kbuild: Drop superfluous compiler option checks

Many of the compiler option checks are not necessary anymore with the
current supported versions of compilers (clang 15+, GCC 8.1+).

Remove them.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260113-kbuild-cc-option-v1-1-011314a0f7f1@weissschuh.net
[nathan: Add minor note about currently supported compilers]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

diff --git a/Makefile b/Makefile
index ad91e6a936aa082dc5b0d0d1506070d2360cfc69..362df202fb8a885fc04d93e363e65819c2c3cdfc 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1102,7 +1102,7 @@ KBUILD_CFLAGS += -fno-builtin-wcslen
 
 # change __FILE__ to the relative path to the source directory
 ifdef building_out_of_srctree
-KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=)
+KBUILD_CPPFLAGS += -fmacro-prefix-map=$(srcroot)/=
 endif
 
 # include additional Makefiles when needed

diff --git a/scripts/Makefile.warn b/scripts/Makefile.warn
index c593ab1257de07d72562682cc1c4b0e59f8b1fb6..5567da6c7dfed072a316d315fb550a104a071b38 100644 (file)
--- a/scripts/Makefile.warn
+++ b/scripts/Makefile.warn
@@ -16,7 +16,7 @@ KBUILD_CFLAGS += -Werror=return-type
 KBUILD_CFLAGS += -Werror=strict-prototypes
 KBUILD_CFLAGS += -Wno-format-security
 KBUILD_CFLAGS += -Wno-trigraphs
-KBUILD_CFLAGS += $(call cc-option, -Wno-frame-address)
+KBUILD_CFLAGS += -Wno-frame-address
 KBUILD_CFLAGS += $(call cc-option, -Wno-address-of-packed-member)
 KBUILD_CFLAGS += -Wmissing-declarations
 KBUILD_CFLAGS += -Wmissing-prototypes
@@ -75,7 +75,7 @@ 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)
+KBUILD_CFLAGS += -Wcast-function-type
 
 # Currently, disable -Wstringop-overflow for GCC 11, globally.
 KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
@@ -102,7 +102,7 @@ KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
 KBUILD_CFLAGS += -Werror=date-time
 
 # enforce correct pointer usage
-KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
+KBUILD_CFLAGS += -Werror=incompatible-pointer-types
 
 # Require designated initializers for all marked structures
 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
@@ -119,7 +119,7 @@ ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
 
 KBUILD_CFLAGS += -Wmissing-format-attribute
 KBUILD_CFLAGS += -Wmissing-include-dirs
-KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
+KBUILD_CFLAGS += -Wunused-const-variable
 
 KBUILD_CPPFLAGS += -Wundef
 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
@@ -128,12 +128,12 @@ else
 
 # Some diagnostics enabled by default are noisy.
 # Suppress them by using -Wno... except for W=1.
-KBUILD_CFLAGS += $(call cc-option, -Wno-unused-but-set-variable)
-KBUILD_CFLAGS += $(call cc-option, -Wno-unused-const-variable)
+KBUILD_CFLAGS += -Wno-unused-but-set-variable
+KBUILD_CFLAGS += -Wno-unused-const-variable
 KBUILD_CFLAGS += $(call cc-option, -Wno-packed-not-aligned)
 KBUILD_CFLAGS += $(call cc-option, -Wno-format-overflow)
 ifdef CONFIG_CC_IS_GCC
-KBUILD_CFLAGS += $(call cc-option, -Wno-format-truncation)
+KBUILD_CFLAGS += -Wno-format-truncation
 endif
 KBUILD_CFLAGS += $(call cc-option, -Wno-stringop-truncation)
 
@@ -148,14 +148,11 @@ KBUILD_CFLAGS += -Wno-format
 # 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-option, -Wno-pointer-to-enum-cast)
+KBUILD_CFLAGS += -Wno-pointer-to-enum-cast
 KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
-KBUILD_CFLAGS += $(call cc-option, -Wno-unaligned-access)
+KBUILD_CFLAGS += -Wno-unaligned-access
 KBUILD_CFLAGS += -Wno-enum-compare-conditional
 endif
 
@@ -169,7 +166,7 @@ ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
 KBUILD_CFLAGS += -Wdisabled-optimization
 KBUILD_CFLAGS += -Wshadow
 KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
-KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
+KBUILD_CFLAGS += -Wunused-macros
 
 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2