GNUmakefile

TARGET     := imk
CC         ?= cc
BUILD_HOST := build_host.h
SRC        := $(wildcard *.c)
OS         := $(shell uname -s)
OBJDIR     := obj

ifeq ($(OS), Linux)
    GRP    := root
    SRC    += compat/poll_linux.c
    CFLAGS += -D_DEFAULT_SOURCE
else ifeq ($(OS), $(filter $(OS), NetBSD OpenBSD FreeBSD Darwin))
    GRP := wheel
    SRC += compat/poll_bsd.c
else
    $(error Unrecognized OS)
endif

OBJ := $(addprefix $(OBJDIR)/,$(notdir $(SRC:.c=.o)))

INSTALL      := install
INSTALL_ARGS := -o root -g $(GRP) -m 755
INSTALL_DIR  := /usr/local/bin/

INCLUDES :=
LIBS     :=

CFLAGS += -Werror -Wall $(INCLUDES)
LFLAGS += $(LIBS)

ifeq ($(CC), $(filter $(CC), clang gcc cc musl-gcc))
    CFLAGS += -std=c99 -pedantic
endif

# version info from git
REVCNT := $(shell git rev-list --count master 2>/dev/null)
ifeq ($(REVCNT),)
	VERSION := devel
else
	REVHASH := $(shell git rev-parse --short HEAD 2>/dev/null)
	ISCLEAN := $(shell git diff-index --quiet HEAD || echo " [devel]" 2>/dev/null)
	VERSION := "$(REVCNT).$(REVHASH)$(ISCLEAN)"
endif

all : debug

debug : CFLAGS += -g -ggdb -DDEBUG
debug : LFLAGS += -g
debug : build

release : CFLAGS += -O3
release : clean build
	strip $(TARGET)

static : CFLAGS += -static
static : LFLAGS += -static
static : release

build : $(OBJDIR) $(BUILD_HOST) $(TARGET)

$(BUILD_HOST):
	@echo "#define BUILD_HOST \"`hostname`\""      > $(BUILD_HOST)
	@echo "#define BUILD_OS \"`uname`\""          >> $(BUILD_HOST)
	@echo "#define BUILD_PLATFORM \"`uname -m`\"" >> $(BUILD_HOST)
	@echo "#define BUILD_KERNEL \"`uname -r`\""   >> $(BUILD_HOST)
	@echo "#define VERSION \"$(VERSION)\""        >> $(BUILD_HOST)

$(TARGET) : $(BUILD_HOST) $(OBJ)
	$(CC) $(LFLAGS) -o $@ $(OBJ)

$(OBJDIR) :
	@mkdir -p $(OBJDIR)

$(OBJDIR)/%.o : %.c
	$(CC) $(CFLAGS) -o $@ -c $<

$(OBJDIR)/%.o : compat/%.c
	$(CC) $(CFLAGS) -o $@ -c $<

install :
	$(INSTALL) $(INSTALL_ARGS) $(TARGET) $(INSTALL_DIR)

clean :
	-rm -f *.core
	-rm -f $(BUILD_HOST)
	-rm -f $(TARGET)
	-rm -rf ./$(OBJDIR)

.PHONY : all build debug release static install install-static clean