Address review comments

Author: hvitved

rust/ql/lib/codeql/rust/dataflow/internal/Node.qll

@@ -118,7 +118,7 @@ class FlowSummaryNode extends Node, TFlowSummaryNode {
   }
 }
 
-/** A data flow node that corresponds directly to a CFG node for an AST node. */
+/** A data flow node that corresponds directly to an AST node. */
 abstract class AstNodeNode extends Node {
   AstNode n;
 

rust/ql/lib/codeql/rust/elements/internal/ParenExprImpl.qll

@@ -24,6 +24,19 @@ module Impl {
     override string toStringImpl() {
       result = "(" + this.getExpr().toAbbreviatedString() + ")"
       or
+      // In macro expansions such as
+      //
+      // ```rust
+      // [
+      //     "a",
+      //     "b",
+      //     #[cfg(target_os = "macos")]
+      //     "c",
+      // ]
+      // ```
+      //
+      // the last array element will give rise to an empty `ParenExpr` when not
+      // compiling for macos.
       not exists(this.getExpr().toAbbreviatedString()) and
       result = "(...)"
     }

rust/ql/lib/codeql/rust/security/AccessAfterLifetimeExtensions.qll

@@ -40,7 +40,7 @@ module AccessAfterLifetime {
   abstract class Barrier extends DataFlow::Node { }
 
   /**
-   * Holds if the value `source` points to accesses a variable `target` with scope `scope`.
+   * Holds if the value pointed to by `source` accesses a variable `target` with scope `scope`.
    */
   pragma[nomagic]
   predicate sourceValueScope(Source source, Variable target, BlockExpr scope) {