SE: Refactor FlowCaptureReference to operation processor (#7353)

analyzers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/OperationDispatcher.cs

@@ -52,6 +52,7 @@ internal static class OperationDispatcher
         { OperationKindEx.EventReference, new EventReference() },
         { OperationKindEx.FieldReference, new FieldReference() },
         { OperationKindEx.FlowCapture, new FlowCapture() },
+        { OperationKindEx.FlowCaptureReference, new FlowCaptureReference() },
         { OperationKindEx.Increment, new IncrementOrDecrement() },
         { OperationKindEx.InstanceReference, new InstanceReference() },
         { OperationKindEx.LocalReference, new LocalReference() },

analyzers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/OperationProcessors/FlowCapture.cs

@@ -28,3 +28,12 @@ protected override IFlowCaptureOperationWrapper Convert(IOperation operation) =>
     protected override ProgramState Process(SymbolicContext context, IFlowCaptureOperationWrapper capture) =>
         context.State.SetCapture(capture.Id, context.State.ResolveCapture(capture.Value));  // Capture can transitively reference another IFlowCaptureReference
 }
+
+internal sealed class FlowCaptureReference : SimpleProcessor<IFlowCaptureReferenceOperationWrapper>
+{
+    protected override IFlowCaptureReferenceOperationWrapper Convert(IOperation operation) =>
+        IFlowCaptureReferenceOperationWrapper.FromOperation(operation);
+
+    protected override ProgramState Process(SymbolicContext context, IFlowCaptureReferenceOperationWrapper capture) =>
+        context.State.SetOperationValue(capture, context.State[context.State.ResolveCapture(capture.WrappedOperation)]);
+}

analyzers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/ProgramState.cs

@@ -39,7 +39,7 @@ public sealed record ProgramState : IEquatable<ProgramState>
     public ExceptionState Exception => Exceptions.IsEmpty ? null : Exceptions.Peek();
     public SymbolicValue this[IOperationWrapperSonar operation] => this[operation.Instance];
     public SymbolicValue this[IOperationWrapper operation] => this[operation.WrappedOperation];
-    public SymbolicValue this[IOperation operation] => OperationValue.TryGetValue(ResolveCapture(operation), out var value) ? value : null;
+    public SymbolicValue this[IOperation operation] => OperationValue.TryGetValue(operation, out var value) ? value : null;
     public SymbolicValue this[ISymbol symbol] => SymbolValue.TryGetValue(symbol, out var value) ? value : null;
     public IOperation this[CaptureId capture] => CaptureOperation.TryGetValue(capture, out var value) ? value : null;
 
@@ -74,10 +74,13 @@ operation is null
             : SetOperationValue(operation.Instance, value);
 
     public ProgramState SetOperationValue(IOperation operation, SymbolicValue value) =>
-        (operation ?? throw new ArgumentNullException(nameof(operation))) is var _
-        && value is null
-            ? this with { OperationValue = OperationValue.Remove(ResolveCapture(operation)) }
-            : this with { OperationValue = OperationValue.SetItem(ResolveCapture(operation), value) };
+        SetOperationValueCore(ResolveCapture(operation), value);
+
+    /// <summary>
+    /// Sets state directly to the FlowCaptureReferenceOperation directly, without resolving the capture itself.
+    /// </summary>
+    public ProgramState SetOperationValue(IFlowCaptureReferenceOperationWrapper capture, SymbolicValue value) =>
+        SetOperationValueCore(capture.WrappedOperation, value);
 
     public ProgramState SetOperationConstraint(IOperationWrapper operation, SymbolicConstraint constraint) =>
         SetOperationConstraint(operation.WrappedOperation, constraint);
@@ -168,6 +171,12 @@ public ProgramState[] ToArray() =>
     public override string ToString() =>
         Equals(Empty) ? "Empty" + Environment.NewLine : SerializeExceptions() + SerializeSymbols() + SerializeOperations() + SerializeCaptures();
 
+    private ProgramState SetOperationValueCore(IOperation operation, SymbolicValue value) =>
+        (operation ?? throw new ArgumentNullException(nameof(operation))) is var _
+        && value is null
+            ? this with { OperationValue = OperationValue.Remove(operation) }
+            : this with { OperationValue = OperationValue.SetItem(operation, value) };
+
     private string SerializeExceptions() =>
         Exceptions.IsEmpty ? null : Exceptions.JoinStr(string.Empty, x => $"Exception: {x}{Environment.NewLine}");
 

analyzers/tests/SonarAnalyzer.UnitTest/SymbolicExecution/Roslyn/ProgramStateTest.OperationValue.cs

@@ -206,6 +206,21 @@ public void SetOperationValue_OnCaptureReference_SetsValueToCapturedOperation()
         sut[capture.Value].Should().Be(value);
     }
 
+    [TestMethod]
+    public void SetOperationValue_OnFlowCaptureReferenceOperationWrapper_SetsValueToOperation()
+    {
+        var value = SymbolicValue.Empty;
+        var cfg = TestHelper.CompileCfgBodyCS("a ??= b;", "object a, object b");
+        var capture = IFlowCaptureOperationWrapper.FromOperation(cfg.Blocks[1].Operations[0]);
+        var captureReference = IFlowCaptureReferenceOperationWrapper.FromOperation(cfg.Blocks[3].Operations[0].Children.First());
+        captureReference.Id.Should().Be(capture.Id);
+        var sut = ProgramState.Empty
+            .SetCapture(capture.Id, capture.Value)
+            .SetOperationValue(captureReference, value);
+        sut[capture.Value].Should().BeNull();
+        sut[captureReference].Should().Be(value);
+    }
+
     [TestMethod]
     public void ResetOperations_IsImmutable()
     {