开始在特定目录中创建目标文件 [英] Getting make to create object files in a specific directory

问题描述

GNU Make 3.82
gcc 4.7.2
c89

我有以下make文件:

I have the following make file:

INC_PATH=-I/home/dev_tools/apr/include/apr-1
LIB_PATH=-L/home/dev_tools/apr/lib
LIBS=-lapr-1 -laprutil-1
RUNTIME_PATH=-Wl,-rpath,/home/dev_tools/apr/lib
CC=gcc
CFLAGS=-Wall -Wextra -g -m32 -O2 -D_DEBUG -D_THREAD_SAFE -D_REENTRANT -D_LARGEFILE64_SOURCE $(INC_PATH)
SOURCES=$(wildcard src/*.c)
OBJECTS=$(patsubst %.c, %.o, $(SOURCES))

EXECUTABLE=bin/to

all:    build $(EXECUTABLE)

$(EXECUTABLE):  $(OBJECTS)
    $(CC) $(CFLAGS) -o $@ $(RUNTIME_PATH) $(OBJECTS) $(LIB_PATH) $(LIBS)

$(OBJECTS): $(SOURCES)
    $(CC) $(CFLAGS) -c $(SOURCES) $(LIB_PATH) $(LIBS)

build:
    @mkdir -p bin

clean:
    rm -rf $(EXECUTABLE) $(OBJECTS) bin
    find . -name "*~" -exec rm {} \;
    find . -name "*.o" -exec rm {} \;

我的目录结构是这样的project/src project/bin.我的Makefile位于project (root)文件夹中，而我所有的* .h和* .c都位于src目录中.目前，我只有一个名为timeout.c的源文件.

My directory structure is like this project/src project/bin. My Makefile is in the project (root) folder, and all my *.h and *.c are in the src directory. Currently I have only one source file called timeout.c

我收到此错误:

gcc: error: src/timeout.o: No such file or directory

我已使用它来获取所有源文件:

I have used this to get all the source files:

SOURCES=$(wildcard src/*.c)

目标文件:

OBJECTS=$(patsubst %.c, %.o, $(SOURCES))

但是，make似乎在Makefile所在的项目根文件夹中创建了目标文件.难道不应该把它放在src目录中吗?

However, the make seems to create the object file in the project root folder where the Makefile is. Should it not put it in the src directory?

推荐答案

此规则有两个问题(三个):

You have two problems in this rule (well, three):

$(OBJECTS): $(SOURCES)
    $(CC) $(CFLAGS) -c $(SOURCES) $(LIB_PATH) $(LIBS)

您还没有注意到，但是规则使每个对象依赖于 all 源，并尝试以这种方式构建.只要您只有一个来源，这不是问题.使用静态模式规则和

You haven't noticed yet, but the rule makes each object dependent on all sources, and tries to build that way. Not a problem as long as you have only one source. Easy to fix with a static pattern rule and an automatic variable:

$(OBJECTS): src/%.o : src/%.c
    $(CC) $(CFLAGS) -c $< $(LIB_PATH) $(LIBS)

此外，命令("$(CC)...")没有指定输出文件名，因此gcc将从源文件名中推断出该文件名；如果给它src/timeout.c，它将产生timeout.o(在工作目录project/中).因此，您应该指定输出文件的所需路径.易于使用另一个自动变量:

Also, the command ("$(CC)...") doesn't specify an output file name, so gcc will infer it from the source file name; if you give it src/timeout.c, it will produce timeout.o (in the working directory, project/). So you should specify the desired path to the output file. Easy to do with another automatic variable:

$(OBJECTS): src/%.o : src/%.c
    $(CC) $(CFLAGS) -c $< $(LIB_PATH) $(LIBS) -o $@

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