linux/arch/um/Makefile
David Gow 6580c5c18f um: clang: Strip out -mno-global-merge from USER_CFLAGS
The things built with USER_CFLAGS don't seem to recognise it as a
compiler option, and print a warning:
clang: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument]

Fixes: 744814d2fa ("um: Allow builds with Clang")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-03-11 10:51:41 +01:00

154 lines
4.8 KiB
Makefile

#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies.
#
# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
# Licensed under the GPL
#
# select defconfig based on actual architecture
ifeq ($(SUBARCH),x86)
ifeq ($(shell uname -m),x86_64)
KBUILD_DEFCONFIG := x86_64_defconfig
else
KBUILD_DEFCONFIG := i386_defconfig
endif
else
KBUILD_DEFCONFIG := $(SUBARCH)_defconfig
endif
ARCH_DIR := arch/um
OS := $(shell uname -s)
# We require bash because the vmlinux link and loader script cpp use bash
# features.
SHELL := /bin/bash
core-y += $(ARCH_DIR)/kernel/ \
$(ARCH_DIR)/drivers/ \
$(ARCH_DIR)/os-$(OS)/
MODE_INCLUDE += -I$(srctree)/$(ARCH_DIR)/include/shared/skas
HEADER_ARCH := $(SUBARCH)
ifneq ($(filter $(SUBARCH),x86 x86_64 i386),)
HEADER_ARCH := x86
endif
ifdef CONFIG_64BIT
KBUILD_CFLAGS += -mcmodel=large
endif
HOST_DIR := arch/$(HEADER_ARCH)
include $(srctree)/$(ARCH_DIR)/Makefile-skas
include $(srctree)/$(HOST_DIR)/Makefile.um
core-y += $(HOST_DIR)/um/
SHARED_HEADERS := $(ARCH_DIR)/include/shared
ARCH_INCLUDE := -I$(srctree)/$(SHARED_HEADERS)
ARCH_INCLUDE += -I$(srctree)/$(HOST_DIR)/um/shared
KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/um
# -Dvmap=kernel_vmap prevents anything from referencing the libpcap.o symbol so
# named - it's a common symbol in libpcap, so we get a binary which crashes.
#
# Same things for in6addr_loopback and mktime - found in libc. For these two we
# only get link-time error, luckily.
#
# -Dlongjmp=kernel_longjmp prevents anything from referencing the libpthread.a
# embedded copy of longjmp, same thing for setjmp.
#
# These apply to USER_CFLAGS to.
KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \
$(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap \
-Dlongjmp=kernel_longjmp -Dsetjmp=kernel_setjmp \
-Din6addr_loopback=kernel_in6addr_loopback \
-Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr
KBUILD_AFLAGS += $(ARCH_INCLUDE)
USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
$(ARCH_INCLUDE) $(MODE_INCLUDE) $(filter -I%,$(CFLAGS)) \
-D_FILE_OFFSET_BITS=64 -idirafter $(srctree)/include \
-idirafter $(objtree)/include -D__KERNEL__ -D__UM_HOST__
ifdef CONFIG_CC_IS_CLANG
USER_CFLAGS := $(patsubst -mno-global-merge,,$(USER_CFLAGS))
endif
#This will adjust *FLAGS accordingly to the platform.
include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/include \
-I$(srctree)/$(HOST_DIR)/include/uapi \
-I$(objtree)/$(HOST_DIR)/include/generated \
-I$(objtree)/$(HOST_DIR)/include/generated/uapi
# -Derrno=kernel_errno - This turns all kernel references to errno into
# kernel_errno to separate them from the libc errno. This allows -fno-common
# in KBUILD_CFLAGS. Otherwise, it would cause ld to complain about the two different
# errnos.
# These apply to kernelspace only.
#
# strip leading and trailing whitespace to make the USER_CFLAGS removal of these
# defines more robust
KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
-Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
KBUILD_CFLAGS += $(KERNEL_DEFINES)
PHONY += linux
all: linux
linux: vmlinux
@echo ' LINK $@'
$(Q)ln -f $< $@
define archhelp
echo '* linux - Binary kernel image (./linux) - for backward'
echo ' compatibility only, this creates a hard link to the'
echo ' real kernel binary, the "vmlinux" binary you'
echo ' find in the kernel root.'
endef
archheaders:
$(Q)$(MAKE) -f $(srctree)/Makefile ARCH=$(HEADER_ARCH) asm-generic archheaders
archprepare:
$(Q)$(MAKE) $(build)=$(HOST_DIR)/um include/generated/user_constants.h
LINK-$(CONFIG_LD_SCRIPT_STATIC) += -static
LINK-$(CONFIG_LD_SCRIPT_DYN) += $(call cc-option, -no-pie)
LINK-$(CONFIG_LD_SCRIPT_DYN_RPATH) += -Wl,-rpath,/lib
CFLAGS_NO_HARDENING := $(call cc-option, -fno-PIC,) $(call cc-option, -fno-pic,) \
-fno-stack-protector $(call cc-option, -fno-stack-protector-all)
# Options used by linker script
export LDS_START := $(START)
export LDS_ELF_ARCH := $(ELF_ARCH)
export LDS_ELF_FORMAT := $(ELF_FORMAT)
# The wrappers will select whether using "malloc" or the kernel allocator.
LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
LD_FLAGS_CMDLINE = $(foreach opt,$(KBUILD_LDFLAGS),-Wl,$(opt))
# Used by link-vmlinux.sh which has special support for um link
export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE)
# When cleaning we don't include .config, so we don't include
# TT or skas makefiles and don't clean skas_ptregs.h.
CLEAN_FILES += linux x.i gmon.out
MRPROPER_FILES += arch/$(SUBARCH)/include/generated
archclean:
@find . \( -name '*.bb' -o -name '*.bbg' -o -name '*.da' \
-o -name '*.gcov' \) -type f -print | xargs rm -f
export HEADER_ARCH SUBARCH USER_CFLAGS CFLAGS_NO_HARDENING OS DEV_NULL_PATH