Report diagnostic for BestFitMapping, ThrowOnUnmappableChar, and LCIDConversion

DllImportGenerator/DllImportGenerator.UnitTests/CodeSnippets.cs

@@ -168,6 +168,24 @@ partial class Test
         ThrowOnUnmappableChar = true)]
     public static partial void Method();
 }
+";
+
+        /// <summary>
+        /// Declaration with all supported DllImport named arguments.
+        /// </summary>
+        public static readonly string AllSupportedDllImportNamedArguments = @"
+using System.Runtime.InteropServices;
+partial class Test
+{
+    [GeneratedDllImport(""DoesNotExist"",
+        CallingConvention = CallingConvention.Cdecl,
+        CharSet = CharSet.Unicode,
+        EntryPoint = ""UserDefinedEntryPoint"",
+        ExactSpelling = true,
+        PreserveSig = false,
+        SetLastError = true)]
+    public static partial void Method();
+}
 ";
 
         /// <summary>
@@ -180,17 +198,26 @@ partial class Test
     private const bool IsTrue = true;
     private const bool IsFalse = false;
     private const string EntryPointName = nameof(Test) + nameof(IsFalse);
+    private const int One = 1;
+    private const int Two = 2;
 
     [GeneratedDllImport(nameof(Test),
-        BestFitMapping = 0 != 1,
         CallingConvention = (CallingConvention)1,
         CharSet = (CharSet)2,
         EntryPoint = EntryPointName,
-        ExactSpelling = IsTrue,
+        ExactSpelling = 0 != 1,
         PreserveSig = IsFalse,
-        SetLastError = !IsFalse,
-        ThrowOnUnmappableChar = !IsTrue)]
-    public static partial void Method();
+        SetLastError = IsTrue)]
+    public static partial void Method1();
+
+    [GeneratedDllImport(nameof(Test),
+        CallingConvention = (CallingConvention)One,
+        CharSet = (CharSet)Two,
+        EntryPoint = EntryPointName,
+        ExactSpelling = One != Two,
+        PreserveSig = !IsFalse,
+        SetLastError = !IsTrue)]
+    public static partial void Method2();
 }
 ";
 
@@ -204,6 +231,19 @@ partial class Test
     [GeneratedDllImport(""DoesNotExist"")]
     public static partial void Method(int t = 0);
 }
+";
+
+        /// <summary>
+        /// Declaration with LCIDConversionAttribute.
+        /// </summary>
+        public static readonly string LCIDConversionAttribute = @"
+using System.Runtime.InteropServices;
+partial class Test
+{
+    [LCIDConversion(0)]
+    [GeneratedDllImport(""DoesNotExist"")]
+    public static partial void Method();
+}
 ";
 
         /// <summary>

DllImportGenerator/DllImportGenerator.UnitTests/CompileFails.cs

@@ -35,6 +35,13 @@ public static IEnumerable<object[]> CodeSnippetsToCompile()
             // Unsupported MarshalAsAttribute usage
             //  * UnmanagedType.CustomMarshaler, MarshalTypeRef, MarshalType, MarshalCookie
             yield return new object[] { CodeSnippets.MarshalAsCustomMarshalerOnTypes, 16, 0 };
+
+            // Unsupported named arguments
+            //  * BestFitMapping, ThrowOnUnmappableChar
+            yield return new object[] { CodeSnippets.AllDllImportNamedArguments, 2, 0 };
+
+            // LCIDConversion
+            yield return new object[] { CodeSnippets.LCIDConversionAttribute, 1, 0 };
         }
 
         [Theory]

DllImportGenerator/DllImportGenerator.UnitTests/Compiles.cs

@@ -17,7 +17,7 @@ public static IEnumerable<object[]> CodeSnippetsToCompile_NoDiagnostics()
             yield return new[] { CodeSnippets.NestedNamespace };
             yield return new[] { CodeSnippets.NestedTypes };
             yield return new[] { CodeSnippets.UserDefinedEntryPoint };
-            yield return new[] { CodeSnippets.AllDllImportNamedArguments };
+            yield return new[] { CodeSnippets.AllSupportedDllImportNamedArguments };
             yield return new[] { CodeSnippets.DefaultParameters };
             yield return new[] { CodeSnippets.UseCSharpFeaturesForConstants };
             yield return new[] { CodeSnippets.BasicParametersAndModifiers<byte>() };