Question

我正在使用NMake创建一个makefile。我有一些实用程序可以将一个文件转换为CPP文件。该实用程序需要在会话期间设置特定的Windows环境变量。我可以在Makefile中设置这个变量，还是我需要创建一个批处理脚本来设置变量才能调用NMake？

Answer 1

继承调用ENVAR时存在的环境变量nmake 作为同名的nmake宏。如果您更改了ENVVAR中的值 makefile，如：

ENVAR=newval

然后环境变量ENVAR假定命令的值为newval 由makefile运行。目标：

foo:
    echo "%ENVAR%"

将回复newval。

但您无法创建这样的环境变量ENVAR。所以你呢必须至少创建之前要使用的环境变量调用nmake

Answer 2

使用!if [set ...] trick：

!if [set myvar=1]
!endif

# Macro values are fine, too, of course:
MYVAL=preprocessed
!if [set myvar=$(MYVAL)]
!endif

# Proof that myvar has really become an env. var. (see the output):
myvar=This is propagated to the env now!
mymacro=(But this isn't, of course.)

# This handy form works, too:
!if [set myA=1] || [set myB=2]
!endif

# But this will *NOT* make myX an env. var., if it hasn't been set yet:
!if [set myX=$(myX)]
!endif
myX=So you'll not see this...

all:
    set my

输出：

D:\tmp>nmake -f test.mak

Microsoft (R) Program Maintenance Utility Version 14.21.27702.2
Copyright (C) Microsoft Corporation.  All rights reserved.

        set my
myA=1
myB=2
myvar=This is propagated to the env now!

如何使用NMake设置环境变量

2 个答案: