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cobalt / cobalt / 4fe09471d0134f1d49ad5034a1c8867d6f9f4551 / . / src / third_party / mozjs / js / src / frontend / Parser.cpp
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/* -*- 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.h"
#include "jstypes.h"
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsversion.h"
#include "jsfun.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsscript.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 "jsobjinlines.h"
#include "jsscriptinlines.h"
#include "frontend/ParseMaps-inl.h"
#include "frontend/ParseNode-inl.h"
#include "frontend/Parser-inl.h"
#include "frontend/SharedContext-inl.h"
#include "vm/NumericConversions.h"
#include "vm/RegExpStatics-inl.h"
using namespace js;
using namespace js::gc;
using mozilla::Maybe;
namespace js {
namespace frontend {
typedef Rooted<StaticBlockObject*> RootedStaticBlockObject;
typedef Handle<StaticBlockObject*> HandleStaticBlockObject;
typedef MutableHandle<PropertyName*> MutableHandlePropertyName;
/*
* Insist that the next token be of type tt, or report errno and return null.
* NB: this macro uses cx and ts from its lexical environment.
*/
#define MUST_MATCH_TOKEN_WITH_FLAGS(tt, errno, __flags) \
JS_BEGIN_MACRO \
if (tokenStream.getToken((__flags)) != tt) { \
report(ParseError, false, null(), errno); \
return null(); \
} \
JS_END_MACRO
#define MUST_MATCH_TOKEN(tt, errno) MUST_MATCH_TOKEN_WITH_FLAGS(tt, errno, 0)
template <typename ParseHandler>
bool
GenerateBlockId(ParseContext<ParseHandler> *pc, uint32_t &blockid)
{
if (pc->blockidGen == JS_BIT(20)) {
JS_ReportErrorNumber(pc->sc->context, js_GetErrorMessage, NULL, JSMSG_NEED_DIET, "program");
return false;
}
JS_ASSERT(pc->blockidGen < JS_BIT(20));
blockid = pc->blockidGen++;
return true;
}
template bool
GenerateBlockId(ParseContext<SyntaxParseHandler> *pc, uint32_t &blockid);
template bool
GenerateBlockId(ParseContext<FullParseHandler> *pc, uint32_t &blockid);
template <typename ParseHandler>
static void
PushStatementPC(ParseContext<ParseHandler> *pc, StmtInfoPC *stmt, StmtType type)
{
stmt->blockid = pc->blockid();
PushStatement(pc, stmt, type);
}
// See comment on member function declaration.
template <>
bool
ParseContext<FullParseHandler>::define(JSContext *cx, HandlePropertyName name,
ParseNode *pn, Definition::Kind kind)
{
JS_ASSERT(!pn->isUsed());
JS_ASSERT_IF(pn->isDefn(), pn->isPlaceholder());
Definition *prevDef = NULL;
if (kind == Definition::LET)
prevDef = decls_.lookupFirst(name);
else
JS_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) ? pn->pn_blockid : bodyid;
while ((pnu = *pnup) != NULL && pnu->pn_blockid >= start) {
JS_ASSERT(pnu->pn_blockid >= bodyid);
JS_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;
}
JS_ASSERT_IF(kind != Definition::LET, !lexdeps->lookup(name));
pn->setDefn(true);
pn->pn_dflags &= ~PND_PLACEHOLDER;
if (kind == Definition::CONST)
pn->pn_dflags |= PND_CONST;
Definition *dn = (Definition *)pn;
switch (kind) {
case Definition::ARG:
JS_ASSERT(sc->isFunctionBox());
dn->setOp(JSOP_GETARG);
dn->pn_dflags |= PND_BOUND;
if (!dn->pn_cookie.set(cx, staticLevel, args_.length()))
return false;
if (!args_.append(dn))
return false;
if (name == cx->names().empty)
break;
if (!decls_.addUnique(name, dn))
return false;
break;
case Definition::CONST:
case Definition::VAR:
if (sc->isFunctionBox()) {
dn->setOp(JSOP_GETLOCAL);
dn->pn_dflags |= PND_BOUND;
if (!dn->pn_cookie.set(cx, staticLevel, vars_.length()))
return false;
if (!vars_.append(dn))
return false;
}
if (!decls_.addUnique(name, dn))
return false;
break;
case Definition::LET:
dn->setOp(JSOP_GETLOCAL);
dn->pn_dflags |= (PND_LET | PND_BOUND);
JS_ASSERT(dn->pn_cookie.level() == staticLevel); /* see bindLet */
if (!decls_.addShadow(name, dn))
return false;
break;
default:
JS_NOT_REACHED("unexpected kind");
break;
}
return true;
}
template <>
bool
ParseContext<SyntaxParseHandler>::define(JSContext *cx, HandlePropertyName name, Node pn,
Definition::Kind kind)
{
JS_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 && !args_.append((Definition *) NULL))
return false;
return decls_.addUnique(name, kind);
}
template <typename ParseHandler>
void
ParseContext<ParseHandler>::prepareToAddDuplicateArg(HandlePropertyName name, DefinitionNode prevDecl)
{
JS_ASSERT(decls_.lookupFirst(name) == prevDecl);
decls_.remove(name);
}
template <typename ParseHandler>
void
ParseContext<ParseHandler>::updateDecl(JSAtom *atom, Node pn)
{
Definition *oldDecl = decls_.lookupFirst(atom);
pn->setDefn(true);
Definition *newDecl = (Definition *)pn;
decls_.updateFirst(atom, newDecl);
if (!sc->isFunctionBox()) {
JS_ASSERT(newDecl->isFreeVar());
return;
}
JS_ASSERT(oldDecl->isBound());
JS_ASSERT(!oldDecl->pn_cookie.isFree());
newDecl->pn_cookie = oldDecl->pn_cookie;
newDecl->pn_dflags |= PND_BOUND;
if (JOF_OPTYPE(oldDecl->getOp()) == JOF_QARG) {
newDecl->setOp(JSOP_GETARG);
JS_ASSERT(args_[oldDecl->pn_cookie.slot()] == oldDecl);
args_[oldDecl->pn_cookie.slot()] = newDecl;
} else {
JS_ASSERT(JOF_OPTYPE(oldDecl->getOp()) == JOF_LOCAL);
newDecl->setOp(JSOP_GETLOCAL);
JS_ASSERT(vars_[oldDecl->pn_cookie.slot()] == oldDecl);
vars_[oldDecl->pn_cookie.slot()] = newDecl;
}
}
template <typename ParseHandler>
void
ParseContext<ParseHandler>::popLetDecl(JSAtom *atom)
{
JS_ASSERT(ParseHandler::getDefinitionKind(decls_.lookupFirst(atom)) == Definition::LET);
decls_.remove(atom);
}
template <typename ParseHandler>
static void
AppendPackedBindings(const ParseContext<ParseHandler> *pc, const DeclVector &vec, Binding *dst)
{
for (unsigned i = 0; i < vec.length(); ++i, ++dst) {
Definition *dn = vec[i];
PropertyName *name = dn->name();
BindingKind kind;
switch (dn->kind()) {
case Definition::VAR:
kind = VARIABLE;
break;
case Definition::CONST:
kind = CONSTANT;
break;
case Definition::ARG:
kind = ARGUMENT;
break;
default:
JS_NOT_REACHED("unexpected dn->kind");
}
/*
* 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.
*/
JS_ASSERT_IF(dn->isClosed(), pc->decls().lookupFirst(name) == dn);
bool aliased = dn->isClosed() ||
(pc->sc->bindingsAccessedDynamically() &&
pc->decls().lookupFirst(name) == dn);
*dst = Binding(name, kind, aliased);
}
}
template <typename ParseHandler>
bool
ParseContext<ParseHandler>::generateFunctionBindings(JSContext *cx, InternalHandle<Bindings*> bindings) const
{
JS_ASSERT(sc->isFunctionBox());
unsigned count = args_.length() + vars_.length();
Binding *packedBindings = cx->tempLifoAlloc().newArrayUninitialized<Binding>(count);
if (!packedBindings) {
js_ReportOutOfMemory(cx);
return false;
}
AppendPackedBindings(this, args_, packedBindings);
AppendPackedBindings(this, vars_, packedBindings + args_.length());
return Bindings::initWithTemporaryStorage(cx, bindings, args_.length(), vars_.length(),
packedBindings);
}
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>::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(JSContext *cx, const CompileOptions &options,
const jschar *chars, size_t length, bool foldConstants,
Parser<SyntaxParseHandler> *syntaxParser,
LazyScript *lazyOuterFunction)
: AutoGCRooter(cx, PARSER),
context(cx),
tokenStream(cx, options, chars, length, thisForCtor(), keepAtoms),
traceListHead(NULL),
pc(NULL),
sct(NULL),
keepAtoms(cx->runtime()),
foldConstants(foldConstants),
compileAndGo(options.compileAndGo),
selfHostingMode(options.selfHostingMode),
abortedSyntaxParse(false),
handler(cx, tokenStream, foldConstants, syntaxParser, lazyOuterFunction)
{
cx->runtime()->activeCompilations++;
// 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 (context->hasExtraWarningsOption())
handler.disableSyntaxParser();
tempPoolMark = cx->tempLifoAlloc().mark();
}
template <typename ParseHandler>
Parser<ParseHandler>::~Parser()
{
JSContext *cx = context;
cx->tempLifoAlloc().release(tempPoolMark);
cx->runtime()->activeCompilations--;
/*
* 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.
*/
cx->tempLifoAlloc().freeAllIfHugeAndUnused();
}
template <typename ParseHandler>
ObjectBox *
Parser<ParseHandler>::newObjectBox(JSObject *obj)
{
JS_ASSERT(obj && !IsPoisonedPtr(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 = context->tempLifoAlloc().new_<ObjectBox>(obj, traceListHead);
if (!objbox) {
js_ReportOutOfMemory(context);
return NULL;
}
traceListHead = objbox;
return objbox;
}
template <typename ParseHandler>
FunctionBox::FunctionBox(JSContext *cx, ObjectBox* traceListHead, JSFunction *fun,
ParseContext<ParseHandler> *outerpc, bool strict)
: ObjectBox(fun, traceListHead),
SharedContext(cx, strict),
bindings(),
bufStart(0),
bufEnd(0),
asmStart(0),
ndefaults(0),
inWith(false), // initialized below
inGenexpLambda(false),
useAsm(false),
insideUseAsm(outerpc && outerpc->useAsmOrInsideUseAsm()),
usesArguments(false),
usesApply(false),
funCxFlags()
{
JS_ASSERT(fun->isTenured());
if (!outerpc) {
inWith = false;
} else if (outerpc->parsingWith) {
// This covers cases that don't involve eval(). For example:
//
// with (o) { (function() { g(); })(); }
//
// In this case, |outerpc| corresponds to global code, and
// outerpc->parsingWith is true.
inWith = true;
} else if (outerpc->sc->isGlobalSharedContext()) {
// This covers the case where a function is nested within an eval()
// within a |with| statement.
//
// with (o) { eval("(function() { g(); })();"); }
//
// In this case, |outerpc| corresponds to the eval(),
// outerpc->parsingWith is false because the eval() breaks the
// ParseContext chain, and |parent| is NULL (again because of the
// eval(), so we have to look at |outerpc|'s scopeChain.
//
JSObject *scope = outerpc->sc->asGlobalSharedContext()->scopeChain();
while (scope) {
if (scope->is<WithObject>())
inWith = true;
scope = scope->enclosingScope();
}
} else if (outerpc->sc->isFunctionBox()) {
// This is like the above case, but for more deeply nested functions.
// For example:
//
// with (o) { eval("(function() { (function() { g(); })(); })();"); } }
//
// In this case, the inner anonymous function needs to inherit the
// setting of |inWith| from the outer one.
FunctionBox *parent = outerpc->sc->asFunctionBox();
if (parent && parent->inWith)
inWith = true;
}
}
template <typename ParseHandler>
FunctionBox *
Parser<ParseHandler>::newFunctionBox(JSFunction *fun,
ParseContext<ParseHandler> *outerpc, bool strict)
{
JS_ASSERT(fun && !IsPoisonedPtr(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 =
context->tempLifoAlloc().new_<FunctionBox>(context, traceListHead, fun, outerpc, strict);
if (!funbox) {
js_ReportOutOfMemory(context);
return NULL;
}
traceListHead = funbox;
return funbox;
}
ModuleBox::ModuleBox(JSContext *cx, ObjectBox *traceListHead, Module *module,
ParseContext<FullParseHandler> *pc)
: ObjectBox(module, traceListHead),
SharedContext(cx, true)
{
}
template <>
ModuleBox *
Parser<FullParseHandler>::newModuleBox(Module *module, ParseContext<FullParseHandler> *outerpc)
{
JS_ASSERT(module && !IsPoisonedPtr(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 script or top-level
* function.
*/
ModuleBox *modulebox =
context->tempLifoAlloc().new_<ModuleBox>(context, traceListHead, module, outerpc);
if (!modulebox) {
js_ReportOutOfMemory(context);
return NULL;
}
traceListHead = modulebox;
return modulebox;
}
template <typename ParseHandler>
void
Parser<ParseHandler>::trace(JSTracer *trc)
{
traceListHead->trace(trc);
}
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(JSObject *chain)
{
/*
* 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.
*/
GlobalSharedContext globalsc(context, chain, StrictModeFromContext(context));
ParseContext<ParseHandler> globalpc(this, NULL, &globalsc, /* staticLevel = */ 0, /* bodyid = */ 0);
if (!globalpc.init())
return null();
Node pn = statements();
if (pn) {
if (!tokenStream.matchToken(TOK_EOF)) {
report(ParseError, false, null(), JSMSG_SYNTAX_ERROR);
return null();
}
if (foldConstants) {
if (!FoldConstants(context, &pn, this))
return null();
}
}
return pn;
}
/*
* Insist on a final return before control flows out of pn. Try to be a bit
* smart about loops: do {...; return e2;} while(0) at the end of a function
* that contains an early return e1 will get a strict warning. Similarly for
* iloops: while (true){...} is treated as though ... returns.
