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