Code

merge-recur: Get rid of debug code
[git.git] / merge-recursive.c
1 /*
2  * Recursive Merge algorithm stolen from git-merge-recursive.py by
3  * Fredrik Kuivinen.
4  * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5  */
6 #include <stdarg.h>
7 #include <string.h>
8 #include <assert.h>
9 #include <sys/wait.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <time.h>
13 #include "cache.h"
14 #include "cache-tree.h"
15 #include "commit.h"
16 #include "blob.h"
17 #include "tree-walk.h"
18 #include "diff.h"
19 #include "diffcore.h"
20 #include "run-command.h"
21 #include "tag.h"
23 #include "path-list.h"
25 /*
26  * A virtual commit has
27  * - (const char *)commit->util set to the name, and
28  * - *(int *)commit->object.sha1 set to the virtual id.
29  */
31 static unsigned commit_list_count(const struct commit_list *l)
32 {
33         unsigned c = 0;
34         for (; l; l = l->next )
35                 c++;
36         return c;
37 }
39 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
40 {
41         struct commit *commit = xcalloc(1, sizeof(struct commit));
42         static unsigned virtual_id = 1;
43         commit->tree = tree;
44         commit->util = (void*)comment;
45         *(int*)commit->object.sha1 = virtual_id++;
46         return commit;
47 }
49 /*
50  * TODO: we should not have to copy the SHA1s around, but rather reference
51  * them. That way, sha_eq() is just sha1 == sha2.
52  */
53 static int sha_eq(const unsigned char *a, const unsigned char *b)
54 {
55         if (!a && !b)
56                 return 2;
57         return a && b && memcmp(a, b, 20) == 0;
58 }
60 /*
61  * TODO: check if we can just reuse the active_cache structure: it is already
62  * sorted (by name, stage).
63  * Only problem: do not write it when flushing the cache.
64  */
65 struct stage_data
66 {
67         struct
68         {
69                 unsigned mode;
70                 unsigned char sha[20];
71         } stages[4];
72         unsigned processed:1;
73 };
75 static struct path_list current_file_set = {NULL, 0, 0, 1};
76 static struct path_list current_directory_set = {NULL, 0, 0, 1};
78 static int output_indent = 0;
80 static void output(const char *fmt, ...)
81 {
82         va_list args;
83         int i;
84         for (i = output_indent; i--;)
85                 fputs("  ", stdout);
86         va_start(args, fmt);
87         vfprintf(stdout, fmt, args);
88         va_end(args);
89         fputc('\n', stdout);
90 }
92 static void output_commit_title(struct commit *commit)
93 {
94         int i;
95         for (i = output_indent; i--;)
96                 fputs("  ", stdout);
97         if (commit->util)
98                 printf("virtual %s\n", (char *)commit->util);
99         else {
100                 printf("%s ", sha1_to_hex(commit->object.sha1));
101                 if (parse_commit(commit) != 0)
102                         printf("(bad commit)\n");
103                 else {
104                         const char *s;
105                         int len;
106                         for (s = commit->buffer; *s; s++)
107                                 if (*s == '\n' && s[1] == '\n') {
108                                         s += 2;
109                                         break;
110                                 }
111                         for (len = 0; s[len] && '\n' != s[len]; len++)
112                                 ; /* do nothing */
113                         printf("%.*s\n", len, s);
114                 }
115         }
118 static const char *original_index_file;
119 static const char *temporary_index_file;
120 static int cache_dirty = 0;
122 static int flush_cache(void)
124         /* flush temporary index */
125         struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
126         int fd = hold_lock_file_for_update(lock, getenv("GIT_INDEX_FILE"));
127         if (fd < 0)
128                 die("could not lock %s", temporary_index_file);
129         if (write_cache(fd, active_cache, active_nr) ||
130                         close(fd) || commit_lock_file(lock))
131                 die ("unable to write %s", getenv("GIT_INDEX_FILE"));
132         discard_cache();
133         cache_dirty = 0;
134         return 0;
137 static void setup_index(int temp)
139         const char *idx = temp ? temporary_index_file: original_index_file;
140         if (cache_dirty)
141                 die("fatal: cache changed flush_cache();");
142         unlink(temporary_index_file);
143         setenv("GIT_INDEX_FILE", idx, 1);
144         discard_cache();
147 static struct cache_entry *make_cache_entry(unsigned int mode,
148                 const unsigned char *sha1, const char *path, int stage, int refresh)
150         int size, len;
151         struct cache_entry *ce;
153         if (!verify_path(path))
154                 return NULL;
156         len = strlen(path);
157         size = cache_entry_size(len);
158         ce = xcalloc(1, size);
160         memcpy(ce->sha1, sha1, 20);
161         memcpy(ce->name, path, len);
162         ce->ce_flags = create_ce_flags(len, stage);
163         ce->ce_mode = create_ce_mode(mode);
165         if (refresh)
166                 return refresh_cache_entry(ce, 0);
168         return ce;
171 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
172                 const char *path, int stage, int refresh, int options)
174         struct cache_entry *ce;
175         if (!cache_dirty)
176                 read_cache_from(getenv("GIT_INDEX_FILE"));
177         cache_dirty++;
178         ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
179         if (!ce)
180                 return error("cache_addinfo failed: %s", strerror(cache_errno));
181         return add_cache_entry(ce, options);
184 /*
185  * This is a global variable which is used in a number of places but
186  * only written to in the 'merge' function.
187  *
188  * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
189  *                       don't update the working directory.
190  *               0    => Leave unmerged entries in the cache and update
191  *                       the working directory.
