Partial properties: diagnostics for mismatch between parts

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -2234,17 +2234,17 @@ If such a class is used as a base class and if the deriving class defines a dest
   <data name="ERR_PartialMethodMustHaveLatent" xml:space="preserve">
     <value>No defining declaration found for implementing declaration of partial method '{0}'</value>
   </data>
-  <data name="ERR_PartialMethodInconsistentTupleNames" xml:space="preserve">
-    <value>Both partial method declarations, '{0}' and '{1}', must use the same tuple element names.</value>
+  <data name="ERR_PartialMemberInconsistentTupleNames" xml:space="preserve">
+    <value>Both partial member declarations, '{0}' and '{1}', must use the same tuple element names.</value>
   </data>
   <data name="ERR_PartialMethodInconsistentConstraints" xml:space="preserve">
     <value>Partial method declarations of '{0}' have inconsistent constraints for type parameter '{1}'</value>
   </data>
   <data name="ERR_PartialMethodToDelegate" xml:space="preserve">
     <value>Cannot create delegate from method '{0}' because it is a partial method without an implementing declaration</value>
   </data>
-  <data name="ERR_PartialMethodStaticDifference" xml:space="preserve">
-    <value>Both partial method declarations must be static or neither may be static</value>
+  <data name="ERR_PartialMemberStaticDifference" xml:space="preserve">
+    <value>Both partial member declarations must be static or neither may be static</value>
   </data>
   <data name="ERR_PartialMethodUnsafeDifference" xml:space="preserve">
     <value>Both partial method declarations must be unsafe or neither may be unsafe</value>
@@ -5752,8 +5752,8 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="ERR_FieldLikeEventCantBeReadOnly" xml:space="preserve">
     <value>Field-like event '{0}' cannot be 'readonly'.</value>
   </data>
-  <data name="ERR_PartialMethodReadOnlyDifference" xml:space="preserve">
-    <value>Both partial method declarations must be readonly or neither may be readonly</value>
+  <data name="ERR_PartialMemberReadOnlyDifference" xml:space="preserve">
+    <value>Both partial member declarations must be readonly or neither may be readonly</value>
   </data>
   <data name="ERR_ReadOnlyModMissingAccessor" xml:space="preserve">
     <value>'{0}': 'readonly' can only be used on accessors if the property or indexer has both a get and a set accessor</value>
@@ -6536,17 +6536,17 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="ERR_PartialMethodWithExtendedModMustHaveAccessMods" xml:space="preserve">
     <value>Partial method '{0}' must have accessibility modifiers because it has a 'virtual', 'override', 'sealed', 'new', or 'extern' modifier.</value>
   </data>
-  <data name="ERR_PartialMethodAccessibilityDifference" xml:space="preserve">
-    <value>Both partial method declarations must have identical accessibility modifiers.</value>
+  <data name="ERR_PartialMemberAccessibilityDifference" xml:space="preserve">
+    <value>Both partial member declarations must have identical accessibility modifiers.</value>
   </data>
-  <data name="ERR_PartialMethodExtendedModDifference" xml:space="preserve">
-    <value>Both partial method declarations must have identical combinations of 'virtual', 'override', 'sealed', and 'new' modifiers.</value>
+  <data name="ERR_PartialMemberExtendedModDifference" xml:space="preserve">
+    <value>Both partial member declarations must have identical combinations of 'virtual', 'override', 'sealed', and 'new' modifiers.</value>
   </data>
   <data name="ERR_PartialMethodReturnTypeDifference" xml:space="preserve">
     <value>Both partial method declarations must have the same return type.</value>
   </data>
-  <data name="ERR_PartialMethodRefReturnDifference" xml:space="preserve">
-    <value>Partial method declarations must have matching ref return values.</value>
+  <data name="ERR_PartialMemberRefReturnDifference" xml:space="preserve">
+    <value>Partial member declarations must have matching ref return values.</value>
   </data>
   <data name="WRN_PartialMethodTypeDifference" xml:space="preserve">
     <value>Partial method declarations '{0}' and '{1}' have signature differences.</value>
@@ -7947,4 +7947,10 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="ERR_PartialPropertyUnexpectedAccessor" xml:space="preserve">
     <value>Property accessor '{0}' does not implement any accessor declared on the definition part</value>
   </data>
+  <data name="ERR_PartialPropertyInitMismatch" xml:space="preserve">
+    <value>Property accessor '{0}' must be '{1}' to match the definition part</value>
+  </data>
+  <data name="ERR_PartialPropertyTypeDifference" xml:space="preserve">
+    <value>Both partial property declarations must have the same type.</value>
+  </data>
 </root>

