diff options
Diffstat (limited to 'js/xpconnect/loader/mozJSComponentLoader.cpp')
| -rw-r--r-- | js/xpconnect/loader/mozJSComponentLoader.cpp | 1356 |
1 files changed, 1356 insertions, 0 deletions
diff --git a/js/xpconnect/loader/mozJSComponentLoader.cpp b/js/xpconnect/loader/mozJSComponentLoader.cpp new file mode 100644 index 0000000000..23c5e1d0c3 --- /dev/null +++ b/js/xpconnect/loader/mozJSComponentLoader.cpp @@ -0,0 +1,1356 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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 "mozilla/Attributes.h" +#include "mozilla/Utf8.h" // mozilla::Utf8Unit + +#include <cstdarg> + +#include "mozilla/Logging.h" +#ifdef ANDROID +# include <android/log.h> +#endif +#ifdef XP_WIN +# include <windows.h> +#endif + +#include "jsapi.h" +#include "js/Array.h" // JS::GetArrayLength, JS::IsArrayObject +#include "js/CharacterEncoding.h" +#include "js/CompilationAndEvaluation.h" +#include "js/CompileOptions.h" // JS::CompileOptions +#include "js/friend/JSMEnvironment.h" // JS::ExecuteInJSMEnvironment, JS::GetJSMEnvironmentOfScriptedCaller, JS::NewJSMEnvironment +#include "js/Object.h" // JS::GetCompartment +#include "js/Printf.h" +#include "js/PropertySpec.h" +#include "js/SourceText.h" // JS::SourceText +#include "nsCOMPtr.h" +#include "nsExceptionHandler.h" +#include "nsIComponentManager.h" +#include "mozilla/Module.h" +#include "nsIFile.h" +#include "mozJSComponentLoader.h" +#include "mozJSLoaderUtils.h" +#include "nsIFileURL.h" +#include "nsIJARURI.h" +#include "nsIChannel.h" +#include "nsNetUtil.h" +#include "nsJSPrincipals.h" +#include "nsJSUtils.h" +#include "xpcprivate.h" +#include "xpcpublic.h" +#include "nsContentUtils.h" +#include "nsReadableUtils.h" +#include "nsXULAppAPI.h" +#include "GeckoProfiler.h" +#include "WrapperFactory.h" + +#include "AutoMemMap.h" +#include "ScriptPreloader-inl.h" + +#include "mozilla/scache/StartupCache.h" +#include "mozilla/scache/StartupCacheUtils.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/MacroForEach.h" +#include "mozilla/Preferences.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/ScriptPreloader.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/dom/ScriptSettings.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/UniquePtrExtensions.h" +#include "mozilla/Unused.h" + +using namespace mozilla; +using namespace mozilla::scache; +using namespace mozilla::loader; +using namespace xpc; +using namespace JS; + +#define JS_CACHE_PREFIX(aType) "jsloader/" aType + +/** + * Buffer sizes for serialization and deserialization of scripts. + * FIXME: bug #411579 (tune this macro!) Last updated: Jan 2008 + */ +#define XPC_SERIALIZATION_BUFFER_SIZE (64 * 1024) +#define XPC_DESERIALIZATION_BUFFER_SIZE (12 * 8192) + +// MOZ_LOG=JSComponentLoader:5 +static LazyLogModule gJSCLLog("JSComponentLoader"); + +#define LOG(args) MOZ_LOG(gJSCLLog, mozilla::LogLevel::Debug, args) + +// Components.utils.import error messages +#define ERROR_SCOPE_OBJ "%s - Second argument must be an object." +#define ERROR_NO_TARGET_OBJECT "%s - Couldn't find target object for import." +#define ERROR_NOT_PRESENT "%s - EXPORTED_SYMBOLS is not present." +#define ERROR_NOT_AN_ARRAY "%s - EXPORTED_SYMBOLS is not an array." +#define ERROR_GETTING_ARRAY_LENGTH \ + "%s - Error getting array length of EXPORTED_SYMBOLS." +#define ERROR_ARRAY_ELEMENT "%s - EXPORTED_SYMBOLS[%d] is not a string." +#define ERROR_GETTING_SYMBOL "%s - Could not get symbol '%s'." +#define ERROR_SETTING_SYMBOL "%s - Could not set symbol '%s' on target object." +#define ERROR_UNINITIALIZED_SYMBOL \ + "%s - Symbol '%s' accessed before initialization. Cyclic import?" + +static bool Dump(JSContext* cx, unsigned argc, Value* vp) { + if (!nsJSUtils::DumpEnabled()) { + return true; + } + + CallArgs args = CallArgsFromVp(argc, vp); + + if (args.length() == 0) { + return true; + } + + RootedString str(cx, JS::ToString(cx, args[0])); + if (!str) { + return false; + } + + JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str); + if (!utf8str) { + return false; + } + +#ifdef ANDROID + __android_log_print(ANDROID_LOG_INFO, "Gecko", "%s", utf8str.get()); +#endif +#ifdef XP_WIN + if (IsDebuggerPresent()) { + nsAutoJSString wstr; + if (!wstr.init(cx, str)) { + return false; + } + OutputDebugStringW(wstr.get()); + } +#endif + fputs(utf8str.get(), stdout); + fflush(stdout); + return true; +} + +static bool Debug(JSContext* cx, unsigned argc, Value* vp) { +#ifdef DEBUG + return Dump(cx, argc, vp); +#else + return true; +#endif +} + +static const JSFunctionSpec gGlobalFun[] = { + JS_FN("dump", Dump, 1, 0), JS_FN("debug", Debug, 1, 0), + JS_FN("atob", Atob, 1, 0), JS_FN("btoa", Btoa, 1, 0), JS_FS_END}; + +class MOZ_STACK_CLASS JSCLContextHelper { + public: + explicit JSCLContextHelper(JSContext* aCx); + ~JSCLContextHelper(); + + void reportErrorAfterPop(UniqueChars&& buf); + + private: + JSContext* mContext; + UniqueChars