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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
90endif
91
92# Hack to avoid type-punned warnings on old systems such as RHEL5:
93# We should be changing CFLAGS and checking gcc version, but this
94# will do for now and keep the above -Wstrict-aliasing=3 in place
95# in newer systems.
96# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h
97#
98# See https://lore.kernel.org/lkml/9a8748490611281710g78402fbeh8ff7fcc162dbcbca@mail.gmail.com/
99# and https://gcc.gnu.org/gcc-4.8/changes.html,
100# that takes into account Linus's comments (search for Wshadow) for the reasoning about
101# -Wshadow not being interesting before gcc 4.8.
102
103ifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3
104EXTRA_WARNINGS += -fno-strict-aliasing
105EXTRA_WARNINGS += -Wno-shadow
106else
107EXTRA_WARNINGS += -Wshadow
108endif
109
110ifneq ($(findstring $(MAKEFLAGS), w),w)
111PRINT_DIR = --no-print-directory
112else
113NO_SUBDIR = :
114endif
115
116ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
117 silent=1
118endif
119
120#
121# Define a callable command for descending to a new directory
122#
123# Call by doing: $(call descend,directory[,target])
124#
125descend = \
126 +mkdir -p $(OUTPUT)$(1) && \
127 $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
128
129QUIET_SUBDIR0 = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir
130QUIET_SUBDIR1 =
131
132ifneq ($(silent),1)
133 ifneq ($(V),1)
134 QUIET_CC = @echo ' CC '$@;
135 QUIET_CC_FPIC = @echo ' CC FPIC '$@;
136 QUIET_CLANG = @echo ' CLANG '$@;
137 QUIET_AR = @echo ' AR '$@;
138 QUIET_LINK = @echo ' LINK '$@;
139 QUIET_MKDIR = @echo ' MKDIR '$@;
140 QUIET_GEN = @echo ' GEN '$@;
141 QUIET_SUBDIR0 = +@subdir=
142 QUIET_SUBDIR1 = ;$(NO_SUBDIR) \
143 echo ' SUBDIR '$$subdir; \
144 $(MAKE) $(PRINT_DIR) -C $$subdir
145 QUIET_FLEX = @echo ' FLEX '$@;
146 QUIET_BISON = @echo ' BISON '$@;
147 QUIET_GENSKEL = @echo ' GENSKEL '$@;
148
149 descend = \
150 +@echo ' DESCEND '$(1); \
151 mkdir -p $(OUTPUT)$(1) && \
152 $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
153
154 QUIET_CLEAN = @printf ' CLEAN %s\n' $1;
155 QUIET_INSTALL = @printf ' INSTALL %s\n' $1;
156 QUIET_UNINST = @printf ' UNINST %s\n' $1;
157 endif
158endif
159
160pound := \#
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),)
55ifneq ($(filter %/,$(LLVM)),)
56LLVM_PREFIX := $(LLVM)
57else ifneq ($(filter -%,$(LLVM)),)
58LLVM_SUFFIX := $(LLVM)
59endif
60
61$(call allow-override,CC,$(LLVM_PREFIX)clang$(LLVM_SUFFIX))
62$(call allow-override,AR,$(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX))
63$(call allow-override,LD,$(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX))
64$(call allow-override,CXX,$(LLVM_PREFIX)clang++$(LLVM_SUFFIX))
65$(call allow-override,STRIP,$(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX))
66else
67# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix.
68$(call allow-override,CC,$(CROSS_COMPILE)gcc)
69$(call allow-override,AR,$(CROSS_COMPILE)ar)
70$(call allow-override,LD,$(CROSS_COMPILE)ld)
71$(call allow-override,CXX,$(CROSS_COMPILE)g++)
72$(call allow-override,STRIP,$(CROSS_COMPILE)strip)
73endif
74
75CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)
76
77ifneq ($(LLVM),)
78HOSTAR ?= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
79HOSTCC ?= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
80HOSTLD ?= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
81else
82HOSTAR ?= ar
83HOSTCC ?= gcc
84HOSTLD ?= ld
85endif
86
87# Some tools require Clang, LLC and/or LLVM utils
88CLANG ?= clang
89LLC ?= llc
90LLVM_CONFIG ?= llvm-config
91LLVM_OBJCOPY ?= llvm-objcopy
92LLVM_STRIP ?= llvm-strip
93
94ifeq ($(CC_NO_CLANG), 1)
95EXTRA_WARNINGS += -Wstrict-aliasing=3
96
97else ifneq ($(CROSS_COMPILE),)
98# Allow userspace to override CLANG_CROSS_FLAGS to specify their own
99# sysroots and flags or to avoid the GCC call in pure Clang builds.
