4 files changed, 79 insertions, 8 deletions

diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 9021fd0284..2421e8c1ea 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -1835,8 +1835,9 @@ JSCodeGen::JSCodeGen(const QString &sourceCode, QV4::Compiler::JSUnitGenerator *
     , _scopeObject(nullptr)
     , _qmlContextSlot(-1)
     , _importedScriptsSlot(-1)
-    , m_globalNames(globalNames)
 {
+    m_globalNames = globalNames;
+
     _module = jsModule;
     _fileNameIsUrl = true;
 }
@@ -2306,15 +2307,10 @@ QV4::Compiler::Codegen::Reference JSCodeGen::fallbackNameLookup(const QString &n
             return Reference::fromQmlContextObject(base, data->coreIndex(), data->notifyIndex(), capturePolicy);
         }
     }
-
-    Reference r = Reference::fromName(this, name);
-    if (m_globalNames.contains(name))
-        r.global = true;
-    return r;
 #else
     Q_UNUSED(name)
-    return Reference();
 #endif // V4_BOOTSTRAP
+    return Reference();
 }
 
 #ifndef V4_BOOTSTRAP
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index d1e2b17bb7..3dde929cc4 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -640,7 +640,6 @@ private:
     QQmlPropertyCache *_scopeObject;
     int _qmlContextSlot;
     int _importedScriptsSlot;
-    QSet<QString> m_globalNames;
 };
 
 struct Q_QML_PRIVATE_EXPORT IRLoader {
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 54aef16970..21fb03c1a4 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -102,6 +102,62 @@ Codegen::Codegen(QV4::Compiler::JSUnitGenerator *jsUnitGenerator, bool strict)
     jsUnitGenerator->codeGeneratorName = QStringLiteral("moth");
 }
 
+const char *globalNames[] = {
+    "isNaN",
+    "parseFloat",
+    "String",
+    "EvalError",
+    "URIError",
+    "Math",
+    "encodeURIComponent",
+    "RangeError",
+    "eval",
+    "isFinite",
+    "ReferenceError",
+    "Infinity",
+    "Function",
+    "RegExp",
+    "Number",
+    "parseInt",
+    "Object",
+    "decodeURI",
+    "TypeError",
+    "Boolean",
+    "encodeURI",
+    "NaN",
+    "Error",
+    "decodeURIComponent",
+    "Date",
+    "Array",
+    "Symbol",
+    "escape",
+    "unescape",
+    "SyntaxError",
+    "undefined",
+    "JSON",
+    "ArrayBuffer",
+    "SharedArrayBuffer",
+    "DataView",
+    "Int8Array",
+    "Uint8Array",
+    "Uint8ClampedArray",
+    "Int16Array",
+    "Uint16Array",
+    "Int32Array",
+    "Uint32Array",
+    "Float32Array",
+    "Float64Array",
+    "WeakSet",
+    "Set",
+    "WeakMap",
+    "Map",
+    "Reflect",
+    "Proxy",
+    "Atomics",
+    "Promise",
+    nullptr
+};
+
 void Codegen::generateFromProgram(const QString &fileName,
                                   const QString &finalUrl,
                                   const QString &sourceCode,
@@ -118,6 +174,18 @@ void Codegen::generateFromProgram(const QString &fileName,
     _module->fileName = fileName;
     _module->finalUrl = finalUrl;
 
+    if (contextType == ContextType::ScriptImportedByQML) {
+        // the global object is frozen, so we know that members of it are
+        // pointing to the global object. This is important so that references
+        // to Math etc. do not go through the expensive path in the context wrapper
+        // that tries to see whether we have a matching type
+        //
+        // Since this can be called from the loader thread we can't get the list
+        // directly from the engine, so let's hardcode the most important ones here
+        for (const char **g = globalNames; *g != nullptr; ++g)
+            m_globalNames << QString::fromLatin1(*g);
+    }
+
     ScanFunctions scan(this, sourceCode, contextType);
     scan(node);
 
@@ -2350,6 +2418,8 @@ Codegen::Reference Codegen::referenceForName(const QString &name, bool isLhs, co
 
     Reference r = Reference::fromName(this, name);
     r.global = useFastLookups && (resolved.type == Context::ResolvedName::Global);
+    if (!r.global && m_globalNames.contains(name))
+        r.global = true;
     return r;
 }
 
diff --git a/src/qml/compiler/qv4codegen_p.h b/src/qml/compiler/qv4codegen_p.h
index e6e7d2e9fb..7630a1f71d 100644
--- a/src/qml/compiler/qv4codegen_p.h
+++ b/src/qml/compiler/qv4codegen_p.h
@@ -708,6 +708,11 @@ public:
         return *_returnLabel;
     }
 
+    void setGlobalNames(const QSet<QString>& globalNames) {
+        m_globalNames = globalNames;
+    }
+
+
 protected:
     friend class ScanFunctions;
     friend struct ControlFlow;
@@ -730,6 +735,7 @@ protected:
     bool inFormalParameterList = false;
     bool functionEndsWithReturn = false;
     bool _tailCallsAreAllowed = true;
+    QSet<QString> m_globalNames;
 
     ControlFlow *controlFlow = nullptr;