1 files changed, 664 insertions, 0 deletions
diff --git a/js/src/debugger/Environment.cpp b/js/src/debugger/Environment.cpp
new file mode 100644
index 0000000000..dbb6851e3a
--- /dev/null
+++ b/js/src/debugger/Environment.cpp
@@ -0,0 +1,664 @@
+/* -*- 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/Environment-inl.h"
+
+#include "mozilla/Assertions.h"  // for AssertionConditionType
+#include "mozilla/Maybe.h"       // for Maybe, Some, Nothing
+#include "mozilla/Vector.h"      // for Vector
+
+#include <string.h>  // for strlen, size_t
+#include <utility>   // for move
+
+#include "debugger/Debugger.h"          // for Env, Debugger, ValueToIdentifier
+#include "debugger/Object.h"            // for DebuggerObject
+#include "debugger/Script.h"            // for DebuggerScript
+#include "frontend/BytecodeCompiler.h"  // for IsIdentifier
+#include "gc/Tracer.h"    // for TraceManuallyBarrieredCrossCompartmentEdge
+#include "js/CallArgs.h"  // for CallArgs
+#include "js/friend/ErrorMessages.h"  // for GetErrorMessage, JSMSG_*
+#include "js/HeapAPI.h"               // for IsInsideNursery
+#include "js/RootingAPI.h"            // for Rooted, MutableHandle
+#include "vm/Compartment.h"           // for Compartment
+#include "vm/JSAtom.h"                // for Atomize
+#include "vm/JSContext.h"             // for JSContext
+#include "vm/JSFunction.h"            // for JSFunction
+#include "vm/JSObject.h"              // for JSObject, RequireObject,
+#include "vm/NativeObject.h"          // for NativeObject, JSObject::is
+#include "vm/Realm.h"                 // for AutoRealm, ErrorCopier
+#include "vm/Scope.h"                 // for ScopeKind, ScopeKindString
+#include "vm/StringType.h"            // for JSAtom
+
+#include "vm/Compartment-inl.h"        // for Compartment::wrap
+#include "vm/EnvironmentObject-inl.h"  // for JSObject::enclosingEnvironment
+#include "vm/JSObject-inl.h"  // for IsInternalFunctionObject, NewObjectWithGivenProtoAndKind
+#include "vm/ObjectOperations-inl.h"  // for HasProperty, GetProperty
+#include "vm/Realm-inl.h"             // for AutoRealm::AutoRealm
+
+namespace js {
+class GlobalObject;
+}
+
+using namespace js;
+
+using js::frontend::IsIdentifier;
+using mozilla::Maybe;
+using mozilla::Nothing;
+using mozilla::Some;
+
+const JSClassOps DebuggerEnvironment::classOps_ = {
+    nullptr,                               // addProperty
+    nullptr,                               // delProperty
+    nullptr,                               // enumerate
+    nullptr,                               // newEnumerate
+    nullptr,                               // resolve
+    nullptr,                               // mayResolve
+    nullptr,                               // finalize
+    nullptr,                               // call
+    nullptr,                               // construct
+    CallTraceMethod<DebuggerEnvironment>,  // trace
+};
+
+const JSClass DebuggerEnvironment::class_ = {
+    "Environment",
+    JSCLASS_HAS_RESERVED_SLOTS(DebuggerEnvironment::RESERVED_SLOTS),
+    &classOps_};
+
+void DebuggerEnvironment::trace(JSTracer* trc) {
+  // There is a barrier on private pointers, so the Unbarriered marking
+  // is okay.