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

@@ -541,7 +541,7 @@ internal enum ErrorCode
         ERR_PartialMethodMustHaveLatent = 759,
         ERR_PartialMethodInconsistentConstraints = 761,
         ERR_PartialMethodToDelegate = 762,
-        ERR_PartialMethodStaticDifference = 763,
+        ERR_PartialMemberStaticDifference = 763,
         ERR_PartialMethodUnsafeDifference = 764,
         ERR_PartialMethodInExpressionTree = 765,
         // ERR_PartialMethodMustReturnVoid = 766, Removed as part of 'extended partial methods' feature
@@ -1392,7 +1392,7 @@ internal enum ErrorCode
         ERR_CantChangeTupleNamesOnOverride = 8139,
         ERR_DuplicateInterfaceWithTupleNamesInBaseList = 8140,
         ERR_ImplBadTupleNames = 8141,
-        ERR_PartialMethodInconsistentTupleNames = 8142,
+        ERR_PartialMemberInconsistentTupleNames = 8142,
         ERR_ExpressionTreeContainsTupleLiteral = 8143,
         ERR_ExpressionTreeContainsTupleConversion = 8144,
         #endregion tuple diagnostics introduced in C# 7
@@ -1709,7 +1709,7 @@ internal enum ErrorCode
         ERR_InvalidPropertyReadOnlyMods = 8660,
         ERR_DuplicatePropertyReadOnlyMods = 8661,
         ERR_FieldLikeEventCantBeReadOnly = 8662,
-        ERR_PartialMethodReadOnlyDifference = 8663,
+        ERR_PartialMemberReadOnlyDifference = 8663,
         ERR_ReadOnlyModMissingAccessor = 8664,
         ERR_OverrideRefConstraintNotSatisfied = 8665,
         ERR_OverrideValConstraintNotSatisfied = 8666,
@@ -1809,8 +1809,8 @@ internal enum ErrorCode
         ERR_PartialMethodWithNonVoidReturnMustHaveAccessMods = 8796,
         ERR_PartialMethodWithOutParamMustHaveAccessMods = 8797,
         ERR_PartialMethodWithExtendedModMustHaveAccessMods = 8798,
-        ERR_PartialMethodAccessibilityDifference = 8799,
-        ERR_PartialMethodExtendedModDifference = 8800,
+        ERR_PartialMemberAccessibilityDifference = 8799,
+        ERR_PartialMemberExtendedModDifference = 8800,
 
         ERR_SimpleProgramLocalIsReferencedOutsideOfTopLevelStatement = 8801,
         ERR_SimpleProgramMultipleUnitsWithTopLevelStatements = 8802,
@@ -1832,7 +1832,7 @@ internal enum ErrorCode
         ERR_ModuleInitializerMethodAndContainingTypesMustNotBeGeneric = 8816,
 
         ERR_PartialMethodReturnTypeDifference = 8817,
-        ERR_PartialMethodRefReturnDifference = 8818,
+        ERR_PartialMemberRefReturnDifference = 8818,
         WRN_NullabilityMismatchInReturnTypeOnPartial = 8819,
 
         ERR_StaticAnonymousFunctionCannotCaptureVariable = 8820,
@@ -2317,6 +2317,8 @@ internal enum ErrorCode
         ERR_PartialPropertyDuplicateImplementation = 9303,
         ERR_PartialPropertyMissingAccessor = 9304,
         ERR_PartialPropertyUnexpectedAccessor = 9305,
+        ERR_PartialPropertyInitMismatch = 9306,
+        ERR_PartialPropertyTypeDifference = 9307,
 
