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