SE - Nullable: Infer constraints for HasValue property (#6850)

SonarSource · Mar 31, 2023 · f2f03e9 · f2f03e9
1 parent 1b0e653
commit f2f03e9
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Showing 2 changed files with 43 additions and 5 deletions.
diff --git a/...yzers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/OperationProcessors/References.cs b/...yzers/src/SonarAnalyzer.Common/SymbolicExecution/Roslyn/OperationProcessors/References.cs
@@ -73,16 +73,28 @@ protected override IPropertyReferenceOperationWrapper Convert(IOperation operati
 
     protected override ProgramState Process(SymbolicContext context, IPropertyReferenceOperationWrapper propertyReference)
     {
+        var state = context.State;
         if (propertyReference.Instance.TrackedSymbol() is { } symbol)
         {
-            var state = context.State.SetSymbolConstraint(symbol, ObjectConstraint.NotNull);
-            return propertyReference.Property.Name == "Value" && propertyReference.Instance.Type.IsNullableValueType() && context.State[symbol] is { } value
-                ? state.SetOperationValue(context.Operation, value)
-                : state;
+            if (propertyReference.Instance.Type.IsNullableValueType())
+            {
+                if (propertyReference.Property.Name == "Value" && state[symbol] is { } value)
+                {
+                    state = state.SetOperationValue(context.Operation, value);
+                }
+                else if (propertyReference.Property.Name == "HasValue")
+                {
+                    // Return directly, do not set NotNull on the symbol itself
+                    return state[symbol]?.Constraint<ObjectConstraint>() is { } objectConstraint
+                        ? state.SetOperationConstraint(context.Operation, BoolConstraint.From(objectConstraint == ObjectConstraint.NotNull))
+                        : state;
+                }
+            }
+            return state.SetSymbolConstraint(symbol, ObjectConstraint.NotNull);
         }
         else
         {
-            return context.State;
+            return state;
         }
     }
 }

diff --git a/...s/SonarAnalyzer.UnitTest/SymbolicExecution/Roslyn/RoslynSymbolicExecutionTest.Nullable.cs b/...s/SonarAnalyzer.UnitTest/SymbolicExecution/Roslyn/RoslynSymbolicExecutionTest.Nullable.cs
@@ -59,4 +59,30 @@ public void Nullable_Value_ReadsConstraintsFromInstance()
         validator.ValidateTag("FalseFirst", x => x.HasConstraint(BoolConstraint.False).Should().BeTrue());
         validator.ValidateTag("FalseFirst", x => x.HasConstraint(TestConstraint.First).Should().BeTrue());
     }
+
+    [TestMethod]
+    public void Nullable_HasValue_ReadsBoolConstraintFromObjectConstraint()
+    {
+        const string code = """
+            var hasValue = arg.HasValue;
+            Tag("HasValueUnknown", hasValue);
+            Tag("SymbolUnknown", arg);
+            arg = true;
+            hasValue = arg.HasValue;
+            Tag("HasValueAfterTrue", hasValue);
+            Tag("SymbolAfterTrue", arg);
+            arg = null;
+            hasValue = arg.HasValue;
+            Tag("HasValueAfterNull", hasValue);
+            Tag("SymbolAfterNull", arg);
+            """;
+        var validator = SETestContext.CreateCS(code, ", bool? arg").Validator;
+        validator.ValidateTag("HasValueUnknown", x => x.Should().BeNull());
+        validator.ValidateTag("SymbolUnknown", x => x.Should().BeNull());
+        validator.ValidateTag("HasValueAfterTrue", x => x.Should().BeNull());   // ToDo: Should be x.HasConstraint(BoolConstraint.True).Should().BeTrue()); after we build NotNull for bool literal.
+        validator.ValidateTag("SymbolAfterTrue", x => x.HasConstraint(BoolConstraint.True).Should().BeTrue());
+        validator.ValidateTag("SymbolAfterTrue", x => x.HasConstraint(ObjectConstraint.NotNull).Should().BeFalse());    // ToDo: Should be BeTrue() after we build NotNull for bool literal
+        validator.ValidateTag("HasValueAfterNull", x => x.HasConstraint(BoolConstraint.False).Should().BeTrue());
+        validator.ValidateTag("SymbolAfterNull", x => x.HasConstraint(ObjectConstraint.Null).Should().BeTrue());
+    }
 }