git-fsck-cache: be stricter about "tree" objects
[git/git.git] / tree.c
1 #include "tree.h"
2 #include "blob.h"
3 #include "cache.h"
4 #include <stdlib.h>
5
6 const char *tree_type = "tree";
7
8 static int read_one_entry(unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
9 {
10 int len = strlen(pathname);
11 unsigned int size = cache_entry_size(baselen + len);
12 struct cache_entry *ce = xmalloc(size);
13
14 memset(ce, 0, size);
15
16 ce->ce_mode = create_ce_mode(mode);
17 ce->ce_flags = create_ce_flags(baselen + len, stage);
18 memcpy(ce->name, base, baselen);
19 memcpy(ce->name + baselen, pathname, len+1);
20 memcpy(ce->sha1, sha1, 20);
21 return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
22 }
23
24 static int match_tree_entry(const char *base, int baselen, const char *path, unsigned int mode, const char **paths)
25 {
26 const char *match;
27 int pathlen;
28
29 if (!paths)
30 return 1;
31 pathlen = strlen(path);
32 while ((match = *paths++) != NULL) {
33 int matchlen = strlen(match);
34
35 if (baselen >= matchlen) {
36 /* If it doesn't match, move along... */
37 if (strncmp(base, match, matchlen))
38 continue;
39 /* The base is a subdirectory of a path which was specified. */
40 return 1;
41 }
42
43 /* Does the base match? */
44 if (strncmp(base, match, baselen))
45 continue;
46
47 match += baselen;
48 matchlen -= baselen;
49
50 if (pathlen > matchlen)
51 continue;
52
53 if (matchlen > pathlen) {
54 if (match[pathlen] != '/')
55 continue;
56 if (!S_ISDIR(mode))
57 continue;
58 }
59
60 if (strncmp(path, match, pathlen))
61 continue;
62
63 return 1;
64 }
65 return 0;
66 }
67
68 static int read_tree_recursive(void *buffer, unsigned long size,
69 const char *base, int baselen,
70 int stage, const char **match)
71 {
72 while (size) {
73 int len = strlen(buffer)+1;
74 unsigned char *sha1 = buffer + len;
75 char *path = strchr(buffer, ' ')+1;
76 unsigned int mode;
77
78 if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
79 return -1;
80
81 buffer = sha1 + 20;
82 size -= len + 20;
83
84 if (!match_tree_entry(base, baselen, path, mode, match))
85 continue;
86
87 if (S_ISDIR(mode)) {
88 int retval;
89 int pathlen = strlen(path);
90 char *newbase;
91 void *eltbuf;
92 char elttype[20];
93 unsigned long eltsize;
94
95 eltbuf = read_sha1_file(sha1, elttype, &eltsize);
96 if (!eltbuf || strcmp(elttype, "tree")) {
97 if (eltbuf) free(eltbuf);
98 return -1;
99 }
100 newbase = xmalloc(baselen + 1 + pathlen);
101 memcpy(newbase, base, baselen);
102 memcpy(newbase + baselen, path, pathlen);
103 newbase[baselen + pathlen] = '/';
104 retval = read_tree_recursive(eltbuf, eltsize,
105 newbase,
106 baselen + pathlen + 1,
107 stage, match);
108 free(eltbuf);
109 free(newbase);
110 if (retval)
111 return -1;
112 continue;
113 }
114 if (read_one_entry(sha1, base, baselen, path, mode, stage) < 0)
115 return -1;
116 }
117 return 0;
118 }
119
120 int read_tree(void *buffer, unsigned long size, int stage, const char **match)
121 {
122 return read_tree_recursive(buffer, size, "", 0, stage, match);
123 }
124
125 struct tree *lookup_tree(const unsigned char *sha1)
126 {
127 struct object *obj = lookup_object(sha1);
128 if (!obj) {
129 struct tree *ret = xmalloc(sizeof(struct tree));
130 memset(ret, 0, sizeof(struct tree));
131 created_object(sha1, &ret->object);
132 ret->object.type = tree_type;
133 return ret;
134 }
135 if (!obj->type)
136 obj->type = tree_type;
137 if (obj->type != tree_type) {
138 error("Object %s is a %s, not a tree",
139 sha1_to_hex(sha1), obj->type);
140 return NULL;
141 }
142 return (struct tree *) obj;
143 }
144
145 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
146 {
147 void *bufptr = buffer;
148 struct tree_entry_list **list_p;
149
150 if (item->object.parsed)
151 return 0;
152 item->object.parsed = 1;
153 list_p = &item->entries;
154 while (size) {
155 struct object *obj;
156 struct tree_entry_list *entry;
157 int len = 1+strlen(bufptr);
158 unsigned char *file_sha1 = bufptr + len;
159 char *path = strchr(bufptr, ' ');
160 unsigned int mode;
161 if (size < len + 20 || !path ||
162 sscanf(bufptr, "%o", &mode) != 1)
163 return -1;
164
165 entry = xmalloc(sizeof(struct tree_entry_list));
166 entry->name = strdup(path + 1);
167 entry->directory = S_ISDIR(mode) != 0;
168 entry->executable = (mode & S_IXUSR) != 0;
169 entry->symlink = S_ISLNK(mode) != 0;
170 entry->zeropad = *(char *)bufptr == '0';
171 entry->mode = mode;
172 entry->next = NULL;
173
174 bufptr += len + 20;
175 size -= len + 20;
176
177 if (entry->directory) {
178 entry->item.tree = lookup_tree(file_sha1);
179 obj = &entry->item.tree->object;
180 } else {
181 entry->item.blob = lookup_blob(file_sha1);
182 obj = &entry->item.blob->object;
183 }
184 if (obj)
185 add_ref(&item->object, obj);
186 entry->parent = NULL; /* needs to be filled by the user */
187 *list_p = entry;
188 list_p = &entry->next;
189 }
190 return 0;
191 }
192
193 int parse_tree(struct tree *item)
194 {
195 char type[20];
196 void *buffer;
197 unsigned long size;
198 int ret;
199
200 if (item->object.parsed)
201 return 0;
202 buffer = read_sha1_file(item->object.sha1, type, &size);
203 if (!buffer)
204 return error("Could not read %s",
205 sha1_to_hex(item->object.sha1));
206 if (strcmp(type, tree_type)) {
207 free(buffer);
208 return error("Object %s not a tree",
209 sha1_to_hex(item->object.sha1));
210 }
211 ret = parse_tree_buffer(item, buffer, size);
212 free(buffer);
213 return ret;
214 }