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/* -*- 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
#include "js/UbiNode.h"
#include "mozilla/Assertions.h"
#include <algorithm>
#include "debugger/Debugger.h"
#include "gc/GC.h"
#include "jit/JitCode.h"
#include "js/Debug.h"
#include "js/TracingAPI.h"
#include "js/TypeDecls.h"
#include "js/UbiNodeUtils.h"
#include "js/Utility.h"
#include "util/Text.h"
#include "vm/BigIntType.h"
#include "vm/Compartment.h"
#include "vm/EnvironmentObject.h"
#include "vm/GetterSetter.h"
#include "vm/GlobalObject.h"
#include "vm/JSContext.h"
#include "vm/JSObject.h"
#include "vm/JSScript.h"
#include "vm/PropMap.h"
#include "vm/Scope.h"
#include "vm/Shape.h"
#include "vm/StringType.h"
#include "vm/SymbolType.h"
#include "debugger/Debugger-inl.h"
#include "gc/StableCellHasher-inl.h"
#include "vm/JSObject-inl.h"
using namespace js;
using JS::ApplyGCThingTyped;
using JS::HandleValue;
using JS::Value;
using JS::ZoneSet;
using JS::ubi::AtomOrTwoByteChars;
using JS::ubi::CoarseType;
using JS::ubi::Concrete;
using JS::ubi::Edge;
using JS::ubi::EdgeRange;
using JS::ubi::EdgeVector;
using JS::ubi::Node;
using JS::ubi::StackFrame;
using JS::ubi::TracerConcrete;
using JS::ubi::TracerConcreteWithRealm;
using mozilla::RangedPtr;
struct CopyToBufferMatcher {
RangedPtr<char16_t> destination;
size_t maxLength;
CopyToBufferMatcher(RangedPtr<char16_t> destination, size_t maxLength)
: destination(destination), maxLength(maxLength) {}
template <typename CharT>
static size_t copyToBufferHelper(const CharT* src, RangedPtr<char16_t> dest,
size_t length) {
size_t i = 0;
for (; i < length; i++) {
dest[i] = src[i];
}
return i;
}
size_t operator()(JSAtom* atom) {
if (!atom) {
return 0;
}
size_t length = std::min(atom->length(), maxLength);
JS::AutoCheckCannotGC noGC;
return atom->hasTwoByteChars()
? copyToBufferHelper(atom->twoByteChars(noGC), destination,
length)
: copyToBufferHelper(atom->latin1Chars(noGC), destination,
length);
}
size_t operator()(const char16_t* chars) {
if (!chars) {
return 0;
}
size_t length = std::min(js_strlen(chars), maxLength);
return copyToBufferHelper(chars, destination, length);
}
};
size_t JS::ubi::AtomOrTwoByteChars::copyToBuffer(
RangedPtr<char16_t> destination, size_t length) {
CopyToBufferMatcher m(destination, length);
return match(m);
}
struct LengthMatcher {
size_t operator()(JSAtom* atom) { return atom ? atom->length() : 0; }
size_t operator()(const char16_t* chars) {
return chars ? js_strlen(chars) : 0;
}
};
size_t JS::ubi::AtomOrTwoByteChars::length() {
LengthMatcher m;
return match(m);
}
size_t StackFrame::source(RangedPtr<char16_t> destination,
size_t length) const {
auto s = source();
return s.copyToBuffer(destination, length);
}
size_t StackFrame::functionDisplayName(RangedPtr<char16_t> destination,
size_t length) const {
auto name = functionDisplayName();
return name.copyToBuffer(destination, length);
}
size_t StackFrame::sourceLength() { return source().length(); }
size_t StackFrame::functionDisplayNameLength() {
return functionDisplayName().length();
}
// All operations on null ubi::Nodes crash.
