Disallow dynamic calls on ref struct receivers

src/Compilers/CSharp/Portable/Binder/Binder_Invocation.cs

@@ -459,6 +459,13 @@ private BoundExpression BindDynamicInvocation(
  methodGroup.ResultKind);
  break;
  }
+
+ if (receiver.Type.IsRefLikeType)
+ {
+ // Cannot perform a dynamic call on a ref struct '{0}'.
+ Error(diagnostics, ErrorCode.ERR_CannotDynamicInvokeOnRefStruct, receiver.Syntax, receiver.Type);
+ hasErrors = true;
+ }
  }
  }
  else

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -7905,4 +7905,7 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
  <data name="ERR_NoModifiersOnUsing" xml:space="preserve">
  <value>Modifiers cannot be placed on using declarations</value>
  </data>
-</root>
+ <data name="ERR_CannotDynamicInvokeOnRefStruct" xml:space="preserve">
+ <value>Cannot perform a dynamic call on a ref struct '{0}'.</value>
+ </data>
+</root>

src/Compilers/CSharp/Portable/Errors/ErrorCode.cs

@@ -2301,10 +2301,15 @@ internal enum ErrorCode
  ERR_ParamsCollectionMissingConstructor = 9228,
 
  ERR_NoModifiersOnUsing = 9229,
+ ERR_CannotDynamicInvokeOnRefStruct = 9230,
 
  #endregion
 
+ // Note: you will need to do the following after adding errors:
+ // 1) Update ErrorFacts.IsBuildOnlyDiagnostic (src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs)
+
  // Note: you will need to do the following after adding warnings:
  // 1) Re-generate compiler code (eng\generate-compiler-code.cmd).
+ // 2) Update ErrorFacts.IsBuildOnlyDiagnostic (src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs)
  }
 }

src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs

@@ -2431,6 +2431,7 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
  case ErrorCode.ERR_ParamsCollectionExtensionAddMethod:
  case ErrorCode.ERR_ParamsCollectionMissingConstructor:
  case ErrorCode.ERR_NoModifiersOnUsing:
+ case ErrorCode.ERR_CannotDynamicInvokeOnRefStruct:
  return false;
  default:
  // NOTE: All error codes must be explicitly handled in this switch statement

