python: expose getNodeFromPath in a nicer way

Author: yoff

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

@@ -70,10 +70,6 @@ abstract class SummarizedCallable extends LibraryCallable, Impl::Public::Summari
 
 class RequiredSummaryComponentStack = Impl::Public::RequiredSummaryComponentStack;
 
-// // This gives access to getNodeFromPath, which is not constrained to `CallNode`s
-// // as `resolvedSummaryBase` is.
-private import semmle.python.frameworks.data.internal.ApiGraphModels as AGM
-
 private class SummarizedCallableFromModel extends SummarizedCallable {
   string type;
   string path;
@@ -92,7 +88,7 @@ private class SummarizedCallableFromModel extends SummarizedCallable {
 
   override ArgumentNode getACallback() {
     exists(API::Node base |
-      base = AGM::getNodeFromPath(type, path) and
+      ModelOutput::resolvedSummaryRefBase(type, path, base) and
       result = base.getAValueReachableFromSource()
     )
   }

python/ql/lib/semmle/python/frameworks/data/internal/ApiGraphModels.qll

@@ -522,7 +522,7 @@ private API::Node getNodeFromSubPath(API::Node base, AccessPath subPath) {
 }
 
 /** Gets the node identified by the given `(type, path)` tuple. */
-API::Node getNodeFromPath(string type, AccessPath path) {
+private API::Node getNodeFromPath(string type, AccessPath path) {
   result = getNodeFromPath(type, path, path.getNumToken())
 }
 
@@ -644,6 +644,15 @@ module ModelOutput {
       baseNode = getInvocationFromPath(type, path)
     }
 
+    /**
+     * Holds if a `baseNode` is an invocation identified by the `type,path` part of a summary row.
+     */
+    cached
+    predicate resolvedSummaryRefBase(string type, string path, API::Node baseNode) {
+      summaryModel(type, path, _, _, _) and
+      baseNode = getNodeFromPath(type, path)
+    }
+
     /**
      * Holds if `node` is seen as an instance of `type` due to a type definition
      * contributed by a CSV model.