Merge branch 'jk/check-connected-with-alternates'
[git] / line-log.c
1 #include "git-compat-util.h"
2 #include "line-range.h"
3 #include "cache.h"
4 #include "tag.h"
5 #include "blob.h"
6 #include "tree.h"
7 #include "diff.h"
8 #include "commit.h"
9 #include "decorate.h"
10 #include "revision.h"
11 #include "xdiff-interface.h"
12 #include "strbuf.h"
13 #include "log-tree.h"
14 #include "graph.h"
15 #include "userdiff.h"
16 #include "line-log.h"
17 #include "argv-array.h"
18
19 static void range_set_grow(struct range_set *rs, size_t extra)
20 {
21         ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
22 }
23
24 /* Either initialization would be fine */
25 #define RANGE_SET_INIT {0}
26
27 void range_set_init(struct range_set *rs, size_t prealloc)
28 {
29         rs->alloc = rs->nr = 0;
30         rs->ranges = NULL;
31         if (prealloc)
32                 range_set_grow(rs, prealloc);
33 }
34
35 void range_set_release(struct range_set *rs)
36 {
37         FREE_AND_NULL(rs->ranges);
38         rs->alloc = rs->nr = 0;
39 }
40
41 /* dst must be uninitialized! */
42 static void range_set_copy(struct range_set *dst, struct range_set *src)
43 {
44         range_set_init(dst, src->nr);
45         COPY_ARRAY(dst->ranges, src->ranges, src->nr);
46         dst->nr = src->nr;
47 }
48
49 static void range_set_move(struct range_set *dst, struct range_set *src)
50 {
51         range_set_release(dst);
52         dst->ranges = src->ranges;
53         dst->nr = src->nr;
54         dst->alloc = src->alloc;
55         src->ranges = NULL;
56         src->alloc = src->nr = 0;
57 }
58
59 /* tack on a _new_ range _at the end_ */
60 void range_set_append_unsafe(struct range_set *rs, long a, long b)
61 {
62         assert(a <= b);
63         range_set_grow(rs, 1);
64         rs->ranges[rs->nr].start = a;
65         rs->ranges[rs->nr].end = b;
66         rs->nr++;
67 }
68
69 void range_set_append(struct range_set *rs, long a, long b)
70 {
71         assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
72         range_set_append_unsafe(rs, a, b);
73 }
74
75 static int range_cmp(const void *_r, const void *_s)
76 {
77         const struct range *r = _r;
78         const struct range *s = _s;
79
80         /* this could be simply 'return r.start-s.start', but for the types */
81         if (r->start == s->start)
82                 return 0;
83         if (r->start < s->start)
84                 return -1;
85         return 1;
86 }
87
88 /*
89  * Check that the ranges are non-empty, sorted and non-overlapping
90  */
91 static void range_set_check_invariants(struct range_set *rs)
92 {
93         unsigned int i;
94
95         if (!rs)
96                 return;
97
98         if (rs->nr)
99                 assert(rs->ranges[0].start < rs->ranges[0].end);
100
101         for (i = 1; i < rs->nr; i++) {
102                 assert(rs->ranges[i-1].end < rs->ranges[i].start);
103                 assert(rs->ranges[i].start < rs->ranges[i].end);
104         }
105 }
106
107 /*
108  * In-place pass of sorting and merging the ranges in the range set,
109  * to establish the invariants when we get the ranges from the user
110  */
111 void sort_and_merge_range_set(struct range_set *rs)
112 {
113         unsigned int i;
114         unsigned int o = 0; /* output cursor */
115
116         QSORT(rs->ranges, rs->nr, range_cmp);
117
118         for (i = 0; i < rs->nr; i++) {
119                 if (rs->ranges[i].start == rs->ranges[i].end)
120                         continue;
121                 if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
122                         if (rs->ranges[o-1].end < rs->ranges[i].end)
123                                 rs->ranges[o-1].end = rs->ranges[i].end;
124                 } else {
125                         rs->ranges[o].start = rs->ranges[i].start;
126                         rs->ranges[o].end = rs->ranges[i].end;
127                         o++;
128                 }
129         }
130         assert(o <= rs->nr);
131         rs->nr = o;
132
133         range_set_check_invariants(rs);
134 }
135
136 /*
137  * Union of range sets (i.e., sets of line numbers).  Used to merge
138  * them when searches meet at a common ancestor.
139  *
140  * This is also where the ranges are consolidated into canonical form:
141  * overlapping and adjacent ranges are merged, and empty ranges are
142  * removed.
