[gjs/wip/ptomato/develop: 4/9] error: Use JSProtoKey to get Error constructor

[Philip Chimento <pchimento src gnome org>]

commit 445ef79c3fe913003ab441833427c42ff91aeb25
Author: Philip Chimento <philip chimento gmail com>
Date:   Mon Sep 18 00:05:24 2017 -0700

    error: Use JSProtoKey to get Error constructor
    
    Instead of looking up the Error prototype by name on the global object
    when we want to throw an error, use JS_GetClassObject and JSProtoKey to
    avoid the conversion of string to ID and the property lookup.

 gi/boxed.cpp                |    6 +++---
 gi/function.cpp             |    2 +-
 gi/fundamental.cpp          |    4 ++--
 gi/object.cpp               |    4 ++--
 gi/param.cpp                |    4 ++--
 gi/union.cpp                |    6 +++---
 gjs/importer.cpp            |    2 +-
 gjs/jsapi-dynamic-class.cpp |    2 +-
 gjs/jsapi-util-error.cpp    |   25 +++++++++++++------------
 gjs/jsapi-util.h            |    2 +-
 10 files changed, 29 insertions(+), 28 deletions(-)
---
diff --git a/gi/boxed.cpp b/gi/boxed.cpp
index 3924bc4..fa8d6c3 100644
--- a/gi/boxed.cpp
+++ b/gi/boxed.cpp
@@ -1284,7 +1284,7 @@ gjs_typecheck_boxed(JSContext       *context,
 
     if (priv->gboxed == NULL) {
         if (throw_error) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is %s.%s.prototype, not an object instance - cannot convert to a boxed 
instance",
                              g_base_info_get_namespace( (GIBaseInfo*) priv->info),
                              g_base_info_get_name( (GIBaseInfo*) priv->info));
@@ -1302,14 +1302,14 @@ gjs_typecheck_boxed(JSContext       *context,
 
     if (!result && throw_error) {
         if (expected_info != NULL) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s.%s - cannot convert to %s.%s",
                              g_base_info_get_namespace((GIBaseInfo*) priv->info),
                              g_base_info_get_name((GIBaseInfo*) priv->info),
                              g_base_info_get_namespace((GIBaseInfo*) expected_info),
                              g_base_info_get_name((GIBaseInfo*) expected_info));
         } else {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s.%s - cannot convert to %s",
                              g_base_info_get_namespace((GIBaseInfo*) priv->info),
                              g_base_info_get_name((GIBaseInfo*) priv->info),
diff --git a/gi/function.cpp b/gi/function.cpp
index 876cc90..b54cc8d 100644
--- a/gi/function.cpp
+++ b/gi/function.cpp
@@ -699,7 +699,7 @@ gjs_fill_method_instance(JSContext       *context,
             if (transfer == GI_TRANSFER_EVERYTHING)
                 gjs_fundamental_ref (context, out_arg->v_pointer);
         } else {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "%s.%s is not an object instance neither a fundamental instance of a supported 
type",
                              g_base_info_get_namespace(container),
                              g_base_info_get_name(container));
diff --git a/gi/fundamental.cpp b/gi/fundamental.cpp
index 5f928ce..9379330 100644
--- a/gi/fundamental.cpp
+++ b/gi/fundamental.cpp
@@ -870,13 +870,13 @@ gjs_typecheck_fundamental(JSContext       *context,
 
     if (!result && throw_error) {
         if (priv->prototype->info) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s.%s - cannot convert to %s",
                              g_base_info_get_namespace((GIBaseInfo *) priv->prototype->info),
                              g_base_info_get_name((GIBaseInfo *) priv->prototype->info),
                              g_type_name(expected_gtype));
         } else {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s - cannot convert to %s",
                              g_type_name(priv->prototype->gtype),
                              g_type_name(expected_gtype));
diff --git a/gi/object.cpp b/gi/object.cpp
index 3694a84..7126461 100644
--- a/gi/object.cpp
+++ b/gi/object.cpp
@@ -2145,13 +2145,13 @@ gjs_typecheck_object(JSContext       *context,
 
     if (!result && throw_error) {
         if (priv->info) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s.%s - cannot convert to %s",
                              g_base_info_get_namespace((GIBaseInfo*) priv->info),
                              g_base_info_get_name((GIBaseInfo*) priv->info),
                              g_type_name(expected_type));
         } else {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s - cannot convert to %s",
                              g_type_name(priv->gtype),
                              g_type_name(expected_type));
diff --git a/gi/param.cpp b/gi/param.cpp
index dbfde0b..4a11142 100644
--- a/gi/param.cpp
+++ b/gi/param.cpp
@@ -304,7 +304,7 @@ gjs_typecheck_param(JSContext       *context,
 
     if (priv->gparam == NULL) {
         if (throw_error) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is GObject.ParamSpec.prototype, not an object instance - "
                              "cannot convert to a GObject.ParamSpec instance");
         }
@@ -318,7 +318,7 @@ gjs_typecheck_param(JSContext       *context,
         result = true;
 
     if (!result && throw_error) {
-        gjs_throw_custom(context, "TypeError", NULL,
+        gjs_throw_custom(context, JSProto_TypeError, nullptr,
                          "Object is of type %s - cannot convert to %s",
                          g_type_name(G_TYPE_FROM_INSTANCE (priv->gparam)),
                          g_type_name(expected_type));
diff --git a/gi/union.cpp b/gi/union.cpp
index b3cbf4a..0168914 100644
--- a/gi/union.cpp
+++ b/gi/union.cpp
@@ -447,7 +447,7 @@ gjs_typecheck_union(JSContext       *context,
 
