Python: change type of LibraryCallable::getACall

The other callables return control flow nodes,
so it is slightly inconsistent for this to return a
data flow node, but it does make models based
on API graphs nicer.

python/ql/lib/semmle/python/dataflow/new/FlowSummary.qll

@@ -84,10 +84,10 @@ private class SummarizedCallableFromModel extends SummarizedCallable {
     this = package + ";" + type + ";" + path
   }
 
-  override CallNode getACall() {
+  override CallCfgNode getACall() {
     exists(API::CallNode base |
       ModelOutput::resolvedSummaryBase(package, type, path, base) and
-      result = base.asCfgNode()
+      result = base.getACall()
     )
   }
 

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowDispatchPointsTo.qll

@@ -281,7 +281,7 @@ abstract class LibraryCallable extends string {
   LibraryCallable() { any() }
 
   /** Gets a call to this library callable. */
-  abstract CallNode getACall();
+  abstract CallCfgNode getACall();
 
   /** Gets a data-flow node, where this library callable is used as a call-back. */
   abstract ArgumentNode getACallback();
@@ -398,7 +398,7 @@ class LibraryCallableValue extends DataFlowCallable, TLibraryCallable {
 
   override string toString() { result = callable.toString() }
 
-  override CallNode getACall() { result = callable.getACall() }
+  override CallNode getACall() { result = callable.getACall().getNode() }
 
   /** Gets a data-flow node, where this library callable is used as a call-back. */
   ArgumentNode getACallback() { result = callable.getACallback() }
@@ -772,7 +772,7 @@ DataFlowCallable viableCallable(DataFlowSourceCall call) {
   // Instead we reolve the call from the summary.
   exists(LibraryCallable callable |
     result = TLibraryCallable(callable) and
-    call.getNode() = callable.getACall()
+    call.getNode() = callable.getACall().getNode()
   )
 }
 

python/ql/lib/semmle/python/frameworks/Builtins.qll

@@ -10,7 +10,7 @@ private import semmle.python.ApiGraphs
 class ReversedSummary extends SummarizedCallable {
   ReversedSummary() { this = "builtins.reversed" }
 
-  override CallNode getACall() { result = API::builtin("reversed").getACall().getNode() }
+  override DataFlow::CallCfgNode getACall() { result = API::builtin("reversed").getACall() }
 
   override DataFlow::ArgumentNode getACallback() {
     result = API::builtin("reversed").getAValueReachableFromSource()

python/ql/test/experimental/dataflow/summaries/TestSummaries.qll

@@ -13,8 +13,8 @@ module RecursionGuard {
   private class RecursionGuard extends SummarizedCallable {
     RecursionGuard() { this = "RecursionGuard" }
 
-    override CallNode getACall() {
-      result.getFunction().(NameNode).getId() = this and
+    override DataFlow::CallCfgNode getACall() {
+      result.getFunction().asCfgNode().(NameNode).getId() = this and
       (TT::callStep(_, _) implies any())
     }
 
@@ -25,7 +25,9 @@ module RecursionGuard {
 private class SummarizedCallableIdentity extends SummarizedCallable {
   SummarizedCallableIdentity() { this = "identity" }
 
-  override CallNode getACall() { result.getFunction().(NameNode).getId() = this }
+  override DataFlow::CallCfgNode getACall() {
+    result.getFunction().asCfgNode().(NameNode).getId() = this
+  }
 
   override DataFlow::ArgumentNode getACallback() { result.asExpr().(Name).getId() = this }
 
@@ -40,7 +42,9 @@ private class SummarizedCallableIdentity extends SummarizedCallable {
 private class SummarizedCallableApplyLambda extends SummarizedCallable {
   SummarizedCallableApplyLambda() { this = "apply_lambda" }
 
-  override CallNode getACall() { result.getFunction().(NameNode).getId() = this }
+  override DataFlow::CallCfgNode getACall() {
+    result.getFunction().asCfgNode().(NameNode).getId() = this
+  }
 
   override DataFlow::ArgumentNode getACallback() { result.asExpr().(Name).getId() = this }
 
@@ -58,7 +62,9 @@ private class SummarizedCallableApplyLambda extends SummarizedCallable {
 private class SummarizedCallableReversed extends SummarizedCallable {
   SummarizedCallableReversed() { this = "reversed" }
 
-  override CallNode getACall() { result.getFunction().(NameNode).getId() = this }
+  override DataFlow::CallCfgNode getACall() {
+    result.getFunction().asCfgNode().(NameNode).getId() = this
+  }
 
   override DataFlow::ArgumentNode getACallback() { result.asExpr().(Name).getId() = this }
 
@@ -72,7 +78,9 @@ private class SummarizedCallableReversed extends SummarizedCallable {
 private class SummarizedCallableMap extends SummarizedCallable {
   SummarizedCallableMap() { this = "list_map" }
 
-  override CallNode getACall() { result.getFunction().(NameNode).getId() = this }
+  override DataFlow::CallCfgNode getACall() {
+    result.getFunction().asCfgNode().(NameNode).getId() = this
+  }
 
   override DataFlow::ArgumentNode getACallback() { result.asExpr().(Name).getId() = this }
 
@@ -90,7 +98,9 @@ private class SummarizedCallableMap extends SummarizedCallable {
 private class SummarizedCallableAppend extends SummarizedCallable {
   SummarizedCallableAppend() { this = "append_to_list" }
 
-  override CallNode getACall() { result.getFunction().(NameNode).getId() = this }
+  override DataFlow::CallCfgNode getACall() {
+    result.getFunction().asCfgNode().(NameNode).getId() = this
+  }
 
   override DataFlow::ArgumentNode getACallback() { result.asExpr().(Name).getId() = this }
 
@@ -108,8 +118,8 @@ private class SummarizedCallableAppend extends SummarizedCallable {
 private class SummarizedCallableJsonLoads extends SummarizedCallable {
   SummarizedCallableJsonLoads() { this = "json.loads" }
 
-  override CallNode getACall() {
-    result = API::moduleImport("json").getMember("loads").getACall().getNode()
+  override DataFlow::CallCfgNode getACall() {
+    result = API::moduleImport("json").getMember("loads").getACall()
   }
 
   override DataFlow::ArgumentNode getACallback() {