Re: Using JavaScriptCore patch

[Ergus <spacibba@aol.com>]

Hi:

I will apply the patch in this thread to master if nobody cares at the
end.

Best,
Ergus

On Tue, Aug 06, 2019 at 06:29:27PM +0200, Ergus wrote:
>Hi:
>
>I just see that there was a TODO in src/xwidget.c to delete a warning
>about deprecations in two functions and use JavaScriptCore API.
>
>I don't know if anyone is working on that already, so I just propose the
>next patch (attachment).
>
>If there is any specialist that want to correct/improve/comment this; it
>is very welcome.
>
>At least it is working for me.
>
>Best,
>Ergus
>

>diff --git a/src/xwidget.c b/src/xwidget.c
>index 121510ebac..ecb3793629 100644
>--- a/src/xwidget.c
>+++ b/src/xwidget.c
>@@ -31,14 +31,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
> #include <webkit2/webkit2.h>
> #include <JavaScriptCore/JavaScript.h>
>
>-/* Suppress GCC deprecation warnings starting in WebKitGTK+ 2.21.1 for
>-   webkit_javascript_result_get_global_context and
>-   webkit_javascript_result_get_value (Bug#33679).
>-   FIXME: Use the JavaScriptCore GLib API instead, and remove this hack.  */
>-#if WEBKIT_CHECK_VERSION (2, 21, 1) && GNUC_PREREQ (4, 2, 0)
>-# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
>-#endif
>-
> static struct xwidget *
> allocate_xwidget (void)
> {
>@@ -284,95 +276,70 @@ webkit_view_load_changed_cb (WebKitWebView *webkitwebview,
>
> /* Recursively convert a JavaScript value to a Lisp value. */
> static Lisp_Object
>-webkit_js_to_lisp (JSContextRef context, JSValueRef value)
>+webkit_js_to_lisp (JSCValue *value)
> {
>-  switch (JSValueGetType (context, value))
>+  if (jsc_value_is_string (value))
>     {
>-    case kJSTypeString:
>-      {
>-        JSStringRef js_str_value;
>-        gchar *str_value;
>-        gsize str_length;
>-
>-        js_str_value = JSValueToStringCopy (context, value, NULL);
>-        str_length = JSStringGetMaximumUTF8CStringSize (js_str_value);
>-        str_value = (gchar *)g_malloc (str_length);
>-        JSStringGetUTF8CString (js_str_value, str_value, str_length);
>-        JSStringRelease (js_str_value);
>-        return build_string (str_value);
>-      }
>-    case kJSTypeBoolean:
>-      return (JSValueToBoolean (context, value)) ? Qt : Qnil;
>-    case kJSTypeNumber:
>-      return make_fixnum (JSValueToNumber (context, value, NULL));
>-    case kJSTypeObject:
>-      {
>-        if (JSValueIsArray (context, value))
>-          {
>-            JSStringRef pname = JSStringCreateWithUTF8CString("length");
>-	    JSValueRef len = JSObjectGetProperty (context, (JSObjectRef) value,
>-						  pname, NULL);
>-	    double dlen = JSValueToNumber (context, len, NULL);
>-            JSStringRelease(pname);
>-
>-            Lisp_Object obj;
>-	    if (! (0 <= dlen && dlen < PTRDIFF_MAX + 1.0))
>-	      memory_full (SIZE_MAX);
>-	    ptrdiff_t n = dlen;
>-            struct Lisp_Vector *p = allocate_vector (n);
>-
>-            for (ptrdiff_t i = 0; i < n; ++i)
>-              {
>-                p->contents[i] =
>-                  webkit_js_to_lisp (context,
>-                                     JSObjectGetPropertyAtIndex (context,
>-                                                                 (JSObjectRef) value,
>-                                                                 i, NULL));
>-              }
>-            XSETVECTOR (obj, p);
>-            return obj;
>-          }
>-        else
>-          {
>-            JSPropertyNameArrayRef properties =
>-              JSObjectCopyPropertyNames (context, (JSObjectRef) value);
>-
>-	    size_t n = JSPropertyNameArrayGetCount (properties);
>-            Lisp_Object obj;
>-
>-            /* TODO: can we use a regular list here?  */
>-	    if (PTRDIFF_MAX < n)
>-	      memory_full (n);
>-            struct Lisp_Vector *p = allocate_vector (n);
>-
>-            for (ptrdiff_t i = 0; i < n; ++i)
>-              {
>-                JSStringRef name = JSPropertyNameArrayGetNameAtIndex (properties, i);
>-                JSValueRef property = JSObjectGetProperty (context,
>-                                                           (JSObjectRef) value,
>-                                                           name, NULL);
>-                gchar *str_name;
>-                gsize str_length;
>-                str_length = JSStringGetMaximumUTF8CStringSize (name);
>-                str_name = (gchar *)g_malloc (str_length);
>-                JSStringGetUTF8CString (name, str_name, str_length);
>-                JSStringRelease (name);
>-
>-                p->contents[i] =
>-                  Fcons (build_string (str_name),
>-                         webkit_js_to_lisp (context, property));
