1090472-Ensure retargeted error symbols cause use-site errors

Also includes VB implementation
 (changeset 1383936)

Src/Compilers/CSharp/Portable/CSharpResources.Designer.cs

@@ -3544,6 +3544,15 @@ internal class CSharpResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to There is an error in a referenced assembly &apos;{0}&apos;..
+        /// </summary>
+        internal static string ERR_ErrorInReferencedAssembly {
+            get {
+                return ResourceManager.GetString("ERR_ErrorInReferencedAssembly", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to A &apos;{0}&apos; character may only be escaped by doubling &apos;{0}{0}&apos; in an interpolated string..
         /// </summary>

Src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -4014,4 +4014,7 @@
   <data name="ERR_EmptyFormatSpecifier" xml:space="preserve">
     <value>Empty format specifier.</value>
   </data>
+  <data name="ERR_ErrorInReferencedAssembly" xml:space="preserve">
+    <value>There is an error in a referenced assembly '{0}'.</value>
+  </data>
 </root>

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

@@ -1301,5 +1301,6 @@ internal enum ErrorCode
         ERR_EscapedCurly = 8087,
         ERR_TrailingWhitespaceInFormatSpecifier = 8088,
         ERR_EmptyFormatSpecifier = 8089,
+        ERR_ErrorInReferencedAssembly = 8090,
     }
 }

Src/Compilers/CSharp/Portable/Symbols/ExtendedErrorTypeSymbol.cs

@@ -50,6 +50,18 @@ internal ExtendedErrorTypeSymbol(NamespaceOrTypeSymbol containingSymbol, string
             this.resultKind = LookupResultKind.Empty;
         }
 
+        private ExtendedErrorTypeSymbol(NamespaceOrTypeSymbol containingSymbol, string name, int arity, DiagnosticInfo errorInfo, bool unreported, bool variableUsedBeforeDeclaration, ImmutableArray<Symbol> candidateSymbols, LookupResultKind resultKind)
+        {
+            this.name = name;
+            this.errorInfo = errorInfo;
+            this.containingSymbol = containingSymbol;
+            this.arity = arity;
+            this.unreported = unreported;
+            this.VariableUsedBeforeDeclaration = variableUsedBeforeDeclaration;
+            this.candidateSymbols = candidateSymbols;
+            this.resultKind = resultKind;
+        }
+
         internal ExtendedErrorTypeSymbol(NamespaceOrTypeSymbol guessSymbol, LookupResultKind resultKind, DiagnosticInfo errorInfo, bool unreported = false)
             : this(guessSymbol.ContainingNamespaceOrType(), guessSymbol, resultKind, errorInfo, unreported)
         {
@@ -68,6 +80,12 @@ internal ExtendedErrorTypeSymbol(NamespaceOrTypeSymbol containingSymbol, Immutab
             Debug.Assert(candidateSymbols.IsEmpty || resultKind != LookupResultKind.Viable, "Shouldn't use LookupResultKind.Viable with candidate symbols");
         }
 
+        internal ExtendedErrorTypeSymbol AsUnreported()
+        {
+            return this.Unreported ? this :
+                new ExtendedErrorTypeSymbol(containingSymbol, name, arity, errorInfo, true, VariableUsedBeforeDeclaration, candidateSymbols, resultKind);
+        }
+
         private static ImmutableArray<Symbol> UnwrapErrorCandidates(ImmutableArray<Symbol> candidateSymbols)
         {
             var candidate = candidateSymbols.IsEmpty ? null : candidateSymbols[0] as ErrorTypeSymbol;

Src/Compilers/CSharp/Portable/Symbols/Retargeting/RetargetingSymbolTranslator.cs

@@ -699,8 +699,20 @@ public PointerTypeSymbol Retarget(PointerTypeSymbol type)
 
             public static ErrorTypeSymbol Retarget(ErrorTypeSymbol type)
             {
-                // TODO: produce an error symbol that will trigger an error on use
-                return type;
+                // TODO: if it is a missing symbol error but no longer missing in the target assembly, then we can resolve it here.
+
+                var useSiteDiagnostic = type.GetUseSiteDiagnostic();
+                if (useSiteDiagnostic != null)
+                {
+                    return type;
+                }
+
+                // A retargeted error symbol must trigger an error on use so that a dependent compilation won't
+                // improperly succeed. We therefore ensure we have a use-site diagnostic.
+                return
+                    (type as ExtendedErrorTypeSymbol)?.AsUnreported() ?? // preserve diagnostic information if possible
+                    new ExtendedErrorTypeSymbol(type, type.ResultKind,
+                        type.ErrorInfo ?? new CSDiagnosticInfo(ErrorCode.ERR_ErrorInReferencedAssembly, type.ContainingAssembly?.Identity.GetDisplayName() ?? string.Empty), true);
             }
 
             public ImmutableArray<Symbol> Retarget(ImmutableArray<Symbol> arr)

