Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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
/*
* JS script operations.
*/
#include "vm/JSScript-inl.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Maybe.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PodOperations.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/Span.h" // mozilla::{Span,Span}
#include "mozilla/Sprintf.h"
#include "mozilla/Utf8.h"
#include "mozilla/Vector.h"
#include <algorithm>
#include <new>
#include <string.h>
#include <type_traits>
#include <utility>
#include "jstypes.h"
#include "frontend/BytecodeSection.h"
#include "frontend/CompilationStencil.h" // frontend::CompilationStencil
#include "frontend/FrontendContext.h" // AutoReportFrontendContext
#include "frontend/ParseContext.h"
#include "frontend/SourceNotes.h" // SrcNote, SrcNoteType, SrcNoteIterator
#include "frontend/Stencil.h" // DumpFunctionFlagsItems, DumpImmutableScriptFlags
#include "frontend/StencilXdr.h" // XDRStencilEncoder
#include "gc/GCContext.h"
#include "jit/BaselineJIT.h"
#include "jit/CacheIRHealth.h"
#include "jit/Ion.h"
#include "jit/IonScript.h"
#include "jit/JitCode.h"
#include "jit/JitOptions.h"
#include "jit/JitRuntime.h"
#include "js/CharacterEncoding.h" // JS_EncodeStringToUTF8
#include "js/ColumnNumber.h" // JS::LimitedColumnNumberOneOrigin, JS::ColumnNumberOneOrigin, JS::ColumnNumberOffset
#include "js/CompileOptions.h"
#include "js/experimental/SourceHook.h"
#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_*
#include "js/HeapAPI.h" // JS::GCCellPtr
#include "js/MemoryMetrics.h"
#include "js/Printer.h" // js::GenericPrinter, js::Fprinter, js::Sprinter, js::QuoteString
#include "js/Transcoding.h"
#include "js/UniquePtr.h"
#include "js/Utility.h" // JS::UniqueChars
#include "js/Value.h" // JS::Value
#include "util/Poison.h"
#include "util/StringBuffer.h"
#include "util/Text.h"
#include "vm/BigIntType.h" // JS::BigInt
#include "vm/BytecodeIterator.h"
#include "vm/BytecodeLocation.h"
#include "vm/BytecodeUtil.h" // Disassemble
#include "vm/Compression.h"
#include "vm/HelperThreadState.h" // js::RunPendingSourceCompressions
#include "vm/JSFunction.h"
#include "vm/JSObject.h"
#include "vm/JSONPrinter.h" // JSONPrinter
#include "vm/Opcodes.h"
#include "vm/PortableBaselineInterpret.h"
#include "vm/Scope.h" // Scope
#include "vm/SharedImmutableStringsCache.h"
#include "vm/StencilEnums.h" // TryNote, TryNoteKind, ScopeNote
#include "vm/StringType.h" // JSString, JSAtom
#include "vm/Time.h" // AutoIncrementalTimer
#include "vm/ToSource.h" // JS::ValueToSource
#ifdef MOZ_VTUNE
# include "vtune/VTuneWrapper.h"
#endif
#include "gc/Marking-inl.h"
#include "vm/BytecodeIterator-inl.h"
#include "vm/BytecodeLocation-inl.h"
#include "vm/Compartment-inl.h"
#include "vm/JSContext-inl.h"
#include "vm/JSObject-inl.h"
#include "vm/SharedImmutableStringsCache-inl.h"
#include "vm/Stack-inl.h"
using namespace js;
using mozilla::CheckedInt;
using mozilla::Maybe;
using mozilla::PodCopy;
using mozilla::PointerRangeSize;
using mozilla::Utf8AsUnsignedChars;
using mozilla::Utf8Unit;
using JS::CompileOptions;
using JS::ReadOnlyCompileOptions;
using JS::SourceText;
bool js::BaseScript::isUsingInterpreterTrampoline(JSRuntime* rt) const {
return jitCodeRaw() == rt->jitRuntime()->interpreterStub().value;
}
js::ScriptSource* js::BaseScript::maybeForwardedScriptSource() const {
return MaybeForwarded(sourceObject())->source();
}
void js::BaseScript::setEnclosingScript(BaseScript* enclosingScript) {
MOZ_ASSERT(enclosingScript);
warmUpData_.initEnclosingScript(enclosingScript);
}
void js::BaseScript::setEnclosingScope(Scope* enclosingScope) {
if (warmUpData_.isEnclosingScript()) {
warmUpData_.clearEnclosingScript();
}
MOZ_ASSERT(enclosingScope);
warmUpData_.initEnclosingScope(enclosingScope);
}
void js::BaseScript::finalize(JS::GCContext* gcx) {
// Scripts with bytecode may have optional data stored in per-runtime or
// per-zone maps. Note that a failed compilation must not have entries since
// the script itself will not be marked as having bytecode.
if (hasBytecode()) {
JSScript* script = this->asJSScript();
if (coverage::IsLCovEnabled()) {
coverage::CollectScriptCoverage(script, true);
}
script->destroyScriptCounts();
}
{
JSRuntime* rt = gcx->runtime();
if (rt->hasJitRuntime() && rt->jitRuntime()->hasInterpreterEntryMap()) {
rt->jitRuntime()->getInterpreterEntryMap()->remove(this);
}
rt->geckoProfiler().onScriptFinalized(this);
}
#ifdef MOZ_VTUNE
if (zone()->scriptVTuneIdMap) {
// Note: we should only get here if the VTune JIT profiler is running.
zone()->scriptVTuneIdMap->remove(this);
}
#endif
if (warmUpData_.isJitScript()) {
JSScript* script = this->asJSScript();
#ifdef JS_CACHEIR_SPEW
maybeUpdateWarmUpCount(script);
#endif
script->releaseJitScriptOnFinalize(gcx);
}
#ifdef JS_CACHEIR_SPEW
if (hasBytecode()) {
maybeSpewScriptFinalWarmUpCount(this->asJSScript());
}
#endif
if (data_) {
// We don't need to triger any barriers here, just free the memory.
size_t size = data_->allocationSize();
AlwaysPoison(data_, JS_POISONED_JSSCRIPT_DATA_PATTERN, size,
MemCheckKind::MakeNoAccess);
gcx->free_(this, data_, size, MemoryUse::ScriptPrivateData);
}
freeSharedData();
}
js::Scope* js::BaseScript::releaseEnclosingScope() {
Scope* enclosing = warmUpData_.toEnclosingScope();
warmUpData_.clearEnclosingScope();
return enclosing;
}
void js::BaseScript::swapData(UniquePtr<PrivateScriptData>& other) {
if (data_) {
RemoveCellMemory(this, data_->allocationSize(),
MemoryUse::ScriptPrivateData);
}
PrivateScriptData* old = data_;
data_.set(zone(), other.release());
other.reset(old);
if (data_) {
AddCellMemory(this, data_->allocationSize(), MemoryUse::ScriptPrivateData);
}
}
js::Scope* js::BaseScript::enclosingScope() const {
MOZ_ASSERT(!warmUpData_.isEnclosingScript(),
"Enclosing scope is not computed yet");
if (warmUpData_.isEnclosingScope()) {
return warmUpData_.toEnclosingScope();
}
MOZ_ASSERT(data_, "Script doesn't seem to be compiled");
return gcthings()[js::GCThingIndex::outermostScopeIndex()]
.as<Scope>()
.enclosing();
}
size_t JSScript::numAlwaysLiveFixedSlots() const {
if (bodyScope()->is<js::FunctionScope>()) {
return bodyScope()->as<js::FunctionScope>().nextFrameSlot();
}
if (bodyScope()->is<js::ModuleScope>()) {
return bodyScope()->as<js::ModuleScope>().nextFrameSlot();
}
if (bodyScope()->is<js::EvalScope>() &&
bodyScope()->kind() == ScopeKind::StrictEval) {
return bodyScope()->as<js::EvalScope>().nextFrameSlot();
}
return 0;
}
unsigned JSScript::numArgs() const {
if (bodyScope()->is<js::FunctionScope>()) {
return bodyScope()->as<js::FunctionScope>().numPositionalFormalParameters();
}
return 0;
}
bool JSScript::functionHasParameterExprs() const {
// Only functions have parameters.
js::Scope* scope = bodyScope();
if (!scope->is<js::FunctionScope>()) {
return false;
}
return scope->as<js::FunctionScope>().hasParameterExprs();
}
bool JSScript::isModule() const { return bodyScope()->is<js::ModuleScope>(); }
js::ModuleObject* JSScript::module() const {
MOZ_ASSERT(isModule());
return bodyScope()->as<js::ModuleScope>().module();
}
bool JSScript::isGlobalCode() const {
return bodyScope()->is<js::GlobalScope>();
}
js::VarScope* JSScript::functionExtraBodyVarScope() const {
MOZ_ASSERT(functionHasExtraBodyVarScope());
for (JS::GCCellPtr gcThing : gcthings()) {
if (!gcThing.is<js::Scope>()) {
continue;
}
js::Scope* scope = &gcThing.as<js::Scope>();
if (scope->kind() == js::ScopeKind::FunctionBodyVar) {
return &scope->as<js::VarScope>();
}
}
MOZ_CRASH("Function extra body var scope not found");
}
bool JSScript::needsBodyEnvironment() const {
for (JS::GCCellPtr gcThing : gcthings()) {
if (!gcThing.is<js::Scope>()) {
continue;
}
js::Scope* scope = &gcThing.as<js::Scope>();
if (ScopeKindIsInBody(scope->kind()) && scope->hasEnvironment()) {
return true;
}
}
return false;
}
bool JSScript::isDirectEvalInFunction() const {
if (!isForEval()) {
return false;
}
return bodyScope()->hasOnChain(js::ScopeKind::Function);
}
// Initialize the optional arrays in the trailing allocation. This is a set of
// offsets that delimit each optional array followed by the arrays themselves.
// See comment before 'ImmutableScriptData' for more details.
void ImmutableScriptData::initOptionalArrays(Offset* pcursor,
uint32_t numResumeOffsets,
uint32_t numScopeNotes,
uint32_t numTryNotes) {
Offset cursor = (*pcursor);
// The byte arrays must have already been padded.
MOZ_ASSERT(isAlignedOffset<CodeNoteAlign>(cursor),
"Bytecode and source notes should be padded to keep alignment");
// Each non-empty optional array needs will need an offset to its end.
unsigned numOptionalArrays = unsigned(numResumeOffsets > 0) +
unsigned(numScopeNotes > 0) +
unsigned(numTryNotes > 0);
// Default-initialize the optional-offsets.
initElements<Offset>(cursor, numOptionalArrays);
cursor += numOptionalArrays * sizeof(Offset);
// Offset between optional-offsets table and the optional arrays. This is
// later used to access the optional-offsets table as well as first optional
// array.
optArrayOffset_ = cursor;
// Each optional array that follows must store an end-offset in the offset
// table. Assign table entries by using this 'offsetIndex'. The index 0 is
// reserved for implicit value 'optArrayOffset'.
int offsetIndex = 0;
// Default-initialize optional 'resumeOffsets'.
MOZ_ASSERT(resumeOffsetsOffset() == cursor);
if (numResumeOffsets > 0) {
initElements<uint32_t>(cursor, numResumeOffsets);
cursor += numResumeOffsets * sizeof(uint32_t);
setOptionalOffset(++offsetIndex, cursor);
}
flagsRef().resumeOffsetsEndIndex = offsetIndex;
// Default-initialize optional 'scopeNotes'.
MOZ_ASSERT(scopeNotesOffset() == cursor);
if (numScopeNotes > 0) {
initElements<ScopeNote>(cursor, numScopeNotes);
cursor += numScopeNotes * sizeof(ScopeNote);
setOptionalOffset(++offsetIndex, cursor);
}
flagsRef().scopeNotesEndIndex = offsetIndex;
// Default-initialize optional 'tryNotes'
MOZ_ASSERT(tryNotesOffset() == cursor);
if (numTryNotes > 0) {
initElements<TryNote>(cursor, numTryNotes);
cursor += numTryNotes * sizeof(TryNote);
setOptionalOffset(++offsetIndex, cursor);
}
flagsRef().tryNotesEndIndex = offsetIndex;
MOZ_ASSERT(endOffset() == cursor);
(*pcursor) = cursor;
}
ImmutableScriptData::ImmutableScriptData(uint32_t codeLength,
uint32_t noteLength,
uint32_t numResumeOffsets,
uint32_t numScopeNotes,
uint32_t numTryNotes)
: codeLength_(codeLength) {
// Variable-length data begins immediately after ImmutableScriptData itself.
Offset cursor = sizeof(ImmutableScriptData);
// The following arrays are byte-aligned with additional padding to ensure
// that together they maintain uint32_t-alignment.
{
MOZ_ASSERT(isAlignedOffset<CodeNoteAlign>(cursor));
// Zero-initialize 'flags'
MOZ_ASSERT(isAlignedOffset<Flags>(cursor));
new (offsetToPointer<void>(cursor)) Flags{};
cursor += sizeof(Flags);
initElements<jsbytecode>(cursor, codeLength);
cursor += codeLength * sizeof(jsbytecode);
initElements<SrcNote>(cursor, noteLength);
cursor += noteLength * sizeof(SrcNote);
MOZ_ASSERT(isAlignedOffset<CodeNoteAlign>(cursor));
}
// Initialization for remaining arrays.
initOptionalArrays(&cursor, numResumeOffsets, numScopeNotes, numTryNotes);
// Check that we correctly recompute the expected values.
MOZ_ASSERT(this->codeLength() == codeLength);
MOZ_ASSERT(this->noteLength() == noteLength);
// Sanity check
MOZ_ASSERT(endOffset() == cursor);
}
void js::FillImmutableFlagsFromCompileOptionsForTopLevel(
const ReadOnlyCompileOptions& options, ImmutableScriptFlags& flags) {
using ImmutableFlags = ImmutableScriptFlagsEnum;
js::FillImmutableFlagsFromCompileOptionsForFunction(options, flags);
flags.setFlag(ImmutableFlags::TreatAsRunOnce, options.isRunOnce);
flags.setFlag(ImmutableFlags::NoScriptRval, options.noScriptRval);
}
void js::FillImmutableFlagsFromCompileOptionsForFunction(
const ReadOnlyCompileOptions& options, ImmutableScriptFlags& flags) {
using ImmutableFlags = ImmutableScriptFlagsEnum;
flags.setFlag(ImmutableFlags::SelfHosted, options.selfHostingMode);
flags.setFlag(ImmutableFlags::ForceStrict, options.forceStrictMode());
flags.setFlag(ImmutableFlags::HasNonSyntacticScope,
options.nonSyntacticScope);
}
// Check if flags matches to compile options for flags set by
// FillImmutableFlagsFromCompileOptionsForTopLevel above.
bool js::CheckCompileOptionsMatch(const ReadOnlyCompileOptions& options,
ImmutableScriptFlags flags) {
using ImmutableFlags = ImmutableScriptFlagsEnum;
bool selfHosted = !!(flags & uint32_t(ImmutableFlags::SelfHosted));
bool forceStrict = !!(flags & uint32_t(ImmutableFlags::ForceStrict));
bool hasNonSyntacticScope =
!!(flags & uint32_t(ImmutableFlags::HasNonSyntacticScope));
bool noScriptRval = !!(flags & uint32_t(ImmutableFlags::NoScriptRval));
bool treatAsRunOnce = !!(flags & uint32_t(ImmutableFlags::TreatAsRunOnce));
return options.selfHostingMode == selfHosted &&
options.noScriptRval == noScriptRval &&
options.isRunOnce == treatAsRunOnce &&
options.forceStrictMode() == forceStrict &&
options.nonSyntacticScope == hasNonSyntacticScope;
}
JS_PUBLIC_API bool JS::CheckCompileOptionsMatch(
const ReadOnlyCompileOptions& options, JSScript* script) {
return js::CheckCompileOptionsMatch(options, script->immutableFlags());
}
bool JSScript::initScriptCounts(JSContext* cx) {
MOZ_ASSERT(!hasScriptCounts());
// Record all pc which are the first instruction of a basic block.
mozilla::Vector<jsbytecode*, 16, SystemAllocPolicy> jumpTargets;
js::BytecodeLocation main = mainLocation();
AllBytecodesIterable iterable(this);
for (auto& loc : iterable) {
if (loc.isJumpTarget() || loc == main) {
if (!jumpTargets.append(loc.toRawBytecode())) {
ReportOutOfMemory(cx);
return false;
}
}
}
// Initialize all PCCounts counters to 0.
