1ifneq ($(O),) 2ifeq ($(origin O), command line) 3 ABSOLUTE_O := $(realpath $(O)) 4 dummy := $(if $(ABSOLUTE_O),,$(error O=$(O) does not exist)) 5 OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/) 6 COMMAND_O := O=$(ABSOLUTE_O) 7ifeq ($(objtree),) 8 objtree := $(O) 9endif 10endif 11endif 12 13# check that the output directory actually exists 14ifneq ($(OUTPUT),) 15OUTDIR := $(realpath $(OUTPUT)) 16$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist)) 17endif 18 19# 20# Include saner warnings here, which can catch bugs: 21# 22EXTRA_WARNINGS := -Wbad-function-cast 23EXTRA_WARNINGS += -Wdeclaration-after-statement 24EXTRA_WARNINGS += -Wformat-security 25EXTRA_WARNINGS += -Wformat-y2k 26EXTRA_WARNINGS += -Winit-self 27EXTRA_WARNINGS += -Wmissing-declarations 28EXTRA_WARNINGS += -Wmissing-prototypes 29EXTRA_WARNINGS += -Wnested-externs 30EXTRA_WARNINGS += -Wno-system-headers 31EXTRA_WARNINGS += -Wold-style-definition 32EXTRA_WARNINGS += -Wpacked 33EXTRA_WARNINGS += -Wredundant-decls 34EXTRA_WARNINGS += -Wshadow 35EXTRA_WARNINGS += -Wstrict-prototypes 36EXTRA_WARNINGS += -Wswitch-default 37EXTRA_WARNINGS += -Wswitch-enum 38EXTRA_WARNINGS += -Wundef 39EXTRA_WARNINGS += -Wwrite-strings 40EXTRA_WARNINGS += -Wformat 41 42CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?) 43 44ifeq ($(CC_NO_CLANG), 1) 45EXTRA_WARNINGS += -Wstrict-aliasing=3 46endif 47 48# Hack to avoid type-punned warnings on old systems such as RHEL5: 49# We should be changing CFLAGS and checking gcc version, but this 50# will do for now and keep the above -Wstrict-aliasing=3 in place 51# in newer systems. 52# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h 53ifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3 54EXTRA_WARNINGS += -fno-strict-aliasing 55endif 56 57ifneq ($(findstring $(MAKEFLAGS), w),w) 58PRINT_DIR = --no-print-directory 59else 60NO_SUBDIR = : 61endif 62 63ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) 64 silent=1 65endif 66 67# 68# Define a callable command for descending to a new directory 69# 70# Call by doing: $(call descend,directory[,target]) 71# 72descend = \ 73 +mkdir -p $(OUTPUT)$(1) && \ 74 $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2) 75 76QUIET_SUBDIR0 = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir 77QUIET_SUBDIR1 = 78 79ifneq ($(silent),1) 80 ifneq ($(V),1) 81 QUIET_CC = @echo ' CC '$@; 82 QUIET_CC_FPIC = @echo ' CC FPIC '$@; 83 QUIET_AR = @echo ' AR '$@; 84 QUIET_LINK = @echo ' LINK '$@; 85 QUIET_MKDIR = @echo ' MKDIR '$@; 86 QUIET_GEN = @echo ' GEN '$@; 87 QUIET_SUBDIR0 = +@subdir= 88 QUIET_SUBDIR1 = ;$(NO_SUBDIR) \ 89 echo ' SUBDIR '$$subdir; \ 90 $(MAKE) $(PRINT_DIR) -C $$subdir 91 QUIET_FLEX = @echo ' FLEX '$@; 92 QUIET_BISON = @echo ' BISON '$@; 93 94 descend = \ 95 +@echo ' DESCEND '$(1); \ 96 mkdir -p $(OUTPUT)$(1) && \ 97 $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2) 98 99 QUIET_CLEAN = @printf ' CLEAN %s\n' $1; 100 QUIET_INSTALL = @printf ' INSTALL %s\n' $1; 101 endif 102endif 103