143  */
144 static void range_set_union(struct range_set *out,
145                              struct range_set *a, struct range_set *b)
146 {
147         unsigned int i = 0, j = 0;
148         struct range *ra = a->ranges;
149         struct range *rb = b->ranges;
150         /* cannot make an alias of out->ranges: it may change during grow */
151
152         assert(out->nr == 0);
153         while (i < a->nr || j < b->nr) {
154                 struct range *new_range;
155                 if (i < a->nr && j < b->nr) {
156                         if (ra[i].start < rb[j].start)
157                                 new_range = &ra[i++];
158                         else if (ra[i].start > rb[j].start)
159                                 new_range = &rb[j++];
160                         else if (ra[i].end < rb[j].end)
161                                 new_range = &ra[i++];
162                         else
163                                 new_range = &rb[j++];
164                 } else if (i < a->nr)      /* b exhausted */
165                         new_range = &ra[i++];
166                 else                       /* a exhausted */
167                         new_range = &rb[j++];
168                 if (new_range->start == new_range->end)
169                         ; /* empty range */
170                 else if (!out->nr || out->ranges[out->nr-1].end < new_range->start) {
171                         range_set_grow(out, 1);
172                         out->ranges[out->nr].start = new_range->start;
173                         out->ranges[out->nr].end = new_range->end;
174                         out->nr++;
175                 } else if (out->ranges[out->nr-1].end < new_range->end) {
176                         out->ranges[out->nr-1].end = new_range->end;
177                 }
178         }
179 }
180
181 /*
182  * Difference of range sets (out = a \ b).  Pass the "interesting"
183  * ranges as 'a' and the target side of the diff as 'b': it removes
184  * the ranges for which the commit is responsible.
185  */
186 static void range_set_difference(struct range_set *out,
187                                   struct range_set *a, struct range_set *b)
188 {
189         unsigned int i, j =  0;
190         for (i = 0; i < a->nr; i++) {
191                 long start = a->ranges[i].start;
192                 long end = a->ranges[i].end;
193                 while (start < end) {
194                         while (j < b->nr && start >= b->ranges[j].end)
195                                 /*
196                                  * a:         |-------
197                                  * b: ------|
198                                  */
199                                 j++;
200                         if (j >= b->nr || end < b->ranges[j].start) {
201                                 /*
202                                  * b exhausted, or
203                                  * a:  ----|
204                                  * b:         |----
205                                  */
206                                 range_set_append(out, start, end);
207                                 break;
208                         }
209                         if (start >= b->ranges[j].start) {
210                                 /*
211                                  * a:     |--????
212                                  * b: |------|
213                                  */
214                                 start = b->ranges[j].end;
215                         } else if (end > b->ranges[j].start) {
216                                 /*
217                                  * a: |-----|
218                                  * b:    |--?????
219                                  */
220                                 if (start < b->ranges[j].start)
221                                         range_set_append(out, start, b->ranges[j].start);
222                                 start = b->ranges[j].end;
223                         }
224                 }
225         }
226 }
227
228 static void diff_ranges_init(struct diff_ranges *diff)
229 {
230         range_set_init(&diff->parent, 0);
231         range_set_init(&diff->target, 0);
232 }
233
234 static void diff_ranges_release(struct diff_ranges *diff)
235 {
236         range_set_release(&diff->parent);
237         range_set_release(&diff->target);
238 }
239
240 static void line_log_data_init(struct line_log_data *r)
241 {
242         memset(r, 0, sizeof(struct line_log_data));
243         range_set_init(&r->ranges, 0);
244 }
245
246 static void line_log_data_clear(struct line_log_data *r)
247 {
248         range_set_release(&r->ranges);
249         if (r->pair)
250                 diff_free_filepair(r->pair);
251 }
252
253 static void free_line_log_data(struct line_log_data *r)
254 {
255         while (r) {
256                 struct line_log_data *next = r->next;
257                 line_log_data_clear(r);
258                 free(r);
259                 r = next;
260         }
261 }
262
263 static struct line_log_data *
264 search_line_log_data(struct line_log_data *list, const char *path,
265                      struct line_log_data **insertion_point)
266 {
267         struct line_log_data *p = list;
268         if (insertion_point)
269                 *insertion_point = NULL;
270         while (p) {
271                 int cmp = strcmp(p->path, path);
272                 if (!cmp)
273                         return p;
274                 if (insertion_point && cmp < 0)
275                         *insertion_point = p;
276                 p = p->next;
277         }
278         return NULL;
279 }
280
281 /*
282  * Note: takes ownership of 'path', which happens to be what the only
283  * caller needs.
