Ruby: Cache ConditionBlock::(immediately)Controls

Author: hvitved

ruby/ql/lib/codeql/ruby/controlflow/BasicBlocks.qll

@@ -309,6 +309,17 @@ private module Cached {
         jbp order by JoinBlockPredecessors::getId(jbp), JoinBlockPredecessors::getSplitString(jbp)
       )
   }
+
+  cached
+  predicate immediatelyControls(ConditionBlock cb, BasicBlock succ, BooleanSuccessor s) {
+    succ = cb.getASuccessor(s) and
+    forall(BasicBlock pred | pred = succ.getAPredecessor() and pred != cb | succ.dominates(pred))
+  }
+
+  cached
+  predicate controls(ConditionBlock cb, BasicBlock controlled, BooleanSuccessor s) {
+    exists(BasicBlock succ | cb.immediatelyControls(succ, s) | succ.dominates(controlled))
+  }
 }
 
 private import Cached
@@ -395,18 +406,14 @@ class ConditionBlock extends BasicBlock {
    * successor of this block, and `succ` can only be reached from
    * the callable entry point by going via the `s` edge out of this basic block.
    */
-  pragma[nomagic]
   predicate immediatelyControls(BasicBlock succ, BooleanSuccessor s) {
-    succ = this.getASuccessor(s) and
-    forall(BasicBlock pred | pred = succ.getAPredecessor() and pred != this | succ.dominates(pred))
+    immediatelyControls(this, succ, s)
   }
 
   /**
    * Holds if basic block `controlled` is controlled by this basic block with
    * conditional value `s`. That is, `controlled` can only be reached from
    * the callable entry point by going via the `s` edge out of this basic block.
    */
-  predicate controls(BasicBlock controlled, BooleanSuccessor s) {
-    exists(BasicBlock succ | this.immediatelyControls(succ, s) | succ.dominates(controlled))
-  }
+  predicate controls(BasicBlock controlled, BooleanSuccessor s) { controls(this, controlled, s) }
 }