[gjs/wip/ptomato/mozjs52: 5/38] js: Use a special object for modules
- From: Philip Chimento <pchimento src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gjs/wip/ptomato/mozjs52: 5/38] js: Use a special object for modules
- Date: Sat, 8 Jul 2017 19:45:49 +0000 (UTC)
commit ace00a4d193497d9a6bbc2871c64d3c202c75af9
Author: Philip Chimento <philip chimento gmail com>
Date: Fri Jun 23 22:22:43 2017 -0700
js: Use a special object for modules
This introduces a new GjsModule class for imported module objects. The
functionality is unchanged, but we will use this as a basis for making
bindings from modules' lexical scopes (variables declared with 'let' and
'const') available for compatibility. In SpiderMonkey 45, these will stop
being exported as properties, as per ES6 standard.
The function GjsModule::evaluate_import() contains duplicated code with
gjs_eval_with_scope(), but that will change when we have to import the
lexical scope separately.
https://bugzilla.gnome.org/show_bug.cgi?id=781429
gjs-srcs.mk | 2 +
gjs/importer.cpp | 57 +++-----
gjs/module.cpp | 209 ++++++++++++++++++++++++++++
gjs/module.h | 42 ++++++
installed-tests/js/jsunit.gresources.xml | 1 +
installed-tests/js/modules/lexicalScope.js | 25 ++++
installed-tests/js/testImporter.js | 20 +++
7 files changed, 319 insertions(+), 37 deletions(-)
---
diff --git a/gjs-srcs.mk b/gjs-srcs.mk
index aa11de5..503c5c9 100644
--- a/gjs-srcs.mk
+++ b/gjs-srcs.mk
@@ -71,6 +71,8 @@ gjs_srcs = \
gjs/jsapi-wrapper.h \
gjs/mem.h \
gjs/mem.cpp \
+ gjs/module.h \
+ gjs/module.cpp \
gjs/native.cpp \
gjs/native.h \
gjs/runtime.cpp \
diff --git a/gjs/importer.cpp b/gjs/importer.cpp
index d87519a..572331d 100644
--- a/gjs/importer.cpp
+++ b/gjs/importer.cpp
@@ -30,6 +30,7 @@
#include "jsapi-class.h"
#include "jsapi-wrapper.h"
#include "mem.h"
+#include "module.h"
#include "native.h"
#include <gio/gio.h>
@@ -185,34 +186,18 @@ import_directory(JSContext *context,
return importer != NULL;
}
-static bool
-define_import(JSContext *context,
- JS::HandleObject obj,
- JS::HandleObject module_obj,
- const char *name)
-{
- if (!JS_DefineProperty(context, obj, name, module_obj,
- GJS_MODULE_PROP_FLAGS & ~JSPROP_PERMANENT)) {
- gjs_debug(GJS_DEBUG_IMPORTER,
- "Failed to define '%s' in importer",
- name);
- return false;
- }
-
- return true;
-}
-
-/* Make the property we set in define_import permament;
+/* Make the property we set in gjs_module_import() permament;
* we do this after the import succesfully completes.
