Bug 467747 - JS version/option unsyncing results in JS modules not being loaded with the very latest JS version, resulting in syntax errors when loading modules that use new JS syntax. r=brendan

js/src/jsapi.cpp

@@ -1191,24 +1191,12 @@ JS_GetOptions(JSContext *cx)
     return cx->options;
 }
 
-#define SYNC_OPTIONS_TO_VERSION(cx)                                           \
-    JS_BEGIN_MACRO                                                            \
-        if ((cx)->options & JSOPTION_XML)                                     \
-            (cx)->version |= JSVERSION_HAS_XML;                               \
-        else                                                                  \
-            (cx)->version &= ~JSVERSION_HAS_XML;                              \
-        if ((cx)->options & JSOPTION_ANONFUNFIX)                              \
-            (cx)->version |= JSVERSION_ANONFUNFIX;                            \
-        else                                                                  \
-            (cx)->version &= ~JSVERSION_ANONFUNFIX;                           \
-    JS_END_MACRO
-
 JS_PUBLIC_API(uint32)
 JS_SetOptions(JSContext *cx, uint32 options)
 {
     uint32 oldopts = cx->options;
     cx->options = options;
-    SYNC_OPTIONS_TO_VERSION(cx);
+    js_SyncOptionsToVersion(cx);
     return oldopts;
 }
 
@@ -1217,7 +1205,7 @@ JS_ToggleOptions(JSContext *cx, uint32 options)
 {
     uint32 oldopts = cx->options;
     cx->options ^= options;
-    SYNC_OPTIONS_TO_VERSION(cx);
+    js_SyncOptionsToVersion(cx);
     return oldopts;
 }
 

js/src/jscntxt.cpp

@@ -1,4 +1,4 @@
-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sw=4 et tw=80:
  *
  * ***** BEGIN LICENSE BLOCK *****
@@ -61,6 +61,7 @@
 #include "jsnum.h"
 #include "jsobj.h"
 #include "jsopcode.h"
+#include "jspubtd.h"
 #include "jsscan.h"
 #include "jsscope.h"
 #include "jsscript.h"
@@ -207,6 +208,38 @@ js_InitContextThread(JSContext *cx, JSThread *thread)
 
 #endif /* JS_THREADSAFE */
 
+/*
+ * JSOPTION_XML and JSOPTION_ANONFUNFIX must be part of the JS version
+ * associated with scripts, so in addition to storing them in cx->options we
+ * duplicate them in cx->version (script->version, etc.) and ensure each bit
+ * remains synchronized between the two through these two functions.
+ */
+void
+js_SyncOptionsToVersion(JSContext* cx)
+{
+    if (cx->options & JSOPTION_XML)
+        cx->version |= JSVERSION_HAS_XML;
+    else
+        cx->version &= ~JSVERSION_HAS_XML;
+    if (cx->options & JSOPTION_ANONFUNFIX)
+        cx->version |= JSVERSION_ANONFUNFIX;
+    else
+        cx->version &= ~JSVERSION_ANONFUNFIX;
+}
+
+inline void
+js_SyncVersionToOptions(JSContext* cx)
+{
+    if (cx->version & JSVERSION_HAS_XML)
+        cx->options |= JSOPTION_XML;
+    else
+        cx->options &= ~JSOPTION_XML;
+    if (cx->version & JSVERSION_ANONFUNFIX)
+        cx->options |= JSOPTION_ANONFUNFIX;
+    else
+        cx->options &= ~JSOPTION_ANONFUNFIX;
+}
+
 void
 js_OnVersionChange(JSContext *cx)
 {
@@ -221,6 +254,7 @@ void
 js_SetVersion(JSContext *cx, JSVersion version)
 {
     cx->version = version;
+    js_SyncVersionToOptions(cx);
     js_OnVersionChange(cx);
 }
 

js/src/jscntxt.h

@@ -1157,6 +1157,14 @@ js_InitThreadPrivateIndex(void (*ptr)(void *));
 extern JSBool
 js_CleanupThreadPrivateData();
 
+/*
+ * Ensures the JSOPTION_XML and JSOPTION_ANONFUNFIX bits of cx->options are
+ * reflected in cx->version, since each bit must travel with a script that has
+ * it set.
+ */
+extern void
+js_SyncOptionsToVersion(JSContext *cx);
+
 /*
  * Common subroutine of JS_SetVersion and js_SetVersion, to update per-context
  * data that depends on version.