Makefile

# SPDX-FileCopyrightText: 2018 Frank Hunleth
#
# SPDX-License-Identifier: Apache-2.0
#
# Makefile for building the ntpd helper "script"
#
# Makefile targets:
#
# all/install   build and install
# clean         clean build products and intermediates
#
# Variables to override:
#
# MIX_APP_PATH  path to the build directory
#
# CC            C compiler. MUST be set if crosscompiling
# 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

NTPD_SCRIPT = $(PREFIX)/ntpd_script

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

LDFLAGS +=
CFLAGS ?= -O2 -Wall -Wextra -Wno-unused-parameter
CFLAGS += -std=c99

SRC = src/ntpd_script.c
OBJ = $(SRC:src/%.c=$(BUILD)/%.o)

calling_from_make:
	mix compile

all: install

install: $(PREFIX) $(BUILD) $(NTPD_SCRIPT)

$(OBJ): Makefile

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

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

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

clean:
	$(RM) $(NTPD_SCRIPT) $(OBJ)

format:
	astyle \
	    --style=kr \
	    --indent=spaces=4 \
	    --align-pointer=name \
	    --align-reference=name \
	    --convert-tabs \
	    --attach-namespaces \
	    --max-code-length=100 \
	    --max-instatement-indent=120 \
	    --pad-header \
	    --pad-oper \
	    src/*.c

.PHONY: all clean calling_from_make install format

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