Ruby: Ssa::WriteDefinition::getWriteAccess should return a CFG node

ruby/ql/src/experimental/performance/UseDetect.ql

@@ -11,6 +11,7 @@
 // This is an implementation of the Rubocop rule
 // https://github.com/rubocop/rubocop-performance/blob/master/lib/rubocop/cop/performance/detect.rb
 import codeql.ruby.AST
+import codeql.ruby.CFG
 import codeql.ruby.dataflow.SSA
 
 /** A call that extracts the first or last element of a list. */
@@ -41,12 +42,12 @@ class EndCall extends MethodCall {
 }
 
 Expr getUniqueRead(Expr e) {
-  exists(AssignExpr ae |
-    e = ae.getRightOperand() and
-    forex(Ssa::WriteDefinition def | def.getWriteAccess() = ae.getLeftOperand() |
+  forex(CfgNode eNode | eNode.getNode() = e |
+    exists(Ssa::WriteDefinition def |
+      def.assigns(eNode) and
       strictcount(def.getARead()) = 1 and
       not def = any(Ssa::PhiNode phi).getAnInput() and
-      def.getARead() = result.getAControlFlowNode()
+      def.getARead().getNode() = result
     )
   )
 }

ruby/ql/src/queries/analysis/Definitions.ql

@@ -48,7 +48,7 @@ newtype DefLoc =
   /** A local variable. */
   LocalVariableLoc(VariableReadAccess read, VariableWriteAccess write) {
     exists(Ssa::WriteDefinition w |
-      write = w.getWriteAccess() and
+      write = w.getWriteAccess().getNode() and
       read = w.getARead().getExpr() and
       not read.isSynthesized()
     )

ruby/ql/src/queries/variables/DeadStoreOfLocal.ql

@@ -24,5 +24,5 @@ from RelevantLocalVariableWriteAccess write, LocalVariable v
 where
   v = write.getVariable() and
   exists(write.getAControlFlowNode()) and
-  not exists(Ssa::WriteDefinition def | def.getWriteAccess() = write)
+  not exists(Ssa::WriteDefinition def | def.getWriteAccess().getNode() = write)
 select write, "This assignment to $@ is useless, since its value is never read.", v, v.getName()

ruby/ql/src/queries/variables/UnusedParameter.ql

@@ -23,5 +23,5 @@ class RelevantParameterVariable extends LocalVariable {
 }
 
 from RelevantParameterVariable v
-where not exists(Ssa::WriteDefinition def | def.getWriteAccess() = v.getDefiningAccess())
+where not exists(Ssa::WriteDefinition def | def.getWriteAccess().getNode() = v.getDefiningAccess())
 select v, "The parameter '" + v.getName() + "' is never used."