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/* -*- Mode: javascript; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4
* -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "shell/ModuleLoader.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/TextUtils.h"
#include "NamespaceImports.h"
#include "js/Modules.h"
#include "js/SourceText.h"
#include "js/StableStringChars.h"
#include "shell/jsshell.h"
#include "shell/OSObject.h"
#include "shell/StringUtils.h"
#include "vm/JSAtom.h"
#include "vm/JSContext.h"
#include "vm/StringType.h"
using namespace js;
using namespace js::shell;
static constexpr char16_t JavaScriptScheme[] = u"javascript:";
static bool IsJavaScriptURL(HandleLinearString path) {
return StringStartsWith(path, JavaScriptScheme);
}
static JSString* ExtractJavaScriptURLSource(JSContext* cx,
HandleLinearString path) {
MOZ_ASSERT(IsJavaScriptURL(path));
const size_t schemeLength = mozilla::ArrayLength(JavaScriptScheme) - 1;
return SubString(cx, path, schemeLength);
}
bool ModuleLoader::init(JSContext* cx, HandleString loadPath) {
loadPathStr = AtomizeString(cx, loadPath, PinAtom);
if (!loadPathStr) {
return false;
}
MOZ_ASSERT(IsAbsolutePath(loadPathStr));
char16_t sep = PathSeparator;
pathSeparatorStr = AtomizeChars(cx, &sep, 1);
if (!pathSeparatorStr) {
return false;
}
JSRuntime* rt = cx->runtime();
JS::SetModuleResolveHook(rt, ModuleLoader::ResolveImportedModule);
JS::SetModuleMetadataHook(rt, ModuleLoader::GetImportMetaProperties);
JS::SetModuleDynamicImportHook(rt, ModuleLoader::ImportModuleDynamically);
return true;
}
// static
JSObject* ModuleLoader::ResolveImportedModule(
JSContext* cx, JS::HandleValue referencingPrivate,
JS::HandleString specifier) {
ShellContext* scx = GetShellContext(cx);
return scx->moduleLoader->resolveImportedModule(cx, referencingPrivate,
specifier);
}
// static
bool ModuleLoader::GetImportMetaProperties(JSContext* cx,
JS::HandleValue privateValue,
JS::HandleObject metaObject) {
ShellContext* scx = GetShellContext(cx);
return scx->moduleLoader->populateImportMeta(cx, privateValue, metaObject);
}
// static
bool ModuleLoader::ImportModuleDynamically(JSContext* cx,
JS::HandleValue referencingPrivate,
JS::HandleString specifier,
JS::HandleObject promise) {
ShellContext* scx = GetShellContext(cx);
return scx->moduleLoader->dynamicImport(cx, referencingPrivate, specifier,
promise);
}
bool ModuleLoader::loadRootModule(JSContext* cx, HandleString path) {
return loadAndExecute(cx, path);
}
bool ModuleLoader::registerTestModule(JSContext* cx, HandleString specifier,
HandleModuleObject module) {
RootedLinearString path(cx, resolve(cx, specifier, UndefinedHandleValue));
if (!path) {
return false;
}
path = normalizePath(cx, path);
if (!path) {
return false;
}
return addModuleToRegistry(cx, path, module);
}
bool ModuleLoader::loadAndExecute(JSContext* cx, HandleString path) {
RootedObject module(cx, loadAndParse(cx, path));
if (!module) {
return false;
}
return JS::ModuleInstantiate(cx, module) && JS::ModuleEvaluate(cx, module);
}
JSObject* ModuleLoader::resolveImportedModule(
JSContext* cx, JS::HandleValue referencingPrivate,
JS::HandleString specifier) {
RootedLinearString path(cx, resolve(cx, specifier, referencingPrivate));
if (!path) {
return nullptr;
}
return loadAndParse(cx, path);
}
bool ModuleLoader::populateImportMeta(JSContext* cx,
JS::HandleValue privateValue,
JS::HandleObject metaObject) {
RootedLinearString path(cx);
if (!privateValue.isUndefined()) {
if (!getScriptPath(cx, privateValue, &path)) {
return false;
}
}
if (!path) {
path = NewStringCopyZ<CanGC>(cx, "(unknown)");
if (!path) {
return false;
}
}
RootedValue pathValue(cx, StringValue(path));
return JS_DefineProperty(cx, metaObject, "url", pathValue, JSPROP_ENUMERATE);
}
bool ModuleLoader::dynamicImport(JSContext* cx,
JS::HandleValue referencingPrivate,
JS::HandleString specifier,
JS::HandleObject promise) {
// To make this more realistic, use a promise to delay the import and make it
// happen asynchronously. This method packages up the arguments and creates a
// resolved promise, which on fullfillment calls doDynamicImport with the
// original arguments.
