From b91dca87eeccb3d4f4f55daba73c7195f23f691a Mon Sep 17 00:00:00 2001
From: Artem S Vybornov <vybornov@gmail.com>
Date: Mon, 16 Dec 2013 21:28:30 +0400
Subject: [PATCH] Asm.js: compliant name mangling

---
 lib/scope.js | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/lib/scope.js b/lib/scope.js
index 6c19c19a..eb9b9723 100644
--- a/lib/scope.js
+++ b/lib/scope.js
@@ -260,6 +260,14 @@ AST_Scope.DEFMETHOD("def_variable", function(symbol){
 
 AST_Scope.DEFMETHOD("next_mangled", function(options){
     var ext = this.enclosed;
+
+    // asm.js: don't mask module-scope names
+    var asm = this.has_directive("use asm"),
+        pasm = this.parent_scope ? this.parent_scope.has_directive("use asm") : false;
+    if (pasm) {
+        this.cname = this.parent_scope.cname;
+    }
+
     out: while (true) {
         var m = base54(++this.cname);
         if (!is_identifier(m)) continue; // skip over "do"
@@ -268,6 +276,21 @@ AST_Scope.DEFMETHOD("next_mangled", function(options){
         // shadow a name excepted from mangling.
         if (options.except.indexOf(m) >= 0) continue;
 
+        // asm.js: don't reuse module name although it is out of the current scope
+        if (asm) {
+            var sym = this.name;
+            var penc = this.parent_scope.enclosed;
+            if (sym && penc.length) {
+                for (var i = 0; i < penc.length; i++) {
+                    var psym = penc[i];
+                    if (sym.name == psym.name) {
+                        var name = psym.mangled_name || (psym.unmangleable(options) && psym.name);
+                        if (m == name) continue out;
+                    }
+                }
+            }
+        }
+
         // we must ensure that the mangled name does not shadow a name
         // from some parent scope that is referenced in this or in
         // inner scopes.