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 object *deref_tag_noverify(struct object *o)
  25 {
  26         while (o && o->type == OBJ_TAG) {
  27                 o = parse_object(o->sha1);
  28                 if (o && o->type == OBJ_TAG && ((struct tag *)o)->tagged)
  29                         o = ((struct tag *)o)->tagged;
  30                 else
  31                         o = NULL;
  32         }
  33         return o;
  34 }
  35
  36 struct tag *lookup_tag(const unsigned char *sha1)
  37 {
  38         struct object *obj = lookup_object(sha1);
  39         if (!obj)
  40                 return create_object(sha1, alloc_tag_node());
  41         return object_as_type(obj, OBJ_TAG, 0);
  42 }
  43
  44 static unsigned long parse_tag_date(const char *buf, const char *tail)
  45 {
  46         const char *dateptr;
  47
  48         while (buf < tail && *buf++ != '>')
  49                 /* nada */;
  50         if (buf >= tail)
  51                 return 0;
  52         dateptr = buf;
  53         while (buf < tail && *buf++ != '\n')
  54                 /* nada */;
  55         if (buf >= tail)
  56                 return 0;
  57         /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  58         return strtoul(dateptr, NULL, 10);
  59 }
  60
  61 int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
  62 {
  63         unsigned char sha1[20];
  64         char type[20];
  65         const char *bufptr = data;
  66         const char *tail = bufptr + size;
  67         const char *nl;
  68
  69         if (item->object.parsed)
  70                 return 0;
  71         item->object.parsed = 1;
  72
  73         if (size < 64)
  74                 return -1;
  75         if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
  76                 return -1;
  77         bufptr += 48; /* "object " + sha1 + "\n" */
  78
  79         if (!starts_with(bufptr, "type "))
  80                 return -1;
  81         bufptr += 5;
  82         nl = memchr(bufptr, '\n', tail - bufptr);
  83         if (!nl || sizeof(type) <= (nl - bufptr))
  84                 return -1;
  85         strncpy(type, bufptr, nl - bufptr);
  86         type[nl - bufptr] = '\0';
  87         bufptr = nl + 1;
  88
  89         if (!strcmp(type, blob_type)) {
  90                 item->tagged = &lookup_blob(sha1)->object;
  91         } else if (!strcmp(type, tree_type)) {
  92                 item->tagged = &lookup_tree(sha1)->object;
  93         } else if (!strcmp(type, commit_type)) {
  94                 item->tagged = &lookup_commit(sha1)->object;
  95         } else if (!strcmp(type, tag_type)) {
  96                 item->tagged = &lookup_tag(sha1)->object;
  97         } else {
  98                 error("Unknown type %s", type);
  99                 item->tagged = NULL;
 100         }
 101
 102         if (bufptr + 4 < tail && starts_with(bufptr, "tag "))
 103                 ;               /* good */
 104         else
 105                 return -1;
 106         bufptr += 4;
 107         nl = memchr(bufptr, '\n', tail - bufptr);
 108         if (!nl)
 109                 return -1;
 110         item->tag = xmemdupz(bufptr, nl - bufptr);
 111         bufptr = nl + 1;
 112
 113         if (bufptr + 7 < tail && starts_with(bufptr, "tagger "))
 114                 item->date = parse_tag_date(bufptr, tail);
 115         else
 116                 item->date = 0;
 117
 118         return 0;
 119 }
 120
 121 int parse_tag(struct tag *item)
 122 {
 123         enum object_type type;
 124         void *data;
 125         unsigned long size;
 126         int ret;
 127
 128         if (item->object.parsed)
 129                 return 0;
 130         data = read_sha1_file(item->object.sha1, &type, &size);
 131         if (!data)
 132                 return error("Could not read %s",
 133                              sha1_to_hex(item->object.sha1));
 134         if (type != OBJ_TAG) {
 135                 free(data);
 136                 return error("Object %s not a tag",
 137                              sha1_to_hex(item->object.sha1));
 138         }
 139         ret = parse_tag_buffer(item, data, size);
 140         free(data);
 141         return ret;
 142 }