From patchwork Thu May 19 17:36:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sandra Loosemore X-Patchwork-Id: 624163 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3r9dY050s6z9t3l for ; Fri, 20 May 2016 03:36:50 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b=ExpC0N18; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:to :from:subject:message-id:date:mime-version:content-type; q=dns; s=default; b=v+bbxiCJosSinevnlUynmgpaWiqK/jonZgCVywyJ8Z7U9YFKxh pgthP012Lu5VBHWfZUw8Ig683AtzxeeAiV4ccjHEgkyoT9mx75LONR/2syoGIR0W ATeX4l7p0l3fwxcCdigv498aHDMkpy7BW8tU1fEqUWSEGbNdZ9mMUf8yI= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:to :from:subject:message-id:date:mime-version:content-type; s= default; bh=rZ5LTk5tI1Y3LHleb+ClUXkM/SI=; b=ExpC0N18/oH0PSrbhaIy rBdyO6HkOen4Xa7Ih/lkg+mx6jnujOVQgM86zL4EhsTUYWLD6RhE2TFkUEoMSKZ1 /oioFOYuPAS0QoRK511CtDPIwlH4nEvTTaXldC27QGbs176Xz9klmMEdeZ+4eWh9 L8/2F7KPAc6dklCqkrbbG54= Received: (qmail 72101 invoked by alias); 19 May 2016 17:36:18 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 71771 invoked by uid 89); 19 May 2016 17:36:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.1 required=5.0 tests=AWL, BAYES_00, KAM_ASCII_DIVIDERS, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=no version=3.3.2 spammy=6789 X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 19 May 2016 17:36:06 +0000 Received: from svr-orw-fem-04.mgc.mentorg.com ([147.34.97.41]) by relay1.mentorg.com with esmtp id 1b3Rrg-0005NH-Fv from Sandra_Loosemore@mentor.com ; Thu, 19 May 2016 10:36:04 -0700 Received: from [127.0.0.1] (147.34.91.1) by svr-orw-fem-04.mgc.mentorg.com (147.34.97.41) with Microsoft SMTP Server id 14.3.224.2; Thu, 19 May 2016 10:36:04 -0700 To: "gcc-patches@gcc.gnu.org" , , From: Sandra Loosemore Subject: [patch] Allow configuration with --disable-sjlj-exceptions on biarch x86 Windows targets Message-ID: <573DF982.8010405@codesourcery.com> Date: Thu, 19 May 2016 11:36:02 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 This is a slightly revised version of the WIP patch against GCC 5.1 I previously posted here: https://gcc.gnu.org/ml/gcc/2016-05/msg00135.html To recap, I needed a biarch x86_64 mingw-w64 target compiler that uses DWARF-2 exception handling in 32-bit mode (for compatibility with an older i686-mingw32 toolchain configured with --disable-sjlj-exceptions). But, the configuration machinery was rejecting this. It used to be that SJLJ exceptions were the only choice for 64-bit mode so it was correct to reject --disable-sjlj-exceptions in a biarch toolchain, but now the default for 64-bit mode is SEH instead. With this patch, configuring with --disable-sjlj-exceptions selects DWARF-2 EH in 32-bit mode and SEH in 64-bit mode. I tested this in a cross-compiler configured to build C and C++ only for x86_64 mingw-w64 target, and test results look about the same as the default configuration, which uses SJLJ for 32-bit mode. (If it's relevant, I also used the compiler built with the 5.1 version of the patch to build complete Windows-host toolchains for nios2-elf and nios2-linux-gnu, which I tested by running the GDB testsuite.) There are no actual code changes here so I'd expect the 32-bit DWARF-2 EH support to work exactly the same as in a 32-bit-only x86 configuration. OK to commit? -Sandra Index: gcc/config/i386/cygming.h =================================================================== --- gcc/config/i386/cygming.h (revision 236256) +++ gcc/config/i386/cygming.h (working copy) @@ -339,16 +339,13 @@ do { \ #define ASM_COMMENT_START " #" #ifndef DWARF2_UNWIND_INFO -/* If configured with --disable-sjlj-exceptions, use DWARF2, else - default to SJLJ. */ +/* If configured with --disable-sjlj-exceptions, use DWARF2 for 32-bit + mode else default to SJLJ. 64-bit code uses SEH unless you request + SJLJ. */ #if (defined (CONFIG_SJLJ_EXCEPTIONS) && !CONFIG_SJLJ_EXCEPTIONS) /* The logic of this #if must be kept synchronised with the logic - for selecting the tmake_eh_file fragment in config.gcc. */ + for selecting the tmake_eh_file fragment in libgcc/config.host. */ #define DWARF2_UNWIND_INFO 1 -/* If multilib is selected break build as sjlj is required. */ -#if defined (TARGET_BI_ARCH) -#error For 64-bit windows and 32-bit based multilib version of gcc just SJLJ exceptions are supported. -#endif #else #define DWARF2_UNWIND_INFO 0 #endif Index: gcc/config/i386/mingw32.h =================================================================== --- gcc/config/i386/mingw32.h (revision 236256) +++ gcc/config/i386/mingw32.h (working copy) @@ -100,10 +100,12 @@ along with GCC; see the file COPYING3. #if DWARF2_UNWIND_INFO /* DW2-unwind is just available for 32-bit mode. */ #if TARGET_64BIT_DEFAULT -#error DW2 unwind is not available for 64-bit. -#endif +#define SHARED_LIBGCC_UNDEFS_SPEC \ + "%{m32: %{shared-libgcc: -u ___register_frame_info -u ___deregister_frame_info}}" +#else #define SHARED_LIBGCC_UNDEFS_SPEC \ "%{shared-libgcc: -u ___register_frame_info -u ___deregister_frame_info}" +#endif #else #define SHARED_LIBGCC_UNDEFS_SPEC "" #endif Index: libgcc/config.host =================================================================== --- libgcc/config.host (revision 236256) +++ libgcc/config.host (working copy) @@ -678,6 +678,9 @@ x86_64-*-cygwin*) # This has to match the logic for DWARF2_UNWIND_INFO in gcc/config/i386/cygming.h if test x$ac_cv_sjlj_exceptions = xyes; then tmake_eh_file="i386/t-sjlj-eh" + elif test "${host_address}" = 32; then + # biarch -m32 with --disable-sjlj-exceptions + tmake_eh_file="i386/t-dw2-eh" else tmake_eh_file="i386/t-seh-eh" fi @@ -730,6 +733,10 @@ x86_64-*-mingw*) # This has to match the logic for DWARF2_UNWIND_INFO in gcc/config/i386/cygming.h if test x$ac_cv_sjlj_exceptions = xyes; then tmake_eh_file="i386/t-sjlj-eh" + elif test "${host_address}" = 32; then + # biarch -m32 with --disable-sjlj-exceptions + tmake_eh_file="i386/t-dw2-eh" + md_unwind_header=i386/w32-unwind.h else tmake_eh_file="i386/t-seh-eh" fi