     if (priv->gboxed == NULL) {
         if (throw_error) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is %s.%s.prototype, not an object instance - cannot convert to a union 
instance",
                              g_base_info_get_namespace( (GIBaseInfo*) priv->info),
                              g_base_info_get_name( (GIBaseInfo*) priv->info));
@@ -465,14 +465,14 @@ gjs_typecheck_union(JSContext       *context,
 
     if (!result && throw_error) {
         if (expected_info != NULL) {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s.%s - cannot convert to %s.%s",
                              g_base_info_get_namespace((GIBaseInfo*) priv->info),
                              g_base_info_get_name((GIBaseInfo*) priv->info),
                              g_base_info_get_namespace((GIBaseInfo*) expected_info),
                              g_base_info_get_name((GIBaseInfo*) expected_info));
         } else {
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object is of type %s.%s - cannot convert to %s",
                              g_base_info_get_namespace((GIBaseInfo*) priv->info),
                              g_base_info_get_name((GIBaseInfo*) priv->info),
diff --git a/gjs/importer.cpp b/gjs/importer.cpp
index 6fd886f..4f8034f 100644
--- a/gjs/importer.cpp
+++ b/gjs/importer.cpp
@@ -626,7 +626,7 @@ do_import(JSContext       *context,
         /* If no exception occurred, the problem is just that we got to the
          * end of the path. Be sure an exception is set.
          */
-        gjs_throw_custom(context, "Error", "ImportError",
+        gjs_throw_custom(context, JSProto_Error, "ImportError",
                          "No JS module '%s' found in search path", name);
     }
 
diff --git a/gjs/jsapi-dynamic-class.cpp b/gjs/jsapi-dynamic-class.cpp
index a660c19..f070dee 100644
--- a/gjs/jsapi-dynamic-class.cpp
+++ b/gjs/jsapi-dynamic-class.cpp
@@ -166,7 +166,7 @@ gjs_typecheck_instance(JSContext       *context,
         if (throw_error) {
             const JSClass *obj_class = JS_GetClass(obj);
 
-            gjs_throw_custom(context, "TypeError", NULL,
+            gjs_throw_custom(context, JSProto_TypeError, nullptr,
                              "Object %p is not a subclass of %s, it's a %s",
                              obj.get(), static_clasp->name,
                              format_dynamic_class_name(obj_class->name));
diff --git a/gjs/jsapi-util-error.cpp b/gjs/jsapi-util-error.cpp
index 0af708d..9ee8e71 100644
--- a/gjs/jsapi-util-error.cpp
+++ b/gjs/jsapi-util-error.cpp
@@ -44,7 +44,7 @@
 static void
 G_GNUC_PRINTF(4, 0)
 gjs_throw_valist(JSContext       *context,
-                 const char      *error_class,
+                 JSProtoKey       error_kind,
                  const char      *error_name,
                  const char      *format,
                  va_list          args)
@@ -87,14 +87,10 @@ gjs_throw_valist(JSContext       *context,
         goto out;
     }
 
-    if (!JS_GetProperty(context, global, error_class, &v_constructor) ||
-        !v_constructor.isObject()) {
-        JS_ReportErrorUTF8(context, "??? Missing Error constructor in global object?");
+    if (!JS_GetClassObject(context, error_kind, &constructor))
         goto out;
-    }
 
     /* throw new Error(message) */
-    constructor = &v_constructor.toObject();
     new_exc = JS_New(context, constructor, error_args);
 
     if (!new_exc)
@@ -141,7 +137,7 @@ gjs_throw(JSContext       *context,
     va_list args;
 
     va_start(args, format);
-    gjs_throw_valist(context, "Error", NULL, format, args);
+    gjs_throw_valist(context, JSProto_Error, nullptr, format, args);
     va_end(args);
 }
 
@@ -151,16 +147,21 @@ gjs_throw(JSContext       *context,
  * error.
  */
 void
-gjs_throw_custom(JSContext       *context,
-                 const char      *error_class,
-                 const char      *error_name,
-                 const char      *format,
+gjs_throw_custom(JSContext  *cx,
+                 JSProtoKey  kind,
+                 const char *error_name,
+                 const char *format,
                  ...)
 {
     va_list args;
+    g_return_if_fail(kind == JSProto_Error || kind == JSProto_InternalError ||
+        kind == JSProto_EvalError || kind == JSProto_RangeError ||
+        kind == JSProto_ReferenceError || kind == JSProto_SyntaxError ||
+        kind == JSProto_TypeError || kind == JSProto_URIError ||
+        kind == JSProto_StopIteration);
 
     va_start(args, format);
-    gjs_throw_valist(context, error_class, error_name, format, args);
+    gjs_throw_valist(cx, kind, error_name, format, args);
     va_end(args);
 }
 
diff --git a/gjs/jsapi-util.h b/gjs/jsapi-util.h
index cb90a2f..41ee04a 100644
--- a/gjs/jsapi-util.h
+++ b/gjs/jsapi-util.h
@@ -180,7 +180,7 @@ void        gjs_throw                        (JSContext       *context,
                                               const char      *format,
                                               ...)  G_GNUC_PRINTF (2, 3);
 void        gjs_throw_custom                 (JSContext       *context,
-                                              const char      *error_class,
+                                              JSProtoKey       error_kind,
                                               const char      *error_name,
                                               const char      *format,
                                               ...)  G_GNUC_PRINTF (4, 5);