192  */
193 static int index_only = 0;
195 /*
196  * TODO: this can be streamlined by refactoring builtin-read-tree.c
197  */
198 static int git_read_tree(const struct tree *tree)
200 #if 0
201         fprintf(stderr, "GIT_INDEX_FILE='%s' git-read-tree %s\n",
202                 getenv("GIT_INDEX_FILE"),
203                 sha1_to_hex(tree->object.sha1));
204 #endif
205         int rc;
206         const char *argv[] = { "git-read-tree", NULL, NULL, };
207         if (cache_dirty)
208                 die("read-tree with dirty cache");
209         argv[1] = sha1_to_hex(tree->object.sha1);
210         rc = run_command_v(2, argv);
211         return rc < 0 ? -1: rc;
214 /*
215  * TODO: this can be streamlined by refactoring builtin-read-tree.c
216  */
217 static int git_merge_trees(const char *update_arg,
218                            struct tree *common,
219                            struct tree *head,
220                            struct tree *merge)
222 #if 0
223         fprintf(stderr, "GIT_INDEX_FILE='%s' git-read-tree %s -m %s %s %s\n",
224                 getenv("GIT_INDEX_FILE"),
225                 update_arg,
226                 sha1_to_hex(common->object.sha1),
227                 sha1_to_hex(head->object.sha1),
228                 sha1_to_hex(merge->object.sha1));
229 #endif
230         int rc;
231         const char *argv[] = {
232                 "git-read-tree", NULL, "-m", NULL, NULL, NULL,
233                 NULL,
234         };
235         if (cache_dirty)
236                 flush_cache();
237         argv[1] = update_arg;
238         argv[3] = sha1_to_hex(common->object.sha1);
239         argv[4] = sha1_to_hex(head->object.sha1);
240         argv[5] = sha1_to_hex(merge->object.sha1);
241         rc = run_command_v(6, argv);
242         return rc < 0 ? -1: rc;
245 /*
246  * TODO: this can be streamlined by refactoring builtin-write-tree.c
247  */
248 static struct tree *git_write_tree(void)
250 #if 0
251         fprintf(stderr, "GIT_INDEX_FILE='%s' git-write-tree\n",
252                 getenv("GIT_INDEX_FILE"));
253 #endif
254         FILE *fp;
255         int rc;
256         char buf[41];
257         unsigned char sha1[20];
258         int ch;
259         unsigned i = 0;
260         if (cache_dirty)
261                 flush_cache();
262         fp = popen("git-write-tree 2>/dev/null", "r");
263         while ((ch = fgetc(fp)) != EOF)
264                 if (i < sizeof(buf)-1 && ch >= '0' && ch <= 'f')
265                         buf[i++] = ch;
266                 else
267                         break;
268         rc = pclose(fp);
269         if (rc == -1 || WEXITSTATUS(rc))
270                 return NULL;
271         buf[i] = '\0';
272         if (get_sha1(buf, sha1) != 0)
273                 return NULL;
274         return lookup_tree(sha1);
277 static int save_files_dirs(const unsigned char *sha1,
278                 const char *base, int baselen, const char *path,
279                 unsigned int mode, int stage)
281         int len = strlen(path);
282         char *newpath = malloc(baselen + len + 1);
283         memcpy(newpath, base, baselen);
284         memcpy(newpath + baselen, path, len);
285         newpath[baselen + len] = '\0';
287         if (S_ISDIR(mode))
288                 path_list_insert(newpath, &current_directory_set);
289         else
290                 path_list_insert(newpath, &current_file_set);
291         free(newpath);
293         return READ_TREE_RECURSIVE;
296 static int get_files_dirs(struct tree *tree)
298         int n;
299         if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
300                 return 0;
301         n = current_file_set.nr + current_directory_set.nr;
302         return n;
305 /*
306  * Returns a index_entry instance which doesn't have to correspond to
307  * a real cache entry in Git's index.
308  */
309 static struct stage_data *insert_stage_data(const char *path,
310                 struct tree *o, struct tree *a, struct tree *b,
311                 struct path_list *entries)
313         struct path_list_item *item;
314         struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
315         get_tree_entry(o->object.sha1, path,
316                         e->stages[1].sha, &e->stages[1].mode);
317         get_tree_entry(a->object.sha1, path,
318                         e->stages[2].sha, &e->stages[2].mode);
319         get_tree_entry(b->object.sha1, path,
320                         e->stages[3].sha, &e->stages[3].mode);
321         item = path_list_insert(path, entries);
322         item->util = e;
323         return e;
326 /*
327  * Create a dictionary mapping file names to stage_data objects. The
328  * dictionary contains one entry for every path with a non-zero stage entry.
329  */
330 static struct path_list *get_unmerged(void)
332         struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
333         int i;
335         unmerged->strdup_paths = 1;
336         if (!cache_dirty) {
337                 read_cache_from(getenv("GIT_INDEX_FILE"));
338                 cache_dirty++;
339         }
340         for (i = 0; i < active_nr; i++) {
341                 struct path_list_item *item;
342                 struct stage_data *e;
343                 struct cache_entry *ce = active_cache[i];
344                 if (!ce_stage(ce))
345                         continue;
347                 item = path_list_lookup(ce->name, unmerged);
348                 if (!item) {
349                         item = path_list_insert(ce->name, unmerged);
350                         item->util = xcalloc(1, sizeof(struct stage_data));
351                 }
352                 e = item->util;
353                 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
354                 memcpy(e->stages[ce_stage(ce)].sha, ce->sha1, 20);
355         }
357         return unmerged;
360 struct rename
362         struct diff_filepair *pair;
363         struct stage_data *src_entry;
364         struct stage_data *dst_entry;
365         unsigned processed:1;
366 };
368 /*
369  * Get information of all renames which occured between 'o_tree' and
370  * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
371  * 'b_tree') to be able to associate the correct cache entries with
372  * the rename information. 'tree' is always equal to either a_tree or b_tree.
