4 * Copyright (C) Linus Torvalds, 2005
6 * This applies patches on top of some (arbitrary) version of the SCM.
8 * NOTE! It does all its work in the index file, and only cares about
9 * the files in the working directory if you tell it to "merge" the
12 * Even when merging it always takes the source from the index, and
13 * uses the working tree as a "branch" for a 3-way merge.
19 // We default to the merge behaviour, since that's what most people would
21 static int merge_patch
= 1;
22 static const char apply_usage
[] = "git-apply <patch>";
25 * For "diff-stat" like behaviour, we keep track of the biggest change
26 * we've seen, and the longest filename. That allows us to do simple
29 static int max_change
, max_len
;
32 * Various "current state", notably line numbers and what
33 * file (and how) we're patching right now.. The "is_xxxx"
34 * things are flags, where -1 means "don't know yet".
36 static int linenr
= 1;
37 static char *def_name
= NULL
;
40 unsigned long oldpos
, oldlines
;
41 unsigned long newpos
, newlines
;
44 struct fragment
*next
;
48 char *new_name
, *old_name
;
49 unsigned int old_mode
, new_mode
;
50 int is_rename
, is_copy
, is_new
, is_delete
;
51 int lines_added
, lines_deleted
;
52 struct fragment
*fragments
;
56 #define CHUNKSIZE (8192)
59 static void *read_patch_file(int fd
, unsigned long *sizep
)
61 unsigned long size
= 0, alloc
= CHUNKSIZE
;
62 void *buffer
= xmalloc(alloc
);
65 int nr
= alloc
- size
;
68 buffer
= xrealloc(buffer
, alloc
);
71 nr
= read(fd
, buffer
+ size
, nr
);
77 die("git-apply: read returned %s", strerror(errno
));
84 * Make sure that we have some slop in the buffer
85 * so that we can do speculative "memcmp" etc, and
86 * see to it that it is NUL-filled.
88 if (alloc
< size
+ SLOP
)
89 buffer
= xrealloc(buffer
, size
+ SLOP
);
90 memset(buffer
+ size
, 0, SLOP
);
94 static unsigned long linelen(char *buffer
, unsigned long size
)
96 unsigned long len
= 0;
99 if (*buffer
++ == '\n')
105 static int is_dev_null(const char *str
)
107 return !memcmp("/dev/null", str
, 9) && isspace(str
[9]);
114 static int name_terminate(const char *name
, int namelen
, int c
, int terminate
)
116 if (c
== ' ' && !(terminate
& TERM_SPACE
))
118 if (c
== '\t' && !(terminate
& TERM_TAB
))
122 * Do we want an existing name? Return false and
123 * continue if it's not there.
125 if (terminate
& TERM_EXIST
)
126 return cache_name_pos(name
, namelen
) >= 0;
131 static char * find_name(const char *line
, char *def
, int p_value
, int terminate
)
134 const char *start
= line
;
143 if (name_terminate(start
, line
-start
, c
, terminate
))
147 if (c
== '/' && !--p_value
)
157 * Generally we prefer the shorter name, especially
158 * if the other one is just a variation of that with
159 * something else tacked on to the end (ie "file.orig"
163 int deflen
= strlen(def
);
164 if (deflen
< len
&& !strncmp(start
, def
, deflen
))
168 name
= xmalloc(len
+ 1);
169 memcpy(name
, start
, len
);
176 * Get the name etc info from the --/+++ lines of a traditional patch header
178 * NOTE! This hardcodes "-p1" behaviour in filename detection.
180 * FIXME! The end-of-filename heuristics are kind of screwy. For existing
181 * files, we can happily check the index for a match, but for creating a
182 * new file we should try to match whatever "patch" does. I have no idea.