100ifeq ($(CLANG_CROSS_FLAGS),)
101CLANG_CROSS_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%))
102GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)gcc 2>/dev/null))
103ifneq ($(GCC_TOOLCHAIN_DIR),)
104CLANG_CROSS_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
105CLANG_CROSS_FLAGS += --sysroot=$(shell $(CROSS_COMPILE)gcc -print-sysroot)
106CLANG_CROSS_FLAGS += --gcc-toolchain=$(realpath $(GCC_TOOLCHAIN_DIR)/..)
107endif # GCC_TOOLCHAIN_DIR
108endif # CLANG_CROSS_FLAGS
109CFLAGS += $(CLANG_CROSS_FLAGS)
110AFLAGS += $(CLANG_CROSS_FLAGS)
111endif # CROSS_COMPILE
112
113# Hack to avoid type-punned warnings on old systems such as RHEL5:
114# We should be changing CFLAGS and checking gcc version, but this
115# will do for now and keep the above -Wstrict-aliasing=3 in place
116# in newer systems.
117# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h
118#
119# See https://lore.kernel.org/lkml/9a8748490611281710g78402fbeh8ff7fcc162dbcbca@mail.gmail.com/
120# and https://gcc.gnu.org/gcc-4.8/changes.html,
121# that takes into account Linus's comments (search for Wshadow) for the reasoning about
122# -Wshadow not being interesting before gcc 4.8.
123
124ifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3
125EXTRA_WARNINGS += -fno-strict-aliasing
126EXTRA_WARNINGS += -Wno-shadow
127else
128EXTRA_WARNINGS += -Wshadow
129endif
130
131ifneq ($(findstring $(MAKEFLAGS), w),w)
132PRINT_DIR = --no-print-directory
133else
134NO_SUBDIR = :
135endif
136
137ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
138 silent=1
139endif
140
141#
142# Define a callable command for descending to a new directory
143#
144# Call by doing: $(call descend,directory[,target])
145#
146descend = \
147 +mkdir -p $(OUTPUT)$(1) && \
148 $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
149
150QUIET_SUBDIR0 = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir
151QUIET_SUBDIR1 =
152
153ifneq ($(silent),1)
154 ifneq ($(V),1)
155 QUIET_CC = @echo ' CC '$@;
156 QUIET_CC_FPIC = @echo ' CC FPIC '$@;
157 QUIET_CLANG = @echo ' CLANG '$@;
158 QUIET_AR = @echo ' AR '$@;
159 QUIET_LINK = @echo ' LINK '$@;
160 QUIET_MKDIR = @echo ' MKDIR '$@;
161 QUIET_GEN = @echo ' GEN '$@;
162 QUIET_SUBDIR0 = +@subdir=
163 QUIET_SUBDIR1 = ;$(NO_SUBDIR) \
164 echo ' SUBDIR '$$subdir; \
165 $(MAKE) $(PRINT_DIR) -C $$subdir
166 QUIET_FLEX = @echo ' FLEX '$@;
167 QUIET_BISON = @echo ' BISON '$@;
168 QUIET_GENSKEL = @echo ' GENSKEL '$@;
169
170 descend = \
171 +@echo ' DESCEND '$(1); \
172 mkdir -p $(OUTPUT)$(1) && \
173 $(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
174
175 QUIET_CLEAN = @printf ' CLEAN %s\n' $1;
176 QUIET_INSTALL = @printf ' INSTALL %s\n' $1;
177 QUIET_UNINST = @printf ' UNINST %s\n' $1;
178 endif
179endif
180
181pound := \#