Andrew's git - gitweb.git/blob

   1/*
   2 * Builtin "git diff"
   3 *
   4 * Copyright (c) 2006 Junio C Hamano
   5 */
   6#include "cache.h"
   7#include "commit.h"
   8#include "blob.h"
   9#include "tag.h"
  10#include "diff.h"
  11#include "diffcore.h"
  12#include "revision.h"
  13#include "log-tree.h"
  14#include "builtin.h"
  15
  16struct blobinfo {
  17        unsigned char sha1[20];
  18        const char *name;
  19        unsigned mode;
  20};
  21
  22static const char builtin_diff_usage[] =
  23"git-diff <options> <rev>{0,2} -- <path>*";
  24
  25static void stuff_change(struct diff_options *opt,
  26                         unsigned old_mode, unsigned new_mode,
  27                         const unsigned char *old_sha1,
  28                         const unsigned char *new_sha1,
  29                         const char *old_name,
  30                         const char *new_name)
  31{
  32        struct diff_filespec *one, *two;
  33
  34        if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  35            !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  36                return;
  37
  38        if (opt->reverse_diff) {
  39                unsigned tmp;
  40                const unsigned char *tmp_u;
  41                const char *tmp_c;
  42                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  43                tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  44                tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  45        }
  46        one = alloc_filespec(old_name);
  47        two = alloc_filespec(new_name);
  48        fill_filespec(one, old_sha1, old_mode);
  49        fill_filespec(two, new_sha1, new_mode);
  50
  51        /* NEEDSWORK: shouldn't this part of diffopt??? */
  52        diff_queue(&diff_queued_diff, one, two);
  53}
  54
  55static int builtin_diff_b_f(struct rev_info *revs,
  56                            int argc, const char **argv,
  57                            struct blobinfo *blob,
  58                            const char *path)
  59{
  60        /* Blob vs file in the working tree*/
  61        struct stat st;
  62
  63        if (argc > 1)
  64                usage(builtin_diff_usage);
  65
  66        if (lstat(path, &st))
  67                die("'%s': %s", path, strerror(errno));
  68        if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  69                die("'%s': not a regular file or symlink", path);
  70
  71        if (blob[0].mode == S_IFINVALID)
  72                blob[0].mode = canon_mode(st.st_mode);
  73
  74        stuff_change(&revs->diffopt,
  75                     blob[0].mode, canon_mode(st.st_mode),
  76                     blob[0].sha1, null_sha1,
  77                     path, path);
  78        diffcore_std(&revs->diffopt);
  79        diff_flush(&revs->diffopt);
  80        return 0;
  81}
  82
  83static int builtin_diff_blobs(struct rev_info *revs,
  84                              int argc, const char **argv,
  85                              struct blobinfo *blob)
  86{
  87        unsigned mode = canon_mode(S_IFREG | 0644);
  88
  89        if (argc > 1)
  90                usage(builtin_diff_usage);
  91
  92        if (blob[0].mode == S_IFINVALID)
  93                blob[0].mode = mode;
  94
  95        if (blob[1].mode == S_IFINVALID)
  96                blob[1].mode = mode;
  97
  98        stuff_change(&revs->diffopt,
  99                     blob[0].mode, blob[1].mode,
 100                     blob[0].sha1, blob[1].sha1,
 101                     blob[0].name, blob[1].name);
 102        diffcore_std(&revs->diffopt);
 103        diff_flush(&revs->diffopt);
 104        return 0;
 105}
 106
 107static int builtin_diff_index(struct rev_info *revs,
 108                              int argc, const char **argv)
 109{
 110        int cached = 0;
 111        while (1 < argc) {
 112                const char *arg = argv[1];
 113                if (!strcmp(arg, "--cached"))
 114                        cached = 1;
 115                else
 116                        usage(builtin_diff_usage);
 117                argv++; argc--;
 118        }
 119        /*
 120         * Make sure there is one revision (i.e. pending object),
 121         * and there is no revision filtering parameters.
