Generic Makefile for C projects. Supports multiple source directories, with out-of-source release, debug and memcheck builds.

Makefile

# Project info

EXEC_NAME := main
SRC_DIRS := src
BUILD_DIR := build

# General config

CFLAGS += -std=c18 -Wall -Wextra -Wconversion -Werror
CPPFLAGS += $(addprefix -I,$(SRC_DIRS))
LDFLAGS +=

# Configure release, debug and memcheck builds

MODE ?= release

ifeq ($(MODE),release)
CFLAGS += -O3

else ifeq ($(MODE),debug)
CFLAGS += -O1 -g -fsanitize=address -fno-omit-frame-pointer
LDFLAGS += -g -fsanitize=address

else ifeq ($(MODE),memcheck)
CFLAGS += -O0 -g
LDFLAGS += -g
START_PREFIX = valgrind --leak-check=yes

else
$(error Invalid MODE: $(MODE))

endif

OUTPUT_DIR := $(BUILD_DIR)/$(MODE)
MAIN_EXEC := $(OUTPUT_DIR)/$(EXEC_NAME)

SRCS = $(shell find $(SRC_DIRS) -name "*.c")
OBJS = $(SRCS:%.c=$(OUTPUT_DIR)/%.o)
DEPS = $(OBJS:.o=.d)

# Rules

.PHONY: all start clean

all: $(MAIN_EXEC)

start: $(MAIN_EXEC)
	$(START_PREFIX) ./$<

clean:
	rm -rf $(BUILD_DIR)

$(MAIN_EXEC): $(OBJS)
	$(CC) $(LDFLAGS) $^ -o $@

$(OUTPUT_DIR)/%.o: %.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) $(CPPFLAGS) -MMD -MP -c $< -o $@

# Generated dependencies

-include $(DEPS)