tag.c

   1 #include "tag.h"
   2 #include "cache.h"
   3
   4 const char *tag_type = "tag";
   5
   6 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
   7 {
   8         while (o && o->type == tag_type)
   9                 o = parse_object(((struct tag *)o)->tagged->sha1);
  10         if (!o && warn) {
  11                 if (!warnlen)
  12                         warnlen = strlen(warn);
  13                 error("missing object referenced by '%.*s'", warnlen, warn);
  14         }
  15         return o;
  16 }
  17
  18 struct tag *lookup_tag(const unsigned char *sha1)
  19 {
  20         struct object *obj = lookup_object(sha1);
  21         if (!obj) {
  22                 struct tag *ret = xmalloc(sizeof(struct tag));
  23                 memset(ret, 0, sizeof(struct tag));
  24                 created_object(sha1, &ret->object);
  25                 ret->object.type = tag_type;
  26                 return ret;
  27         }
  28         if (!obj->type)
  29                 obj->type = tag_type;
  30         if (obj->type != tag_type) {
  31                 error("Object %s is a %s, not a tree",
  32                       sha1_to_hex(sha1), obj->type);
  33                 return NULL;
  34         }
  35         return (struct tag *) obj;
  36 }
  37
  38 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  39 {
  40         int typelen, taglen;
  41         unsigned char object[20];
  42         const char *type_line, *tag_line, *sig_line;
  43         char type[20];
  44
  45         if (item->object.parsed)
  46                 return 0;
  47         item->object.parsed = 1;
  48
  49         if (size < 64)
  50                 return -1;
  51         if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
  52                 return -1;
  53
  54         type_line = data + 48;
  55         if (memcmp("\ntype ", type_line-1, 6))
  56                 return -1;
  57
  58         tag_line = strchr(type_line, '\n');
  59         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  60                 return -1;
  61
  62         sig_line = strchr(tag_line, '\n');
  63         if (!sig_line)
  64                 return -1;
  65         sig_line++;
  66
  67         typelen = tag_line - type_line - strlen("type \n");
  68         if (typelen >= 20)
  69                 return -1;
  70         memcpy(type, type_line + 5, typelen);
  71         type[typelen] = '\0';
  72         taglen = sig_line - tag_line - strlen("tag \n");
  73         item->tag = xmalloc(taglen + 1);
  74         memcpy(item->tag, tag_line + 4, taglen);
  75         item->tag[taglen] = '\0';
  76
  77         item->tagged = lookup_object_type(object, type);
  78         if (item->tagged)
  79                 add_ref(&item->object, item->tagged);
  80
  81         return 0;
  82 }
  83
  84 int parse_tag(struct tag *item)
  85 {
  86         char type[20];
  87         void *data;
  88         unsigned long size;
  89         int ret;
  90
  91         if (item->object.parsed)
  92                 return 0;
  93         data = read_sha1_file(item->object.sha1, type, &size);
  94         if (!data)
  95                 return error("Could not read %s",
  96                              sha1_to_hex(item->object.sha1));
  97         if (strcmp(type, tag_type)) {
  98                 free(data);
  99                 return error("Object %s not a tag",
 100                              sha1_to_hex(item->object.sha1));
 101         }
 102         ret = parse_tag_buffer(item, data, size);
 103         free(data);
 104         return ret;
 105 }