C#: Improve implementation.

Author: michaelnebel

csharp/ql/lib/semmle/code/csharp/dataflow/FlowSummary.qll

@@ -2,6 +2,7 @@
 
 import csharp
 private import dotnet
+private import internal.FlowSummaryImplSpecific as FlowSummaryImplSpecific
 private import internal.FlowSummaryImpl as Impl
 private import internal.DataFlowDispatch as DataFlowDispatch
 
@@ -160,6 +161,13 @@ abstract class SummarizedCallable extends DotNet::Callable {
   predicate isAutoGenerated() { none() }
 }
 
+private class SourceSinkSummarizedCallable extends SummarizedCallable {
+  SourceSinkSummarizedCallable() {
+    FlowSummaryImplSpecific::sourceElement(this, _, _, _) or
+    FlowSummaryImplSpecific::sinkElement(this, _, _, _)
+  }
+}
+
 private class SummarizedCallableAdapter extends Impl::Public::SummarizedCallable {
   private SummarizedCallable sc;
 

csharp/ql/lib/semmle/code/csharp/dataflow/internal/FlowSummaryImplSpecific.qll

@@ -256,10 +256,16 @@ class InterpretNode extends TInterpretNode {
   DataFlowCall asCall() { this = TDataFlowCall_(result) }
 
   /** Gets the callable that this node corresponds to, if any. */
-  DataFlowCallable asCallable() { result.asCallable() = this.asElement() }
+  DataFlowCallable asCallable() {
+    result.asCallable() = this.asElement() or
+    result.asSummarizedCallable() = this.asElement()
+  }
 
   /** Gets the target of this call, if any. */
-  Callable getCallTarget() { result = viableCallable(this.asCall()).asCallable() }
+  Callable getCallTarget() {
+    result = viableCallable(this.asCall()).asSummarizedCallable() or
+    result = viableCallable(this.asCall()).asCallable()
+  }
 
   /** Gets a textual representation of this node. */
   string toString() {