CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning, because that causes a ridiculous amount of false positives when combined with -Os.
This means a lot of warnings don't show up in testing by the developers that should see them with an 'allmodconfig' kernel that has CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds that don't. This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE that gets added for this purpose. The allmodconfig and allyesconfig kernels now default to -O2 with the maybe-unused warning enabled. Signed-off-by: Arnd Bergmann <[email protected]> --- init/Kconfig | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/init/Kconfig b/init/Kconfig index 651ec15ecddb..159a542ef3fc 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1305,6 +1305,17 @@ source "usr/Kconfig" endif +choice + prompt "Compiler optimization level" + default CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE + +config CC_OPTIMIZE_FOR_PERFORMANCE + bool "Optimize for performance" + help + This is the default optimization level for the kernel, building + with the "-O2" compiler flag for best performance and most + helpful compile-time warnings. + config CC_OPTIMIZE_FOR_SIZE bool "Optimize for size" help @@ -1313,6 +1324,8 @@ config CC_OPTIMIZE_FOR_SIZE If unsure, say N. +endchoice + config SYSCTL bool -- 2.7.0
