Re: [PATCH 4/4] transport: drop "int cmp = cmp" hack
- From
Torsten Bögershausen <tboegi@web.de>
- Date
- Mar 24, 2013, 14:54 UTC
- Message-ID
- <514F13AC.6000100@web.de>
- In-Reply-To
- <20130324093212.GA28234@sigill.intra.peff.net>
On 24.03.13 10:32, Jeff King wrote:
Show 24 quoted lines
> On Sat, Mar 23, 2013 at 09:00:05PM -0700, Junio C Hamano wrote: > >> On Thu, Mar 21, 2013 at 4:13 AM, Jeff King <peff@peff.net> wrote: >>> >>> According to 47ec794, this initialization is meant to >>> squelch an erroneous uninitialized variable warning from gcc >>> 4.0.1. That version is quite old at this point, and gcc 4.1 >>> and up handle it fine, with one exception. There seems to be >>> a regression in gcc 4.6.3, which produces the warning; >>> however, gcc versions 4.4.7 and 4.7.2 do not. >>> >> >> transport.c: In function 'get_refs_via_rsync': >> transport.c:127:29: error: 'cmp' may be used uninitialized in this >> function [-Werror=uninitialized] >> transport.c:109:7: note: 'cmp' was declared here >> >> gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3 > > Right, that's the same version I noted above. Is 4.6.3 the default > compiler under a particular release of Ubuntu, or did you use their > gcc-4.6 package? > > -Peff
Side question: How much does it hurt to write like this:
diff --git a/transport.c b/transport.c index 6b2ae94..8020b62 100644 --- a/transport.c +++ b/transport.c @@ -106,7 +106,7 @@ static void insert_packed_refs(const char *packed_refs, struct ref **list) return; for (;;) { - int cmp, len; + int cmp=0, len; ============== Using Ubuntu 10.4, using gcc (Ubuntu 4.4.3-4ubuntu5.1) 4.4.3 the compiler will add a line like this: 2e83: 31 ff xor %edi,%edi (Which should not be to slow to execute) Looking at a later gcc, from upcoming Debian, with gcc (Debian 4.7.2-5) 4.7.2 the assembly code is exactly the same ;-)