From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44C55C433DF for ; Tue, 2 Jun 2020 19:43:22 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A523D206A2 for ; Tue, 2 Jun 2020 19:43:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A523D206A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49c2X70S5RzDqZ1 for ; Wed, 3 Jun 2020 05:43:19 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49c2VC2tKrzDqRs for ; Wed, 3 Jun 2020 05:41:39 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 49c2VC1kLDz8tRl for ; Wed, 3 Jun 2020 05:41:39 +1000 (AEST) Received: by ozlabs.org (Postfix) id 49c2VC1Bvnz9sSc; Wed, 3 Jun 2020 05:41:39 +1000 (AEST) Authentication-Results: ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by ozlabs.org (Postfix) with ESMTP id 49c2VB1vbQz9sSF for ; Wed, 3 Jun 2020 05:41:36 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 052JfYfB007295; Tue, 2 Jun 2020 14:41:34 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 052JfX01007294; Tue, 2 Jun 2020 14:41:33 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Tue, 2 Jun 2020 14:41:33 -0500 From: Segher Boessenkool To: Jordan Niethe Subject: Re: [PATCH 1/4] powerpc: Add a ppc_inst_as_str() helper Message-ID: <20200602194133.GT31009@gate.crashing.org> References: <20200602052728.18227-1-jniethe5@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200602052728.18227-1-jniethe5@gmail.com> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@ozlabs.org, alistair@popple.id.au Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Jun 02, 2020 at 03:27:25PM +1000, Jordan Niethe wrote: > There are quite a few places where instructions are printed, this is > done using a '%x' format specifier. With the introduction of prefixed > instructions, this does not work well. Currently in these places, > ppc_inst_val() is used for the value for %x so only the first word of > prefixed instructions are printed. > > When the instructions are word instructions, only a single word should > be printed. For prefixed instructions both the prefix and suffix should > be printed. To accommodate both of these situations, instead of a '%x' > specifier use '%s' and introduce a helper, __ppc_inst_as_str() which > returns a char *. The char * __ppc_inst_as_str() returns is buffer that > is passed to it by the caller. > > It is cumbersome to require every caller of __ppc_inst_as_str() to now > declare a buffer. To make it more convenient to use __ppc_inst_as_str(), > wrap it in a macro that uses a compound statement to allocate a buffer > on the caller's stack before calling it. > > Signed-off-by: Jordan Niethe Acked-by: Segher Boessenkool > +#define PPC_INST_STR_LEN sizeof("0x00000000 0x00000000") sizeof is not a function or anything function-like; it's just an operator, like (unary) "+" or "-" or dereference "*". The parentheses are completely redundant here. And it kind of matters, as written a reader might think that a string object is actually constructed here. But, so very many people do this, I'm not going to fight this fight ;-) Segher