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No A/W suffix probing on non-Windows platforms

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The .NET runtimes no longer add an A or W suffix to function export names during probing for P/Invokes on non-Windows platforms.

Version introduced

5.0

Change description

Windows has a convention of adding an A or W suffix to Windows SDK function names, which correspond to the Windows code page and Unicode versions, respectively.

In previous versions of .NET, both the CoreCLR and Mono runtimes add an A or W suffix to the export name during export discovery for P/Invokes on all platforms.

In .NET 5 and later versions, an A or W suffix is added to the export name during export discovery on Windows only. On Unix platforms, the suffix is not added. The semantics of both runtimes on the Windows platform remain unchanged.

Reason for change

This change was made to simplify cross-platform probing. It's overhead that shouldn't be incurred, given that non-Windows platforms don't contain this semantic.

To mitigate the change, you can manually add the desired suffix on non-Windows platforms. For example:

[DllImport(...)]
extern static void SetWindowTextW();

Affected APIs