使用 gcc 自动生成依赖项

Question

New to GNU Make and trying to build a Makefile that automatically generates its dependencies for rebuilding so that the necessary objects get rebuilt and linked upon changing a header file.

Rather than using .d files I want to have a single file like .depend so I have a rule that creates the file and include it as a dependency like this (using sed to append obj/ in front of every line)

.depend: $(SRC_FILES)
    rm -f ./.depend
    $(CC) $(CFLAGS) -MM $^ | sed 's/^/$(OBJECT_DIR)\//' >> ./.depend;

include .depend

The problem is, upon building it only compiles the first rule in the .depend file and then stops with a succession. This is very likely a problem with the way I have my rules/targets set up but I can't figure out what's making it stop at the first built object, my file looks like this

BIN_NAME := test

# Compiler
CC      := gcc
CFLAGS  := -Wall -O3

# Directories
BINARY_DIR := bin
OBJECT_DIR := obj
SOURCE_DIR := src

# Files 
SRC_FILES := $(wildcard $(SOURCE_DIR)/*.c)
OBJ_FILES := $(patsubst $(SOURCE_DIR)/%.c,$(OBJECT_DIR)/%.o, $(SRC_FILES))

# Dependencies
.depend: $(SRC_FILES)
    rm -f ./.depend
    $(CC) $(CFLAGS) -MM $^ | sed 's/^/$(OBJECT_DIR)\//' >> ./.depend;

#include .depend

# Targets
$(OBJECT_DIR)/%.o: $(SOURCE_DIR)/%.c
    $(CC) $(CFLAGS) -c $< -o $@

$(BINARY_DIR)/$(BIN_NAME): $(OBJ_FILES)
    $(CC) $(CFLAGS) -o $@ $^

clean:
    rm $(OBJECT_DIR)/* $(BINARY_DIR)/* .depend

Commenting include .depend skips generation of the .depend file and outputs the binary properly but only updates when changing a source file as expected when not using dependency gen. I want to know what causes this behavior, and the problems with my targets. The sample .depend file looks like this

obj/message.o: src/message.c src/message.h
obj/hello.o: src/hello.c src/message.h

Answer 1

Read the intro section in the GNU make manual and you will see in the first sentence:

By default, make starts with the first target.

What's the first target in your makefile? Since the include comes before any other targets, it's the first target in the include d file.

As Beta says, simply put the include line at the end of your makefile (or at least, not at the beginning) and your problem will be solved.