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 static int get_mode(const char *path, int *mode)
  45 {
  46         struct stat st;
  47
  48         if (!path || !strcmp(path, "/dev/null"))
  49                 *mode = 0;
  50 #ifdef GIT_WINDOWS_NATIVE
  51         else if (!strcasecmp(path, "nul"))
  52                 *mode = 0;
  53 #endif
  54         else if (path == file_from_standard_input)
  55                 *mode = create_ce_mode(0666);
  56         else if (lstat(path, &st))
  57                 return error("Could not access '%s'", path);
  58         else
  59                 *mode = st.st_mode;
  60         return 0;
  61 }
  62
  63 static void populate_from_stdin(struct diff_filespec *s)
  64 {
  65         struct strbuf buf = STRBUF_INIT;
  66         size_t size = 0;
  67
  68         if (strbuf_read(&buf, 0, 0) < 0)
  69                 die_errno("error while reading from stdin");
  70
  71         s->should_munmap = 0;
  72         s->data = strbuf_detach(&buf, &size);
  73         s->size = size;
  74         s->should_free = 1;
  75         s->is_stdin = 1;
  76 }
  77
  78 static struct diff_filespec *noindex_filespec(const char *name, int mode)
  79 {
  80         struct diff_filespec *s;
  81
  82         if (!name)
  83                 name = "/dev/null";
  84         s = alloc_filespec(name);
  85         fill_filespec(s, null_oid(), 0, mode);
  86         if (name == file_from_standard_input)
  87                 populate_from_stdin(s);
  88         return s;
  89 }
  90
  91 static int queue_diff(struct diff_options *o,
  92                       const char *name1, const char *name2)
  93 {
  94         int mode1 = 0, mode2 = 0;
  95
  96         if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
  97                 return -1;
  98
  99         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2)) {
 100                 struct diff_filespec *d1, *d2;
 101
 102                 if (S_ISDIR(mode1)) {
 103                         /* 2 is file that is created */
 104                         d1 = noindex_filespec(NULL, 0);
 105                         d2 = noindex_filespec(name2, mode2);
 106                         name2 = NULL;
 107                         mode2 = 0;
 108                 } else {
 109                         /* 1 is file that is deleted */
 110                         d1 = noindex_filespec(name1, mode1);
 111                         d2 = noindex_filespec(NULL, 0);
 112                         name1 = NULL;
 113                         mode1 = 0;
 114                 }
 115                 /* emit that file */
 116                 diff_queue(&diff_queued_diff, d1, d2);
 117
 118                 /* and then let the entire directory be created or deleted */
 119         }
 120
 121         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
 122                 struct strbuf buffer1 = STRBUF_INIT;
 123                 struct strbuf buffer2 = STRBUF_INIT;
 124                 struct string_list p1 = STRING_LIST_INIT_DUP;
 125                 struct string_list p2 = STRING_LIST_INIT_DUP;
 126                 int i1, i2, ret = 0;
 127                 size_t len1 = 0, len2 = 0;
 128
 129                 if (name1 && read_directory_contents(name1, &p1))
 130                         return -1;
 131                 if (name2 && read_directory_contents(name2, &p2)) {
 132                         string_list_clear(&p1, 0);
 133                         return -1;
 134                 }
 135
 136                 if (name1) {
 137                         strbuf_addstr(&buffer1, name1);
 138                         strbuf_complete(&buffer1, '/');
 139                         len1 = buffer1.len;
 140                 }
 141
 142                 if (name2) {
 143                         strbuf_addstr(&buffer2, name2);
 144                         strbuf_complete(&buffer2, '/');
 145                         len2 = buffer2.len;
 146                 }
 147
 148                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
 149                         const char *n1, *n2;
 150                         int comp;
 151
 152                         strbuf_setlen(&buffer1, len1);
 153                         strbuf_setlen(&buffer2, len2);
 154
 155                         if (i1 == p1.nr)
 156                                 comp = 1;
 157                         else if (i2 == p2.nr)
 158                                 comp = -1;
 159                         else
 160                                 comp = strcmp(p1.items[i1].string, p2.items[i2].string);
 161
 162                         if (comp > 0)
 163                                 n1 = NULL;
 164                         else {
 165                                 strbuf_addstr(&buffer1, p1.items[i1++].string);
 166                                 n1 = buffer1.buf;
 167                         }
 168
 169                         if (comp < 0)
 170                                 n2 = NULL;
 171                         else {
 172                                 strbuf_addstr(&buffer2, p2.items[i2++].string);
 173                                 n2 = buffer2.buf;
 174                         }
 175
 176                         ret = queue_diff(o, n1, n2);
 177                 }
 178                 string_list_clear(&p1, 0);
 179                 string_list_clear(&p2, 0);
 180                 strbuf_release(&buffer1);
 181                 strbuf_release(&buffer2);
 182
 183                 return ret;
 184         } else {
 185                 struct diff_filespec *d1, *d2;
 186
 187                 if (o->flags.reverse_diff) {
 188                         SWAP(mode1, mode2);
 189                         SWAP(name1, name2);
 190                 }
 191
 192                 d1 = noindex_filespec(name1, mode1);
 193                 d2 = noindex_filespec(name2, mode2);
 194                 diff_queue(&diff_queued_diff, d1, d2);
 195                 return 0;
 196         }
 197 }
 198
 199 /* append basename of F to D */
 200 static void append_basename(struct strbuf *path, const char *dir, const char *file)
 201 {
 202         const char *tail = strrchr(file, '/');
 203
 204         strbuf_addstr(path, dir);
 205         while (path->len && path->buf[path->len - 1] == '/')
 206                 path->len--;
 207         strbuf_addch(path, '/');
 208         strbuf_addstr(path, tail ? tail + 1 : file);
 209 }
 210
 211 /*
 212  * DWIM "diff D F" into "diff D/F F" and "diff F D" into "diff F D/F"
 213  * Note that we append the basename of F to D/, so "diff a/b/file D"
 214  * becomes "diff a/b/file D/file", not "diff a/b/file D/a/b/file".
