Code

add: allow configurations to be overriden by command line
[git.git] / combine-diff.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "blob.h"
4 #include "diff.h"
5 #include "diffcore.h"
6 #include "quote.h"
7 #include "xdiff-interface.h"
8 #include "log-tree.h"
9 #include "refs.h"
11 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
12 {
13         struct diff_queue_struct *q = &diff_queued_diff;
14         struct combine_diff_path *p;
15         int i;
17         if (!n) {
18                 struct combine_diff_path *list = NULL, **tail = &list;
19                 for (i = 0; i < q->nr; i++) {
20                         int len;
21                         const char *path;
22                         if (diff_unmodified_pair(q->queue[i]))
23                                 continue;
24                         path = q->queue[i]->two->path;
25                         len = strlen(path);
26                         p = xmalloc(combine_diff_path_size(num_parent, len));
27                         p->path = (char*) &(p->parent[num_parent]);
28                         memcpy(p->path, path, len);
29                         p->path[len] = 0;
30                         p->len = len;
31                         p->next = NULL;
32                         memset(p->parent, 0,
33                                sizeof(p->parent[0]) * num_parent);
35                         hashcpy(p->sha1, q->queue[i]->two->sha1);
36                         p->mode = q->queue[i]->two->mode;
37                         hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
38                         p->parent[n].mode = q->queue[i]->one->mode;
39                         p->parent[n].status = q->queue[i]->status;
40                         *tail = p;
41                         tail = &p->next;
42                 }
43                 return list;
44         }
46         for (p = curr; p; p = p->next) {
47                 int found = 0;
48                 if (!p->len)
49                         continue;
50                 for (i = 0; i < q->nr; i++) {
51                         const char *path;
52                         int len;
54                         if (diff_unmodified_pair(q->queue[i]))
55                                 continue;
56                         path = q->queue[i]->two->path;
57                         len = strlen(path);
58                         if (len == p->len && !memcmp(path, p->path, len)) {
59                                 found = 1;
60                                 hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
61                                 p->parent[n].mode = q->queue[i]->one->mode;
62                                 p->parent[n].status = q->queue[i]->status;
63                                 break;
64                         }
65                 }
66                 if (!found)
67                         p->len = 0;
68         }
69         return curr;
70 }
72 /* Lines lost from parent */
73 struct lline {
74         struct lline *next;
75         int len;
76         unsigned long parent_map;
77         char line[FLEX_ARRAY];
78 };
80 /* Lines surviving in the merge result */
81 struct sline {
82         struct lline *lost_head, **lost_tail;
83         char *bol;
84         int len;
85         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
86          * we did not change it).
87          * bit N is used for "interesting" lines, including context.
88          * bit (N+1) is used for "do not show deletion before this".
89          */
90         unsigned long flag;
91         unsigned long *p_lno;
92 };
94 static char *grab_blob(const unsigned char *sha1, unsigned int mode, unsigned long *size)
95 {
96         char *blob;
97         enum object_type type;
99         if (S_ISGITLINK(mode)) {
100                 blob = xmalloc(100);
101                 *size = snprintf(blob, 100,
102                                  "Subproject commit %s\n", sha1_to_hex(sha1));
103         } else if (is_null_sha1(sha1)) {
104                 /* deleted blob */
105                 *size = 0;
106                 return xcalloc(1, 1);
107         } else {
108                 blob = read_sha1_file(sha1, &type, size);
109                 if (type != OBJ_BLOB)
110                         die("object '%s' is not a blob!", sha1_to_hex(sha1));
111         }
112         return blob;
115 static void append_lost(struct sline *sline, int n, const char *line, int len)
117         struct lline *lline;
118         unsigned long this_mask = (1UL<<n);
119         if (line[len-1] == '\n')
120                 len--;
122         /* Check to see if we can squash things */
123         if (sline->lost_head) {
124                 struct lline *last_one = NULL;
125                 /* We cannot squash it with earlier one */
126                 for (lline = sline->lost_head;
127                      lline;
128                      lline = lline->next)
129                         if (lline->parent_map & this_mask)
130                                 last_one = lline;
131                 lline = last_one ? last_one->next : sline->lost_head;
132                 while (lline) {
133                         if (lline->len == len &&
134                             !memcmp(lline->line, line, len)) {
135                                 lline->parent_map |= this_mask;
136                                 return;
137                         }
138                         lline = lline->next;
139                 }
140         }
142         lline = xmalloc(sizeof(*lline) + len + 1);
143         lline->len = len;
144         lline->next = NULL;
145         lline->parent_map = this_mask;
146         memcpy(lline->line, line, len);
147         lline->line[len] = 0;
148         *sline->lost_tail = lline;
149         sline->lost_tail = &lline->next;
152 struct combine_diff_state {
153         struct xdiff_emit_state xm;
155         unsigned int lno;
156         int ob, on, nb, nn;
157         unsigned long nmask;
158         int num_parent;
159         int n;
160         struct sline *sline;
161         struct sline *lost_bucket;
162 };
164 static void consume_line(void *state_, char *line, unsigned long len)
166         struct combine_diff_state *state = state_;
167         if (5 < len && !memcmp("@@ -", line, 4)) {
168                 if (parse_hunk_header(line, len,
169                                       &state->ob, &state->on,
170                                       &state->nb, &state->nn))
171                         return;
172                 state->lno = state->nb;
173                 if (!state->nb)
174                         /* @@ -1,2 +0,0 @@ to remove the
175                          * first two lines...