284  */
285 static void line_log_data_insert(struct line_log_data **list,
286                                  char *path,
287                                  long begin, long end)
288 {
289         struct line_log_data *ip;
290         struct line_log_data *p = search_line_log_data(*list, path, &ip);
291
292         if (p) {
293                 range_set_append_unsafe(&p->ranges, begin, end);
294                 free(path);
295                 return;
296         }
297
298         p = xcalloc(1, sizeof(struct line_log_data));
299         p->path = path;
300         range_set_append(&p->ranges, begin, end);
301         if (ip) {
302                 p->next = ip->next;
303                 ip->next = p;
304         } else {
305                 p->next = *list;
306                 *list = p;
307         }
308 }
309
310 struct collect_diff_cbdata {
311         struct diff_ranges *diff;
312 };
313
314 static int collect_diff_cb(long start_a, long count_a,
315                            long start_b, long count_b,
316                            void *data)
317 {
318         struct collect_diff_cbdata *d = data;
319
320         if (count_a >= 0)
321                 range_set_append(&d->diff->parent, start_a, start_a + count_a);
322         if (count_b >= 0)
323                 range_set_append(&d->diff->target, start_b, start_b + count_b);
324
325         return 0;
326 }
327
328 static int collect_diff(mmfile_t *parent, mmfile_t *target, struct diff_ranges *out)
329 {
330         struct collect_diff_cbdata cbdata = {NULL};
331         xpparam_t xpp;
332         xdemitconf_t xecfg;
333         xdemitcb_t ecb;
334
335         memset(&xpp, 0, sizeof(xpp));
336         memset(&xecfg, 0, sizeof(xecfg));
337         xecfg.ctxlen = xecfg.interhunkctxlen = 0;
338
339         cbdata.diff = out;
340         xecfg.hunk_func = collect_diff_cb;
341         memset(&ecb, 0, sizeof(ecb));
342         ecb.priv = &cbdata;
343         return xdi_diff(parent, target, &xpp, &xecfg, &ecb);
344 }
345
346 /*
347  * These are handy for debugging.  Removing them with #if 0 silences
348  * the "unused function" warning.
349  */
350 #if 0
351 static void dump_range_set(struct range_set *rs, const char *desc)
352 {
353         int i;
354         printf("range set %s (%d items):\n", desc, rs->nr);
355         for (i = 0; i < rs->nr; i++)
356                 printf("\t[%ld,%ld]\n", rs->ranges[i].start, rs->ranges[i].end);
357 }
358
359 static void dump_line_log_data(struct line_log_data *r)
360 {
361         char buf[4096];
362         while (r) {
363                 snprintf(buf, 4096, "file %s\n", r->path);
364                 dump_range_set(&r->ranges, buf);
365                 r = r->next;
366         }
367 }
368
369 static void dump_diff_ranges(struct diff_ranges *diff, const char *desc)
370 {
371         int i;
372         assert(diff->parent.nr == diff->target.nr);
373         printf("diff ranges %s (%d items):\n", desc, diff->parent.nr);
374         printf("\tparent\ttarget\n");
375         for (i = 0; i < diff->parent.nr; i++) {
376                 printf("\t[%ld,%ld]\t[%ld,%ld]\n",
377                        diff->parent.ranges[i].start,
378                        diff->parent.ranges[i].end,
379                        diff->target.ranges[i].start,
380                        diff->target.ranges[i].end);
381         }
382 }
383 #endif
384
385
386 static int ranges_overlap(struct range *a, struct range *b)
387 {
388         return !(a->end <= b->start || b->end <= a->start);
389 }
390
391 /*
392  * Given a diff and the set of interesting ranges, determine all hunks
393  * of the diff which touch (overlap) at least one of the interesting
394  * ranges in the target.
395  */
396 static void diff_ranges_filter_touched(struct diff_ranges *out,
397                                        struct diff_ranges *diff,
398                                        struct range_set *rs)
399 {
400         unsigned int i, j = 0;
401
402         assert(out->target.nr == 0);
403
404         for (i = 0; i < diff->target.nr; i++) {
405                 while (diff->target.ranges[i].start > rs->ranges[j].end) {
406                         j++;
407                         if (j == rs->nr)
408                                 return;
409                 }
410                 if (ranges_overlap(&diff->target.ranges[i], &rs->ranges[j])) {
411                         range_set_append(&out->parent,
412                                          diff->parent.ranges[i].start,
413                                          diff->parent.ranges[i].end);
414                         range_set_append(&out->target,
415                                          diff->target.ranges[i].start,
416                                          diff->target.ranges[i].end);
417                 }
418         }
419 }
420
421 /*
422  * Adjust the line counts in 'rs' to account for the lines
423  * added/removed in the diff.
424  */
425 static void range_set_shift_diff(struct range_set *out,
426                                  struct range_set *rs,
427                                  struct diff_ranges *diff)
428 {
429         unsigned int i, j = 0;
430         long offset = 0;
431         struct range *src = rs->ranges;
432         struct range *target = diff->target.ranges;
433         struct range *parent = diff->parent.ranges;
434
435         for (i = 0; i < rs->nr; i++) {
436                 while (j < diff->target.nr && src[i].start >= target[j].start) {
437                         offset += (parent[j].end-parent[j].start)
438                                 - (target[j].end-target[j].start);
439                         j++;
440                 }
441                 range_set_append(out, src[i].start+offset, src[i].end+offset);
442         }
443 }
444
445 /*
446  * Given a diff and the set of interesting ranges, map the ranges
447  * across the diff.  That is: observe that the target commit takes
448  * blame for all the + (target-side) ranges.  So for every pair of
449  * ranges in the diff that was touched, we remove the latter and add
450  * its parent side.
