builtin-diff.c

   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
  16 /* NEEDSWORK: struct object has place for name but we _do_
  17  * know mode when we extracted the blob out of a tree, which
  18  * we currently lose.
  19  */
  20 struct blobinfo {
  21         unsigned char sha1[20];
  22         const char *name;
  23 };
  24
  25 static const char builtin_diff_usage[] =
  26 "diff <options> <rev>{0,2} -- <path>*";
  27
  28 static int builtin_diff_files(struct rev_info *revs,
  29                               int argc, const char **argv)
  30 {
  31         int silent = 0;
  32         while (1 < argc) {
  33                 const char *arg = argv[1];
  34                 if (!strcmp(arg, "--base"))
  35                         revs->max_count = 1;
  36                 else if (!strcmp(arg, "--ours"))
  37                         revs->max_count = 2;
  38                 else if (!strcmp(arg, "--theirs"))
  39                         revs->max_count = 3;
  40                 else if (!strcmp(arg, "-q"))
  41                         silent = 1;
  42                 else if (!strcmp(arg, "--raw"))
  43                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
  44                 else
  45                         usage(builtin_diff_usage);
  46                 argv++; argc--;
  47         }
  48         /*
  49          * Make sure there are NO revision (i.e. pending object) parameter,
  50          * specified rev.max_count is reasonable (0 <= n <= 3), and
  51          * there is no other revision filtering parameter.
  52          */
  53         if (revs->pending_objects ||
  54             revs->min_age != -1 ||
  55             revs->max_age != -1 ||
  56             3 < revs->max_count)
  57                 usage(builtin_diff_usage);
  58         if (revs->max_count < 0 &&
  59             (revs->diffopt.output_format == DIFF_FORMAT_PATCH))
  60                 revs->combine_merges = revs->dense_combined_merges = 1;
  61         /*
  62          * Backward compatibility wart - "diff-files -s" used to
  63          * defeat the common diff option "-s" which asked for
  64          * DIFF_FORMAT_NO_OUTPUT.
  65          */
  66         if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
  67                 revs->diffopt.output_format = DIFF_FORMAT_RAW;
  68         return run_diff_files(revs, silent);
  69 }
  70
  71 static void stuff_change(struct diff_options *opt,
  72                          unsigned old_mode, unsigned new_mode,
  73                          const unsigned char *old_sha1,
  74                          const unsigned char *new_sha1,
  75                          const char *old_name,
  76                          const char *new_name)
  77 {
  78         struct diff_filespec *one, *two;
  79
  80         if (memcmp(null_sha1, old_sha1, 20) &&
  81             memcmp(null_sha1, new_sha1, 20) &&
  82             !memcmp(old_sha1, new_sha1, 20))
  83                 return;
  84
  85         if (opt->reverse_diff) {
  86                 unsigned tmp;
  87                 const
  88                         const unsigned char *tmp_u;
  89                 const char *tmp_c;
  90                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  91                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  92                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  93         }
  94         one = alloc_filespec(old_name);
  95         two = alloc_filespec(new_name);
  96         fill_filespec(one, old_sha1, old_mode);
  97         fill_filespec(two, new_sha1, new_mode);
  98
  99         /* NEEDSWORK: shouldn't this part of diffopt??? */
 100         diff_queue(&diff_queued_diff, one, two);
 101 }
 102
 103 static int builtin_diff_b_f(struct rev_info *revs,
 104                             int argc, const char **argv,
 105                             struct blobinfo *blob,
 106                             const char *path)
 107 {
 108         /* Blob vs file in the working tree*/
 109         struct stat st;
 110
 111         while (1 < argc) {
 112                 const char *arg = argv[1];
 113                 if (!strcmp(arg, "--raw"))
 114                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 115                 else
 116                         usage(builtin_diff_usage);
 117                 argv++; argc--;
 118         }
 119         if (lstat(path, &st))
 120                 die("'%s': %s", path, strerror(errno));
 121         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
 122                 die("'%s': not a regular file or symlink", path);
 123         stuff_change(&revs->diffopt,
 124                      canon_mode(st.st_mode), canon_mode(st.st_mode),
 125                      blob[0].sha1, null_sha1,
 126                      blob[0].name, path);
 127         diffcore_std(&revs->diffopt);
 128         diff_flush(&revs->diffopt);
 129         return 0;