*/
static bool
seal_import(JSContext *cx,
JS::HandleObject obj,
+ JS::HandleId id,
const char *name)
{
JS::Rooted<JSPropertyDescriptor> descr(cx);
- if (!JS_GetOwnPropertyDescriptor(cx, obj, name, &descr) ||
+ if (!JS_GetOwnPropertyDescriptorById(cx, obj, id, &descr) ||
descr.object() == NULL) {
gjs_debug(GJS_DEBUG_IMPORTER,
"Failed to get attributes to seal '%s' in importer",
@@ -223,10 +208,10 @@ seal_import(JSContext *cx,
/* COMPAT: in mozjs45 use .setConfigurable(false) and the form of
* JS_DefineProperty that takes the JSPropertyDescriptor directly */
- if (!JS_DefineProperty(cx, descr.object(), name, descr.value(),
- descr.attributes() | JSPROP_PERMANENT,
- JS_PROPERTYOP_GETTER(descr.getter()),
- JS_PROPERTYOP_SETTER(descr.setter()))) {
+ if (!JS_DefinePropertyById(cx, descr.object(), id, descr.value(),
+ descr.attributes() | JSPROP_PERMANENT,
+ JS_PROPERTYOP_GETTER(descr.getter()),
+ JS_PROPERTYOP_SETTER(descr.setter()))) {
gjs_debug(GJS_DEBUG_IMPORTER,
"Failed to redefine attributes to seal '%s' in importer",
name);
@@ -327,10 +312,9 @@ import_native_file(JSContext *context,
}
static bool
-import_file(JSContext *context,
- const char *name,
- GFile *file,
- JS::HandleObject module_obj)
+import_module_init(JSContext *context,
+ GFile *file,
+ JS::HandleObject module_obj)
{
bool ret = false;
char *script = NULL;
@@ -387,7 +371,7 @@ load_module_init(JSContext *context,
JS::RootedObject module_obj(context, JS_NewPlainObject(context));
GjsAutoUnref<GFile> file = g_file_new_for_commandline_arg(full_path);
- if (!import_file (context, "__init__", file, module_obj))
+ if (!import_module_init(context, file, module_obj))
return module_obj;
gjs_object_define_property(context, in_object,
@@ -456,18 +440,16 @@ import_symbol_from_init_js(JSContext *cx,
static bool
import_file_on_module(JSContext *context,
JS::HandleObject obj,
+ JS::HandleId id,
const char *name,
GFile *file)
{
bool retval = false;
char *full_path = NULL;
- JS::RootedObject module_obj(context, JS_NewPlainObject(context));
-
- if (!define_import(context, obj, module_obj, name))
- goto out;
-
- if (!import_file(context, name, file, module_obj))
+ JS::RootedObject module_obj(context,
+ gjs_module_import(context, obj, id, name, file));
+ if (!module_obj)
goto out;
full_path = g_file_get_parse_name (file);
@@ -478,7 +460,7 @@ import_file_on_module(JSContext *context,
0, 0))
goto out;
- if (!seal_import(context, obj, name))
+ if (!seal_import(context, obj, id, name))
goto out;
retval = true;
@@ -495,6 +477,7 @@ static bool
do_import(JSContext *context,
JS::HandleObject obj,
Importer *priv,
+ JS::HandleId id,
const char *name)
{
char *filename;
@@ -617,7 +600,7 @@ do_import(JSContext *context,
continue;
}
- if (import_file_on_module (context, obj, name, gfile)) {
+ if (import_file_on_module(context, obj, id, name, gfile)) {
gjs_debug(GJS_DEBUG_IMPORTER,
"successfully imported module '%s'", name);
result = true;
@@ -817,7 +800,7 @@ importer_resolve(JSContext *context,
}
JSAutoRequest ar(context);
- if (!do_import(context, obj, priv, name))
+ if (!do_import(context, obj, priv, id, name))
return false;
*resolved = true;
diff --git a/gjs/module.cpp b/gjs/module.cpp
new file mode 100644
index 0000000..0a4ea97
--- /dev/null
+++ b/gjs/module.cpp
@@ -0,0 +1,209 @@
+/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
+/*
+ * Copyright (c) 2017 Philip Chimento <philip chimento gmail com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <gio/gio.h>
+
+#include "jsapi-private.h"
+#include "jsapi-util.h"
+#include "jsapi-wrapper.h"
+#include "module.h"
+#include "util/log.h"
+
+class GjsModule {
+ char *m_name;
+
+ GjsModule(const char *name)
+ {
+ m_name = g_strdup(name);
