# SPDX-License-Identifier: GPL-2.0-only
# ===========================================================================
# Module final link
# ===========================================================================

PHONY := __modfinal
__modfinal:

include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include

# for c_flags and objtool_args
include $(srctree)/scripts/Makefile.lib

# find all modules listed in modules.order
modules := $(sort $(shell cat $(MODORDER)))

__modfinal: $(modules)
	@:

# modname and part-of-module are set to make c_flags define proper module flags
modname = $(notdir $(@:.mod.o=))
part-of-module = y

quiet_cmd_cc_o_c = CC [M]  $@
      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

%.mod.o: %.mod.c FORCE
	$(call if_changed_dep,cc_o_c)

ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)

ifdef CONFIG_LTO_CLANG
# With CONFIG_LTO_CLANG, reuse the object file we compiled for modpost to
# avoid a second slow LTO link
prelink-ext := .lto

# ELF processing was skipped earlier because we didn't have native code,
# so let's now process the prelinked binary before we link the module.

ifdef CONFIG_STACK_VALIDATION
ifneq ($(SKIP_STACK_VALIDATION),1)
cmd_ld_ko_o +=								\
	$(objtree)/tools/objtool/objtool $(objtool_args)		\
		$(@:.ko=$(prelink-ext).o);

endif # SKIP_STACK_VALIDATION
endif # CONFIG_STACK_VALIDATION

endif # CONFIG_LTO_CLANG

quiet_cmd_ld_ko_o = LD [M]  $@
      cmd_ld_ko_o +=							\
	$(LD) -r $(KBUILD_LDFLAGS)					\
		$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE)		\
		-T scripts/module.lds -o $@ $(filter %.o, $^);		\
	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)

quiet_cmd_btf_ko = BTF [M] $@
      cmd_btf_ko = 							\
	if [ -f vmlinux ]; then						\
		LLVM_OBJCOPY=$(OBJCOPY) $(PAHOLE) -J --btf_base vmlinux $@; \
	else								\
		printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
	fi;

# Same as newer-prereqs, but allows to exclude specified extra dependencies
newer_prereqs_except = $(filter-out $(PHONY) $(1),$?)

# Same as if_changed, but allows to exclude specified extra dependencies
if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check),      \
	$(cmd);                                                              \
	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)


# Re-generate module BTFs if either module's .ko or vmlinux changed
$(modules): %.ko: %$(prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
	+$(call if_changed_except,ld_ko_o,vmlinux)
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
	+$(if $(newer-prereqs),$(call cmd,btf_ko))
endif

targets += $(modules) $(modules:.ko=.mod.o)

# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------

PHONY += FORCE
FORCE:

# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.

existing-targets := $(wildcard $(sort $(targets)))

-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)

.PHONY: $(PHONY)