Expose more of Roslyn to the XPath queries of MA0240

[meziantou]

What

Adds the members that were missing from the data an MA0240 banned syntax query can select, and fixes two inconsistencies in how the operations are exposed.

The kind of a type

Each of the four type prefixes gains a …Kind suffix (semantic:TypeKind, semantic:ConvertedTypeKind, semantic:ReturnTypeKind, semantic:ContainingTypeKind, and @PKind for the type properties of the operations). Only IsValueType and SpecialType were exposed, so a query could not select the interfaces, the enumerations or the delegates:

//Parameter/*[@semantic:TypeKind='Interface']; Do not take an interface

The attribute is not present for the types that do not compile (Unknown and Error), like semantic:TypeSpecialType is not present for the types that are not special.

The modifiers of a symbol

IsAbstract, IsVirtual, IsOverride, IsSealed, IsAsync, IsExtensionMethod and Arity, on the semantic attributes and on the symbol properties of the operations (@TargetMethodIsAbstract, @TargetMethodArity, ...). Only IsStatic was exposed:

//MethodDeclaration[@semantic:IsAsync='true' and @semantic:ReturnTypeSpecialType='System_Void']; Do not write async void
//operation:Invocation[@TargetMethodIsExtensionMethod='true']

The modifiers that only a method or a type has are not exposed for the other symbols, so [not(@semantic:IsAsync)] selects the nodes whose symbol is not a method, whereas [@semantic:IsAsync='false'] selects the ones whose symbol is a method that is not async. The logic is shared by the two navigators (XPathAttributeFormatter.AddSymbolModifiers), so the two lists cannot drift apart.

Two inconsistencies of the operations

• A property that returns several symbols, such as Locals or InitializedFields, only had @P and @PName. It now also has @PDocumentationId.
• A property that returns several types was exposed as the symbols that are not types, so it had no metadata name and no reference id. ImmutableArray<ITypeSymbol> is now matched before ImmutableArray<ISymbol> and exposes @PName, @PMetadataName, @PDocumentationId and @PReferenceId.
• CommonConversion was dropped by CreateProperty, so IConversionOperation.Conversion was unreachable and a query could not tell a user-defined conversion from a numeric one. It now exposes @PExists, @PIsIdentity, @PIsImplicit, @PIsNullable, @PIsNumeric, @PIsReference, @PIsUserDefined, and the operator as the symbol @PMethod:

//operation:Conversion[@ConversionIsUserDefined='true']; Do not rely on the implicit operators

This covers IConversionOperation.Conversion, the two conversions of IArgumentOperation and of ICompoundAssignmentOperation, ICoalesceOperation.ValueConversion, and ISpreadOperation.ElementConversion on the versions of Roslyn that have it. IsUnion is not exposed, as it only exists from Roslyn 5.9 and an entry must mean the same thing in every supported version.

Why

The operations are exposed by reflection, so they follow the API of Roslyn, but the semantic attributes are a hand-written list that was missing the modifiers and the kind of a type. The attributes are only computed when a query can select them (XPathAttributeFilter), so the entries that do not use the new attributes pay nothing for them. The list properties declare only the names they can produce, so asking for @PIsStatic on a Locals no longer costs a reflection call.

Breaking change

@TypeArguments becomes @TypeArgumentsMetadataName, as a list of types is now exposed like a single type, which has no bare @P. It only applies to IDynamicMemberReferenceOperation.TypeArguments, an attribute that was introduced recently and that operation:DynamicMemberReference is the only element to have.

Testing

• 18 new tests in DoNotUseBannedSyntaxAnalyzerTests, which bring the MA0240/MA0241 tests to 153. They pass on roslyn4.8, roslyn4.14, roslyn5.0, roslyn5.6 and roslyn5.9.
• The whole roslyn5.9 test project passes (4953 tests).
• dotnet run --project src/DocumentationGenerator exits 0 and changes no markdown file beyond the edits to docs/Rules/MA0240.md that are in this PR.