# SPDX-License-Identifier: BSD-3-Clause
# Copyright 2015, Olivier MATZ <zer0@droids-corp.org>

# obj-y-$(obj) is provided by the user
#  $(obj) is the path of the object, and the variable contains
#  the list of sources. Several obj-y-$(obj) can be present.

# list all object builds requested by user
all-obj := $(patsubst obj-y-%,%,$(filter obj-y-%,$(.VARIABLES)))

# add them to the list of targets
all-targets += $(all-obj)

# convert source path to intermediate object path, and filter
# objects from sources
#  $1: list of source paths
#  $2: output directory (including trailing slash)
#  return: list of intermediate object paths
src2iobj = $(addprefix $(filter-out ./,$(2)),$(notdir $(strip \
	$(patsubst %.c,%.o,\
	$(patsubst %.s,%.o,\
	$(filter-out %.o,$(1)))))))

# return the file if it matches a extension that is built with cc
#   $1: source file
is_cc_source = $(filter %.c %.s %S,$(1))

# return the file if it's already an object file: in this case no
# intermediate object is needed
#   $1: source file
is_obj_source = $(filter %.o,$(1))

# return the file if it's a static library
#   $1: source file
is_alib_source = $(filter %.a,$(1))

# for each obj, create the following variables:
#   out-$(obj) = output path of the object
#   pre-$(obj) = list of prerequisites for this object
# Some source files need intermediate objects, we define these variables
# for them too, and add them in a list: $(all-iobj).
# Last, we add the generated files in $(all-clean-file).
$(foreach obj,$(all-obj),\
	$(eval out-$(obj) := $(dir $(obj))) \
	$(eval pre-$(obj) := ) \
	$(foreach src,$(obj-y-$(obj)), \
		$(if $(call is_cc_source,$(src)), \
			$(eval iobj := $(call src2iobj,$(src),$(out-$(obj)))) \
			$(eval pre-$(iobj) := $(src)) \
			$(eval all-iobj += $(iobj)) \
			$(eval all-clean-file += $(iobj)) \
			$(eval pre-$(obj) += $(iobj)) \
		, \
		$(if $(call is_obj_source,$(src)),\
			$(eval pre-$(obj) += $(src)) \
		, \
		$(error "unsupported source format: $(src)"))) \
	)\
	$(eval all-clean-file += $(obj)) \
)

# fix the format of .o.d.tmp (generated by gcc) to a .o.d that defines
# dependencies as makefile variables
#  $1: object file (.o)
obj-fixdep = if [ -f $(call file2tmpdep,$(1)) ]; then\
		echo -n "dep-$(1) = " > $(call depfile,$(1)) && \
		sed 's,^[^ ][^:]*: ,,' $(call file2tmpdep,$(1)) >> $(call depfile,$(1)) && \
		rm -f $(call file2tmpdep,$(1)); \
	else \
		$(call create_empty_depfile,$(1)); \
	fi

# compile a file
#  $1: sources
#  $2: dst
compile_cmd = $(CC) -Wp,-MD,$(call file2tmpdep,$(2)) \
	$(CPPFLAGS) $(cppflags-$(2)) \
	$(CFLAGS) $(cflags-$(2)) \
	-c -o $2 $1

# print line used to compile a file
ifeq ($(V),1)
compile_print_cmd = echo $(call protect_quote,$(call compile_cmd,$1,$2))
else
compile_print_cmd = echo "  CC $(2)"
endif

# combine several *.o files into one
#   $1: sources (*.o)
#   $2: dst (xyz.o too)
combine_cmd = $(LD) -r $(1) -o $(2)

# print line used to combine object files
ifeq ($(V),1)
combine_print_cmd = echo $(call protect_quote,$(call combine_cmd,$1,$2))
else
combine_print_cmd = echo "  LD $(2)"
endif

all-clean-file += $(all-obj)