+ }
+
+ ~GjsModule()
+ {
+ g_free(m_name);
+ }
+
+ /* Private data accessors */
+
+ static inline GjsModule *
+ priv(JSObject *module)
+ {
+ return static_cast<GjsModule *>(JS_GetPrivate(module));
+ }
+
+ /* Creates a JS module object. Use instead of the class's constructor */
+ static JSObject *
+ create(JSContext *cx,
+ const char *name)
+ {
+ JSObject *module = JS_NewObject(cx, &GjsModule::klass);
+ JS_SetPrivate(module, new GjsModule(name));
+ return module;
+ }
+
+ /* Defines the empty module as a property on the importer */
+ bool
+ define_import(JSContext *cx,
+ JS::HandleObject module,
+ JS::HandleObject importer,
+ JS::HandleId name)
+ {
+ if (!JS_DefinePropertyById(cx, importer, name, module,
+ GJS_MODULE_PROP_FLAGS & ~JSPROP_PERMANENT)) {
+ gjs_debug(GJS_DEBUG_IMPORTER, "Failed to define '%s' in importer",
+ m_name);
+ return false;
+ }
+
+ return true;
+ }
+
+ /* Carries out the actual execution of the module code */
+ bool
+ evaluate_import(JSContext *cx,
+ JS::HandleObject module,
+ const char *script,
+ size_t script_len,
+ const char *filename,
+ int line_number)
+ {
+ JS::CompileOptions options(cx);
+ options.setUTF8(true)
+ .setFileAndLine(filename, line_number)
+ .setSourceIsLazy(true);
+
+ JS::RootedScript compiled_script(cx);
+ if (!JS::Compile(cx, module, options, script, script_len,
+ &compiled_script))
+ return false;
+
+ JS::AutoObjectVector scope_chain(cx);
+ scope_chain.append(module);
+ JS::RootedValue ignored_retval(cx);
+ if (!JS_ExecuteScript(cx, scope_chain, compiled_script, &ignored_retval))
+ return false;
+
+ gjs_schedule_gc_if_needed(cx);
+
+ gjs_debug(GJS_DEBUG_IMPORTER, "Importing module %s succeeded", m_name);
+
+ return true;
+ }
+
+ /* Loads JS code from a file and imports it */
+ bool
+ import_file(JSContext *cx,
+ JS::HandleObject module,
+ GFile *file)
+ {
+ GError *error = nullptr;
+ char *unowned_script;
+ size_t script_len = 0;
+ int start_line_number = 1;
+
+ if (!(g_file_load_contents(file, nullptr, &unowned_script, &script_len,
+ nullptr, &error))) {
+ gjs_throw_g_error(cx, error);
+ return false;
+ }
+
+ GjsAutoChar script = unowned_script; /* steals ownership */
+ g_assert(script != nullptr);
+
+ const char *stripped_script =
+ gjs_strip_unix_shebang(script, &script_len, &start_line_number);
+
+ GjsAutoChar full_path = g_file_get_parse_name(file);
+ return evaluate_import(cx, module, stripped_script, script_len,
+ full_path, start_line_number);
+ }
+
+ /* JSClass operations */
+
+ static void
+ finalize(JSFreeOp *op,
+ JSObject *module)
+ {
+ delete priv(module);
+ }
+
+ static constexpr JSClass klass = {
+ "GjsModule",
+ JSCLASS_HAS_PRIVATE | JSCLASS_BACKGROUND_FINALIZE |
+ JSCLASS_IMPLEMENTS_BARRIERS,
+ nullptr, /* addProperty */
+ nullptr, /* deleteProperty */
+ nullptr, /* getProperty */
+ nullptr, /* setProperty */
+ nullptr, /* enumerate */
+ nullptr, /* resolve */
+ nullptr, /* mayResolve */
+ &GjsModule::finalize,
+ };
+
+public:
+
+ /* Carries out the import operation */
+ static JSObject *
+ import(JSContext *cx,
+ JS::HandleObject importer,
+ JS::HandleId id,
+ const char *name,
+ GFile *file)
+ {
+ JS::RootedObject module(cx, GjsModule::create(cx, name));
+ if (!module ||
+ !priv(module)->define_import(cx, module, importer, id) ||
+ !priv(module)->import_file(cx, module, file))
+ return nullptr;
+
+ return module;
+ }
+};
+
+/**
+ * gjs_module_import:
+ * @cx: the JS context
+ * @importer: the JS importer object, parent of the module to be imported
+ * @id: module name in the form of a jsid
+ * @name: module name, used for logging and identification
+ * @file: location of the file to import
+ *
+ * Carries out an import of a GJS module.
