Moving compiler option tests to Kconfig means you need to re-run
Kconfig when you update your compiler. All CC_HAS_... symbols
and other symbols that depend on them must be re-calculated.
It will be nice to detect the compiler update and automatically
invoke silentoldconfig.
This can be done by adding one environment. With this, silentoldconfig
will add something like follows into include/config/auto.conf.cmd:
ifneq "$(CC_VERSION_TEXT)" "gcc (Ubuntu 5.4.0-6ubuntu1~16.04.6) 5.4.0 20160609"
include/config/auto.conf: FORCE
endif
CC_VERSION_TEXT contains the first line of "$(CC) --version". If this text
is changed, silentoldconfig will be invoked.
Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
---
Makefile | 2 ++
init/Kconfig | 9 +++++++++
2 files changed, 11 insertions(+)
diff --git a/Makefile b/Makefile
index 2ee49c9..9afd617 100644
--- a/Makefile
+++ b/Makefile
@@ -441,6 +441,8 @@ export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE
KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
export KBUILD_ARFLAGS
+export CC_VERSION_TEXT := $(shell $(CC) --version | head -n 1)
+
# When compiling out-of-tree modules, put MODVERDIR in the module
# tree rather than in the kernel tree. The kernel tree might
# even be read-only.
diff --git a/init/Kconfig b/init/Kconfig
index e37f4b2..64f9dd2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -16,6 +16,15 @@ config DEFCONFIG_LIST
default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
+# CC_VERSION_TEXT is needed here to invoke Kconfig when compiler is updated
+config CC_VERSION_TEXT
+ string
+ option env="CC_VERSION_TEXT"
+ help
+ This is used to detect if the compiler is changed. If the version
+ text does not match, silentoldconfig will be invoked because we need
+ to re-compute compiler capabilities and symbols that depends on them.
+
config CONSTRUCTORS
bool
depends on !UML
--
2.7.4
