7 #include "xdiff-interface.h"
9 static int uninteresting(struct diff_filepair
*p
)
11 if (diff_unmodified_pair(p
))
16 static struct combine_diff_path
*intersect_paths(struct combine_diff_path
*curr
, int n
, int num_parent
)
18 struct diff_queue_struct
*q
= &diff_queued_diff
;
19 struct combine_diff_path
*p
;
23 struct combine_diff_path
*list
= NULL
, **tail
= &list
;
24 for (i
= 0; i
< q
->nr
; i
++) {
27 if (uninteresting(q
->queue
[i
]))
29 path
= q
->queue
[i
]->two
->path
;
31 p
= xmalloc(combine_diff_path_size(num_parent
, len
));
32 p
->path
= (char*) &(p
->parent
[num_parent
]);
33 memcpy(p
->path
, path
, len
);
38 sizeof(p
->parent
[0]) * num_parent
);
40 memcpy(p
->sha1
, q
->queue
[i
]->two
->sha1
, 20);
41 p
->mode
= q
->queue
[i
]->two
->mode
;
42 memcpy(p
->parent
[n
].sha1
, q
->queue
[i
]->one
->sha1
, 20);
43 p
->parent
[n
].mode
= q
->queue
[i
]->one
->mode
;
44 p
->parent
[n
].status
= q
->queue
[i
]->status
;
51 for (p
= curr
; p
; p
= p
->next
) {
55 for (i
= 0; i
< q
->nr
; i
++) {
59 if (uninteresting(q
->queue
[i
]))
61 path
= q
->queue
[i
]->two
->path
;
63 if (len
== p
->len
&& !memcmp(path
, p
->path
, len
)) {
65 memcpy(p
->parent
[n
].sha1
,
66 q
->queue
[i
]->one
->sha1
, 20);
67 p
->parent
[n
].mode
= q
->queue
[i
]->one
->mode
;
68 p
->parent
[n
].status
= q
->queue
[i
]->status
;
78 /* Lines lost from parent */
82 unsigned long parent_map
;
83 char line
[FLEX_ARRAY
];
86 /* Lines surviving in the merge result */
88 struct lline
*lost_head
, **lost_tail
;
91 /* bit 0 up to (N-1) are on if the parent has this line (i.e.
92 * we did not change it).
93 * bit N is used for "interesting" lines, including context.
99 static char *grab_blob(const unsigned char *sha1
, unsigned long *size
)
103 if (!memcmp(sha1
, null_sha1
, 20)) {
106 return xcalloc(1, 1);
108 blob
= read_sha1_file(sha1
, type
, size
);
109 if (strcmp(type
, blob_type
))
110 die("object '%s' is not a blob!", sha1_to_hex(sha1
));
114 static void append_lost(struct sline
*sline
, int n
, const char *line
, int len
)
117 unsigned long this_mask
= (1UL<<n
);
118 if (line
[len
-1] == '\n')
121 /* Check to see if we can squash things */
122 if (sline
->lost_head
) {
123 struct lline
*last_one
= NULL
;
124 /* We cannot squash it with earlier one */
125 for (lline
= sline
->lost_head
;
128 if (lline
->parent_map
& this_mask
)
130 lline
= last_one
? last_one
->next
: sline
->lost_head
;
132 if (lline
->len
== len
&&
133 !memcmp(lline
->line
, line
, len
)) {
134 lline
->parent_map
|= this_mask
;
141 lline
= xmalloc(sizeof(*lline
) + len
+ 1);
144 lline
->parent_map
= this_mask
;
145 memcpy(lline
->line
, line
, len
);
146 lline
->line
[len
] = 0;
147 *sline
->lost_tail
= lline
;
148 sline
->lost_tail
= &lline
->next
;
151 struct combine_diff_state
{
152 struct xdiff_emit_state xm
;
154 unsigned int lno
, ob
, on
, nb
, nn
;
159 struct sline
*lost_bucket
;
162 static void consume_line(void *state_
, char *line
, unsigned long len
)
164 struct combine_diff_state
*state
= state_
;
165 if (5 < len
&& !memcmp("@@ -", line
, 4)) {
166 if (parse_hunk_header(line
, len
,
167 &state
->ob
, &state
