Merge pull request #16143 from CyrusNajmabadi/parserDiagnostics16

Allow parsing any types in catch clauses in the parser.

src/Compilers/CSharp/Portable/Parser/LanguageParser.cs

@@ -7543,16 +7543,17 @@ private CatchClauseSyntax ParseCatchClause()
             if (this.CurrentToken.Kind == SyntaxKind.OpenParenToken)
             {
                 var openParen = this.EatToken();
+
                 _termState |= TerminatorState.IsEndOfCatchClause;
-                var type = this.ParseClassType();
+                var type = this.ParseType();
                 SyntaxToken name = null;
-
                 if (this.IsTrueIdentifier())
                 {
                     name = this.ParseIdentifierToken();
                 }
 
                 _termState = saveTerm;
+
                 var closeParen = this.EatToken(SyntaxKind.CloseParenToken);
                 decl = _syntaxFactory.CatchDeclaration(openParen, type, name, closeParen);
             }
@@ -7613,31 +7614,6 @@ private bool IsEndOfCatchBlock()
                 || this.CurrentToken.Kind == SyntaxKind.FinallyKeyword;
         }
 
-        private TypeSyntax ParseClassType()
-        {
-            var type = this.ParseType();
-            switch (type.Kind)
-            {
-                case SyntaxKind.PredefinedType:
-                    var kt = ((PredefinedTypeSyntax)type).Keyword.Kind;
-                    if (kt != SyntaxKind.ObjectKeyword && kt != SyntaxKind.StringKeyword)
-                    {
-                        goto default;
-                    }
-
-                    break;
-                default:
-                    if (!SyntaxFacts.IsName(type.Kind))
-                    {
-                        type = this.AddError(type, ErrorCode.ERR_ClassTypeExpected);
-                    }
-
-                    break;
-            }
-
-            return type;
-        }
-
         private StatementSyntax ParseCheckedStatement()
         {
             Debug.Assert(this.CurrentToken.Kind == SyntaxKind.CheckedKeyword || this.CurrentToken.Kind == SyntaxKind.UncheckedKeyword);

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

@@ -46,6 +46,32 @@ static void Main()
             Assert.Equal("string.operator !=(string, string)", filterExprInfo.Symbol.ToDisplayString());
         }
 
+        [Fact]
+        public void CatchClauseValueType()
+        {
+            var source = @"
+class C
+{
+    static void Main()
+    {
+        try
+        {
+        }
+        catch (int e)
+        {
+        }
+    }
+}
+";
+            CreateCompilationWithMscorlib(source).VerifyDiagnostics(
+                // (9,16): error CS0155: The type caught or thrown must be derived from System.Exception
+                //         catch (int e)
+                Diagnostic(ErrorCode.ERR_BadExceptionType, "int").WithLocation(9, 16),
+                // (9,20): warning CS0168: The variable 'e' is declared but never used
+                //         catch (int e)
+                Diagnostic(ErrorCode.WRN_UnreferencedVar, "e").WithArguments("e").WithLocation(9, 20));
+        }
+
         [ConditionalFact(typeof(x86))]
         [WorkItem(7030, "https://github.com/dotnet/roslyn/issues/7030")]
         public void Issue7030()

src/Compilers/CSharp/Test/Syntax/Parsing/ParserErrorMessageTests.cs

@@ -1647,9 +1647,16 @@ public static void Main()
 }
 ";
 
-            ParseAndValidate(test,
-Diagnostic(ErrorCode.ERR_ClassTypeExpected, "int"),
-Diagnostic(ErrorCode.ERR_ClassTypeExpected, "byte"));
+            CreateCompilationWithMscorlib(test).VerifyDiagnostics(
+                // (10,15): error CS0155: The type caught or thrown must be derived from System.Exception
+                //         catch(int)
+                Diagnostic(ErrorCode.ERR_BadExceptionType, "int").WithLocation(10, 15),
+                // (13,15): error CS0155: The type caught or thrown must be derived from System.Exception
+                //         catch(byte)
+                Diagnostic(ErrorCode.ERR_BadExceptionType, "byte").WithLocation(13, 15),
+                // (2,1): hidden CS8019: Unnecessary using directive.
+                // using System;
+                Diagnostic(ErrorCode.HDN_UnusedUsingDirective, "using System;").WithLocation(2, 1));
         }
 
         [WorkItem(863382, "DevDiv/Personal")]