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Diffstat (limited to '')
| -rw-r--r-- | js/src/debugger/Frame.cpp | 1950 |
1 files changed, 1950 insertions, 0 deletions
diff --git a/js/src/debugger/Frame.cpp b/js/src/debugger/Frame.cpp new file mode 100644 index 0000000000..1ae529be78 --- /dev/null +++ b/js/src/debugger/Frame.cpp @@ -0,0 +1,1950 @@ +/* -*- 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 "debugger/Frame-inl.h" + +#include "mozilla/Assertions.h" // for AssertionConditionType +#include "mozilla/HashTable.h" // for HashMapEntry +#include "mozilla/Maybe.h" // for Maybe +#include "mozilla/Range.h" // for Range +#include "mozilla/RangedPtr.h" // for RangedPtr +#include "mozilla/Result.h" // for Result +#include "mozilla/ScopeExit.h" // for MakeScopeExit, ScopeExit +#include "mozilla/ThreadLocal.h" // for ThreadLocal +#include "mozilla/Vector.h" // for Vector + +#include <stddef.h> // for size_t +#include <stdint.h> // for int32_t +#include <string.h> // for strlen +#include <utility> // for std::move + +#include "jsnum.h" // for Int32ToString + +#include "builtin/Array.h" // for NewDenseCopiedArray +#include "debugger/Debugger.h" // for Completion, Debugger +#include "debugger/DebugScript.h" +#include "debugger/Environment.h" // for DebuggerEnvironment +#include "debugger/NoExecute.h" // for LeaveDebuggeeNoExecute +#include "debugger/Object.h" // for DebuggerObject +#include "debugger/Script.h" // for DebuggerScript +#include "frontend/BytecodeCompilation.h" // for CompileEvalScript +#include "frontend/FrontendContext.h" // for AutoReportFrontendContext +#include "gc/Barrier.h" // for HeapPtr +#include "gc/GC.h" // for MemoryUse +#include "gc/GCContext.h" // for JS::GCContext +#include "gc/Marking.h" // for IsAboutToBeFinalized +#include "gc/Tracer.h" // for TraceCrossCompartmentEdge +#include "gc/ZoneAllocator.h" // for AddCellMemory +#include "jit/JSJitFrameIter.h" // for InlineFrameIterator +#include "jit/RematerializedFrame.h" // for RematerializedFrame +#include "js/CallArgs.h" // for CallArgs +#include "js/friend/ErrorMessages.h" // for GetErrorMessage, JSMSG_* +#include "js/Object.h" // for SetReservedSlot +#include "js/Proxy.h" // for PrivateValue +#include "js/RootingAPI.h" // for Handle +#include "js/SourceText.h" // for SourceText, SourceOwnership +#include "js/StableStringChars.h" // for AutoStableStringChars +#include "vm/ArgumentsObject.h" // for ArgumentsObject +#include "vm/ArrayObject.h" // for ArrayObject +#include "vm/AsyncFunction.h" // for AsyncFunctionGeneratorObject +#include "vm/AsyncIteration.h" // for AsyncGeneratorObject +#include "vm/BytecodeUtil.h" // for JSDVG_SEARCH_STACK +#include "vm/Compartment.h" // for Compartment +#include "vm/EnvironmentObject.h" // for IsGlobalLexicalEnvironment +#include "vm/GeneratorObject.h" // for AbstractGeneratorObject +#include "vm/GlobalObject.h" // for GlobalObject +#include "vm/Interpreter.h" // for Call, ExecuteKernel +#include "vm/JSAtom.h" // for Atomize +#include "vm/JSContext.h" // for JSContext, ReportValueError +#include "vm/JSFunction.h" // for JSFunction, NewNativeFunction +#include "vm/JSObject.h" // for JSObject, RequireObject +#include "vm/JSScript.h" // for JSScript +#include "vm/NativeObject.h" // for NativeDefineDataProperty +#include "vm/Realm.h" // for AutoRealm +#include "vm/Runtime.h" // for JSAtomState +#include "vm/Scope.h" // for PositionalFormalParameterIter +#include "vm/Stack.h" // for AbstractFramePtr, FrameIter +#include "vm/StringType.h" // for PropertyName, JSString +#include "wasm/WasmDebug.h" // for DebugState +#include "wasm/WasmDebugFrame.h" // for DebugFrame +#include "wasm/WasmInstance.h" // for Instance +#include "wasm/WasmJS.h" // for WasmInstanceObject + +#include "debugger/Debugger-inl.h" // for Debugger::fromJSObject +#include "gc/WeakMap-inl.h" // for WeakMap::remove +#include "vm/Compartment-inl.h" // for Compartment::wrap +#include "vm/JSContext-inl.h" // for JSContext::check +#include "vm/JSObject-inl.h" // for NewObjectWithGivenProto +#include "vm/NativeObject-inl.h" // for NativeObject::global +#include "vm/ObjectOperations-inl.h" // for GetProperty +#include "vm/Realm-inl.h" // for AutoRealm::AutoRealm +#include "vm/Stack-inl.h" // for AbstractFramePtr::script + +namespace js { +namespace jit { +class JitFrameLayout; +} /* namespace jit */ +} /* namespace js */ + +using namespace js; + +using JS::AutoStableStringChars; +using JS::CompileOptions; +using JS::SourceOwnership; +using JS::SourceText; +using mozilla::MakeScopeExit; +using mozilla::Maybe; + +ScriptedOnStepHandler::ScriptedOnStepHandler(JSObject* object) + : object_(object) { + MOZ_ASSERT(object_->isCallable()); +} + +JSObject* ScriptedOnStepHandler::object() const { return object_; } + +void ScriptedOnStepHandler::hold(JSObject* owner) { + AddCellMemory(owner, allocSize(), MemoryUse::DebuggerOnStepHandler); +} + +void ScriptedOnStepHandler::drop(JS::GCContext* gcx, JSObject* owner) { + gcx->delete_(owner, this, allocSize(), MemoryUse::DebuggerOnStepHandler); +} + +void ScriptedOnStepHandler::trace(JSTracer* tracer) { + TraceEdge(tracer, &object_, "OnStepHandlerFunction.object"); +} + +bool ScriptedOnStepHandler::onStep(JSContext* cx, Handle<DebuggerFrame*> frame, + ResumeMode& resumeMode, + MutableHandleValue vp) { + RootedValue fval(cx, ObjectValue(*object_)); + RootedValue rval(cx); + if (!js::Call(cx, fval, frame, &rval)) { + return false; + } + + return ParseResumptionValue(cx, rval, resumeMode, vp); +}; + +size_t ScriptedOnStepHandler::allocSize() const { return sizeof(*this); } + +ScriptedOnPopHandler::ScriptedOnPopHandler(JSObject* object) : object_(object) { + MOZ_ASSERT(object->isCallable()); +} + +JSObject* ScriptedOnPopHandler::object() const { return object_; } + +void ScriptedOnPopHandler::hold(JSObject* owner) { + AddCellMemory(owner, allocSize(), MemoryUse::DebuggerOnPopHandler); +} + +void ScriptedOnPopHandler::drop(JS::GCContext* gcx, JSObject* owner) { + gcx->delete_(owner, this, allocSize(), MemoryUse::DebuggerOnPopHandler); +} + +void ScriptedOnPopHandler::trace(JSTracer* tracer) { + TraceEdge(tracer, &object_, "OnStepHandlerFunction.object"); +} + +bool ScriptedOnPopHandler::onPop(JSContext* cx, Handle<DebuggerFrame*> frame, + const Completion& completion, + ResumeMode& resumeMode, + MutableHandleValue vp) { + Debugger* dbg = frame->owner(); + + RootedValue completionValue(cx); + if (!completion.buildCompletionValue(cx, dbg, &completionValue)) { + return false; + } + + RootedValue fval(cx, ObjectValue(*object_)); + RootedValue rval(cx); + if (!js::Call(cx, fval, frame, completionValue, &rval)) { + return false; + } + + return ParseResumptionValue(cx, rval, resumeMode, vp); +}; + +size_t ScriptedOnPopHandler::allocSize() const { return sizeof(*this); } + +js::Debugger* js::DebuggerFrame::owner() const { + JSObject* dbgobj = &getReservedSlot(OWNER_SLOT).toObject(); + return Debugger::fromJSObject(dbgobj); +} + +const JSClassOps DebuggerFrame::classOps_ = { + nullptr, // addProperty + nullptr, // delProperty + nullptr, // enumerate + nullptr, // newEnumerate + nullptr, // resolve + nullptr, // mayResolve + finalize, // finalize + nullptr, // call + nullptr, // construct + CallTraceMethod<DebuggerFrame>, // trace +}; + +const JSClass DebuggerFrame::class_ = { + "Frame", + JSCLASS_HAS_RESERVED_SLOTS(RESERVED_SLOTS) | + // We require foreground finalization so we can destruct GeneratorInfo's + // HeapPtrs. + JSCLASS_FOREGROUND_FINALIZE, + &DebuggerFrame::classOps_}; + +enum { JSSLOT_DEBUGARGUMENTS_FRAME, JSSLOT_DEBUGARGUMENTS_COUNT }; + +const JSClass DebuggerArguments::class_ = { + "Arguments", JSCLASS_HAS_RESERVED_SLOTS(JSSLOT_DEBUGARGUMENTS_COUNT)}; + +bool DebuggerFrame::resume(const FrameIter& iter) { + FrameIter::Data* data = iter.copyData(); + if (!data) { + return false; + } + setFrameIterData(data); + return true; +} + +bool DebuggerFrame::hasAnyHooks() const { + return !getReservedSlot(ONSTEP_HANDLER_SLOT).isUndefined() || + !getReservedSlot(ONPOP_HANDLER_SLOT).isUndefined(); +} + +/* static */ +NativeObject* DebuggerFrame::initClass(JSContext* cx, + Handle<GlobalObject*> global, + HandleObject dbgCtor) { + return InitClass(cx, dbgCtor, nullptr, nullptr, "Frame", construct, 0, + properties_, methods_, nullptr, nullptr); +} + +/* static */ +DebuggerFrame* DebuggerFrame::create( + JSContext* cx, HandleObject proto, Handle<NativeObject*> debugger, + const FrameIter* maybeIter, + Handle<AbstractGeneratorObject*> maybeGenerator) { + Rooted<DebuggerFrame*> frame( + cx, NewObjectWithGivenProto<DebuggerFrame>(cx, proto)); + if (!frame) { + return nullptr; + } + + frame->setReservedSlot(OWNER_SLOT, ObjectValue(*debugger)); + + if (maybeIter) { + FrameIter::Data* data = maybeIter->copyData(); + if (!data) { + return nullptr; + } + + frame->setFrameIterData(data); + } + + if (maybeGenerator) { + if (!DebuggerFrame::setGeneratorInfo(cx, frame, maybeGenerator)) { + frame->freeFrameIterData(cx->gcContext()); + return nullptr; + } + } + + return frame; +} + +/** + * Information held by a DebuggerFrame about a generator/async call. A + * Debugger.Frame's GENERATOR_INFO_SLOT, if set, holds a PrivateValue pointing + * to one of these. + * + * This is created and attached as soon as a generator object is created for a + * debuggee generator/async frame, retained across suspensions and resumptions, + * and cleared when the generator call ends permanently. + * + * It may seem like this information might belong in ordinary reserved slots on + * the DebuggerFrame object. But that isn't possible: + * + * 1) Slots cannot contain cross-compartment references directly. + * 2) Ordinary cross-compartment wrappers aren't good enough, because the + * debugger must create its own magic entries in the wrapper table for the GC + * to get zone collection groups right. + * 3) Even if we make debugger wrapper table entries by hand, hiding + * cross-compartment edges as PrivateValues doesn't call post-barriers, and + * the generational GC won't update our pointer when the generator object + * gets tenured. + * + * Yes, officer, I definitely knew all this in advance and designed it this way + * the first time. + * + * Note that it is not necessary to have a second cross-compartment wrapper + * table entry to cover the pointer to the generator's script. The wrapper table + * entries play two roles: they help the GC put a debugger zone in the same zone + * group as its debuggee, and they serve as roots when collecting the debuggee + * zone, but not the debugger zone. Since an AbstractGeneratorObject holds a + * strong reference to its callee's script (via the callee), and the AGO and the + * script are always in the same compartment, it suffices to add a + * cross-compartment wrapper table entry for the Debugger.Frame -> AGO edge. + */ +class DebuggerFrame::GeneratorInfo { + // An unwrapped cross-compartment reference to the generator object. + // + // Always an object. + // + // This cannot be GCPtr because we are not always destructed during sweeping; + // a Debugger.Frame's generator is also cleared when the generator returns + // permanently. + const HeapPtr<Value> unwrappedGenerator_; + + // A cross-compartment reference to the generator's script. + const HeapPtr<JSScript*> generatorScript_; + + public: + GeneratorInfo(Handle<AbstractGeneratorObject*> unwrappedGenerator, + HandleScript generatorScript) + : unwrappedGenerator_(ObjectValue(*unwrappedGenerator)), + generatorScript_(generatorScript) {} + + // Trace a rooted instance of this class, e.g. a Rooted<GeneratorInfo>. + void trace(JSTracer* tracer) { + TraceRoot(tracer, &unwrappedGenerator_, "Debugger.Frame generator object"); + TraceRoot(tracer, &generatorScript_, "Debugger.Frame generator script"); + } + // Trace a GeneratorInfo from a DebuggerFrame object. + void trace(JSTracer* tracer, DebuggerFrame& frameObj) { + TraceCrossCompartmentEdge(tracer, &frameObj, &unwrappedGenerator_, + "Debugger.Frame generator object"); + TraceCrossCompartmentEdge(tracer, &frameObj, &generatorScript_, + "Debugger.Frame generator script"); + } + + AbstractGeneratorObject& unwrappedGenerator() const { + return unwrappedGenerator_.toObject().as<AbstractGeneratorObject>(); + } + + JSScript* generatorScript() { return generatorScript_; } + + bool isGeneratorScriptAboutToBeFinalized() { + return IsAboutToBeFinalized(generatorScript_); + } +}; + +bool js::DebuggerFrame::isSuspended() const { + return hasGeneratorInfo() && + generatorInfo()->unwrappedGenerator().isSuspended(); +} + +js::AbstractGeneratorObject& js::DebuggerFrame::unwrappedGenerator() const { + return generatorInfo()->unwrappedGenerator(); +} + +#ifdef DEBUG +JSScript* js::DebuggerFrame::generatorScript() const { + return generatorInfo()->generatorScript(); +} +#endif + +/* static */ +bool DebuggerFrame::setGeneratorInfo(JSContext* cx, + Handle<DebuggerFrame*> frame, + Handle<AbstractGeneratorObject*> genObj) { + cx->check(frame); + + MOZ_ASSERT(!frame->hasGeneratorInfo()); + MOZ_ASSERT(!genObj->isClosed()); + + // When we initialize the generator information, we do not need to adjust + // the stepper increment, because either it was already incremented when + // the step hook was added, or we're setting this into on a new DebuggerFrame + // that has not yet had the chance for a hook to be added to it. + MOZ_ASSERT_IF(frame->onStepHandler(), frame->frameIterData()); + MOZ_ASSERT_IF(!frame->frameIterData(), !frame->onStepHandler()); + + // There are two relations we must establish: + // + // 1) The DebuggerFrame must point to the AbstractGeneratorObject. + // + // 2) The generator's script's observer count must be bumped. + + RootedScript script(cx, genObj->callee().nonLazyScript()); + Rooted<UniquePtr<GeneratorInfo>> info( + cx, cx->make_unique<GeneratorInfo>(genObj, script)); + if (!info) { + return false; + } + + AutoRealm ar(cx, script); + + // All frames running a debuggee script must themselves be marked as + // debuggee frames. Bumping a script's generator observer count makes it a + // debuggee, so we need to mark all frames on the stack running it as + // debuggees as well, not just this one. This call takes care of all that. + if (!Debugger::ensureExecutionObservabilityOfScript(cx, script)) { + return false; + } + + if (!DebugScript::incrementGeneratorObserverCount(cx, script)) { + return