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 "cache.h"
   8 #include "color.h"
   9 #include "commit.h"
  10 #include "blob.h"
  11 #include "tag.h"
  12 #include "diff.h"
  13 #include "diffcore.h"
  14 #include "revision.h"
  15 #include "log-tree.h"
  16 #include "parse-options.h"
  17 #include "string-list.h"
  18 #include "dir.h"
  19
  20 static int read_directory_contents(const char *path, struct string_list *list)
  21 {
  22         DIR *dir;
  23         struct dirent *e;
  24
  25         if (!(dir = opendir(path)))
  26                 return error("Could not open directory %s", path);
  27
  28         while ((e = readdir_skip_dot_and_dotdot(dir)))
  29                 string_list_insert(list, e->d_name);
  30
  31         closedir(dir);
  32         return 0;
  33 }
  34
  35 /*
  36  * This should be "(standard input)" or something, but it will
  37  * probably expose many more breakages in the way no-index code
  38  * is bolted onto the diff callchain.
  39  */
  40 static const char file_from_standard_input[] = "-";
  41
  42 static int get_mode(const char *path, int *mode)
  43 {
  44         struct stat st;
  45
  46         if (!path || !strcmp(path, "/dev/null"))
  47                 *mode = 0;
  48 #ifdef GIT_WINDOWS_NATIVE
  49         else if (!strcasecmp(path, "nul"))
  50                 *mode = 0;
  51 #endif
  52         else if (path == file_from_standard_input)
  53                 *mode = create_ce_mode(0666);
  54         else if (lstat(path, &st))
  55                 return error("Could not access '%s'", path);
  56         else
  57                 *mode = st.st_mode;
  58         return 0;
  59 }
  60
  61 static int populate_from_stdin(struct diff_filespec *s)
  62 {
  63         struct strbuf buf = STRBUF_INIT;
  64         size_t size = 0;
  65
  66         if (strbuf_read(&buf, 0, 0) < 0)
  67                 return error_errno("error while reading from stdin");
  68
  69         s->should_munmap = 0;
  70         s->data = strbuf_detach(&buf, &size);
  71         s->size = size;
  72         s->should_free = 1;
  73         s->is_stdin = 1;
  74         return 0;
  75 }
  76
  77 static struct diff_filespec *noindex_filespec(const char *name, int mode)
  78 {
  79         struct diff_filespec *s;
  80
  81         if (!name)
  82                 name = "/dev/null";
  83         s = alloc_filespec(name);
  84         fill_filespec(s, null_oid(), 0, mode);
  85         if (name == file_from_standard_input)
  86                 populate_from_stdin(s);
  87         return s;
  88 }
  89
  90 static int queue_diff(struct diff_options *o,
  91                       const char *name1, const char *name2)
  92 {
  93         int mode1 = 0, mode2 = 0;
  94
  95         if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
  96                 return -1;
  97
  98         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2)) {
  99                 struct diff_filespec *d1, *d2;
 100
 101                 if (S_ISDIR(mode1)) {
 102                         /* 2 is file that is created */
 103                         d1 = noindex_filespec(NULL, 0);
 104                         d2 = noindex_filespec(name2, mode2);
 105                         name2 = NULL;
 106                         mode2 = 0;
 107                 } else {
 108                         /* 1 is file that is deleted */
 109                         d1 = noindex_filespec(name1, mode1);
 110                         d2 = noindex_filespec(NULL, 0);
 111                         name1 = NULL;
 112                         mode1 = 0;
 113                 }
 114                 /* emit that file */
 115                 diff_queue(&diff_queued_diff, d1, d2);
 116
 117                 /* and then let the entire directory be created or deleted */
 118         }
 119
 120         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
 121                 struct strbuf buffer1 = STRBUF_INIT;
 122                 struct strbuf buffer2 = STRBUF_INIT;
 123                 struct string_list p1 = STRING_LIST_INIT_DUP;
 124                 struct string_list p2 = STRING_LIST_INIT_DUP;
 125                 int i1, i2, ret = 0;
 126                 size_t len1 = 0, len2 = 0;
 127
 128                 if (name1 && read_directory_contents(name1, &p1))
 129                         return -1;
 130                 if (name2 && read_directory_contents(name2, &p2)) {
 131                         string_list_clear(&p1, 0);
 132                         return -1;
 133                 }
 134
 135                 if (name1) {
 136                         strbuf_addstr(&buffer1, name1);
 137                         strbuf_complete(&buffer1, '/');
 138                         len1 = buffer1.len;
 139                 }
 140
 141                 if (name2) {
 142                         strbuf_addstr(&buffer2, name2);
 143                         strbuf_complete(&buffer2, '/');
 144                         len2 = buffer2.len;
 145                 }
 146
 147                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
 148                         const char *n1, *n2;
 149                         int comp;
 150
 151                         strbuf_setlen(&buffer1, len1);
 152                         strbuf_setlen(&buffer2, len2);
 153
 154                         if (i1 == p1.nr)
 155                                 comp = 1;
 156                         else if (i2 == p2.nr)
 157                                 comp = -1;
 158                         else
 159                                 comp = strcmp(p1.items[i1].string, p2.items[i2].string);
 160
 161                         if (comp > 0)
 162                                 n1 = NULL;
 163                         else {
 164                                 strbuf_addstr(&buffer1, p1.items[i1++].string);