CoarseType Concrete<void>::coarseType() const { MOZ_CRASH("null ubi::Node"); }
const char16_t* Concrete<void>::typeName() const {
MOZ_CRASH("null ubi::Node");
}
JS::Zone* Concrete<void>::zone() const { MOZ_CRASH("null ubi::Node"); }
JS::Compartment* Concrete<void>::compartment() const {
MOZ_CRASH("null ubi::Node");
}
JS::Realm* Concrete<void>::realm() const { MOZ_CRASH("null ubi::Node"); }
UniquePtr<EdgeRange> Concrete<void>::edges(JSContext*, bool) const {
MOZ_CRASH("null ubi::Node");
}
Node::Size Concrete<void>::size(mozilla::MallocSizeOf mallocSizeof) const {
MOZ_CRASH("null ubi::Node");
}
Node::Node(JS::GCCellPtr thing) {
ApplyGCThingTyped(thing, [this](auto t) { this->construct(t); });
}
Node::Node(HandleValue value) {
if (!ApplyGCThingTyped(value, [this](auto t) { this->construct(t); })) {
construct<void>(nullptr);
}
}
static bool IsSafeToExposeToJS(JSObject* obj) {
if (obj->is<js::EnvironmentObject>() || obj->is<js::ScriptSourceObject>() ||
obj->is<js::DebugEnvironmentProxy>()) {
return false;
}
if (obj->is<JSFunction>() && js::IsInternalFunctionObject(*obj)) {
return false;
}
return true;
}
Value Node::exposeToJS() const {
Value v;
if (is<JSObject>()) {
JSObject* obj = as<JSObject>();
if (IsSafeToExposeToJS(obj)) {
v.setObject(*obj);
} else {
v.setUndefined();
}
} else if (is<JSString>()) {
v.setString(as<JSString>());
} else if (is<JS::Symbol>()) {
v.setSymbol(as<JS::Symbol>());
} else if (is<BigInt>()) {
v.setBigInt(as<BigInt>());
} else {
v.setUndefined();
}
ExposeValueToActiveJS(v);
return v;
}
// A JS::CallbackTracer subclass that adds a Edge to a Vector for each
// edge on which it is invoked.
class EdgeVectorTracer final : public JS::CallbackTracer {
// The vector to which we add Edges.
EdgeVector* vec;
// True if we should populate the edge's names.
bool wantNames;
void onChild(JS::GCCellPtr thing, const char* name) override {
if (!okay) {
return;
}
// Don't trace permanent atoms and well-known symbols that are owned by
// a parent JSRuntime.
if (thing.is<JSString>() && thing.as<JSString>().isPermanentAtom()) {
return;
}
if (thing.is<JS::Symbol>() && thing.as<JS::Symbol>().isWellKnownSymbol()) {
return;
}
char16_t* name16 = nullptr;
if (wantNames) {
// Ask the tracer to compute an edge name for us.
char buffer[1024];
context().getEdgeName(name, buffer, sizeof(buffer));
name = buffer;
// Convert the name to char16_t characters.
name16 = js_pod_malloc<char16_t>(strlen(name) + 1);
if (!name16) {
okay = false;
return;
}
size_t i;
for (i = 0; name[i]; i++) {
name16[i] = name[i];
}
name16[i] = '\0';
}
// The simplest code is correct! The temporary Edge takes
// ownership of name; if the append succeeds, the vector element
// then takes ownership; if the append fails, then the temporary
// retains it, and its destructor will free it.
if (!vec->append(Edge(name16, Node(thing)))) {
okay = false;
return;
}
}
public:
// True if no errors (OOM, say) have yet occurred.
bool okay;
EdgeVectorTracer(JSRuntime* rt, EdgeVector* vec, bool wantNames)
: JS::CallbackTracer(rt), vec(vec), wantNames(wantNames), okay(true) {}
};
template <typename Referent>
JS::Zone* TracerConcrete<Referent>::zone() const {
return get().zoneFromAnyThread();
}
template JS::Zone* TracerConcrete<js::BaseScript>::zone() const;
template JS::Zone* TracerConcrete<js::Shape>::zone() const;
template JS::Zone* TracerConcrete<js::BaseShape>::zone() const;
template JS::Zone* TracerConcrete<js::GetterSetter>::zone() const;
template JS::Zone* TracerConcrete<js::PropMap>::zone() const;
template JS::Zone* TracerConcrete<js::RegExpShared>::zone() const;
template JS::Zone* TracerConcrete<js::Scope>::zone() const;
template JS::Zone* TracerConcrete<JS::Symbol>::zone() const;
template JS::Zone* TracerConcrete<BigInt>::zone() const;
template JS::Zone* TracerConcrete<JSString>::zone() const;
template <typename Referent>
UniquePtr<EdgeRange> TracerConcrete<Referent>::edges(JSContext* cx,
bool wantNames) const {
auto range = js::MakeUnique<SimpleEdgeRange>();
if (!range) {
return nullptr;
}
if (!range->addTracerEdges(cx->runtime(), ptr,
JS::MapTypeToTraceKind<Referent>::kind,
wantNames)) {
return nullptr;
}
// Note: Clang 3.8 (or older) require an explicit construction of the
// target UniquePtr type. When we no longer require to support these Clang
// versions the return statement can be simplified to |return range;|.