mBuf; + + // prevent copying and assignment + JSCLContextHelper(const JSCLContextHelper&) = delete; + const JSCLContextHelper& operator=(const JSCLContextHelper&) = delete; +}; + +static nsresult MOZ_FORMAT_PRINTF(2, 3) + ReportOnCallerUTF8(JSContext* callerContext, const char* format, ...) { + if (!callerContext) { + return NS_ERROR_FAILURE; + } + + va_list ap; + va_start(ap, format); + + UniqueChars buf = JS_vsmprintf(format, ap); + if (!buf) { + va_end(ap); + return NS_ERROR_OUT_OF_MEMORY; + } + + JS_ReportErrorUTF8(callerContext, "%s", buf.get()); + + va_end(ap); + return NS_OK; +} + +mozJSComponentLoader::mozJSComponentLoader() + : mModules(16), + mImports(16), + mInProgressImports(16), + mLocations(16), + mInitialized(false), + mLoaderGlobal(dom::RootingCx()) { + MOZ_ASSERT(!sSelf, "mozJSComponentLoader should be a singleton"); +} + +#define ENSURE_DEP(name) \ + { \ + nsresult rv = Ensure##name(); \ + NS_ENSURE_SUCCESS(rv, rv); \ + } +#define ENSURE_DEPS(...) MOZ_FOR_EACH(ENSURE_DEP, (), (__VA_ARGS__)); +#define BEGIN_ENSURE(self, ...) \ + { \ + if (m##self) return NS_OK; \ + ENSURE_DEPS(__VA_ARGS__); \ + } + +class MOZ_STACK_CLASS ComponentLoaderInfo { + public: + explicit ComponentLoaderInfo(const nsACString& aLocation) + : mLocation(aLocation) {} + + nsIIOService* IOService() { + MOZ_ASSERT(mIOService); + return mIOService; + } + nsresult EnsureIOService() { + if (mIOService) { + return NS_OK; + } + nsresult rv; + mIOService = do_GetIOService(&rv); + return rv; + } + + nsIURI* URI() { + MOZ_ASSERT(mURI); + return mURI; + } + nsresult EnsureURI() { + BEGIN_ENSURE(URI, IOService); + return mIOService->NewURI(mLocation, nullptr, nullptr, + getter_AddRefs(mURI)); + } + + nsIChannel* ScriptChannel() { + MOZ_ASSERT(mScriptChannel); + return mScriptChannel; + } + nsresult EnsureScriptChannel() { + BEGIN_ENSURE(ScriptChannel, IOService, URI); + return NS_NewChannel( + getter_AddRefs(mScriptChannel), mURI, + nsContentUtils::GetSystemPrincipal(), + nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL, + nsIContentPolicy::TYPE_SCRIPT, + nullptr, // nsICookieJarSettings + nullptr, // aPerformanceStorage + nullptr, // aLoadGroup + nullptr, // aCallbacks + nsIRequest::LOAD_NORMAL, mIOService); + } + + nsIURI* ResolvedURI() { + MOZ_ASSERT(mResolvedURI); + return mResolvedURI; + } + nsresult EnsureResolvedURI() { + BEGIN_ENSURE(ResolvedURI, URI); + return ResolveURI(mURI, getter_AddRefs(mResolvedURI)); + } + + const nsACString& Key() { return mLocation; } + + MOZ_MUST_USE nsresult GetLocation(nsCString& aLocation) { + nsresult rv = EnsureURI(); + NS_ENSURE_SUCCESS(rv, rv); + return mURI->GetSpec(aLocation); + } + + private: + const nsACString& mLocation; + nsCOMPtr<nsIIOService> mIOService; + nsCOMPtr<nsIURI> mURI; + nsCOMPtr<nsIChannel> mScriptChannel; + nsCOMPtr<nsIURI> mResolvedURI; +}; + +template <typename... Args> +static nsresult ReportOnCallerUTF8(JSCLContextHelper& helper, + const char* format, + ComponentLoaderInfo& info, Args... args) { + nsCString location; + MOZ_TRY(info.GetLocation(location)); + + UniqueChars buf = JS_smprintf(format, location.get(), args...); + if (!buf) { + return NS_ERROR_OUT_OF_MEMORY; + } + + helper.reportErrorAfterPop(std::move(buf)); + return NS_ERROR_FAILURE; +} + +#undef BEGIN_ENSURE +#undef ENSURE_DEPS +#undef ENSURE_DEP + +mozJSComponentLoader::~mozJSComponentLoader() { + MOZ_ASSERT(!mInitialized, + "UnloadModules() was not explicitly called before cleaning up " + "mozJSComponentLoader"); + + if (mInitialized) { + UnloadModules(); + } + + sSelf = nullptr; +} + +StaticRefPtr<mozJSComponentLoader> mozJSComponentLoader::sSelf; + +// For terrible compatibility reasons, we need to consider both the global +// lexical environment and the global of modules when searching for exported +// symbols. +static JSObject* ResolveModuleObjectProperty(JSContext* aCx, + HandleObject aModObj, + const char* name) { + if (JS_HasExtensibleLexicalEnvironment(aModObj)) { + RootedObject lexical(aCx, JS_ExtensibleLexicalEnvironment(aModObj)); + bool found; + if (!JS_HasOwnProperty(aCx, lexical, name, &found)) { + return nullptr; + } + if (found) { + return lexical; + } + } + return aModObj; +} + +static mozilla::Result<nsCString, nsresult> ReadScript( + ComponentLoaderInfo& aInfo); + +static nsresult AnnotateScriptContents(CrashReporter::Annotation aName, + const nsACString& aURI) { + ComponentLoaderInfo info(aURI); + + nsCString str; + MOZ_TRY_VAR(str, ReadScript(info)); + + // The crash reporter won't accept any strings with embedded nuls. We + // shouldn't have any here, but if we do because of data corruption, we + // still want the annotation. So replace any embedded nuls before + // annotating. + str.ReplaceSubstring("\0"_ns, "\\0"_ns); + + CrashReporter::AnnotateCrashReport(aName, str); + + return NS_OK; +} + +nsresult mozJSComponentLoader::AnnotateCrashReport() { + Unused << AnnotateScriptContents( + CrashReporter::Annotation::nsAsyncShutdownComponent, + "resource://gre/components/nsAsyncShutdown.js"_ns); + + Unused << AnnotateScriptContents( + CrashReporter::Annotation::AsyncShutdownModule, + "resource://gre/modules/AsyncShutdown.jsm"_ns); + + return NS_OK; +} + +const mozilla::Module* mozJSComponentLoader::LoadModule(FileLocation& aFile) { + if (!NS_IsMainThread()) { + MOZ_ASSERT(false, "Don't use JS components off the main thread"); + return nullptr; + } + + nsCOMPtr<nsIFile> file = aFile.GetBaseFile(); + + nsCString spec; + aFile.GetURIString(spec); + ComponentLoaderInfo info(spec); + nsresult rv = info.EnsureURI(); + NS_ENSURE_SUCCESS(rv, nullptr); + + mInitialized = true; + + AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING("mozJSComponentLoader::LoadModule", + OTHER, spec); + AUTO_PROFILER_MARKER_TEXT("JS XPCOM", JS, MarkerStack::Capture(), spec); + + ModuleEntry* mod; + if (mModules.Get(spec, &mod)) { + return mod; + } + + dom::AutoJSAPI jsapi; + jsapi.Init(); + JSContext* cx = jsapi.cx(); + + bool isCriticalModule = StringEndsWith(spec, "/nsAsyncShutdown.js"_ns); + + auto entry = MakeUnique<ModuleEntry>(RootingContext::get(cx)); + RootedValue exn(cx); + rv = ObjectForLocation(info, file, &entry->obj, &entry->thisObjectKey, + &entry->location, isCriticalModule, &exn); + if (NS_FAILED(rv)) { + // Temporary debugging assertion for bug 1403348: + if (isCriticalModule && !exn.isUndefined()) { + AnnotateCrashReport(); + + JSAutoRealm ar(cx, xpc::PrivilegedJunkScope()); + JS_WrapValue(cx, &exn); + + nsAutoCString file; + uint32_t line; + uint32_t column; + nsAutoString msg; + nsContentUtils::ExtractErrorValues(cx, exn, file, &line, &column, msg); + + NS_ConvertUTF16toUTF8 cMsg(msg); + MOZ_CRASH_UNSAFE_PRINTF( + "Failed to load module \"%s\": " + "[\"%s\" {file: \"%s\", line: %u}]", + spec.get(), cMsg.get(), file.get(), line); + } + return nullptr; + } + + nsCOMPtr<nsIComponentManager> cm; + rv = NS_GetComponentManager(getter_AddRefs(cm)); + if (NS_FAILED(rv)) { + return nullptr; + } + + JSAutoRealm ar(cx, entry->obj); + RootedObject entryObj(cx, entry->obj); + + RootedObject NSGetFactoryHolder( + cx, ResolveModuleObjectProperty(cx, entryObj, "NSGetFactory")); + RootedValue NSGetFactory_val(cx); + if (!NSGetFactoryHolder || + !JS_GetProperty(cx, NSGetFactoryHolder, "NSGetFactory", + &NSGetFactory_val) || + NSGetFactory_val.isUndefined()) { + return nullptr; + } + + if (JS_TypeOfValue(cx, NSGetFactory_val) != JSTYPE_FUNCTION) { + /* + * spec's encoding is ASCII unless it's zip file, otherwise it's + * random encoding. Latin1 variant is safe for random encoding. + */ + JS_ReportErrorLatin1( + cx, "%s has NSGetFactory property that is not a function", spec.get()); + return nullptr; + } + + RootedObject jsGetFactoryObj(cx); + if (!JS_ValueToObject(cx, NSGetFactory_val, &jsGetFactoryObj) || + !jsGetFactoryObj) { + /* XXX report error properly */ + return nullptr; + } + + rv = nsXPConnect::XPConnect()->WrapJS(cx, jsGetFactoryObj, + NS_GET_IID(xpcIJSGetFactory), + getter_AddRefs(entry->getfactoryobj)); + if (NS_FAILED(rv)) { + /* XXX report error properly */ +#ifdef DEBUG + fprintf(stderr, "mJCL: couldn't get nsIModule from jsval\n"); +#endif + return nullptr; + } + +#if defined(NIGHTLY_BUILD) || defined(DEBUG) + if (Preferences::GetBool("browser.startup.record", false)) { + entry->importStack = xpc_PrintJSStack(cx, false, false, false).get(); + } +#endif + + // Cache this module for later + mModules.Put(spec, entry.get()); + + // The hash owns the ModuleEntry now, forget about it + return entry.release(); +} + +void mozJSComponentLoader::FindTargetObject(JSContext* aCx, + MutableHandleObject aTargetObject) { + aTargetObject.set(JS::GetJSMEnvironmentOfScriptedCaller(aCx)); + + // The above could fail if the scripted caller is not a component/JSM (it + // could be a DOM scope, for instance). + // + // If the target object was not in the JSM shared global, return the global + // instead. This is needed when calling the subscript loader within a frame + // script, since it the FrameScript NSVO will have been found. + if (!aTargetObject || + !IsLoaderGlobal(JS::GetNonCCWObjectGlobal(aTargetObject))) { + aTargetObject.set(JS::GetScriptedCallerGlobal(aCx)); + + // Return nullptr if the scripted caller is in a different compartment. + if (JS::GetCompartment(aTargetObject) != js::GetContextCompartment(aCx)) { + aTargetObject.set(nullptr); + } + } +} + +void mozJSComponentLoader::InitStatics() { + MOZ_ASSERT(!sSelf); + sSelf = new mozJSComponentLoader(); +} + +void mozJSComponentLoader::Unload() { + if (sSelf) { + sSelf->UnloadModules(); + } +} + +void mozJSComponentLoader::Shutdown() { + MOZ_ASSERT(sSelf); + sSelf = nullptr; +} + +// This requires that the keys be strings and the values be pointers. +template <class Key, class Data, class UserData, class Converter> +static size_t SizeOfTableExcludingThis( + const nsBaseHashtable<Key, Data, UserData, Converter>& aTable, + MallocSizeOf aMallocSizeOf) { + size_t n = aTable.ShallowSizeOfExcludingThis(aMallocSizeOf); + for (auto iter = aTable.ConstIter(); !iter.Done(); iter.Next()) { + n += iter.Key().SizeOfExcludingThisIfUnshared(aMallocSizeOf); + n += iter.Data()->SizeOfIncludingThis(aMallocSizeOf); + } + return n; +} + +size_t mozJSComponentLoader::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) { + size_t n = aMallocSizeOf(this); + n += SizeOfTableExcludingThis(mModules, aMallocSizeOf); + n += SizeOfTableExcludingThis(mImports, aMallocSizeOf); + n += mLocations.ShallowSizeOfExcludingThis(aMallocSizeOf); + n += SizeOfTableExcludingThis(mInProgressImports, aMallocSizeOf); + return n; +} + +void mozJSComponentLoader::CreateLoaderGlobal(JSContext* aCx, + const nsACString& aLocation, + MutableHandleObject aGlobal) { + auto backstagePass = MakeRefPtr<BackstagePass>(); + RealmOptions options; + + options.creationOptions().setNewCompartmentInSystemZone(); + xpc::SetPrefableRealmOptions(options); + + // Defer firing OnNewGlobalObject until after the __URI__ property has + // been defined so the JS debugger can tell what module the global is + // for + RootedObject global(aCx); + nsresult rv = xpc::InitClassesWithNewWrappedGlobal( + aCx, static_cast<nsIGlobalObject*>(backstagePass), + nsContentUtils::GetSystemPrincipal(), xpc::DONT_FIRE_ONNEWGLOBALHOOK, + options, &global); + NS_ENSURE_SUCCESS_VOID(rv); + + NS_ENSURE_TRUE_VOID(global); + + backstagePass->SetGlobalObject(global); + + JSAutoRealm ar(aCx, global); + if (!JS_DefineFunctions(aCx, global, gGlobalFun)) { + return; + } + + // Set the location information for the new global, so that tools like + // about:memory may use that information + xpc::SetLocationForGlobal(global, aLocation); + + aGlobal.set(global); +} + +JSObject* mozJSComponentLoader::GetSharedGlobal(JSContext* aCx) { + if (!mLoaderGlobal) { + JS::RootedObject globalObj(aCx); + CreateLoaderGlobal(aCx, "shared JSM global"_ns, &globalObj); + + // If we fail to create a module global this early, we're not going to + // get very far, so just bail out now. + MOZ_RELEASE_ASSERT(globalObj); + mLoaderGlobal = globalObj; + + // AutoEntryScript required to invoke debugger hook, which is a + // Gecko-specific concept at present. + dom::AutoEntryScript aes(globalObj, "component loader report global"); + JS_FireOnNewGlobalObject(aes.cx(), globalObj); + } + + return mLoaderGlobal; +} + +JSObject* mozJSComponentLoader::PrepareObjectForLocation( + JSContext* aCx, nsIFile* aComponentFile, nsIURI* aURI, bool* aRealFile) { + nsAutoCString nativePath; + NS_ENSURE_SUCCESS(aURI->GetSpec(nativePath), nullptr); + + RootedObject globalObj(aCx, GetSharedGlobal(aCx)); + + // |thisObj| is the object we set properties on for a particular .jsm. + RootedObject thisObj(aCx, globalObj); + NS_ENSURE_TRUE(thisObj, nullptr); + + JSAutoRealm ar(aCx, thisObj); + + thisObj = JS::NewJSMEnvironment(aCx); + NS_ENSURE_TRUE(thisObj, nullptr); + + *aRealFile = false; + + // need to be extra careful checking for URIs pointing to files + // EnsureFile may not always get called, especially on resource URIs + // so we need to call GetFile to make sure this is a valid file + { + // Create an extra scope so that ~nsCOMPtr will run before the returned + // JSObject* is placed on the stack, since otherwise a GC in the destructor + // would invalidate the return value. + nsresult rv = NS_OK; + nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv); + nsCOMPtr<nsIFile> testFile; + if (NS_SUCCEEDED(rv)) { + fileURL->GetFile(getter_AddRefs(testFile)); + } + + if (testFile) { + *aRealFile = true; + + if (XRE_IsParentProcess()) { + RootedObject locationObj(aCx); + + rv = nsXPConnect::XPConnect()->WrapNative(aCx, thisObj, aComponentFile, + NS_GET_IID(nsIFile), + locationObj.address()); + NS_ENSURE_SUCCESS(rv, nullptr); + NS_ENSURE_TRUE(locationObj, nullptr); + + if (!JS_DefineProperty(aCx, thisObj, "__LOCATION__", locationObj, 0)) { + return nullptr; + } + } + } + } + + // Expose the URI from which the script was imported through a special + // variable that we insert into the JSM. + RootedString exposedUri( + aCx, JS_NewStringCopyN(aCx, nativePath.get(), nativePath.Length())); + NS_ENSURE_TRUE(exposedUri, nullptr); + + if (!JS_DefineProperty(aCx, thisObj, "__URI__", exposedUri, 0)) { + return nullptr; + } + + return thisObj; +} + +static mozilla::Result<nsCString, nsresult> ReadScript( + ComponentLoaderInfo& aInfo) { + MOZ_TRY(aInfo.EnsureScriptChannel()); + + nsCOMPtr<nsIInputStream> scriptStream; + MOZ_TRY(NS_MaybeOpenChannelUsingOpen(aInfo.ScriptChannel(), + getter_AddRefs(scriptStream))); + + uint64_t len64; + uint32_t bytesRead; + + MOZ_TRY(scriptStream->Available(&len64)); + NS_ENSURE_TRUE(len64 < UINT32_MAX, Err(NS_ERROR_FILE_TOO_BIG)); + NS_ENSURE_TRUE(len64, Err(NS_ERROR_FAILURE)); + uint32_t