[gjs/wip/ptomato/mozjs38: 22/23] WIP - importer: Switch back to lazy enumeration

[Philip Chimento <pchimento src gnome org>]

commit 14e63c57f1a0d8ef9e1cc9bd158fec3a82bec33f
Author: Philip Chimento <philip chimento gmail com>
Date:   Wed Jan 11 23:38:42 2017 -0800

    WIP - importer: Switch back to lazy enumeration
    
    Lazy enumeration is still available through the jsfriend API in
    js::Class, which is really JSClass but with some extra fields that are
    masked in the public version.
    
    In addition, JSNewEnumerateOp has changed somewhat, compared with
    SpiderMonkey 31. Instead of the enumerate callback being called
    incrementally for each property, now it is just called once the first
    time an object's properties are enumerated, and you have to fill in the
    passed-in JS::AutoIdVector with any names of lazy properties.
    
    FIXME: This changes the behaviour, since the AutoIdVector already
    contains any enumerable property names that the JS engine already knows
    about, before the enumerate callback is called! So we now get searchPath,
    byteArray, etc. when we enumerate the importer.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777962

 gjs/importer.cpp            |   66 +++++++++++++++++++++++++-----------------
 gjs/jsapi-dynamic-class.cpp |    2 +-
 gjs/jsapi-util.h            |    2 +-
 3 files changed, 41 insertions(+), 29 deletions(-)
---
diff --git a/gjs/importer.cpp b/gjs/importer.cpp
index d5f871f..7b1957c 100644
--- a/gjs/importer.cpp
+++ b/gjs/importer.cpp
@@ -53,9 +53,11 @@ typedef struct {
     unsigned int index;
 } ImporterIterator;
 
-extern struct JSClass gjs_importer_class;
+extern const js::Class gjs_importer_class;
 
-GJS_DEFINE_PRIV_FROM_JS(Importer, gjs_importer_class)
+/* Bizarrely, the API for safely casting const js::Class * to const JSClass *
+ * is called "js::Jsvalify" */
+GJS_DEFINE_PRIV_FROM_JS(Importer, (*js::Jsvalify(&gjs_importer_class)))
 
 static bool
 importer_to_string(JSContext *cx,
@@ -97,7 +99,8 @@ define_meta_properties(JSContext       *context,
     /* We define both __moduleName__ and __parentModule__ to null
      * on the root importer
      */
-    parent_is_module = parent && JS_InstanceOf(context, parent, &gjs_importer_class, NULL);
+    parent_is_module = parent && JS_InstanceOf(context, parent,
+        js::Jsvalify(&gjs_importer_class), NULL);
 
     gjs_debug(GJS_DEBUG_IMPORTER, "Defining parent %p of %p '%s' is mod %d",
               parent.get(), module_obj.get(),
@@ -674,8 +677,9 @@ do_import(JSContext       *context,
  * then on its prototype.
  */
 static bool
-importer_enumerate(JSContext       *context,
-                   JS::HandleObject object)
+importer_enumerate(JSContext        *context,
+                   JS::HandleObject  object,
+                   JS::AutoIdVector& properties)
 {
     Importer *priv;
     guint32 search_path_len;
@@ -729,20 +733,10 @@ importer_enumerate(JSContext       *context,
 
         init_path = g_build_filename(dirname, MODULE_INIT_FILENAME, NULL);
 
-        JS::AutoIdVector module_props(context);
-        JS::RootedValue v_prop_name(context);
-        load_module_elements(context, object, module_props, init_path);
+        load_module_elements(context, object, properties, init_path);
 
         g_free(init_path);
 
-        for (const jsid *id = module_props.begin(); id != module_props.end(); id++) {
-            v_prop_name.setString(JSID_TO_STRING(*id));
-            g_autofree char *prop_name = NULL;
-            if (!gjs_string_to_filename(context, v_prop_name, &prop_name) ||
-                !do_import(context, object, priv, prop_name))
-                return false;
-        }
-
         /* new_for_commandline_arg handles resource:/// paths */
         GjsAutoUnref<GFile> dir = g_file_new_for_commandline_arg(dirname);
         g_free(dirname);
@@ -769,14 +763,12 @@ importer_enumerate(JSContext       *context,
                 continue;
 