false; + } + + InitReservedSlot(frame, GENERATOR_INFO_SLOT, info.release(), + MemoryUse::DebuggerFrameGeneratorInfo); + return true; +} + +void DebuggerFrame::terminate(JS::GCContext* gcx, AbstractFramePtr frame) { + if (frameIterData()) { + // If no frame pointer was provided to decrement the stepper counter, + // then we must be terminating a generator, otherwise the stepper count + // would have no way to synchronize properly. + MOZ_ASSERT_IF(!frame, hasGeneratorInfo()); + + freeFrameIterData(gcx); + if (frame && !hasGeneratorInfo() && onStepHandler()) { + // If we are terminating a non-generator frame that had a step handler, + // we need to decrement the counter to keep things in sync. + decrementStepperCounter(gcx, frame); + } + } + + if (!hasGeneratorInfo()) { + return; + } + + GeneratorInfo* info = generatorInfo(); + + // 3) The generator's script's observer count must be dropped. + // + // For ordinary calls, Debugger.Frame objects drop the script's stepper count + // when the frame is popped, but for generators, they leave the stepper count + // incremented across suspensions. This means that, whereas ordinary calls + // never need to drop the stepper count from the D.F finalizer, generator + // calls may. + if (!info->isGeneratorScriptAboutToBeFinalized()) { + JSScript* generatorScript = info->generatorScript(); + DebugScript::decrementGeneratorObserverCount(gcx, generatorScript); + if (onStepHandler()) { + // If we are terminating a generator frame that had a step handler, + // we need to decrement the counter to keep things in sync. + decrementStepperCounter(gcx, generatorScript); + } + } + + // 1) The DebuggerFrame must no longer point to the AbstractGeneratorObject. + setReservedSlot(GENERATOR_INFO_SLOT, UndefinedValue()); + gcx->delete_(this, info, MemoryUse::DebuggerFrameGeneratorInfo); +} + +void DebuggerFrame::suspend(JS::GCContext* gcx) { + // There must be generator info because otherwise this would be the same + // overall behavior as terminate() except that here we do not properly + // adjust stepper counts. + MOZ_ASSERT(hasGeneratorInfo()); + + freeFrameIterData(gcx); +} + +/* static */ +bool DebuggerFrame::getCallee(JSContext* cx, Handle<DebuggerFrame*> frame, + MutableHandle<DebuggerObject*> result) { + RootedObject callee(cx); + if (frame->isOnStack()) { + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + if (referent.isFunctionFrame()) { + callee = referent.callee(); + } + } else { + MOZ_ASSERT(frame->isSuspended()); + + callee = &frame->generatorInfo()->unwrappedGenerator().callee(); + } + + return frame->owner()->wrapNullableDebuggeeObject(cx, callee, result); +} + +/* static */ +bool DebuggerFrame::getIsConstructing(JSContext* cx, + Handle<DebuggerFrame*> frame, + bool& result) { + if (frame->isOnStack()) { + FrameIter iter = frame->getFrameIter(cx); + + result = iter.isFunctionFrame() && iter.isConstructing(); + } else { + MOZ_ASSERT(frame->isSuspended()); + + // Generators and async functions can't be constructed. + result = false; + } + return true; +} + +static void UpdateFrameIterPc(FrameIter& iter) { + if (iter.abstractFramePtr().isWasmDebugFrame()) { + // Wasm debug frames don't need their pc updated -- it's null. + return; + } + + if (iter.abstractFramePtr().isRematerializedFrame()) { +#ifdef DEBUG + // Rematerialized frames don't need their pc updated. The reason we + // need to update pc is because we might get the same Debugger.Frame + // object for multiple re-entries into debugger code from debuggee + // code. This reentrancy is not possible with rematerialized frames, + // because when returning to debuggee code, we would have bailed out + // to baseline. + // + // We walk the stack to assert that it doesn't need updating. + jit::RematerializedFrame* frame = + iter.abstractFramePtr().asRematerializedFrame(); + jit::JitFrameLayout* jsFrame = (jit::JitFrameLayout*)frame->top(); + jit::JitActivation* activation = iter.activation()->asJit(); + + JSContext* cx = TlsContext.get(); + MOZ_ASSERT(cx == activation->cx()); + + ActivationIterator activationIter(cx); + while (activationIter.activation() != activation) { + ++activationIter; + } + + OnlyJSJitFrameIter jitIter(activationIter); + while (!jitIter.frame().isIonJS() || jitIter.frame().jsFrame() != jsFrame) { + ++jitIter; + } + + jit::InlineFrameIterator ionInlineIter(cx, &jitIter.frame()); + while (ionInlineIter.frameNo() != frame->frameNo()) { + ++ionInlineIter; + } + + MOZ_ASSERT(ionInlineIter.pc() == iter.pc()); +#endif + return; + } + + iter.updatePcQuadratic(); +} + +/* static */ +bool DebuggerFrame::getEnvironment(JSContext* cx, Handle<DebuggerFrame*> frame, + MutableHandle<DebuggerEnvironment*> result) { + Debugger* dbg = frame->owner(); + Rooted<Env*> env(cx); + + if (frame->isOnStack()) { + FrameIter iter = frame->getFrameIter(cx); + + { + AutoRealm ar(cx, iter.abstractFramePtr().environmentChain()); + UpdateFrameIterPc(iter); + env = GetDebugEnvironmentForFrame(cx, iter.abstractFramePtr(), iter.pc()); + } + } else { + MOZ_ASSERT(frame->isSuspended()); + + AbstractGeneratorObject& genObj = + frame->generatorInfo()->unwrappedGenerator(); + JSScript* script = frame->generatorInfo()->generatorScript(); + + { + AutoRealm ar(cx, &genObj.environmentChain()); + env = GetDebugEnvironmentForSuspendedGenerator(cx, script, genObj); + } + } + + if (!env) { + return false; + } + + return dbg->wrapEnvironment(cx, env, result); +} + +/* static */ +bool DebuggerFrame::getOffset(JSContext* cx, Handle<DebuggerFrame*> frame, + size_t& result) { + if (frame->isOnStack()) { + FrameIter iter = frame->getFrameIter(cx); + + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + if (referent.isWasmDebugFrame()) { + iter.wasmUpdateBytecodeOffset(); + result = iter.wasmBytecodeOffset(); + } else { + JSScript* script = iter.script(); + UpdateFrameIterPc(iter); + jsbytecode* pc = iter.pc(); + result = script->pcToOffset(pc); + } + } else { + MOZ_ASSERT(frame->isSuspended()); + + AbstractGeneratorObject& genObj = + frame->generatorInfo()->unwrappedGenerator(); + JSScript* script = frame->generatorInfo()->generatorScript(); + result = script->resumeOffsets()[genObj.resumeIndex()]; + } + return true; +} + +/* static */ +bool DebuggerFrame::getOlder(JSContext* cx, Handle<DebuggerFrame*> frame, + MutableHandle<DebuggerFrame*> result) { + if (frame->isOnStack()) { + Debugger* dbg = frame->owner(); + FrameIter iter = frame->getFrameIter(cx); + + while (true) { + Activation& activation = *iter.activation(); + ++iter; + + // If the parent frame crosses an explicit async stack boundary, we + // treat that as an indication to stop traversing sync frames, so that + // the on-stack Debugger.Frame instances align with what you would + // see in a stringified stack trace. + if (iter.activation() != &activation && activation.asyncStack() && + activation.asyncCallIsExplicit()) { + break; + } + + // If there is no parent frame, we're done. + if (iter.done()) { + break; + } + + if (dbg->observesFrame(iter)) { + if (iter.isIon() && !iter.ensureHasRematerializedFrame(cx)) { + return false; + } + return dbg->getFrame(cx, iter, result); + } + } + } else { + MOZ_ASSERT(frame->isSuspended()); + + // If the frame is suspended, there is no older frame. + } + + result.set(nullptr); + return true; +} + +/* static */ +bool DebuggerFrame::getAsyncPromise(JSContext* cx, Handle<DebuggerFrame*> frame, + MutableHandle<DebuggerObject*> result) { + MOZ_ASSERT(frame->isOnStack() || frame->isSuspended()); + + if (!frame->hasGeneratorInfo()) { + // An on-stack frame may not have an associated generator yet when the + // frame is initially entered. + result.set(nullptr); + return true; + } + + RootedObject resultObject(cx); + AbstractGeneratorObject& generator = frame->unwrappedGenerator(); + if (generator.is<AsyncFunctionGeneratorObject>()) { + resultObject = generator.as<AsyncFunctionGeneratorObject>().promise(); + } else if (generator.is<AsyncGeneratorObject>()) { + Rooted<AsyncGeneratorObject*> asyncGen( + cx, &generator.as<AsyncGeneratorObject>()); + // In initial function execution, there is no promise. + if (!asyncGen->isQueueEmpty()) { + resultObject = AsyncGeneratorObject::peekRequest(asyncGen)->promise(); + } + } else { + MOZ_CRASH("Unknown async generator type"); + } + + return frame->owner()->wrapNullableDebuggeeObject(cx, resultObject, result); +} + +/* static */ +bool DebuggerFrame::getThis(JSContext* cx, Handle<DebuggerFrame*> frame, + MutableHandleValue result) { + Debugger* dbg = frame->owner(); + + if (frame->isOnStack()) { + if (!requireScriptReferent(cx, frame)) { + return false; + } + FrameIter iter = frame->getFrameIter(cx); + + { + AbstractFramePtr frame = iter.abstractFramePtr(); + AutoRealm ar(cx, frame.environmentChain()); + + UpdateFrameIterPc(iter); + + if (!GetThisValueForDebuggerFrameMaybeOptimizedOut(cx, frame, iter.pc(), + result)) { + return false; + } + } + } else { + MOZ_ASSERT(frame->isSuspended()); + + AbstractGeneratorObject& genObj = + frame->generatorInfo()->unwrappedGenerator(); + AutoRealm ar(cx, &genObj); + JSScript* script = frame->generatorInfo()->generatorScript(); + + if (!GetThisValueForDebuggerSuspendedGeneratorMaybeOptimizedOut( + cx, genObj, script, result)) { + return false; + } + } + + return dbg->wrapDebuggeeValue(cx, result); +} + +/* static */ +DebuggerFrameType DebuggerFrame::getType(Handle<DebuggerFrame*> frame) { + if (frame->isOnStack()) { + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + + // Indirect eval frames are both isGlobalFrame() and isEvalFrame(), so the + // order of checks here is significant. + if (referent.isEvalFrame()) { + return DebuggerFrameType::Eval; + } + + if (referent.isGlobalFrame()) { + return DebuggerFrameType::Global; + } + + if (referent.isFunctionFrame()) { + return DebuggerFrameType::Call; + } + + if (referent.isModuleFrame()) { + return DebuggerFrameType::Module; + } + + if (referent.isWasmDebugFrame()) { + return DebuggerFrameType::WasmCall; + } + } else { + MOZ_ASSERT(frame->isSuspended()); + + return DebuggerFrameType::Call; + } + + MOZ_CRASH("Unknown frame type"); +} + +/* static */ +DebuggerFrameImplementation DebuggerFrame::getImplementation( + Handle<DebuggerFrame*> frame) { + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + + if (referent.isBaselineFrame()) { + return DebuggerFrameImplementation::Baseline; + } + + if (referent.isRematerializedFrame()) { + return DebuggerFrameImplementation::Ion; + } + + if (referent.isWasmDebugFrame()) { + return DebuggerFrameImplementation::Wasm; + } + + return DebuggerFrameImplementation::Interpreter; +} + +/* + * If succesful, transfers the ownership of the given `handler` to this + * Debugger.Frame. Note that on failure, the ownership of `handler` is not + * transferred, and the caller is responsible for cleaning it up. + */ +/* static */ +bool DebuggerFrame::setOnStepHandler(JSContext* cx, + Handle<DebuggerFrame*> frame, + UniquePtr<OnStepHandler> handlerArg) { + // Handler has never been successfully associated with the frame so allow + // UniquePtr to delete it rather than calling drop() if we return early from + // this method.. + Rooted<UniquePtr<OnStepHandler>> handler(cx, std::move(handlerArg)); + + OnStepHandler* prior = frame->onStepHandler(); + if (handler.get() == prior) { + return true; + } + + JS::GCContext* gcx = cx->gcContext(); + if (frame->isOnStack()) { + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + + // Adjust execution observability and step counts on whatever code (JS or + // Wasm) this frame is running. + if (handler && !prior) { + if (!frame->incrementStepperCounter(cx, referent)) { + return false; + } + } else if (!handler && prior) { + frame->decrementStepperCounter(cx->gcContext(), referent); + } + } else if (frame->isSuspended()) { + RootedScript script(cx, frame->generatorInfo()->generatorScript()); + + if (handler && !prior) { + if (!frame->incrementStepperCounter(cx, script)) { + return false; + } + } else if (!handler && prior) { + frame->decrementStepperCounter(cx->gcContext(), script); + } + } else { + // If the frame is entirely dead, we still allow setting the onStep + // handler, but it has no effect. + } + + // Now that the stepper counts and observability are set correctly, we can + // actually switch the handler. + if (prior) { + prior->drop(gcx, frame); + } + + if (handler) { + handler->hold(frame); + frame->setReservedSlot(ONSTEP_HANDLER_SLOT, + PrivateValue(handler.get().release())); + } else { + frame->setReservedSlot(ONSTEP_HANDLER_SLOT, UndefinedValue()); + } + + return true; +} + +bool DebuggerFrame::incrementStepperCounter(JSContext* cx, + AbstractFramePtr referent) { + if (!referent.isWasmDebugFrame()) { + RootedScript script(cx, referent.script()); + return incrementStepperCounter(cx, script); + } + + wasm::Instance* instance = referent.asWasmDebugFrame()->instance(); + wasm::DebugFrame* wasmFrame = referent.asWasmDebugFrame(); + // Single stepping toggled off->on. + if (!instance->debug().incrementStepperCount(cx, instance, + wasmFrame->funcIndex())) { + return false; + } + + return true; +} + +bool DebuggerFrame::incrementStepperCounter(JSContext* cx, + HandleScript script) { + // Single stepping toggled off->on. + AutoRealm ar(cx, script); + // Ensure observability *before* incrementing the step mode count. + // Calling this function after calling incrementStepperCount + // will make it a no-op. + if (!Debugger::ensureExecutionObservabilityOfScript(cx, script)) { + return false; + } + if (!DebugScript::incrementStepperCount(cx, script)) { + return false; + } + + return true; +} + +void DebuggerFrame::decrementStepperCounter(JS::GCContext* gcx, + AbstractFramePtr referent) { + if (!referent.isWasmDebugFrame()) { + decrementStepperCounter(gcx, referent.script()); + return; + } + + wasm::Instance* instance = referent.asWasmDebugFrame()->instance(); + wasm::DebugFrame* wasmFrame = referent.asWasmDebugFrame(); + // Single stepping toggled on->off. + instance->debug().decrementStepperCount(gcx, instance, + wasmFrame->funcIndex()); +} + +void DebuggerFrame::decrementStepperCounter(JS::GCContext* gcx, + JSScript* script) { + // Single stepping toggled on->off. + DebugScript::decrementStepperCount(gcx, script); +} + +/* static */ +bool DebuggerFrame::getArguments(JSContext* cx, Handle<DebuggerFrame*> frame, + MutableHandle<DebuggerArguments*> result) { + Value argumentsv = frame->getReservedSlot(ARGUMENTS_SLOT); + if (!argumentsv.isUndefined()) { + result.set(argumentsv.isObject() + ? &argumentsv.toObject().as<DebuggerArguments>() + : nullptr); + return true; + } + + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + + Rooted<DebuggerArguments*> arguments(cx); + if (referent.hasArgs()) { + Rooted<GlobalObject*> global(cx, &frame->global()); + RootedObject proto(cx, GlobalObject::getOrCreateArrayPrototype(cx, global)); + if (!proto) { + return false; + } + arguments = DebuggerArguments::create(cx, proto, frame); + if (!arguments) { + return false; + } + } else { + arguments = nullptr; + } + + result.set(arguments); + frame->setReservedSlot(ARGUMENTS_SLOT, ObjectOrNullValue(result)); + return true; +} + +/* + * Evaluate |chars[0..length-1]| in the environment |env|, treating that + * source as appearing starting at |lineno| in |filename|. Store the return + * value in |*rval|. Use |thisv| as the 'this' value. + * + * If |frame| is non-nullptr, evaluate as for a direct eval in that frame; |env| + * must be either |frame|'s DebugScopeObject, or some extension of that + * environment; either way, |frame|'s scope is where newly declared variables + * go. In this case, |frame| must have a computed 'this' value, equal to + * |thisv|. + */ +static bool EvaluateInEnv(JSContext* cx, Handle<Env*> env, + AbstractFramePtr frame, + mozilla::Range<const char16_t> chars, + const EvalOptions& evalOptions, + MutableHandleValue rval) { + cx->check(env, frame); + + CompileOptions options(cx); + const char* filename = + evalOptions.filename() ? evalOptions.filename() : "debugger eval code"; + options.setIsRunOnce(true) + .setNoScriptRval(false) + .setFileAndLine(filename, evalOptions.lineno()) + .setHideScriptFromDebugger(evalOptions.hideFromDebugger()) + .setIntroductionType("debugger eval") + /* Do not perform the Javascript filename validation security check for + * javascript executions sent through the debugger. Besides making up + * a filename for these codepaths, we must allow arbitrary JS execution + * for the Browser toolbox to function. */ + .setSkipFilenameValidation(true) + /* Don't lazy parse. We need full-parsing to correctly support bytecode + * emission for private fields/methods. See EmitterScope::lookupPrivate. + */ + .setForceFullParse(); + + if (frame && frame.hasScript() && frame.script()->strict()) { + options.setForceStrictMode(); + } + + SourceText<char16_t> srcBuf; + if (!srcBuf.init(cx, chars.begin().get(), chars.length(), + SourceOwnership::Borrowed)) { + return false; + } + + RootedScript callerScript( + cx, frame && frame.hasScript() ? frame.script() : nullptr); + RootedScript script(cx); + + ScopeKind scopeKind; + if (IsGlobalLexicalEnvironment(env)) { + scopeKind = ScopeKind::Global; + } else { + scopeKind = ScopeKind::NonSyntactic; + options.setNonSyntacticScope(true); + } + + if (frame) { + MOZ_ASSERT(scopeKind == ScopeKind::NonSyntactic); + Rooted<Scope*> scope(cx, + GlobalScope::createEmpty(cx, ScopeKind::NonSyntactic)); + if (!scope) { + return false; + } + + script = frontend::CompileEvalScript(cx, options, srcBuf, scope, env); + if (!script) { + return false; + } + } else { + // Do not consider executeInGlobal{WithBindings} as an eval, but instead + // as executing a series of statements at the global level. This is to + // circumvent the fresh lexical scope that all eval have, so that the + // users of executeInGlobal, like the web console, may add new bindings to + // the global scope. + + MOZ_ASSERT(scopeKind == ScopeKind::Global || + scopeKind == ScopeKind::NonSyntactic); + + AutoReportFrontendContext fc(cx); + script = frontend::CompileGlobalScript(cx, &fc, + cx->stackLimitForCurrentPrincipal(), + options, srcBuf, scopeKind); + if (!script) { + return false; + } + } + + return ExecuteKernel(cx, script, env, frame, rval); +} + +Result<Completion> js::DebuggerGenericEval( + JSContext* cx, const mozilla::Range<const char16_t> chars, + HandleObject bindings, const EvalOptions& options, Debugger* dbg, + HandleObject envArg, FrameIter* iter) { + // Either we're specifying the frame, or a global. + MOZ_ASSERT_IF(iter, !envArg); + MOZ_ASSERT_IF(!iter, envArg && IsGlobalLexicalEnvironment(envArg)); + + // Gather keys and values of bindings, if any. This must be done in the + // debugger compartment, since that is where any exceptions must be thrown. + RootedIdVector keys(cx); + RootedValueVector values(cx); + if (bindings) { + if (!GetPropertyKeys(cx, bindings, JSITER_OWNONLY, &keys) || + !values.growBy(keys.length())) { + return cx->alreadyReportedError(); + } + for (size_t i = 0; i < keys.length(); i++) { + MutableHandleValue valp = values[i]; + if (!GetProperty(cx, bindings, bindings, keys[i], valp) || + !dbg->unwrapDebuggeeValue(cx, valp)) { + return cx->alreadyReportedError(); + } + } + } + + Maybe<AutoRealm> ar; + if (iter) { + ar.emplace(cx, iter->environmentChain(cx)); + } else { + ar.emplace(cx, envArg); + } + + Rooted<Env*> env(cx); + if (iter) { + env = GetDebugEnvironmentForFrame(cx, iter->abstractFramePtr(), iter->pc()); + if (!env) { + return cx->alreadyReportedError(); + } + } else { + env = envArg; + } + + // If evalWithBindings, create the inner environment. + if (bindings) { + Rooted<PlainObject*> nenv(cx, NewPlainObjectWithProto(cx, nullptr)); + if (!nenv) { + return cx->alreadyReportedError(); + } + RootedId id(cx); + for (size_t i = 0; i < keys.length(); i++) { + id = keys[i]; + cx->markId(id); + MutableHandleValue val = values[i]; + if (!cx->compartment()->wrap(cx, val) || + !NativeDefineDataProperty(cx, nenv, id, val, 0)) { + return cx->alreadyReportedError(); + } + } + + RootedObjectVector envChain(cx); + if (!envChain.append(nenv)) { + return cx->alreadyReportedError(); + } + + RootedObject newEnv(cx); + if (!CreateObjectsForEnvironmentChain(cx, envChain, env, &newEnv)) { + return cx->alreadyReportedError(); + } + + env = newEnv; + } + + // Note whether we are in an evaluation that might invoke the OnNativeCall + // hook, so that the JITs will be disabled. + AutoNoteDebuggerEvaluationWithOnNativeCallHook noteEvaluation( + cx, dbg->observesNativeCalls() ? dbg : nullptr); + + // Run the code and produce the completion value. + LeaveDebuggeeNoExecute nnx(cx); + RootedValue rval(cx); + AbstractFramePtr frame = iter ? iter->abstractFramePtr() : NullFramePtr(); + + bool ok = EvaluateInEnv(cx, env, frame, chars, options, &rval); + Rooted<Completion> completion(cx, Completion::fromJSResult(cx, ok, rval)); + ar.reset(); + return completion.get(); +} + +/* static */ +Result<Completion> DebuggerFrame::eval(JSContext* cx, + Handle<DebuggerFrame*> frame, + mozilla::Range<const char16_t> chars, + HandleObject bindings, + const EvalOptions& options) { + MOZ_ASSERT(frame->isOnStack()); + + Debugger* dbg = frame->owner(); + FrameIter iter = frame->getFrameIter(cx); + + UpdateFrameIterPc(iter); + + return DebuggerGenericEval(cx, chars, bindings, options, dbg, nullptr, &iter); +} + +bool DebuggerFrame::isOnStack() const { + // Note: this is equivalent to checking frameIterData() != nullptr, but works + // also when called from the trace hook during a moving GC. + return !getFixedSlot(FRAME_ITER_SLOT).isUndefined(); +} + +OnStepHandler* DebuggerFrame::onStepHandler() const { + return maybePtrFromReservedSlot<OnStepHandler>(ONSTEP_HANDLER_SLOT); +} + +OnPopHandler* DebuggerFrame::onPopHandler() const { + return maybePtrFromReservedSlot<OnPopHandler>(ONPOP_HANDLER_SLOT); +} + +void DebuggerFrame::setOnPopHandler(JSContext* cx, OnPopHandler* handler) { + OnPopHandler* prior = onPopHandler(); + if (handler == prior) { + return; + } + + JS::GCContext* gcx = cx->gcContext(); + + if (prior) { + prior->drop(gcx, this); + } + + if (handler) { + setReservedSlot(ONPOP_HANDLER_SLOT, PrivateValue(handler)); + handler->hold(this); + } else { + setReservedSlot(ONPOP_HANDLER_SLOT, UndefinedValue()); + } +} + +FrameIter::Data* DebuggerFrame::frameIterData() const { + return maybePtrFromReservedSlot<FrameIter::Data>(FRAME_ITER_SLOT); +} + +/* static */ +AbstractFramePtr DebuggerFrame::getReferent(Handle<DebuggerFrame*> frame) { + FrameIter iter(*frame->frameIterData()); + return iter.abstractFramePtr(); +} + +FrameIter DebuggerFrame::getFrameIter(JSContext* cx) { + FrameIter::Data* data = frameIterData(); + MOZ_ASSERT(data); + MOZ_ASSERT(data->cx_ == cx); + + return FrameIter(*data); +} + +/* static */ +bool DebuggerFrame::requireScriptReferent(JSContext* cx, + Handle<DebuggerFrame*> frame) { + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + if (!referent.hasScript()) { + RootedValue frameobj(cx, ObjectValue(*frame)); + ReportValueError(cx, JSMSG_DEBUG_BAD_REFERENT, JSDVG_SEARCH_STACK, frameobj, + nullptr, "a script frame"); + return false; + } + return true; +} + +void DebuggerFrame::setFrameIterData(FrameIter::Data* data) { + MOZ_ASSERT(data); + MOZ_ASSERT(!frameIterData()); + InitReservedSlot(this, FRAME_ITER_SLOT, data, + MemoryUse::DebuggerFrameIterData); +} + +void DebuggerFrame::freeFrameIterData(JS::GCContext* gcx) { + if (FrameIter::Data* data = frameIterData()) { + gcx->delete_(this, data, MemoryUse::DebuggerFrameIterData); + setReservedSlot(FRAME_ITER_SLOT, UndefinedValue()); + } +} + +bool DebuggerFrame::replaceFrameIterData(JSContext* cx, const FrameIter& iter) { + FrameIter::Data* data = iter.copyData(); + if (!data) { + return false; + } + freeFrameIterData(cx->gcContext()); + setFrameIterData(data); + return true; +} + +/* static */ +void DebuggerFrame::finalize(JS::GCContext* gcx, JSObject* obj) { + MOZ_ASSERT(gcx->onMainThread()); + + DebuggerFrame& frameobj = obj->as<DebuggerFrame>(); + + // Connections between dying Debugger.Frames and their + // AbstractGeneratorObjects, as well as the frame's stack data should have + // been by a call to terminate() from sweepAll or some other place. + MOZ_ASSERT(!frameobj.hasGeneratorInfo()); + MOZ_ASSERT(!frameobj.frameIterData()); + OnStepHandler* onStepHandler = frameobj.onStepHandler(); + if (onStepHandler) { + onStepHandler->drop(gcx, &frameobj); + } + OnPopHandler* onPopHandler = frameobj.onPopHandler(); + if (onPopHandler) { + onPopHandler->drop(gcx, &frameobj); + } +} + +void DebuggerFrame::trace(JSTracer* trc) { + OnStepHandler* onStepHandler = this->onStepHandler(); + if (onStepHandler) { + onStepHandler->trace(trc); + } + OnPopHandler* onPopHandler = this->onPopHandler(); + if (onPopHandler) { + onPopHandler->trace(trc); + } + + if (hasGeneratorInfo()) { + generatorInfo()->trace(trc, *this); + } +} + +/* static */ +DebuggerFrame* DebuggerFrame::check(JSContext* cx, HandleValue thisv) { + JSObject* thisobj = RequireObject(cx, thisv); + if (!thisobj) { + return nullptr; + } + if (!thisobj->is<DebuggerFrame>()) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_INCOMPATIBLE_PROTO, "Debugger.Frame", + "method", thisobj->getClass()->name); + return nullptr; + } + + return &thisobj->as<DebuggerFrame>(); +} + +struct MOZ_STACK_CLASS DebuggerFrame::CallData { + JSContext* cx; + const CallArgs& args; + + Handle<DebuggerFrame*> frame; + + CallData(JSContext* cx, const CallArgs& args, Handle<DebuggerFrame*> frame) + : cx(cx), args(args), frame(frame) {} + + bool argumentsGetter(); + bool calleeGetter(); + bool constructingGetter(); + bool environmentGetter(); + bool generatorGetter(); + bool asyncPromiseGetter(); + bool olderSavedFrameGetter(); + bool liveGetter(); + bool onStackGetter(); + bool terminatedGetter(); + bool offsetGetter(); + bool olderGetter(); + bool getScript(); + bool thisGetter(); + bool typeGetter(); + bool implementationGetter(); + bool onStepGetter(); + bool onStepSetter(); + bool onPopGetter(); + bool onPopSetter(); + bool evalMethod(); + bool evalWithBindingsMethod(); + + using Method = bool (CallData::*)(); + + template <Method MyMethod> + static bool ToNative(JSContext* cx, unsigned argc, Value* vp); + + bool ensureOnStack() const; + bool ensureOnStackOrSuspended() const; +}; + +template <DebuggerFrame::CallData::Method MyMethod> +/* static */ +bool DebuggerFrame::CallData::ToNative(JSContext* cx, unsigned argc, + Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + Rooted<DebuggerFrame*> frame(cx, DebuggerFrame::check(cx, args.thisv())); + if (!frame) { + return false; + } + + CallData data(cx, args, frame); + return (data.*MyMethod)(); +} + +static bool EnsureOnStack(JSContext* cx, Handle<DebuggerFrame*> frame) { + MOZ_ASSERT(frame); + if (!frame->isOnStack()) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_DEBUG_NOT_ON_STACK, "Debugger.Frame"); + return false; + } + + return true; +} +static bool EnsureOnStackOrSuspended(JSContext* cx, + Handle<DebuggerFrame*> frame) { + MOZ_ASSERT(frame); + if (!frame->isOnStack() && !frame->isSuspended()) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_DEBUG_NOT_ON_STACK_OR_SUSPENDED, + "Debugger.Frame"); + return false; + } + + return true; +} + +bool DebuggerFrame::CallData::ensureOnStack() const { + return EnsureOnStack(cx, frame); +} +bool DebuggerFrame::CallData::ensureOnStackOrSuspended() const { + return EnsureOnStackOrSuspended(cx, frame); +} + +bool DebuggerFrame::CallData::typeGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + DebuggerFrameType type = DebuggerFrame::getType(frame); + + JSString* str; + switch (type) { + case DebuggerFrameType::Eval: + str = cx->names().eval; + break; + case DebuggerFrameType::Global: + str = cx->names().global; + break; + case DebuggerFrameType::Call: + str = cx->names().call; + break; + case DebuggerFrameType::Module: + str = cx->names().module; + break; + case DebuggerFrameType::WasmCall: + str = cx->names().wasmcall; + break; + default: + MOZ_CRASH("bad DebuggerFrameType value"); + } + + args.rval().setString(str); + return true; +} + +bool DebuggerFrame::CallData::implementationGetter() { + if (!ensureOnStack()) { + return false; + } + + DebuggerFrameImplementation implementation = + DebuggerFrame::getImplementation(frame); + + const char* s; + switch (implementation) { + case DebuggerFrameImplementation::Baseline: + s = "baseline"; + break; + case DebuggerFrameImplementation::Ion: + s = "ion"; + break; + case DebuggerFrameImplementation::Interpreter: + s = "interpreter"; + break; + case DebuggerFrameImplementation::Wasm: + s = "wasm"; + break; + default: + MOZ_CRASH("bad DebuggerFrameImplementation value"); + } + + JSAtom* str = Atomize(cx, s, strlen(s)); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; +} + +bool DebuggerFrame::CallData::environmentGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + Rooted<DebuggerEnvironment*> result(cx); + if (!DebuggerFrame::getEnvironment(cx, frame, &result)) { + return false; + } + + args.rval().setObject(*result); + return true; +} + +bool DebuggerFrame::CallData::calleeGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + Rooted<DebuggerObject*> result(cx); + if (!DebuggerFrame::getCallee(cx, frame, &result)) { + return false; + } + + args.rval().setObjectOrNull(result); + return true; +} + +bool DebuggerFrame::CallData::generatorGetter() { + JS_ReportErrorASCII(cx, + "Debugger.Frame.prototype.generator has been removed. " + "Use frame.script.isGeneratorFunction instead."); + return false; +} + +bool DebuggerFrame::CallData::constructingGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + bool result; + if (!DebuggerFrame::getIsConstructing(cx, frame, result)) { + return false; + } + + args.rval().setBoolean(result); + return true; +} + +bool DebuggerFrame::CallData::asyncPromiseGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + RootedScript script(cx); + if (frame->isOnStack()) { + FrameIter iter = frame->getFrameIter(cx); + AbstractFramePtr framePtr = iter.abstractFramePtr(); + + if (!framePtr.isWasmDebugFrame()) { + script = framePtr.script(); + } + } else { + MOZ_ASSERT(frame->isSuspended()); + script = frame->generatorInfo()->generatorScript(); + } + // The async promise value is only provided for async functions and + // async generator functions. + if (!script || !script->isAsync()) { + args.rval().setUndefined(); + return true; + } + + Rooted<DebuggerObject*> result(cx); + if (!DebuggerFrame::getAsyncPromise(cx, frame, &result)) { + return false; + } + + args.rval().setObjectOrNull(result); + return true; +} + +bool DebuggerFrame::CallData::olderSavedFrameGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + Rooted<SavedFrame*> result(cx); + if (!DebuggerFrame::getOlderSavedFrame(cx, frame, &result)) { + return false; + } + + args.rval().setObjectOrNull(result); + return true; +} + +/* static */ +bool DebuggerFrame::getOlderSavedFrame(JSContext* cx, + Handle<DebuggerFrame*> frame, + MutableHandle<SavedFrame*> result) { + if (frame->isOnStack()) { + Debugger* dbg = frame->owner(); + FrameIter iter = frame->getFrameIter(cx); + + while (true) { + Activation& activation = *iter.activation(); + ++iter; + + // If the parent frame crosses an explicit async stack boundary, or we + // have hit the end of the synchronous frames, we want to switch over + // to using SavedFrames. + if (iter.activation() != &activation && activation.asyncStack() && + (activation.asyncCallIsExplicit() || iter.done())) { + const char* cause = activation.asyncCause(); + Rooted<JSAtom*> causeAtom(cx, + AtomizeUTF8Chars(cx, cause, strlen(cause))); + if (!causeAtom) { + return false; + } + Rooted<SavedFrame*> stackObj(cx, activation.asyncStack()); + + return cx->realm()->savedStacks().copyAsyncStack( + cx, stackObj, causeAtom, result, mozilla::Nothing()); + } + + // If there are no more parent frames, we're done. + if (iter.done()) { + break; + } + + // If we hit another frame that we observe, then there is no saved + // frame that we'd want to return. + if (dbg->observesFrame(iter)) { + break; + } + } + } else { + MOZ_ASSERT(frame->isSuspended()); + } + + result.set(nullptr); + return true; +} + +bool DebuggerFrame::CallData::thisGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + return DebuggerFrame::getThis(cx, frame, args.rval()); +} + +bool DebuggerFrame::CallData::olderGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + Rooted<DebuggerFrame*> result(cx); + if (!DebuggerFrame::getOlder(cx, frame, &result)) { + return false; + } + + args.rval().setObjectOrNull(result); + return true; +} + +// The getter used for each element of frame.arguments. +// See DebuggerFrame::getArguments. +static bool DebuggerArguments_getArg(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + int32_t i = args.callee().as<JSFunction>().getExtendedSlot(0).toInt32(); + + // Check that the this value is an Arguments object. + RootedObject argsobj(cx, RequireObject(cx, args.thisv())); + if (!argsobj) { + return false; + } + if (argsobj->getClass() != &DebuggerArguments::class_) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_INCOMPATIBLE_PROTO, "Arguments", + "getArgument", argsobj->getClass()->name); + return false; + } + + RootedValue framev(cx, argsobj->as<NativeObject>().getReservedSlot( + JSSLOT_DEBUGARGUMENTS_FRAME)); + Rooted<DebuggerFrame*> thisobj(cx, DebuggerFrame::check(cx, framev)); + if (!thisobj || !EnsureOnStack(cx, thisobj)) { + return false; + } + + FrameIter iter = thisobj->getFrameIter(cx); + AbstractFramePtr frame = iter.abstractFramePtr(); + + // TODO handle wasm frame arguments -- they are not yet reflectable. + MOZ_ASSERT(!frame.isWasmDebugFrame(), "a wasm frame args"); + + // Since getters can be extracted and applied to other objects, + // there is no guarantee this object has an ith argument. + MOZ_ASSERT(i >= 0); + RootedValue arg(cx); + RootedScript script(cx); + if (unsigned(i) < frame.numActualArgs()) { + script = frame.script(); + if (unsigned(i) < frame.numFormalArgs()) { + for (PositionalFormalParameterIter fi(script); fi; fi++) { + if (fi.argumentSlot() == unsigned(i)) { + // We might've been called before the CallObject was + // created. + if (fi.closedOver() && frame.hasInitialEnvironment()) { + arg = frame.callObj().aliasedBinding(fi); + } else { + arg = frame.unaliasedActual(i, DONT_CHECK_ALIASING); + } + break; + } + } + } else if (script->argsObjAliasesFormals() && frame.hasArgsObj()) { + arg = frame.argsObj().arg(i); + } else { + arg = frame.unaliasedActual(i, DONT_CHECK_ALIASING); + } + } else { + arg.setUndefined(); + } + + if (!thisobj->owner()->wrapDebuggeeValue(cx, &arg)) { + return false; + } + args.rval().set(arg); + return true; +} + +/* static */ +DebuggerArguments* DebuggerArguments::create(JSContext* cx, HandleObject proto, + Handle<DebuggerFrame*> frame) { + AbstractFramePtr referent = DebuggerFrame::getReferent(frame); + + Rooted<DebuggerArguments*> obj( + cx, NewObjectWithGivenProto<DebuggerArguments>(cx, proto)); + if (!obj) { + return nullptr; + } + + JS::SetReservedSlot(obj, FRAME_SLOT, ObjectValue(*frame)); + + MOZ_ASSERT(referent.numActualArgs() <= 0x7fffffff); + unsigned fargc = referent.numActualArgs(); + RootedValue fargcVal(cx, Int32Value(fargc)); + if (!NativeDefineDataProperty(cx, obj, cx->names().length, fargcVal, + JSPROP_PERMANENT | JSPROP_READONLY)) { + return nullptr; + } + + Rooted<jsid> id(cx); + for (unsigned i = 0; i < fargc; i++) { + RootedFunction getobj(cx); + getobj = NewNativeFunction(cx, DebuggerArguments_getArg, 0, nullptr, + gc::AllocKind::FUNCTION_EXTENDED); + if (!getobj) { + return nullptr; + } + id = PropertyKey::Int(i); + if (!NativeDefineAccessorProperty(cx, obj, id, getobj, nullptr, + JSPROP_ENUMERATE)) { + return nullptr; + } + getobj->setExtendedSlot(0, Int32Value(i)); + } + + return obj; +} + +bool DebuggerFrame::CallData::argumentsGetter() { + if (!ensureOnStack()) { + return