ScriptCounts::PCCountsVector base;
if (!base.reserve(jumpTargets.length())) {
ReportOutOfMemory(cx);
return false;
}
for (size_t i = 0; i < jumpTargets.length(); i++) {
base.infallibleEmplaceBack(pcToOffset(jumpTargets[i]));
}
// Create zone's scriptCountsMap if necessary.
if (!zone()->scriptCountsMap) {
auto map = cx->make_unique<ScriptCountsMap>();
if (!map) {
return false;
}
zone()->scriptCountsMap = std::move(map);
}
// Allocate the ScriptCounts.
UniqueScriptCounts sc = cx->make_unique<ScriptCounts>(std::move(base));
if (!sc) {
return false;
}
MOZ_ASSERT(this->hasBytecode());
// Register the current ScriptCounts in the zone's map.
if (!zone()->scriptCountsMap->putNew(this, std::move(sc))) {
ReportOutOfMemory(cx);
return false;
}
// safe to set this; we can't fail after this point.
setHasScriptCounts();
// Enable interrupts in any interpreter frames running on this script. This
// is used to let the interpreter increment the PCCounts, if present.
for (ActivationIterator iter(cx); !iter.done(); ++iter) {
if (iter->isInterpreter()) {
iter->asInterpreter()->enableInterruptsIfRunning(this);
}
}
return true;
}
static inline ScriptCountsMap::Ptr GetScriptCountsMapEntry(JSScript* script) {
MOZ_ASSERT(script->hasScriptCounts());
ScriptCountsMap::Ptr p = script->zone()->scriptCountsMap->lookup(script);
MOZ_ASSERT(p);
return p;
}
ScriptCounts& JSScript::getScriptCounts() {
ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this);
return *p->value();
}
js::PCCounts* ScriptCounts::maybeGetPCCounts(size_t offset) {
PCCounts searched = PCCounts(offset);
PCCounts* elem =
std::lower_bound(pcCounts_.begin(), pcCounts_.end(), searched);
if (elem == pcCounts_.end() || elem->pcOffset() != offset) {
return nullptr;
}
return elem;
}
const js::PCCounts* ScriptCounts::maybeGetPCCounts(size_t offset) const {
PCCounts searched = PCCounts(offset);
const PCCounts* elem =
std::lower_bound(pcCounts_.begin(), pcCounts_.end(), searched);
if (elem == pcCounts_.end() || elem->pcOffset() != offset) {
return nullptr;
}
return elem;
}
js::PCCounts* ScriptCounts::getImmediatePrecedingPCCounts(size_t offset) {
PCCounts searched = PCCounts(offset);
PCCounts* elem =
std::lower_bound(pcCounts_.begin(), pcCounts_.end(), searched);
if (elem == pcCounts_.end()) {
return &pcCounts_.back();
}
if (elem->pcOffset() == offset) {
return elem;
}
if (elem != pcCounts_.begin()) {
return elem - 1;
}
return nullptr;
}
const js::PCCounts* ScriptCounts::maybeGetThrowCounts(size_t offset) const {
PCCounts searched = PCCounts(offset);
const PCCounts* elem =
std::lower_bound(throwCounts_.begin(), throwCounts_.end(), searched);
if (elem == throwCounts_.end() || elem->pcOffset() != offset) {
return nullptr;
}
return elem;
}
const js::PCCounts* ScriptCounts::getImmediatePrecedingThrowCounts(
size_t offset) const {
PCCounts searched = PCCounts(offset);
const PCCounts* elem =
std::lower_bound(throwCounts_.begin(), throwCounts_.end(), searched);
if (elem == throwCounts_.end()) {
if (throwCounts_.begin() == throwCounts_.end()) {
return nullptr;
}
return &throwCounts_.back();
}
if (elem->pcOffset() == offset) {
return elem;
}
if (elem != throwCounts_.begin()) {
return elem - 1;
}
return nullptr;
}
js::PCCounts* ScriptCounts::getThrowCounts(size_t offset) {
PCCounts searched = PCCounts(offset);
PCCounts* elem =
std::lower_bound(throwCounts_.begin(), throwCounts_.end(), searched);
if (elem == throwCounts_.end() || elem->pcOffset() != offset) {
elem = throwCounts_.insert(elem, searched);
}
return elem;
}
size_t ScriptCounts::sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) {
size_t size = mallocSizeOf(this);
size += pcCounts_.sizeOfExcludingThis(mallocSizeOf);
size += throwCounts_.sizeOfExcludingThis(mallocSizeOf);
if (ionCounts_) {
size += ionCounts_->sizeOfIncludingThis(mallocSizeOf);
}
return size;
}
js::PCCounts* JSScript::maybeGetPCCounts(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc));
return getScriptCounts().maybeGetPCCounts(pcToOffset(pc));
}
const js::PCCounts* JSScript::maybeGetThrowCounts(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc));
return getScriptCounts().maybeGetThrowCounts(pcToOffset(pc));
}
js::PCCounts* JSScript::getThrowCounts(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc));
return getScriptCounts().getThrowCounts(pcToOffset(pc));
}
uint64_t JSScript::getHitCount(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc));
if (pc < main()) {
pc = main();
}
ScriptCounts& sc = getScriptCounts();
size_t targetOffset = pcToOffset(pc);
const js::PCCounts* baseCount =
sc.getImmediatePrecedingPCCounts(targetOffset);
if (!baseCount) {
return 0;
}
if (baseCount->pcOffset() == targetOffset) {
return baseCount->numExec();
}
MOZ_ASSERT(baseCount->pcOffset() < targetOffset);
uint64_t count = baseCount->numExec();
do {
const js::PCCounts* throwCount =
sc.getImmediatePrecedingThrowCounts(targetOffset);
if (!throwCount) {
return count;
}
if (throwCount->pcOffset() <= baseCount->pcOffset()) {
return count;
}
count -= throwCount->numExec();
targetOffset = throwCount->pcOffset() - 1;
} while (true);
}
void JSScript::addIonCounts(jit::IonScriptCounts* ionCounts) {
ScriptCounts& sc = getScriptCounts();
if (sc.ionCounts_) {
ionCounts->setPrevious(sc.ionCounts_);
}
sc.ionCounts_ = ionCounts;
}
jit::IonScriptCounts* JSScript::getIonCounts() {
return getScriptCounts().ionCounts_;
}
void JSScript::releaseScriptCounts(ScriptCounts* counts) {
ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this);
*counts = std::move(*p->value().get());
zone()->scriptCountsMap->remove(p);
clearHasScriptCounts();
}
void JSScript::destroyScriptCounts() {
if (hasScriptCounts()) {
ScriptCounts scriptCounts;
releaseScriptCounts(&scriptCounts);
}
}
void JSScript::resetScriptCounts() {
if (!hasScriptCounts()) {
return;
}
ScriptCounts& sc = getScriptCounts();
for (PCCounts& elem : sc.pcCounts_) {
elem.numExec() = 0;
}
for (PCCounts& elem : sc.throwCounts_) {
elem.numExec() = 0;
}
}
void ScriptSourceObject::finalize(JS::GCContext* gcx, JSObject* obj) {
MOZ_ASSERT(gcx->onMainThread());
ScriptSourceObject* sso = &obj->as<ScriptSourceObject>();
sso->source()->Release();
// Clear the private value, calling the release hook if necessary.
sso->setPrivate(gcx->runtime(), UndefinedValue());
}
static const JSClassOps ScriptSourceObjectClassOps = {
nullptr, // addProperty
nullptr, // delProperty
nullptr, // enumerate
nullptr, // newEnumerate
nullptr, // resolve
nullptr, // mayResolve
ScriptSourceObject::finalize, // finalize
nullptr, // call
nullptr, // construct
nullptr, // trace
};
const JSClass ScriptSourceObject::class_ = {
"ScriptSource",
JSCLASS_HAS_RESERVED_SLOTS(RESERVED_SLOTS) | JSCLASS_FOREGROUND_FINALIZE,
&ScriptSourceObjectClassOps};
ScriptSourceObject* ScriptSourceObject::create(JSContext* cx,
ScriptSource* source) {
ScriptSourceObject* obj =
NewObjectWithGivenProto<ScriptSourceObject>(cx, nullptr);
if (!obj) {
return nullptr;
}
// The matching decref is in ScriptSourceObject::finalize.
obj->initReservedSlot(SOURCE_SLOT, PrivateValue(do_AddRef(source).take()));
// The slots below should be populated by a call to initFromOptions. Poison
// them.
obj->initReservedSlot(ELEMENT_PROPERTY_SLOT, MagicValue(JS_GENERIC_MAGIC));
obj->initReservedSlot(INTRODUCTION_SCRIPT_SLOT, MagicValue(JS_GENERIC_MAGIC));
return obj;
}
[[nodiscard]] static bool MaybeValidateFilename(
JSContext* cx, Handle<ScriptSourceObject*> sso,
const JS::InstantiateOptions& options) {
if (!gFilenameValidationCallback) {
return true;
}
const char* filename = sso->source()->filename();
if (!filename || options.skipFilenameValidation) {
return true;
}
if (gFilenameValidationCallback(cx, filename)) {
return true;
}
const char* utf8Filename;
if (mozilla::IsUtf8(mozilla::MakeStringSpan(filename))) {
utf8Filename = filename;
} else {
utf8Filename = "(invalid UTF-8 filename)";
}
JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, JSMSG_UNSAFE_FILENAME,
utf8Filename);
return false;
}
/* static */
bool ScriptSourceObject::initFromOptions(
JSContext* cx, Handle<ScriptSourceObject*> source,
const JS::InstantiateOptions& options) {
cx->releaseCheck(source);
MOZ_ASSERT(
source->getReservedSlot(ELEMENT_PROPERTY_SLOT).isMagic(JS_GENERIC_MAGIC));
MOZ_ASSERT(source->getReservedSlot(INTRODUCTION_SCRIPT_SLOT)
.isMagic(JS_GENERIC_MAGIC));
if (!MaybeValidateFilename(cx, source, options)) {
return false;
}
if (options.deferDebugMetadata) {
return true;
}
// Initialize the element attribute slot and introduction script slot
// this marks the SSO as initialized for asserts.
RootedString elementAttributeName(cx);
if (!initElementProperties(cx, source, elementAttributeName)) {
return false;
}
RootedValue introductionScript(cx);
source->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, introductionScript);
return true;
}
/* static */
bool ScriptSourceObject::initElementProperties(
JSContext* cx, Handle<ScriptSourceObject*> source,
HandleString elementAttrName) {
RootedValue nameValue(cx);
if (elementAttrName) {
nameValue = StringValue(elementAttrName);
}
if (!cx->compartment()->wrap(cx, &nameValue)) {
return false;
}
source->setReservedSlot(ELEMENT_PROPERTY_SLOT, nameValue);
return true;
}
void ScriptSourceObject::setPrivate(JSRuntime* rt, const Value& value) {
// Update the private value, calling addRef/release hooks if necessary
// to allow the embedding to maintain a reference count for the
// private data.
JS::AutoSuppressGCAnalysis nogc;
Value prevValue = getReservedSlot(PRIVATE_SLOT);
rt->releaseScriptPrivate(prevValue);
setReservedSlot(PRIVATE_SLOT, value);
rt->addRefScriptPrivate(value);
}
void ScriptSourceObject::clearPrivate(JSRuntime* rt) {
// Clear the private value, calling release hook if necessary.
// |this| may be gray, be careful not to create edges to it.
JS::AutoSuppressGCAnalysis nogc;
Value prevValue = getReservedSlot(PRIVATE_SLOT);
rt->releaseScriptPrivate(prevValue);
getSlotRef(PRIVATE_SLOT).setUndefinedUnchecked();
}
class ScriptSource::LoadSourceMatcher {
JSContext* const cx_;
ScriptSource* const ss_;
bool* const loaded_;
public:
explicit LoadSourceMatcher(JSContext* cx, ScriptSource* ss, bool* loaded)
: cx_(cx), ss_(ss), loaded_(loaded) {}
template <typename Unit, SourceRetrievable CanRetrieve>
bool operator()(const Compressed<Unit, CanRetrieve>&) const {
*loaded_ = true;
return true;
}
template <typename Unit, SourceRetrievable CanRetrieve>
bool operator()(const Uncompressed<Unit, CanRetrieve>&) const {
*loaded_ = true;
return true;
}
template <typename Unit>
bool operator()(const Retrievable<Unit>&) {
if (!cx_->runtime()->sourceHook.ref()) {
*loaded_ = false;
return true;
}
size_t length;
// The first argument is just for overloading -- its value doesn't matter.
