Resolve SizeParamIndex to a TypePositionInfo during MarshallingInfo p…

…arsing (#1293)
dotnet · Jul 7, 2021 · eea0bae · eea0bae
1 parent d4b5fd0
commit eea0bae
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Showing 11 changed files with 142 additions and 139 deletions.
diff --git a/DllImportGenerator/DllImportGenerator.UnitTests/CodeSnippets.cs b/DllImportGenerator/DllImportGenerator.UnitTests/CodeSnippets.cs
@@ -1327,6 +1327,17 @@ public static partial void Method(
         [MarshalUsing(CountElementName=""arr"")] ref int[] arr2
     );
 }
+";
+        public static string MutuallyRecursiveSizeParamIndexOnParameter => @"
+using System.Runtime.InteropServices;
+partial class Test
+{
+    [GeneratedDllImport(""DoesNotExist"")]
+    public static partial void Method(
+        [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=1)] ref int[] arr,
+        [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=0)] ref int[] arr2
+    );
+}
 ";
 
         public static string CollectionsOfCollectionsStress => @"

diff --git a/DllImportGenerator/DllImportGenerator.UnitTests/CompileFails.cs b/DllImportGenerator/DllImportGenerator.UnitTests/CompileFails.cs
@@ -121,6 +121,7 @@ public static IEnumerable<object[]> CodeSnippetsToCompile()
             yield return new object[] { CodeSnippets.RecursiveCountElementNameOnReturnValue, 2, 0 };
             yield return new object[] { CodeSnippets.RecursiveCountElementNameOnParameter, 2, 0 };
             yield return new object[] { CodeSnippets.MutuallyRecursiveCountElementNameOnParameter, 4, 0 };
+            yield return new object[] { CodeSnippets.MutuallyRecursiveSizeParamIndexOnParameter, 4, 0 };
         }
 
         [Theory]

diff --git a/DllImportGenerator/DllImportGenerator/ContiguousCollectionElementMarshallingCodeContext.cs b/DllImportGenerator/DllImportGenerator/ContiguousCollectionElementMarshallingCodeContext.cs
@@ -57,12 +57,6 @@ public override string GetAdditionalIdentifier(TypePositionInfo info, string nam
             return $"{nativeSpanIdentifier}__{IndexerIdentifier}__{name}";
         }
 
-        public override TypePositionInfo? GetTypePositionInfoForManagedIndex(int index)
-        {
-            // We don't have parameters to look at when we're in the middle of marshalling an array.
-            return null;
-        }
-
         private static string CalculateIndexerIdentifierBasedOnParentContext(StubCodeContext? parentContext)
         {
             int i = 0;

diff --git a/DllImportGenerator/DllImportGenerator/Marshalling/Forwarder.cs b/DllImportGenerator/DllImportGenerator/Marshalling/Forwarder.cs
@@ -48,20 +48,20 @@ private bool TryRehydrateMarshalAsAttribute(TypePositionInfo info, out Attribute
 
                 if (collectionMarshalling.ElementCountInfo is SizeAndParamIndexInfo countInfo)
                 {
-                    if (countInfo.ConstSize != SizeAndParamIndexInfo.UnspecifiedData)
+                    if (countInfo.ConstSize != SizeAndParamIndexInfo.UnspecifiedConstSize)
                     {
                         marshalAsArguments.Add(
                             AttributeArgument(NameEquals("SizeConst"), null,
                                 LiteralExpression(SyntaxKind.NumericLiteralExpression,
                                     Literal(countInfo.ConstSize)))
                         );
                     }
-                    if (countInfo.ParamIndex != SizeAndParamIndexInfo.UnspecifiedData)
+                    if (countInfo.ParamAtIndex is { ManagedIndex: int paramIndex })
                     {
                         marshalAsArguments.Add(
                             AttributeArgument(NameEquals("SizeParamIndex"), null,
                                 LiteralExpression(SyntaxKind.NumericLiteralExpression,
-                                    Literal(countInfo.ParamIndex)))
+                                    Literal(paramIndex)))
                         );
                     }
                 }

diff --git a/DllImportGenerator/DllImportGenerator/Marshalling/ICustomNativeTypeMarshallingStrategy.cs b/DllImportGenerator/DllImportGenerator/Marshalling/ICustomNativeTypeMarshallingStrategy.cs
@@ -137,11 +137,6 @@ public CustomNativeTypeWithValuePropertyStubContext(StubCodeContext parentContex
 
         public override bool AdditionalTemporaryStateLivesAcrossStages => ParentContext!.AdditionalTemporaryStateLivesAcrossStages;
 
-        public override TypePositionInfo? GetTypePositionInfoForManagedIndex(int index)
-        {
-            return ParentContext!.GetTypePositionInfoForManagedIndex(index);
-        }
-
         public override (string managed, string native) GetIdentifiers(TypePositionInfo info)
         {
             return (ParentContext!.GetIdentifiers(info).managed, MarshallerHelpers.GetMarshallerIdentifier(info, ParentContext));

diff --git a/DllImportGenerator/DllImportGenerator/Marshalling/MarshallingGenerator.cs b/DllImportGenerator/DllImportGenerator/Marshalling/MarshallingGenerator.cs
@@ -376,14 +376,14 @@ private static IMarshallingGenerator CreateStringMarshaller(TypePositionInfo inf
             throw new MarshallingNotSupportedException(info, context);
         }
 
