From 4bbd06f51fedb02a8c6ba3cd1707131fe199c6c0 Mon Sep 17 00:00:00 2001
From: Erik Krogh Kristensen <erik-krogh@github.com>
Date: Mon, 31 May 2021 08:06:49 +0000
Subject: [PATCH] improve performance of module resolution

---
 ql/src/codeql_ql/ast/internal/Module.qll | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/ql/src/codeql_ql/ast/internal/Module.qll b/ql/src/codeql_ql/ast/internal/Module.qll
index 210e7f6b352..2a3eeaeca20 100644
--- a/ql/src/codeql_ql/ast/internal/Module.qll
+++ b/ql/src/codeql_ql/ast/internal/Module.qll
@@ -186,13 +186,21 @@ private module Cached {
   predicate resolveModuleExpr(ModuleExpr me, FileOrModule m) {
     not m = TFile(any(File f | f.getExtension() = "ql")) and
     not exists(me.getQualifier()) and
-    definesModule(getEnclosingModule(me).getEnclosing*(), me.getName(), m, _)
+    exists(ContainerOrModule enclosing, string name | resolveModuleExprHelper(me, enclosing, name) |
+      definesModule(enclosing.getEnclosing*(), name, m, _)
+    )
     or
     exists(FileOrModule mid |
       resolveModuleExpr(me.getQualifier(), mid) and
       definesModule(mid, me.getName(), m, true)
     )
   }
+
+  pragma[noinline]
+  private predicate resolveModuleExprHelper(ModuleExpr me, ContainerOrModule enclosing, string name) {
+    enclosing = getEnclosingModule(me) and
+    name = me.getName()
+  }
 }
 
 import Cached