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 int diffstat = 0;
24 static const char apply_usage[] = "git-apply <patch>";
27 * For "diff-stat" like behaviour, we keep track of the biggest change
28 * we've seen, and the longest filename. That allows us to do simple
31 static int max_change, max_len;
34 * Various "current state", notably line numbers and what
35 * file (and how) we're patching right now.. The "is_xxxx"
36 * things are flags, where -1 means "don't know yet".
38 static int linenr = 1;
41 unsigned long oldpos, oldlines;
42 unsigned long newpos, newlines;
45 struct fragment *next;
49 char *new_name, *old_name, *def_name;
50 unsigned int old_mode, new_mode;
51 int is_rename, is_copy, is_new, is_delete;
52 int lines_added, lines_deleted;
53 struct fragment *fragments;
57 #define CHUNKSIZE (8192)
60 static void *read_patch_file(int fd, unsigned long *sizep)
62 unsigned long size = 0, alloc = CHUNKSIZE;
63 void *buffer = xmalloc(alloc);
66 int nr = alloc - size;
69 buffer = xrealloc(buffer, alloc);
72 nr = read(fd, buffer + size, nr);
78 die("git-apply: read returned %s", strerror(errno));
85 * Make sure that we have some slop in the buffer
86 * so that we can do speculative "memcmp" etc, and
87 * see to it that it is NUL-filled.
89 if (alloc < size + SLOP)
90 buffer = xrealloc(buffer, size + SLOP);
91 memset(buffer + size, 0, SLOP);
95 static unsigned long linelen(char *buffer, unsigned long size)
97 unsigned long len = 0;
100 if (*buffer++ == '\n')
106 static int is_dev_null(const char *str)
108 return !memcmp("/dev/null", str, 9) && isspace(str[9]);
115 static int name_terminate(const char *name, int namelen, int c, int terminate)
117 if (c == ' ' && !(terminate & TERM_SPACE))
119 if (c == '\t' && !(terminate & TERM_TAB))
123 * Do we want an existing name? Return false and
124 * continue if it's not there.
126 if (terminate & TERM_EXIST)
127 return cache_name_pos(name, namelen) >= 0;
132 static char * find_name(const char *line, char *def, int p_value, int terminate)
135 const char *start = line;
144 if (name_terminate(start, line-start, c, terminate))
148 if (c == '/' && !--p_value)
158 * Generally we prefer the shorter name, especially
159 * if the other one is just a variation of that with
160 * something else tacked on to the end (ie "file.orig"
164 int deflen = strlen(def);
165 if (deflen < len && !strncmp(start, def, deflen))
169 name = xmalloc(len + 1);
170 memcpy(name, start, len);
177 * Get the name etc info from the --/+++ lines of a traditional patch header
179 * NOTE! This hardcodes "-p1" behaviour in filename detection.
181 * FIXME! The end-of-filename heuristics are kind of screwy. For existing
182 * files, we can happily check the index for a match, but for creating a
183 * new file we should try to match whatever "patch" does. I have no idea.
185 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
190 first += 4; // skip "--- "
191 second += 4; // skip "+++ "
192 if (is_dev_null(first)) {
194 patch->is_delete = 0;
195 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
196 patch->new_name = name;
197 } else if (is_dev_null(second)) {
199 patch->is_delete = 1;
200 name = find_name(first, NULL, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
201 patch->old_name = name;
203 name = find_name(first, NULL, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
204 name = find_name(second, name, p_value, TERM_EXIST | TERM_SPACE | TERM_TAB);
205 patch->old_name = patch->new_name = name;
208 die("unable to find filename in patch at line %d", linenr);
211 static int gitdiff_hdrend(const char *line, struct patch *patch)
217 * We're anal about diff header consistency, to make
218 * sure that we don't end up having strange ambiguous
219 * patches floating around.