+  if (Env* referent = maybeReferent()) {
+    TraceManuallyBarrieredCrossCompartmentEdge(trc, this, &referent,
+                                               "Debugger.Environment referent");
+    if (referent != maybeReferent()) {
+      setReservedSlotGCThingAsPrivateUnbarriered(ENV_SLOT, referent);
+    }
+  }
+}
+
+static DebuggerEnvironment* DebuggerEnvironment_checkThis(
+    JSContext* cx, const CallArgs& args) {
+  JSObject* thisobj = RequireObject(cx, args.thisv());
+  if (!thisobj) {
+    return nullptr;
+  }
+  if (!thisobj->is<DebuggerEnvironment>()) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                              JSMSG_INCOMPATIBLE_PROTO, "Debugger.Environment",
+                              "method", thisobj->getClass()->name);
+    return nullptr;
+  }
+
+  return &thisobj->as<DebuggerEnvironment>();
+}
+
+struct MOZ_STACK_CLASS DebuggerEnvironment::CallData {
+  JSContext* cx;
+  const CallArgs& args;
+
+  Handle<DebuggerEnvironment*> environment;
+
+  CallData(JSContext* cx, const CallArgs& args,
+           Handle<DebuggerEnvironment*> env)
+      : cx(cx), args(args), environment(env) {}
+
+  bool typeGetter();
+  bool scopeKindGetter();
+  bool parentGetter();
+  bool objectGetter();
+  bool calleeScriptGetter();
+  bool inspectableGetter();
+  bool optimizedOutGetter();
+
+  bool namesMethod();
+  bool findMethod();
+  bool getVariableMethod();
+  bool setVariableMethod();
+
+  using Method = bool (CallData::*)();
+
+  template <Method MyMethod>
+  static bool ToNative(JSContext* cx, unsigned argc, Value* vp);
+};
+
+template <DebuggerEnvironment::CallData::Method MyMethod>
+/* static */
+bool DebuggerEnvironment::CallData::ToNative(JSContext* cx, unsigned argc,
+                                             Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  Rooted<DebuggerEnvironment*> environment(
+      cx, DebuggerEnvironment_checkThis(cx, args));
+  if (!environment) {
+    return false;
+  }
+
+  CallData data(cx, args, environment);
+  return (data.*MyMethod)();
+}
+
+/* static */
+bool DebuggerEnvironment::construct(JSContext* cx, unsigned argc, Value* vp) {
+  JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_NO_CONSTRUCTOR,
+                            "Debugger.Environment");
+  return false;
+}
+
+static bool IsDeclarative(Env* env) {
+  return env->is<DebugEnvironmentProxy>() &&
+         env->as<DebugEnvironmentProxy>().isForDeclarative();
+}
+
+template <typename T>
+static bool IsDebugEnvironmentWrapper(Env* env) {
+  return env->is<DebugEnvironmentProxy>() &&
+         env->as<DebugEnvironmentProxy>().environment().is<T>();
+}
+
+bool DebuggerEnvironment::CallData::typeGetter() {
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  DebuggerEnvironmentType type = environment->type();
+
+  const char* s;
+  switch (type) {
+    case DebuggerEnvironmentType::Declarative:
+      s = "declarative";
+      break;
+    case DebuggerEnvironmentType::With:
+      s = "with";
+      break;
+    case DebuggerEnvironmentType::Object:
+      s = "object";
+      break;
+  }
+
+  JSAtom* str = Atomize(cx, s, strlen(s));
+  if (!str) {
+    return false;
+  }
+
+  args.rval().setString(str);
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::scopeKindGetter() {
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  Maybe<ScopeKind> kind = environment->scopeKind();
+  if (kind.isSome()) {
+    const char* s = ScopeKindString(*kind);
+    JSAtom* str = Atomize(cx, s, strlen(s));
+    if (!str) {
+      return false;
+    }
+    args.rval().setString(str);
+  } else {
+    args.rval().setNull();
+  }
+
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::parentGetter() {
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  Rooted<DebuggerEnvironment*> result(cx);
+  if (!environment->getParent(cx, &result)) {
+    return false;
+  }
+
+  args.rval().setObjectOrNull(result);
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::objectGetter() {
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  if (environment->type() == DebuggerEnvironmentType::Declarative) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                              JSMSG_DEBUG_NO_ENV_OBJECT);
+    return false;
+  }
+
+  Rooted<DebuggerObject*> result(cx);
+  if (!environment->getObject(cx, &result)) {
+    return false;
+  }
+
+  args.rval().setObject(*result);
