diff-index.c: "git diff" has no need to read blob from the standard input
[git] / 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 "string-list.h"
18
19 static int read_directory(const char *path, struct string_list *list)
20 {
21         DIR *dir;
22         struct dirent *e;
23
24         if (!(dir = opendir(path)))
25                 return error("Could not open directory %s", path);
26
27         while ((e = readdir(dir)))
28                 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
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 _WIN32
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("error while reading from stdin %s",
68                                      strerror(errno));
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_sha1, 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                 return error("file/directory conflict: %s, %s", name1, name2);
101
102         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
103                 char buffer1[PATH_MAX], buffer2[PATH_MAX];
104                 struct string_list p1 = STRING_LIST_INIT_DUP;
105                 struct string_list p2 = STRING_LIST_INIT_DUP;
106                 int len1 = 0, len2 = 0, i1, i2, ret = 0;
107
108                 if (name1 && read_directory(name1, &p1))
109                         return -1;
110                 if (name2 && read_directory(name2, &p2)) {
111                         string_list_clear(&p1, 0);
112                         return -1;
113                 }
114
115                 if (name1) {
116                         len1 = strlen(name1);
117                         if (len1 > 0 && name1[len1 - 1] == '/')
118                                 len1--;
119                         memcpy(buffer1, name1, len1);
120                         buffer1[len1++] = '/';
121                 }
122
123                 if (name2) {
124                         len2 = strlen(name2);
125                         if (len2 > 0 && name2[len2 - 1] == '/')
126                                 len2--;
127                         memcpy(buffer2, name2, len2);
128                         buffer2[len2++] = '/';
129                 }
130
131                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
132                         const char *n1, *n2;
133                         int comp;
134
135                         if (i1 == p1.nr)
136                                 comp = 1;
137                         else if (i2 == p2.nr)
138                                 comp = -1;
139                         else
140                                 comp = strcmp(p1.items[i1].string,
141                                         p2.items[i2].string);
142
143                         if (comp > 0)
144                                 n1 = NULL;
145                         else {
146                                 n1 = buffer1;
147                                 strncpy(buffer1 + len1, p1.items[i1++].string,
148                                                 PATH_MAX - len1);
149                         }
150
151                         if (comp < 0)
152                                 n2 = NULL;
153                         else {
154                                 n2 = buffer2;
155                                 strncpy(buffer2 + len2, p2.items[i2++].string,
156                                                 PATH_MAX - len2);
157                         }
158
159                         ret = queue_diff(o, n1, n2);
160                 }
161                 string_list_clear(&p1, 0);
162                 string_list_clear(&p2, 0);
163
164                 return ret;
165         } else {
166                 struct diff_filespec *d1, *d2;
167
168                 if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
169                         unsigned tmp;
170                         const char *tmp_c;
171                         tmp = mode1; mode1 = mode2; mode2 = tmp;
172                         tmp_c = name1; name1 = name2; name2 = tmp_c;
173                 }
174
175                 d1 = noindex_filespec(name1, mode1);
176                 d2 = noindex_filespec(name2, mode2);
177                 diff_queue(&diff_queued_diff, d1, d2);
178                 return 0;
179         }
180 }
181
182 static int path_outside_repo(const char *path)
183 {
184         const char *work_tree;
185         size_t len;
186
187         if (!is_absolute_path(path))
188                 return 0;
189         work_tree = get_git_work_tree();
190         if (!work_tree)
191                 return 1;
192         len = strlen(work_tree);
193         if (strncmp(path, work_tree, len) ||
194             (path[len] != '\0' && path[len] != '/'))
195                 return 1;
196         return 0;
197 }
198
199 void diff_no_index(struct rev_info *revs,
200                    int argc, const char **argv,
201                    int nongit, const char *prefix)
202 {
203         int i, prefixlen;
204         int no_index = 0;
205         unsigned options = 0;
206         const char *paths[2];
207
208         /* Were we asked to do --no-index explicitly? */
209         for (i = 1; i < argc; i++) {
210                 if (!strcmp(argv[i], "--")) {
211                         i++;
212                         break;
213                 }
214                 if (!strcmp(argv[i], "--no-index"))
215                         no_index = 1;
216                 if (argv[i][0] != '-')
217                         break;
218         }
219
220         if (!no_index && !nongit) {
221                 /*
222                  * Inside a git repository, without --no-index.  Only
223                  * when a path outside the repository is given,
224                  * e.g. "git diff /var/tmp/[12]", or "git diff
225                  * Makefile /var/tmp/Makefile", allow it to be used as
226                  * a colourful "diff" replacement.
227                  */
228                 if ((argc != i + 2) ||
229                     (!path_outside_repo(argv[i]) &&
230                      !path_outside_repo(argv[i+1])))
231                         return;
232         }
233         if (argc != i + 2)
234                 usagef("git diff %s <path> <path>",
235                        no_index ? "--no-index" : "[--no-index]");
236
237         diff_setup(&revs->diffopt);
238         for (i = 1; i < argc - 2; ) {
239                 int j;
240                 if (!strcmp(argv[i], "--no-index"))
241                         i++;
242                 else if (!strcmp(argv[i], "-q")) {
243                         options |= DIFF_SILENT_ON_REMOVED;
244                         i++;
245                 }
246                 else if (!strcmp(argv[i], "--"))
247                         i++;
248                 else {
249                         j = diff_opt_parse(&revs->diffopt, argv + i, argc - i);
250                         if (!j)
251                                 die("invalid diff option/value: %s", argv[i]);
252                         i += j;
253                 }
254         }
255
256         /*
257          * If the user asked for our exit code then don't start a
258          * pager or we would end up reporting its exit code instead.
259          */
260         if (!DIFF_OPT_TST(&revs->diffopt, EXIT_WITH_STATUS))
261                 setup_pager();
262
263         prefixlen = prefix ? strlen(prefix) : 0;
264         for (i = 0; i < 2; i++) {
265                 const char *p = argv[argc - 2 + i];
266                 if (!strcmp(p, "-"))
267                         /*
268                          * stdin should be spelled as "-"; if you have
269                          * path that is "-", spell it as "./-".
270                          */
271                         p = file_from_standard_input;
272                 else if (prefixlen)
273                         p = xstrdup(prefix_filename(prefix, prefixlen, p));
274                 paths[i] = p;
275         }
276         revs->diffopt.skip_stat_unmatch = 1;
277         if (!revs->diffopt.output_format)
278                 revs->diffopt.output_format = DIFF_FORMAT_PATCH;
279
280         DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
281         DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
282
283         revs->max_count = -2;
284         if (diff_setup_done(&revs->diffopt) < 0)
285                 die("diff_setup_done failed");
286
287         if (queue_diff(&revs->diffopt, paths[0], paths[1]))
288                 exit(1);
289         diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
290         diffcore_std(&revs->diffopt);
291         diff_flush(&revs->diffopt);
292
293         /*
294          * The return code for --no-index imitates diff(1):
295          * 0 = no changes, 1 = changes, else error
296          */
297         exit(revs->diffopt.found_changes);
298 }