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tubestation/dom/base/JSExecutionContext.cpp

336 lines
9.7 KiB
C++

/* -*- 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/. */
/**
* This is not a generated file. It contains common utility functions
* invoked from the JavaScript code generated from IDL interfaces.
* The goal of the utility functions is to cut down on the size of
* the generated code itself.
*/
#include "mozilla/dom/JSExecutionContext.h"
#include <utility>
#include "ErrorList.h"
#include "MainThreadUtils.h"
#include "js/CompilationAndEvaluation.h"
#include "js/CompileOptions.h"
#include "js/Conversions.h"
#include "js/experimental/JSStencil.h"
#include "js/HeapAPI.h"
#include "js/ProfilingCategory.h"
#include "js/Promise.h"
#include "js/SourceText.h"
#include "js/Transcoding.h"
#include "js/Value.h"
#include "js/Wrapper.h"
#include "jsapi.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/dom/ScriptLoadContext.h"
#include "mozilla/Likely.h"
#include "nsContentUtils.h"
#include "nsTPromiseFlatString.h"
#include "xpcpublic.h"
#if !defined(DEBUG) && !defined(MOZ_ENABLE_JS_DUMP)
# include "mozilla/StaticPrefs_browser.h"
#endif
using namespace mozilla;
using namespace mozilla::dom;
namespace mozilla::dom {
nsresult EvaluationExceptionToNSResult(ErrorResult& aRv) {
if (aRv.IsJSContextException()) {
aRv.SuppressException();
return NS_SUCCESS_DOM_SCRIPT_EVALUATION_THREW;
}
if (aRv.IsUncatchableException()) {
aRv.SuppressException();
return NS_SUCCESS_DOM_SCRIPT_EVALUATION_THREW_UNCATCHABLE;
}
if (aRv.ErrorCodeIs(NS_ERROR_DOM_NOT_ALLOWED_ERR)) {
aRv.SuppressException();
return NS_OK;
}
// cases like NS_OK, NS_ERROR_DOM_JS_DECODING_ERROR and NS_ERROR_OUT_OF_MEMORY
return aRv.StealNSResult();
}
} // namespace mozilla::dom
JSExecutionContext::JSExecutionContext(
JSContext* aCx, JS::Handle<JSObject*> aGlobal,
JS::CompileOptions& aCompileOptions, ErrorResult& aRv,
JS::Handle<JS::Value> aDebuggerPrivateValue,
JS::Handle<JSScript*> aDebuggerIntroductionScript)
: mAutoProfilerLabel("JSExecutionContext",
/* dynamicStr */ nullptr,
JS::ProfilingCategoryPair::JS),
mCx(aCx),
mRealm(aCx, aGlobal),
mRetValue(aCx),
mScript(aCx),
mDebuggerPrivateValue(aCx, aDebuggerPrivateValue),
mDebuggerIntroductionScript(aCx, aDebuggerIntroductionScript),
mSkip(false),
mCoerceToString(false),
mEncodeBytecode(false)
#ifdef DEBUG
,
mWantsReturnValue(false),
mScriptUsed(false)
#endif
{
MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(CycleCollectedJSContext::Get() &&
CycleCollectedJSContext::Get()->MicroTaskLevel());
MOZ_ASSERT(mRetValue.isUndefined());
MOZ_ASSERT(JS_IsGlobalObject(aGlobal));
if (MOZ_UNLIKELY(!xpc::Scriptability::Get(aGlobal).Allowed())) {
mSkip = true;
aRv = NS_ERROR_DOM_NOT_ALLOWED_ERR;
}
}
void JSExecutionContext::JoinOffThread(JS::CompileOptions& aCompileOptions,
ScriptLoadContext* aContext,
ErrorResult& aRv) {
MOZ_ASSERT(!mSkip);
MOZ_ASSERT(!mWantsReturnValue);
JS::InstantiationStorage storage;
RefPtr<JS::Stencil> stencil = aContext->StealOffThreadResult(mCx, &storage);
if (!stencil) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
if (mKeepStencil) {
mStencil = JS::DuplicateStencil(mCx, stencil.get());
if (!mStencil) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
}
bool unused;
InstantiateStencil(aCompileOptions, std::move(stencil), unused, aRv,
&storage);
}
template <typename Unit>
void JSExecutionContext::InternalCompile(JS::CompileOptions& aCompileOptions,
JS::SourceText<Unit>& aSrcBuf,
ErrorResult& aRv) {
MOZ_ASSERT(!mSkip);
MOZ_ASSERT(aSrcBuf.get());
MOZ_ASSERT(mRetValue.isUndefined());
#ifdef DEBUG
mWantsReturnValue = !aCompileOptions.noScriptRval;
#endif
RefPtr<JS::Stencil> stencil =
CompileGlobalScriptToStencil(mCx, aCompileOptions, aSrcBuf);
if (!stencil) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
if (mKeepStencil) {
mStencil = JS::DuplicateStencil(mCx, stencil.get());
if (!mStencil) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
}
bool unused;
InstantiateStencil(aCompileOptions, std::move(stencil), unused, aRv);
}
void JSExecutionContext::Compile(JS::CompileOptions& aCompileOptions,
JS::SourceText<char16_t>& aSrcBuf,
