combine-diff: do not send NULL to printf
[git.git] / diff-tree.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4
5 static int show_root_diff = 0;
6 static int no_commit_id = 0;
7 static int verbose_header = 0;
8 static int ignore_merges = 1;
9 static int combine_merges = 0;
10 static int dense_combined_merges = 0;
11 static int read_stdin = 0;
12 static int always_show_header = 0;
13
14 static const char *header = NULL;
15 static const char *header_prefix = "";
16 static enum cmit_fmt commit_format = CMIT_FMT_RAW;
17
18 static struct diff_options diff_options;
19
20 static int call_diff_flush(void)
21 {
22         diffcore_std(&diff_options);
23         if (diff_queue_is_empty()) {
24                 int saved_fmt = diff_options.output_format;
25                 diff_options.output_format = DIFF_FORMAT_NO_OUTPUT;
26                 diff_flush(&diff_options);
27                 diff_options.output_format = saved_fmt;
28                 return 0;
29         }
30         if (header) {
31                 if (!no_commit_id)
32                         printf("%s%c", header, diff_options.line_termination);
33                 header = NULL;
34         }
35         diff_flush(&diff_options);
36         return 1;
37 }
38
39 static int diff_tree_sha1_top(const unsigned char *old,
40                               const unsigned char *new, const char *base)
41 {
42         int ret;
43
44         ret = diff_tree_sha1(old, new, base, &diff_options);
45         call_diff_flush();
46         return ret;
47 }
48
49 static int diff_root_tree(const unsigned char *new, const char *base)
50 {
51         int retval;
52         void *tree;
53         struct tree_desc empty, real;
54
55         tree = read_object_with_reference(new, "tree", &real.size, NULL);
56         if (!tree)
57                 die("unable to read root tree (%s)", sha1_to_hex(new));
58         real.buf = tree;
59
60         empty.buf = "";
61         empty.size = 0;
62         retval = diff_tree(&empty, &real, base, &diff_options);
63         free(tree);
64         call_diff_flush();
65         return retval;
66 }
67
68 static const char *generate_header(const unsigned char *commit_sha1,
69                                    const unsigned char *parent_sha1,
70                                    const struct commit *commit)
71 {
72         static char this_header[16384];
73         int offset;
74         unsigned long len;
75         int abbrev = diff_options.abbrev;
76         const char *msg = commit->buffer;
77
78         if (!verbose_header)
79                 return sha1_to_hex(commit_sha1);
80
81         len = strlen(msg);
82
83         offset = sprintf(this_header, "%s%s ",
84                          header_prefix,
85                          diff_unique_abbrev(commit_sha1, abbrev));
86         if (commit_sha1 != parent_sha1)
87                 offset += sprintf(this_header + offset, "(from %s)\n",
88                                   parent_sha1
89                                   ? diff_unique_abbrev(parent_sha1, abbrev)
90                                   : "root");
91         else
92                 offset += sprintf(this_header + offset, "(from parents)\n");
93         offset += pretty_print_commit(commit_format, commit, len,
94                                       this_header + offset,
95                                       sizeof(this_header) - offset, abbrev);
96         if (always_show_header) {
97                 puts(this_header);
98                 return NULL;
99         }
100         return this_header;
101 }
102
103 static int diff_tree_commit(struct commit *commit)
104 {
105         struct commit_list *parents;
106         unsigned const char *sha1 = commit->object.sha1;
107
108         /* Root commit? */
109         if (show_root_diff && !commit->parents) {
110                 header = generate_header(sha1, NULL, commit);
111                 diff_root_tree(sha1, "");
112         }
113
114         /* More than one parent? */
115         if (commit->parents && commit->parents->next) {
116                 if (ignore_merges)
117                         return 0;
118                 else if (combine_merges) {
119                         header = generate_header(sha1, sha1, commit);
120                         return diff_tree_combined_merge(sha1, header,
121                                                         dense_combined_merges);
122                 }
123         }
124
125         for (parents = commit->parents; parents; parents = parents->next) {
126                 struct commit *parent = parents->item;
127                 header = generate_header(sha1, parent->object.sha1, commit);
128                 diff_tree_sha1_top(parent->object.sha1, sha1, "");
129                 if (!header && verbose_header) {
130                         header_prefix = "\ndiff-tree ";
131                         /*
132                          * Don't print multiple merge entries if we
133                          * don't print the diffs.
