####
# kbuild: Generic definitions

# Convenient variables
comma   := ,
squote  := '
#'
empty   :=
space   := $(empty) $(empty)

BUILD_DIR_NAME = _build
COMPILED_DIR_NAME = _compiled

USER_INCLUDE_DIR := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/include
USER_LIB_DIR     := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/lib
USER_UTILS_DIR   := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/bin-utils
USER_TESTS_DIR   := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/bin-tests
USER_BIN_DIR     := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/bin
USER_BUILD_DIR   := $(OUTPUT_DIR)/$(BUILD_DIR_NAME)/user
LINK_BUILD_DIR   := $(OUTPUT_DIR)/$(BUILD_DIR_NAME)/link

USER_OBJS_DIR = $(USER_BUILD_DIR)/$(RELATIVE_DIR)
KERN_OBJS_DIR = $(KERN_BUILD_DIR)/$(RELATIVE_DIR)
OMK_WORK_DIR  = $(USER_OBJS_DIR)

strip_out = $(patsubst $(OUTPUT_DIR)/%,%,$(1))
repl_out  = $(patsubst $(OUTPUT_DIR)/%,$$(OUTPUT_DIR)/%,$(1))

.PHONY: FORCE

#####################
# Build pseudo-pass #
#####################

rule_targets = $($(1)_targets)
rule_deps    = $($(1)_deps)
rule_msg     = $($(1)_msg)
rule_cmd     = $($(1)_cmd)

# Usage: $(call build_rule,<target>)
define build_rule
$(rule_target): $(rule_deps) $(omk_inc_file)
	@$(QUIET_CMD_ECHO) "  "$(rule_msg) "$$(call strip_out,$$(@))"
	$(Q)$(rule_cmd)
endef

# TODO: Include target.omk only in the subtree
-include $(shell true; find $(USER_BUILD_DIR) -name '*omk.inc') # `true' is a hack for MinGW

$(foreach rule,$(prepared_rules),$(eval $(call build_rule,$(rule))))

.PHONY: build-pseudo-pass
build-pseudo-pass: $(foreach target,$(default_build_targets),$(target))

################
# Prepare pass #
################

$(eval $(call omk_pass_template,prepare-pass,$(USER_OBJS_DIR),,always))

###
# Name of the prepared rule.  This name is used as prefix of variable
# names in .omk.inc and is based on the first target
omk_inc_rule = $(firstword $(1:$(OUTPUT_DIR)/%=%))

# The name of .omk.inc file is derived from $(omk_inc_rule) and
# depends whether the target is under _build or elsewhere.
omk_inc_file = $(if $(filter $(BUILD_DIR_NAME)%,$(omk_inc_rule)),\
		    $(OMK_WORK_DIR)/$(notdir $(omk_inc_rule)).omk.inc,\
		    $(OMK_WORK_DIR)/$(subst /,_,$(omk_inc_rule)).omk.inc)

target_omk_file = $(OMK_WORK_DIR)/$(notdir $(1)).target.omk

###
# prepare_rule is used to generate .omk.inc files during prepare-pass.
# All paths in this file should be relative to $(OUTPUT_DIR)
# Usage: $(call prepare_rule,<targets>,<deps>,<msg>,<cmd>)
define prepare_rule
prepare-pass-local: $(omk_inc_file)

$(omk_inc_file): FORCE
	$(Q)echo 'prepared_rules += $(omk_inc_rule)' > $$@.tmp; \
	    echo '$(omk_inc_rule)_targets = $$(call strip_out,$(1))' >> $$@.tmp; \
	    echo '$(omk_inc_rule)_deps += $$(call strip_out,$(2))' >> $$@.tmp; \
	    echo '$(omk_inc_rule)_msg = $(3)' >> $$@.tmp; \
	    echo '$(omk_inc_rule)_cmd = $$(call repl_out,$(4))' >> $$@.tmp; \
	if cmp -s $$@.tmp $$@; then rm $$@.tmp; else mv $$@.tmp $$@; fi
endef

###
# prepare_rule_default - same as prepare rules but the target is put
# as dependency to the default build rule, which causes it to be built
# upon calling make
define prepare_rule_default
$(call prepare_rule,$(1),$(2),$(3),$(4))
prepared_default_build_targets += $(call strip_out,$(1))
endef

prepare-pass-local: $(OMK_WORK_DIR)/omk.inc
$(OMK_WORK_DIR)/omk.inc: FORCE
	$(Q)echo 'default_build_targets += $(prepared_default_build_targets)' > $@.tmp; \
	    if cmp -s $@.tmp $@; then rm $@.tmp; else mv $@.tmp $@; fi


############
# Programs #
############

# Usage: $(call program_template,<executable-name>,<bin|utils|test>)
define program_template
$(1)_OBJS += $$(patsubst %.c,%.o,$$(filter %.c,$$($(1)_SOURCES)))
$(1)_OBJS := $$(addprefix $(USER_OBJS_DIR),$$(sort $$($(1)_OBJS:%/=%)))

USER_OBJS  += $$($(1)_OBJS)
USER_SOURCES += $$($(1)_SOURCES)



program_cmd = $$(if $$(filter %.cc,$$($(1)_SOURCES)),$$(CXX),$$(CC)) \
	$$($(1)_OBJS) $$($(1)_LIBS:%=-l%) $$(LOADLIBES) $$(LDFLAGS) -Wl,-rpath-link,$(USER_LIB_DIR) \
	-Wl,-Map,$(USER_OBJS_DIR)/$(1).exe.map -o $$$$@

$(call prepare_rule_default,\
	$(USER_BIN_DIR)/$(1)$(EXE_SUFFIX),\
	$$($(1)_OBJS) $$($(1)_LIBS),\
	"LINK    ",\
	$$(program_cmd))
endef

c_o_cmd := set -e; cd $$(dir $$@); \
	if $$(c_o_COMPILE) $$(CC_DEPFLAGS) -o $$@ -c $$< ; \
	then mv -f "$$@.d.tmp" "$$@.d" ; \
	else rm -f "$$@.d.tmp" ; \
	fi


$(foreach prog,$(bin_PROGRAMS),$(eval $(call program_template,$(prog),bin)))
$(foreach src,$(filter %.c,$(USER_SOURCES)),$(eval $(call prepare_rule,\
	$(USER_OBJS_DIR)/$(src:%.c=%.o),\
	$(SOURCES_DIR)/$(src),\
	"CC      ",\
	$(c_o_cmd))))

default: prepare-pass
	$(MAKE) -qp build-pseudo-pass > make.dp.build-pseudo-pass
	$(MAKE) build-pseudo-pass