Google Git
Sign in
cobalt / cobalt / c73ce7d5dfce7ae20bcc30efc5f220e0fbac12b1 / . / src / third_party / mozjs-45 / js / src / frontend / Parser.cpp
blob: 4e4aa7130709d87b7f87c20149806942c08694cb [file] [log] [blame]
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* JS parser.
*
* This is a recursive-descent parser for the JavaScript language specified by
* "The JavaScript 1.5 Language Specification". It uses lexical and semantic
* feedback to disambiguate non-LL(1) structures. It generates trees of nodes
* induced by the recursive parsing (not precise syntax trees, see Parser.h).
* After tree construction, it rewrites trees to fold constants and evaluate
* compile-time expressions.
*
* This parser attempts no error recovery.
*/
#include "frontend/Parser-inl.h"
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsfun.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsscript.h"
#include "jstypes.h"
#include "asmjs/AsmJSValidate.h"
#include "builtin/ModuleObject.h"
#include "frontend/BytecodeCompiler.h"
#include "frontend/FoldConstants.h"
#include "frontend/ParseMaps.h"
#include "frontend/TokenStream.h"
#include "vm/Shape.h"
#include "jsatominlines.h"
#include "jsscriptinlines.h"
#include "frontend/ParseNode-inl.h"
#include "vm/ScopeObject-inl.h"
using namespace js;
using namespace js::gc;
using mozilla::Maybe;
using JS::AutoGCRooter;
JSFunction::AutoParseUsingFunctionBox::AutoParseUsingFunctionBox(ExclusiveContext* cx,
frontend::FunctionBox* funbox)
: fun_(cx, funbox->function()),
oldEnv_(cx, fun_->environment())
{
fun_->unsetEnvironment();
fun_->setFunctionBox(funbox);
funbox->computeAllowSyntax(fun_);
funbox->computeInWith(fun_);
funbox->computeThisBinding(fun_);
}
JSFunction::AutoParseUsingFunctionBox::~AutoParseUsingFunctionBox()
{
fun_->unsetFunctionBox();
fun_->initEnvironment(oldEnv_);
}
namespace js {
namespace frontend {
typedef Rooted<StaticBlockObject*> RootedStaticBlockObject;
typedef Handle<StaticBlockObject*> HandleStaticBlockObject;
typedef Rooted<NestedScopeObject*> RootedNestedScopeObject;
typedef Handle<NestedScopeObject*> HandleNestedScopeObject;
/* Read a token. Report an error and return null() if that token isn't of type tt. */
#define MUST_MATCH_TOKEN_MOD(tt, modifier, errno) \
JS_BEGIN_MACRO \
TokenKind token; \
if (!tokenStream.getToken(&token, modifier)) \
return null(); \
if (token != tt) { \
report(ParseError, false, null(), errno); \
return null(); \
} \
JS_END_MACRO
#define MUST_MATCH_TOKEN(tt, errno) MUST_MATCH_TOKEN_MOD(tt, TokenStream::None, errno)
template <>
bool
ParseContext<FullParseHandler>::checkLocalsOverflow(TokenStream& ts)
{
if (vars_.length() + bodyLevelLexicals_.length() >= LOCALNO_LIMIT) {
ts.reportError(JSMSG_TOO_MANY_LOCALS);
return false;
}
return true;
}
static void
MarkUsesAsHoistedLexical(ParseNode* pn)
{
MOZ_ASSERT(pn->isDefn());
Definition* dn = (Definition*)pn;
ParseNode** pnup = &dn->dn_uses;
ParseNode* pnu;
unsigned start = pn->pn_blockid;
// In ES6, lexical bindings cannot be accessed until initialized.
// Distinguish hoisted uses as a different JSOp for easier compilation.
while ((pnu = *pnup) != nullptr && pnu->pn_blockid >= start) {
MOZ_ASSERT(pnu->isUsed());
pnu->pn_dflags |= PND_LEXICAL;
pnup = &pnu->pn_link;
}
}
void
SharedContext::computeAllowSyntax(JSObject* staticScope)
{
for (StaticScopeIter<CanGC> it(context, staticScope); !it.done(); it++) {
if (it.type() == StaticScopeIter<CanGC>::Function && !it.fun().isArrow()) {
// Any function supports new.target.
allowNewTarget_ = true;
allowSuperProperty_ = it.fun().allowSuperProperty();
if (it.maybeFunctionBox()) {
superScopeAlreadyNeedsHomeObject_ = it.maybeFunctionBox()->needsHomeObject();
allowSuperCall_ = it.maybeFunctionBox()->isDerivedClassConstructor();
} else {
allowSuperCall_ = it.fun().isDerivedClassConstructor();
}
break;
}
}
}
void
SharedContext::computeThisBinding(JSObject* staticScope)
{
for (StaticScopeIter<CanGC> it(context, staticScope); !it.done(); it++) {
if (it.type() == StaticScopeIter<CanGC>::Module) {
thisBinding_ = ThisBinding::Module;
return;
}
if (it.type() == StaticScopeIter<CanGC>::Function) {
// Arrow functions and generator expression lambdas don't have
// their own `this` binding.
if (it.fun().isArrow())
continue;
bool isDerived;
if (it.maybeFunctionBox()) {
if (it.maybeFunctionBox()->inGenexpLambda)
continue;
isDerived = it.maybeFunctionBox()->isDerivedClassConstructor();
} else {
if (it.fun().nonLazyScript()->isGeneratorExp())
continue;
isDerived = it.fun().isDerivedClassConstructor();
}
// Derived class constructors (including nested arrow functions and
// eval) need TDZ checks when accessing |this|.
if (isDerived)
needsThisTDZChecks_ = true;
thisBinding_ = ThisBinding::Function;
return;
}
}
thisBinding_ = ThisBinding::Global;
}
void
SharedContext::computeInWith(JSObject* staticScope)
{
for (StaticScopeIter<CanGC> it(context, staticScope); !it.done(); it++) {
if (it.type() == StaticScopeIter<CanGC>::With) {
inWith_ = true;
break;
}
}
}
void
SharedContext::markSuperScopeNeedsHomeObject()
{
MOZ_ASSERT(allowSuperProperty());
if (superScopeAlreadyNeedsHomeObject_)
return;
for (StaticScopeIter<CanGC> it(context, staticScope()); !it.done(); it++) {
if (it.type() == StaticScopeIter<CanGC>::Function && !it.fun().isArrow()) {
MOZ_ASSERT(it.fun().allowSuperProperty());
// If we are still emitting the outer function that needs a home
// object, mark it as needing one. Otherwise, we must be emitting
// an eval script, and the outer function must already be marked
// as needing a home object since it contains an eval.
if (it.maybeFunctionBox())
it.maybeFunctionBox()->setNeedsHomeObject();
else
MOZ_ASSERT(it.fun().nonLazyScript()->needsHomeObject());
superScopeAlreadyNeedsHomeObject_ = true;
return;
}
}
MOZ_CRASH("Must have found an enclosing function box scope that allows super.property");
}
// See comment on member function declaration.
template <>
bool
ParseContext<FullParseHandler>::define(TokenStream& ts,
HandlePropertyName name, ParseNode* pn, Definition::Kind kind)
{
MOZ_ASSERT(!pn->isUsed());
MOZ_ASSERT_IF(pn->isDefn(), pn->isPlaceholder());
Definition* prevDef = nullptr;
if (kind == Definition::LET || kind == Definition::CONSTANT)
prevDef = decls_.lookupFirst(name);
else
MOZ_ASSERT(!decls_.lookupFirst(name));
if (!prevDef)
prevDef = lexdeps.lookupDefn<FullParseHandler>(name);
if (prevDef) {
ParseNode** pnup = &prevDef->dn_uses;
ParseNode* pnu;
unsigned start = (kind == Definition::LET || kind == Definition::CONSTANT)
? pn->pn_blockid : bodyid;
while ((pnu = *pnup) != nullptr && pnu->pn_blockid >= start) {
MOZ_ASSERT(pnu->pn_blockid >= bodyid);
MOZ_ASSERT(pnu->isUsed());
pnu->pn_lexdef = (Definition*) pn;
pn->pn_dflags |= pnu->pn_dflags & PND_USE2DEF_FLAGS;
pnup = &pnu->pn_link;
}
if (!pnu || pnu != prevDef->dn_uses) {
*pnup = pn->dn_uses;
pn->dn_uses = prevDef->dn_uses;
prevDef->dn_uses = pnu;
if (!pnu && prevDef->isPlaceholder())
lexdeps->remove(name);
}
pn->pn_dflags |= prevDef->pn_dflags & PND_CLOSED;
}
MOZ_ASSERT_IF(kind != Definition::LET && kind != Definition::CONSTANT, !lexdeps->lookup(name));
pn->setDefn(true);
pn->pn_dflags &= ~PND_PLACEHOLDER;
if (kind == Definition::CONSTANT)
pn->pn_dflags |= PND_CONST;
Definition* dn = (Definition*)pn;
switch (kind) {
case Definition::ARG:
MOZ_ASSERT(sc->isFunctionBox());
dn->setOp((CodeSpec[dn->getOp()].format & JOF_SET) ? JSOP_SETARG : JSOP_GETARG);
dn->pn_blockid = bodyid;
dn->pn_dflags |= PND_BOUND;
if (!dn->pn_scopecoord.setSlot(ts, args_.length()))
return false;
if (!args_.append(dn))
return false;
if (args_.length() >= ARGNO_LIMIT) {
ts.reportError(JSMSG_TOO_MANY_FUN_ARGS);
return false;
}
if (name == ts.names().empty)
break;
if (!decls_.addUnique(name, dn))
return false;
break;
case Definition::VAR:
// Unlike args, var bindings keep the blockid of where the statement
// was found until ParseContext::generateBindings. In practice, this
// means when we emit bytecode for function scripts, var Definition
// nodes will have their static scopes correctly set to the static
// scope of the body. For global scripts, vars are dynamically defined
// on the global object and their static scope is never consulted.
if (!vars_.append(dn))
return false;
// We always track vars for redeclaration checks, but only non-global
// and non-deoptimized (e.g., inside a with scope) vars live in frame
// or CallObject slots.
if (!sc->isGlobalContext() && !dn->isDeoptimized()) {
dn->setOp((CodeSpec[dn->getOp()].format & JOF_SET) ? JSOP_SETLOCAL : JSOP_GETLOCAL);
dn->pn_dflags |= PND_BOUND;
if (!dn->pn_scopecoord.setSlot(ts, vars_.length() - 1))
return false;
if (!checkLocalsOverflow(ts))
return false;
}
if (atModuleScope())
dn->pn_dflags |= PND_CLOSED;
if (!decls_.addUnique(name, dn))
return false;
break;
case Definition::LET:
case Definition::CONSTANT:
// See FullParseHandler::setLexicalDeclarationOp.
dn->setOp(dn->pn_scopecoord.isFree() ? JSOP_INITGLEXICAL : JSOP_INITLEXICAL);
dn->pn_dflags |= (PND_LEXICAL | PND_BOUND);
if (atModuleLevel())
dn->pn_dflags |= PND_CLOSED;
if (atBodyLevel()) {
if (!bodyLevelLexicals_.append(dn))
return false;
if (!checkLocalsOverflow(ts))
return false;
}
// In ES6, lexical bindings cannot be accessed until initialized. If
// the definition has existing uses, they need to be marked so that we
// emit dead zone checks.
MarkUsesAsHoistedLexical(pn);
if (!decls_.addShadow(name, dn))
return false;
break;
case Definition::IMPORT:
dn->pn_dflags |= PND_LEXICAL | PND_CLOSED;
MOZ_ASSERT(atBodyLevel());
if (!decls_.addShadow(name, dn))
return false;
break;
default:
MOZ_CRASH("unexpected kind");
}
return true;
}
template <>
bool
ParseContext<SyntaxParseHandler>::checkLocalsOverflow(TokenStream& ts)
{
return true;
}
template <>
bool
ParseContext<SyntaxParseHandler>::define(TokenStream& ts, HandlePropertyName name, Node pn,
Definition::Kind kind)
{
MOZ_ASSERT(!decls_.lookupFirst(name));
if (lexdeps.lookupDefn<SyntaxParseHandler>(name))
lexdeps->remove(name);
// Keep track of the number of arguments in args_, for fun->nargs.
if (kind == Definition::ARG) {
if (!args_.append((Definition*) nullptr))
return false;
if (args_.length() >= ARGNO_LIMIT) {
ts.reportError(JSMSG_TOO_MANY_FUN_ARGS);
return false;
}
}
return decls_.addUnique(name, kind);
}
template <typename ParseHandler>
void
ParseContext<ParseHandler>::prepareToAddDuplicateArg(HandlePropertyName name, DefinitionNode prevDecl)
{
MOZ_ASSERT(decls_.lookupFirst(name) == prevDecl);
decls_.remove(name);
}
template <typename ParseHandler>
void
ParseContext<ParseHandler>::updateDecl(TokenStream& ts, JSAtom* atom, Node pn)
{
Definition* oldDecl = decls_.lookupFirst(atom);
pn->setDefn(true);
Definition* newDecl = (Definition*)pn;
decls_.updateFirst(atom, newDecl);
if (sc->isGlobalContext() || oldDecl->isDeoptimized()) {
MOZ_ASSERT(newDecl->isFreeVar());
// Global 'var' bindings have no slots, but are still tracked for
// redeclaration checks.
for (uint32_t i = 0; i < vars_.length(); i++) {
if (vars_[i] == oldDecl) {
// Terribly, deoptimized bindings may be updated with
// optimized bindings due to hoisted function statements, so
// give the new declaration a slot.
//
// Global bindings are excluded as currently they are never
// frame slots. The notion of being deoptimized is not
// applicable to them.
if (oldDecl->isDeoptimized() && !newDecl->isDeoptimized() &&
!sc->isGlobalContext())
{
newDecl->pn_dflags |= PND_BOUND;
newDecl->pn_scopecoord.setSlot(ts, i);
newDecl->setOp(JSOP_GETLOCAL);
}
vars_[i] = newDecl;
break;
}
}
return;
}
MOZ_ASSERT(oldDecl->isBound());
MOZ_ASSERT(!oldDecl->pn_scopecoord.isFree());
newDecl->pn_scopecoord = oldDecl->pn_scopecoord;
newDecl->pn_dflags |= PND_BOUND;
if (IsArgOp(oldDecl->getOp())) {
newDecl->setOp(JSOP_GETARG);
MOZ_ASSERT(args_[oldDecl->pn_scopecoord.slot()] == oldDecl);
args_[oldDecl->pn_scopecoord.slot()] = newDecl;
} else {
MOZ_ASSERT(IsLocalOp(oldDecl->getOp()));
newDecl->setOp(JSOP_GETLOCAL);
MOZ_ASSERT(vars_[oldDecl->pn_scopecoord.slot()] == oldDecl);
vars_[oldDecl->pn_scopecoord.slot()] = newDecl;
}
}
template <typename ParseHandler>
void
ParseContext<ParseHandler>::popLetDecl(JSAtom* atom)
{
MOZ_ASSERT(ParseHandler::getDefinitionKind(decls_.lookupFirst(atom)) == Definition::LET ||
ParseHandler::getDefinitionKind(decls_.lookupFirst(atom)) == Definition::CONSTANT);
decls_.remove(atom);
}
template <typename ParseHandler>
static void
AppendPackedBindings(const ParseContext<ParseHandler>* pc, const DeclVector& vec, Binding* dst,
uint32_t* numUnaliased = nullptr)
{
for (size_t i = 0; i < vec.length(); ++i, ++dst) {
Definition* dn = vec[i];
PropertyName* name = dn->name();
Binding::Kind kind;
switch (dn->kind()) {
case Definition::LET:
// Treat body-level let declarations as var bindings by falling
// through. The fact that the binding is in fact a let declaration
// is reflected in the slot. All body-level lets go after the
// vars.
case Definition::VAR:
kind = Binding::VARIABLE;
break;
case Definition::CONSTANT:
kind = Binding::CONSTANT;
break;
case Definition::ARG:
kind = Binding::ARGUMENT;
break;
case Definition::IMPORT:
// Skip module imports.
continue;
default:
MOZ_CRASH("unexpected dn->kind");
}
bool aliased;
if (pc->sc->isGlobalContext()) {
// Bindings for global and eval scripts are used solely for redeclaration
// checks in the prologue. Neither 'true' nor 'false' accurately describe
// their aliased-ness. These bindings don't live in CallObjects or the
// frame, but either on the global object and the global lexical
// scope. Force aliased to be false to avoid confusing other analyses in
// the engine that assumes the frame has a call object if there are
// aliased bindings.
aliased = false;
} else {
/*
* Bindings::init does not check for duplicates so we must ensure that
* only one binding with a given name is marked aliased. pc->decls
* maintains the canonical definition for each name, so use that.
*/
MOZ_ASSERT_IF(dn->isClosed(), pc->decls().lookupFirst(name) == dn);
aliased = dn->isClosed() ||
(pc->sc->allLocalsAliased() &&
pc->decls().lookupFirst(name) == dn);
}
*dst = Binding(name, kind, aliased);
if (!aliased && numUnaliased)
++*numUnaliased;
}
}
template <typename ParseHandler>
bool
ParseContext<ParseHandler>::generateBindings(ExclusiveContext* cx, TokenStream& ts, LifoAlloc& alloc,
MutableHandle<Bindings> bindings) const
{
MOZ_ASSERT_IF(sc->isFunctionBox(), args_.length() < ARGNO_LIMIT);
MOZ_ASSERT_IF(sc->isModuleBox(), args_.length() == 0);
MOZ_ASSERT(vars_.length() + bodyLevelLexicals_.length() < LOCALNO_LIMIT);
/*
* Avoid pathological edge cases by explicitly limiting the total number of
* bindings to what will fit in a uint32_t.
*/
if (UINT32_MAX - args_.length() <= vars_.length() + bodyLevelLexicals_.length())
return ts.reportError(JSMSG_TOO_MANY_LOCALS);
// Fix up slots in non-global contexts. In global contexts all body-level
// names are dynamically defined and do not live in either frame or
// CallObject slots.
if (!sc->isGlobalContext()) {
// Fix up the blockids of vars, whose static scope is always at the body
// level. This could not be done up front in ParseContext::define, as
// the original blockids are used for redeclaration checks.
for (size_t i = 0; i < vars_.length(); i++)
vars_[i]->pn_blockid = bodyid;
// Fix up the slots of body-level lets to come after the vars now that we
// know how many vars there are.
for (size_t i = 0; i < bodyLevelLexicals_.length(); i++) {
Definition* dn = bodyLevelLexicals_[i];
if (!dn->pn_scopecoord.setSlot(ts, vars_.length() + i))
return false;
}
}
uint32_t count = args_.length() + vars_.length() + bodyLevelLexicals_.length();
Binding* packedBindings = alloc.newArrayUninitialized<Binding>(count);
if (!packedBindings) {
ReportOutOfMemory(cx);
return false;
}
uint32_t numUnaliasedVars = 0;
uint32_t numUnaliasedBodyLevelLexicals = 0;
AppendPackedBindings(this, args_, packedBindings);
AppendPackedBindings(this, vars_, packedBindings + args_.length(), &numUnaliasedVars);
AppendPackedBindings(this, bodyLevelLexicals_,
packedBindings + args_.length() + vars_.length(), &numUnaliasedBodyLevelLexicals);
return Bindings::initWithTemporaryStorage(cx, bindings, args_.length(), vars_.length(),
bodyLevelLexicals_.length(), blockScopeDepth,
numUnaliasedVars, numUnaliasedBodyLevelLexicals,
packedBindings, sc->isModuleBox());
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportHelper(ParseReportKind kind, bool strict, uint32_t offset,
unsigned errorNumber, va_list args)
{
bool result = false;
switch (kind) {
case ParseError:
result = tokenStream.reportCompileErrorNumberVA(offset, JSREPORT_ERROR, errorNumber, args);
break;
case ParseWarning:
result =
tokenStream.reportCompileErrorNumberVA(offset, JSREPORT_WARNING, errorNumber, args);
break;
case ParseExtraWarning:
result = tokenStream.reportStrictWarningErrorNumberVA(offset, errorNumber, args);
break;
case ParseStrictError:
result = tokenStream.reportStrictModeErrorNumberVA(offset, strict, errorNumber, args);
break;
}
return result;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::report(ParseReportKind kind, bool strict, Node pn, unsigned errorNumber, ...)
{
uint32_t offset = (pn ? handler.getPosition(pn) : pos()).begin;
va_list args;
va_start(args, errorNumber);
bool result = reportHelper(kind, strict, offset, errorNumber, args);
va_end(args);
return result;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportNoOffset(ParseReportKind kind, bool strict, unsigned errorNumber, ...)
{
va_list args;
va_start(args, errorNumber);
bool result = reportHelper(kind, strict, TokenStream::NoOffset, errorNumber, args);
va_end(args);
return result;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportWithOffset(ParseReportKind kind, bool strict, uint32_t offset,
unsigned errorNumber, ...)
{
va_list args;
va_start(args, errorNumber);
bool result = reportHelper(kind, strict, offset, errorNumber, args);
va_end(args);
return result;
}
template <>
bool
Parser<FullParseHandler>::abortIfSyntaxParser()
{
handler.disableSyntaxParser();
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::abortIfSyntaxParser()
{
abortedSyntaxParse = true;
return false;
}
template <typename ParseHandler>
Parser<ParseHandler>::Parser(ExclusiveContext* cx, LifoAlloc* alloc,
const ReadOnlyCompileOptions& options,
const char16_t* chars, size_t length,
bool foldConstants,
Parser<SyntaxParseHandler>* syntaxParser,
LazyScript* lazyOuterFunction)
: AutoGCRooter(cx, PARSER),
context(cx),
alloc(*alloc),
tokenStream(cx, options, chars, length, thisForCtor()),
traceListHead(nullptr),
pc(nullptr),
blockScopes(cx),
sct(nullptr),
ss(nullptr),
keepAtoms(cx->perThreadData),
foldConstants(foldConstants),
#ifdef DEBUG
checkOptionsCalled(false),
#endif
abortedSyntaxParse(false),
isUnexpectedEOF_(false),
handler(cx, *alloc, tokenStream, syntaxParser, lazyOuterFunction)
{
{
AutoLockForExclusiveAccess lock(cx);
cx->perThreadData->addActiveCompilation();
}
// The Mozilla specific JSOPTION_EXTRA_WARNINGS option adds extra warnings
// which are not generated if functions are parsed lazily. Note that the
// standard "use strict" does not inhibit lazy parsing.
if (options.extraWarningsOption)
handler.disableSyntaxParser();
tempPoolMark = alloc->mark();
}
template<typename ParseHandler>
bool
Parser<ParseHandler>::checkOptions()
{
#ifdef DEBUG
checkOptionsCalled = true;
#endif
if (!tokenStream.checkOptions())
return false;
return true;
}
template <typename ParseHandler>
Parser<ParseHandler>::~Parser()
{
MOZ_ASSERT(checkOptionsCalled);
alloc.release(tempPoolMark);
/*
* The parser can allocate enormous amounts of memory for large functions.
* Eagerly free the memory now (which otherwise won't be freed until the
* next GC) to avoid unnecessary OOMs.
*/
alloc.freeAllIfHugeAndUnused();
{
AutoLockForExclusiveAccess lock(context);
context->perThreadData->removeActiveCompilation();
}
}
template <typename ParseHandler>
ObjectBox*
Parser<ParseHandler>::newObjectBox(JSObject* obj)
{
MOZ_ASSERT(obj);
/*
* We use JSContext.tempLifoAlloc to allocate parsed objects and place them
* on a list in this Parser to ensure GC safety. Thus the tempLifoAlloc
* arenas containing the entries must be alive until we are done with
* scanning, parsing and code generation for the whole script or top-level
* function.
*/
ObjectBox* objbox = alloc.new_<ObjectBox>(obj, traceListHead);
if (!objbox) {
ReportOutOfMemory(context);
return nullptr;
}
traceListHead = objbox;
return objbox;
}
template <typename ParseHandler>
FunctionBox::FunctionBox(ExclusiveContext* cx, ObjectBox* traceListHead, JSFunction* fun,
JSObject* enclosingStaticScope, ParseContext<ParseHandler>* outerpc,
Directives directives, bool extraWarnings, GeneratorKind generatorKind)
: ObjectBox(fun, traceListHead),
SharedContext(cx, directives, extraWarnings),
bindings(),
enclosingStaticScope_(enclosingStaticScope),
bufStart(0),
bufEnd(0),
startLine(1),
startColumn(0),
length(0),
generatorKindBits_(GeneratorKindAsBits(generatorKind)),
inGenexpLambda(false),
hasDestructuringArgs(false),
useAsm(false),
insideUseAsm(outerpc && outerpc->useAsmOrInsideUseAsm()),
wasEmitted(false),
usesArguments(false),
usesApply(false),
usesThis(false),
usesReturn(false),
funCxFlags()
{
// Functions created at parse time may be set singleton after parsing and
// baked into JIT code, so they must be allocated tenured. They are held by
// the JSScript so cannot be collected during a minor GC anyway.
MOZ_ASSERT(fun->isTenured());
}
template <typename ParseHandler>
FunctionBox*
Parser<ParseHandler>::newFunctionBox(Node fn, JSFunction* fun,
ParseContext<ParseHandler>* outerpc,
Directives inheritedDirectives,
GeneratorKind generatorKind,
JSObject* enclosingStaticScope)
{
MOZ_ASSERT_IF(outerpc, enclosingStaticScope == outerpc->innermostStaticScope());
MOZ_ASSERT(fun);
/*
* We use JSContext.tempLifoAlloc to allocate parsed objects and place them
* on a list in this Parser to ensure GC safety. Thus the tempLifoAlloc
* arenas containing the entries must be alive until we are done with
* scanning, parsing and code generation for the whole script or top-level
* function.
*/
FunctionBox* funbox =
alloc.new_<FunctionBox>(context, traceListHead, fun, enclosingStaticScope, outerpc,
inheritedDirectives, options().extraWarningsOption,
generatorKind);
if (!funbox) {
ReportOutOfMemory(context);
return nullptr;
}
traceListHead = funbox;
if (fn)
handler.setFunctionBox(fn, funbox);
return funbox;
}
template <typename ParseHandler>
ModuleBox::ModuleBox(ExclusiveContext* cx, ObjectBox* traceListHead, ModuleObject* module,
ParseContext<ParseHandler>* outerpc)
: ObjectBox(module, traceListHead),
SharedContext(cx, Directives(true), false),
bindings(),
exportNames(cx)
{
computeThisBinding(staticScope());
}
template <typename ParseHandler>
ModuleBox*
Parser<ParseHandler>::newModuleBox(Node pn, HandleModuleObject module)
{
MOZ_ASSERT(module);
/*
* We use JSContext.tempLifoAlloc to allocate parsed objects and place them
* on a list in this Parser to ensure GC safety. Thus the tempLifoAlloc
* arenas containing the entries must be alive until we are done with
* scanning, parsing and code generation for the whole module.
*/
ParseContext<ParseHandler>* outerpc = nullptr;
ModuleBox* modbox =
alloc.new_<ModuleBox>(context, traceListHead, module, outerpc);
if (!modbox) {
ReportOutOfMemory(context);
return nullptr;
}
traceListHead = modbox;
if (pn)
handler.setModuleBox(pn, modbox);
return modbox;
}
template <>
ModuleBox*
Parser<SyntaxParseHandler>::newModuleBox(Node pn, HandleModuleObject module)
{
MOZ_ALWAYS_FALSE(abortIfSyntaxParser());
return nullptr;
}
template <typename ParseHandler>
void
Parser<ParseHandler>::trace(JSTracer* trc)
{
ObjectBox::TraceList(trc, traceListHead);
}
void
MarkParser(JSTracer* trc, AutoGCRooter* parser)
{
static_cast<Parser<FullParseHandler>*>(parser)->trace(trc);
}
/*
* Parse a top-level JS script.
*/
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::parse()
{
MOZ_ASSERT(checkOptionsCalled);
/*
* Protect atoms from being collected by a GC activation, which might
* - nest on this thread due to out of memory (the so-called "last ditch"
* GC attempted within js_NewGCThing), or
* - run for any reason on another thread if this thread is suspended on
* an object lock before it finishes generating bytecode into a script
* protected from the GC by a root or a stack frame reference.
*/
Rooted<ScopeObject*> staticLexical(context, &context->global()->lexicalScope().staticBlock());
Directives directives(options().strictOption);
GlobalSharedContext globalsc(context, staticLexical, directives,
options().extraWarningsOption);
ParseContext<ParseHandler> globalpc(this, /* parent = */ nullptr, ParseHandler::null(),
&globalsc, /* newDirectives = */ nullptr);
if (!globalpc.init(*this))
return null();
Node pn = statements(YieldIsName);
if (pn) {
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
if (tt != TOK_EOF) {
report(ParseError, false, null(), JSMSG_GARBAGE_AFTER_INPUT,
"script", TokenKindToDesc(tt));
return null();
}
if (foldConstants) {
if (!FoldConstants(context, &pn, this))
return null();
}
}
return pn;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportBadReturn(Node pn, ParseReportKind kind,
unsigned errnum, unsigned anonerrnum)
{
JSAutoByteString name;
JSAtom* atom = pc->sc->asFunctionBox()->function()->atom();
if (atom) {
if (!AtomToPrintableString(context, atom, &name))
return false;
} else {
errnum = anonerrnum;
}
return report(kind, pc->sc->strict(), pn, errnum, name.ptr());
}
/*
* Check that it is permitted to introduce a binding for atom. Strict mode
* forbids introducing new definitions for 'eval', 'arguments', or for any
* strict mode reserved keyword. Use pn for reporting error locations, or use
* pc's token stream if pn is nullptr.
*/
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkStrictBinding(PropertyName* name, Node pn)
{
if (!pc->sc->needStrictChecks())
return true;
if (name == context->names().eval || name == context->names().arguments || IsKeyword(name)) {
JSAutoByteString bytes;
if (!AtomToPrintableString(context, name, &bytes))
return false;
return report(ParseStrictError, pc->sc->strict(), pn,
JSMSG_BAD_BINDING, bytes.ptr());
}
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::standaloneModule(HandleModuleObject module)
{
MOZ_ASSERT(checkOptionsCalled);
Node mn = handler.newModule();
if (!mn)
return null();
ModuleBox* modulebox = newModuleBox(mn, module);
if (!modulebox)
return null();
handler.setModuleBox(mn, modulebox);
ParseContext<FullParseHandler> modulepc(this, pc, mn, modulebox, nullptr);
if (!modulepc.init(*this))
return null();
ParseNode* pn = statements(YieldIsKeyword);
if (!pn)
return null();
pn->pn_blockid = modulepc.blockid();
MOZ_ASSERT(pn->isKind(PNK_STATEMENTLIST));
mn->pn_body = pn;
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
if (tt != TOK_EOF) {
report(ParseError, false, null(), JSMSG_GARBAGE_AFTER_INPUT, "module", TokenKindToDesc(tt));
return null();
}
if (!FoldConstants(context, &pn, this))
return null();
Rooted<Bindings> bindings(context, modulebox->bindings);
if (!modulepc.generateBindings(context, tokenStream, alloc, &bindings))
return null();
modulebox->bindings = bindings;
MOZ_ASSERT(mn->pn_modulebox == modulebox);
return mn;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::standaloneModule(HandleModuleObject module)
{
MOZ_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template <>
bool
Parser<FullParseHandler>::checkStatementsEOF()
{
// This is designed to be paired with parsing a statement list at the top
// level.
//
// The statements() call breaks on TOK_RC, so make sure we've
// reached EOF here.
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return false;
if (tt != TOK_EOF) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"expression", TokenKindToDesc(tt));
return false;
}
return true;
}
template <>
ParseNode*
Parser<FullParseHandler>::evalBody()
{
AutoPushStmtInfoPC stmtInfo(*this, StmtType::BLOCK);
ParseNode* block = pushLexicalScope(stmtInfo);
if (!block)
return nullptr;
// For parsing declarations and directives, eval scripts must be
// considered body level despite having a lexical scope.
MOZ_ASSERT(pc->atBodyLevel());
ParseNode* body = statements(YieldIsName);
if (!body)
return nullptr;
if (!checkStatementsEOF())
return nullptr;
block->pn_expr = body;
block->pn_pos = body->pn_pos;
return block;
}
template <>
ParseNode*
Parser<FullParseHandler>::globalBody()
{
MOZ_ASSERT(pc->atGlobalLevel());
ParseNode* body = statements(YieldIsName);
if (!body)
return nullptr;
if (!checkStatementsEOF())
return nullptr;
return body;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newThisName()
{
Node thisName = newName(context->names().dotThis);
if (!thisName)
return null();
if (!noteNameUse(context->names().dotThis, thisName))
return null();
return thisName;
}
template <>
bool
Parser<FullParseHandler>::defineFunctionThis()
{
HandlePropertyName dotThis = context->names().dotThis;
// Create a declaration for '.this' if there are any unbound uses in the
// function body.
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront()) {
if (r.front().key() == dotThis) {
Definition* dn = r.front().value().get<FullParseHandler>();
MOZ_ASSERT(dn->isPlaceholder());
pc->sc->asFunctionBox()->setHasThisBinding();
return pc->define(tokenStream, dotThis, dn, Definition::VAR);
}
}
// Also define a this-binding if direct eval is used, in derived class
// constructors (JSOP_CHECKRETURN relies on it) or if there's a debugger
// statement.
if (pc->sc->hasDirectEval() ||
pc->sc->asFunctionBox()->isDerivedClassConstructor() ||
pc->sc->hasDebuggerStatement())
{
ParseNode* pn = newName(dotThis);
if (!pn)
return false;
pc->sc->asFunctionBox()->setHasThisBinding();
return pc->define(tokenStream, dotThis, pn, Definition::VAR);
}
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::defineFunctionThis()
{
return true;
}
template <>
ParseNode*
Parser<FullParseHandler>::standaloneFunctionBody(HandleFunction fun,
Handle<PropertyNameVector> formals,
GeneratorKind generatorKind,
Directives inheritedDirectives,
Directives* newDirectives,
HandleObject enclosingStaticScope)
{
MOZ_ASSERT(checkOptionsCalled);
Node fn = handler.newFunctionDefinition();
if (!fn)
return null();
ParseNode* argsbody = handler.newList(PNK_ARGSBODY);
if (!argsbody)
return null();
fn->pn_body = argsbody;
FunctionBox* funbox = newFunctionBox(fn, fun, inheritedDirectives, generatorKind,
enclosingStaticScope);
if (!funbox)
return null();
funbox->length = fun->nargs() - fun->hasRest();
handler.setFunctionBox(fn, funbox);
ParseContext<FullParseHandler> funpc(this, pc, fn, funbox, newDirectives);
if (!funpc.init(*this))
return null();
for (unsigned i = 0; i < formals.length(); i++) {
if (!defineArg(fn, formals[i]))
return null();
}
YieldHandling yieldHandling = generatorKind != NotGenerator ? YieldIsKeyword : YieldIsName;
ParseNode* pn = functionBody(InAllowed, yieldHandling, Statement, StatementListBody);
if (!pn)
return null();
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
if (tt != TOK_EOF) {
report(ParseError, false, null(), JSMSG_GARBAGE_AFTER_INPUT,
"function body", TokenKindToDesc(tt));
return null();
}
if (!FoldConstants(context, &pn, this))
return null();
fn->pn_pos.end = pos().end;
MOZ_ASSERT(fn->pn_body->isKind(PNK_ARGSBODY));
fn->pn_body->append(pn);
/*
* Make sure to deoptimize lexical dependencies that are polluted
* by eval and function statements (which both flag the function as
* having an extensible scope).
