# SPDX-License-Identifier: GPL-2.0

# LEX
# ---------------------------------------------------------------------------
quiet_cmd_flex = LEX     $@
      cmd_flex = $(LEX) -o$@ -L $<

$(obj)/%.lex.c: $(src)/%.l FORCE
	$(call if_changed,flex)

# YACC
# ---------------------------------------------------------------------------
quiet_cmd_bison = YACC    $(basename $@).[ch]
      cmd_bison = $(YACC) -o $(basename $@).c --defines=$(basename $@).h -t -l $<

$(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
	$(call if_changed,bison)

# ==========================================================================
# Building binaries on the host system
# Binaries are used during the compilation of the kernel, for example
# to preprocess a data file.
#
# Both C and C++ are supported, but preferred language is C for such utilities.
# Rust is also supported, but it may only be used in scenarios where a Rust
# toolchain is required to be available (e.g. when  `CONFIG_RUST` is enabled).
#
# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
# hostprogs := bin2hex
# Will compile bin2hex.c and create an executable named bin2hex
#
# hostprogs     := lxdialog
# lxdialog-objs := checklist.o lxdialog.o
# Will compile lxdialog.c and checklist.c, and then link the executable
# lxdialog, based on checklist.o and lxdialog.o
#
# hostprogs       := qconf
# qconf-cxxobjs   := qconf.o
# qconf-objs      := menu.o
# Will compile qconf as a C++ program, and menu as a C program.
# They are linked as C++ code to the executable qconf
#
# hostprogs   := target
# target-rust := y
# Will compile `target` as a Rust program, using `target.rs` as the crate root.
# The crate may consist of several source files.

# C code
# Executables compiled from a single .c file
host-csingle	:= $(foreach m,$(hostprogs), \
			$(if $($(m)-objs)$($(m)-cxxobjs)$($(m)-rust),,$(m)))

# C executables linked based on several .o files
host-cmulti	:= $(foreach m,$(hostprogs),\
		   $(if $($(m)-cxxobjs)$($(m)-rust),,$(if $($(m)-objs),$(m))))

# Object (.o) files compiled from .c files
host-cobjs	:= $(sort $(foreach m,$(hostprogs),$($(m)-objs)))

# C++ code
# C++ executables compiled from at least one .cc file
# and zero or more .c files
host-cxxmulti	:= $(foreach m,$(hostprogs),$(if $($(m)-cxxobjs),$(m)))

# C++ Object (.o) files compiled from .cc files
host-cxxobjs	:= $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))

# Rust code
# Executables compiled from a single Rust crate (which may consist of
# one or more .rs files)
host-rust	:= $(foreach m,$(hostprogs),$(if $($(m)-rust),$(m)))

host-csingle	:= $(addprefix $(obj)/,$(host-csingle))
host-cmulti	:= $(addprefix $(obj)/,$(host-cmulti))
host-cobjs	:= $(addprefix $(obj)/,$(host-cobjs))
host-cxxmulti	:= $(addprefix $(obj)/,$(host-cxxmulti))
host-cxxobjs	:= $(addprefix $(obj)/,$(host-cxxobjs))
host-rust	:= $(addprefix $(obj)/,$(host-rust))

#####
# Handle options to gcc. Support building with separate output directory

hostc_flags    = -Wp,-MMD,$(depfile) \
                 $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
                 $(HOSTCFLAGS_$(target-stem).o)
hostcxx_flags  = -Wp,-MMD,$(depfile) \
                 $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
                 $(HOSTCXXFLAGS_$(target-stem).o)

# `--out-dir` is required to avoid temporaries being created by `rustc` in the
# current working directory, which may be not accessible in the out-of-tree
# modules case.
hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
		 -Clinker-flavor=gcc -Clinker=$(HOSTCC) \
		 -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
                 $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
                 $(HOSTRUSTFLAGS_$(target-stem))

# $(obj) for including generated headers from checkin source files
ifdef building_out_of_srctree
hostc_flags   += -I $(obj)
hostcxx_flags += -I $(obj)
endif

#####
# Compile programs on the host

# Create executable from a single .c file
# host-csingle -> Executable
quiet_cmd_host-csingle 	= HOSTCC  $@
      cmd_host-csingle	= $(HOSTCC) $(hostc_flags) $(KBUILD_HOSTLDFLAGS) -o $@ $< \
		$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
$(host-csingle): $(obj)/%: $(obj)/%.c FORCE
	$(call if_changed_dep,host-csingle)

# Link an executable based on list of .o files, all plain c
# host-cmulti -> executable
quiet_cmd_host-cmulti	= HOSTLD  $@
      cmd_host-cmulti	= $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ \
			  $(addprefix $(obj)/, $($(target-stem)-objs)) \
			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
$(host-cmulti): FORCE
	$(call if_changed,host-cmulti)
$(call multi_depend, $(host-cmulti), , -objs)

# Create .o file from a single .c file
# host-cobjs -> .o
quiet_cmd_host-cobjs	= HOSTCC  $@
      cmd_host-cobjs	= $(HOSTCC) $(hostc_flags) -c -o $@ $<
$(host-cobjs): $(obj)/%.o: $(obj)/%.c FORCE
	$(call if_changed_dep,host-cobjs)

# Link an executable based on list of .o files, a mixture of .c and .cc
# host-cxxmulti -> executable
quiet_cmd_host-cxxmulti	= HOSTLD  $@
      cmd_host-cxxmulti	= $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -o $@ \
			  $(foreach o,objs cxxobjs,\
			  $(addprefix $(obj)/, $($(target-stem)-$(o)))) \
			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
$(host-cxxmulti): FORCE
	$(call if_changed,host-cxxmulti)
$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs)

# Create .o file from a single .cc (C++) file
quiet_cmd_host-cxxobjs	= HOSTCXX $@
      cmd_host-cxxobjs	= $(HOSTCXX) $(hostcxx_flags) -c -o $@ $<
$(host-cxxobjs): $(obj)/%.o: $(obj)/%.cc FORCE
	$(call if_changed_dep,host-cxxobjs)

# Create executable from a single Rust crate (which may consist of
# one or more `.rs` files)
# host-rust -> Executable
quiet_cmd_host-rust	= HOSTRUSTC $@
      cmd_host-rust	= \
	$(HOSTRUSTC) $(hostrust_flags) --emit=link=$@ $<
$(host-rust): $(obj)/%: $(src)/%.rs FORCE
	+$(call if_changed_dep,host-rust)

targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \
	   $(host-cxxmulti) $(host-cxxobjs) $(host-rust)

# %.lex.o <- %.lex.c <- %.l
# %.tab.o <- %.tab.[ch] <- %.y
targets += $(call intermediate_targets, .lex.o, .lex.c) \
           $(call intermediate_targets, .tab.o, .tab.c .tab.h)