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		11b3d5175e
		
	
	
	
	
		
			
			There has been a long-standing request to support building external modules in a separate build directory. This commit introduces a new environment variable, KBUILD_EXTMOD_OUTPUT, and its shorthand Make variable, MO. A simple usage: $ make -C <kernel-dir> M=<module-src-dir> MO=<module-build-dir> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
		
			
				
	
	
		
			165 lines
		
	
	
	
		
			6 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			165 lines
		
	
	
	
		
			6 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| # SPDX-License-Identifier: GPL-2.0
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| 
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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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| 
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| $(obj)/%.lex.c: $(src)/%.l FORCE
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| 	$(call if_changed,flex)
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| 
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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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| 
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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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| # ==========================================================================
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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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| # Rust is also supported, but it may only be used in scenarios where a Rust
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| # toolchain is required to be available (e.g. when  `CONFIG_RUST` is enabled).
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| #
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| # Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
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| # hostprogs := bin2hex
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| # Will compile bin2hex.c and create an executable named bin2hex
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| #
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| # hostprogs     := 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       := 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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| #
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| # hostprogs   := target
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| # target-rust := y
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| # Will compile `target` as a Rust program, using `target.rs` as the crate root.
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| # The crate may consist of several source files.
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| 
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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)-rust),,$(m)))
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| 
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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)$($(m)-rust),,$(if $($(m)-objs),$(m))))
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| 
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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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| 
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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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| 
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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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| 
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| # Rust code
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| # Executables compiled from a single Rust crate (which may consist of
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| # one or more .rs files)
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| host-rust	:= $(foreach m,$(hostprogs),$(if $($(m)-rust),$(m)))
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| 
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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-rust	:= $(addprefix $(obj)/,$(host-rust))
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| 
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| #####
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| # Handle options to gcc. Support building with separate output directory
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| 
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| hostc_flags    = -Wp,-MMD,$(depfile) \
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|                  $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
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|                  $(HOSTCFLAGS_$(target-stem).o)
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| hostcxx_flags  = -Wp,-MMD,$(depfile) \
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|                  $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
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|                  $(HOSTCXXFLAGS_$(target-stem).o)
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| 
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| # `--out-dir` is required to avoid temporaries being created by `rustc` in the
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| # current working directory, which may be not accessible in the out-of-tree
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| # modules case.
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| hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
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| 		 -Clinker-flavor=gcc -Clinker=$(HOSTCC) \
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| 		 -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
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|                  $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
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|                  $(HOSTRUSTFLAGS_$(target-stem))
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| 
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| # $(obj) for including generated headers from checkin source files
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| ifdef building_out_of_srctree
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| hostc_flags   += -I $(obj)
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| hostcxx_flags += -I $(obj)
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| endif
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| 
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| #####
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| # Compile programs on the host
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| 
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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)/%: $(obj)/%.c FORCE
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| 	$(call if_changed_dep,host-csingle)
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| 
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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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| 
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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: $(obj)/%.c FORCE
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| 	$(call if_changed_dep,host-cobjs)
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| 
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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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| 
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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: $(obj)/%.cc FORCE
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| 	$(call if_changed_dep,host-cxxobjs)
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| 
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| # Create executable from a single Rust crate (which may consist of
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| # one or more `.rs` files)
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| # host-rust -> Executable
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| quiet_cmd_host-rust	= HOSTRUSTC $@
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|       cmd_host-rust	= \
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| 	$(HOSTRUSTC) $(hostrust_flags) --emit=link=$@ $<
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| $(host-rust): $(obj)/%: $(src)/%.rs FORCE
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| 	+$(call if_changed_dep,host-rust)
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| 
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| targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \
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| 	   $(host-cxxmulti) $(host-cxxobjs) $(host-rust)
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| 
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| # %.lex.o <- %.lex.c <- %.l
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| # %.tab.o <- %.tab.[ch] <- %.y
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| targets += $(call intermediate_targets, .lex.o, .lex.c) \
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|            $(call intermediate_targets, .tab.o, .tab.c .tab.h)
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