373  */
374 static struct path_list *get_renames(struct tree *tree,
375                                         struct tree *o_tree,
376                                         struct tree *a_tree,
377                                         struct tree *b_tree,
378                                         struct path_list *entries)
380         int i;
381         struct path_list *renames;
382         struct diff_options opts;
384         renames = xcalloc(1, sizeof(struct path_list));
385         diff_setup(&opts);
386         opts.recursive = 1;
387         opts.detect_rename = DIFF_DETECT_RENAME;
388         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
389         if (diff_setup_done(&opts) < 0)
390                 die("diff setup failed");
391         diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
392         diffcore_std(&opts);
393         for (i = 0; i < diff_queued_diff.nr; ++i) {
394                 struct path_list_item *item;
395                 struct rename *re;
396                 struct diff_filepair *pair = diff_queued_diff.queue[i];
397                 if (pair->status != 'R') {
398                         diff_free_filepair(pair);
399                         continue;
400                 }
401                 re = xmalloc(sizeof(*re));
402                 re->processed = 0;
403                 re->pair = pair;
404                 item = path_list_lookup(re->pair->one->path, entries);
405                 if (!item)
406                         re->src_entry = insert_stage_data(re->pair->one->path,
407                                         o_tree, a_tree, b_tree, entries);
408                 else
409                         re->src_entry = item->util;
411                 item = path_list_lookup(re->pair->two->path, entries);
412                 if (!item)
413                         re->dst_entry = insert_stage_data(re->pair->two->path,
414                                         o_tree, a_tree, b_tree, entries);
415                 else
416                         re->dst_entry = item->util;
417                 item = path_list_insert(pair->one->path, renames);
418                 item->util = re;
419         }
420         opts.output_format = DIFF_FORMAT_NO_OUTPUT;
421         diff_queued_diff.nr = 0;
422         diff_flush(&opts);
423         return renames;
426 int update_stages(const char *path, struct diff_filespec *o,
427                 struct diff_filespec *a, struct diff_filespec *b, int clear)
429         int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
430         if (clear)
431                 if (remove_file_from_cache(path))
432                         return -1;
433         if (o)
434                 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
435                         return -1;
436         if (a)
437                 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
438                         return -1;
439         if (b)
440                 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
441                         return -1;
442         return 0;
445 static int remove_path(const char *name)
447         int ret, len;
448         char *slash, *dirs;
450         ret = unlink(name);
451         if (ret)
452                 return ret;
453         len = strlen(name);
454         dirs = malloc(len+1);
455         memcpy(dirs, name, len);
456         dirs[len] = '\0';
457         while ((slash = strrchr(name, '/'))) {
458                 *slash = '\0';
459                 len = slash - name;
460                 if (rmdir(name) != 0)
461                         break;
462         }
463         free(dirs);
464         return ret;
467 /*
468  * TODO: once we no longer call external programs, we'd probably be better off
469  * not setting / getting the environment variable GIT_INDEX_FILE all the time.
470  */
471 int remove_file(int clean, const char *path)
473         int update_cache = index_only || clean;
474         int update_working_directory = !index_only;
476         if (update_cache) {
477                 if (!cache_dirty)
478                         read_cache_from(getenv("GIT_INDEX_FILE"));
479                 cache_dirty++;
480                 if (remove_file_from_cache(path))
481                         return -1;
482         }
483         if (update_working_directory)
484         {
485                 unlink(path);
486                 if (errno != ENOENT || errno != EISDIR)
487                         return -1;
488                 remove_path(path);
489         }
490         return 0;
493 static char *unique_path(const char *path, const char *branch)
495         char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
496         int suffix = 0;
497         struct stat st;
498         char *p = newpath + strlen(newpath);
499         strcpy(newpath, path);
500         strcat(newpath, "~");
501         strcpy(p, branch);
502         for (; *p; ++p)
503                 if ('/' == *p)
504                         *p = '_';
505         while (path_list_has_path(&current_file_set, newpath) ||
506                path_list_has_path(&current_directory_set, newpath) ||
507                lstat(newpath, &st) == 0)
508                 sprintf(p, "_%d", suffix++);
510         path_list_insert(newpath, &current_file_set);
511         return newpath;
514 static int mkdir_p(const char *path, unsigned long mode)
516         /* path points to cache entries, so strdup before messing with it */
517         char *buf = strdup(path);
518         int result = safe_create_leading_directories(buf);
519         free(buf);
520         return result;
523 static void flush_buffer(int fd, const char *buf, unsigned long size)
525         while (size > 0) {
526                 long ret = xwrite(fd, buf, size);
527                 if (ret < 0) {
528                         /* Ignore epipe */
529                         if (errno == EPIPE)
530                                 break;
531                         die("merge-recursive: %s", strerror(errno));
532                 } else if (!ret) {
533                         die("merge-recursive: disk full?");
534                 }
535                 size -= ret;
536                 buf += ret;
537         }
540 void update_file_flags(const unsigned char *sha,
541                        unsigned mode,
542                        const char *path,
543                        int update_cache,
544                        int update_wd)
546         if (index_only)
547                 update_wd = 0;
549         if (update_wd) {
550                 char type[20];
551                 void *buf;
552                 unsigned long size;
554                 buf = read_sha1_file(sha, type, &size);
555                 if (!buf)
556                         die("cannot read object %s '%s'", sha1_to_hex(sha), path);
557                 if (strcmp(type, blob_type) != 0)
558                         die("blob expected for %s '%s'", sha1_to_hex(sha), path);
560                 if (S_ISREG(mode)) {
561                         int fd;
562                         if (mkdir_p(path, 0777))
563                                 die("failed to create path %s: %s", path, strerror(errno));
564                         unlink(path);
565                         if (mode & 0100)
566                                 mode = 0777;
567                         else
568                                 mode = 0666;
569                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
