diff-no-index.c

   1 /*
   2  * "diff --no-index" support
   3  * Copyright (c) 2007 by Johannes Schindelin
   4  * Copyright (c) 2008 by Junio C Hamano
   5  */
   6
   7 #define DISABLE_SIGN_COMPARE_WARNINGS
   8
   9 #include "git-compat-util.h"
  10 #include "abspath.h"
  11 #include "color.h"
  12 #include "commit.h"
  13 #include "diff.h"
  14 #include "diffcore.h"
  15 #include "gettext.h"
  16 #include "revision.h"
  17 #include "parse-options.h"
  18 #include "pathspec.h"
  19 #include "string-list.h"
  20 #include "dir.h"
  21
  22 static int read_directory_contents(const char *path, struct string_list *list,
  23                                    const struct pathspec *pathspec,
  24                                    int skip)
  25 {
  26         struct strbuf match = STRBUF_INIT;
  27         int len;
  28         DIR *dir;
  29         struct dirent *e;
  30
  31         if (!(dir = opendir(path)))
  32                 return error("Could not open directory %s", path);
  33
  34         if (pathspec) {
  35                 strbuf_addstr(&match, path);
  36                 strbuf_complete(&match, '/');
  37                 strbuf_remove(&match, 0, skip);
  38
  39                 len = match.len;
  40         }
  41
  42         while ((e = readdir_skip_dot_and_dotdot(dir))) {
  43                 if (pathspec) {
  44                         int is_dir = 0;
  45
  46                         strbuf_setlen(&match, len);
  47                         strbuf_addstr(&match, e->d_name);
  48                         if (NOT_CONSTANT(DTYPE(e)) != DT_UNKNOWN) {
  49                                 is_dir = (DTYPE(e) == DT_DIR);
  50                         } else {
  51                                 struct strbuf pathbuf = STRBUF_INIT;
  52
  53                                 strbuf_addstr(&pathbuf, path);
  54                                 strbuf_complete(&pathbuf, '/');
  55                                 is_dir = get_dtype(e, &pathbuf, 0) == DT_DIR;
  56                                 strbuf_release(&pathbuf);
  57                         }
  58
  59                         if (!match_leading_pathspec(NULL, pathspec,
  60                                                     match.buf, match.len,
  61                                                     0, NULL, is_dir))
  62                                 continue;
  63                 }
  64
  65                 string_list_insert(list, e->d_name);
  66         }
  67
  68         strbuf_release(&match);
  69         closedir(dir);
  70         return 0;
  71 }
  72
  73 /*
  74  * This should be "(standard input)" or something, but it will
  75  * probably expose many more breakages in the way no-index code
  76  * is bolted onto the diff callchain.
  77  */
  78 static const char file_from_standard_input[] = "-";
  79
  80 /*
  81  * For paths given on the command-line we treat "-" as stdin and named
  82  * pipes and symbolic links to named pipes specially.
  83  */
  84 enum special {
  85         SPECIAL_NONE,
  86         SPECIAL_STDIN,
  87         SPECIAL_PIPE,
  88 };
  89
  90 static int get_mode(const char *path, int *mode, enum special *special)
  91 {
  92         struct stat st;
  93
  94         if (!path || !strcmp(path, "/dev/null")) {
  95                 *mode = 0;
  96 #ifdef GIT_WINDOWS_NATIVE
  97         } else if (!strcasecmp(path, "nul")) {
  98                 *mode = 0;
  99 #endif
 100         } else if (path == file_from_standard_input) {
 101                 *mode = create_ce_mode(0666);
 102                 *special = SPECIAL_STDIN;
 103         } else if (lstat(path, &st)) {
 104                 return error("Could not access '%s'", path);
 105         } else {
 106                 *mode = st.st_mode;
 107         }
 108         /*
 109          * For paths on the command-line treat named pipes and symbolic
 110          * links that resolve to a named pipe specially.