+ * Defines a property @name on @importer pointing to the module object, which
+ * is necessary in the case of cyclic imports.
+ * This property is not permanent; the caller is responsible for making it
+ * permanent if the import succeeds.
+ *
+ * Returns: the JS module object, or nullptr on failure.
+ */
+JSObject *
+gjs_module_import(JSContext *cx,
+ JS::HandleObject importer,
+ JS::HandleId id,
+ const char *name,
+ GFile *file)
+{
+ return GjsModule::import(cx, importer, id, name, file);
+}
+
+decltype(GjsModule::klass) constexpr GjsModule::klass;
diff --git a/gjs/module.h b/gjs/module.h
new file mode 100644
index 0000000..9041391
--- /dev/null
+++ b/gjs/module.h
@@ -0,0 +1,42 @@
+/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
+/*
+ * Copyright (c) 2017 Philip Chimento <philip chimento gmail com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef GJS_MODULE_H
+#define GJS_MODULE_H
+
+#include <gio/gio.h>
+
+#include "jsapi-wrapper.h"
+
+G_BEGIN_DECLS
+
+JSObject *
+gjs_module_import(JSContext *cx,
+ JS::HandleObject importer,
+ JS::HandleId id,
+ const char *name,
+ GFile *file);
+
+G_END_DECLS
+
+#endif /* GJS_MODULE_H */
diff --git a/installed-tests/js/jsunit.gresources.xml b/installed-tests/js/jsunit.gresources.xml
index 3fe08f2..15bd330 100644
--- a/installed-tests/js/jsunit.gresources.xml
+++ b/installed-tests/js/jsunit.gresources.xml
@@ -6,6 +6,7 @@
<file>minijasmine.js</file>
<file>modules/alwaysThrows.js</file>
<file>modules/foobar.js</file>
+ <file>modules/lexicalScope.js</file>
<file>modules/modunicode.js</file>
<file>modules/mutualImport/a.js</file>
<file>modules/mutualImport/b.js</file>
diff --git a/installed-tests/js/modules/lexicalScope.js b/installed-tests/js/modules/lexicalScope.js
new file mode 100644
index 0000000..6542952
--- /dev/null
+++ b/installed-tests/js/modules/lexicalScope.js
@@ -0,0 +1,25 @@
+/* exported a, b, c */
+
+// Tests bindings in the global scope (var) and lexical environment (let, const)
+
+// This should be exported as a property when importing this module:
+var a = 1;
+
+// These should not be exported, but for compatibility we will pretend they are
+// for the time being:
+let b = 2;
+const c = 3;
+
+// It's not clear whether this should be exported in ES6, but for compatibility
+// it should be:
+this.d = 4;
+
+// Modules should have access to standard properties on the global object.
+if (typeof imports === 'undefined')
+ throw new Error('fail the import');
+
+// This should probably not be supported in the future, but I'm not sure how
+// we can phase it out compatibly. The module should also have access to
+// properties that the importing code defines.
+if (typeof expectMe === 'undefined')
+ throw new Error('fail the import');
diff --git a/installed-tests/js/testImporter.js b/installed-tests/js/testImporter.js
index 6b73643..35879b1 100644
--- a/installed-tests/js/testImporter.js
+++ b/installed-tests/js/testImporter.js
@@ -156,6 +156,26 @@ describe('Importer', function () {
expect(ModUnicode.uval).toEqual('const \u2665 utf8');
});
+ describe("properties defined in the module's lexical scope", function () {
+ let LexicalScope;
+
+ beforeAll(function () {
+ window.expectMe = true;
+ LexicalScope = imports.lexicalScope;
+ });
+
+ it('can be accessed', function () {
+ expect(LexicalScope.a).toEqual(1);
+ expect(LexicalScope.b).toEqual(2);
+ expect(LexicalScope.c).toEqual(3);
+ expect(LexicalScope.d).toEqual(4);
+ });
+
+ it('does not leak module properties into the global scope', function () {
+ expect(window.d).not.toBeDefined();
+ });
+ });
+
describe('enumerating modules', function () {
let keys;
beforeEach(function () {
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