src/Compilers/CSharp/Test/Semantic/Semantics/DynamicTests.cs

@@ -4545,5 +4545,183 @@ class C2 : C1
 
  CompileAndVerify(comp, expectedOutput: "int").VerifyDiagnostics();
  }
+
+ [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/72606")]
+ public void RefStructReceiver01()
+ {
+ var code = """
+ var s = new S();
+ dynamic d = null;
+
+ s.M(d);
+
+ ref struct S
+ {
+ public void M<T>(T t) { }
+ }
+ """;
+
+ CreateCompilation(code).VerifyDiagnostics(
+ // (4,1): error CS9230: Cannot perform a dynamic call on a ref struct 'S'.
+ // s.M(d);
+ Diagnostic(ErrorCode.ERR_CannotDynamicInvokeOnRefStruct, "s").WithArguments("S").WithLocation(4, 1)
+ );
+ }
+
+ [Theory, WorkItem("https://github.com/dotnet/roslyn/issues/72606")]
+ [InlineData("object")]
+ [InlineData("dynamic")]
+ public void RefStructReceiver02(string argType)
+ {
+ var code = $$"""
+ var s = new S();
+ dynamic d = "Hello world";
+
+ s.M(d);
+
+ ref struct S
+ {
+ public void M({{argType}} o) => System.Console.WriteLine(o);
+ }
+ """;
+
+ var verifier = CompileAndVerify(code, expectedOutput: "Hello world", targetFramework: TargetFramework.StandardAndCSharp);
+ verifier.VerifyDiagnostics();
+ verifier.VerifyIL("<top-level-statements-entry-point>", $$"""
+ {
+ // Code size 23 (0x17)
+ .maxstack 2
+ .locals init (S V_0, //s
+ object V_1) //d
+ IL_0000: ldloca.s V_0
+ IL_0002: initobj "S"
+ IL_0008: ldstr "Hello world"
+ IL_000d: stloc.1
+ IL_000e: ldloca.s V_0
+ IL_0010: ldloc.1
+ IL_0011: call "void S.M({{argType}})"
+ IL_0016: ret
+ }
+ """);
+ }
+
+ [Theory, WorkItem("https://github.com/dotnet/roslyn/issues/72606")]
+ [InlineData("string")]
+ [InlineData("int")]
+ public void RefStructReceiver03(string argType)
+ {
+ var code = $$"""
+ var s = new S();
+ dynamic d = "Hello world";
+
+ try
+ {
+ s.M(d);
+ }
+ catch
+ {
+ System.Console.WriteLine("Caught exception");
+ }
+
+ ref struct S
+ {
+ public void M({{argType}} o) => System.Console.WriteLine(o);
+ }
+ """;
+
+ var verifier = CompileAndVerify(code, expectedOutput: argType == "string" ? "Hello world" : "Caught exception", targetFramework: TargetFramework.StandardAndCSharp);
+ verifier.VerifyDiagnostics();
+ verifier.VerifyIL("<top-level-statements-entry-point>", $$"""
+ {
+ // Code size 101 (0x65)
+ .maxstack 4
+ .locals init (S V_0, //s
+ object V_1) //d
+ IL_0000: ldloca.s V_0
+ IL_0002: initobj "S"
+ IL_0008: ldstr "Hello world"
+ IL_000d: stloc.1
+ .try
+ {
+ IL_000e: ldloca.s V_0
+ IL_0010: ldsfld "System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>> Program.<>o__0.<>p__0"
+ IL_0015: brtrue.s IL_003b
+ IL_0017: ldc.i4.0
+ IL_0018: ldtoken "{{argType}}"
+ IL_001d: call "System.Type System.Type.GetTypeFromHandle(System.RuntimeTypeHandle)"
+ IL_0022: ldtoken "Program"
+ IL_0027: call "System.Type System.Type.GetTypeFromHandle(System.RuntimeTypeHandle)"
+ IL_002c: call "System.Runtime.CompilerServices.CallSiteBinder Microsoft.CSharp.RuntimeBinder.Binder.Convert(Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags, System.Type, System.Type)"
+ IL_0031: call "System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>> System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>>.Create(System.Runtime.CompilerServices.CallSiteBinder)"
+ IL_0036: stsfld "System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>> Program.<>o__0.<>p__0"
+ IL_003b: ldsfld "System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>> Program.<>o__0.<>p__0"
+ IL_0040: ldfld "System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}> System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>>.Target"
+ IL_0045: ldsfld "System.Runtime.CompilerServices.CallSite<System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>> Program.<>o__0.<>p__0"
+ IL_004a: ldloc.1
+ IL_004b: callvirt "{{argType}} System.Func<System.Runtime.CompilerServices.CallSite, dynamic, {{argType}}>.Invoke(System.Runtime.CompilerServices.CallSite, dynamic)"
+ IL_0050: call "void S.M({{argType}})"
+ IL_0055: leave.s IL_0064
+ }
+ catch object
+ {
+ IL_0057: pop
+ IL_0058: ldstr "Caught exception"
+ IL_005d: call "void System.Console.WriteLine(string)"
+ IL_0062: leave.s IL_0064
+ }
+ IL_0064: ret
+ }
+ """);
+ }
+
+ [Theory, WorkItem("https://github.com/dotnet/roslyn/issues/72606")]
+ [InlineData("object")]
+ [InlineData("dynamic")]
+ public void RefStructReceiver04(string argType)
+ {
+ var code = $$"""
+ var s = new S();
+ dynamic d = "Hello world";
+
+ s.M(d);
+
+ ref struct S
+ {
+ public void M({{argType}} o) => System.Console.WriteLine(o);
+ public void M(string s) => System.Console.WriteLine(s);
+ }
+ """;
+
+ CreateCompilation(code).VerifyDiagnostics(
+ // (4,1): error CS9230: Cannot perform a dynamic call on a ref struct 'S'.
+ // s.M(d);
+ Diagnostic(ErrorCode.ERR_CannotDynamicInvokeOnRefStruct, "s").WithArguments("S").WithLocation(4, 1)
+ );
+ }
+
+ [Theory, WorkItem("https://github.com/dotnet/roslyn/issues/72606")]
+ [InlineData("object")]
+ [InlineData("dynamic")]
+ public void RefStructReceiver05(string argType)
+ {
+ var code = $$"""
+ var s = new S();
+ dynamic d = "Hello world";
+
+ s.M(d);
+
+ ref struct S
+ {
+ public void M({{argType}} o) => System.Console.WriteLine(o);
+ public void M<T>(T t) => System.Console.WriteLine(t);
+ }
+ """;
+
+ CreateCompilation(code).VerifyDiagnostics(
+ // (4,1): error CS9230: Cannot perform a dynamic call on a ref struct 'S'.
+ // s.M(d);
+ Diagnostic(ErrorCode.ERR_CannotDynamicInvokeOnRefStruct, "s").WithArguments("S").WithLocation(4, 1)
+ );
+ }
  }
 }