Src/Compilers/CSharp/Test/Emit/Emit/NoPiaEmbedTypes.cs

@@ -4880,8 +4880,12 @@ public void M1(ITest34 y)
 ";
 
             DiagnosticDescription[] expected = {
-    // error CS0246: The type or namespace name 'ITest33' could not be found (are you missing a using directive or an assembly reference?)
-    Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound).WithArguments("ITest33")
+                // error CS0246: The type or namespace name 'ITest33' could not be found (are you missing a using directive or an assembly reference?)
+                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound).WithArguments("ITest33").WithLocation(1, 1),
+                // error CS0246: The type or namespace name 'ITest33' could not be found (are you missing a using directive or an assembly reference?)
+                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound).WithArguments("ITest33").WithLocation(1, 1),
+                // error CS0246: The type or namespace name 'ITest33' could not be found (are you missing a using directive or an assembly reference?)
+                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound).WithArguments("ITest33").WithLocation(1, 1)
                                                };
 
             var compilation1 = CreateCompilationWithMscorlib(consumer, options: TestOptions.ReleaseExe,
@@ -4933,7 +4937,7 @@ public void M1(ITest34 y)
             {
                 // (10,9): error CS0246: The type or namespace name 'ITest33' could not be found (are you missing a using directive or an assembly reference?)
                 //         y.M2(null);
-                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound, "y.M2(null)").WithArguments("ITest33")
+                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound, "y.M2").WithArguments("ITest33").WithLocation(10, 9)
             };
 
             VerifyEmitDiagnostics(compilation1, true, expected);

Src/Compilers/VisualBasic/Portable/Errors/Errors.vb

@@ -1672,6 +1672,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
         ERR_ExpressionDoesntHaveName = 37244
         ERR_InvalidNameOfSubExpression = 37245
         ERR_MethodTypeArgsUnexpected = 37246
+        ERR_InReferencedAssembly = 37247
 
         ERR_LastPlusOne
 

Src/Compilers/VisualBasic/Portable/Symbols/Retargeting/RetargetingSymbolTranslator.vb

@@ -771,15 +771,17 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols.Retargeting
             End Function
 
             Public Function Retarget(type As ErrorTypeSymbol) As ErrorTypeSymbol
-                Dim missing As MissingMetadataTypeSymbol = TryCast(type, MissingMetadataTypeSymbol)
+                ' TODO: if it is no longer missing in the target assembly, then we can resolve it here.
 
-                If missing IsNot Nothing Then
-                    ' TODO: if it is no longer missing in the target assembly, then we can resolve it here.
-                    Return missing
+                ' A retargeted error symbol must trigger an error on use so that a dependent compilation won't
+                ' improperly succeed. We therefore ensure we have a use-site diagnostic.
+                Dim useSiteDiagnostic = type.GetUseSiteErrorInfo
+                If useSiteDiagnostic IsNot Nothing Then
+                    Return type
                 End If
 
-                'TODO: produce an error symbol that will trigger an error on use
-                Return type
+                Dim errorInfo = If(type.ErrorInfo, ErrorFactory.ErrorInfo(ERRID.ERR_InReferencedAssembly, If(type.ContainingAssembly?.Identity.GetDisplayName, "")))
+                Return New ExtendedErrorTypeSymbol(errorInfo, type.Name, type.Arity, type.CandidateSymbols, type.ResultKind, True)
             End Function
 
             Public Function Retarget(sequence As IEnumerable(Of NamedTypeSymbol)) As IEnumerable(Of NamedTypeSymbol)

Src/Compilers/VisualBasic/Portable/VBResources.Designer.vb

@@ -5432,6 +5432,15 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End Get
         End Property
         