if (!tryLoadAndSetSource(Unit('0'), &length)) {
return false;
}
return true;
}
bool operator()(const Missing&) const {
*loaded_ = false;
return true;
}
private:
bool tryLoadAndSetSource(const Utf8Unit&, size_t* length) const {
char* utf8Source;
if (!cx_->runtime()->sourceHook->load(cx_, ss_->filename(), nullptr,
&utf8Source, length)) {
return false;
}
if (!utf8Source) {
*loaded_ = false;
return true;
}
if (!ss_->setRetrievedSource(
cx_, EntryUnits<Utf8Unit>(reinterpret_cast<Utf8Unit*>(utf8Source)),
*length)) {
return false;
}
*loaded_ = true;
return true;
}
bool tryLoadAndSetSource(const char16_t&, size_t* length) const {
char16_t* utf16Source;
if (!cx_->runtime()->sourceHook->load(cx_, ss_->filename(), &utf16Source,
nullptr, length)) {
return false;
}
if (!utf16Source) {
*loaded_ = false;
return true;
}
if (!ss_->setRetrievedSource(cx_, EntryUnits<char16_t>(utf16Source),
*length)) {
return false;
}
*loaded_ = true;
return true;
}
};
/* static */
bool ScriptSource::loadSource(JSContext* cx, ScriptSource* ss, bool* loaded) {
return ss->data.match(LoadSourceMatcher(cx, ss, loaded));
}
/* static */
JSLinearString* JSScript::sourceData(JSContext* cx, HandleScript script) {
MOZ_ASSERT(script->scriptSource()->hasSourceText());
return script->scriptSource()->substring(cx, script->sourceStart(),
script->sourceEnd());
}
bool BaseScript::appendSourceDataForToString(JSContext* cx, StringBuffer& buf) {
MOZ_ASSERT(scriptSource()->hasSourceText());
return scriptSource()->appendSubstring(cx, buf, toStringStart(),
toStringEnd());
}
void UncompressedSourceCache::holdEntry(AutoHoldEntry& holder,
const ScriptSourceChunk& ssc) {
MOZ_ASSERT(!holder_);
holder.holdEntry(this, ssc);
holder_ = &holder;
}
void UncompressedSourceCache::releaseEntry(AutoHoldEntry& holder) {
MOZ_ASSERT(holder_ == &holder);
holder_ = nullptr;
}
template <typename Unit>
const Unit* UncompressedSourceCache::lookup(const ScriptSourceChunk& ssc,
AutoHoldEntry& holder) {
MOZ_ASSERT(!holder_);
MOZ_ASSERT(ssc.ss->isCompressed<Unit>());
if (!map_) {
return nullptr;
}
if (Map::Ptr p = map_->lookup(ssc)) {
holdEntry(holder, ssc);
return static_cast<const Unit*>(p->value().get());
}
return nullptr;
}
bool UncompressedSourceCache::put(const ScriptSourceChunk& ssc, SourceData data,
AutoHoldEntry& holder) {
MOZ_ASSERT(!holder_);
if (!map_) {
map_ = MakeUnique<Map>();
if (!map_) {
return false;
}
}
if (!map_->put(ssc, std::move(data))) {
return false;
}
holdEntry(holder, ssc);
return true;
}
void UncompressedSourceCache::purge() {
if (!map_) {
return;
}
for (Map::Range r = map_->all(); !r.empty(); r.popFront()) {
if (holder_ && r.front().key() == holder_->sourceChunk()) {
holder_->deferDelete(std::move(r.front().value()));
holder_ = nullptr;
}
}
map_ = nullptr;
}
size_t UncompressedSourceCache::sizeOfExcludingThis(
mozilla::MallocSizeOf mallocSizeOf) {
size_t n = 0;
if (map_ && !map_->empty()) {
n += map_->shallowSizeOfIncludingThis(mallocSizeOf);
for (Map::Range r = map_->all(); !r.empty(); r.popFront()) {
n += mallocSizeOf(r.front().value().get());
}
}
return n;
}
template <typename Unit>
const Unit* ScriptSource::chunkUnits(
JSContext* cx, UncompressedSourceCache::AutoHoldEntry& holder,
size_t chunk) {
const CompressedData<Unit>& c = *compressedData<Unit>();
ScriptSourceChunk ssc(this, chunk);
if (const Unit* decompressed =
cx->caches().uncompressedSourceCache.lookup<Unit>(ssc, holder)) {
return decompressed;
}
size_t totalLengthInBytes = length() * sizeof(Unit);
size_t chunkBytes = Compressor::chunkSize(totalLengthInBytes, chunk);
MOZ_ASSERT((chunkBytes % sizeof(Unit)) == 0);
const size_t chunkLength = chunkBytes / sizeof(Unit);
EntryUnits<Unit> decompressed(js_pod_malloc<Unit>(chunkLength));
if (!decompressed) {
JS_ReportOutOfMemory(cx);
return nullptr;
}
// Compression treats input and output memory as plain ol' bytes. These
// reinterpret_cast<>s accord exactly with that.
if (!DecompressStringChunk(
reinterpret_cast<const unsigned char*>(c.raw.chars()), chunk,
reinterpret_cast<unsigned char*>(decompressed.get()), chunkBytes)) {
JS_ReportOutOfMemory(cx);
return nullptr;
}
const Unit* ret = decompressed.get();
if (!cx->caches().uncompressedSourceCache.put(
ssc, ToSourceData(std::move(decompressed)), holder)) {
JS_ReportOutOfMemory(cx);
return nullptr;
}
return ret;
}
template <typename Unit>
void ScriptSource::convertToCompressedSource(SharedImmutableString compressed,
size_t uncompressedLength) {
MOZ_ASSERT(isUncompressed<Unit>());
MOZ_ASSERT(uncompressedData<Unit>()->length() == uncompressedLength);
if (data.is<Uncompressed<Unit, SourceRetrievable::Yes>>()) {
data = SourceType(Compressed<Unit, SourceRetrievable::Yes>(
std::move(compressed), uncompressedLength));
} else {
data = SourceType(Compressed<Unit, SourceRetrievable::No>(
std::move(compressed), uncompressedLength));
}
}
template <typename Unit>
void ScriptSource::performDelayedConvertToCompressedSource(
ExclusiveData<ReaderInstances>::Guard& g) {
// There might not be a conversion to compressed source happening at all.
if (g->pendingCompressed.empty()) {
return;
}
CompressedData<Unit>& pending =
g->pendingCompressed.ref<CompressedData<Unit>>();
convertToCompressedSource<Unit>(std::move(pending.raw),
pending.uncompressedLength);
g->pendingCompressed.destroy();
}
void ScriptSource::PinnedUnitsBase::addReader() {
auto guard = source_->readers_.lock();
guard->count++;
}
template <typename Unit>
void ScriptSource::PinnedUnitsBase::removeReader() {
// Note: We use a Mutex with Exclusive access, such that no PinnedUnits
// instance is live while we are compressing the source.
auto guard = source_->readers_.lock();
MOZ_ASSERT(guard->count > 0);
if (--guard->count) {
source_->performDelayedConvertToCompressedSource<Unit>(guard);
}
}
template <typename Unit>
ScriptSource::PinnedUnits<Unit>::~PinnedUnits() {
if (units_) {
removeReader<Unit>();
}
}
template <typename Unit>
ScriptSource::PinnedUnitsIfUncompressed<Unit>::~PinnedUnitsIfUncompressed() {
if (units_) {
removeReader<Unit>();
}
}
template <typename Unit>
const Unit* ScriptSource::units(JSContext* cx,
UncompressedSourceCache::AutoHoldEntry& holder,
size_t begin, size_t len) {
MOZ_ASSERT(begin <= length());
MOZ_ASSERT(begin + len <= length());
if (isUncompressed<Unit>()) {
const Unit* units = uncompressedData<Unit>()->units();
if (!units) {
return nullptr;
}
return units + begin;
}
if (data.is<Missing>()) {
MOZ_CRASH("ScriptSource::units() on ScriptSource with missing source");
}
if (data.is<Retrievable<Unit>>()) {
MOZ_CRASH("ScriptSource::units() on ScriptSource with retrievable source");
}
MOZ_ASSERT(isCompressed<Unit>());
// Determine first/last chunks, the offset (in bytes) into the first chunk
// of the requested units, and the number of bytes in the last chunk.
//
// Note that first and last chunk sizes are miscomputed and *must not be
// used* when the first chunk is the last chunk.
size_t firstChunk, firstChunkOffset, firstChunkSize;
size_t lastChunk, lastChunkSize;
Compressor::rangeToChunkAndOffset(
begin * sizeof(Unit), (begin + len) * sizeof(Unit), &firstChunk,
&firstChunkOffset, &firstChunkSize, &lastChunk, &lastChunkSize);
MOZ_ASSERT(firstChunk <= lastChunk);
MOZ_ASSERT(firstChunkOffset % sizeof(Unit) == 0);
MOZ_ASSERT(firstChunkSize % sizeof(Unit) == 0);
size_t firstUnit = firstChunkOffset / sizeof(Unit);
// Directly return units within a single chunk. UncompressedSourceCache
// and |holder| will hold the units alive past function return.
if (firstChunk == lastChunk) {
const Unit* units = chunkUnits<Unit>(cx, holder, firstChunk);
if (!units) {
return nullptr;
}
return units + firstUnit;
}
// Otherwise the units span multiple chunks. Copy successive chunks'
// decompressed units into freshly-allocated memory to return.
EntryUnits<Unit> decompressed(js_pod_malloc<Unit>(len));
if (!decompressed) {
JS_ReportOutOfMemory(cx);
return nullptr;
}
Unit* cursor;
{
// |AutoHoldEntry| is single-shot, and a holder successfully filled in
// by |chunkUnits| must be destroyed before another can be used. Thus
// we can't use |holder| with |chunkUnits| when |chunkUnits| is used
// with multiple chunks, and we must use and destroy distinct, fresh
// holders for each chunk.
UncompressedSourceCache::AutoHoldEntry firstHolder;
const Unit* units = chunkUnits<Unit>(cx, firstHolder, firstChunk);
if (!units) {
return nullptr;
}
cursor = std::copy_n(units + firstUnit, firstChunkSize / sizeof(Unit),
decompressed.get());
}
for (size_t i = firstChunk + 1; i < lastChunk; i++) {
UncompressedSourceCache::AutoHoldEntry chunkHolder;
const Unit* units = chunkUnits<Unit>(cx, chunkHolder, i);
if (!units) {
return nullptr;
}
cursor = std::copy_n(units, Compressor::CHUNK_SIZE / sizeof(Unit), cursor);
}
{
UncompressedSourceCache::AutoHoldEntry lastHolder;
const Unit* units = chunkUnits<Unit>(cx, lastHolder, lastChunk);
if (!units) {
return nullptr;
}
cursor = std::copy_n(units, lastChunkSize / sizeof(Unit), cursor);
}
MOZ_ASSERT(PointerRangeSize(decompressed.get(), cursor) == len);
// Transfer ownership to |holder|.
const Unit* ret = decompressed.get();
holder.holdUnits(std::move(decompressed));
return ret;
}
template <typename Unit>
const Unit* ScriptSource::uncompressedUnits(size_t begin, size_t len) {
MOZ_ASSERT(begin <= length());
MOZ_ASSERT(begin + len <= length());
if (!isUncompressed<Unit>()) {
return nullptr;
}
const Unit* units = uncompressedData<Unit>()->units();
if (!units) {
return nullptr;
}
return units + begin;
}
template <typename Unit>
ScriptSource::PinnedUnits<Unit>::PinnedUnits(
JSContext* cx, ScriptSource* source,
UncompressedSourceCache::AutoHoldEntry& holder, size_t begin, size_t len)
: PinnedUnitsBase(source) {
MOZ_ASSERT(source->hasSourceType<Unit>(), "must pin units of source's type");
units_ = source->units<Unit>(cx, holder, begin, len);
if (units_) {
addReader();
}
}
template class ScriptSource::PinnedUnits<Utf8Unit>;
template class ScriptSource::PinnedUnits<char16_t>;
template <typename Unit>
ScriptSource::PinnedUnitsIfUncompressed<Unit>::PinnedUnitsIfUncompressed(
ScriptSource* source, size_t begin, size_t len)
: PinnedUnitsBase(source) {
MOZ_ASSERT(source->hasSourceType<Unit>(), "must pin units of source's type");
units_ = source->uncompressedUnits<Unit>(begin, len);
if (units_) {
addReader();
}
}
template class ScriptSource::PinnedUnitsIfUncompressed<Utf8Unit>;
template class ScriptSource::PinnedUnitsIfUncompressed<char16_t>;
JSLinearString* ScriptSource::substring(JSContext* cx, size_t start,
size_t stop) {
MOZ_ASSERT(start <= stop);
size_t len = stop - start;
if (!len) {
return cx->emptyString();
}
UncompressedSourceCache::AutoHoldEntry holder;
// UTF-8 source text.
if (hasSourceType<Utf8Unit>()) {
PinnedUnits<Utf8Unit> units(cx, this, holder, start, len);
if (!units.asChars()) {
return nullptr;
}
const char* str = units.asChars();
return NewStringCopyUTF8N(cx, JS::UTF8Chars(str, len));
}
// UTF-16 source text.
PinnedUnits<char16_t> units(cx, this, holder, start, len);
if (!units.asChars()) {
return nullptr;
}
return NewStringCopyN<CanGC>(cx, units.asChars(), len);
}
JSLinearString* ScriptSource::substringDontDeflate(JSContext* cx, size_t start,
size_t stop) {
MOZ_ASSERT(start <= stop);
size_t len = stop - start;
if (!len) {
return cx->emptyString();
}
UncompressedSourceCache::AutoHoldEntry holder;
// UTF-8 source text.
if (hasSourceType<Utf8Unit>()) {
PinnedUnits<Utf8Unit> units(cx, this, holder, start, len);
if (!units.asChars()) {
return nullptr;
}
const char* str = units.asChars();
// There doesn't appear to be a non-deflating UTF-8 string creation
// function -- but then again, it's not entirely clear how current
// callers benefit from non-deflation.
return NewStringCopyUTF8N(cx, JS::UTF8Chars(str, len));
}
// UTF-16 source text.
PinnedUnits<char16_t> units(cx, this, holder, start, len);
if (!units.asChars()) {
return nullptr;
}
return NewStringCopyNDontDeflate<CanGC>(cx, units.asChars(), len);
}
bool ScriptSource::appendSubstring(JSContext* cx, StringBuffer& buf,
size_t start, size_t stop) {
MOZ_ASSERT(start <= stop);
size_t len = stop - start;
UncompressedSourceCache::AutoHoldEntry holder;
if (hasSourceType<Utf8Unit>()) {
PinnedUnits<Utf8Unit> pinned(cx, this, holder, start, len);
if (!pinned.get()) {
return false;
}
if (len > SourceDeflateLimit && !buf.ensureTwoByteChars()) {
return false;
}
const Utf8Unit* units = pinned.get();
return buf.append(units, len);
} else {
PinnedUnits<char16_t> pinned(cx, this, holder, start, len);
if (!pinned.get()) {
return false;
}
if (len > SourceDeflateLimit && !buf.ensureTwoByteChars()) {
return false;
}
const char16_t* units = pinned.get();
return buf.append(units, len);
}
}
JSLinearString* ScriptSource::functionBodyString(JSContext* cx) {
MOZ_ASSERT(isFunctionBody());
size_t start = parameterListEnd_ + FunctionConstructorMedialSigils.length();
size_t stop = length() - FunctionConstructorFinalBrace.length();
return substring(cx, start, stop);
}
template <typename ContextT, typename Unit>
[[nodiscard]] bool ScriptSource::setUncompressedSourceHelper(
ContextT* cx, EntryUnits<Unit>&& source, size_t length,
SourceRetrievable retrievable) {
auto& cache = SharedImmutableStringsCache::getSingleton();
auto uniqueChars = SourceTypeTraits<Unit>::toCacheable(std::move(source));
auto deduped = cache.getOrCreate(std::move(uniqueChars), length);
if (!deduped) {
ReportOutOfMemory(cx);
return false;
}
if (retrievable == SourceRetrievable::Yes) {
data = SourceType(
Uncompressed<Unit, SourceRetrievable::Yes>(std::move(deduped)));
} else {
data = SourceType(
Uncompressed<Unit, SourceRetrievable::No>(std::move(deduped)));
}
return true;
}
template <typename Unit>
[[nodiscard]] bool ScriptSource::setRetrievedSource(JSContext* cx,
EntryUnits<Unit>&& source,
size_t length) {
MOZ_ASSERT(data.is<Retrievable<Unit>>(),
"retrieved source can only overwrite the corresponding "
"retrievable source");
return setUncompressedSourceHelper(cx, std::move(source), length,
SourceRetrievable::Yes);
}
bool js::IsOffThreadSourceCompressionEnabled() {
// If we don't have concurrent execution compression will contend with
// main-thread execution, in which case we disable. Similarly we don't want to
// block the thread pool if it is too small.
return GetHelperThreadCPUCount() > 1 && GetHelperThreadCount() > 1 &&
CanUseExtraThreads();
}
bool ScriptSource::tryCompressOffThread(JSContext* cx) {
// Beware: |js::SynchronouslyCompressSource| assumes that this function is
// only called once, just after a script has been compiled, and it's never
// called at some random time after that. If multiple calls of this can ever
// occur, that function may require changes.
