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                 return create_object(sha1, OBJ_TAG, alloc_tag_node());
  26         if (!obj->type)
  27                 obj->type = OBJ_TAG;
  28         if (obj->type != OBJ_TAG) {
  29                 error("Object %s is a %s, not a tag",
  30                       sha1_to_hex(sha1), typename(obj->type));
  31                 return NULL;
  32         }
  33         return (struct tag *) obj;
  34 }
  35
  36 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  37 {
  38         int typelen, taglen;
  39         unsigned char sha1[20];
  40         const char *type_line, *tag_line, *sig_line;
  41         char type[20];
  42         const char *start = data;
  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, sha1))
  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 = memchr(type_line, '\n', size - (type_line - start));
  58         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  59                 return -1;
  60
  61         sig_line = memchr(tag_line, '\n', size - (tag_line - start));
  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 = xmemdupz(tag_line + 4, taglen);
  73
  74         if (!strcmp(type, blob_type)) {
  75                 item->tagged = &lookup_blob(sha1)->object;
  76         } else if (!strcmp(type, tree_type)) {
  77                 item->tagged = &lookup_tree(sha1)->object;
  78         } else if (!strcmp(type, commit_type)) {
  79                 item->tagged = &lookup_commit(sha1)->object;
  80         } else if (!strcmp(type, tag_type)) {
  81                 item->tagged = &lookup_tag(sha1)->object;
  82         } else {
  83                 error("Unknown type %s", type);
  84                 item->tagged = NULL;
  85         }
  86
  87         if (item->tagged && track_object_refs) {
  88                 struct object_refs *refs = alloc_object_refs(1);
  89                 refs->ref[0] = item->tagged;
  90                 set_object_refs(&item->object, refs);
  91         }
  92
  93         return 0;
  94 }
  95
  96 int parse_tag(struct tag *item)
  97 {
  98         enum object_type type;
  99         void *data;
 100         unsigned long size;
 101         int ret;
 102
 103         if (item->object.parsed)
 104                 return 0;
 105         data = read_sha1_file(item->object.sha1, &type, &size);
 106         if (!data)
 107                 return error("Could not read %s",
 108                              sha1_to_hex(item->object.sha1));
 109         if (type != OBJ_TAG) {
 110                 free(data);
 111                 return error("Object %s not a tag",
 112                              sha1_to_hex(item->object.sha1));
 113         }
 114         ret = parse_tag_buffer(item, data, size);
 115         free(data);
 116         return ret;
 117 }