->on
,
168 &state
->nb
, &state
->nn
))
170 state
->lno
= state
->nb
;
172 /* @@ -1,2 +0,0 @@ to remove the
177 /* @@ -X,Y +N,0 @@ removed Y lines
178 * that would have come *after* line N
179 * in the result. Our lost buckets hang
180 * to the line after the removed lines,
182 state
->lost_bucket
= &state
->sline
[state
->nb
];
184 state
->lost_bucket
= &state
->sline
[state
->nb
-1];
185 if (!state
->sline
[state
->nb
-1].p_lno
)
186 state
->sline
[state
->nb
-1].p_lno
=
187 xcalloc(state
->num_parent
,
188 sizeof(unsigned long));
189 state
->sline
[state
->nb
-1].p_lno
[state
->n
] = state
->ob
;
192 if (!state
->lost_bucket
)
193 return; /* not in any hunk yet */
196 append_lost(state
->lost_bucket
, state
->n
, line
+1, len
-1);
199 state
->sline
[state
->lno
-1].flag
|= state
->nmask
;
205 static void combine_diff(const unsigned char *parent
, mmfile_t
*result_file
,
206 struct sline
*sline
, int cnt
, int n
, int num_parent
)
208 unsigned int p_lno
, lno
;
209 unsigned long nmask
= (1UL << n
);
212 mmfile_t parent_file
;
214 struct combine_diff_state state
;
218 return; /* result deleted */
220 parent_file
.ptr
= grab_blob(parent
, &sz
);
221 parent_file
.size
= sz
;
222 xpp
.flags
= XDF_NEED_MINIMAL
;
225 ecb
.outf
= xdiff_outf
;
227 memset(&state
, 0, sizeof(state
));
228 state
.xm
.consume
= consume_line
;
232 state
.num_parent
= num_parent
;
235 xdl_diff(&parent_file
, result_file
, &xpp
, &xecfg
, &ecb
);
236 free(parent_file
.ptr
);
238 /* Assign line numbers for this parent.
240 * sline[lno].p_lno[n] records the first line number
241 * (counting from 1) for parent N if the final hunk display
242 * started by showing sline[lno] (possibly showing the lost
243 * lines attached to it first).
245 for (lno
= 0, p_lno
= 1; lno
< cnt
; lno
++) {
247 sline
[lno
].p_lno
[n
] = p_lno
;
249 /* How many lines would this sline advance the p_lno? */
250 ll
= sline
[lno
].lost_head
;
252 if (ll
->parent_map
& nmask
)
253 p_lno
++; /* '-' means parent had it */
256 if (!(sline
[lno
].flag
& nmask
))
257 p_lno
++; /* no '+' means parent had it */
259 sline
[lno
].p_lno
[n
] = p_lno
; /* trailer */
262 static unsigned long context
= 3;
263 static char combine_marker
= '@';
265 static int interesting(struct sline
*sline
, unsigned long all_mask
)
267 /* If some parents lost lines here, or if we have added to
268 * some parent, it is interesting.
270 return ((sline
->flag
& all_mask
) || sline
->lost_head
);
273 static unsigned long adjust_hunk_tail(struct sline
*sline
,
274 unsigned long all_mask
,
275 unsigned long hunk_begin
,
278 /* i points at the first uninteresting line. If the last line
279 * of the hunk was interesting only because it has some
280 * deletion, then it is not all that interesting for the
281 * purpose of giving trailing context lines. This is because
282 * we output '-' line and then unmodified sline[i-1] itself in
283 * that case which gives us one extra context line.
285 if ((hunk_begin
+ 1 <= i
) && !(sline
[i
-1].flag
& all_mask
))
290 static unsigned long find_next(struct sline
*sline
,
296 /* We have examined up to i-1 and are about to look at i.