570                         if (fd < 0)
571                                 die("failed to open %s: %s", path, strerror(errno));
572                         flush_buffer(fd, buf, size);
573                         close(fd);
574                 } else if (S_ISLNK(mode)) {
575                         char *lnk = malloc(size + 1);
576                         memcpy(lnk, buf, size);
577                         lnk[size] = '\0';
578                         mkdir_p(path, 0777);
579                         unlink(lnk);
580                         symlink(lnk, path);
581                 } else
582                         die("do not know what to do with %06o %s '%s'",
583                             mode, sha1_to_hex(sha), path);
584         }
585         if (update_cache)
586                 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
589 void update_file(int clean,
590                 const unsigned char *sha,
591                 unsigned mode,
592                 const char *path)
594         update_file_flags(sha, mode, path, index_only || clean, !index_only);
597 /* Low level file merging, update and removal */
599 struct merge_file_info
601         unsigned char sha[20];
602         unsigned mode;
603         unsigned clean:1,
604                  merge:1;
605 };
607 static char *git_unpack_file(const unsigned char *sha1, char *path)
609         void *buf;
610         char type[20];
611         unsigned long size;
612         int fd;
614         buf = read_sha1_file(sha1, type, &size);
615         if (!buf || strcmp(type, blob_type))
616                 die("unable to read blob object %s", sha1_to_hex(sha1));
618         strcpy(path, ".merge_file_XXXXXX");
619         fd = mkstemp(path);
620         if (fd < 0)
621                 die("unable to create temp-file");
622         flush_buffer(fd, buf, size);
623         close(fd);
624         return path;
627 static struct merge_file_info merge_file(struct diff_filespec *o,
628                 struct diff_filespec *a, struct diff_filespec *b,
629                 const char *branch1Name, const char *branch2Name)
631         struct merge_file_info result;
632         result.merge = 0;
633         result.clean = 1;
635         if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
636                 result.clean = 0;
637                 if (S_ISREG(a->mode)) {
638                         result.mode = a->mode;
639                         memcpy(result.sha, a->sha1, 20);
640                 } else {
641                         result.mode = b->mode;
642                         memcpy(result.sha, b->sha1, 20);
643                 }
644         } else {
645                 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
646                         result.merge = 1;
648                 result.mode = a->mode == o->mode ? b->mode: a->mode;
650                 if (sha_eq(a->sha1, o->sha1))
651                         memcpy(result.sha, b->sha1, 20);
652                 else if (sha_eq(b->sha1, o->sha1))
653                         memcpy(result.sha, a->sha1, 20);
654                 else if (S_ISREG(a->mode)) {
655                         int code = 1, fd;
656                         struct stat st;
657                         char orig[PATH_MAX];
658                         char src1[PATH_MAX];
659                         char src2[PATH_MAX];
660                         const char *argv[] = {
661                                 "merge", "-L", NULL, "-L", NULL, "-L", NULL,
662                                 src1, orig, src2,
663                                 NULL
664                         };
665                         char *la, *lb, *lo;
667                         git_unpack_file(o->sha1, orig);
668                         git_unpack_file(a->sha1, src1);
669                         git_unpack_file(b->sha1, src2);
671                         argv[2] = la = strdup(mkpath("%s/%s", branch1Name, a->path));
672                         argv[6] = lb = strdup(mkpath("%s/%s", branch2Name, b->path));
673                         argv[4] = lo = strdup(mkpath("orig/%s", o->path));
675 #if 0
676                         printf("%s %s %s %s %s %s %s %s %s %s\n",
677                                argv[0], argv[1], argv[2], argv[3], argv[4],
678                                argv[5], argv[6], argv[7], argv[8], argv[9]);
679 #endif
680                         code = run_command_v(10, argv);
682                         free(la);
683                         free(lb);
684                         free(lo);
685                         if (code && code < -256) {
686                                 die("Failed to execute 'merge'. merge(1) is used as the "
687                                     "file-level merge tool. Is 'merge' in your path?");
688                         }
689                         fd = open(src1, O_RDONLY);
690                         if (fd < 0 || fstat(fd, &st) < 0 ||
691                                         index_fd(result.sha, fd, &st, 1,
692                                                 "blob"))
693                                 die("Unable to add %s to database", src1);
695                         unlink(orig);
696                         unlink(src1);
697                         unlink(src2);
699                         result.clean = WEXITSTATUS(code) == 0;
700                 } else {
701                         if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
702                                 die("cannot merge modes?");
704                         memcpy(result.sha, a->sha1, 20);
706                         if (!sha_eq(a->sha1, b->sha1))
707                                 result.clean = 0;
708                 }
709         }
711         return result;
714 static void conflict_rename_rename(struct rename *ren1,
715                                    const char *branch1,
716                                    struct rename *ren2,
717                                    const char *branch2)
719         char *del[2];
720         int delp = 0;
721         const char *ren1_dst = ren1->pair->two->path;
722         const char *ren2_dst = ren2->pair->two->path;
723         const char *dst_name1 = ren1_dst;
724         const char *dst_name2 = ren2_dst;
725         if (path_list_has_path(&current_directory_set, ren1_dst)) {
726                 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
727                 output("%s is a directory in %s adding as %s instead",
728                        ren1_dst, branch2, dst_name1);
729                 remove_file(0, ren1_dst);
730         }
731         if (path_list_has_path(&current_directory_set, ren2_dst)) {
732                 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
733                 output("%s is a directory in %s adding as %s instead",
734                        ren2_dst, branch1, dst_name2);
735                 remove_file(0, ren2_dst);
736         }
737         update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
738         update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
739         while (delp--)
740                 free(del[delp]);
743 static void conflict_rename_dir(struct rename *ren1,
744                                 const char *branch1)
746         char *new_path = unique_path(ren1->pair->two->path, branch1);
747         output("Renaming %s to %s instead", ren1->pair->one->path, new_path);
748         remove_file(0, ren1->pair->two->path);