184 static void parse_traditional_patch(const char *first
, const char *second
, struct patch
*patch
)
189 first
+= 4; // skip "--- "
190 second
+= 4; // skip "+++ "
191 if (is_dev_null(first
)) {
193 patch
->is_delete
= 0;
194 name
= find_name(second
, def_name
, p_value
, TERM_SPACE
| TERM_TAB
);
195 patch
->new_name
= name
;
196 } else if (is_dev_null(second
)) {
198 patch
->is_delete
= 1;
199 name
= find_name(first
, def_name
, p_value
, TERM_EXIST
| TERM_SPACE
| TERM_TAB
);
200 patch
->old_name
= name
;
202 name
= find_name(first
, def_name
, p_value
, TERM_EXIST
| TERM_SPACE
| TERM_TAB
);
203 name
= find_name(second
, name
, p_value
, TERM_EXIST
| TERM_SPACE
| TERM_TAB
);
204 patch
->old_name
= patch
->new_name
= name
;
207 die("unable to find filename in patch at line %d", linenr
);
210 static int gitdiff_hdrend(const char *line
, struct patch
*patch
)
216 * We're anal about diff header consistency, to make
217 * sure that we don't end up having strange ambiguous
218 * patches floating around.
220 * As a result, gitdiff_{old|new}name() will check
221 * their names against any previous information, just
224 static char *gitdiff_verify_name(const char *line
, int isnull
, char *orig_name
, const char *oldnew
)
229 if (!orig_name
&& !isnull
)
230 return find_name(line
, NULL
, 1, 0);
238 die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name
, linenr
);
251 if (memcmp(line
, name
, len
) || line
[len
] != '\n')
255 die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew
, linenr
);
259 static int gitdiff_oldname(const char *line
, struct patch
*patch
)
261 patch
->old_name
= gitdiff_verify_name(line
, patch
->is_new
, patch
->old_name
, "old");
265 static int gitdiff_newname(const char *line
, struct patch
*patch
)
267 patch
->new_name
= gitdiff_verify_name(line
, patch
->is_delete
, patch
->new_name
, "new");
271 static int gitdiff_oldmode(const char *line
, struct patch
*patch
)
273 patch
->old_mode
= strtoul(line
, NULL
, 8);
277 static int gitdiff_newmode(const char *line
, struct patch
*patch
)
279 patch
->new_mode
= strtoul(line
, NULL
, 8);
283 static int gitdiff_delete(const char *line
, struct patch
*patch
)
285 patch
->is_delete
= 1;
286 return gitdiff_oldmode(line
, patch
);
289 static int gitdiff_newfile(const char *line
, struct patch
*patch
)
292 return gitdiff_newmode(line
, patch
);
295 static int gitdiff_copysrc(const char *line
, struct patch
*patch
)
298 patch
->old_name
= find_name(line
, NULL
, 0, 0);
302 static int gitdiff_copydst(const char *line
, struct patch
*patch
)
305 patch
->new_name
= find_name(line
, NULL
, 0, 0);
309 static int gitdiff_renamesrc(const char *line
, struct patch
*patch
)
311 patch
->is_rename
= 1;
312 patch
->old_name
= find_name(line
, NULL
, 0, 0);
316 static int gitdiff_renamedst(const char *line
, struct patch
*patch
)
318 patch
->is_rename
= 1;
319 patch
->new_name
= find_name(line
, NULL
, 0, 0);
323 static int gitdiff_similarity(const char *line
, struct patch
*patch
)
329 * This is normal for a diff that doesn't change anything: we'll fall through
330 * into the next diff. Tell the parser to break out.