297 * Find next interesting or uninteresting line. Here,
298 * "interesting" does not mean interesting(), but marked by
299 * the give_context() function below (i.e. it includes context
300 * lines that are not interesting to interesting() function
301 * that are surrounded by interesting() ones.
305 ? !(sline
[i
].flag
& mark
)
306 : (sline
[i
].flag
& mark
))
313 static int give_context(struct sline
*sline
, unsigned long cnt
, int num_parent
)
315 unsigned long all_mask
= (1UL<<num_parent
) - 1;
316 unsigned long mark
= (1UL<<num_parent
);
319 /* Two groups of interesting lines may have a short gap of
320 * unintersting lines. Connect such groups to give them a
323 * We first start from what the interesting() function says,
324 * and mark them with "mark", and paint context lines with the
325 * mark. So interesting() would still say false for such context
326 * lines but they are treated as "interesting" in the end.
328 i
= find_next(sline
, mark
, 0, cnt
, 0);
333 unsigned long j
= (context
< i
) ? (i
- context
) : 0;
336 /* Paint a few lines before the first interesting line. */
338 sline
[j
++].flag
|= mark
;
341 /* we know up to i is to be included. where does the
342 * next uninteresting one start?
344 j
= find_next(sline
, mark
, i
, cnt
, 1);
346 break; /* the rest are all interesting */
348 /* lookahead context lines */
349 k
= find_next(sline
, mark
, j
, cnt
, 0);
350 j
= adjust_hunk_tail(sline
, all_mask
, i
, j
);
352 if (k
< j
+ context
) {
353 /* k is interesting and [j,k) are not, but
354 * paint them interesting because the gap is small.
357 sline
[j
++].flag
|= mark
;
362 /* j is the first uninteresting line and there is
363 * no overlap beyond it within context lines. Paint
364 * the trailing edge a bit.
367 k
= (j
+ context
< cnt
) ? j
+ context
: cnt
;
369 sline
[j
++].flag
|= mark
;
374 static int make_hunks(struct sline
*sline
, unsigned long cnt
,
375 int num_parent
, int dense
)
377 unsigned long all_mask
= (1UL<<num_parent
) - 1;
378 unsigned long mark
= (1UL<<num_parent
);
380 int has_interesting
= 0;
382 for (i
= 0; i
< cnt
; i
++) {
383 if (interesting(&sline
[i
], all_mask
))
384 sline
[i
].flag
|= mark
;
386 sline
[i
].flag
&= ~mark
;
389 return give_context(sline
, cnt
, num_parent
);
391 /* Look at each hunk, and if we have changes from only one
392 * parent, or the changes are the same from all but one
393 * parent, mark that uninteresting.
397 unsigned long j
, hunk_begin
, hunk_end
;
398 unsigned long same_diff
;
399 while (i
< cnt
&& !(sline
[i
].flag
& mark
))
402 break; /* No more interesting hunks */
404 for (j
= i
+ 1; j
< cnt
; j
++) {
405 if (!(sline
[j
].flag
& mark
)) {
406 /* Look beyond the end to see if there
407 * is an interesting line after this
408 * hunk within context span.
410 unsigned long la
; /* lookahead */
412 la
= adjust_hunk_tail(sline
, all_mask
,
414 la
= (la
+ context
< cnt
) ?
415 (la
+ context
) : cnt
;
417 if (sline
[la
].flag
& mark
) {
429 /* [i..hunk_end) are interesting. Now is it really
430 * interesting? We check if there are only two versions
431 * and the result matches one of them. That is, we look
433 * (+) line, which records lines added to which parents;
434 * this line appears in the result.
435 * (-) line, which records from what parents the line
436 * was removed; this line does not appear in the result.
437 * then check the set of parents the result has difference
438 * from, from all lines. If there are lines that has
439 * different set of parents that the result has differences
440 * from, that means we have more than two versions.