         #endregion
 

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

@@ -1079,7 +1079,7 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
                 case ErrorCode.ERR_PartialMethodMustHaveLatent:
                 case ErrorCode.ERR_PartialMethodInconsistentConstraints:
                 case ErrorCode.ERR_PartialMethodToDelegate:
-                case ErrorCode.ERR_PartialMethodStaticDifference:
+                case ErrorCode.ERR_PartialMemberStaticDifference:
                 case ErrorCode.ERR_PartialMethodUnsafeDifference:
                 case ErrorCode.ERR_PartialMethodInExpressionTree:
                 case ErrorCode.ERR_ExplicitImplCollisionOnRefOut:
@@ -1744,7 +1744,7 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
                 case ErrorCode.ERR_CantChangeTupleNamesOnOverride:
                 case ErrorCode.ERR_DuplicateInterfaceWithTupleNamesInBaseList:
                 case ErrorCode.ERR_ImplBadTupleNames:
-                case ErrorCode.ERR_PartialMethodInconsistentTupleNames:
+                case ErrorCode.ERR_PartialMemberInconsistentTupleNames:
                 case ErrorCode.ERR_ExpressionTreeContainsTupleLiteral:
                 case ErrorCode.ERR_ExpressionTreeContainsTupleConversion:
                 case ErrorCode.ERR_AutoPropertyCannotBeRefReturning:
@@ -1983,7 +1983,7 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
                 case ErrorCode.ERR_InvalidPropertyReadOnlyMods:
                 case ErrorCode.ERR_DuplicatePropertyReadOnlyMods:
                 case ErrorCode.ERR_FieldLikeEventCantBeReadOnly:
-                case ErrorCode.ERR_PartialMethodReadOnlyDifference:
+                case ErrorCode.ERR_PartialMemberReadOnlyDifference:
                 case ErrorCode.ERR_ReadOnlyModMissingAccessor:
                 case ErrorCode.ERR_OverrideRefConstraintNotSatisfied:
                 case ErrorCode.ERR_OverrideValConstraintNotSatisfied:
@@ -2053,8 +2053,8 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
                 case ErrorCode.ERR_PartialMethodWithNonVoidReturnMustHaveAccessMods:
                 case ErrorCode.ERR_PartialMethodWithOutParamMustHaveAccessMods:
                 case ErrorCode.ERR_PartialMethodWithExtendedModMustHaveAccessMods:
-                case ErrorCode.ERR_PartialMethodAccessibilityDifference:
-                case ErrorCode.ERR_PartialMethodExtendedModDifference:
+                case ErrorCode.ERR_PartialMemberAccessibilityDifference:
+                case ErrorCode.ERR_PartialMemberExtendedModDifference:
                 case ErrorCode.ERR_SimpleProgramLocalIsReferencedOutsideOfTopLevelStatement:
                 case ErrorCode.ERR_SimpleProgramMultipleUnitsWithTopLevelStatements:
                 case ErrorCode.ERR_TopLevelStatementAfterNamespaceOrType:
@@ -2072,7 +2072,7 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
                 case ErrorCode.ERR_ModuleInitializerMethodMustBeStaticParameterlessVoid:
                 case ErrorCode.ERR_ModuleInitializerMethodAndContainingTypesMustNotBeGeneric:
                 case ErrorCode.ERR_PartialMethodReturnTypeDifference:
-                case ErrorCode.ERR_PartialMethodRefReturnDifference:
+                case ErrorCode.ERR_PartialMemberRefReturnDifference:
                 case ErrorCode.WRN_NullabilityMismatchInReturnTypeOnPartial:
                 case ErrorCode.ERR_StaticAnonymousFunctionCannotCaptureVariable:
                 case ErrorCode.ERR_StaticAnonymousFunctionCannotCaptureThis:
@@ -2445,6 +2445,8 @@ internal static bool IsBuildOnlyDiagnostic(ErrorCode code)
                 case ErrorCode.ERR_PartialPropertyDuplicateImplementation:
                 case ErrorCode.ERR_PartialPropertyMissingAccessor:
                 case ErrorCode.ERR_PartialPropertyUnexpectedAccessor:
+                case ErrorCode.ERR_PartialPropertyInitMismatch:
+                case ErrorCode.ERR_PartialPropertyTypeDifference:
                     return false;
                 default:
                     // NOTE: All error codes must be explicitly handled in this switch statement

src/Compilers/CSharp/Portable/Symbols/MemberSymbolExtensions.cs

@@ -547,6 +547,7 @@ internal static bool IsExplicitInterfaceImplementation(this Symbol member)
 