176                          */
177                         state->nb = 1;
178                 if (state->nn == 0)
179                         /* @@ -X,Y +N,0 @@ removed Y lines
180                          * that would have come *after* line N
181                          * in the result.  Our lost buckets hang
182                          * to the line after the removed lines,
183                          */
184                         state->lost_bucket = &state->sline[state->nb];
185                 else
186                         state->lost_bucket = &state->sline[state->nb-1];
187                 if (!state->sline[state->nb-1].p_lno)
188                         state->sline[state->nb-1].p_lno =
189                                 xcalloc(state->num_parent,
190                                         sizeof(unsigned long));
191                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
192                 return;
193         }
194         if (!state->lost_bucket)
195                 return; /* not in any hunk yet */
196         switch (line[0]) {
197         case '-':
198                 append_lost(state->lost_bucket, state->n, line+1, len-1);
199                 break;
200         case '+':
201                 state->sline[state->lno-1].flag |= state->nmask;
202                 state->lno++;
203                 break;
204         }
207 static void combine_diff(const unsigned char *parent, unsigned int mode,
208                          mmfile_t *result_file,
209                          struct sline *sline, unsigned int cnt, int n,
210                          int num_parent)
212         unsigned int p_lno, lno;
213         unsigned long nmask = (1UL << n);
214         xpparam_t xpp;
215         xdemitconf_t xecfg;
216         mmfile_t parent_file;
217         xdemitcb_t ecb;
218         struct combine_diff_state state;
219         unsigned long sz;
221         if (!cnt)
222                 return; /* result deleted */
224         parent_file.ptr = grab_blob(parent, mode, &sz);
225         parent_file.size = sz;
226         xpp.flags = XDF_NEED_MINIMAL;
227         memset(&xecfg, 0, sizeof(xecfg));
228         ecb.outf = xdiff_outf;
229         ecb.priv = &state;
230         memset(&state, 0, sizeof(state));
231         state.xm.consume = consume_line;
232         state.nmask = nmask;
233         state.sline = sline;
234         state.lno = 1;
235         state.num_parent = num_parent;
236         state.n = n;
238         xdi_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
239         free(parent_file.ptr);
241         /* Assign line numbers for this parent.
242          *
243          * sline[lno].p_lno[n] records the first line number
244          * (counting from 1) for parent N if the final hunk display
245          * started by showing sline[lno] (possibly showing the lost
246          * lines attached to it first).
247          */
248         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
249                 struct lline *ll;
250                 sline[lno].p_lno[n] = p_lno;
252                 /* How many lines would this sline advance the p_lno? */
253                 ll = sline[lno].lost_head;
254                 while (ll) {
255                         if (ll->parent_map & nmask)
256                                 p_lno++; /* '-' means parent had it */
257                         ll = ll->next;
258                 }
259                 if (lno < cnt && !(sline[lno].flag & nmask))
260                         p_lno++; /* no '+' means parent had it */
261         }
262         sline[lno].p_lno[n] = p_lno; /* trailer */
265 static unsigned long context = 3;
266 static char combine_marker = '@';
268 static int interesting(struct sline *sline, unsigned long all_mask)
270         /* If some parents lost lines here, or if we have added to
271          * some parent, it is interesting.
