Fix edge cases of getting attribute data from syntax (#75728)

Fix two customer-discovered edge cases that were causing analyzer crashes.

Fixes #75681
Fixes #75706

Co-authored-by: Jeremy Koritzinsky <jekoritz@microsoft.com>

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/Analyzers/SyntaxExtensions.cs

@@ -33,7 +33,17 @@ public static Location FindTypeExpressionOrNullLocation(this AttributeArgumentSy
  switch (attributeTarget.Identifier.Kind())
  {
  case SyntaxKind.ReturnKeyword:
- return ((IMethodSymbol)targetSymbol).GetReturnTypeAttributes().First(attributeSyntaxLocationMatches);
+ if (targetSymbol is IMethodSymbol method)
+ {
+ // Sometimes an attribute is put on a symbol that is nested within the containing symbol.
+ // For example, the ContainingSymbol for an AttributeSyntax on a local function have a ContainingSymbol of the method.
+ // Since this method is internal and the callers don't care about attributes on local functions,
+ // we just allow this method to return null in those cases.
+ return method.GetReturnTypeAttributes().FirstOrDefault(attributeSyntaxLocationMatches);
+ }
+ // An attribute on the return value of a delegate type's Invoke method has a ContainingSymbol of the delegate type.
+ // We don't care about the attributes in this case for the callers, so we'll just return null.
+ return null;
  case SyntaxKind.AssemblyKeyword:
  return targetSymbol.ContainingAssembly.GetAttributes().First(attributeSyntaxLocationMatches);
  case SyntaxKind.ModuleKeyword:
@@ -43,7 +53,8 @@ public static Location FindTypeExpressionOrNullLocation(this AttributeArgumentSy
  }
  }
  // Sometimes an attribute is put on a symbol that is nested within the containing symbol.
- // For example, the ContainingSymbol for an AttributeSyntax on a parameter have a ContainingSymbol of the method.
+ // For example, the ContainingSymbol for an AttributeSyntax on a parameter have a ContainingSymbol of the method
+ // and an AttributeSyntax on a local function have a ContainingSymbol of the containing method.
  // Since this method is internal and the callers don't care about attributes on parameters, we just allow
  // this method to return null in those cases.
  return targetSymbol.GetAttributes().FirstOrDefault(attributeSyntaxLocationMatches);

src/libraries/System.Runtime.InteropServices/tests/LibraryImportGenerator.UnitTests/NativeMarshallingAttributeAnalyzerTests.cs

@@ -272,8 +272,18 @@ public class X
  {
  void Foo([MarshalAs(UnmanagedType.I4)] int i)
  {
+ [return:MarshalAs(UnmanagedType.I4)]
+ [SkipLocalsInit]
+ static int Local()
+ {
+ return 0;
+ }
  }
  }
+
+ [return:MarshalAs(UnmanagedType.I4)]
+ delegate int Y();
+
  """;
 
  await VerifyCS.VerifyAnalyzerAsync(source);