From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35731) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gEetg-0002x4-FA for qemu-devel@nongnu.org; Mon, 22 Oct 2018 14:25:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gEetc-0003fd-F0 for qemu-devel@nongnu.org; Mon, 22 Oct 2018 14:25:48 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:45496) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gEetc-0003cM-7O for qemu-devel@nongnu.org; Mon, 22 Oct 2018 14:25:44 -0400 Received: by mail-wr1-f68.google.com with SMTP id f17-v6so14277865wrs.12 for ; Mon, 22 Oct 2018 11:25:41 -0700 (PDT) References: <20181022181623.8810-1-richard.henderson@linaro.org> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: <615be422-c338-a4bb-cf66-eeda2b553b7c@redhat.com> Date: Mon, 22 Oct 2018 20:25:38 +0200 MIME-Version: 1.0 In-Reply-To: <20181022181623.8810-1-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: peter.maydell@linaro.org On 22/10/18 20:16, 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 >