*/
enum {
ENDS_IN_OTHER = 0,
ENDS_IN_RETURN = 1,
ENDS_IN_BREAK = 2
};
static int
HasFinalReturn(ParseNode *pn)
{
ParseNode *pn2, *pn3;
unsigned rv, rv2, hasDefault;
switch (pn->getKind()) {
case PNK_STATEMENTLIST:
if (!pn->pn_head)
return ENDS_IN_OTHER;
return HasFinalReturn(pn->last());
case PNK_IF:
if (!pn->pn_kid3)
return ENDS_IN_OTHER;
return HasFinalReturn(pn->pn_kid2) & HasFinalReturn(pn->pn_kid3);
case PNK_WHILE:
pn2 = pn->pn_left;
if (pn2->isKind(PNK_TRUE))
return ENDS_IN_RETURN;
if (pn2->isKind(PNK_NUMBER) && pn2->pn_dval)
return ENDS_IN_RETURN;
return ENDS_IN_OTHER;
case PNK_DOWHILE:
pn2 = pn->pn_right;
if (pn2->isKind(PNK_FALSE))
return HasFinalReturn(pn->pn_left);
if (pn2->isKind(PNK_TRUE))
return ENDS_IN_RETURN;
if (pn2->isKind(PNK_NUMBER)) {
if (pn2->pn_dval == 0)
return HasFinalReturn(pn->pn_left);
return ENDS_IN_RETURN;
}
return ENDS_IN_OTHER;
case PNK_FOR:
pn2 = pn->pn_left;
if (pn2->isArity(PN_TERNARY) && !pn2->pn_kid2)
return ENDS_IN_RETURN;
return ENDS_IN_OTHER;
case PNK_SWITCH:
rv = ENDS_IN_RETURN;
hasDefault = ENDS_IN_OTHER;
pn2 = pn->pn_right;
if (pn2->isKind(PNK_LEXICALSCOPE))
pn2 = pn2->expr();
for (pn2 = pn2->pn_head; rv && pn2; pn2 = pn2->pn_next) {
if (pn2->isKind(PNK_DEFAULT))
hasDefault = ENDS_IN_RETURN;
pn3 = pn2->pn_right;
JS_ASSERT(pn3->isKind(PNK_STATEMENTLIST));
if (pn3->pn_head) {
rv2 = HasFinalReturn(pn3->last());
if (rv2 == ENDS_IN_OTHER && pn2->pn_next)
/* Falling through to next case or default. */;
else
rv &= rv2;
}
}
/* If a final switch has no default case, we judge it harshly. */
rv &= hasDefault;
return rv;
case PNK_BREAK:
return ENDS_IN_BREAK;
case PNK_WITH:
return HasFinalReturn(pn->pn_right);
case PNK_RETURN:
return ENDS_IN_RETURN;
case PNK_COLON:
case PNK_LEXICALSCOPE:
return HasFinalReturn(pn->expr());
case PNK_THROW:
return ENDS_IN_RETURN;
case PNK_TRY:
/* If we have a finally block that returns, we are done. */
if (pn->pn_kid3) {
rv = HasFinalReturn(pn->pn_kid3);
if (rv == ENDS_IN_RETURN)
return rv;
}
/* Else check the try block and any and all catch statements. */
rv = HasFinalReturn(pn->pn_kid1);
if (pn->pn_kid2) {
JS_ASSERT(pn->pn_kid2->isArity(PN_LIST));
for (pn2 = pn->pn_kid2->pn_head; pn2; pn2 = pn2->pn_next)
rv &= HasFinalReturn(pn2);
}
return rv;
case PNK_CATCH:
/* Check this catch block's body. */
return HasFinalReturn(pn->pn_kid3);
case PNK_LET:
/* Non-binary let statements are let declarations. */
if (!pn->isArity(PN_BINARY))
return ENDS_IN_OTHER;
return HasFinalReturn(pn->pn_right);
default:
return ENDS_IN_OTHER;
}
}
static int
HasFinalReturn(SyntaxParseHandler::Node pn)
{
return ENDS_IN_RETURN;
}
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 (!js_AtomToPrintableString(context, atom, &name))
return false;
} else {
errnum = anonerrnum;
}
return report(kind, pc->sc->strict, pn, errnum, name.ptr());
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkFinalReturn(Node pn)
{
JS_ASSERT(pc->sc->isFunctionBox());
return HasFinalReturn(pn) == ENDS_IN_RETURN ||
reportBadReturn(pn, ParseExtraWarning,
JSMSG_NO_RETURN_VALUE, JSMSG_ANON_NO_RETURN_VALUE);
}
/*
* Check that it is permitted to assign to lhs. Strict mode code may not
* assign to 'eval' or 'arguments'.
*/
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkStrictAssignment(Node lhs)
{
if (!pc->sc->needStrictChecks())
return true;
JSAtom *atom = handler.isName(lhs);
if (!atom)
return true;
if (atom == context->names().eval || atom == context->names().arguments) {
JSAutoByteString name;
if (!js_AtomToPrintableString(context, atom, &name) ||
!report(ParseStrictError, pc->sc->strict, lhs,
JSMSG_DEPRECATED_ASSIGN, name.ptr()))
{
return false;
}
}
return true;
}
/*
* 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 NULL.
*/
template <typename ParseHandler>
bool
Parser<ParseHandler>::checkStrictBinding(HandlePropertyName name, Node pn)
{
if (!pc->sc->needStrictChecks())
return true;
if (name == context->names().eval || name == context->names().arguments || IsKeyword(name)) {
JSAutoByteString bytes;
if (!js_AtomToPrintableString(context, name, &bytes))
return false;
return report(ParseStrictError, pc->sc->strict, pn,
JSMSG_BAD_BINDING, bytes.ptr());
}
return true;
}
template <>
ParseNode *
Parser<FullParseHandler>::standaloneFunctionBody(HandleFunction fun, const AutoNameVector &formals,
HandleScript script, Node fn, FunctionBox **funbox,
bool strict, bool *becameStrict)
{
if (becameStrict)
*becameStrict = false;
*funbox = newFunctionBox(fun, /* outerpc = */ NULL, strict);
if (!funbox)
return null();
handler.setFunctionBox(fn, *funbox);
ParseContext<FullParseHandler> funpc(this, pc, *funbox, /* staticLevel = */ 0, /* bodyid = */ 0);
if (!funpc.init())
return null();
for (unsigned i = 0; i < formals.length(); i++) {
if (!defineArg(fn, formals[i]))
return null();
}
ParseNode *pn = functionBody(Statement, StatementListBody);
if (!pn) {
if (becameStrict && pc->funBecameStrict)
*becameStrict = true;
return null();
}
if (!tokenStream.matchToken(TOK_EOF)) {
report(ParseError, false, null(), JSMSG_SYNTAX_ERROR);
return null();
}
if (!FoldConstants(context, &pn, this))
return null();
InternalHandle<Bindings*> scriptBindings(script, &script->bindings);
if (!funpc.generateFunctionBindings(context, scriptBindings))
return null();
// Also populate the internal bindings of the function box, so that
// heavyweight tests while emitting bytecode work.
InternalHandle<Bindings*> funboxBindings =
InternalHandle<Bindings*>::fromMarkedLocation(&(*funbox)->bindings);
if (!funpc.generateFunctionBindings(context, funboxBindings))
return null();
return pn;
}
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(context, arguments, dn, Definition::VAR))
return false;
pc->sc->asFunctionBox()->usesArguments = true;
break;
}
}
/*
* Report error if both rest parameters and 'arguments' are used. Do this
* check before adding artificial 'arguments' below.
*/
Definition *maybeArgDef = pc->decls().lookupFirst(arguments);
bool argumentsHasBinding = !!maybeArgDef;
bool argumentsHasLocalBinding = maybeArgDef && maybeArgDef->kind() != Definition::ARG;
bool hasRest = pc->sc->asFunctionBox()->function()->hasRest();
if (hasRest && argumentsHasLocalBinding) {
report(ParseError, false, NULL, JSMSG_ARGUMENTS_AND_REST);
return false;
}
/*
* Even if 'arguments' isn't explicitly mentioned, dynamic name lookup
* forces an 'arguments' binding. The exception is that functions with rest
* parameters are free from 'arguments'.
*/
if (!argumentsHasBinding && pc->sc->bindingsAccessedDynamically() && !hasRest) {
ParseNode *pn = newName(arguments);
if (!pn)
return false;
if (!pc->define(context, 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();
/*
* If a script has both explicit mentions of 'arguments' and dynamic
* name lookups which could access the arguments, an arguments object
* must be created eagerly. The SSA analysis used for lazy arguments
* cannot cope with dynamic name accesses, so any 'arguments' accessed
* via a NAME opcode must force construction of the arguments object.
*/
if (pc->sc->bindingsAccessedDynamically() && maybeArgDef)
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. In strict mode 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) be assigned.
*/
if (pc->sc->needStrictChecks()) {
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();
}
}
/* Watch for mutation of arguments through e.g. eval(). */
if (pc->sc->bindingsAccessedDynamically())
funbox->setDefinitelyNeedsArgsObj();
}
}
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::checkFunctionArguments()
{
bool hasRest = pc->sc->asFunctionBox()->function()->hasRest();
if (pc->lexdeps->lookup(context->names().arguments)) {
pc->sc->asFunctionBox()->usesArguments = true;
if (hasRest) {
report(ParseError, false, null(), JSMSG_ARGUMENTS_AND_REST);
return false;
}
} else if (hasRest) {
DefinitionNode maybeArgDef = pc->decls().lookupFirst(context->names().arguments);
if (maybeArgDef && handler.getDefinitionKind(maybeArgDef) != Definition::ARG) {
report(ParseError, false, null(), JSMSG_ARGUMENTS_AND_REST);
return false;
}
}
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionBody(FunctionSyntaxKind kind, FunctionBodyType type)
{
JS_ASSERT(pc->sc->isFunctionBox());
JS_ASSERT(!pc->funHasReturnExpr && !pc->funHasReturnVoid);
Node pn;
if (type == StatementListBody) {
pn = statements();
if (!pn)
return null();
} else {
JS_ASSERT(type == ExpressionBody);
JS_ASSERT(JS_HAS_EXPR_CLOSURES);
Node kid = assignExpr();
if (!kid)
return null();
pn = handler.newReturnStatement(kid, handler.getPosition(kid));
if (!pn)
return null();
if (pc->sc->asFunctionBox()->isGenerator()) {
reportBadReturn(pn, ParseError,
JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
return null();
}
}
/* Check for falling off the end of a function that returns a value. */
if (context->hasExtraWarningsOption() && pc->funHasReturnExpr && !checkFinalReturn(pn))
return null();
/* Define the 'arguments' binding if necessary. */
if (!checkFunctionArguments())
return null();
return pn;
}
/* See comment for use in Parser::functionDef. */
template <>
bool
Parser<FullParseHandler>::makeDefIntoUse(Definition *dn, ParseNode *pn, JSAtom *atom)
{
/* Turn pn into a definition. */
pc->updateDecl(atom, pn);
/* Change all uses of dn to be uses of pn. */
for (ParseNode *pnu = dn->dn_uses; pnu; pnu = pnu->pn_link) {
JS_ASSERT(pnu->isUsed());
JS_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) {
JS_ASSERT(dn->functionIsHoisted());
pn->dn_uses = dn->pn_link;
handler.prepareNodeForMutation(dn);
dn->setKind(PNK_NOP);
dn->setArity(PN_NULLARY);
return true;
}
/*
* If dn is arg, or 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 = NULL;
dn = (Definition *) lhs;
}
}
/* Turn dn into a use of pn. */
JS_ASSERT(dn->isKind(PNK_NAME));
JS_ASSERT(dn->isArity(PN_NAME));
JS_ASSERT(dn->pn_atom == atom);
dn->setOp((js_CodeSpec[dn->getOp()].format & JOF_SET) ? JSOP_SETNAME : JSOP_NAME);
dn->setDefn(false);
dn->setUsed(true);
dn->pn_lexdef = (Definition *) pn;
dn->pn_cookie.makeFree();
dn->pn_dflags &= ~PND_BOUND;
return true;
}
/*
* Parameter block types for the several Binder functions. We use a common
* helper function signature in order to share code among destructuring and
* simple variable declaration parsers. In the destructuring case, the binder
* function is called indirectly from the variable declaration parser by way
* of CheckDestructuring and its friends.
*/
template <typename ParseHandler>
struct BindData
{
BindData(JSContext *cx) : let(cx) {}
typedef bool
(*Binder)(JSContext *cx, BindData *data, HandlePropertyName name, Parser<ParseHandler> *parser);
/* name node for definition processing and error source coordinates */
typename ParseHandler::Node pn;
JSOp op; /* prolog bytecode or nop */
Binder binder; /* binder, discriminates u */
struct LetData {
LetData(JSContext *cx) : blockObj(cx) {}
VarContext varContext;
RootedStaticBlockObject blockObj;
unsigned overflow;
} let;
void initLet(VarContext varContext, StaticBlockObject &blockObj, unsigned overflow) {
this->pn = ParseHandler::null();
this->op = JSOP_NOP;
this->binder = Parser<ParseHandler>::bindLet;
this->let.varContext = varContext;
this->let.blockObj = &blockObj;
this->let.overflow = overflow;
}
void initVarOrConst(JSOp op) {
this->op = op;
this->binder = Parser<ParseHandler>::bindVarOrConst;
}
};
template <typename ParseHandler>
JSFunction *
Parser<ParseHandler>::newFunction(GenericParseContext *pc, HandleAtom atom,
FunctionSyntaxKind kind)
{
JS_ASSERT_IF(kind == Statement, atom != NULL);
/*
* Find the global compilation context in order to pre-set the newborn
* function's parent slot to pc->sc->as<GlobalObject>()->scopeChain. If the
* global context is a compile-and-go one, we leave the pre-set parent
* intact; otherwise we clear parent and proto.
*/
while (pc->parent)
pc = pc->parent;
RootedObject parent(context);
parent = pc->sc->isFunctionBox() ? NULL : pc->sc->asGlobalSharedContext()->scopeChain();
RootedFunction fun(context);
JSFunction::Flags flags = (kind == Expression)
? JSFunction::INTERPRETED_LAMBDA
: (kind == Arrow)
? JSFunction::INTERPRETED_LAMBDA_ARROW
: JSFunction::INTERPRETED;
fun = NewFunction(context, NullPtr(), NULL, 0, flags, parent, atom,
JSFunction::FinalizeKind, MaybeSingletonObject);
if (selfHostingMode)
fun->setIsSelfHostedBuiltin();
if (fun && !compileAndGo) {
if (!JSObject::clearParent(context, fun))
return NULL;
if (!JSObject::clearType(context, fun))
return NULL;
fun->setEnvironment(NULL);
}
return fun;
}
static bool
MatchOrInsertSemicolon(JSContext *cx, TokenStream *ts)
{
TokenKind tt = ts->peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_ERROR)
return false;
if (tt != TOK_EOF && tt != TOK_EOL && tt != TOK_SEMI && tt != TOK_RC) {
/* Advance the scanner for proper error location reporting. */
ts->getToken(TSF_OPERAND);
ts->reportError(JSMSG_SEMI_BEFORE_STMNT);
return false;
}
(void) ts->matchToken(TOK_SEMI);
return true;
}
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->inBlock(), 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(JSContext *cx, ParseContext<FullParseHandler> *pc,
FunctionBox *funbox, Definition *dn)
{
dn->setOp(JSOP_CALLEE);
if (!dn->pn_cookie.set(cx, pc->staticLevel, UpvarCookie::CALLEE_SLOT))
return false;
dn->pn_dflags |= PND_BOUND;
JS_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 generateFunctionBindings).
