Expose and implement generic math interfaces on core types (#54650)

* Pin MicrosoftNetCompilersToolsetVersion to a version that supports Static Abstracts in Interfaces

* Fixed issues related to enabling generic math in a general sense (#4)

- Disable constraint checking during EEInit
- Disable il linker running on CoreLib
- Fixup generic math tests to actually build

* Adding interfaces to support generic math

* Implement generic math interfaces on core types

* Updating the System.Runtime ref assembly to support generic math

* Add a basic xunit test for generic-math

* Removing unnecessary nullable annotations

* Ensure all preview interface members are explicitly implemented

* Don't use var for various methods in Double/Half/Single

* Ensure FeatureGenericMath is defined for Mono

* Skip generic math tests on Mono WASM due to dotnet/runtime#54910

* Apply suggestions from code review

Co-authored-by: Aleksey Kliger (λgeek) <akliger@gmail.com>

Co-authored-by: David Wrighton <davidwr@microsoft.com>
Co-authored-by: Aleksey Kliger (λgeek) <akliger@gmail.com>

eng/Versions.props

@@ -17,6 +17,8 @@
     <DotNetFinalVersionKind Condition="'$(StabilizePackageVersion)' == 'true'">release</DotNetFinalVersionKind>
     <!-- Opt-in/out repo features -->
     <UsingToolMicrosoftNetCompilers>true</UsingToolMicrosoftNetCompilers>
+    <!-- TODO: Upgrade compiler version to enable Static Abstracts in Interfaces; remove this once the employed SDK uses a new enough version. -->
+    <MicrosoftNetCompilersToolsetVersion>4.0.0-2.21323.11</MicrosoftNetCompilersToolsetVersion>
     <UsingToolMicrosoftNetILLinkTasks>true</UsingToolMicrosoftNetILLinkTasks>
     <UsingToolIbcOptimization>false</UsingToolIbcOptimization>
     <UsingToolXliff>false</UsingToolXliff>

src/coreclr/clr.featuredefines.props

@@ -9,6 +9,7 @@
         <FeaturePerfTracing>true</FeaturePerfTracing>
         <FeatureTypeEquivalence>true</FeatureTypeEquivalence>
         <FeatureBasicFreeze>true</FeatureBasicFreeze>
+        <FeatureGenericMath>true</FeatureGenericMath>
         <ProfilingSupportedBuild>true</ProfilingSupportedBuild>
     </PropertyGroup>
 
@@ -58,7 +59,8 @@
         <DefineConstants Condition="'$(FeatureBasicFreeze)' == 'true'">$(DefineConstants);FEATURE_BASICFREEZE</DefineConstants>
         <DefineConstants Condition="'$(FeaturePortableShuffleThunks)' == 'true'">$(DefineConstants);FEATURE_PORTABLE_SHUFFLE_THUNKS</DefineConstants>
         <DefineConstants Condition="'$(FeatureICastable)' == 'true'">$(DefineConstants);FEATURE_ICASTABLE</DefineConstants>
-
+        <DefineConstants Condition="'$(FeatureGenericMath)' == 'true'">$(DefineConstants);FEATURE_GENERIC_MATH</DefineConstants>
+
         <DefineConstants Condition="'$(ProfilingSupportedBuild)' == 'true'">$(DefineConstants);PROFILING_SUPPORTED</DefineConstants>
         <DefineConstants Condition="'$(FeatureProfAttach)' == 'true'">$(DefineConstants);FEATURE_PROFAPI_ATTACH_DETACH</DefineConstants>
     </PropertyGroup>

src/coreclr/vm/typedesc.cpp

@@ -1730,6 +1730,11 @@ BOOL TypeVarTypeDesc::SatisfiesConstraints(SigTypeContext *pTypeContextOfConstra
     }
     CONTRACTL_END;
 
+    // During EEStartup, we cannot safely validate constraints, but we can also be confident that the code doesn't violate them
+    // Just skip validation and declare that the constraints are satisfied.
+    if (g_fEEInit)
+        return TRUE;
+
     IMDInternalImport* pInternalImport = GetModule()->GetMDImport();
     mdGenericParamConstraint tkConstraint;
 

src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems

@@ -2257,4 +2257,27 @@
       <Link>Interop\Windows\Kernel32\Interop.Threading.cs</Link>
     </Compile>
   </ItemGroup>
+  <ItemGroup Condition="'$(FeatureGenericMath)' == 'true'">
+    <Compile Include="$(MSBuildThisFileDirectory)System\IAdditionOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IAdditiveIdentity.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IBitwiseOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IComparisonOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IDecrementOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IDivisionOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IEqualityOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IFloatingPoint.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IIncrementOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IInteger.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IMinMaxValue.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IModulusOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IMultiplicativeIdentity.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IMultiplyOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\INumber.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IParseable.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IShiftOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\ISpanParseable.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\ISubtractionOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IUnaryNegationOperators.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\IUnaryPlusOperators.cs" />
+  </ItemGroup>
 </Project>