442 * Even when we have only two versions, if the result does
443 * not match any of the parents, the it should be considered
444 * interesting. In such a case, we would have all '+' line.
445 * After passing the above "two versions" test, that would
446 * appear as "the same set of parents" to be "all parents".
450 for (j
= i
; j
< hunk_end
&& !has_interesting
; j
++) {
451 unsigned long this_diff
= sline
[j
].flag
& all_mask
;
452 struct lline
*ll
= sline
[j
].lost_head
;
454 /* This has some changes. Is it the
458 same_diff
= this_diff
;
459 else if (same_diff
!= this_diff
) {
464 while (ll
&& !has_interesting
) {
465 /* Lost this line from these parents;
466 * who are they? Are they the same?
468 this_diff
= ll
->parent_map
;
470 same_diff
= this_diff
;
471 else if (same_diff
!= this_diff
) {
478 if (!has_interesting
&& same_diff
!= all_mask
) {
479 /* This hunk is not that interesting after all */
480 for (j
= hunk_begin
; j
< hunk_end
; j
++)
481 sline
[j
].flag
&= ~mark
;
486 has_interesting
= give_context(sline
, cnt
, num_parent
);
487 return has_interesting
;
490 static void show_parent_lno(struct sline
*sline
, unsigned long l0
, unsigned long l1
, unsigned long cnt
, int n
)
492 l0
= sline
[l0
].p_lno
[n
];
493 l1
= sline
[l1
].p_lno
[n
];
494 printf(" -%lu,%lu", l0
, l1
-l0
);
497 static void dump_sline(struct sline
*sline
, unsigned long cnt
, int num_parent
)
499 unsigned long mark
= (1UL<<num_parent
);
501 unsigned long lno
= 0;
504 return; /* result deleted */
507 struct sline
*sl
= &sline
[lno
];
509 while (lno
< cnt
&& !(sline
[lno
].flag
& mark
))
513 for (hunk_end
= lno
+ 1; hunk_end
< cnt
; hunk_end
++)
514 if (!(sline
[hunk_end
].flag
& mark
))
516 for (i
= 0; i
<= num_parent
; i
++) putchar(combine_marker
);
517 for (i
= 0; i
< num_parent
; i
++)
518 show_parent_lno(sline
, lno
, hunk_end
, cnt
, i
);
519 printf(" +%lu,%lu ", lno
+1, hunk_end
-lno
);
520 for (i
= 0; i
<= num_parent
; i
++) putchar(combine_marker
);
522 while (lno
< hunk_end
) {
525 unsigned long p_mask
;
529 for (j
= 0; j
< num_parent
; j
++) {
530 if (ll
->parent_map
& (1UL<<j
))
539 for (j
= 0; j
< num_parent
; j
++) {
540 if (p_mask
& sl
->flag
)
546 printf("%.*s\n", sl
->len
, sl
->bol
);
551 static void reuse_combine_diff(struct sline
*sline
, unsigned long cnt
,
554 /* We have already examined parent j and we know parent i
555 * and parent j are the same, so reuse the combined result
556 * of parent j for parent i.
