如何在自定义CMake命令中包含文字双引号? [英] How do I include a literal double quote in a custom CMake command?

问题描述

我正在尝试创建一个自定义命令，该命令与某些环境变量(例如LDFLAGS)一起运行，如果其值包含空格，则需要将其引用:

I'm trying to create a custom command that runs with some environment variables, such as LDFLAGS, whose value needs to be quoted if it contains spaces:

LDFLAGS="-Lmydir -Lmyotherdir"

由于CMake的转义规则，我找不到在CMake自定义命令中包含此参数的方法.到目前为止，这是我尝试过的:

I cannot find a way to include this argument in a CMake custom command, due to CMake's escaping rules. Here's what I've tried so far:

COMMAND LDFLAGS="-Ldir -Ldir2" echo blah VERBATIM)

产量"LDFLAGS=\"-Ldir -Ldir2\"" echo blah

COMMAND LDFLAGS=\"-Ldir -Ldir2\" echo blah VERBATIM)

产量LDFLAGS=\"-Ldir -Ldir2\" echo blah

似乎我要么将整个字符串都用引号引起来，要么用作命令的一部分时转义的引号无法解析.

It seems I either get the whole string quoted, or the escaped quotes don't resolve when used as part of the command.

我希望可以使用包含双引号的方法，也可以选择一种更好的方法来为命令设置环境变量.请注意，我仍然使用CMake 2.8，因此我在3.2中没有新的"env"命令.

I would appreciate either a way to include the literal double-quote or as an alternative a better way to set environment variables for a command. Please note that I'm still on CMake 2.8, so I don't have the new "env" command available in 3.2.

请注意，这不是 何时引用变量的副本? ，因为这些引号方法都不适用于这种特殊情况.

Note that this is not a duplicate of When to quote variables? as none of those quoting methods work for this particular case.

推荐答案

最明显的选择-使用外部脚本.当碰到COMMAND的边界时，尤其是在较早版本的CMake中，通常建议这样做.

The obvious choice - often recommended when hitting the boundaries of COMMAND especially with older versions of CMake - is to use an external script.

我只是想添加一些简单的COMMAND变体，这些变体可以工作并且不需要外壳，但是-我不得不承认-仍然部分依赖于平台.

I just wanted to add some simple COMMAND only variations that do work and won't need a shell, but are - I have to admit - still partly platform dependent.

• 一个示例是仅将引用的部分放入变量中:

• One example would be to put only the quoted part into a variable:

set(vars_as_string "-Ldir -Ldir2")
add_custom_target(
    QuotedEnvVar
    COMMAND env LD_FLAGS=${vars_as_string} | grep LD_FLAGS
)

实际上会转义空格而不是引号.

Which actually does escape the space and not the quotes.

另一个示例是使用转义引号将其添加为启动器"规则:

Another example would be to add it with escaped quotes as a "launcher" rule:

add_custom_target(
    LauncherEnvVar
    COMMAND env | grep LD_FLAGS
)
set_target_properties(
    LauncherEnvVar 
    PROPERTIES RULE_LAUNCH_CUSTOM "env LD_FLAGS=\"-Ldir -Ldir2\""
)

编辑:添加了多个带引号的参数的示例，而无需转义引号

Edit: Added examples for multiple quoted arguments without the need of escaping quotes

• 另一个示例是在函数中隐藏一些复杂性"，并且-如果要将其添加到所有自定义命令调用中，请使用全局/目录

替代(对于CMake> = 3.0)

Alternative (for CMake >= 3.0)

• 我认为我们实际上在这里(cmake -E env ...之外)的名称是

• I think what we actually are looking for here (besides the cmake -E env ...) is named Bracket Argument and does allow any character without the need of adding backslashes:

set_property(
    GLOBAL PROPERTY 
        RULE_LAUNCH_CUSTOM [=[env LDFLAGS="-Ldir1 -Ldir2" CFLAGS="-Idira -Idirb"]=]
)
add_custom_target(
    MultipleEnvVarNew
    COMMAND env | grep -E 'LDFLAGS|CFLAGS'
)

参考

• 0005145:为ADD_CUSTOM_COMMAND/ADD_CUSTOM_TARGET设置环境变量
• 如何修改传递给自定义CMake的环境变量目标?
• [CMake]如何为自定义命令设置环境变量
• cmake:何时引用变量?
• 0005145: Set environment variables for ADD_CUSTOM_COMMAND/ADD_CUSTOM_TARGET
• How to modify environment variables passed to custom CMake target?
• [CMake] How to set environment variable for custom command
• cmake: when to quote variables?

这篇关于如何在自定义CMake命令中包含文字双引号?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！