451  */
452 static void range_set_map_across_diff(struct range_set *out,
453                                       struct range_set *rs,
454                                       struct diff_ranges *diff,
455                                       struct diff_ranges **touched_out)
456 {
457         struct diff_ranges *touched = xmalloc(sizeof(*touched));
458         struct range_set tmp1 = RANGE_SET_INIT;
459         struct range_set tmp2 = RANGE_SET_INIT;
460
461         diff_ranges_init(touched);
462         diff_ranges_filter_touched(touched, diff, rs);
463         range_set_difference(&tmp1, rs, &touched->target);
464         range_set_shift_diff(&tmp2, &tmp1, diff);
465         range_set_union(out, &tmp2, &touched->parent);
466         range_set_release(&tmp1);
467         range_set_release(&tmp2);
468
469         *touched_out = touched;
470 }
471
472 static struct commit *check_single_commit(struct rev_info *revs)
473 {
474         struct object *commit = NULL;
475         int found = -1;
476         int i;
477
478         for (i = 0; i < revs->pending.nr; i++) {
479                 struct object *obj = revs->pending.objects[i].item;
480                 if (obj->flags & UNINTERESTING)
481                         continue;
482                 obj = deref_tag(revs->repo, obj, NULL, 0);
483                 if (obj->type != OBJ_COMMIT)
484                         die("Non commit %s?", revs->pending.objects[i].name);
485                 if (commit)
486                         die("More than one commit to dig from: %s and %s?",
487                             revs->pending.objects[i].name,
488                             revs->pending.objects[found].name);
489                 commit = obj;
490                 found = i;
491         }
492
493         if (!commit)
494                 die("No commit specified?");
495
496         return (struct commit *) commit;
497 }
498
499 static void fill_blob_sha1(struct repository *r, struct commit *commit,
500                            struct diff_filespec *spec)
501 {
502         unsigned short mode;
503         struct object_id oid;
504
505         if (get_tree_entry(r, &commit->object.oid, spec->path, &oid, &mode))
506                 die("There is no path %s in the commit", spec->path);
507         fill_filespec(spec, &oid, 1, mode);
508
509         return;
510 }
511
512 static void fill_line_ends(struct repository *r,
513                            struct diff_filespec *spec,
514                            long *lines,
515                            unsigned long **line_ends)
516 {
517         int num = 0, size = 50;
518         long cur = 0;
519         unsigned long *ends = NULL;
520         char *data = NULL;
521
522         if (diff_populate_filespec(r, spec, 0))
523                 die("Cannot read blob %s", oid_to_hex(&spec->oid));
524
525         ALLOC_ARRAY(ends, size);
526         ends[cur++] = 0;
527         data = spec->data;
528         while (num < spec->size) {
529                 if (data[num] == '\n' || num == spec->size - 1) {
530                         ALLOC_GROW(ends, (cur + 1), size);
531                         ends[cur++] = num;
532                 }
533                 num++;
534         }
535
536         /* shrink the array to fit the elements */
537         REALLOC_ARRAY(ends, cur);
538         *lines = cur-1;
539         *line_ends = ends;
540 }
541
542 struct nth_line_cb {
543         struct diff_filespec *spec;
544         long lines;
545         unsigned long *line_ends;
546 };
547
548 static const char *nth_line(void *data, long line)
549 {
550         struct nth_line_cb *d = data;
551         assert(d && line <= d->lines);
552         assert(d->spec && d->spec->data);
553
554         if (line == 0)
555                 return (char *)d->spec->data;
556         else
557                 return (char *)d->spec->data + d->line_ends[line] + 1;
558 }
559
560 static struct line_log_data *
561 parse_lines(struct repository *r, struct commit *commit,
562             const char *prefix, struct string_list *args)
563 {
564         long lines = 0;
565         unsigned long *ends = NULL;
566         struct nth_line_cb cb_data;
567         struct string_list_item *item;
568         struct line_log_data *ranges = NULL;
569         struct line_log_data *p;
570
571         for_each_string_list_item(item, args) {
572                 const char *name_part, *range_part;
573                 char *full_name;
574                 struct diff_filespec *spec;
575                 long begin = 0, end = 0;
576                 long anchor;
577
578                 name_part = skip_range_arg(item->string, r->index);
579                 if (!name_part || *name_part != ':' || !name_part[1])
580                         die("-L argument not 'start,end:file' or ':funcname:file': %s",
581                             item->string);
582                 range_part = xstrndup(item->string, name_part - item->string);
583                 name_part++;
584
585                 full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
586                                         name_part);
587
588                 spec = alloc_filespec(full_name);
589                 fill_blob_sha1(r, commit, spec);
590                 fill_line_ends(r, spec, &lines, &ends);
591                 cb_data.spec = spec;
592                 cb_data.lines = lines;
593                 cb_data.line_ends = ends;
594
595                 p = search_line_log_data(ranges, full_name, NULL);
596                 if (p && p->ranges.nr)
597                         anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
598                 else
599                         anchor = 1;
600
601                 if (parse_range_arg(range_part, nth_line, &cb_data,
602                                     lines, anchor, &begin, &end,
603                                     full_name, r->index))
604                         die("malformed -L argument '%s'", range_part);
605                 if ((!lines && (begin || end)) || lines < begin)
606                         die("file %s has only %lu lines", name_part, lines);