-        private static ExpressionSyntax GetNumElementsExpressionFromMarshallingInfo(TypePositionInfo info, CountInfo count, StubCodeContext context, AnalyzerConfigOptions options)
+        private static ExpressionSyntax GetNumElementsExpressionFromMarshallingInfo(TypePositionInfo info, CountInfo count, StubCodeContext context)
         {
             return count switch
             {
-                SizeAndParamIndexInfo(int size, SizeAndParamIndexInfo.UnspecifiedData) => GetConstSizeExpression(size),
+                SizeAndParamIndexInfo(int size, SizeAndParamIndexInfo.UnspecifiedParam) => GetConstSizeExpression(size),
                 ConstSizeCountInfo(int size) => GetConstSizeExpression(size),
-                SizeAndParamIndexInfo(SizeAndParamIndexInfo.UnspecifiedData, int paramIndex) => CheckedExpression(SyntaxKind.CheckedExpression, GetExpressionForParam(context.GetTypePositionInfoForManagedIndex(paramIndex))),
-                SizeAndParamIndexInfo(int size, int paramIndex) => CheckedExpression(SyntaxKind.CheckedExpression, BinaryExpression(SyntaxKind.AddExpression, GetConstSizeExpression(size), GetExpressionForParam(context.GetTypePositionInfoForManagedIndex(paramIndex)))),
+                SizeAndParamIndexInfo(SizeAndParamIndexInfo.UnspecifiedConstSize, TypePositionInfo param) => CheckedExpression(SyntaxKind.CheckedExpression, GetExpressionForParam(param)),
+                SizeAndParamIndexInfo(int size, TypePositionInfo param) => CheckedExpression(SyntaxKind.CheckedExpression, BinaryExpression(SyntaxKind.AddExpression, GetConstSizeExpression(size), GetExpressionForParam(param))),
                 CountElementCountInfo(TypePositionInfo elementInfo) => CheckedExpression(SyntaxKind.CheckedExpression, GetExpressionForParam(elementInfo)),
                 _ => throw new MarshallingNotSupportedException(info, context)
                 {
@@ -396,53 +396,43 @@ static LiteralExpressionSyntax GetConstSizeExpression(int size)
                 return LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(size));
             }
 
-            ExpressionSyntax GetExpressionForParam(TypePositionInfo? paramInfo)
+            ExpressionSyntax GetExpressionForParam(TypePositionInfo paramInfo)
             {
-                if (paramInfo is null)
-                {
-                    throw new MarshallingNotSupportedException(info, context)
-                    {
-                        NotSupportedDetails = Resources.ArraySizeParamIndexOutOfRange
-                    };
-                }
-                else
-                {
-                    ExpressionSyntax numElementsExpression = GetIndexedNumElementsExpression(
-                        context,
-                        paramInfo,
-                        out int numIndirectionLevels);
+                ExpressionSyntax numElementsExpression = GetIndexedNumElementsExpression(
+                           context,
+                           paramInfo,
+                           out int numIndirectionLevels);
 
-                    ITypeSymbol type = paramInfo.ManagedType;
-                    MarshallingInfo marshallingInfo = paramInfo.MarshallingAttributeInfo;
+                ITypeSymbol type = paramInfo.ManagedType;
+                MarshallingInfo marshallingInfo = paramInfo.MarshallingAttributeInfo;
 
-                    for (int i = 0; i < numIndirectionLevels; i++)
+                for (int i = 0; i < numIndirectionLevels; i++)
+                {
+                    if (marshallingInfo is NativeContiguousCollectionMarshallingInfo collectionInfo)
                     {
-                        if (marshallingInfo is NativeContiguousCollectionMarshallingInfo collectionInfo)
-                        {
-                            type = collectionInfo.ElementType;
-                            marshallingInfo = collectionInfo.ElementMarshallingInfo;
-                        }
-                        else
-                        {
-                            throw new MarshallingNotSupportedException(info, context)
-                            {
-                                NotSupportedDetails = Resources.CollectionSizeParamTypeMustBeIntegral
-                            };
-                        }
+                        type = collectionInfo.ElementType;
+                        marshallingInfo = collectionInfo.ElementMarshallingInfo;
                     }
-
-                    if (!type.IsIntegralType())
+                    else
                     {
                         throw new MarshallingNotSupportedException(info, context)
                         {
                             NotSupportedDetails = Resources.CollectionSizeParamTypeMustBeIntegral
                         };
                     }
+                }
 
-                    return CastExpression(
-                            PredefinedType(Token(SyntaxKind.IntKeyword)),
-                            ParenthesizedExpression(numElementsExpression));
+                if (!type.IsIntegralType())
+                {
+                    throw new MarshallingNotSupportedException(info, context)
+                    {
+                        NotSupportedDetails = Resources.CollectionSizeParamTypeMustBeIntegral
+                    };
                 }
+
+                return CastExpression(
+                        PredefinedType(Token(SyntaxKind.IntKeyword)),
+                        ParenthesizedExpression(numElementsExpression));
             }
 
             static ExpressionSyntax GetIndexedNumElementsExpression(StubCodeContext context, TypePositionInfo numElementsInfo, out int numIndirectionLevels)
@@ -607,7 +597,7 @@ private static IMarshallingGenerator CreateNativeCollectionMarshaller(
             if (info.IsManagedReturnPosition || (info.IsByRef && info.RefKind != RefKind.In))
             {
                 // In this case, we need a numElementsExpression supplied from metadata, so we'll calculate it here.
-                numElementsExpression = GetNumElementsExpressionFromMarshallingInfo(info, collectionInfo.ElementCountInfo, context, options);
+                numElementsExpression = GetNumElementsExpressionFromMarshallingInfo(info, collectionInfo.ElementCountInfo, context);
             }
 
             marshallingStrategy = new NumElementsExpressionMarshalling(