749         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
750         free(new_path);
753 static void conflict_rename_rename_2(struct rename *ren1,
754                                      const char *branch1,
755                                      struct rename *ren2,
756                                      const char *branch2)
758         char *new_path1 = unique_path(ren1->pair->two->path, branch1);
759         char *new_path2 = unique_path(ren2->pair->two->path, branch2);
760         output("Renaming %s to %s and %s to %s instead",
761                ren1->pair->one->path, new_path1,
762                ren2->pair->one->path, new_path2);
763         remove_file(0, ren1->pair->two->path);
764         update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
765         update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
766         free(new_path2);
767         free(new_path1);
770 static int process_renames(struct path_list *a_renames,
771                            struct path_list *b_renames,
772                            const char *a_branch,
773                            const char *b_branch)
775         int clean_merge = 1, i, j;
776         struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
777         const struct rename *sre;
779         for (i = 0; i < a_renames->nr; i++) {
780                 sre = a_renames->items[i].util;
781                 path_list_insert(sre->pair->two->path, &a_by_dst)->util
782                         = sre->dst_entry;
783         }
784         for (i = 0; i < b_renames->nr; i++) {
785                 sre = b_renames->items[i].util;
786                 path_list_insert(sre->pair->two->path, &b_by_dst)->util
787                         = sre->dst_entry;
788         }
790         for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
791                 int compare;
792                 char *src;
793                 struct path_list *renames1, *renames2, *renames2Dst;
794                 struct rename *ren1 = NULL, *ren2 = NULL;
795                 const char *branch1, *branch2;
796                 const char *ren1_src, *ren1_dst;
798                 if (i >= a_renames->nr) {
799                         compare = 1;
800                         ren2 = b_renames->items[j++].util;
801                 } else if (j >= b_renames->nr) {
802                         compare = -1;
803                         ren1 = a_renames->items[i++].util;
804                 } else {
805                         compare = strcmp(a_renames->items[i].path,
806                                         b_renames->items[j].path);
807                         ren1 = a_renames->items[i++].util;
808                         ren2 = b_renames->items[j++].util;
809                 }
811                 /* TODO: refactor, so that 1/2 are not needed */
812                 if (ren1) {
813                         renames1 = a_renames;
814                         renames2 = b_renames;
815                         renames2Dst = &b_by_dst;
816                         branch1 = a_branch;
817                         branch2 = b_branch;
818                 } else {
819                         struct rename *tmp;
820                         renames1 = b_renames;
821                         renames2 = a_renames;
822                         renames2Dst = &a_by_dst;
823                         branch1 = b_branch;
824                         branch2 = a_branch;
825                         tmp = ren2;
826                         ren2 = ren1;
827                         ren1 = tmp;
828                 }
829                 src = ren1->pair->one->path;
831                 ren1->dst_entry->processed = 1;
832                 ren1->src_entry->processed = 1;
834                 if (ren1->processed)
835                         continue;
836                 ren1->processed = 1;
838                 ren1_src = ren1->pair->one->path;
839                 ren1_dst = ren1->pair->two->path;
841                 if (ren2) {
842                         const char *ren2_src = ren2->pair->one->path;
843                         const char *ren2_dst = ren2->pair->two->path;
844                         /* Renamed in 1 and renamed in 2 */
845                         if (strcmp(ren1_src, ren2_src) != 0)
846                                 die("ren1.src != ren2.src");
847                         ren2->dst_entry->processed = 1;
848                         ren2->processed = 1;
849                         if (strcmp(ren1_dst, ren2_dst) != 0) {
850                                 clean_merge = 0;
851                                 output("CONFLICT (rename/rename): "
852                                        "Rename %s->%s in branch %s "
853                                        "rename %s->%s in %s",
854                                        src, ren1_dst, branch1,
855                                        src, ren2_dst, branch2);
856                                 conflict_rename_rename(ren1, branch1, ren2, branch2);
857                         } else {
858                                 struct merge_file_info mfi;
859                                 remove_file(1, ren1_src);
860                                 mfi = merge_file(ren1->pair->one,
861                                                  ren1->pair->two,
862                                                  ren2->pair->two,
863                                                  branch1,
864                                                  branch2);
865                                 if (mfi.merge || !mfi.clean)
866                                         output("Renaming %s->%s", src, ren1_dst);
868                                 if (mfi.merge)
869                                         output("Auto-merging %s", ren1_dst);
871                                 if (!mfi.clean) {
872                                         output("CONFLICT (content): merge conflict in %s",
873                                                ren1_dst);
874                                         clean_merge = 0;
876                                         if (!index_only)
877                                                 update_stages(ren1_dst,
878                                                               ren1->pair->one,
879                                                               ren1->pair->two,
880                                                               ren2->pair->two,
881                                                               1 /* clear */);
882                                 }
883                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
884                         }
885                 } else {
886                         /* Renamed in 1, maybe changed in 2 */
887                         struct path_list_item *item;
888                         /* we only use sha1 and mode of these */
889                         struct diff_filespec src_other, dst_other;
890                         int try_merge, stage = a_renames == renames1 ? 3: 2;
892                         remove_file(1, ren1_src);
894                         memcpy(src_other.sha1,
895                                         ren1->src_entry->stages[stage].sha, 20);
896                         src_other.mode = ren1->src_entry->stages[stage].mode;
897                         memcpy(dst_other.sha1,
898                                         ren1->dst_entry->stages[stage].sha, 20);
