1*4882a593Smuzhiyun# SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyunifneq ($(O),) 3*4882a593Smuzhiyunifeq ($(origin O), command line) 4*4882a593Smuzhiyun dummy := $(if $(shell cd $(PWD); test -d $(O) || echo $(O)),$(error O=$(O) does not exist),) 5*4882a593Smuzhiyun ABSOLUTE_O := $(shell cd $(PWD); cd $(O) ; pwd) 6*4882a593Smuzhiyun OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/) 7*4882a593Smuzhiyun COMMAND_O := O=$(ABSOLUTE_O) 8*4882a593Smuzhiyunifeq ($(objtree),) 9*4882a593Smuzhiyun objtree := $(O) 10*4882a593Smuzhiyunendif 11*4882a593Smuzhiyunendif 12*4882a593Smuzhiyunendif 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun# check that the output directory actually exists 15*4882a593Smuzhiyunifneq ($(OUTPUT),) 16*4882a593SmuzhiyunOUTDIR := $(shell cd $(OUTPUT) && pwd) 17*4882a593Smuzhiyun$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist)) 18*4882a593Smuzhiyunendif 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun# 21*4882a593Smuzhiyun# Include saner warnings here, which can catch bugs: 22*4882a593Smuzhiyun# 23*4882a593SmuzhiyunEXTRA_WARNINGS := -Wbad-function-cast 24*4882a593SmuzhiyunEXTRA_WARNINGS += -Wdeclaration-after-statement 25*4882a593SmuzhiyunEXTRA_WARNINGS += -Wformat-security 26*4882a593SmuzhiyunEXTRA_WARNINGS += -Wformat-y2k 27*4882a593SmuzhiyunEXTRA_WARNINGS += -Winit-self 28*4882a593SmuzhiyunEXTRA_WARNINGS += -Wmissing-declarations 29*4882a593SmuzhiyunEXTRA_WARNINGS += -Wmissing-prototypes 30*4882a593SmuzhiyunEXTRA_WARNINGS += -Wnested-externs 31*4882a593SmuzhiyunEXTRA_WARNINGS += -Wno-system-headers 32*4882a593SmuzhiyunEXTRA_WARNINGS += -Wold-style-definition 33*4882a593SmuzhiyunEXTRA_WARNINGS += -Wpacked 34*4882a593SmuzhiyunEXTRA_WARNINGS += -Wredundant-decls 35*4882a593SmuzhiyunEXTRA_WARNINGS += -Wstrict-prototypes 36*4882a593SmuzhiyunEXTRA_WARNINGS += -Wswitch-default 37*4882a593SmuzhiyunEXTRA_WARNINGS += -Wswitch-enum 38*4882a593SmuzhiyunEXTRA_WARNINGS += -Wundef 39*4882a593SmuzhiyunEXTRA_WARNINGS += -Wwrite-strings 40*4882a593SmuzhiyunEXTRA_WARNINGS += -Wformat 41*4882a593Smuzhiyun 42*4882a593Smuzhiyun# Makefiles suck: This macro sets a default value of $(2) for the 43*4882a593Smuzhiyun# variable named by $(1), unless the variable has been set by 44*4882a593Smuzhiyun# environment or command line. This is necessary for CC and AR 45*4882a593Smuzhiyun# because make sets default values, so the simpler ?= approach 46*4882a593Smuzhiyun# won't work as expected. 47*4882a593Smuzhiyundefine allow-override 48*4882a593Smuzhiyun $(if $(or $(findstring environment,$(origin $(1))),\ 49*4882a593Smuzhiyun $(findstring command line,$(origin $(1)))),,\ 50*4882a593Smuzhiyun $(eval $(1) = $(2))) 51*4882a593Smuzhiyunendef 52*4882a593Smuzhiyun 53*4882a593Smuzhiyunifneq ($(LLVM),) 54*4882a593Smuzhiyun$(call allow-override,CC,clang) 55*4882a593Smuzhiyun$(call allow-override,AR,llvm-ar) 56*4882a593Smuzhiyun$(call allow-override,LD,ld.lld) 57*4882a593Smuzhiyun$(call allow-override,CXX,clang++) 58*4882a593Smuzhiyun$(call allow-override,STRIP,llvm-strip) 59*4882a593Smuzhiyunelse 60*4882a593Smuzhiyun# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix. 61*4882a593Smuzhiyun$(call allow-override,CC,$(CROSS_COMPILE)gcc) 62*4882a593Smuzhiyun$(call allow-override,AR,$(CROSS_COMPILE)ar) 63*4882a593Smuzhiyun$(call allow-override,LD,$(CROSS_COMPILE)ld) 64*4882a593Smuzhiyun$(call allow-override,CXX,$(CROSS_COMPILE)g++) 65*4882a593Smuzhiyun$(call allow-override,STRIP,$(CROSS_COMPILE)strip) 66*4882a593Smuzhiyunendif 67*4882a593Smuzhiyun 68*4882a593SmuzhiyunCC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?) 69*4882a593Smuzhiyun 70*4882a593Smuzhiyunifneq ($(LLVM),) 71*4882a593SmuzhiyunHOSTAR ?