*
* 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;
}
/*
* 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, HandlePropertyName funName,
ParseContext<FullParseHandler> *outerpc,
FunctionSyntaxKind kind)
{
outerpc->blockidGen = pc->blockidGen;
FunctionBox *funbox = fn->pn_funbox;
JS_ASSERT(funbox == pc->sc->asFunctionBox());
if (!outerpc->topStmt || outerpc->topStmt->type == STMT_BLOCK)
fn->pn_dflags |= PND_BLOCKCHILD;
/* 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>();
JS_ASSERT(dn->isPlaceholder());
if (atom == funName && kind == Expression) {
if (!ConvertDefinitionToNamedLambdaUse(context, 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() || outerpc->parsingWith)
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 CompExprTransplanter::transplant, the PN_CODE/PN_NAME
* case), and nowhere else, currently.
*/
if (dn != outer_dn) {
if (ParseNode *pnu = dn->dn_uses) {
while (true) {
pnu->pn_lexdef = outer_dn;
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 = NULL;
}
outer_dn->pn_dflags |= dn->pn_dflags & ~PND_PLACEHOLDER;
}
/* Mark the outer dn as escaping. */
outer_dn->pn_dflags |= PND_CLOSED;
}
}
InternalHandle<Bindings*> bindings =
InternalHandle<Bindings*>::fromMarkedLocation(&funbox->bindings);
return pc->generateFunctionBindings(context, bindings);
}
template <>
bool
Parser<SyntaxParseHandler>::leaveFunction(Node fn, HandlePropertyName funName,
ParseContext<SyntaxParseHandler> *outerpc,
FunctionSyntaxKind kind)
{
outerpc->blockidGen = pc->blockidGen;
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 (!js_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. */
JS_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(context, name, argpn, Definition::ARG);
}
#if JS_HAS_DESTRUCTURING
template <typename ParseHandler>
/* static */ bool
Parser<ParseHandler>::bindDestructuringArg(JSContext *cx, BindData<ParseHandler> *data,
HandlePropertyName name, Parser<ParseHandler> *parser)
{
ParseContext<ParseHandler> *pc = parser->pc;
JS_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->pn))
return false;
return pc->define(cx, name, data->pn, Definition::VAR);
}
#endif /* JS_HAS_DESTRUCTURING */
template <typename ParseHandler>
bool
Parser<ParseHandler>::functionArguments(FunctionSyntaxKind kind, Node *listp, Node funcpn,
bool &hasRest)
{
FunctionBox *funbox = pc->sc->asFunctionBox();
bool parenFreeArrow = false;
if (kind == Arrow && tokenStream.peekToken() == TOK_NAME) {
parenFreeArrow = true;
} else {
if (tokenStream.getToken() != 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);
}
hasRest = false;
Node argsbody = handler.newList(PNK_ARGSBODY);
if (!argsbody)
return false;
handler.setFunctionBody(funcpn, argsbody);
if (parenFreeArrow || !tokenStream.matchToken(TOK_RP)) {
bool hasDefaults = false;
Node duplicatedArg = null();
bool destructuringArg = false;
#if JS_HAS_DESTRUCTURING
Node list = null();
#endif
do {
if (hasRest) {
report(ParseError, false, null(), JSMSG_PARAMETER_AFTER_REST);
return false;
}
TokenKind tt = tokenStream.getToken();
JS_ASSERT_IF(parenFreeArrow, tt == TOK_NAME);
switch (tt) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
{
/* See comment below in the TOK_NAME case. */
if (duplicatedArg) {
report(ParseError, false, duplicatedArg, JSMSG_BAD_DUP_ARGS);
return false;
}
if (hasDefaults) {
report(ParseError, false, null(), JSMSG_NONDEFAULT_FORMAL_AFTER_DEFAULT);
return false;
}
destructuringArg = 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.pn = ParseHandler::null();
data.op = JSOP_DEFVAR;
data.binder = bindDestructuringArg;
Node lhs = destructuringExpr(&data, tt);
if (!lhs)
return false;
/*
* Synthesize a destructuring assignment from the single
* anonymous positional parameter into the destructuring
* left-hand-side expression and accumulate it in list.
*/
HandlePropertyName name = context->names().empty;
Node rhs = newName(name);
if (!rhs)
return false;
if (!pc->define(context, name, rhs, Definition::ARG))
return false;
Node item = handler.newBinary(PNK_ASSIGN, lhs, rhs);
if (!item)
return false;
if (list) {
handler.addList(list, item);
} else {
list = handler.newList(PNK_VAR, item);
if (!list)
return false;
*listp = list;
}
break;
}
#endif /* JS_HAS_DESTRUCTURING */
case TOK_TRIPLEDOT:
{
hasRest = true;
tt = tokenStream.getToken();
if (tt != TOK_NAME) {
if (tt != TOK_ERROR)
report(ParseError, false, null(), JSMSG_NO_REST_NAME);
return false;
}
/* Fall through */
}
case TOK_NAME:
{
if (parenFreeArrow)
funbox->setStart(tokenStream);
RootedPropertyName name(context, tokenStream.currentToken().name());
bool disallowDuplicateArgs = destructuringArg || hasDefaults;
if (!defineArg(funcpn, name, disallowDuplicateArgs, &duplicatedArg))
return false;
if (tokenStream.matchToken(TOK_ASSIGN)) {
// 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.
JS_ASSERT(!parenFreeArrow);
if (hasRest) {
report(ParseError, false, null(), JSMSG_REST_WITH_DEFAULT);
return false;
}
if (duplicatedArg) {
report(ParseError, false, duplicatedArg, JSMSG_BAD_DUP_ARGS);
return false;
}
hasDefaults = true;
Node def_expr = assignExprWithoutYield(JSMSG_YIELD_IN_DEFAULT);
if (!def_expr)
return false;
handler.setLastFunctionArgumentDefault(funcpn, def_expr);
funbox->ndefaults++;
} else if (!hasRest && hasDefaults) {
report(ParseError, false, null(), JSMSG_NONDEFAULT_FORMAL_AFTER_DEFAULT);
return false;
}
break;
}
default:
report(ParseError, false, null(), JSMSG_MISSING_FORMAL);
/* FALL THROUGH */
case TOK_ERROR:
return false;
}
} while (!parenFreeArrow && tokenStream.matchToken(TOK_COMMA));
if (!parenFreeArrow && tokenStream.getToken() != TOK_RP) {
report(ParseError, false, null(), JSMSG_PAREN_AFTER_FORMAL);
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)) {
JS_ASSERT(!dn->isUsed());
JS_ASSERT(dn->isDefn());
if (context->hasExtraWarningsOption() || dn->kind() == Definition::CONST) {
JSAutoByteString name;
ParseReportKind reporter = (dn->kind() != Definition::CONST)
? ParseExtraWarning
: ParseError;
if (!js_AtomToPrintableString(context, funName, &name) ||
!report(reporter, false, NULL, 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 && !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)) {
JS_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 = NULL;
fn->pn_cookie.makeFree();
pc->lexdeps->remove(funName);
handler.freeTree(pn);
pn = fn;
}
if (!pc->define(context, funName, pn, Definition::VAR))
return false;
}
if (bodyLevel) {
JS_ASSERT(pn->functionIsHoisted());
JS_ASSERT_IF(pc->sc->isFunctionBox(), !pn->pn_cookie.isFree());
JS_ASSERT_IF(!pc->sc->isFunctionBox(), pn->pn_cookie.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.
*/
JS_ASSERT(!pc->sc->strict);
JS_ASSERT(pn->pn_cookie.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 = context->new_<FuncStmtSet>(context);
if (!pc->funcStmts || !pc->funcStmts->init())
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(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.
if (LazyScript *lazyOuter = handler.lazyOuterFunction()) {
JSFunction *fun = handler.nextLazyInnerFunction();
FunctionBox *funbox = newFunctionBox(fun, pc, /* strict = */ false);
if (!funbox)
return false;
handler.setFunctionBox(pn, funbox);
if (!addFreeVariablesFromLazyFunction(fun, pc))
return false;
// The position passed to tokenStream.advance() is relative to
// userbuf.base() while LazyScript::{begin,end} offsets are relative to
// the outermost script source. N.B: userbuf.base() is initialized
// (in TokenStream()) to begin() - column() so that column numbers in
// the lazily parsed script are correct.
uint32_t userbufBase = lazyOuter->begin() - lazyOuter->column();
tokenStream.advance(fun->lazyScript()->end() - userbufBase);
*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();
}
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.
LazyScript *lazy = fun->lazyScript();
HeapPtrAtom *freeVariables = lazy->freeVariables();
for (size_t i = 0; i < lazy->numFreeVariables(); i++) {
JSAtom *atom = freeVariables[i];
// 'arguments' will be implicitly bound within the inner function.
if (atom == context->names().arguments)
continue;
DefinitionNode dn = pc->decls().lookupFirst(atom);
if (!dn) {
dn = getOrCreateLexicalDependency(pc, atom);
if (!dn)
return false;
}
/* 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::CONST) {
JSAutoByteString name;
if (!js_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(context, 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>
typename ParseHandler::Node
Parser<ParseHandler>::functionDef(HandlePropertyName funName, const TokenStream::Position &start,
size_t startOffset, FunctionType type, FunctionSyntaxKind kind)
{
JS_ASSERT_IF(kind == Statement, funName);
/* Make a TOK_FUNCTION node. */
Node pn = handler.newFunctionDefinition();
if (!pn)
return null();
bool bodyProcessed;
if (!checkFunctionDefinition(funName, &pn, kind, &bodyProcessed))
return null();
if (bodyProcessed)
return pn;
RootedFunction fun(context, newFunction(pc, funName, kind));
if (!fun)
return null();
// If the outer scope is strict, immediately parse the function in strict
// mode. Otherwise, we parse it normally. If we see a "use strict"
// directive, we backup and reparse it as strict.
handler.setFunctionBody(pn, null());
bool initiallyStrict = pc->sc->strict;
bool becameStrict;
if (!functionArgsAndBody(pn, fun, funName, startOffset, type, kind, initiallyStrict,
&becameStrict))
{
if (initiallyStrict || !becameStrict || tokenStream.hadError())
return null();
// Reparse the function in strict mode.
tokenStream.seek(start);
if (funName && tokenStream.getToken() == TOK_ERROR)
return null();
handler.setFunctionBody(pn, null());
if (!functionArgsAndBody(pn, fun, funName, startOffset, type, kind, true))
return null();
}
return pn;
}
template <>
bool
Parser<FullParseHandler>::finishFunctionDefinition(ParseNode *pn, FunctionBox *funbox,
ParseNode *prelude, ParseNode *body)
{
pn->pn_pos.end = pos().end;
#if JS_HAS_DESTRUCTURING
/*
* If there were destructuring formal parameters, prepend the initializing
* comma expression that we synthesized to body. If the body is a return
* node, we must make a special PNK_SEQ node, to prepend the destructuring
* code without bracing the decompilation of the function body.
*/
if (prelude) {
if (!body->isArity(PN_LIST)) {
ParseNode *block;
block = ListNode::create(PNK_SEQ, &handler);
if (!block)
return false;
block->pn_pos = body->pn_pos;
block->initList(body);
body = block;
}
ParseNode *item = UnaryNode::create(PNK_SEMI, &handler);
if (!item)
return false;
item->pn_pos.begin = item->pn_pos.end = body->pn_pos.begin;
item->pn_kid = prelude;
item->pn_next = body->pn_head;
body->pn_head = item;
if (body->pn_tail == &body->pn_head)
body->pn_tail = &item->pn_next;
++body->pn_count;
body->pn_xflags |= PNX_DESTRUCT;
}
#endif
pn->pn_funbox = funbox;
pn->pn_body->append(body);
pn->pn_body->pn_pos = body->pn_pos;
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::finishFunctionDefinition(Node pn, FunctionBox *funbox,
Node prelude, 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::Create(context, fun, numFreeVariables, numInnerFunctions, versionNumber(),
funbox->bufStart, funbox->bufEnd,
funbox->startLine, funbox->startColumn);
if (!lazy)
return false;
HeapPtrAtom *freeVariables = lazy->freeVariables();
size_t i = 0;
for (AtomDefnRange r = pc->lexdeps->all(); !r.empty(); r.popFront())
freeVariables[i++].init(r.front().key());
JS_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();
if (funbox->usesArguments && funbox->usesApply)
lazy->setUsesArgumentsAndApply();
PropagateTransitiveParseFlags(funbox, lazy);
fun->initLazyScript(lazy);
return true;
}
template <>
bool
Parser<FullParseHandler>::functionArgsAndBody(ParseNode *pn, HandleFunction fun,
HandlePropertyName funName,
size_t startOffset, FunctionType type,
FunctionSyntaxKind kind,
bool strict, bool *becameStrict)
{
if (becameStrict)
*becameStrict = false;
ParseContext<FullParseHandler> *outerpc = pc;
// Create box for fun->object early to protect against last-ditch GC.
FunctionBox *funbox = newFunctionBox(fun, pc, strict);
if (!funbox)
return false;
// Try a syntax parse for this inner function.
do {
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);
parser->tokenStream.seek(position, tokenStream);
ParseContext<SyntaxParseHandler> funpc(parser, outerpc, funbox,
outerpc->staticLevel + 1, outerpc->blockidGen);
if (!funpc.init())
return false;
if (!parser->functionArgsAndBodyGeneric(SyntaxParseHandler::NodeGeneric,
fun, funName, type, kind, strict, becameStrict))
{
if (parser->hadAbortedSyntaxParse()) {
// Try again with a full parse.
parser->clearAbortedSyntaxParse();
break;
}
return false;
}
outerpc->blockidGen = funpc.blockidGen;
// Advance this parser over tokens processed by the syntax parser.
parser->tokenStream.tell(&position);
tokenStream.seek(position, parser->tokenStream);
}
pn->pn_funbox = funbox;
if (!addFreeVariablesFromLazyFunction(fun, pc))
return false;
pn->pn_blockid = outerpc->blockid();
PropagateTransitiveParseFlags(funbox, outerpc->sc);
return true;
} while (false);
// Continue doing a full parse for this inner function.