134                          */
135                 }
136         }
137         return 0;
138 }
139
140 static int diff_tree_commit_sha1(const unsigned char *sha1)
141 {
142         struct commit *commit = lookup_commit_reference(sha1);
143         if (!commit)
144                 return -1;
145         return diff_tree_commit(commit);
146 }
147
148 static int diff_tree_stdin(char *line)
149 {
150         int len = strlen(line);
151         unsigned char sha1[20];
152         struct commit *commit;
153
154         if (!len || line[len-1] != '\n')
155                 return -1;
156         line[len-1] = 0;
157         if (get_sha1_hex(line, sha1))
158                 return -1;
159         commit = lookup_commit(sha1);
160         if (!commit || parse_commit(commit))
161                 return -1;
162         if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
163                 /* Graft the fake parents locally to the commit */
164                 int pos = 41;
165                 struct commit_list **pptr, *parents;
166
167                 /* Free the real parent list */
168                 for (parents = commit->parents; parents; ) {
169                         struct commit_list *tmp = parents->next;
170                         free(parents);
171                         parents = tmp;
172                 }
173                 commit->parents = NULL;
174                 pptr = &(commit->parents);
175                 while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
176                         struct commit *parent = lookup_commit(sha1);
177                         if (parent) {
178                                 pptr = &commit_list_insert(parent, pptr)->next;
179                         }
180                         pos += 41;
181                 }
182         }
183         return diff_tree_commit(commit);
184 }
185
186 static const char diff_tree_usage[] =
187 "git-diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
188 "[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
189 "  -r            diff recursively\n"
190 "  --root        include the initial commit as diff against /dev/null\n"
191 COMMON_DIFF_OPTIONS_HELP;
192
193 int main(int argc, const char **argv)
194 {
195         int nr_sha1;
196         char line[1000];
197         unsigned char sha1[2][20];
198         const char *prefix = setup_git_directory();
199
200         git_config(git_diff_config);
201         nr_sha1 = 0;
202         diff_setup(&diff_options);
203
204         for (;;) {
205                 int diff_opt_cnt;
206                 const char *arg;
207
208                 argv++;
209                 argc--;
210                 arg = *argv;
211                 if (!arg)
212                         break;
213
214                 if (*arg != '-') {
215                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
216                                 nr_sha1++;
217                                 continue;
218                         }
219                         break;
220                 }
221
222                 diff_opt_cnt = diff_opt_parse(&diff_options, argv, argc);
223                 if (diff_opt_cnt < 0)
224                         usage(diff_tree_usage);
225                 else if (diff_opt_cnt) {
226                         argv += diff_opt_cnt - 1;
227                         argc -= diff_opt_cnt - 1;
228                         continue;
229                 }
230
231
232                 if (!strcmp(arg, "--")) {
233                         argv++;
234                         argc--;
235                         break;
236                 }
237                 if (!strcmp(arg, "-r")) {
238                         diff_options.recursive = 1;
239                         continue;
240                 }
241                 if (!strcmp(arg, "-t")) {
242                         diff_options.recursive = 1;
243                         diff_options.tree_in_recursive = 1;
244                         continue;
245                 }
246                 if (!strcmp(arg, "-m")) {
247                         ignore_merges = 0;
248                         continue;
249                 }
250                 if (!strcmp(arg, "-c")) {
251                         combine_merges = 1;
252                         continue;
253                 }
254                 if (!strcmp(arg, "--cc")) {
255                         dense_combined_merges = combine_merges = 1;
256                         continue;
257                 }
258                 if (!strcmp(arg, "-v")) {
259                         verbose_header = 1;
260                         header_prefix = "diff-tree ";
261                         continue;
262                 }
263                 if (!strncmp(arg, "--pretty", 8)) {
264                         verbose_header = 1;
265                         header_prefix = "diff-tree ";
266                         commit_format = get_commit_format(arg+8);
267                         continue;
268                 }
269                 if (!strcmp(arg, "--stdin")) {
270                         read_stdin = 1;
271                         continue;
272                 }
273                 if (!strcmp(arg, "--root")) {
274                         show_root_diff = 1;
275                         continue;
276                 }
277                 if (!strcmp(arg, "--no-commit-id")) {
278                         no_commit_id = 1;
279                         continue;
280                 }
281                 if (!strcmp(arg, "--always")) {
282                         always_show_header = 1;
283                         continue;
284                 }
285                 usage(diff_tree_usage);
286         }
287         if (diff_options.output_format == DIFF_FORMAT_PATCH)
288                 diff_options.recursive = 1;
289
290         if (combine_merges) {
291                 diff_options.output_format = DIFF_FORMAT_PATCH;
292                 ignore_merges = 0;
293         }
294
295         diff_tree_setup_paths(get_pathspec(prefix, argv));
296         diff_setup_done(&diff_options);
297
298         switch (nr_sha1) {
299         case 0:
300                 if (!read_stdin)
301                         usage(diff_tree_usage);
302                 break;
303         case 1:
304                 diff_tree_commit_sha1(sha1[0]);
305                 break;
306         case 2:
307                 diff_tree_sha1_top(sha1[0], sha1[1], "");
308                 break;
309         }
310
311         if (!read_stdin)
312                 return 0;
313
314         if (diff_options.detect_rename)
315                 diff_options.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
316                                        DIFF_SETUP_USE_CACHE);
317         while (fgets(line, sizeof(line), stdin))
318                 diff_tree_stdin(line);
319
320         return 0;
321 }