332 static int gitdiff_unrecognized(const char *line
, struct patch
*patch
)
337 /* Verify that we recognize the lines following a git header */
338 static int parse_git_header(char *line
, int len
, unsigned int size
, struct patch
*patch
)
340 unsigned long offset
;
342 /* A git diff has explicit new/delete information, so we don't guess */
344 patch
->is_delete
= 0;
349 for (offset
= len
; size
> 0 ; offset
+= len
, size
-= len
, line
+= len
, linenr
++) {
350 static const struct opentry
{
352 int (*fn
)(const char *, struct patch
*);
354 { "@@ -", gitdiff_hdrend
},
355 { "--- ", gitdiff_oldname
},
356 { "+++ ", gitdiff_newname
},
357 { "old mode ", gitdiff_oldmode
},
358 { "new mode ", gitdiff_newmode
},
359 { "deleted file mode ", gitdiff_delete
},
360 { "new file mode ", gitdiff_newfile
},
361 { "copy from ", gitdiff_copysrc
},
362 { "copy to ", gitdiff_copydst
},
363 { "rename from ", gitdiff_renamesrc
},
364 { "rename to ", gitdiff_renamedst
},
365 { "similarity index ", gitdiff_similarity
},
366 { "", gitdiff_unrecognized
},
370 len
= linelen(line
, size
);
371 if (!len
|| line
[len
-1] != '\n')
373 for (i
= 0; i
< sizeof(optable
) / sizeof(optable
[0]); i
++) {
374 const struct opentry
*p
= optable
+ i
;
375 int oplen
= strlen(p
->str
);
376 if (len
< oplen
|| memcmp(p
->str
, line
, oplen
))
378 if (p
->fn(line
+ oplen
, patch
) < 0)
387 static int parse_num(const char *line
, int len
, int offset
, const char *expect
, unsigned long *p
)
392 if (offset
< 0 || offset
>= len
)
399 *p
= strtoul(line
, &ptr
, 10);
410 if (memcmp(line
, expect
, ex
))
417 * Parse a unified diff fragment header of the
418 * form "@@ -a,b +c,d @@"
420 static int parse_fragment_header(char *line
, int len
, struct fragment
*fragment
)
424 if (!len
|| line
[len
-1] != '\n')
427 /* Figure out the number of lines in a fragment */
428 offset
= parse_num(line
, len
, 4, ",", &fragment
->oldpos
);
429 offset
= parse_num(line
, len
, offset
, " +", &fragment
->oldlines
);
430 offset
= parse_num(line
, len
, offset
, ",", &fragment
->newpos
);
431 offset
= parse_num(line
, len
, offset
, " @@", &fragment
->newlines
);
436 static int find_header(char *line
, unsigned long size
, int *hdrsize
, struct patch
*patch
)
438 unsigned long offset
, len
;
440 patch
->is_rename
= patch
->is_copy
= 0;
441 patch
->is_new
= patch
->is_delete
= -1;
442 patch
->old_mode
= patch
->new_mode
= 0;
443 patch
->old_name
= patch
->new_name
= NULL
;
444 for (offset
= 0; size
> 0; offset
+= len
, size
-= len
, line
+= len
, linenr
++) {
445 unsigned long nextlen
;
447 len
= linelen(line
, size
);
451 /* Testing this early allows us to take a few shortcuts.. */
456 * Make sure we don't find any unconnected patch fragmants.
457 * That's a sign that we didn't find a header, and that a
458 * patch has become corrupted/broken up.
460 if (!memcmp("@@ -", line
, 4)) {
461 struct fragment dummy
;
462 if (parse_fragment_header(line
, len
, &dummy
) < 0)
464 error("patch fragment without header at line %d: %.*s", linenr
, len
-1, line
);
471 * Git patch? It might not have a real patch, just a rename
472 * or mode change, so we handle that specially
474 if (!memcmp("diff --git ", line
, 11)) {
475 int git_hdr_len
= parse_git_header(line
, len
, size
, patch
);
479 *hdrsize
= git_hdr_len
;
483 /** --- followed by +++ ? */
484 if (memcmp("--- ", line
, 4) || memcmp("+++ ", line
+ len
, 4))
488 * We only accept unified patches, so we want it to
489 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
492 nextlen
= linelen(line
+ len
, size
- len
);
493 if (size
< nextlen
+ 14 || memcmp("@@ -", line
+ len
+ nextlen
, 4))
496 /* Ok, we'll consider it a patch */
497 parse_traditional_patch(line
, line
+len
, patch
);
498 *hdrsize
= len
+ nextlen
;
506 * Parse a unified diff. Note that this really needs
507 * to parse each fragment separately, since the only
508 * way to know the difference between a "---" that is
509 * part of a patch, and a "---" that starts the next
510 * patch is to look at the line counts..