 130 }
 131
 132 static int builtin_diff_blobs(struct rev_info *revs,
 133                               int argc, const char **argv,
 134                               struct blobinfo *blob)
 135 {
 136         /* Blobs */
 137         unsigned mode = canon_mode(S_IFREG | 0644);
 138
 139         while (1 < argc) {
 140                 const char *arg = argv[1];
 141                 if (!strcmp(arg, "--raw"))
 142                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 143                 else
 144                         usage(builtin_diff_usage);
 145                 argv++; argc--;
 146         }
 147         stuff_change(&revs->diffopt,
 148                      mode, mode,
 149                      blob[0].sha1, blob[1].sha1,
 150                      blob[1].name, blob[1].name);
 151         diffcore_std(&revs->diffopt);
 152         diff_flush(&revs->diffopt);
 153         return 0;
 154 }
 155
 156 static int builtin_diff_index(struct rev_info *revs,
 157                               int argc, const char **argv)
 158 {
 159         int cached = 0;
 160         while (1 < argc) {
 161                 const char *arg = argv[1];
 162                 if (!strcmp(arg, "--cached"))
 163                         cached = 1;
 164                 else if (!strcmp(arg, "--raw"))
 165                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 166                 else
 167                         usage(builtin_diff_usage);
 168                 argv++; argc--;
 169         }
 170         /*
 171          * Make sure there is one revision (i.e. pending object),
 172          * and there is no revision filtering parameters.
 173          */
 174         if (!revs->pending_objects || revs->pending_objects->next ||
 175             revs->max_count != -1 || revs->min_age != -1 ||
 176             revs->max_age != -1)
 177                 usage(builtin_diff_usage);
 178         return run_diff_index(revs, cached);
 179 }
 180
 181 static int builtin_diff_tree(struct rev_info *revs,
 182                              int argc, const char **argv,
 183                              struct object_list *ent)
 184 {
 185         const unsigned char *(sha1[2]);
 186         int swap = 1;
 187         while (1 < argc) {
 188                 const char *arg = argv[1];
 189                 if (!strcmp(arg, "--raw"))
 190                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 191                 else
 192                         usage(builtin_diff_usage);
 193                 argv++; argc--;
 194         }
 195
 196         /* We saw two trees, ent[0] and ent[1].
 197          * unless ent[0] is unintesting, they are swapped
 198          */
 199         if (ent[0].item->flags & UNINTERESTING)
 200                 swap = 0;
 201         sha1[swap] = ent[0].item->sha1;
 202         sha1[1-swap] = ent[1].item->sha1;
 203         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 204         log_tree_diff_flush(revs);
 205         return 0;
 206 }
 207
 208 static int builtin_diff_combined(struct rev_info *revs,
 209                                  int argc, const char **argv,
 210                                  struct object_list *ent,
 211                                  int ents)
 212 {
 213         const unsigned char (*parent)[20];
 214         int i;
 215
 216         while (1 < argc) {
 217                 const char *arg = argv[1];
 218                 if (!strcmp(arg, "--raw"))
 219                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 220                 else
 221                         usage(builtin_diff_usage);
 222                 argv++; argc--;
 223         }
 224         if (!revs->dense_combined_merges && !revs->combine_merges)
 225                 revs->dense_combined_merges = revs->combine_merges = 1;
 226         parent = xmalloc(ents * sizeof(*parent));
 227         /* Again, the revs are all reverse */
 228         for (i = 0; i < ents; i++)
 229                 memcpy(parent + i, ent[ents - 1 - i].item->sha1, 20);
 230         diff_tree_combined(parent[0], parent + 1, ents - 1,
 231                            revs->dense_combined_merges, revs);
 232         return 0;
 233 }
 234
 235 static void add_head(struct rev_info *revs)
 236 {
 237         unsigned char sha1[20];
 238         struct object *obj;
 239         if (get_sha1("HEAD", sha1))
 240                 return;
 241         obj = parse_object(sha1);
 242         if (!obj)
 243                 return;
 244         add_object(obj, &revs->pending_objects, NULL, "HEAD");
 245 }
 246
 247 int cmd_diff(int argc, const char **argv, char **envp)
 248 {
 249         struct rev_info rev;
 250         struct object_list *list, ent[100];
 251         int ents = 0, blobs = 0, paths = 0;
 252         const char *path = NULL;
 253         struct blobinfo blob[2];
 254
 255         /*
 256          * We could get N tree-ish in the rev.pending_objects list.