// The SourceCompressionTask needs to record the major GC number for
// scheduling.
MOZ_ASSERT(CurrentThreadCanAccessRuntime(cx->runtime()));
// If source compression was already attempted, do not queue a new task.
if (hadCompressionTask_) {
return true;
}
if (!hasUncompressedSource()) {
// This excludes compressed, missing, and retrievable source.
return true;
}
// There are several cases where source compression is not a good idea:
// - If the script is tiny, then compression will save little or no space.
// - If there is only one core, then compression will contend with JS
// execution (which hurts benchmarketing).
//
// Otherwise, enqueue a compression task to be processed when a major
// GC is requested.
if (length() < ScriptSource::MinimumCompressibleLength ||
!IsOffThreadSourceCompressionEnabled()) {
return true;
}
// Heap allocate the task. It will be freed upon compression
// completing in AttachFinishedCompressedSources.
auto task = MakeUnique<SourceCompressionTask>(cx->runtime(), this);
if (!task) {
ReportOutOfMemory(cx);
return false;
}
return EnqueueOffThreadCompression(cx, std::move(task));
}
template <typename Unit>
void ScriptSource::triggerConvertToCompressedSource(
SharedImmutableString compressed, size_t uncompressedLength) {
MOZ_ASSERT(isUncompressed<Unit>(),
"should only be triggering compressed source installation to "
"overwrite identically-encoded uncompressed source");
MOZ_ASSERT(uncompressedData<Unit>()->length() == uncompressedLength);
// If units aren't pinned -- and they probably won't be, we'd have to have a
// GC in the small window of time where a |PinnedUnits| was live -- then we
// can immediately convert.
{
auto guard = readers_.lock();
if (MOZ_LIKELY(!guard->count)) {
convertToCompressedSource<Unit>(std::move(compressed),
uncompressedLength);
return;
}
// Otherwise, set aside the compressed-data info. The conversion is
// performed when the last |PinnedUnits| dies.
MOZ_ASSERT(guard->pendingCompressed.empty(),
"shouldn't be multiple conversions happening");
guard->pendingCompressed.construct<CompressedData<Unit>>(
std::move(compressed), uncompressedLength);
}
}
template <typename Unit>
[[nodiscard]] bool ScriptSource::initializeWithUnretrievableCompressedSource(
FrontendContext* fc, UniqueChars&& compressed, size_t rawLength,
size_t sourceLength) {
MOZ_ASSERT(data.is<Missing>(), "shouldn't be double-initializing");
MOZ_ASSERT(compressed != nullptr);
auto& cache = SharedImmutableStringsCache::getSingleton();
auto deduped = cache.getOrCreate(std::move(compressed), rawLength);
if (!deduped) {
ReportOutOfMemory(fc);
return false;
}
#ifdef DEBUG
{
auto guard = readers_.lock();
MOZ_ASSERT(
guard->count == 0,
"shouldn't be initializing a ScriptSource while its characters "
"are pinned -- that only makes sense with a ScriptSource actively "
"being inspected");
}
#endif
data = SourceType(Compressed<Unit, SourceRetrievable::No>(std::move(deduped),
sourceLength));
return true;
}
template bool ScriptSource::initializeWithUnretrievableCompressedSource<
Utf8Unit>(FrontendContext* fc, UniqueChars&& compressed, size_t rawLength,
size_t sourceLength);
template bool ScriptSource::initializeWithUnretrievableCompressedSource<
char16_t>(FrontendContext* fc, UniqueChars&& compressed, size_t rawLength,
size_t sourceLength);
template <typename Unit>
bool ScriptSource::assignSource(FrontendContext* fc,
const ReadOnlyCompileOptions& options,
SourceText<Unit>& srcBuf) {
MOZ_ASSERT(data.is<Missing>(),
"source assignment should only occur on fresh ScriptSources");
mutedErrors_ = options.mutedErrors();
delazificationMode_ = options.eagerDelazificationStrategy();
if (options.discardSource) {
return true;
}
if (options.sourceIsLazy) {
data = SourceType(Retrievable<Unit>());
return true;
}
auto& cache = SharedImmutableStringsCache::getSingleton();
auto deduped = cache.getOrCreate(srcBuf.get(), srcBuf.length(), [&srcBuf]() {
using CharT = typename SourceTypeTraits<Unit>::CharT;
return srcBuf.ownsUnits()
? UniquePtr<CharT[], JS::FreePolicy>(srcBuf.takeChars())
: DuplicateString(srcBuf.get(), srcBuf.length());
});
if (!deduped) {
ReportOutOfMemory(fc);
return false;
}
data =
SourceType(Uncompressed<Unit, SourceRetrievable::No>(std::move(deduped)));
return true;
}
template bool ScriptSource::assignSource(FrontendContext* fc,
const ReadOnlyCompileOptions& options,
SourceText<char16_t>& srcBuf);
template bool ScriptSource::assignSource(FrontendContext* fc,
const ReadOnlyCompileOptions& options,
SourceText<Utf8Unit>& srcBuf);
[[nodiscard]] static bool reallocUniquePtr(UniqueChars& unique, size_t size) {
auto newPtr = static_cast<char*>(js_realloc(unique.get(), size));
if (!newPtr) {
return false;
}
// Since the realloc succeeded, unique is now holding a freed pointer.
(void)unique.release();
unique.reset(newPtr);
return true;
}
template <typename Unit>
void SourceCompressionTask::workEncodingSpecific() {
MOZ_ASSERT(source_->isUncompressed<Unit>());
// Try to keep the maximum memory usage down by only allocating half the
// size of the string, first.
size_t inputBytes = source_->length() * sizeof(Unit);
size_t firstSize = inputBytes / 2;
UniqueChars compressed(js_pod_malloc<char>(firstSize));
if (!compressed) {
return;
}
const Unit* chars = source_->uncompressedData<Unit>()->units();
Compressor comp(reinterpret_cast<const unsigned char*>(chars), inputBytes);
if (!comp.init()) {
return;
}
comp.setOutput(reinterpret_cast<unsigned char*>(compressed.get()), firstSize);
bool cont = true;
bool reallocated = false;
while (cont) {
if (shouldCancel()) {
return;
}
switch (comp.compressMore()) {
case Compressor::CONTINUE:
break;
case Compressor::MOREOUTPUT: {
if (reallocated) {
// The compressed string is longer than the original string.
return;
}
// The compressed output is greater than half the size of the
// original string. Reallocate to the full size.
if (!reallocUniquePtr(compressed, inputBytes)) {
return;
}
comp.setOutput(reinterpret_cast<unsigned char*>(compressed.get()),
inputBytes);
reallocated = true;
break;
}
case Compressor::DONE:
cont = false;
break;
case Compressor::OOM:
return;
}
}
size_t totalBytes = comp.totalBytesNeeded();
// Shrink the buffer to the size of the compressed data.
if (!reallocUniquePtr(compressed, totalBytes)) {
return;
}
comp.finish(compressed.get(), totalBytes);
if (shouldCancel()) {
return;
}
auto& strings = SharedImmutableStringsCache::getSingleton();
resultString_ = strings.getOrCreate(std::move(compressed), totalBytes);
}
struct SourceCompressionTask::PerformTaskWork {
SourceCompressionTask* const task_;
explicit PerformTaskWork(SourceCompressionTask* task) : task_(task) {}
template <typename Unit, SourceRetrievable CanRetrieve>
void operator()(const ScriptSource::Uncompressed<Unit, CanRetrieve>&) {
task_->workEncodingSpecific<Unit>();
}
template <typename T>
void operator()(const T&) {
MOZ_CRASH(
"why are we compressing missing, missing-but-retrievable, "
"or already-compressed source?");
}
};
void ScriptSource::performTaskWork(SourceCompressionTask* task) {
MOZ_ASSERT(hasUncompressedSource());
data.match(SourceCompressionTask::PerformTaskWork(task));
}
void SourceCompressionTask::runTask() {
if (shouldCancel()) {
return;
}
MOZ_ASSERT(source_->hasUncompressedSource());
source_->performTaskWork(this);
}
void SourceCompressionTask::runHelperThreadTask(
AutoLockHelperThreadState& locked) {
{
AutoUnlockHelperThreadState unlock(locked);
this->runTask();
}
{
AutoEnterOOMUnsafeRegion oomUnsafe;
if (!HelperThreadState().compressionFinishedList(locked).append(this)) {
oomUnsafe.crash("SourceCompressionTask::runHelperThreadTask");
}
}
}
void ScriptSource::triggerConvertToCompressedSourceFromTask(
SharedImmutableString compressed) {
data.match(TriggerConvertToCompressedSourceFromTask(this, compressed));
}
void SourceCompressionTask::complete() {
if (!shouldCancel() && resultString_) {
source_->triggerConvertToCompressedSourceFromTask(std::move(resultString_));
}
}
bool js::SynchronouslyCompressSource(JSContext* cx,
JS::Handle<BaseScript*> script) {
// Finish all pending source compressions, including the single compression
// task that may have been created (by |ScriptSource::tryCompressOffThread|)
// just after the script was compiled. Because we have flushed this queue,
// no code below needs to synchronize with an off-thread parse task that
// assumes the immutability of a |ScriptSource|'s data.
//
// This *may* end up compressing |script|'s source. If it does -- we test
// this below -- that takes care of things. But if it doesn't, we will
// synchronously compress ourselves (and as noted above, this won't race
// anything).
RunPendingSourceCompressions(cx->runtime());
ScriptSource* ss = script->scriptSource();
#ifdef DEBUG
{
auto guard = ss->readers_.lock();
MOZ_ASSERT(guard->count == 0,
"can't synchronously compress while source units are in use");
}
#endif
// In principle a previously-triggered compression on a helper thread could
// have already completed. If that happens, there's nothing more to do.
if (ss->hasCompressedSource()) {
return true;
}
MOZ_ASSERT(ss->hasUncompressedSource(),
"shouldn't be compressing uncompressible source");
// Use an explicit scope to delineate the lifetime of |task|, for simplicity.
{
#ifdef DEBUG
uint32_t sourceRefs = ss->refs;
#endif
MOZ_ASSERT(sourceRefs > 0, "at least |script| here should have a ref");
// |SourceCompressionTask::shouldCancel| can periodically result in source
// compression being canceled if we're not careful. Guarantee that two refs
// to |ss| are always live in this function (at least one preexisting and
// one held by the task) so that compression is never canceled.
auto task = MakeUnique<SourceCompressionTask>(cx->runtime(), ss);
if (!task) {
ReportOutOfMemory(cx);
return false;
}
MOZ_ASSERT(ss->refs > sourceRefs, "must have at least two refs now");
// Attempt to compress. This may not succeed if OOM happens, but (because
// it ordinarily happens on a helper thread) no error will ever be set here.
MOZ_ASSERT(!cx->isExceptionPending());
ss->performTaskWork(task.get());
MOZ_ASSERT(!cx->isExceptionPending());
// Convert |ss| from uncompressed to compressed data.
task->complete();
MOZ_ASSERT(!cx->isExceptionPending());
}
// The only way source won't be compressed here is if OOM happened.
return ss->hasCompressedSource();
}
void ScriptSource::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
JS::ScriptSourceInfo* info) const {
info->misc += mallocSizeOf(this);
info->numScripts++;
}
bool ScriptSource::startIncrementalEncoding(
JSContext* cx,
UniquePtr<frontend::ExtensibleCompilationStencil>&& initial) {
// We don't support asm.js in XDR.
// Encoding failures are reported by the xdrFinalizeEncoder function.
if (initial->asmJS) {
return true;
}
// Remove the reference to the source, to avoid the circular reference.
initial->source = nullptr;
AutoIncrementalTimer timer(cx->realm()->timers.xdrEncodingTime);
auto failureCase = mozilla::MakeScopeExit([&] { xdrEncoder_.reset(); });
if (!xdrEncoder_.setInitial(
cx, std::forward<UniquePtr<frontend::ExtensibleCompilationStencil>>(
initial))) {
// On encoding failure, let failureCase destroy encoder and return true
// to avoid failing any currently executing script.
return false;
}
failureCase.release();
return true;
}
bool ScriptSource::addDelazificationToIncrementalEncoding(
JSContext* cx, const frontend::CompilationStencil& stencil) {
MOZ_ASSERT(hasEncoder());
AutoIncrementalTimer timer(cx->realm()->timers.xdrEncodingTime);
auto failureCase = mozilla::MakeScopeExit([&] { xdrEncoder_.reset(); });
if (!xdrEncoder_.addDelazification(cx, stencil)) {
// On encoding failure, let failureCase destroy encoder and return true
// to avoid failing any currently executing script.
return false;
}
failureCase.release();
return true;
}
bool ScriptSource::xdrFinalizeEncoder(JSContext* cx,
JS::TranscodeBuffer& buffer) {
if (!hasEncoder()) {
JS_ReportErrorASCII(cx, "XDR encoding failure");
return false;
}
auto cleanup = mozilla::MakeScopeExit([&] { xdrEncoder_.reset(); });
AutoReportFrontendContext fc(cx);
XDRStencilEncoder encoder(&fc, buffer);
frontend::BorrowingCompilationStencil borrowingStencil(
xdrEncoder_.merger_->getResult());
XDRResult res = encoder.codeStencil(this, borrowingStencil);
if (res.isErr()) {
if (JS::IsTranscodeFailureResult(res.unwrapErr())) {
fc.clearAutoReport();
JS_ReportErrorASCII(cx, "XDR encoding failure");
}
return false;
}
return true;
}
void ScriptSource::xdrAbortEncoder() { xdrEncoder_.reset(); }
template <typename Unit>
[[nodiscard]] bool ScriptSource::initializeUnretrievableUncompressedSource(
FrontendContext* fc, EntryUnits<Unit>&& source, size_t length) {
MOZ_ASSERT(data.is<Missing>(), "must be initializing a fresh ScriptSource");
return setUncompressedSourceHelper(fc, std::move(source), length,
SourceRetrievable::No);
}
template bool ScriptSource::initializeUnretrievableUncompressedSource(
FrontendContext* fc, EntryUnits<Utf8Unit>&& source, size_t length);
template bool ScriptSource::initializeUnretrievableUncompressedSource(
FrontendContext* fc, EntryUnits<char16_t>&& source, size_t length);
// Format and return a cx->pod_malloc'ed URL for a generated script like:
// {filename} line {lineno} > {introducer}
// For example:
// foo.js line 7 > eval
// indicating code compiled by the call to 'eval' on line 7 of foo.js.
UniqueChars js::FormatIntroducedFilename(const char* filename, uint32_t lineno,
const char* introducer) {
// Compute the length of the string in advance, so we can allocate a
// buffer of the right size on the first shot.