899                         dst_other.mode = ren1->dst_entry->stages[stage].mode;
901                         try_merge = 0;
903                         if (path_list_has_path(&current_directory_set, ren1_dst)) {
904                                 clean_merge = 0;
905                                 output("CONFLICT (rename/directory): Rename %s->%s in %s "
906                                        " directory %s added in %s",
907                                        ren1_src, ren1_dst, branch1,
908                                        ren1_dst, branch2);
909                                 conflict_rename_dir(ren1, branch1);
910                         } else if (sha_eq(src_other.sha1, null_sha1)) {
911                                 clean_merge = 0;
912                                 output("CONFLICT (rename/delete): Rename %s->%s in %s "
913                                        "and deleted in %s",
914                                        ren1_src, ren1_dst, branch1,
915                                        branch2);
916                                 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
917                         } else if (!sha_eq(dst_other.sha1, null_sha1)) {
918                                 const char *new_path;
919                                 clean_merge = 0;
920                                 try_merge = 1;
921                                 output("CONFLICT (rename/add): Rename %s->%s in %s. "
922                                        "%s added in %s",
923                                        ren1_src, ren1_dst, branch1,
924                                        ren1_dst, branch2);
925                                 new_path = unique_path(ren1_dst, branch2);
926                                 output("Adding as %s instead", new_path);
927                                 update_file(0, dst_other.sha1, dst_other.mode, new_path);
928                         } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
929                                 ren2 = item->util;
930                                 clean_merge = 0;
931                                 ren2->processed = 1;
932                                 output("CONFLICT (rename/rename): Rename %s->%s in %s. "
933                                        "Rename %s->%s in %s",
934                                        ren1_src, ren1_dst, branch1,
935                                        ren2->pair->one->path, ren2->pair->two->path, branch2);
936                                 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
937                         } else
938                                 try_merge = 1;
940                         if (try_merge) {
941                                 struct diff_filespec *o, *a, *b;
942                                 struct merge_file_info mfi;
943                                 src_other.path = (char *)ren1_src;
945                                 o = ren1->pair->one;
946                                 if (a_renames == renames1) {
947                                         a = ren1->pair->two;
948                                         b = &src_other;
949                                 } else {
950                                         b = ren1->pair->two;
951                                         a = &src_other;
952                                 }
953                                 mfi = merge_file(o, a, b,
954                                                 a_branch, b_branch);
956                                 if (mfi.merge || !mfi.clean)
957                                         output("Renaming %s => %s", ren1_src, ren1_dst);
958                                 if (mfi.merge)
959                                         output("Auto-merging %s", ren1_dst);
960                                 if (!mfi.clean) {
961                                         output("CONFLICT (rename/modify): Merge conflict in %s",
962                                                ren1_dst);
963                                         clean_merge = 0;
965                                         if (!index_only)
966                                                 update_stages(ren1_dst,
967                                                                 o, a, b, 1);
968                                 }
969                                 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
970                         }
971                 }
972         }
973         path_list_clear(&a_by_dst, 0);
974         path_list_clear(&b_by_dst, 0);
976         if (cache_dirty)
977                 flush_cache();
978         return clean_merge;
981 static unsigned char *has_sha(const unsigned char *sha)
983         return memcmp(sha, null_sha1, 20) == 0 ? NULL: (unsigned char *)sha;
986 /* Per entry merge function */
987 static int process_entry(const char *path, struct stage_data *entry,
988                          const char *branch1Name,
989                          const char *branch2Name)
991         /*
992         printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
993         print_index_entry("\tpath: ", entry);
994         */
995         int clean_merge = 1;
996         unsigned char *o_sha = has_sha(entry->stages[1].sha);
997         unsigned char *a_sha = has_sha(entry->stages[2].sha);
998         unsigned char *b_sha = has_sha(entry->stages[3].sha);
999         unsigned o_mode = entry->stages[1].mode;
1000         unsigned a_mode = entry->stages[2].mode;
1001         unsigned b_mode = entry->stages[3].mode;
1003         if (o_sha && (!a_sha || !b_sha)) {
1004                 /* Case A: Deleted in one */
1005                 if ((!a_sha && !b_sha) ||
1006                     (sha_eq(a_sha, o_sha) && !b_sha) ||
1007                     (!a_sha && sha_eq(b_sha, o_sha))) {
1008                         /* Deleted in both or deleted in one and
1009                          * unchanged in the other */
1010                         if (a_sha)
1011                                 output("Removing %s", path);
1012                         remove_file(1, path);
1013                 } else {
1014                         /* Deleted in one and changed in the other */
1015                         clean_merge = 0;
1016                         if (!a_sha) {
1017                                 output("CONFLICT (delete/modify): %s deleted in %s "
1018                                        "and modified in %s. Version %s of %s left in tree.",
1019                                        path, branch1Name,
1020                                        branch2Name, branch2Name, path);
1021                                 update_file(0, b_sha, b_mode, path);
1022                         } else {
1023                                 output("CONFLICT (delete/modify): %s deleted in %s "
1024                                        "and modified in %s. Version %s of %s left in tree.",
1025                                        path, branch2Name,
1026                                        branch1Name, branch1Name, path);
1027                                 update_file(0, a_sha, a_mode, path);
1028                         }
1029                 }
1031         } else if ((!o_sha && a_sha && !b_sha) ||
1032                    (!o_sha && !a_sha && b_sha)) {
1033                 /* Case B: Added in one. */
1034                 const char *add_branch;
1035                 const char *other_branch;