>-              }
>-
>-            JSPropertyNameArrayRelease (properties);
>-            XSETVECTOR (obj, p);
>-            return obj;
>-          }
>-      }
>-    case kJSTypeUndefined:
>-    case kJSTypeNull:
>-    default:
>-      return Qnil;
>+      gchar *str_value = jsc_value_to_string (value);
>+      Lisp_Object ret = build_string (str_value);
>+      g_free (str_value);
>+
>+      return ret;
>+    }
>+  else if (jsc_value_is_boolean (value))
>+    {
>+      return (jsc_value_to_boolean (value)) ? Qt : Qnil;
>+    }
>+  else if (jsc_value_is_number (value))
>+    {
>+      return make_fixnum (jsc_value_to_int32 (value));
>+    }
>+  else if (jsc_value_is_array (value))
>+    {
>+      JSCValue *len = jsc_value_object_get_property (value, "length");
>+      const gint32 dlen = jsc_value_to_int32 (len);
>+
>+      Lisp_Object obj;
>+      if (! (0 <= dlen && dlen < PTRDIFF_MAX + 1.0))
>+	memory_full (SIZE_MAX);
>+
>+      ptrdiff_t n = dlen;
>+      struct Lisp_Vector *p = allocate_vector (n);
>+
>+      for (ptrdiff_t i = 0; i < n; ++i)
>+	{
>+	  p->contents[i] =
>+	    webkit_js_to_lisp (jsc_value_object_get_property_at_index (value, i));
>+	}
>+      XSETVECTOR (obj, p);
>+      return obj;
>+    }
>+  else if (jsc_value_is_object (value))
>+    {
>+      char **properties_names = jsc_value_object_enumerate_properties (value);
>+      guint n = g_strv_length (properties_names);
>+
>+      Lisp_Object obj;
>+      if (PTRDIFF_MAX < n)
>+	memory_full (n);
>+      struct Lisp_Vector *p = allocate_vector (n);
>+
>+      for (ptrdiff_t i = 0; i < n; ++i)
>+	{
>+	  const char *name = properties_names[i];
>+	  JSCValue *property = jsc_value_object_get_property (value, name);
>+
>+	  p->contents[i] =
>+	    Fcons (build_string (name), webkit_js_to_lisp (property));
>+	}
>+
>+      g_strfreev (properties_names);
>+
>+      XSETVECTOR (obj, p);
>+      return obj;
>     }
>+
>+  return Qnil;
> }
>
> static void
>@@ -380,41 +347,39 @@ webkit_javascript_finished_cb (GObject      *webview,
>                                GAsyncResult *result,
>                                gpointer      arg)
> {
>-    WebKitJavascriptResult *js_result;
>-    JSValueRef value;
>-    JSGlobalContextRef context;
>-    GError *error = NULL;
>-    struct xwidget *xw = g_object_get_data (G_OBJECT (webview),
>-                                            XG_XWIDGET);
>-    ptrdiff_t script_idx = (intptr_t) arg;
>-    Lisp_Object script_callback = AREF (xw->script_callbacks, script_idx);
>-    ASET (xw->script_callbacks, script_idx, Qnil);
>-    if (!NILP (script_callback))
>-      xfree (xmint_pointer (XCAR (script_callback)));
>-
>-    js_result = webkit_web_view_run_javascript_finish
>-      (WEBKIT_WEB_VIEW (webview), result, &error);
>-
>-    if (!js_result)
>-      {
>-        g_warning ("Error running javascript: %s", error->message);
>-        g_error_free (error);
>-        return;
>-      }
>+  GError *error = NULL;
>+  struct xwidget *xw = g_object_get_data (G_OBJECT (webview), XG_XWIDGET);
>
>-    if (!NILP (script_callback) && !NILP (XCDR (script_callback)))
>-      {
>-	context = webkit_javascript_result_get_global_context (js_result);
>-	value = webkit_javascript_result_get_value (js_result);
>-	Lisp_Object lisp_value = webkit_js_to_lisp (context, value);
>-
>-	/* Register an xwidget event here, which then runs the callback.
>-	   This ensures that the callback runs in sync with the Emacs
>-	   event loop.  */
>-	store_xwidget_js_callback_event (xw, XCDR (script_callback), lisp_value);
>-      }
>+  ptrdiff_t script_idx = (intptr_t) arg;
>+  Lisp_Object script_callback = AREF (xw->script_callbacks, script_idx);
>+  ASET (xw->script_callbacks, script_idx, Qnil);
>+  if (!NILP (script_callback))
>+    xfree (xmint_pointer (XCAR (script_callback)));
>+
>+  WebKitJavascriptResult *js_result =
>+    webkit_web_view_run_javascript_finish
>+    (WEBKIT_WEB_VIEW (webview), result, &error);
>+
>+  if (!js_result)
>+    {
>+      g_warning ("Error running javascript: %s", error->message);
>+      g_error_free (error);
>+      return;
>+    }
>+
>+  if (!NILP (script_callback) && !NILP (XCDR (script_callback)))
>+    {
>+      JSCValue *value = webkit_javascript_result_get_js_value (js_result);
>+
>+      Lisp_Object lisp_value = webkit_js_to_lisp (value);
>+
>+      /* Register an xwidget event here, which then runs the callback.
>+	 This ensures that the callback runs in sync with the Emacs
>+	 event loop.  */
>+      store_xwidget_js_callback_event (xw, XCDR (script_callback), lisp_value);
>+    }
>
>-    webkit_javascript_result_unref (js_result);
>+  webkit_javascript_result_unref (js_result);
> }
>
>