+        '''<summary>
+        '''  Looks up a localized string similar to There is an error in a referenced assembly &apos;{0}&apos;..
+        '''</summary>
+        Friend ReadOnly Property ERR_InReferencedAssembly() As String
+            Get
+                Return ResourceManager.GetString("ERR_InReferencedAssembly", resourceCulture)
+            End Get
+        End Property
+        
         '''<summary>
         '''  Looks up a localized string similar to An expression is too long or complex to compile.
         '''</summary>

Src/Compilers/VisualBasic/Portable/VBResources.resx

@@ -4717,4 +4717,7 @@
   <data name="ERR_InvalidAssemblyCulture" xml:space="preserve">
     <value>Assembly culture strings may not contain embedded NUL characters.</value>
   </data>
+  <data name="ERR_InReferencedAssembly" xml:space="preserve">
+    <value>There is an error in a referenced assembly '{0}'.</value>
+  </data>
 </root>

Src/Compilers/VisualBasic/Test/Emit/Emit/NoPiaEmbedTypes.vb

@@ -3894,7 +3894,9 @@ End Class
 ]]></file>
                            </compilation>
             Dim errors = <errors>
-BC36970: Failed to emit module 'Consumer.dll'.
+BC30002: Type 'I1' is not defined.
+        o.M2(Nothing)
+        ~~~~~~~~~~~~~
 </errors>
             Dim piaCompilation2 = CreateCompilationWithMscorlib(pia2)
             'CompileAndVerify(piaCompilation2, emitOptions:=EmitOptions.RefEmitBug)

Src/Compilers/VisualBasic/Test/Semantic/Binding/BadSymbolReference.vb

@@ -319,26 +319,54 @@ BC30652: Reference required to assembly 'CL2, Version=0.0.0.0, Culture=neutral,
 
             Dim errors2 =
 <errors>
+BC30002: Type 'CL2_C1' is not defined.
+        CL3_C1.Test1()
+        ~~~~~~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+        Global.CL3_C1.Test1()
+        ~~~~~~~~~~~~~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+        Dim z As Object = y.x
+                          ~~~
+BC30002: Type 'CL2_C1' is not defined.
+        Inherits CL3_C1
+                 ~~~~~~
 BC30258: Classes can inherit only from other classes.
         Inherits CL3_S1
                  ~~~~~~
+BC30002: Type 'CL2_I1' is not defined.
+        Inherits CL3_I1, I1(Of CL3_I1)
+                 ~~~~~~
+BC30002: Type 'CL2_I1' is not defined.
+        Implements CL3_I1, I1(Of CL3_I1)
+                   ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+        CL3_C2.Test1()
+        ~~~~~~~~~~~~~~
 BC30469: Reference to a non-shared member requires an object reference.
         CL3_C2.Test1(1)
         ~~~~~~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+        CL3_C2.Test3()
+        ~~~~~~~~~~~~~~
 BC30516: Overload resolution failed because no accessible 'Test4' accepts this number of arguments.
         CL3_C2.Test4()
                ~~~~~
-BC30521: Overload resolution failed because no accessible 'Test4' is most specific for these arguments:
-    'Public Shared Sub Test4(x As CL3_C1)': Not most specific.
-    'Public Shared Sub Test4(x As CL3_C3)': Not most specific.
+BC30002: Type 'CL2_C1' is not defined.
         CL3_C2.Test4(nothing)
-               ~~~~~
-BC42025: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.
+        ~~~~~~~~~~~~~~~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
         y.Test1()
-        ~~~~~~~
-BC31143: Method 'Public Sub Test2(x As Integer)' does not have a signature compatible with delegate 'Delegate Sub CL3_D1(x As CL2_C1)'.
+        ~~~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
         Dim d1 As CL3_D1 = AddressOf y.Test2
-                                     ~~~~~~~
+                           ~~~~~~~~~~~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+        y.w(Nothing)
+        ~~~
+BC30002: Type 'CL2_C1' is not defined.
+        Dim u As CL3_D1 = Sub(uuu) System.Console.WriteLine()
+                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 </errors>
             CompilationUtils.AssertTheseDiagnostics(compilation4, errors2)
 
@@ -385,8 +413,87 @@ BC30002: Type 'CL2_I1' is not defined.
 
