mirror of
https://github.com/torvalds/linux.git
synced 2024-11-01 13:03:25 +01:00
c2bd08ba20
In Makefiles, $(error ), $(warning ), and $(info ) expand to the empty string, as explained in the GNU Make manual [1]: "The result of the expansion of this function is the empty string." Therefore, they are no-op except for logging purposes. $(shell ...) expands to the output of the command. It expands to the empty string when the command does not print anything to stdout. Hence, $(shell mkdir ...) is no-op except for creating the directory. Remove meaningless assignments. [1]: https://www.gnu.org/software/make/manual/make.html#Make-Control-Functions Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com> Reviewed-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20240221134201.2656908-1-masahiroy@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-perf-users@vger.kernel.org
191 lines
6.1 KiB
Text
191 lines
6.1 KiB
Text
# SPDX-License-Identifier: GPL-2.0
|
|
ifneq ($(O),)
|
|
ifeq ($(origin O), command line)
|
|
$(if $(shell cd $(PWD); test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
|
|
ABSOLUTE_O := $(shell cd $(PWD); cd $(O) ; pwd)
|
|
OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
|
|
COMMAND_O := O=$(ABSOLUTE_O)
|
|
ifeq ($(objtree),)
|
|
objtree := $(O)
|
|
endif
|
|
endif
|
|
endif
|
|
|
|
# check that the output directory actually exists
|
|
ifneq ($(OUTPUT),)
|
|
OUTDIR := $(shell cd $(OUTPUT) && pwd)
|
|
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
|
|
endif
|
|
|
|
#
|
|
# Include saner warnings here, which can catch bugs:
|
|
#
|
|
EXTRA_WARNINGS := -Wbad-function-cast
|
|
EXTRA_WARNINGS += -Wdeclaration-after-statement
|
|
EXTRA_WARNINGS += -Wformat-security
|
|
EXTRA_WARNINGS += -Wformat-y2k
|
|
EXTRA_WARNINGS += -Winit-self
|
|
EXTRA_WARNINGS += -Wmissing-declarations
|
|
EXTRA_WARNINGS += -Wmissing-prototypes
|
|
EXTRA_WARNINGS += -Wnested-externs
|
|
EXTRA_WARNINGS += -Wno-system-headers
|
|
EXTRA_WARNINGS += -Wold-style-definition
|
|
EXTRA_WARNINGS += -Wpacked
|
|
EXTRA_WARNINGS += -Wredundant-decls
|
|
EXTRA_WARNINGS += -Wstrict-prototypes
|
|
EXTRA_WARNINGS += -Wswitch-default
|
|
EXTRA_WARNINGS += -Wswitch-enum
|
|
EXTRA_WARNINGS += -Wundef
|
|
EXTRA_WARNINGS += -Wwrite-strings
|
|
EXTRA_WARNINGS += -Wformat
|
|
EXTRA_WARNINGS += -Wno-type-limits
|
|
|
|
# Makefiles suck: This macro sets a default value of $(2) for the
|
|
# variable named by $(1), unless the variable has been set by
|
|
# environment or command line. This is necessary for CC and AR
|
|
# because make sets default values, so the simpler ?= approach
|
|
# won't work as expected.
|
|
define allow-override
|
|
$(if $(or $(findstring environment,$(origin $(1))),\
|
|
$(findstring command line,$(origin $(1)))),,\
|
|
$(eval $(1) = $(2)))
|
|
endef
|
|
|
|
ifneq ($(LLVM),)
|
|
ifneq ($(filter %/,$(LLVM)),)
|
|
LLVM_PREFIX := $(LLVM)
|
|
else ifneq ($(filter -%,$(LLVM)),)
|
|
LLVM_SUFFIX := $(LLVM)
|
|
endif
|
|
|
|
$(call allow-override,CC,$(LLVM_PREFIX)clang$(LLVM_SUFFIX))
|
|
$(call allow-override,AR,$(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX))
|
|
$(call allow-override,LD,$(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX))
|
|
$(call allow-override,CXX,$(LLVM_PREFIX)clang++$(LLVM_SUFFIX))
|
|
$(call allow-override,STRIP,$(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX))
|
|
else
|
|
# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix.
|
|
$(call allow-override,CC,$(CROSS_COMPILE)gcc)
|
|
$(call allow-override,AR,$(CROSS_COMPILE)ar)
|
|
$(call allow-override,LD,$(CROSS_COMPILE)ld)
|
|
$(call allow-override,CXX,$(CROSS_COMPILE)g++)
|
|
$(call allow-override,STRIP,$(CROSS_COMPILE)strip)
|
|
endif
|
|
|
|
CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)
|
|
|
|
ifneq ($(LLVM),)
|
|
HOSTAR ?= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
|
|
HOSTCC ?= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
|
|
HOSTLD ?= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
|
|
else
|
|
HOSTAR ?= ar
|
|
HOSTCC ?= gcc
|
|
HOSTLD ?= ld
|
|
endif
|
|
|
|
# Some tools require Clang, LLC and/or LLVM utils
|
|
CLANG ?= clang
|
|
LLC ?= llc
|
|
LLVM_CONFIG ?= llvm-config
|
|
LLVM_OBJCOPY ?= llvm-objcopy
|
|
LLVM_STRIP ?= llvm-strip
|
|
|
|
ifeq ($(CC_NO_CLANG), 1)
|
|
EXTRA_WARNINGS += -Wstrict-aliasing=3
|
|
|
|
else ifneq ($(CROSS_COMPILE),)
