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54b8ae66ae
Kbuild provides per-file compiler flag addition/removal:
CFLAGS_<basetarget>.o
CFLAGS_REMOVE_<basetarget>.o
AFLAGS_<basetarget>.o
AFLAGS_REMOVE_<basetarget>.o
CPPFLAGS_<basetarget>.lds
HOSTCFLAGS_<basetarget>.o
HOSTCXXFLAGS_<basetarget>.o
The <basetarget> is the filename of the target with its directory and
suffix stripped.
This syntax comes into a trouble when two files with the same basename
appear in one Makefile, for example:
obj-y += foo.o
obj-y += dir/foo.o
CFLAGS_foo.o := <some-flags>
Here, the <some-flags> applies to both foo.o and dir/foo.o
The real world problem is:
scripts/kconfig/util.c
scripts/kconfig/lxdialog/util.c
Both files are compiled into scripts/kconfig/mconf, but only the
latter should be given with the ncurses flags.
It is more sensible to use the relative path to the Makefile, like this:
obj-y += foo.o
CFLAGS_foo.o := <some-flags>
obj-y += dir/foo.o
CFLAGS_dir/foo.o := <other-flags>
At first, I attempted to replace $(basetarget) with $*. The $* variable
is replaced with the stem ('%') part in a pattern rule. This works with
most of cases, but does not for explicit rules.
For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own
explicit rules, so $* will be empty, resulting in ignoring the per-file
AFLAGS.
I introduced a new variable, target-stem, which can be used also from
explicit rules.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Marc Zyngier <maz@kernel.org>
182 lines
6.9 KiB
Makefile
182 lines
6.9 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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# LEX
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# ---------------------------------------------------------------------------
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quiet_cmd_flex = LEX $@
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cmd_flex = $(LEX) -o$@ -L $<
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$(obj)/%.lex.c: $(src)/%.l FORCE
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$(call if_changed,flex)
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# YACC
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# ---------------------------------------------------------------------------
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quiet_cmd_bison = YACC $(basename $@).[ch]
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cmd_bison = $(YACC) -o $(basename $@).c --defines=$(basename $@).h -t -l $<
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$(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
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$(call if_changed,bison)
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# ==========================================================================
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# Building binaries on the host system
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# Binaries are used during the compilation of the kernel, for example
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# to preprocess a data file.
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#
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# Both C and C++ are supported, but preferred language is C for such utilities.
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#
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# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
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# hostprogs-y := bin2hex
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# Will compile bin2hex.c and create an executable named bin2hex
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#
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# hostprogs-y := lxdialog
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# lxdialog-objs := checklist.o lxdialog.o
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# Will compile lxdialog.c and checklist.c, and then link the executable
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# lxdialog, based on checklist.o and lxdialog.o
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#
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# hostprogs-y := qconf
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# qconf-cxxobjs := qconf.o
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# qconf-objs := menu.o
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# Will compile qconf as a C++ program, and menu as a C program.
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# They are linked as C++ code to the executable qconf
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__hostprogs := $(sort $(hostprogs-y) $(hostprogs-m))
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host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m))
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host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m))
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# C code
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# Executables compiled from a single .c file
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host-csingle := $(foreach m,$(__hostprogs), \
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$(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
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# C executables linked based on several .o files
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host-cmulti := $(foreach m,$(__hostprogs),\
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$(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
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# Object (.o) files compiled from .c files
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host-cobjs := $(sort $(foreach m,$(__hostprogs),$($(m)-objs)))
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# C++ code
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# C++ executables compiled from at least one .cc file
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# and zero or more .c files
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host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m)))
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# C++ Object (.o) files compiled from .cc files
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host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
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# Object (.o) files used by the shared libaries
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host-cshobjs := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
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host-cxxshobjs := $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs))))
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host-csingle := $(addprefix $(obj)/,$(host-csingle))
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host-cmulti := $(addprefix $(obj)/,$(host-cmulti))
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host-cobjs := $(addprefix $(obj)/,$(host-cobjs))
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host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti))
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host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs))
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host-cshlib := $(addprefix $(obj)/,$(host-cshlib))
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host-cxxshlib := $(addprefix $(obj)/,$(host-cxxshlib))
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host-cshobjs := $(addprefix $(obj)/,$(host-cshobjs))
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host-cxxshobjs := $(addprefix $(obj)/,$(host-cxxshobjs))
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#####
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# Handle options to gcc. Support building with separate output directory
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_hostc_flags = $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
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$(HOSTCFLAGS_$(target-stem).o)
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_hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