*/
if (funbox->hasExtensibleScope() && pc->lexdeps->count()) {
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront()) {
Definition* dn = r.front().value().get<FullParseHandler>();
MOZ_ASSERT(dn->isPlaceholder());
handler.deoptimizeUsesWithin(dn, fn->pn_pos);
}
}
Rooted<Bindings> bindings(context, funbox->bindings);
if (!funpc.generateBindings(context, tokenStream, alloc, &bindings))
return null();
funbox->bindings = bindings;
return fn;
}
template <>
bool
Parser<FullParseHandler>::checkFunctionArguments()
{
/*
* Non-top-level functions use JSOP_DEFFUN which is a dynamic scope
* operation which means it aliases any bindings with the same name.
*/
if (FuncStmtSet* set = pc->funcStmts) {
for (FuncStmtSet::Range r = set->all(); !r.empty(); r.popFront()) {
PropertyName* name = r.front()->asPropertyName();
if (Definition* dn = pc->decls().lookupFirst(name))
dn->pn_dflags |= PND_CLOSED;
}
}
/* Time to implement the odd semantics of 'arguments'. */
HandlePropertyName arguments = context->names().arguments;
/*
* As explained by the ContextFlags::funArgumentsHasLocalBinding comment,
* create a declaration for 'arguments' if there are any unbound uses in
* the function body.
*/
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront()) {
if (r.front().key() == arguments) {
Definition* dn = r.front().value().get<FullParseHandler>();
pc->lexdeps->remove(arguments);
dn->pn_dflags |= PND_IMPLICITARGUMENTS;
if (!pc->define(tokenStream, arguments, dn, Definition::VAR))
return false;
pc->sc->asFunctionBox()->usesArguments = true;
break;
}
}
Definition* maybeArgDef = pc->decls().lookupFirst(arguments);
bool argumentsHasBinding = !!maybeArgDef;
// ES6 9.2.13.17 says that a lexical binding of 'arguments' shadows the
// arguments object.
bool argumentsHasLocalBinding = maybeArgDef && (maybeArgDef->kind() != Definition::ARG &&
maybeArgDef->kind() != Definition::LET &&
maybeArgDef->kind() != Definition::CONSTANT);
/*
* Even if 'arguments' isn't explicitly mentioned, dynamic name lookup
* forces an 'arguments' binding.
*/
if (!argumentsHasBinding && pc->sc->bindingsAccessedDynamically()) {
ParseNode* pn = newName(arguments);
if (!pn)
return false;
if (!pc->define(tokenStream, arguments, pn, Definition::VAR))
return false;
argumentsHasBinding = true;
argumentsHasLocalBinding = true;
}
/*
* Now that all possible 'arguments' bindings have been added, note whether
* 'arguments' has a local binding and whether it unconditionally needs an
* arguments object. (Also see the flags' comments in ContextFlags.)
*/
if (argumentsHasLocalBinding) {
FunctionBox* funbox = pc->sc->asFunctionBox();
funbox->setArgumentsHasLocalBinding();
/* Dynamic scope access destroys all hope of optimization. */
if (pc->sc->bindingsAccessedDynamically())
funbox->setDefinitelyNeedsArgsObj();
/*
* If a script contains the debugger statement either directly or
* within an inner function, the arguments object must be created
* eagerly. The debugger can walk the scope chain and observe any
* values along it.
*/
if (pc->sc->hasDebuggerStatement())
funbox->setDefinitelyNeedsArgsObj();
/*
* Check whether any parameters have been assigned within this
* function. If the arguments object is unmapped (strict mode or
* function with default/rest/destructing args), parameters do not alias
* arguments[i], and to make the arguments object reflect initial
* parameter values prior to any mutation we create it eagerly whenever
* parameters are (or might, in the case of calls to eval) assigned.
*/
if (!funbox->hasMappedArgsObj()) {
for (AtomDefnListMap::Range r = pc->decls().all(); !r.empty(); r.popFront()) {
DefinitionList& dlist = r.front().value();
for (DefinitionList::Range dr = dlist.all(); !dr.empty(); dr.popFront()) {
Definition* dn = dr.front<FullParseHandler>();
if (dn->kind() == Definition::ARG && dn->isAssigned())
funbox->setDefinitelyNeedsArgsObj();
}
}
}
}
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::checkFunctionArguments()
{
if (pc->lexdeps->lookup(context->names().arguments))
pc->sc->asFunctionBox()->usesArguments = true;
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionBody(InHandling inHandling, YieldHandling yieldHandling,
FunctionSyntaxKind kind, FunctionBodyType type)
{
MOZ_ASSERT(pc->sc->isFunctionBox());
MOZ_ASSERT(!pc->funHasReturnExpr && !pc->funHasReturnVoid);
#ifdef DEBUG
uint32_t startYieldOffset = pc->lastYieldOffset;
#endif
Node pn;
if (type == StatementListBody) {
pn = statements(yieldHandling);
if (!pn)
return null();
} else {
MOZ_ASSERT(type == ExpressionBody);
Node kid = assignExpr(inHandling, yieldHandling, TripledotProhibited);
if (!kid)
return null();
pn = handler.newReturnStatement(kid, handler.getPosition(kid));
if (!pn)
return null();
}
switch (pc->generatorKind()) {
case NotGenerator:
MOZ_ASSERT(pc->lastYieldOffset == startYieldOffset);
break;
case LegacyGenerator:
// FIXME: Catch these errors eagerly, in Parser::yieldExpression.
MOZ_ASSERT(pc->lastYieldOffset != startYieldOffset);
if (kind == Arrow) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
JSMSG_YIELD_IN_ARROW, js_yield_str);
return null();
}
if (type == ExpressionBody) {
reportBadReturn(pn, ParseError,
JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
return null();
}
break;
case StarGenerator:
MOZ_ASSERT(kind != Arrow);
MOZ_ASSERT(type == StatementListBody);
break;
}
if (pc->isGenerator()) {
MOZ_ASSERT(type == StatementListBody);
Node generator = newName(context->names().dotGenerator);
if (!generator)
return null();
if (!pc->define(tokenStream, context->names().dotGenerator, generator, Definition::VAR))
return null();
generator = newName(context->names().dotGenerator);
if (!generator)
return null();
if (!noteNameUse(context->names().dotGenerator, generator))
return null();
if (!handler.prependInitialYield(pn, generator))
return null();
}
if (kind != Arrow) {
// Define the 'arguments' and 'this' bindings if necessary. Arrow
// functions don't have these bindings.
if (!checkFunctionArguments())
return null();
if (!defineFunctionThis())
return null();
}
return pn;
}
/* See comment for use in Parser::functionDef. */
template <>
bool
Parser<FullParseHandler>::makeDefIntoUse(Definition* dn, ParseNode* pn, HandleAtom atom)
{
/* Turn pn into a definition. */
pc->updateDecl(tokenStream, atom, pn);
/* Change all uses of dn to be uses of pn. */
for (ParseNode* pnu = dn->dn_uses; pnu; pnu = pnu->pn_link) {
MOZ_ASSERT(pnu->isUsed());
MOZ_ASSERT(!pnu->isDefn());
pnu->pn_lexdef = (Definition*) pn;
pn->pn_dflags |= pnu->pn_dflags & PND_USE2DEF_FLAGS;
}
pn->pn_dflags |= dn->pn_dflags & PND_USE2DEF_FLAGS;
pn->dn_uses = dn;
/*
* A PNK_FUNCTION node must be a definition, so convert shadowed function
* statements into nops. This is valid since all body-level function
* statement initialization happens at the beginning of the function
* (thus, only the last statement's effect is visible). E.g., in
*
* function outer() {
* function g() { return 1 }
* assertEq(g(), 2);
* function g() { return 2 }
* assertEq(g(), 2);
* }
*
* both asserts are valid.
*/
if (dn->getKind() == PNK_FUNCTION) {
MOZ_ASSERT(dn->functionIsHoisted());
pn->dn_uses = dn->pn_link;
handler.prepareNodeForMutation(dn);
dn->setKind(PNK_NOP);
dn->setArity(PN_NULLARY);
dn->setDefn(false);
return true;
}
/*
* If dn is in [var, const, let] and has an initializer, then we
* must rewrite it to be an assignment node, whose freshly allocated
* left-hand side becomes a use of pn.
*/
if (dn->canHaveInitializer()) {
if (ParseNode* rhs = dn->expr()) {
ParseNode* lhs = handler.makeAssignment(dn, rhs);
if (!lhs)
return false;
pn->dn_uses = lhs;
dn->pn_link = nullptr;
dn = (Definition*) lhs;
}
}
/* Turn dn into a use of pn. */
MOZ_ASSERT(dn->isKind(PNK_NAME));
MOZ_ASSERT(dn->isArity(PN_NAME));
MOZ_ASSERT(dn->pn_atom == atom);
dn->setOp((CodeSpec[dn->getOp()].format & JOF_SET) ? JSOP_SETNAME : JSOP_GETNAME);
dn->setDefn(false);
dn->setUsed(true);
dn->pn_lexdef = (Definition*) pn;
dn->pn_scopecoord.makeFree();
dn->pn_dflags &= ~PND_BOUND;
return true;
}
/*
* Helper class for creating bindings.
*
* The same instance can be used more than once by repeatedly calling
* setNameNode() followed by bind().
*
* In the destructuring case, bind() is called indirectly from the variable
* declaration parser by way of checkDestructuringPattern and its friends.
*/
template <typename ParseHandler>
struct BindData
{
struct LetData {
explicit LetData(ExclusiveContext* cx) : blockObj(cx) {}
VarContext varContext;
RootedStaticBlockObject blockObj;
unsigned overflow;
};
explicit BindData(ExclusiveContext* cx)
: kind_(Uninitialized), nameNode_(ParseHandler::null()), letData_(cx)
{}
void initLexical(VarContext varContext, JSOp op, StaticBlockObject* blockObj,
unsigned overflow)
{
init(LexicalBinding, op, op == JSOP_DEFCONST);
letData_.varContext = varContext;
letData_.blockObj = blockObj;
letData_.overflow = overflow;
}
void initVar(JSOp op) {
init(VarBinding, op, false);
}
void initDestructuring(JSOp op) {
init(DestructuringBinding, op, false);
}
void setNameNode(typename ParseHandler::Node pn) {
MOZ_ASSERT(isInitialized());
nameNode_ = pn;
}
typename ParseHandler::Node nameNode() {
MOZ_ASSERT(isInitialized());
return nameNode_;
}
JSOp op() {
MOZ_ASSERT(isInitialized());
return op_;
}
bool isConst() {
MOZ_ASSERT(isInitialized());
return isConst_;
}
const LetData& letData() {
MOZ_ASSERT(kind_ == LexicalBinding);
return letData_;
}
bool bind(HandlePropertyName name, Parser<ParseHandler>* parser) {
MOZ_ASSERT(isInitialized());
MOZ_ASSERT(nameNode_ != ParseHandler::null());
switch (kind_) {
case LexicalBinding:
return Parser<ParseHandler>::bindLexical(this, name, parser);
case VarBinding:
return Parser<ParseHandler>::bindVar(this, name, parser);
case DestructuringBinding:
return Parser<ParseHandler>::bindDestructuringArg(this, name, parser);
default:
MOZ_CRASH();
}
nameNode_ = ParseHandler::null();
}
private:
enum BindingKind {
Uninitialized,
LexicalBinding,
VarBinding,
DestructuringBinding
};
BindingKind kind_;
// Name node for definition processing and error source coordinates.
typename ParseHandler::Node nameNode_;
JSOp op_; // Prologue bytecode or nop.
bool isConst_; // Whether this is a const binding.
LetData letData_;
bool isInitialized() {
return kind_ != Uninitialized;
}
void init(BindingKind kind, JSOp op, bool isConst) {
MOZ_ASSERT(!isInitialized());
kind_ = kind;
op_ = op;
isConst_ = isConst;
}
};
template <typename ParseHandler>
JSFunction*
Parser<ParseHandler>::newFunction(HandleAtom atom, FunctionSyntaxKind kind,
GeneratorKind generatorKind, HandleObject proto)
{
MOZ_ASSERT_IF(kind == Statement, atom != nullptr);
RootedFunction fun(context);
gc::AllocKind allocKind = gc::AllocKind::FUNCTION;
JSFunction::Flags flags;
switch (kind) {
case Expression:
flags = (generatorKind == NotGenerator
? JSFunction::INTERPRETED_LAMBDA
: JSFunction::INTERPRETED_LAMBDA_GENERATOR);
break;
case Arrow:
flags = JSFunction::INTERPRETED_LAMBDA_ARROW;
allocKind = gc::AllocKind::FUNCTION_EXTENDED;
break;
case Method:
MOZ_ASSERT(generatorKind == NotGenerator || generatorKind == StarGenerator);
flags = (generatorKind == NotGenerator
? JSFunction::INTERPRETED_METHOD
: JSFunction::INTERPRETED_METHOD_GENERATOR);
allocKind = gc::AllocKind::FUNCTION_EXTENDED;
break;
case ClassConstructor:
case DerivedClassConstructor:
flags = JSFunction::INTERPRETED_CLASS_CONSTRUCTOR;
allocKind = gc::AllocKind::FUNCTION_EXTENDED;
break;
case Getter:
case GetterNoExpressionClosure:
flags = JSFunction::INTERPRETED_GETTER;
allocKind = gc::AllocKind::FUNCTION_EXTENDED;
break;
case Setter:
case SetterNoExpressionClosure:
flags = JSFunction::INTERPRETED_SETTER;
allocKind = gc::AllocKind::FUNCTION_EXTENDED;
break;
default:
flags = (generatorKind == NotGenerator
? JSFunction::INTERPRETED_NORMAL
: JSFunction::INTERPRETED_GENERATOR);
}
fun = NewFunctionWithProto(context, nullptr, 0, flags, nullptr, atom, proto,
allocKind, TenuredObject);
if (!fun)
return nullptr;
if (options().selfHostingMode)
fun->setIsSelfHostedBuiltin();
return fun;
}
/*
* WARNING: Do not call this function directly.
* Call either MatchOrInsertSemicolonAfterExpression or
* MatchOrInsertSemicolonAfterNonExpression instead, depending on context.
*/
static bool
MatchOrInsertSemicolonHelper(TokenStream& ts, TokenStream::Modifier modifier)
{
TokenKind tt = TOK_EOF;
if (!ts.peekTokenSameLine(&tt, modifier))
return false;
if (tt != TOK_EOF && tt != TOK_EOL && tt != TOK_SEMI && tt != TOK_RC) {
/* Advance the scanner for proper error location reporting. */
ts.consumeKnownToken(tt, modifier);
ts.reportError(JSMSG_SEMI_BEFORE_STMNT);
return false;
}
bool matched;
if (!ts.matchToken(&matched, TOK_SEMI, modifier))
return false;
if (!matched && modifier == TokenStream::None)
ts.addModifierException(TokenStream::OperandIsNone);
return true;
}
static bool
MatchOrInsertSemicolonAfterExpression(TokenStream& ts)
{
return MatchOrInsertSemicolonHelper(ts, TokenStream::None);
}
static bool
MatchOrInsertSemicolonAfterNonExpression(TokenStream& ts)
{
return MatchOrInsertSemicolonHelper(ts, TokenStream::Operand);
}
/*
* The function LexicalLookup searches a static binding for the given name in
* the stack of statements enclosing the statement currently being parsed. Each
* statement that introduces a new scope has a corresponding scope object, on
* which the bindings for that scope are stored. LexicalLookup either returns
* the innermost statement which has a scope object containing a binding with
* the given name, or nullptr.
*/
template <class ContextT>
static StmtInfoPC*
LexicalLookup(ContextT* ct, HandleAtom atom, StmtInfoPC* stmt = nullptr)
{
RootedId id(ct->sc->context, AtomToId(atom));
if (!stmt)
stmt = ct->innermostScopeStmt();
for (; stmt; stmt = stmt->enclosingScope) {
/*
* With-statements introduce dynamic bindings. Since dynamic bindings
* can potentially override any static bindings introduced by statements
* further up the stack, we have to abort the search.
*/
if (stmt->type == StmtType::WITH && !ct->sc->isDotVariable(atom))
break;
// Skip statements that do not introduce a new scope
if (!stmt->isBlockScope)
continue;
StaticBlockObject& blockObj = stmt->staticBlock();
Shape* shape = blockObj.lookup(ct->sc->context, id);
if (shape)
return stmt;
}
return stmt;
}
template <typename ParseHandler>
typename ParseHandler::DefinitionNode
Parser<ParseHandler>::getOrCreateLexicalDependency(ParseContext<ParseHandler>* pc, JSAtom* atom)
{
AtomDefnAddPtr p = pc->lexdeps->lookupForAdd(atom);
if (p)
return p.value().get<ParseHandler>();
DefinitionNode dn = handler.newPlaceholder(atom, pc->blockid(), pos());
if (!dn)
return ParseHandler::nullDefinition();
DefinitionSingle def = DefinitionSingle::new_<ParseHandler>(dn);
if (!pc->lexdeps->add(p, atom, def))
return ParseHandler::nullDefinition();
return dn;
}
static bool
ConvertDefinitionToNamedLambdaUse(TokenStream& ts, ParseContext<FullParseHandler>* pc,
FunctionBox* funbox, Definition* dn)
{
dn->setOp(JSOP_CALLEE);
if (!dn->pn_scopecoord.setSlot(ts, 0))
return false;
dn->pn_blockid = pc->blockid();
dn->pn_dflags |= PND_BOUND;
MOZ_ASSERT(dn->kind() == Definition::NAMED_LAMBDA);
/*
* Since 'dn' is a placeholder, it has not been defined in the
* ParseContext and hence we must manually flag a closed-over
* callee name as needing a dynamic scope (this is done for all
* definitions in the ParseContext by generateBindings).
*
* If 'dn' has been assigned to, then we also flag the function
* scope has needing a dynamic scope so that dynamic scope
* setter can either ignore the set (in non-strict mode) or
* produce an error (in strict mode).
*/
if (dn->isClosed() || dn->isAssigned())
funbox->setNeedsDeclEnvObject();
return true;
}
static bool
IsNonDominatingInScopedSwitch(ParseContext<FullParseHandler>* pc, HandleAtom name,
Definition* dn)
{
MOZ_ASSERT(dn->isLexical());
StmtInfoPC* stmt = LexicalLookup(pc, name);
if (stmt && stmt->type == StmtType::SWITCH)
return dn->pn_scopecoord.slot() < stmt->firstDominatingLexicalInCase;
return false;
}
static void
AssociateUsesWithOuterDefinition(ParseNode* pnu, Definition* dn, Definition* outer_dn,
bool markUsesAsLexical)
{
uint32_t dflags = markUsesAsLexical ? PND_LEXICAL : 0;
while (true) {
pnu->pn_lexdef = outer_dn;
pnu->pn_dflags |= dflags;
if (!pnu->pn_link)
break;
pnu = pnu->pn_link;
}
pnu->pn_link = outer_dn->dn_uses;
outer_dn->dn_uses = dn->dn_uses;
dn->dn_uses = nullptr;
}
/*
* Beware: this function is called for functions nested in other functions or
* global scripts but not for functions compiled through the Function
* constructor or JSAPI. To always execute code when a function has finished
* parsing, use Parser::functionBody.
*/
template <>
bool
Parser<FullParseHandler>::leaveFunction(ParseNode* fn, ParseContext<FullParseHandler>* outerpc,
FunctionSyntaxKind kind)
{
bool bodyLevel = outerpc->atBodyLevel();
FunctionBox* funbox = fn->pn_funbox;
MOZ_ASSERT(funbox == pc->sc->asFunctionBox());
/* Propagate unresolved lexical names up to outerpc->lexdeps. */
if (pc->lexdeps->count()) {
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront()) {
JSAtom* atom = r.front().key();
Definition* dn = r.front().value().get<FullParseHandler>();
MOZ_ASSERT(dn->isPlaceholder());
if (atom == funbox->function()->name() && kind == Expression) {
if (!ConvertDefinitionToNamedLambdaUse(tokenStream, pc, funbox, dn))
return false;
continue;
}
Definition* outer_dn = outerpc->decls().lookupFirst(atom);
/*
* Make sure to deoptimize lexical dependencies that are polluted
* by eval and function statements (which both flag the function as
* having an extensible scope) or any enclosing 'with'.
*/
if (funbox->hasExtensibleScope() || funbox->inWith())
handler.deoptimizeUsesWithin(dn, fn->pn_pos);
if (!outer_dn) {
/*
* Create a new placeholder for our outer lexdep. We could
* simply re-use the inner placeholder, but that introduces
* subtleties in the case where we find a later definition
* that captures an existing lexdep. For example:
*
* function f() { function g() { x; } let x; }
*
* Here, g's TOK_UPVARS node lists the placeholder for x,
* which must be captured by the 'let' declaration later,
* since 'let's are hoisted. Taking g's placeholder as our
* own would work fine. But consider:
*
* function f() { x; { function g() { x; } let x; } }
*
* Here, the 'let' must not capture all the uses of f's
* lexdep entry for x, but it must capture the x node
* referred to from g's TOK_UPVARS node. Always turning
* inherited lexdeps into uses of a new outer definition
* allows us to handle both these cases in a natural way.
*/
outer_dn = getOrCreateLexicalDependency(outerpc, atom);
if (!outer_dn)
return false;
}
/*
* Insert dn's uses list at the front of outer_dn's list.
*
* Without loss of generality or correctness, we allow a dn to
* be in inner and outer lexdeps, since the purpose of lexdeps
* is one-pass coordination of name use and definition across
* functions, and if different dn's are used we'll merge lists
* when leaving the inner function.
*
* The dn == outer_dn case arises with generator expressions
* (see LegacyCompExprTransplanter::transplant, the PN_CODE/PN_NAME
* case), and nowhere else, currently.
*/
if (dn != outer_dn) {
if (ParseNode* pnu = dn->dn_uses) {
// In ES6, lexical bindings cannot be accessed until
// initialized. If we are parsing a body-level function,
// it is hoisted to the top, so we conservatively mark all
// uses linked to an outer lexical binding as needing TDZ
// checks. e.g.,
//
// function outer() {
// inner2();
// function inner() { use(x); }
// function inner2() { inner(); }
// let x;
// }
//
// The use of 'x' inside 'inner' needs to be marked.
//
// Note that to not be fully conservative requires a call
// graph analysis of all body-level functions to compute
// the transitive closure of which hoisted body level use
// of which function forces TDZ checks on which uses. This
// is unreasonably difficult to do in a single pass parser
// like ours.
//
// Similarly, if we are closing over a lexical binding
// from another case in a switch, those uses also need to
// be marked as needing dead zone checks.
RootedAtom name(context, atom);
bool markUsesAsLexical = outer_dn->isLexical() &&
(bodyLevel ||
IsNonDominatingInScopedSwitch(outerpc, name, outer_dn));
AssociateUsesWithOuterDefinition(pnu, dn, outer_dn, markUsesAsLexical);
}
outer_dn->pn_dflags |= dn->pn_dflags & ~PND_PLACEHOLDER;
}
/* Mark the outer dn as escaping. */
outer_dn->pn_dflags |= PND_CLOSED;
}
}
Rooted<Bindings> bindings(context, funbox->bindings);
if (!pc->generateBindings(context, tokenStream, alloc, &bindings))
return false;
funbox->bindings = bindings;
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::leaveFunction(Node fn, ParseContext<SyntaxParseHandler>* outerpc,
FunctionSyntaxKind kind)
{
FunctionBox* funbox = pc->sc->asFunctionBox();
return addFreeVariablesFromLazyFunction(funbox->function(), outerpc);
}
/*
* defineArg is called for both the arguments of a regular function definition
* and the arguments specified by the Function constructor.
*
* The 'disallowDuplicateArgs' bool indicates whether the use of another
* feature (destructuring or default arguments) disables duplicate arguments.
* (ECMA-262 requires us to support duplicate parameter names, but, for newer
* features, we consider the code to have "opted in" to higher standards and
* forbid duplicates.)
*
* If 'duplicatedArg' is non-null, then DefineArg assigns to it any previous
* argument with the same name. The caller may use this to report an error when
* one of the abovementioned features occurs after a duplicate.
*/
template <typename ParseHandler>
bool
Parser<ParseHandler>::defineArg(Node funcpn, HandlePropertyName name,
bool disallowDuplicateArgs, Node* duplicatedArg)
{
SharedContext* sc = pc->sc;
/* Handle duplicate argument names. */
if (DefinitionNode prevDecl = pc->decls().lookupFirst(name)) {
Node pn = handler.getDefinitionNode(prevDecl);
/*
* Strict-mode disallows duplicate args. We may not know whether we are
* in strict mode or not (since the function body hasn't been parsed).
* In such cases, report will queue up the potential error and return
* 'true'.
*/
if (sc->needStrictChecks()) {
JSAutoByteString bytes;
if (!AtomToPrintableString(context, name, &bytes))
return false;
if (!report(ParseStrictError, pc->sc->strict(), pn,
JSMSG_DUPLICATE_FORMAL, bytes.ptr()))
{
return false;
}
}
if (disallowDuplicateArgs) {
report(ParseError, false, pn, JSMSG_BAD_DUP_ARGS);
return false;
}
if (duplicatedArg)
*duplicatedArg = pn;
/* ParseContext::define assumes and asserts prevDecl is not in decls. */
MOZ_ASSERT(handler.getDefinitionKind(prevDecl) == Definition::ARG);
pc->prepareToAddDuplicateArg(name, prevDecl);
}
Node argpn = newName(name);
if (!argpn)
return false;
if (!checkStrictBinding(name, argpn))
return false;
handler.addFunctionArgument(funcpn, argpn);
return pc->define(tokenStream, name, argpn, Definition::ARG);
}
template <typename ParseHandler>
/* static */ bool
Parser<ParseHandler>::bindDestructuringArg(BindData<ParseHandler>* data,
HandlePropertyName name, Parser<ParseHandler>* parser)
{
ParseContext<ParseHandler>* pc = parser->pc;
MOZ_ASSERT(pc->sc->isFunctionBox());
if (pc->decls().lookupFirst(name)) {
parser->report(ParseError, false, null(), JSMSG_BAD_DUP_ARGS);
return false;
}
if (!parser->checkStrictBinding(name, data->nameNode()))
return false;
return pc->define(parser->tokenStream, name, data->nameNode(), Definition::VAR);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::functionArguments(YieldHandling yieldHandling, FunctionSyntaxKind kind,
Node funcpn, bool* hasRest)
{
FunctionBox* funbox = pc->sc->asFunctionBox();
*hasRest = false;
bool parenFreeArrow = false;
TokenStream::Modifier modifier = TokenStream::None;
if (kind == Arrow) {
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return false;
if (tt == TOK_NAME)
parenFreeArrow = true;
else
modifier = TokenStream::Operand;
}
if (!parenFreeArrow) {
TokenKind tt;
if (!tokenStream.getToken(&tt, modifier))
return false;
if (tt != TOK_LP) {
report(ParseError, false, null(),
kind == Arrow ? JSMSG_BAD_ARROW_ARGS : JSMSG_PAREN_BEFORE_FORMAL);
return false;
}
// Record the start of function source (for FunctionToString). If we
// are parenFreeArrow, we will set this below, after consuming the NAME.
funbox->setStart(tokenStream);
}
Node argsbody = handler.newList(PNK_ARGSBODY);
if (!argsbody)
return false;
handler.setFunctionBody(funcpn, argsbody);
bool hasArguments = false;
if (parenFreeArrow) {
hasArguments = true;
} else {
bool matched;
if (!tokenStream.matchToken(&matched, TOK_RP, TokenStream::Operand))
return false;
if (!matched)
hasArguments = true;
}
if (hasArguments) {
bool hasDefaults = false;
Node duplicatedArg = null();
bool disallowDuplicateArgs = kind == Arrow || kind == Method || kind == ClassConstructor;
if (IsGetterKind(kind)) {
report(ParseError, false, null(), JSMSG_ACCESSOR_WRONG_ARGS, "getter", "no", "s");
return false;
}
while (true) {
if (*hasRest) {
report(ParseError, false, null(), JSMSG_PARAMETER_AFTER_REST);
return false;
}
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return false;
MOZ_ASSERT_IF(parenFreeArrow, tt == TOK_NAME);
switch (tt) {
case TOK_LB:
case TOK_LC:
{
/* See comment below in the TOK_NAME case. */
disallowDuplicateArgs = true;
if (duplicatedArg) {
report(ParseError, false, duplicatedArg, JSMSG_BAD_DUP_ARGS);
return false;
}
funbox->hasDestructuringArgs = true;
/*
* A destructuring formal parameter turns into one or more
* local variables initialized from properties of a single
* anonymous positional parameter, so here we must tweak our
* binder and its data.
*/
BindData<ParseHandler> data(context);
data.initDestructuring(JSOP_DEFVAR);
Node destruct = destructuringExprWithoutYield(yieldHandling, &data, tt,
JSMSG_YIELD_IN_DEFAULT);
if (!destruct)
return false;
/*
* Make a single anonymous positional parameter, and store
* destructuring expression into the node.
*/
HandlePropertyName name = context->names().empty;
Node arg = newName(name);
if (!arg)
return false;
handler.addFunctionArgument(funcpn, arg);
if (!pc->define(tokenStream, name, arg, Definition::ARG))
return false;
handler.setLastFunctionArgumentDestructuring(funcpn, destruct);
break;
}
case TOK_YIELD:
if (!checkYieldNameValidity())
return false;
MOZ_ASSERT(yieldHandling == YieldIsName);
goto TOK_NAME;
case TOK_TRIPLEDOT:
{
if (IsSetterKind(kind)) {
report(ParseError, false, null(),
JSMSG_ACCESSOR_WRONG_ARGS, "setter", "one", "");
return false;
}
*hasRest = true;
if (!tokenStream.getToken(&tt))
return false;
// FIXME: This fails to handle a rest parameter named |yield|
// correctly outside of generators: that is,
// |var f = (...yield) => 42;| should be valid code!
// When this is fixed, make sure to consult both
// |yieldHandling| and |checkYieldNameValidity| for
// correctness until legacy generator syntax is removed.
if (tt != TOK_NAME) {
report(ParseError, false, null(), JSMSG_NO_REST_NAME);
return false;
}
disallowDuplicateArgs = true;
if (duplicatedArg) {
// Has duplicated args before the rest parameter.
report(ParseError, false, duplicatedArg, JSMSG_BAD_DUP_ARGS);
return false;
}
goto TOK_NAME;
}
TOK_NAME:
case TOK_NAME:
{
if (parenFreeArrow)
funbox->setStart(tokenStream);
RootedPropertyName name(context, tokenStream.currentName());
if (!defineArg(funcpn, name, disallowDuplicateArgs, &duplicatedArg))
return false;
break;
}
default:
report(ParseError, false, null(), JSMSG_MISSING_FORMAL);
return false;
}
bool matched;
if (!tokenStream.matchToken(&matched, TOK_ASSIGN))
return false;
if (matched) {
// A default argument without parentheses would look like:
// a = expr => body, but both operators are right-associative, so
// that would have been parsed as a = (expr => body) instead.
// Therefore it's impossible to get here with parenFreeArrow.
MOZ_ASSERT(!parenFreeArrow);
if (*hasRest) {
report(ParseError, false, null(), JSMSG_REST_WITH_DEFAULT);
return false;
}
disallowDuplicateArgs = true;
if (duplicatedArg) {
report(ParseError, false, duplicatedArg, JSMSG_BAD_DUP_ARGS);
return false;
}
if (!hasDefaults) {
hasDefaults = true;
// The Function.length property is the number of formals
// before the first default argument.
funbox->length = pc->numArgs() - 1;
}
Node def_expr = assignExprWithoutYield(yieldHandling, JSMSG_YIELD_IN_DEFAULT);
if (!def_expr)
return false;
if (!handler.setLastFunctionArgumentDefault(funcpn, def_expr))
return false;
}
if (parenFreeArrow || IsSetterKind(kind))
break;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return false;
if (!matched)
break;
}
if (!parenFreeArrow) {
TokenKind tt;
if (!tokenStream.getToken(&tt))
return false;
if (tt != TOK_RP) {
if (IsSetterKind(kind)) {
report(ParseError, false, null(),
JSMSG_ACCESSOR_WRONG_ARGS, "setter", "one", "");
return false;
}
report(ParseError, false, null(), JSMSG_PAREN_AFTER_FORMAL);
return false;
}
}
if (!hasDefaults)
funbox->length = pc->numArgs() - *hasRest;
} else if (IsSetterKind(kind)) {
report(ParseError, false, null(), JSMSG_ACCESSOR_WRONG_ARGS, "setter", "one", "");
return false;
}
return true;
}
template <>
bool
Parser<FullParseHandler>::checkFunctionDefinition(HandlePropertyName funName,
ParseNode** pn_, FunctionSyntaxKind kind,
bool* pbodyProcessed)
{
ParseNode*& pn = *pn_;
*pbodyProcessed = false;
/* Function statements add a binding to the enclosing scope. */
bool bodyLevel = pc->atBodyLevel();
if (kind == Statement) {
/*
* Handle redeclaration and optimize cases where we can statically bind the
* function (thereby avoiding JSOP_DEFFUN and dynamic name lookup).
*/
if (Definition* dn = pc->decls().lookupFirst(funName)) {
MOZ_ASSERT(!dn->isUsed());
MOZ_ASSERT(dn->isDefn());
bool throwRedeclarationError = dn->kind() == Definition::CONSTANT ||
dn->kind() == Definition::LET;
if (options().extraWarningsOption || throwRedeclarationError) {
JSAutoByteString name;
ParseReportKind reporter = throwRedeclarationError
? ParseError
: ParseExtraWarning;
if (!AtomToPrintableString(context, funName, &name) ||
!report(reporter, false, nullptr, JSMSG_REDECLARED_VAR,
Definition::kindString(dn->kind()), name.ptr()))
{
return false;
}
}
/*
* Body-level function statements are effectively variable
* declarations where the initialization is hoisted to the
* beginning of the block. This means that any other variable
* declaration with the same name is really just an assignment to
* the function's binding (which is mutable), so turn any existing
* declaration into a use.
*/
if (bodyLevel) {
if (dn->kind() == Definition::ARG) {
// The exception to the above comment is when the function
// has the same name as an argument. Then the argument node
// remains a definition. But change the function node pn so
// that it knows where the argument is located.
pn->setOp(JSOP_GETARG);
pn->setDefn(true);
pn->pn_scopecoord = dn->pn_scopecoord;
pn->pn_blockid = dn->pn_blockid;
pn->pn_dflags |= PND_BOUND;
dn->markAsAssigned();
} else {
if (!makeDefIntoUse(dn, pn, funName))
return false;
}
}
} else if (bodyLevel) {
/*
* If this function was used before it was defined, claim the
* pre-created definition node for this function that primaryExpr
* put in pc->lexdeps on first forward reference, and recycle pn.
