Only tread FlowCaptureReference as read when it's not an assignment t…

…arget
SonarSource · Jul 19, 2024 · fa2b72f · fa2b72f
1 parent 1558760
commit fa2b72f
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Showing 2 changed files with 8 additions and 12 deletions.
diff --git a/analyzers/src/SonarAnalyzer.CFG/LiveVariableAnalysis/RoslynLiveVariableAnalysis.cs b/analyzers/src/SonarAnalyzer.CFG/LiveVariableAnalysis/RoslynLiveVariableAnalysis.cs
@@ -243,14 +243,7 @@ public void ProcessBlock(ControlFlowGraph cfg, BasicBlock block, Dictionary<Capt
         {
             foreach (var operation in block.OperationsAndBranchValue.ToReversedExecutionOrder().Select(x => x.Instance))
             {
-                if (operation.AsFlowCaptureReference() is { } flowCaptureReference  && flowCaptureOperations.TryGetValue(flowCaptureReference.Id, out var symbols))
-                {
-                    UsedBeforeAssigned.UnionWith(symbols);
-                }
-                else
-                {
-                    ProcessOperation(cfg, operation);
-                }
+                ProcessOperation(cfg, operation);
             }
         }
 
@@ -265,6 +258,9 @@ private void ProcessOperation(ControlFlowGraph cfg, IOperation operation)
                 case OperationKindEx.ParameterReference:
                     ProcessParameterOrLocalReference(IParameterReferenceOperationWrapper.FromOperation(operation));
                     break;
+                case OperationKindEx.FlowCaptureReference:
+                    ProcessParameterOrLocalReference(IFlowCaptureReferenceOperationWrapper.FromOperation(operation));
+                    break;
                 case OperationKindEx.SimpleAssignment:
                     ProcessSimpleAssignment(ISimpleAssignmentOperationWrapper.FromOperation(operation));
                     break;
@@ -288,7 +284,7 @@ private void ProcessParameterOrLocalReference(IOperationWrapper reference)
                 Assigned.UnionWith(symbols);
                 UsedBeforeAssigned.ExceptWith(symbols);
             }
-            else if (!reference.IsAssignmentTarget())
+            else if (!reference.IsAssignmentTarget() && reference.ToSonar().Parent?.Kind != OperationKindEx.FlowCapture)
             {
                 UsedBeforeAssigned.UnionWith(symbols);
             }

diff --git a/analyzers/tests/SonarAnalyzer.Test/TestCases/DeadStores.RoslynCfg.cs b/analyzers/tests/SonarAnalyzer.Test/TestCases/DeadStores.RoslynCfg.cs
@@ -648,14 +648,14 @@ public void Unused()
         private void ConditionalEvaluation(bool b1, bool b2, object coalesce, object coalesceAssignment)
         {
             var x = false;  // Compliant ignored value
-            x = true;       // Roslyn CFG FN: Consequence of inaccurate LVA state below
-            x = b1 && b2;   // Roslyn CFG FN: Branching with FlowCaptureOperation
+            x = true;       // Noncompliant
+            x = b1 && b2;   // Noncompliant
             x = b1 || b2;   // Noncompliant
             coalesce = coalesce ?? "Value";   // Noncompliant
             coalesceAssignment ??= "Value";   // Noncompliant
 
             DeadStores lst;
-            lst = new DeadStores  // FN
+            lst = new DeadStores  // Noncompliant
             {
                 Property = 42
             };