 122         */
 123        if (revs->pending.nr != 1 ||
 124            revs->max_count != -1 || revs->min_age != -1 ||
 125            revs->max_age != -1)
 126                usage(builtin_diff_usage);
 127        if (read_cache() < 0) {
 128                perror("read_cache");
 129                return -1;
 130        }
 131        return run_diff_index(revs, cached);
 132}
 133
 134static int builtin_diff_tree(struct rev_info *revs,
 135                             int argc, const char **argv,
 136                             struct object_array_entry *ent)
 137{
 138        const unsigned char *(sha1[2]);
 139        int swap = 0;
 140
 141        if (argc > 1)
 142                usage(builtin_diff_usage);
 143
 144        /* We saw two trees, ent[0] and ent[1].
 145         * if ent[1] is uninteresting, they are swapped
 146         */
 147        if (ent[1].item->flags & UNINTERESTING)
 148                swap = 1;
 149        sha1[swap] = ent[0].item->sha1;
 150        sha1[1-swap] = ent[1].item->sha1;
 151        diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 152        log_tree_diff_flush(revs);
 153        return 0;
 154}
 155
 156static int builtin_diff_combined(struct rev_info *revs,
 157                                 int argc, const char **argv,
 158                                 struct object_array_entry *ent,
 159                                 int ents)
 160{
 161        const unsigned char (*parent)[20];
 162        int i;
 163
 164        if (argc > 1)
 165                usage(builtin_diff_usage);
 166
 167        if (!revs->dense_combined_merges && !revs->combine_merges)
 168                revs->dense_combined_merges = revs->combine_merges = 1;
 169        parent = xmalloc(ents * sizeof(*parent));
 170        /* Again, the revs are all reverse */
 171        for (i = 0; i < ents; i++)
 172                hashcpy((unsigned char *)(parent + i),
 173                        ent[ents - 1 - i].item->sha1);
 174        diff_tree_combined(parent[0], parent + 1, ents - 1,
 175                           revs->dense_combined_merges, revs);
 176        return 0;
 177}
 178
 179void add_head(struct rev_info *revs)
 180{
 181        unsigned char sha1[20];
 182        struct object *obj;
 183        if (get_sha1("HEAD", sha1))
 184                return;
 185        obj = parse_object(sha1);
 186        if (!obj)
 187                return;
 188        add_pending_object(revs, obj, "HEAD");
 189}
 190
 191int cmd_diff(int argc, const char **argv, const char *prefix)
 192{
 193        int i;
 194        struct rev_info rev;
 195        struct object_array_entry ent[100];
 196        int ents = 0, blobs = 0, paths = 0;
 197        const char *path = NULL;
 198        struct blobinfo blob[2];
 199        int nongit = 0;
 200        int result = 0;
 201
 202        /*
 203         * We could get N tree-ish in the rev.pending_objects list.
 204         * Also there could be M blobs there, and P pathspecs.
 205         *
 206         * N=0, M=0:
 207         *      cache vs files (diff-files)
 208         * N=0, M=2:
 209         *      compare two random blobs.  P must be zero.
 210         * N=0, M=1, P=1:
 211         *      compare a blob with a working tree file.
 212         *
 213         * N=1, M=0:
 214         *      tree vs cache (diff-index --cached)
 215         *
 216         * N=2, M=0:
 217         *      tree vs tree (diff-tree)
 218         *
 219         * Other cases are errors.
 220         */
 221
 222        prefix = setup_git_directory_gently(&nongit);
 223        git_config(git_diff_ui_config);
 224        init_revisions(&rev, prefix);
 225
 226        if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
 227                argc = 0;
 228        else
 229                argc = setup_revisions(argc, argv, &rev, NULL);
 230        if (!rev.diffopt.output_format) {
 231                rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 232                if (diff_setup_done(&rev.diffopt) < 0)
 233                        die("diff_setup_done failed");
 234        }
 235        rev.diffopt.allow_external = 1;
 236
 237        /* Do we have --cached and not have a pending object, then
 238         * default to HEAD by hand.  Eek.