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::calleeScriptGetter() {
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  Rooted<DebuggerScript*> result(cx);
+  if (!environment->getCalleeScript(cx, &result)) {
+    return false;
+  }
+
+  args.rval().setObjectOrNull(result);
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::inspectableGetter() {
+  args.rval().setBoolean(environment->isDebuggee());
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::optimizedOutGetter() {
+  args.rval().setBoolean(environment->isOptimized());
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::namesMethod() {
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  RootedIdVector ids(cx);
+  if (!DebuggerEnvironment::getNames(cx, environment, &ids)) {
+    return false;
+  }
+
+  JSObject* obj = IdVectorToArray(cx, ids);
+  if (!obj) {
+    return false;
+  }
+
+  args.rval().setObject(*obj);
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::findMethod() {
+  if (!args.requireAtLeast(cx, "Debugger.Environment.find", 1)) {
+    return false;
+  }
+
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  RootedId id(cx);
+  if (!ValueToIdentifier(cx, args[0], &id)) {
+    return false;
+  }
+
+  Rooted<DebuggerEnvironment*> result(cx);
+  if (!DebuggerEnvironment::find(cx, environment, id, &result)) {
+    return false;
+  }
+
+  args.rval().setObjectOrNull(result);
+  return true;
+}
+
+bool DebuggerEnvironment::CallData::getVariableMethod() {
+  if (!args.requireAtLeast(cx, "Debugger.Environment.getVariable", 1)) {
+    return false;
+  }
+
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  RootedId id(cx);
+  if (!ValueToIdentifier(cx, args[0], &id)) {
+    return false;
+  }
+
+  return DebuggerEnvironment::getVariable(cx, environment, id, args.rval());
+}
+
+bool DebuggerEnvironment::CallData::setVariableMethod() {
+  if (!args.requireAtLeast(cx, "Debugger.Environment.setVariable", 2)) {
+    return false;
+  }
+
+  if (!environment->requireDebuggee(cx)) {
+    return false;
+  }
+
+  RootedId id(cx);
+  if (!ValueToIdentifier(cx, args[0], &id)) {
+    return false;
+  }
+
+  if (!DebuggerEnvironment::setVariable(cx, environment, id, args[1])) {
+    return false;
+  }
+
+  args.rval().setUndefined();
+  return true;
+}
+
+bool DebuggerEnvironment::requireDebuggee(JSContext* cx) const {
+  if (!isDebuggee()) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                              JSMSG_DEBUG_NOT_DEBUGGEE, "Debugger.Environment",
+                              "environment");
+
+    return false;
+  }
+
+  return true;
+}
+
+const JSPropertySpec DebuggerEnvironment::properties_[] = {
+    JS_DEBUG_PSG("type", typeGetter),
+    JS_DEBUG_PSG("scopeKind", scopeKindGetter),
+    JS_DEBUG_PSG("parent", parentGetter),
+    JS_DEBUG_PSG("object", objectGetter),
+    JS_DEBUG_PSG("calleeScript", calleeScriptGetter),
+    JS_DEBUG_PSG("inspectable", inspectableGetter),
+    JS_DEBUG_PSG("optimizedOut", optimizedOutGetter),
+    JS_PS_END};
+
+const JSFunctionSpec DebuggerEnvironment::methods_[] = {
+    JS_DEBUG_FN("names", namesMethod, 0), JS_DEBUG_FN("find", findMethod, 1),
+    JS_DEBUG_FN("getVariable", getVariableMethod, 1),
+    JS_DEBUG_FN("setVariable", setVariableMethod, 2), JS_FS_END};
+
+/* static */
+NativeObject* DebuggerEnvironment::initClass(JSContext* cx,
+                                             Handle<GlobalObject*> global,
+                                             HandleObject dbgCtor) {
+  return InitClass(cx, dbgCtor, nullptr, nullptr, "Environment", construct, 0,
+                   properties_, methods_, nullptr, nullptr);
+}
+
+/* static */
+DebuggerEnvironment* DebuggerEnvironment::create(
+    JSContext* cx, HandleObject proto, HandleObject referent,
+    Handle<NativeObject*> debugger) {
+  DebuggerEnvironment* obj =
+      IsInsideNursery(referent)
+          ? NewObjectWithGivenProto<DebuggerEnvironment>(cx, proto)
+          : NewTenuredObjectWithGivenProto<DebuggerEnvironment>(cx, proto);
+  if (!obj) {
+    return nullptr;
+  }
+
+  obj->setReservedSlotGCThingAsPrivate(ENV_SLOT, referent);
+  obj->setReservedSlot(OWNER_SLOT, ObjectValue(*debugger));
+
+  return obj;
+}
+
+/* static */
+DebuggerEnvironmentType DebuggerEnvironment::type() const {
+  // Don't bother switching compartments just to check env's type.
