从不同的源文件夹构建到不同的目标文件夹

这个 Makefile 的主要特点：

• 自动检测指定文件夹中的 C 源
• 多个源文件夹
• 对象和依赖项文件的多个相应目标文件夹
• 为每个目标文件夹生成自动规则
• 在目标文件夹不存在时创建它们
• 使用 gcc 进行依赖管理：仅构建必要的内容
• 适用于 Unix 和 DOS 系统
• 为 GNU Make 编写

此 Makefile 可用于构建具有此类结构的项目：

\---Project
    +---Sources
    |   +---Folder0
    |   |       main.c
    |   |       
    |   +---Folder1
    |   |       file1_1.c
    |   |       file1_1.h
    |   |       
    |   \---Folder2
    |           file2_1.c
    |           file2_1.h
    |           file2_2.c
    |           file2_2.h
    \---Build
        |   Makefile
        |   myApp.exe
        |   
        +---Folder0
        |       main.d
        |       main.o
        |       
        +---Folder1
        |       file1_1.d
        |       file1_1.o
        |       
        \---Folder2
                file2_1.d
                file2_1.o
                file2_2.d
                file2_2.o

Makefile 文件

# Set project directory one level above of Makefile directory. $(CURDIR) is a GNU make variable containing the path to the current working directory
PROJDIR := $(realpath $(CURDIR)/..)
SOURCEDIR := $(PROJDIR)/Sources
BUILDDIR := $(PROJDIR)/Build

# Name of the final executable
TARGET = myApp.exe

# Decide whether the commands will be shwon or not
VERBOSE = TRUE

# Create the list of directories
DIRS = Folder0 Folder1 Folder2
SOURCEDIRS = $(foreach dir, $(DIRS), $(addprefix $(SOURCEDIR)/, $(dir)))
TARGETDIRS = $(foreach dir, $(DIRS), $(addprefix $(BUILDDIR)/, $(dir)))

# Generate the GCC includes parameters by adding -I before each source folder
INCLUDES = $(foreach dir, $(SOURCEDIRS), $(addprefix -I, $(dir)))

# Add this list to VPATH, the place make will look for the source files
VPATH = $(SOURCEDIRS)

# Create a list of *.c sources in DIRS
SOURCES = $(foreach dir,$(SOURCEDIRS),$(wildcard $(dir)/*.c))

# Define objects for all sources
OBJS := $(subst $(SOURCEDIR),$(BUILDDIR),$(SOURCES:.c=.o))

# Define dependencies files for all objects
DEPS = $(OBJS:.o=.d)

# Name the compiler
CC = gcc

# OS specific part
ifeq ($(OS),Windows_NT)
    RM = del /F /Q 
    RMDIR = -RMDIR /S /Q
    MKDIR = -mkdir
    ERRIGNORE = 2>NUL || true
    SEP=\\
else
    RM = rm -rf 
    RMDIR = rm -rf 
    MKDIR = mkdir -p
    ERRIGNORE = 2>/dev/null
    SEP=/
endif

# Remove space after separator
PSEP = $(strip $(SEP))

# Hide or not the calls depending of VERBOSE
ifeq ($(VERBOSE),TRUE)
    HIDE =  
else
    HIDE = @
endif

# Define the function that will generate each rule
define generateRules
$(1)/%.o: %.c
    @echo Building $$@
    $(HIDE)$(CC) -c $$(INCLUDES) -o $$(subst /,$$(PSEP),$$@) $$(subst /,$$(PSEP),$$<) -MMD
endef

.PHONY: all clean directories 

all: directories $(TARGET)

$(TARGET): $(OBJS)
    $(HIDE)echo Linking $@
    $(HIDE)$(CC) $(OBJS) -o $(TARGET)

# Include dependencies
-include $(DEPS)

# Generate rules
$(foreach targetdir, $(TARGETDIRS), $(eval $(call generateRules, $(targetdir))))

directories: 
    $(HIDE)$(MKDIR) $(subst /,$(PSEP),$(TARGETDIRS)) $(ERRIGNORE)

# Remove all objects, dependencies and executable files generated during the build
clean:
    $(HIDE)$(RMDIR) $(subst /,$(PSEP),$(TARGETDIRS)) $(ERRIGNORE)
    $(HIDE)$(RM) $(TARGET) $(ERRIGNORE)
    @echo Cleaning done ! 

如何使用此 Makefile 要使此 Makefile 适应你的项目，你必须：

1. 更改 TARGET 变量以匹配你的目标名称
2. 在 SOURCEDIR 和 BUILDDIR 中更改 Sources 和 Build 文件夹的名称
3. 在 Makefile 本身或 make 调用中更改 Makefile 的详细级别
4. 更改 DIRS 中文件夹的名称以匹配你的源和构建文件夹
5. 如果需要，请更改编译器和标志