len = (uint32_t)len64; + + /* malloc an internal buf the size of the file */ + nsCString str; + if (!str.SetLength(len, fallible)) { + return Err(NS_ERROR_OUT_OF_MEMORY); + } + + /* read the file in one swoop */ + MOZ_TRY(scriptStream->Read(str.BeginWriting(), len, &bytesRead)); + if (bytesRead != len) { + return Err(NS_BASE_STREAM_OSERROR); + } + + return std::move(str); +} + +nsresult mozJSComponentLoader::ObjectForLocation( + ComponentLoaderInfo& aInfo, nsIFile* aComponentFile, + MutableHandleObject aObject, MutableHandleScript aTableScript, + char** aLocation, bool aPropagateExceptions, + MutableHandleValue aException) { + MOZ_ASSERT(NS_IsMainThread(), "Must be on main thread."); + + dom::AutoJSAPI jsapi; + jsapi.Init(); + JSContext* cx = jsapi.cx(); + + bool realFile = false; + nsresult rv = aInfo.EnsureURI(); + NS_ENSURE_SUCCESS(rv, rv); + RootedObject obj( + cx, PrepareObjectForLocation(cx, aComponentFile, aInfo.URI(), &realFile)); + NS_ENSURE_TRUE(obj, NS_ERROR_FAILURE); + MOZ_ASSERT(!JS_IsGlobalObject(obj)); + + JSAutoRealm ar(cx, obj); + + RootedScript script(cx); + + nsAutoCString nativePath; + rv = aInfo.URI()->GetSpec(nativePath); + NS_ENSURE_SUCCESS(rv, rv); + + // Before compiling the script, first check to see if we have it in + // the startupcache. Note: as a rule, startupcache errors are not fatal + // to loading the script, since we can always slow-load. + + bool writeToCache = false; + StartupCache* cache = StartupCache::GetSingleton(); + + aInfo.EnsureResolvedURI(); + + nsAutoCString cachePath(JS_CACHE_PREFIX("non-syntactic")); + rv = PathifyURI(aInfo.ResolvedURI(), cachePath); + NS_ENSURE_SUCCESS(rv, rv); + + CompileOptions options(cx); + ScriptPreloader::FillCompileOptionsForCachedScript(options); + options.setForceStrictMode() + .setFileAndLine(nativePath.get(), 1) + .setSourceIsLazy(true) + .setNonSyntacticScope(true); + + script = + ScriptPreloader::GetSingleton().GetCachedScript(cx, options, cachePath); + if (!script && cache) { + ReadCachedScript(cache, cachePath, cx, options, &script); + } + + if (script) { + LOG(("Successfully loaded %s from startupcache\n", nativePath.get())); + } else if (cache) { + // This is ok, it just means the script is not yet in the + // cache. Could mean that the cache was corrupted and got removed, + // but either way we're going to write this out. + writeToCache = true; + // ReadCachedScript may have set a pending exception. + JS_ClearPendingException(cx); + } + + if (!script) { + // The script wasn't in the cache , so compile it now. + LOG(("Slow loading %s\n", nativePath.get())); + + // If we can no longer write to caches, we should stop using lazy sources + // and instead let normal syntax parsing occur. This can occur in content + // processes after the ScriptPreloader is flushed where we can read but no + // longer write. + if (!cache && !ScriptPreloader::GetSingleton().Active()) { + options.setSourceIsLazy(false); + } + + if (realFile) { + AutoMemMap map; + MOZ_TRY(map.init(aComponentFile)); + + // Note: exceptions will get handled further down; + // don't early return for them here. + auto buf = map.get<char>(); + + JS::SourceText<mozilla::Utf8Unit> srcBuf; + if (srcBuf.init(cx, buf.get(), map.size(), + JS::SourceOwnership::Borrowed)) { + script = Compile(cx, options, srcBuf); + } else { + MOZ_ASSERT(!script); + } + } else { + nsCString str; + MOZ_TRY_VAR(str, ReadScript(aInfo)); + + JS::SourceText<mozilla::Utf8Unit> srcBuf; + if (srcBuf.init(cx, str.get(), str.Length(), + JS::SourceOwnership::Borrowed)) { + script = Compile(cx, options, srcBuf); + } else { + MOZ_ASSERT(!script); + } + } + // Propagate the exception, if one exists. Also, don't leave the stale + // exception on this context. + if (!script && aPropagateExceptions && jsapi.HasException()) { + if (!jsapi.StealException(aException)) { + return NS_ERROR_OUT_OF_MEMORY; + } + } + } + + if (!script) { + return NS_ERROR_FAILURE; + } + + MOZ_ASSERT_IF(ScriptPreloader::GetSingleton().Active(), options.sourceIsLazy); + ScriptPreloader::GetSingleton().NoteScript(nativePath, cachePath, script); + + if (writeToCache) { + MOZ_ASSERT(options.sourceIsLazy); + + // We successfully compiled the script, so cache it. + rv = WriteCachedScript(cache, cachePath, cx, script); + + // Don't treat failure to write as fatal, since we might be working + // with a read-only cache. + if (NS_SUCCEEDED(rv)) { + LOG(("Successfully wrote to cache\n")); + } else { + LOG(("Failed to write to cache\n")); + } + } + + // Assign aObject here so that it's available to recursive imports. + // See bug 384168. + aObject.set(obj); + + aTableScript.set(script); + + { // Scope for AutoEntryScript + AutoAllowLegacyScriptExecution exemption; + + // We're going to run script via JS_ExecuteScript, so we need an + // AutoEntryScript. This is Gecko-specific and not in any spec. + dom::AutoEntryScript aes(CurrentGlobalOrNull(cx), + "component loader load module"); + JSContext* aescx = aes.cx(); + + bool executeOk = false; + if (JS_IsGlobalObject(obj)) { + JS::RootedValue rval(cx); + executeOk = JS::CloneAndExecuteScript(aescx, script, &rval); + } else { + executeOk = JS::ExecuteInJSMEnvironment(aescx, script, obj); + } + + if (!executeOk) { + if (aPropagateExceptions && aes.HasException()) { + // Ignore return value because we're returning an error code + // anyway. + Unused << aes.StealException(aException); + } + aObject.set(nullptr); + aTableScript.set(nullptr); + return NS_ERROR_FAILURE; + } + } + + /* Freed when we remove from the table. */ + *aLocation = ToNewCString(nativePath, mozilla::fallible); + if (!