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