221 * As a result, gitdiff_{old|new}name() will check
222 * their names against any previous information, just
225 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
230 if (!orig_name && !isnull)
231 return find_name(line, NULL, 1, 0);
239 die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
252 if (memcmp(line, name, len) || line[len] != '\n')
256 die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
260 static int gitdiff_oldname(const char *line, struct patch *patch)
262 patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
266 static int gitdiff_newname(const char *line, struct patch *patch)
268 patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
272 static int gitdiff_oldmode(const char *line, struct patch *patch)
274 patch->old_mode = strtoul(line, NULL, 8);
278 static int gitdiff_newmode(const char *line, struct patch *patch)
280 patch->new_mode = strtoul(line, NULL, 8);
284 static int gitdiff_delete(const char *line, struct patch *patch)
286 patch->is_delete = 1;
287 patch->old_name = patch->def_name;
288 return gitdiff_oldmode(line, patch);
291 static int gitdiff_newfile(const char *line, struct patch *patch)
294 patch->new_name = patch->def_name;
295 return gitdiff_newmode(line, patch);
298 static int gitdiff_copysrc(const char *line, struct patch *patch)
301 patch->old_name = find_name(line, NULL, 0, 0);
305 static int gitdiff_copydst(const char *line, struct patch *patch)
308 patch->new_name = find_name(line, NULL, 0, 0);
312 static int gitdiff_renamesrc(const char *line, struct patch *patch)
314 patch->is_rename = 1;
315 patch->old_name = find_name(line, NULL, 0, 0);
319 static int gitdiff_renamedst(const char *line, struct patch *patch)
321 patch->is_rename = 1;
322 patch->new_name = find_name(line, NULL, 0, 0);
326 static int gitdiff_similarity(const char *line, struct patch *patch)
332 * This is normal for a diff that doesn't change anything: we'll fall through
333 * into the next diff. Tell the parser to break out.
335 static int gitdiff_unrecognized(const char *line, struct patch *patch)
340 static char *git_header_name(char *line)
358 * We don't accept absolute paths (/dev/null) as possibly valid
364 * Accept a name only if it shows up twice, exactly the same
367 for (len = 0 ; ; len++) {
384 if (second[len] == '\n' && !memcmp(name, second, len)) {
385 char *ret = xmalloc(len + 1);
386 memcpy(ret, name, len);
395 /* Verify that we recognize the lines following a git header */
396 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
398 unsigned long offset;
400 /* A git diff has explicit new/delete information, so we don't guess */
402 patch->is_delete = 0;
405 * Some things may not have the old name in the
406 * rest of the headers anywhere (pure mode changes,
407 * or removing or adding empty files), so we get
408 * the default name from the header.
410 patch->def_name = git_header_name(line + strlen("diff --git "));
415 for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
416 static const struct opentry {
418 int (*fn)(const char *, struct patch *);
420 { "@@ -", gitdiff_hdrend },
421 { "--- ", gitdiff_oldname },
422 { "+++ ", gitdiff_newname },
423 { "old mode ", gitdiff_oldmode },
424 { "new mode ", gitdiff_newmode },
425 { "deleted file mode ", gitdiff_delete },
426 { "new file mode ", gitdiff_newfile },
427 { "copy from ", gitdiff_copysrc },
428 { "copy to ", gitdiff_copydst },
429 { "rename from ", gitdiff_renamesrc },
430 { "rename to ", gitdiff_renamedst },
431 { "similarity index ", gitdiff_similarity },
432 { "", gitdiff_unrecognized },
436 len = linelen(line, size);
437 if (!len || line[len-1] != '\n')
439 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
440 const struct opentry *p = optable + i;
441 int oplen = strlen(p->str);
442 if (len < oplen || memcmp(p->str, line, oplen))
444 if (p->fn(line + oplen, patch) < 0)
453 static int parse_num(const char *line, unsigned long *p)
459 *p = strtoul(line, &ptr, 10);
463 static int parse_range(const char *line, int len, int offset, const char *expect,
464 unsigned long *p1, unsigned long *p2)
468 if (offset < 0 || offset >= len)
473 digits = parse_num(line, p1);
483 digits = parse_num(line+1, p2);
495 if (memcmp(line, expect, ex))
502 * Parse a unified diff fragment header of the
503 * form "@@ -a,b +c,d @@"
505 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
509 if (!len || line[len-1] != '\n')
512 /* Figure out the number of lines in a fragment */
513 offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
514 offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
519 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
521 unsigned long offset, len;
523 patch->is_rename = patch->is_copy = 0;
524 patch->is_new = patch->is_delete = -1;
525 patch->old_mode = patch->new_mode = 0;
526 patch->old_name = patch->new_name = NULL;
527 for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
528 unsigned long nextlen;
530 len = linelen(line, size);
534 /* Testing this early allows us to take a few shortcuts.. */
539 * Make sure we don't find any unconnected patch fragmants.
540 * That's a sign that we didn't find a header, and that a
541 * patch has become corrupted/broken up.