ParseContext<FullParseHandler> funpc(this, pc, funbox,
outerpc->staticLevel + 1, outerpc->blockidGen);
if (!funpc.init())
return false;
if (!functionArgsAndBodyGeneric(pn, fun, funName, type, kind, strict, becameStrict))
return false;
if (!leaveFunction(pn, funName, 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(Node pn, HandleFunction fun,
HandlePropertyName funName,
size_t startOffset, FunctionType type,
FunctionSyntaxKind kind,
bool strict, bool *becameStrict)
{
if (becameStrict)
*becameStrict = false;
ParseContext<SyntaxParseHandler> *outerpc = pc;
// Create box for fun->object early to protect against last-ditch GC.
FunctionBox *funbox = newFunctionBox(fun, pc, strict);
if (!funbox)
return false;
// Initialize early for possible flags mutation via destructuringExpr.
ParseContext<SyntaxParseHandler> funpc(this, pc, funbox,
outerpc->staticLevel + 1, outerpc->blockidGen);
if (!funpc.init())
return false;
if (!functionArgsAndBodyGeneric(pn, fun, funName, type, kind, strict, becameStrict))
return false;
if (!leaveFunction(pn, funName, 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.
JS_ASSERT(fun->lazyScript());
return outerpc->innerFunctions.append(fun);
}
template <>
ParseNode *
Parser<FullParseHandler>::standaloneLazyFunction(HandleFunction fun, unsigned staticLevel,
bool strict)
{
Node pn = handler.newFunctionDefinition();
if (!pn)
return null();
FunctionBox *funbox = newFunctionBox(fun, /* outerpc = */ NULL, strict);
if (!funbox)
return null();
handler.setFunctionBox(pn, funbox);
ParseContext<FullParseHandler> funpc(this, NULL, funbox, staticLevel, 0);
if (!funpc.init())
return null();
RootedPropertyName funName(context, fun->atom() ? fun->atom()->asPropertyName() : NULL);
if (!functionArgsAndBodyGeneric(pn, fun, funName, Normal, Statement, strict, NULL))
return null();
if (fun->isNamedLambda()) {
if (AtomDefnPtr p = pc->lexdeps->lookup(funName)) {
Definition *dn = p.value().get<FullParseHandler>();
if (!ConvertDefinitionToNamedLambdaUse(context, pc, funbox, dn))
return NULL;
}
}
InternalHandle<Bindings*> bindings =
InternalHandle<Bindings*>::fromMarkedLocation(&funbox->bindings);
if (!pc->generateFunctionBindings(context, bindings))
return null();
return pn;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::functionArgsAndBodyGeneric(Node pn, HandleFunction fun,
HandlePropertyName funName, FunctionType type,
FunctionSyntaxKind kind,
bool strict, bool *becameStrict)
{
// 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.
Node prelude = null();
bool hasRest;
if (!functionArguments(kind, &prelude, pn, hasRest))
return false;
FunctionBox *funbox = pc->sc->asFunctionBox();
fun->setArgCount(pc->numArgs());
if (funbox->ndefaults)
fun->setHasDefaults();
if (hasRest)
fun->setHasRest();
if (type == Getter && fun->nargs > 0) {
report(ParseError, false, null(), JSMSG_ACCESSOR_WRONG_ARGS, "getter", "no", "s");
return false;
}
if (type == Setter && fun->nargs != 1) {
report(ParseError, false, null(), JSMSG_ACCESSOR_WRONG_ARGS, "setter", "one", "");
return false;
}
if (kind == Arrow && !tokenStream.matchToken(TOK_ARROW)) {
report(ParseError, false, null(), JSMSG_BAD_ARROW_ARGS);
return false;
}
// Parse the function body.
Maybe<GenexpGuard<ParseHandler> > yieldGuard;
if (kind == Arrow)
yieldGuard.construct(this);
FunctionBodyType bodyType = StatementListBody;
if (tokenStream.getToken(TSF_OPERAND) != TOK_LC) {
tokenStream.ungetToken();
bodyType = ExpressionBody;
fun->setIsExprClosure();
}
Node body = functionBody(kind, bodyType);
if (!body) {
// Notify the caller if this function was discovered to be strict.
if (becameStrict && pc->funBecameStrict)
*becameStrict = true;
return false;
}
if (!yieldGuard.empty() && !yieldGuard.ref().checkValidBody(body, JSMSG_YIELD_IN_ARROW))
return false;
if (funName && !checkStrictBinding(funName, pn))
return false;
#if JS_HAS_EXPR_CLOSURES
if (bodyType == StatementListBody) {
#endif
if (!tokenStream.matchToken(TOK_RC)) {
report(ParseError, false, null(), JSMSG_CURLY_AFTER_BODY);
return false;
}
funbox->bufEnd = pos().begin + 1;
#if JS_HAS_EXPR_CLOSURES
} else {
if (tokenStream.hadError())
return false;
funbox->bufEnd = pos().end;
if (kind == Statement && !MatchOrInsertSemicolon(context, &tokenStream))
return false;
}
#endif
return finishFunctionDefinition(pn, funbox, prelude, body);
}
template <>
ParseNode *
Parser<FullParseHandler>::moduleDecl()
{
JS_ASSERT(tokenStream.currentToken().name() == context->runtime()->atomState.module);
if (!((pc->sc->isGlobalSharedContext() || pc->sc->isModuleBox()) && pc->atBodyLevel()))
{
report(ParseError, false, NULL, JSMSG_MODULE_STATEMENT);
return NULL;
}
ParseNode *pn = CodeNode::create(PNK_MODULE, &handler);
if (!pn)
return NULL;
JS_ALWAYS_TRUE(tokenStream.matchToken(TOK_STRING));
RootedAtom atom(context, tokenStream.currentToken().atom());
Module *module = Module::create(context, atom);
if (!module)
return NULL;
ModuleBox *modulebox = newModuleBox(module, pc);
if (!modulebox)
return NULL;
pn->pn_modulebox = modulebox;
ParseContext<FullParseHandler> modulepc(this, pc, modulebox, pc->staticLevel + 1, pc->blockidGen);
if (!modulepc.init())
return NULL;
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_MODULE);
pn->pn_body = statements();
if (!pn->pn_body)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_MODULE);
return pn;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::moduleDecl()
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionStmt()
{
JS_ASSERT(tokenStream.currentToken().type == TOK_FUNCTION);
RootedPropertyName name(context);
if (tokenStream.getToken(TSF_KEYWORD_IS_NAME) == TOK_NAME) {
name = tokenStream.currentToken().name();
} else {
/* Unnamed function expressions are forbidden in statement context. */
report(ParseError, false, null(), JSMSG_UNNAMED_FUNCTION_STMT);
return null();
}
TokenStream::Position start(keepAtoms);
tokenStream.positionAfterLastFunctionKeyword(start);
/* 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(name, start, tokenStream.positionToOffset(start), Normal, Statement);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::functionExpr()
{
RootedPropertyName name(context);
JS_ASSERT(tokenStream.currentToken().type == TOK_FUNCTION);
TokenStream::Position start(keepAtoms);
tokenStream.positionAfterLastFunctionKeyword(start);
if (tokenStream.getToken(TSF_KEYWORD_IS_NAME) == TOK_NAME)
name = tokenStream.currentToken().name();
else
tokenStream.ungetToken();
return functionDef(name, start, tokenStream.positionToOffset(start), Normal, Expression);
}
/*
* 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;
}
/*
* 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 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->runtime()->atomState.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->funBecameStrict = true;
return false;
} else {
// 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->strict = true;
}
}
} else if (directive == context->names().useAsm) {
if (pc->sc->isFunctionBox()) {
pc->sc->asFunctionBox()->useAsm = true;
pc->sc->asFunctionBox()->asmStart = handler.getPosition(pn).begin;
if (!abortIfSyntaxParser())
return false;
} else {
if (!report(ParseWarning, false, pn, JSMSG_USE_ASM_DIRECTIVE_FAIL))
return false;
}
}
}
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()
{
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();
for (;;) {
TokenKind tt = tokenStream.peekToken(TSF_OPERAND);
if (tt <= TOK_EOF || tt == TOK_RC) {
if (tt == TOK_ERROR) {
if (tokenStream.isEOF())
tokenStream.setUnexpectedEOF();
return null();
}
break;
}
Node next = statement(canHaveDirectives);
if (!next) {
if (tokenStream.isEOF())
tokenStream.setUnexpectedEOF();
return null();
}
if (canHaveDirectives) {
if (!maybeParseDirective(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()
{
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_COND);
Node pn = parenExpr();
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.isOperationWithoutParens(pn, PNK_ASSIGN) &&
!report(ParseExtraWarning, false, null(), JSMSG_EQUAL_AS_ASSIGN))
{
return null();
}
return pn;
}
static bool
MatchLabel(JSContext *cx, TokenStream *ts, MutableHandlePropertyName label)
{
TokenKind tt = ts->peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_ERROR)
return false;
if (tt == TOK_NAME) {
(void) ts->getToken();
label.set(ts->currentToken().name());
} else {
label.set(NULL);
}
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::reportRedeclaration(Node pn, bool isConst, JSAtom *atom)
{
JSAutoByteString name;
if (js_AtomToPrintableString(context, atom, &name))
report(ParseError, false, pn, JSMSG_REDECLARED_VAR, isConst ? "const" : "variable", name.ptr());
return false;
}
/*
* Define a let-variable in a block, let-expression, 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->blockChain;
* 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>::bindLet(JSContext *cx, BindData<FullParseHandler> *data,
HandlePropertyName name, Parser<FullParseHandler> *parser)
{
ParseContext<FullParseHandler> *pc = parser->pc;
ParseNode *pn = data->pn;
if (!parser->checkStrictBinding(name, pn))
return false;
Rooted<StaticBlockObject *> blockObj(cx, data->let.blockObj);
unsigned blockCount = blockObj->slotCount();
if (blockCount == JS_BIT(16)) {
parser->report(ParseError, false, pn, data->let.overflow);
return false;
}
/*
* Assign block-local index to pn->pn_cookie right away, encoding it as an
* upvar cookie whose skip tells the current static level. 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.
*/
if (!pn->pn_cookie.set(parser->context, pc->staticLevel, uint16_t(blockCount)))
return false;
/*
* For bindings that are hoisted to the beginning of the block/function,
* define() right now. Otherwise, delay define until PushLetScope.
*/
if (data->let.varContext == HoistVars) {
JS_ASSERT(!pc->atBodyLevel());
Definition *dn = pc->decls().lookupFirst(name);
if (dn && dn->pn_blockid == pc->blockid())
return parser->reportRedeclaration(pn, dn->isConst(), name);
if (!pc->define(cx, name, pn, Definition::LET))
return false;
}
/*
* Define the let binding's property before storing pn in the the binding's
* slot indexed by blockCount off the class-reserved slot base.
*/
bool redeclared;
RootedId id(cx, NameToId(name));
RootedShape shape(cx, StaticBlockObject::addVar(cx, blockObj, id, blockCount, &redeclared));
if (!shape) {
if (redeclared)
parser->reportRedeclaration(pn, false, name);
return false;
}
/* Store pn in the static block object. */
blockObj->setDefinitionParseNode(blockCount, reinterpret_cast<Definition *>(pn));
return true;
}
template <>
/* static */ bool
Parser<SyntaxParseHandler>::bindLet(JSContext *cx, BindData<SyntaxParseHandler> *data,
HandlePropertyName name, Parser<SyntaxParseHandler> *parser)
{
return true;
}
template <typename ParseHandler, class Op>
static inline bool
ForEachLetDef(JSContext *cx, ParseContext<ParseHandler> *pc,
HandleStaticBlockObject blockObj, Op op)
{
for (Shape::Range<CanGC> r(cx, blockObj->lastProperty()); !r.empty(); r.popFront()) {
Shape &shape = r.front();
/* Beware the destructuring dummy slots. */
if (JSID_IS_INT(shape.propid()))
continue;
if (!op(cx, pc, blockObj, shape, JSID_TO_ATOM(shape.propid())))
return false;
}
return true;
}
template <typename ParseHandler>
struct PopLetDecl {
bool operator()(JSContext *, ParseContext<ParseHandler> *pc, HandleStaticBlockObject,
const Shape &, JSAtom *atom)
{
pc->popLetDecl(atom);
return true;
}
};
template <typename ParseHandler>
static void
PopStatementPC(JSContext *cx, ParseContext<ParseHandler> *pc)
{
RootedStaticBlockObject blockObj(cx, pc->topStmt->blockObj);
JS_ASSERT(!!blockObj == (pc->topStmt->isBlockScope));
FinishPopStatement(pc);
if (blockObj) {
JS_ASSERT(!blockObj->inDictionaryMode());
ForEachLetDef(cx, pc, blockObj, PopLetDecl<ParseHandler>());
blockObj->resetPrevBlockChainFromParser();
}
}
/*
* 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 NULL.
*/
template <class ContextT>
typename ContextT::StmtInfo *
LexicalLookup(ContextT *ct, HandleAtom atom, int *slotp, typename ContextT::StmtInfo *stmt)
{
RootedId id(ct->sc->context, AtomToId(atom));
if (!stmt)
stmt = ct->topScopeStmt;
for (; stmt; stmt = stmt->downScope) {
/*
* 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 == STMT_WITH)
break;
// Skip statements that do not introduce a new scope
if (!stmt->isBlockScope)
continue;
StaticBlockObject &blockObj = *stmt->blockObj;
Shape *shape = blockObj.nativeLookup(ct->sc->context, id);
if (shape) {
JS_ASSERT(shape->hasShortID());
if (slotp)
*slotp = blockObj.stackDepth() + shape->shortid();
return stmt;
}
}
if (slotp)
*slotp = -1;
return stmt;
}
template <typename ParseHandler>
static inline bool
OuterLet(ParseContext<ParseHandler> *pc, StmtInfoPC *stmt, HandleAtom atom)
{
while (stmt->downScope) {
stmt = LexicalLookup(pc, atom, NULL, stmt->downScope);
if (!stmt)
return false;
if (stmt->type == STMT_BLOCK)
return true;
}
return false;
}
template <typename ParseHandler>
/* static */ bool
Parser<ParseHandler>::bindVarOrConst(JSContext *cx, BindData<ParseHandler> *data,
HandlePropertyName name, Parser<ParseHandler> *parser)
{
ParseContext<ParseHandler> *pc = parser->pc;
Node pn = data->pn;
bool isConstDecl = data->op == JSOP_DEFCONST;
/* Default best op for pn is JSOP_NAME; we'll try to improve below. */
parser->handler.setOp(pn, JSOP_NAME);
if (!parser->checkStrictBinding(name, pn))
return false;
StmtInfoPC *stmt = LexicalLookup(pc, name, NULL, (StmtInfoPC *)NULL);
if (stmt && stmt->type == STMT_WITH) {
parser->handler.setFlag(pn, PND_DEOPTIMIZED);
if (pc->sc->isFunctionBox()) {
FunctionBox *funbox = pc->sc->asFunctionBox();
funbox->setMightAliasLocals();
/*
* This definition isn't being added to the parse context's
* declarations, so make sure to indicate the need to deoptimize
* the script's arguments object.
