Merge pull request #20370 from MathiasVP/source-bounded-fast-tc-in-typetracking

Shared: Use `sourceBoundedFastTC` in TypeTracking

Author: MathiasVP

shared/typetracking/codeql/typetracking/internal/TypeTrackingImpl.qll

@@ -70,6 +70,10 @@ module TypeTracking<LocationSig Location, TypeTrackingInput<Location> I> {
 
   private class ContentOption = ContentOption::Option;
 
+  private predicate isLocalSourceNode(LocalSourceNode n) {
+    not nonStandardFlowsTo(_, _) and exists(n)
+  }
+
   cached
   private module Cached {
     cached
@@ -249,21 +253,9 @@ module TypeTracking<LocationSig Location, TypeTrackingInput<Location> I> {
       returnStep(nodeFrom, nodeTo) and summary = ReturnStep()
     }
 
-    pragma[inline]
-    private predicate isLocalSourceNode(LocalSourceNode n) { any() }
-
     cached
-    predicate standardFlowsTo(Node localSource, Node dst) {
-      not nonStandardFlowsTo(_, _) and
-      // explicit type check in base case to avoid repeated type tests in recursive case
-      isLocalSourceNode(localSource) and
-      dst = localSource
-      or
-      exists(Node mid |
-        standardFlowsTo(localSource, mid) and
-        simpleLocalSmallStep(mid, dst)
-      )
-    }
+    predicate simpleLocalSmallStepPlus(Node localSource, Node dst) =
+      sourceBoundedFastTC(simpleLocalSmallStep/2, isLocalSourceNode/1)(localSource, dst)
 
     cached
     predicate stepNoCall(LocalSourceNode nodeFrom, LocalSourceNode nodeTo, StepSummary summary) {
@@ -276,6 +268,14 @@ module TypeTracking<LocationSig Location, TypeTrackingInput<Location> I> {
     }
   }
 
+  pragma[inline]
+  private predicate standardFlowsTo(Node localSource, Node dst) {
+    isLocalSourceNode(localSource) and
+    dst = localSource
+    or
+    simpleLocalSmallStepPlus(localSource, dst)
+  }
+
   import Cached
 
   /**