543 if (!memcmp("@@ -", line, 4)) {
544 struct fragment dummy;
545 if (parse_fragment_header(line, len, &dummy) < 0)
547 error("patch fragment without header at line %d: %.*s", linenr, len-1, line);
554 * Git patch? It might not have a real patch, just a rename
555 * or mode change, so we handle that specially
557 if (!memcmp("diff --git ", line, 11)) {
558 int git_hdr_len = parse_git_header(line, len, size, patch);
561 if (!patch->old_name && !patch->new_name)
562 die("git diff header lacks filename information");
563 *hdrsize = git_hdr_len;
567 /** --- followed by +++ ? */
568 if (memcmp("--- ", line, 4) || memcmp("+++ ", line + len, 4))
572 * We only accept unified patches, so we want it to
573 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
576 nextlen = linelen(line + len, size - len);
577 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
580 /* Ok, we'll consider it a patch */
581 parse_traditional_patch(line, line+len, patch);
582 *hdrsize = len + nextlen;
590 * Parse a unified diff. Note that this really needs
591 * to parse each fragment separately, since the only
592 * way to know the difference between a "---" that is
593 * part of a patch, and a "---" that starts the next
594 * patch is to look at the line counts..
596 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
599 int len = linelen(line, size), offset;
600 unsigned long pos[4], oldlines, newlines;
602 offset = parse_fragment_header(line, len, fragment);
605 oldlines = fragment->oldlines;
606 newlines = fragment->newlines;
608 if (patch->is_new < 0 && (pos[0] || oldlines))
610 if (patch->is_delete < 0 && (pos[1] || newlines))
611 patch->is_delete = 0;
613 /* Parse the thing.. */
618 for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
619 if (!oldlines && !newlines)
621 len = linelen(line, size);
622 if (!len || line[len-1] != '\n')
639 /* We allow "\ No newline at end of file" */
644 patch->lines_added += added;
645 patch->lines_deleted += deleted;
649 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
651 unsigned long offset = 0;
652 struct fragment **fragp = &patch->fragments;
654 while (size > 4 && !memcmp(line, "@@ -", 4)) {
655 struct fragment *fragment;
658 fragment = xmalloc(sizeof(*fragment));
659 memset(fragment, 0, sizeof(*fragment));
660 len = parse_fragment(line, size, patch, fragment);
662 die("corrupt patch at line %d", linenr);
664 fragment->patch = line;
665 fragment->size = len;
668 fragp = &fragment->next;
677 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
679 int hdrsize, patchsize;
680 int offset = find_header(buffer, size, &hdrsize, patch);
685 patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
687 return offset + hdrsize + patchsize;
690 const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
691 const char minuses[]= "----------------------------------------------------------------------";
693 static void show_stats(struct patch *patch)
695 char *name = patch->old_name;
696 int len, max, add, del;
699 name = patch->new_name;
702 * "scale" the filename
713 * scale the add/delete
719 add = (patch->lines_added * max + max_change/2) / max_change;
720 del = (patch->lines_deleted * max + max_change/2) / max_change;
721 printf(" %-*s |%5d %.*s%.*s\n",
722 len, name, patch->lines_added + patch->lines_deleted,
723 add, pluses, del, minuses);
726 static void check_patch(struct patch *patch)
728 const char *old_name = patch->old_name;
729 const char *new_name = patch->new_name;
732 if (cache_name_pos(old_name, strlen(old_name)) < 0)
733 die("file %s does not exist", old_name);
734 if (patch->is_new < 0)
737 if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
738 if (cache_name_pos(new_name, strlen(new_name)) >= 0)
739 die("file %s already exists", new_name);
743 static void apply_patch_list(struct patch *patch)
745 int files, adds, dels;
747 files = adds = dels = 0;
749 die("no patch found");
756 adds += patch->lines_added;
757 dels += patch->lines_deleted;
760 } while ((patch = patch->next) != NULL);
763 printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
766 static void patch_stats(struct patch *patch)
768 int lines = patch->lines_added + patch->lines_deleted;
770 if (lines > max_change)
772 if (patch->old_name) {
773 int len = strlen(patch->old_name);
777 if (patch->new_name) {
778 int len = strlen(patch->new_name);
784 static int apply_patch(int fd)
786 unsigned long offset, size;
787 char *buffer = read_patch_file(fd, &size);
788 struct patch *list = NULL, **listp = &list;
797 patch = xmalloc(sizeof(*patch));
798 memset(patch, 0, sizeof(*patch));
799 nr = parse_chunk(buffer + offset, size, patch);
804 listp = &patch->next;
809 apply_patch_list(list);
815 int main(int argc, char **argv)
820 if (read_cache() < 0)
821 die("unable to read index file");
823 for (i = 1; i < argc; i++) {
824 const char *arg = argv[i];
827 if (!strcmp(arg, "-")) {
832 if (!strcmp(arg, "--no-merge")) {
836 if (!strcmp(arg, "--stat")) {
841 fd = open(arg, O_RDONLY);