//
// (JS_smprintf would be perfect, as that allocates the result
// dynamically as it formats the string, but it won't allocate from cx,
// and wants us to use a special free function.)
char linenoBuf[15];
size_t filenameLen = strlen(filename);
size_t linenoLen = SprintfLiteral(linenoBuf, "%u", lineno);
size_t introducerLen = strlen(introducer);
size_t len = filenameLen + 6 /* == strlen(" line ") */ + linenoLen +
3 /* == strlen(" > ") */ + introducerLen + 1 /* \0 */;
UniqueChars formatted(js_pod_malloc<char>(len));
if (!formatted) {
return nullptr;
}
mozilla::DebugOnly<size_t> checkLen = snprintf(
formatted.get(), len, "%s line %s > %s", filename, linenoBuf, introducer);
MOZ_ASSERT(checkLen == len - 1);
return formatted;
}
bool ScriptSource::initFromOptions(FrontendContext* fc,
const ReadOnlyCompileOptions& options) {
MOZ_ASSERT(!filename_);
MOZ_ASSERT(!introducerFilename_);
mutedErrors_ = options.mutedErrors();
delazificationMode_ = options.eagerDelazificationStrategy();
startLine_ = options.lineno;
startColumn_ = JS::LimitedColumnNumberOneOrigin::fromUnlimited(
JS::ColumnNumberOneOrigin(options.column));
introductionType_ = options.introductionType;
setIntroductionOffset(options.introductionOffset);
// The parameterListEnd_ is initialized later by setParameterListEnd, before
// we expose any scripts that use this ScriptSource to the debugger.
if (options.hasIntroductionInfo) {
MOZ_ASSERT(options.introductionType != nullptr);
const char* filename =
options.filename() ? options.filename().c_str() : "<unknown>";
UniqueChars formatted = FormatIntroducedFilename(
filename, options.introductionLineno, options.introductionType);
if (!formatted) {
ReportOutOfMemory(fc);
return false;
}
if (!setFilename(fc, std::move(formatted))) {
return false;
}
} else if (options.filename()) {
if (!setFilename(fc, options.filename().c_str())) {
return false;
}
}
if (options.introducerFilename()) {
if (!setIntroducerFilename(fc, options.introducerFilename().c_str())) {
return false;
}
}
return true;
}
// Use the SharedImmutableString map to deduplicate input string. The input
// string must be null-terminated.
template <typename SharedT, typename CharT>
static SharedT GetOrCreateStringZ(FrontendContext* fc,
UniquePtr<CharT[], JS::FreePolicy>&& str) {
size_t lengthWithNull = std::char_traits<CharT>::length(str.get()) + 1;
auto res = SharedImmutableStringsCache::getSingleton().getOrCreate(
std::move(str), lengthWithNull);
if (!res) {
ReportOutOfMemory(fc);
}
return res;
}
SharedImmutableString ScriptSource::getOrCreateStringZ(FrontendContext* fc,
UniqueChars&& str) {
return GetOrCreateStringZ<SharedImmutableString>(fc, std::move(str));
}
SharedImmutableTwoByteString ScriptSource::getOrCreateStringZ(
FrontendContext* fc, UniqueTwoByteChars&& str) {
return GetOrCreateStringZ<SharedImmutableTwoByteString>(fc, std::move(str));
}
bool ScriptSource::setFilename(FrontendContext* fc, const char* filename) {
UniqueChars owned = DuplicateString(fc, filename);
if (!owned) {
return false;
}
return setFilename(fc, std::move(owned));
}
bool ScriptSource::setFilename(FrontendContext* fc, UniqueChars&& filename) {
MOZ_ASSERT(!filename_);
filename_ = getOrCreateStringZ(fc, std::move(filename));
if (filename_) {
filenameHash_ =
mozilla::HashStringKnownLength(filename_.chars(), filename_.length());
return true;
}
return false;
}
bool ScriptSource::setIntroducerFilename(FrontendContext* fc,
const char* filename) {
UniqueChars owned = DuplicateString(fc, filename);
if (!owned) {
return false;
}
return setIntroducerFilename(fc, std::move(owned));
}
bool ScriptSource::setIntroducerFilename(FrontendContext* fc,
UniqueChars&& filename) {
MOZ_ASSERT(!introducerFilename_);
introducerFilename_ = getOrCreateStringZ(fc, std::move(filename));
return bool(introducerFilename_);
}
bool ScriptSource::setDisplayURL(FrontendContext* fc, const char16_t* url) {
UniqueTwoByteChars owned = DuplicateString(fc, url);
if (!owned) {
return false;
}
return setDisplayURL(fc, std::move(owned));
}
bool ScriptSource::setDisplayURL(FrontendContext* fc,
UniqueTwoByteChars&& url) {
MOZ_ASSERT(!hasDisplayURL());
MOZ_ASSERT(url);
if (url[0] == '\0') {
return true;
}
displayURL_ = getOrCreateStringZ(fc, std::move(url));
return bool(displayURL_);
}
bool ScriptSource::setSourceMapURL(FrontendContext* fc, const char16_t* url) {
UniqueTwoByteChars owned = DuplicateString(fc, url);
if (!owned) {
return false;
}
return setSourceMapURL(fc, std::move(owned));
}
bool ScriptSource::setSourceMapURL(FrontendContext* fc,
UniqueTwoByteChars&& url) {
MOZ_ASSERT(url);
if (url[0] == '\0') {
return true;
}
sourceMapURL_ = getOrCreateStringZ(fc, std::move(url));
return bool(sourceMapURL_);
}
/* static */ mozilla::Atomic<uint32_t, mozilla::SequentiallyConsistent>
ScriptSource::idCount_;
/*
* [SMDOC] JSScript data layout (immutable)
*
* Script data that shareable across processes. There are no pointers (GC or
* otherwise) and the data is relocatable.
*
* Array elements Pointed to by Length
* -------------- ------------- ------
* jsbytecode code() codeLength()
* jsscrnote notes() noteLength()
* uint32_t resumeOffsets()
* ScopeNote scopeNotes()
* TryNote tryNotes()
*/
/* static */ CheckedInt<uint32_t> ImmutableScriptData::sizeFor(
uint32_t codeLength, uint32_t noteLength, uint32_t numResumeOffsets,
uint32_t numScopeNotes, uint32_t numTryNotes) {
// Take a count of which optional arrays will be used and need offset info.
unsigned numOptionalArrays = unsigned(numResumeOffsets > 0) +
unsigned(numScopeNotes > 0) +
unsigned(numTryNotes > 0);
// Compute size including trailing arrays.
CheckedInt<uint32_t> size = sizeof(ImmutableScriptData);
size += sizeof(Flags);
size += CheckedInt<uint32_t>(codeLength) * sizeof(jsbytecode);
size += CheckedInt<uint32_t>(noteLength) * sizeof(SrcNote);
size += CheckedInt<uint32_t>(numOptionalArrays) * sizeof(Offset);
size += CheckedInt<uint32_t>(numResumeOffsets) * sizeof(uint32_t);
size += CheckedInt<uint32_t>(numScopeNotes) * sizeof(ScopeNote);
size += CheckedInt<uint32_t>(numTryNotes) * sizeof(TryNote);
return size;
}
js::UniquePtr<ImmutableScriptData> js::ImmutableScriptData::new_(
FrontendContext* fc, uint32_t codeLength, uint32_t noteLength,
uint32_t numResumeOffsets, uint32_t numScopeNotes, uint32_t numTryNotes) {
auto size = sizeFor(codeLength, noteLength, numResumeOffsets, numScopeNotes,
numTryNotes);
if (!size.isValid()) {
ReportAllocationOverflow(fc);
return nullptr;
}
// Allocate contiguous raw buffer.
void* raw = fc->getAllocator()->pod_malloc<uint8_t>(size.value());
MOZ_ASSERT(uintptr_t(raw) % alignof(ImmutableScriptData) == 0);
if (!raw) {
return nullptr;
}
// Constuct the ImmutableScriptData. Trailing arrays are uninitialized but
// GCPtrs are put into a safe state.
UniquePtr<ImmutableScriptData> result(new (raw) ImmutableScriptData(
codeLength, noteLength, numResumeOffsets, numScopeNotes, numTryNotes));
if (!result) {
return nullptr;
}
// Sanity check
MOZ_ASSERT(result->endOffset() == size.value());
return result;
}
js::UniquePtr<ImmutableScriptData> js::ImmutableScriptData::new_(
FrontendContext* fc, uint32_t totalSize) {
void* raw = fc->getAllocator()->pod_malloc<uint8_t>(totalSize);
MOZ_ASSERT(uintptr_t(raw) % alignof(ImmutableScriptData) == 0);
UniquePtr<ImmutableScriptData> result(
reinterpret_cast<ImmutableScriptData*>(raw));
return result;
}
bool js::ImmutableScriptData::validateLayout(uint32_t expectedSize) {
constexpr size_t HeaderSize = sizeof(js::ImmutableScriptData);
constexpr size_t OptionalOffsetsMaxSize = 3 * sizeof(Offset);
// Check that the optional-offsets array lies within the allocation before we
// try to read from it while computing sizes. Remember that the array *ends*
// at the `optArrayOffset_`.
static_assert(OptionalOffsetsMaxSize <= HeaderSize);
if (HeaderSize > optArrayOffset_) {
return false;
}
if (optArrayOffset_ > expectedSize) {
return false;
}
// Round-trip the size computation using `CheckedInt` to detect overflow. This
// should indirectly validate most alignment, size, and ordering requirments.
auto size = sizeFor(codeLength(), noteLength(), resumeOffsets().size(),
scopeNotes().size(), tryNotes().size());
return size.isValid() && (size.value() == expectedSize);
}
/* static */
SharedImmutableScriptData* SharedImmutableScriptData::create(
FrontendContext* fc) {
return fc->getAllocator()->new_<SharedImmutableScriptData>();
}
/* static */
SharedImmutableScriptData* SharedImmutableScriptData::createWith(
FrontendContext* fc, js::UniquePtr<ImmutableScriptData>&& isd) {
MOZ_ASSERT(isd.get());
SharedImmutableScriptData* sisd = create(fc);
if (!sisd) {
return nullptr;
}
sisd->setOwn(std::move(isd));
return sisd;
}
void JSScript::relazify(JSRuntime* rt) {
js::Scope* scope = enclosingScope();
UniquePtr<PrivateScriptData> scriptData;
// Any JIT compiles should have been released, so we already point to the
// interpreter trampoline which supports lazy scripts.
MOZ_ASSERT_IF(jit::HasJitBackend(), isUsingInterpreterTrampoline(rt));
// Without bytecode, the script counts are invalid so destroy them if they
// still exist.
destroyScriptCounts();
// Release the bytecode and gcthings list.
// NOTE: We clear the PrivateScriptData to nullptr. This is fine because we
// only allowed relazification (via AllowRelazify) if the original lazy
// script we compiled from had a nullptr PrivateScriptData.
swapData(scriptData);
freeSharedData();
// We should not still be in any side-tables for the debugger or
// code-coverage. The finalizer will not be able to clean them up once
// bytecode is released. We check in JSFunction::maybeRelazify() for these
// conditions before requesting relazification.
MOZ_ASSERT(!coverage::IsLCovEnabled());
MOZ_ASSERT(!hasScriptCounts());
MOZ_ASSERT(!hasDebugScript());
// Rollback warmUpData_ to have enclosingScope.
MOZ_ASSERT(warmUpData_.isWarmUpCount(),
"JitScript should already be released");
warmUpData_.resetWarmUpCount(0);
warmUpData_.initEnclosingScope(scope);
MOZ_ASSERT(isReadyForDelazification());
}
// Takes ownership of the passed SharedImmutableScriptData and either adds it
// into the runtime's SharedImmutableScriptDataTable, or frees it if a matching
// entry already exists and replaces the passed RefPtr with the existing entry.
/* static */
bool SharedImmutableScriptData::shareScriptData(
FrontendContext* fc, RefPtr<SharedImmutableScriptData>& sisd) {
MOZ_ASSERT(sisd);
MOZ_ASSERT(sisd->refCount() == 1);
SharedImmutableScriptData* data = sisd.get();
SharedImmutableScriptData::Hasher::Lookup lookup(data);
Maybe<AutoLockGlobalScriptData> lock;
js::SharedImmutableScriptDataTable& table =
fc->scriptDataTableHolder()->getMaybeLocked(lock);
SharedImmutableScriptDataTable::AddPtr p = table.lookupForAdd(lookup);
if (p) {
MOZ_ASSERT(data != *p);
sisd = *p;
} else {
if (!table.add(p, data)) {
ReportOutOfMemory(fc);
return false;
}
// Being in the table counts as a reference on the script data.
data->AddRef();
}
// Refs: sisd argument, SharedImmutableScriptDataTable
MOZ_ASSERT(sisd->refCount() >= 2);
return true;
}
static void SweepScriptDataTable(SharedImmutableScriptDataTable& table) {
// Entries are removed from the table when their reference count is one,
// i.e. when the only reference to them is from the table entry.
for (SharedImmutableScriptDataTable::Enum e(table); !e.empty();
e.popFront()) {
SharedImmutableScriptData* sharedData = e.front();
if (sharedData->refCount() == 1) {
sharedData->Release();
e.removeFront();
}
}
}
void js::SweepScriptData(JSRuntime* rt) {
SweepScriptDataTable(rt->scriptDataTableHolder().getWithoutLock());
AutoLockGlobalScriptData lock;
SweepScriptDataTable(js::globalSharedScriptDataTableHolder.get(lock));
}
inline size_t PrivateScriptData::allocationSize() const { return endOffset(); }
// Initialize and placement-new the trailing arrays.
PrivateScriptData::PrivateScriptData(uint32_t ngcthings)
: ngcthings(ngcthings) {
// Variable-length data begins immediately after PrivateScriptData itself.
// NOTE: Alignment is computed using cursor/offset so the alignment of
// PrivateScriptData must be stricter than any trailing array type.
Offset cursor = sizeof(PrivateScriptData);
// Layout and initialize the gcthings array.
{
initElements<JS::GCCellPtr>(cursor, ngcthings);
cursor += ngcthings * sizeof(JS::GCCellPtr);
}
// Sanity check.
MOZ_ASSERT(endOffset() == cursor);
}
/* static */
PrivateScriptData* PrivateScriptData::new_(JSContext* cx, uint32_t ngcthings) {
// Compute size including trailing arrays.
CheckedInt<Offset> size = sizeof(PrivateScriptData);
size += CheckedInt<Offset>(ngcthings) * sizeof(JS::GCCellPtr);
if (!size.isValid()) {
ReportAllocationOverflow(cx);
return nullptr;
}
// Allocate contiguous raw buffer for the trailing arrays.
void* raw = cx->pod_malloc<uint8_t>(size.value());
MOZ_ASSERT(uintptr_t(raw) % alignof(PrivateScriptData) == 0);
if (!raw) {
return nullptr;
}
// Constuct the PrivateScriptData. Trailing arrays are uninitialized but
// GCPtrs are put into a safe state.
PrivateScriptData* result = new (raw) PrivateScriptData(ngcthings);
if (!result) {
return nullptr;
}
// Sanity check.
