Remove ExactSpelling from GeneratedDllImport

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

@@ -79,9 +79,47 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
                         methodSymbol,
                         dllImportAttr!,
                         generatedDllImportAttrType,
+                        entryPointSuffix: null,
                         cancelToken),
                     equivalenceKey: ConvertToGeneratedDllImportKey),
                 context.Diagnostics);
+
+            DllImportData dllImportData = methodSymbol.GetDllImportData()!;
+            if (!dllImportData.ExactSpelling)
+            {
+                if (dllImportData.CharacterSet is CharSet.None or CharSet.Ansi or CharSet.Auto)
+                {
+                    context.RegisterCodeFix(
+                        CodeAction.Create(
+                            string.Format(Resources.ConvertToGeneratedDllImportWithSuffix, "A"),
+                            cancelToken => ConvertToGeneratedDllImport(
+                                context.Document,
+                                methodSyntax,
+                                methodSymbol,
+                                dllImportAttr!,
+                                generatedDllImportAttrType,
+                                entryPointSuffix: 'A',
+                                cancelToken),
+                            equivalenceKey: ConvertToGeneratedDllImportKey + "A"),
+                        context.Diagnostics);
+                }
+                if (dllImportData.CharacterSet is CharSet.Unicode or CharSet.Auto)
+                {
+                    context.RegisterCodeFix(
+                        CodeAction.Create(
+                            string.Format(Resources.ConvertToGeneratedDllImportWithSuffix, "W"),
+                            cancelToken => ConvertToGeneratedDllImport(
+                                context.Document,
+                                methodSyntax,
+                                methodSymbol,
+                                dllImportAttr!,
+                                generatedDllImportAttrType,
+                                entryPointSuffix: 'W',
+                                cancelToken),
+                            equivalenceKey: ConvertToGeneratedDllImportKey + "W"),
+                        context.Diagnostics);
+                }
+            }
         }
 
         private async Task<Document> ConvertToGeneratedDllImport(
@@ -90,6 +128,7 @@ private async Task<Document> ConvertToGeneratedDllImport(
             IMethodSymbol methodSymbol,
             AttributeData dllImportAttr,
             INamedTypeSymbol generatedDllImportAttrType,
+            char? entryPointSuffix,
             CancellationToken cancellationToken)
         {
             DocumentEditor editor = await DocumentEditor.CreateAsync(doc, cancellationToken).ConfigureAwait(false);
@@ -104,6 +143,8 @@ private async Task<Document> ConvertToGeneratedDllImport(
                 dllImportSyntax,
                 methodSymbol.GetDllImportData()!,
                 generatedDllImportAttrType,
+                methodSymbol.Name,
+                entryPointSuffix,
                 out SyntaxNode? unmanagedCallConvAttributeMaybe);
 
             // Add annotation about potential behavioural and compatibility changes
@@ -137,6 +178,8 @@ private SyntaxNode GetGeneratedDllImportAttribute(
             AttributeSyntax dllImportSyntax,
             DllImportData dllImportData,
             INamedTypeSymbol generatedDllImportAttrType,
+            string methodName,
+            char? entryPointSuffix,
             out SyntaxNode? unmanagedCallConvAttributeMaybe)
         {
             unmanagedCallConvAttributeMaybe = null;
@@ -147,6 +190,7 @@ private SyntaxNode GetGeneratedDllImportAttribute(
 