272          */
273         return ((sline->flag & all_mask) || sline->lost_head);
276 static unsigned long adjust_hunk_tail(struct sline *sline,
277                                       unsigned long all_mask,
278                                       unsigned long hunk_begin,
279                                       unsigned long i)
281         /* i points at the first uninteresting line.  If the last line
282          * of the hunk was interesting only because it has some
283          * deletion, then it is not all that interesting for the
284          * purpose of giving trailing context lines.  This is because
285          * we output '-' line and then unmodified sline[i-1] itself in
286          * that case which gives us one extra context line.
287          */
288         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
289                 i--;
290         return i;
293 static unsigned long find_next(struct sline *sline,
294                                unsigned long mark,
295                                unsigned long i,
296                                unsigned long cnt,
297                                int look_for_uninteresting)
299         /* We have examined up to i-1 and are about to look at i.
300          * Find next interesting or uninteresting line.  Here,
301          * "interesting" does not mean interesting(), but marked by
302          * the give_context() function below (i.e. it includes context
303          * lines that are not interesting to interesting() function
304          * that are surrounded by interesting() ones.
305          */
306         while (i <= cnt)
307                 if (look_for_uninteresting
308                     ? !(sline[i].flag & mark)
309                     : (sline[i].flag & mark))
310                         return i;
311                 else
312                         i++;
313         return i;
316 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
318         unsigned long all_mask = (1UL<<num_parent) - 1;
319         unsigned long mark = (1UL<<num_parent);
320         unsigned long no_pre_delete = (2UL<<num_parent);
321         unsigned long i;
323         /* Two groups of interesting lines may have a short gap of
324          * uninteresting lines.  Connect such groups to give them a
325          * bit of context.
326          *
327          * We first start from what the interesting() function says,
328          * and mark them with "mark", and paint context lines with the
329          * mark.  So interesting() would still say false for such context
330          * lines but they are treated as "interesting" in the end.
331          */
332         i = find_next(sline, mark, 0, cnt, 0);
333         if (cnt < i)
334                 return 0;
336         while (i <= cnt) {
337                 unsigned long j = (context < i) ? (i - context) : 0;
338                 unsigned long k;
340                 /* Paint a few lines before the first interesting line. */
341                 while (j < i)
342                         sline[j++].flag |= mark | no_pre_delete;
344         again:
345                 /* we know up to i is to be included.  where does the
346                  * next uninteresting one start?
347                  */
348                 j = find_next(sline, mark, i, cnt, 1);
349                 if (cnt < j)
350                         break; /* the rest are all interesting */
352                 /* lookahead context lines */
353                 k = find_next(sline, mark, j, cnt, 0);
354                 j = adjust_hunk_tail(sline, all_mask, i, j);
356                 if (k < j + context) {
357                         /* k is interesting and [j,k) are not, but
358                          * paint them interesting because the gap is small.
359                          */
360                         while (j < k)
361                                 sline[j++].flag |= mark;
362                         i = k;
363                         goto again;
364                 }
366                 /* j is the first uninteresting line and there is
367                  * no overlap beyond it within context lines.  Paint
368                  * the trailing edge a bit.
369                  */
370                 i = k;
371                 k = (j + context < cnt+1) ? j + context : cnt+1;
372                 while (j < k)
373                         sline[j++].flag |= mark;
374         }
375         return 1;
378 static int make_hunks(struct sline *sline, unsigned long cnt,
379                        int num_parent, int dense)
381         unsigned long all_mask = (1UL<<num_parent) - 1;
382         unsigned long mark = (1UL<<num_parent);
383         unsigned long i;
384         int has_interesting = 0;
386         for (i = 0; i <= cnt; i++) {
387                 if (interesting(&sline[i], all_mask))
388                         sline[i].flag |= mark;
389                 else
390                         sline[i].flag &= ~mark;
391         }
392         if (!dense)
393                 return give_context(sline, cnt, num_parent);
395         /* Look at each hunk, and if we have changes from only one
396          * parent, or the changes are the same from all but one
397          * parent, mark that uninteresting.