*aLocation) { + aObject.set(nullptr); + aTableScript.set(nullptr); + return NS_ERROR_OUT_OF_MEMORY; + } + + return NS_OK; +} + +void mozJSComponentLoader::UnloadModules() { + mInitialized = false; + + if (mLoaderGlobal) { + MOZ_ASSERT(JS_HasExtensibleLexicalEnvironment(mLoaderGlobal)); + JS::RootedObject lexicalEnv(dom::RootingCx(), + JS_ExtensibleLexicalEnvironment(mLoaderGlobal)); + JS_SetAllNonReservedSlotsToUndefined(lexicalEnv); + JS_SetAllNonReservedSlotsToUndefined(mLoaderGlobal); + mLoaderGlobal = nullptr; + } + + mInProgressImports.Clear(); + mImports.Clear(); + mLocations.Clear(); + + for (auto iter = mModules.Iter(); !iter.Done(); iter.Next()) { + iter.Data()->Clear(); + iter.Remove(); + } +} + +nsresult mozJSComponentLoader::ImportInto(const nsACString& registryLocation, + HandleValue targetValArg, + JSContext* cx, uint8_t optionalArgc, + MutableHandleValue retval) { + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + + RootedValue targetVal(cx, targetValArg); + RootedObject targetObject(cx, nullptr); + + if (optionalArgc) { + // The caller passed in the optional second argument. Get it. + if (targetVal.isObject()) { + // If we're passing in something like a content DOM window, chances + // are the caller expects the properties to end up on the object + // proper and not on the Xray holder. This is dubious, but can be used + // during testing. Given that dumb callers can already leak JSMs into + // content by passing a raw content JS object (where Xrays aren't + // possible), we aim for consistency here. Waive xray. + if (WrapperFactory::IsXrayWrapper(&targetVal.toObject()) && + !WrapperFactory::WaiveXrayAndWrap(cx, &targetVal)) { + return NS_ERROR_FAILURE; + } + targetObject = &targetVal.toObject(); + } else if (!targetVal.isNull()) { + // If targetVal isNull(), we actually want to leave targetObject null. + // Not doing so breaks |make package|. + return ReportOnCallerUTF8(cx, ERROR_SCOPE_OBJ, + PromiseFlatCString(registryLocation).get()); + } + } else { + FindTargetObject(cx, &targetObject); + if (!targetObject) { + return ReportOnCallerUTF8(cx, ERROR_NO_TARGET_OBJECT, + PromiseFlatCString(registryLocation).get()); + } + } + + js::AssertSameCompartment(cx, targetObject); + + RootedObject global(cx); + nsresult rv = ImportInto(registryLocation, targetObject, cx, &global); + + if (global) { + if (!JS_WrapObject(cx, &global)) { + NS_ERROR("can't wrap return value"); + return NS_ERROR_FAILURE; + } + + retval.setObject(*global); + } + return rv; +} + +nsresult mozJSComponentLoader::IsModuleLoaded(const nsACString& aLocation, + bool* retval) { + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + + mInitialized = true; + ComponentLoaderInfo info(aLocation); + *retval = !!mImports.Get(info.Key()); + return NS_OK; +} + +void mozJSComponentLoader::GetLoadedModules( + nsTArray<nsCString>& aLoadedModules) { + aLoadedModules.SetCapacity(mImports.Count()); + for (auto iter = mImports.Iter(); !iter.Done(); iter.Next()) { + aLoadedModules.AppendElement(iter.Data()->location); + } +} + +void mozJSComponentLoader::GetLoadedComponents( + nsTArray<nsCString>& aLoadedComponents) { + aLoadedComponents.SetCapacity(mModules.Count()); + for (auto iter = mModules.Iter(); !iter.Done(); iter.Next()) { + aLoadedComponents.AppendElement(iter.Data()->location); + } +} + +nsresult mozJSComponentLoader::GetModuleImportStack(const nsACString& aLocation, + nsACString& retval) { +#ifdef STARTUP_RECORDER_ENABLED + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + MOZ_ASSERT(mInitialized); + + ComponentLoaderInfo info(aLocation); + + ModuleEntry* mod; + if (!mImports.Get(info.Key(), &mod)) { + return NS_ERROR_FAILURE; + } + + retval = mod->importStack; + return NS_OK; +#else + return NS_ERROR_NOT_IMPLEMENTED; +#endif +} + +nsresult mozJSComponentLoader::GetComponentLoadStack( + const nsACString& aLocation, nsACString& retval) { +#ifdef STARTUP_RECORDER_ENABLED + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + MOZ_ASSERT(mInitialized); + + ComponentLoaderInfo info(aLocation); + nsresult rv = info.EnsureURI(); + NS_ENSURE_SUCCESS(rv, rv); + + ModuleEntry* mod; + if (!mModules.Get(info.Key(), &mod)) { + return