*/
if (Definition* fn = pc->lexdeps.lookupDefn<FullParseHandler>(funName)) {
MOZ_ASSERT(fn->isDefn());
fn->setKind(PNK_FUNCTION);
fn->setArity(PN_CODE);
fn->pn_pos.begin = pn->pn_pos.begin;
fn->pn_pos.end = pn->pn_pos.end;
fn->pn_body = nullptr;
fn->pn_scopecoord.makeFree();
pc->lexdeps->remove(funName);
handler.freeTree(pn);
pn = fn;
}
if (!pc->define(tokenStream, funName, pn, Definition::VAR))
return false;
}
if (bodyLevel) {
MOZ_ASSERT(pn->functionIsHoisted());
MOZ_ASSERT(pc->sc->isGlobalContext() == pn->pn_scopecoord.isFree());
} else {
/*
* As a SpiderMonkey-specific extension, non-body-level function
* statements (e.g., functions in an "if" or "while" block) are
* dynamically bound when control flow reaches the statement.
*/
MOZ_ASSERT(!pc->sc->strict());
MOZ_ASSERT(pn->pn_scopecoord.isFree());
if (pc->sc->isFunctionBox()) {
FunctionBox* funbox = pc->sc->asFunctionBox();
funbox->setMightAliasLocals();
funbox->setHasExtensibleScope();
}
pn->setOp(JSOP_DEFFUN);
/*
* Instead of setting bindingsAccessedDynamically, which would be
* overly conservative, remember the names of all function
* statements and mark any bindings with the same as aliased at the
* end of functionBody.
*/
if (!pc->funcStmts) {
pc->funcStmts = alloc.new_<FuncStmtSet>(alloc);
if (!pc->funcStmts || !pc->funcStmts->init()) {
ReportOutOfMemory(context);
return false;
}
}
if (!pc->funcStmts->put(funName))
return false;
/*
* Due to the implicit declaration mechanism, 'arguments' will not
* have decls and, even if it did, they will not be noted as closed
* in the emitter. Thus, in the corner case of function statements
* overridding arguments, flag the whole scope as dynamic.
*/
if (funName == context->names().arguments)
pc->sc->setBindingsAccessedDynamically();
}
/* No further binding (in BindNameToSlot) is needed for functions. */
pn->pn_dflags |= PND_BOUND;
} else {
/* A function expression does not introduce any binding. */
pn->setOp(kind == Arrow ? JSOP_LAMBDA_ARROW : JSOP_LAMBDA);
}
// When a lazily-parsed function is called, we only fully parse (and emit)
// that function, not any of its nested children. The initial syntax-only
// parse recorded the free variables of nested functions and their extents,
// so we can skip over them after accounting for their free variables.
Rooted<LazyScript*> lazyOuter(context, handler.lazyOuterFunction());
if (lazyOuter) {
RootedFunction fun(context, handler.nextLazyInnerFunction());
MOZ_ASSERT(!fun->isLegacyGenerator());
FunctionBox* funbox = newFunctionBox(pn, fun, pc, Directives(/* strict = */ false),
fun->generatorKind());
if (!funbox)
return false;
if (fun->lazyScript()->needsHomeObject())
funbox->setNeedsHomeObject();
if (!addFreeVariablesFromLazyFunction(fun, pc))
return false;
// The position passed to tokenStream.advance() is an offset of the sort
// returned by userbuf.offset() and expected by userbuf.rawCharPtrAt(),
// while LazyScript::{begin,end} offsets are relative to the outermost
// script source.
uint32_t userbufBase = lazyOuter->begin() - lazyOuter->column();
if (!tokenStream.advance(fun->lazyScript()->end() - userbufBase))
return false;
*pbodyProcessed = true;
return true;
}
return true;
}
template <class T, class U>
static inline void
PropagateTransitiveParseFlags(const T* inner, U* outer)
{
if (inner->bindingsAccessedDynamically())
outer->setBindingsAccessedDynamically();
if (inner->hasDebuggerStatement())
outer->setHasDebuggerStatement();
if (inner->hasDirectEval())
outer->setHasDirectEval();
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::addFreeVariablesFromLazyFunction(JSFunction* fun,
ParseContext<ParseHandler>* pc)
{
// Update any definition nodes in this context according to free variables
// in a lazily parsed inner function.
bool bodyLevel = pc->atBodyLevel();
LazyScript* lazy = fun->lazyScript();
LazyScript::FreeVariable* freeVariables = lazy->freeVariables();
for (size_t i = 0; i < lazy->numFreeVariables(); i++) {
JSAtom* atom = freeVariables[i].atom();
// 'arguments' will be implicitly bound within the inner function,
// except if the inner function is an arrow function.
if (atom == context->names().arguments && !fun->isArrow())
continue;
DefinitionNode dn = pc->decls().lookupFirst(atom);
if (!dn) {
dn = getOrCreateLexicalDependency(pc, atom);
if (!dn)
return false;
}
// In ES6, lexical bindings are unaccessible before initialization. If
// the inner function closes over a placeholder definition, we need to
// mark the variable as maybe needing a dead zone check when we emit
// bytecode.
//
// Note that body-level function declaration statements are always
// hoisted to the top, so all accesses to free let variables need the
// dead zone check.
//
// Subtlety: we don't need to check for closing over a non-dominating
// lexical binding in a switch, as lexical declarations currently
// disable syntax parsing. So a non-dominating but textually preceding
// lexical declaration would have aborted syntax parsing, and a
// textually following declaration would return true for
// handler.isPlaceholderDefinition(dn) below.
if (handler.isPlaceholderDefinition(dn) || bodyLevel)
freeVariables[i].setIsHoistedUse();
/* Mark the outer dn as escaping. */
handler.setFlag(handler.getDefinitionNode(dn), PND_CLOSED);
}
PropagateTransitiveParseFlags(lazy, pc->sc);
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::checkFunctionDefinition(HandlePropertyName funName,
Node* pn, FunctionSyntaxKind kind,
bool* pbodyProcessed)
{
*pbodyProcessed = false;
/* Function statements add a binding to the enclosing scope. */
bool bodyLevel = pc->atBodyLevel();
if (kind == Statement) {
/*
* Handle redeclaration and optimize cases where we can statically bind the
* function (thereby avoiding JSOP_DEFFUN and dynamic name lookup).
*/
if (DefinitionNode dn = pc->decls().lookupFirst(funName)) {
if (dn == Definition::CONSTANT || dn == Definition::LET) {
JSAutoByteString name;
if (!AtomToPrintableString(context, funName, &name) ||
!report(ParseError, false, null(), JSMSG_REDECLARED_VAR,
Definition::kindString(dn), name.ptr()))
{
return false;
}
}
} else if (bodyLevel) {
if (pc->lexdeps.lookupDefn<SyntaxParseHandler>(funName))
pc->lexdeps->remove(funName);
if (!pc->define(tokenStream, funName, *pn, Definition::VAR))
return false;
}
if (!bodyLevel && funName == context->names().arguments)
pc->sc->setBindingsAccessedDynamically();
}
if (kind == Arrow) {
/* Arrow functions cannot yet be parsed lazily. */
return abortIfSyntaxParser();
}
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::addExprAndGetNextTemplStrToken(YieldHandling yieldHandling, Node nodeList,
TokenKind* ttp)
{
Node pn = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!pn)
return false;
handler.addList(nodeList, pn);
TokenKind tt;
if (!tokenStream.getToken(&tt))
return false;
if (tt != TOK_RC) {
report(ParseError, false, null(), JSMSG_TEMPLSTR_UNTERM_EXPR);
return false;
}
return tokenStream.getToken(ttp, TokenStream::TemplateTail);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::taggedTemplate(YieldHandling yieldHandling, Node nodeList, TokenKind tt)
{
Node callSiteObjNode = handler.newCallSiteObject(pos().begin);
if (!callSiteObjNode)
return false;
handler.addList(nodeList, callSiteObjNode);
while (true) {
if (!appendToCallSiteObj(callSiteObjNode))
return false;
if (tt != TOK_TEMPLATE_HEAD)
break;
if (!addExprAndGetNextTemplStrToken(yieldHandling, nodeList, &tt))
return false;
}
handler.setEndPosition(nodeList, callSiteObjNode);
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::templateLiteral(YieldHandling yieldHandling)
{
Node pn = noSubstitutionTemplate();
if (!pn)
return null();
Node nodeList = handler.newList(PNK_TEMPLATE_STRING_LIST, pn);
TokenKind tt;
do {
if (!addExprAndGetNextTemplStrToken(yieldHandling, nodeList, &tt))
return null();
pn = noSubstitutionTemplate();
if (!pn)
return null();
handler.addList(nodeList, pn);
} while (tt == TOK_TEMPLATE_HEAD);
return nodeList;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionDef(InHandling inHandling, YieldHandling yieldHandling,
HandlePropertyName funName, FunctionSyntaxKind kind,
GeneratorKind generatorKind, InvokedPrediction invoked)
{
MOZ_ASSERT_IF(kind == Statement, funName);
/* Make a TOK_FUNCTION node. */
Node pn = handler.newFunctionDefinition();
if (!pn)
return null();
if (invoked)
pn = handler.setLikelyIIFE(pn);
bool bodyProcessed;
if (!checkFunctionDefinition(funName, &pn, kind, &bodyProcessed))
return null();
if (bodyProcessed)
return pn;
RootedObject proto(context);
if (generatorKind == StarGenerator) {
// If we are off the main thread, the generator meta-objects have
// already been created by js::StartOffThreadParseScript, so cx will not
// be necessary.
JSContext* cx = context->maybeJSContext();
proto = GlobalObject::getOrCreateStarGeneratorFunctionPrototype(cx, context->global());
if (!proto)
return null();
}
RootedFunction fun(context, newFunction(funName, kind, generatorKind, proto));
if (!fun)
return null();
// Speculatively parse using the directives of the parent parsing context.
// If a directive is encountered (e.g., "use strict") that changes how the
// function should have been parsed, we backup and reparse with the new set
// of directives.
Directives directives(pc);
Directives newDirectives = directives;
TokenStream::Position start(keepAtoms);
tokenStream.tell(&start);
while (true) {
if (functionArgsAndBody(inHandling, pn, fun, kind, generatorKind, directives,
&newDirectives))
{
break;
}
if (tokenStream.hadError() || directives == newDirectives)
return null();
// Assignment must be monotonic to prevent reparsing iloops
MOZ_ASSERT_IF(directives.strict(), newDirectives.strict());
MOZ_ASSERT_IF(directives.asmJS(), newDirectives.asmJS());
directives = newDirectives;
tokenStream.seek(start);
// functionArgsAndBody may have already set pn->pn_body before failing.
handler.setFunctionBody(pn, null());
}
return pn;
}
template <>
bool
Parser<FullParseHandler>::finishFunctionDefinition(ParseNode* pn, FunctionBox* funbox,
ParseNode* body)
{
pn->pn_pos.end = pos().end;
MOZ_ASSERT(pn->pn_funbox == funbox);
MOZ_ASSERT(pn->pn_body->isKind(PNK_ARGSBODY));
pn->pn_body->append(body);
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::finishFunctionDefinition(Node pn, FunctionBox* funbox,
Node body)
{
// The LazyScript for a lazily parsed function needs to be constructed
// while its ParseContext and associated lexdeps and inner functions are
// still available.
if (funbox->inWith())
return abortIfSyntaxParser();
size_t numFreeVariables = pc->lexdeps->count();
size_t numInnerFunctions = pc->innerFunctions.length();
RootedFunction fun(context, funbox->function());
LazyScript* lazy = LazyScript::CreateRaw(context, fun, numFreeVariables, numInnerFunctions,
versionNumber(), funbox->bufStart, funbox->bufEnd,
funbox->startLine, funbox->startColumn);
if (!lazy)
return false;
LazyScript::FreeVariable* freeVariables = lazy->freeVariables();
size_t i = 0;
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront())
freeVariables[i++] = LazyScript::FreeVariable(r.front().key());
MOZ_ASSERT(i == numFreeVariables);
HeapPtrFunction* innerFunctions = lazy->innerFunctions();
for (size_t i = 0; i < numInnerFunctions; i++)
innerFunctions[i].init(pc->innerFunctions[i]);
if (pc->sc->strict())
lazy->setStrict();
lazy->setGeneratorKind(funbox->generatorKind());
if (funbox->isLikelyConstructorWrapper())
lazy->setLikelyConstructorWrapper();
if (funbox->isDerivedClassConstructor())
lazy->setIsDerivedClassConstructor();
if (funbox->needsHomeObject())
lazy->setNeedsHomeObject();
PropagateTransitiveParseFlags(funbox, lazy);
fun->initLazyScript(lazy);
return true;
}
template <>
bool
Parser<FullParseHandler>::functionArgsAndBody(InHandling inHandling, ParseNode* pn,
HandleFunction fun, FunctionSyntaxKind kind,
GeneratorKind generatorKind,
Directives inheritedDirectives,
Directives* newDirectives)
{
ParseContext<FullParseHandler>* outerpc = pc;
// Create box for fun->object early to protect against last-ditch GC.
FunctionBox* funbox = newFunctionBox(pn, fun, pc, inheritedDirectives, generatorKind);
if (!funbox)
return false;
if (kind == DerivedClassConstructor)
funbox->setDerivedClassConstructor();
YieldHandling yieldHandling = generatorKind != NotGenerator ? YieldIsKeyword : YieldIsName;
// We need to roll back the block scope vector if syntax parsing fails.
uint32_t oldBlockScopesLength = blockScopes.length();
// Try a syntax parse for this inner function.
do {
// If we're assuming this function is an IIFE, always perform a full
// parse to avoid the overhead of a lazy syntax-only parse. Although
// the prediction may be incorrect, IIFEs are common enough that it
// pays off for lots of code.
if (pn->isLikelyIIFE() && !funbox->isGenerator())
break;
Parser<SyntaxParseHandler>* parser = handler.syntaxParser;
if (!parser)
break;
{
// Move the syntax parser to the current position in the stream.
TokenStream::Position position(keepAtoms);
tokenStream.tell(&position);
if (!parser->tokenStream.seek(position, tokenStream))
return false;
ParseContext<SyntaxParseHandler> funpc(parser, outerpc, SyntaxParseHandler::null(),
funbox, newDirectives);
if (!funpc.init(*parser))
return false;
if (!parser->functionArgsAndBodyGeneric(inHandling, yieldHandling,
SyntaxParseHandler::NodeGeneric, fun, kind))
{
if (parser->hadAbortedSyntaxParse()) {
// Try again with a full parse.
parser->clearAbortedSyntaxParse();
MOZ_ASSERT_IF(parser->context->isJSContext(),
!parser->context->asJSContext()->isExceptionPending());
break;
}
return false;
}
// Advance this parser over tokens processed by the syntax parser.
parser->tokenStream.tell(&position);
if (!tokenStream.seek(position, parser->tokenStream))
return false;
// Update the end position of the parse node.
pn->pn_pos.end = tokenStream.currentToken().pos.end;
}
if (!addFreeVariablesFromLazyFunction(fun, pc))
return false;
pn->pn_blockid = outerpc->blockid();
PropagateTransitiveParseFlags(funbox, outerpc->sc);
return true;
} while (false);
blockScopes.resize(oldBlockScopesLength);
// Continue doing a full parse for this inner function.
ParseContext<FullParseHandler> funpc(this, pc, pn, funbox, newDirectives);
if (!funpc.init(*this))
return false;
if (!functionArgsAndBodyGeneric(inHandling, yieldHandling, pn, fun, kind))
return false;
if (!leaveFunction(pn, outerpc, kind))
return false;
pn->pn_blockid = outerpc->blockid();
/*
* Fruit of the poisonous tree: if a closure contains a dynamic name access
* (eval, with, etc), we consider the parent to do the same. The reason is
* that the deoptimizing effects of dynamic name access apply equally to
* parents: any local can be read at runtime.
*/
PropagateTransitiveParseFlags(funbox, outerpc->sc);
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::functionArgsAndBody(InHandling inHandling, Node pn, HandleFunction fun,
FunctionSyntaxKind kind,
GeneratorKind generatorKind,
Directives inheritedDirectives,
Directives* newDirectives)
{
ParseContext<SyntaxParseHandler>* outerpc = pc;
// Create box for fun->object early to protect against last-ditch GC.
FunctionBox* funbox = newFunctionBox(pn, fun, pc, inheritedDirectives, generatorKind);
if (!funbox)
return false;
// Initialize early for possible flags mutation via destructuringExpr.
ParseContext<SyntaxParseHandler> funpc(this, pc, handler.null(), funbox, newDirectives);
if (!funpc.init(*this))
return false;
YieldHandling yieldHandling = generatorKind != NotGenerator ? YieldIsKeyword : YieldIsName;
if (!functionArgsAndBodyGeneric(inHandling, yieldHandling, pn, fun, kind))
return false;
if (!leaveFunction(pn, outerpc, kind))
return false;
// This is a lazy function inner to another lazy function. Remember the
// inner function so that if the outer function is eventually parsed we do
// not need any further parsing or processing of the inner function.
MOZ_ASSERT(fun->lazyScript());
return outerpc->innerFunctions.append(fun);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::appendToCallSiteObj(Node callSiteObj)
{
Node cookedNode = noSubstitutionTemplate();
if (!cookedNode)
return false;
JSAtom* atom = tokenStream.getRawTemplateStringAtom();
if (!atom)
return false;
Node rawNode = handler.newTemplateStringLiteral(atom, pos());
if (!rawNode)
return false;
return handler.addToCallSiteObject(callSiteObj, rawNode, cookedNode);
}
template <>
ParseNode*
Parser<FullParseHandler>::standaloneLazyFunction(HandleFunction fun, bool strict,
GeneratorKind generatorKind)
{
MOZ_ASSERT(checkOptionsCalled);
Node pn = handler.newFunctionDefinition();
if (!pn)
return null();
// Our tokenStream has no current token, so pn's position is garbage.
// Substitute the position of the first token in our source.
if (!tokenStream.peekTokenPos(&pn->pn_pos))
return null();
RootedObject enclosing(context, fun->lazyScript()->enclosingScope());
Directives directives(/* strict = */ strict);
FunctionBox* funbox = newFunctionBox(pn, fun, directives, generatorKind, enclosing);
if (!funbox)
return null();
funbox->length = fun->nargs() - fun->hasRest();
if (fun->lazyScript()->isDerivedClassConstructor())
funbox->setDerivedClassConstructor();
Directives newDirectives = directives;
ParseContext<FullParseHandler> funpc(this, /* parent = */ nullptr, pn, funbox,
&newDirectives);
if (!funpc.init(*this))
return null();
YieldHandling yieldHandling = generatorKind != NotGenerator ? YieldIsKeyword : YieldIsName;
FunctionSyntaxKind syntaxKind = Statement;
if (fun->isClassConstructor())
syntaxKind = ClassConstructor;
else if (fun->isMethod())
syntaxKind = Method;
else if (fun->isGetter())
syntaxKind = Getter;
else if (fun->isSetter())
syntaxKind = Setter;
if (!functionArgsAndBodyGeneric(InAllowed, yieldHandling, pn, fun, syntaxKind)) {
MOZ_ASSERT(directives == newDirectives);
return null();
}
if (fun->isNamedLambda()) {
if (AtomDefnPtr p = pc->lexdeps->lookup(fun->name())) {
Definition* dn = p.value().get<FullParseHandler>();
if (!ConvertDefinitionToNamedLambdaUse(tokenStream, pc, funbox, dn))
return nullptr;
}
}
Rooted<Bindings> bindings(context, funbox->bindings);
if (!pc->generateBindings(context, tokenStream, alloc, &bindings))
return null();
funbox->bindings = bindings;
if (!FoldConstants(context, &pn, this))
return null();
return pn;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::functionArgsAndBodyGeneric(InHandling inHandling,
YieldHandling yieldHandling, Node pn,
HandleFunction fun, FunctionSyntaxKind kind)
{
// Given a properly initialized parse context, try to parse an actual
// function without concern for conversion to strict mode, use of lazy
// parsing and such.
bool hasRest;
if (!functionArguments(yieldHandling, kind, pn, &hasRest))
return false;
FunctionBox* funbox = pc->sc->asFunctionBox();
fun->setArgCount(pc->numArgs());
if (hasRest)
fun->setHasRest();
if (kind == Arrow) {
bool matched;
if (!tokenStream.matchToken(&matched, TOK_ARROW))
return false;
if (!matched) {
report(ParseError, false, null(), JSMSG_BAD_ARROW_ARGS);
return false;
}
}
// Parse the function body.
FunctionBodyType bodyType = StatementListBody;
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return false;
if (tt != TOK_LC) {
if (funbox->isStarGenerator() || kind == Method ||
kind == GetterNoExpressionClosure || kind == SetterNoExpressionClosure ||
IsConstructorKind(kind)) {
report(ParseError, false, null(), JSMSG_CURLY_BEFORE_BODY);
return false;
}
if (kind != Arrow) {
#if JS_HAS_EXPR_CLOSURES
addTelemetry(JSCompartment::DeprecatedExpressionClosure);
if (!warnOnceAboutExprClosure())
return false;
#else
report(ParseError, false, null(), JSMSG_CURLY_BEFORE_BODY);
return false;
#endif
}
tokenStream.ungetToken();
bodyType = ExpressionBody;
#if JS_HAS_EXPR_CLOSURES
fun->setIsExprBody();
#endif
}
Node body = functionBody(inHandling, yieldHandling, kind, bodyType);
if (!body)
return false;
if ((kind != Method && !IsConstructorKind(kind)) && fun->name() &&
!checkStrictBinding(fun->name(), pn))
{
return false;
}
if (bodyType == StatementListBody) {
bool matched;
if (!tokenStream.matchToken(&matched, TOK_RC, TokenStream::Operand))
return false;
if (!matched) {
report(ParseError, false, null(), JSMSG_CURLY_AFTER_BODY);
return false;
}
funbox->bufEnd = pos().begin + 1;
} else {
#if !JS_HAS_EXPR_CLOSURES
MOZ_ASSERT(kind == Arrow);
#endif
if (tokenStream.hadError())
return false;
funbox->bufEnd = pos().end;
if (kind == Statement && !MatchOrInsertSemicolonAfterExpression(tokenStream))
return false;
}
return finishFunctionDefinition(pn, funbox, body);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkYieldNameValidity()
{
// In star generators and in JS >= 1.7, yield is a keyword. Otherwise in
// strict mode, yield is a future reserved word.
if (pc->isStarGenerator() || versionNumber() >= JSVERSION_1_7 || pc->sc->strict()) {
report(ParseError, false, null(), JSMSG_RESERVED_ID, "yield");
return false;
}
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionStmt(YieldHandling yieldHandling, DefaultHandling defaultHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FUNCTION));
RootedPropertyName name(context);
GeneratorKind generatorKind = NotGenerator;
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_MUL) {
generatorKind = StarGenerator;
if (!tokenStream.getToken(&tt))
return null();
}
if (tt == TOK_NAME) {
name = tokenStream.currentName();
} else if (tt == TOK_YIELD) {
if (!checkYieldNameValidity())
return null();
name = tokenStream.currentName();
} else if (defaultHandling == AllowDefaultName) {
name = context->names().starDefaultStar;
tokenStream.ungetToken();
} else {
/* Unnamed function expressions are forbidden in statement context. */
report(ParseError, false, null(), JSMSG_UNNAMED_FUNCTION_STMT);
return null();
}
/* We forbid function statements in strict mode code. */
if (!pc->atBodyLevel() && pc->sc->needStrictChecks() &&
!report(ParseStrictError, pc->sc->strict(), null(), JSMSG_STRICT_FUNCTION_STATEMENT))
return null();
return functionDef(InAllowed, yieldHandling, name, Statement, generatorKind);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionExpr(InvokedPrediction invoked)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FUNCTION));
GeneratorKind generatorKind = NotGenerator;
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_MUL) {
generatorKind = StarGenerator;
if (!tokenStream.getToken(&tt))
return null();
}
RootedPropertyName name(context);
if (tt == TOK_NAME) {
name = tokenStream.currentName();
} else if (tt == TOK_YIELD) {
if (!checkYieldNameValidity())
return null();
name = tokenStream.currentName();
} else {
tokenStream.ungetToken();
}
YieldHandling yieldHandling = generatorKind != NotGenerator ? YieldIsKeyword : YieldIsName;
return functionDef(InAllowed, yieldHandling, name, Expression, generatorKind, invoked);
}
/*
* Return true if this node, known to be an unparenthesized string literal,
* could be the string of a directive in a Directive Prologue. Directive
* strings never contain escape sequences or line continuations.
* isEscapeFreeStringLiteral, below, checks whether the node itself could be
* a directive.
*/
static inline bool
IsEscapeFreeStringLiteral(const TokenPos& pos, JSAtom* str)
{
/*
* If the string's length in the source code is its length as a value,
* accounting for the quotes, then it must not contain any escape
* sequences or line continuations.
*/
return pos.begin + str->length() + 2 == pos.end;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkUnescapedName()
{
if (!tokenStream.currentToken().nameContainsEscape())
return true;
report(ParseError, false, null(), JSMSG_ESCAPED_KEYWORD);
return false;
}
template <>
bool
Parser<SyntaxParseHandler>::asmJS(Node list)
{
// While asm.js could technically be validated and compiled during syntax
// parsing, we have no guarantee that some later JS wouldn't abort the
// syntax parse and cause us to re-parse (and re-compile) the asm.js module.
// For simplicity, unconditionally abort the syntax parse when "use asm" is
// encountered so that asm.js is always validated/compiled exactly once
// during a full parse.
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return false;
}
template <>
bool
Parser<FullParseHandler>::asmJS(Node list)
{
// Disable syntax parsing in anything nested inside the asm.js module.
handler.disableSyntaxParser();
// We should be encountering the "use asm" directive for the first time; if
// the directive is already, we must have failed asm.js validation and we're
// reparsing. In that case, don't try to validate again. A non-null
// newDirectives means we're not in a normal function.
if (!pc->newDirectives || pc->newDirectives->asmJS())
return true;
// If there is no ScriptSource, then we are doing a non-compiling parse and
// so we shouldn't (and can't, without a ScriptSource) compile.
if (ss == nullptr)
return true;
pc->sc->asFunctionBox()->useAsm = true;
// Attempt to validate and compile this asm.js module. On success, the
// tokenStream has been advanced to the closing }. On failure, the
// tokenStream is in an indeterminate state and we must reparse the
// function from the beginning. Reparsing is triggered by marking that a
// new directive has been encountered and returning 'false'.
bool validated;
if (!ValidateAsmJS(context, *this, list, &validated))
return false;
if (!validated) {
pc->newDirectives->setAsmJS();
return false;
}
return true;
}
/*
* Recognize Directive Prologue members and directives. Assuming |pn| is a
* candidate for membership in a directive prologue, recognize directives and
* set |pc|'s flags accordingly. If |pn| is indeed part of a prologue, set its
* |pn_prologue| flag.
*
* Note that the following is a strict mode function:
*
* function foo() {
* "blah" // inserted semi colon
* "blurgh"
* "use\x20loose"
* "use strict"
* }
*
* That is, even though "use\x20loose" can never be a directive, now or in the
* future (because of the hex escape), the Directive Prologue extends through it
* to the "use strict" statement, which is indeed a directive.
*/
template <typename ParseHandler>
bool
Parser<ParseHandler>::maybeParseDirective(Node list, Node pn, bool* cont)
{
TokenPos directivePos;
JSAtom* directive = handler.isStringExprStatement(pn, &directivePos);
*cont = !!directive;
if (!*cont)
return true;
if (IsEscapeFreeStringLiteral(directivePos, directive)) {
// Mark this statement as being a possibly legitimate part of a
// directive prologue, so the bytecode emitter won't warn about it being
// useless code. (We mustn't just omit the statement entirely yet, as it
// could be producing the value of an eval or JSScript execution.)
//
// Note that even if the string isn't one we recognize as a directive,
// the emitter still shouldn't flag it as useless, as it could become a
// directive in the future. We don't want to interfere with people
// taking advantage of directive-prologue-enabled features that appear
// in other browsers first.
handler.setPrologue(pn);
if (directive == context->names().useStrict) {
// We're going to be in strict mode. Note that this scope explicitly
// had "use strict";
pc->sc->setExplicitUseStrict();
if (!pc->sc->strict()) {
if (pc->sc->isFunctionBox()) {
// Request that this function be reparsed as strict.
pc->newDirectives->setStrict();
return false;
}
// We don't reparse global scopes, so we keep track of the one
// possible strict violation that could occur in the directive
// prologue -- octal escapes -- and complain now.
if (tokenStream.sawOctalEscape()) {
report(ParseError, false, null(), JSMSG_DEPRECATED_OCTAL);
return false;
}
pc->sc->strictScript = true;
}
} else if (directive == context->names().useAsm) {
if (pc->sc->isFunctionBox())
return asmJS(list);
return report(ParseWarning, false, pn, JSMSG_USE_ASM_DIRECTIVE_FAIL);
}
}
return true;
}
/*
* Parse the statements in a block, creating a StatementList node that lists
* the statements. If called from block-parsing code, the caller must match
* '{' before and '}' after.
*/
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::statements(YieldHandling yieldHandling)
{
JS_CHECK_RECURSION(context, return null());
Node pn = handler.newStatementList(pc->blockid(), pos());
if (!pn)
return null();
Node saveBlock = pc->blockNode;
pc->blockNode = pn;
bool canHaveDirectives = pc->atBodyLevel();
bool afterReturn = false;
bool warnedAboutStatementsAfterReturn = false;
uint32_t statementBegin = 0;
for (;;) {
TokenKind tt = TOK_EOF;
if (!tokenStream.peekToken(&tt, TokenStream::Operand)) {
if (tokenStream.isEOF())
isUnexpectedEOF_ = true;
return null();
}
if (tt == TOK_EOF || tt == TOK_RC)
break;
if (afterReturn) {
TokenPos pos(0, 0);
if (!tokenStream.peekTokenPos(&pos, TokenStream::Operand))
return null();
statementBegin = pos.begin;
}
Node next = statement(yieldHandling, canHaveDirectives);
if (!next) {
if (tokenStream.isEOF())
isUnexpectedEOF_ = true;
return null();
}
if (!warnedAboutStatementsAfterReturn) {
if (afterReturn) {
if (!handler.isStatementPermittedAfterReturnStatement(next)) {
if (!reportWithOffset(ParseWarning, false, statementBegin,
JSMSG_STMT_AFTER_RETURN))
{
return null();
}
warnedAboutStatementsAfterReturn = true;
}
} else if (handler.isReturnStatement(next)) {
afterReturn = true;
}
}
if (canHaveDirectives) {
if (!maybeParseDirective(pn, next, &canHaveDirectives))
return null();
}
handler.addStatementToList(pn, next, pc);
}
/*
* Handle the case where there was a let declaration under this block. If
* it replaced pc->blockNode with a new block node then we must refresh pn
* and then restore pc->blockNode.
*/
if (pc->blockNode != pn)
pn = pc->blockNode;
pc->blockNode = saveBlock;
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::condition(InHandling inHandling, YieldHandling yieldHandling)
{
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_COND);
Node pn = exprInParens(inHandling, yieldHandling, TripledotProhibited);
if (!pn)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_COND);
/* Check for (a = b) and warn about possible (a == b) mistype. */
if (handler.isUnparenthesizedAssignment(pn)) {
if (!report(ParseExtraWarning, false, null(), JSMSG_EQUAL_AS_ASSIGN))
return null();
}
return pn;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::matchLabel(YieldHandling yieldHandling, MutableHandle<PropertyName*> label)
{
TokenKind tt = TOK_EOF;
if (!tokenStream.peekTokenSameLine(&tt, TokenStream::Operand))
return false;
if (tt == TOK_NAME) {
tokenStream.consumeKnownToken(TOK_NAME, TokenStream::Operand);
MOZ_ASSERT_IF(tokenStream.currentName() == context->names().yield,
yieldHandling == YieldIsName);
label.set(tokenStream.currentName());
} else if (tt == TOK_YIELD) {
// We might still consider |yield| to be valid here, contrary to ES6.
// Fix bug 1104014, then stop shipping legacy generators in chrome
// code, then remove this check!
tokenStream.consumeKnownToken(TOK_YIELD, TokenStream::Operand);
if (!checkYieldNameValidity())
return false;
label.set(tokenStream.currentName());
} else {
label.set(nullptr);
}
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportRedeclaration(Node pn, Definition::Kind redeclKind, HandlePropertyName name)
{
JSAutoByteString printable;
if (!AtomToPrintableString(context, name, &printable))
return false;
StmtInfoPC* stmt = LexicalLookup(pc, name);
if (stmt && stmt->type == StmtType::CATCH) {
report(ParseError, false, pn, JSMSG_REDECLARED_CATCH_IDENTIFIER, printable.ptr());
} else {
if (redeclKind == Definition::ARG) {
report(ParseError, false, pn, JSMSG_REDECLARED_PARAM, printable.ptr());
} else {
report(ParseError, false, pn, JSMSG_REDECLARED_VAR, Definition::kindString(redeclKind),
printable.ptr());
}
}
return false;
}
/*
* Define a lexical binding in a block, or comprehension scope. pc must
* already be in such a scope.
*
* Throw a SyntaxError if 'atom' is an invalid name. Otherwise create a
* property for the new variable on the block object,
* pc->topStmtScope()->staticScope; populate
* data->pn->pn_{op,cookie,defn,dflags}; and stash a pointer to data->pn in a
* slot of the block object.
*/
template <>
/* static */ bool
Parser<FullParseHandler>::bindLexical(BindData<FullParseHandler>* data,
HandlePropertyName name, Parser<FullParseHandler>* parser)
{
ParseContext<FullParseHandler>* pc = parser->pc;
ParseNode* pn = data->nameNode();
if (!parser->checkStrictBinding(name, pn))
return false;
ExclusiveContext* cx = parser->context;
Rooted<StaticBlockObject*> blockObj(cx, data->letData().blockObj);
uint32_t index = StaticBlockObject::LOCAL_INDEX_LIMIT;
if (blockObj) {
// Leave the scope coordinate free on global lexicals.
//
// For block-level lets, assign block-local index to pn->pn_scopecoord
// right away. The emitter will adjust the node's slot based on its
// stack depth model -- and, for global and eval code,
// js::frontend::CompileScript will adjust the slot again to include
// script->nfixed and body-level lets.
//
// XXXshu: I should like to optimize global lexicals, but we rely on
// being able to clone JSScripts to run on multiple globals and to be
// able to parse scripts off-thread in a different compartment.
if (!blockObj->isGlobal()) {
index = blockObj->numVariables();
if (index >= StaticBlockObject::LOCAL_INDEX_LIMIT) {
parser->report(ParseError, false, pn, data->letData().overflow);
return false;
}
if (!pn->pn_scopecoord.setSlot(parser->tokenStream, index))
return false;
}
} else if (!pc->sc->isGlobalContext()) {
// If we don't have a block object and are parsing a function
// body-level let, use a bogus index. It is adjusted when creating the
// function's Bindings. See ParseContext::generateFunctionBindings and
// AppendPackedBindings.
index = 0;
if (!pn->pn_scopecoord.setSlot(parser->tokenStream, index))
return false;
}
Definition::Kind bindingKind;
if (pn->isImport())
bindingKind = Definition::IMPORT;
else if (data->isConst())
bindingKind = Definition::CONSTANT;
else
bindingKind = Definition::LET;
Definition* dn = pc->decls().lookupFirst(name);
/*
* For bindings that are hoisted to the beginning of the block/function,
* define() right now. Otherwise, delay define until pushLetScope.