             // Update attribute arguments for GeneratedDllImport
             List<SyntaxNode> argumentsToRemove = new List<SyntaxNode>();
+            AttributeArgumentSyntax? entryPointAttributeArgument = null;
             foreach (SyntaxNode argument in generator.GetAttributeArguments(generatedDllImportSyntax))
             {
                 if (argument is not AttributeArgumentSyntax attrArg)
@@ -181,9 +225,49 @@ private SyntaxNode GetGeneratedDllImportAttribute(
                         argumentsToRemove.Add(argument);
                     }
                 }
+                else if (IsMatchingNamedArg(attrArg, nameof(DllImportAttribute.ExactSpelling)))
+                {
+                    argumentsToRemove.Add(argument);
+                }
+                else if (IsMatchingNamedArg(attrArg, nameof(DllImportAttribute.EntryPoint)))
+                {
+                    entryPointAttributeArgument = attrArg;
+                    if (!dllImportData.ExactSpelling && entryPointSuffix.HasValue)
+                    {
+                        if (entryPointAttributeArgument.Expression.IsKind(SyntaxKind.StringLiteralExpression))
+                        {
+                            string? entryPoint = (string?)((LiteralExpressionSyntax)entryPointAttributeArgument.Expression).Token.Value;
+                            if (entryPoint is not null)
+                            {
+                                entryPointAttributeArgument = entryPointAttributeArgument.WithExpression(
+                                    SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression,
+                                        SyntaxFactory.Literal(entryPoint + entryPointSuffix)));
+                            }
+                        }
+                        else
+                        {
+                            entryPointAttributeArgument = entryPointAttributeArgument.WithExpression(
+                                SyntaxFactory.BinaryExpression(SyntaxKind.AddExpression,
+                                entryPointAttributeArgument.Expression,
+                                SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression,
+                                    SyntaxFactory.Literal(entryPointSuffix.ToString()))));
+                        }
+                    }
+                    argumentsToRemove.Add(attrArg);
+                }
+            }
+
+            if (entryPointSuffix.HasValue && entryPointAttributeArgument is null)
+            {
+                entryPointAttributeArgument = (AttributeArgumentSyntax)generator.AttributeArgument("EntryPoint",
+                    generator.LiteralExpression(methodName + entryPointSuffix.Value));
             }
 
             generatedDllImportSyntax = generator.RemoveNodes(generatedDllImportSyntax, argumentsToRemove);
+            if (entryPointAttributeArgument is not null)
+            {
+                generatedDllImportSyntax = generator.AddAttributeArguments(generatedDllImportSyntax, new[] { entryPointAttributeArgument });
+            }
             return SortDllImportAttributeArguments((AttributeSyntax)generatedDllImportSyntax, generator);
         }
 

src/libraries/System.Runtime.InteropServices/gen/DllImportGenerator/Resources.resx

@@ -187,6 +187,9 @@
     <value>Conversion to 'GeneratedDllImport' may change behavior and compatibility. See {0} for more information.</value>
     <comment>{0} is a documentation link</comment>
   </data>
+  <data name="ConvertToGeneratedDllImportWithSuffix" xml:space="preserve">
+    <value>Convert to 'GeneratedDllImport' with '{0}' suffix</value>
+  </data>
   <data name="CustomTypeMarshallingManagedToNativeUnsupported" xml:space="preserve">
     <value>The specified parameter needs to be marshalled from managed to native, but the native type '{0}' does not support it.</value>
   </data>

src/libraries/System.Runtime.InteropServices/tests/DllImportGenerator.UnitTests/CodeSnippets.cs

@@ -193,7 +193,6 @@ partial class Test
     [GeneratedDllImport(""DoesNotExist"",
         CharSet = CharSet.Unicode,
         EntryPoint = ""UserDefinedEntryPoint"",
-        ExactSpelling = true,
         SetLastError = true)]
     public static partial void Method();
 }
@@ -215,16 +214,20 @@ partial class Test
     [GeneratedDllImport(nameof(Test),
         CharSet = (CharSet)2,
         EntryPoint = EntryPointName,
-        ExactSpelling = 0 != 1,
         SetLastError = IsFalse)]
     public static partial void Method1();
 
     [GeneratedDllImport(nameof(Test),
         CharSet = (CharSet)Two,
         EntryPoint = EntryPointName,
-        ExactSpelling = One != Two,
         SetLastError = !IsTrue)]
     public static partial void Method2();
+
+    [GeneratedDllImport(nameof(Test),
+        CharSet = (CharSet)2,
+        EntryPoint = EntryPointName,
+        SetLastError = 0 != 1)]
+    public static partial void Method3();
 }
 ";