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From:   Nathan Chancellor <nathan@kernel.org>
To:     Masahiro Yamada <masahiroy@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>
Cc:     linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        clang-built-linux@googlegroups.com,
        Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH 2/3] kbuild: Add a comment above -Wno-gnu
Date:   Mon, 16 Aug 2021 13:20:55 -0700
Message-Id: <20210816202056.4586-2-nathan@kernel.org>
In-Reply-To: <20210816202056.4586-1-nathan@kernel.org>
References: <20210816202056.4586-1-nathan@kernel.org>
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Whenever a warning is disabled, it is helpful for future travelers to
understand why the warning is disabled and why it is acceptable to do
so. Add a comment for -Wno-gnu so that people understand why it is
disabled.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index 3900f5824721..07b76274396e 100644
--- a/Makefile
+++ b/Makefile
@@ -777,6 +777,7 @@ KBUILD_CFLAGS += $(stackp-flags-y)
 
 ifdef CONFIG_CC_IS_CLANG
 KBUILD_CPPFLAGS += -Qunused-arguments
+# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
 KBUILD_CFLAGS += -Wno-gnu
 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
-- 
2.33.0.rc2