Merge pull request #11624 from jcogs33/jcogs33/exclude-paramless-constructors-from-dataflowtargetapi

Java/C#: exclude parameterless constructors from `DataFlowTargetApi`

Author: jcogs33

csharp/ql/lib/semmle/code/csharp/Callable.qll

@@ -358,6 +358,9 @@ class Constructor extends DotNet::Constructor, Callable, Member, Attributable, @
     if this.isStatic() then result = this.getParameter(i) else result = this.getParameter(i - 1)
   }
 
+  /** Holds if this is a constructor without parameters. */
+  predicate isParameterless() { this.getNumberOfParameters() = 0 }
+
   override string getUndecoratedName() { result = ".ctor" }
 }
 

csharp/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll

@@ -38,7 +38,8 @@ private predicate isRelevantForModels(CS::Callable api) {
   api.getDeclaringType().getNamespace().getFullName() != "" and
   not api instanceof CS::ConversionOperator and
   not api instanceof Util::MainMethod and
-  not api instanceof CS::Destructor
+  not api instanceof CS::Destructor and
+  not api.(CS::Constructor).isParameterless()
 }
 
 /**

csharp/ql/test/utils/model-generator/dataflow/NoSummaries.cs

@@ -131,4 +131,15 @@ public Dictionary<int, int> ReturnSimpleTypeDictionary(Dictionary<int, int> a)
     {
         return a;
     }
-}
+}
+
+// A neutral model should not be created for a parameterless constructor.
+public class ParameterlessConstructor
+{
+    public bool IsInitialized;
+
+    public ParameterlessConstructor()
+    {
+        IsInitialized = true;
+    }
+}

java/ql/lib/semmle/code/java/Member.qll

@@ -628,6 +628,9 @@ class Constructor extends Callable, @constructor {
   /** Holds if this is a default constructor, not explicitly declared in source code. */
   predicate isDefaultConstructor() { isDefConstr(this) }
 
+  /** Holds if this is a constructor without parameters. */
+  predicate isParameterless() { this.getNumberOfParameters() = 0 }
+
   override Constructor getSourceDeclaration() { constrs(this, _, _, _, _, result) }
 
   override string getSignature() { constrs(this, _, result, _, _, _) }

java/ql/src/utils/modelgenerator/internal/CaptureModelsSpecific.qll

@@ -59,7 +59,8 @@ private predicate isRelevantForModels(J::Callable api) {
   not isInTestFile(api.getCompilationUnit().getFile()) and
   not isJdkInternal(api.getCompilationUnit()) and
   not api instanceof J::MainMethod and
-  not api instanceof J::StaticInitializer
+  not api instanceof J::StaticInitializer and
+  not api.(J::Constructor).isParameterless()
 }
 
 /**

java/ql/test/utils/model-generator/dataflow/CaptureNeutralModels.expected

@@ -1,25 +1,11 @@
-| p;AbstractImplOfExternalSPI;AbstractImplOfExternalSPI;();generated |
 | p;Factory;getIntValue;();generated |
-| p;FinalClass;FinalClass;();generated |
 | p;FinalClass;returnsConstant;();generated |
-| p;FluentAPI$Inner;Inner;();generated |
 | p;FluentAPI$Inner;notThis;(String);generated |
-| p;FluentAPI;FluentAPI;();generated |
 | p;ImmutablePojo;getX;();generated |
-| p;ImplOfExternalSPI;ImplOfExternalSPI;();generated |
-| p;InnerClasses$CaptureMe;CaptureMe;();generated |
-| p;InnerClasses;InnerClasses;();generated |
-| p;InnerHolder;InnerHolder;();generated |
 | p;Joiner;length;();generated |
-| p;MultipleImpls$Strat1;Strat1;();generated |
-| p;MultipleImpls$Strat2;Strat2;();generated |
-| p;MultipleImpls$Strat3;Strat3;();generated |
 | p;MultipleImpls$Strategy;doSomething;(String);generated |
-| p;MultipleImpls;MultipleImpls;();generated |
-| p;ParamFlow;ParamFlow;();generated |
 | p;ParamFlow;ignorePrimitiveReturnValue;(String);generated |
 | p;ParamFlow;mapType;(Class);generated |
-| p;Pojo;Pojo;();generated |
 | p;Pojo;doNotSetValue;(String);generated |
 | p;Pojo;getBigDecimal;();generated |
 | p;Pojo;getBigInt;();generated |
@@ -31,13 +17,10 @@
 | p;Pojo;getPrimitiveArray;();generated |
 | p;PrivateFlowViaPublicInterface$SPI;openStream;();generated |
 | p;PrivateFlowViaPublicInterface$SPI;openStreamNone;();generated |
-| p;PrivateFlowViaPublicInterface;PrivateFlowViaPublicInterface;();generated |
 | p;PrivateFlowViaPublicInterface;createAnSPIWithoutTrackingFile;(File);generated |
-| p;Sinks;Sinks;();generated |
 | p;Sinks;copyFileToDirectory;(Path,Path,CopyOption[]);generated |
 | p;Sinks;propagate;(String);generated |
 | p;Sinks;readUrl;(URL,Charset);generated |
-| p;Sources;Sources;();generated |
 | p;Sources;readUrl;(URL);generated |
 | p;Sources;socketStream;();generated |
 | p;Sources;sourceToParameter;(InputStream[],List);generated |