607                 if (begin < 1)
608                         begin = 1;
609                 if (end < 1 || lines < end)
610                         end = lines;
611                 begin--;
612                 line_log_data_insert(&ranges, full_name, begin, end);
613
614                 free_filespec(spec);
615                 FREE_AND_NULL(ends);
616         }
617
618         for (p = ranges; p; p = p->next)
619                 sort_and_merge_range_set(&p->ranges);
620
621         return ranges;
622 }
623
624 static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
625 {
626         struct line_log_data *ret = xmalloc(sizeof(*ret));
627
628         assert(r);
629         line_log_data_init(ret);
630         range_set_copy(&ret->ranges, &r->ranges);
631
632         ret->path = xstrdup(r->path);
633
634         return ret;
635 }
636
637 static struct line_log_data *
638 line_log_data_copy(struct line_log_data *r)
639 {
640         struct line_log_data *ret = NULL;
641         struct line_log_data *tmp = NULL, *prev = NULL;
642
643         assert(r);
644         ret = tmp = prev = line_log_data_copy_one(r);
645         r = r->next;
646         while (r) {
647                 tmp = line_log_data_copy_one(r);
648                 prev->next = tmp;
649                 prev = tmp;
650                 r = r->next;
651         }
652
653         return ret;
654 }
655
656 /* merge two range sets across files */
657 static struct line_log_data *line_log_data_merge(struct line_log_data *a,
658                                                  struct line_log_data *b)
659 {
660         struct line_log_data *head = NULL, **pp = &head;
661
662         while (a || b) {
663                 struct line_log_data *src;
664                 struct line_log_data *src2 = NULL;
665                 struct line_log_data *d;
666                 int cmp;
667                 if (!a)
668                         cmp = 1;
669                 else if (!b)
670                         cmp = -1;
671                 else
672                         cmp = strcmp(a->path, b->path);
673                 if (cmp < 0) {
674                         src = a;
675                         a = a->next;
676                 } else if (cmp == 0) {
677                         src = a;
678                         a = a->next;
679                         src2 = b;
680                         b = b->next;
681                 } else {
682                         src = b;
683                         b = b->next;
684                 }
685                 d = xmalloc(sizeof(struct line_log_data));
686                 line_log_data_init(d);
687                 d->path = xstrdup(src->path);
688                 *pp = d;
689                 pp = &d->next;
690                 if (src2)
691                         range_set_union(&d->ranges, &src->ranges, &src2->ranges);
692                 else
693                         range_set_copy(&d->ranges, &src->ranges);
694         }
695
696         return head;
697 }
698
699 static void add_line_range(struct rev_info *revs, struct commit *commit,
700                            struct line_log_data *range)
701 {
702         struct line_log_data *old_line = NULL;
703         struct line_log_data *new_line = NULL;
704
705         old_line = lookup_decoration(&revs->line_log_data, &commit->object);
706         if (old_line && range) {
707                 new_line = line_log_data_merge(old_line, range);
708                 free_line_log_data(old_line);
709         } else if (range)
710                 new_line = line_log_data_copy(range);
711
712         if (new_line)
713                 add_decoration(&revs->line_log_data, &commit->object, new_line);
714 }
715
716 static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
717 {
718         struct line_log_data *r;
719         r = lookup_decoration(&revs->line_log_data, &commit->object);
720         if (!r)
721                 return;
722         free_line_log_data(r);
723         add_decoration(&revs->line_log_data, &commit->object, NULL);
724 }
725
726 static struct line_log_data *lookup_line_range(struct rev_info *revs,
727                                                struct commit *commit)
728 {
729         struct line_log_data *ret = NULL;
730         struct line_log_data *d;
731
732         ret = lookup_decoration(&revs->line_log_data, &commit->object);
733
734         for (d = ret; d; d = d->next)
735                 range_set_check_invariants(&d->ranges);
736
737         return ret;
738 }
739
740 void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
741 {
742         struct commit *commit = NULL;
743         struct line_log_data *range;
744
745         commit = check_single_commit(rev);
746         range = parse_lines(rev->diffopt.repo, commit, prefix, args);
747         add_line_range(rev, commit, range);
748
749         if (!rev->diffopt.detect_rename) {
750                 struct line_log_data *r;
751                 struct argv_array array = ARGV_ARRAY_INIT;
752                 const char **paths;
753
754                 for (r = range; r; r = r->next)
755                         argv_array_push(&array, r->path);
756                 paths = argv_array_detach(&array);
757
758                 parse_pathspec(&rev->diffopt.pathspec, 0,
759                                PATHSPEC_PREFER_FULL, "", paths);
760                 /* strings are now owned by pathspec */
761                 free(paths);
762         }
763 }
764
765 static void move_diff_queue(struct diff_queue_struct *dst,
766                             struct diff_queue_struct *src)
767 {
768         assert(src != dst);
769         memcpy(dst, src, sizeof(struct diff_queue_struct));
770         DIFF_QUEUE_CLEAR(src);
771 }
772
773 static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
774 {
775         int i;
776         struct diff_queue_struct outq;
777         DIFF_QUEUE_CLEAR(&outq);
778
779         for (i = 0; i < diff_queued_diff.nr; i++) {
780                 struct diff_filepair *p = diff_queued_diff.queue[i];