512 static int parse_fragment(char *line
, unsigned long size
, struct patch
*patch
, struct fragment
*fragment
)
515 int len
= linelen(line
, size
), offset
;
516 unsigned long pos
[4], oldlines
, newlines
;
518 offset
= parse_fragment_header(line
, len
, fragment
);
521 oldlines
= fragment
->oldlines
;
522 newlines
= fragment
->newlines
;
524 if (patch
->is_new
< 0 && (pos
[0] || oldlines
))
526 if (patch
->is_delete
< 0 && (pos
[1] || newlines
))
527 patch
->is_delete
= 0;
529 /* Parse the thing.. */
534 for (offset
= len
; size
> 0; offset
+= len
, size
-= len
, line
+= len
, linenr
++) {
535 if (!oldlines
&& !newlines
)
537 len
= linelen(line
, size
);
538 if (!len
|| line
[len
-1] != '\n')
557 patch
->lines_added
+= added
;
558 patch
->lines_deleted
+= deleted
;
562 static int parse_single_patch(char *line
, unsigned long size
, struct patch
*patch
)
564 unsigned long offset
= 0;
565 struct fragment
**fragp
= &patch
->fragments
;
567 while (size
> 4 && !memcmp(line
, "@@ -", 4)) {
568 struct fragment
*fragment
;
571 fragment
= xmalloc(sizeof(*fragment
));
572 memset(fragment
, 0, sizeof(*fragment
));
573 len
= parse_fragment(line
, size
, patch
, fragment
);
575 die("corrupt patch at line %d", linenr
);
577 fragment
->patch
= line
;
578 fragment
->size
= len
;
581 fragp
= &fragment
->next
;
590 static int parse_chunk(char *buffer
, unsigned long size
, struct patch
*patch
)
592 int hdrsize
, patchsize
;
593 int offset
= find_header(buffer
, size
, &hdrsize
, patch
);
598 patchsize
= parse_single_patch(buffer
+ offset
+ hdrsize
, size
- offset
- hdrsize
, patch
);
600 return offset
+ hdrsize
+ patchsize
;
603 const char pluses
[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
604 const char minuses
[]= "----------------------------------------------------------------------";
606 static void show_stats(struct patch
*patch
)
608 char *name
= patch
->old_name
;
609 int len
, max
, add
, del
;
612 name
= patch
->new_name
;
615 * "scale" the filename
626 * scale the add/delete
632 add
= (patch
->lines_added
* max
+ max_change
/2) / max_change
;
633 del
= (patch
->lines_deleted
* max
+ max_change
/2) / max_change
;
634 printf(" %-*s |%5d %.*s%.*s\n",
635 len
, name
, patch
->lines_added
+ patch
->lines_deleted
,
636 add
, pluses
, del
, minuses
);
639 static void apply_patch_list(struct patch
*patch
)
641 int files
, adds
, dels
;
643 files
= adds
= dels
= 0;
645 die("no patch found");
647 const char *old_name
= patch
->old_name
;
648 const char *new_name
= patch
->new_name
;
651 if (cache_name_pos(old_name
, strlen(old_name
)) < 0)
652 die("file %s does not exist", old_name
);
653 if (patch
->is_new
< 0)
656 if (new_name
&& (patch
->is_new
| patch
->is_rename
| patch
->is_copy
)) {
657 if (cache_name_pos(new_name
, strlen(new_name
)) >= 0)
658 die("file %s already exists", new_name
);
662 adds
+= patch
->lines_added
;
663 dels
+= patch
->lines_deleted
;
665 } while ((patch
= patch
->next
) != NULL
);
666 printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files
, adds
, dels
);
669 static void patch_stats(struct patch
*patch
)
671 int lines
= patch
->lines_added
+ patch
->lines_deleted
;
673 if (lines
> max_change
)
675 if (patch
->old_name
) {
676 int len
= strlen(patch
->old_name
);
680 if (patch
->new_name
) {
681 int len
= strlen(patch
->new_name
);
687 static int apply_patch(int fd
)
689 unsigned long offset
, size
;
690 char *buffer
= read_patch_file(fd
, &size
);
691 struct patch
*list
= NULL
, **listp
= &list
;
700 patch
= xmalloc(sizeof(*patch
));
701 memset(patch
, 0, sizeof(*patch
));
702 nr
= parse_chunk(buffer
+ offset
, size
, patch
);
707 listp
= &patch
->next
;
712 apply_patch_list(list
);
718 int main(int argc
, char **argv
)
723 if (read_cache() < 0)
724 die("unable to read index file");
726 for (i
= 1; i
< argc
; i
++) {
727 const char *arg
= argv
[i
];
730 if (!strcmp(arg
, "-")) {
735 if (!strcmp(arg
, "--no-merge")) {
739 fd
= open(arg
, O_RDONLY
);