# SPDX-License-Identifier: GPL-2.0

ifneq ($(O),)

ifeq ($(origin O), command line)

dummy := $(if $(shell test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)

ABSOLUTE_O := $(shell 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 += -Wshadow

EXTRA_WARNINGS += -Wstrict-prototypes

EXTRA_WARNINGS += -Wswitch-default

EXTRA_WARNINGS += -Wswitch-enum

EXTRA_WARNINGS += -Wundef

EXTRA_WARNINGS += -Wwrite-strings

EXTRA_WARNINGS += -Wformat

CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)

ifeq ($(CC_NO_CLANG), 1)

EXTRA_WARNINGS += -Wstrict-aliasing=3

endif

# 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

ifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3

EXTRA_WARNINGS += -fno-strict-aliasing

endif

ifneq ($(findstring $(MAKEFLAGS), w),w)

PRINT_DIR = --no-print-directory

else

NO_SUBDIR = :

endif

ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)

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_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 '$@;

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;

endif

endif