398          */
399         i = 0;
400         while (i <= cnt) {
401                 unsigned long j, hunk_begin, hunk_end;
402                 unsigned long same_diff;
403                 while (i <= cnt && !(sline[i].flag & mark))
404                         i++;
405                 if (cnt < i)
406                         break; /* No more interesting hunks */
407                 hunk_begin = i;
408                 for (j = i + 1; j <= cnt; j++) {
409                         if (!(sline[j].flag & mark)) {
410                                 /* Look beyond the end to see if there
411                                  * is an interesting line after this
412                                  * hunk within context span.
413                                  */
414                                 unsigned long la; /* lookahead */
415                                 int contin = 0;
416                                 la = adjust_hunk_tail(sline, all_mask,
417                                                      hunk_begin, j);
418                                 la = (la + context < cnt + 1) ?
419                                         (la + context) : cnt + 1;
420                                 while (j <= --la) {
421                                         if (sline[la].flag & mark) {
422                                                 contin = 1;
423                                                 break;
424                                         }
425                                 }
426                                 if (!contin)
427                                         break;
428                                 j = la;
429                         }
430                 }
431                 hunk_end = j;
433                 /* [i..hunk_end) are interesting.  Now is it really
434                  * interesting?  We check if there are only two versions
435                  * and the result matches one of them.  That is, we look
436                  * at:
437                  *   (+) line, which records lines added to which parents;
438                  *       this line appears in the result.
439                  *   (-) line, which records from what parents the line
440                  *       was removed; this line does not appear in the result.
441                  * then check the set of parents the result has difference
442                  * from, from all lines.  If there are lines that has
443                  * different set of parents that the result has differences
444                  * from, that means we have more than two versions.
445                  *
446                  * Even when we have only two versions, if the result does
447                  * not match any of the parents, the it should be considered
448                  * interesting.  In such a case, we would have all '+' line.
449                  * After passing the above "two versions" test, that would
450                  * appear as "the same set of parents" to be "all parents".
451                  */
452                 same_diff = 0;
453                 has_interesting = 0;
454                 for (j = i; j < hunk_end && !has_interesting; j++) {
455                         unsigned long this_diff = sline[j].flag & all_mask;
456                         struct lline *ll = sline[j].lost_head;
457                         if (this_diff) {
458                                 /* This has some changes.  Is it the
459                                  * same as others?
460                                  */
461                                 if (!same_diff)
462                                         same_diff = this_diff;
463                                 else if (same_diff != this_diff) {
464                                         has_interesting = 1;
465                                         break;
466                                 }
467                         }
468                         while (ll && !has_interesting) {
469                                 /* Lost this line from these parents;
470                                  * who are they?  Are they the same?
471                                  */
472                                 this_diff = ll->parent_map;
473                                 if (!same_diff)
474                                         same_diff = this_diff;
475                                 else if (same_diff != this_diff) {
476                                         has_interesting = 1;
477                                 }
478                                 ll = ll->next;
479                         }
480                 }
482                 if (!has_interesting && same_diff != all_mask) {
483                         /* This hunk is not that interesting after all */
484                         for (j = hunk_begin; j < hunk_end; j++)
485                                 sline[j].flag &= ~mark;
486                 }
487                 i = hunk_end;
488         }
490         has_interesting = give_context(sline, cnt, num_parent);
491         return has_interesting;
494 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
496         l0 = sline[l0].p_lno[n];
497         l1 = sline[l1].p_lno[n];
498         printf(" -%lu,%lu", l0, l1-l0-null_context);
501 static int hunk_comment_line(const char *bol)
503         int ch;
505         if (!bol)
506                 return 0;
507         ch = *bol & 0xff;
508         return (isalpha(ch) || ch == '_' || ch == '$');
511 static void show_line_to_eol(const char *line, int len, const char *reset)
513         int saw_cr_at_eol = 0;
514         if (len < 0)
515                 len = strlen(line);
516         saw_cr_at_eol = (len && line[len-1] == '\r');
518         printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
519                reset,
520                saw_cr_at_eol ? "\r" : "");
523 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
524                        int use_color)
526         unsigned long mark = (1UL<<num_parent);
527         unsigned long no_pre_delete = (2UL<<num_parent);
528         int i;
529         unsigned long lno = 0;
530         const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
531         const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
532         const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
533         const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
534         const char *c_reset = diff_get_color(use_color, DIFF_RESET);
536         if (!cnt)
537                 return; /* result deleted */
539         while (1) {
540                 struct sline *sl = &sline[lno];
541                 unsigned long hunk_end;
542                 unsigned long rlines;
543                 const char *hunk_comment = NULL;
544                 unsigned long null_context = 0;
546                 while (lno <= cnt && !(sline[lno].flag & mark)) {
547                         if (hunk_comment_line(sline[lno].bol))
548                                 hunk_comment = sline[lno].bol;
549                         lno++;
550                 }
551                 if (cnt < lno)
552                         break;
553                 else {
554                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
555                                 if (!(sline[hunk_end].flag & mark))
556                                         break;
557                 }
558                 rlines = hunk_end - lno;
559                 if (cnt < hunk_end)
560                         rlines--; /* pointing at the last delete hunk */
562                 if (!context) {
563                         /*
564                          * Even when running with --unified=0, all
565                          * lines in the hunk needs to be processed in
566                          * the loop below in order to show the
567                          * deletion recorded in lost_head.  However,
568                          * we do not want to show the resulting line
569                          * with all blank context markers in such a
570                          * case.  Compensate.