+  if (IsDeclarative(referent())) {
+    return DebuggerEnvironmentType::Declarative;
+  }
+  if (IsDebugEnvironmentWrapper<WithEnvironmentObject>(referent())) {
+    return DebuggerEnvironmentType::With;
+  }
+  return DebuggerEnvironmentType::Object;
+}
+
+mozilla::Maybe<ScopeKind> DebuggerEnvironment::scopeKind() const {
+  if (!referent()->is<DebugEnvironmentProxy>()) {
+    return Nothing();
+  }
+  EnvironmentObject& env =
+      referent()->as<DebugEnvironmentProxy>().environment();
+  Scope* scope = GetEnvironmentScope(env);
+  return scope ? Some(scope->kind()) : Nothing();
+}
+
+bool DebuggerEnvironment::getParent(
+    JSContext* cx, MutableHandle<DebuggerEnvironment*> result) const {
+  // Don't bother switching compartments just to get env's parent.
+  Rooted<Env*> parent(cx, referent()->enclosingEnvironment());
+  if (!parent) {
+    result.set(nullptr);
+    return true;
+  }
+
+  return owner()->wrapEnvironment(cx, parent, result);
+}
+
+bool DebuggerEnvironment::getObject(
+    JSContext* cx, MutableHandle<DebuggerObject*> result) const {
+  MOZ_ASSERT(type() != DebuggerEnvironmentType::Declarative);
+
+  // Don't bother switching compartments just to get env's object.
+  RootedObject object(cx);
+  if (IsDebugEnvironmentWrapper<WithEnvironmentObject>(referent())) {
+    object.set(&referent()
+                    ->as<DebugEnvironmentProxy>()
+                    .environment()
+                    .as<WithEnvironmentObject>()
+                    .object());
+  } else if (IsDebugEnvironmentWrapper<NonSyntacticVariablesObject>(
+                 referent())) {
+    object.set(&referent()
+                    ->as<DebugEnvironmentProxy>()
+                    .environment()
+                    .as<NonSyntacticVariablesObject>());
+  } else {
+    object.set(referent());
+    MOZ_ASSERT(!object->is<DebugEnvironmentProxy>());
+  }
+
+  return owner()->wrapDebuggeeObject(cx, object, result);
+}
+
+bool DebuggerEnvironment::getCalleeScript(
+    JSContext* cx, MutableHandle<DebuggerScript*> result) const {
+  if (!referent()->is<DebugEnvironmentProxy>()) {
+    result.set(nullptr);
+    return true;
+  }
+
+  JSObject& scope = referent()->as<DebugEnvironmentProxy>().environment();
+  if (!scope.is<CallObject>()) {
+    result.set(nullptr);
+    return true;
+  }
+
+  Rooted<BaseScript*> script(cx, scope.as<CallObject>().callee().baseScript());
+
+  DebuggerScript* scriptObject = owner()->wrapScript(cx, script);
+  if (!scriptObject) {
+    return false;
+  }
+
+  result.set(scriptObject);
+  return true;
+}
+
+bool DebuggerEnvironment::isDebuggee() const {
+  MOZ_ASSERT(referent());
+  MOZ_ASSERT(!referent()->is<EnvironmentObject>());
+
+  return owner()->observesGlobal(&referent()->nonCCWGlobal());
+}
+
+bool DebuggerEnvironment::isOptimized() const {
+  return referent()->is<DebugEnvironmentProxy>() &&
+         referent()->as<DebugEnvironmentProxy>().isOptimizedOut();
+}
+
+/* static */
+bool DebuggerEnvironment::getNames(JSContext* cx,
+                                   Handle<DebuggerEnvironment*> environment,
+                                   MutableHandleIdVector result) {
+  MOZ_ASSERT(environment->isDebuggee());
+  MOZ_ASSERT(result.empty());
+
+  Rooted<Env*> referent(cx, environment->referent());
+  {
+    Maybe<AutoRealm> ar;
+    ar.emplace(cx, referent);
+
+    ErrorCopier ec(ar);
+    if (!GetPropertyKeys(cx, referent, JSITER_HIDDEN, result)) {
+      return false;
+    }
+  }
+
+  result.eraseIf([](PropertyKey key) {
+    return !key.isAtom() || !IsIdentifier(key.toAtom());
+  });
+
+  for (size_t i = 0; i < result.length(); ++i) {
+    cx->markAtom(result[i].toAtom());
+  }
+
+  return true;
+}
+
+/* static */
+bool DebuggerEnvironment::find(JSContext* cx,
+                               Handle<DebuggerEnvironment*> environment,
+                               HandleId id,
+                               MutableHandle<DebuggerEnvironment*> result) {
+  MOZ_ASSERT(environment->isDebuggee());
+
+  Rooted<Env*> env(cx, environment->referent());
+  Debugger* dbg = environment->owner();
+
+  {
+    Maybe<AutoRealm> ar;
+    ar.emplace(cx, env);
+
+    cx->markId(id);
+
+    // This can trigger resolve hooks.