MOZ_ASSERT(promise);
RootedValue specifierValue(cx, StringValue(specifier));
RootedValue promiseValue(cx, ObjectValue(*promise));
RootedObject closure(cx, JS_NewPlainObject(cx));
if (!closure ||
!JS_DefineProperty(cx, closure, "referencingPrivate", referencingPrivate,
JSPROP_ENUMERATE) ||
!JS_DefineProperty(cx, closure, "specifier", specifierValue,
JSPROP_ENUMERATE) ||
!JS_DefineProperty(cx, closure, "promise", promiseValue,
JSPROP_ENUMERATE)) {
return false;
}
RootedFunction onResolved(
cx, NewNativeFunction(cx, DynamicImportDelayFulfilled, 1, nullptr));
if (!onResolved) {
return false;
}
RootedFunction onRejected(
cx, NewNativeFunction(cx, DynamicImportDelayRejected, 1, nullptr));
if (!onRejected) {
return false;
}
RootedObject delayPromise(cx);
RootedValue closureValue(cx, ObjectValue(*closure));
delayPromise = PromiseObject::unforgeableResolve(cx, closureValue);
if (!delayPromise) {
return false;
}
return JS::AddPromiseReactions(cx, delayPromise, onResolved, onRejected);
}
bool ModuleLoader::DynamicImportDelayFulfilled(JSContext* cx, unsigned argc,
Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
RootedObject closure(cx, &args[0].toObject());
RootedValue referencingPrivate(cx);
RootedValue specifierValue(cx);
RootedValue promiseValue(cx);
if (!JS_GetProperty(cx, closure, "referencingPrivate", &referencingPrivate) ||
!JS_GetProperty(cx, closure, "specifier", &specifierValue) ||
!JS_GetProperty(cx, closure, "promise", &promiseValue)) {
return false;
}
RootedString specifier(cx, specifierValue.toString());
RootedObject promise(cx, &promiseValue.toObject());
ShellContext* scx = GetShellContext(cx);
return scx->moduleLoader->doDynamicImport(cx, referencingPrivate, specifier,
promise);
}
bool ModuleLoader::DynamicImportDelayRejected(JSContext* cx, unsigned argc,
Value* vp) {
MOZ_CRASH("This promise should never be rejected");
}
bool ModuleLoader::doDynamicImport(JSContext* cx,
JS::HandleValue referencingPrivate,
JS::HandleString specifier,
JS::HandleObject promise) {
// Exceptions during dynamic import are handled by calling
// FinishDynamicModuleImport with a pending exception on the context.
bool ok = tryDynamicImport(cx, referencingPrivate, specifier, promise);
JS::DynamicImportStatus status =
ok ? JS::DynamicImportStatus::Ok : JS::DynamicImportStatus::Failed;
return JS::FinishDynamicModuleImport(cx, status, referencingPrivate,
specifier, promise);
}
bool ModuleLoader::tryDynamicImport(JSContext* cx,
JS::HandleValue referencingPrivate,
JS::HandleString specifier,
JS::HandleObject promise) {
RootedLinearString path(cx, resolve(cx, specifier, referencingPrivate));
if (!path) {
return false;
}
return loadAndExecute(cx, path);
}
JSLinearString* ModuleLoader::resolve(JSContext* cx, HandleString nameArg,
HandleValue referencingInfo) {
if (nameArg->length() == 0) {
JS_ReportErrorASCII(cx, "Invalid module specifier");
return nullptr;
}
RootedLinearString name(cx, JS_EnsureLinearString(cx, nameArg));
if (!name) {
return nullptr;
}
if (IsJavaScriptURL(name) || IsAbsolutePath(name)) {
return name;
}
// Treat |name| as a relative path if it starts with either "./" or "../".
