From patchwork Thu Jun 17 09:31:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 1493363 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=OjAj1GuO; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4G5HjR1bwFz9s5R for ; Thu, 17 Jun 2021 20:04:59 +1000 (AEST) Received: from localhost ([::1]:53188 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltotM-0005Jj-Rf for incoming@patchwork.ozlabs.org; Thu, 17 Jun 2021 06:04:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55446) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltoNf-0003Fr-00 for qemu-devel@nongnu.org; Thu, 17 Jun 2021 05:32:11 -0400 Received: from mail-ej1-x634.google.com ([2a00:1450:4864:20::634]:33425) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ltoNc-0006RS-8e for qemu-devel@nongnu.org; Thu, 17 Jun 2021 05:32:09 -0400 Received: by mail-ej1-x634.google.com with SMTP id g20so8826890ejt.0 for ; Thu, 17 Jun 2021 02:32:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=xNQYL3e/qOseQC5VO9f224envW8cvgsN2R0SpAwLVbk=; b=OjAj1GuOTJ6Yp1FgleT7b4Jeq69OVbocUmu4HzW4sVfhNszU4p4KT1R+86QaiYMclw T9qUe4nStfUjMwExmPrgc59Gy2gw+iSI9gVhdHVKkpBCPSX26wrnmheYCH8836DUSQTZ hnEfwA8jD0RuV5yS1C9XLeGa0dCGUWSQ9GkgG5uqVO32AT1su4Xzgu74IXjYH/QJD7jr Y6LIxLMHIJWFywxv030oyX86t06szGbtTpvSXf/DFSKlFzlD+crjLDcpNSeyj1JjVKap UmIg7yvxSFFDZ/tvUclHAI67omwywswlGP8PSmQgXFI3zdfxDcGKN/Rc0CXkL60DsiaU Ka6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=xNQYL3e/qOseQC5VO9f224envW8cvgsN2R0SpAwLVbk=; b=tg776WiErbHjiuQVghWcT9xqrhsilYyIoiOPpaDUhzoeVzdqJVZeqV6m7KHPNTZV7C YyIgmSKNGRa0gDZ6CHVTDnmcAfMimnH2lUzBaLvY33HhvzZh13iZqMtSjwixuzRbD3sQ YxgTLPu6ngDlDz9U1N0rzCtZ4/l7j7jm2BQ14676mmWMoYq1uO9mnzxoqX5NcvZfd9N/ JFtRHeNXK/5JstgxuTSA5d1wOebV/e/zKEj13Gx88XSn6AM/jAQwackMZ8G8DmONJpRz fedNYY2i7yCOxugRdA9/PH9S6NEKD56rQV6oMVtosgW+0vz6tMAXdvGrCvuWihSoDic/ baBw== X-Gm-Message-State: AOAM531PqCZlaDjBqi37vdxCg5wQueNJ2wsSiS6R/V/Bs1DdsnZSLeeU Cs7/YkV7kvWOrJMo9Lb17HoOqy6Q/GE= X-Google-Smtp-Source: ABdhPJx3bIFzZ9Ts20mZSRraK73qFOIAsldEmyyXUav8SkceSqwgzHkj5ygfmzQ0J9eBTt/dtknv1A== X-Received: by 2002:a17:906:eb17:: with SMTP id mb23mr4269825ejb.239.1623922326921; Thu, 17 Jun 2021 02:32:06 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id m18sm3328140ejx.56.2021.06.17.02.32.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Jun 2021 02:32:06 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 43/45] include/qemu/lockable: Use _Generic instead of QEMU_GENERIC Date: Thu, 17 Jun 2021 11:31:32 +0200 Message-Id: <20210617093134.900014-44-pbonzini@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210617093134.900014-1-pbonzini@redhat.com> References: <20210617093134.900014-1-pbonzini@redhat.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::634; envelope-from=paolo.bonzini@gmail.com; helo=mail-ej1-x634.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.248, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Alex_Benn=C3=A9e?= , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Richard Henderson This is both more and less complicated than our expansion using __builtin_choose_expr and __builtin_types_compatible_p. The expansion through QEMU_MAKE_LOCKABLE_ doesn't work because we're not emumerating all of the types within the same _Generic, which results in errors about unhandled cases. We must also handle void* explicitly, so that the NULL constant can be used. Signed-off-by: Richard Henderson Reviewed-by: Alex Bennée Tested-by: Alex Bennée Message-Id: <20210614233143.1221879-7-richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini --- include/qemu/lockable.h | 90 +++++++++++++++++++---------------------- 1 file changed, 41 insertions(+), 49 deletions(-) diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h index b620023141..86db7cb04c 100644 --- a/include/qemu/lockable.h +++ b/include/qemu/lockable.h @@ -24,79 +24,71 @@ struct QemuLockable { QemuLockUnlockFunc *unlock; }; -/* This function gives an error if an invalid, non-NULL pointer type is passed - * to QEMU_MAKE_LOCKABLE. For optimized builds, we can rely on dead-code elimination - * from the compiler, and give the errors already at link time. - */ -#if defined(__OPTIMIZE__) && !defined(__SANITIZE_ADDRESS__) -void unknown_lock_type(void *); -#else -static inline void unknown_lock_type(void *unused) -{ - abort(); -} -#endif - static inline __attribute__((__always_inline__)) QemuLockable * qemu_make_lockable(void *x, QemuLockable *lockable) { - /* We cannot test this in a macro, otherwise we get compiler + /* + * We cannot test this in a macro, otherwise we get compiler * warnings like "the address of 'm' will always evaluate as 'true'". */ return x ? lockable : NULL; } -/* Auxiliary macros to simplify QEMU_MAKE_LOCABLE. */ -#define QEMU_LOCK_FUNC(x) ((QemuLockUnlockFunc *) \ - QEMU_GENERIC(x, \ - (QemuMutex *, qemu_mutex_lock), \ - (QemuRecMutex *, qemu_rec_mutex_lock), \ - (CoMutex *, qemu_co_mutex_lock), \ - (QemuSpin *, qemu_spin_lock), \ - unknown_lock_type)) +static inline __attribute__((__always_inline__)) QemuLockable * +qemu_null_lockable(void *x) +{ + if (x != NULL) { + qemu_build_not_reached(); + } + return NULL; +} -#define QEMU_UNLOCK_FUNC(x) ((QemuLockUnlockFunc *) \ - QEMU_GENERIC(x, \ - (QemuMutex *, qemu_mutex_unlock), \ - (QemuRecMutex *, qemu_rec_mutex_unlock), \ - (CoMutex *, qemu_co_mutex_unlock), \ - (QemuSpin *, qemu_spin_unlock), \ - unknown_lock_type)) - -/* In C, compound literals have the lifetime of an automatic variable. +/* + * In C, compound literals have the lifetime of an automatic variable. * In C++ it would be different, but then C++ wouldn't need QemuLockable * either... */ -#define QEMU_MAKE_LOCKABLE_(x) (&(QemuLockable) { \ - .object = (x), \ - .lock = QEMU_LOCK_FUNC(x), \ - .unlock = QEMU_UNLOCK_FUNC(x), \ +#define QML_OBJ_(x, name) (&(QemuLockable) { \ + .object = (x), \ + .lock = (QemuLockUnlockFunc *) qemu_ ## name ## _lock, \ + .unlock = (QemuLockUnlockFunc *) qemu_ ## name ## _unlock \ }) -/* QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable +/** + * QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable * - * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin). + * @x: a lock object (currently one of QemuMutex, QemuRecMutex, + * CoMutex, QemuSpin). * * Returns a QemuLockable object that can be passed around * to a function that can operate with locks of any kind, or * NULL if @x is %NULL. - */ -#define QEMU_MAKE_LOCKABLE(x) \ - QEMU_GENERIC(x, \ - (QemuLockable *, (x)), \ - qemu_make_lockable((x), QEMU_MAKE_LOCKABLE_(x))) - -/* QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable * - * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin). + * Note the special case for void *, so that we may pass "NULL". + */ +#define QEMU_MAKE_LOCKABLE(x) \ + _Generic((x), QemuLockable *: (x), \ + void *: qemu_null_lockable(x), \ + QemuMutex *: qemu_make_lockable(x, QML_OBJ_(x, mutex)), \ + QemuRecMutex *: qemu_make_lockable(x, QML_OBJ_(x, rec_mutex)), \ + CoMutex *: qemu_make_lockable(x, QML_OBJ_(x, co_mutex)), \ + QemuSpin *: qemu_make_lockable(x, QML_OBJ_(x, spin))) + +/** + * QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable + * + * @x: a lock object (currently one of QemuMutex, QemuRecMutex, + * CoMutex, QemuSpin). * * Returns a QemuLockable object that can be passed around * to a function that can operate with locks of any kind. */ -#define QEMU_MAKE_LOCKABLE_NONNULL(x) \ - QEMU_GENERIC(x, \ - (QemuLockable *, (x)), \ - QEMU_MAKE_LOCKABLE_(x)) +#define QEMU_MAKE_LOCKABLE_NONNULL(x) \ + _Generic((x), QemuLockable *: (x), \ + QemuMutex *: QML_OBJ_(x, mutex), \ + QemuRecMutex *: QML_OBJ_(x, rec_mutex), \ + CoMutex *: QML_OBJ_(x, co_mutex), \ + QemuSpin *: QML_OBJ_(x, spin)) static inline void qemu_lockable_lock(QemuLockable *x) {