*/
if (data->letData().varContext == HoistVars) {
// The reason we compare using >= instead of == on the block id is to
// detect redeclarations where a 'var' binding first appeared in a
// nested block: |{ var x; } let x;|
if (dn && dn->pn_blockid >= pc->blockid())
return parser->reportRedeclaration(pn, dn->kind(), name);
if (!pc->define(parser->tokenStream, name, pn, bindingKind))
return false;
}
if (blockObj) {
if (!blockObj->isGlobal()) {
bool redeclared;
RootedId id(cx, NameToId(name));
RootedShape shape(cx, StaticBlockObject::addVar(cx, blockObj, id,
data->isConst(), index, &redeclared));
if (!shape) {
if (redeclared) {
// The only way to be redeclared without a previous definition is if we're in a
// comma separated list in a DontHoistVars block, so a let block of for header. In
// that case, we must be redeclaring the same type of definition as we're trying to
// make.
Definition::Kind dnKind = dn ? dn->kind() : bindingKind;
parser->reportRedeclaration(pn, dnKind, name);
}
return false;
}
/* Store pn in the static block object. */
blockObj->setDefinitionParseNode(index, reinterpret_cast<Definition*>(pn));
}
} else {
// Body-level lets are hoisted and need to have been defined via
// pc->define above.
MOZ_ASSERT(data->letData().varContext == HoistVars);
MOZ_ASSERT(pc->decls().lookupFirst(name));
}
return true;
}
template <>
/* static */ bool
Parser<SyntaxParseHandler>::bindLexical(BindData<SyntaxParseHandler>* data,
HandlePropertyName name, Parser<SyntaxParseHandler>* parser)
{
if (!parser->checkStrictBinding(name, data->nameNode()))
return false;
return true;
}
template <typename ParseHandler, class Op>
static inline bool
ForEachLetDef(TokenStream& ts, ParseContext<ParseHandler>* pc,
HandleStaticBlockObject blockObj, Op op)
{
for (Shape::Range<CanGC> r(ts.context(), blockObj->lastProperty()); !r.empty(); r.popFront()) {
Shape& shape = r.front();
/* Beware the destructuring dummy slots. */
if (JSID_IS_INT(shape.propid()))
continue;
if (!op(ts, pc, blockObj, shape, JSID_TO_ATOM(shape.propid())))
return false;
}
return true;
}
template <typename ParseHandler>
struct PopLetDecl {
bool operator()(TokenStream&, ParseContext<ParseHandler>* pc, HandleStaticBlockObject,
const Shape&, JSAtom* atom)
{
pc->popLetDecl(atom);
return true;
}
};
// We compute the maximum block scope depth, in slots, of a compilation unit at
// parse-time. Each nested statement has a field indicating the maximum block
// scope depth that is nested inside it. When we leave a nested statement, we
// add the number of slots in the statement to the nested depth, and use that to
// update the maximum block scope depth of the outer statement or parse
// context. In the end, pc->blockScopeDepth will indicate the number of slots
// to reserve in the fixed part of a stack frame.
//
template <typename ParseHandler>
static void
AccumulateBlockScopeDepth(ParseContext<ParseHandler>* pc)
{
StmtInfoPC* stmt = pc->innermostStmt();
uint32_t innerDepth = stmt->innerBlockScopeDepth;
StmtInfoPC* outer = stmt->enclosing;
if (stmt->isBlockScope)
innerDepth += stmt->staticScope->template as<StaticBlockObject>().numVariables();
if (outer) {
if (outer->innerBlockScopeDepth < innerDepth)
outer->innerBlockScopeDepth = innerDepth;
} else {
if (pc->blockScopeDepth < innerDepth)
pc->blockScopeDepth = innerDepth;
}
}
template <typename ParseHandler>
Parser<ParseHandler>::AutoPushStmtInfoPC::AutoPushStmtInfoPC(Parser<ParseHandler>& parser,
StmtType type)
: parser_(parser),
stmt_(parser.context)
{
stmt_.blockid = parser.pc->blockid();
parser.pc->stmtStack.push(&stmt_, type);
}
template <typename ParseHandler>
Parser<ParseHandler>::AutoPushStmtInfoPC::AutoPushStmtInfoPC(Parser<ParseHandler>& parser,
StmtType type,
NestedScopeObject& staticScope)
: parser_(parser),
stmt_(parser.context)
{
stmt_.blockid = parser.pc->blockid();
staticScope.initEnclosingScopeFromParser(parser.pc->innermostStaticScope());
parser.pc->stmtStack.pushNestedScope(&stmt_, type, staticScope);
}
template <typename ParseHandler>
Parser<ParseHandler>::AutoPushStmtInfoPC::~AutoPushStmtInfoPC()
{
// While this destructor is infallible, it is preferable to fail fast on
// aborted syntax parses.
if (parser_.hadAbortedSyntaxParse())
return;
ParseContext<ParseHandler>* pc = parser_.pc;
TokenStream& ts = parser_.tokenStream;
MOZ_ASSERT(pc->innermostStmt() == &stmt_);
RootedNestedScopeObject scopeObj(parser_.context, stmt_.staticScope);
AccumulateBlockScopeDepth(pc);
pc->stmtStack.pop();
if (scopeObj) {
if (scopeObj->is<StaticBlockObject>()) {
RootedStaticBlockObject blockObj(parser_.context, &scopeObj->as<StaticBlockObject>());
MOZ_ASSERT(!blockObj->inDictionaryMode());
ForEachLetDef(ts, pc, blockObj, PopLetDecl<ParseHandler>());
}
scopeObj->resetEnclosingScopeFromParser();
}
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::AutoPushStmtInfoPC::generateBlockId()
{
return parser_.generateBlockId(stmt_.staticScope, &stmt_.blockid);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::AutoPushStmtInfoPC::makeInnermostLexicalScope(StaticBlockObject& blockObj)
{
MOZ_ASSERT(parser_.pc->stmtStack.innermost() == &stmt_);
parser_.pc->stmtStack.makeInnermostLexicalScope(blockObj);
return generateBlockId();
}
template <typename ParseHandler>
static inline bool
OuterLet(ParseContext<ParseHandler>* pc, StmtInfoPC* stmt, HandleAtom atom)
{
while (stmt->enclosingScope) {
stmt = LexicalLookup(pc, atom, stmt->enclosingScope);
if (!stmt)
return false;
if (stmt->type == StmtType::BLOCK)
return true;
}
return false;
}
template <typename ParseHandler>
/* static */ bool
Parser<ParseHandler>::bindVar(BindData<ParseHandler>* data,
HandlePropertyName name, Parser<ParseHandler>* parser)
{
ExclusiveContext* cx = parser->context;
ParseContext<ParseHandler>* pc = parser->pc;
Node pn = data->nameNode();
/* Default best op for pn is JSOP_GETNAME; we'll try to improve below. */
parser->handler.setOp(pn, JSOP_GETNAME);
if (!parser->checkStrictBinding(name, pn))
return false;
StmtInfoPC* stmt = LexicalLookup(pc, name);
if (stmt && stmt->type == StmtType::WITH) {
parser->handler.setFlag(pn, PND_DEOPTIMIZED);
if (pc->sc->isFunctionBox()) {
FunctionBox* funbox = pc->sc->asFunctionBox();
funbox->setMightAliasLocals();
}
/*
* Make sure to indicate the need to deoptimize the script's arguments
* object. Mark the function as if it contained a debugger statement,
* which will deoptimize arguments as much as possible.
*/
if (name == cx->names().arguments)
pc->sc->setHasDebuggerStatement();
// Find the nearest enclosing non-with scope that defined name, if
// any, for redeclaration checks below.
while (stmt && stmt->type == StmtType::WITH) {
if (stmt->enclosingScope)
stmt = LexicalLookup(pc, name, stmt->enclosingScope);
else
stmt = nullptr;
}
}
DefinitionList::Range defs = pc->decls().lookupMulti(name);
MOZ_ASSERT_IF(stmt, !defs.empty());
// TODOshu: ES6 Annex B.3.5 is not implemented.
if (defs.empty())
return pc->define(parser->tokenStream, name, pn, Definition::VAR);
/*
* There was a previous declaration with the same name. The standard
* disallows several forms of redeclaration. Critically,
* let (x) { var x; } // error
* is not allowed which allows us to turn any non-error redeclaration
* into a use of the initial declaration.
*/
DefinitionNode dn = defs.front<ParseHandler>();
Definition::Kind dn_kind = parser->handler.getDefinitionKind(dn);
if (dn_kind == Definition::ARG) {
JSAutoByteString bytes;
if (!AtomToPrintableString(cx, name, &bytes))
return false;
if (!parser->report(ParseExtraWarning, false, pn, JSMSG_VAR_HIDES_ARG, bytes.ptr()))
return false;
} else {
bool inCatchBody = (stmt && stmt->type == StmtType::CATCH);
bool error = (dn_kind == Definition::IMPORT ||
dn_kind == Definition::CONSTANT ||
(dn_kind == Definition::LET &&
(!inCatchBody || OuterLet(pc, stmt, name))));
if (parser->options().extraWarningsOption
? data->op() != JSOP_DEFVAR || dn_kind != Definition::VAR
: error)
{
JSAutoByteString bytes;
if (!AtomToPrintableString(cx, name, &bytes))
return false;
ParseReportKind reporter = error ? ParseError : ParseExtraWarning;
if (!(inCatchBody
? parser->report(reporter, false, pn,
JSMSG_REDECLARED_CATCH_IDENTIFIER, bytes.ptr())
: parser->report(reporter, false, pn, JSMSG_REDECLARED_VAR,
Definition::kindString(dn_kind), bytes.ptr())))
{
return false;
}
}
}
parser->handler.linkUseToDef(pn, dn);
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::makeSetCall(Node target, unsigned msg)
{
MOZ_ASSERT(handler.isFunctionCall(target));
// Assignment to function calls is forbidden in ES6. We're still somewhat
// concerned about sites using this in dead code, so forbid it only in
// strict mode code (or if the werror option has been set), and otherwise
// warn.
if (!report(ParseStrictError, pc->sc->strict(), target, msg))
return false;
handler.markAsSetCall(target);
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::noteNameUse(HandlePropertyName name, Node pn)
{
/*
* The asm.js validator does all its own symbol-table management so, as an
* optimization, avoid doing any work here. Use-def links are only necessary
* for emitting bytecode and successfully-validated asm.js does not emit
* bytecode. (On validation failure, the asm.js module is reparsed.)
*/
if (pc->useAsmOrInsideUseAsm())
return true;
StmtInfoPC* stmt = LexicalLookup(pc, name);
DefinitionList::Range defs = pc->decls().lookupMulti(name);
DefinitionNode dn;
if (!defs.empty()) {
dn = defs.front<ParseHandler>();
} else {
/*
* No definition before this use in any lexical scope.
* Create a placeholder definition node to either:
* - Be adopted when we parse the real defining
* declaration, or
* - Be left as a free variable definition if we never
* see the real definition.
*/
dn = getOrCreateLexicalDependency(pc, name);
if (!dn)
return false;
}
handler.linkUseToDef(pn, dn);
if (stmt) {
if (stmt->type == StmtType::WITH) {
handler.setFlag(pn, PND_DEOPTIMIZED);
} else if (stmt->type == StmtType::SWITCH && stmt->isBlockScope) {
// See comments above StmtInfoPC and switchStatement for how
// firstDominatingLexicalInCase is computed.
MOZ_ASSERT(stmt->firstDominatingLexicalInCase <= stmt->staticBlock().numVariables());
handler.markMaybeUninitializedLexicalUseInSwitch(pn, dn,
stmt->firstDominatingLexicalInCase);
}
}
return true;
}
template <>
bool
Parser<FullParseHandler>::bindUninitialized(BindData<FullParseHandler>* data, ParseNode* pn)
{
MOZ_ASSERT(pn->isKind(PNK_NAME));
RootedPropertyName name(context, pn->pn_atom->asPropertyName());
data->setNameNode(pn);
if (!data->bind(name, this))
return false;
return true;
}
template <>
bool
Parser<FullParseHandler>::bindInitialized(BindData<FullParseHandler>* data, ParseNode* pn)
{
if (!bindUninitialized(data, pn))
return false;
/*
* Select the appropriate name-setting opcode, respecting eager selection
* done by the data->bind function.
*/
if (data->op() == JSOP_DEFLET || data->op() == JSOP_DEFCONST)
pn->setOp(pn->pn_scopecoord.isFree() ? JSOP_INITGLEXICAL : JSOP_INITLEXICAL);
else if (pn->pn_dflags & PND_BOUND)
pn->setOp(JSOP_SETLOCAL);
else
pn->setOp(JSOP_SETNAME);
if (data->op() == JSOP_DEFCONST)
pn->pn_dflags |= PND_CONST;
pn->markAsAssigned();
return true;
}
template <>
bool
Parser<FullParseHandler>::checkDestructuringName(BindData<FullParseHandler>* data, ParseNode* expr)
{
MOZ_ASSERT(!handler.isUnparenthesizedDestructuringPattern(expr));
// Parentheses are forbidden around destructuring *patterns* (but allowed
// around names). Use our nicer error message for parenthesized, nested
// patterns.
if (handler.isParenthesizedDestructuringPattern(expr)) {
report(ParseError, false, expr, JSMSG_BAD_DESTRUCT_PARENS);
return false;
}
// This expression might be in a variable-binding pattern where only plain,
// unparenthesized names are permitted.
if (data) {
// Destructuring patterns in declarations must only contain
// unparenthesized names.
if (!handler.maybeUnparenthesizedName(expr)) {
report(ParseError, false, expr, JSMSG_NO_VARIABLE_NAME);
return false;
}
return bindInitialized(data, expr);
}
// Otherwise this is an expression in destructuring outside a declaration.
if (!reportIfNotValidSimpleAssignmentTarget(expr, KeyedDestructuringAssignment))
return false;
MOZ_ASSERT(!handler.isFunctionCall(expr),
"function calls shouldn't be considered valid targets in "
"destructuring patterns");
if (handler.maybeNameAnyParentheses(expr)) {
// The arguments/eval identifiers are simple in non-strict mode code.
// Warn to discourage their use nonetheless.
if (!reportIfArgumentsEvalTarget(expr))
return false;
// We may be called on a name node that has already been
// specialized, in the very weird "for (var [x] = i in o) ..."
// case. See bug 558633.
//
// XXX Is this necessary with the changes in bug 1164741? This is
// likely removable now.
handler.maybeDespecializeSet(expr);
handler.markAsAssigned(expr);
return true;
}
// Nothing further to do for property accesses.
MOZ_ASSERT(handler.isPropertyAccess(expr));
return true;
}
template <>
bool
Parser<FullParseHandler>::checkDestructuringPattern(BindData<FullParseHandler>* data, ParseNode* pattern);
template <>
bool
Parser<FullParseHandler>::checkDestructuringObject(BindData<FullParseHandler>* data,
ParseNode* objectPattern)
{
MOZ_ASSERT(objectPattern->isKind(PNK_OBJECT));
for (ParseNode* member = objectPattern->pn_head; member; member = member->pn_next) {
ParseNode* target;
if (member->isKind(PNK_MUTATEPROTO)) {
target = member->pn_kid;
} else {
MOZ_ASSERT(member->isKind(PNK_COLON) || member->isKind(PNK_SHORTHAND));
MOZ_ASSERT_IF(member->isKind(PNK_SHORTHAND),
member->pn_left->isKind(PNK_OBJECT_PROPERTY_NAME) &&
member->pn_right->isKind(PNK_NAME) &&
member->pn_left->pn_atom == member->pn_right->pn_atom);
target = member->pn_right;
}
if (handler.isUnparenthesizedAssignment(target))
target = target->pn_left;
if (handler.isUnparenthesizedDestructuringPattern(target)) {
if (!checkDestructuringPattern(data, target))
return false;
} else {
if (!checkDestructuringName(data, target))
return false;
}
}
return true;
}
template <>
bool
Parser<FullParseHandler>::checkDestructuringArray(BindData<FullParseHandler>* data,
ParseNode* arrayPattern)
{
MOZ_ASSERT(arrayPattern->isKind(PNK_ARRAY));
for (ParseNode* element = arrayPattern->pn_head; element; element = element->pn_next) {
if (element->isKind(PNK_ELISION))
continue;
ParseNode* target;
if (element->isKind(PNK_SPREAD)) {
if (element->pn_next) {
report(ParseError, false, element->pn_next, JSMSG_PARAMETER_AFTER_REST);
return false;
}
target = element->pn_kid;
if (handler.isUnparenthesizedDestructuringPattern(target)) {
report(ParseError, false, target, JSMSG_BAD_DESTRUCT_TARGET);
return false;
}
} else if (handler.isUnparenthesizedAssignment(element)) {
target = element->pn_left;
} else {
target = element;
}
if (handler.isUnparenthesizedDestructuringPattern(target)) {
if (!checkDestructuringPattern(data, target))
return false;
} else {
if (!checkDestructuringName(data, target))
return false;
}
}
return true;
}
/*
* Destructuring patterns can appear in two kinds of contexts:
*
* - assignment-like: assignment expressions and |for| loop heads. In
* these cases, the patterns' property value positions can be
* arbitrary lvalue expressions; the destructuring is just a fancy
* assignment.
*
* - binding-like: |var| and |let| declarations, functions' formal
* parameter lists, |catch| clauses, and comprehension tails. In
* these cases, the patterns' property value positions must be
* simple names; the destructuring defines them as new variables.
*
* In both cases, other code parses the pattern as an arbitrary
* primaryExpr, and then, here in checkDestructuringPattern, verify
* that the tree is a valid AssignmentPattern or BindingPattern.
*
* In assignment-like contexts, we parse the pattern with
* pc->inDeclDestructuring clear, so the lvalue expressions in the
* pattern are parsed normally. primaryExpr links variable references
* into the appropriate use chains; creates placeholder definitions;
* and so on. checkDestructuringPattern is called with |data| nullptr
* (since we won't be binding any new names), and we specialize lvalues
* as appropriate.
*
* In declaration-like contexts, the normal variable reference
* processing would just be an obstruction, because we're going to
* define the names that appear in the property value positions as new
* variables anyway. In this case, we parse the pattern with
* pc->inDeclDestructuring set, which directs primaryExpr to leave
* whatever name nodes it creates unconnected. Then, here in
* checkDestructuringPattern, we require the pattern's property value
* positions to be simple names, and define them as appropriate to the
* context. For these calls, |data| points to the right sort of
* BindData.
*/
template <>
bool
Parser<FullParseHandler>::checkDestructuringPattern(BindData<FullParseHandler>* data, ParseNode* pattern)
{
if (pattern->isKind(PNK_ARRAYCOMP)) {
report(ParseError, false, pattern, JSMSG_ARRAY_COMP_LEFTSIDE);
return false;
}
if (pattern->isKind(PNK_ARRAY))
return checkDestructuringArray(data, pattern);
return checkDestructuringObject(data, pattern);
}
template <>
bool
Parser<SyntaxParseHandler>::checkDestructuringPattern(BindData<SyntaxParseHandler>* data, Node pattern)
{
return abortIfSyntaxParser();
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::destructuringExpr(YieldHandling yieldHandling, BindData<ParseHandler>* data,
TokenKind tt)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(tt));
pc->inDeclDestructuring = true;
Node pn = primaryExpr(yieldHandling, TripledotProhibited, tt);
pc->inDeclDestructuring = false;
if (!pn)
return null();
if (!checkDestructuringPattern(data, pn))
return null();
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::destructuringExprWithoutYield(YieldHandling yieldHandling,
BindData<ParseHandler>* data, TokenKind tt,
unsigned msg)
{
uint32_t startYieldOffset = pc->lastYieldOffset;
Node res = destructuringExpr(yieldHandling, data, tt);
if (res && pc->lastYieldOffset != startYieldOffset) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
msg, js_yield_str);
return null();
}
return res;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::pushLexicalScope(HandleStaticBlockObject blockObj,
AutoPushStmtInfoPC& stmt)
{
ObjectBox* blockbox = newObjectBox(blockObj);
if (!blockbox)
return null();
Node pn = handler.newLexicalScope(blockbox);
if (!pn)
return null();
blockObj->initEnclosingScopeFromParser(pc->innermostStaticScope());
if (!stmt.makeInnermostLexicalScope(*blockObj))
return null();
handler.setBlockId(pn, stmt->blockid);
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::pushLexicalScope(AutoPushStmtInfoPC& stmt)
{
RootedStaticBlockObject blockObj(context, StaticBlockObject::create(context));
if (!blockObj)
return null();
return pushLexicalScope(blockObj, stmt);
}
struct AddLetDecl
{
uint32_t blockid;
explicit AddLetDecl(uint32_t blockid) : blockid(blockid) {}
bool operator()(TokenStream& ts, ParseContext<FullParseHandler>* pc,
HandleStaticBlockObject blockObj, const Shape& shape, JSAtom*)
{
ParseNode* def = (ParseNode*) blockObj->getSlot(shape.slot()).toPrivate();
def->pn_blockid = blockid;
RootedPropertyName name(ts.context(), def->name());
return pc->define(ts, name, def, Definition::LET);
}
};
template <>
ParseNode*
Parser<FullParseHandler>::pushLetScope(HandleStaticBlockObject blockObj, AutoPushStmtInfoPC& stmt)
{
MOZ_ASSERT(blockObj);
ParseNode* pn = pushLexicalScope(blockObj, stmt);
if (!pn)
return null();
pn->pn_dflags |= PND_LEXICAL;
/* Populate the new scope with decls found in the head with updated blockid. */
if (!ForEachLetDef(tokenStream, pc, blockObj, AddLetDecl(stmt->blockid)))
return null();
return pn;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::pushLetScope(HandleStaticBlockObject blockObj,
AutoPushStmtInfoPC& stmt)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::blockStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_LC));
AutoPushStmtInfoPC stmtInfo(*this, StmtType::BLOCK);
if (!stmtInfo.generateBlockId())
return null();
Node list = statements(yieldHandling);
if (!list)
return null();
MUST_MATCH_TOKEN_MOD(TOK_RC, TokenStream::Operand, JSMSG_CURLY_IN_COMPOUND);
return list;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newBindingNode(PropertyName* name, bool functionScope, VarContext varContext)
{
/*
* If this name is being injected into an existing block/function, see if
* it has already been declared or if it resolves an outstanding lexdep.
* Otherwise, this is a let block/expr that introduces a new scope and thus
* shadows existing decls and doesn't resolve existing lexdeps. Duplicate
* names are caught by bindLet.
*/
if (varContext == HoistVars) {
if (AtomDefnPtr p = pc->lexdeps->lookup(name)) {
DefinitionNode lexdep = p.value().get<ParseHandler>();
MOZ_ASSERT(handler.getDefinitionKind(lexdep) == Definition::PLACEHOLDER);
Node pn = handler.getDefinitionNode(lexdep);
if (handler.dependencyCovered(pn, pc->blockid(), functionScope)) {
handler.setBlockId(pn, pc->blockid());
pc->lexdeps->remove(p);
handler.setPosition(pn, pos());
return pn;
}
}
}
/* Make a new node for this declarator name (or destructuring pattern). */
return newName(name);
}
/*
* The 'blockObj' parameter is non-null when parsing the 'vars' in a let
* expression, block statement, non-top-level let declaration in statement
* context, and the let-initializer of a for-statement.
*/
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::variables(YieldHandling yieldHandling,
ParseNodeKind kind,
ForInitLocation location,
bool* psimple, StaticBlockObject* blockObj, VarContext varContext)
{
MOZ_ASSERT(kind == PNK_VAR || kind == PNK_CONST || kind == PNK_LET);
/*
* The simple flag is set if the declaration has the form 'var x', with
* only one variable declared and no initializer expression.
*/
MOZ_ASSERT_IF(psimple, *psimple);
JSOp op;
switch (kind) {
case PNK_VAR: op = JSOP_DEFVAR; break;
case PNK_CONST: op = JSOP_DEFCONST; break;
case PNK_LET: op = JSOP_DEFLET; break;
default: MOZ_CRASH("unknown variable kind");
}
Node pn = handler.newDeclarationList(kind, op);
if (!pn)
return null();
BindData<ParseHandler> data(context);
if (kind == PNK_VAR)
data.initVar(op);
else
data.initLexical(varContext, op, blockObj, JSMSG_TOO_MANY_LOCALS);
bool first = true;
Node pn2;
while (true) {
do {
if (psimple && !first)
*psimple = false;
first = false;
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_LB || tt == TOK_LC) {
if (psimple)
*psimple = false;
pc->inDeclDestructuring = true;
pn2 = primaryExpr(yieldHandling, TripledotProhibited, tt);
pc->inDeclDestructuring = false;
if (!pn2)
return null();
bool parsingForInOrOfInit = false;
if (location == InForInit) {
bool isForIn, isForOf;
if (!matchInOrOf(&isForIn, &isForOf))
return null();
parsingForInOrOfInit = isForIn || isForOf;
}
// See comment below for bindBeforeInitializer in the code that
// handles the non-destructuring case.
bool bindBeforeInitializer = (kind != PNK_LET && kind != PNK_CONST) ||
parsingForInOrOfInit;
if (bindBeforeInitializer && !checkDestructuringPattern(&data, pn2))
return null();
if (parsingForInOrOfInit) {
tokenStream.ungetToken();
handler.addList(pn, pn2);
break;
}
MUST_MATCH_TOKEN(TOK_ASSIGN, JSMSG_BAD_DESTRUCT_DECL);
Node init = assignExpr(location == InForInit ? InProhibited : InAllowed,
yieldHandling, TripledotProhibited);
if (!init)
return null();
// Ban the nonsensical |for (var V = E1 in E2);| where V is a
// destructuring pattern. See bug 1164741 for background.
if (location == InForInit && kind == PNK_VAR) {
TokenKind afterInit;
if (!tokenStream.peekToken(&afterInit))
return null();
if (afterInit == TOK_IN) {
report(ParseError, false, init, JSMSG_INVALID_FOR_INOF_DECL_WITH_INIT,
"in");
return null();
}
}
if (!bindBeforeInitializer && !checkDestructuringPattern(&data, pn2))
return null();
pn2 = handler.newBinary(PNK_ASSIGN, pn2, init);
if (!pn2)
return null();
handler.addList(pn, pn2);
break;
}
if (tt != TOK_NAME) {
if (tt == TOK_YIELD) {
if (!checkYieldNameValidity())
return null();
} else {
report(ParseError, false, null(), JSMSG_NO_VARIABLE_NAME);
return null();
}
}
RootedPropertyName name(context, tokenStream.currentName());
pn2 = newBindingNode(name, kind == PNK_VAR, varContext);
if (!pn2)
return null();
if (data.isConst())
handler.setFlag(pn2, PND_CONST);
data.setNameNode(pn2);
handler.addList(pn, pn2);
bool matched;
// The '=' context after a variable name in a declaration is an
// opportunity for ASI, and thus for the next token to start an
// ExpressionStatement:
//
// var foo // VariableDeclaration
// /bar/g; // ExpressionStatement
//
// Therefore we must get the token here as Operand.
if (!tokenStream.matchToken(&matched, TOK_ASSIGN, TokenStream::Operand))
return null();
if (!matched) {
tokenStream.addModifierException(TokenStream::NoneIsOperand);
if (data.isConst() && location == NotInForInit) {
report(ParseError, false, null(), JSMSG_BAD_CONST_DECL);
return null();
}
if (!data.bind(name, this))
return null();
} else {
if (psimple)
*psimple = false;
// In ES6, lexical bindings may not be accessed until
// initialized. So a declaration of the form |let x = x| results
// in a ReferenceError, as the 'x' on the RHS is accessing the let
// binding before it is initialized.
//
// If we are not parsing a let declaration, bind the name
// now. Otherwise we must wait until after parsing the initializing
// assignment.
bool bindBeforeInitializer = kind != PNK_LET && kind != PNK_CONST;
if (bindBeforeInitializer && !data.bind(name, this))
return null();
Node init = assignExpr(location == InForInit ? InProhibited : InAllowed,
yieldHandling, TripledotProhibited);
if (!init)
return null();
// Ignore an initializer if we have a for-in loop declaring a
// |var| with an initializer: |for (var v = ... in ...);|.
// Warn that this syntax is invalid so that developers looking
// in the console know to fix this. ES<6 permitted the
// initializer while ES6 doesn't; ignoring it seems the best
// way to incrementally move to ES6 semantics.
bool performAssignment = true;
if (location == InForInit && kind == PNK_VAR) {
TokenKind afterInit;
if (!tokenStream.peekToken(&afterInit))
return null();
if (afterInit == TOK_IN) {
performAssignment = false;
if (!report(ParseWarning, pc->sc->strict(), init,
JSMSG_INVALID_FOR_INOF_DECL_WITH_INIT, "in"))
{
return null();
}
}
}
if (performAssignment) {
if (!bindBeforeInitializer && !data.bind(name, this))
return null();
if (!handler.finishInitializerAssignment(pn2, init, data.op()))
return null();
}
}
handler.setLexicalDeclarationOp(pn2, data.op());
handler.setEndPosition(pn, pn2);
} while (false);
bool matched;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return null();
if (!matched)
break;
}
return pn;
}
template <>
bool
Parser<FullParseHandler>::checkAndPrepareLexical(bool isConst, const TokenPos& errorPos)
{
/*
* This is a lexical declaration. We must be directly under a block per the
* proposed ES4 specs, but not an implicit block created due to
* 'for (let ...)'. If we pass this error test, make the enclosing
* StmtInfoPC be our scope. Further let declarations in this block will
* find this scope statement and use the same block object.
*
* If we are the first let declaration in this block (i.e., when the
* enclosing maybe-scope StmtInfoPC isn't yet a scope statement) then
* we also need to set pc->blockNode to be our PNK_LEXICALSCOPE.
*/
StmtInfoPC* stmt = pc->innermostStmt();
if (stmt && (!stmt->maybeScope() || stmt->isForLetBlock)) {
reportWithOffset(ParseError, false, errorPos.begin, JSMSG_LEXICAL_DECL_NOT_IN_BLOCK,
isConst ? "const" : "lexical");
return false;
}
if (!stmt) {
MOZ_ASSERT(pc->atBodyLevel());
/*
* Self-hosted code must be usable against *any* global object,
* including ones with other let variables -- variables possibly
* placed in conflicting slots. Forbid top-level let declarations to
* prevent such conflicts from ever occurring.
*/
bool isGlobal = !pc->sc->isFunctionBox() && stmt == pc->innermostScopeStmt();
if (options().selfHostingMode && isGlobal) {
report(ParseError, false, null(), JSMSG_SELFHOSTED_TOP_LEVEL_LEXICAL,
isConst ? "'const'" : "'let'");
return false;
}
return true;
}
if (stmt->isBlockScope) {
// Nothing to do, the top statement already has a block scope.
MOZ_ASSERT(pc->innermostScopeStmt() == stmt);
} else {
/* Convert the block statement into a scope statement. */
StaticBlockObject* blockObj = StaticBlockObject::create(context);
if (!blockObj)
return false;
blockObj->initEnclosingScopeFromParser(pc->innermostStaticScope());
ObjectBox* blockbox = newObjectBox(blockObj);
if (!blockbox)
return false;
/*
* Some obvious assertions here, but they may help clarify the
* situation. This stmt is not yet a scope, so it must not be a
* catch block (catch is a lexical scope by definition).
*/
MOZ_ASSERT(stmt->canBeBlockScope() && stmt->type != StmtType::CATCH);
pc->stmtStack.makeInnermostLexicalScope(*blockObj);
MOZ_ASSERT(!blockScopes[stmt->blockid]);
blockScopes[stmt->blockid].set(blockObj);
#ifdef DEBUG
ParseNode* tmp = pc->blockNode;
MOZ_ASSERT(!tmp || !tmp->isKind(PNK_LEXICALSCOPE));
#endif
/* Create a new lexical scope node for these statements. */
ParseNode* pn1 = handler.new_<LexicalScopeNode>(blockbox, pc->blockNode);
if (!pn1)
return false;;
pc->blockNode = pn1;
}
return true;
}
static StaticBlockObject*
CurrentLexicalStaticBlock(ParseContext<FullParseHandler>* pc)
{
if (pc->innermostStaticScope()->is<StaticBlockObject>())
return &pc->innermostStaticScope()->as<StaticBlockObject>();
MOZ_ASSERT(pc->atBodyLevel() &&
(!pc->sc->isGlobalContext() ||
HasNonSyntacticStaticScopeChain(pc->innermostStaticScope())));
return nullptr;
}
template <>
ParseNode*
Parser<FullParseHandler>::makeInitializedLexicalBinding(HandlePropertyName name, bool isConst,
const TokenPos& pos)
{
BindData<FullParseHandler> data(context);
if (!checkAndPrepareLexical(isConst, pos))
return null();
data.initLexical(HoistVars, isConst ? JSOP_DEFCONST : JSOP_DEFLET,
CurrentLexicalStaticBlock(pc), JSMSG_TOO_MANY_LOCALS);
ParseNode* dn = newBindingNode(name, false);
if (!dn)
return null();
handler.setPosition(dn, pos);
if (!bindInitialized(&data, dn))
return null();
return dn;
}
template <>
ParseNode*
Parser<FullParseHandler>::lexicalDeclaration(YieldHandling yieldHandling, bool isConst)
{
handler.disableSyntaxParser();
if (!checkAndPrepareLexical(isConst, pos()))
return null();
/*
* Parse body-level lets without a new block object. ES6 specs
* that an execution environment's initial lexical environment
* is the VariableEnvironment, i.e., body-level lets are in
* the same environment record as vars.
*
* However, they cannot be parsed exactly as vars, as ES6
* requires that uninitialized lets throw ReferenceError on use.
*
* See 8.1.1.1.6 and the note in 13.2.1.
*/
ParseNodeKind kind = isConst ? PNK_CONST : PNK_LET;
ParseNode* pn = variables(yieldHandling, kind, NotInForInit,
nullptr, CurrentLexicalStaticBlock(pc), HoistVars);
if (!pn)
return null();
return MatchOrInsertSemicolonAfterExpression(tokenStream) ? pn : nullptr;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::lexicalDeclaration(YieldHandling, bool)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template<>
ParseNode*
Parser<FullParseHandler>::newBoundImportForCurrentName()
{
Node importNode = newName(tokenStream.currentName());
if (!importNode)
return null();
importNode->pn_dflags |= PND_CONST | PND_IMPORT;
BindData<FullParseHandler> data(context);
data.initLexical(HoistVars, JSOP_DEFLET, nullptr, JSMSG_TOO_MANY_LOCALS);
handler.setPosition(importNode, pos());
if (!bindUninitialized(&data, importNode))
return null();
return importNode;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::newBoundImportForCurrentName()
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template<>
bool
Parser<FullParseHandler>::namedImportsOrNamespaceImport(TokenKind tt, Node importSpecSet)
{
if (tt == TOK_LC) {
TokenStream::Modifier modifier = TokenStream::KeywordIsName;
while (true) {
// Handle the forms |import {} from 'a'| and
// |import { ..., } from 'a'| (where ... is non empty), by
// escaping the loop early if the next token is }.
if (!tokenStream.peekToken(&tt, TokenStream::KeywordIsName))
return false;
if (tt == TOK_RC)
break;
// If the next token is a keyword, the previous call to
// peekToken matched it as a TOK_NAME, and put it in the
// lookahead buffer, so this call will match keywords as well.