         internal static bool IsPartialMember(this Symbol member)
         {
+            Debug.Assert(member.IsDefinition);
             return member
                 is SourceOrdinaryMethodSymbol { IsPartial: true }
                 or SourcePropertySymbol { IsPartial: true }
@@ -555,6 +556,7 @@ internal static bool IsPartialMember(this Symbol member)
 
         internal static bool IsPartialImplementation(this Symbol member)
         {
+            Debug.Assert(member.IsDefinition);
             return member
                 is SourceOrdinaryMethodSymbol { IsPartialImplementation: true }
                 or SourcePropertySymbol { IsPartialImplementation: true }
@@ -563,6 +565,7 @@ internal static bool IsPartialImplementation(this Symbol member)
 
         internal static bool IsPartialDefinition(this Symbol member)
         {
+            Debug.Assert(member.IsDefinition);
             return member
                 is SourceOrdinaryMethodSymbol { IsPartialDefinition: true }
                 or SourcePropertySymbol { IsPartialDefinition: true }

src/Compilers/CSharp/Portable/Symbols/Source/SourceOrdinaryMethodSymbol.cs

@@ -471,6 +471,10 @@ protected sealed override void PartialMethodChecks(BindingDiagnosticBag diagnost
         /// parts of a partial method. Diagnostics are reported on the
         /// implementing part, matching Dev10 behavior.
         /// </summary>
+        /// <remarks>
+        /// This method is analogous to <see cref="SourcePropertySymbol.PartialPropertyChecks" />.
+        /// Whenever new checks are added to this method, the other method should also have those checks added, if applicable.
+        /// </remarks>
         private static void PartialMethodChecks(SourceOrdinaryMethodSymbol definition, SourceOrdinaryMethodSymbol implementation, BindingDiagnosticBag diagnostics)
         {
             Debug.Assert(!ReferenceEquals(definition, implementation));
@@ -484,22 +488,22 @@ private static void PartialMethodChecks(SourceOrdinaryMethodSymbol definition, S
             else if (MemberSignatureComparer.ConsideringTupleNamesCreatesDifference(definition, implementation))
             {
                 hasTypeDifferences = true;
-                diagnostics.Add(ErrorCode.ERR_PartialMethodInconsistentTupleNames, implementation.GetFirstLocation(), definition, implementation);
+                diagnostics.Add(ErrorCode.ERR_PartialMemberInconsistentTupleNames, implementation.GetFirstLocation(), definition, implementation);
             }
 
             if (definition.RefKind != implementation.RefKind)
             {
-                diagnostics.Add(ErrorCode.ERR_PartialMethodRefReturnDifference, implementation.GetFirstLocation());
+                diagnostics.Add(ErrorCode.ERR_PartialMemberRefReturnDifference, implementation.GetFirstLocation());
             }
 
             if (definition.IsStatic != implementation.IsStatic)
             {
-                diagnostics.Add(ErrorCode.ERR_PartialMethodStaticDifference, implementation.GetFirstLocation());
+                diagnostics.Add(ErrorCode.ERR_PartialMemberStaticDifference, implementation.GetFirstLocation());
             }
 
             if (definition.IsDeclaredReadOnly != implementation.IsDeclaredReadOnly)
             {
-                diagnostics.Add(ErrorCode.ERR_PartialMethodReadOnlyDifference, implementation.GetFirstLocation());
+                diagnostics.Add(ErrorCode.ERR_PartialMemberReadOnlyDifference, implementation.GetFirstLocation());
             }
 
             if (definition.IsExtensionMethod != implementation.IsExtensionMethod)
@@ -520,15 +524,15 @@ private static void PartialMethodChecks(SourceOrdinaryMethodSymbol definition, S
             if (definition.HasExplicitAccessModifier != implementation.HasExplicitAccessModifier
                 || definition.DeclaredAccessibility != implementation.DeclaredAccessibility)
             {
-                diagnostics.Add(ErrorCode.ERR_PartialMethodAccessibilityDifference, implementation.GetFirstLocation());
+                diagnostics.Add(ErrorCode.ERR_PartialMemberAccessibilityDifference, implementation.GetFirstLocation());
             }
 
             if (definition.IsVirtual != implementation.IsVirtual
                 || definition.IsOverride != implementation.IsOverride
                 || definition.IsSealed != implementation.IsSealed
                 || definition.IsNew != implementation.IsNew)
             {
-                diagnostics.Add(ErrorCode.ERR_PartialMethodExtendedModDifference, implementation.GetFirstLocation());
+                diagnostics.Add(ErrorCode.ERR_PartialMemberExtendedModDifference, implementation.GetFirstLocation());
             }
 
