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From:   Masahiro Yamada <yamada.masahiro@socionext.com>
To:     linux-kbuild@vger.kernel.org
Cc:     Sam Ravnborg <sam@ravnborg.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Ulf Magnusson <ulfalizer@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        "Luis R . Rodriguez" <mcgrof@kernel.org>,
        Nicolas Pitre <nico@linaro.org>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 10/21] kconfig: add 'success' and 'cc-option' macros
Date:   Tue, 27 Mar 2018 14:29:24 +0900
Message-Id: <1522128575-5326-11-git-send-email-yamada.masahiro@socionext.com>
In-Reply-To: <1522128575-5326-1-git-send-email-yamada.masahiro@socionext.com>
References: <1522128575-5326-1-git-send-email-yamada.masahiro@socionext.com>
Sender: linux-kernel-owner@vger.kernel.org
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'cc-option' will be the most frequently used macro.  It evaluates to 'y'
if the given argument is supported by the compiler, or 'n' otherwise.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v2:
  - Implement 'success' as a macro

 init/Kconfig | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/init/Kconfig b/init/Kconfig
index 0d6fe20..c456030 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -8,6 +8,12 @@ config DEFCONFIG_LIST
 	default ARCH_DEFCONFIG
 	default "arch/$ARCH/defconfig"
 
+# expanded to y if the command exits with 0, n otherwise
+macro success $(shell ($(1) && echo y) || echo n)
+
+# expanded to y if the given compiler flag is supported, n otherwise
+macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null)
+
 config CONSTRUCTORS
 	bool
 	depends on !UML
-- 
2.7.4