571                          */
572                         unsigned long j;
573                         for (j = lno; j < hunk_end; j++)
574                                 if (!(sline[j].flag & (mark-1)))
575                                         null_context++;
576                         rlines -= null_context;
577                 }
579                 fputs(c_frag, stdout);
580                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
581                 for (i = 0; i < num_parent; i++)
582                         show_parent_lno(sline, lno, hunk_end, i, null_context);
583                 printf(" +%lu,%lu ", lno+1, rlines);
584                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
586                 if (hunk_comment) {
587                         int comment_end = 0;
588                         for (i = 0; i < 40; i++) {
589                                 int ch = hunk_comment[i] & 0xff;
590                                 if (!ch || ch == '\n')
591                                         break;
592                                 if (!isspace(ch))
593                                     comment_end = i;
594                         }
595                         if (comment_end)
596                                 putchar(' ');
597                         for (i = 0; i < comment_end; i++)
598                                 putchar(hunk_comment[i]);
599                 }
601                 printf("%s\n", c_reset);
602                 while (lno < hunk_end) {
603                         struct lline *ll;
604                         int j;
605                         unsigned long p_mask;
606                         sl = &sline[lno++];
607                         ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
608                         while (ll) {
609                                 fputs(c_old, stdout);
610                                 for (j = 0; j < num_parent; j++) {
611                                         if (ll->parent_map & (1UL<<j))
612                                                 putchar('-');
613                                         else
614                                                 putchar(' ');
615                                 }
616                                 show_line_to_eol(ll->line, -1, c_reset);
617                                 ll = ll->next;
618                         }
619                         if (cnt < lno)
620                                 break;
621                         p_mask = 1;
622                         if (!(sl->flag & (mark-1))) {
623                                 /*
624                                  * This sline was here to hang the
625                                  * lost lines in front of it.
626                                  */
627                                 if (!context)
628                                         continue;
629                                 fputs(c_plain, stdout);
630                         }
631                         else
632                                 fputs(c_new, stdout);
633                         for (j = 0; j < num_parent; j++) {
634                                 if (p_mask & sl->flag)
635                                         putchar('+');
636                                 else
637                                         putchar(' ');
638                                 p_mask <<= 1;
639                         }
640                         show_line_to_eol(sl->bol, sl->len, c_reset);
641                 }
642         }
645 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
646                                int i, int j)
648         /* We have already examined parent j and we know parent i
649          * and parent j are the same, so reuse the combined result
650          * of parent j for parent i.
