From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf2c.google.com (mail-qv1-xf2c.google.com [IPv6:2607:f8b0:4864:20::f2c]) by sourceware.org (Postfix) with ESMTPS id 44F113858C20 for ; Mon, 29 Aug 2022 18:24:40 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 44F113858C20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-qv1-xf2c.google.com with SMTP id u6so6944413qvp.5 for ; Mon, 29 Aug 2022 11:24:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=6ln+AqdlcvQCNRJo+RwPbvgNb/qzrWf0fXQ2XxuqUko=; b=Pfo0mmFMzFNiXdipiNALqtuK8OaVHr/sqE+0TMKg1W81RU+CtwKXHYaJWColkwoN4S 4H8KSwirReyHrEF3KlEzZB/8TR9IDI651+DqdwdwLNvutd2FXSrwq+9EI2zkSEbSqdaT 6xNhm2Fzag8c/orn7P9EHfT1y5YxvYYVbJzNw4pTaEkiiu+Jkk3NFUZny7lBvY5P+bXS b3QNbykt8qRCJl5KjrSiz/aIZgjfyvROUh+1n0tXnqsN2DWZMhqNheXCHkb1k24tftaI b/8nlDnHK0iHybXkKm9wcAKaRB+Nf/LNz/YC19PJ0vwk3vA7UJnPMp6mbeE5XWYzLyDO mrog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=6ln+AqdlcvQCNRJo+RwPbvgNb/qzrWf0fXQ2XxuqUko=; b=0L8YG4aQg32tXw2Uqpm6WQEmGogmY2g3rHa0fal+0PqpgzebfKRH4BRbbLEiwtNJkE bCnqzAEo3kl+AW1vNbCP9b9h91hbRTT3UTxHTnWSTNP3Ytv3VBkPFzGNt2FDNqhLRVdZ 95ICYPS5us/+2FXZ8VKN6xGZT3pjcFHsG8yHoNbaI4dp1wJvaXsP+7XB/g8O6WOzYlDo elCt5EvV9mnGdyYmK8f/BPvqcwiXgAYis49C816z7fjY4FfxukBpAteZE03w0nP7aZJG QyaldvOoUao1FQRiycXi2Wv6gI6uWD3C9w3xpZyNQAe2O917LWT/Edsd565oOj8Og9LG TOHQ== X-Gm-Message-State: ACgBeo1wog7Cw6eXwHoUHdyyRsFwrW6166f50tq4HYTQYQNL/d1Iivao j25mIH+0y/YrJQ6Hcz+A7JJZ4Y1WDI7eClEd7rA= X-Google-Smtp-Source: AA6agR7QuQHKt0DMAeegLzC6g2MJ1HHy+EMkbG2s9RTGoe2bWfsoMiHEpwHIQhXJGgnXfsqXDHehHI76NWc8DKL/dns= X-Received: by 2002:ad4:5bc3:0:b0:482:5a89:c107 with SMTP id t3-20020ad45bc3000000b004825a89c107mr11849089qvt.84.1661797479050; Mon, 29 Aug 2022 11:24:39 -0700 (PDT) MIME-Version: 1.0 References: <20220827151845.1583899-1-aburgess@redhat.com> In-Reply-To: <20220827151845.1583899-1-aburgess@redhat.com> From: "H.J. Lu" Date: Mon, 29 Aug 2022 11:24:03 -0700 Message-ID: Subject: Re: [PATCH] opcodes/i386: use '; ' as comment character for intel style disassembly To: Andrew Burgess Cc: Binutils Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3017.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Sat, Aug 27, 2022 at 8:19 AM Andrew Burgess via Binutils wrote: > > While working on a disassembly related GDB issue I was comparing the > disassembly output for x86-64 in att mode and intel mode. > > I ended up trying to cut & paste some disassembly snippets from the > disassembler, and feed the instructions back through the assembler. > > For the att style disassembly this worked fine, but for the intel > style disassembly I ran into a problem as the '#' character, which is > used for comments in i386-dis.c was not recognised by either of the > intel style assemblers I have to handle (nasm and yasm). > > Searching online, every example I could find that has intel style > assembly syntax, used ';' for the comment character, and indeed, when > I switch '#' to ';', my same code assembled fine. But, ';' marks the end of instructions for GNU assembler: [hjl@gnu-efi-2 tmp]$ cat x.s .intel_syntax noprefix mov eax, edx; mov eax, edx; [hjl@gnu-efi-2 tmp]$ gcc -c x.s [hjl@gnu-efi-2 tmp]$ objdump -dw -Mintel x.o x.o: file format elf64-x86-64 Disassembly of section .text: 0000000000000000 <.text>: 0: 89 d0 mov eax,edx 2: 89 d0 mov eax,edx [hjl@gnu-efi-2 tmp]$ > In i386-dis.c we already have a bunch of characters that are > customised based on the selected syntax, see open_char, close_char, > separator_char, and scale_char. > > I propose to add comment_char to this list. This will be '#' for att > syntax, and ';' for intel syntax. > > I've updated the gas tests to account for this change. -- H.J.