tag.c

   1 #include "cache.h"
   2 #include "tag.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 == OBJ_TAG)
   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 = alloc_tag_node();
  23                 created_object(sha1, &ret->object);
  24                 ret->object.type = OBJ_TAG;
  25                 return ret;
  26         }
  27         if (!obj->type)
  28                 obj->type = OBJ_TAG;
  29         if (obj->type != OBJ_TAG) {
  30                 error("Object %s is a %s, not a tree",
  31                       sha1_to_hex(sha1), typename(obj->type));
  32                 return NULL;
  33         }
  34         return (struct tag *) obj;
  35 }
  36
  37 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  38 {
  39         int typelen, taglen;
  40         unsigned char object[20];
  41         const char *type_line, *tag_line, *sig_line;
  42         char type[20];
  43
  44         if (item->object.parsed)
  45                 return 0;
  46         item->object.parsed = 1;
  47
  48         if (size < 64)
  49                 return -1;
  50         if (memcmp("object ", data, 7) || get_sha1_hex((char *) data + 7, object))
  51                 return -1;
  52
  53         type_line = (char *) data + 48;
  54         if (memcmp("\ntype ", type_line-1, 6))
  55                 return -1;
  56
  57         tag_line = strchr(type_line, '\n');
  58         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  59                 return -1;
  60
  61         sig_line = strchr(tag_line, '\n');
  62         if (!sig_line)
  63                 return -1;
  64         sig_line++;
  65
  66         typelen = tag_line - type_line - strlen("type \n");
  67         if (typelen >= 20)
  68                 return -1;
  69         memcpy(type, type_line + 5, typelen);
  70         type[typelen] = '\0';
  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         item->tagged = lookup_object_type(object, type);
  77         if (item->tagged && track_object_refs) {
  78                 struct object_refs *refs = alloc_object_refs(1);
  79                 refs->ref[0] = item->tagged;
  80                 set_object_refs(&item->object, refs);
  81         }
  82
  83         return 0;
  84 }
  85
  86 int parse_tag(struct tag *item)
  87 {
  88         char type[20];
  89         void *data;
  90         unsigned long size;
  91         int ret;
  92
  93         if (item->object.parsed)
  94                 return 0;
  95         data = read_sha1_file(item->object.sha1, type, &size);
  96         if (!data)
  97                 return error("Could not read %s",
  98                              sha1_to_hex(item->object.sha1));
  99         if (strcmp(type, tag_type)) {
 100                 free(data);
 101                 return error("Object %s not a tag",
 102                              sha1_to_hex(item->object.sha1));
 103         }
 104         ret = parse_tag_buffer(item, data, size);
 105         free(data);
 106         return ret;
 107 }