1036                 unsigned mode;
1037                 const unsigned char *sha;
1038                 const char *conf;
1040                 if (a_sha) {
1041                         add_branch = branch1Name;
1042                         other_branch = branch2Name;
1043                         mode = a_mode;
1044                         sha = a_sha;
1045                         conf = "file/directory";
1046                 } else {
1047                         add_branch = branch2Name;
1048                         other_branch = branch1Name;
1049                         mode = b_mode;
1050                         sha = b_sha;
1051                         conf = "directory/file";
1052                 }
1053                 if (path_list_has_path(&current_directory_set, path)) {
1054                         const char *new_path = unique_path(path, add_branch);
1055                         clean_merge = 0;
1056                         output("CONFLICT (%s): There is a directory with name %s in %s. "
1057                                "Adding %s as %s",
1058                                conf, path, other_branch, path, new_path);
1059                         remove_file(0, path);
1060                         update_file(0, sha, mode, new_path);
1061                 } else {
1062                         output("Adding %s", path);
1063                         update_file(1, sha, mode, path);
1064                 }
1065         } else if (!o_sha && a_sha && b_sha) {
1066                 /* Case C: Added in both (check for same permissions). */
1067                 if (sha_eq(a_sha, b_sha)) {
1068                         if (a_mode != b_mode) {
1069                                 clean_merge = 0;
1070                                 output("CONFLICT: File %s added identically in both branches, "
1071                                        "but permissions conflict %06o->%06o",
1072                                        path, a_mode, b_mode);
1073                                 output("CONFLICT: adding with permission: %06o", a_mode);
1074                                 update_file(0, a_sha, a_mode, path);
1075                         } else {
1076                                 /* This case is handled by git-read-tree */
1077                                 assert(0 && "This case must be handled by git-read-tree");
1078                         }
1079                 } else {
1080                         const char *new_path1, *new_path2;
1081                         clean_merge = 0;
1082                         new_path1 = unique_path(path, branch1Name);
1083                         new_path2 = unique_path(path, branch2Name);
1084                         output("CONFLICT (add/add): File %s added non-identically "
1085                                "in both branches. Adding as %s and %s instead.",
1086                                path, new_path1, new_path2);
1087                         remove_file(0, path);
1088                         update_file(0, a_sha, a_mode, new_path1);
1089                         update_file(0, b_sha, b_mode, new_path2);
1090                 }
1092         } else if (o_sha && a_sha && b_sha) {
1093                 /* case D: Modified in both, but differently. */
1094                 struct merge_file_info mfi;
1095                 struct diff_filespec o, a, b;
1097                 output("Auto-merging %s", path);
1098                 o.path = a.path = b.path = (char *)path;
1099                 memcpy(o.sha1, o_sha, 20);
1100                 o.mode = o_mode;
1101                 memcpy(a.sha1, a_sha, 20);
1102                 a.mode = a_mode;
1103                 memcpy(b.sha1, b_sha, 20);
1104                 b.mode = b_mode;
1106                 mfi = merge_file(&o, &a, &b,
1107                                  branch1Name, branch2Name);
1109                 if (mfi.clean)
1110                         update_file(1, mfi.sha, mfi.mode, path);
1111                 else {
1112                         clean_merge = 0;
1113                         output("CONFLICT (content): Merge conflict in %s", path);
1115                         if (index_only)
1116                                 update_file(0, mfi.sha, mfi.mode, path);
1117                         else
1118                                 update_file_flags(mfi.sha, mfi.mode, path,
1119                                               0 /* update_cache */, 1 /* update_working_directory */);
1120                 }
1121         } else
1122                 die("Fatal merge failure, shouldn't happen.");
1124         if (cache_dirty)
1125                 flush_cache();
1127         return clean_merge;
1130 static int merge_trees(struct tree *head,
1131                        struct tree *merge,
1132                        struct tree *common,
1133                        const char *branch1Name,
1134                        const char *branch2Name,
1135                        struct tree **result)
1137         int code, clean;
1138         if (sha_eq(common->object.sha1, merge->object.sha1)) {
1139                 output("Already uptodate!");
1140                 *result = head;
1141                 return 1;
1142         }
1144         code = git_merge_trees(index_only ? "-i": "-u", common, head, merge);
1146         if (code != 0)
1147                 die("merging of trees %s and %s failed",
1148                     sha1_to_hex(head->object.sha1),
1149                     sha1_to_hex(merge->object.sha1));
1151         *result = git_write_tree();
1153         if (!*result) {
1154                 struct path_list *entries, *re_head, *re_merge;
1155                 int i;
1156                 path_list_clear(&current_file_set, 1);
1157                 path_list_clear(&current_directory_set, 1);
1158                 get_files_dirs(head);
1159                 get_files_dirs(merge);
1161                 entries = get_unmerged();
1162                 re_head  = get_renames(head, common, head, merge, entries);
1163                 re_merge = get_renames(merge, common, head, merge, entries);
1164                 clean = process_renames(re_head, re_merge,
1165                                 branch1Name, branch2Name);
1166                 for (i = 0; i < entries->nr; i++) {
1167                         const char *path = entries->items[i].path;
1168                         struct stage_data *e = entries->items[i].util;
1169                         if (e->processed)
1170                                 continue;
1171                         if (!process_entry(path, e, branch1Name, branch2Name))
1172                                 clean = 0;
1173                 }
1175                 path_list_clear(re_merge, 0);
1176                 path_list_clear(re_head, 0);
1177                 path_list_clear(entries, 1);
1179                 if (clean || index_only)
1180                         *result = git_write_tree();
1181                 else
1182                         *result = NULL;
1183         } else {
1184                 clean = 1;
1185                 printf("merging of trees %s and %s resulted in %s\n",
1186                        sha1_to_hex(head->object.sha1),
1187                        sha1_to_hex(merge->object.sha1),
1188                        sha1_to_hex((*result)->object.sha1));
1189         }
1191         return clean;
1194 /*
1195  * Merge the commits h1 and h2, return the resulting virtual
1196  * commit object and a flag indicating the cleaness of the merge.
