fix FP

SonarSource · Jul 4, 2024 · 2ab75e6 · 2ab75e6
1 parent 0a1a90e
commit 2ab75e6
Showing 1 changed file with 44 additions and 12 deletions.
diff --git a/...onarAnalyzer.Common/SymbolicExecution/Roslyn/OperationProcessors/Invocation.Enumerable.cs b/...onarAnalyzer.Common/SymbolicExecution/Roslyn/OperationProcessors/Invocation.Enumerable.cs
@@ -18,6 +18,8 @@
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 using SonarAnalyzer.SymbolicExecution.Constraints;
 
 namespace SonarAnalyzer.SymbolicExecution.Roslyn.OperationProcessors;
@@ -89,24 +91,46 @@ private static ProgramState[] ProcessLinqEnumerableAndQueryable(ProgramState sta
         // ElementAtOrDefault is intentionally not supported. It's causing many FPs
         else if (name is nameof(Enumerable.FirstOrDefault) or nameof(Enumerable.LastOrDefault) or nameof(Enumerable.SingleOrDefault)
                 && invocation.TryGetInstance(state) is { } instance
-                && instance.TrackedSymbol(state) is { } instanceSymbol)
+                && instance.TrackedSymbol(state) is { } instanceSymbol
+                && GetElementType(instanceSymbol) is { } elementType)
         {
-            return states.SelectMany(x =>
-                x[instanceSymbol]?.Constraint<CollectionConstraint>() switch
-                {
-                    CollectionConstraint constraint when constraint == CollectionConstraint.Empty => x.SetOperationConstraint(invocation, ObjectConstraint.Null).ToArray(),
-                    CollectionConstraint constraint when constraint == CollectionConstraint.NotEmpty => x.SetOperationConstraint(invocation, ObjectConstraint.NotNull).ToArray(),
-                    _ =>
-                    [
-                        x.SetOperationConstraint(invocation, ObjectConstraint.Null),
-                        x.SetOperationConstraint(invocation, ObjectConstraint.NotNull)
-                    ]
-                }).ToArray();
+            return states.SelectMany(x => GetStuff(x, elementType, instanceSymbol)).ToArray();
         }
         else
         {
             return states;
         }
+
+        IEnumerable<ProgramState> GetStuff(ProgramState state, ITypeSymbol elementType, ISymbol instanceSymbol)
+        {
+            if (elementType.IsReferenceType)
+            {
+                return state[instanceSymbol]?.Constraint<CollectionConstraint>() switch
+                    {
+                        CollectionConstraint constraint when constraint == CollectionConstraint.Empty => [state.SetOperationConstraint(invocation, ObjectConstraint.Null)],
+                        CollectionConstraint constraint when constraint == CollectionConstraint.NotEmpty =>
+                        [
+                            state,
+                            state.SetOperationConstraint(invocation, ObjectConstraint.NotNull)
+                        ],
+                        _ =>
+                        [
+                            state.SetOperationConstraint(invocation, ObjectConstraint.Null),
+                            state.SetOperationConstraint(invocation, ObjectConstraint.NotNull)
+                        ]
+                    };
+            }
+            else
+            {
+               return  state[instanceSymbol]?.Constraint<CollectionConstraint>() == CollectionConstraint.Empty
+                    ? state.SetOperationConstraint(invocation, ObjectConstraint.Null).ToArray()
+                    : [
+                        state.SetOperationConstraint(invocation, ObjectConstraint.Null),
+                        state.SetOperationConstraint(invocation, ObjectConstraint.NotNull)
+                      ]
+                ;
+            }
+        }
     }
 
     private static ProgramState[] ProcessBoolCollectionMethods(ProgramState state, IInvocationOperationWrapper invocation)
@@ -137,4 +161,12 @@ static bool HasNoParameters(IMethodSymbol symbol) =>
             (symbol.IsExtensionMethod && symbol.Parameters.Length == 1)
             || symbol.Parameters.IsEmpty;
     }
+
+    private static ITypeSymbol GetElementType(ISymbol instance) =>
+        instance.GetSymbolType() switch
+        {
+            INamedTypeSymbol { TypeArguments: { Length: 1 } typeArguments } => typeArguments.First(),
+            IArrayTypeSymbol arrayType => arrayType.ElementType,
+            _ => null
+        };
 }