python/javascript: add qldoc

Author: yoff

javascript/ql/lib/semmle/javascript/dataflow/internal/BarrierGuards.qll

@@ -36,6 +36,9 @@ module MakeBarrierGuard<BarrierGuardSig BaseGuard> {
   }
 }
 
+/**
+ * Provides access to barrier guards defined via models-as-data.
+ */
 module ExternalBarrierGuard {
   private predicate guardCheck(DataFlow::Node g, Expr e, boolean branch, string kind) {
     exists(API::CallNode call, API::Node parameter |
@@ -47,14 +50,17 @@ module ExternalBarrierGuard {
     )
   }
 
-  class BarrierGuard extends DataFlow::Node {
+  private class BarrierGuard extends DataFlow::Node {
     BarrierGuard() { guardCheck(this, _, _, _) }
 
     predicate blocksExpr(boolean outcome, Expr e, string kind) {
       guardCheck(this, e, outcome, kind)
     }
   }
 
+  /**
+   * Gets a barrier guard node of the given `kind` defined via models-as-data.
+   */
   DataFlow::Node getAnExternalBarrierNode(string kind) {
     result = MakeStateBarrierGuard<string, BarrierGuard>::getABarrierNode(kind)
   }

python/ql/lib/semmle/python/security/dataflow/UrlRedirectCustomizations.qll

@@ -161,6 +161,9 @@ module UrlRedirect {
   /** DEPRECATED: Use ConstCompareAsSanitizerGuard instead. */
   deprecated class StringConstCompareAsSanitizerGuard = ConstCompareAsSanitizerGuard;
 
+  /**
+   * A sanitizer defined via models-as-data with kind "url-redirection".
+   */
   class SanitizerFromModel extends Sanitizer {
     SanitizerFromModel() {
       this = DataFlow::ExternalBarrierGuard::getAnExternalBarrierNode("url-redirection")