xref: /linux/tools/scripts/Makefile.include (revision a4eb44a6435d6d8f9e642407a4a06f65eb90ca04) 
1# SPDX-License-Identifier: GPL-2.0
2ifneq ($(O),)
3ifeq ($(origin O), command line)
4	dummy := $(if $(shell cd $(PWD); test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
5	ABSOLUTE_O := $(shell cd $(PWD); cd $(O) ; pwd)
6	OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
7	COMMAND_O := O=$(ABSOLUTE_O)
8ifeq ($(objtree),)
9	objtree := $(O)
10endif
11endif
12endif
13
14# check that the output directory actually exists
15ifneq ($(OUTPUT),)
16OUTDIR := $(shell cd $(OUTPUT) && pwd)
17$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
18endif
19
20#
21# Include saner warnings here, which can catch bugs:
22#
23EXTRA_WARNINGS := -Wbad-function-cast
24EXTRA_WARNINGS += -Wdeclaration-after-statement
25EXTRA_WARNINGS += -Wformat-security
26EXTRA_WARNINGS += -Wformat-y2k
27EXTRA_WARNINGS += -Winit-self
28EXTRA_WARNINGS += -Wmissing-declarations
29EXTRA_WARNINGS += -Wmissing-prototypes
30EXTRA_WARNINGS += -Wnested-externs
31EXTRA_WARNINGS += -Wno-system-headers
32EXTRA_WARNINGS += -Wold-style-definition
33EXTRA_WARNINGS += -Wpacked
34EXTRA_WARNINGS += -Wredundant-decls
35EXTRA_WARNINGS += -Wstrict-prototypes
36EXTRA_WARNINGS += -Wswitch-default
37EXTRA_WARNINGS += -Wswitch-enum
38EXTRA_WARNINGS += -Wundef
39EXTRA_WARNINGS += -Wwrite-strings
40EXTRA_WARNINGS += -Wformat
41EXTRA_WARNINGS += -Wno-type-limits
42
43# Makefiles suck: This macro sets a default value of $(2) for the
44# variable named by $(1), unless the variable has been set by
45# environment or command line. This is necessary for CC and AR
46# because make sets default values, so the simpler ?= approach
47# won't work as expected.
48define allow-override
49  $(if $(or $(findstring environment,$(origin $(1))),\
50            $(findstring command line,$(origin $(1)))),,\
51    $(eval $(1) = $(2)))
52endef
53
54ifneq ($(LLVM),)
55$(call allow-override,CC,clang)
56$(call allow-override,AR,llvm-ar)
57$(call allow-override,LD,ld.lld)
58$(call allow-override,CXX,clang++)
59$(call allow-override,STRIP,llvm-strip)
60else
61# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix.
62$(call allow-override,CC,$(CROSS_COMPILE)gcc)
63$(call allow-override,AR,$(CROSS_COMPILE)ar)
64$(call allow-override,LD,$(CROSS_COMPILE)ld)
65$(call allow-override,CXX,$(CROSS_COMPILE)g++)
66$(call allow-override,STRIP,$(CROSS_COMPILE)strip)
67endif
68
69CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)
70
71ifneq ($(LLVM),)
72HOSTAR  ?= llvm-ar
73HOSTCC  ?= clang
74HOSTLD  ?= ld.lld
75else
76HOSTAR  ?= ar
77HOSTCC  ?= gcc
78HOSTLD  ?= ld
79endif
80
81# Some tools require Clang, LLC and/or LLVM utils
82CLANG		?= clang
83LLC		?= llc
84LLVM_CONFIG	?= llvm-config
85LLVM_OBJCOPY	?= llvm-objcopy
86LLVM_STRIP	?= llvm-strip
87
88ifeq ($(CC_NO_CLANG), 1)
89EXTRA_WARNINGS += -Wstrict-aliasing=3
90
91else ifneq ($(CROSS_COMPILE),)
92CLANG_CROSS_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
93GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)gcc 2>/dev/null))
94ifneq ($(GCC_TOOLCHAIN_DIR),)
95CLANG_CROSS_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
96CLANG_CROSS_FLAGS += --sysroot=$(shell $(CROSS_COMPILE)gcc -print-sysroot)
97CLANG_CROSS_FLAGS += --gcc-toolchain=$(realpath $(GCC_TOOLCHAIN_DIR)/..)
98endif # GCC_TOOLCHAIN_DIR
99CFLAGS += $(CLANG_CROSS_FLAGS)
100AFLAGS += $(CLANG_CROSS_FLAGS)
101endif # CROSS_COMPILE
102
103# Hack to avoid type-punned warnings on old systems such as RHEL5:
104# We should be changing CFLAGS and checking gcc version, but this
105# will do for now and keep the above -Wstrict-aliasing=3 in place
106# in newer systems.
107# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h
108#
109# See https://lore.kernel.org/lkml/9a8748490611281710g78402fbeh8ff7fcc162dbcbca@mail.gmail.com/
110# and https://gcc.gnu.org/gcc-4.8/changes.html,
111# that takes into account Linus's comments (search for Wshadow) for the reasoning about
112# -Wshadow not being interesting before gcc 4.8.
113
114ifneq ($(filter 3.%,$(MAKE_VERSION)),)  # make-3
115EXTRA_WARNINGS += -fno-strict-aliasing
116EXTRA_WARNINGS += -Wno-shadow
117else
118EXTRA_WARNINGS += -Wshadow
119endif
120
121ifneq ($(findstring $(MAKEFLAGS), w),w)
122PRINT_DIR = --no-print-directory
123else
124NO_SUBDIR = :
125endif
126
127ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
128  silent=1
129endif
130
131#
132# Define a callable command for descending to a new directory
133#
134# Call by doing: $(call descend,directory[,target])
135#
136descend = \
137	+mkdir -p $(OUTPUT)$(1) && \
138	$(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
139
140QUIET_SUBDIR0  = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir
141QUIET_SUBDIR1  =
142
143ifneq ($(silent),1)
144  ifneq ($(V),1)
145	QUIET_CC       = @echo '  CC      '$@;
146	QUIET_CC_FPIC  = @echo '  CC FPIC '$@;
147	QUIET_CLANG    = @echo '  CLANG   '$@;
148	QUIET_AR       = @echo '  AR      '$@;
149	QUIET_LINK     = @echo '  LINK    '$@;
150	QUIET_MKDIR    = @echo '  MKDIR   '$@;
151	QUIET_GEN      = @echo '  GEN     '$@;
152	QUIET_SUBDIR0  = +@subdir=
153	QUIET_SUBDIR1  = ;$(NO_SUBDIR) \
154			  echo '  SUBDIR  '$$subdir; \
155			 $(MAKE) $(PRINT_DIR) -C $$subdir
156	QUIET_FLEX     = @echo '  FLEX    '$@;
157	QUIET_BISON    = @echo '  BISON   '$@;
158	QUIET_GENSKEL  = @echo '  GENSKEL '$@;
159
160	descend = \
161		+@echo	       '  DESCEND '$(1); \
162		mkdir -p $(OUTPUT)$(1) && \
163		$(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
164
165	QUIET_CLEAN    = @printf '  CLEAN   %s\n' $1;
166	QUIET_INSTALL  = @printf '  INSTALL %s\n' $1;
167	QUIET_UNINST   = @printf '  UNINST  %s\n' $1;
168  endif
169endif
170
171pound := \#
172