781                 struct line_log_data *rg = NULL;
782
783                 if (!DIFF_FILE_VALID(p->two)) {
784                         if (keep_deletions)
785                                 diff_q(&outq, p);
786                         else
787                                 diff_free_filepair(p);
788                         continue;
789                 }
790                 for (rg = range; rg; rg = rg->next) {
791                         if (!strcmp(rg->path, p->two->path))
792                                 break;
793                 }
794                 if (rg)
795                         diff_q(&outq, p);
796                 else
797                         diff_free_filepair(p);
798         }
799         free(diff_queued_diff.queue);
800         diff_queued_diff = outq;
801 }
802
803 static inline int diff_might_be_rename(void)
804 {
805         int i;
806         for (i = 0; i < diff_queued_diff.nr; i++)
807                 if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
808                         /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
809                         /*      diff_queued_diff.queue[i]->two->path); */
810                         return 1;
811                 }
812         return 0;
813 }
814
815 static void queue_diffs(struct line_log_data *range,
816                         struct diff_options *opt,
817                         struct diff_queue_struct *queue,
818                         struct commit *commit, struct commit *parent)
819 {
820         assert(commit);
821
822         DIFF_QUEUE_CLEAR(&diff_queued_diff);
823         diff_tree_oid(parent ? get_commit_tree_oid(parent) : NULL,
824                       get_commit_tree_oid(commit), "", opt);
825         if (opt->detect_rename) {
826                 filter_diffs_for_paths(range, 1);
827                 if (diff_might_be_rename())
828                         diffcore_std(opt);
829                 filter_diffs_for_paths(range, 0);
830         }
831         move_diff_queue(queue, &diff_queued_diff);
832 }
833
834 static char *get_nth_line(long line, unsigned long *ends, void *data)
835 {
836         if (line == 0)
837                 return (char *)data;
838         else
839                 return (char *)data + ends[line] + 1;
840 }
841
842 static void print_line(const char *prefix, char first,
843                        long line, unsigned long *ends, void *data,
844                        const char *color, const char *reset, FILE *file)
845 {
846         char *begin = get_nth_line(line, ends, data);
847         char *end = get_nth_line(line+1, ends, data);
848         int had_nl = 0;
849
850         if (end > begin && end[-1] == '\n') {
851                 end--;
852                 had_nl = 1;
853         }
854
855         fputs(prefix, file);
856         fputs(color, file);
857         putc(first, file);
858         fwrite(begin, 1, end-begin, file);
859         fputs(reset, file);
860         putc('\n', file);
861         if (!had_nl)
862                 fputs("\\ No newline at end of file\n", file);
863 }
864
865 static char *output_prefix(struct diff_options *opt)
866 {
867         char *prefix = "";
868
869         if (opt->output_prefix) {
870                 struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
871                 prefix = sb->buf;
872         }
873
874         return prefix;
875 }
876
877 static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
878 {
879         unsigned int i, j = 0;
880         long p_lines, t_lines;
881         unsigned long *p_ends = NULL, *t_ends = NULL;
882         struct diff_filepair *pair = range->pair;
883         struct diff_ranges *diff = &range->diff;
884
885         struct diff_options *opt = &rev->diffopt;
886         char *prefix = output_prefix(opt);
887         const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
888         const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
889         const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
890         const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
891         const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
892         const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);
893
894         if (!pair || !diff)
895                 return;
896
897         if (pair->one->oid_valid)
898                 fill_line_ends(rev->diffopt.repo, pair->one, &p_lines, &p_ends);
899         fill_line_ends(rev->diffopt.repo, pair->two, &t_lines, &t_ends);
900
901         fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
902         fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
903                pair->one->oid_valid ? "a/" : "",
904                pair->one->oid_valid ? pair->one->path : "/dev/null",
905                c_reset);
906         fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
907         for (i = 0; i < range->ranges.nr; i++) {
908                 long p_start, p_end;
909                 long t_start = range->ranges.ranges[i].start;
910                 long t_end = range->ranges.ranges[i].end;
911                 long t_cur = t_start;
912                 unsigned int j_last;
913
914                 while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
915                         j++;
916                 if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
917                         continue;
918
919                 /* Scan ahead to determine the last diff that falls in this range */
920                 j_last = j;
921                 while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
922                         j_last++;
923                 if (j_last > j)
924                         j_last--;
925
926                 /*
927                  * Compute parent hunk headers: we know that the diff
928                  * has the correct line numbers (but not all hunks).
929                  * So it suffices to shift the start/end according to
930                  * the line numbers of the first/last hunk(s) that
931                  * fall in this range.