*/
HandlePropertyName arguments = cx->names().arguments;
if (name == arguments) {
Node pn = parser->newName(arguments);
if (!pc->define(parser->context, arguments, pn, Definition::VAR))
return false;
funbox->setArgumentsHasLocalBinding();
funbox->setDefinitelyNeedsArgsObj();
}
}
return true;
}
DefinitionList::Range defs = pc->decls().lookupMulti(name);
JS_ASSERT_IF(stmt, !defs.empty());
if (defs.empty())
return pc->define(cx, name, pn, isConstDecl ? Definition::CONST : 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 (!js_AtomToPrintableString(cx, name, &bytes))
return false;
if (isConstDecl) {
parser->report(ParseError, false, pn, JSMSG_REDECLARED_PARAM, bytes.ptr());
return false;
}
if (!parser->report(ParseExtraWarning, false, pn, JSMSG_VAR_HIDES_ARG, bytes.ptr()))
return false;
} else {
bool error = (isConstDecl ||
dn_kind == Definition::CONST ||
(dn_kind == Definition::LET &&
(stmt->type != STMT_CATCH || OuterLet(pc, stmt, name))));
if (cx->hasExtraWarningsOption()
? data->op != JSOP_DEFVAR || dn_kind != Definition::VAR
: error)
{
JSAutoByteString bytes;
ParseReportKind reporter = error ? ParseError : ParseExtraWarning;
if (!js_AtomToPrintableString(cx, name, &bytes) ||
!parser->report(reporter, false, pn, JSMSG_REDECLARED_VAR,
Definition::kindString(dn_kind), bytes.ptr()))
{
return false;
}
}
}
parser->handler.linkUseToDef(pn, dn);
return true;
}
template <>
bool
Parser<FullParseHandler>::makeSetCall(ParseNode *pn, unsigned msg)
{
JS_ASSERT(pn->isKind(PNK_CALL));
JS_ASSERT(pn->isArity(PN_LIST));
JS_ASSERT(pn->isOp(JSOP_CALL) || pn->isOp(JSOP_EVAL) ||
pn->isOp(JSOP_FUNCALL) || pn->isOp(JSOP_FUNAPPLY));
if (!report(ParseStrictError, pc->sc->strict, pn, msg))
return false;
handler.markAsSetCall(pn);
return true;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::noteNameUse(HandlePropertyName name, Node pn)
{
StmtInfoPC *stmt = LexicalLookup(pc, name, NULL, (StmtInfoPC *)NULL);
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 && stmt->type == STMT_WITH)
handler.setFlag(pn, PND_DEOPTIMIZED);
return true;
}
#if JS_HAS_DESTRUCTURING
template <>
bool
Parser<FullParseHandler>::bindDestructuringVar(BindData<FullParseHandler> *data, ParseNode *pn)
{
JS_ASSERT(pn->isKind(PNK_NAME));
RootedPropertyName name(context, pn->pn_atom->asPropertyName());
data->pn = pn;
if (!data->binder(context, data, name, this))
return false;
/*
* Select the appropriate name-setting opcode, respecting eager selection
* done by the data->binder function.
*/
if (pn->pn_dflags & PND_BOUND)
pn->setOp(JSOP_SETLOCAL);
else if (data->op == JSOP_DEFCONST)
pn->setOp(JSOP_SETCONST);
else
pn->setOp(JSOP_SETNAME);
if (data->op == JSOP_DEFCONST)
pn->pn_dflags |= PND_CONST;
pn->markAsAssigned();
return true;
}
/*
* Here, we are destructuring {... P: Q, ...} = R, where P is any id, Q is any
* LHS expression except a destructuring initialiser, and R is on the stack.
* Because R is already evaluated, the usual LHS-specialized bytecodes won't
* work. After pushing R[P] we need to evaluate Q's "reference base" QB and
* then push its property name QN. At this point the stack looks like
*
* [... R, R[P], QB, QN]
*
* We need to set QB[QN] = R[P]. This is a job for JSOP_ENUMELEM, which takes
* its operands with left-hand side above right-hand side:
*
* [rval, lval, xval]
*
* and pops all three values, setting lval[xval] = rval. But we cannot select
* JSOP_ENUMELEM yet, because the LHS may turn out to be an arg or local var,
* which can be optimized further. So we select JSOP_SETNAME.
*/
template <>
bool
Parser<FullParseHandler>::bindDestructuringLHS(ParseNode *pn)
{
switch (pn->getKind()) {
case PNK_NAME:
pn->markAsAssigned();
/* FALL THROUGH */
case PNK_DOT:
case PNK_ELEM:
/*
* We may be called on a name node that has already been specialized,
* in the very weird and ECMA-262-required "for (var [x] = i in o) ..."
* case. See bug 558633.
*/
if (!(js_CodeSpec[pn->getOp()].format & JOF_SET))
pn->setOp(JSOP_SETNAME);
break;
case PNK_CALL:
if (!makeSetCall(pn, JSMSG_BAD_LEFTSIDE_OF_ASS))
return false;
break;
default:
report(ParseError, false, pn, JSMSG_BAD_LEFTSIDE_OF_ASS);
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.
*
* - declaration-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 CheckDestructuring, verify that the
* tree is a valid destructuring expression.
*
* 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. CheckDestructuring is called with |data| NULL (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
* CheckDestructuring, 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.
*
* The 'toplevel' is a private detail of the recursive strategy used by
* CheckDestructuring and callers should use the default value.
*/
template <>
bool
Parser<FullParseHandler>::checkDestructuring(BindData<FullParseHandler> *data,
ParseNode *left, bool toplevel)
{
bool ok;
if (left->isKind(PNK_ARRAYCOMP)) {
report(ParseError, false, left, JSMSG_ARRAY_COMP_LEFTSIDE);
return false;
}
Rooted<StaticBlockObject *> blockObj(context);
blockObj = data && data->binder == bindLet ? data->let.blockObj.get() : NULL;
uint32_t blockCountBefore = blockObj ? blockObj->slotCount() : 0;
if (left->isKind(PNK_ARRAY)) {
for (ParseNode *pn = left->pn_head; pn; pn = pn->pn_next) {
if (!pn->isKind(PNK_ELISION)) {
if (pn->isKind(PNK_ARRAY) || pn->isKind(PNK_OBJECT)) {
ok = checkDestructuring(data, pn, false);
} else {
if (data) {
if (!pn->isKind(PNK_NAME)) {
report(ParseError, false, pn, JSMSG_NO_VARIABLE_NAME);
return false;
}
ok = bindDestructuringVar(data, pn);
} else {
ok = bindDestructuringLHS(pn);
}
}
if (!ok)
return false;
}
}
} else {
JS_ASSERT(left->isKind(PNK_OBJECT));
for (ParseNode *pair = left->pn_head; pair; pair = pair->pn_next) {
JS_ASSERT(pair->isKind(PNK_COLON));
ParseNode *pn = pair->pn_right;
if (pn->isKind(PNK_ARRAY) || pn->isKind(PNK_OBJECT)) {
ok = checkDestructuring(data, pn, false);
} else if (data) {
if (!pn->isKind(PNK_NAME)) {
report(ParseError, false, pn, JSMSG_NO_VARIABLE_NAME);
return false;
}
ok = bindDestructuringVar(data, pn);
} else {
/*
* If right and left point to the same node, then this is
* destructuring shorthand ({x} = ...). In that case,
* identifierName was not used to parse 'x' so 'x' has not been
* officially linked to its def or registered in lexdeps. Do
* that now.
*/
if (pair->pn_right == pair->pn_left) {
RootedPropertyName name(context, pn->pn_atom->asPropertyName());
if (!noteNameUse(name, pn))
return false;
}
ok = bindDestructuringLHS(pn);
}
if (!ok)
return false;
}
}
/*
* The catch/finally handler implementation in the interpreter assumes
* that any operation that introduces a new scope (like a "let" or "with"
* block) increases the stack depth. This way, it is possible to restore
* the scope chain based on stack depth of the handler alone. "let" with
* an empty destructuring pattern like in
*
* let [] = 1;
*
* would violate this assumption as the there would be no let locals to
* store on the stack.
*
* Furthermore, the decompiler needs an abstract stack location to store
* the decompilation of each let block/expr initializer. E.g., given:
*
* let (x = 1, [[]] = b, y = 3, {a:[]} = c) { ... }
*
* four slots are needed.
*
* To satisfy both constraints, we push a dummy slot (and add a
* corresponding dummy property to the block object) for each initializer
* that doesn't introduce at least one binding.
*/
if (toplevel && blockObj && blockCountBefore == blockObj->slotCount()) {
bool redeclared;
RootedId id(context, INT_TO_JSID(blockCountBefore));
if (!StaticBlockObject::addVar(context, blockObj, id, blockCountBefore, &redeclared))
return false;
JS_ASSERT(!redeclared);
JS_ASSERT(blockObj->slotCount() == blockCountBefore + 1);
}
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::checkDestructuring(BindData<SyntaxParseHandler> *data,
Node left, bool toplevel)
{
return abortIfSyntaxParser();
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::destructuringExpr(BindData<ParseHandler> *data, TokenKind tt)
{
JS_ASSERT(tokenStream.isCurrentTokenType(tt));
pc->inDeclDestructuring = true;
Node pn = primaryExpr(tt);
pc->inDeclDestructuring = false;
if (!pn)
return null();
if (!checkDestructuring(data, pn))
return null();
return pn;
}
#endif /* JS_HAS_DESTRUCTURING */
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::pushLexicalScope(HandleStaticBlockObject blockObj, StmtInfoPC *stmt)
{
JS_ASSERT(blockObj);
ObjectBox *blockbox = newObjectBox(blockObj);
if (!blockbox)
return null();
PushStatementPC(pc, stmt, STMT_BLOCK);
blockObj->initPrevBlockChainFromParser(pc->blockChain);
FinishPushBlockScope(pc, stmt, *blockObj.get());
Node pn = handler.newLexicalScope(blockbox);
if (!pn)
return null();
if (!GenerateBlockId(pc, stmt->blockid))
return null();
handler.setBlockId(pn, stmt->blockid);
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::pushLexicalScope(StmtInfoPC *stmt)
{
RootedStaticBlockObject blockObj(context, StaticBlockObject::create(context));
if (!blockObj)
return null();
return pushLexicalScope(blockObj, stmt);
}
#if JS_HAS_BLOCK_SCOPE
struct AddLetDecl
{
uint32_t blockid;
AddLetDecl(uint32_t blockid) : blockid(blockid) {}
bool operator()(JSContext *cx, ParseContext<FullParseHandler> *pc,
HandleStaticBlockObject blockObj, const Shape &shape, JSAtom *)
{
ParseNode *def = (ParseNode *) blockObj->getSlot(shape.slot()).toPrivate();
def->pn_blockid = blockid;
RootedPropertyName name(cx, def->name());
return pc->define(cx, name, def, Definition::LET);
}
};
template <>
ParseNode *
Parser<FullParseHandler>::pushLetScope(HandleStaticBlockObject blockObj, StmtInfoPC *stmt)
{
JS_ASSERT(blockObj);
ParseNode *pn = pushLexicalScope(blockObj, stmt);
if (!pn)
return null();
/* Tell codegen to emit JSOP_ENTERLETx (not JSOP_ENTERBLOCK). */
pn->pn_dflags |= PND_LET;
/* Populate the new scope with decls found in the head with updated blockid. */
if (!ForEachLetDef(context, pc, blockObj, AddLetDecl(stmt->blockid)))
return null();
return pn;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::pushLetScope(HandleStaticBlockObject blockObj, StmtInfoPC *stmt)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
/*
* Parse a let block statement or let expression (determined by 'letContext').
* In both cases, bindings are not hoisted to the top of the enclosing block
* and thus must be carefully injected between variables() and the let body.
*/
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::letBlock(LetContext letContext)
{
JS_ASSERT(tokenStream.currentToken().type == TOK_LET);
RootedStaticBlockObject blockObj(context, StaticBlockObject::create(context));
if (!blockObj)
return null();
uint32_t begin = pos().begin;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_LET);
Node vars = variables(PNK_LET, NULL, blockObj, DontHoistVars);
if (!vars)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_LET);
StmtInfoPC stmtInfo(context);
Node block = pushLetScope(blockObj, &stmtInfo);
if (!block)
return null();
Node pnlet = handler.newBinary(PNK_LET, vars, block);
if (!pnlet)
return null();
handler.setBeginPosition(pnlet, begin);
bool needExprStmt = false;
if (letContext == LetStatement && !tokenStream.matchToken(TOK_LC, TSF_OPERAND)) {
/*
* Strict mode eliminates a grammar ambiguity with unparenthesized
* LetExpressions in an ExpressionStatement. If followed immediately
* by an arguments list, it's ambiguous whether the let expression
* is the callee or the call is inside the let expression body.
*
* See bug 569464.
*/
if (!report(ParseStrictError, pc->sc->strict, pnlet,
JSMSG_STRICT_CODE_LET_EXPR_STMT))
{
return null();
}
/*
* If this is really an expression in let statement guise, then we
* need to wrap the PNK_LET node in a PNK_SEMI node so that we pop
* the return value of the expression.