|
|
# Allow userspace to override CLANG_CROSS_FLAGS to specify their own
|
|
# sysroots and flags or to avoid the GCC call in pure Clang builds.
|
|
ifeq ($(CLANG_CROSS_FLAGS),)
|
|
CLANG_CROSS_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
|
|
GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)gcc 2>/dev/null))
|
|
ifneq ($(GCC_TOOLCHAIN_DIR),)
|
|
CLANG_CROSS_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
|
|
CLANG_CROSS_FLAGS += --sysroot=$(shell $(CROSS_COMPILE)gcc -print-sysroot)
|
|
CLANG_CROSS_FLAGS += --gcc-toolchain=$(realpath $(GCC_TOOLCHAIN_DIR)/..)
|
|
endif # GCC_TOOLCHAIN_DIR
|
|
endif # CLANG_CROSS_FLAGS
|
|
CFLAGS += $(CLANG_CROSS_FLAGS)
|
|
AFLAGS += $(CLANG_CROSS_FLAGS)
|
|
else
|
|
CLANG_CROSS_FLAGS :=
|
|
endif # CROSS_COMPILE
|
|
|
|
# Hack to avoid type-punned warnings on old systems such as RHEL5:
|
|
# We should be changing CFLAGS and checking gcc version, but this
|
|
# will do for now and keep the above -Wstrict-aliasing=3 in place
|
|
# in newer systems.
|
|
# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h
|
|
#
|
|
# See https://lore.kernel.org/lkml/9a8748490611281710g78402fbeh8ff7fcc162dbcbca@mail.gmail.com/
|
|
# and https://gcc.gnu.org/gcc-4.8/changes.html,
|
|
# that takes into account Linus's comments (search for Wshadow) for the reasoning about
|
|
# -Wshadow not being interesting before gcc 4.8.
|
|
|
|
ifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3
|
|
EXTRA_WARNINGS += -fno-strict-aliasing
|
|
EXTRA_WARNINGS += -Wno-shadow
|
|
else
|
|
EXTRA_WARNINGS += -Wshadow
|
|
endif
|
|
|
|
ifneq ($(findstring $(MAKEFLAGS), w),w)
|
|
PRINT_DIR = --no-print-directory
|
|
else
|
|
NO_SUBDIR = :
|
|
endif
|
|
|
|
# If the user is running make -s (silent mode), suppress echoing of commands
|
|
# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
|
|
ifeq ($(filter 3.%,$(MAKE_VERSION)),)
|
|
short-opts := $(firstword -$(MAKEFLAGS))
|
|
else
|
|
short-opts := $(filter-out --%,$(MAKEFLAGS))
|
|
endif
|
|
|
|
ifneq ($(findstring s,$(short-opts)),)
|
|
silent=1
|
|
endif
|
|
|
|
#
|
|
# Define a callable command for descending to a new directory
|
|
#
|
|
# Call by doing: $(call descend,directory[,target])
|
|
#
|
|
descend = \
|
|
+mkdir -p $(OUTPUT)$(1) && \
|
|
$(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
|
|
|
|
QUIET_SUBDIR0 = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir
|
|
QUIET_SUBDIR1 =
|
|
|
|
ifneq ($(silent),1)
|
|
ifneq ($(V),1)
|
|
QUIET_CC = @echo ' CC '$@;
|
|
QUIET_CC_FPIC = @echo ' CC FPIC '$@;
|
|
QUIET_CLANG = @echo ' CLANG '$@;
|
|
QUIET_AR = @echo ' AR '$@;
|
|
QUIET_LINK = @echo ' LINK '$@;
|
|
QUIET_MKDIR = @echo ' MKDIR '$@;
|
|
QUIET_GEN = @echo ' GEN '$@;
|
|
QUIET_SUBDIR0 = +@subdir=
|
|
QUIET_SUBDIR1 = ;$(NO_SUBDIR) \
|
|
echo ' SUBDIR '$$subdir; \
|
|
$(MAKE) $(PRINT_DIR) -C $$subdir
|
|
QUIET_FLEX = @echo ' FLEX '$@;
|
|
QUIET_BISON = @echo ' BISON '$@;
|
|
QUIET_GENSKEL = @echo ' GENSKEL '$@;
|
|
|
|
descend = \
|
|
+@echo ' DESCEND '$(1); \
|
|
mkdir -p $(OUTPUT)$(1) && \
|
|
$(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
|
|
|
|
QUIET_CLEAN = @printf ' CLEAN %s\n' $1;
|
|
QUIET_INSTALL = @printf ' INSTALL %s\n' $1;
|
|
QUIET_UNINST = @printf ' UNINST %s\n' $1;
|
|
endif
|
|
endif
|
|
|
|
pound := \#
|