Received-SPF: pass (google.com: domain of linux-kernel+bounces-145055-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
From: Arnd Bergmann <arnd@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	Nicolas Schier <nicolas@fjasle.eu>,
	Kees Cook <keescook@chromium.org>,
	linux-kbuild@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 1/6] [v3] kbuild: turn on -Wextra by default
Date: Mon, 15 Apr 2024 14:20:32 +0200
Message-Id: <20240415122037.1983124-2-arnd@kernel.org>
In-Reply-To: <20240415122037.1983124-1-arnd@kernel.org>
References: <20240415122037.1983124-1-arnd@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

From: Arnd Bergmann <arnd@arndb.de>

The -Wextra option controls a number of different warnings that differ
slightly by compiler version. Some are useful in general, others are
better left at W=1 or higher. Based on earlier work, the ones that
should be disabled by default are left for the higher warning levels
already, and a lot of the useful ones have no remaining output when
enabled.

Move the -Wextra option up into the set of default-enabled warnings
and just rely on the individual ones getting disabled as needed.

The -Wunused warning was always grouped with this, so turn it on
by default as well, except for the -Wunused-parameter warning that
really has no value at all for the kernel since many interfaces
have intentionally unused arguments.

Acked-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 scripts/Makefile.extrawarn | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index c5af566e911a..c247552c192c 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -82,12 +82,14 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
 # Warn if there is an enum types mismatch
 KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion)
 
+KBUILD_CFLAGS += -Wextra
+KBUILD_CFLAGS += -Wunused
+
 #
 # W=1 - warnings which may be relevant and do not occur too often
 #
 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
 
-KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter
 KBUILD_CFLAGS += $(call cc-option, -Wrestrict)
 KBUILD_CFLAGS += -Wmissing-format-attribute
 KBUILD_CFLAGS += -Wold-style-definition
@@ -190,6 +192,7 @@ else
 
 # The following turn off the warnings enabled by -Wextra
 KBUILD_CFLAGS += -Wno-sign-compare
+KBUILD_CFLAGS += -Wno-unused-parameter
 
 endif
 
-- 
2.39.2