 257          * Also there could be M blobs there, and P pathspecs.
 258          *
 259          * N=0, M=0:
 260          *      cache vs files (diff-files)
 261          * N=0, M=2:
 262          *      compare two random blobs.  P must be zero.
 263          * N=0, M=1, P=1:
 264          *      compare a blob with a working tree file.
 265          *
 266          * N=1, M=0:
 267          *      tree vs cache (diff-index --cached)
 268          *
 269          * N=2, M=0:
 270          *      tree vs tree (diff-tree)
 271          *
 272          * Other cases are errors.
 273          */
 274
 275         git_config(git_diff_config);
 276         init_revisions(&rev);
 277         rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 278
 279         argc = setup_revisions(argc, argv, &rev, NULL);
 280         /* Do we have --cached and not have a pending object, then
 281          * default to HEAD by hand.  Eek.
 282          */
 283         if (!rev.pending_objects) {
 284                 int i;
 285                 for (i = 1; i < argc; i++) {
 286                         const char *arg = argv[i];
 287                         if (!strcmp(arg, "--"))
 288                                 break;
 289                         else if (!strcmp(arg, "--cached")) {
 290                                 add_head(&rev);
 291                                 break;
 292                         }
 293                 }
 294         }
 295
 296         for (list = rev.pending_objects; list; list = list->next) {
 297                 struct object *obj = list->item;
 298                 const char *name = list->name;
 299                 int flags = (obj->flags & UNINTERESTING);
 300                 if (!obj->parsed)
 301                         obj = parse_object(obj->sha1);
 302                 obj = deref_tag(obj, NULL, 0);
 303                 if (!obj)
 304                         die("invalid object '%s' given.", name);
 305                 if (!strcmp(obj->type, commit_type))
 306                         obj = &((struct commit *)obj)->tree->object;
 307                 if (!strcmp(obj->type, tree_type)) {
 308                         if (ARRAY_SIZE(ent) <= ents)
 309                                 die("more than %d trees given: '%s'",
 310                                     (int) ARRAY_SIZE(ent), name);
 311                         obj->flags |= flags;
 312                         ent[ents].item = obj;
 313                         ent[ents].name = name;
 314                         ents++;
 315                         continue;
 316                 }
 317                 if (!strcmp(obj->type, blob_type)) {
 318                         if (2 <= blobs)
 319                                 die("more than two blobs given: '%s'", name);
 320                         memcpy(blob[blobs].sha1, obj->sha1, 20);
 321                         blob[blobs].name = name;
 322                         blobs++;
 323                         continue;
 324
 325                 }
 326                 die("unhandled object '%s' given.", name);
 327         }
 328         if (rev.prune_data) {
 329                 const char **pathspec = rev.prune_data;
 330                 while (*pathspec) {
 331                         if (!path)
 332                                 path = *pathspec;
 333                         paths++;
 334                         pathspec++;
 335                 }
 336         }
 337
 338         /*
 339          * Now, do the arguments look reasonable?
 340          */
 341         if (!ents) {
 342                 switch (blobs) {
 343                 case 0:
 344                         return builtin_diff_files(&rev, argc, argv);
 345                         break;
 346                 case 1:
 347                         if (paths != 1)
 348                                 usage(builtin_diff_usage);
 349                         return builtin_diff_b_f(&rev, argc, argv, blob, path);
 350                         break;
 351                 case 2:
 352                         if (paths)
 353                                 usage(builtin_diff_usage);
 354                         return builtin_diff_blobs(&rev, argc, argv, blob);
 355                         break;
 356                 default:
 357                         usage(builtin_diff_usage);
 358                 }
 359         }
 360         else if (blobs)
 361                 usage(builtin_diff_usage);
 362         else if (ents == 1)
 363                 return builtin_diff_index(&rev, argc, argv);
 364         else if (ents == 2)
 365                 return builtin_diff_tree(&rev, argc, argv, ent);
 366         else
 367                 return builtin_diff_combined(&rev, argc, argv, ent, ents);
 368         usage(builtin_diff_usage);
 369 }