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9564a8cf42
I tried building using a freshly built Make (4.2.1-69-g8a731d1), but
already the objtool build broke with
orc_dump.c: In function ‘orc_dump’:
orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations]
if (elf_getshdrnum(elf, &nr_sections)) {
Turns out that with that new Make, the backslash was not removed, so cpp
didn't see a #include directive, grep found nothing, and
-DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS.
Now, that new Make behaviour is documented in their NEWS file:
* WARNING: Backward-incompatibility!
Number signs (#) appearing inside a macro reference or function invocation
no longer introduce comments and should not be escaped with backslashes:
thus a call such as:
foo := $(shell echo '#')
is legal. Previously the number sign needed to be escaped, for example:
foo := $(shell echo '\#')
Now this latter will resolve to "\#". If you want to write makefiles
portable to both versions, assign the number sign to a variable:
C := \#
foo := $(shell echo '$C')
This was claimed to be fixed in 3.81, but wasn't, for some reason.
To detect this change search for 'nocomment' in the .FEATURES variable.
This also fixes up the two make-cmd instances to replace # with $(pound)
rather than with \#. There might very well be other places that need
similar fixup in preparation for whatever future Make release contains
the above change, but at least this builds an x86_64 defconfig with the
new make.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
125 lines
3.8 KiB
Makefile
125 lines
3.8 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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ifneq ($(O),)
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ifeq ($(origin O), command line)
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dummy := $(if $(shell test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
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ABSOLUTE_O := $(shell cd $(O) ; pwd)
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OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
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COMMAND_O := O=$(ABSOLUTE_O)
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ifeq ($(objtree),)
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objtree := $(O)
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endif
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endif
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endif
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# check that the output directory actually exists
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ifneq ($(OUTPUT),)
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OUTDIR := $(shell cd $(OUTPUT) && pwd)
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$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
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endif
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#
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# Include saner warnings here, which can catch bugs:
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#
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EXTRA_WARNINGS := -Wbad-function-cast
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EXTRA_WARNINGS += -Wdeclaration-after-statement
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EXTRA_WARNINGS += -Wformat-security
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EXTRA_WARNINGS += -Wformat-y2k
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EXTRA_WARNINGS += -Winit-self
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EXTRA_WARNINGS += -Wmissing-declarations
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EXTRA_WARNINGS += -Wmissing-prototypes
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EXTRA_WARNINGS += -Wnested-externs
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EXTRA_WARNINGS += -Wno-system-headers
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EXTRA_WARNINGS += -Wold-style-definition
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EXTRA_WARNINGS += -Wpacked
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EXTRA_WARNINGS += -Wredundant-decls
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EXTRA_WARNINGS += -Wshadow
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EXTRA_WARNINGS += -Wstrict-prototypes
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EXTRA_WARNINGS += -Wswitch-default
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EXTRA_WARNINGS += -Wswitch-enum
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EXTRA_WARNINGS += -Wundef
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EXTRA_WARNINGS += -Wwrite-strings
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EXTRA_WARNINGS += -Wformat
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CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)
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# Makefiles suck: This macro sets a default value of $(2) for the
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# variable named by $(1), unless the variable has been set by
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# environment or command line. This is necessary for CC and AR
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# because make sets default values, so the simpler ?= approach
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# won't work as expected.
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define allow-override
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$(if $(or $(findstring environment,$(origin $(1))),\
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$(findstring command line,$(origin $(1)))),,\
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$(eval $(1) = $(2)))
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endef
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# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix.
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$(call allow-override,CC,$(CROSS_COMPILE)gcc)
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$(call allow-override,AR,$(CROSS_COMPILE)ar)
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$(call allow-override,LD,$(CROSS_COMPILE)ld)
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$(call allow-override,CXX,$(CROSS_COMPILE)g++)
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$(call allow-override,STRIP,$(CROSS_COMPILE)strip)
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ifeq ($(CC_NO_CLANG), 1)
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EXTRA_WARNINGS += -Wstrict-aliasing=3
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endif
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# Hack to avoid type-punned warnings on old systems such as RHEL5:
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# We should be changing CFLAGS and checking gcc version, but this
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# will do for now and keep the above -Wstrict-aliasing=3 in place
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# in newer systems.
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# Needed for the __raw_cmpxchg in tools/arch/x86/include/asm/cmpxchg.h
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ifneq ($(filter 3.%,$(MAKE_VERSION)),) # make-3
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EXTRA_WARNINGS += -fno-strict-aliasing
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endif
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ifneq ($(findstring $(MAKEFLAGS), w),w)
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PRINT_DIR = --no-print-directory
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else
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NO_SUBDIR = :
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endif
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ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
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silent=1
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endif
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#
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# Define a callable command for descending to a new directory
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#
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# Call by doing: $(call descend,directory[,target])
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#
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descend = \
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+mkdir -p $(OUTPUT)$(1) && \
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$(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
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QUIET_SUBDIR0 = +$(MAKE) $(COMMAND_O) -C # space to separate -C and subdir
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QUIET_SUBDIR1 =
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ifneq ($(silent),1)
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ifneq ($(V),1)
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QUIET_CC = @echo ' CC '$@;
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QUIET_CC_FPIC = @echo ' CC FPIC '$@;
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QUIET_AR = @echo ' AR '$@;
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QUIET_LINK = @echo ' LINK '$@;
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QUIET_MKDIR = @echo ' MKDIR '$@;
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QUIET_GEN = @echo ' GEN '$@;
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QUIET_SUBDIR0 = +@subdir=
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QUIET_SUBDIR1 = ;$(NO_SUBDIR) \
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echo ' SUBDIR '$$subdir; \
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$(MAKE) $(PRINT_DIR) -C $$subdir
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QUIET_FLEX = @echo ' FLEX '$@;
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QUIET_BISON = @echo ' BISON '$@;
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descend = \
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+@echo ' DESCEND '$(1); \
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mkdir -p $(OUTPUT)$(1) && \
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$(MAKE) $(COMMAND_O) subdir=$(if $(subdir),$(subdir)/$(1),$(1)) $(PRINT_DIR) -C $(1) $(2)
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QUIET_CLEAN = @printf ' CLEAN %s\n' $1;
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QUIET_INSTALL = @printf ' INSTALL %s\n' $1;
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QUIET_UNINST = @printf ' UNINST %s\n' $1;
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endif
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endif
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pound := \#
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