return UniquePtr<EdgeRange>(range.release());
}
template UniquePtr<EdgeRange> TracerConcrete<js::BaseScript>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<js::Shape>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<js::BaseShape>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<js::GetterSetter>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<js::PropMap>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<js::RegExpShared>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<js::Scope>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<JS::Symbol>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<BigInt>::edges(
JSContext* cx, bool wantNames) const;
template UniquePtr<EdgeRange> TracerConcrete<JSString>::edges(
JSContext* cx, bool wantNames) const;
template <typename Referent>
JS::Compartment* TracerConcreteWithRealm<Referent>::compartment() const {
return TracerBase::get().compartment();
}
template <typename Referent>
Realm* TracerConcreteWithRealm<Referent>::realm() const {
return TracerBase::get().realm();
}
template Realm* TracerConcreteWithRealm<js::BaseScript>::realm() const;
template JS::Compartment* TracerConcreteWithRealm<js::BaseScript>::compartment()
const;
bool Concrete<JSObject>::hasAllocationStack() const {
return !!js::Debugger::getObjectAllocationSite(get());
}
StackFrame Concrete<JSObject>::allocationStack() const {
MOZ_ASSERT(hasAllocationStack());
return StackFrame(js::Debugger::getObjectAllocationSite(get()));
}
const char* Concrete<JSObject>::jsObjectClassName() const {
return Concrete::get().getClass()->name;
}
JS::Compartment* Concrete<JSObject>::compartment() const {
return Concrete::get().compartment();
}
Realm* Concrete<JSObject>::realm() const {
// Cross-compartment wrappers are shared by all realms in the compartment,
// so we return nullptr in that case.
return JS::GetObjectRealmOrNull(&Concrete::get());
}
const char16_t Concrete<JS::Symbol>::concreteTypeName[] = u"JS::Symbol";
const char16_t Concrete<BigInt>::concreteTypeName[] = u"JS::BigInt";
const char16_t Concrete<js::BaseScript>::concreteTypeName[] = u"js::BaseScript";
const char16_t Concrete<js::jit::JitCode>::concreteTypeName[] =
u"js::jit::JitCode";
const char16_t Concrete<js::Shape>::concreteTypeName[] = u"js::Shape";
const char16_t Concrete<js::BaseShape>::concreteTypeName[] = u"js::BaseShape";
const char16_t Concrete<js::GetterSetter>::concreteTypeName[] =
u"js::GetterSetter";
const char16_t Concrete<js::PropMap>::concreteTypeName[] = u"js::PropMap";
const char16_t Concrete<js::Scope>::concreteTypeName[] = u"js::Scope";
const char16_t Concrete<js::RegExpShared>::concreteTypeName[] =
u"js::RegExpShared";
namespace JS {
namespace ubi {
RootList::RootList(JSContext* cx, bool wantNames /* = false */)
: cx(cx), wantNames(wantNames), inited(false) {}
std::pair<bool, JS::AutoCheckCannotGC> RootList::init() {
EdgeVectorTracer tracer(cx->runtime(), &edges, wantNames);
js::TraceRuntime(&tracer);
inited = tracer.okay;
return {tracer.okay, JS::AutoCheckCannotGC(cx)};
}
std::pair<bool, JS::AutoCheckCannotGC> RootList::init(
CompartmentSet& debuggees) {
EdgeVector allRootEdges;
EdgeVectorTracer tracer(cx->runtime(), &allRootEdges, wantNames);
ZoneSet debuggeeZones;
