From b5007211b6582fc38647ff695b5ac51541ea9de8 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Thu, 27 Nov 2014 00:24:01 -0500 Subject: pack-bitmap: do not use gcc packed attribute The "__attribute__" flag may be a noop on some compilers. That's OK as long as the code is correct without the attribute, but in this case it is not. We would typically end up with a struct that is 2 bytes too long due to struct padding, breaking both reading and writing of bitmaps. Instead of marshalling the data in a struct, let's just provide helpers for reading and writing the appropriate types. Besides being correct on all platforms, the result is more efficient and simpler to read. Signed-off-by: Karsten Blees Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- pack-bitmap.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'pack-bitmap.c') diff --git a/pack-bitmap.c b/pack-bitmap.c index 91e410153..9f8b90981 100644 --- a/pack-bitmap.c +++ b/pack-bitmap.c @@ -197,13 +197,24 @@ static struct stored_bitmap *store_bitmap(struct bitmap_index *index, return stored; } +static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos) +{ + uint32_t result = get_be32(buffer + *pos); + (*pos) += sizeof(result); + return result; +} + +static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos) +{ + return buffer[(*pos)++]; +} + static int load_bitmap_entries_v1(struct bitmap_index *index) { static const size_t MAX_XOR_OFFSET = 160; uint32_t i; struct stored_bitmap **recent_bitmaps; - struct bitmap_disk_entry *entry; recent_bitmaps = xcalloc(MAX_XOR_OFFSET, sizeof(struct stored_bitmap)); @@ -214,15 +225,12 @@ static int load_bitmap_entries_v1(struct bitmap_index *index) uint32_t commit_idx_pos; const unsigned char *sha1; - entry = (struct bitmap_disk_entry *)(index->map + index->map_pos); - index->map_pos += sizeof(struct bitmap_disk_entry); + commit_idx_pos = read_be32(index->map, &index->map_pos); + xor_offset = read_u8(index->map, &index->map_pos); + flags = read_u8(index->map, &index->map_pos); - commit_idx_pos = ntohl(entry->object_pos); sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos); - xor_offset = (int)entry->xor_offset; - flags = (int)entry->flags; - bitmap = read_bitmap_1(index); if (!bitmap) return -1; -- cgit v1.2.3