MOZ_ASSERT(result->endOffset() == size.value());
return result;
}
/* static */
bool PrivateScriptData::InitFromStencil(
JSContext* cx, js::HandleScript script,
const js::frontend::CompilationAtomCache& atomCache,
const js::frontend::CompilationStencil& stencil,
js::frontend::CompilationGCOutput& gcOutput,
const js::frontend::ScriptIndex scriptIndex) {
js::frontend::ScriptStencil& scriptStencil = stencil.scriptData[scriptIndex];
uint32_t ngcthings = scriptStencil.gcThingsLength;
MOZ_ASSERT(ngcthings <= INDEX_LIMIT);
// Create and initialize PrivateScriptData
if (!JSScript::createPrivateScriptData(cx, script, ngcthings)) {
return false;
}
js::PrivateScriptData* data = script->data_;
if (ngcthings) {
if (!EmitScriptThingsVector(cx, atomCache, stencil, gcOutput,
scriptStencil.gcthings(stencil),
data->gcthings())) {
return false;
}
}
return true;
}
void PrivateScriptData::trace(JSTracer* trc) {
for (JS::GCCellPtr& elem : gcthings()) {
TraceManuallyBarrieredGCCellPtr(trc, &elem, "script-gcthing");
}
}
/*static*/
JSScript* JSScript::Create(JSContext* cx, JS::Handle<JSFunction*> function,
js::Handle<ScriptSourceObject*> sourceObject,
const SourceExtent& extent,
js::ImmutableScriptFlags flags) {
return static_cast<JSScript*>(
BaseScript::New(cx, function, sourceObject, extent, flags));
}
#ifdef MOZ_VTUNE
uint32_t JSScript::vtuneMethodID() {
if (!zone()->scriptVTuneIdMap) {
auto map = MakeUnique<ScriptVTuneIdMap>();
if (!map) {
MOZ_CRASH("Failed to allocate ScriptVTuneIdMap");
}
zone()->scriptVTuneIdMap = std::move(map);
}
ScriptVTuneIdMap::AddPtr p = zone()->scriptVTuneIdMap->lookupForAdd(this);
if (p) {
return p->value();
}
MOZ_ASSERT(this->hasBytecode());
uint32_t id = vtune::GenerateUniqueMethodID();
if (!zone()->scriptVTuneIdMap->add(p, this, id)) {
MOZ_CRASH("Failed to add vtune method id");
}
return id;
}
#endif
/* static */
bool JSScript::createPrivateScriptData(JSContext* cx, HandleScript script,
uint32_t ngcthings) {
cx->check(script);
UniquePtr<PrivateScriptData> data(PrivateScriptData::new_(cx, ngcthings));
if (!data) {
return false;
}
script->swapData(data);
MOZ_ASSERT(!data);
return true;
}
/* static */
bool JSScript::fullyInitFromStencil(
JSContext* cx, const js::frontend::CompilationAtomCache& atomCache,
const js::frontend::CompilationStencil& stencil,
frontend::CompilationGCOutput& gcOutput, HandleScript script,
const js::frontend::ScriptIndex scriptIndex) {
MutableScriptFlags lazyMutableFlags;
Rooted<Scope*> lazyEnclosingScope(cx);
// A holder for the lazy PrivateScriptData that we must keep around in case
// this process fails and we must return the script to its original state.
//
// This is initialized by BaseScript::swapData() which will run pre-barriers
// for us. On successful conversion to non-lazy script, the old script data
// here will be released by the UniquePtr.
Rooted<UniquePtr<PrivateScriptData>> lazyData(cx);
// Whether we are a newborn script or an existing lazy script, we should
// already be pointing to the interpreter trampoline.
MOZ_ASSERT_IF(jit::HasJitBackend(),
script->isUsingInterpreterTrampoline(cx->runtime()));
// If we are using an existing lazy script, record enough info to be able to
// rollback on failure.
if (script->isReadyForDelazification()) {
lazyMutableFlags = script->mutableFlags_;
lazyEnclosingScope = script->releaseEnclosingScope();
script->swapData(lazyData.get());
MOZ_ASSERT(script->sharedData_ == nullptr);
}
// Restore the script to lazy state on failure. If this was a fresh script, we
// just need to clear bytecode to mark script as incomplete.
auto rollbackGuard = mozilla::MakeScopeExit([&] {
if (lazyEnclosingScope) {
script->mutableFlags_ = lazyMutableFlags;
script->warmUpData_.initEnclosingScope(lazyEnclosingScope);
script->swapData(lazyData.get());
script->sharedData_ = nullptr;
MOZ_ASSERT(script->isReadyForDelazification());
} else {
script->sharedData_ = nullptr;
}
});
// The counts of indexed things must be checked during code generation.
MOZ_ASSERT(stencil.scriptData[scriptIndex].gcThingsLength <= INDEX_LIMIT);
// Note: These flags should already be correct when the BaseScript was
// allocated.
MOZ_ASSERT_IF(stencil.isInitialStencil(),
script->immutableFlags() ==
stencil.scriptExtra[scriptIndex].immutableFlags);
// Create and initialize PrivateScriptData
if (!PrivateScriptData::InitFromStencil(cx, script, atomCache, stencil,
gcOutput, scriptIndex)) {
return false;
}
// Member-initializer data is computed in initial parse only. If we are
// delazifying, make sure to copy it off the `lazyData` before we throw it
// away.
if (script->useMemberInitializers()) {
if (stencil.isInitialStencil()) {
MemberInitializers initializers(
stencil.scriptExtra[scriptIndex].memberInitializers());
script->setMemberInitializers(initializers);
} else {
script->setMemberInitializers(lazyData.get()->getMemberInitializers());
}
}
auto* scriptData = stencil.sharedData.get(scriptIndex);
script->initSharedData(scriptData);
// NOTE: JSScript is now constructed and should be linked in.
rollbackGuard.release();
// Link Scope -> JSFunction -> BaseScript.
if (script->isFunction()) {
JSFunction* fun = gcOutput.getFunction(scriptIndex);
script->bodyScope()->as<FunctionScope>().initCanonicalFunction(fun);
if (fun->isIncomplete()) {
fun->initScript(script);
} else if (fun->hasSelfHostedLazyScript()) {
fun->clearSelfHostedLazyScript();
fun->initScript(script);
} else {
// We are delazifying in-place.
MOZ_ASSERT(fun->baseScript() == script);
}
}
// NOTE: The caller is responsible for linking ModuleObjects if this is a
// module script.
#ifdef JS_STRUCTURED_SPEW
// We want this to happen after line number initialization to allow filtering
// to work.
script->setSpewEnabled(cx->spewer().enabled(script));
#endif
#ifdef DEBUG
script->assertValidJumpTargets();
#endif
if (coverage::IsLCovEnabled()) {
if (!coverage::InitScriptCoverage(cx, script)) {
return false;
}
}
return true;
}
JSScript* JSScript::fromStencil(JSContext* cx,
frontend::CompilationAtomCache& atomCache,
const frontend::CompilationStencil& stencil,
frontend::CompilationGCOutput& gcOutput,
frontend::ScriptIndex scriptIndex) {
js::frontend::ScriptStencil& scriptStencil = stencil.scriptData[scriptIndex];
js::frontend::ScriptStencilExtra& scriptExtra =
stencil.scriptExtra[scriptIndex];
MOZ_ASSERT(scriptStencil.hasSharedData(),
"Need generated bytecode to use JSScript::fromStencil");
Rooted<JSFunction*> function(cx);
if (scriptStencil.isFunction()) {
function = gcOutput.getFunction(scriptIndex);
}
Rooted<ScriptSourceObject*> sourceObject(cx, gcOutput.sourceObject);
RootedScript script(cx, Create(cx, function, sourceObject, scriptExtra.extent,
scriptExtra.immutableFlags));
if (!script) {
return nullptr;
}
if (!fullyInitFromStencil(cx, atomCache, stencil, gcOutput, script,
scriptIndex)) {
return nullptr;
}
return script;
}
#ifdef DEBUG
void JSScript::assertValidJumpTargets() const {
BytecodeLocation mainLoc = mainLocation();
BytecodeLocation endLoc = endLocation();
AllBytecodesIterable iter(this);
for (BytecodeLocation loc : iter) {
// Check jump instructions' target.
if (loc.isJump()) {
BytecodeLocation target = loc.getJumpTarget();
MOZ_ASSERT(mainLoc <= target && target < endLoc);
MOZ_ASSERT(target.isJumpTarget());
// All backward jumps must be to a JSOp::LoopHead op. This is an invariant
// we want to maintain to simplify JIT compilation and bytecode analysis.
MOZ_ASSERT_IF(target < loc, target.is(JSOp::LoopHead));
MOZ_ASSERT_IF(target < loc, IsBackedgePC(loc.toRawBytecode()));
// All forward jumps must be to a JSOp::JumpTarget op.
MOZ_ASSERT_IF(target > loc, target.is(JSOp::JumpTarget));
// Jumps must not cross scope boundaries.
MOZ_ASSERT(loc.innermostScope(this) == target.innermostScope(this));
// Check fallthrough of conditional jump instructions.
if (loc.fallsThrough()) {
BytecodeLocation fallthrough = loc.next();
MOZ_ASSERT(mainLoc <= fallthrough && fallthrough < endLoc);
MOZ_ASSERT(fallthrough.isJumpTarget());
}
}
// Check table switch case labels.
if (loc.is(JSOp::TableSwitch)) {
BytecodeLocation target = loc.getTableSwitchDefaultTarget();
// Default target.
MOZ_ASSERT(mainLoc <= target && target < endLoc);
MOZ_ASSERT(target.is(JSOp::JumpTarget));
int32_t low = loc.getTableSwitchLow();
int32_t high = loc.getTableSwitchHigh();
for (int i = 0; i < high - low + 1; i++) {
BytecodeLocation switchCase = loc.getTableSwitchCaseTarget(this, i);
MOZ_ASSERT(mainLoc <= switchCase && switchCase < endLoc);
MOZ_ASSERT(switchCase.is(JSOp::JumpTarget));
}
}
}
// Check catch/finally blocks as jump targets.
for (const TryNote& tn : trynotes()) {
if (tn.kind() != TryNoteKind::Catch && tn.kind() != TryNoteKind::Finally) {
continue;
}
jsbytecode* tryStart = offsetToPC(tn.start);
jsbytecode* tryPc = tryStart - JSOpLength_Try;
MOZ_ASSERT(JSOp(*tryPc) == JSOp::Try);
jsbytecode* tryTarget = tryStart + tn.length;
MOZ_ASSERT(main() <= tryTarget && tryTarget < codeEnd());
MOZ_ASSERT(BytecodeIsJumpTarget(JSOp(*tryTarget)));
}
}
#endif
void JSScript::addSizeOfJitScript(mozilla::MallocSizeOf mallocSizeOf,
size_t* sizeOfJitScript,
size_t* sizeOfAllocSites) const {
if (!hasJitScript()) {
return;
}
jitScript()->addSizeOfIncludingThis(mallocSizeOf, sizeOfJitScript,
sizeOfAllocSites);
}
js::GlobalObject& JSScript::uninlinedGlobal() const { return global(); }
unsigned js::PCToLineNumber(unsigned startLine,
JS::LimitedColumnNumberOneOrigin startCol,
SrcNote* notes, SrcNote* notesEnd, jsbytecode* code,
jsbytecode* pc,
JS::LimitedColumnNumberOneOrigin* columnp) {
unsigned lineno = startLine;
JS::LimitedColumnNumberOneOrigin column = startCol;
/*
* Walk through source notes accumulating their deltas, keeping track of
* line-number notes, until we pass the note for pc's offset within
* script->code.
*/
ptrdiff_t offset = 0;
ptrdiff_t target = pc - code;
for (SrcNoteIterator iter(notes, notesEnd); !iter.atEnd(); ++iter) {
const auto* sn = *iter;
offset += sn->delta();
if (offset > target) {
break;
}
SrcNoteType type = sn->type();
if (type == SrcNoteType::SetLine) {
lineno = SrcNote::SetLine::getLine(sn, startLine);
column = JS::LimitedColumnNumberOneOrigin();
} else if (type == SrcNoteType::SetLineColumn) {
lineno = SrcNote::SetLineColumn::getLine(sn, startLine);
column = SrcNote::SetLineColumn::getColumn(sn);
} else if (type == SrcNoteType::NewLine) {
lineno++;
column = JS::LimitedColumnNumberOneOrigin();
} else if (type == SrcNoteType::NewLineColumn) {
lineno++;
column = SrcNote::NewLineColumn::getColumn(sn);
} else if (type == SrcNoteType::ColSpan) {
column += SrcNote::ColSpan::getSpan(sn);
}
}
if (columnp) {
*columnp = column;
}
return lineno;
}
unsigned js::PCToLineNumber(JSScript* script, jsbytecode* pc,
JS::LimitedColumnNumberOneOrigin* columnp) {
/* Cope with InterpreterFrame.pc value prior to entering Interpret. */
if (!pc) {
return 0;
}
return PCToLineNumber(
script->lineno(), JS::LimitedColumnNumberOneOrigin(script->column()),
script->notes(), script->notesEnd(), script->code(), pc, columnp);
}
jsbytecode* js::LineNumberToPC(JSScript* script, unsigned target) {
ptrdiff_t offset = 0;
ptrdiff_t best = -1;
unsigned lineno = script->lineno();
unsigned bestdiff = SrcNote::MaxOperand;
for (SrcNoteIterator iter(script->notes(), script->notesEnd()); !iter.atEnd();
++iter) {
const auto* sn = *iter;
/*
* Exact-match only if offset is not in the prologue; otherwise use
* nearest greater-or-equal line number match.
*/
if (lineno == target && offset >= ptrdiff_t(script->mainOffset())) {
goto out;
}
if (lineno >= target) {
unsigned diff = lineno - target;
if (diff < bestdiff) {
bestdiff = diff;
best = offset;
}
}
offset += sn->delta();
SrcNoteType type = sn->type();
if (type == SrcNoteType::SetLine) {
lineno = SrcNote::SetLine::getLine(sn, script->lineno());
} else if (type == SrcNoteType::SetLineColumn) {
lineno = SrcNote::SetLineColumn::getLine(sn, script->lineno());
} else if (type == SrcNoteType::NewLine ||
type == SrcNoteType::NewLineColumn) {
lineno++;
}
}
if (best >= 0) {
offset = best;
}
out:
return script->offsetToPC(offset);
}
JS_PUBLIC_API unsigned js::GetScriptLineExtent(JSScript* script) {
unsigned lineno = script->lineno();
unsigned maxLineNo = lineno;
for (SrcNoteIterator iter(script->notes(), script->notesEnd()); !iter.atEnd();
++iter) {
const auto* sn = *iter;
SrcNoteType type = sn->type();
if (type == SrcNoteType::SetLine) {
lineno = SrcNote::SetLine::getLine(sn, script->lineno());
} else if (type == SrcNoteType::SetLineColumn) {
lineno = SrcNote::SetLineColumn::getLine(sn, script->lineno());
} else if (type == SrcNoteType::NewLine ||
type == SrcNoteType::NewLineColumn) {
lineno++;
}
if (maxLineNo < lineno) {
maxLineNo = lineno;
}
}
return 1 + maxLineNo - script->lineno();
}
#ifdef JS_CACHEIR_SPEW
void js::maybeUpdateWarmUpCount(JSScript* script) {
if (script->needsFinalWarmUpCount()) {
ScriptFinalWarmUpCountMap* map =
script->zone()->scriptFinalWarmUpCountMap.get();
// If needsFinalWarmUpCount is true, ScriptFinalWarmUpCountMap must have
// already been created and thus must be asserted.
MOZ_ASSERT(map);
ScriptFinalWarmUpCountMap::Ptr p = map->lookup(script);
MOZ_ASSERT(p);
std::get<0>(p->value()) += script->jitScript()->warmUpCount();
}
}
void js::maybeSpewScriptFinalWarmUpCount(JSScript* script) {
if (script->needsFinalWarmUpCount()) {
ScriptFinalWarmUpCountMap* map =
script->zone()->scriptFinalWarmUpCountMap.get();
// If needsFinalWarmUpCount is true, ScriptFinalWarmUpCountMap must have
// already been created and thus must be asserted.