             if (g_file_info_get_file_type(info) == G_FILE_TYPE_DIRECTORY) {
-                if (!do_import(context, object, priv, filename))
-                    return false;
+                properties.append(gjs_intern_string_to_id(context, filename));
             } else if (g_str_has_suffix(filename, "." G_MODULE_SUFFIX) ||
                        g_str_has_suffix(filename, ".js")) {
                 GjsAutoChar filename_noext =
                     g_strndup(filename, strlen(filename) - 3);
-                if (!do_import(context, object, priv, filename_noext))
-                    return false;
+                properties.append(gjs_intern_string_to_id(context, filename_noext));
             }
         }
     }
@@ -836,8 +828,8 @@ importer_resolve(JSContext        *context,
 GJS_NATIVE_CONSTRUCTOR_DEFINE_ABSTRACT(importer)
 
 static void
-importer_finalize(JSFreeOp *fop,
-                  JSObject *obj)
+importer_finalize(js::FreeOp *fop,
+                  JSObject   *obj)
 {
     Importer *priv;
 
@@ -855,7 +847,7 @@ importer_finalize(JSFreeOp *fop,
  * instances of the object, and to the prototype that instances of the
  * class have.
  */
-struct JSClass gjs_importer_class = {
+const js::Class gjs_importer_class = {
     "GjsFileImporter",
     JSCLASS_HAS_PRIVATE |
     JSCLASS_IMPLEMENTS_BARRIERS,
@@ -863,10 +855,30 @@ struct JSClass gjs_importer_class = {
     NULL,  /* deleteProperty */
     NULL,  /* getProperty */
     NULL,  /* setProperty */
-    importer_enumerate,
+    NULL,  /* enumerate (see below) */
     importer_resolve,
     NULL,  /* convert */
-    importer_finalize
+    importer_finalize,
+    NULL,  /* call */
+    NULL,  /* hasInstance */
+    NULL,  /* construct */
+    NULL,  /* trace */
+    JS_NULL_CLASS_SPEC,
+    JS_NULL_CLASS_EXT,
+    {
+        NULL,  /* lookupProperty */
+        NULL,  /* defineProperty */
+        NULL,  /* hasProperty */
+        NULL,  /* getProperty */
+        NULL,  /* setProperty */
+        NULL,  /* getOwnPropertyDescriptor */
+        NULL,  /* deleteProperty */
+        NULL,  /* watch */
+        NULL,  /* unwatch */
+        NULL,  /* getElements */
+        importer_enumerate,
+        NULL,  /* thisObject */
+    }
 };
 
 JSPropertySpec gjs_importer_proto_props[] = {
@@ -898,7 +910,7 @@ importer_new(JSContext *context,
                                   * Object.prototype
                                   */
                                  JS::NullPtr(),
-                                 &gjs_importer_class,
+                                 js::Jsvalify(&gjs_importer_class),
                                  /* constructor for instances (NULL for
                                   * none - just name the prototype like
                                   * Math - rarely correct)
@@ -922,7 +934,7 @@ importer_new(JSContext *context,
     }
 
     JS::RootedObject importer(context,
-        JS_NewObject(context, &gjs_importer_class, global));
+        JS_NewObject(context, js::Jsvalify(&gjs_importer_class), global));
     if (importer == NULL)
         g_error("No memory to create importer importer");
 
diff --git a/gjs/jsapi-dynamic-class.cpp b/gjs/jsapi-dynamic-class.cpp
index c1e57c2..a645f14 100644
--- a/gjs/jsapi-dynamic-class.cpp
+++ b/gjs/jsapi-dynamic-class.cpp
@@ -147,7 +147,7 @@ format_dynamic_class_name (const char *name)
 bool
 gjs_typecheck_instance(JSContext       *context,
                        JS::HandleObject obj,
-                       JSClass         *static_clasp,
+                       const JSClass   *static_clasp,
                        bool             throw_error)
 {
     if (!JS_InstanceOf(context, obj, static_clasp, NULL)) {
diff --git a/gjs/jsapi-util.h b/gjs/jsapi-util.h
index a4b1ec4..912db24 100644
--- a/gjs/jsapi-util.h
+++ b/gjs/jsapi-util.h
@@ -348,7 +348,7 @@ void gjs_throw_abstract_constructor_error(JSContext    *context,
 
 bool gjs_typecheck_instance(JSContext       *context,
                             JS::HandleObject obj,
-                            JSClass         *static_clasp,
+                            const JSClass   *static_clasp,
                             bool             throw_error);
 
 JSObject *gjs_construct_object_dynamic(JSContext                  *context,