tag.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "tree.h"
   5 #include "blob.h"
   6
   7 const char *tag_type = "tag";
   8
   9 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
  10 {
  11         while (o && o->type == OBJ_TAG)
  12                 o = parse_object(((struct tag *)o)->tagged->sha1);
  13         if (!o && warn) {
  14                 if (!warnlen)
  15                         warnlen = strlen(warn);
  16                 error("missing object referenced by '%.*s'", warnlen, warn);
  17         }
  18         return o;
  19 }
  20
  21 struct tag *lookup_tag(const unsigned char *sha1)
  22 {
  23         struct object *obj = lookup_object(sha1);
  24         if (!obj) {
  25                 struct tag *ret = alloc_tag_node();
  26                 created_object(sha1, &ret->object);
  27                 ret->object.type = OBJ_TAG;
  28                 return ret;
  29         }
  30         if (!obj->type)
  31                 obj->type = OBJ_TAG;
  32         if (obj->type != OBJ_TAG) {
  33                 error("Object %s is a %s, not a tree",
  34                       sha1_to_hex(sha1), typename(obj->type));
  35                 return NULL;
  36         }
  37         return (struct tag *) obj;
  38 }
  39
  40 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  41 {
  42         int typelen, taglen;
  43         unsigned char sha1[20];
  44         const char *type_line, *tag_line, *sig_line;
  45         char type[20];
  46
  47         if (item->object.parsed)
  48                 return 0;
  49         item->object.parsed = 1;
  50
  51         if (size < 64)
  52                 return -1;
  53         if (memcmp("object ", data, 7) || get_sha1_hex((char *) data + 7, sha1))
  54                 return -1;
  55
  56         type_line = (char *) data + 48;
  57         if (memcmp("\ntype ", type_line-1, 6))
  58                 return -1;
  59
  60         tag_line = strchr(type_line, '\n');
  61         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  62                 return -1;
  63
  64         sig_line = strchr(tag_line, '\n');
  65         if (!sig_line)
  66                 return -1;
  67         sig_line++;
  68
  69         typelen = tag_line - type_line - strlen("type \n");
  70         if (typelen >= 20)
  71                 return -1;
  72         memcpy(type, type_line + 5, typelen);
  73         type[typelen] = '\0';
  74         taglen = sig_line - tag_line - strlen("tag \n");
  75         item->tag = xmalloc(taglen + 1);
  76         memcpy(item->tag, tag_line + 4, taglen);
  77         item->tag[taglen] = '\0';
  78
  79         if (!strcmp(type, blob_type)) {
  80                 item->tagged = &lookup_blob(sha1)->object;
  81         } else if (!strcmp(type, tree_type)) {
  82                 item->tagged = &lookup_tree(sha1)->object;
  83         } else if (!strcmp(type, commit_type)) {
  84                 item->tagged = &lookup_commit(sha1)->object;
  85         } else if (!strcmp(type, tag_type)) {
  86                 item->tagged = &lookup_tag(sha1)->object;
  87         } else {
  88                 error("Unknown type %s", type);
  89                 item->tagged = NULL;
  90         }
  91
  92         if (item->tagged && track_object_refs) {
  93                 struct object_refs *refs = alloc_object_refs(1);
  94                 refs->ref[0] = item->tagged;
  95                 set_object_refs(&item->object, refs);
  96         }
  97
  98         return 0;
  99 }
 100
 101 int parse_tag(struct tag *item)
 102 {
 103         enum object_type type;
 104         void *data;
 105         unsigned long size;
 106         int ret;
 107
 108         if (item->object.parsed)
 109                 return 0;
 110         data = read_sha1_file(item->object.sha1, &type, &size);
 111         if (!data)
 112                 return error("Could not read %s",
 113                              sha1_to_hex(item->object.sha1));
 114         if (type != OBJ_TAG) {
 115                 free(data);
 116                 return error("Object %s not a tag",
 117                              sha1_to_hex(item->object.sha1));
 118         }
 119         ret = parse_tag_buffer(item, data, size);
 120         free(data);
 121         return ret;
 122 }