*/
needExprStmt = true;
letContext = LetExpresion;
}
Node expr;
if (letContext == LetStatement) {
expr = statements();
if (!expr)
return null();
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_LET);
} else {
JS_ASSERT(letContext == LetExpresion);
expr = assignExpr();
if (!expr)
return null();
}
handler.setLeaveBlockResult(block, expr, letContext != LetStatement);
PopStatementPC(context, pc);
handler.setEndPosition(pnlet, pos().end);
if (needExprStmt) {
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
return handler.newExprStatement(pnlet, pos().end);
}
return pnlet;
}
#endif /* JS_HAS_BLOCK_SCOPE */
template <typename ParseHandler>
static bool
PushBlocklikeStatement(StmtInfoPC *stmt, StmtType type, ParseContext<ParseHandler> *pc)
{
PushStatementPC(pc, stmt, type);
return GenerateBlockId(pc, stmt->blockid);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::blockStatement()
{
JS_ASSERT(tokenStream.currentToken().type == TOK_LC);
StmtInfoPC stmtInfo(context);
if (!PushBlocklikeStatement(&stmtInfo, STMT_BLOCK, pc))
return null();
Node list = statements();
if (!list)
return null();
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_IN_COMPOUND);
PopStatementPC(context, pc);
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>();
JS_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). */
JS_ASSERT(tokenStream.currentToken().type == TOK_NAME);
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(ParseNodeKind kind, bool *psimple,
StaticBlockObject *blockObj, VarContext varContext)
{
/*
* The four options here are:
* - PNK_VAR: We're parsing var declarations.
* - PNK_CONST: We're parsing const declarations.
* - PNK_LET: We are parsing a let declaration.
* - PNK_CALL: We are parsing the head of a let block.
*/
JS_ASSERT(kind == PNK_VAR || kind == PNK_CONST || kind == PNK_LET || kind == PNK_CALL);
/*
* The simple flag is set if the declaration has the form 'var x', with
* only one variable declared and no initializer expression.
*/
JS_ASSERT_IF(psimple, *psimple);
JSOp op = blockObj ? JSOP_NOP : kind == PNK_VAR ? JSOP_DEFVAR : JSOP_DEFCONST;
Node pn = handler.newList(kind, null(), op);
if (!pn)
return null();
/*
* SpiderMonkey const is really "write once per initialization evaluation"
* var, whereas let is block scoped. ES-Harmony wants block-scoped const so
* this code will change soon.
*/
BindData<ParseHandler> data(context);
if (blockObj)
data.initLet(varContext, *blockObj, JSMSG_TOO_MANY_LOCALS);
else
data.initVarOrConst(op);
bool first = true;
Node pn2;
do {
if (psimple && !first)
*psimple = false;
first = false;
TokenKind tt = tokenStream.getToken();
#if JS_HAS_DESTRUCTURING
if (tt == TOK_LB || tt == TOK_LC) {
if (psimple)
*psimple = false;
pc->inDeclDestructuring = true;
pn2 = primaryExpr(tt);
pc->inDeclDestructuring = false;
if (!pn2)
return null();
if (!checkDestructuring(&data, pn2))
return null();
bool ignored;
if (pc->parsingForInit && matchInOrOf(&ignored)) {
tokenStream.ungetToken();
handler.addList(pn, pn2);
continue;
}
MUST_MATCH_TOKEN(TOK_ASSIGN, JSMSG_BAD_DESTRUCT_DECL);
JS_ASSERT(tokenStream.currentToken().t_op == JSOP_NOP);
Node init = assignExpr();
if (!init)
return null();
pn2 = handler.newBinaryOrAppend(PNK_ASSIGN, pn2, init, pc);
if (!pn2)
return null();
handler.addList(pn, pn2);
continue;
}
#endif /* JS_HAS_DESTRUCTURING */
if (tt != TOK_NAME) {
if (tt != TOK_ERROR)
report(ParseError, false, null(), JSMSG_NO_VARIABLE_NAME);
return null();
}
RootedPropertyName name(context, tokenStream.currentToken().name());
pn2 = newBindingNode(name, kind == PNK_VAR || kind == PNK_CONST, varContext);
if (!pn2)
return null();
if (data.op == JSOP_DEFCONST)
handler.setFlag(pn2, PND_CONST);
data.pn = pn2;
if (!data.binder(context, &data, name, this))
return null();
handler.addList(pn, pn2);
if (tokenStream.matchToken(TOK_ASSIGN)) {
JS_ASSERT(tokenStream.currentToken().t_op == JSOP_NOP);
if (psimple)
*psimple = false;
Node init = assignExpr();
if (!init)
return null();
if (!handler.finishInitializerAssignment(pn2, init, data.op))
return null();
}
} while (tokenStream.matchToken(TOK_COMMA));
return pn;
}
#if JS_HAS_BLOCK_SCOPE
template <>
ParseNode *
Parser<FullParseHandler>::letStatement()
{
handler.disableSyntaxParser();
ParseNode *pn;
do {
/* Check for a let statement or let expression. */
if (tokenStream.peekToken() == TOK_LP) {
pn = letBlock(LetStatement);
JS_ASSERT_IF(pn, pn->isKind(PNK_LET) || pn->isKind(PNK_SEMI));
JS_ASSERT_IF(pn && pn->isKind(PNK_LET) && pn->pn_expr->getOp() != JSOP_LEAVEBLOCK,
pn->isOp(JSOP_NOP));
return pn;
}
/*
* This is a let 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->topStmt;
if (stmt && (!stmt->maybeScope() || stmt->isForLetBlock)) {
report(ParseError, false, null(), JSMSG_LET_DECL_NOT_IN_BLOCK);
return null();
}
if (stmt && stmt->isBlockScope) {
JS_ASSERT(pc->blockChain == stmt->blockObj);
} else {
if (pc->atBodyLevel()) {
/*
* ES4 specifies that let at top level and at body-block scope
* does not shadow var, so convert back to var.
*/
pn = variables(PNK_VAR);
if (!pn)
return null();
pn->pn_xflags |= PNX_POPVAR;
break;
}
/*
* 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).
*/
JS_ASSERT(!stmt->isBlockScope);
JS_ASSERT(stmt != pc->topScopeStmt);
JS_ASSERT(stmt->type == STMT_BLOCK ||
stmt->type == STMT_SWITCH ||
stmt->type == STMT_TRY ||
stmt->type == STMT_FINALLY);
JS_ASSERT(!stmt->downScope);
/* Convert the block statement into a scope statement. */
StaticBlockObject *blockObj = StaticBlockObject::create(context);
if (!blockObj)
return null();
ObjectBox *blockbox = newObjectBox(blockObj);
if (!blockbox)
return null();
/*
* Insert stmt on the pc->topScopeStmt/stmtInfo.downScope linked
* list stack, if it isn't already there. If it is there, but it
* lacks the SIF_SCOPE flag, it must be a try, catch, or finally
* block.
*/
stmt->isBlockScope = true;
stmt->downScope = pc->topScopeStmt;
pc->topScopeStmt = stmt;
blockObj->initPrevBlockChainFromParser(pc->blockChain);
pc->blockChain = blockObj;
stmt->blockObj = blockObj;
#ifdef DEBUG
ParseNode *tmp = pc->blockNode;
JS_ASSERT(!tmp || !tmp->isKind(PNK_LEXICALSCOPE));
#endif
/* Create a new lexical scope node for these statements. */
ParseNode *pn1 = LexicalScopeNode::create(PNK_LEXICALSCOPE, &handler);
if (!pn1)
return null();
pn1->setOp(JSOP_LEAVEBLOCK);
pn1->pn_pos = pc->blockNode->pn_pos;
pn1->pn_objbox = blockbox;
pn1->pn_expr = pc->blockNode;
pn1->pn_blockid = pc->blockNode->pn_blockid;
pc->blockNode = pn1;
}
pn = variables(PNK_LET, NULL, pc->blockChain, HoistVars);
if (!pn)
return null();
pn->pn_xflags = PNX_POPVAR;
} while (0);
/* Check termination of this primitive statement. */
return MatchOrInsertSemicolon(context, &tokenStream) ? pn : NULL;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::letStatement()
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
#endif // JS_HAS_BLOCK_SCOPE
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::expressionStatement()
{
tokenStream.ungetToken();
Node pnexpr = expr();
if (!pnexpr)
return null();
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
return handler.newExprStatement(pnexpr, pos().end);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::ifStatement()
{
uint32_t begin = pos().begin;
/* An IF node has three kids: condition, then, and optional else. */
Node cond = condition();
if (!cond)
return null();
if (tokenStream.peekToken(TSF_OPERAND) == TOK_SEMI &&
!report(ParseExtraWarning, false, null(), JSMSG_EMPTY_CONSEQUENT))
{
return null();
}
StmtInfoPC stmtInfo(context);
PushStatementPC(pc, &stmtInfo, STMT_IF);
Node thenBranch = statement();
if (!thenBranch)
return null();
Node elseBranch;
if (tokenStream.matchToken(TOK_ELSE, TSF_OPERAND)) {
stmtInfo.type = STMT_ELSE;
elseBranch = statement();
if (!elseBranch)
return null();
} else {
elseBranch = null();
}
PopStatementPC(context, pc);
return handler.newIfStatement(begin, cond, thenBranch, elseBranch);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::doWhileStatement()
{
uint32_t begin = pos().begin;
StmtInfoPC stmtInfo(context);
PushStatementPC(pc, &stmtInfo, STMT_DO_LOOP);
Node body = statement();
if (!body)
return null();
MUST_MATCH_TOKEN(TOK_WHILE, JSMSG_WHILE_AFTER_DO);
Node cond = condition();
if (!cond)
return null();
PopStatementPC(context, pc);
if (versionNumber() == JSVERSION_ECMA_3) {
// Pedantically require a semicolon or line break, following ES3.
// Bug 880329 proposes removing this case.
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
} else {
// 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
(void) tokenStream.matchToken(TOK_SEMI);
}
return handler.newDoWhileStatement(body, cond, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::whileStatement()
{
uint32_t begin = pos().begin;
StmtInfoPC stmtInfo(context);
PushStatementPC(pc, &stmtInfo, STMT_WHILE_LOOP);
Node cond = condition();
if (!cond)
return null();
Node body = statement();
if (!body)
return null();
PopStatementPC(context, pc);
return handler.newWhileStatement(begin, cond, body);
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::matchInOrOf(bool *isForOfp)
{
if (tokenStream.matchToken(TOK_IN)) {
*isForOfp = false;
return true;
}
if (tokenStream.matchToken(TOK_NAME)) {
if (tokenStream.currentToken().name() == context->names().of) {
*isForOfp = true;
return true;
}
tokenStream.ungetToken();
}
return false;
}
template <>
bool
Parser<FullParseHandler>::isValidForStatementLHS(ParseNode *pn1, JSVersion version,
bool isForDecl, bool isForEach, bool isForOf)
{
if (isForDecl) {
if (pn1->pn_count > 1)
return false;
if (pn1->isOp(JSOP_DEFCONST))
return false;
#if JS_HAS_DESTRUCTURING
// In JS 1.7 only, for (var [K, V] in EXPR) has a special meaning.
// Hence all other destructuring decls are banned there.
if (version == JSVERSION_1_7 && !isForEach && !isForOf) {
ParseNode *lhs = pn1->pn_head;
if (lhs->isKind(PNK_ASSIGN))
lhs = lhs->pn_left;
if (lhs->isKind(PNK_OBJECT))
return false;
if (lhs->isKind(PNK_ARRAY) && lhs->pn_count != 2)
return false;
}
#endif
return true;
}
switch (pn1->getKind()) {
case PNK_NAME:
case PNK_DOT:
case PNK_CALL:
case PNK_ELEM:
return true;
#if JS_HAS_DESTRUCTURING
case PNK_ARRAY:
case PNK_OBJECT:
// In JS 1.7 only, for ([K, V] in EXPR) has a special meaning.
// Hence all other destructuring left-hand sides are banned there.
if (version == JSVERSION_1_7 && !isForEach && !isForOf)
return pn1->isKind(PNK_ARRAY) && pn1->pn_count == 2;
return true;
#endif
default:
return false;
}
}
template <>
ParseNode *
Parser<FullParseHandler>::forStatement()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
uint32_t begin = pos().begin;
StmtInfoPC forStmt(context);
PushStatementPC(pc, &forStmt, STMT_FOR_LOOP);
bool isForEach = false;
unsigned iflags = 0;
if (allowsForEachIn() && tokenStream.matchToken(TOK_NAME)) {
if (tokenStream.currentToken().name() == context->names().each) {
iflags = JSITER_FOREACH;
isForEach = true;
} else {
tokenStream.ungetToken();
}
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
/*
* True if we have 'for (var/let/const ...)', except in the oddball case
* where 'let' begins a let-expression in 'for (let (...) ...)'.
*/
bool isForDecl = false;
/* Non-null when isForDecl is true for a 'for (let ...)' statement. */
RootedStaticBlockObject blockObj(context);
/* Set to 'x' in 'for (x ;... ;...)' or 'for (x in ...)'. */
ParseNode *pn1;
{
TokenKind tt = tokenStream.peekToken(TSF_OPERAND);
if (tt == TOK_SEMI) {
pn1 = NULL;
} else {
/*
* Set pn1 to a var list or an initializing expression.
*
* Set the parsingForInit flag during parsing of the first clause
* of the for statement. This flag will be used by the RelExpr
* production; if it is set, then the 'in' keyword will not be
* recognized as an operator, leaving it available to be parsed as
* part of a for/in loop.
*
* A side effect of this restriction is that (unparenthesized)
* expressions involving an 'in' operator are illegal in the init
* clause of an ordinary for loop.
*/
pc->parsingForInit = true;
if (tt == TOK_VAR || tt == TOK_CONST) {
isForDecl = true;
tokenStream.consumeKnownToken(tt);
pn1 = variables(tt == TOK_VAR ? PNK_VAR : PNK_CONST);
}
#if JS_HAS_BLOCK_SCOPE
else if (tt == TOK_LET) {
handler.disableSyntaxParser();
(void) tokenStream.getToken();
if (tokenStream.peekToken() == TOK_LP) {
pn1 = letBlock(LetExpresion);
} else {
isForDecl = true;
blockObj = StaticBlockObject::create(context);
if (!blockObj)
return null();
pn1 = variables(PNK_LET, NULL, blockObj, DontHoistVars);
}
}
#endif
else {
pn1 = expr();
}
pc->parsingForInit = false;
if (!pn1)
return null();
}
}
JS_ASSERT_IF(isForDecl, pn1->isArity(PN_LIST));
JS_ASSERT(!!blockObj == (isForDecl && pn1->isOp(JSOP_NOP)));
// The form 'for (let <vars>; <expr2>; <expr3>) <stmt>' generates an
// implicit block even if stmt is not a BlockStatement.
// If the loop has that exact form, then:
// - forLetImpliedBlock is the node for the implicit block scope.
// - forLetDecl is the node for the decl 'let <vars>'.
// Otherwise both are null.
ParseNode *forLetImpliedBlock = NULL;
ParseNode *forLetDecl = NULL;
// If non-null, the node for the decl 'var v = expr1' in the weirdo form
// 'for (var v = expr1 in expr2) stmt'.
