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