Track delegate parameter and return types in symbol-based mode#142
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Track delegate parameter and return types in symbol-based mode#142
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The symbol-based usage analyzer (ReferenceTrimmerUseSymbolAnalysis=true)
missed delegate parameter and return types because the implicitly-declared
DelegateInvokeMethod does not fire the SymbolKind.Method action. With a
declaration like:
public delegate void Configure(IServiceCollection services);
if IServiceCollection's containing assembly was referenced only through
this delegate, RT0002 would falsely flag the reference as removable.
Fix: when the symbol action sees an INamedTypeSymbol with TypeKind.Delegate,
walk DelegateInvokeMethod's return type, parameter types, and return-type
attributes — mirroring the existing IMethodSymbol branch (type-parameter
constraints are already covered by the surrounding INamedTypeSymbol case).
Adds five regression tests: external parameter type, external return type,
external generic-argument return type, generic delegate with type-parameter
constraint, and a negative test that a delegate using only same-assembly
types does not mark unrelated external assemblies as used.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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In the symbol-based analysis path, member access via an `override` only credited the override's containing assembly. The C# compiler validates the entire override chain at compile time, so any assembly that declares an overridden base member must remain a reference -- removing it produces CS0012 errors. Symbol-based RT, on `IPropertyReferenceOperation` / `IInvocationOperation` / `IEventReferenceOperation`, walked only `Member.ContainingAssembly` (= override's assembly) and never visited `Member.OverriddenProperty?.ContainingAssembly` (= base's assembly), so the consumer's reference to the base assembly was wrongly flagged RT0002 removable. Fix: add a `TrackOverriddenChain` helper that walks `OverriddenMethod` / `OverriddenProperty` / `OverriddenEvent` chains and tracks every containing assembly. Call it from the `IInvocationOperation` and `IMemberReferenceOperation` branches. Fields don't have override chains. Adds five regression tests that all fail without this change: - `UsedViaOverridePropertyAccess`: the canonical scenario - `UsedViaOverrideMethodCall`: method variant - `UsedViaOverrideEventAccess`: event variant - `UsedViaOverrideMultiLevelChain`: three-level A -> B -> C chain - `UnrelatedReferenceNotMarkedByOverride`: negative test ensuring the fix doesn't over-credit unrelated assemblies Different code path from #141 (qualifier tracking on inherited static member access) and #142 (delegate parameter / return types). Surfaced by a QuickBuild trial of the symbol-based mode. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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…145) In the symbol-based analysis path, only the immediate base type's containing assembly was credited via `TrackType(namedType.BaseType)`. The C# compiler validates the entire base-type chain plus implemented interfaces at type-check time -- CS0012 fires when *any* link's defining assembly is missing -- so any assembly along the chain must remain a reference. With `<DisableTransitiveProjectReferences>true</...>`, the chain doesn't flow transitively, so the consumer must explicitly reference grandparent assemblies. Symbol-based RT, when handling `INamedTypeSymbol`, walked only the immediate `BaseType` and direct `Interfaces`, never recursing further up. So for `Consumer : Provider` where `Provider : ProviderDependency` in another assembly, the consumer's reference to `ProviderDependency` was wrongly flagged RT0002 removable. Fix: extend `TrackType`'s `INamedTypeSymbol` branch to walk the full `BaseType` chain and `AllInterfaces` collection. `AllInterfaces` is broader than `Interfaces` (includes transitively-implemented interfaces) and mirrors what the compiler validates. A `ConcurrentDictionary<ISymbol, byte>` keyed via `SymbolEqualityComparer.Default` gates the chain walk to break self-referential cycles such as `int -> AllInterfaces[IComparable<int>] -> typeArg int -> ...` and to avoid redundant work. Adds seven regression tests that all fail without this change: - `UsedViaInheritedBaseType`: the canonical issue #144 scenario - `UsedViaImplementedInterface`: interface in the chain - `UsedViaMultiLevelInheritanceChain`: three-level A <- B <- C - `UsedViaInheritanceChainOnVariableType`: chain via parameter type - `UsedViaMixedBaseAndInterfaceChain`: base + interface, four asms - `UsedViaGenericConstraintBaseChain`: `where T : Provider` constraint - `UnrelatedReferenceNotMarkedByInheritance`: negative test ensuring the fix doesn't over-credit unrelated assemblies Verified against upstream repro https://github.com/olstakh/RT_Gap_Inheritance: `Consumer` builds with 0 RT warnings (was emitting RT0002 with v3.5.2). Different code path from #141 (qualifier tracking on inherited static member access), #142 (delegate parameter / return types), and #143 (override chains). Same family of "symbol traversal misses a chain" gaps; same reporter (olstakh). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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The symbol-based usage analyzer (
ReferenceTrimmerUseSymbolAnalysis=true) missed delegate parameter and return types because the implicitly-declaredDelegateInvokeMethoddoes not fire theSymbolKind.Methodaction. With a declaration like:if
IServiceCollection's containing assembly was referenced only through this delegate, RT0002 would falsely flag the reference as removable.Fix
When the symbol action sees an
INamedTypeSymbolwithTypeKind.Delegate, walkDelegateInvokeMethod's return type, parameter types, and return-type attributes — mirroring the existingIMethodSymbolbranch. (Type-parameter constraints are already covered by the surroundingINamedTypeSymbolcase.)Tests
Adds five regression tests:
List<External>)