From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D083E1A9F82 for ; Wed, 8 Jul 2026 05:03:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783486994; cv=none; b=ihHQvDXMO9OavagcN/BOnrAzAsmD1EIot469gqL+xtDxZtGzwhocYHWHQeNXFAbYO2ZIeHGhvSHHOuB2/AkxlxbSb/6ttA7DakcOEC0w23VZ4eYS1Z3uwyzOGjLtSBOJUQYudwLiHnpgg4vH93wj0WtAhafC94fyX1E3Md9yxwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783486994; c=relaxed/simple; bh=0s7BJ+FxK/YFD3+S83bx6PCvXT8fkgxarVDsfVtsuLA=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=DkpLCmv1j9/6hJnolNQI8vZ5/qSVdYUCmVZt6XOKjUaur4f7mRKMnJ/BhcLyLdjHIMeRRb4/ORad9mIHiygurqalpTpWIT1OhRO/vm9dc0ZWbrkAR0Nj5iQl1RGkEnzM4AWepNJrm2MUxvbx7uKzVKw4fQKzHigo+LcyHss8eYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OVV6TEmP; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OVV6TEmP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4005F1F000E9; Wed, 8 Jul 2026 05:03:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783486993; bh=bdKcydcJ5OaDmKzHwgJ7cgxHKCy8madTwla4XzbMNic=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=OVV6TEmPRse02mXvSAngaAIX7CMrX/87CsH1l+vNXtExE9phbGLd2gkb855KK2Kai LPJAtF4qgnQZ+dI03u8PF6JGxP1185W4PpXfTvfCH3/rwbodAxFd00hkJUoekkmNTr CUUpCoOeGboZzrDCur57pvjrmKGQ6IwfA8/H32RAVUZ2NFgqnChmmtd1OPA0AEQQq8 4rbQ+srTmYFfSitNNYDLVsMGmDo8BB7+uGa+PR6hbXJzxKbvRvXiLavXl+AV3ZNIOm U5Q/kKW5dmku6lskF9O1xJnF2QDHGrDJMleAemSIq+I8QbS9AChMDtlqVD9heDhY9T EZfPW9syMcKtg== From: sashiko-bot@kernel.org Subject: Re: [PATCH 2/3] perf build: Apply EXTRA_CXXFLAGS to C++ builds Reply-To: sashiko-reviews@lists.linux.dev To: "Trevor Allison" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20260708045606.43649-3-tallison@redhat.com> References: <20260708045606.43649-1-tallison@redhat.com> <20260708045606.43649-3-tallison@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 08 Jul 2026 05:03:12 +0000 Message-Id: <20260708050313.4005F1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 2 potential issue(= s) to consider: - [Medium] C++ feature detection tests do not receive `EXTRA_CFLAGS`, causi= ng a structural mismatch between feature detection and actual build compila= tion flags. - [Low] Injecting `EXTRA_CFLAGS` into `CXXFLAGS` breaks C++ builds when C-s= pecific flags are present. -- --- Patch [2]: [PATCH 2/3] perf build: Apply EXTRA_CXXFLAGS to C++ builds -= -- commit 4b2b9e4dd8644e0e1fa95ec876a875596e1e9178 Author: Trevor Allison perf build: Apply EXTRA_CXXFLAGS to C++ builds The commit initializes CXXFLAGS in tools/perf/Makefile.config with both EXTRA_CXXFLAGS and EXTRA_CFLAGS so that C++ objects receive the same builder flags as the rest of perf. > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config > index 0ba307e78fe1f..052a6cc7942f9 100644 > --- a/tools/perf/Makefile.config > +++ b/tools/perf/Makefile.config > @@ -17,6 +17,7 @@ detected =3D $(shell echo "$(1)=3Dy" >> $(OUT= PUT).config-detected) > detected_var =3D $(shell echo "$(1)=3D$($(1))" >> $(OUTPUT).config-detec= ted) > =20 > CFLAGS :=3D $(EXTRA_CFLAGS) $(filter-out -Wnested-externs,$(EXTRA_WARNIN= GS)) > +CXXFLAGS :=3D $(EXTRA_CXXFLAGS) $(EXTRA_CFLAGS) [Severity: Low] Could this cause a build regression if EXTRA_CFLAGS contains C-only flags? If EXTRA_CFLAGS contains flags that are only valid for C/ObjC (such as -Wstrict-prototypes), applying them to C++ files causes compiler warnings. With -Werror enabled, this results in a build failure. [Severity: Medium] Does this create a mismatch between feature detection and the main build? While CXXFLAGS here receives EXTRA_CFLAGS, the C++ feature detection tests = in tools/build/Makefile.feature still only use: CXXFLAGS=3D"$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" If EXTRA_CFLAGS contains mandatory compiler flags like --sysroot or -m32, the C++ feature detection tests will fail without EXTRA_CFLAGS. This causes false negatives where the perf binary silently lacks supported features, despite the main build succeeding. > HOSTCFLAGS :=3D $(filter-out -Wnested-externs,$(EXTRA_WARNINGS)) --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260708045606.4364= 9-1-tallison@redhat.com?part=3D2