MSBuild conditionals depending on task parameters

Question

In MSBuild it's straightforward to define, say, a PropertyGroup which depends on the value of a property Foo:

<PropertyGroup Conditional="'$(Foo)'=='Bar'" />

Is it also possible for the conditional to depend on a task parameter?

For example, I'd like to use the value of the Link task's SubSystemparameter roughly like this:

<PropertyGroup Conditional="'$(Link/SubSystem)'=='Console'" />

but don't know if it is possible, and if it is, what the correct syntax is.

I'm pretty new to MSBuild though, so it's perfectly possible that I've missed something.

Answer 1

I don't have the VC SDK on my machine here, so I can't try a Link Task but you could try using the <Output /> of the Task:

...
<PropertyGroup Condition="'$(LinkSubSystem)'=='Console'">
    <MyDependentProp>Whatever</MyDependentProp>
</PropertyGroup>

<Target Name="Linker">
    <Link Sources="@(LinkerSources)" SubSystem="Console">
        <Output TaskParameter="SubSystem" ItemName="LinkSubSystem" />
    </Link>
</Target>
...

A second approach could be to use a property for Link Task SubSystem param itself an just recycle it for your PropertyGroup.

...
<PropertyGroup>
    <LinkerSubSystem>Console</LinkerSubSystem>
</PropertyGroup>

<PropertyGroup Condition="'$(LinkerSubSystem)'=='Console'">
    <MyDependentProp>Whatever</MyDependentProp>
</PropertyGroup>

<Target Name="Linker">
    <Link Sources="@(LinkerSources)" SubSystem="$(LinkerSubSystem)" />
</Target>
...