MUST_MATCH_TOKEN_MOD(TOK_NAME, TokenStream::KeywordIsName, JSMSG_NO_IMPORT_NAME);
Node importName = newName(tokenStream.currentName());
if (!importName)
return false;
bool foundAs;
if (!tokenStream.matchContextualKeyword(&foundAs, context->names().as))
return false;
if (foundAs) {
MUST_MATCH_TOKEN(TOK_NAME, JSMSG_NO_BINDING_NAME);
} else {
// Keywords cannot be bound to themselves, so an import name
// that is a keyword is a syntax error if it is not followed
// by the keyword 'as'.
// See the ImportSpecifier production in ES6 section 15.2.2.
if (IsKeyword(importName->name())) {
JSAutoByteString bytes;
if (!AtomToPrintableString(context, importName->name(), &bytes))
return false;
report(ParseError, false, null(), JSMSG_AS_AFTER_RESERVED_WORD, bytes.ptr());
return false;
}
}
Node bindingName = newBoundImportForCurrentName();
if (!bindingName)
return false;
Node importSpec = handler.newBinary(PNK_IMPORT_SPEC, importName, bindingName);
if (!importSpec)
return false;
handler.addList(importSpecSet, importSpec);
bool matched;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return false;
if (!matched) {
modifier = TokenStream::None;
break;
}
}
MUST_MATCH_TOKEN_MOD(TOK_RC, modifier, JSMSG_RC_AFTER_IMPORT_SPEC_LIST);
} else {
MOZ_ASSERT(tt == TOK_MUL);
if (!tokenStream.getToken(&tt))
return false;
if (tt != TOK_NAME || tokenStream.currentName() != context->names().as) {
report(ParseError, false, null(), JSMSG_AS_AFTER_IMPORT_STAR);
return false;
}
if (!checkUnescapedName())
return false;
MUST_MATCH_TOKEN(TOK_NAME, JSMSG_NO_BINDING_NAME);
Node importName = newName(context->names().star);
if (!importName)
return null();
Node bindingName = newName(tokenStream.currentName());
if (!bindingName)
return null();
// Namespace imports are are not indirect bindings but lexical
// definitions that hold a module namespace object. They are treated as
// const variables which are initialized during the
// ModuleDeclarationInstantiation step. Thus we don't set the PND_IMPORT
// flag on the definition.
bindingName->pn_dflags |= PND_CONST;
BindData<FullParseHandler> data(context);
data.initLexical(HoistVars, JSOP_DEFLET, nullptr, JSMSG_TOO_MANY_LOCALS);
handler.setPosition(bindingName, pos());
if (!bindUninitialized(&data, bindingName))
return null();
Node importSpec = handler.newBinary(PNK_IMPORT_SPEC, importName, bindingName);
if (!importSpec)
return false;
handler.addList(importSpecSet, importSpec);
}
return true;
}
template<>
bool
Parser<SyntaxParseHandler>::namedImportsOrNamespaceImport(TokenKind tt, Node importSpecSet)
{
MOZ_ALWAYS_FALSE(abortIfSyntaxParser());
return false;
}
template<typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::importDeclaration()
{
MOZ_ASSERT(tokenStream.currentToken().type == TOK_IMPORT);
if (!pc->atModuleLevel()) {
report(ParseError, false, null(), JSMSG_IMPORT_DECL_AT_TOP_LEVEL);
return null();
}
uint32_t begin = pos().begin;
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
Node importSpecSet = handler.newList(PNK_IMPORT_SPEC_LIST);
if (!importSpecSet)
return null();
if (tt == TOK_NAME || tt == TOK_LC || tt == TOK_MUL) {
if (tt == TOK_NAME) {
// Handle the form |import a from 'b'|, by adding a single import
// specifier to the list, with 'default' as the import name and
// 'a' as the binding name. This is equivalent to
// |import { default as a } from 'b'|.
Node importName = newName(context->names().default_);
if (!importName)
return null();
Node bindingName = newBoundImportForCurrentName();
if (!bindingName)
return null();
Node importSpec = handler.newBinary(PNK_IMPORT_SPEC, importName, bindingName);
if (!importSpec)
return null();
handler.addList(importSpecSet, importSpec);
if (!tokenStream.peekToken(&tt))
return null();
if (tt == TOK_COMMA) {
if (!tokenStream.getToken(&tt) || !tokenStream.getToken(&tt))
return null();
if (tt != TOK_LC && tt != TOK_MUL) {
report(ParseError, false, null(), JSMSG_NAMED_IMPORTS_OR_NAMESPACE_IMPORT);
return null();
}
if (!namedImportsOrNamespaceImport(tt, importSpecSet))
return null();
}
} else {
if (!namedImportsOrNamespaceImport(tt, importSpecSet))
return null();
}
if (!tokenStream.getToken(&tt))
return null();
if (tt != TOK_NAME || tokenStream.currentName() != context->names().from) {
report(ParseError, false, null(), JSMSG_FROM_AFTER_IMPORT_CLAUSE);
return null();
}
if (!checkUnescapedName())
return null();
MUST_MATCH_TOKEN(TOK_STRING, JSMSG_MODULE_SPEC_AFTER_FROM);
} else if (tt == TOK_STRING) {
// Handle the form |import 'a'| by leaving the list empty. This is
// equivalent to |import {} from 'a'|.
importSpecSet->pn_pos.end = importSpecSet->pn_pos.begin;
} else {
report(ParseError, false, null(), JSMSG_DECLARATION_AFTER_IMPORT);
return null();
}
Node moduleSpec = stringLiteral();
if (!moduleSpec)
return null();
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
return handler.newImportDeclaration(importSpecSet, moduleSpec, TokenPos(begin, pos().end));
}
template<>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::importDeclaration()
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template <>
ParseNode*
Parser<FullParseHandler>::classDefinition(YieldHandling yieldHandling,
ClassContext classContext,
DefaultHandling defaultHandling);
template<>
bool
Parser<FullParseHandler>::addExportName(JSAtom* exportName)
{
TraceableVector<JSAtom*>& exportNames = pc->sc->asModuleBox()->exportNames;
for (JSAtom* name : exportNames) {
if (name == exportName) {
JSAutoByteString str;
if (AtomToPrintableString(context, exportName, &str))
report(ParseError, false, null(), JSMSG_DUPLICATE_EXPORT_NAME, str.ptr());
return false;
}
}
return exportNames.append(exportName);
}
template<>
bool
Parser<SyntaxParseHandler>::addExportName(JSAtom* exportName)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template<>
ParseNode*
Parser<FullParseHandler>::exportDeclaration()
{
MOZ_ASSERT(tokenStream.currentToken().type == TOK_EXPORT);
if (!pc->atModuleLevel()) {
report(ParseError, false, null(), JSMSG_EXPORT_DECL_AT_TOP_LEVEL);
return null();
}
uint32_t begin = pos().begin;
Node kid;
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
switch (tt) {
case TOK_LC: {
kid = handler.newList(PNK_EXPORT_SPEC_LIST);
if (!kid)
return null();
while (true) {
// Handle the forms |export {}| and |export { ..., }| (where ...
// is non empty), by escaping the loop early if the next token
// is }.
if (!tokenStream.peekToken(&tt))
return null();
if (tt == TOK_RC)
break;
MUST_MATCH_TOKEN(TOK_NAME, JSMSG_NO_BINDING_NAME);
Node bindingName = newName(tokenStream.currentName());
if (!bindingName)
return null();
bool foundAs;
if (!tokenStream.matchContextualKeyword(&foundAs, context->names().as))
return null();
if (foundAs) {
if (!tokenStream.getToken(&tt, TokenStream::KeywordIsName))
return null();
if (tt != TOK_NAME) {
report(ParseError, false, null(), JSMSG_NO_EXPORT_NAME);
return null();
}
}
Node exportName = newName(tokenStream.currentName());
if (!exportName)
return null();
if (!addExportName(exportName->pn_atom))
return null();
Node exportSpec = handler.newBinary(PNK_EXPORT_SPEC, bindingName, exportName);
if (!exportSpec)
return null();
handler.addList(kid, exportSpec);
bool matched;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return null();
if (!matched)
break;
}
MUST_MATCH_TOKEN(TOK_RC, JSMSG_RC_AFTER_EXPORT_SPEC_LIST);
// Careful! If |from| follows, even on a new line, it must start a
// FromClause:
//
// export { x }
// from "foo"; // a single ExportDeclaration
//
// But if it doesn't, we might have an ASI opportunity in Operand
// context, so simply matching a contextual keyword won't work:
//
// export { x } // ExportDeclaration, terminated by ASI
// fro\u006D // ExpressionStatement, the name "from"
//
// In that case let MatchOrInsertSemicolonAfterNonExpression sort out
// ASI or any necessary error.
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_NAME &&
tokenStream.currentToken().name() == context->names().from &&
!tokenStream.currentToken().nameContainsEscape())
{
MUST_MATCH_TOKEN(TOK_STRING, JSMSG_MODULE_SPEC_AFTER_FROM);
Node moduleSpec = stringLiteral();
if (!moduleSpec)
return null();
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
return handler.newExportFromDeclaration(begin, kid, moduleSpec);
}
tokenStream.ungetToken();
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
break;
}
case TOK_MUL: {
kid = handler.newList(PNK_EXPORT_SPEC_LIST);
if (!kid)
return null();
// Handle the form |export *| by adding a special export batch
// specifier to the list.
Node exportSpec = handler.newNullary(PNK_EXPORT_BATCH_SPEC, JSOP_NOP, pos());
if (!exportSpec)
return null();
handler.addList(kid, exportSpec);
if (!tokenStream.getToken(&tt))
return null();
if (tt != TOK_NAME || tokenStream.currentName() != context->names().from) {
report(ParseError, false, null(), JSMSG_FROM_AFTER_EXPORT_STAR);
return null();
}
if (!checkUnescapedName())
return null();
MUST_MATCH_TOKEN(TOK_STRING, JSMSG_MODULE_SPEC_AFTER_FROM);
Node moduleSpec = stringLiteral();
if (!moduleSpec)
return null();
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
return handler.newExportFromDeclaration(begin, kid, moduleSpec);
}
case TOK_FUNCTION:
kid = functionStmt(YieldIsKeyword, NameRequired);
if (!kid)
return null();
if (!addExportName(kid->pn_funbox->function()->atom()))
return null();
break;
case TOK_CLASS: {
kid = classDefinition(YieldIsKeyword, ClassStatement, NameRequired);
if (!kid)
return null();
const ClassNode& cls = kid->as<ClassNode>();
MOZ_ASSERT(cls.names());
if (!addExportName(cls.names()->innerBinding()->pn_atom))
return null();
break;
}
case TOK_VAR:
kid = variables(YieldIsName, PNK_VAR, NotInForInit);
if (!kid)
return null();
if (!MatchOrInsertSemicolonAfterExpression(tokenStream))
return null();
MOZ_ASSERT(kid->isArity(PN_LIST));
for (ParseNode* var = kid->pn_head; var; var = var->pn_next) {
if (var->isKind(PNK_ASSIGN))
var = var->pn_left;
MOZ_ASSERT(var->isKind(PNK_NAME));
if (!addExportName(var->pn_atom))
return null();
}
break;
case TOK_DEFAULT: {
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
if (!addExportName(context->names().default_))
return null();
ParseNode* binding = nullptr;
switch (tt) {
case TOK_FUNCTION:
kid = functionStmt(YieldIsKeyword, AllowDefaultName);
if (!kid)
return null();
break;
case TOK_CLASS:
kid = classDefinition(YieldIsKeyword, ClassStatement, AllowDefaultName);
if (!kid)
return null();
break;
default:
tokenStream.ungetToken();
RootedPropertyName name(context, context->names().starDefaultStar);
binding = makeInitializedLexicalBinding(name, true, pos());
if (!binding)
return null();
kid = assignExpr(InAllowed, YieldIsKeyword, TripledotProhibited);
if (!kid)
return null();
if (!MatchOrInsertSemicolonAfterExpression(tokenStream))
return null();
break;
}
return handler.newExportDefaultDeclaration(kid, binding, TokenPos(begin, pos().end));
}
case TOK_LET:
case TOK_CONST:
kid = lexicalDeclaration(YieldIsName, tt == TOK_CONST);
if (!kid)
return null();
break;
default:
report(ParseError, false, null(), JSMSG_DECLARATION_AFTER_EXPORT);
return null();
}
return handler.newExportDeclaration(kid, TokenPos(begin, pos().end));
}
template<>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::exportDeclaration()
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::expressionStatement(YieldHandling yieldHandling, InvokedPrediction invoked)
{
tokenStream.ungetToken();
Node pnexpr = expr(InAllowed, yieldHandling, TripledotProhibited, invoked);
if (!pnexpr)
return null();
if (!MatchOrInsertSemicolonAfterExpression(tokenStream))
return null();
return handler.newExprStatement(pnexpr, pos().end);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::ifStatement(YieldHandling yieldHandling)
{
Vector<Node, 4> condList(context), thenList(context);
Vector<uint32_t, 4> posList(context);
Node elseBranch;
AutoPushStmtInfoPC stmtInfo(*this, StmtType::IF);
while (true) {
uint32_t begin = pos().begin;
/* An IF node has three kids: condition, then, and optional else. */
Node cond = condition(InAllowed, yieldHandling);
if (!cond)
return null();
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_SEMI) {
if (!report(ParseExtraWarning, false, null(), JSMSG_EMPTY_CONSEQUENT))
return null();
}
Node thenBranch = statement(yieldHandling);
if (!thenBranch)
return null();
if (!condList.append(cond) || !thenList.append(thenBranch) || !posList.append(begin))
return null();
bool matched;
if (!tokenStream.matchToken(&matched, TOK_ELSE, TokenStream::Operand))
return null();
if (matched) {
if (!tokenStream.matchToken(&matched, TOK_IF, TokenStream::Operand))
return null();
if (matched)
continue;
elseBranch = statement(yieldHandling);
if (!elseBranch)
return null();
} else {
elseBranch = null();
}
break;
}
for (int i = condList.length() - 1; i >= 0; i--) {
elseBranch = handler.newIfStatement(posList[i], condList[i], thenList[i], elseBranch);
if (!elseBranch)
return null();
}
return elseBranch;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::doWhileStatement(YieldHandling yieldHandling)
{
uint32_t begin = pos().begin;
AutoPushStmtInfoPC stmtInfo(*this, StmtType::DO_LOOP);
Node body = statement(yieldHandling);
if (!body)
return null();
MUST_MATCH_TOKEN_MOD(TOK_WHILE, TokenStream::Operand, JSMSG_WHILE_AFTER_DO);
Node cond = condition(InAllowed, yieldHandling);
if (!cond)
return null();
// The semicolon after do-while is even more optional than most
// semicolons in JS. Web compat required this by 2004:
// http://bugzilla.mozilla.org/show_bug.cgi?id=238945
// ES3 and ES5 disagreed, but ES6 conforms to Web reality:
// https://bugs.ecmascript.org/show_bug.cgi?id=157
// To parse |do {} while (true) false| correctly, use Operand.
bool ignored;
if (!tokenStream.matchToken(&ignored, TOK_SEMI, TokenStream::Operand))
return null();
return handler.newDoWhileStatement(body, cond, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::whileStatement(YieldHandling yieldHandling)
{
uint32_t begin = pos().begin;
AutoPushStmtInfoPC stmtInfo(*this, StmtType::WHILE_LOOP);
Node cond = condition(InAllowed, yieldHandling);
if (!cond)
return null();
Node body = statement(yieldHandling);
if (!body)
return null();
return handler.newWhileStatement(begin, cond, body);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::matchInOrOf(bool* isForInp, bool* isForOfp)
{
TokenKind tt;
if (!tokenStream.getToken(&tt))
return false;
*isForInp = tt == TOK_IN;
*isForOfp = tt == TOK_NAME && tokenStream.currentToken().name() == context->names().of;
if (!*isForInp && !*isForOfp) {
tokenStream.ungetToken();
} else {
if (tt == TOK_NAME && !checkUnescapedName())
return false;
}
return true;
}
template <>
bool
Parser<FullParseHandler>::isValidForStatementLHS(ParseNode* pn1, JSVersion version,
bool isForDecl, bool isForEach,
ParseNodeKind headKind)
{
if (isForDecl)
return pn1->pn_count < 2 && !pn1->isKind(PNK_CONST);
switch (pn1->getKind()) {
case PNK_ARRAY:
case PNK_CALL:
case PNK_DOT:
case PNK_ELEM:
case PNK_NAME:
case PNK_OBJECT:
return true;
default:
return false;
}
}
template <>
bool
Parser<FullParseHandler>::checkForHeadConstInitializers(ParseNode* pn1)
{
if (!pn1->isKind(PNK_CONST))
return true;
for (ParseNode* assign = pn1->pn_head; assign; assign = assign->pn_next) {
MOZ_ASSERT(assign->isKind(PNK_ASSIGN) || assign->isKind(PNK_NAME));
if (assign->isKind(PNK_NAME) && !assign->isAssigned())
return false;
// PNK_ASSIGN nodes (destructuring assignment) are always assignments.
}
return true;
}
template <>
ParseNode*
Parser<FullParseHandler>::forStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
uint32_t begin = pos().begin;
AutoPushStmtInfoPC forStmt(*this, StmtType::FOR_LOOP);
bool isForEach = false;
unsigned iflags = 0;
if (allowsForEachIn()) {
bool matched;
if (!tokenStream.matchContextualKeyword(&matched, context->names().each))
return null();
if (matched) {
iflags = JSITER_FOREACH;
isForEach = true;
addTelemetry(JSCompartment::DeprecatedForEach);
if (versionNumber() < JSVERSION_LATEST) {
if (!report(ParseWarning, pc->sc->strict(), null(), JSMSG_DEPRECATED_FOR_EACH))
return null();
}
}
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
// True if we have 'for (var/let/const ...)'.
bool isForDecl = false;
// The next three variables are used to implement `for (let/const ...)`.
//
// We generate an implicit block, wrapping the whole loop, to store loop
// variables declared this way. Note that if the loop uses `for (var...)`
// instead, those variables go on some existing enclosing scope, so no
// implicit block scope is created.
//
// All three variables remain null/none if the loop is any other form.
//
// blockObj is the static block object for the implicit block scope.
RootedStaticBlockObject blockObj(context);
// letStmt is the BLOCK StmtInfo for the implicit block.
//
// Caution: `letStmt.emplace()` creates some Rooted objects. Rooteds must
// be created/destroyed in FIFO order. Therefore adding a Rooted in this
// function, between this point and the .emplace() call below, would trip
// assertions.
Maybe<AutoPushStmtInfoPC> letStmt;
// The PNK_LEXICALSCOPE node containing blockObj's ObjectBox.
ParseNode* forLetImpliedBlock = nullptr;
// True if a 'let' token at the head is parsed as an identifier instead of
// as starting a declaration.
bool letIsIdentifier = false;
// Set to 'x' in 'for (x; ...; ...)' or 'for (x in ...)'.
ParseNode* pn1;
TokenStream::Modifier modifier = TokenStream::Operand;
{
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_SEMI) {
pn1 = nullptr;
} else {
// Set pn1 to a variable list or an initializing expression.
//
// Pass |InForInit| to Parser::variables when parsing declarations
// to trigger |for|-specific parsing for that one position. In a
// normal variable declaration, any initializer may be an |in|
// expression. But for declarations at the start of a for-loop
// head, initializers can't contain |in|. (Such syntax conflicts
// with ES5's |for (var i = 0 in foo)| syntax, removed in ES6, that
// we "support" by ignoring the |= 0|.)
if (tt == TOK_VAR) {
isForDecl = true;
tokenStream.consumeKnownToken(tt, TokenStream::Operand);
pn1 = variables(yieldHandling, PNK_VAR, InForInit);
} else if (tt == TOK_LET || tt == TOK_CONST ||
(tt == TOK_NAME && tokenStream.nextName() == context->names().let)) {
handler.disableSyntaxParser();
// Check for the backwards-compatibility corner case in sloppy
// mode like |for (let in e)| where the 'let' token should be
// parsed as an identifier.
bool parseDecl;
if (tt == TOK_NAME) {
if (!peekShouldParseLetDeclaration(&parseDecl, TokenStream::Operand))
return null();
letIsIdentifier = !parseDecl;
} else {
parseDecl = true;
tokenStream.consumeKnownToken(tt, TokenStream::Operand);
}
if (parseDecl) {
bool constDecl = tt == TOK_CONST;
isForDecl = true;
// Initialize the enclosing scope manually for the call to
// |variables| below.
blockObj = StaticBlockObject::create(context);
if (!blockObj)
return null();
blockObj->initEnclosingScopeFromParser(pc->innermostStaticScope());
letStmt.emplace(*this, StmtType::BLOCK);
forLetImpliedBlock = pushLetScope(blockObj, *letStmt);
if (!forLetImpliedBlock)
return null();
(*letStmt)->isForLetBlock = true;
MOZ_ASSERT(CurrentLexicalStaticBlock(pc) == blockObj);
pn1 = variables(yieldHandling, constDecl ? PNK_CONST : PNK_LET, InForInit,
nullptr, blockObj, HoistVars);
} else {
pn1 = expr(InProhibited, yieldHandling, TripledotProhibited);
}
} else {
// Pass |InProhibited| when parsing an expression so that |in|
// isn't parsed in a RelationalExpression as a binary operator.
// In this context, |in| is part of a for-in loop -- *not* part
// of a binary expression.
pn1 = expr(InProhibited, yieldHandling, TripledotProhibited);
}
if (!pn1)
return null();
modifier = TokenStream::None;
}
}
MOZ_ASSERT_IF(isForDecl, pn1->isArity(PN_LIST));
MOZ_ASSERT(letStmt.isSome() == (isForDecl && (pn1->isOp(JSOP_DEFLET) || pn1->isOp(JSOP_DEFCONST))));
// If there's an |in| keyword here, it's a for-in loop, by dint of careful
// parsing of |pn1|.
ParseNode* pn2; /* forHead->pn_kid2 */
ParseNode* pn3; /* forHead->pn_kid3 */
ParseNodeKind headKind = PNK_FORHEAD;
if (pn1) {
bool isForIn, isForOf;
if (!matchInOrOf(&isForIn, &isForOf))
return null();
// In for-in loops, a 'let' token may be used as an identifier for
// backwards-compatibility reasons, e.g., |for (let in e)|. In for-of
// loops, a 'let' token is never parsed as an identifier. Forbid
// trying to parse a for-of loop if we have parsed a 'let' token as an
// identifier above.
//
// See ES6 13.7.5.1.
if (isForIn)
headKind = PNK_FORIN;
else if (isForOf && !letIsIdentifier)
headKind = PNK_FOROF;
}
if (headKind == PNK_FOROF || headKind == PNK_FORIN) {
/*
* Parse the rest of the for/in or for/of head.
*
* Here pn1 is everything to the left of 'in' or 'of'. At the end of
* this block, pn1 is a decl or nullptr, pn2 is the assignment target
* that receives the enumeration value each iteration, and pn3 is the
* rhs of 'in'.
*/
if (headKind == PNK_FOROF) {
forStmt->type = StmtType::FOR_OF_LOOP;
if (isForEach) {
report(ParseError, false, null(), JSMSG_BAD_FOR_EACH_LOOP);
return null();
}
} else {
forStmt->type = StmtType::FOR_IN_LOOP;
iflags |= JSITER_ENUMERATE;
}
/* Check that the left side of the 'in' or 'of' is valid. */
if (!isValidForStatementLHS(pn1, versionNumber(), isForDecl, isForEach, headKind)) {
report(ParseError, false, pn1, JSMSG_BAD_FOR_LEFTSIDE);
return null();
}
/*
* After the following if-else, pn2 will point to the name or
* destructuring pattern on in's left. pn1 will point to the decl, if
* any, else nullptr. Note that the "declaration with initializer" case
* rewrites the loop-head, moving the decl and setting pn1 to nullptr.
*/
if (isForDecl) {
pn2 = pn1->pn_head;
if ((pn2->isKind(PNK_NAME) && pn2->maybeExpr()) || pn2->isKind(PNK_ASSIGN)) {
MOZ_ASSERT(!(headKind == PNK_FORIN && pn1->isKind(PNK_VAR)),
"Parser::variables should have ignored the "
"initializer in the ES5-sanctioned, ES6-prohibited "
"|for (var ... = ... in ...)| syntax");
// Otherwise, this bizarre |for (const/let x = ... in/of ...)|
// loop isn't valid ES6 and has never been permitted in
// SpiderMonkey.
report(ParseError, false, pn2, JSMSG_INVALID_FOR_INOF_DECL_WITH_INIT,
headKind == PNK_FOROF ? "of" : "in");
return null();
}
} else {
/* Not a declaration. */
MOZ_ASSERT(!letStmt);
pn2 = pn1;
pn1 = nullptr;
if (!checkAndMarkAsAssignmentLhs(pn2, PlainAssignment))
return null();
}
pn3 = (headKind == PNK_FOROF)
? assignExpr(InAllowed, yieldHandling, TripledotProhibited)
: expr(InAllowed, yieldHandling, TripledotProhibited);
if (!pn3)
return null();
modifier = TokenStream::None;
if (isForDecl) {
/*
* pn2 is part of a declaration. Make a copy that can be passed to
* BytecodeEmitter::emitAssignment.
*/
pn2 = cloneLeftHandSide(pn2);
if (!pn2)
return null();
}
ParseNodeKind kind2 = pn2->getKind();
MOZ_ASSERT(kind2 != PNK_ASSIGN, "forStatement TOK_ASSIGN");
if (kind2 == PNK_NAME) {
/* Beware 'for (arguments in ...)' with or without a 'var'. */
pn2->markAsAssigned();
}
} else {
if (isForEach) {
reportWithOffset(ParseError, false, begin, JSMSG_BAD_FOR_EACH_LOOP);
return null();
}
MOZ_ASSERT(headKind == PNK_FORHEAD);
if (letStmt) {
// Ensure here that the previously-unchecked assignment mandate for
// const declarations holds.
if (!checkForHeadConstInitializers(pn1)) {
report(ParseError, false, nullptr, JSMSG_BAD_CONST_DECL);
return null();
}
}
/* Parse the loop condition or null into pn2. */
MUST_MATCH_TOKEN_MOD(TOK_SEMI, modifier, JSMSG_SEMI_AFTER_FOR_INIT);
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_SEMI) {
pn2 = nullptr;
modifier = TokenStream::Operand;
} else {
pn2 = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!pn2)
return null();
modifier = TokenStream::None;
}
/* Parse the update expression or null into pn3. */
MUST_MATCH_TOKEN_MOD(TOK_SEMI, modifier, JSMSG_SEMI_AFTER_FOR_COND);
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_RP) {
pn3 = nullptr;
modifier = TokenStream::Operand;
} else {
pn3 = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!pn3)
return null();
modifier = TokenStream::None;
}
}
MUST_MATCH_TOKEN_MOD(TOK_RP, modifier, JSMSG_PAREN_AFTER_FOR_CTRL);
TokenPos headPos(begin, pos().end);
ParseNode* forHead = handler.newForHead(headKind, pn1, pn2, pn3, headPos);
if (!forHead)
return null();
/* Parse the loop body. */
ParseNode* body = statement(yieldHandling);
if (!body)
return null();
ParseNode* forLoop = handler.newForStatement(begin, forHead, body, iflags);
if (!forLoop)
return null();
if (forLetImpliedBlock) {
forLetImpliedBlock->pn_expr = forLoop;
forLetImpliedBlock->pn_pos = forLoop->pn_pos;
return forLetImpliedBlock;
}
return forLoop;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::forStatement(YieldHandling yieldHandling)
{
/*
* 'for' statement parsing is fantastically complicated and requires being
* able to inspect the parse tree for previous parts of the 'for'. Syntax
* parsing of 'for' statements is thus done separately, and only handles
* the types of 'for' statements likely to be seen in web content.
*/
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
AutoPushStmtInfoPC forStmt(*this, StmtType::FOR_LOOP);
/* Don't parse 'for each' loops. */
if (allowsForEachIn()) {
TokenKind tt;
if (!tokenStream.peekToken(&tt))
return null();
// Not all "yield" tokens are names, but the ones that aren't names are
// invalid in this context anyway.
if (tt == TOK_NAME || tt == TOK_YIELD) {
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
/* True if we have 'for (var ...)'. */
bool isForDecl = false;
bool simpleForDecl = true;
/* Set to 'x' in 'for (x ;... ;...)' or 'for (x in ...)'. */
Node lhsNode;
TokenStream::Modifier modifier = TokenStream::Operand;
{
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_SEMI) {
lhsNode = null();
} else {
/* Set lhsNode to a var list or an initializing expression. */
if (tt == TOK_VAR) {
isForDecl = true;
tokenStream.consumeKnownToken(tt, TokenStream::Operand);
lhsNode = variables(yieldHandling, PNK_VAR, InForInit, &simpleForDecl);
} else if (tt == TOK_CONST || tt == TOK_LET ||
(tt == TOK_NAME && tokenStream.nextName() == context->names().let))
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
} else {
lhsNode = expr(InProhibited, yieldHandling, TripledotProhibited);
}
if (!lhsNode)
return null();
modifier = TokenStream::None;
}
}
// If there's an |in| keyword here, it's a for-in loop, by dint of careful
// parsing of |pn1|.
bool isForIn = false, isForOf = false;
if (lhsNode) {
if (!matchInOrOf(&isForIn, &isForOf))
return null();
}
if (isForIn || isForOf) {
/* Parse the rest of the for/in or for/of head. */
forStmt->type = isForOf ? StmtType::FOR_OF_LOOP : StmtType::FOR_IN_LOOP;
/* Check that the left side of the 'in' or 'of' is valid. */
if (!isForDecl &&
!handler.maybeNameAnyParentheses(lhsNode) &&
!handler.isPropertyAccess(lhsNode))
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
if (!simpleForDecl) {
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
if (!isForDecl && !checkAndMarkAsAssignmentLhs(lhsNode, PlainAssignment))
return null();
if (!(isForIn
? expr(InAllowed, yieldHandling, TripledotProhibited)
: assignExpr(InAllowed, yieldHandling, TripledotProhibited)))
{
return null();
}
modifier = TokenStream::None;
} else {
/* Parse the loop condition or null. */
MUST_MATCH_TOKEN_MOD(TOK_SEMI, modifier, JSMSG_SEMI_AFTER_FOR_INIT);
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
modifier = TokenStream::Operand;
if (tt != TOK_SEMI) {
if (!expr(InAllowed, yieldHandling, TripledotProhibited))
return null();
modifier = TokenStream::None;
}
/* Parse the update expression or null. */
MUST_MATCH_TOKEN_MOD(TOK_SEMI, modifier, JSMSG_SEMI_AFTER_FOR_COND);
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
modifier = TokenStream::Operand;
if (tt != TOK_RP) {
if (!expr(InAllowed, yieldHandling, TripledotProhibited))
return null();
modifier = TokenStream::None;
}
}
MUST_MATCH_TOKEN_MOD(TOK_RP, modifier, JSMSG_PAREN_AFTER_FOR_CTRL);
/* Parse the loop body. */
if (!statement(yieldHandling))
return null();
return SyntaxParseHandler::NodeGeneric;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::switchStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_SWITCH));
uint32_t begin = pos().begin;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_SWITCH);
Node discriminant = exprInParens(InAllowed, yieldHandling, TripledotProhibited);
if (!discriminant)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_SWITCH);
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_SWITCH);
AutoPushStmtInfoPC stmtInfo(*this, StmtType::SWITCH);
if (!stmtInfo.generateBlockId())
return null();
Node caseList = handler.newStatementList(pc->blockid(), pos());
if (!caseList)
return null();
Node saveBlock = pc->blockNode;
pc->blockNode = caseList;
bool seenDefault = false;
TokenKind tt;
while (true) {
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_RC)
break;
uint32_t caseBegin = pos().begin;
Node caseExpr;
switch (tt) {
case TOK_DEFAULT:
if (seenDefault) {
report(ParseError, false, null(), JSMSG_TOO_MANY_DEFAULTS);
return null();
}
seenDefault = true;
caseExpr = null(); // The default case has pn_left == nullptr.
break;
case TOK_CASE:
caseExpr = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!caseExpr)
return null();
break;
default:
report(ParseError, false, null(), JSMSG_BAD_SWITCH);
return null();
}
MUST_MATCH_TOKEN(TOK_COLON, JSMSG_COLON_AFTER_CASE);
Node body = handler.newStatementList(pc->blockid(), pos());
if (!body)
return null();
bool afterReturn = false;
bool warnedAboutStatementsAfterReturn = false;
uint32_t statementBegin = 0;
while (true) {
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_RC || tt == TOK_CASE || tt == TOK_DEFAULT)
break;
if (afterReturn) {
TokenPos pos(0, 0);
if (!tokenStream.peekTokenPos(&pos, TokenStream::Operand))
return null();
statementBegin = pos.begin;
}
Node stmt = statement(yieldHandling);
if (!stmt)
return null();
if (!warnedAboutStatementsAfterReturn) {
if (afterReturn) {
if (!handler.isStatementPermittedAfterReturnStatement(stmt)) {
if (!reportWithOffset(ParseWarning, false, statementBegin,
JSMSG_STMT_AFTER_RETURN))
{
return null();
}
warnedAboutStatementsAfterReturn = true;
}
} else if (handler.isReturnStatement(stmt)) {
afterReturn = true;
}
}
handler.addList(body, stmt);
}
// In ES6, lexical bindings cannot be accessed until initialized. If
// there was a 'let' declaration in the case we just parsed, remember
// the slot starting at which new lexical bindings will be
// assigned. Since lexical bindings from previous cases will not
// dominate uses in the current case, any such uses will require a
// dead zone check.
//
// Currently this is overly conservative; we could do better, but
// declaring lexical bindings within switch cases without introducing
// a new block is poor form and should be avoided.
if (stmtInfo->isBlockScope)
stmtInfo->firstDominatingLexicalInCase = stmtInfo->staticBlock().numVariables();
Node casepn = handler.newCaseOrDefault(caseBegin, caseExpr, body);
if (!casepn)
return null();
handler.addList(caseList, casepn);
}
/*
* Handle the case where there was a let declaration in any case in
* the switch body, but not within an inner block. If it replaced
* pc->blockNode with a new block node then we must refresh caseList and
* then restore pc->blockNode.
