tag.c

   1 #include "tag.h"
   2 #include "cache.h"
   3
   4 const char *tag_type = "tag";
   5
   6 struct tag *lookup_tag(unsigned char *sha1)
   7 {
   8         struct object *obj = lookup_object(sha1);
   9         if (!obj) {
  10                 struct tag *ret = xmalloc(sizeof(struct tag));
  11                 memset(ret, 0, sizeof(struct tag));
  12                 created_object(sha1, &ret->object);
  13                 ret->object.type = tag_type;
  14                 return ret;
  15         }
  16         if (obj->type != tag_type) {
  17                 error("Object %s is a %s, not a tree",
  18                       sha1_to_hex(sha1), obj->type);
  19                 return NULL;
  20         }
  21         return (struct tag *) obj;
  22 }
  23
  24 int parse_tag(struct tag *item)
  25 {
  26         char type[20];
  27         void *data, *bufptr;
  28         unsigned long size;
  29         int typelen, taglen;
  30         unsigned char object[20];
  31         const char *type_line, *tag_line, *sig_line;
  32
  33         if (item->object.parsed)
  34                 return 0;
  35         item->object.parsed = 1;
  36         data = bufptr = read_sha1_file(item->object.sha1, type, &size);
  37         if (!data)
  38                 return error("Could not read %s",
  39                              sha1_to_hex(item->object.sha1));
  40         if (strcmp(type, tag_type)) {
  41                 free(data);
  42                 return error("Object %s not a tag",
  43                              sha1_to_hex(item->object.sha1));
  44         }
  45
  46         if (size < 64)
  47                 goto err;
  48         if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
  49                 goto err;
  50
  51         item->tagged = parse_object(object);
  52         if (item->tagged)
  53                 add_ref(&item->object, item->tagged);
  54
  55         type_line = data + 48;
  56         if (memcmp("\ntype ", type_line-1, 6))
  57                 goto err;
  58
  59         tag_line = strchr(type_line, '\n');
  60         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  61                 goto err;
  62
  63         sig_line = strchr(tag_line, '\n');
  64         if (!sig_line)
  65                 goto err;
  66         sig_line++;
  67
  68         typelen = tag_line - type_line - strlen("type \n");
  69         if (typelen >= 20)
  70                 goto err;
  71         taglen = sig_line - tag_line - strlen("tag \n");
  72         item->tag = xmalloc(taglen + 1);
  73         memcpy(item->tag, tag_line + 4, taglen);
  74         item->tag[taglen] = '\0';
  75
  76         free(data);
  77         return 0;
  78
  79 err:
  80         free(data);
  81         return -1;
  82 }