+    ErrorCopier ec(ar);
+    for (; env; env = env->enclosingEnvironment()) {
+      bool found;
+      if (!HasProperty(cx, env, id, &found)) {
+        return false;
+      }
+      if (found) {
+        break;
+      }
+    }
+  }
+
+  if (!env) {
+    result.set(nullptr);
+    return true;
+  }
+
+  return dbg->wrapEnvironment(cx, env, result);
+}
+
+/* static */
+bool DebuggerEnvironment::getVariable(JSContext* cx,
+                                      Handle<DebuggerEnvironment*> environment,
+                                      HandleId id, MutableHandleValue result) {
+  MOZ_ASSERT(environment->isDebuggee());
+
+  Rooted<Env*> referent(cx, environment->referent());
+  Debugger* dbg = environment->owner();
+
+  {
+    Maybe<AutoRealm> ar;
+    ar.emplace(cx, referent);
+
+    cx->markId(id);
+
+    // This can trigger getters.
+    ErrorCopier ec(ar);
+
+    bool found;
+    if (!HasProperty(cx, referent, id, &found)) {
+      return false;
+    }
+    if (!found) {
+      result.setUndefined();
+      return true;
+    }
+
+    // For DebugEnvironmentProxys, we get sentinel values for optimized out
+    // slots and arguments instead of throwing (the default behavior).
+    //
+    // See wrapDebuggeeValue for how the sentinel values are wrapped.
+    if (referent->is<DebugEnvironmentProxy>()) {
+      Rooted<DebugEnvironmentProxy*> env(
+          cx, &referent->as<DebugEnvironmentProxy>());
+      if (!DebugEnvironmentProxy::getMaybeSentinelValue(cx, env, id, result)) {
+        return false;
+      }
+    } else {
+      if (!GetProperty(cx, referent, referent, id, result)) {
+        return false;
+      }
+    }
+  }
+
+  // When we've faked up scope chain objects for optimized-out scopes,
+  // declarative environments may contain internal JSFunction objects, which
+  // we shouldn't expose to the user.
+  if (result.isObject()) {
+    RootedObject obj(cx, &result.toObject());
+    if (obj->is<JSFunction>() &&
+        IsInternalFunctionObject(obj->as<JSFunction>()))
+      result.setMagic(JS_OPTIMIZED_OUT);
+  }
+
+  return dbg->wrapDebuggeeValue(cx, result);
+}
+
+/* static */
+bool DebuggerEnvironment::setVariable(JSContext* cx,
+                                      Handle<DebuggerEnvironment*> environment,
+                                      HandleId id, HandleValue value_) {
+  MOZ_ASSERT(environment->isDebuggee());
+
+  Rooted<Env*> referent(cx, environment->referent());
+  Debugger* dbg = environment->owner();
+
+  RootedValue value(cx, value_);
+  if (!dbg->unwrapDebuggeeValue(cx, &value)) {
+    return false;
+  }
+
+  {
+    Maybe<AutoRealm> ar;
+    ar.emplace(cx, referent);
+    if (!cx->compartment()->wrap(cx, &value)) {
+      return false;
+    }
+    cx->markId(id);
+
+    // This can trigger setters.
+    ErrorCopier ec(ar);
+
+    // Make sure the environment actually has the specified binding.
+    bool found;
+    if (!HasProperty(cx, referent, id, &found)) {
+      return false;
+    }
+    if (!found) {
+      JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                                JSMSG_DEBUG_VARIABLE_NOT_FOUND);
+      return false;
+    }
+
+    // Just set the property.
+    if (!SetProperty(cx, referent, id, value)) {
+      return false;
+    }
+  }
+
+  return true;
+}