*/
if (pc->blockNode != caseList)
caseList = pc->blockNode;
pc->blockNode = saveBlock;
handler.setEndPosition(caseList, pos().end);
return handler.newSwitchStatement(begin, discriminant, caseList);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::continueStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_CONTINUE));
uint32_t begin = pos().begin;
RootedPropertyName label(context);
if (!matchLabel(yieldHandling, &label))
return null();
StmtInfoPC* stmt = pc->innermostStmt();
if (label) {
for (StmtInfoPC* stmt2 = nullptr; ; stmt = stmt->enclosing) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_LABEL_NOT_FOUND);
return null();
}
if (stmt->type == StmtType::LABEL) {
if (stmt->label == label) {
if (!stmt2 || !stmt2->isLoop()) {
report(ParseError, false, null(), JSMSG_BAD_CONTINUE);
return null();
}
break;
}
} else {
stmt2 = stmt;
}
}
} else {
for (; ; stmt = stmt->enclosing) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_BAD_CONTINUE);
return null();
}
if (stmt->isLoop())
break;
}
}
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
return handler.newContinueStatement(label, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::breakStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_BREAK));
uint32_t begin = pos().begin;
RootedPropertyName label(context);
if (!matchLabel(yieldHandling, &label))
return null();
StmtInfoPC* stmt = pc->innermostStmt();
if (label) {
for (; ; stmt = stmt->enclosing) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_LABEL_NOT_FOUND);
return null();
}
if (stmt->type == StmtType::LABEL && stmt->label == label)
break;
}
} else {
for (; ; stmt = stmt->enclosing) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_TOUGH_BREAK);
return null();
}
if (stmt->isLoop() || stmt->type == StmtType::SWITCH)
break;
}
}
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
return handler.newBreakStatement(label, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::returnStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_RETURN));
uint32_t begin = pos().begin;
MOZ_ASSERT(pc->sc->isFunctionBox());
pc->sc->asFunctionBox()->usesReturn = true;
// Parse an optional operand.
//
// This is ugly, but we don't want to require a semicolon.
Node exprNode;
TokenKind tt = TOK_EOF;
if (!tokenStream.peekTokenSameLine(&tt, TokenStream::Operand))
return null();
switch (tt) {
case TOK_EOL:
case TOK_EOF:
case TOK_SEMI:
case TOK_RC:
exprNode = null();
pc->funHasReturnVoid = true;
break;
default: {
exprNode = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!exprNode)
return null();
pc->funHasReturnExpr = true;
}
}
if (exprNode) {
if (!MatchOrInsertSemicolonAfterExpression(tokenStream))
return null();
} else {
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
}
Node pn = handler.newReturnStatement(exprNode, TokenPos(begin, pos().end));
if (!pn)
return null();
if (pc->isLegacyGenerator() && exprNode) {
/* Disallow "return v;" in legacy generators. */
reportBadReturn(pn, ParseError, JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
return null();
}
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newYieldExpression(uint32_t begin, typename ParseHandler::Node expr,
bool isYieldStar)
{
Node generator = newName(context->names().dotGenerator);
if (!generator)
return null();
if (!noteNameUse(context->names().dotGenerator, generator))
return null();
if (isYieldStar)
return handler.newYieldStarExpression(begin, expr, generator);
return handler.newYieldExpression(begin, expr, generator);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::yieldExpression(InHandling inHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_YIELD));
uint32_t begin = pos().begin;
switch (pc->generatorKind()) {
case StarGenerator:
{
MOZ_ASSERT(pc->sc->isFunctionBox());
pc->lastYieldOffset = begin;
Node exprNode;
ParseNodeKind kind = PNK_YIELD;
TokenKind tt = TOK_EOF;
if (!tokenStream.peekTokenSameLine(&tt, TokenStream::Operand))
return null();
switch (tt) {
// TOK_EOL is special; it implements the [no LineTerminator here]
// quirk in the grammar.
case TOK_EOL:
// The rest of these make up the complete set of tokens that can
// appear after any of the places where AssignmentExpression is used
// throughout the grammar. Conveniently, none of them can also be the
// start an expression.
case TOK_EOF:
case TOK_SEMI:
case TOK_RC:
case TOK_RB:
case TOK_RP:
case TOK_COLON:
case TOK_COMMA:
// No value.
exprNode = null();
tokenStream.addModifierException(TokenStream::NoneIsOperand);
break;
case TOK_MUL:
kind = PNK_YIELD_STAR;
tokenStream.consumeKnownToken(TOK_MUL, TokenStream::Operand);
// Fall through.
default:
exprNode = assignExpr(inHandling, YieldIsKeyword, TripledotProhibited);
if (!exprNode)
return null();
}
return newYieldExpression(begin, exprNode, kind == PNK_YIELD_STAR);
}
case NotGenerator:
// We are in code that has not seen a yield, but we are in JS 1.7 or
// later. Try to transition to being a legacy generator.
MOZ_ASSERT(tokenStream.versionNumber() >= JSVERSION_1_7);
MOZ_ASSERT(pc->lastYieldOffset == ParseContext<ParseHandler>::NoYieldOffset);
if (!abortIfSyntaxParser())
return null();
if (!pc->sc->isFunctionBox()) {
report(ParseError, false, null(), JSMSG_BAD_RETURN_OR_YIELD, js_yield_str);
return null();
}
pc->sc->asFunctionBox()->setGeneratorKind(LegacyGenerator);
addTelemetry(JSCompartment::DeprecatedLegacyGenerator);
if (pc->funHasReturnExpr) {
/* As in Python (see PEP-255), disallow return v; in generators. */
reportBadReturn(null(), ParseError, JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
return null();
}
// Fall through.
case LegacyGenerator:
{
// We are in a legacy generator: a function that has already seen a
// yield, or in a legacy generator comprehension.
MOZ_ASSERT(pc->sc->isFunctionBox());
pc->lastYieldOffset = begin;
// Legacy generators do not require a value.
Node exprNode;
TokenKind tt = TOK_EOF;
if (!tokenStream.peekTokenSameLine(&tt, TokenStream::Operand))
return null();
switch (tt) {
case TOK_EOF:
case TOK_EOL:
case TOK_SEMI:
case TOK_RC:
case TOK_RB:
case TOK_RP:
case TOK_COLON:
case TOK_COMMA:
// No value.
exprNode = null();
tokenStream.addModifierException(TokenStream::NoneIsOperand);
break;
default:
exprNode = assignExpr(inHandling, YieldIsKeyword, TripledotProhibited);
if (!exprNode)
return null();
}
return newYieldExpression(begin, exprNode);
}
}
MOZ_CRASH("yieldExpr");
}
template <>
ParseNode*
Parser<FullParseHandler>::withStatement(YieldHandling yieldHandling)
{
// test262/ch12/12.10/12.10-0-1.js fails if we try to parse with-statements
// in syntax-parse mode. See bug 892583.
if (handler.syntaxParser) {
handler.disableSyntaxParser();
abortedSyntaxParse = true;
return null();
}
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_WITH));
uint32_t begin = pos().begin;
// In most cases, we want the constructs forbidden in strict mode code to be
// a subset of those that JSOPTION_EXTRA_WARNINGS warns about, and we should
// use reportStrictModeError. However, 'with' is the sole instance of a
// construct that is forbidden in strict mode code, but doesn't even merit a
// warning under JSOPTION_EXTRA_WARNINGS. See
// https://bugzilla.mozilla.org/show_bug.cgi?id=514576#c1.
if (pc->sc->strict() && !report(ParseStrictError, true, null(), JSMSG_STRICT_CODE_WITH))
return null();
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_WITH);
Node objectExpr = exprInParens(InAllowed, yieldHandling, TripledotProhibited);
if (!objectExpr)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_WITH);
Rooted<StaticWithObject*> staticWith(context, StaticWithObject::create(context));
if (!staticWith)
return null();
Node innerBlock;
{
AutoPushStmtInfoPC stmtInfo(*this, StmtType::WITH, *staticWith);
innerBlock = statement(yieldHandling);
if (!innerBlock)
return null();
}
pc->sc->setBindingsAccessedDynamically();
/*
* Make sure to deoptimize lexical dependencies inside the |with|
* to safely optimize binding globals (see bug 561923).
*/
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront()) {
DefinitionNode defn = r.front().value().get<FullParseHandler>();
DefinitionNode lexdep = handler.resolve(defn);
if (!pc->sc->isDotVariable(lexdep->name()))
handler.deoptimizeUsesWithin(lexdep, TokenPos(begin, pos().begin));
}
ObjectBox* staticWithBox = newObjectBox(staticWith);
if (!staticWithBox)
return null();
return handler.newWithStatement(begin, objectExpr, innerBlock, staticWithBox);
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::withStatement(YieldHandling yieldHandling)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::labeledStatement(YieldHandling yieldHandling)
{
uint32_t begin = pos().begin;
RootedPropertyName label(context, tokenStream.currentName());
for (StmtInfoPC* stmt = pc->innermostStmt(); stmt; stmt = stmt->enclosing) {
if (stmt->type == StmtType::LABEL && stmt->label == label) {
report(ParseError, false, null(), JSMSG_DUPLICATE_LABEL);
return null();
}
}
tokenStream.consumeKnownToken(TOK_COLON);
/* Push a label struct and parse the statement. */
AutoPushStmtInfoPC stmtInfo(*this, StmtType::LABEL);
stmtInfo->label = label;
Node pn = statement(yieldHandling);
if (!pn)
return null();
return handler.newLabeledStatement(label, pn, begin);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::throwStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_THROW));
uint32_t begin = pos().begin;
/* ECMA-262 Edition 3 says 'throw [no LineTerminator here] Expr'. */
TokenKind tt = TOK_EOF;
if (!tokenStream.peekTokenSameLine(&tt, TokenStream::Operand))
return null();
if (tt == TOK_EOF || tt == TOK_SEMI || tt == TOK_RC) {
report(ParseError, false, null(), JSMSG_MISSING_EXPR_AFTER_THROW);
return null();
}
if (tt == TOK_EOL) {
report(ParseError, false, null(), JSMSG_LINE_BREAK_AFTER_THROW);
return null();
}
Node throwExpr = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!throwExpr)
return null();
if (!MatchOrInsertSemicolonAfterExpression(tokenStream))
return null();
return handler.newThrowStatement(throwExpr, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::tryStatement(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_TRY));
uint32_t begin = pos().begin;
/*
* try nodes are ternary.
* kid1 is the try statement
* kid2 is the catch node list or null
* kid3 is the finally statement
*
* catch nodes are ternary.
* kid1 is the lvalue (TOK_NAME, TOK_LB, or TOK_LC)
* kid2 is the catch guard or null if no guard
* kid3 is the catch block
*
* catch lvalue nodes are either:
* TOK_NAME for a single identifier
* TOK_RB or TOK_RC for a destructuring left-hand side
*
* finally nodes are TOK_LC statement lists.
*/
Node innerBlock;
{
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_TRY);
AutoPushStmtInfoPC stmtInfo(*this, StmtType::TRY);
if (!stmtInfo.generateBlockId())
return null();
innerBlock = statements(yieldHandling);
if (!innerBlock)
return null();
MUST_MATCH_TOKEN_MOD(TOK_RC, TokenStream::Operand, JSMSG_CURLY_AFTER_TRY);
}
bool hasUnconditionalCatch = false;
Node catchList = null();
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_CATCH) {
catchList = handler.newCatchList();
if (!catchList)
return null();
do {
Node pnblock;
BindData<ParseHandler> data(context);
/* Check for another catch after unconditional catch. */
if (hasUnconditionalCatch) {
report(ParseError, false, null(), JSMSG_CATCH_AFTER_GENERAL);
return null();
}
/*
* Create a lexical scope node around the whole catch clause,
* including the head.
*/
AutoPushStmtInfoPC stmtInfo(*this, StmtType::CATCH);
pnblock = pushLexicalScope(stmtInfo);
if (!pnblock)
return null();
/*
* Legal catch forms are:
* catch (lhs)
* catch (lhs if <boolean_expression>)
* where lhs is a name or a destructuring left-hand side.
* (the latter is legal only #ifdef JS_HAS_CATCH_GUARD)
*/
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_CATCH);
/*
* Contrary to ECMA Ed. 3, the catch variable is lexically
* scoped, not a property of a new Object instance. This is
* an intentional change that anticipates ECMA Ed. 4.
*/
data.initLexical(HoistVars, JSOP_DEFLET,
&stmtInfo->staticScope->template as<StaticBlockObject>(),
JSMSG_TOO_MANY_CATCH_VARS);
MOZ_ASSERT(data.letData().blockObj);
if (!tokenStream.getToken(&tt))
return null();
Node catchName;
switch (tt) {
case TOK_LB:
case TOK_LC:
catchName = destructuringExpr(yieldHandling, &data, tt);
if (!catchName)
return null();
break;
case TOK_YIELD:
if (yieldHandling == YieldIsKeyword) {
report(ParseError, false, null(), JSMSG_RESERVED_ID, "yield");
return null();
}
// Even if yield is *not* necessarily a keyword, we still must
// check its validity for legacy generators.
if (!checkYieldNameValidity())
return null();
// Fall through.
case TOK_NAME:
{
RootedPropertyName label(context, tokenStream.currentName());
catchName = newBindingNode(label, false);
if (!catchName)
return null();
data.setNameNode(catchName);
if (!data.bind(label, this))
return null();
break;
}
default:
report(ParseError, false, null(), JSMSG_CATCH_IDENTIFIER);
return null();
}
Node catchGuard = null();
#if JS_HAS_CATCH_GUARD
/*
* We use 'catch (x if x === 5)' (not 'catch (x : x === 5)')
* to avoid conflicting with the JS2/ECMAv4 type annotation
* catchguard syntax.
*/
bool matched;
if (!tokenStream.matchToken(&matched, TOK_IF))
return null();
if (matched) {
catchGuard = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!catchGuard)
return null();
}
#endif
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_CATCH);
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_CATCH);
Node catchBody = statements(yieldHandling);
if (!catchBody)
return null();
MUST_MATCH_TOKEN_MOD(TOK_RC, TokenStream::Operand, JSMSG_CURLY_AFTER_CATCH);
if (!catchGuard)
hasUnconditionalCatch = true;
if (!handler.addCatchBlock(catchList, pnblock, catchName, catchGuard, catchBody))
return null();
handler.setEndPosition(catchList, pos().end);
handler.setEndPosition(pnblock, pos().end);
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
} while (tt == TOK_CATCH);
}
Node finallyBlock = null();
if (tt == TOK_FINALLY) {
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_FINALLY);
AutoPushStmtInfoPC stmtInfo(*this, StmtType::TRY);
if (!stmtInfo.generateBlockId())
return null();
finallyBlock = statements(yieldHandling);
if (!finallyBlock)
return null();
MUST_MATCH_TOKEN_MOD(TOK_RC, TokenStream::Operand, JSMSG_CURLY_AFTER_FINALLY);
} else {
tokenStream.ungetToken();
}
if (!catchList && !finallyBlock) {
report(ParseError, false, null(), JSMSG_CATCH_OR_FINALLY);
return null();
}
return handler.newTryStatement(begin, innerBlock, catchList, finallyBlock);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::debuggerStatement()
{
TokenPos p;
p.begin = pos().begin;
if (!MatchOrInsertSemicolonAfterNonExpression(tokenStream))
return null();
p.end = pos().end;
pc->sc->setBindingsAccessedDynamically();
pc->sc->setHasDebuggerStatement();
return handler.newDebuggerStatement(p);
}
static JSOp
JSOpFromPropertyType(PropertyType propType)
{
switch (propType) {
case PropertyType::Getter:
case PropertyType::GetterNoExpressionClosure:
return JSOP_INITPROP_GETTER;
case PropertyType::Setter:
case PropertyType::SetterNoExpressionClosure:
return JSOP_INITPROP_SETTER;
case PropertyType::Normal:
case PropertyType::Method:
case PropertyType::GeneratorMethod:
case PropertyType::Constructor:
case PropertyType::DerivedConstructor:
return JSOP_INITPROP;
default:
MOZ_CRASH("unexpected property type");
}
}
static FunctionSyntaxKind
FunctionSyntaxKindFromPropertyType(PropertyType propType)
{
switch (propType) {
case PropertyType::Getter:
return Getter;
case PropertyType::GetterNoExpressionClosure:
return GetterNoExpressionClosure;
case PropertyType::Setter:
return Setter;
case PropertyType::SetterNoExpressionClosure:
return SetterNoExpressionClosure;
case PropertyType::Method:
return Method;
case PropertyType::GeneratorMethod:
return Method;
case PropertyType::Constructor:
return ClassConstructor;
case PropertyType::DerivedConstructor:
return DerivedClassConstructor;
default:
MOZ_CRASH("unexpected property type");
}
}
static GeneratorKind
GeneratorKindFromPropertyType(PropertyType propType)
{
return propType == PropertyType::GeneratorMethod ? StarGenerator : NotGenerator;
}
template <>
ParseNode*
Parser<FullParseHandler>::classDefinition(YieldHandling yieldHandling,
ClassContext classContext,
DefaultHandling defaultHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_CLASS));
bool savedStrictness = setLocalStrictMode(true);
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
RootedPropertyName name(context);
if (tt == TOK_NAME) {
name = tokenStream.currentName();
} else if (tt == TOK_YIELD) {
if (!checkYieldNameValidity())
return null();
MOZ_ASSERT(yieldHandling != YieldIsKeyword);
name = tokenStream.currentName();
} else if (classContext == ClassStatement) {
if (defaultHandling == AllowDefaultName) {
name = context->names().starDefaultStar;
tokenStream.ungetToken();
} else {
// Class statements must have a bound name
report(ParseError, false, null(), JSMSG_UNNAMED_CLASS_STMT);
return null();
}
} else {
// Make sure to put it back, whatever it was
tokenStream.ungetToken();
}
if (name == context->names().let) {
report(ParseError, false, null(), JSMSG_LET_CLASS_BINDING);
return null();
}
ParseNode* classBlock = null();
RootedAtom propAtom(context);
// A named class creates a new lexical scope with a const binding of the
// class name.
Maybe<AutoPushStmtInfoPC> classStmt;
if (name) {
classStmt.emplace(*this, StmtType::BLOCK);
classBlock = pushLexicalScope(*classStmt);
if (!classBlock)
return null();
}
// Because the binding definitions keep track of their blockId, we need to
// create at least the inner binding later. Keep track of the name's position
// in order to provide it for the nodes created later.
TokenPos namePos = pos();
ParseNode* classHeritage = null();
bool hasHeritage;
if (!tokenStream.matchToken(&hasHeritage, TOK_EXTENDS))
return null();
if (hasHeritage) {
if (!tokenStream.getToken(&tt))
return null();
classHeritage = memberExpr(yieldHandling, TripledotProhibited, tt, true);
if (!classHeritage)
return null();
}
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_CLASS);
ParseNode* classMethods = handler.newClassMethodList(pos().begin);
bool seenConstructor = false;
for (;;) {
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::KeywordIsName))
return null();
if (tt == TOK_RC)
break;
if (tt == TOK_SEMI)
continue;
bool isStatic = false;
if (tt == TOK_NAME && tokenStream.currentName() == context->names().static_) {
if (!tokenStream.peekToken(&tt, TokenStream::KeywordIsName))
return null();
if (tt != TOK_LP) {
if (!checkUnescapedName())
return null();
isStatic = true;
} else {
tokenStream.addModifierException(TokenStream::NoneIsKeywordIsName);
tokenStream.ungetToken();
}
} else {
tokenStream.ungetToken();
}
PropertyType propType;
ParseNode* propName = propertyName(yieldHandling, classMethods, &propType, &propAtom);
if (!propName)
return null();
if (propType != PropertyType::Getter && propType != PropertyType::Setter &&
propType != PropertyType::Method && propType != PropertyType::GeneratorMethod &&
propType != PropertyType::Constructor && propType != PropertyType::DerivedConstructor)
{
report(ParseError, false, null(), JSMSG_BAD_METHOD_DEF);
return null();
}
if (propType == PropertyType::Getter)
propType = PropertyType::GetterNoExpressionClosure;
if (propType == PropertyType::Setter)
propType = PropertyType::SetterNoExpressionClosure;
if (!isStatic && propAtom == context->names().constructor) {
if (propType != PropertyType::Method) {
report(ParseError, false, propName, JSMSG_BAD_METHOD_DEF);
return null();
}
if (seenConstructor) {
report(ParseError, false, propName, JSMSG_DUPLICATE_PROPERTY, "constructor");
return null();
}
seenConstructor = true;
propType = hasHeritage ? PropertyType::DerivedConstructor : PropertyType::Constructor;
} else if (isStatic && propAtom == context->names().prototype) {
report(ParseError, false, propName, JSMSG_BAD_METHOD_DEF);
return null();
}
// FIXME: Implement ES6 function "name" property semantics
// (bug 883377).
RootedPropertyName funName(context);
switch (propType) {
case PropertyType::GetterNoExpressionClosure:
case PropertyType::SetterNoExpressionClosure:
funName = nullptr;
break;
case PropertyType::Constructor:
case PropertyType::DerivedConstructor:
funName = name;
break;
default:
if (tokenStream.isCurrentTokenType(TOK_NAME))
funName = tokenStream.currentName();
else
funName = nullptr;
}
ParseNode* fn = methodDefinition(yieldHandling, propType, funName);
if (!fn)
return null();
JSOp op = JSOpFromPropertyType(propType);
if (!handler.addClassMethodDefinition(classMethods, propName, fn, op, isStatic))
return null();
}
ParseNode* nameNode = null();
ParseNode* methodsOrBlock = classMethods;
if (name) {
ParseNode* innerBinding = makeInitializedLexicalBinding(name, true, namePos);
if (!innerBinding)
return null();
MOZ_ASSERT(classBlock);
handler.setLexicalScopeBody(classBlock, classMethods);
methodsOrBlock = classBlock;
classStmt.reset();
ParseNode* outerBinding = null();
if (classContext == ClassStatement) {
outerBinding = makeInitializedLexicalBinding(name, false, namePos);
if (!outerBinding)
return null();
}
nameNode = handler.newClassNames(outerBinding, innerBinding, namePos);
if (!nameNode)
return null();
}
MOZ_ALWAYS_TRUE(setLocalStrictMode(savedStrictness));
return handler.newClass(nameNode, classHeritage, methodsOrBlock);
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::classDefinition(YieldHandling yieldHandling,
ClassContext classContext,
DefaultHandling defaultHandling)
{
MOZ_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::shouldParseLetDeclaration(bool* parseDeclOut)
{
TokenKind tt;
*parseDeclOut = false;
if (!tokenStream.peekToken(&tt))
return false;
switch (tt) {
case TOK_NAME:
// |let let| is disallowed per ES6 13.3.1.1.
*parseDeclOut = tokenStream.nextName() != context->names().let;
break;
case TOK_LC:
case TOK_LB:
// |let {| and |let [| are destructuring declarations.
*parseDeclOut = true;
break;
default:
break;
}
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::peekShouldParseLetDeclaration(bool* parseDeclOut,
TokenStream::Modifier modifier)
{
// 'let' is a reserved keyword in strict mode and we shouldn't get here.
MOZ_ASSERT(!pc->sc->strict());
*parseDeclOut = false;
#ifdef DEBUG
TokenKind tt;
if (!tokenStream.peekToken(&tt, modifier))
return false;
MOZ_ASSERT(tt == TOK_NAME && tokenStream.nextName() == context->names().let);
#endif
tokenStream.consumeKnownToken(TOK_NAME, modifier);
if (!shouldParseLetDeclaration(parseDeclOut))
return false;
// Unget the TOK_NAME of 'let' if not parsing a declaration.
if (!*parseDeclOut)
tokenStream.ungetToken();
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::statement(YieldHandling yieldHandling, bool canHaveDirectives)
{
MOZ_ASSERT(checkOptionsCalled);
JS_CHECK_RECURSION(context, return null());
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
switch (tt) {
// BlockStatement[?Yield, ?Return]
case TOK_LC:
return blockStatement(yieldHandling);
// VariableStatement[?Yield]
case TOK_VAR: {
Node pn = variables(yieldHandling, PNK_VAR, NotInForInit);
if (!pn)
return null();
if (!MatchOrInsertSemicolonAfterExpression(tokenStream))
return null();
return pn;
}
// EmptyStatement
case TOK_SEMI:
return handler.newEmptyStatement(pos());
// ExpressionStatement[?Yield].
//
// These should probably be handled by a single ExpressionStatement
// function in a default, not split up this way.
case TOK_STRING:
if (!canHaveDirectives && tokenStream.currentToken().atom() == context->names().useAsm) {
if (!abortIfSyntaxParser())
return null();
if (!report(ParseWarning, false, null(), JSMSG_USE_ASM_DIRECTIVE_FAIL))
return null();
}
return expressionStatement(yieldHandling);
case TOK_YIELD: {
// Don't use a ternary operator here due to obscure linker issues
// around using static consts in the arms of a ternary.
TokenStream::Modifier modifier;
if (yieldExpressionsSupported())
modifier = TokenStream::Operand;
else
modifier = TokenStream::None;
TokenKind next;
if (!tokenStream.peekToken(&next, modifier))
return null();
if (next == TOK_COLON) {
if (!checkYieldNameValidity())
return null();
return labeledStatement(yieldHandling);
}
return expressionStatement(yieldHandling);
}
case TOK_NAME: {
// 'let' is a contextual keyword in sloppy node. In strict mode, it is
// always lexed as TOK_LET except following case:
//
// "use strict"
// let a = 1;
//
// There 'let' is lexed as TOK_NAME before parsing directive.
if (tokenStream.currentName() == context->names().let) {
bool parseDecl;
if (!shouldParseLetDeclaration(&parseDecl))
return null();
if (parseDecl)
return lexicalDeclaration(yieldHandling, /* isConst = */ false);
}
TokenKind next;
if (!tokenStream.peekToken(&next))
return null();
if (next == TOK_COLON)
return labeledStatement(yieldHandling);
return expressionStatement(yieldHandling);
}
case TOK_NEW:
return expressionStatement(yieldHandling, PredictInvoked);
default:
return expressionStatement(yieldHandling);
// IfStatement[?Yield, ?Return]
case TOK_IF:
return ifStatement(yieldHandling);
// BreakableStatement[?Yield, ?Return]
//
// BreakableStatement[Yield, Return]:
// IterationStatement[?Yield, ?Return]
// SwitchStatement[?Yield, ?Return]
case TOK_DO:
return doWhileStatement(yieldHandling);
case TOK_WHILE:
return whileStatement(yieldHandling);
case TOK_FOR:
return forStatement(yieldHandling);
case TOK_SWITCH:
return switchStatement(yieldHandling);
// ContinueStatement[?Yield]
case TOK_CONTINUE:
return continueStatement(yieldHandling);
// BreakStatement[?Yield]
case TOK_BREAK:
return breakStatement(yieldHandling);
// [+Return] ReturnStatement[?Yield]
case TOK_RETURN:
// The Return parameter is only used here, and the effect is easily
// detected this way, so don't bother passing around an extra parameter
// everywhere.
if (!pc->sc->isFunctionBox()) {
report(ParseError, false, null(), JSMSG_BAD_RETURN_OR_YIELD, js_return_str);
return null();
}
return returnStatement(yieldHandling);
// WithStatement[?Yield, ?Return]
case TOK_WITH:
return withStatement(yieldHandling);
// LabelledStatement[?Yield, ?Return]
// This is really handled by TOK_NAME and TOK_YIELD cases above.
// ThrowStatement[?Yield]
case TOK_THROW:
return throwStatement(yieldHandling);
// TryStatement[?Yield, ?Return]
case TOK_TRY:
return tryStatement(yieldHandling);
// DebuggerStatement
case TOK_DEBUGGER:
return debuggerStatement();
// HoistableDeclaration[?Yield]
case TOK_FUNCTION:
return functionStmt(yieldHandling, NameRequired);
// ClassDeclaration[?Yield]
case TOK_CLASS:
if (!abortIfSyntaxParser())
return null();
return classDefinition(yieldHandling, ClassStatement, NameRequired);
// LexicalDeclaration[In, ?Yield]
case TOK_LET:
case TOK_CONST:
if (!abortIfSyntaxParser())
return null();
// [In] is the default behavior, because for-loops currently specially
// parse their heads to handle |in| in this situation.
return lexicalDeclaration(yieldHandling, /* isConst = */ tt == TOK_CONST);
// ImportDeclaration (only inside modules)
case TOK_IMPORT:
return importDeclaration();
// ExportDeclaration (only inside modules)
case TOK_EXPORT:
return exportDeclaration();
// Miscellaneous error cases arguably better caught here than elsewhere.
case TOK_CATCH:
report(ParseError, false, null(), JSMSG_CATCH_WITHOUT_TRY);
return null();
case TOK_FINALLY:
report(ParseError, false, null(), JSMSG_FINALLY_WITHOUT_TRY);
return null();
// NOTE: default case handled in the ExpressionStatement section.
}
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::expr(InHandling inHandling, YieldHandling yieldHandling,
TripledotHandling tripledotHandling, InvokedPrediction invoked)
{
Node pn = assignExpr(inHandling, yieldHandling, tripledotHandling, invoked);
if (!pn)
return null();
bool matched;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return null();
if (!matched)
return pn;
Node seq = handler.newCommaExpressionList(pn);
if (!seq)
return null();
while (true) {
if (handler.isUnparenthesizedYieldExpression(pn)) {
report(ParseError, false, pn, JSMSG_BAD_YIELD_SYNTAX);
return null();
}
pn = assignExpr(inHandling, yieldHandling, tripledotHandling);
if (!pn)
return null();
handler.addList(seq, pn);
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return null();
if (!matched)
break;
}
return seq;
}
static const JSOp ParseNodeKindToJSOp[] = {
JSOP_OR,
JSOP_AND,
JSOP_BITOR,
JSOP_BITXOR,
JSOP_BITAND,
JSOP_STRICTEQ,
JSOP_EQ,
JSOP_STRICTNE,
JSOP_NE,
JSOP_LT,
JSOP_LE,
JSOP_GT,
JSOP_GE,
JSOP_INSTANCEOF,
JSOP_IN,
JSOP_LSH,
JSOP_RSH,
JSOP_URSH,
JSOP_ADD,
JSOP_SUB,
JSOP_MUL,
JSOP_DIV,
JSOP_MOD,
JSOP_POW
};
static inline JSOp
BinaryOpParseNodeKindToJSOp(ParseNodeKind pnk)
{
MOZ_ASSERT(pnk >= PNK_BINOP_FIRST);
MOZ_ASSERT(pnk <= PNK_BINOP_LAST);
return ParseNodeKindToJSOp[pnk - PNK_BINOP_FIRST];
}
static ParseNodeKind
BinaryOpTokenKindToParseNodeKind(TokenKind tok)
{
MOZ_ASSERT(TokenKindIsBinaryOp(tok));
return ParseNodeKind(PNK_BINOP_FIRST + (tok - TOK_BINOP_FIRST));
}
static const int PrecedenceTable[] = {
1, /* PNK_OR */
2, /* PNK_AND */
3, /* PNK_BITOR */
4, /* PNK_BITXOR */
5, /* PNK_BITAND */
6, /* PNK_STRICTEQ */
6, /* PNK_EQ */
6, /* PNK_STRICTNE */
6, /* PNK_NE */
7, /* PNK_LT */
7, /* PNK_LE */
7, /* PNK_GT */
7, /* PNK_GE */
7, /* PNK_INSTANCEOF */
7, /* PNK_IN */
8, /* PNK_LSH */
8, /* PNK_RSH */
8, /* PNK_URSH */
9, /* PNK_ADD */
9, /* PNK_SUB */
10, /* PNK_STAR */
10, /* PNK_DIV */
10, /* PNK_MOD */
11 /* PNK_POW */
};
static const int PRECEDENCE_CLASSES = 11;
static int
Precedence(ParseNodeKind pnk) {
// Everything binds tighter than PNK_LIMIT, because we want to reduce all
// nodes to a single node when we reach a token that is not another binary
// operator.
if (pnk == PNK_LIMIT)
return 0;
MOZ_ASSERT(pnk >= PNK_BINOP_FIRST);
MOZ_ASSERT(pnk <= PNK_BINOP_LAST);
return PrecedenceTable[pnk - PNK_BINOP_FIRST];
}
template <typename ParseHandler>
MOZ_ALWAYS_INLINE typename ParseHandler::Node
Parser<ParseHandler>::orExpr1(InHandling inHandling, YieldHandling yieldHandling,
TripledotHandling tripledotHandling, InvokedPrediction invoked)
{
// Shift-reduce parser for the binary operator part of the JS expression
// syntax.
// Conceptually there's just one stack, a stack of pairs (lhs, op).
// It's implemented using two separate arrays, though.
Node nodeStack[PRECEDENCE_CLASSES];
ParseNodeKind kindStack[PRECEDENCE_CLASSES];
int depth = 0;
Node pn;
for (;;) {
pn = unaryExpr(yieldHandling, tripledotHandling, invoked);
if (!pn)
return pn;
// If a binary operator follows, consume it and compute the
// corresponding operator.
TokenKind tok;
if (!tokenStream.getToken(&tok))
return null();
ParseNodeKind pnk;
if (tok == TOK_IN ? inHandling == InAllowed : TokenKindIsBinaryOp(tok)) {
pnk = BinaryOpTokenKindToParseNodeKind(tok);
} else {
tok = TOK_EOF;
pnk = PNK_LIMIT;
}
// If pnk has precedence less than or equal to another operator on the
// stack, reduce. This combines nodes on the stack until we form the
// actual lhs of pnk.
//
// The >= in this condition works because it is appendOrCreateList's
// job to decide if the operator in question is left- or
// right-associative, and build the corresponding tree.
while (depth > 0 && Precedence(kindStack[depth - 1]) >= Precedence(pnk)) {
depth--;
ParseNodeKind combiningPnk = kindStack[depth];
JSOp combiningOp = BinaryOpParseNodeKindToJSOp(combiningPnk);
pn = handler.appendOrCreateList(combiningPnk, nodeStack[depth], pn, pc, combiningOp);
if (!pn)
return pn;
}
if (pnk == PNK_LIMIT)
break;
nodeStack[depth] = pn;
kindStack[depth] = pnk;
depth++;
MOZ_ASSERT(depth <= PRECEDENCE_CLASSES);
}
MOZ_ASSERT(depth == 0);
return pn;
}
template <typename ParseHandler>
MOZ_ALWAYS_INLINE typename ParseHandler::Node
Parser<ParseHandler>::condExpr1(InHandling inHandling, YieldHandling yieldHandling,
TripledotHandling tripledotHandling, InvokedPrediction invoked)
{
Node condition = orExpr1(inHandling, yieldHandling, tripledotHandling, invoked);
if (!condition || !tokenStream.isCurrentTokenType(TOK_HOOK))
return condition;
Node thenExpr = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
if (!thenExpr)
return null();
MUST_MATCH_TOKEN(TOK_COLON, JSMSG_COLON_IN_COND);
Node elseExpr = assignExpr(inHandling, yieldHandling, TripledotProhibited);
if (!elseExpr)
return null();
// Advance to the next token; the caller is responsible for interpreting it.
TokenKind ignored;
if (!tokenStream.getToken(&ignored))
return null();
return handler.newConditional(condition, thenExpr, elseExpr);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkAndMarkAsAssignmentLhs(Node target, AssignmentFlavor flavor)
{
MOZ_ASSERT(flavor != KeyedDestructuringAssignment,
"destructuring must use special checking/marking code, not "
"this method");
if (handler.isUnparenthesizedDestructuringPattern(target)) {
if (flavor == CompoundAssignment) {
report(ParseError, false, null(), JSMSG_BAD_DESTRUCT_ASS);
return false;
}
return checkDestructuringPattern(nullptr, target);
}
// All other permitted targets are simple.
if (!reportIfNotValidSimpleAssignmentTarget(target, flavor))
return false;
if (handler.isPropertyAccess(target))
return true;
if (handler.maybeNameAnyParentheses(target)) {
// The arguments/eval identifiers are simple in non-strict mode code,
// but warn to discourage use nonetheless.
if (!reportIfArgumentsEvalTarget(target))
return false;
handler.adjustGetToSet(target);
handler.markAsAssigned(target);
return true;
}
MOZ_ASSERT(handler.isFunctionCall(target));
return makeSetCall(target, JSMSG_BAD_LEFTSIDE_OF_ASS);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::assignExpr(InHandling inHandling, YieldHandling yieldHandling,
TripledotHandling tripledotHandling, InvokedPrediction invoked)
{
JS_CHECK_RECURSION(context, return null());
// It's very common at this point to have a "detectably simple" expression,
// i.e. a name/number/string token followed by one of the following tokens
// that obviously isn't part of an expression: , ; : ) ] }
//
// (In Parsemark this happens 81.4% of the time; in code with large
// numeric arrays, such as some Kraken benchmarks, it happens more often.)
