Code

Don't use memcpy when source and dest. buffers may overlap
[git.git] / tree.c
1 #include "cache.h"
2 #include "tree.h"
3 #include "blob.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include "tree-walk.h"
7 #include <stdlib.h>
9 const char *tree_type = "tree";
11 static int read_one_entry(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
12 {
13         int len;
14         unsigned int size;
15         struct cache_entry *ce;
17         if (S_ISDIR(mode))
18                 return READ_TREE_RECURSIVE;
20         len = strlen(pathname);
21         size = cache_entry_size(baselen + len);
22         ce = xcalloc(1, size);
24         ce->ce_mode = create_ce_mode(mode);
25         ce->ce_flags = create_ce_flags(baselen + len, stage);
26         memcpy(ce->name, base, baselen);
27         memcpy(ce->name + baselen, pathname, len+1);
28         hashcpy(ce->sha1, sha1);
29         return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
30 }
32 static int match_tree_entry(const char *base, int baselen, const char *path, unsigned int mode, const char **paths)
33 {
34         const char *match;
35         int pathlen;
37         if (!paths)
38                 return 1;
39         pathlen = strlen(path);
40         while ((match = *paths++) != NULL) {
41                 int matchlen = strlen(match);
43                 if (baselen >= matchlen) {
44                         /* If it doesn't match, move along... */
45                         if (strncmp(base, match, matchlen))
46                                 continue;
47                         /* The base is a subdirectory of a path which was specified. */
48                         return 1;
49                 }
51                 /* Does the base match? */
52                 if (strncmp(base, match, baselen))
53                         continue;
55                 match += baselen;
56                 matchlen -= baselen;
58                 if (pathlen > matchlen)
59                         continue;
61                 if (matchlen > pathlen) {
62                         if (match[pathlen] != '/')
63                                 continue;
64                         if (!S_ISDIR(mode))
65                                 continue;
66                 }
68                 if (strncmp(path, match, pathlen))
69                         continue;
71                 return 1;
72         }
73         return 0;
74 }
76 int read_tree_recursive(struct tree *tree,
77                         const char *base, int baselen,
78                         int stage, const char **match,
79                         read_tree_fn_t fn)
80 {
81         struct tree_desc desc;
82         struct name_entry entry;
84         if (parse_tree(tree))
85                 return -1;
87         desc.buf = tree->buffer;
88         desc.size = tree->size;
90         while (tree_entry(&desc, &entry)) {
91                 if (!match_tree_entry(base, baselen, entry.path, entry.mode, match))
92                         continue;
94                 switch (fn(entry.sha1, base, baselen, entry.path, entry.mode, stage)) {
95                 case 0:
96                         continue;
97                 case READ_TREE_RECURSIVE:
98                         break;;
99                 default:
100                         return -1;
101                 }
102                 if (S_ISDIR(entry.mode)) {
103                         int retval;
104                         char *newbase;
106                         newbase = xmalloc(baselen + 1 + entry.pathlen);
107                         memcpy(newbase, base, baselen);
108                         memcpy(newbase + baselen, entry.path, entry.pathlen);
109                         newbase[baselen + entry.pathlen] = '/';
110                         retval = read_tree_recursive(lookup_tree(entry.sha1),
111                                                      newbase,
112                                                      baselen + entry.pathlen + 1,
113                                                      stage, match, fn);
114                         free(newbase);
115                         if (retval)
116                                 return -1;
117                         continue;
118                 }
119         }
120         return 0;
123 int read_tree(struct tree *tree, int stage, const char **match)
125         return read_tree_recursive(tree, "", 0, stage, match, read_one_entry);
128 struct tree *lookup_tree(const unsigned char *sha1)
130         struct object *obj = lookup_object(sha1);
131         if (!obj) {
132                 struct tree *ret = alloc_tree_node();
133                 created_object(sha1, &ret->object);
134                 ret->object.type = OBJ_TREE;
135                 return ret;
136         }
137         if (!obj->type)
138                 obj->type = OBJ_TREE;
139         if (obj->type != OBJ_TREE) {
140                 error("Object %s is a %s, not a tree",
141                       sha1_to_hex(sha1), typename(obj->type));
142                 return NULL;
143         }
144         return (struct tree *) obj;
147 static void track_tree_refs(struct tree *item)
149         int n_refs = 0, i;
150         struct object_refs *refs;
151         struct tree_desc desc;
152         struct name_entry entry;
154         /* Count how many entries there are.. */
155         desc.buf = item->buffer;
156         desc.size = item->size;
157         while (desc.size) {
158                 n_refs++;
159                 update_tree_entry(&desc);
160         }
162         /* Allocate object refs and walk it again.. */
163         i = 0;
164         refs = alloc_object_refs(n_refs);
165         desc.buf = item->buffer;
166         desc.size = item->size;
167         while (tree_entry(&desc, &entry)) {
168                 struct object *obj;
170                 if (S_ISDIR(entry.mode))
171                         obj = &lookup_tree(entry.sha1)->object;
172                 else
173                         obj = &lookup_blob(entry.sha1)->object;
174                 refs->ref[i++] = obj;
175         }
176         set_object_refs(&item->object, refs);
179 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
181         if (item->object.parsed)
182                 return 0;
183         item->object.parsed = 1;
184         item->buffer = buffer;
185         item->size = size;
187         if (track_object_refs)
188                 track_tree_refs(item);
189         return 0;
192 int parse_tree(struct tree *item)
194          char type[20];
195          void *buffer;
196          unsigned long size;
198         if (item->object.parsed)
199                 return 0;
200         buffer = read_sha1_file(item->object.sha1, type, &size);
201         if (!buffer)
202                 return error("Could not read %s",
203                              sha1_to_hex(item->object.sha1));
204         if (strcmp(type, tree_type)) {
205                 free(buffer);
206                 return error("Object %s not a tree",
207                              sha1_to_hex(item->object.sha1));
208         }
209         return parse_tree_buffer(item, buffer, size);
212 struct tree *parse_tree_indirect(const unsigned char *sha1)
214         struct object *obj = parse_object(sha1);
215         do {
216                 if (!obj)
217                         return NULL;
218                 if (obj->type == OBJ_TREE)
219                         return (struct tree *) obj;
220                 else if (obj->type == OBJ_COMMIT)
221                         obj = &(((struct commit *) obj)->tree->object);
222                 else if (obj->type == OBJ_TAG)
223                         obj = ((struct tag *) obj)->tagged;
224                 else
225                         return NULL;
226                 if (!obj->parsed)
227                         parse_object(obj->sha1);
228         } while (1);