# Copyright (c) 2014-2015, Loïc Hoguin <essen@ninenines.eu>
# This file is part of erlang.mk and subject to the terms of the ISC License.

.PHONY: clean-c_src distclean-c_src-env

# Configuration.

C_SRC_DIR = $(CURDIR)/c_src
C_SRC_ENV ?= $(C_SRC_DIR)/env.mk
C_SRC_OUTPUT ?= $(CURDIR)/priv/$(PROJECT).so

# System type and C compiler/flags.

UNAME_SYS := $(shell uname -s)
ifeq ($(UNAME_SYS), Darwin)
	CC ?= cc
	CFLAGS ?= -O3 -std=c99 -arch x86_64 -finline-functions -Wall -Wmissing-prototypes
	CXXFLAGS ?= -O3 -arch x86_64 -finline-functions -Wall
	LDFLAGS ?= -arch x86_64 -flat_namespace -undefined suppress
else ifeq ($(UNAME_SYS), FreeBSD)
	CC ?= cc
	CFLAGS ?= -O3 -std=c99 -finline-functions -Wall -Wmissing-prototypes
	CXXFLAGS ?= -O3 -finline-functions -Wall
else ifeq ($(UNAME_SYS), Linux)
	CC ?= gcc
	CFLAGS ?= -O3 -std=c99 -finline-functions -Wall -Wmissing-prototypes
	CXXFLAGS ?= -O3 -finline-functions -Wall
endif

CFLAGS += -fPIC -I $(ERTS_INCLUDE_DIR) -I $(ERL_INTERFACE_INCLUDE_DIR)
CXXFLAGS += -fPIC -I $(ERTS_INCLUDE_DIR) -I $(ERL_INTERFACE_INCLUDE_DIR)

LDLIBS += -L $(ERL_INTERFACE_LIB_DIR) -lerl_interface -lei
LDFLAGS += -shared

# Verbosity.

c_verbose_0 = @echo " C     " $(?F);
c_verbose = $(c_verbose_$(V))

cpp_verbose_0 = @echo " CPP   " $(?F);
cpp_verbose = $(cpp_verbose_$(V))

link_verbose_0 = @echo " LD    " $(@F);
link_verbose = $(link_verbose_$(V))

# Targets.

ifeq ($(wildcard $(C_SRC_DIR)),)
else ifneq ($(wildcard $(C_SRC_DIR)/Makefile),)
app::
	$(MAKE) -C $(C_SRC_DIR) \
		CFLAGS="$(CFLAGS)" \
		CXXFLAGS="$(CXXFLAGS)" \
		LDLIBS="$(LDLIBS)" \
		LDFLAGS="$(LDFLAGS)"

clean::
	$(MAKE) -C $(C_SRC_DIR) clean

else
SOURCES := $(shell find $(C_SRC_DIR) -type f \( -name "*.c" -o -name "*.C" -o -name "*.cc" -o -name "*.cpp" \))
OBJECTS = $(addsuffix .o, $(basename $(SOURCES)))

COMPILE_C = $(c_verbose) $(CC) $(CFLAGS) $(CPPFLAGS) -c
COMPILE_CPP = $(cpp_verbose) $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c

app:: $(C_SRC_ENV) $(C_SRC_OUTPUT)

$(C_SRC_OUTPUT): $(OBJECTS)
	@mkdir -p priv/
	$(link_verbose) $(CC) $(OBJECTS) $(LDFLAGS) $(LDLIBS) -o $(C_SRC_OUTPUT)

%.o: %.c
	$(COMPILE_C) $(OUTPUT_OPTION) $<

%.o: %.cc
	$(COMPILE_CPP) $(OUTPUT_OPTION) $<

%.o: %.C
	$(COMPILE_CPP) $(OUTPUT_OPTION) $<

%.o: %.cpp
	$(COMPILE_CPP) $(OUTPUT_OPTION) $<

clean:: clean-c_src

clean-c_src:
	$(gen_verbose) rm -f $(C_SRC_OUTPUT) $(OBJECTS)

endif

ifneq ($(wildcard $(C_SRC_DIR)),)
$(C_SRC_ENV):
	@$(ERL) -eval "file:write_file(\"$(C_SRC_ENV)\", \
		io_lib:format( \
			\"ERTS_INCLUDE_DIR ?= ~s/erts-~s/include/~n\" \
			\"ERL_INTERFACE_INCLUDE_DIR ?= ~s~n\" \
			\"ERL_INTERFACE_LIB_DIR ?= ~s~n\", \
			[code:root_dir(), erlang:system_info(version), \
			code:lib_dir(erl_interface, include), \
			code:lib_dir(erl_interface, lib)])), \
		halt()."

distclean:: distclean-c_src-env

distclean-c_src-env:
	$(gen_verbose) rm -f $(C_SRC_ENV)

-include $(C_SRC_ENV)
endif