558 unsigned long lno
, imask
, jmask
;
562 for (lno
= 0; lno
< cnt
; lno
++) {
563 struct lline
*ll
= sline
->lost_head
;
564 sline
->p_lno
[i
] = sline
->p_lno
[j
];
566 if (ll
->parent_map
& jmask
)
567 ll
->parent_map
|= imask
;
570 if (sline
->flag
& jmask
)
571 sline
->flag
|= imask
;
574 /* the overall size of the file (sline[cnt]) */
575 sline
->p_lno
[i
] = sline
->p_lno
[j
];
578 static int show_patch_diff(struct combine_diff_path
*elem
, int num_parent
,
579 int dense
, const char *header
,
580 struct diff_options
*opt
)
582 unsigned long result_size
, cnt
, lno
;
583 char *result
, *cp
, *ep
;
584 struct sline
*sline
; /* survived lines */
585 int mode_differs
= 0;
586 int i
, show_hunks
, shown_header
= 0;
587 int working_tree_file
= !memcmp(elem
->sha1
, null_sha1
, 20);
588 int abbrev
= opt
->full_index
? 40 : DEFAULT_ABBREV
;
589 mmfile_t result_file
;
591 /* Read the result of merge first */
592 if (!working_tree_file
)
593 result
= grab_blob(elem
->sha1
, &result_size
);
595 /* Used by diff-tree to read from the working tree */
598 if (0 <= (fd
= open(elem
->path
, O_RDONLY
)) &&
600 int len
= st
.st_size
;
603 elem
->mode
= canon_mode(st
.st_mode
);
605 result
= xmalloc(len
+ 1);
607 int done
= xread(fd
, result
+cnt
, len
-cnt
);
611 die("read error '%s'", elem
->path
);
627 for (cnt
= 0, cp
= result
; cp
- result
< result_size
; cp
++) {
631 if (result_size
&& result
[result_size
-1] != '\n')
632 cnt
++; /* incomplete line */
634 sline
= xcalloc(cnt
+1, sizeof(*sline
));
636 sline
[0].bol
= result
;
637 for (lno
= 0; lno
<= cnt
; lno
++) {
638 sline
[lno
].lost_tail
= &sline
[lno
].lost_head
;
641 for (lno
= 0, cp
= result
; cp
- result
< result_size
; cp
++) {
643 sline
[lno
].len
= cp
- sline
[lno
].bol
;
646 sline
[lno
].bol
= cp
+ 1;
649 if (result_size
&& result
[result_size
-1] != '\n')
650 sline
[cnt
-1].len
= result_size
- (sline
[cnt
-1].bol
- result
);
652 result_file
.ptr
= result
;
653 result_file
.size
= result_size
;
655 sline
[0].p_lno
= xcalloc((cnt
+1) * num_parent
, sizeof(unsigned long));
656 for (lno
= 0; lno
< cnt
; lno
++)
657 sline
[lno
+1].p_lno
= sline
[lno
].p_lno
+ num_parent
;
659 for (i
= 0; i
< num_parent
; i
++) {
661 for (j
= 0; j
< i
; j
++) {
662 if (!memcmp(elem
->parent
[i
].sha1
,
663 elem
->parent
[j
].sha1
, 20)) {
664 reuse_combine_diff(sline
, cnt
, i
, j
);
669 combine_diff(elem
->parent
[i
].sha1
, &result_file
, sline
,
671 if (elem
->parent
[i
].mode
!= elem
->mode
)
675 show_hunks
= make_hunks(sline
, cnt
, num_parent
, dense
);
677 if (show_hunks
|| mode_differs
|| working_tree_file
) {
682 printf("%s%c", header
, opt
->line_termination
);
684 printf("diff --%s ", dense
? "cc" : "combined");
685 if (quote_c_style(elem
->path
, NULL
, NULL
, 0))
686 quote_c_style(elem
->path
, NULL
, stdout
, 0);
688 printf("%s", elem
->path
);
691 for (i
= 0; i
< num_parent
; i
++) {
692 abb
= find_unique_abbrev(elem
->parent
[i
].sha1
,
694 printf("%s%s", i
? "," : "", abb
);
696 abb
= find_unique_abbrev(elem
->sha1
, abbrev
);
697 printf("..%s\n", abb
);
700 int added
= !!elem
->mode
;
701 for (i
= 0; added
&& i
< num_parent
; i
++)
702 if (elem
->parent
[i
].status
!=
706 printf("new file mode %06o", elem
->mode
);
709 printf("deleted file ");
711 for (i
