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.NET API reference documentation (.NET 5+, .NET Core, .NET Framework)
https://docs.microsoft.com/dotnet/api/
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Incomplete DefaultDllImportSearchPaths docs #3205

Open Zenexer opened 5 years ago

Zenexer commented 5 years ago

https://github.com/dotnet/dotnet-api-docs/blob/8adb892bc4a3f45fdeaa24f716d2dbd4ba0365ab/xml/System.Runtime.InteropServices/DefaultDllImportSearchPathsAttribute.xml

.NET Core 3.0 will bring DefaultDllImportSearchPathsAttribute, and the Roslyn analyzers will flag P/Invokes that lack DefaultDllImportSearchPathsAttribute by default. However, the documentation on DefaultDllImportSearchPathsAttribute is Windows-centric; it doesn't describe how DefaultDllImportSearchPathsAttribute works on Linux, for example.

This is a problem for code such at the following snippet taken from https://github.com/dotnet/corefx/blob/master/src/Common/src/Interop/Unix/System.Security.Cryptography.Native/Interop.RAND.cs (with a constant replaced with a literal):

[DllImport("System.Security.Cryptography.Native.OpenSsl")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern unsafe bool CryptoNative_GetRandomBytes(byte* buffer, int length);

The options available for DefaultDllImportSearchPathsAttribute are aimed at Windows, and the documentation doesn't make it clear how to handle this. Is the attribute completely ignored? Are only certain options available?

Zenexer commented 5 years ago

Related: https://github.com/dotnet/roslyn-analyzers/issues/2855

mairaw commented 5 years ago

@AaronRobinsonMSFT, @jkoritzinsky can you guys help with this feedback? Is there anything we can add to the docs about this API behavior in .NET Core? Thanks.

jkoritzinsky commented 5 years ago

I've just checked to confirm, and the DllImportSearchPath enumeration values are ignored on non-Windows. We should add that to the docs.