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从命令行传递附加变量到 make

发布于 2024-09-01 06:11:37 字数 77 浏览 10 评论 0 原文

我可以将变量作为命令行参数传递给 GNU Makefile 吗？换句话说，我想传递一些参数，这些参数最终将成为 Makefile 中的变量。

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太阳哥哥 2024-09-08 06:11:37

您可以通过多种方式从 makefile 外部设置变量：

从环境 - 每个环境变量都会转换为具有相同名称和值的 makefile 变量。

您可能还想设置 -e 选项（又名 --environments-override），并且您的环境变量将覆盖 makefile 中的分配（除非这些分配他们自己使用 override 指令但是，不建议这样做，使用 ?= 赋值（条件变量赋值运算符，只有在变量尚未定义时才有效）要好得多、更灵活：
```
FOO?=default_value_if_not_set_in_environment
```
请注意，某些变量不是从环境继承的：
- MAKE 从脚本名称中获取
- SHELL 要么在 makefile 中设置，要么默认为 /bin/sh （基本原理：命令在 makefile 中指定，并且它们是特定于 shell 的） .
从命令行 - make 可以将变量赋值作为命令行的一部分，与目标混合：
```
使目标 FOO=bar
```
但是makefile中对FOO变量的所有赋值都将被忽略，除非您使用override 指令赋值。（效果与环境变量的 -e 选项相同）。
从父 Make 导出 - 如果从 Makefile 调用 Make，通常不应显式编写如下变量赋值：
```
# 不要这样做！
目标：
        $(MAKE) -C 目标 CC=$(CC) CFLAGS=$(CFLAGS)
```
相反，更好的解决方案可能是导出这些变量。导出变量会使其进入每个 shell 调用的环境中，并且从这些命令中进行调用会选择上面指定的这些环境变量。
```
# 这样做
CFLAGS=-g
导出CFLAGS
目标：
        $(MAKE) -C 目标
```
您还可以使用不带参数的 export 导出所有变量。

You have several options to set up variables from outside your makefile:

From environment - each environment variable is transformed into a makefile variable with the same name and value.

You may also want to set -e option (aka --environments-override) on, and your environment variables will override assignments made into makefile (unless these assignments themselves use the override directive . However, it's not recommended, and it's much better and flexible to use ?= assignment (the conditional variable assignment operator, it only has an effect if the variable is not yet defined):
```
FOO?=default_value_if_not_set_in_environment
```
Note that certain variables are not inherited from environment:
- MAKE is gotten from name of the script
- SHELL is either set within a makefile, or defaults to /bin/sh (rationale: commands are specified within the makefile, and they're shell-specific).
From command line - make can take variable assignments as part of his command line, mingled with targets:
```
make target FOO=bar
```
But then all assignments to FOO variable within the makefile will be ignored unless you use the override directive in assignment. (The effect is the same as with -e option for environment variables).
Exporting from the parent Make - if you call Make from a Makefile, you usually shouldn't explicitly write variable assignments like this:
```
# Don't do this!
target:
        $(MAKE) -C target CC=$(CC) CFLAGS=$(CFLAGS)
```
Instead, better solution might be to export these variables. Exporting a variable makes it into the environment of every shell invocation, and Make calls from these commands pick these environment variable as specified above.
```
# Do like this
CFLAGS=-g
export CFLAGS
target:
        $(MAKE) -C target
```
You can also export all variables by using export without arguments.

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書生途 2024-09-08 06:11:37

最简单的方法是：

make foo=bar target

然后在你的makefile中你可以引用$(foo)。请注意，这不会自动传播到子品牌。

如果您使用子品牌，请参阅本文：将变量传递给子品牌-制作

The simplest way is:

make foo=bar target

Then in your makefile you can refer to $(foo). Note that this won't propagate to sub-makes automatically.

If you are using sub-makes, see this article: Communicating Variables to a Sub-make

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枉心 2024-09-08 06:11:37

假设您有一个如下所示的 makefile：

action:
    echo argument is $(argument)

然后您可以将其命名为 make action argument=something

Say you have a makefile like this:

action:
    echo argument is $(argument)

You would then call it make action argument=something

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那支青花 2024-09-08 06:11:37

看来命令参数覆盖了环境变量。

Makefile：

send:
    echo $(MESSAGE1) $(MESSAGE2)

示例运行：

$ MESSAGE1=YES MESSAGE2=NG  make send MESSAGE2=OK
echo YES OK
YES OK

It seems command args overwrite environment variable.

Makefile:

send:
    echo $(MESSAGE1) $(MESSAGE2)

Example run:

$ MESSAGE1=YES MESSAGE2=NG  make send MESSAGE2=OK
echo YES OK
YES OK

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心在旅行 2024-09-08 06:11:37

来自手册：

make 中的变量可以来自 make 运行的环境。 make 启动时看到的每个环境变量都会转换为具有相同名称和值的 make 变量。但是，makefile 中的显式赋值或使用命令参数会覆盖环境。

所以你可以（从bash）：

FOOBAR=1 make

在你的Makefile中产生一个变量FOOBAR。

From the manual:

Variables in make can come from the environment in which make is run. Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value. However, an explicit assignment in the makefile, or with a command argument, overrides the environment.

So you can do (from bash):

FOOBAR=1 make

resulting in a variable FOOBAR in your Makefile.

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风为裳 2024-09-08 06:11:37

这里没有引用另一个选项，它包含在 Stallman 和 McGrath 的 GNU Make 书中（参见 http://www.chemie.fu-berlin.de/chemnet/use/info/make/make_7.html）。它提供了示例：

archive.a: ...
ifneq (,$(findstring t,$(MAKEFLAGS)))
        +touch archive.a
        +ranlib -t archive.a
else
        ranlib archive.a
endif

它涉及验证给定参数是否出现在 MAKEFLAGS 中。例如..假设您正在研究 c++11 中的线程，并且您已将研究分为多个文件（class01、...、classNM）并且您想要：编译全部并单独运行，或者一次编译一个并在指定标志（例如 -r）的情况下运行它。因此，您可以想出以下 Makefile：

CXX=clang++-3.5
CXXFLAGS = -Wall -Werror -std=c++11
LDLIBS = -lpthread

SOURCES = class01 class02 class03

%: %.cxx
    $(CXX) $(CXXFLAGS) -o [email protected] $^ $(LDLIBS)
ifneq (,$(findstring r,  $(MAKEFLAGS)))
    ./[email protected]
endif

all: $(SOURCES)

.PHONY: clean

clean:
    find . -name "*.out" -delete

有了它，您就可以：使用

make -r class02 构建并运行一个文件；
使用 make 或 make all 构建所有内容；
使用 make -r 构建并运行所有内容（假设它们都包含某种特定类型的断言内容，并且您只想测试它们）

There's another option not cited here which is included in the GNU Make book by Stallman and McGrath (see http://www.chemie.fu-berlin.de/chemnet/use/info/make/make_7.html). It provides the example:

archive.a: ...
ifneq (,$(findstring t,$(MAKEFLAGS)))
        +touch archive.a
        +ranlib -t archive.a
else
        ranlib archive.a
endif

It involves verifying if a given parameter appears in MAKEFLAGS. For example .. suppose that you're studying about threads in c++11 and you've divided your study across multiple files (class01, ... , classNM) and you want to: compile then all and run individually or compile one at a time and run it if a flag is specified (-r, for instance). So, you could come up with the following Makefile:

CXX=clang++-3.5
CXXFLAGS = -Wall -Werror -std=c++11
LDLIBS = -lpthread

SOURCES = class01 class02 class03

%: %.cxx
    $(CXX) $(CXXFLAGS) -o [email protected] $^ $(LDLIBS)
ifneq (,$(findstring r,  $(MAKEFLAGS)))
    ./[email protected]
endif

all: $(SOURCES)

.PHONY: clean

clean:
    find . -name "*.out" -delete

Having that, you'd:

build and run a file w/ make -r class02;
build all w/ make or make all;
build and run all w/ make -r (suppose that all of them contain some certain kind of assert stuff and you just want to test them all)

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最终幸福 2024-09-08 06:11:37

如果你创建一个名为 Makefile 的文件并添加一个像这样的变量 $(unittest)
那么你就可以在 Makefile 中使用这个变量，即使有通配符

示例：

make unittest=*

我使用 BOOST_TEST 并给参数提供通配符 --run_test=$(unittest)
然后我将能够使用正则表达式来过滤掉我想要我的 Makefile 的测试
运行

If you make a file called Makefile and add a variable like this $(unittest)
then you will be able to use this variable inside the Makefile even with wildcards

example :

make unittest=*

I use BOOST_TEST and by giving a wildcard to parameter --run_test=$(unittest)
then I will be able to use regular expression to filter out the test I want my Makefile
to run

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