Merge branch 'cb/filter-branch-prune-empty-degenerate-merges'
[git] / builtin / diff-tree.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "log-tree.h"
5 #include "builtin.h"
6 #include "submodule.h"
7
8 static struct rev_info log_tree_opt;
9
10 static int diff_tree_commit_sha1(const unsigned char *sha1)
11 {
12         struct commit *commit = lookup_commit_reference(sha1);
13         if (!commit)
14                 return -1;
15         return log_tree_commit(&log_tree_opt, commit);
16 }
17
18 /* Diff one or more commits. */
19 static int stdin_diff_commit(struct commit *commit, char *line, int len)
20 {
21         unsigned char sha1[20];
22         if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
23                 /* Graft the fake parents locally to the commit */
24                 int pos = 41;
25                 struct commit_list **pptr;
26
27                 /* Free the real parent list */
28                 free_commit_list(commit->parents);
29                 commit->parents = NULL;
30                 pptr = &(commit->parents);
31                 while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
32                         struct commit *parent = lookup_commit(sha1);
33                         if (parent) {
34                                 pptr = &commit_list_insert(parent, pptr)->next;
35                         }
36                         pos += 41;
37                 }
38         }
39         return log_tree_commit(&log_tree_opt, commit);
40 }
41
42 /* Diff two trees. */
43 static int stdin_diff_trees(struct tree *tree1, char *line, int len)
44 {
45         unsigned char sha1[20];
46         struct tree *tree2;
47         if (len != 82 || !isspace(line[40]) || get_sha1_hex(line + 41, sha1))
48                 return error("Need exactly two trees, separated by a space");
49         tree2 = lookup_tree(sha1);
50         if (!tree2 || parse_tree(tree2))
51                 return -1;
52         printf("%s %s\n", sha1_to_hex(tree1->object.sha1),
53                           sha1_to_hex(tree2->object.sha1));
54         diff_tree_sha1(tree1->object.sha1, tree2->object.sha1,
55                        "", &log_tree_opt.diffopt);
56         log_tree_diff_flush(&log_tree_opt);
57         return 0;
58 }
59
60 static int diff_tree_stdin(char *line)
61 {
62         int len = strlen(line);
63         unsigned char sha1[20];
64         struct object *obj;
65
66         if (!len || line[len-1] != '\n')
67                 return -1;
68         line[len-1] = 0;
69         if (get_sha1_hex(line, sha1))
70                 return -1;
71         obj = lookup_unknown_object(sha1);
72         if (!obj || !obj->parsed)
73                 obj = parse_object(sha1);
74         if (!obj)
75                 return -1;
76         if (obj->type == OBJ_COMMIT)
77                 return stdin_diff_commit((struct commit *)obj, line, len);
78         if (obj->type == OBJ_TREE)
79                 return stdin_diff_trees((struct tree *)obj, line, len);
80         error("Object %s is a %s, not a commit or tree",
81               sha1_to_hex(sha1), typename(obj->type));
82         return -1;
83 }
84
85 static const char diff_tree_usage[] =
86 "git diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
87 "[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
88 "  -r            diff recursively\n"
89 "  --root        include the initial commit as diff against /dev/null\n"
90 COMMON_DIFF_OPTIONS_HELP;
91
92 static void diff_tree_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
93 {
94         if (!rev->diffopt.output_format) {
95                 if (rev->dense_combined_merges)
96                         rev->diffopt.output_format = DIFF_FORMAT_PATCH;
97                 else
98                         rev->diffopt.output_format = DIFF_FORMAT_RAW;
99         }
100 }
101
102 int cmd_diff_tree(int argc, const char **argv, const char *prefix)
103 {
104         int nr_sha1;
105         char line[1000];
106         struct object *tree1, *tree2;
107         static struct rev_info *opt = &log_tree_opt;
108         struct setup_revision_opt s_r_opt;
109         int read_stdin = 0;
110
111         init_revisions(opt, prefix);
112         gitmodules_config();
113         git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
114         opt->abbrev = 0;
115         opt->diff = 1;
116         opt->disable_stdin = 1;
117         memset(&s_r_opt, 0, sizeof(s_r_opt));
118         s_r_opt.tweak = diff_tree_tweak_rev;
119         argc = setup_revisions(argc, argv, opt, &s_r_opt);
120
121         while (--argc > 0) {
122                 const char *arg = *++argv;
123
124                 if (!strcmp(arg, "--stdin")) {
125                         read_stdin = 1;
126                         continue;
127                 }
128                 usage(diff_tree_usage);
129         }
130
131         /*
132          * NOTE! We expect "a ^b" to be equal to "a..b", so we
133          * reverse the order of the objects if the second one
134          * is marked UNINTERESTING.
135          */
136         nr_sha1 = opt->pending.nr;
137         switch (nr_sha1) {
138         case 0:
139                 if (!read_stdin)
140                         usage(diff_tree_usage);
141                 break;
142         case 1:
143                 tree1 = opt->pending.objects[0].item;
144                 diff_tree_commit_sha1(tree1->sha1);
145                 break;
146         case 2:
147                 tree1 = opt->pending.objects[0].item;
148                 tree2 = opt->pending.objects[1].item;
149                 if (tree2->flags & UNINTERESTING) {
150                         struct object *tmp = tree2;
151                         tree2 = tree1;
152                         tree1 = tmp;
153                 }
154                 diff_tree_sha1(tree1->sha1,
155                                tree2->sha1,
156                                "", &opt->diffopt);
157                 log_tree_diff_flush(opt);
158                 break;
159         }
160
161         if (read_stdin) {
162                 int saved_nrl = 0;
163                 int saved_dcctc = 0;
164
165                 if (opt->diffopt.detect_rename)
166                         opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
167                                                DIFF_SETUP_USE_CACHE);
168                 while (fgets(line, sizeof(line), stdin)) {
169                         unsigned char sha1[20];
170
171                         if (get_sha1_hex(line, sha1)) {
172                                 fputs(line, stdout);
173                                 fflush(stdout);
174                         }
175                         else {
176                                 diff_tree_stdin(line);
177                                 if (saved_nrl < opt->diffopt.needed_rename_limit)
178                                         saved_nrl = opt->diffopt.needed_rename_limit;
179                                 if (opt->diffopt.degraded_cc_to_c)
180                                         saved_dcctc = 1;
181                         }
182                 }
183                 opt->diffopt.degraded_cc_to_c = saved_dcctc;
184                 opt->diffopt.needed_rename_limit = saved_nrl;
185         }
186
187         return diff_result_code(&opt->diffopt, 0);
188 }