bool isRelative =
StringStartsWith(name, u"./") || StringStartsWith(name, u"../")
#ifdef XP_WIN
|| StringStartsWith(name, u".\\") || StringStartsWith(name, u"..\\")
#endif
;
RootedString path(cx, loadPathStr);
if (isRelative) {
if (referencingInfo.isUndefined()) {
JS_ReportErrorASCII(cx, "No referencing module for relative import");
return nullptr;
}
RootedLinearString refPath(cx);
if (!getScriptPath(cx, referencingInfo, &refPath)) {
return nullptr;
}
if (!refPath) {
JS_ReportErrorASCII(cx, "No path set for referencing module");
return nullptr;
}
int32_t sepIndex = LastIndexOf(refPath, u'/');
#ifdef XP_WIN
sepIndex = std::max(sepIndex, LastIndexOf(refPath, u'\\'));
#endif
if (sepIndex >= 0) {
path = SubString(cx, refPath, 0, sepIndex);
if (!path) {
return nullptr;
}
}
}
RootedString result(cx);
RootedString pathSep(cx, pathSeparatorStr);
result = JS_ConcatStrings(cx, path, pathSep);
if (!result) {
return nullptr;
}
result = JS_ConcatStrings(cx, result, name);
if (!result) {
return nullptr;
}
return JS_EnsureLinearString(cx, result);
}
JSObject* ModuleLoader::loadAndParse(JSContext* cx, HandleString pathArg) {
RootedLinearString path(cx, JS_EnsureLinearString(cx, pathArg));
if (!path) {
return nullptr;
}
path = normalizePath(cx, path);
if (!path) {
return nullptr;
}
RootedObject module(cx);
if (!lookupModuleInRegistry(cx, path, &module)) {
return nullptr;
}
if (module) {
return module;
}
UniqueChars filename = JS_EncodeStringToLatin1(cx, path);
if (!filename) {
return nullptr;
}
JS::CompileOptions options(cx);
options.setFileAndLine(filename.get(), 1);
RootedString source(cx, fetchSource(cx, path));
if (!source) {
return nullptr;
}
JS::AutoStableStringChars stableChars(cx);
if (!stableChars.initTwoByte(cx, source)) {
return nullptr;
}
const char16_t* chars = stableChars.twoByteRange().begin().get();
JS::SourceText<char16_t> srcBuf;
if (!srcBuf.init(cx, chars, source->length(),
JS::SourceOwnership::Borrowed)) {
return nullptr;
}
module = JS::CompileModule(cx, options, srcBuf);
if (!module) {
return nullptr;
}
RootedObject info(cx, CreateScriptPrivate(cx, path));
if (!info) {
return nullptr;
}
JS::SetModulePrivate(module, ObjectValue(*info));
if (!addModuleToRegistry(cx, path, module)) {
return nullptr;
}
return module;
}
bool ModuleLoader::lookupModuleInRegistry(JSContext* cx, HandleString path,
MutableHandleObject moduleOut) {
moduleOut.set(nullptr);
RootedObject registry(cx, getOrCreateModuleRegistry(cx));
if (!registry) {
return false;
}
RootedValue pathValue(cx, StringValue(path));
RootedValue moduleValue(cx);
if (!JS::MapGet(cx, registry, pathValue, &moduleValue)) {
return false;
}
if (!moduleValue.isUndefined()) {
moduleOut.set(&moduleValue.toObject());
}
return true;
}
bool ModuleLoader::addModuleToRegistry(JSContext* cx, HandleString path,
HandleObject module) {
RootedObject registry(cx, getOrCreateModuleRegistry(cx));
if (!registry) {
return false;
}
RootedValue pathValue(cx, StringValue(path));
RootedValue moduleValue(cx, ObjectValue(*module));
return JS::MapSet(cx, registry, pathValue, moduleValue);
}