NS_ERROR_FAILURE; + } + + retval = mod->importStack; + return NS_OK; +#else + return NS_ERROR_NOT_IMPLEMENTED; +#endif +} + +static JSObject* ResolveModuleObjectPropertyById(JSContext* aCx, + HandleObject aModObj, + HandleId id) { + if (JS_HasExtensibleLexicalEnvironment(aModObj)) { + RootedObject lexical(aCx, JS_ExtensibleLexicalEnvironment(aModObj)); + bool found; + if (!JS_HasOwnPropertyById(aCx, lexical, id, &found)) { + return nullptr; + } + if (found) { + return lexical; + } + } + return aModObj; +} + +nsresult mozJSComponentLoader::ImportInto(const nsACString& aLocation, + HandleObject targetObj, JSContext* cx, + MutableHandleObject vp) { + vp.set(nullptr); + + JS::RootedObject exports(cx); + MOZ_TRY(Import(cx, aLocation, vp, &exports, !targetObj)); + + if (targetObj) { + JS::Rooted<JS::IdVector> ids(cx, JS::IdVector(cx)); + if (!JS_Enumerate(cx, exports, &ids)) { + return NS_ERROR_OUT_OF_MEMORY; + } + + JS::RootedValue value(cx); + JS::RootedId id(cx); + for (jsid idVal : ids) { + id = idVal; + if (!JS_GetPropertyById(cx, exports, id, &value) || + !JS_SetPropertyById(cx, targetObj, id, value)) { + return NS_ERROR_FAILURE; + } + } + } + + return NS_OK; +} + +nsresult mozJSComponentLoader::ExtractExports( + JSContext* aCx, ComponentLoaderInfo& aInfo, ModuleEntry* aMod, + JS::MutableHandleObject aExports) { + // cxhelper must be created before jsapi, so that jsapi is destroyed and + // pops any context it has pushed before we report to the caller context. + JSCLContextHelper cxhelper(aCx); + + // Even though we are calling JS_SetPropertyById on targetObj, we want + // to ensure that we never run script here, so we use an AutoJSAPI and + // not an AutoEntryScript. + dom::AutoJSAPI jsapi; + jsapi.Init(); + JSContext* cx = jsapi.cx(); + JSAutoRealm ar(cx, aMod->obj); + + RootedValue symbols(cx); + { + RootedObject obj( + cx, ResolveModuleObjectProperty(cx, aMod->obj, "EXPORTED_SYMBOLS")); + if (!obj || !JS_GetProperty(cx, obj, "EXPORTED_SYMBOLS", &symbols)) { + return ReportOnCallerUTF8(cxhelper, ERROR_NOT_PRESENT, aInfo); + } + } + + bool isArray; + if (!JS::IsArrayObject(cx, symbols, &isArray)) { + return NS_ERROR_FAILURE; + } + if (!isArray) { + return ReportOnCallerUTF8(cxhelper, ERROR_NOT_AN_ARRAY, aInfo); + } + + RootedObject symbolsObj(cx, &symbols.toObject()); + + // Iterate over symbols array, installing symbols on targetObj: + + uint32_t symbolCount = 0; + if (!JS::GetArrayLength(cx, symbolsObj, &symbolCount)) { + return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_ARRAY_LENGTH, aInfo); + } + +#ifdef DEBUG + nsAutoCString logBuffer; +#endif + + aExports.set(JS_NewPlainObject(cx)); + if (!aExports) { + return NS_ERROR_OUT_OF_MEMORY; + } + + bool missing = false; + + RootedValue value(cx); + RootedId symbolId(cx); + RootedObject symbolHolder(cx); + for (uint32_t i = 0; i < symbolCount; ++i) { + if (!JS_GetElement(cx, symbolsObj, i, &value) || !value.isString() || + !JS_ValueToId(cx, value, &symbolId)) { + return ReportOnCallerUTF8(cxhelper, ERROR_ARRAY_ELEMENT, aInfo, i); + } + + symbolHolder = ResolveModuleObjectPropertyById(cx, aMod->obj, symbolId); + if (!symbolHolder || + !JS_GetPropertyById(cx, symbolHolder, symbolId, &value)) { + RootedString symbolStr(cx, JSID_TO_STRING(symbolId)); + JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr); + if (!bytes) { + return NS_ERROR_FAILURE; + } + return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_SYMBOL, aInfo, + bytes.get()); + } + + // It's possible |value| is the uninitialized lexical MagicValue when + // there's a cyclic import: const obj = ChromeUtils.import("parent.jsm"). + if (value.isMagic(JS_UNINITIALIZED_LEXICAL)) { + RootedString symbolStr(cx, JSID_TO_STRING(symbolId)); + JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr); + if (!bytes) { + return NS_ERROR_FAILURE; + } + return ReportOnCallerUTF8(cxhelper, ERROR_UNINITIALIZED_SYMBOL, aInfo, + bytes.get()); + } + + if (value.isUndefined()) { + missing = true; + } + + if (!JS_SetPropertyById(cx, aExports, symbolId, value)) { + RootedString symbolStr(cx, JSID_TO_STRING(symbolId)); + JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr); + if (!bytes) { + return NS_ERROR_FAILURE; + } + return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_SYMBOL, aInfo, + bytes.get()); + } +#ifdef DEBUG + if (i == 0) { + logBuffer.AssignLiteral("Installing symbols [ "); + } + JS::UniqueChars bytes = + JS_EncodeStringToLatin1(cx, JSID_TO_STRING(symbolId)); + if (!!bytes) { + logBuffer.Append(bytes.get()); + } + logBuffer.Append(' '); + if (i == symbolCount - 1) { + nsCString location; + MOZ_TRY(aInfo.GetLocation(location)); + LOG(("%s] from %s\n", logBuffer.get(), location.get())); + } +#endif + } + + // Don't cache the exports object if any of its exported symbols are + // missing. If the module hasn't finished loading yet, they may be + // defined the next time we try to