.pending.objects[i].name);
2263                 if (sb.final)
2264                         die("More than one commit to dig from %s and %s?",
2265                             revs.pending.objects[i].name,
2266                             final_commit_name);
2267                 sb.final = (struct commit *) obj;
2268                 final_commit_name = revs.pending.objects[i].name;
2269         }
2270
2271         if (!sb.final) {
2272                 /*
2273                  * "--not A B -- path" without anything positive;
2274                  * do not default to HEAD, but use the working tree
2275                  * or "--contents".
2276                  */
2277                 sb.final = fake_working_tree_commit(path, contents_from);
2278                 add_pending_object(&revs, &(sb.final->object), ":");
2279         }
2280         else if (contents_from)
2281                 die("Cannot use --contents with final commit object name");
2282
2283         /*
2284          * If we have bottom, this will mark the ancestors of the
2285          * bottom commits we would reach while traversing as
2286          * uninteresting.
2287          */
2288         prepare_revision_walk(&revs);
2289
2290         if (is_null_sha1(sb.final->object.sha1)) {
2291                 char *buf;
2292                 o = sb.final->util;
2293                 buf = xmalloc(o->file.size + 1);
2294                 memcpy(buf, o->file.ptr, o->file.size + 1);
2295                 sb.final_buf = buf;
2296                 sb.final_buf_size = o->file.size;
2297         }
2298         else {
2299                 o = get_origin(&sb, sb.final, path);
2300                 if (fill_blob_sha1(o))
2301                         die("no such path %s in %s", path, final_commit_name);
2302
2303                 sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2304                                               &sb.final_buf_size);
2305         }
2306         num_read_blob++;
2307         lno = prepare_lines(&sb);
2308
2309         bottom = top = 0;
2310         if (bottomtop)
2311                 prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2312         if (bottom && top && top < bottom) {
2313                 long tmp;
2314                 tmp = top; top = bottom; bottom = tmp;
2315         }
2316         if (bottom < 1)
2317                 bottom = 1;
2318         if (top < 1)
2319                 top = lno;
2320         bottom--;
2321         if (lno < top)
2322                 die("file %s has only %lu lines", path, lno);
2323
2324         ent = xcalloc(1, sizeof(*ent));
2325         ent->lno = bottom;
2326         ent->num_lines = top - bottom;
2327         ent->suspect = o;
2328         ent->s_lno = bottom;
2329
2330         sb.ent = ent;
2331         sb.path = path;
2332
2333         if (revs_file && read_ancestry(revs_file))
2334                 die("reading graft file %s failed: %s",
2335                     revs_file, strerror(errno));
2336
2337         assign_blame(&sb, &revs, opt);
2338
2339         if (incremental)
2340                 return 0;
2341
2342         coalesce(&sb);
2343
2344         if (!(output_option & OUTPUT_PORCELAIN))
2345                 find_alignment(&sb, &output_option);
2346
2347         output(&sb, output_option);
2348         free((void *)sb.final_buf);
2349         for (ent = sb.ent; ent; ) {
2350                 struct blame_entry *e = ent->next;
2351                 free(ent);
2352                 ent = e;
2353         }
2354
2355         if (show_stats) {
2356                 printf("num read blob: %d\n", num_read_blob);
2357                 printf("num get patch: %d\n", num_get_patch);
2358                 printf("num commits: %d\n", num_commits);
2359         }
2360         return 0;
2361 }