             PartialMethodConstraintsChecks(definition, implementation, diagnostics);

src/Compilers/CSharp/Portable/Symbols/Source/SourcePropertyAccessorSymbol.cs

@@ -145,7 +145,18 @@ internal sealed override ImmutableArray<string> NotNullWhenFalseMembers
             bool isNullableAnalysisEnabled,
             BindingDiagnosticBag diagnostics) :
             base(containingType, syntax.GetReference(), location, isIterator: false,
-                 MakeModifiersAndFlags(property, propertyModifiers, isNullableAnalysisEnabled))
+                MakeModifiersAndFlags(
+                    containingType,
+                    property,
+                    propertyModifiers,
+                    location,
+                    hasBlockBody: false,
+                    hasExpressionBody: true,
+                    modifiers: [],
+                    methodKind: MethodKind.PropertyGet,
+                    isNullableAnalysisEnabled,
+                    diagnostics,
+                    out var modifierErrors))
         {
             _property = property;
             _isAutoPropertyAccessor = false;
@@ -158,21 +169,6 @@ internal sealed override ImmutableArray<string> NotNullWhenFalseMembers
             this.CheckModifiers(location, hasBody: true, isAutoPropertyOrExpressionBodied: true, diagnostics: diagnostics);
         }
 
-        private static (DeclarationModifiers, Flags) MakeModifiersAndFlags(SourcePropertySymbol property, DeclarationModifiers propertyModifiers, bool isNullableAnalysisEnabled)
-        {
-            // The modifiers for the accessor are the same as the modifiers for the property,
-            // minus the indexer and readonly bit
-            var declarationModifiers = GetAccessorModifiers(propertyModifiers);
-
-            // ReturnsVoid property is overridden in this class so
-            // returnsVoid argument to MakeFlags is ignored.
-            Flags flags = MakeFlags(MethodKind.PropertyGet, property.RefKind, declarationModifiers, returnsVoid: false, returnsVoidIsSet: false,
-                                    isExpressionBodied: true, isExtensionMethod: false, isNullableAnalysisEnabled: isNullableAnalysisEnabled,
-                                    isVarArg: false, isExplicitInterfaceImplementation: property.IsExplicitInterfaceImplementation, hasThisInitializer: false);
-
-            return (declarationModifiers, flags);
-        }
-
 #nullable enable
         protected SourcePropertyAccessorSymbol(
             NamedTypeSymbol containingType,
@@ -821,5 +817,27 @@ internal override void AddSynthesizedAttributes(PEModuleBuilder moduleBuilder, r
         internal bool IsPartialImplementation => _property is SourcePropertySymbol { IsPartialImplementation: true };
 
         public sealed override bool IsExtern => PartialImplementationPart is { } implementation ? implementation.IsExtern : base.IsExtern;
+
+        internal void PartialAccessorChecks(SourcePropertyAccessorSymbol implementationAccessor, BindingDiagnosticBag diagnostics)
+        {
+            Debug.Assert(IsPartialDefinition);
+
+            if (LocalAccessibility != implementationAccessor.LocalAccessibility)
+            {
+                diagnostics.Add(ErrorCode.ERR_PartialMemberAccessibilityDifference, implementationAccessor.GetFirstLocation());
+            }
+
+            if (_property.HasReadOnlyModifier == implementationAccessor._property.HasReadOnlyModifier
+                && IsDeclaredReadOnly != implementationAccessor.IsDeclaredReadOnly)
+            {
+                diagnostics.Add(ErrorCode.ERR_PartialMemberReadOnlyDifference, implementationAccessor.GetFirstLocation());
+            }
+
+            if (_usesInit != implementationAccessor._usesInit)
+            {
+                var accessorName = _usesInit ? "init" : "get";
+                diagnostics.Add(ErrorCode.ERR_PartialPropertyInitMismatch, implementationAccessor.GetFirstLocation(), implementationAccessor, accessorName);
+            }
+        }
     }
 }