 215  */
 216 static void fixup_paths(const char **path, struct strbuf *replacement)
 217 {
 218         unsigned int isdir0, isdir1;
 219
 220         isdir0 = path[0] != file_from_standard_input && is_directory(path[0]);
 221         isdir1 = path[1] != file_from_standard_input && is_directory(path[1]);
 222
 223         if ((path[0] == file_from_standard_input && isdir1) ||
 224             (isdir0 && path[1] == file_from_standard_input))
 225                 die(_("cannot compare stdin to a directory"));
 226
 227         if (isdir0 == isdir1)
 228                 return;
 229         if (isdir0) {
 230                 append_basename(replacement, path[0], path[1]);
 231                 path[0] = replacement->buf;
 232         } else {
 233                 append_basename(replacement, path[1], path[0]);
 234                 path[1] = replacement->buf;
 235         }
 236 }
 237
 238 static const char * const diff_no_index_usage[] = {
 239         N_("git diff --no-index [<options>] <path> <path>"),
 240         NULL
 241 };
 242
 243 int diff_no_index(struct rev_info *revs,
 244                   int implicit_no_index,
 245                   int argc, const char **argv)
 246 {
 247         int i, no_index;
 248         int ret = 1;
 249         const char *paths[2];
 250         char *to_free[ARRAY_SIZE(paths)] = { 0 };
 251         struct strbuf replacement = STRBUF_INIT;
 252         const char *prefix = revs->prefix;
 253         struct option no_index_options[] = {
 254                 OPT_BOOL_F(0, "no-index", &no_index, "",
 255                            PARSE_OPT_NONEG | PARSE_OPT_HIDDEN),
 256                 OPT_END(),
 257         };
 258         struct option *options;
 259
 260         options = add_diff_options(no_index_options, &revs->diffopt);
 261         argc = parse_options(argc, argv, revs->prefix, options,
 262                              diff_no_index_usage, 0);
 263         if (argc != 2) {
 264                 if (implicit_no_index)
 265                         warning(_("Not a git repository. Use --no-index to "
 266                                   "compare two paths outside a working tree"));
 267                 usage_with_options(diff_no_index_usage, options);
 268         }
 269         FREE_AND_NULL(options);
 270         for (i = 0; i < 2; i++) {
 271                 const char *p = argv[i];
 272                 if (!strcmp(p, "-"))
 273                         /*
 274                          * stdin should be spelled as "-"; if you have
 275                          * path that is "-", spell it as "./-".
 276                          */
 277                         p = file_from_standard_input;
 278                 else if (prefix)
 279                         p = to_free[i] = prefix_filename(prefix, p);
 280                 paths[i] = p;
 281         }
 282
 283         fixup_paths(paths, &replacement);
 284
 285         revs->diffopt.skip_stat_unmatch = 1;
 286         if (!revs->diffopt.output_format)
 287                 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 288
 289         revs->diffopt.flags.no_index = 1;
 290
 291         revs->diffopt.flags.relative_name = 1;
 292         revs->diffopt.prefix = prefix;
 293
 294         revs->max_count = -2;
 295         diff_setup_done(&revs->diffopt);
 296
 297         setup_diff_pager(&revs->diffopt);
 298         revs->diffopt.flags.exit_with_status = 1;
 299
 300         if (queue_diff(&revs->diffopt, paths[0], paths[1]))
 301                 goto out;
 302         diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
 303         diffcore_std(&revs->diffopt);
 304         diff_flush(&revs->diffopt);
 305
 306         /*
 307          * The return code for --no-index imitates diff(1):
 308          * 0 = no changes, 1 = changes, else error
 309          */
 310         ret = diff_result_code(&revs->diffopt, 0);
 311
 312 out:
 313         for (i = 0; i < ARRAY_SIZE(to_free); i++)
 314                 free(to_free[i]);
 315         strbuf_release(&replacement);
 316         return ret;
 317 }