 111          */
 112         if (special &&
 113             (S_ISFIFO(*mode) ||
 114              (S_ISLNK(*mode) && !stat(path, &st) && S_ISFIFO(st.st_mode)))) {
 115                 *mode = create_ce_mode(0666);
 116                 *special = SPECIAL_PIPE;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static void populate_common(struct diff_filespec *s, struct strbuf *buf)
 123 {
 124         size_t size = 0;
 125
 126         s->should_munmap = 0;
 127         s->data = strbuf_detach(buf, &size);
 128         s->size = size;
 129         s->should_free = 1;
 130         s->is_stdin = 1;
 131 }
 132
 133 static void populate_from_pipe(struct diff_filespec *s)
 134 {
 135         struct strbuf buf = STRBUF_INIT;
 136         int fd = xopen(s->path, O_RDONLY);
 137
 138         if (strbuf_read(&buf, fd, 0) < 0)
 139                 die_errno("error while reading from '%s'", s->path);
 140         close(fd);
 141         populate_common(s, &buf);
 142 }
 143
 144 static void populate_from_stdin(struct diff_filespec *s)
 145 {
 146         struct strbuf buf = STRBUF_INIT;
 147
 148         if (strbuf_read(&buf, 0, 0) < 0)
 149                 die_errno("error while reading from stdin");
 150         populate_common(s, &buf);
 151 }
 152
 153 static struct diff_filespec *noindex_filespec(const struct git_hash_algo *algop,
 154                                               const char *name, int mode,
 155                                               enum special special)
 156 {
 157         struct diff_filespec *s;
 158
 159         if (!name)
 160                 name = "/dev/null";
 161         s = alloc_filespec(name);
 162         fill_filespec(s, null_oid(algop), 0, mode);
 163         if (special == SPECIAL_STDIN)
 164                 populate_from_stdin(s);
 165         else if (special == SPECIAL_PIPE)
 166                 populate_from_pipe(s);
 167         return s;
 168 }
 169
 170 static int queue_diff(struct diff_options *o, const struct git_hash_algo *algop,
 171                       const char *name1, const char *name2, int recursing,
 172                       const struct pathspec *ps, int skip1, int skip2)
 173 {
 174         int mode1 = 0, mode2 = 0;
 175         enum special special1 = SPECIAL_NONE, special2 = SPECIAL_NONE;
 176
 177         /* Paths can only be special if we're not recursing. */
 178         if (get_mode(name1, &mode1, recursing ? NULL : &special1) ||
 179             get_mode(name2, &mode2, recursing ? NULL : &special2))
 180                 return -1;
 181
 182         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2)) {
 183                 struct diff_filespec *d1, *d2;
 184
 185                 if (S_ISDIR(mode1)) {
 186                         /* 2 is file that is created */
 187                         d1 = noindex_filespec(algop, NULL, 0, SPECIAL_NONE);
 188                         d2 = noindex_filespec(algop, name2, mode2, special2);
 189                         name2 = NULL;
 190                         mode2 = 0;
 191                 } else {
 192                         /* 1 is file that is deleted */
 193                         d1 = noindex_filespec(algop, name1, mode1, special1);
 194                         d2 = noindex_filespec(algop, NULL, 0, SPECIAL_NONE);
 195                         name1 = NULL;
 196                         mode1 = 0;
 197                 }
 198                 /* emit that file */
 199                 diff_queue(&diff_queued_diff, d1, d2);
 200
 201                 /* and then let the entire directory be created or deleted */
 202         }
 203
 204         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
 205                 struct strbuf buffer1 = STRBUF_INIT;
 206                 struct strbuf buffer2 = STRBUF_INIT;
 207                 struct string_list p1 = STRING_LIST_INIT_DUP;
 208                 struct string_list p2 = STRING_LIST_INIT_DUP;
 209                 int i1, i2, ret = 0;
 210                 size_t len1 = 0, len2 = 0;
 211
 212                 if (name1 && read_directory_contents(name1, &p1, ps, skip1))
 213                         return -1;
 214                 if (name2 && read_directory_contents(name2, &p2, ps, skip2)) {
 215                         string_list_clear(&p1, 0);
 216                         return -1;
 217                 }
 218
 219                 if (name1) {
 220                         strbuf_addstr(&buffer1, name1);