false; + } + + Rooted<DebuggerArguments*> result(cx); + if (!DebuggerFrame::getArguments(cx, frame, &result)) { + return false; + } + + args.rval().setObjectOrNull(result); + return true; +} + +bool DebuggerFrame::CallData::getScript() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + Rooted<DebuggerScript*> scriptObject(cx); + + Debugger* debug = frame->owner(); + if (frame->isOnStack()) { + FrameIter iter = frame->getFrameIter(cx); + AbstractFramePtr framePtr = iter.abstractFramePtr(); + + if (framePtr.isWasmDebugFrame()) { + Rooted<WasmInstanceObject*> instance(cx, + framePtr.wasmInstance()->object()); + scriptObject = debug->wrapWasmScript(cx, instance); + } else { + RootedScript script(cx, framePtr.script()); + scriptObject = debug->wrapScript(cx, script); + } + } else { + MOZ_ASSERT(frame->isSuspended()); + RootedScript script(cx, frame->generatorInfo()->generatorScript()); + scriptObject = debug->wrapScript(cx, script); + } + if (!scriptObject) { + return false; + } + + args.rval().setObject(*scriptObject); + return true; +} + +bool DebuggerFrame::CallData::offsetGetter() { + if (!ensureOnStackOrSuspended()) { + return false; + } + + size_t result; + if (!DebuggerFrame::getOffset(cx, frame, result)) { + return false; + } + + args.rval().setNumber(double(result)); + return true; +} + +bool DebuggerFrame::CallData::liveGetter() { + JS_ReportErrorASCII( + cx, "Debugger.Frame.prototype.live has been renamed to .onStack"); + return false; +} + +bool DebuggerFrame::CallData::onStackGetter() { + args.rval().setBoolean(frame->isOnStack()); + return true; +} + +bool DebuggerFrame::CallData::terminatedGetter() { + args.rval().setBoolean(!frame->isOnStack() && !frame->isSuspended()); + return true; +} + +static bool IsValidHook(const Value& v) { + return v.isUndefined() || (v.isObject() && v.toObject().isCallable()); +} + +bool DebuggerFrame::CallData::onStepGetter() { + OnStepHandler* handler = frame->onStepHandler(); + RootedValue value( + cx, handler ? ObjectOrNullValue(handler->object()) : UndefinedValue()); + MOZ_ASSERT(IsValidHook(value)); + args.rval().set(value); + return true; +} + +bool DebuggerFrame::CallData::onStepSetter() { + if (!args.requireAtLeast(cx, "Debugger.Frame.set onStep", 1)) { + return false; + } + if (!IsValidHook(args[0])) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_NOT_CALLABLE_OR_UNDEFINED); + return false; + } + + UniquePtr<ScriptedOnStepHandler> handler; + if (!args[0].isUndefined()) { + handler = cx->make_unique<ScriptedOnStepHandler>(&args[0].toObject()); + if (!handler) { + return false; + } + } + + if (!DebuggerFrame::setOnStepHandler(cx, frame, std::move(handler))) { + return false; + } + + args.rval().setUndefined(); + return true; +} + +bool DebuggerFrame::CallData::onPopGetter() { + OnPopHandler* handler = frame->onPopHandler(); + RootedValue value( + cx, handler ? ObjectValue(*handler->object()) : UndefinedValue()); + MOZ_ASSERT(IsValidHook(value)); + args.rval().set(value); + return true; +} + +bool DebuggerFrame::CallData::onPopSetter() { + if (!args.requireAtLeast(cx, "Debugger.Frame.set onPop", 1)) { + return false; + } + if (!IsValidHook(args[0])) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_NOT_CALLABLE_OR_UNDEFINED); + return false; + } + + ScriptedOnPopHandler* handler = nullptr; + if (!args[0].isUndefined()) { + handler = cx->new_<ScriptedOnPopHandler>(&args[0].toObject()); + if (!handler) { + return false; + } + } + + frame->setOnPopHandler(cx, handler); + + args.rval().setUndefined(); + return true; +} + +bool DebuggerFrame::CallData::evalMethod() { + if (!ensureOnStack()) { + return false; + } + + if (!args.requireAtLeast(cx, "Debugger.Frame.prototype.eval", 1)) { + return false; + } + + AutoStableStringChars stableChars(cx); + if (!ValueToStableChars(cx, "Debugger.Frame.prototype.eval", args[0], + stableChars)) { + return false; + } + mozilla::Range<const char16_t> chars = stableChars.twoByteRange(); + + EvalOptions options; + if (!ParseEvalOptions(cx, args.get(1), options)) { + return false; + } + + Rooted<Completion> comp(cx); + JS_TRY_VAR_OR_RETURN_FALSE( + cx, comp, DebuggerFrame::eval(cx, frame, chars, nullptr, options)); + return comp.get().buildCompletionValue(cx, frame->owner(), args.rval()); +} + +bool DebuggerFrame::CallData::evalWithBindingsMethod() { + if (!ensureOnStack()) { + return false; + } + + if (!args.requireAtLeast(cx, "Debugger.Frame.prototype.evalWithBindings", + 2)) { + return false; + } + + AutoStableStringChars stableChars(cx); + if (!ValueToStableChars(cx, "Debugger.Frame.prototype.evalWithBindings", + args[0], stableChars)) { + return false; + } + mozilla::Range<const char16_t> chars = stableChars.twoByteRange(); + + RootedObject bindings(cx, RequireObject(cx, args[1])); + if (!bindings) { + return false; + } + + EvalOptions options; + if (!ParseEvalOptions(cx, args.get(2), options)) { + return false; + } + + Rooted<Completion> comp(cx); + JS_TRY_VAR_OR_RETURN_FALSE( + cx, comp, DebuggerFrame::eval(cx, frame, chars, bindings, options)); + return comp.get().buildCompletionValue(cx, frame->owner(), args.rval()); +} + +/* static */ +bool DebuggerFrame::construct(JSContext* cx, unsigned argc, Value* vp) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_NO_CONSTRUCTOR, + "Debugger.Frame"); + return false; +} + +const JSPropertySpec DebuggerFrame::properties_[] = { + JS_DEBUG_PSG("arguments", argumentsGetter), + JS_DEBUG_PSG("callee", calleeGetter), + JS_DEBUG_PSG("constructing", constructingGetter), + JS_DEBUG_PSG("environment", environmentGetter), + JS_DEBUG_PSG("generator", generatorGetter), + JS_DEBUG_PSG("live", liveGetter), + JS_DEBUG_PSG("onStack", onStackGetter), + JS_DEBUG_PSG("terminated", terminatedGetter), + JS_DEBUG_PSG("offset", offsetGetter), + JS_DEBUG_PSG("older", olderGetter), + JS_DEBUG_PSG("olderSavedFrame", olderSavedFrameGetter), + JS_DEBUG_PSG("script", getScript), + JS_DEBUG_PSG("this", thisGetter), + JS_DEBUG_PSG("asyncPromise", asyncPromiseGetter), + JS_DEBUG_PSG("type", typeGetter), + JS_DEBUG_PSG("implementation", implementationGetter), + JS_DEBUG_PSGS("onStep", onStepGetter, onStepSetter), + JS_DEBUG_PSGS("onPop", onPopGetter, onPopSetter), + JS_PS_END}; + +const JSFunctionSpec DebuggerFrame::methods_[] = { + JS_DEBUG_FN("eval", evalMethod, 1), + JS_DEBUG_FN("evalWithBindings", evalWithBindingsMethod, 1), JS_FS_END}; + +JSObject* js::IdVectorToArray(JSContext* cx, HandleIdVector ids) { + if (MOZ_UNLIKELY(ids.length() > UINT32_MAX)) { + ReportAllocationOverflow(cx); + return nullptr; + } + + Rooted<ArrayObject*> arr(cx, NewDenseFullyAllocatedArray(cx, ids.length())); + if (!arr) { + return nullptr; + } + + arr->ensureDenseInitializedLength(0, ids.length()); + + for (size_t i = 0, len = ids.length(); i < len; i++) { + jsid id = ids[i]; + Value v; + if (id.isInt()) { + JSString* str = Int32ToString<CanGC>(cx, id.toInt()); + if (!str) { + return nullptr; + } + v = StringValue(str); + } else if (id.isAtom()) { + v = StringValue(id.toAtom()); + } else if (id.isSymbol()) { + v = SymbolValue(id.toSymbol()); + } else { + MOZ_CRASH("IdVector must contain only string, int, and Symbol jsids"); + } + + arr->initDenseElement(i, v); + } + + return arr; +} |