ParseNode *hoistedVar = NULL;
/*
* We can be sure that it's a for/in loop if there's still an 'in'
* keyword here, even if JavaScript recognizes 'in' as an operator,
* as we've excluded 'in' from being parsed in RelExpr by setting
* pc->parsingForInit.
*/
StmtInfoPC letStmt(context); /* used if blockObj != NULL. */
ParseNode *pn2, *pn3; /* forHead->pn_kid2 and pn_kid3. */
bool isForOf;
bool isForInOrOf = pn1 && matchInOrOf(&isForOf);
if (isForInOrOf) {
/*
* 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 NULL, pn2 is the assignment target that
* receives the enumeration value each iteration, and pn3 is the rhs of
* 'in'.
*/
forStmt.type = STMT_FOR_IN_LOOP;
/* Set iflags and rule out invalid combinations. */
if (isForOf && isForEach) {
report(ParseError, false, null(), JSMSG_BAD_FOR_EACH_LOOP);
return null();
}
iflags |= (isForOf ? JSITER_FOR_OF : JSITER_ENUMERATE);
/* Check that the left side of the 'in' or 'of' is valid. */
if (!isValidForStatementLHS(pn1, versionNumber(), isForDecl, isForEach, isForOf)) {
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 NULL. Note that the "declaration with initializer" case
* rewrites the loop-head, moving the decl and setting pn1 to NULL.
*/
if (isForDecl) {
pn2 = pn1->pn_head;
if ((pn2->isKind(PNK_NAME) && pn2->maybeExpr())
#if JS_HAS_DESTRUCTURING
|| pn2->isKind(PNK_ASSIGN)
#endif
)
{
/*
* Declaration with initializer.
*
* Rewrite 'for (<decl> x = i in o)' where <decl> is 'var' or
* 'const' to hoist the initializer or the entire decl out of
* the loop head.
*/
#if JS_HAS_BLOCK_SCOPE
if (blockObj) {
report(ParseError, false, pn2, JSMSG_INVALID_FOR_IN_INIT);
return null();
}
#endif /* JS_HAS_BLOCK_SCOPE */
hoistedVar = pn1;
/*
* All of 'var x = i' is hoisted above 'for (x in o)'.
*
* Request JSOP_POP here since the var is for a simple
* name (it is not a destructuring binding's left-hand
* side) and it has an initializer.
*/
pn1->pn_xflags |= PNX_POPVAR;
pn1 = NULL;
#if JS_HAS_DESTRUCTURING
if (pn2->isKind(PNK_ASSIGN)) {
pn2 = pn2->pn_left;
JS_ASSERT(pn2->isKind(PNK_ARRAY) || pn2->isKind(PNK_OBJECT) ||
pn2->isKind(PNK_NAME));
}
#endif
}
} else {
/* Not a declaration. */
JS_ASSERT(!blockObj);
pn2 = pn1;
pn1 = NULL;
if (!setAssignmentLhsOps(pn2, JSOP_NOP))
return null();
}
pn3 = expr();
if (!pn3)
return null();
if (blockObj) {
/*
* Now that the pn3 has been parsed, push the let scope. To hold
* the blockObj for the emitter, wrap the PNK_LEXICALSCOPE node
* created by PushLetScope around the for's initializer. This also
* serves to indicate the let-decl to the emitter.
*/
ParseNode *block = pushLetScope(blockObj, &letStmt);
if (!block)
return null();
letStmt.isForLetBlock = true;
block->pn_expr = pn1;
block->pn_pos = pn1->pn_pos;
pn1 = block;
}
if (isForDecl) {
/*
* pn2 is part of a declaration. Make a copy that can be passed to
* EmitAssignment. Take care to do this after PushLetScope.
*/
pn2 = cloneLeftHandSide(pn2);
if (!pn2)
return null();
}
switch (pn2->getKind()) {
case PNK_NAME:
/* Beware 'for (arguments in ...)' with or without a 'var'. */
pn2->markAsAssigned();
break;
#if JS_HAS_DESTRUCTURING
case PNK_ASSIGN:
JS_NOT_REACHED("forStatement TOK_ASSIGN");
break;
case PNK_ARRAY:
case PNK_OBJECT:
if (versionNumber() == JSVERSION_1_7) {
/*
* Destructuring for-in requires [key, value] enumeration
* in JS1.7.
*/
if (!isForEach && !isForOf)
iflags |= JSITER_FOREACH | JSITER_KEYVALUE;
}
break;
#endif
default:;
}
} else {
if (isForEach) {
reportWithOffset(ParseError, false, begin, JSMSG_BAD_FOR_EACH_LOOP);
return null();
}
if (blockObj) {
/*
* Desugar 'for (let A; B; C) D' into 'let (A) { for (; B; C) D }'
* to induce the correct scoping for A.
*/
forLetImpliedBlock = pushLetScope(blockObj, &letStmt);
if (!forLetImpliedBlock)
return null();
letStmt.isForLetBlock = true;
forLetDecl = pn1;
pn1 = NULL;
}
/* Parse the loop condition or null into pn2. */
MUST_MATCH_TOKEN(TOK_SEMI, JSMSG_SEMI_AFTER_FOR_INIT);
if (tokenStream.peekToken(TSF_OPERAND) == TOK_SEMI) {
pn2 = NULL;
} else {
pn2 = expr();
if (!pn2)
return null();
}
/* Parse the update expression or null into pn3. */
MUST_MATCH_TOKEN(TOK_SEMI, JSMSG_SEMI_AFTER_FOR_COND);
if (tokenStream.peekToken(TSF_OPERAND) == TOK_RP) {
pn3 = NULL;
} else {
pn3 = expr();
if (!pn3)
return null();
}
}
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_FOR_CTRL);
TokenPos headPos(begin, pos().end);
ParseNode *forHead = handler.newForHead(isForInOrOf, pn1, pn2, pn3, headPos);
if (!forHead)
return null();
/* Parse the loop body. */
ParseNode *body = statement();
if (!body)
return null();
#if JS_HAS_BLOCK_SCOPE
if (blockObj)
PopStatementPC(context, pc);
#endif
PopStatementPC(context, pc);
ParseNode *forLoop = handler.newForStatement(begin, forHead, body, iflags);
if (!forLoop)
return null();
if (hoistedVar) {
ParseNode *pnseq = handler.newList(PNK_SEQ, hoistedVar);
if (!pnseq)
return null();
pnseq->pn_pos = forLoop->pn_pos;
pnseq->append(forLoop);
return pnseq;
}
if (forLetImpliedBlock) {
forLetImpliedBlock->pn_expr = forLoop;
forLetImpliedBlock->pn_pos = forLoop->pn_pos;
ParseNode *let = handler.newBinary(PNK_LET, forLetDecl, forLetImpliedBlock);
if (!let)
return null();
let->pn_pos = forLoop->pn_pos;
return let;
}
return forLoop;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::forStatement()
{
/*
* '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.
*/
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
StmtInfoPC forStmt(context);
PushStatementPC(pc, &forStmt, STMT_FOR_LOOP);
/* Don't parse 'for each' loops. */
if (allowsForEachIn() && tokenStream.peekToken() == TOK_NAME) {
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;
{
TokenKind tt = tokenStream.peekToken(TSF_OPERAND);
if (tt == TOK_SEMI) {
lhsNode = null();
} else {
/* Set lhsNode to a var list or an initializing expression. */
pc->parsingForInit = true;
if (tt == TOK_VAR) {
isForDecl = true;
tokenStream.consumeKnownToken(tt);
lhsNode = variables(tt == TOK_VAR ? PNK_VAR : PNK_CONST, &simpleForDecl);
}
#if JS_HAS_BLOCK_SCOPE
else if (tt == TOK_CONST || tt == TOK_LET) {
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
#endif
else {
lhsNode = expr();
}
if (!lhsNode)
return null();
pc->parsingForInit = false;
}
}
/*
* We can be sure that it's a for/in loop if there's still an 'in'
* keyword here, even if JavaScript recognizes 'in' as an operator,
* as we've excluded 'in' from being parsed in RelExpr by setting
* pc->parsingForInit.
*/
bool isForOf;
if (lhsNode && matchInOrOf(&isForOf)) {
/* Parse the rest of the for/in or for/of head. */
forStmt.type = STMT_FOR_IN_LOOP;
/* Check that the left side of the 'in' or 'of' is valid. */
if (!isForDecl &&
lhsNode != SyntaxParseHandler::NodeName &&
lhsNode != SyntaxParseHandler::NodeGetProp &&
lhsNode != SyntaxParseHandler::NodeLValue)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
if (!simpleForDecl) {
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
if (!isForDecl && !setAssignmentLhsOps(lhsNode, JSOP_NOP))
return null();
if (!expr())
return null();
} else {
/* Parse the loop condition or null. */
MUST_MATCH_TOKEN(TOK_SEMI, JSMSG_SEMI_AFTER_FOR_INIT);
if (tokenStream.peekToken(TSF_OPERAND) != TOK_SEMI) {
if (!expr())
return null();
}
/* Parse the update expression or null. */
MUST_MATCH_TOKEN(TOK_SEMI, JSMSG_SEMI_AFTER_FOR_COND);
if (tokenStream.peekToken(TSF_OPERAND) != TOK_RP) {
if (!expr())
return null();
}
}
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_FOR_CTRL);
/* Parse the loop body. */
if (!statement())
return null();
PopStatementPC(context, pc);
return SyntaxParseHandler::NodeGeneric;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::switchStatement()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_SWITCH));
uint32_t begin = pos().begin;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_SWITCH);
Node discriminant = parenExpr();
if (!discriminant)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_SWITCH);
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_SWITCH);
StmtInfoPC stmtInfo(context);
PushStatementPC(pc, &stmtInfo, STMT_SWITCH);
if (!GenerateBlockId(pc, pc->topStmt->blockid))
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 ((tt = tokenStream.getToken()) != TOK_RC) {
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 == NULL.
break;
case TOK_CASE:
caseExpr = expr();
if (!caseExpr)
return null();
break;
case TOK_ERROR:
return null();
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();
while ((tt = tokenStream.peekToken(TSF_OPERAND)) != TOK_RC &&
tt != TOK_CASE && tt != TOK_DEFAULT) {
if (tt == TOK_ERROR)
return null();
Node stmt = statement();
if (!stmt)
return null();
handler.addList(body, stmt);
}
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;
PopStatementPC(context, pc);
handler.setEndPosition(caseList, pos().end);
return handler.newSwitchStatement(begin, discriminant, caseList);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::continueStatement()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_CONTINUE));
uint32_t begin = pos().begin;
RootedPropertyName label(context);
if (!MatchLabel(context, &tokenStream, &label))
return null();
StmtInfoPC *stmt = pc->topStmt;
if (label) {
for (StmtInfoPC *stmt2 = NULL; ; stmt = stmt->down) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_LABEL_NOT_FOUND);
return null();
}
if (stmt->type == STMT_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->down) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_BAD_CONTINUE);
return null();
}
if (stmt->isLoop())
break;
}
}
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
return handler.newContinueStatement(label, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::breakStatement()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_BREAK));
uint32_t begin = pos().begin;
RootedPropertyName label(context);
if (!MatchLabel(context, &tokenStream, &label))
return null();
StmtInfoPC *stmt = pc->topStmt;
if (label) {
for (; ; stmt = stmt->down) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_LABEL_NOT_FOUND);
return null();
}
if (stmt->type == STMT_LABEL && stmt->label == label)
break;
}
} else {
for (; ; stmt = stmt->down) {
if (!stmt) {
report(ParseError, false, null(), JSMSG_TOUGH_BREAK);
return null();
}
if (stmt->isLoop() || stmt->type == STMT_SWITCH)
break;
}
}
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
return handler.newBreakStatement(label, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::returnStatementOrYieldExpression()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_RETURN) ||
tokenStream.isCurrentTokenType(TOK_YIELD));
bool isYield = tokenStream.isCurrentTokenType(TOK_YIELD);
uint32_t begin = pos().begin;
if (!pc->sc->isFunctionBox()) {
report(ParseError, false, null(), JSMSG_BAD_RETURN_OR_YIELD,
isYield ? js_yield_str : js_return_str);
return null();
}
if (isYield) {
JS_ASSERT(JS_HAS_GENERATORS);
if (!abortIfSyntaxParser())
return null();
// If we're within parens, we won't know if this is a generator
// expression until we see a |for| token, so we have to delay flagging
// the current function.
if (pc->parenDepth == 0) {
pc->sc->asFunctionBox()->setIsGenerator();
} else {
pc->yieldCount++;
pc->yieldOffset = begin;
}
}
// Parse an optional operand.
//
// Checking whether yield has an operand is especially wonky since
// there is not a mandatory semicolon.
//
// ES6 does not permit yield without an operand. We will have to sunset
// this extension in order to conform to the ES6 syntax, which treats
// "yield \n expr;" as a single ExpressionStatement.
