From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35063) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gEuSV-0000nO-D9 for qemu-devel@nongnu.org; Tue, 23 Oct 2018 07:02:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gEuSR-0000Il-DB for qemu-devel@nongnu.org; Tue, 23 Oct 2018 07:02:46 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:40566) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gEuSR-0000Gb-67 for qemu-devel@nongnu.org; Tue, 23 Oct 2018 07:02:43 -0400 Received: by mail-wr1-f67.google.com with SMTP id d2-v6so1188316wro.7 for ; Tue, 23 Oct 2018 04:02:43 -0700 (PDT) References: <20181023070253.6407-1-richard.henderson@linaro.org> <20181023070253.6407-3-richard.henderson@linaro.org> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: <2c94b099-ea22-43b5-e8e1-4c858c69bf26@redhat.com> Date: Tue, 23 Oct 2018 13:02:40 +0200 MIME-Version: 1.0 In-Reply-To: <20181023070253.6407-3-richard.henderson@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH, build fix] osdep: Work around MinGW assert List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson , qemu-devel@nongnu.org Cc: cota@braap.org On 23/10/18 9:02, Richard Henderson wrote: > In several places we use assert(FEATURE), and assume that if FEATURE > is disabled, all following code is removed as unreachable. Which allows > us to compile-out functions that are only present with FEATURE, and > have a link-time failure if the functions remain used. > > MinGW does not mark its internal function _assert() as noreturn, so the > compiler cannot see when code is unreachable, which leads to link errors > for this host that are not present elsewhere. > > The current build-time failure concerns 62823083b8a2, but I remember > having seen this same error before. Fix it once and for all for MinGW. > > Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé > --- > include/qemu/osdep.h | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h > index 4f8559e550..0c1e335a43 100644 > --- a/include/qemu/osdep.h > +++ b/include/qemu/osdep.h > @@ -122,6 +122,18 @@ extern int daemon(int, int); > #include "glib-compat.h" > #include "qemu/typedefs.h" > > +/* > + * For mingw, as of v6.0.0, the function implementing the assert macro is > + * not marked a noreturn, so the compiler cannot delete code following an > + * assert(false) as unused. We rely on this within the code base to delete > + * code that is unreachable when features are disabled. > + * All supported versions of Glib's g_assert() satisfy this requirement. > + */ > +#ifdef __MINGW32__ > +#undef assert > +#define assert(x) g_assert(x) > +#endif > + > /* > * According to waitpid man page: > * WCOREDUMP >