import it. + if (!missing) { + aMod->exports = aExports; + } + return NS_OK; +} + +nsresult mozJSComponentLoader::Import(JSContext* aCx, + const nsACString& aLocation, + JS::MutableHandleObject aModuleGlobal, + JS::MutableHandleObject aModuleExports, + bool aIgnoreExports) { + mInitialized = true; + + AUTO_PROFILER_MARKER_TEXT("ChromeUtils.import", JS, MarkerStack::Capture(), + aLocation); + + ComponentLoaderInfo info(aLocation); + + nsresult rv; + ModuleEntry* mod; + UniquePtr<ModuleEntry> newEntry; + if (!mImports.Get(info.Key(), &mod) && + !mInProgressImports.Get(info.Key(), &mod)) { + // We're trying to import a new JSM, but we're late in shutdown and this + // will likely not succeed and might even crash, so fail here. + if (PastShutdownPhase(ShutdownPhase::ShutdownFinal)) { + return NS_ERROR_ILLEGAL_DURING_SHUTDOWN; + } + + newEntry = MakeUnique<ModuleEntry>(RootingContext::get(aCx)); + + // Note: This implies EnsureURI(). + MOZ_TRY(info.EnsureResolvedURI()); + + // get the JAR if there is one + nsCOMPtr<nsIJARURI> jarURI; + jarURI = do_QueryInterface(info.ResolvedURI(), &rv); + nsCOMPtr<nsIFileURL> baseFileURL; + if (NS_SUCCEEDED(rv)) { + nsCOMPtr<nsIURI> baseURI; + while (jarURI) { + jarURI->GetJARFile(getter_AddRefs(baseURI)); + jarURI = do_QueryInterface(baseURI, &rv); + } + baseFileURL = do_QueryInterface(baseURI, &rv); + NS_ENSURE_SUCCESS(rv, rv); + } else { + baseFileURL = do_QueryInterface(info.ResolvedURI(), &rv); + NS_ENSURE_SUCCESS(rv, rv); + } + + nsCOMPtr<nsIFile> sourceFile; + rv = baseFileURL->GetFile(getter_AddRefs(sourceFile)); + NS_ENSURE_SUCCESS(rv, rv); + + rv = info.ResolvedURI()->GetSpec(newEntry->resolvedURL); + NS_ENSURE_SUCCESS(rv, rv); + + nsCString* existingPath; + if (mLocations.Get(newEntry->resolvedURL, &existingPath) && + *existingPath != info.Key()) { + return NS_ERROR_UNEXPECTED; + } + + mLocations.Put(newEntry->resolvedURL, new nsCString(info.Key())); + + RootedValue exception(aCx); + { + mInProgressImports.Put(info.Key(), newEntry.get()); + auto cleanup = + MakeScopeExit([&]() { mInProgressImports.Remove(info.Key()); }); + + rv = ObjectForLocation(info, sourceFile, &newEntry->obj, + &newEntry->thisObjectKey, &newEntry->location, + true, &exception); + } + + if (NS_FAILED(rv)) { + if (!exception.isUndefined()) { + // An exception was thrown during compilation. Propagate it + // out to our caller so they can report it. + if (!JS_WrapValue(aCx, &exception)) { + return NS_ERROR_OUT_OF_MEMORY; + } + JS_SetPendingException(aCx, exception); + return NS_ERROR_FAILURE; + } + + // Something failed, but we don't know what it is, guess. + return NS_ERROR_FILE_NOT_FOUND; + } + +#ifdef STARTUP_RECORDER_ENABLED + if (Preferences::GetBool("browser.startup.record", false)) { + newEntry->importStack = xpc_PrintJSStack(aCx, false, false, false).get(); + } +#endif + + mod = newEntry.get(); + } + + MOZ_ASSERT(mod->obj, "Import table contains entry with no object"); + aModuleGlobal.set(mod->obj); + + JS::RootedObject exports(aCx, mod->exports); + if (!exports && !aIgnoreExports) { + MOZ_TRY(ExtractExports(aCx, info, mod, &exports)); + } + + if (exports && !JS_WrapObject(aCx, &exports)) { + return NS_ERROR_FAILURE; + } + aModuleExports.set(exports); + + // Cache this module for later + if (newEntry) { + mImports.Put(info.Key(), newEntry.release()); + } + + return NS_OK; +} + +nsresult mozJSComponentLoader::Unload(const nsACString& aLocation) { + if (!mInitialized) { + return NS_OK; + } + + ComponentLoaderInfo info(aLocation); + + ModuleEntry* mod; + if (mImports.Get(info.Key(), &mod)) { + mLocations.Remove(mod->resolvedURL); + mImports.Remove(info.Key()); + } + + // If this is the last module to be unloaded, we will leak mLoaderGlobal + // until UnloadModules is called. So be it. + + return NS_OK; +} + +size_t mozJSComponentLoader::ModuleEntry::SizeOfIncludingThis( + MallocSizeOf aMallocSizeOf) const { + size_t n = aMallocSizeOf(this); + n += aMallocSizeOf(location); + + return n; +} + +/* static */ +already_AddRefed<nsIFactory> mozJSComponentLoader::ModuleEntry::GetFactory( + const mozilla::Module& module, const mozilla::Module::CIDEntry& entry) { + const ModuleEntry& self = static_cast<const ModuleEntry&>(module); + MOZ_ASSERT(self.getfactoryobj, "Handing out an uninitialized module?"); + + nsCOMPtr<nsIFactory> f; + nsresult rv = self.getfactoryobj->Get(*entry.cid, getter_AddRefs(f)); + if (NS_FAILED(rv)) { + return nullptr; + } + + return f.forget(); +} + +//---------------------------------------------------------------------- + +JSCLContextHelper::JSCLContextHelper(JSContext* aCx) + : mContext(aCx), mBuf(nullptr) {} + +JSCLContextHelper::~JSCLContextHelper() { + if (mBuf) { + JS_ReportErrorUTF8(mContext, "%s", mBuf.get()); + } +} + +void JSCLContextHelper::reportErrorAfterPop(UniqueChars&& buf) { + MOZ_ASSERT(!mBuf, "Already called reportErrorAfterPop"); + mBuf = std::move(buf); +} |