# SPDX-FileCopyrightText: 2021 Frank Hunleth
#
# SPDX-License-Identifier: Apache-2.0
#
# Makefile for building the NIF
#
# Makefile targets:
#
# all/install   build and install the NIF
# clean         clean build products and intermediates
#
# Variables to override:
#
# MIX_APP_PATH  path to the build directory
#
# CC            C compiler for the target
# CC_FOR_BUILD  C compiler for host tools
# CFLAGS	compiler flags for compiling all C files
# ERL_CFLAGS	additional compiler flags for files using Erlang header files
# ERL_EI_INCLUDE_DIR include path to ei.h (Required for crosscompile)
# ERL_EI_LIBDIR path to libei.a (Required for crosscompile)
# LDFLAGS	linker flags for linking all binaries
# ERL_LDFLAGS	additional linker flags for projects referencing Erlang libraries

PREFIX = $(MIX_APP_PATH)/priv
BUILD  = $(MIX_APP_PATH)/obj

NIF = $(PREFIX)/nif.so

CFLAGS ?= -O2 -Wall -Wextra -Wno-unused-parameter -pedantic
CFLAGS += -fPIC

ifeq ($(CROSSCOMPILE),)
    # Native build
    ifeq ($(shell uname -s),Darwin)
        LDFLAGS += -undefined dynamic_lookup -dynamiclib
    else
        LDFLAGS += -fPIC -shared
    endif
else
    # Crosscompiled build
    LDFLAGS += -fPIC -shared
endif

# Set Erlang-specific compile and linker flags
ERL_CFLAGS ?= -I"$(ERL_EI_INCLUDE_DIR)"
ERL_LDFLAGS ?= -L"$(ERL_EI_LIBDIR)" -lei

SRC = c_src/nif.c
HEADERS =$(wildcard src/*.h)
OBJ = $(SRC:c_src/%.c=$(BUILD)/%.o)

calling_from_make:
	mix compile

all: install tzdata

install: $(PREFIX) $(BUILD) $(NIF)

tzdata:
	$(MAKE) -f tzdata.mk all

$(OBJ): $(HEADERS) Makefile

$(BUILD)/%.o: c_src/%.c
	@echo "     CC $(notdir $@)"
	$(CC) -c $(ERL_CFLAGS) $(CFLAGS) -o $@ $<

$(NIF): $(OBJ)
	@echo "     LD $(notdir $@)"
	$(CC) -o $@ $(ERL_LDFLAGS) $(LDFLAGS) $^

$(PREFIX) $(BUILD):
	mkdir -p $@

clean:
	$(RM) $(NIF) $(OBJ)

.PHONY: all clean calling_from_make install tzdata

# Don't echo commands unless the caller exports "V=1"
${V}.SILENT: