特定目标变量为prerequisites在一个Makefile [英] Target-specific Variables as Prerequisites in a Makefile

问题描述

我想写一个GNU使Makefile文件里面有类似的目标，在构建命令它们之间略有不同的负载。
我试图使用特定目标变量来重新present这些变化。其中的一些变量值的参考我想为prerequisites使用的文件。例如：

  target_1：special_filename = target1_ preREQ
target_2：special_filename = target2_ preREQtarget_1 target_2：common_filename $（special_filename）
    do_something common_filename --a-怪异选项= $（special_filename）
 

当我称之为做target_1'，我想它做target1_ preREQ如果它不存在。目前，它似乎并没有使用target1_ preREQ为prerequisite，即使build命令（do_something）被调用合适的参数。

我使用GNU做3.80。

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编辑：
一些并发症多从实际系统。是一些变量本身基于其它变量的值。手动指定prerequisites无法扩展。
稍微复杂一点的例子：

  target_1：special_filename_base = target1_ preREQ
target_2：special_filename_base = target2_ preREQsome_filename_a = $（special_filename_base）.exta
some_filename_b = $（special_filename_base）.extbtarget_1 target_2：common_filename $（special_filename_b）$（special_filename_a）
    do_something common_filename --a-怪异选项= $（special_filename_a）--second = $（special_filename_b）
 

解决方案

一个特定目标变量在目标的命令只能定义（或其他特定目标的任务）;它不能被用作靶的prereqs之一。我不认为有一个干净的方式做你制作想要的东西，但有几个kludgey方式，如下面的：

EXTENSIONS = .exta .extb
target_1：$（添加preFIX target1_ preREQ，$（扩展））
target_2：$（添加preFIX target2_ preREQ，$（扩展））target_1 target_2：common_filename
    do_something common_filename --a-怪异选项= $（过滤％.exta，$ ^）--second = $（过滤％.extb，$ ^）

I'm trying to write a GNU make Makefile which has a load of similar targets, where the build commands vary slightly between them. I'm trying to use target-specific variables to represent these variations. Some of these variable values refer to files I want to use as prerequisites. For example:

target_1:special_filename=target1_prereq
target_2:special_filename=target2_prereq

target_1 target_2: common_filename $(special_filename)
    do_something common_filename --a-weird-option=$(special_filename)

When I call 'make target_1', I want it to make target1_prereq if it doesn't exist. At the moment, it doesn't seem to use target1_prereq as a prerequisite, even though the build command (do_something) is called with the right parameter.

I'm using GNU Make 3.80.

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Edit: A few more complications from the real system. Some of the variables are themselves based on the values of other variables. Manually specifying the prerequisites wouldn't scale. A slightly more complicated example:

target_1:special_filename_base=target1_prereq
target_2:special_filename_base=target2_prereq

some_filename_a = $(special_filename_base).exta
some_filename_b = $(special_filename_base).extb

target_1 target_2: common_filename $(special_filename_b) $(special_filename_a)
    do_something common_filename --a-weird-option=$(special_filename_a) --second=$(special_filename_b)

解决方案

A target-specific variable is defined only in the target's commands (or in other target-specific assignments); it can't be used as one of the target's prereqs. I don't think there's a clean way to do what you want in Make, but there are several kludgey approaches, such as the following:

EXTENSIONS = .exta .extb
target_1: $(addprefix target1_prereq,$(EXTENSIONS))
target_2: $(addprefix target2_prereq,$(EXTENSIONS))

target_1 target_2: common_filename
    do_something common_filename --a-weird-option=$(filter %.exta,$^) --second=$(filter %.extb,$^)

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