From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1WnwZa-0007QX-AT for mharc-qemu-trivial@gnu.org; Fri, 23 May 2014 17:00:14 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49351) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnwZU-0007Fo-Pg for qemu-trivial@nongnu.org; Fri, 23 May 2014 17:00:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WnwZP-0007qu-Sc for qemu-trivial@nongnu.org; Fri, 23 May 2014 17:00:08 -0400 Received: from isrv.corpit.ru ([86.62.121.231]:60101) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnwZE-0007ai-8U; Fri, 23 May 2014 16:59:52 -0400 Received: from [192.168.88.2] (mjt.vpn.tls.msk.ru [192.168.177.99]) by isrv.corpit.ru (Postfix) with ESMTP id 3072042B94; Sat, 24 May 2014 00:59:51 +0400 (MSK) Message-ID: <537FB6C7.5000900@msgid.tls.msk.ru> Date: Sat, 24 May 2014 00:59:51 +0400 From: Michael Tokarev Organization: Telecom Service, JSC User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.5.0 MIME-Version: 1.0 To: Markus Armbruster References: <1399569594-31678-1-git-send-email-mjt@msgid.tls.msk.ru> <536F2DC0.9080809@redhat.com> <536F6180.1010905@msgid.tls.msk.ru> <87mwenz734.fsf@blackfin.pond.sub.org> In-Reply-To: <87mwenz734.fsf@blackfin.pond.sub.org> X-Enigmail-Version: 1.6 OpenPGP: id=804465C5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 86.62.121.231 Cc: qemu-trivial@nongnu.org, Alon Levy , qemu-devel@nongnu.org Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH] libcacard: remove useless initializers X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 May 2014 21:00:13 -0000 So, should we apply this or not? It's been waiting for quite some time, and during this time we've found a very good example of why it should be applied (I think anyway). Thanks, /mjt 12.05.2014 13:20, Markus Armbruster wrote: > Michael Tokarev writes: > >> 11.05.2014 11:58, Alon Levy wrote: >>> On 05/08/2014 08:19 PM, Michael Tokarev wrote: >>>> libcacard has many functions which initializes local variables >>>> at declaration time, which are always assigned some values later >>>> (often right after declaration). Clean up these initializers. >>> >>> How is this an improvement? Doesn't the compiler ignore this anyhow? >> >> Just less code. >> >> To me, when I see something like >> >> Type *var = NULL; >> >> in a function, it somehow "translates" to a construct like >> >> Type *found = NULL; >> >> That is -- so this variable will be used either as an accumulator >> or a search result, so that initial value is really important. >> >> So when I see the same variable receives its initial value in >> the next line, I start wondering what's missed in the code which >> should be there. Or why I don't read the code correctly. Or >> something like this. >> >> So, basically, this is a cleanup patch just to avoid confusion, >> it most likely not needed for current compiler who can figure >> it out by its own. And for consistency - why not initialize >> other variables too? > > I hate redundant initializers for yet another reason: when I change the > code, and accidentally add a path bypassing the *real* initialization, I > don't get a "may be used uninitialized" warning, I get the stupid > redundant initialization and quite possibly a crash to debug some time > later. > >> Maybe that's just my old-scool mind works this way. >> >> At any rate you can just ignore this patch. > > Please consider it. > From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49328) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnwZK-00075Z-PQ for qemu-devel@nongnu.org; Fri, 23 May 2014 17:00:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WnwZE-0007bx-G4 for qemu-devel@nongnu.org; Fri, 23 May 2014 16:59:58 -0400 Message-ID: <537FB6C7.5000900@msgid.tls.msk.ru> Date: Sat, 24 May 2014 00:59:51 +0400 From: Michael Tokarev MIME-Version: 1.0 References: <1399569594-31678-1-git-send-email-mjt@msgid.tls.msk.ru> <536F2DC0.9080809@redhat.com> <536F6180.1010905@msgid.tls.msk.ru> <87mwenz734.fsf@blackfin.pond.sub.org> In-Reply-To: <87mwenz734.fsf@blackfin.pond.sub.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-trivial] [PATCH] libcacard: remove useless initializers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-trivial@nongnu.org, Alon Levy , qemu-devel@nongnu.org So, should we apply this or not? It's been waiting for quite some time, and during this time we've found a very good example of why it should be applied (I think anyway). Thanks, /mjt 12.05.2014 13:20, Markus Armbruster wrote: > Michael Tokarev writes: > >> 11.05.2014 11:58, Alon Levy wrote: >>> On 05/08/2014 08:19 PM, Michael Tokarev wrote: >>>> libcacard has many functions which initializes local variables >>>> at declaration time, which are always assigned some values later >>>> (often right after declaration). Clean up these initializers. >>> >>> How is this an improvement? Doesn't the compiler ignore this anyhow? >> >> Just less code. >> >> To me, when I see something like >> >> Type *var = NULL; >> >> in a function, it somehow "translates" to a construct like >> >> Type *found = NULL; >> >> That is -- so this variable will be used either as an accumulator >> or a search result, so that initial value is really important. >> >> So when I see the same variable receives its initial value in >> the next line, I start wondering what's missed in the code which >> should be there. Or why I don't read the code correctly. Or >> something like this. >> >> So, basically, this is a cleanup patch just to avoid confusion, >> it most likely not needed for current compiler who can figure >> it out by its own. And for consistency - why not initialize >> other variables too? > > I hate redundant initializers for yet another reason: when I change the > code, and accidentally add a path bypassing the *real* initialization, I > don't get a "may be used uninitialized" warning, I get the stupid > redundant initialization and quite possibly a crash to debug some time > later. > >> Maybe that's just my old-scool mind works this way. >> >> At any rate you can just ignore this patch. > > Please consider it. >