PS: Rename getExpr to getBase on ParenExpr.

powershell/ql/lib/semmle/code/powershell/ParenExpression.qll

@@ -1,7 +1,7 @@
 import powershell
 
 class ParenExpr extends @paren_expression, Expr {
-  PipelineBase getExpr() { paren_expression(this, result) }
+  PipelineBase getBase() { paren_expression(this, result) }
 
   override SourceLocation getLocation() { paren_expression_location(this, result) }
 

powershell/ql/lib/semmle/code/powershell/controlflow/CfgNodes.qll

@@ -501,6 +501,20 @@ module ExprNodes {
 
     TypeConstraint getType() { result = e.getType() }
   }
+
+  class ParenExprChildMapping extends ExprChildMapping, ParenExpr {
+    override predicate relevantChild(Ast n) { n = this.getBase() }
+  }
+
+  class ParenCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "ParenExprCfgNode" }
+
+    override ParenExprChildMapping e;
+
+    override ParenExpr getExpr() { result = e }
+
+    final StmtCfgNode getBase() { e.hasCfgChild(e.getBase(), this, result) }
+  }
 }
 
 module StmtNodes {

powershell/ql/lib/semmle/code/powershell/controlflow/internal/ControlFlowGraphImpl.qll

@@ -601,7 +601,7 @@ module Trees {
   }
 
   class ParenExprTree extends StandardPostOrderTree instanceof ParenExpr {
-    override AstNode getChildNode(int i) { i = 0 and result = super.getExpr() }
+    override AstNode getChildNode(int i) { i = 0 and result = super.getBase() }
   }
 
   class TypeNameExprTree extends LeafTree instanceof TypeNameExpr { }