git-tar-tree: no more void pointer arithmetic
[git.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
7 static struct rev_info log_tree_opt;
8
9 static int diff_tree_commit_sha1(const unsigned char *sha1)
10 {
11         struct commit *commit = lookup_commit_reference(sha1);
12         if (!commit)
13                 return -1;
14         return log_tree_commit(&log_tree_opt, commit);
15 }
16
17 static int diff_tree_stdin(char *line)
18 {
19         int len = strlen(line);
20         unsigned char sha1[20];
21         struct commit *commit;
22
23         if (!len || line[len-1] != '\n')
24                 return -1;
25         line[len-1] = 0;
26         if (get_sha1_hex(line, sha1))
27                 return -1;
28         commit = lookup_commit(sha1);
29         if (!commit || parse_commit(commit))
30                 return -1;
31         if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
32                 /* Graft the fake parents locally to the commit */
33                 int pos = 41;
34                 struct commit_list **pptr, *parents;
35
36                 /* Free the real parent list */
37                 for (parents = commit->parents; parents; ) {
38                         struct commit_list *tmp = parents->next;
39                         free(parents);
40                         parents = tmp;
41                 }
42                 commit->parents = NULL;
43                 pptr = &(commit->parents);
44                 while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
45                         struct commit *parent = lookup_commit(sha1);
46                         if (parent) {
47                                 pptr = &commit_list_insert(parent, pptr)->next;
48                         }
49                         pos += 41;
50                 }
51         }
52         return log_tree_commit(&log_tree_opt, commit);
53 }
54
55 static const char diff_tree_usage[] =
56 "git-diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
57 "[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
58 "  -r            diff recursively\n"
59 "  --root        include the initial commit as diff against /dev/null\n"
60 COMMON_DIFF_OPTIONS_HELP;
61
62 int cmd_diff_tree(int argc, const char **argv, char **envp)
63 {
64         int nr_sha1;
65         char line[1000];
66         struct object *tree1, *tree2;
67         static struct rev_info *opt = &log_tree_opt;
68         struct object_list *list;
69         int read_stdin = 0;
70
71         git_config(git_diff_config);
72         nr_sha1 = 0;
73         init_revisions(opt);
74         opt->abbrev = 0;
75         opt->diff = 1;
76         argc = setup_revisions(argc, argv, opt, NULL);
77
78         while (--argc > 0) {
79                 const char *arg = *++argv;
80
81                 if (!strcmp(arg, "--stdin")) {
82                         read_stdin = 1;
83                         continue;
84                 }
85                 usage(diff_tree_usage);
86         }
87
88         /*
89          * NOTE! "setup_revisions()" will have inserted the revisions
90          * it parsed in reverse order. So if you do
91          *
92          *      git-diff-tree a b
93          *
94          * the commit list will be "b" -> "a" -> NULL, so we reverse
95          * the order of the objects if the first one is not marked
96          * UNINTERESTING.
97          */
98         nr_sha1 = 0;
99         list = opt->pending_objects;
100         if (list) {
101                 nr_sha1++;
102                 tree1 = list->item;
103                 list = list->next;
104                 if (list) {
105                         nr_sha1++;
106                         tree2 = tree1;
107                         tree1 = list->item;
108                         if (list->next)
109                                 usage(diff_tree_usage);
110                         /* Switch them around if the second one was uninteresting.. */
111                         if (tree2->flags & UNINTERESTING) {
112                                 struct object *tmp = tree2;
113                                 tree2 = tree1;
114                                 tree1 = tmp;
115                         }
116                 }
117         }
118
119         switch (nr_sha1) {
120         case 0:
121                 if (!read_stdin)
122                         usage(diff_tree_usage);
123                 break;
124         case 1:
125                 diff_tree_commit_sha1(tree1->sha1);
126                 break;
127         case 2:
128                 diff_tree_sha1(tree1->sha1,
129                                tree2->sha1,
130                                "", &opt->diffopt);
131                 log_tree_diff_flush(opt);
132                 break;
133         }
134
135         if (!read_stdin)
136                 return 0;
137
138         if (opt->diffopt.detect_rename)
139                 opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
140                                        DIFF_SETUP_USE_CACHE);
141         while (fgets(line, sizeof(line), stdin)) {
142                 unsigned char sha1[20];
143
144                 if (get_sha1_hex(line, sha1)) {
145                         fputs(line, stdout);
146                         fflush(stdout);
147                 }
148                 else
149                         diff_tree_stdin(line);
150         }
151         return 0;
152 }