MOZ_ASSERT(map);
ScriptFinalWarmUpCountMap::Ptr p = map->lookup(script);
MOZ_ASSERT(p);
auto& tuple = p->value();
uint32_t warmUpCount = std::get<0>(tuple);
SharedImmutableString& scriptName = std::get<1>(tuple);
JSContext* cx = TlsContext.get();
cx->spewer().enableSpewing();
// In the case that we care about a script's final warmup count but the
// spewer is not enabled, AutoSpewChannel automatically sets and unsets
// the proper channel for the duration of spewing a health report's warm
// up count.
AutoSpewChannel channel(cx, SpewChannel::CacheIRHealthReport, script);
jit::CacheIRHealth cih;
cih.spewScriptFinalWarmUpCount(cx, scriptName.chars(), script, warmUpCount);
script->zone()->scriptFinalWarmUpCountMap->remove(script);
script->setNeedsFinalWarmUpCount(false);
}
}
#endif
void js::DescribeScriptedCallerForDirectEval(JSContext* cx, HandleScript script,
jsbytecode* pc, const char** file,
uint32_t* linenop,
uint32_t* pcOffset,
bool* mutedErrors) {
MOZ_ASSERT(script->containsPC(pc));
static_assert(JSOpLength_SpreadEval == JSOpLength_StrictSpreadEval,
"next op after a spread must be at consistent offset");
static_assert(JSOpLength_Eval == JSOpLength_StrictEval,
"next op after a direct eval must be at consistent offset");
MOZ_ASSERT(JSOp(*pc) == JSOp::Eval || JSOp(*pc) == JSOp::StrictEval ||
JSOp(*pc) == JSOp::SpreadEval ||
JSOp(*pc) == JSOp::StrictSpreadEval);
bool isSpread =
(JSOp(*pc) == JSOp::SpreadEval || JSOp(*pc) == JSOp::StrictSpreadEval);
jsbytecode* nextpc =
pc + (isSpread ? JSOpLength_SpreadEval : JSOpLength_Eval);
MOZ_ASSERT(JSOp(*nextpc) == JSOp::Lineno);
*file = script->filename();
*linenop = GET_UINT32(nextpc);
*pcOffset = script->pcToOffset(pc);
*mutedErrors = script->mutedErrors();
}
void js::DescribeScriptedCallerForCompilation(
JSContext* cx, MutableHandleScript maybeScript, const char** file,
uint32_t* linenop, uint32_t* pcOffset, bool* mutedErrors) {
NonBuiltinFrameIter iter(cx, cx->realm()->principals());
if (iter.done()) {
maybeScript.set(nullptr);
*file = nullptr;
*linenop = 0;
*pcOffset = 0;
*mutedErrors = false;
return;
}
*file = iter.filename();
*linenop = iter.computeLine();
*mutedErrors = iter.mutedErrors();
// These values are only used for introducer fields which are debugging
// information and can be safely left null for wasm frames.
if (iter.hasScript()) {
maybeScript.set(iter.script());
*pcOffset = iter.pc() - maybeScript->code();
} else {
maybeScript.set(nullptr);
*pcOffset = 0;
}
}
template <typename SourceSpan, typename TargetSpan>
void CopySpan(const SourceSpan& source, TargetSpan target) {
MOZ_ASSERT(source.size() == target.size());
std::copy(source.cbegin(), source.cend(), target.begin());
}
/* static */
js::UniquePtr<ImmutableScriptData> ImmutableScriptData::new_(
FrontendContext* fc, uint32_t mainOffset, uint32_t nfixed, uint32_t nslots,
GCThingIndex bodyScopeIndex, uint32_t numICEntries, bool isFunction,
uint16_t funLength, uint16_t propertyCountEstimate,
mozilla::Span<const jsbytecode> code, mozilla::Span<const SrcNote> notes,
mozilla::Span<const uint32_t> resumeOffsets,
mozilla::Span<const ScopeNote> scopeNotes,
mozilla::Span<const TryNote> tryNotes) {
MOZ_RELEASE_ASSERT(code.Length() <= frontend::MaxBytecodeLength);
// There are 1-4 copies of SrcNoteType::Null appended after the source
// notes. These are a combination of sentinel and padding values.
static_assert(frontend::MaxSrcNotesLength <= UINT32_MAX - CodeNoteAlign,
"Length + CodeNoteAlign shouldn't overflow UINT32_MAX");
size_t noteLength = notes.Length();
MOZ_RELEASE_ASSERT(noteLength <= frontend::MaxSrcNotesLength);
size_t notePaddingLength = ComputeNotePadding(code.Length(), noteLength);
// Allocate ImmutableScriptData
js::UniquePtr<ImmutableScriptData> data(ImmutableScriptData::new_(
fc, code.Length(), noteLength + notePaddingLength, resumeOffsets.Length(),
scopeNotes.Length(), tryNotes.Length()));
if (!data) {
return data;
}
// Initialize POD fields
data->mainOffset = mainOffset;
data->nfixed = nfixed;
data->nslots = nslots;
data->bodyScopeIndex = bodyScopeIndex;
data->numICEntries = numICEntries;
data->propertyCountEstimate = propertyCountEstimate;
if (isFunction) {
data->funLength = funLength;
}
// Initialize trailing arrays
CopySpan(code, data->codeSpan());
CopySpan(notes, data->notesSpan().To(noteLength));
std::fill_n(data->notes() + noteLength, notePaddingLength,
SrcNote::padding());
CopySpan(resumeOffsets, data->resumeOffsets());
CopySpan(scopeNotes, data->scopeNotes());
CopySpan(tryNotes, data->tryNotes());
return data;
}
void ScriptWarmUpData::trace(JSTracer* trc) {
uintptr_t tag = data_ & TagMask;
switch (tag) {
case EnclosingScriptTag: {
BaseScript* enclosingScript = toEnclosingScript();
BaseScript* prior = enclosingScript;
TraceManuallyBarrieredEdge(trc, &enclosingScript, "enclosingScript");
if (enclosingScript != prior) {
setTaggedPtr<EnclosingScriptTag>(enclosingScript);
}
break;
}
case EnclosingScopeTag: {
Scope* enclosingScope = toEnclosingScope();
Scope* prior = enclosingScope;
TraceManuallyBarrieredEdge(trc, &enclosingScope, "enclosingScope");
if (enclosingScope != prior) {
setTaggedPtr<EnclosingScopeTag>(enclosingScope);
}
break;
}
case JitScriptTag: {
toJitScript()->trace(trc);
break;
}
default: {
MOZ_ASSERT(isWarmUpCount());
break;
}
}
}
size_t JSScript::calculateLiveFixed(jsbytecode* pc) {
size_t nlivefixed = numAlwaysLiveFixedSlots();
if (nfixed() != nlivefixed) {
Scope* scope = lookupScope(pc);
if (scope) {
scope = MaybeForwarded(scope);
}
// Find the nearest LexicalScope in the same script.
while (scope && scope->is<WithScope>()) {
scope = scope->enclosing();
if (scope) {
scope = MaybeForwarded(scope);
}
}
if (scope) {
if (scope->is<LexicalScope>()) {
nlivefixed = scope->as<LexicalScope>().nextFrameSlot();
} else if (scope->is<VarScope>()) {
nlivefixed = scope->as<VarScope>().nextFrameSlot();
} else if (scope->is<ClassBodyScope>()) {
nlivefixed = scope->as<ClassBodyScope>().nextFrameSlot();
}
}
}
MOZ_ASSERT(nlivefixed <= nfixed());
MOZ_ASSERT(nlivefixed >= numAlwaysLiveFixedSlots());
return nlivefixed;
}
Scope* JSScript::lookupScope(const jsbytecode* pc) const {
MOZ_ASSERT(containsPC(pc));
size_t offset = pc - code();
auto notes = scopeNotes();
Scope* scope = nullptr;
// Find the innermost block chain using a binary search.
size_t bottom = 0;
size_t top = notes.size();
while (bottom < top) {
size_t mid = bottom + (top - bottom) / 2;
const ScopeNote* note = ¬es[mid];
if (note->start <= offset) {
// Block scopes are ordered in the list by their starting offset, and
// since blocks form a tree ones earlier in the list may cover the pc even
// if later blocks end before the pc. This only happens when the earlier
// block is a parent of the later block, so we need to check parents of
// |mid| in the searched range for coverage.
size_t check = mid;
while (check >= bottom) {
const ScopeNote* checkNote = ¬es[check];
MOZ_ASSERT(checkNote->start <= offset);
if (offset < checkNote->start + checkNote->length) {
// We found a matching block chain but there may be inner ones
// at a higher block chain index than mid. Continue the binary search.
if (checkNote->index == ScopeNote::NoScopeIndex) {
scope = nullptr;
} else {
scope = getScope(checkNote->index);
}
break;
}
if (checkNote->parent == UINT32_MAX) {
break;
}
check = checkNote->parent;
}
bottom = mid + 1;
} else {
top = mid;
}
}
return scope;
}
Scope* JSScript::innermostScope(const jsbytecode* pc) const {
if (Scope* scope = lookupScope(pc)) {
return scope;
}
return bodyScope();
}
void js::SetFrameArgumentsObject(JSContext* cx, AbstractFramePtr frame,
HandleScript script, JSObject* argsobj) {
/*
* If the arguments object was optimized out by scalar replacement,
* we must recreate it when we bail out. Because 'arguments' may have
* already been overwritten, we must check to see if the slot already
* contains a value.
*/
Rooted<BindingIter> bi(cx, BindingIter(script));
while (bi && bi.name() != cx->names().arguments) {
bi++;
}
if (!bi) {
return;
}
if (bi.location().kind() == BindingLocation::Kind::Environment) {
#ifdef DEBUG
/*
* If |arguments| lives in the call object, we should not have
* optimized it. Scan the script to find the slot in the call
* object that |arguments| is assigned to and verify that it
* already exists.
*/
jsbytecode* pc = script->code();
while (JSOp(*pc) != JSOp::Arguments) {
pc += GetBytecodeLength(pc);
}
pc += JSOpLength_Arguments;
MOZ_ASSERT(JSOp(*pc) == JSOp::SetAliasedVar);
EnvironmentObject& env = frame.callObj().as<EnvironmentObject>();
MOZ_ASSERT(!env.aliasedBinding(bi).isMagic(JS_OPTIMIZED_OUT));
#endif
return;
}
MOZ_ASSERT(bi.location().kind() == BindingLocation::Kind::Frame);
uint32_t frameSlot = bi.location().slot();
if (frame.unaliasedLocal(frameSlot).isMagic(JS_OPTIMIZED_OUT)) {
frame.unaliasedLocal(frameSlot) = ObjectValue(*argsobj);
}
}
bool JSScript::formalIsAliased(unsigned argSlot) {
if (functionHasParameterExprs()) {
return false;
}
for (PositionalFormalParameterIter fi(this); fi; fi++) {
if (fi.argumentSlot() == argSlot) {
return fi.closedOver();
}
}
MOZ_CRASH("Argument slot not found");
}
// Returns true if any formal argument is mapped by the arguments
// object, but lives in the call object.
bool JSScript::anyFormalIsForwarded() {
if (!argsObjAliasesFormals()) {
return false;
}
for (PositionalFormalParameterIter fi(this); fi; fi++) {
if (fi.closedOver()) {
return true;
}
}
return false;
}
bool JSScript::formalLivesInArgumentsObject(unsigned argSlot) {
return argsObjAliasesFormals() && !formalIsAliased(argSlot);
}
BaseScript::BaseScript(uint8_t* stubEntry, JSFunction* function,
ScriptSourceObject* sourceObject,
const SourceExtent& extent, uint32_t immutableFlags)
: TenuredCellWithNonGCPointer(stubEntry),
function_(function),
sourceObject_(sourceObject),
extent_(extent),
immutableFlags_(immutableFlags) {
MOZ_ASSERT(extent_.toStringStart <= extent_.sourceStart);
MOZ_ASSERT(extent_.sourceStart <= extent_.sourceEnd);
MOZ_ASSERT(extent_.sourceEnd <= extent_.toStringEnd);
}
/* static */
BaseScript* BaseScript::New(JSContext* cx, JS::Handle<JSFunction*> function,
Handle<ScriptSourceObject*> sourceObject,
const SourceExtent& extent,
uint32_t immutableFlags) {
uint8_t* stubEntry = nullptr;
if (jit::HasJitBackend()) {
stubEntry = cx->runtime()->jitRuntime()->interpreterStub().value;
}
MOZ_ASSERT_IF(function,
function->compartment() == sourceObject->compartment());
MOZ_ASSERT_IF(function, function->realm() == sourceObject->realm());
return cx->newCell<BaseScript>(stubEntry, function, sourceObject, extent,
immutableFlags);
}
/* static */
BaseScript* BaseScript::CreateRawLazy(JSContext* cx, uint32_t ngcthings,
HandleFunction fun,
Handle<ScriptSourceObject*> sourceObject,
const SourceExtent& extent,
uint32_t immutableFlags) {
cx->check(fun);
BaseScript* lazy = New(cx, fun, sourceObject, extent, immutableFlags);
if (!lazy) {
return nullptr;
}
// Allocate a PrivateScriptData if it will not be empty. Lazy class
// constructors that use member initializers also need PrivateScriptData for
// field data.