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$(HOSTCXXFLAGS_$(target-stem).o)
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# $(objtree)/$(obj) for including generated headers from checkin source files
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ifeq ($(KBUILD_EXTMOD),)
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ifdef building_out_of_srctree
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_hostc_flags += -I $(objtree)/$(obj)
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_hostcxx_flags += -I $(objtree)/$(obj)
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endif
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endif
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hostc_flags = -Wp,-MD,$(depfile) $(_hostc_flags)
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hostcxx_flags = -Wp,-MD,$(depfile) $(_hostcxx_flags)
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#####
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# Compile programs on the host
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# Create executable from a single .c file
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# host-csingle -> Executable
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quiet_cmd_host-csingle = HOSTCC $@
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cmd_host-csingle = $(HOSTCC) $(hostc_flags) $(KBUILD_HOSTLDFLAGS) -o $@ $< \
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$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
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$(host-csingle): $(obj)/%: $(src)/%.c FORCE
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$(call if_changed_dep,host-csingle)
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# Link an executable based on list of .o files, all plain c
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# host-cmulti -> executable
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quiet_cmd_host-cmulti = HOSTLD $@
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cmd_host-cmulti = $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ \
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$(addprefix $(obj)/, $($(target-stem)-objs)) \
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$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
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$(host-cmulti): FORCE
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$(call if_changed,host-cmulti)
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$(call multi_depend, $(host-cmulti), , -objs)
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# Create .o file from a single .c file
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# host-cobjs -> .o
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quiet_cmd_host-cobjs = HOSTCC $@
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cmd_host-cobjs = $(HOSTCC) $(hostc_flags) -c -o $@ $<
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$(host-cobjs): $(obj)/%.o: $(src)/%.c FORCE
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$(call if_changed_dep,host-cobjs)
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# Link an executable based on list of .o files, a mixture of .c and .cc
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# host-cxxmulti -> executable
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quiet_cmd_host-cxxmulti = HOSTLD $@
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cmd_host-cxxmulti = $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -o $@ \
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$(foreach o,objs cxxobjs,\
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$(addprefix $(obj)/, $($(target-stem)-$(o)))) \
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$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
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$(host-cxxmulti): FORCE
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$(call if_changed,host-cxxmulti)
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$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs)
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# Create .o file from a single .cc (C++) file
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quiet_cmd_host-cxxobjs = HOSTCXX $@
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cmd_host-cxxobjs = $(HOSTCXX) $(hostcxx_flags) -c -o $@ $<
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$(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
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$(call if_changed_dep,host-cxxobjs)
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# Compile .c file, create position independent .o file
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# host-cshobjs -> .o
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quiet_cmd_host-cshobjs = HOSTCC -fPIC $@
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cmd_host-cshobjs = $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $<
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$(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE
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$(call if_changed_dep,host-cshobjs)
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# Compile .c file, create position independent .o file
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# Note that plugin capable gcc versions can be either C or C++ based
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# therefore plugin source files have to be compilable in both C and C++ mode.
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# This is why a C++ compiler is invoked on a .c file.
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# host-cxxshobjs -> .o
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quiet_cmd_host-cxxshobjs = HOSTCXX -fPIC $@
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cmd_host-cxxshobjs = $(HOSTCXX) $(hostcxx_flags) -fPIC -c -o $@ $<
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$(host-cxxshobjs): $(obj)/%.o: $(src)/%.c FORCE
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$(call if_changed_dep,host-cxxshobjs)
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# Link a shared library, based on position independent .o files
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# *.o -> .so shared library (host-cshlib)
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quiet_cmd_host-cshlib = HOSTLLD -shared $@
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cmd_host-cshlib = $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \
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$(addprefix $(obj)/, $($(target-stem)-objs)) \
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$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem).so)
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$(host-cshlib): FORCE
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$(call if_changed,host-cshlib)
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$(call multi_depend, $(host-cshlib), .so, -objs)
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# Link a shared library, based on position independent .o files
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# *.o -> .so shared library (host-cxxshlib)
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quiet_cmd_host-cxxshlib = HOSTLLD -shared $@
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cmd_host-cxxshlib = $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \
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$(addprefix $(obj)/, $($(target-stem)-objs)) \
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$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem).so)
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$(host-cxxshlib): FORCE
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$(call if_changed,host-cxxshlib)
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$(call multi_depend, $(host-cxxshlib), .so, -objs)
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targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\
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$(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs) $(host-cxxshlib) $(host-cxxshobjs)
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