 165                                 n1 = buffer1.buf;
 166                         }
 167
 168                         if (comp < 0)
 169                                 n2 = NULL;
 170                         else {
 171                                 strbuf_addstr(&buffer2, p2.items[i2++].string);
 172                                 n2 = buffer2.buf;
 173                         }
 174
 175                         ret = queue_diff(o, n1, n2);
 176                 }
 177                 string_list_clear(&p1, 0);
 178                 string_list_clear(&p2, 0);
 179                 strbuf_release(&buffer1);
 180                 strbuf_release(&buffer2);
 181
 182                 return ret;
 183         } else {
 184                 struct diff_filespec *d1, *d2;
 185
 186                 if (o->flags.reverse_diff) {
 187                         SWAP(mode1, mode2);
 188                         SWAP(name1, name2);
 189                 }
 190
 191                 d1 = noindex_filespec(name1, mode1);
 192                 d2 = noindex_filespec(name2, mode2);
 193                 diff_queue(&diff_queued_diff, d1, d2);
 194                 return 0;
 195         }
 196 }
 197
 198 /* append basename of F to D */
 199 static void append_basename(struct strbuf *path, const char *dir, const char *file)
 200 {
 201         const char *tail = strrchr(file, '/');
 202
 203         strbuf_addstr(path, dir);
 204         while (path->len && path->buf[path->len - 1] == '/')
 205                 path->len--;
 206         strbuf_addch(path, '/');
 207         strbuf_addstr(path, tail ? tail + 1 : file);
 208 }
 209
 210 /*
 211  * DWIM "diff D F" into "diff D/F F" and "diff F D" into "diff F D/F"
 212  * Note that we append the basename of F to D/, so "diff a/b/file D"
 213  * becomes "diff a/b/file D/file", not "diff a/b/file D/a/b/file".
 214  */
 215 static void fixup_paths(const char **path, struct strbuf *replacement)
 216 {
 217         unsigned int isdir0, isdir1;
 218
 219         if (path[0] == file_from_standard_input ||
 220             path[1] == file_from_standard_input)
 221                 return;
 222         isdir0 = is_directory(path[0]);
 223         isdir1 = is_directory(path[1]);
 224         if (isdir0 == isdir1)
 225                 return;
 226         if (isdir0) {
 227                 append_basename(replacement, path[0], path[1]);
 228                 path[0] = replacement->buf;
 229         } else {
 230                 append_basename(replacement, path[1], path[0]);
 231                 path[1] = replacement->buf;
 232         }
 233 }
 234
 235 static const char * const diff_no_index_usage[] = {
 236         N_("git diff --no-index [<options>] <path> <path>"),
 237         NULL
 238 };
 239
 240 int diff_no_index(struct rev_info *revs,
 241                   int implicit_no_index,
 242                   int argc, const char **argv)
 243 {
 244         int i, no_index;
 245         int ret = 1;
 246         const char *paths[2];
 247         char *to_free[ARRAY_SIZE(paths)] = { 0 };
 248         struct strbuf replacement = STRBUF_INIT;
 249         const char *prefix = revs->prefix;
 250         struct option no_index_options[] = {
 251                 OPT_BOOL_F(0, "no-index", &no_index, "",
 252                            PARSE_OPT_NONEG | PARSE_OPT_HIDDEN),
 253                 OPT_END(),
 254         };
 255         struct option *options;
 256
 257         options = add_diff_options(no_index_options, &revs->diffopt);
 258         argc = parse_options(argc, argv, revs->prefix, options,
 259                              diff_no_index_usage, 0);
 260         if (argc != 2) {
 261                 if (implicit_no_index)
 262                         warning(_("Not a git repository. Use --no-index to "
 263                                   "compare two paths outside a working tree"));
 264                 usage_with_options(diff_no_index_usage, options);
 265         }
 266         FREE_AND_NULL(options);
 267         for (i = 0; i < 2; i++) {
 268                 const char *p = argv[i];
 269                 if (!strcmp(p, "-"))
 270                         /*
 271                          * stdin should be spelled as "-"; if you have
 272                          * path that is "-", spell it as "./-".
 273                          */
 274                         p = file_from_standard_input;
 275                 else if (prefix)
 276                         p = to_free[i] = prefix_filename(prefix, p);
 277                 paths[i] = p;
 278         }
 279
 280         fixup_paths(paths, &replacement);
 281
 282         revs->diffopt.skip_stat_unmatch = 1;
 283         if (!revs->diffopt.output_format)
 284                 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 285
 286         revs->diffopt.flags.no_index = 1;
 287
 288         revs->diffopt.flags.relative_name = 1;
 289         revs->diffopt.prefix = prefix;
 290
 291         revs->max_count = -2;
 292         diff_setup_done(&revs->diffopt);
 293
 294         setup_diff_pager(&revs->diffopt);
 295         revs->diffopt.flags.exit_with_status = 1;
 296
 297         if (queue_diff(&revs->diffopt, paths[0], paths[1]))
 298                 goto out;
 299         diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
 300         diffcore_std(&revs->diffopt);
 301         diff_flush(&revs->diffopt);
 302
 303         /*
 304          * The return code for --no-index imitates diff(1):
 305          * 0 = no changes, 1 = changes, else error
 306          */
 307         ret = diff_result_code(&revs->diffopt, 0);
 308
 309 out:
 310         for (i = 0; i < ARRAY_SIZE(to_free); i++)
 311                 free(to_free[i]);
 312         strbuf_release(&replacement);
 313         return ret;
 314 }