             Dim compilation5 = CompilationUtils.CreateCompilationWithMscorlibAndVBRuntimeAndReferences(source, {New VisualBasicCompilationReference(cl3BadCompilation2)}, options:=TestOptions.ReleaseExe)
 
-            CompilationUtils.AssertTheseDiagnostics(compilation5, errors2)
+            Dim errors5 =
+<errors>
+BC30258: Classes can inherit only from other classes.
+        Inherits CL3_S1
+                 ~~~~~~
+BC30469: Reference to a non-shared member requires an object reference.
+        CL3_C2.Test1(1)
+        ~~~~~~~~~~~~
+BC30516: Overload resolution failed because no accessible 'Test4' accepts this number of arguments.
+        CL3_C2.Test4()
+               ~~~~~
+BC30521: Overload resolution failed because no accessible 'Test4' is most specific for these arguments:
+    'Public Shared Sub Test4(x As CL3_C1)': Not most specific.
+    'Public Shared Sub Test4(x As CL3_C3)': Not most specific.
+        CL3_C2.Test4(nothing)
+               ~~~~~
+BC42025: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.
+        y.Test1()
+        ~~~~~~~
+BC31143: Method 'Public Sub Test2(x As Integer)' does not have a signature compatible with delegate 'Delegate Sub CL3_D1(x As CL2_C1)'.
+        Dim d1 As CL3_D1 = AddressOf y.Test2
+                                     ~~~~~~~
+</errors>
+            CompilationUtils.AssertTheseDiagnostics(compilation5, errors5)
 
+            Dim errors6 =
+<errors>
+BC30258: Classes can inherit only from other classes.
+        Inherits CL3_S1
+                 ~~~~~~
+BC30469: Reference to a non-shared member requires an object reference.
+        CL3_C2.Test1(1)
+        ~~~~~~~~~~~~
+BC30516: Overload resolution failed because no accessible 'Test4' accepts this number of arguments.
+        CL3_C2.Test4()
+               ~~~~~
+BC30521: Overload resolution failed because no accessible 'Test4' is most specific for these arguments:
+    'Public Shared Sub Test4(x As CL3_C1)': Not most specific.
+    'Public Shared Sub Test4(x As CL3_C3)': Not most specific.
+        CL3_C2.Test4(nothing)
+               ~~~~~
+BC42025: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.
+        y.Test1()
+        ~~~~~~~
+BC31143: Method 'Public Sub Test2(x As Integer)' does not have a signature compatible with delegate 'Delegate Sub CL3_D1(x As CL2_C1)'.
+        Dim d1 As CL3_D1 = AddressOf y.Test2
+                                     ~~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+    Inherits CL2_C1
+             ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+    Public Shared Function Test2() As CL2_C1
+                                      ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+    Public Function Test3() As CL2_C1
+                               ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+    Public Shared Function Test1() As CL2_C1
+                                      ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+    Public x As CL2_C1
+                ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+    Public Shared Function Test3() As CL2_C1
+                                      ~~~~~~
+BC30002: Type 'CL2_I1' is not defined.
+    Implements CL2_I1, CL2_I2
+               ~~~~~~
+BC30002: Type 'CL2_I2' is not defined.
+    Implements CL2_I1, CL2_I2
+                       ~~~~~~
+BC30002: Type 'CL2_C1' is not defined.
+Public Delegate Sub CL3_D1(x As CL2_C1)
+                                ~~~~~~
+BC30002: Type 'CL2_I1' is not defined.
+    Implements CL2_I1
+               ~~~~~~
+BC30002: Type 'CL2_I1' is not defined.
+    Inherits CL2_I1
+             ~~~~~~
+</errors>
             Dim cl4Source =
     <compilation name="cl4">
         <%= a_vb %>
@@ -395,8 +502,7 @@ BC30002: Type 'CL2_I1' is not defined.
 
             Dim compilation6 = CompilationUtils.CreateCompilationWithMscorlibAndVBRuntime(cl4Source)
 
-            CompilationUtils.AssertTheseDiagnostics(compilation6,
-<error><%= errors2.Value.TrimEnd() + errors3.Value %></error>)
+            CompilationUtils.AssertTheseDiagnostics(compilation6, errors6)
 
             CompilationUtils.AssertNoErrors(compilation1)
         End Sub