 221                         strbuf_complete(&buffer1, '/');
 222                         len1 = buffer1.len;
 223                 }
 224
 225                 if (name2) {
 226                         strbuf_addstr(&buffer2, name2);
 227                         strbuf_complete(&buffer2, '/');
 228                         len2 = buffer2.len;
 229                 }
 230
 231                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
 232                         const char *n1, *n2;
 233                         int comp;
 234
 235                         strbuf_setlen(&buffer1, len1);
 236                         strbuf_setlen(&buffer2, len2);
 237
 238                         if (i1 == p1.nr)
 239                                 comp = 1;
 240                         else if (i2 == p2.nr)
 241                                 comp = -1;
 242                         else
 243                                 comp = strcmp(p1.items[i1].string, p2.items[i2].string);
 244
 245                         if (comp > 0)
 246                                 n1 = NULL;
 247                         else {
 248                                 strbuf_addstr(&buffer1, p1.items[i1++].string);
 249                                 n1 = buffer1.buf;
 250                         }
 251
 252                         if (comp < 0)
 253                                 n2 = NULL;
 254                         else {
 255                                 strbuf_addstr(&buffer2, p2.items[i2++].string);
 256                                 n2 = buffer2.buf;
 257                         }
 258
 259                         ret = queue_diff(o, algop, n1, n2, 1, ps, skip1, skip2);
 260                 }
 261                 string_list_clear(&p1, 0);
 262                 string_list_clear(&p2, 0);
 263                 strbuf_release(&buffer1);
 264                 strbuf_release(&buffer2);
 265
 266                 return ret;
 267         } else {
 268                 struct diff_filespec *d1, *d2;
 269
 270                 if (o->flags.reverse_diff) {
 271                         SWAP(mode1, mode2);
 272                         SWAP(name1, name2);
 273                         SWAP(special1, special2);
 274                 }
 275
 276                 d1 = noindex_filespec(algop, name1, mode1, special1);
 277                 d2 = noindex_filespec(algop, name2, mode2, special2);
 278                 diff_queue(&diff_queued_diff, d1, d2);
 279                 return 0;
 280         }
 281 }
 282
 283 /* append basename of F to D */
 284 static void append_basename(struct strbuf *path, const char *dir, const char *file)
 285 {
 286         const char *tail = strrchr(file, '/');
 287
 288         strbuf_addstr(path, dir);
 289         while (path->len && path->buf[path->len - 1] == '/')
 290                 path->len--;
 291         strbuf_addch(path, '/');
 292         strbuf_addstr(path, tail ? tail + 1 : file);
 293 }
 294
 295 /*
 296  * DWIM "diff D F" into "diff D/F F" and "diff F D" into "diff F D/F"
 297  * Note that we append the basename of F to D/, so "diff a/b/file D"
 298  * becomes "diff a/b/file D/file", not "diff a/b/file D/a/b/file".
 299  *
 300  * Return 1 if both paths are directories, 0 otherwise.
 301  */
 302 static int fixup_paths(const char **path, struct strbuf *replacement)
 303 {
 304         struct stat st;
 305         unsigned int isdir0 = 0, isdir1 = 0;
 306         unsigned int ispipe0 = 0, ispipe1 = 0;
 307
 308         if (path[0] != file_from_standard_input && !stat(path[0], &st)) {
 309                 isdir0 = S_ISDIR(st.st_mode);
 310                 ispipe0 = S_ISFIFO(st.st_mode);
 311         }
 312
 313         if (path[1] != file_from_standard_input && !stat(path[1], &st)) {
 314                 isdir1 = S_ISDIR(st.st_mode);
 315                 ispipe1 = S_ISFIFO(st.st_mode);
 316         }
 317
 318         if ((path[0] == file_from_standard_input && isdir1) ||
 319             (isdir0 && path[1] == file_from_standard_input))
 320                 die(_("cannot compare stdin to a directory"));
 321
 322         if ((isdir0 && ispipe1) || (ispipe0 && isdir1))
 323                 die(_("cannot compare a named pipe to a directory"));
 324
 325         /* if both paths are directories, we will enable pathspecs */
 326         if (isdir0 && isdir1)
 327                 return 1;
 328
 329         if (isdir0) {
 330                 append_basename(replacement, path[0], path[1]);
