Fix FPs in LocksReleasedAllPaths.Mutex.NetFx.cs

SonarSource · Mar 29, 2023 · d382b3c · d382b3c
1 parent f74847a
commit d382b3c
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Showing 3 changed files with 25 additions and 17 deletions.
diff --git a/...zers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/Extensions/IOperationExtensions.cs b/...zers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/Extensions/IOperationExtensions.cs
@@ -31,6 +31,7 @@ OperationKindEx.FieldReference when operation.ToFieldReference() is var fieldRef
                 OperationKindEx.LocalReference => operation.ToLocalReference().Local,
                 OperationKindEx.ParameterReference => operation.ToParameterReference().Parameter,
                 OperationKindEx.Argument => operation.ToArgument().Value.TrackedSymbol(),
+                OperationKindEx.DeclarationExpression => IDeclarationExpressionOperationWrapper.FromOperation(operation).Expression.TrackedSymbol(),
                 _ => null
             };
 

diff --git a/...src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/RuleChecks/LocksReleasedAllPathsBase.cs b/...src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/RuleChecks/LocksReleasedAllPathsBase.cs
@@ -94,6 +94,27 @@ public override ProgramState[] PostProcess(SymbolicContext context)
                     };
                 }
             }
+            else if (context.Operation.Instance.AsObjectCreation() is { } objectCreation
+                && objectCreation.Type.Is(KnownType.System_Threading_Mutex)
+                && context.Operation.Parent.AsAssignment() is { } assignment
+                && assignment.Target.TrackedSymbol() is { } symbol
+                && objectCreation.Arguments.Length > 0
+                && objectCreation.Arguments.ToDictionary(x => x.ToArgument().Parameter.Name, x => x.ToArgument().Value) is var arguments
+                && arguments.TryGetValue("initiallyOwned", out var initiallyOwned)
+                && context.State[initiallyOwned] is { } initiallyOwnedValue
+                && initiallyOwnedValue.HasConstraint(BoolConstraint.True))
+            {
+                lastSymbolLock[symbol] = objectCreation.ToSonar();
+                return arguments.TryGetValue("createdNew", out var createdNew)
+                    && createdNew.TrackedSymbol() is { } trackedCreatedNew
+                    ? new[]
+                        {
+                            AddLock(context, symbol).SetSymbolConstraint(trackedCreatedNew, BoolConstraint.True),
+                            context.State.SetSymbolConstraint(trackedCreatedNew, BoolConstraint.False),
+                        }
+                    : AddLock(context, objectCreation.WrappedOperation).Preserve(symbol).ToArray();
+            }
+
             return base.PostProcess(context);
         }
 
@@ -131,21 +152,7 @@ ProgramState ProcessCondition(ISymbol lockSymbol)
 
         protected override ProgramState PostProcessSimple(SymbolicContext context)
         {
-            if (context.Operation.Instance.AsObjectCreation() is { } objectCreation)
-            {
-                if (objectCreation.Type.Is(KnownType.System_Threading_Mutex)
-                    && context.Operation.Parent.AsAssignment() is { } assignment
-                    && objectCreation.Arguments.Length > 0
-                    && objectCreation.Arguments.First().ToArgument().Value is { } firstArgument
-                    && context.State[firstArgument] is { } firstArgumentValue
-                    && firstArgumentValue.HasConstraint(BoolConstraint.True)
-                    && assignment.Target.TrackedSymbol() is { } symbol)
-                {
-                    lastSymbolLock[symbol] = objectCreation.ToSonar();
-                    return AddLock(context, objectCreation.WrappedOperation).Preserve(symbol);
-                }
-            }
-            else if (context.Operation.Instance.AsInvocation() is { } invocation)
+            if (context.Operation.Instance.AsInvocation() is { } invocation)
             {
                 // ToDo: we ignore the number of parameters for now.
                 if (invocation.TargetMethod.IsAny(KnownType.System_Threading_Monitor, "Enter", "TryEnter"))

diff --git a/...Analyzer.UnitTest/TestCases/SymbolicExecution/Roslyn/LocksReleasedAllPaths.Mutex.NetFx.cs b/...Analyzer.UnitTest/TestCases/SymbolicExecution/Roslyn/LocksReleasedAllPaths.Mutex.NetFx.cs
@@ -14,7 +14,7 @@ public class MutexTest
     public static void Noncompliant(MutexSecurity mutexSecurity, bool cond)
     {
         // Note that Dispose() closes the underlying WaitHandle, but does not release the mutex
-        var m0 = new Mutex(true, "foo", out var mutexWasCreated, mutexSecurity); // Noncompliant
+        var m0 = new Mutex(true, "foo", out var mutexWasCreated, mutexSecurity);
         if (cond)
         {
             m0.ReleaseMutex();
@@ -61,7 +61,7 @@ public static void CompliantFromDocs(string mutexName, MutexSecurity mutexSecuri
         if (doesNotExist)
         {
             // The mutex does not exist, so create it.
-            m = new Mutex(true, mutexName, out mutexWasCreated, mutexSecurity); // Noncompliant FP, because the rule is not aware that the mutex didn't exist before and doesn't support out mutexWasCreated. Only awareness of both can fix it.
+            m = new Mutex(true, mutexName, out mutexWasCreated, mutexSecurity);
             if (!mutexWasCreated)
             {
                 // unable to create the mutex