651          */
652         unsigned long lno, imask, jmask;
653         imask = (1UL<<i);
654         jmask = (1UL<<j);
656         for (lno = 0; lno <= cnt; lno++) {
657                 struct lline *ll = sline->lost_head;
658                 sline->p_lno[i] = sline->p_lno[j];
659                 while (ll) {
660                         if (ll->parent_map & jmask)
661                                 ll->parent_map |= imask;
662                         ll = ll->next;
663                 }
664                 if (sline->flag & jmask)
665                         sline->flag |= imask;
666                 sline++;
667         }
668         /* the overall size of the file (sline[cnt]) */
669         sline->p_lno[i] = sline->p_lno[j];
672 static void dump_quoted_path(const char *head,
673                              const char *prefix,
674                              const char *path,
675                              const char *c_meta, const char *c_reset)
677         static struct strbuf buf = STRBUF_INIT;
679         strbuf_reset(&buf);
680         strbuf_addstr(&buf, c_meta);
681         strbuf_addstr(&buf, head);
682         quote_two_c_style(&buf, prefix, path, 0);
683         strbuf_addstr(&buf, c_reset);
684         puts(buf.buf);
687 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
688                             int dense, struct rev_info *rev)
690         struct diff_options *opt = &rev->diffopt;
691         unsigned long result_size, cnt, lno;
692         char *result, *cp;
693         struct sline *sline; /* survived lines */
694         int mode_differs = 0;
695         int i, show_hunks;
696         int working_tree_file = is_null_sha1(elem->sha1);
697         int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
698         mmfile_t result_file;
700         context = opt->context;
701         /* Read the result of merge first */
702         if (!working_tree_file)
703                 result = grab_blob(elem->sha1, elem->mode, &result_size);
704         else {
705                 /* Used by diff-tree to read from the working tree */
706                 struct stat st;
707                 int fd = -1;
709                 if (lstat(elem->path, &st) < 0)
710                         goto deleted_file;
712                 if (S_ISLNK(st.st_mode)) {
713                         size_t len = xsize_t(st.st_size);
714                         result_size = len;
715                         result = xmalloc(len + 1);
716                         if (result_size != readlink(elem->path, result, len)) {
717                                 error("readlink(%s): %s", elem->path,
718                                       strerror(errno));
719                                 return;
720                         }
721                         result[len] = 0;
722                         elem->mode = canon_mode(st.st_mode);
723                 } else if (S_ISDIR(st.st_mode)) {
724                         unsigned char sha1[20];
725                         if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
726                                 result = grab_blob(elem->sha1, elem->mode, &result_size);
727                         else
728                                 result = grab_blob(sha1, elem->mode, &result_size);
729                 } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
730                         size_t len = xsize_t(st.st_size);
731                         ssize_t done;
732                         int is_file, i;
734                         elem->mode = canon_mode(st.st_mode);
735                         /* if symlinks don't work, assume symlink if all parents
736                          * are symlinks
737                          */
738                         is_file = has_symlinks;
739                         for (i = 0; !is_file && i < num_parent; i++)
740                                 is_file = !S_ISLNK(elem->parent[i].mode);
741                         if (!is_file)
742                                 elem->mode = canon_mode(S_IFLNK);
744                         result_size = len;
745                         result = xmalloc(len + 1);
747                         done = read_in_full(fd, result, len);
748                         if (done < 0)
749                                 die("read error '%s'", elem->path);
750                         else if (done < len)
751                                 die("early EOF '%s'", elem->path);
753                         result[len] = 0;
755                         /* If not a fake symlink, apply filters, e.g. autocrlf */
756                         if (is_file) {
757                                 struct strbuf buf;
759                                 strbuf_init(&buf, 0);
760                                 if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
761                                         free(result);
762                                         result = strbuf_detach(&buf, &len);
763                                         result_size = len;
764                                 }
765                         }
766                 }
767                 else {
768                 deleted_file:
769                         result_size = 0;
770                         elem->mode = 0;
771                         result = xcalloc(1, 1);
772                 }
774                 if (0 <= fd)
775                         close(fd);
776         }
778         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
779                 if (*cp == '\n')
780                         cnt++;
781         }
782         if (result_size && result[result_size-1] != '\n')
783                 cnt++; /* incomplete line */
785         sline = xcalloc(cnt+2, sizeof(*sline));
786         sline[0].bol = result;
787         for (lno = 0; lno <= cnt + 1; lno++) {
788                 sline[lno].lost_tail = &sline[lno].lost_head;
789                 sline[lno].flag = 0;
790         }
791         for (lno = 0, cp = result; cp < result + result_size; cp++) {
792                 if (*cp == '\n') {
793                         sline[lno].len = cp - sline[lno].bol;
794                         lno++;
795                         if (lno < cnt)
796                                 sline[lno].bol = cp + 1;
797                 }
798         }
799         if (result_size && result[result_size-1] != '\n')
800                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
802         result_file.ptr = result;
803         result_file.size = result_size;
805         /* Even p_lno[cnt+1] is valid -- that is for the end line number
806          * for deletion hunk at the end.