= llvm-ar 72*4882a593SmuzhiyunHOSTCC ?= clang 73*4882a593SmuzhiyunHOSTLD ?= ld.lld 74*4882a593Smuzhiyunelse 75*4882a593SmuzhiyunHOSTAR ?= ar 76*4882a593SmuzhiyunHOSTCC ?= gcc 77*4882a593SmuzhiyunHOSTLD ?= ld 78*4882a593Smuzhiyunendif 79*4882a593Smuzhiyun 80*4882a593Smuzhiyunifeq ($(CC_NO_CLANG), 1) 81*4882a593SmuzhiyunEXTRA_WARNINGS += -Wstrict-aliasing=3 82*4882a593Smuzhiyunendif 83*4882a593Smuzhiyun 84*4882a593Smuzhiyun# Hack to avoid type-punned warnings on old systems such as RHEL5: 85*4882a593Smuzhiyun# We should be changing CFLAGS and checking gcc version, but this 86*4882a593Smuzhiyun# will do for now and keep the above -Wstrict-aliasing=3 in place 87*4882a593Smuzhiyun# in newer systems. 88*4882a593Smuzhiyun# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h 89*4882a593Smuzhiyun# 90*4882a593Smuzhiyun# See https://lkml.org/lkml/2006/11/28/253 and https://gcc.gnu.org/gcc-4.8/changes.html, 91*4882a593Smuzhiyun# that takes into account Linus's comments (search for Wshadow) for the reasoning about 92*4882a593Smuzhiyun# -Wshadow not being interesting before gcc 4.8. 93*4882a593Smuzhiyun 94*4882a593Smuzhiyunifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3 95*4882a593SmuzhiyunEXTRA_WARNINGS += -fno-strict-aliasing 96*4882a593SmuzhiyunEXTRA_WARNINGS += -Wno-shadow 97*4882a593Smuzhiyunelse 98*4882a593SmuzhiyunEXTRA_WARNINGS += -Wshadow 99*4882a593Smuzhiyunendif 100*4882a593Smuzhiyun 101*4882a593Smuzhiyunifneq ($(findstring $(MAKEFLAGS), w),w) 102*4882a593SmuzhiyunPRINT_DIR = --no-print-directory 103*4882a593Smuzhiyunelse 104*4882a593SmuzhiyunNO_SUBDIR = : 105*4882a593Smuzhiyunendif 106*4882a593Smuzhiyun 107*4882a593Smuzhiyunifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) 108*4882a593Smuzhiyun silent=1 109*4882a593Smuzhiyunendif 110*4882a593Smuzhiyun 111*4882a593Smuzhiyun# 112*4882a593Smuzhiyun# Define a callable command for descending to a new directory 113*4882a593Smuzhiyun# 114*4882a593Smuzhiyun# Call by doing: $(call descend,directory[,target]) 115*4882a593Smuzhiyun# 116*4882a593Smuzhiyundescend = \ 117*4882a593Smuzhiyun +mkdir -p $(OUTPUT)$(1) && \ 118*4882a593Smuzhiyun $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2) 119*4882a593Smuzhiyun 120*4882a593SmuzhiyunQUIET_SUBDIR0 = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir 121*4882a593SmuzhiyunQUIET_SUBDIR1 = 122*4882a593Smuzhiyun 123*4882a593Smuzhiyunifneq ($(silent),1) 124*4882a593Smuzhiyun ifneq ($(V),1) 125*4882a593Smuzhiyun QUIET_CC = @echo ' CC '$@; 126*4882a593Smuzhiyun QUIET_CC_FPIC = @echo ' CC FPIC '$@; 127*4882a593Smuzhiyun QUIET_CLANG = @echo ' CLANG '$@; 128*4882a593Smuzhiyun QUIET_AR = @echo ' AR '$@; 129*4882a593Smuzhiyun QUIET_LINK = @echo ' LINK '$@; 130*4882a593Smuzhiyun QUIET_MKDIR = @echo ' MKDIR '$@; 131*4882a593Smuzhiyun QUIET_GEN = @echo ' GEN '$@; 132*4882a593Smuzhiyun QUIET_SUBDIR0 = +@subdir= 133*4882a593Smuzhiyun QUIET_SUBDIR1 = ;$(NO_SUBDIR) \ 134*4882a593Smuzhiyun echo ' SUBDIR '$$subdir; \ 135*4882a593Smuzhiyun $(MAKE) $(PRINT_DIR) -C $$subdir 136*4882a593Smuzhiyun QUIET_FLEX = @echo ' FLEX '$@; 137*4882a593Smuzhiyun QUIET_BISON = @echo ' BISON '$@; 138*4882a593Smuzhiyun 139*4882a593Smuzhiyun descend = \ 140*4882a593Smuzhiyun +@echo ' DESCEND '$(1); \ 141*4882a593Smuzhiyun mkdir -p $(OUTPUT)$(1) && \ 142*4882a593Smuzhiyun $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2) 143*4882a593Smuzhiyun 144*4882a593Smuzhiyun QUIET_CLEAN = @printf ' CLEAN %s\n' $1; 145*4882a593Smuzhiyun QUIET_INSTALL = @printf ' INSTALL %s\n' $1; 146*4882a593Smuzhiyun QUIET_UNINST = @printf ' UNINST %s\n' $1; 147*4882a593Smuzhiyun endif 148*4882a593Smuzhiyunendif 149*4882a593Smuzhiyun 150*4882a593Smuzhiyunpound := \# 151