 239         */
 240        if (!rev.pending.nr) {
 241                int i;
 242                for (i = 1; i < argc; i++) {
 243                        const char *arg = argv[i];
 244                        if (!strcmp(arg, "--"))
 245                                break;
 246                        else if (!strcmp(arg, "--cached")) {
 247                                add_head(&rev);
 248                                if (!rev.pending.nr)
 249                                        die("No HEAD commit to compare with (yet)");
 250                                break;
 251                        }
 252                }
 253        }
 254
 255        for (i = 0; i < rev.pending.nr; i++) {
 256                struct object_array_entry *list = rev.pending.objects+i;
 257                struct object *obj = list->item;
 258                const char *name = list->name;
 259                int flags = (obj->flags & UNINTERESTING);
 260                if (!obj->parsed)
 261                        obj = parse_object(obj->sha1);
 262                obj = deref_tag(obj, NULL, 0);
 263                if (!obj)
 264                        die("invalid object '%s' given.", name);
 265                if (obj->type == OBJ_COMMIT)
 266                        obj = &((struct commit *)obj)->tree->object;
 267                if (obj->type == OBJ_TREE) {
 268                        if (ARRAY_SIZE(ent) <= ents)
 269                                die("more than %d trees given: '%s'",
 270                                    (int) ARRAY_SIZE(ent), name);
 271                        obj->flags |= flags;
 272                        ent[ents].item = obj;
 273                        ent[ents].name = name;
 274                        ents++;
 275                        continue;
 276                }
 277                if (obj->type == OBJ_BLOB) {
 278                        if (2 <= blobs)
 279                                die("more than two blobs given: '%s'", name);
 280                        hashcpy(blob[blobs].sha1, obj->sha1);
 281                        blob[blobs].name = name;
 282                        blob[blobs].mode = list->mode;
 283                        blobs++;
 284                        continue;
 285
 286                }
 287                die("unhandled object '%s' given.", name);
 288        }
 289        if (rev.prune_data) {
 290                const char **pathspec = rev.prune_data;
 291                while (*pathspec) {
 292                        if (!path)
 293                                path = *pathspec;
 294                        paths++;
 295                        pathspec++;
 296                }
 297        }
 298
 299        /*
 300         * Now, do the arguments look reasonable?
 301         */
 302        if (!ents) {
 303                switch (blobs) {
 304                case 0:
 305                        result = run_diff_files_cmd(&rev, argc, argv);
 306                        break;
 307                case 1:
 308                        if (paths != 1)
 309                                usage(builtin_diff_usage);
 310                        result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 311                        break;
 312                case 2:
 313                        if (paths)
 314                                usage(builtin_diff_usage);
 315                        result = builtin_diff_blobs(&rev, argc, argv, blob);
 316                        break;
 317                default:
 318                        usage(builtin_diff_usage);
 319                }
 320        }
 321        else if (blobs)
 322                usage(builtin_diff_usage);
 323        else if (ents == 1)
 324                result = builtin_diff_index(&rev, argc, argv);
 325        else if (ents == 2)
 326                result = builtin_diff_tree(&rev, argc, argv, ent);
 327        else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
 328                /* diff A...B where there is one sane merge base between
 329                 * A and B.  We have ent[0] == merge-base, ent[1] == A,
 330                 * and ent[2] == B.  Show diff between the base and B.
 331                 */
 332                ent[1] = ent[2];
 333                result = builtin_diff_tree(&rev, argc, argv, ent);
 334        }
 335        else
 336                result = builtin_diff_combined(&rev, argc, argv,
 337                                             ent, ents);
 338        if (rev.diffopt.exit_with_status)
 339                result = rev.diffopt.has_changes;
 340        return result;
 341}