Re: [libvirt] [RFC PATCH 1/6] util: Add API for converting virBitmap into printable string

On 02/09/2011 09:01 AM, Jiri Denemark wrote: I probably would have written: while (sz--) virBufferVSprintf(&buf, "%08x", bitmap->map[sz]); since sz is guaranteed to be non-zero to start with. But your way works, and the compiler (hopefully) generates the same code (when optimizing). Problem - "%08x" is not portable. bitmap->map[x] is a uint32_t, which means we need to use "%08"PRIx32 (since some platforms declare uint32_t as long rather than int) to avoid a gcc warning. For that matter, why did we make the bitset use uint32_t as the underlying type, instead of just using long? We already have macros VIR_BITMAP_BITS_PER_UNIT that make the rest of the code immune to size changes, if we resize the bitmap to 64-bits on LP64 (like x86_64) while keeping it at 32-bits on ILP32 (like i686). Of course, making that change would mean that this new code would need to use "%0*lx",VIR_BITMAP_BITS_PER_UNIT/4,bitmap->map[x]. I like the patch, but think it needs a v2. -- Eric Blake eblake(a)redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org