 331                 path[0] = replacement->buf;
 332         } else if (isdir1) {
 333                 append_basename(replacement, path[1], path[0]);
 334                 path[1] = replacement->buf;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static const char * const diff_no_index_usage[] = {
 341         N_("git diff --no-index [<options>] <path> <path> [<pathspec>...]"),
 342         NULL
 343 };
 344
 345 int diff_no_index(struct rev_info *revs, const struct git_hash_algo *algop,
 346                   int implicit_no_index, int argc, const char **argv)
 347 {
 348         struct pathspec pathspec, *ps = NULL;
 349         int i, no_index, skip1 = 0, skip2 = 0;
 350         int ret = 1;
 351         const char *paths[2];
 352         char *to_free[ARRAY_SIZE(paths)] = { 0 };
 353         struct strbuf replacement = STRBUF_INIT;
 354         const char *prefix = revs->prefix;
 355         struct option no_index_options[] = {
 356                 OPT_BOOL_F(0, "no-index", &no_index, "",
 357                            PARSE_OPT_NONEG | PARSE_OPT_HIDDEN),
 358                 OPT_END(),
 359         };
 360         struct option *options;
 361
 362         options = add_diff_options(no_index_options, &revs->diffopt);
 363         argc = parse_options(argc, argv, revs->prefix, options,
 364                              diff_no_index_usage, 0);
 365         if (argc < 2) {
 366                 if (implicit_no_index)
 367                         warning(_("Not a git repository. Use --no-index to "
 368                                   "compare two paths outside a working tree"));
 369                 usage_with_options(diff_no_index_usage, options);
 370         }
 371         for (i = 0; i < 2; i++) {
 372                 const char *p = argv[i];
 373                 if (!strcmp(p, "-"))
 374                         /*
 375                          * stdin should be spelled as "-"; if you have
 376                          * path that is "-", spell it as "./-".
 377                          */
 378                         p = file_from_standard_input;
 379                 else if (prefix)
 380                         p = to_free[i] = prefix_filename(prefix, p);
 381                 paths[i] = p;
 382         }
 383
 384         if (fixup_paths(paths, &replacement)) {
 385                 parse_pathspec(&pathspec, PATHSPEC_FROMTOP | PATHSPEC_ATTR,
 386                                PATHSPEC_PREFER_FULL | PATHSPEC_NO_REPOSITORY,
 387                                NULL, &argv[2]);
 388                 if (pathspec.nr)
 389                         ps = &pathspec;
 390
 391                 skip1 = strlen(paths[0]);
 392                 skip1 += paths[0][skip1] == '/' ? 0 : 1;
 393                 skip2 = strlen(paths[1]);
 394                 skip2 += paths[1][skip2] == '/' ? 0 : 1;
 395         } else if (argc > 2) {
 396                 warning(_("Limiting comparison with pathspecs is only "
 397                           "supported if both paths are directories."));
 398                 usage_with_options(diff_no_index_usage, options);
 399         }
 400         FREE_AND_NULL(options);
 401
 402         revs->diffopt.skip_stat_unmatch = 1;
 403         if (!revs->diffopt.output_format)
 404                 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 405
 406         revs->diffopt.flags.no_index = 1;
 407
 408         revs->diffopt.flags.relative_name = 1;
 409         revs->diffopt.prefix = prefix;
 410
 411         revs->max_count = -2;
 412         diff_setup_done(&revs->diffopt);
 413
 414         setup_diff_pager(&revs->diffopt);
 415         revs->diffopt.flags.exit_with_status = 1;
 416
 417         if (queue_diff(&revs->diffopt, algop, paths[0], paths[1], 0, ps,
 418                        skip1, skip2))
 419                 goto out;
 420         diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
 421         diffcore_std(&revs->diffopt);
 422         diff_flush(&revs->diffopt);
 423
 424         /*
 425          * The return code for --no-index imitates diff(1):
 426          * 0 = no changes, 1 = changes, else error
 427          */
 428         ret = diff_result_code(revs);
 429
 430 out:
 431         for (i = 0; i < ARRAY_SIZE(to_free); i++)
 432                 free(to_free[i]);
 433         strbuf_release(&replacement);
 434         if (ps)
 435                 clear_pathspec(ps);
 436         return ret;
 437 }