1197  */
1198 static
1199 int merge(struct commit *h1,
1200                           struct commit *h2,
1201                           const char *branch1Name,
1202                           const char *branch2Name,
1203                           int call_depth /* =0 */,
1204                           struct commit *ancestor /* =None */,
1205                           struct commit **result)
1207         struct commit_list *ca = NULL, *iter;
1208         struct commit *merged_common_ancestors;
1209         struct tree *mrtree;
1210         int clean;
1212         output("Merging:");
1213         output_commit_title(h1);
1214         output_commit_title(h2);
1216         if (ancestor)
1217                 commit_list_insert(ancestor, &ca);
1218         else
1219                 ca = get_merge_bases(h1, h2, 1);
1221         output("found %u common ancestor(s):", commit_list_count(ca));
1222         for (iter = ca; iter; iter = iter->next)
1223                 output_commit_title(iter->item);
1225         merged_common_ancestors = pop_commit(&ca);
1227         for (iter = ca; iter; iter = iter->next) {
1228                 output_indent = call_depth + 1;
1229                 /*
1230                  * When the merge fails, the result contains files
1231                  * with conflict markers. The cleanness flag is
1232                  * ignored, it was never acutally used, as result of
1233                  * merge_trees has always overwritten it: the commited
1234                  * "conflicts" were already resolved.
1235                  */
1236                 merge(merged_common_ancestors, iter->item,
1237                       "Temporary merge branch 1",
1238                       "Temporary merge branch 2",
1239                       call_depth + 1,
1240                       NULL,
1241                       &merged_common_ancestors);
1242                 output_indent = call_depth;
1244                 if (!merged_common_ancestors)
1245                         die("merge returned no commit");
1246         }
1248         if (call_depth == 0) {
1249                 setup_index(0 /* $GIT_DIR/index */);
1250                 index_only = 0;
1251         } else {
1252                 setup_index(1 /* temporary index */);
1253                 git_read_tree(h1->tree);
1254                 index_only = 1;
1255         }
1257         clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1258                             branch1Name, branch2Name, &mrtree);
1260         if (!ancestor && (clean || index_only)) {
1261                 *result = make_virtual_commit(mrtree, "merged tree");
1262                 commit_list_insert(h1, &(*result)->parents);
1263                 commit_list_insert(h2, &(*result)->parents->next);
1264         } else
1265                 *result = NULL;
1267         return clean;
1270 static struct commit *get_ref(const char *ref)
1272         unsigned char sha1[20];
1273         struct object *object;
1275         if (get_sha1(ref, sha1))
1276                 die("Could not resolve ref '%s'", ref);
1277         object = deref_tag(parse_object(sha1), ref, strlen(ref));
1278         if (object->type != OBJ_COMMIT)
1279                 return NULL;
1280         if (parse_commit((struct commit *)object))
1281                 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1282         return (struct commit *)object;
1285 int main(int argc, char *argv[])
1287         static const char *bases[2];
1288         static unsigned bases_count = 0;
1289         int i, clean;
1290         const char *branch1, *branch2;
1291         struct commit *result, *h1, *h2;
1293         original_index_file = getenv("GIT_INDEX_FILE");
1295         if (!original_index_file)
1296                 original_index_file = strdup(git_path("index"));
1298         temporary_index_file = strdup(git_path("mrg-rcrsv-tmp-idx"));
1300         if (argc < 4)
1301                 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1303         for (i = 1; i < argc; ++i) {
1304                 if (!strcmp(argv[i], "--"))
1305                         break;
1306                 if (bases_count < sizeof(bases)/sizeof(*bases))
1307                         bases[bases_count++] = argv[i];
1308         }
1309         if (argc - i != 3) /* "--" "<head>" "<remote>" */
1310                 die("Not handling anything other than two heads merge.");
1312         branch1 = argv[++i];
1313         branch2 = argv[++i];
1314         printf("Merging %s with %s\n", branch1, branch2);
1316         h1 = get_ref(branch1);
1317         h2 = get_ref(branch2);
1319         if (bases_count == 1) {
1320                 struct commit *ancestor = get_ref(bases[0]);
1321                 clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
1322         } else
1323                 clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
1325         if (cache_dirty)
1326                 flush_cache();
1328         return clean ? 0: 1;
1331 /*
1332 vim: sw=8 noet
1333 */