//
// In such cases, we can avoid the full expression parsing route through
// assignExpr(), condExpr1(), orExpr1(), unaryExpr(), memberExpr(), and
// primaryExpr().
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
bool endsExpr;
if (tt == TOK_NAME) {
if (!tokenStream.nextTokenEndsExpr(&endsExpr))
return null();
if (endsExpr)
return identifierName(yieldHandling);
}
if (tt == TOK_NUMBER) {
if (!tokenStream.nextTokenEndsExpr(&endsExpr))
return null();
if (endsExpr)
return newNumber(tokenStream.currentToken());
}
if (tt == TOK_STRING) {
if (!tokenStream.nextTokenEndsExpr(&endsExpr))
return null();
if (endsExpr)
return stringLiteral();
}
if (tt == TOK_YIELD && yieldExpressionsSupported())
return yieldExpression(inHandling);
tokenStream.ungetToken();
// Save the tokenizer state in case we find an arrow function and have to
// rewind.
TokenStream::Position start(keepAtoms);
tokenStream.tell(&start);
Node lhs = condExpr1(inHandling, yieldHandling, tripledotHandling, invoked);
if (!lhs)
return null();
ParseNodeKind kind;
JSOp op;
switch (tokenStream.currentToken().type) {
case TOK_ASSIGN: kind = PNK_ASSIGN; op = JSOP_NOP; break;
case TOK_ADDASSIGN: kind = PNK_ADDASSIGN; op = JSOP_ADD; break;
case TOK_SUBASSIGN: kind = PNK_SUBASSIGN; op = JSOP_SUB; break;
case TOK_BITORASSIGN: kind = PNK_BITORASSIGN; op = JSOP_BITOR; break;
case TOK_BITXORASSIGN: kind = PNK_BITXORASSIGN; op = JSOP_BITXOR; break;
case TOK_BITANDASSIGN: kind = PNK_BITANDASSIGN; op = JSOP_BITAND; break;
case TOK_LSHASSIGN: kind = PNK_LSHASSIGN; op = JSOP_LSH; break;
case TOK_RSHASSIGN: kind = PNK_RSHASSIGN; op = JSOP_RSH; break;
case TOK_URSHASSIGN: kind = PNK_URSHASSIGN; op = JSOP_URSH; break;
case TOK_MULASSIGN: kind = PNK_MULASSIGN; op = JSOP_MUL; break;
case TOK_DIVASSIGN: kind = PNK_DIVASSIGN; op = JSOP_DIV; break;
case TOK_MODASSIGN: kind = PNK_MODASSIGN; op = JSOP_MOD; break;
case TOK_POWASSIGN: kind = PNK_POWASSIGN; op = JSOP_POW; break;
case TOK_ARROW: {
// A line terminator between ArrowParameters and the => should trigger a SyntaxError.
tokenStream.ungetToken();
TokenKind next = TOK_EOF;
if (!tokenStream.peekTokenSameLine(&next) || next != TOK_ARROW) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"expression", TokenKindToDesc(TOK_ARROW));
return null();
}
tokenStream.consumeKnownToken(TOK_ARROW);
bool isBlock = false;
if (!tokenStream.peekToken(&next, TokenStream::Operand))
return null();
if (next == TOK_LC)
isBlock = true;
tokenStream.seek(start);
if (!abortIfSyntaxParser())
return null();
TokenKind ignored;
if (!tokenStream.peekToken(&ignored, TokenStream::Operand))
return null();
Node arrowFunc = functionDef(inHandling, yieldHandling, nullptr, Arrow, NotGenerator);
if (!arrowFunc)
return null();
if (isBlock) {
// This arrow function could be a non-trailing member of a comma
// expression or a semicolon terminating a full expression. If so,
// the next token is that comma/semicolon, gotten with None:
//
// a => {}, b; // as if (a => {}), b;
// a => {};
//
// But if this arrow function ends a statement, ASI permits the
// next token to start an expression statement. In that case the
// next token must be gotten as Operand:
//
// a => {} // complete expression statement
// /x/g; // regular expression as a statement, *not* division
//
// Getting the second case right requires the first token-peek
// after the arrow function use Operand, and that peek must occur
// before Parser::expr() looks for a comma. Do so here, then
// immediately add the modifier exception needed for the first
// case.
//
// Note that the second case occurs *only* if the arrow function
// has block body. An arrow function not ending in such, ends in
// another AssignmentExpression that we can inductively assume was
// peeked consistently.
if (!tokenStream.peekToken(&ignored, TokenStream::Operand))
return null();
tokenStream.addModifierException(TokenStream::NoneIsOperand);
}
return arrowFunc;
}
default:
MOZ_ASSERT(!tokenStream.isCurrentTokenAssignment());
tokenStream.ungetToken();
return lhs;
}
AssignmentFlavor flavor = kind == PNK_ASSIGN ? PlainAssignment : CompoundAssignment;
if (!checkAndMarkAsAssignmentLhs(lhs, flavor))
return null();
bool saved = pc->inDeclDestructuring;
pc->inDeclDestructuring = false;
Node rhs = assignExpr(inHandling, yieldHandling, TripledotProhibited);
pc->inDeclDestructuring = saved;
if (!rhs)
return null();
return handler.newAssignment(kind, lhs, rhs, pc, op);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::isValidSimpleAssignmentTarget(Node node,
FunctionCallBehavior behavior /* = ForbidAssignmentToFunctionCalls */)
{
// Note that this method implements *only* a boolean test. Reporting an
// error for the various syntaxes that fail this, and warning for the
// various syntaxes that "pass" this but should not, occurs elsewhere.
if (PropertyName* name = handler.maybeNameAnyParentheses(node)) {
if (!pc->sc->strict())
return true;
return name != context->names().arguments && name != context->names().eval;
}
if (handler.isPropertyAccess(node))
return true;
if (behavior == PermitAssignmentToFunctionCalls) {
if (handler.isFunctionCall(node))
return true;
}
return false;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportIfArgumentsEvalTarget(Node nameNode)
{
PropertyName* name = handler.maybeNameAnyParentheses(nameNode);
MOZ_ASSERT(name, "must only call this function on known names");
const char* chars = (name == context->names().arguments)
? js_arguments_str
: (name == context->names().eval)
? js_eval_str
: nullptr;
if (!chars)
return true;
if (!report(ParseStrictError, pc->sc->strict(), nameNode, JSMSG_BAD_STRICT_ASSIGN, chars))
return false;
MOZ_ASSERT(!pc->sc->strict(), "in strict mode an error should have been reported");
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportIfNotValidSimpleAssignmentTarget(Node target, AssignmentFlavor flavor)
{
FunctionCallBehavior behavior = flavor == KeyedDestructuringAssignment
? ForbidAssignmentToFunctionCalls
: PermitAssignmentToFunctionCalls;
if (isValidSimpleAssignmentTarget(target, behavior))
return true;
if (handler.maybeNameAnyParentheses(target)) {
// Use a special error if the target is arguments/eval. This ensures
// targeting these names is consistently a SyntaxError (which error numbers
// below don't guarantee) while giving us a nicer error message.
if (!reportIfArgumentsEvalTarget(target))
return false;
}
unsigned errnum = 0;
const char* extra = nullptr;
switch (flavor) {
case IncrementAssignment:
errnum = JSMSG_BAD_OPERAND;
extra = "increment";
break;
case DecrementAssignment:
errnum = JSMSG_BAD_OPERAND;
extra = "decrement";
break;
case KeyedDestructuringAssignment:
errnum = JSMSG_BAD_DESTRUCT_TARGET;
break;
case PlainAssignment:
case CompoundAssignment:
errnum = JSMSG_BAD_LEFTSIDE_OF_ASS;
break;
}
report(ParseError, pc->sc->strict(), target, errnum, extra);
return false;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkAndMarkAsIncOperand(Node target, AssignmentFlavor flavor)
{
MOZ_ASSERT(flavor == IncrementAssignment || flavor == DecrementAssignment);
// Check.
if (!reportIfNotValidSimpleAssignmentTarget(target, flavor))
return false;
// Mark.
if (handler.maybeNameAnyParentheses(target)) {
// Assignment to arguments/eval is allowed outside strict mode code,
// but it's dodgy. Report a strict warning (error, if werror was set).
if (!reportIfArgumentsEvalTarget(target))
return false;
handler.markAsAssigned(target);
} else if (handler.isFunctionCall(target)) {
if (!makeSetCall(target, JSMSG_BAD_INCOP_OPERAND))
return false;
}
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::unaryOpExpr(YieldHandling yieldHandling, ParseNodeKind kind, JSOp op,
uint32_t begin)
{
Node kid = unaryExpr(yieldHandling, TripledotProhibited);
if (!kid)
return null();
return handler.newUnary(kind, op, begin, kid);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::unaryExpr(YieldHandling yieldHandling, TripledotHandling tripledotHandling,
InvokedPrediction invoked)
{
JS_CHECK_RECURSION(context, return null());
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
uint32_t begin = pos().begin;
switch (tt) {
case TOK_VOID:
return unaryOpExpr(yieldHandling, PNK_VOID, JSOP_VOID, begin);
case TOK_NOT:
return unaryOpExpr(yieldHandling, PNK_NOT, JSOP_NOT, begin);
case TOK_BITNOT:
return unaryOpExpr(yieldHandling, PNK_BITNOT, JSOP_BITNOT, begin);
case TOK_ADD:
return unaryOpExpr(yieldHandling, PNK_POS, JSOP_POS, begin);
case TOK_SUB:
return unaryOpExpr(yieldHandling, PNK_NEG, JSOP_NEG, begin);
case TOK_TYPEOF: {
// The |typeof| operator is specially parsed to distinguish its
// application to a name, from its application to a non-name
// expression:
//
// // Looks up the name, doesn't find it and so evaluates to
// // "undefined".
// assertEq(typeof nonExistentName, "undefined");
//
// // Evaluates expression, triggering a runtime ReferenceError for
// // the undefined name.
// typeof (1, nonExistentName);
Node kid = unaryExpr(yieldHandling, TripledotProhibited);
if (!kid)
return null();
return handler.newTypeof(begin, kid);
}
case TOK_INC:
case TOK_DEC:
{
TokenKind tt2;
if (!tokenStream.getToken(&tt2, TokenStream::Operand))
return null();
Node pn2 = memberExpr(yieldHandling, TripledotProhibited, tt2, true);
if (!pn2)
return null();
AssignmentFlavor flavor = (tt == TOK_INC) ? IncrementAssignment : DecrementAssignment;
if (!checkAndMarkAsIncOperand(pn2, flavor))
return null();
return handler.newUnary((tt == TOK_INC) ? PNK_PREINCREMENT : PNK_PREDECREMENT,
JSOP_NOP,
begin,
pn2);
}
case TOK_DELETE: {
Node expr = unaryExpr(yieldHandling, TripledotProhibited);
if (!expr)
return null();
// Per spec, deleting any unary expression is valid -- it simply
// returns true -- except for one case that is illegal in strict mode.
if (handler.maybeNameAnyParentheses(expr)) {
if (!report(ParseStrictError, pc->sc->strict(), expr, JSMSG_DEPRECATED_DELETE_OPERAND))
return null();
pc->sc->setBindingsAccessedDynamically();
}
return handler.newDelete(begin, expr);
}
default: {
Node pn = memberExpr(yieldHandling, tripledotHandling, tt, /* allowCallSyntax = */ true,
invoked);
if (!pn)
return null();
/* Don't look across a newline boundary for a postfix incop. */
if (!tokenStream.peekTokenSameLine(&tt))
return null();
if (tt == TOK_INC || tt == TOK_DEC) {
tokenStream.consumeKnownToken(tt);
AssignmentFlavor flavor = (tt == TOK_INC) ? IncrementAssignment : DecrementAssignment;
if (!checkAndMarkAsIncOperand(pn, flavor))
return null();
return handler.newUnary((tt == TOK_INC) ? PNK_POSTINCREMENT : PNK_POSTDECREMENT,
JSOP_NOP,
begin,
pn);
}
return pn;
}
}
}
/*** Comprehensions *******************************************************************************
*
* We currently support four flavors of comprehensions, all deprecated:
*
* [EXPR for (V in OBJ) if (COND)] // legacy array comprehension
* (EXPR for (V in OBJ) if (COND)) // legacy generator expression
* [for (V of OBJ) if (COND) EXPR] // ES6-era array comprehension
* (for (V of OBJ) if (COND) EXPR) // ES6-era generator expression
*
* (The last two flavors are called "ES6-era" because they were in ES6 draft
* specifications for a while. Shortly after this syntax was implemented in SM,
* TC39 decided to drop it.)
*
* Legacy generator expressions evaluate to legacy generators (using the
* StopIteration protocol); ES6-era generator expressions evaluate to ES6
* generators (using the `{done:, value:}` protocol).
*/
/*
* A dedicated helper for transplanting the legacy comprehension expression E in
*
* [E for (V in I)] // legacy array comprehension
* (E for (V in I)) // legacy generator expression
*
* from its initial location in the AST, on the left of the 'for', to its final
* position on the right. To avoid a separate pass we do this by adjusting the
* blockids and name binding links that were established when E was parsed.
*
* A legacy generator expression desugars like so:
*
* (E for (V in I)) => (function () { for (var V in I) yield E; })()
*
* The transplanter transplants all name ParseNodes inside E with the original
* blockid to the block scope of the new function. E's source coordinates in
* root->pn_pos are critical to deciding which binding links to preserve and
* which to cut.
*
* NB: This is not a general tree transplanter -- it knows in particular that
* the one or more bindings induced by V have not yet been created.
*/
class LegacyCompExprTransplanter
{
ParseNode* root;
Parser<FullParseHandler>* parser;
ParseContext<FullParseHandler>* outerpc;
GeneratorKind comprehensionKind;
uint32_t fromBlockId;
uint32_t toBlockId;
HashSet<Definition*> visitedImplicitArguments;
public:
LegacyCompExprTransplanter(ParseNode* pn, Parser<FullParseHandler>* parser,
ParseContext<FullParseHandler>* outerpc,
GeneratorKind kind, uint32_t fromBlockId,
uint32_t toBlockId)
: root(pn),
parser(parser),
outerpc(outerpc),
comprehensionKind(kind),
fromBlockId(fromBlockId),
toBlockId(toBlockId),
visitedImplicitArguments(parser->context)
{}
bool init() {
return visitedImplicitArguments.init();
}
bool transplant(ParseNode* pn);
void adjustBlockId(ParseNode* pn);
};
void
LegacyCompExprTransplanter::adjustBlockId(ParseNode* pn)
{
MOZ_ASSERT(pn->isArity(PN_LIST) || pn->isArity(PN_CODE) || pn->isArity(PN_NAME));
if (pn->pn_blockid == fromBlockId)
pn->pn_blockid = toBlockId;
}
bool
LegacyCompExprTransplanter::transplant(ParseNode* pn)
{
ParseContext<FullParseHandler>* pc = parser->pc;
bool isGenexp = comprehensionKind != NotGenerator;
if (!pn)
return true;
switch (pn->getArity()) {
case PN_LIST:
for (ParseNode* pn2 = pn->pn_head; pn2; pn2 = pn2->pn_next) {
if (!transplant(pn2))
return false;
}
if (pn->pn_pos >= root->pn_pos)
adjustBlockId(pn);
break;
case PN_TERNARY:
if (!transplant(pn->pn_kid1) ||
!transplant(pn->pn_kid2) ||
!transplant(pn->pn_kid3))
return false;
break;
case PN_BINARY:
case PN_BINARY_OBJ:
if (!transplant(pn->pn_left))
return false;
/* Binary TOK_COLON nodes can have left == right. See bug 492714. */
if (pn->pn_right != pn->pn_left) {
if (!transplant(pn->pn_right))
return false;
}
break;
case PN_UNARY:
if (!transplant(pn->pn_kid))
return false;
break;
case PN_CODE:
case PN_NAME:
if (!transplant(pn->maybeExpr()))
return false;
if (pn->isUsed()) {
MOZ_ASSERT(pn->pn_scopecoord.isFree());
Definition* dn = pn->pn_lexdef;
MOZ_ASSERT(dn->isDefn());
/*
* Adjust the definition's block id only if it is a placeholder not
* to the left of the root node, and if pn is the last use visited
* in the legacy comprehension expression (to avoid adjusting the
* blockid multiple times).
*
* Non-placeholder definitions within the legacy comprehension
* expression will be visited further below.
*/
if (dn->isPlaceholder() && dn->pn_pos >= root->pn_pos && dn->dn_uses == pn)
adjustBlockId(dn);
RootedAtom atom(parser->context, pn->pn_atom);
#ifdef DEBUG
StmtInfoPC* stmt = LexicalLookup(pc, atom);
MOZ_ASSERT(!stmt || stmt != pc->innermostStmt());
#endif
if (isGenexp && !dn->isOp(JSOP_CALLEE)) {
MOZ_ASSERT_IF(!pc->sc->isDotVariable(atom), !pc->decls().lookupFirst(atom));
if (pc->sc->isDotVariable(atom)) {
if (dn->dn_uses == pn)
adjustBlockId(dn);
dn->pn_dflags |= PND_CLOSED;
} else if (dn->pn_pos < root->pn_pos) {
/*
* The variable originally appeared to be a use of a
* definition or placeholder outside the generator, but now
* we know it is scoped within the legacy comprehension
* tail's clauses. Make it (along with any other uses within
* the generator) a use of a new placeholder in the
* generator's lexdeps.
*/
Definition* dn2 = parser->handler.newPlaceholder(atom, parser->pc->blockid(),
parser->pos());
if (!dn2)
return false;
dn2->pn_pos = root->pn_pos;
/*
* Change all uses of |dn| that lie within the generator's
* |yield| expression into uses of dn2.
*/
ParseNode** pnup = &dn->dn_uses;
ParseNode* pnu;
while ((pnu = *pnup) != nullptr && pnu->pn_pos >= root->pn_pos) {
pnu->pn_lexdef = dn2;
dn2->pn_dflags |= pnu->pn_dflags & PND_USE2DEF_FLAGS;
pnup = &pnu->pn_link;
}
dn2->dn_uses = dn->dn_uses;
dn->dn_uses = *pnup;
*pnup = nullptr;
DefinitionSingle def = DefinitionSingle::new_<FullParseHandler>(dn2);
if (!pc->lexdeps->put(atom, def))
return false;
if (dn->isClosed())
dn2->pn_dflags |= PND_CLOSED;
} else if (dn->isPlaceholder()) {
/*
* The variable first occurs free in the 'yield' expression;
* move the existing placeholder node (and all its uses)
* from the parent's lexdeps into the generator's lexdeps.
*/
outerpc->lexdeps->remove(atom);
DefinitionSingle def = DefinitionSingle::new_<FullParseHandler>(dn);
if (!pc->lexdeps->put(atom, def))
return false;
} else if (dn->isImplicitArguments()) {
/*
* Implicit 'arguments' Definition nodes (see
* PND_IMPLICITARGUMENTS in Parser::functionBody) are only
* reachable via the lexdefs of their uses. Unfortunately,
* there may be multiple uses, so we need to maintain a set
* to only bump the definition once.
*/
if (isGenexp && !visitedImplicitArguments.has(dn)) {
adjustBlockId(dn);
if (!visitedImplicitArguments.put(dn))
return false;
}
}
}
}
if (pn->pn_pos >= root->pn_pos)
adjustBlockId(pn);
break;
case PN_NULLARY:
/* Nothing. */
break;
}
return true;
}
// Parsing legacy (JS1.7-style) comprehensions is terrible: we parse the head
// expression as if it's part of a comma expression, then when we see the "for"
// we transplant the parsed expression into the inside of a constructed
// for-of/for-in/for-each tail. Transplanting an already-parsed expression is
// tricky, but the LegacyCompExprTransplanter handles most of that.
//
// The one remaining thing to patch up is the block scope depth. We need to
// compute the maximum block scope depth of a function, so we know how much
// space to reserve in the fixed part of a stack frame. Normally this is done
// whenever we leave a statement, via AccumulateBlockScopeDepth.
//
// Thing is, we don't actually know what that depth is, because the only
// information we keep is the maximum nested depth within a statement, so we
// just conservatively propagate the maximum nested depth from the top statement
// to the comprehension tail.
//
template <typename ParseHandler>
static unsigned
LegacyComprehensionHeadBlockScopeDepth(ParseContext<ParseHandler>* pc)
{
return pc->innermostStmt() ? pc->innermostStmt()->innerBlockScopeDepth : pc->blockScopeDepth;
}
/*
* Starting from a |for| keyword after the first array initialiser element or
* an expression in an open parenthesis, parse the tail of the comprehension
* or generator expression signified by this |for| keyword in context.
*
* Return null on failure, else return the top-most parse node for the array
* comprehension or generator expression, with a unary node as the body of the
* (possibly nested) for-loop, initialized by |kind, op, kid|.
*/
template <>
ParseNode*
Parser<FullParseHandler>::legacyComprehensionTail(ParseNode* bodyExpr, unsigned blockid,
GeneratorKind comprehensionKind,
ParseContext<FullParseHandler>* outerpc,
unsigned innerBlockScopeDepth)
{
/*
* If we saw any inner functions while processing the generator expression
* then they may have upvars referring to the let vars in this generator
* which were not correctly processed. Bail out and start over without
* allowing lazy parsing.
*/
if (handler.syntaxParser) {
handler.disableSyntaxParser();
abortedSyntaxParse = true;
return nullptr;
}
unsigned targetBlockId;
ParseNode* pn;
ParseNode* pn3;
ParseNode** pnp;
BindData<FullParseHandler> data(context);
TokenKind tt;
AutoPushStmtInfoPC stmtInfo(*this, StmtType::BLOCK);
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
bool isGenexp = comprehensionKind != NotGenerator;
MOZ_ASSERT_IF(isGenexp, comprehensionKind == LegacyGenerator);
// Transplant bodyExpr into a new block scope we push.
pn = pushLexicalScope(stmtInfo);
if (!pn)
return null();
targetBlockId = pn->pn_blockid;
handler.setBeginPosition(pn, bodyExpr);
pnp = &pn->pn_expr;
LegacyCompExprTransplanter transplanter(bodyExpr, this, outerpc, comprehensionKind,
blockid, targetBlockId);
if (!transplanter.init())
return null();
if (!transplanter.transplant(bodyExpr))
return null();
MOZ_ASSERT(pc->innermostScopeStmt() &&
pc->innermostScopeStmt()->staticScope == pn->pn_objbox->object);
data.initLexical(HoistVars, JSOP_DEFLET,
&pc->innermostScopeStmt()->staticScope->as<StaticBlockObject>(),
JSMSG_ARRAY_INIT_TOO_BIG);
while (true) {
// PNK_COMPREHENSIONFOR is binary: left is loop control, right is body.
// Use index to count each block-local let-variable on the left-hand
// side of the in/of.
ParseNode* pn2 = handler.new_<BinaryNode>(PNK_COMPREHENSIONFOR, JSOP_ITER, pos(),
nullptr, nullptr);
if (!pn2)
return null();
pn2->pn_iflags = JSITER_ENUMERATE;
if (allowsForEachIn()) {
bool matched;
if (!tokenStream.matchContextualKeyword(&matched, context->names().each))
return null();
if (matched) {
pn2->pn_iflags |= JSITER_FOREACH;
addTelemetry(JSCompartment::DeprecatedForEach);
if (versionNumber() < JSVERSION_LATEST) {
if (!report(ParseWarning, pc->sc->strict(), pn2, JSMSG_DEPRECATED_FOR_EACH))
return null();
}
}
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
uint32_t startYieldOffset = pc->lastYieldOffset;
RootedPropertyName name(context);
if (!tokenStream.getToken(&tt))
return null();
switch (tt) {
case TOK_LB:
case TOK_LC:
pc->inDeclDestructuring = true;
pn3 = primaryExpr(YieldIsKeyword, TripledotProhibited, tt);
pc->inDeclDestructuring = false;
if (!pn3)
return null();
break;
case TOK_NAME:
name = tokenStream.currentName();
/*
* Create a name node with pn_op JSOP_GETNAME. We can't set pn_op to
* JSOP_GETLOCAL here, because we don't yet know the block's depth
* in the operand stack frame. The code generator computes that,
* and it tries to bind all names to slots, so we must let it do
* the deed.
*/
pn3 = newBindingNode(name, false);
if (!pn3)
return null();
break;
default:
report(ParseError, false, null(), JSMSG_NO_VARIABLE_NAME);
return null();
}
bool isForIn, isForOf;
if (!matchInOrOf(&isForIn, &isForOf))
return null();
if (!isForIn && !isForOf) {
report(ParseError, false, null(), JSMSG_IN_AFTER_FOR_NAME);
return null();
}
ParseNodeKind headKind = PNK_FORIN;
if (isForOf) {
if (pn2->pn_iflags != JSITER_ENUMERATE) {
MOZ_ASSERT(pn2->pn_iflags == (JSITER_FOREACH | JSITER_ENUMERATE));
report(ParseError, false, null(), JSMSG_BAD_FOR_EACH_LOOP);
return null();
}
pn2->pn_iflags = 0;
headKind = PNK_FOROF;
}
ParseNode* pn4 = expr(InAllowed, YieldIsKeyword, TripledotProhibited);
if (!pn4)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_FOR_CTRL);
if (isGenexp && pc->lastYieldOffset != startYieldOffset) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
JSMSG_BAD_GENEXP_BODY, js_yield_str);
return null();
}
switch (tt) {
case TOK_LB:
case TOK_LC:
if (!checkDestructuringPattern(&data, pn3))
return null();
break;
case TOK_NAME:
data.setNameNode(pn3);
if (!data.bind(name, this))
return null();
break;
default:;
}
/*
* Synthesize a declaration. Every definition must appear in the parse
* tree in order for ComprehensionTranslator to work.
*
* These are lets to tell the bytecode emitter to emit initialization
* code for the temporal dead zone.
*/
ParseNode* lets = handler.newDeclarationList(PNK_LET, pn3, JSOP_DEFLET);
if (!lets)
return null();
/* Definitions can't be passed directly to EmitAssignment as lhs. */
pn3 = cloneLeftHandSide(pn3);
if (!pn3)
return null();
pn2->pn_left = handler.newTernary(headKind, lets, pn3, pn4);
if (!pn2->pn_left)
return null();
*pnp = pn2;
pnp = &pn2->pn_right;
bool matched;
if (!tokenStream.matchToken(&matched, TOK_FOR))
return null();
if (!matched)
break;
}
bool matched;
if (!tokenStream.matchToken(&matched, TOK_IF))
return null();
if (matched) {
ParseNode* cond = condition(InAllowed, YieldIsKeyword);
if (!cond)
return null();
ParseNode* ifNode = handler.new_<TernaryNode>(PNK_IF, JSOP_NOP, cond, nullptr, nullptr,
cond->pn_pos);
if (!ifNode)
return null();
*pnp = ifNode;
pnp = &ifNode->pn_kid2;
}
ParseNode* bodyStmt;
if (isGenexp) {
ParseNode* yieldExpr = newYieldExpression(bodyExpr->pn_pos.begin, bodyExpr);
if (!yieldExpr)
return null();
yieldExpr->setInParens(true);
bodyStmt = handler.newExprStatement(yieldExpr, bodyExpr->pn_pos.end);
if (!bodyStmt)
return null();
} else {
bodyStmt = handler.newUnary(PNK_ARRAYPUSH, JSOP_ARRAYPUSH,
bodyExpr->pn_pos.begin, bodyExpr);
if (!bodyStmt)
return null();
}
*pnp = bodyStmt;
pc->innermostStmt()->innerBlockScopeDepth += innerBlockScopeDepth;
handler.setEndPosition(pn, pos().end);
return pn;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::legacyComprehensionTail(SyntaxParseHandler::Node bodyStmt,
unsigned blockid,
GeneratorKind comprehensionKind,
ParseContext<SyntaxParseHandler>* outerpc,
unsigned innerBlockScopeDepth)
{
abortIfSyntaxParser();
return null();
}
template <>
ParseNode*
Parser<FullParseHandler>::legacyArrayComprehension(ParseNode* array)
{
// Discard our presumed array literal containing only a single element, and
// instead return an array comprehension node. Extract the few bits of
// information needed from the array literal, then free it.
MOZ_ASSERT(array->isKind(PNK_ARRAY));
MOZ_ASSERT(array->pn_count == 1);
uint32_t arrayBegin = handler.getPosition(array).begin;
ParseNode* bodyExpr = array->pn_head;
array->pn_count = 0;
array->pn_tail = &array->pn_head;
*array->pn_tail = nullptr;
handler.freeTree(array);
ParseNode* comp = legacyComprehensionTail(bodyExpr, pc->blockid(), NotGenerator, nullptr,
LegacyComprehensionHeadBlockScopeDepth(pc));
if (!comp)
return null();
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_AFTER_ARRAY_COMPREHENSION);
return handler.newArrayComprehension(comp, TokenPos(arrayBegin, pos().end));
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::legacyArrayComprehension(Node array)
{
abortIfSyntaxParser();
return null();
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::generatorComprehensionLambda(GeneratorKind comprehensionKind,
unsigned begin, Node innerExpr)
{
MOZ_ASSERT(comprehensionKind == LegacyGenerator || comprehensionKind == StarGenerator);
MOZ_ASSERT(!!innerExpr == (comprehensionKind == LegacyGenerator));
Node genfn = handler.newFunctionDefinition();
if (!genfn)
return null();
handler.setOp(genfn, JSOP_LAMBDA);
ParseContext<ParseHandler>* outerpc = pc;
// If we are off the main thread, the generator meta-objects have
// already been created by js::StartOffThreadParseScript, so cx will not
// be necessary.
RootedObject proto(context);
if (comprehensionKind == StarGenerator) {
JSContext* cx = context->maybeJSContext();
proto = GlobalObject::getOrCreateStarGeneratorFunctionPrototype(cx, context->global());
if (!proto)
return null();
}
RootedFunction fun(context, newFunction(/* atom = */ nullptr, Expression,
comprehensionKind, proto));
if (!fun)
return null();
// Create box for fun->object early to root it.
Directives directives(/* strict = */ outerpc->sc->strict());
FunctionBox* genFunbox = newFunctionBox(genfn, fun, outerpc, directives, comprehensionKind);
if (!genFunbox)
return null();
genFunbox->inGenexpLambda = true;
ParseContext<ParseHandler> genpc(this, outerpc, genfn, genFunbox,
/* newDirectives = */ nullptr);
if (!genpc.init(*this))
return null();
/*
* We assume conservatively that any deoptimization flags in pc->sc
* come from the kid. So we propagate these flags into genfn. For code
* simplicity we also do not detect if the flags were only set in the
* kid and could be removed from pc->sc.
*/
genFunbox->anyCxFlags = outerpc->sc->anyCxFlags;
if (outerpc->sc->isFunctionBox())
genFunbox->funCxFlags = outerpc->sc->asFunctionBox()->funCxFlags;
MOZ_ASSERT(genFunbox->generatorKind() == comprehensionKind);
handler.setBlockId(genfn, genpc.bodyid);
Node generator = newName(context->names().dotGenerator);
if (!generator)
return null();
if (!pc->define(tokenStream, context->names().dotGenerator, generator, Definition::VAR))
return null();
Node body = handler.newStatementList(pc->blockid(), TokenPos(begin, pos().end));
if (!body)
return null();
Node comp;
if (comprehensionKind == StarGenerator) {
comp = comprehension(StarGenerator);
if (!comp)
return null();
} else {
MOZ_ASSERT(comprehensionKind == LegacyGenerator);
comp = legacyComprehensionTail(innerExpr, outerpc->blockid(), LegacyGenerator,
outerpc, LegacyComprehensionHeadBlockScopeDepth(outerpc));
if (!comp)
return null();
}
if (comprehensionKind == StarGenerator)
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_IN_PAREN);
handler.setBeginPosition(comp, begin);
handler.setEndPosition(comp, pos().end);
handler.addStatementToList(body, comp, pc);
handler.setEndPosition(body, pos().end);
handler.setBeginPosition(genfn, begin);
handler.setEndPosition(genfn, pos().end);
generator = newName(context->names().dotGenerator);
if (!generator)
return null();
if (!noteNameUse(context->names().dotGenerator, generator))
return null();
if (!handler.prependInitialYield(body, generator))
return null();
// Note that if we ever start syntax-parsing generators, we will also
// need to propagate the closed-over variable set to the inner
// lazyscript, as in finishFunctionDefinition.
handler.setFunctionBody(genfn, body);
PropagateTransitiveParseFlags(genFunbox, outerpc->sc);
if (!leaveFunction(genfn, outerpc))
return null();
return genfn;
}
#if JS_HAS_GENERATOR_EXPRS
/*
* Starting from a |for| keyword after an expression, parse the comprehension
* tail completing this generator expression. Wrap the expression |expr| in a
* generator function that is immediately called to evaluate to the generator
* iterator that is the value of this legacy generator expression.
*
* |expr| must be the expression before the |for| keyword; we return an
* application of a generator function that includes the |for| loops and
* |if| guards, with |expr| as the operand of a |yield| expression as the
* innermost loop body.
*
* Unlike Python, we do not evaluate the expression to the right of the first
* |in| in the chain of |for| heads. Instead, a generator expression is merely
* sugar for a generator function expression and its application.
*/
template <>
ParseNode*
Parser<FullParseHandler>::legacyGeneratorExpr(ParseNode* expr)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
// Make a new node for the desugared generator function.
ParseNode* genfn = generatorComprehensionLambda(LegacyGenerator, expr->pn_pos.begin, expr);
if (!genfn)
return null();
// Our result is a call expression that invokes the anonymous generator
// function object.
return handler.newList(PNK_GENEXP, genfn, JSOP_CALL);
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::legacyGeneratorExpr(Node kid)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
#endif /* JS_HAS_GENERATOR_EXPRS */
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::comprehensionFor(GeneratorKind comprehensionKind)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
uint32_t begin = pos().begin;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
// FIXME: Destructuring binding (bug 980828).
