From c9c6837d39311b0cc14cdbe7c18e815ab44aefb1 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 10 May 2016 23:30:01 +0200 Subject: [PATCH] kbuild: move -Wunused-const-variable to W=1 warning level gcc-6 started warning by default about variables that are not used anywhere and that are marked 'const', generating many false positives in an allmodconfig build, e.g.: arch/arm/mach-davinci/board-da830-evm.c:282:20: warning: 'da830_evm_emif25_pins' defined but not used [-Wunused-const-variable=] arch/arm/plat-omap/dmtimer.c:958:34: warning: 'omap_timer_match' defined but not used [-Wunused-const-variable=] drivers/bluetooth/hci_bcm.c:625:39: warning: 'acpi_bcm_default_gpios' defined but not used [-Wunused-const-variable=] drivers/char/hw_random/omap-rng.c:92:18: warning: 'reg_map_omap4' defined but not used [-Wunused-const-variable=] drivers/devfreq/exynos/exynos5_bus.c:381:32: warning: 'exynos5_busfreq_int_pm' defined but not used [-Wunused-const-variable=] drivers/dma/mv_xor.c:1139:34: warning: 'mv_xor_dt_ids' defined but not used [-Wunused-const-variable=] This is similar to the existing -Wunused-but-set-variable warning that was added in an earlier release and that we disable by default now and only enable when W=1 is set, so it makes sense to do the same here. Once we have eliminated the majority of the warnings for both, we can put them back into the default list. We probably want this in backport kernels as well, to allow building them with gcc-6 without introducing extra warnings. Signed-off-by: Arnd Bergmann Acked-by: Olof Johansson Acked-by: Lee Jones Cc: stable@vger.kernel.org Signed-off-by: Michal Marek --- Makefile | 5 +++-- scripts/Makefile.extrawarn | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 51ed29502c5fbe..6698a9a951cdec 100644 --- a/Makefile +++ b/Makefile @@ -705,9 +705,10 @@ KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,) KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior) else -# This warning generated too much noise in a regular build. -# Use make W=1 to enable this warning (see scripts/Makefile.build) +# These warnings generated too much noise in a regular build. +# Use make W=1 to enable them (see scripts/Makefile.build) KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) endif ifdef CONFIG_FRAME_POINTER diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index f9e47a70509c9b..53449a6ff6aa7d 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -24,6 +24,7 @@ warning-1 += $(call cc-option, -Wmissing-prototypes) warning-1 += -Wold-style-definition warning-1 += $(call cc-option, -Wmissing-include-dirs) warning-1 += $(call cc-option, -Wunused-but-set-variable) +warning-1 += $(call cc-option, -Wunused-const-variable) warning-1 += $(call cc-disable-warning, missing-field-initializers) warning-1 += $(call cc-disable-warning, sign-compare)