807          */
808         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
809         for (lno = 0; lno <= cnt; lno++)
810                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
812         for (i = 0; i < num_parent; i++) {
813                 int j;
814                 for (j = 0; j < i; j++) {
815                         if (!hashcmp(elem->parent[i].sha1,
816                                      elem->parent[j].sha1)) {
817                                 reuse_combine_diff(sline, cnt, i, j);
818                                 break;
819                         }
820                 }
821                 if (i <= j)
822                         combine_diff(elem->parent[i].sha1,
823                                      elem->parent[i].mode,
824                                      &result_file, sline,
825                                      cnt, i, num_parent);
826                 if (elem->parent[i].mode != elem->mode)
827                         mode_differs = 1;
828         }
830         show_hunks = make_hunks(sline, cnt, num_parent, dense);
832         if (show_hunks || mode_differs || working_tree_file) {
833                 const char *abb;
834                 int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
835                 const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
836                 const char *c_reset = diff_get_color(use_color, DIFF_RESET);
837                 int added = 0;
838                 int deleted = 0;
840                 if (rev->loginfo && !rev->no_commit_id)
841                         show_log(rev);
842                 dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
843                                  "", elem->path, c_meta, c_reset);
844                 printf("%sindex ", c_meta);
845                 for (i = 0; i < num_parent; i++) {
846                         abb = find_unique_abbrev(elem->parent[i].sha1,
847                                                  abbrev);
848                         printf("%s%s", i ? "," : "", abb);
849                 }
850                 abb = find_unique_abbrev(elem->sha1, abbrev);
851                 printf("..%s%s\n", abb, c_reset);
853                 if (mode_differs) {
854                         deleted = !elem->mode;
856                         /* We say it was added if nobody had it */
857                         added = !deleted;
858                         for (i = 0; added && i < num_parent; i++)
859                                 if (elem->parent[i].status !=
860                                     DIFF_STATUS_ADDED)
861                                         added = 0;
862                         if (added)
863                                 printf("%snew file mode %06o",
864                                        c_meta, elem->mode);
865                         else {
866                                 if (deleted)
867                                         printf("%sdeleted file ", c_meta);
868                                 printf("mode ");
869                                 for (i = 0; i < num_parent; i++) {
870                                         printf("%s%06o", i ? "," : "",
871                                                elem->parent[i].mode);
872                                 }
873                                 if (elem->mode)
874                                         printf("..%06o", elem->mode);
875                         }
876                         printf("%s\n", c_reset);
877                 }
878                 if (added)
879                         dump_quoted_path("--- ", "", "/dev/null",
880                                          c_meta, c_reset);
881                 else
882                         dump_quoted_path("--- ", opt->a_prefix, elem->path,
883                                          c_meta, c_reset);
884                 if (deleted)
885                         dump_quoted_path("+++ ", "", "/dev/null",
886                                          c_meta, c_reset);
887                 else
888                         dump_quoted_path("+++ ", opt->b_prefix, elem->path,
889                                          c_meta, c_reset);
890                 dump_sline(sline, cnt, num_parent,
891                            DIFF_OPT_TST(opt, COLOR_DIFF));
892         }
893         free(result);
895         for (lno = 0; lno < cnt; lno++) {
896                 if (sline[lno].lost_head) {
897                         struct lline *ll = sline[lno].lost_head;
898                         while (ll) {
899                                 struct lline *tmp = ll;
900                                 ll = ll->next;
901                                 free(tmp);
902                         }
903                 }
904         }
905         free(sline[0].p_lno);
906         free(sline);
909 #define COLONS "::::::::::::::::::::::::::::::::"
911 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
913         struct diff_options *opt = &rev->diffopt;
914         int i, offset;
915         const char *prefix;
916         int line_termination, inter_name_termination;
918         line_termination = opt->line_termination;
919         inter_name_termination = '\t';
920         if (!line_termination)
921                 inter_name_termination = 0;
923         if (rev->loginfo && !rev->no_commit_id)
924                 show_log(rev);
926         if (opt->output_format & DIFF_FORMAT_RAW) {
927                 offset = strlen(COLONS) - num_parent;
928                 if (offset < 0)
929                         offset = 0;
930                 prefix = COLONS + offset;
932                 /* Show the modes */
933                 for (i = 0; i < num_parent; i++) {
934                         printf("%s%06o", prefix, p->parent[i].mode);