ErrorResult& aRv) {
InternalCompile(aCompileOptions, aSrcBuf, aRv);
}
void JSExecutionContext::Compile(JS::CompileOptions& aCompileOptions,
JS::SourceText<Utf8Unit>& aSrcBuf,
ErrorResult& aRv) {
InternalCompile(aCompileOptions, aSrcBuf, aRv);
}
void JSExecutionContext::Compile(JS::CompileOptions& aCompileOptions,
const nsAString& aScript, ErrorResult& aRv) {
MOZ_ASSERT(!mSkip);
const nsPromiseFlatString& flatScript = PromiseFlatString(aScript);
JS::SourceText<char16_t> srcBuf;
if (!srcBuf.init(mCx, flatScript.get(), flatScript.Length(),
JS::SourceOwnership::Borrowed)) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
Compile(aCompileOptions, srcBuf, aRv);
}
void JSExecutionContext::Decode(JS::CompileOptions& aCompileOptions,
const JS::TranscodeRange& aBytecodeBuf,
ErrorResult& aRv) {
MOZ_ASSERT(!mSkip);
JS::DecodeOptions decodeOptions(aCompileOptions);
decodeOptions.borrowBuffer = true;
MOZ_ASSERT(!mWantsReturnValue);
RefPtr<JS::Stencil> stencil;
JS::TranscodeResult tr = JS::DecodeStencil(mCx, decodeOptions, aBytecodeBuf,
getter_AddRefs(stencil));
// These errors are external parameters which should be handled before the
// decoding phase, and which are the only reasons why you might want to
// fallback on decoding failures.
MOZ_ASSERT(tr != JS::TranscodeResult::Failure_BadBuildId);
if (tr != JS::TranscodeResult::Ok) {
mSkip = true;
aRv = NS_ERROR_DOM_JS_DECODING_ERROR;
return;
}
if (mKeepStencil) {
mStencil = JS::DuplicateStencil(mCx, stencil.get());
if (!mStencil) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
}
bool unused;
InstantiateStencil(aCompileOptions, std::move(stencil), unused, aRv);
}
void JSExecutionContext::InstantiateStencil(
JS::CompileOptions& aCompileOptions, RefPtr<JS::Stencil>&& aStencil,
bool& incrementalEncodingAlreadyStarted, ErrorResult& aRv,
JS::InstantiationStorage* aStorage) {
JS::InstantiateOptions instantiateOptions(aCompileOptions);
JS::Rooted<JSScript*> script(
mCx, JS::InstantiateGlobalStencil(mCx, instantiateOptions, aStencil,
aStorage));
if (!script) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
if (mEncodeBytecode) {
if (!JS::StartIncrementalEncoding(mCx, std::move(aStencil),
incrementalEncodingAlreadyStarted)) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
}
MOZ_ASSERT(!mScript);
mScript.set(script);
if (instantiateOptions.deferDebugMetadata) {
if (!JS::UpdateDebugMetadata(mCx, mScript, instantiateOptions,
mDebuggerPrivateValue, nullptr,
mDebuggerIntroductionScript, nullptr)) {
aRv = NS_ERROR_OUT_OF_MEMORY;
}
}
}
JSScript* JSExecutionContext::GetScript() {
#ifdef DEBUG
MOZ_ASSERT(!mSkip);
MOZ_ASSERT(mScript);
mScriptUsed = true;
#endif
return MaybeGetScript();
}
JSScript* JSExecutionContext::MaybeGetScript() { return mScript; }
void JSExecutionContext::ExecScript(ErrorResult& aRv) {
MOZ_ASSERT(!mSkip);
MOZ_ASSERT(mScript);
if (!JS_ExecuteScript(mCx, mScript)) {
mSkip = true;
aRv.NoteJSContextException(mCx);
}
}
static bool IsPromiseValue(JSContext* aCx, JS::Handle<JS::Value> aValue) {
if (!aValue.isObject()) {
return false;
}
// We only care about Promise here, so CheckedUnwrapStatic is fine.
JS::Rooted<JSObject*> obj(aCx, js::CheckedUnwrapStatic(&aValue.toObject()));
if (!obj) {
return false;
}
return JS::IsPromiseObject(obj);
}
void JSExecutionContext::ExecScript(JS::MutableHandle<JS::Value> aRetValue,
ErrorResult& aRv) {
MOZ_ASSERT(!mSkip);
MOZ_ASSERT(mScript);
MOZ_ASSERT(mWantsReturnValue);
if (!JS_ExecuteScript(mCx, mScript, aRetValue)) {
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
#ifdef DEBUG
mWantsReturnValue = false;
#endif
if (mCoerceToString && IsPromiseValue(mCx, aRetValue)) {
// We're a javascript: url and we should treat Promise return values as
// undefined.
//
// Once bug 1477821 is fixed this code might be able to go away, or will
// become enshrined in the spec, depending.
aRetValue.setUndefined();
}
if (mCoerceToString && !aRetValue.isUndefined()) {
JSString* str = JS::ToString(mCx, aRetValue);
if (!str) {
// ToString can be a function call, so an exception can be raised while
// executing the function.
mSkip = true;
aRv.NoteJSContextException(mCx);
return;
}
aRetValue.set(JS::StringValue(str));
}
}