JSObject* ModuleLoader::getOrCreateModuleRegistry(JSContext* cx) {
Handle<GlobalObject*> global = cx->global();
RootedValue value(cx, global->getReservedSlot(GlobalAppSlotModuleRegistry));
if (!value.isUndefined()) {
return &value.toObject();
}
JSObject* registry = JS::NewMapObject(cx);
if (!registry) {
return nullptr;
}
global->setReservedSlot(GlobalAppSlotModuleRegistry, ObjectValue(*registry));
return registry;
}
bool ModuleLoader::getScriptPath(JSContext* cx, HandleValue privateValue,
MutableHandle<JSLinearString*> pathOut) {
pathOut.set(nullptr);
RootedObject infoObj(cx, &privateValue.toObject());
RootedValue pathValue(cx);
if (!JS_GetProperty(cx, infoObj, "path", &pathValue)) {
return false;
}
if (pathValue.isUndefined()) {
return true;
}
RootedString path(cx, pathValue.toString());
pathOut.set(JS_EnsureLinearString(cx, path));
return pathOut;
}
JSLinearString* ModuleLoader::normalizePath(JSContext* cx,
HandleLinearString pathArg) {
RootedLinearString path(cx, pathArg);
if (IsJavaScriptURL(path)) {
return path;
}
#ifdef XP_WIN
// Replace all forward slashes with backward slashes.
path = ReplaceCharGlobally(cx, path, u'/', PathSeparator);
if (!path) {
return nullptr;
}
// Remove the drive letter, if present.
RootedLinearString drive(cx);
if (path->length() > 2 && mozilla::IsAsciiAlpha(CharAt(path, 0)) &&
CharAt(path, 1) == u':' && CharAt(path, 2) == u'\\') {
drive = SubString(cx, path, 0, 2);
path = SubString(cx, path, 2);
if (!drive || !path) {
return nullptr;
}
}
#endif // XP_WIN
// Normalize the path by removing redundant path components.
Rooted<GCVector<JSLinearString*>> components(cx);
size_t lastSep = 0;
while (lastSep < path->length()) {
int32_t i = IndexOf(path, PathSeparator, lastSep);
if (i < 0) {
i = path->length();
}
RootedLinearString part(cx, SubString(cx, path, lastSep, i));
if (!part) {
return nullptr;
}
lastSep = i + 1;
// Remove "." when preceded by a path component.
if (StringEquals(part, u".") && !components.empty()) {
continue;
}
if (StringEquals(part, u"..") && !components.empty()) {
// Replace "./.." with "..".
if (StringEquals(components.back(), u".")) {
components.back() = part;
continue;
}
// When preceded by a non-empty path component, remove ".." and the
// preceding component, unless the preceding component is also "..".
if (!StringEquals(components.back(), u"") &&
!StringEquals(components.back(), u"..")) {
components.popBack();
continue;
}
}
if (!components.append(part)) {
return nullptr;
}
}
RootedLinearString pathSep(cx, pathSeparatorStr);
RootedString normalized(cx, JoinStrings(cx, components, pathSep));
if (!normalized) {
return nullptr;
}
#ifdef XP_WIN
if (drive) {
normalized = JS_ConcatStrings(cx, drive, normalized);
if (!normalized) {
return nullptr;
}
}
#endif
return JS_EnsureLinearString(cx, normalized);
}
JSString* ModuleLoader::fetchSource(JSContext* cx, HandleLinearString path) {
if (IsJavaScriptURL(path)) {
return ExtractJavaScriptURLSource(cx, path);
}
RootedString resolvedPath(cx, ResolvePath(cx, path, RootRelative));
if (!resolvedPath) {
return nullptr;
}
return FileAsString(cx, resolvedPath);
}