//
// This condition is implicit in BaseScript::hasPrivateScriptData, and should
// be mirrored on InputScript::hasPrivateScriptData.
if (ngcthings || lazy->useMemberInitializers()) {
UniquePtr<PrivateScriptData> data(PrivateScriptData::new_(cx, ngcthings));
if (!data) {
return nullptr;
}
lazy->swapData(data);
MOZ_ASSERT(!data);
}
return lazy;
}
#ifdef ENABLE_PORTABLE_BASELINE_INTERP
// This is an arbitrary non-null pointer that we use as a placeholder
// for scripts that can be run in PBL: the rest of the engine expects
// a "non-null jitcode pointer" but we'll never actually call it. We
// have to ensure alignment to keep GC happy.
static uint8_t* const PBLJitCodePtr = reinterpret_cast<uint8_t*>(8);
#endif
void JSScript::updateJitCodeRaw(JSRuntime* rt) {
MOZ_ASSERT(rt);
if (hasBaselineScript() && baselineScript()->hasPendingIonCompileTask()) {
MOZ_ASSERT(!isIonCompilingOffThread());
setJitCodeRaw(rt->jitRuntime()->lazyLinkStub().value);
} else if (hasIonScript()) {
jit::IonScript* ion = ionScript();
setJitCodeRaw(ion->method()->raw());
} else if (hasBaselineScript()) {
setJitCodeRaw(baselineScript()->method()->raw());
} else if (hasJitScript() && js::jit::IsBaselineInterpreterEnabled()) {
bool usingEntryTrampoline = false;
if (js::jit::JitOptions.emitInterpreterEntryTrampoline) {
auto p = rt->jitRuntime()->getInterpreterEntryMap()->lookup(this);
if (p) {
setJitCodeRaw(p->value().raw());
usingEntryTrampoline = true;
}
}
if (!usingEntryTrampoline) {
setJitCodeRaw(rt->jitRuntime()->baselineInterpreter().codeRaw());
}
#ifdef ENABLE_PORTABLE_BASELINE_INTERP
} else if (hasJitScript() &&
js::jit::IsPortableBaselineInterpreterEnabled()) {
// The portable baseline interpreter does not dispatch on this
// pointer, but it needs to be non-null to trigger the appropriate
// code-paths, so we set it to a placeholder value here.
setJitCodeRaw(PBLJitCodePtr);
#endif // ENABLE_PORTABLE_BASELINE_INTERP
} else if (!js::jit::IsBaselineInterpreterEnabled()) {
setJitCodeRaw(nullptr);
} else {
setJitCodeRaw(rt->jitRuntime()->interpreterStub().value);
}
MOZ_ASSERT_IF(!js::jit::IsPortableBaselineInterpreterEnabled(), jitCodeRaw());
}
bool JSScript::hasLoops() {
for (const TryNote& tn : trynotes()) {
if (tn.isLoop()) {
return true;
}
}
return false;
}
bool JSScript::mayReadFrameArgsDirectly() {
return needsArgsObj() || usesArgumentsIntrinsics() || hasRest();
}
void JSScript::resetWarmUpCounterToDelayIonCompilation() {
// Reset the warm-up count only if it's greater than the BaselineCompiler
// threshold. We do this to ensure this has no effect on Baseline compilation
// because we don't want scripts to get stuck in the (Baseline) interpreter in
// pathological cases.
if (getWarmUpCount() > jit::JitOptions.baselineJitWarmUpThreshold) {
incWarmUpResetCounter();
uint32_t newCount = jit::JitOptions.baselineJitWarmUpThreshold;
if (warmUpData_.isWarmUpCount()) {
warmUpData_.resetWarmUpCount(newCount);
} else {
warmUpData_.toJitScript()->resetWarmUpCount(newCount);
}
}
}
#if defined(DEBUG) || defined(JS_JITSPEW)
void BaseScript::dumpStringContent(js::GenericPrinter& out) const {
StringEscape esc('"');
EscapePrinter ep(out, esc);
ep.printf("%s:%u:%u @ 0x%p", filename() ? filename() : "<null>", lineno(),
column().oneOriginValue(), this);
}
void JSScript::dump(JSContext* cx) {
JS::Rooted<JSScript*> script(cx, this);
js::Sprinter sp(cx);
if (!sp.init()) {
return;
}
DumpOptions options;
options.runtimeData = true;
if (!dump(cx, script, options, &sp)) {
return;
}
JS::UniqueChars str = sp.release();
if (!str) {
return;
}
fprintf(stderr, "%s\n", str.get());
}
void JSScript::dumpRecursive(JSContext* cx) {
JS::Rooted<JSScript*> script(cx, this);
js::Sprinter sp(cx);
if (!sp.init()) {
return;
}
DumpOptions options;
options.runtimeData = true;
options.recursive = true;
if (!dump(cx, script, options, &sp)) {
return;
}
JS::UniqueChars str = sp.release();
if (!str) {
return;
}
fprintf(stderr, "%s\n", str.get());
}
static void DumpMutableScriptFlags(js::JSONPrinter& json,
MutableScriptFlags mutableFlags) {
// Skip warmup data.
static_assert(int(MutableScriptFlagsEnum::WarmupResets_MASK) == 0xff);
for (uint32_t i = 0x100; i; i = i << 1) {
if (uint32_t(mutableFlags) & i) {
switch (MutableScriptFlagsEnum(i)) {
case MutableScriptFlagsEnum::HasRunOnce:
json.value("HasRunOnce");
break;
case MutableScriptFlagsEnum::HasBeenCloned:
json.value("HasBeenCloned");
break;
case MutableScriptFlagsEnum::HasScriptCounts:
json.value("HasScriptCounts");
break;
case MutableScriptFlagsEnum::HasDebugScript:
json.value("HasDebugScript");
break;
case MutableScriptFlagsEnum::AllowRelazify:
json.value("AllowRelazify");
break;
case MutableScriptFlagsEnum::SpewEnabled:
json.value("SpewEnabled");
break;
case MutableScriptFlagsEnum::NeedsFinalWarmUpCount:
json.value("NeedsFinalWarmUpCount");
break;
case MutableScriptFlagsEnum::BaselineDisabled:
json.value("BaselineDisabled");
break;
case MutableScriptFlagsEnum::IonDisabled:
json.value("IonDisabled");
break;
case MutableScriptFlagsEnum::Uninlineable:
json.value("Uninlineable");
break;
case MutableScriptFlagsEnum::NoEagerBaselineHint:
json.value("NoEagerBaselineHint");
break;
case MutableScriptFlagsEnum::FailedBoundsCheck:
json.value("FailedBoundsCheck");
break;
case MutableScriptFlagsEnum::HadLICMInvalidation:
json.value("HadLICMInvalidation");
break;
case MutableScriptFlagsEnum::HadReorderingBailout:
json.value("HadReorderingBailout");
break;
case MutableScriptFlagsEnum::HadEagerTruncationBailout:
json.value("HadEagerTruncationBailout");
break;
case MutableScriptFlagsEnum::FailedLexicalCheck:
json.value("FailedLexicalCheck");
break;
case MutableScriptFlagsEnum::HadSpeculativePhiBailout:
json.value("HadSpeculativePhiBailout");
break;
case MutableScriptFlagsEnum::HadUnboxFoldingBailout:
json.value("HadUnboxFoldingBailout");
break;
default:
json.value("Unknown(%x)", i);
break;
}
}
}
}
/* static */
bool JSScript::dump(JSContext* cx, JS::Handle<JSScript*> script,
DumpOptions& options, js::StringPrinter* sp) {
{
JSONPrinter json(*sp);
json.beginObject();
if (const char* filename = script->filename()) {
json.property("file", filename);
} else {
json.nullProperty("file");
}
json.property("lineno", script->lineno());
json.property("column", script->column().oneOriginValue());
json.beginListProperty("immutableFlags");
DumpImmutableScriptFlags(json, script->immutableFlags());
json.endList();
if (options.runtimeData) {
json.beginListProperty("mutableFlags");
DumpMutableScriptFlags(json, script->mutableFlags_);
json.endList();
}
if (script->isFunction()) {
JS::Rooted<JSFunction*> fun(cx, script->function());
JS::Rooted<JSAtom*> name(cx, fun->fullDisplayAtom());
if (name) {
UniqueChars bytes = JS_EncodeStringToUTF8(cx, name);
if (!bytes) {
return false;
}
json.property("functionName", bytes.get());
} else {
json.nullProperty("functionName");
}
json.beginListProperty("functionFlags");
DumpFunctionFlagsItems(json, fun->flags());
json.endList();
}
json.endObject();
}
if (sp->hadOutOfMemory()) {
sp->forwardOutOfMemory();
return false;
}
sp->put("\n");
if (!Disassemble(cx, script, /* lines = */ true, sp)) {
return false;
}
if (!dumpSrcNotes(cx, script, sp)) {
return false;
}
if (!dumpTryNotes(cx, script, sp)) {
return false;
}
if (!dumpScopeNotes(cx, script, sp)) {
return false;
}
if (!dumpGCThings(cx, script, sp)) {
return false;
}
if (options.recursive) {
for (JS::GCCellPtr gcThing : script->gcthings()) {
if (!gcThing.is<JSObject>()) {
continue;
}
JSObject* obj = &gcThing.as<JSObject>();
if (obj->is<JSFunction>()) {
sp->put("\n");
JS::Rooted<JSFunction*> fun(cx, &obj->as<JSFunction>());
if (fun->isInterpreted()) {
JS::Rooted<JSScript*> innerScript(
cx, JSFunction::getOrCreateScript(cx, fun));
if (!innerScript) {
return false;
}
if (!dump(cx, innerScript, options, sp)) {
return false;
}
} else {
sp->put("[native code]\n");
}
}
}
}
return true;
}
/* static */
bool JSScript::dumpSrcNotes(JSContext* cx, JS::Handle<JSScript*> script,
js::GenericPrinter* sp) {
sp->put("\nSource notes:\n");
sp->printf("%4s %4s %6s %5s %6s %-16s %s\n", "ofs", "line", "column", "pc",
"delta", "desc", "args");
sp->put("---- ---- ------ ----- ------ ---------------- ------\n");
unsigned offset = 0;
unsigned lineno = script->lineno();
JS::LimitedColumnNumberOneOrigin column = script->column();
SrcNote* notes = script->notes();
SrcNote* notesEnd = script->notesEnd();
for (SrcNoteIterator iter(notes, notesEnd); !iter.atEnd(); ++iter) {
const auto* sn = *iter;
unsigned delta = sn->delta();
offset += delta;
SrcNoteType type = sn->type();
const char* name = sn->name();
sp->printf("%3u: %4u %6u %5u [%4u] %-16s", unsigned(sn - notes), lineno,
column.oneOriginValue(), offset, delta, name);
switch (type) {
case SrcNoteType::Breakpoint:
case SrcNoteType::BreakpointStepSep:
case SrcNoteType::XDelta:
break;
case SrcNoteType::ColSpan: {
JS::ColumnNumberOffset colspan = SrcNote::ColSpan::getSpan(sn);
sp->printf(" colspan %u", colspan.value());
column += colspan;
break;
}
case SrcNoteType::SetLine:
lineno = SrcNote::SetLine::getLine(sn, script->lineno());
sp->printf(" lineno %u", lineno);
column = JS::LimitedColumnNumberOneOrigin();
break;
case SrcNoteType::SetLineColumn:
lineno = SrcNote::SetLineColumn::getLine(sn, script->lineno());
column = SrcNote::SetLineColumn::getColumn(sn);
sp->printf(" lineno %u column %u", lineno, column.oneOriginValue());
break;
case SrcNoteType::NewLine:
++lineno;
column = JS::LimitedColumnNumberOneOrigin();
break;
case SrcNoteType::NewLineColumn:
column = SrcNote::NewLineColumn::getColumn(sn);
sp->printf(" column %u", column.oneOriginValue());
++lineno;
break;
default:
MOZ_ASSERT_UNREACHABLE("unrecognized srcnote");
}
sp->put("\n");
}
return true;
}
static const char* TryNoteName(TryNoteKind kind) {
switch (kind) {
case TryNoteKind::Catch:
return "catch";
case TryNoteKind::Finally:
return "finally";
case TryNoteKind::ForIn:
return "for-in";
case TryNoteKind::ForOf:
return "for-of";
case TryNoteKind::Loop:
return "loop";
case TryNoteKind::ForOfIterClose:
return "for-of-iterclose";
case TryNoteKind::Destructuring:
return "destructuring";
}
MOZ_CRASH("Bad TryNoteKind");
}
/* static */
bool JSScript::dumpTryNotes(JSContext* cx, JS::Handle<JSScript*> script,
js::GenericPrinter* sp) {
sp->put("\nException table:\nkind stack start end\n");
for (const js::TryNote& tn : script->trynotes()) {
sp->printf(" %-16s %6u %8u %8u\n", TryNoteName(tn.kind()), tn.stackDepth,
tn.start, tn.start + tn.length);
}
return true;
}
/* static */
bool JSScript::dumpScopeNotes(JSContext* cx, JS::Handle<JSScript*> script,
js::GenericPrinter* sp) {
sp->put("\nScope notes:\n index parent start end\n");
for (const ScopeNote& note : script->scopeNotes()) {
if (note.index == ScopeNote::NoScopeIndex) {
sp->printf("%8s ", "(none)");
} else {
sp->printf("%8u ", note.index.index);
}
if (note.parent == ScopeNote::NoScopeIndex) {
sp->printf("%8s ", "(none)");
} else {
sp->printf("%8u ", note.parent);
}
sp->printf("%8u %8u\n", note.start, note.start + note.length);
}
return true;
}
/* static */
bool JSScript::dumpGCThings(JSContext* cx, JS::Handle<JSScript*> script,
js::GenericPrinter* sp) {
sp->put("\nGC things:\n index type value\n");
size_t i = 0;
for (JS::GCCellPtr gcThing : script->gcthings()) {
sp->printf("%8zu ", i);
if (gcThing.is<JS::BigInt>()) {
sp->put("BigInt ");
gcThing.as<JS::BigInt>().dump(*sp);
sp->put("\n");
} else if (gcThing.is<Scope>()) {
sp->put("Scope ");
JS::Rooted<Scope*> scope(cx, &gcThing.as<Scope>());
if (!Scope::dumpForDisassemble(cx, scope, *sp,
" ")) {
return false;
}
sp->put("\n");
} else if (gcThing.is<JSObject>()) {
JSObject* obj = &gcThing.as<JSObject>();
if (obj->is<JSFunction>()) {
sp->put("Function ");
JS::Rooted<JSFunction*> fun(cx, &obj->as<JSFunction>());
if (fun->fullDisplayAtom()) {
JS::Rooted<JSAtom*> name(cx, fun->fullDisplayAtom());
JS::UniqueChars utf8chars = JS_EncodeStringToUTF8(cx, name);
if (!utf8chars) {
return false;
}
sp->put(utf8chars.get());
} else {
sp->put("(anonymous)");
}
if (fun->hasBaseScript()) {
BaseScript* script = fun->baseScript();
sp->printf(" @ %u:%u\n", script->lineno(),
script->column().oneOriginValue());
} else {
sp->put(" (no script)\n");
}
} else {
if (obj->is<RegExpObject>()) {
sp->put("RegExp ");
} else {
sp->put("Object ");
}
JS::Rooted<JS::Value> objValue(cx, ObjectValue(*obj));
JS::Rooted<JSString*> str(cx, ValueToSource(cx, objValue));
if (!str) {
return false;
}
JS::UniqueChars utf8chars = JS_EncodeStringToUTF8(cx, str);
if (!utf8chars) {
return false;
}
sp->put(utf8chars.get());
sp->put("\n");
}
} else if (gcThing.is<JSString>()) {
JS::Rooted<JSString*> str(cx, &gcThing.as<JSString>());
if (str->isAtom()) {
sp->put("Atom ");
} else {
sp->put("String ");
}
JS::UniqueChars chars = QuoteString(cx, str, '"');
if (!chars) {
return false;
}
sp->put(chars.get());
sp->put("\n");
} else {
sp->put("Unknown\n");
}
i++;
}
return true;
}
#endif // defined(DEBUG) || defined(JS_JITSPEW)
void JSScript::AutoDelazify::holdScript(JS::HandleFunction fun) {
if (fun) {
JSAutoRealm ar(cx_, fun);
script_ = JSFunction::getOrCreateScript(cx_, fun);
if (script_) {
oldAllowRelazify_ = script_->allowRelazify();
script_->clearAllowRelazify();
}
}
}
void JSScript::AutoDelazify::dropScript() {
if (script_) {
script_->setAllowRelazify(oldAllowRelazify_);
}
script_ = nullptr;
}
JS::ubi::Base::Size JS::ubi::Concrete<BaseScript>::size(
mozilla::MallocSizeOf mallocSizeOf) const {
BaseScript* base = &get();
Size size = gc::Arena::thingSize(base->getAllocKind());
size += base->sizeOfExcludingThis(mallocSizeOf);
// Include any JIT data if it exists.
if (base->hasJitScript()) {
JSScript* script = base->asJSScript();
size_t jitScriptSize = 0;
size_t allocSitesSize = 0;
script->addSizeOfJitScript(mallocSizeOf, &jitScriptSize, &allocSitesSize);
size += jitScriptSize;
size += allocSitesSize;
size_t baselineSize = 0;
jit::AddSizeOfBaselineData(script, mallocSizeOf, &baselineSize);
size += baselineSize;
size += jit::SizeOfIonData(script, mallocSizeOf);
}
MOZ_ASSERT(size > 0);
return size;
}
const char* JS::ubi::Concrete<BaseScript>::scriptFilename() const {
return get().filename();
}