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                 if (((struct tag *)o)->tagged)
  13                         o = parse_object(((struct tag *)o)->tagged->sha1);
  14                 else
  15                         o = NULL;
  16         if (!o && warn) {
  17                 if (!warnlen)
  18                         warnlen = strlen(warn);
  19                 error("missing object referenced by '%.*s'", warnlen, warn);
  20         }
  21         return o;
  22 }
  23
  24 struct tag *lookup_tag(const unsigned char *sha1)
  25 {
  26         struct object *obj = lookup_object(sha1);
  27         if (!obj)
  28                 return create_object(sha1, OBJ_TAG, alloc_tag_node());
  29         if (!obj->type)
  30                 obj->type = OBJ_TAG;
  31         if (obj->type != OBJ_TAG) {
  32                 error("Object %s is a %s, not a tag",
  33                       sha1_to_hex(sha1), typename(obj->type));
  34                 return NULL;
  35         }
  36         return (struct tag *) obj;
  37 }
  38
  39 static unsigned long parse_tag_date(const char *buf, const char *tail)
  40 {
  41         const char *dateptr;
  42
  43         while (buf < tail && *buf++ != '>')
  44                 /* nada */;
  45         if (buf >= tail)
  46                 return 0;
  47         dateptr = buf;
  48         while (buf < tail && *buf++ != '\n')
  49                 /* nada */;
  50         if (buf >= tail)
  51                 return 0;
  52         /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  53         return strtoul(dateptr, NULL, 10);
  54 }
  55
  56 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  57 {
  58         unsigned char sha1[20];
  59         char type[20];
  60         const char *bufptr = data;
  61         const char *tail = bufptr + size;
  62         const char *nl;
  63
  64         if (item->object.parsed)
  65                 return 0;
  66         item->object.parsed = 1;
  67
  68         if (size < 64)
  69                 return -1;
  70         if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
  71                 return -1;
  72         bufptr += 48; /* "object " + sha1 + "\n" */
  73
  74         if (prefixcmp(bufptr, "type "))
  75                 return -1;
  76         bufptr += 5;
  77         nl = memchr(bufptr, '\n', tail - bufptr);
  78         if (!nl || sizeof(type) <= (nl - bufptr))
  79                 return -1;
  80         strncpy(type, bufptr, nl - bufptr);
  81         type[nl - bufptr] = '\0';
  82         bufptr = nl + 1;
  83
  84         if (!strcmp(type, blob_type)) {
  85                 item->tagged = &lookup_blob(sha1)->object;
  86         } else if (!strcmp(type, tree_type)) {
  87                 item->tagged = &lookup_tree(sha1)->object;
  88         } else if (!strcmp(type, commit_type)) {
  89                 item->tagged = &lookup_commit(sha1)->object;
  90         } else if (!strcmp(type, tag_type)) {
  91                 item->tagged = &lookup_tag(sha1)->object;
  92         } else {
  93                 error("Unknown type %s", type);
  94                 item->tagged = NULL;
  95         }
  96
  97         if (prefixcmp(bufptr, "tag "))
  98                 return -1;
  99         bufptr += 4;
 100         nl = memchr(bufptr, '\n', tail - bufptr);
 101         if (!nl)
 102                 return -1;
 103         item->tag = xmemdupz(bufptr, nl - bufptr);
 104         bufptr = nl + 1;
 105
 106         if (!prefixcmp(bufptr, "tagger "))
 107                 item->date = parse_tag_date(bufptr, tail);
 108         else
 109                 item->date = 0;
 110
 111         return 0;
 112 }
 113
 114 int parse_tag(struct tag *item)
 115 {
 116         enum object_type type;
 117         void *data;
 118         unsigned long size;
 119         int ret;
 120
 121         if (item->object.parsed)
 122                 return 0;
 123         data = read_sha1_file(item->object.sha1, &type, &size);
 124         if (!data)
 125                 return error("Could not read %s",
 126                              sha1_to_hex(item->object.sha1));
 127         if (type != OBJ_TAG) {
 128                 free(data);
 129                 return error("Object %s not a tag",
 130                              sha1_to_hex(item->object.sha1));
 131         }
 132         ret = parse_tag_buffer(item, data, size);
 133         free(data);
 134         return ret;
 135 }