tag.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "tree.h"
   5 #include "blob.h"
   6
   7 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
   8
   9 const char *tag_type = "tag";
  10
  11 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
  12 {
  13         while (o && o->type == OBJ_TAG)
  14                 if (((struct tag *)o)->tagged)
  15                         o = parse_object(((struct tag *)o)->tagged->sha1);
  16                 else
  17                         o = NULL;
  18         if (!o && warn) {
  19                 if (!warnlen)
  20                         warnlen = strlen(warn);
  21                 error("missing object referenced by '%.*s'", warnlen, warn);
  22         }
  23         return o;
  24 }
  25
  26 struct tag *lookup_tag(const unsigned char *sha1)
  27 {
  28         struct object *obj = lookup_object(sha1);
  29         if (!obj)
  30                 return create_object(sha1, OBJ_TAG, alloc_tag_node());
  31         if (!obj->type)
  32                 obj->type = OBJ_TAG;
  33         if (obj->type != OBJ_TAG) {
  34                 error("Object %s is a %s, not a tag",
  35                       sha1_to_hex(sha1), typename(obj->type));
  36                 return NULL;
  37         }
  38         return (struct tag *) obj;
  39 }
  40
  41 static unsigned long parse_tag_date(const char *buf, const char *tail)
  42 {
  43         const char *dateptr;
  44
  45         while (buf < tail && *buf++ != '>')
  46                 /* nada */;
  47         if (buf >= tail)
  48                 return 0;
  49         dateptr = buf;
  50         while (buf < tail && *buf++ != '\n')
  51                 /* nada */;
  52         if (buf >= tail)
  53                 return 0;
  54         /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  55         return strtoul(dateptr, NULL, 10);
  56 }
  57
  58 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  59 {
  60         unsigned char sha1[20];
  61         char type[20];
  62         const char *bufptr = data;
  63         const char *tail = bufptr + size;
  64         const char *nl;
  65
  66         if (item->object.parsed)
  67                 return 0;
  68         item->object.parsed = 1;
  69
  70         if (size < 64)
  71                 return -1;
  72         if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
  73                 return -1;
  74         bufptr += 48; /* "object " + sha1 + "\n" */
  75
  76         if (prefixcmp(bufptr, "type "))
  77                 return -1;
  78         bufptr += 5;
  79         nl = memchr(bufptr, '\n', tail - bufptr);
  80         if (!nl || sizeof(type) <= (nl - bufptr))
  81                 return -1;
  82         strncpy(type, bufptr, nl - bufptr);
  83         type[nl - bufptr] = '\0';
  84         bufptr = nl + 1;
  85
  86         if (!strcmp(type, blob_type)) {
  87                 item->tagged = &lookup_blob(sha1)->object;
  88         } else if (!strcmp(type, tree_type)) {
  89                 item->tagged = &lookup_tree(sha1)->object;
  90         } else if (!strcmp(type, commit_type)) {
  91                 item->tagged = &lookup_commit(sha1)->object;
  92         } else if (!strcmp(type, tag_type)) {
  93                 item->tagged = &lookup_tag(sha1)->object;
  94         } else {
  95                 error("Unknown type %s", type);
  96                 item->tagged = NULL;
  97         }
  98
  99         if (prefixcmp(bufptr, "tag "))
 100                 return -1;
 101         bufptr += 4;
 102         nl = memchr(bufptr, '\n', tail - bufptr);
 103         if (!nl)
 104                 return -1;
 105         item->tag = xmemdupz(bufptr, nl - bufptr);
 106         bufptr = nl + 1;
 107
 108         if (!prefixcmp(bufptr, "tagger "))
 109                 item->date = parse_tag_date(bufptr, tail);
 110         else
 111                 item->date = 0;
 112
 113         return 0;
 114 }
 115
 116 int parse_tag(struct tag *item)
 117 {
 118         enum object_type type;
 119         void *data;
 120         unsigned long size;
 121         int ret;
 122
 123         if (item->object.parsed)
 124                 return 0;
 125         data = read_sha1_file(item->object.sha1, &type, &size);
 126         if (!data)
 127                 return error("Could not read %s",
 128                              sha1_to_hex(item->object.sha1));
 129         if (type != OBJ_TAG) {
 130                 free(data);
 131                 return error("Object %s not a tag",
 132                              sha1_to_hex(item->object.sha1));
 133         }
 134         ret = parse_tag_buffer(item, data, size);
 135         free(data);
 136         return ret;
 137 }
 138
 139 size_t parse_signature(const char *buf, unsigned long size)
 140 {
 141         char *eol;
 142         size_t len = 0;
 143         while (len < size && prefixcmp(buf + len, PGP_SIGNATURE)) {
 144                 eol = memchr(buf + len, '\n', size - len);
 145                 len += eol ? eol - (buf + len) + 1 : size - len;
 146         }
 147         return len;
 148 }