Fix IDE0008 in DllImportGenerator and Microsoft.Interop.SourceGeneration (#59885)

Author: elinor-fung

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Analyzers/ConvertToGeneratedDllImportAnalyzer.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Runtime.InteropServices;
@@ -101,7 +102,7 @@ private static bool RequiresMarshalling(IMethodSymbol method, DllImportData dllI
             }
 
             Debug.Assert(dllImportAttr != null);
-            foreach (var namedArg in dllImportAttr!.NamedArguments)
+            foreach (KeyValuePair<string, TypedConstant> namedArg in dllImportAttr!.NamedArguments)
             {
                 if (namedArg.Key != nameof(DllImportAttribute.PreserveSig))
                     continue;

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Analyzers/ConvertToGeneratedDllImportFixer.cs

@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Runtime.InteropServices;
@@ -103,7 +102,7 @@ private async Task<Document> ConvertToGeneratedDllImport(
             var dllImportSyntax = (AttributeSyntax)dllImportAttr!.ApplicationSyntaxReference!.GetSyntax(cancellationToken);
 
             // Create GeneratedDllImport attribute based on the DllImport attribute
-            var generatedDllImportSyntax = GetGeneratedDllImportAttribute(
+            SyntaxNode generatedDllImportSyntax = GetGeneratedDllImportAttribute(
                 editor,
                 generator,
                 dllImportSyntax,
@@ -154,7 +153,7 @@ private async Task<Document> ConvertToGeneratedDllImport(
                         }));
 
                 // Remove existing leading trivia - it will be on the GeneratedDllImport method
-                var updatedDeclaration = methodSyntax.WithLeadingTrivia();
+                MethodDeclarationSyntax updatedDeclaration = methodSyntax.WithLeadingTrivia();
 
                 // #endif
                 updatedDeclaration = updatedDeclaration.WithTrailingTrivia(
@@ -184,7 +183,7 @@ private SyntaxNode GetGeneratedDllImportAttribute(
         {
             unmanagedCallConvAttributeMaybe = null;
             // Create GeneratedDllImport based on the DllImport attribute
-            var generatedDllImportSyntax = generator.ReplaceNode(dllImportSyntax,
+            SyntaxNode generatedDllImportSyntax = generator.ReplaceNode(dllImportSyntax,
                 dllImportSyntax.Name,
                 generator.TypeExpression(generatedDllImportAttrType));
 
@@ -283,7 +282,7 @@ private bool TryCreateUnmanagedCallConvAttributeToEmit(
         private static bool TryGetAttribute(IMethodSymbol method, INamedTypeSymbol attributeType, out AttributeData? attr)
         {
             attr = default;
-            foreach (var attrLocal in method.GetAttributes())
+            foreach (AttributeData attrLocal in method.GetAttributes())
             {
                 if (SymbolEqualityComparer.Default.Equals(attrLocal.AttributeClass, attributeType))
                 {

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Analyzers/GeneratedDllImportAnalyzer.cs

@@ -74,9 +74,9 @@ private static void AnalyzeSymbol(SymbolAnalysisContext context, INamedTypeSymbo
             {
                 // Make sure declarations are marked partial. Technically, we can just check one
                 // declaration, since Roslyn would error on inconsistent partial declarations.
-                foreach (var reference in methodSymbol.DeclaringSyntaxReferences)
+                foreach (SyntaxReference reference in methodSymbol.DeclaringSyntaxReferences)
                 {
-                    var syntax = reference.GetSyntax(context.CancellationToken);
+                    SyntaxNode syntax = reference.GetSyntax(context.CancellationToken);
                     if (syntax is MethodDeclarationSyntax methodSyntax && !methodSyntax.Modifiers.Any(SyntaxKind.PartialKeyword))
                     {
                         // Must be marked partial
@@ -87,9 +87,9 @@ private static void AnalyzeSymbol(SymbolAnalysisContext context, INamedTypeSymbo
 
                 for (INamedTypeSymbol? typeSymbol = methodSymbol.ContainingType; typeSymbol is not null; typeSymbol = typeSymbol.ContainingType)
                 {
-                    foreach (var reference in typeSymbol.DeclaringSyntaxReferences)
+                    foreach (SyntaxReference reference in typeSymbol.DeclaringSyntaxReferences)
                     {
-                        var syntax = reference.GetSyntax(context.CancellationToken);
+                        SyntaxNode syntax = reference.GetSyntax(context.CancellationToken);
                         if (syntax is TypeDeclarationSyntax typeSyntax && !typeSyntax.Modifiers.Any(SyntaxKind.PartialKeyword))
                         {
                             // Must be marked partial

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Analyzers/ManualTypeMarshallingAnalyzer.cs

@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Immutable;
 using System.Linq;
 
@@ -195,12 +194,12 @@ public override void Initialize(AnalysisContext context)
 
         private void PrepareForAnalysis(CompilationStartAnalysisContext context)
         {
-            var generatedMarshallingAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.GeneratedMarshallingAttribute);
-            var blittableTypeAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.BlittableTypeAttribute);
-            var nativeMarshallingAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.NativeMarshallingAttribute);
-            var marshalUsingAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.MarshalUsingAttribute);
-            var genericContiguousCollectionMarshallerAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.GenericContiguousCollectionMarshallerAttribute);
-            var spanOfByte = context.Compilation.GetTypeByMetadataName(TypeNames.System_Span_Metadata)!.Construct(context.Compilation.GetSpecialType(SpecialType.System_Byte));
+            INamedTypeSymbol? generatedMarshallingAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.GeneratedMarshallingAttribute);
+            INamedTypeSymbol? blittableTypeAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.BlittableTypeAttribute);
+            INamedTypeSymbol? nativeMarshallingAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.NativeMarshallingAttribute);
+            INamedTypeSymbol? marshalUsingAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.MarshalUsingAttribute);
+            INamedTypeSymbol? genericContiguousCollectionMarshallerAttribute = context.Compilation.GetTypeByMetadataName(TypeNames.GenericContiguousCollectionMarshallerAttribute);
+            INamedTypeSymbol? spanOfByte = context.Compilation.GetTypeByMetadataName(TypeNames.System_Span_Metadata)!.Construct(context.Compilation.GetSpecialType(SpecialType.System_Byte));
 
             if (generatedMarshallingAttribute is not null
                 && blittableTypeAttribute is not null
@@ -256,7 +255,7 @@ public void AnalyzeTypeDefinition(SymbolAnalysisContext context)
 
                 AttributeData? blittableTypeAttributeData = null;
                 AttributeData? nativeMarshallingAttributeData = null;
-                foreach (var attr in type.GetAttributes())
+                foreach (AttributeData attr in type.GetAttributes())
                 {
                     if (SymbolEqualityComparer.Default.Equals(attr.AttributeClass, _generatedMarshallingAttribute))
                     {
@@ -416,7 +415,7 @@ private void AnalyzeNativeMarshalerType(SymbolAnalysisContext context, ITypeSymb
 
                 bool hasConstructor = false;
                 bool hasStackallocConstructor = false;
-                foreach (var ctor in marshalerType.Constructors)
+                foreach (IMethodSymbol ctor in marshalerType.Constructors)
                 {
                     if (ctor.IsStatic)
                     {