Allow additional arguments be passed to userprogs compilation. Reproducible clang builds need to provide a sysroot and gcc path to ensure same toolchain is used across hosts. KCFLAGS is not currently used for any user programs compilation, so add new USERCFLAGS and USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS. Specifically, I'm trying to force CC_CAN_LINK to consistently fail in an environment where a user sysroot is not specifically available. Currently, Clang might automatically detect GCC installation on hosts which have it installed to a default location in /. With addition of these environment variables, our build environment can do like "--sysroot=/dev/null" to force sysroot detection to fail. Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx> --- Documentation/kbuild/kbuild.rst | 8 ++++++++ Makefile | 9 ++++++--- init/Kconfig | 8 ++++---- usr/include/Makefile | 3 +++ 4 files changed, 21 insertions(+), 7 deletions(-) diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst index 2d1fc03d346e..16e90a3ae01b 100644 --- a/Documentation/kbuild/kbuild.rst +++ b/Documentation/kbuild/kbuild.rst @@ -77,6 +77,14 @@ HOSTLDLIBS ---------- Additional libraries to link against when building host programs. +USERCFLAGS +---------- +Additional options used for $(CC) when compiling userprogs. + +USERLDFLAGS +---------- +Additional options used for $(LD) when linking userprogs. + KBUILD_KCONFIG -------------- Set the top-level Kconfig file to the value of this environment diff --git a/Makefile b/Makefile index 45278d508d81..4a55537c8ca0 100644 --- a/Makefile +++ b/Makefile @@ -431,15 +431,17 @@ HOSTCC = gcc HOSTCXX = g++ endif -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ - -O2 -fomit-frame-pointer -std=gnu89 -export KBUILD_USERLDFLAGS := +KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ + -O2 -fomit-frame-pointer -std=gnu89 +KBUILD_USERLDFLAGS := $(USERLDFLAGGS) KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS) KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) +KBUILD_USERCFLAGS += $(USERCFLAGS) + # Make variables (CC, etc...) CPP = $(CC) -E ifneq ($(LLVM),) @@ -530,6 +532,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE diff --git a/init/Kconfig b/init/Kconfig index f2ae41e6717f..164706c38e8b 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -62,13 +62,13 @@ config LLD_VERSION config CC_CAN_LINK bool - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag)) + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag)) config CC_CAN_LINK_STATIC bool - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static) + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static) config CC_HAS_ASM_GOTO def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC)) diff --git a/usr/include/Makefile b/usr/include/Makefile index 1c2ae1368079..6a8c7dd9ccaf 100644 --- a/usr/include/Makefile +++ b/usr/include/Makefile @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64. UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS)) +# USERCFLAGS might contain sysroot location for CC +UAPI_CFLAGS += $(USERCFLAGS) + override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include # The following are excluded for now because they fail to build. -- 2.25.1