MUST_MATCH_TOKEN(TOK_NAME, JSMSG_NO_VARIABLE_NAME);
RootedPropertyName name(context, tokenStream.currentName());
if (name == context->names().let) {
report(ParseError, false, null(), JSMSG_LET_COMP_BINDING);
return null();
}
Node assignLhs = newName(name);
if (!assignLhs)
return null();
Node lhs = newName(name);
if (!lhs)
return null();
bool matched;
if (!tokenStream.matchContextualKeyword(&matched, context->names().of))
return null();
if (!matched) {
report(ParseError, false, null(), JSMSG_OF_AFTER_FOR_NAME);
return null();
}
Node rhs = assignExpr(InAllowed, YieldIsKeyword, TripledotProhibited);
if (!rhs)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_FOR_OF_ITERABLE);
TokenPos headPos(begin, pos().end);
AutoPushStmtInfoPC stmtInfo(*this, StmtType::BLOCK);
BindData<ParseHandler> data(context);
RootedStaticBlockObject blockObj(context, StaticBlockObject::create(context));
if (!blockObj)
return null();
// Initialize the enclosing scope manually for the call to |bind|
// below, which is before the call to |pushLetScope|.
blockObj->initEnclosingScopeFromParser(pc->innermostStaticScope());
data.initLexical(DontHoistVars, JSOP_DEFLET, blockObj, JSMSG_TOO_MANY_LOCALS);
Node decls = handler.newList(PNK_LET, lhs);
if (!decls)
return null();
data.setNameNode(lhs);
if (!data.bind(name, this))
return null();
Node letScope = pushLetScope(blockObj, stmtInfo);
if (!letScope)
return null();
handler.setLexicalScopeBody(letScope, decls);
if (!noteNameUse(name, assignLhs))
return null();
handler.setOp(assignLhs, JSOP_SETNAME);
Node head = handler.newForHead(PNK_FOROF, letScope, assignLhs, rhs, headPos);
if (!head)
return null();
Node tail = comprehensionTail(comprehensionKind);
if (!tail)
return null();
return handler.newComprehensionFor(begin, head, tail);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::comprehensionIf(GeneratorKind comprehensionKind)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_IF));
uint32_t begin = pos().begin;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_COND);
Node cond = assignExpr(InAllowed, YieldIsKeyword, TripledotProhibited);
if (!cond)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_COND);
/* Check for (a = b) and warn about possible (a == b) mistype. */
if (handler.isUnparenthesizedAssignment(cond)) {
if (!report(ParseExtraWarning, false, null(), JSMSG_EQUAL_AS_ASSIGN))
return null();
}
Node then = comprehensionTail(comprehensionKind);
if (!then)
return null();
return handler.newIfStatement(begin, cond, then, null());
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::comprehensionTail(GeneratorKind comprehensionKind)
{
JS_CHECK_RECURSION(context, return null());
bool matched;
if (!tokenStream.matchToken(&matched, TOK_FOR, TokenStream::Operand))
return null();
if (matched)
return comprehensionFor(comprehensionKind);
if (!tokenStream.matchToken(&matched, TOK_IF, TokenStream::Operand))
return null();
if (matched)
return comprehensionIf(comprehensionKind);
uint32_t begin = pos().begin;
Node bodyExpr = assignExpr(InAllowed, YieldIsKeyword, TripledotProhibited);
if (!bodyExpr)
return null();
if (comprehensionKind == NotGenerator)
return handler.newUnary(PNK_ARRAYPUSH, JSOP_ARRAYPUSH, begin, bodyExpr);
MOZ_ASSERT(comprehensionKind == StarGenerator);
Node yieldExpr = newYieldExpression(begin, bodyExpr);
if (!yieldExpr)
return null();
yieldExpr = handler.parenthesize(yieldExpr);
return handler.newExprStatement(yieldExpr, pos().end);
}
// Parse an ES6-era generator or array comprehension, starting at the first
// `for`. The caller is responsible for matching the ending TOK_RP or TOK_RB.
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::comprehension(GeneratorKind comprehensionKind)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
uint32_t startYieldOffset = pc->lastYieldOffset;
Node body = comprehensionFor(comprehensionKind);
if (!body)
return null();
if (comprehensionKind != NotGenerator && pc->lastYieldOffset != startYieldOffset) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
JSMSG_BAD_GENEXP_BODY, js_yield_str);
return null();
}
return body;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::arrayComprehension(uint32_t begin)
{
Node inner = comprehension(NotGenerator);
if (!inner)
return null();
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_AFTER_ARRAY_COMPREHENSION);
Node comp = handler.newList(PNK_ARRAYCOMP, inner);
if (!comp)
return null();
handler.setBeginPosition(comp, begin);
handler.setEndPosition(comp, pos().end);
return comp;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::generatorComprehension(uint32_t begin)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
// We have no problem parsing generator comprehensions inside lazy
// functions, but the bytecode emitter currently can't handle them that way,
// because when it goes to emit the code for the inner generator function,
// it expects outer functions to have non-lazy scripts.
if (!abortIfSyntaxParser())
return null();
Node genfn = generatorComprehensionLambda(StarGenerator, begin, null());
if (!genfn)
return null();
Node result = handler.newList(PNK_GENEXP, genfn, JSOP_CALL);
if (!result)
return null();
handler.setBeginPosition(result, begin);
handler.setEndPosition(result, pos().end);
return result;
}
/* * */
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::assignExprWithoutYield(YieldHandling yieldHandling, unsigned msg)
{
uint32_t startYieldOffset = pc->lastYieldOffset;
Node res = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
if (res && pc->lastYieldOffset != startYieldOffset) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
msg, js_yield_str);
return null();
}
return res;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::argumentList(YieldHandling yieldHandling, Node listNode, bool* isSpread)
{
bool matched;
if (!tokenStream.matchToken(&matched, TOK_RP, TokenStream::Operand))
return false;
if (matched) {
handler.setEndPosition(listNode, pos().end);
return true;
}
uint32_t startYieldOffset = pc->lastYieldOffset;
bool arg0 = true;
while (true) {
bool spread = false;
uint32_t begin = 0;
if (!tokenStream.matchToken(&matched, TOK_TRIPLEDOT, TokenStream::Operand))
return false;
if (matched) {
spread = true;
begin = pos().begin;
*isSpread = true;
}
Node argNode = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
if (!argNode)
return false;
if (spread) {
argNode = handler.newUnary(PNK_SPREAD, JSOP_NOP, begin, argNode);
if (!argNode)
return false;
}
if (handler.isUnparenthesizedYieldExpression(argNode)) {
TokenKind tt;
if (!tokenStream.peekToken(&tt))
return false;
if (tt == TOK_COMMA) {
report(ParseError, false, argNode, JSMSG_BAD_YIELD_SYNTAX);
return false;
}
}
#if JS_HAS_GENERATOR_EXPRS
if (!spread) {
if (!tokenStream.matchToken(&matched, TOK_FOR))
return false;
if (matched) {
if (pc->lastYieldOffset != startYieldOffset) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
JSMSG_BAD_GENEXP_BODY, js_yield_str);
return false;
}
argNode = legacyGeneratorExpr(argNode);
if (!argNode)
return false;
if (!arg0) {
report(ParseError, false, argNode, JSMSG_BAD_GENERATOR_SYNTAX);
return false;
}
TokenKind tt;
if (!tokenStream.peekToken(&tt))
return false;
if (tt == TOK_COMMA) {
report(ParseError, false, argNode, JSMSG_BAD_GENERATOR_SYNTAX);
return false;
}
}
}
#endif
arg0 = false;
handler.addList(listNode, argNode);
bool matched;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return false;
if (!matched)
break;
}
TokenKind tt;
if (!tokenStream.getToken(&tt))
return false;
if (tt != TOK_RP) {
report(ParseError, false, null(), JSMSG_PAREN_AFTER_ARGS);
return false;
}
handler.setEndPosition(listNode, pos().end);
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkAndMarkSuperScope()
{
if (!pc->sc->allowSuperProperty())
return false;
pc->sc->markSuperScopeNeedsHomeObject();
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::memberExpr(YieldHandling yieldHandling, TripledotHandling tripledotHandling,
TokenKind tt, bool allowCallSyntax, InvokedPrediction invoked)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(tt));
Node lhs;
JS_CHECK_RECURSION(context, return null());
/* Check for new expression first. */
if (tt == TOK_NEW) {
uint32_t newBegin = pos().begin;
// Make sure this wasn't a |new.target| in disguise.
Node newTarget;
if (!tryNewTarget(newTarget))
return null();
if (newTarget) {
lhs = newTarget;
} else {
lhs = handler.newList(PNK_NEW, newBegin, JSOP_NEW);
if (!lhs)
return null();
// Gotten by tryNewTarget
tt = tokenStream.currentToken().type;
Node ctorExpr = memberExpr(yieldHandling, TripledotProhibited, tt, false, PredictInvoked);
if (!ctorExpr)
return null();
handler.addList(lhs, ctorExpr);
bool matched;
if (!tokenStream.matchToken(&matched, TOK_LP))
return null();
if (matched) {
bool isSpread = false;
if (!argumentList(yieldHandling, lhs, &isSpread))
return null();
if (isSpread)
handler.setOp(lhs, JSOP_SPREADNEW);
}
}
} else if (tt == TOK_SUPER) {
Node thisName = newThisName();
if (!thisName)
return null();
lhs = handler.newSuperBase(thisName, pos());
if (!lhs)
return null();
} else {
lhs = primaryExpr(yieldHandling, tripledotHandling, tt, invoked);
if (!lhs)
return null();
}
MOZ_ASSERT_IF(handler.isSuperBase(lhs), tokenStream.isCurrentTokenType(TOK_SUPER));
while (true) {
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_EOF)
break;
Node nextMember;
if (tt == TOK_DOT) {
if (!tokenStream.getToken(&tt, TokenStream::KeywordIsName))
return null();
if (tt == TOK_NAME) {
PropertyName* field = tokenStream.currentName();
if (handler.isSuperBase(lhs) && !checkAndMarkSuperScope()) {
report(ParseError, false, null(), JSMSG_BAD_SUPERPROP, "property");
return null();
}
nextMember = handler.newPropertyAccess(lhs, field, pos().end);
if (!nextMember)
return null();
} else {
report(ParseError, false, null(), JSMSG_NAME_AFTER_DOT);
return null();
}
} else if (tt == TOK_LB) {
Node propExpr = expr(InAllowed, yieldHandling, TripledotProhibited);
if (!propExpr)
return null();
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_IN_INDEX);
if (handler.isSuperBase(lhs) && !checkAndMarkSuperScope()) {
report(ParseError, false, null(), JSMSG_BAD_SUPERPROP, "member");
return null();
}
nextMember = handler.newPropertyByValue(lhs, propExpr, pos().end);
if (!nextMember)
return null();
} else if ((allowCallSyntax && tt == TOK_LP) ||
tt == TOK_TEMPLATE_HEAD ||
tt == TOK_NO_SUBS_TEMPLATE)
{
if (handler.isSuperBase(lhs)) {
if (!pc->sc->allowSuperCall()) {
report(ParseError, false, null(), JSMSG_BAD_SUPERCALL);
return null();
}
if (tt != TOK_LP) {
report(ParseError, false, null(), JSMSG_BAD_SUPER);
return null();
}
nextMember = handler.newList(PNK_SUPERCALL, lhs, JSOP_SUPERCALL);
if (!nextMember)
return null();
// Despite the fact that it's impossible to have |super()| is a
// generator, we still inherity the yieldHandling of the
// memberExpression, per spec. Curious.
bool isSpread = false;
if (!argumentList(yieldHandling, nextMember, &isSpread))
return null();
if (isSpread)
handler.setOp(nextMember, JSOP_SPREADSUPERCALL);
Node thisName = newThisName();
if (!thisName)
return null();
return handler.newSetThis(thisName, nextMember);
}
if (options().selfHostingMode && handler.isPropertyAccess(lhs)) {
report(ParseError, false, null(), JSMSG_SELFHOSTED_METHOD_CALL);
return null();
}
nextMember = tt == TOK_LP ? handler.newCall() : handler.newTaggedTemplate();
if (!nextMember)
return null();
JSOp op = JSOP_CALL;
if (PropertyName* name = handler.maybeNameAnyParentheses(lhs)) {
if (tt == TOK_LP && name == context->names().eval) {
/* Select JSOP_EVAL and flag pc as needsCallObject. */
op = pc->sc->strict() ? JSOP_STRICTEVAL : JSOP_EVAL;
pc->sc->setBindingsAccessedDynamically();
pc->sc->setHasDirectEval();
/*
* In non-strict mode code, direct calls to eval can add
* variables to the call object.
*/
if (pc->sc->isFunctionBox() && !pc->sc->strict())
pc->sc->asFunctionBox()->setHasExtensibleScope();
// If we're in a method, mark the method as requiring
// support for 'super', since direct eval code can use it.
// (If we're not in a method, that's fine, so ignore the
// return value.)
checkAndMarkSuperScope();
}
} else if (PropertyName* prop = handler.maybeDottedProperty(lhs)) {
// Use the JSOP_FUN{APPLY,CALL} optimizations given the right
// syntax.
if (prop == context->names().apply) {
op = JSOP_FUNAPPLY;
if (pc->sc->isFunctionBox())
pc->sc->asFunctionBox()->usesApply = true;
} else if (prop == context->names().call) {
op = JSOP_FUNCALL;
}
}
handler.setBeginPosition(nextMember, lhs);
handler.addList(nextMember, lhs);
if (tt == TOK_LP) {
bool isSpread = false;
if (!argumentList(yieldHandling, nextMember, &isSpread))
return null();
if (isSpread) {
if (op == JSOP_EVAL)
op = JSOP_SPREADEVAL;
else if (op == JSOP_STRICTEVAL)
op = JSOP_STRICTSPREADEVAL;
else
op = JSOP_SPREADCALL;
}
} else {
if (!taggedTemplate(yieldHandling, nextMember, tt))
return null();
}
handler.setOp(nextMember, op);
} else {
tokenStream.ungetToken();
if (handler.isSuperBase(lhs))
break;
return lhs;
}
lhs = nextMember;
}
if (handler.isSuperBase(lhs)) {
report(ParseError, false, null(), JSMSG_BAD_SUPER);
return null();
}
return lhs;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newName(PropertyName* name)
{
return handler.newName(name, pc->blockid(), pos(), context);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::identifierName(YieldHandling yieldHandling)
{
RootedPropertyName name(context, tokenStream.currentName());
if (yieldHandling == YieldIsKeyword && name == context->names().yield) {
report(ParseError, false, null(), JSMSG_RESERVED_ID, "yield");
return null();
}
// If we're inside a function that later becomes a legacy generator, then
// a |yield| identifier name here will be detected by a subsequent
// |checkYieldNameValidity| call.
Node pn = newName(name);
if (!pn)
return null();
if (!pc->inDeclDestructuring && !noteNameUse(name, pn))
return null();
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::stringLiteral()
{
return handler.newStringLiteral(stopStringCompression(), pos());
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::noSubstitutionTemplate()
{
return handler.newTemplateStringLiteral(stopStringCompression(), pos());
}
template <typename ParseHandler>
JSAtom * Parser<ParseHandler>::stopStringCompression() {
JSAtom* atom = tokenStream.currentToken().atom();
// Large strings are fast to parse but slow to compress. Stop compression on
// them, so we don't wait for a long time for compression to finish at the
// end of compilation.
const size_t HUGE_STRING = 50000;
if (sct && sct->active() && atom->length() >= HUGE_STRING)
sct->abort();
return atom;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newRegExp()
{
MOZ_ASSERT(!options().selfHostingMode);
// Create the regexp even when doing a syntax parse, to check the regexp's syntax.
const char16_t* chars = tokenStream.getTokenbuf().begin();
size_t length = tokenStream.getTokenbuf().length();
RegExpFlag flags = tokenStream.currentToken().regExpFlags();
Rooted<RegExpObject*> reobj(context);
RegExpStatics* res = context->global()->getRegExpStatics(context);
if (!res)
return null();
reobj = RegExpObject::create(context, res, chars, length, flags, &tokenStream, alloc);
if (!reobj)
return null();
return handler.newRegExp(reobj, pos(), *this);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::arrayInitializer(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_LB));
uint32_t begin = pos().begin;
Node literal = handler.newArrayLiteral(begin);
if (!literal)
return null();
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::Operand))
return null();
// Handle an ES6-era array comprehension first.
if (tt == TOK_FOR)
return arrayComprehension(begin);
if (tt == TOK_RB) {
/*
* Mark empty arrays as non-constant, since we cannot easily
* determine their type.
*/
handler.setListFlag(literal, PNX_NONCONST);
} else {
tokenStream.ungetToken();
bool spread = false, missingTrailingComma = false;
uint32_t index = 0;
TokenStream::Modifier modifier = TokenStream::Operand;
for (; ; index++) {
if (index >= NativeObject::MAX_DENSE_ELEMENTS_COUNT) {
report(ParseError, false, null(), JSMSG_ARRAY_INIT_TOO_BIG);
return null();
}
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::Operand))
return null();
if (tt == TOK_RB)
break;
if (tt == TOK_COMMA) {
tokenStream.consumeKnownToken(TOK_COMMA, TokenStream::Operand);
if (!handler.addElision(literal, pos()))
return null();
} else if (tt == TOK_TRIPLEDOT) {
spread = true;
tokenStream.consumeKnownToken(TOK_TRIPLEDOT, TokenStream::Operand);
uint32_t begin = pos().begin;
Node inner = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
if (!inner)
return null();
if (!handler.addSpreadElement(literal, begin, inner))
return null();
} else {
Node element = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
if (!element)
return null();
if (foldConstants && !FoldConstants(context, &element, this))
return null();
handler.addArrayElement(literal, element);
}
if (tt != TOK_COMMA) {
/* If we didn't already match TOK_COMMA in above case. */
bool matched;
if (!tokenStream.matchToken(&matched, TOK_COMMA))
return null();
if (!matched) {
missingTrailingComma = true;
modifier = TokenStream::None;
break;
}
}
}
/*
* At this point, (index == 0 && missingTrailingComma) implies one
* element initialiser was parsed.
*
* A legacy array comprehension of the form:
*
* [i * j for (i in o) for (j in p) if (i != j)]
*
* translates to roughly the following code:
*
* {
* let array = new Array, i, j;
* for (i in o) let {
* for (j in p)
* if (i != j)
* array.push(i * j)
* }
* array
* }
*
* where array is a nameless block-local variable. The "roughly" means
* that an implementation may optimize away the array.push. A legacy
* array comprehension opens exactly one block scope, no matter how many
* for heads it contains.
*
* Each let () {...} or for (let ...) ... compiles to:
*
* JSOP_PUSHN <N> // Push space for block-scoped locals.
* (JSOP_PUSHBLOCKSCOPE <O>) // If a local is aliased, push on scope
* // chain.
* ...
* JSOP_DEBUGLEAVEBLOCK // Invalidate any DebugScope proxies.
* JSOP_POPBLOCKSCOPE? // Pop off scope chain, if needed.
* JSOP_POPN <N> // Pop space for block-scoped locals.
*
* where <o> is a literal object representing the block scope,
* with <n> properties, naming each var declared in the block.
*
* Each var declaration in a let-block binds a name in <o> at compile
* time. A block-local var is accessed by the JSOP_GETLOCAL and
* JSOP_SETLOCAL ops. These ops have an immediate operand, the local
* slot's stack index from fp->spbase.
*
* The legacy array comprehension iteration step, array.push(i * j) in
* the example above, is done by <i * j>; JSOP_ARRAYPUSH <array>, where
* <array> is the index of array's stack slot.
*/
if (index == 0 && !spread) {
bool matched;
if (!tokenStream.matchToken(&matched, TOK_FOR, modifier))
return null();
if (matched && missingTrailingComma)
return legacyArrayComprehension(literal);
if (matched)
modifier = TokenStream::None;
}
MUST_MATCH_TOKEN_MOD(TOK_RB, modifier, JSMSG_BRACKET_AFTER_LIST);
}
handler.setEndPosition(literal, pos().end);
return literal;
}
static JSAtom*
DoubleToAtom(ExclusiveContext* cx, double value)
{
// This is safe because doubles can not be moved.
Value tmp = DoubleValue(value);
return ToAtom<CanGC>(cx, HandleValue::fromMarkedLocation(&tmp));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::propertyName(YieldHandling yieldHandling, Node propList,
PropertyType* propType, MutableHandleAtom propAtom)
{
TokenKind ltok;
if (!tokenStream.getToken(&ltok, TokenStream::KeywordIsName))
return null();
// TOK_RC should be handled in caller.
MOZ_ASSERT(ltok != TOK_RC);
bool isGenerator = false;
if (ltok == TOK_MUL) {
isGenerator = true;
if (!tokenStream.getToken(&ltok, TokenStream::KeywordIsName))
return null();
}
propAtom.set(nullptr);
Node propName;
switch (ltok) {
case TOK_NUMBER:
propAtom.set(DoubleToAtom(context, tokenStream.currentToken().number()));
if (!propAtom.get())
return null();
propName = newNumber(tokenStream.currentToken());
if (!propName)
return null();
break;
case TOK_LB:
propName = computedPropertyName(yieldHandling, propList);
if (!propName)
return null();
break;
case TOK_NAME: {
propAtom.set(tokenStream.currentName());
// Do not look for accessor syntax on generators
if (isGenerator ||
!(propAtom.get() == context->names().get ||
propAtom.get() == context->names().set))
{
propName = handler.newObjectLiteralPropertyName(propAtom, pos());
if (!propName)
return null();
break;
}
*propType = propAtom.get() == context->names().get ? PropertyType::Getter
: PropertyType::Setter;
// We have parsed |get| or |set|. Look for an accessor property
// name next.
TokenKind tt;
if (!tokenStream.peekToken(&tt, TokenStream::KeywordIsName))
return null();
if (tt == TOK_NAME) {
if (!checkUnescapedName())
return null();
tokenStream.consumeKnownToken(TOK_NAME, TokenStream::KeywordIsName);
propAtom.set(tokenStream.currentName());
return handler.newObjectLiteralPropertyName(propAtom, pos());
}
if (tt == TOK_STRING) {
if (!checkUnescapedName())
return null();
tokenStream.consumeKnownToken(TOK_STRING, TokenStream::KeywordIsName);
propAtom.set(tokenStream.currentToken().atom());
uint32_t index;
if (propAtom->isIndex(&index)) {
propAtom.set(DoubleToAtom(context, index));
if (!propAtom.get())
return null();
return handler.newNumber(index, NoDecimal, pos());
}
return stringLiteral();
}
if (tt == TOK_NUMBER) {
if (!checkUnescapedName())
return null();
tokenStream.consumeKnownToken(TOK_NUMBER, TokenStream::KeywordIsName);
propAtom.set(DoubleToAtom(context, tokenStream.currentToken().number()));
if (!propAtom.get())
return null();
return newNumber(tokenStream.currentToken());
}
if (tt == TOK_LB) {
if (!checkUnescapedName())
return null();
tokenStream.consumeKnownToken(TOK_LB, TokenStream::KeywordIsName);
return computedPropertyName(yieldHandling, propList);
}
// Not an accessor property after all.
propName = handler.newObjectLiteralPropertyName(propAtom.get(), pos());
if (!propName)
return null();
tokenStream.addModifierException(TokenStream::NoneIsKeywordIsName);
break;
}
case TOK_STRING: {
propAtom.set(tokenStream.currentToken().atom());
uint32_t index;
if (propAtom->isIndex(&index)) {
propName = handler.newNumber(index, NoDecimal, pos());
if (!propName)
return null();
break;
}
propName = stringLiteral();
if (!propName)
return null();
break;
}
default:
report(ParseError, false, null(), JSMSG_BAD_PROP_ID);
return null();
}
TokenKind tt;
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_COLON) {
if (isGenerator) {
report(ParseError, false, null(), JSMSG_BAD_PROP_ID);
return null();
}
*propType = PropertyType::Normal;
return propName;
}
if (ltok == TOK_NAME && (tt == TOK_COMMA || tt == TOK_RC)) {
if (isGenerator) {
report(ParseError, false, null(), JSMSG_BAD_PROP_ID);
return null();
}
tokenStream.ungetToken();
*propType = PropertyType::Shorthand;
return propName;
}
if (tt == TOK_LP) {
tokenStream.ungetToken();
*propType = isGenerator ? PropertyType::GeneratorMethod : PropertyType::Method;
return propName;
}
report(ParseError, false, null(), JSMSG_COLON_AFTER_ID);
return null();
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::computedPropertyName(YieldHandling yieldHandling, Node literal)
{
uint32_t begin = pos().begin;
// Turn off the inDeclDestructuring flag when parsing computed property
// names. In short, when parsing 'let {[x + y]: z} = obj;', noteNameUse()
// should be called on x and y, but not on z. See the comment on
// Parser<>::checkDestructuringPattern() for details.
bool saved = pc->inDeclDestructuring;
pc->inDeclDestructuring = false;
Node assignNode = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
pc->inDeclDestructuring = saved;
if (!assignNode)
return null();
MUST_MATCH_TOKEN(TOK_RB, JSMSG_COMP_PROP_UNTERM_EXPR);
Node propname = handler.newComputedName(assignNode, begin, pos().end);
if (!propname)
return null();
handler.setListFlag(literal, PNX_NONCONST);
return propname;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::objectLiteral(YieldHandling yieldHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_LC));
Node literal = handler.newObjectLiteral(pos().begin);
if (!literal)
return null();
bool seenPrototypeMutation = false;
RootedAtom propAtom(context);
for (;;) {
TokenKind tt;
if (!tokenStream.getToken(&tt, TokenStream::KeywordIsName))
return null();
if (tt == TOK_RC)
break;
tokenStream.ungetToken();
PropertyType propType;
Node propName = propertyName(yieldHandling, literal, &propType, &propAtom);
if (!propName)
return null();
if (propType == PropertyType::Normal) {
Node propExpr = assignExpr(InAllowed, yieldHandling, TripledotProhibited);
if (!propExpr)
return null();
if (foldConstants && !FoldConstants(context, &propExpr, this))
return null();
if (propAtom == context->names().proto) {
if (seenPrototypeMutation) {
report(ParseError, false, propName, JSMSG_DUPLICATE_PROPERTY, "__proto__");
return null();
}
seenPrototypeMutation = true;
// Note: this occurs *only* if we observe TOK_COLON! Only
// __proto__: v mutates [[Prototype]]. Getters, setters,
// method/generator definitions, computed property name
// versions of all of these, and shorthands do not.
uint32_t begin = handler.getPosition(propName).begin;
if (!handler.addPrototypeMutation(literal, begin, propExpr))
return null();
} else {
if (!handler.isConstant(propExpr))
handler.setListFlag(literal, PNX_NONCONST);
if (!handler.addPropertyDefinition(literal, propName, propExpr))
return null();
}
} else if (propType == PropertyType::Shorthand) {
/*
* Support, e.g., |var {x, y} = o| as destructuring shorthand
* for |var {x: x, y: y} = o|, per proposed JS2/ES4 for JS1.8.
*/
if (!tokenStream.checkForKeyword(propAtom, nullptr))
return null();
Node nameExpr = identifierName(yieldHandling);
if (!nameExpr)
return null();
if (!handler.addShorthand(literal, propName, nameExpr))
return null();
} else {
// FIXME: Implement ES6 function "name" property semantics
// (bug 883377).
RootedPropertyName funName(context);
switch (propType) {
case PropertyType::Getter:
case PropertyType::Setter:
funName = nullptr;
break;
default:
if (tokenStream.isCurrentTokenType(TOK_NAME))
funName = tokenStream.currentName();
else
funName = nullptr;
}
Node fn = methodDefinition(yieldHandling, propType, funName);
if (!fn)
return null();
JSOp op = JSOpFromPropertyType(propType);
if (!handler.addObjectMethodDefinition(literal, propName, fn, op))
return null();
}
if (!tokenStream.getToken(&tt))
return null();
if (tt == TOK_RC)
break;
if (tt != TOK_COMMA) {
report(ParseError, false, null(), JSMSG_CURLY_AFTER_LIST);
return null();
}
}
handler.setEndPosition(literal, pos().end);
return literal;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::methodDefinition(YieldHandling yieldHandling, PropertyType propType,
HandlePropertyName funName)
{
FunctionSyntaxKind kind = FunctionSyntaxKindFromPropertyType(propType);
GeneratorKind generatorKind = GeneratorKindFromPropertyType(propType);
return functionDef(InAllowed, yieldHandling, funName, kind, generatorKind);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::tryNewTarget(Node &newTarget)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_NEW));
newTarget = null();
Node newHolder = handler.newPosHolder(pos());
if (!newHolder)
return false;
uint32_t begin = pos().begin;
// |new| expects to look for an operand, so we will honor that.
TokenKind next;
if (!tokenStream.getToken(&next, TokenStream::Operand))
return false;
// Don't unget the token, since lookahead cannot handle someone calling
// getToken() with a different modifier. Callers should inspect currentToken().
if (next != TOK_DOT)
return true;
if (!tokenStream.getToken(&next))
return false;
if (next != TOK_NAME || tokenStream.currentName() != context->names().target) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"target", TokenKindToDesc(next));
return false;
}
if (!checkUnescapedName())
return false;
if (!pc->sc->allowNewTarget()) {
reportWithOffset(ParseError, false, begin, JSMSG_BAD_NEWTARGET);
return false;
}
Node targetHolder = handler.newPosHolder(pos());
if (!targetHolder)
return false;
newTarget = handler.newNewTarget(newHolder, targetHolder);
return !!newTarget;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::primaryExpr(YieldHandling yieldHandling, TripledotHandling tripledotHandling,
TokenKind tt, InvokedPrediction invoked)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(tt));
JS_CHECK_RECURSION(context, return null());
switch (tt) {
case TOK_FUNCTION:
return functionExpr(invoked);
case TOK_CLASS:
return classDefinition(yieldHandling, ClassExpression, NameRequired);
case TOK_LB:
return arrayInitializer(yieldHandling);
case TOK_LC:
return objectLiteral(yieldHandling);
case TOK_LP: {
TokenKind next;
if (!tokenStream.peekToken(&next, TokenStream::Operand))
return null();
if (next == TOK_RP) {
// Not valid expression syntax, but this is valid in an arrow function
// with no params: `() => body`.
tokenStream.consumeKnownToken(next, TokenStream::Operand);
if (!tokenStream.peekToken(&next))
return null();
if (next != TOK_ARROW) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"expression", TokenKindToDesc(TOK_RP));
return null();
}
// Now just return something that will allow parsing to continue.
// It doesn't matter what; when we reach the =>, we will rewind and
// reparse the whole arrow function. See Parser::assignExpr.
return handler.newNullLiteral(pos());
}
if (next == TOK_FOR) {
uint32_t begin = pos().begin;
tokenStream.consumeKnownToken(next, TokenStream::Operand);
return generatorComprehension(begin);
}
Node expr = exprInParens(InAllowed, yieldHandling, TripledotAllowed);
if (!expr)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_IN_PAREN);
handler.setEndPosition(expr, pos().end);
return handler.parenthesize(expr);
}
case TOK_TEMPLATE_HEAD:
return templateLiteral(yieldHandling);
case TOK_NO_SUBS_TEMPLATE:
return noSubstitutionTemplate();
case TOK_STRING:
return stringLiteral();
case TOK_YIELD:
if (!checkYieldNameValidity())
return null();
// Fall through.
case TOK_NAME:
return identifierName(yieldHandling);
case TOK_REGEXP:
return newRegExp();
case TOK_NUMBER:
return newNumber(tokenStream.currentToken());
case TOK_TRUE:
return handler.newBooleanLiteral(true, pos());
case TOK_FALSE:
return handler.newBooleanLiteral(false, pos());
case TOK_THIS: {
if (pc->sc->isFunctionBox())
pc->sc->asFunctionBox()->usesThis = true;
Node thisName = null();
if (pc->sc->thisBinding() == ThisBinding::Function) {
thisName = newThisName();
if (!thisName)
return null();
}
return handler.newThisLiteral(pos(), thisName);
}
case TOK_NULL:
return handler.newNullLiteral(pos());
case TOK_TRIPLEDOT: {
// This isn't valid expression syntax, but it's valid in an arrow
// function as a trailing rest param: `(a, b, ...rest) => body`. Check
// if it's directly under
// CoverParenthesizedExpressionAndArrowParameterList, and check for a
// name, closing parenthesis, and arrow, and allow it only if all are
// present.
if (tripledotHandling != TripledotAllowed) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"expression", TokenKindToDesc(tt));
return null();
}
TokenKind next;
if (!tokenStream.getToken(&next))
return null();
// FIXME: This fails to handle a rest parameter named |yield| correctly
// outside of generators: |var f = (...yield) => 42;| should be
// valid code! When this is fixed, make sure to consult both
// |yieldHandling| and |checkYieldNameValidity| for correctness
// until legacy generator syntax is removed.
if (next != TOK_NAME) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"rest argument name", TokenKindToDesc(next));
return null();
}
if (!tokenStream.getToken(&next))
return null();
if (next != TOK_RP) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"closing parenthesis", TokenKindToDesc(next));
return null();
}
if (!tokenStream.peekTokenSameLine(&next))
return null();
if (next != TOK_ARROW) {
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"'=>' after argument list", TokenKindToDesc(next));
return null();
}
tokenStream.ungetToken(); // put back right paren
// Return an arbitrary expression node. See case TOK_RP above.
return handler.newNullLiteral(pos());
}
default:
report(ParseError, false, null(), JSMSG_UNEXPECTED_TOKEN,
"expression", TokenKindToDesc(tt));
return null();
}
}
// Legacy generator comprehensions can appear anywhere an expression is
// enclosed in parentheses, even if those parentheses are part of statement
// syntax or a function call:
//
// if (_)
// while (_) {}
// do {} while (_)
// switch (_) {}
// with (_) {}
// foo(_) // must be first and only argument
//
// This is not the case for also-nonstandard ES6-era generator comprehensions.
// Those must be enclosed in PrimaryExpression parentheses.
//
// sum(x*x for (x in y)); // ok
// sum(for (x of y) x*x); // SyntaxError: needs more parens
//
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::exprInParens(InHandling inHandling, YieldHandling yieldHandling,
TripledotHandling tripledotHandling)
{
MOZ_ASSERT(tokenStream.isCurrentTokenType(TOK_LP));
uint32_t begin = pos().begin;
uint32_t startYieldOffset = pc->lastYieldOffset;
Node pn = expr(inHandling, yieldHandling, tripledotHandling, PredictInvoked);
if (!pn)
return null();
#if JS_HAS_GENERATOR_EXPRS
bool matched;
if (!tokenStream.matchToken(&matched, TOK_FOR))
return null();
if (matched) {
if (pc->lastYieldOffset != startYieldOffset) {
reportWithOffset(ParseError, false, pc->lastYieldOffset,
JSMSG_BAD_GENEXP_BODY, js_yield_str);
return null();
}
if (handler.isUnparenthesizedCommaExpression(pn)) {
report(ParseError, false, null(), JSMSG_BAD_GENERATOR_SYNTAX);
return null();
}
pn = legacyGeneratorExpr(pn);
if (!pn)
return null();
handler.setBeginPosition(pn, begin);
}
#endif /* JS_HAS_GENERATOR_EXPRS */
return pn;
}
template <typename ParseHandler>
void
Parser<ParseHandler>::addTelemetry(JSCompartment::DeprecatedLanguageExtension e)
{
JSContext* cx = context->maybeJSContext();
if (!cx)
return;
cx->compartment()->addTelemetry(getFilename(), e);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::warnOnceAboutExprClosure()
{
#ifndef RELEASE_BUILD
JSContext* cx = context->maybeJSContext();
if (!cx)
return true;
if (!cx->compartment()->warnedAboutExprClosure) {
if (!report(ParseWarning, false, null(), JSMSG_DEPRECATED_EXPR_CLOSURE))
return false;
cx->compartment()->warnedAboutExprClosure = true;
}
#endif
return true;
}
template class Parser<FullParseHandler>;
template class Parser<SyntaxParseHandler>;
} /* namespace frontend */
} /* namespace js */