935                         prefix = " ";
936                 }
937                 printf("%s%06o", prefix, p->mode);
939                 /* Show sha1's */
940                 for (i = 0; i < num_parent; i++)
941                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
942                                                          opt->abbrev));
943                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
944         }
946         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
947                 for (i = 0; i < num_parent; i++)
948                         putchar(p->parent[i].status);
949                 putchar(inter_name_termination);
950         }
952         write_name_quoted(p->path, stdout, line_termination);
955 void show_combined_diff(struct combine_diff_path *p,
956                        int num_parent,
957                        int dense,
958                        struct rev_info *rev)
960         struct diff_options *opt = &rev->diffopt;
961         if (!p->len)
962                 return;
963         if (opt->output_format & (DIFF_FORMAT_RAW |
964                                   DIFF_FORMAT_NAME |
965                                   DIFF_FORMAT_NAME_STATUS))
966                 show_raw_diff(p, num_parent, rev);
967         else if (opt->output_format & DIFF_FORMAT_PATCH)
968                 show_patch_diff(p, num_parent, dense, rev);
971 void diff_tree_combined(const unsigned char *sha1,
972                         const unsigned char parent[][20],
973                         int num_parent,
974                         int dense,
975                         struct rev_info *rev)
977         struct diff_options *opt = &rev->diffopt;
978         struct diff_options diffopts;
979         struct combine_diff_path *p, *paths = NULL;
980         int i, num_paths, needsep, show_log_first;
982         diffopts = *opt;
983         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
984         DIFF_OPT_SET(&diffopts, RECURSIVE);
985         DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
987         show_log_first = !!rev->loginfo && !rev->no_commit_id;
988         needsep = 0;
989         /* find set of paths that everybody touches */
990         for (i = 0; i < num_parent; i++) {
991                 /* show stat against the first parent even
992                  * when doing combined diff.
993                  */
994                 int stat_opt = (opt->output_format &
995                                 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
996                 if (i == 0 && stat_opt)
997                         diffopts.output_format = stat_opt;
998                 else
999                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1000                 diff_tree_sha1(parent[i], sha1, "", &diffopts);
1001                 diffcore_std(&diffopts);
1002                 paths = intersect_paths(paths, i, num_parent);
1004                 if (show_log_first && i == 0) {
1005                         show_log(rev);
1006                         if (rev->verbose_header && opt->output_format)
1007                                 putchar(opt->line_termination);
1008                 }
1009                 diff_flush(&diffopts);
1010         }
1012         /* find out surviving paths */
1013         for (num_paths = 0, p = paths; p; p = p->next) {
1014                 if (p->len)
1015                         num_paths++;
1016         }
1017         if (num_paths) {
1018                 if (opt->output_format & (DIFF_FORMAT_RAW |
1019                                           DIFF_FORMAT_NAME |
1020                                           DIFF_FORMAT_NAME_STATUS)) {
1021                         for (p = paths; p; p = p->next) {
1022                                 if (p->len)
1023                                         show_raw_diff(p, num_parent, rev);
1024                         }
1025                         needsep = 1;
1026                 }
1027                 else if (opt->output_format &
1028                          (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1029                         needsep = 1;
1030                 if (opt->output_format & DIFF_FORMAT_PATCH) {
1031                         if (needsep)
1032                                 putchar(opt->line_termination);
1033                         for (p = paths; p; p = p->next) {
1034                                 if (p->len)
1035                                         show_patch_diff(p, num_parent, dense,
1036                                                         rev);
1037                         }
1038                 }
1039         }
1041         /* Clean things up */
1042         while (paths) {
1043                 struct combine_diff_path *tmp = paths;
1044                 paths = paths->next;
1045                 free(tmp);
1046         }
1049 void diff_tree_combined_merge(const unsigned char *sha1,
1050                              int dense, struct rev_info *rev)
1052         int num_parent;
1053         const unsigned char (*parent)[20];
1054         struct commit *commit = lookup_commit(sha1);
1055         struct commit_list *parents;
1057         /* count parents */
1058         for (parents = commit->parents, num_parent = 0;
1059              parents;
1060              parents = parents->next, num_parent++)
1061                 ; /* nothing */
1063         parent = xmalloc(num_parent * sizeof(*parent));
1064         for (parents = commit->parents, num_parent = 0;
1065              parents;
1066              parents = parents->next, num_parent++)
1067                 hashcpy((unsigned char*)(parent + num_parent),
1068                         parents->item->object.sha1);
1069         diff_tree_combined(sha1, parent, num_parent, dense, rev);