= 0; i
< num_parent
; i
++) {
712 printf("%s%06o", i
? "," : "",
713 elem
->parent
[i
].mode
);
716 printf("..%06o", elem
->mode
);
720 dump_sline(sline
, cnt
, num_parent
);
724 for (i
= 0; i
< cnt
; i
++) {
725 if (sline
[i
].lost_head
) {
726 struct lline
*ll
= sline
[i
].lost_head
;
728 struct lline
*tmp
= ll
;
734 free(sline
[0].p_lno
);
739 #define COLONS "::::::::::::::::::::::::::::::::"
741 static void show_raw_diff(struct combine_diff_path
*p
, int num_parent
, const char *header
, struct diff_options
*opt
)
743 int i
, offset
, mod_type
= 'A';
745 int line_termination
, inter_name_termination
;
747 line_termination
= opt
->line_termination
;
748 inter_name_termination
= '\t';
749 if (!line_termination
)
750 inter_name_termination
= 0;
753 printf("%s%c", header
, line_termination
);
755 for (i
= 0; i
< num_parent
; i
++) {
756 if (p
->parent
[i
].mode
)
762 if (opt
->output_format
== DIFF_FORMAT_RAW
) {
763 offset
= strlen(COLONS
) - num_parent
;
766 prefix
= COLONS
+ offset
;
769 for (i
= 0; i
< num_parent
; i
++) {
770 printf("%s%06o", prefix
, p
->parent
[i
].mode
);
773 printf("%s%06o", prefix
, p
->mode
);
776 for (i
= 0; i
< num_parent
; i
++)
777 printf(" %s", diff_unique_abbrev(p
->parent
[i
].sha1
,
779 printf(" %s ", diff_unique_abbrev(p
->sha1
, opt
->abbrev
));
782 if (opt
->output_format
== DIFF_FORMAT_RAW
||
783 opt
->output_format
== DIFF_FORMAT_NAME_STATUS
) {
784 for (i
= 0; i
< num_parent
; i
++)
785 putchar(p
->parent
[i
].status
);
786 putchar(inter_name_termination
);
789 if (line_termination
) {
790 if (quote_c_style(p
->path
, NULL
, NULL
, 0))
791 quote_c_style(p
->path
, NULL
, stdout
, 0);
793 printf("%s", p
->path
);
794 putchar(line_termination
);
797 printf("%s%c", p
->path
, line_termination
);
801 int show_combined_diff(struct combine_diff_path
*p
,
805 struct diff_options
*opt
)
809 switch (opt
->output_format
) {
810 case DIFF_FORMAT_RAW
:
811 case DIFF_FORMAT_NAME_STATUS
:
812 case DIFF_FORMAT_NAME
:
813 show_raw_diff(p
, num_parent
, header
, opt
);
817 case DIFF_FORMAT_PATCH
:
818 return show_patch_diff(p
, num_parent
, dense
, header
, opt
);
822 const char *diff_tree_combined_merge(const unsigned char *sha1
,
823 const char *header
, int dense
,
824 struct diff_options
*opt
)
826 struct commit
*commit
= lookup_commit(sha1
);
827 struct diff_options diffopts
;
828 struct commit_list
*parents
;
829 struct combine_diff_path
*p
, *paths
= NULL
;
830 int num_parent
, i
, num_paths
;
833 diffopts
.output_format
= DIFF_FORMAT_NO_OUTPUT
;
834 diffopts
.recursive
= 1;
837 for (parents
= commit
->parents
, num_parent
= 0;
839 parents
= parents
->next
, num_parent
++)
842 /* find set of paths that everybody touches */
843 for (parents
= commit
->parents
, i
= 0;
845 parents
= parents
->next
, i
++) {
846 struct commit
*parent
= parents
->item
;
847 diff_tree_sha1(parent
->object
.sha1
, commit
->object
.sha1
, "",
849 diffcore_std(&diffopts
);
850 paths
= intersect_paths(paths
, i
, num_parent
);
851 diff_flush(&diffopts
);
854 /* find out surviving paths */
855 for (num_paths
= 0, p
= paths
; p
; p
= p
->next
) {
860 for (p
= paths
; p
; p
= p
->next
) {
861 if (show_combined_diff(p
, num_parent
, dense
,
867 /* Clean things up */
869 struct combine_diff_path
*tmp
= paths
;