diff options
Diffstat (limited to 'scripts/Makefile.extrawarn')
| -rw-r--r-- | scripts/Makefile.extrawarn | 245 |
1 files changed, 187 insertions, 58 deletions
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 3ab8d1a303cd..a9e552a1e910 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -1,77 +1,206 @@ # SPDX-License-Identifier: GPL-2.0 # ========================================================================== -# # make W=... settings # -# W=1 - warnings that may be relevant and does not occur too often -# W=2 - warnings that occur quite often but may still be relevant -# W=3 - the more obscure warnings, can most likely be ignored -# -# $(call cc-option, -W...) handles gcc -W.. options which -# are not supported by all versions of the compiler +# There are four warning groups enabled by W=1, W=2, W=3, and W=e +# They are independent, and can be combined like W=12 or W=123e. # ========================================================================== +# Default set of warnings, always enabled +KBUILD_CFLAGS += -Wall +KBUILD_CFLAGS += -Wundef +KBUILD_CFLAGS += -Werror=implicit-function-declaration +KBUILD_CFLAGS += -Werror=implicit-int +KBUILD_CFLAGS += -Werror=return-type +KBUILD_CFLAGS += -Werror=strict-prototypes +KBUILD_CFLAGS += -Wno-format-security +KBUILD_CFLAGS += -Wno-trigraphs +KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) +KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) +KBUILD_CFLAGS += -Wmissing-declarations +KBUILD_CFLAGS += -Wmissing-prototypes + +ifneq ($(CONFIG_FRAME_WARN),0) +KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN) +endif + +KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror +KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y) +KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds + +ifdef CONFIG_CC_IS_CLANG +# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable. +KBUILD_CFLAGS += -Wno-gnu +else + +# gcc inanely warns about local variables called 'main' +KBUILD_CFLAGS += -Wno-main +endif + +# These warnings generated too much noise in a regular build. +# Use make W=1 to enable them (see scripts/Makefile.extrawarn) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) + +# These result in bogus false positives +KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer) + +# Variable Length Arrays (VLAs) should not be used anywhere in the kernel +KBUILD_CFLAGS += -Wvla + +# disable pointer signed / unsigned warnings in gcc 4.0 +KBUILD_CFLAGS += -Wno-pointer-sign + +# In order to make sure new function cast mismatches are not introduced +# in the kernel (to avoid tripping CFI checking), the kernel should be +# globally built with -Wcast-function-type. +KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type) + +# The allocators already balk at large sizes, so silence the compiler +# warnings for bounds checks involving those possible values. While +# -Wno-alloc-size-larger-than would normally be used here, earlier versions +# of gcc (<9.1) weirdly don't handle the option correctly when _other_ +# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX +# doesn't work (as it is documented to), silently resolving to "0" prior to +# version 9.1 (and producing an error more recently). Numeric values larger +# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently +# ignored, continuing to default to PTRDIFF_MAX. So, left with no other +# choice, we must perform a versioned check to disable this warning. +# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au +KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than +KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) + +# Prohibit date/time macros, which would make the build non-deterministic +KBUILD_CFLAGS += -Werror=date-time + +# enforce correct pointer usage +KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types) + +# Require designated initializers for all marked structures +KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) + +# Warn if there is an enum types mismatch +KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion) + +# +# W=1 - warnings which may be relevant and do not occur too often +# +ifneq ($(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 +KBUILD_CFLAGS += -Wmissing-include-dirs +KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable) +KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable) +KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned) +KBUILD_CFLAGS += $(call cc-option, -Wformat-overflow) +KBUILD_CFLAGS += $(call cc-option, -Wformat-truncation) +KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) + +KBUILD_CPPFLAGS += -Wundef +KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 + +else + +# Some diagnostics enabled by default are noisy. +# Suppress them by using -Wno... except for W=1. +KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) +KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) +KBUILD_CFLAGS += $(call cc-disable-warning, restrict) KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) +KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) +KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) +KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation) -ifeq ("$(origin W)", "command line") - export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W) +ifdef CONFIG_CC_IS_CLANG +# Clang before clang-16 would warn on default argument promotions. +ifneq ($(call clang-min-version, 160000),y) +# Disable -Wformat +KBUILD_CFLAGS += -Wno-format +# Then re-enable flags that were part of the -Wformat group that aren't +# problematic. +KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier +KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull +# Requires clang-12+. +ifeq ($(call clang-min-version, 120000),y) +KBUILD_CFLAGS += -Wformat-insufficient-args +endif +endif +KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) +KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare +KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) +KBUILD_CFLAGS += $(call cc-disable-warning, cast-function-type-strict) endif -ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS -warning- := $(empty) - -warning-1 := -Wextra -Wunused -Wno-unused-parameter -warning-1 += -Wmissing-declarations -warning-1 += -Wmissing-format-attribute -warning-1 += -Wmissing-prototypes -warning-1 += -Wold-style-definition -warning-1 += -Wmissing-include-dirs -warning-1 += $(call cc-option, -Wunused-but-set-variable) -warning-1 += $(call cc-option, -Wunused-const-variable) -warning-1 += $(call cc-option, -Wpacked-not-aligned) -warning-1 += $(call cc-option, -Wstringop-truncation) -# The following turn off the warnings enabled by -Wextra -warning-1 += -Wno-missing-field-initializers -warning-1 += -Wno-sign-compare - -warning-2 := -Waggregate-return -warning-2 += -Wcast-align -warning-2 += -Wdisabled-optimization -warning-2 += -Wnested-externs -warning-2 += -Wshadow -warning-2 += $(call cc-option, -Wlogical-op) -warning-2 += -Wmissing-field-initializers -warning-2 += -Wsign-compare -warning-2 += $(call cc-option, -Wmaybe-uninitialized) -warning-2 += $(call cc-option, -Wunused-macros) - -warning-3 := -Wbad-function-cast -warning-3 += -Wcast-qual -warning-3 += -Wconversion -warning-3 += -Wpacked -warning-3 += -Wpadded -warning-3 += -Wpointer-arith -warning-3 += -Wredundant-decls -warning-3 += -Wswitch-default -warning-3 += $(call cc-option, -Wpacked-bitfield-compat) - -warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) -warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) -warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) - -ifeq ("$(strip $(warning))","") - $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown) endif -KBUILD_CFLAGS += $(warning) +# +# W=2 - warnings which occur quite often but may still be relevant +# +ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Wdisabled-optimization +KBUILD_CFLAGS += -Wshadow +KBUILD_CFLAGS += $(call cc-option, -Wlogical-op) +KBUILD_CFLAGS += -Wmissing-field-initializers +KBUILD_CFLAGS += -Wtype-limits +KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized) +KBUILD_CFLAGS += $(call cc-option, -Wunused-macros) + +ifdef CONFIG_CC_IS_CLANG +KBUILD_CFLAGS += -Winitializer-overrides +endif + +KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2 + else +# The following turn off the warnings enabled by -Wextra +KBUILD_CFLAGS += -Wno-missing-field-initializers +KBUILD_CFLAGS += -Wno-type-limits +KBUILD_CFLAGS += -Wno-shift-negative-value + ifdef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += -Wno-initializer-overrides -KBUILD_CFLAGS += -Wno-unused-value -KBUILD_CFLAGS += -Wno-format +else +KBUILD_CFLAGS += -Wno-maybe-uninitialized +endif + +endif + +# +# W=3 - more obscure warnings, can most likely be ignored +# +ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Wbad-function-cast +KBUILD_CFLAGS += -Wcast-align +KBUILD_CFLAGS += -Wcast-qual +KBUILD_CFLAGS += -Wconversion +KBUILD_CFLAGS += -Wpacked +KBUILD_CFLAGS += -Wpadded +KBUILD_CFLAGS += -Wpointer-arith +KBUILD_CFLAGS += -Wredundant-decls +KBUILD_CFLAGS += -Wsign-compare +KBUILD_CFLAGS += -Wswitch-default +KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat) + +KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 + +else + +# The following turn off the warnings enabled by -Wextra KBUILD_CFLAGS += -Wno-sign-compare -KBUILD_CFLAGS += -Wno-format-zero-length -KBUILD_CFLAGS += -Wno-uninitialized + endif + +# +# W=e - error out on warnings +# +ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Werror + endif |