932                  */
933                 if (t_start < diff->target.ranges[j].start)
934                         p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
935                 else
936                         p_start = diff->parent.ranges[j].start;
937                 if (t_end > diff->target.ranges[j_last].end)
938                         p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
939                 else
940                         p_end = diff->parent.ranges[j_last].end;
941
942                 if (!p_start && !p_end) {
943                         p_start = -1;
944                         p_end = -1;
945                 }
946
947                 /* Now output a diff hunk for this range */
948                 fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
949                        prefix, c_frag,
950                        p_start+1, p_end-p_start, t_start+1, t_end-t_start,
951                        c_reset);
952                 while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
953                         int k;
954                         for (; t_cur < diff->target.ranges[j].start; t_cur++)
955                                 print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
956                                            c_context, c_reset, opt->file);
957                         for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
958                                 print_line(prefix, '-', k, p_ends, pair->one->data,
959                                            c_old, c_reset, opt->file);
960                         for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
961                                 print_line(prefix, '+', t_cur, t_ends, pair->two->data,
962                                            c_new, c_reset, opt->file);
963                         j++;
964                 }
965                 for (; t_cur < t_end; t_cur++)
966                         print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
967                                    c_context, c_reset, opt->file);
968         }
969
970         free(p_ends);
971         free(t_ends);
972 }
973
974 /*
975  * NEEDSWORK: manually building a diff here is not the Right
976  * Thing(tm).  log -L should be built into the diff pipeline.
977  */
978 static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
979 {
980         fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
981         while (range) {
982                 dump_diff_hacky_one(rev, range);
983                 range = range->next;
984         }
985 }
986
987 /*
988  * Unlike most other functions, this destructively operates on
989  * 'range'.
990  */
991 static int process_diff_filepair(struct rev_info *rev,
992                                  struct diff_filepair *pair,
993                                  struct line_log_data *range,
994                                  struct diff_ranges **diff_out)
995 {
996         struct line_log_data *rg = range;
997         struct range_set tmp;
998         struct diff_ranges diff;
999         mmfile_t file_parent, file_target;
1000
1001         assert(pair->two->path);
1002         while (rg) {
1003                 assert(rg->path);
1004                 if (!strcmp(rg->path, pair->two->path))
1005                         break;
1006                 rg = rg->next;
1007         }
1008
1009         if (!rg)
1010                 return 0;
1011         if (rg->ranges.nr == 0)
1012                 return 0;
1013
1014         assert(pair->two->oid_valid);
1015         diff_populate_filespec(rev->diffopt.repo, pair->two, 0);
1016         file_target.ptr = pair->two->data;
1017         file_target.size = pair->two->size;
1018
1019         if (pair->one->oid_valid) {
1020                 diff_populate_filespec(rev->diffopt.repo, pair->one, 0);
1021                 file_parent.ptr = pair->one->data;
1022                 file_parent.size = pair->one->size;
1023         } else {
1024                 file_parent.ptr = "";
1025                 file_parent.size = 0;
1026         }
1027
1028         diff_ranges_init(&diff);
1029         if (collect_diff(&file_parent, &file_target, &diff))
1030                 die("unable to generate diff for %s", pair->one->path);
1031
1032         /* NEEDSWORK should apply some heuristics to prevent mismatches */
1033         free(rg->path);
1034         rg->path = xstrdup(pair->one->path);
1035
1036         range_set_init(&tmp, 0);
1037         range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
1038         range_set_release(&rg->ranges);
1039         range_set_move(&rg->ranges, &tmp);
1040
1041         diff_ranges_release(&diff);
1042
1043         return ((*diff_out)->parent.nr > 0);
1044 }
1045
1046 static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
1047 {
1048         struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
1049         new_filepair->one = pair->one;
1050         new_filepair->two = pair->two;
1051         new_filepair->one->count++;
1052         new_filepair->two->count++;
1053         return new_filepair;
1054 }
1055
1056 static void free_diffqueues(int n, struct diff_queue_struct *dq)
1057 {
1058         int i, j;
1059         for (i = 0; i < n; i++)
1060                 for (j = 0; j < dq[i].nr; j++)
1061                         diff_free_filepair(dq[i].queue[j]);
1062         free(dq);
1063 }
1064
1065 static int process_all_files(struct line_log_data **range_out,
1066                              struct rev_info *rev,
1067                              struct diff_queue_struct *queue,
1068                              struct line_log_data *range)
1069 {
1070         int i, changed = 0;
1071
1072         *range_out = line_log_data_copy(range);
1073
1074         for (i = 0; i < queue->nr; i++) {
1075                 struct diff_ranges *pairdiff = NULL;
1076                 struct diff_filepair *pair = queue->queue[i];
1077                 if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
1078                         /*
1079                          * Store away the diff for later output.  We
1080                          * tuck it in the ranges we got as _input_,
1081                          * since that's the commit that caused the
1082                          * diff.
1083                          *
1084                          * NEEDSWORK not enough when we get around to
1085                          * doing something interesting with merges;
1086                          * currently each invocation on a merge parent
1087                          * trashes the previous one's diff.