for (auto range = debuggees.all(); !range.empty(); range.popFront()) {
if (!debuggeeZones.put(range.front()->zone())) {
return {false, JS::AutoCheckCannotGC(cx)};
}
}
js::TraceRuntime(&tracer);
if (!tracer.okay) {
return {false, JS::AutoCheckCannotGC(cx)};
}
js::gc::TraceIncomingCCWs(&tracer, debuggees);
if (!tracer.okay) {
return {false, JS::AutoCheckCannotGC(cx)};
}
for (EdgeVector::Range r = allRootEdges.all(); !r.empty(); r.popFront()) {
Edge& edge = r.front();
JS::Compartment* compartment = edge.referent.compartment();
if (compartment && !debuggees.has(compartment)) {
continue;
}
Zone* zone = edge.referent.zone();
if (zone && !debuggeeZones.has(zone)) {
continue;
}
if (!edges.append(std::move(edge))) {
return {false, JS::AutoCheckCannotGC(cx)};
}
}
inited = true;
return {true, JS::AutoCheckCannotGC(cx)};
}
std::pair<bool, JS::AutoCheckCannotGC> RootList::init(HandleObject debuggees) {
MOZ_ASSERT(debuggees && JS::dbg::IsDebugger(*debuggees));
js::Debugger* dbg = js::Debugger::fromJSObject(debuggees.get());
CompartmentSet debuggeeCompartments;
for (js::WeakGlobalObjectSet::Range r = dbg->allDebuggees(); !r.empty();
r.popFront()) {
if (!debuggeeCompartments.put(r.front()->compartment())) {
return {false, JS::AutoCheckCannotGC(cx)};
}
}
auto [ok, nogc] = init(debuggeeCompartments);
if (!ok) {
return {false, nogc};
}
// Ensure that each of our debuggee globals are in the root list.
for (js::WeakGlobalObjectSet::Range r = dbg->allDebuggees(); !r.empty();
r.popFront()) {
if (!addRoot(JS::ubi::Node(static_cast<JSObject*>(r.front())),
u"debuggee global")) {
return {false, nogc};
}
}
inited = true;
return {true, nogc};
}
bool RootList::addRoot(Node node, const char16_t* edgeName) {
MOZ_ASSERT_IF(wantNames, edgeName);
UniqueTwoByteChars name;
if (edgeName) {
name = js::DuplicateString(edgeName);
if (!name) {
return false;
}
}
return edges.append(Edge(name.release(), node));
}
const char16_t Concrete<RootList>::concreteTypeName[] = u"JS::ubi::RootList";
UniquePtr<EdgeRange> Concrete<RootList>::edges(JSContext* cx,
bool wantNames) const {
MOZ_ASSERT_IF(wantNames, get().wantNames);
return js::MakeUnique<PreComputedEdgeRange>(get().edges);
}
bool SimpleEdgeRange::addTracerEdges(JSRuntime* rt, void* thing,
JS::TraceKind kind, bool wantNames) {
EdgeVectorTracer tracer(rt, &edges, wantNames);
JS::TraceChildren(&tracer, JS::GCCellPtr(thing, kind));
settle();
return tracer.okay;
}
void Concrete<JSObject>::construct(void* storage, JSObject* ptr) {
if (ptr) {
auto clasp = ptr->getClass();
auto callback = ptr->compartment()
->runtimeFromMainThread()
->constructUbiNodeForDOMObjectCallback;
if (clasp->isDOMClass() && callback) {
AutoSuppressGCAnalysis suppress;
callback(storage, ptr);
return;
}
}
new (storage) Concrete(ptr);
}
void SetConstructUbiNodeForDOMObjectCallback(JSContext* cx,
void (*callback)(void*,
JSObject*)) {
cx->runtime()->constructUbiNodeForDOMObjectCallback = callback;
}
JS_PUBLIC_API const char* CoarseTypeToString(CoarseType type) {
switch (type) {
case CoarseType::Other:
return "Other";
case CoarseType::Object:
return "Object";
case CoarseType::Script:
return "Script";
case CoarseType::String:
return "String";
case CoarseType::DOMNode:
return "DOMNode";
default:
return "Unknown";
}
};
} // namespace ubi
} // namespace JS