core.prefersymlinkrefs: use symlinks for .git/HEAD
[git/git.git] / diff-tree.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "log-tree.h"
5
6 static struct log_tree_opt log_tree_opt;
7
8 static int diff_tree_commit_sha1(const unsigned char *sha1)
9 {
10 struct commit *commit = lookup_commit_reference(sha1);
11 if (!commit)
12 return -1;
13 return log_tree_commit(&log_tree_opt, commit);
14 }
15
16 static int diff_tree_stdin(char *line)
17 {
18 int len = strlen(line);
19 unsigned char sha1[20];
20 struct commit *commit;
21
22 if (!len || line[len-1] != '\n')
23 return -1;
24 line[len-1] = 0;
25 if (get_sha1_hex(line, sha1))
26 return -1;
27 commit = lookup_commit(sha1);
28 if (!commit || parse_commit(commit))
29 return -1;
30 if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
31 /* Graft the fake parents locally to the commit */
32 int pos = 41;
33 struct commit_list **pptr, *parents;
34
35 /* Free the real parent list */
36 for (parents = commit->parents; parents; ) {
37 struct commit_list *tmp = parents->next;
38 free(parents);
39 parents = tmp;
40 }
41 commit->parents = NULL;
42 pptr = &(commit->parents);
43 while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
44 struct commit *parent = lookup_commit(sha1);
45 if (parent) {
46 pptr = &commit_list_insert(parent, pptr)->next;
47 }
48 pos += 41;
49 }
50 }
51 return log_tree_commit(&log_tree_opt, commit);
52 }
53
54 static const char diff_tree_usage[] =
55 "git-diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
56 "[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
57 " -r diff recursively\n"
58 " --root include the initial commit as diff against /dev/null\n"
59 COMMON_DIFF_OPTIONS_HELP;
60
61 int main(int argc, const char **argv)
62 {
63 int nr_sha1;
64 char line[1000];
65 unsigned char sha1[2][20];
66 const char *prefix = setup_git_directory();
67 static struct log_tree_opt *opt = &log_tree_opt;
68 int read_stdin = 0;
69
70 git_config(git_diff_config);
71 nr_sha1 = 0;
72 init_log_tree_opt(opt);
73
74 for (;;) {
75 int opt_cnt;
76 const char *arg;
77
78 argv++;
79 argc--;
80 arg = *argv;
81 if (!arg)
82 break;
83
84 if (*arg != '-') {
85 if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
86 nr_sha1++;
87 continue;
88 }
89 break;
90 }
91
92 opt_cnt = log_tree_opt_parse(opt, argv, argc);
93 if (opt_cnt < 0)
94 usage(diff_tree_usage);
95 else if (opt_cnt) {
96 argv += opt_cnt - 1;
97 argc -= opt_cnt - 1;
98 continue;
99 }
100
101 if (!strcmp(arg, "--")) {
102 argv++;
103 argc--;
104 break;
105 }
106 if (!strcmp(arg, "--stdin")) {
107 read_stdin = 1;
108 continue;
109 }
110 usage(diff_tree_usage);
111 }
112
113 if (opt->combine_merges)
114 opt->ignore_merges = 0;
115
116 /* We can only do dense combined merges with diff output */
117 if (opt->dense_combined_merges)
118 opt->diffopt.output_format = DIFF_FORMAT_PATCH;
119
120 diff_tree_setup_paths(get_pathspec(prefix, argv), &opt->diffopt);
121 diff_setup_done(&opt->diffopt);
122
123 switch (nr_sha1) {
124 case 0:
125 if (!read_stdin)
126 usage(diff_tree_usage);
127 break;
128 case 1:
129 diff_tree_commit_sha1(sha1[0]);
130 break;
131 case 2:
132 diff_tree_sha1(sha1[0], sha1[1], "", &opt->diffopt);
133 log_tree_diff_flush(opt);
134 break;
135 }
136
137 if (!read_stdin)
138 return 0;
139
140 if (opt->diffopt.detect_rename)
141 opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
142 DIFF_SETUP_USE_CACHE);
143 while (fgets(line, sizeof(line), stdin))
144 diff_tree_stdin(line);
145
146 return 0;
147 }