1088                          *
1089                          * NEEDSWORK tramples over data structures not owned here
1090                          */
1091                         struct line_log_data *rg = range;
1092                         changed++;
1093                         while (rg && strcmp(rg->path, pair->two->path))
1094                                 rg = rg->next;
1095                         assert(rg);
1096                         rg->pair = diff_filepair_dup(queue->queue[i]);
1097                         memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
1098                 }
1099                 free(pairdiff);
1100         }
1101
1102         return changed;
1103 }
1104
1105 int line_log_print(struct rev_info *rev, struct commit *commit)
1106 {
1107
1108         show_log(rev);
1109         if (!(rev->diffopt.output_format & DIFF_FORMAT_NO_OUTPUT)) {
1110                 struct line_log_data *range = lookup_line_range(rev, commit);
1111                 dump_diff_hacky(rev, range);
1112         }
1113         return 1;
1114 }
1115
1116 static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
1117                                           struct line_log_data *range)
1118 {
1119         struct commit *parent = NULL;
1120         struct diff_queue_struct queue;
1121         struct line_log_data *parent_range;
1122         int changed;
1123
1124         if (commit->parents)
1125                 parent = commit->parents->item;
1126
1127         queue_diffs(range, &rev->diffopt, &queue, commit, parent);
1128         changed = process_all_files(&parent_range, rev, &queue, range);
1129         if (parent)
1130                 add_line_range(rev, parent, parent_range);
1131         free_line_log_data(parent_range);
1132         return changed;
1133 }
1134
1135 static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
1136                                        struct line_log_data *range)
1137 {
1138         struct diff_queue_struct *diffqueues;
1139         struct line_log_data **cand;
1140         struct commit **parents;
1141         struct commit_list *p;
1142         int i;
1143         int nparents = commit_list_count(commit->parents);
1144
1145         if (nparents > 1 && rev->first_parent_only)
1146                 nparents = 1;
1147
1148         ALLOC_ARRAY(diffqueues, nparents);
1149         ALLOC_ARRAY(cand, nparents);
1150         ALLOC_ARRAY(parents, nparents);
1151
1152         p = commit->parents;
1153         for (i = 0; i < nparents; i++) {
1154                 parents[i] = p->item;
1155                 p = p->next;
1156                 queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
1157         }
1158
1159         for (i = 0; i < nparents; i++) {
1160                 int changed;
1161                 cand[i] = NULL;
1162                 changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
1163                 if (!changed) {
1164                         /*
1165                          * This parent can take all the blame, so we
1166                          * don't follow any other path in history
1167                          */
1168                         add_line_range(rev, parents[i], cand[i]);
1169                         clear_commit_line_range(rev, commit);
1170                         commit_list_append(parents[i], &commit->parents);
1171                         free(parents);
1172                         free(cand);
1173                         free_diffqueues(nparents, diffqueues);
1174                         /* NEEDSWORK leaking like a sieve */
1175                         return 0;
1176                 }
1177         }
1178
1179         /*
1180          * No single parent took the blame.  We add the candidates
1181          * from the above loop to the parents.
1182          */
1183         for (i = 0; i < nparents; i++) {
1184                 add_line_range(rev, parents[i], cand[i]);
1185         }
1186
1187         clear_commit_line_range(rev, commit);
1188         free(parents);
1189         free(cand);
1190         free_diffqueues(nparents, diffqueues);
1191         return 1;
1192
1193         /* NEEDSWORK evil merge detection stuff */
1194         /* NEEDSWORK leaking like a sieve */
1195 }
1196
1197 static int process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
1198 {
1199         struct line_log_data *range = lookup_line_range(rev, commit);
1200         int changed = 0;
1201
1202         if (range) {
1203                 if (!commit->parents || !commit->parents->next)
1204                         changed = process_ranges_ordinary_commit(rev, commit, range);
1205                 else
1206                         changed = process_ranges_merge_commit(rev, commit, range);
1207         }
1208
1209         if (!changed)
1210                 commit->object.flags |= TREESAME;
1211
1212         return changed;
1213 }
1214
1215 static enum rewrite_result line_log_rewrite_one(struct rev_info *rev, struct commit **pp)
1216 {
1217         for (;;) {
1218                 struct commit *p = *pp;
1219                 if (p->parents && p->parents->next)
1220                         return rewrite_one_ok;
1221                 if (p->object.flags & UNINTERESTING)
1222                         return rewrite_one_ok;
1223                 if (!(p->object.flags & TREESAME))
1224                         return rewrite_one_ok;
1225                 if (!p->parents)
1226                         return rewrite_one_noparents;
1227                 *pp = p->parents->item;
1228         }
1229 }
1230
1231 int line_log_filter(struct rev_info *rev)
1232 {
1233         struct commit *commit;
1234         struct commit_list *list = rev->commits;
1235         struct commit_list *out = NULL, **pp = &out;
1236
1237         while (list) {
1238                 struct commit_list *to_free = NULL;
1239                 commit = list->item;
1240                 if (process_ranges_arbitrary_commit(rev, commit)) {
1241                         *pp = list;
1242                         pp = &list->next;
1243                 } else
1244                         to_free = list;
1245                 list = list->next;
1246                 free(to_free);
1247         }
1248         *pp = NULL;
1249
1250         for (list = out; list; list = list->next)
1251                 rewrite_parents(rev, list->item, line_log_rewrite_one);
1252
1253         rev->commits = out;
1254
1255         return 0;
1256 }