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 "builtin.h"
  17 #include "parse-options.h"
  18 #include "string-list.h"
  19 #include "dir.h"
  20
  21 static int read_directory_contents(const char *path, struct string_list *list)
  22 {
  23         DIR *dir;
  24         struct dirent *e;
  25
  26         if (!(dir = opendir(path)))
  27                 return error("Could not open directory %s", path);
  28
  29         while ((e = readdir_skip_dot_and_dotdot(dir)))
  30                 string_list_insert(list, e->d_name);
  31
  32         closedir(dir);
  33         return 0;
  34 }
  35
  36 /*
  37  * This should be "(standard input)" or something, but it will
  38  * probably expose many more breakages in the way no-index code
  39  * is bolted onto the diff callchain.
  40  */
  41 static const char file_from_standard_input[] = "-";
  42
  43 static int get_mode(const char *path, int *mode)
  44 {
  45         struct stat st;
  46
  47         if (!path || !strcmp(path, "/dev/null"))
  48                 *mode = 0;
  49 #ifdef GIT_WINDOWS_NATIVE
  50         else if (!strcasecmp(path, "nul"))
  51                 *mode = 0;
  52 #endif
  53         else if (path == file_from_standard_input)
  54                 *mode = create_ce_mode(0666);
  55         else if (lstat(path, &st))
  56                 return error("Could not access '%s'", path);
  57         else
  58                 *mode = st.st_mode;
  59         return 0;
  60 }
  61
  62 static int populate_from_stdin(struct diff_filespec *s)
  63 {
  64         struct strbuf buf = STRBUF_INIT;
  65         size_t size = 0;
  66
  67         if (strbuf_read(&buf, 0, 0) < 0)
  68                 return error_errno("error while reading from stdin");
  69
  70         s->should_munmap = 0;
  71         s->data = strbuf_detach(&buf, &size);
  72         s->size = size;
  73         s->should_free = 1;
  74         s->is_stdin = 1;
  75         return 0;
  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         if (path[0] == file_from_standard_input ||
 221             path[1] == file_from_standard_input)
 222                 return;
 223         isdir0 = is_directory(path[0]);
 224         isdir1 = is_directory(path[1]);
 225         if (isdir0 == isdir1)
 226                 return;
 227         if (isdir0) {
 228                 append_basename(replacement, path[0], path[1]);
 229                 path[0] = replacement->buf;
 230         } else {
 231                 append_basename(replacement, path[1], path[0]);
 232                 path[1] = replacement->buf;
 233         }
 234 }
 235
 236 static const char * const diff_no_index_usage[] = {
 237         N_("git diff --no-index [<options>] <path> <path>"),
 238         NULL
 239 };
 240
 241 int diff_no_index(struct rev_info *revs,
 242                   int implicit_no_index,
 243                   int argc, const char **argv)
 244 {
 245         int i, no_index;
 246         int ret = 1;
 247         const char *paths[2];
 248         char *to_free[ARRAY_SIZE(paths)] = { 0 };
 249         struct strbuf replacement = STRBUF_INIT;
 250         const char *prefix = revs->prefix;
 251         struct option no_index_options[] = {
 252                 OPT_BOOL_F(0, "no-index", &no_index, "",
 253                            PARSE_OPT_NONEG | PARSE_OPT_HIDDEN),
 254                 OPT_END(),
 255         };
 256         struct option *options;
 257
 258         options = add_diff_options(no_index_options, &revs->diffopt);
 259         argc = parse_options(argc, argv, revs->prefix, options,
 260                              diff_no_index_usage, 0);
 261         if (argc != 2) {
 262                 if (implicit_no_index)
 263                         warning(_("Not a git repository. Use --no-index to "
 264                                   "compare two paths outside a working tree"));
 265                 usage_with_options(diff_no_index_usage, options);
 266         }
 267         FREE_AND_NULL(options);
 268         for (i = 0; i < 2; i++) {
 269                 const char *p = argv[i];
 270                 if (!strcmp(p, "-"))
 271                         /*
 272                          * stdin should be spelled as "-"; if you have
 273                          * path that is "-", spell it as "./-".
 274                          */
 275                         p = file_from_standard_input;
 276                 else if (prefix)
 277                         p = to_free[i] = prefix_filename(prefix, p);
 278                 paths[i] = p;
 279         }
 280
 281         fixup_paths(paths, &replacement);
 282
 283         revs->diffopt.skip_stat_unmatch = 1;
 284         if (!revs->diffopt.output_format)
 285                 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 286
 287         revs->diffopt.flags.no_index = 1;
 288
 289         revs->diffopt.flags.relative_name = 1;
 290         revs->diffopt.prefix = prefix;
 291
 292         revs->max_count = -2;
 293         diff_setup_done(&revs->diffopt);
 294
 295         setup_diff_pager(&revs->diffopt);
 296         revs->diffopt.flags.exit_with_status = 1;
 297
 298         if (queue_diff(&revs->diffopt, paths[0], paths[1]))
 299                 goto out;
 300         diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
 301         diffcore_std(&revs->diffopt);
 302         diff_flush(&revs->diffopt);
 303
 304         /*
 305          * The return code for --no-index imitates diff(1):
 306          * 0 = no changes, 1 = changes, else error
 307          */
 308         ret = diff_result_code(&revs->diffopt, 0);
 309
 310 out:
 311         for (i = 0; i < ARRAY_SIZE(to_free); i++)
 312                 free(to_free[i]);
 313         strbuf_release(&replacement);
 314         return ret;
 315 }