From: René Scharfe Date: Tue, 19 May 2015 20:29:18 GMT Subject: Re: [PATCH] pack-bitmaps: plug memory leak, fix allocation size for recent_bitmaps Message-ID: <555B9D1E.2050609@web.de> In-Reply-To: Am 19.05.2015 um 02:57 schrieb Stefan Beller: > On Mon, May 18, 2015 at 4:24 PM, René Scharfe wrote: >> diff --git a/pack-bitmap.c b/pack-bitmap.c >> index 62a98cc..e5abb8a 100644 >> --- a/pack-bitmap.c >> +++ b/pack-bitmap.c >> @@ -209,14 +209,12 @@ static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos) >> return buffer[(*pos)++]; >> } >> >> +#define MAX_XOR_OFFSET 160 >> + >> static int load_bitmap_entries_v1(struct bitmap_index *index) >> { >> - static const size_t MAX_XOR_OFFSET = 160; > > Is there a reason why we prefer defines over a static const size_t here? Yes, see below. >> - >> uint32_t i; >> - struct stored_bitmap **recent_bitmaps; >> - >> - recent_bitmaps = xcalloc(MAX_XOR_OFFSET, sizeof(struct stored_bitmap)); >> + struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL }; If MAX_XOR_OFFSET is a const then C89 does not allow this declaration. C99 gives you a variable-length array here. VLAs can't be initialized at declaration time, so we'd need to add a memset() call (at least with GCC 4.9). Overall it's simpler and shorter to use a macro. We could also use an enum, but that's not exactly common. René