Node exprNode;
TokenKind next = tokenStream.peekTokenSameLine(TSF_OPERAND);
if (next == TOK_ERROR)
return null();
if (next == TOK_EOF || next == TOK_EOL || next == TOK_SEMI || next == TOK_RC ||
(isYield && (next == TOK_YIELD || next == TOK_RB || next == TOK_RP ||
next == TOK_COLON || next == TOK_COMMA)))
{
exprNode = null();
if (!isYield)
pc->funHasReturnVoid = true;
} else {
exprNode = isYield ? assignExpr() : expr();
if (!exprNode)
return null();
if (!isYield)
pc->funHasReturnExpr = true;
}
if (!isYield) {
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
}
Node pn = isYield
? handler.newUnary(PNK_YIELD, JSOP_YIELD, begin, exprNode)
: handler.newReturnStatement(exprNode, TokenPos(begin, pos().end));
if (!pn)
return null();
if (pc->funHasReturnExpr && pc->sc->asFunctionBox()->isGenerator()) {
/* As in Python (see PEP-255), disallow return v; in generators. */
reportBadReturn(pn, ParseError, JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
return null();
}
if (context->hasExtraWarningsOption() && pc->funHasReturnExpr && pc->funHasReturnVoid &&
!reportBadReturn(pn, ParseExtraWarning,
JSMSG_NO_RETURN_VALUE, JSMSG_ANON_NO_RETURN_VALUE))
{
return null();
}
return pn;
}
template <>
ParseNode *
Parser<FullParseHandler>::withStatement()
{
if (handler.syntaxParser) {
handler.disableSyntaxParser();
abortedSyntaxParse = true;
return null();
}
JS_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 = parenExpr();
if (!objectExpr)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_WITH);
bool oldParsingWith = pc->parsingWith;
pc->parsingWith = true;
StmtInfoPC stmtInfo(context);
PushStatementPC(pc, &stmtInfo, STMT_WITH);
Node innerBlock = statement();
if (!innerBlock)
return null();
PopStatementPC(context, pc);
pc->sc->setBindingsAccessedDynamically();
pc->parsingWith = oldParsingWith;
/*
* 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);
handler.deoptimizeUsesWithin(lexdep, TokenPos(begin, pos().begin));
}
return handler.newWithStatement(begin, objectExpr, innerBlock);
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::withStatement()
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return null();
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::labeledStatement()
{
uint32_t begin = pos().begin;
RootedPropertyName label(context, tokenStream.currentToken().name());
for (StmtInfoPC *stmt = pc->topStmt; stmt; stmt = stmt->down) {
if (stmt->type == STMT_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. */
StmtInfoPC stmtInfo(context);
PushStatementPC(pc, &stmtInfo, STMT_LABEL);
stmtInfo.label = label;
Node pn = statement();
if (!pn)
return null();
/* Pop the label, set pn_expr, and return early. */
PopStatementPC(context, pc);
return handler.newLabeledStatement(label, pn, begin);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::throwStatement()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_THROW));
uint32_t begin = pos().begin;
/* ECMA-262 Edition 3 says 'throw [no LineTerminator here] Expr'. */
TokenKind tt = tokenStream.peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_ERROR)
return null();
if (tt == TOK_EOF || tt == TOK_EOL || tt == TOK_SEMI || tt == TOK_RC) {
report(ParseError, false, null(), JSMSG_SYNTAX_ERROR);
return null();
}
Node throwExpr = expr();
if (!throwExpr)
return null();
if (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
return handler.newThrowStatement(throwExpr, TokenPos(begin, pos().end));
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::tryStatement()
{
JS_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.
*/
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_TRY);
StmtInfoPC stmtInfo(context);
if (!PushBlocklikeStatement(&stmtInfo, STMT_TRY, pc))
return null();
Node innerBlock = statements();
if (!innerBlock)
return null();
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_TRY);
PopStatementPC(context, pc);
bool hasUnconditionalCatch = false;
Node catchList = null();
TokenKind tt = tokenStream.getToken();
if (tt == TOK_CATCH) {
catchList = handler.newList(PNK_CATCH);
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.
*/
pnblock = pushLexicalScope(&stmtInfo);
if (!pnblock)
return null();
stmtInfo.type = STMT_CATCH;
/*
* 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.initLet(HoistVars, *pc->blockChain, JSMSG_TOO_MANY_CATCH_VARS);
JS_ASSERT(data.let.blockObj);
tt = tokenStream.getToken();
Node catchName;
switch (tt) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
catchName = destructuringExpr(&data, tt);
if (!catchName)
return null();
break;
#endif
case TOK_NAME:
{
RootedPropertyName label(context, tokenStream.currentToken().name());
catchName = newBindingNode(label, false);
if (!catchName)
return null();
data.pn = catchName;
if (!data.binder(context, &data, 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.
*/
if (tokenStream.matchToken(TOK_IF)) {
catchGuard = expr();
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();
if (!catchBody)
return null();
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_CATCH);
PopStatementPC(context, pc);
if (!catchGuard)
hasUnconditionalCatch = true;
if (!handler.addCatchBlock(catchList, pnblock, catchName, catchGuard, catchBody))
return null();
handler.setEndPosition(catchList, pos().end);
handler.setEndPosition(pnblock, pos().end);
tt = tokenStream.getToken(TSF_OPERAND);
} while (tt == TOK_CATCH);
}
Node finallyBlock = null();
if (tt == TOK_FINALLY) {
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_FINALLY);
if (!PushBlocklikeStatement(&stmtInfo, STMT_FINALLY, pc))
return null();
finallyBlock = statements();
if (!finallyBlock)
return null();
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_FINALLY);
PopStatementPC(context, pc);
} 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 (!MatchOrInsertSemicolon(context, &tokenStream))
return null();
p.end = pos().end;
pc->sc->setBindingsAccessedDynamically();
pc->sc->setHasDebuggerStatement();
return handler.newDebuggerStatement(p);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::statement(bool canHaveDirectives)
{
Node pn;
JS_CHECK_RECURSION(context, return null());
switch (tokenStream.getToken(TSF_OPERAND)) {
case TOK_LC:
return blockStatement();
case TOK_VAR:
pn = variables(PNK_VAR);
if (!pn)
return null();
/* Tell js_EmitTree to generate a final POP. */
handler.setListFlag(pn, PNX_POPVAR);
break;
case TOK_CONST:
if (!abortIfSyntaxParser())
return null();
pn = variables(PNK_CONST);
if (!pn)
return null();
/* Tell js_EmitTree to generate a final POP. */
handler.setListFlag(pn, PNX_POPVAR);
break;
#if JS_HAS_BLOCK_SCOPE
case TOK_LET:
return letStatement();
#endif
case TOK_SEMI:
return handler.newEmptyStatement(pos());
case TOK_IF:
return ifStatement();
case TOK_DO:
return doWhileStatement();
case TOK_WHILE:
return whileStatement();
case TOK_FOR:
return forStatement();
case TOK_SWITCH:
return switchStatement();
case TOK_CONTINUE:
return continueStatement();
case TOK_BREAK:
return breakStatement();
case TOK_RETURN:
return returnStatementOrYieldExpression();
case TOK_WITH:
return withStatement();
case TOK_THROW:
return throwStatement();
case TOK_TRY:
return tryStatement();
case TOK_FUNCTION:
return functionStmt();
case TOK_DEBUGGER:
return debuggerStatement();
/* TOK_CATCH and TOK_FINALLY are both handled in the TOK_TRY case */
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();
case TOK_ERROR:
return null();
case TOK_STRING:
if (!canHaveDirectives && tokenStream.currentToken().atom() == context->names().useAsm) {
if (!report(ParseWarning, false, null(), JSMSG_USE_ASM_DIRECTIVE_FAIL))
return null();
}
return expressionStatement();
case TOK_NAME:
if (tokenStream.peekToken() == TOK_COLON)
return labeledStatement();
if (tokenStream.currentToken().name() == context->names().module
&& tokenStream.peekTokenSameLine() == TOK_STRING)
{
return moduleDecl();
}
return expressionStatement();
default:
return expressionStatement();
}
/* Check termination of this primitive statement. */
return MatchOrInsertSemicolon(context, &tokenStream) ? pn : null();
}
template <>
ParseNode *
Parser<FullParseHandler>::expr()
{
ParseNode *pn = assignExpr();
if (pn && tokenStream.matchToken(TOK_COMMA)) {
ParseNode *pn2 = ListNode::create(PNK_COMMA, &handler);
if (!pn2)
return null();
pn2->pn_pos.begin = pn->pn_pos.begin;
pn2->initList(pn);
pn = pn2;
do {
#if JS_HAS_GENERATORS
pn2 = pn->last();
if (pn2->isKind(PNK_YIELD) && !pn2->isInParens()) {
report(ParseError, false, pn2, JSMSG_BAD_GENERATOR_SYNTAX, js_yield_str);
return null();
}
#endif
pn2 = assignExpr();
if (!pn2)
return null();
pn->append(pn2);
} while (tokenStream.matchToken(TOK_COMMA));
pn->pn_pos.end = pn->last()->pn_pos.end;
}
return pn;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::expr()
{
Node pn = assignExpr();
if (pn && tokenStream.matchToken(TOK_COMMA)) {
do {
if (!assignExpr())
return null();
} while (tokenStream.matchToken(TOK_COMMA));
return SyntaxParseHandler::NodeGeneric;
}
return pn;
}
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
};
static inline JSOp
BinaryOpParseNodeKindToJSOp(ParseNodeKind pnk)
{
JS_ASSERT(pnk >= PNK_BINOP_FIRST);
JS_ASSERT(pnk <= PNK_BINOP_LAST);
return ParseNodeKindToJSOp[pnk - PNK_BINOP_FIRST];
}
static bool
IsBinaryOpToken(TokenKind tok, bool parsingForInit)
{
return tok == TOK_IN ? !parsingForInit : TokenKindIsBinaryOp(tok);
}
static ParseNodeKind
BinaryOpTokenKindToParseNodeKind(TokenKind tok)
{
JS_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 */
};
static const int PRECEDENCE_CLASSES = 10;
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;
JS_ASSERT(pnk >= PNK_BINOP_FIRST);
JS_ASSERT(pnk <= PNK_BINOP_LAST);
return PrecedenceTable[pnk - PNK_BINOP_FIRST];
}
template <typename ParseHandler>
JS_ALWAYS_INLINE typename ParseHandler::Node
Parser<ParseHandler>::orExpr1()
{
// Shift-reduce parser for the left-associative binary operator part of
// the JS 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;
bool oldParsingForInit = pc->parsingForInit;
pc->parsingForInit = false;
Node pn;
for (;;) {
pn = unaryExpr();
if (!pn)
return pn;
// If a binary operator follows, consume it and compute the
// corresponding operator.
TokenKind tok = tokenStream.getToken();
if (tok == TOK_ERROR)
return null();
ParseNodeKind pnk;
if (IsBinaryOpToken(tok, oldParsingForInit)) {
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 all the operators in question
// are left-associative; if any were not, the case where two operators
// have equal precedence would need to be handled specially, and the
// stack would need to be a Vector.
while (depth > 0 && Precedence(kindStack[depth - 1]) >= Precedence(pnk)) {
depth--;
ParseNodeKind combiningPnk = kindStack[depth];
JSOp combiningOp = BinaryOpParseNodeKindToJSOp(combiningPnk);
pn = handler.newBinaryOrAppend(combiningPnk, nodeStack[depth], pn, pc, combiningOp);
if (!pn)
return pn;
}
if (pnk == PNK_LIMIT)
break;
nodeStack[depth] = pn;
kindStack[depth] = pnk;
depth++;
JS_ASSERT(depth <= PRECEDENCE_CLASSES);
}
JS_ASSERT(depth == 0);
pc->parsingForInit = oldParsingForInit;
return pn;
}
template <typename ParseHandler>
JS_ALWAYS_INLINE typename ParseHandler::Node
Parser<ParseHandler>::condExpr1()
{
Node condition = orExpr1();
if (!condition || !tokenStream.isCurrentTokenType(TOK_HOOK))
return condition;
/*
* Always accept the 'in' operator in the middle clause of a ternary,
* where it's unambiguous, even if we might be parsing the init of a
* for statement.
*/
bool oldParsingForInit = pc->parsingForInit;
pc->parsingForInit = false;
Node thenExpr = assignExpr();
pc->parsingForInit = oldParsingForInit;
if (!thenExpr)
return null();
MUST_MATCH_TOKEN(TOK_COLON, JSMSG_COLON_IN_COND);
Node elseExpr = assignExpr();
if (!elseExpr)
return null();
tokenStream.getToken(); /* read one token past the end */
return handler.newConditional(condition, thenExpr, elseExpr);
}
template <>
bool
Parser<FullParseHandler>::setAssignmentLhsOps(ParseNode *pn, JSOp op)
{
switch (pn->getKind()) {
case PNK_NAME:
if (!checkStrictAssignment(pn))
return false;
pn->setOp(pn->isOp(JSOP_GETLOCAL) ? JSOP_SETLOCAL : JSOP_SETNAME);
pn->markAsAssigned();
break;
case PNK_DOT:
pn->setOp(JSOP_SETPROP);
break;
case PNK_ELEM:
pn->setOp(JSOP_SETELEM);
break;
#if JS_HAS_DESTRUCTURING
case PNK_ARRAY:
case PNK_OBJECT:
if (op != JSOP_NOP) {
report(ParseError, false, null(), JSMSG_BAD_DESTRUCT_ASS);
return false;
}
if (!checkDestructuring(NULL, pn))
return false;
break;
#endif
case PNK_CALL:
if (!makeSetCall(pn, JSMSG_BAD_LEFTSIDE_OF_ASS))
return false;
break;
default:
report(ParseError, false, null(), JSMSG_BAD_LEFTSIDE_OF_ASS);
return false;
}
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::setAssignmentLhsOps(Node pn, JSOp op)
{
/* Full syntax checking of valid assignment LHS terms requires a parse tree. */
if (pn != SyntaxParseHandler::NodeName &&
pn != SyntaxParseHandler::NodeGetProp &&
pn != SyntaxParseHandler::NodeLValue)
{
return abortIfSyntaxParser();
}
return checkStrictAssignment(pn);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::assignExpr()
{
JS_CHECK_RECURSION(context, return null());
#if JS_HAS_GENERATORS
if (tokenStream.matchToken(TOK_YIELD, TSF_OPERAND))
return returnStatementOrYieldExpression();
if (tokenStream.hadError())
return null();
#endif
// 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();
if (!lhs)
return null();
ParseNodeKind kind;
switch (tokenStream.currentToken().type) {
case TOK_ASSIGN: kind = PNK_ASSIGN; break;
case TOK_ADDASSIGN: kind = PNK_ADDASSIGN; break;
case TOK_SUBASSIGN: kind = PNK_SUBASSIGN; break;
case TOK_BITORASSIGN: kind = PNK_BITORASSIGN; break;
case TOK_BITXORASSIGN: kind = PNK_BITXORASSIGN; break;
case TOK_BITANDASSIGN: kind = PNK_BITANDASSIGN; break;
case TOK_LSHASSIGN: kind = PNK_LSHASSIGN; break;
case TOK_RSHASSIGN: kind = PNK_RSHASSIGN; break;
case TOK_URSHASSIGN: kind = PNK_URSHASSIGN; break;
case TOK_MULASSIGN: kind = PNK_MULASSIGN; break;
case TOK_DIVASSIGN: kind = PNK_DIVASSIGN; break;
case TOK_MODASSIGN: kind = PNK_MODASSIGN; break;
case TOK_ARROW: {
tokenStream.seek(start);
if (!abortIfSyntaxParser())
return null();
if (tokenStream.getToken() == TOK_ERROR)
return null();
size_t offset = pos().begin;
tokenStream.ungetToken();
return functionDef(NullPtr(), start, offset, Normal, Arrow);
}
default:
JS_ASSERT(!tokenStream.isCurrentTokenAssignment());
tokenStream.ungetToken();
return lhs;
}
JSOp op = tokenStream.currentToken().t_op;
if (!setAssignmentLhsOps(lhs, op))
return null();
Node rhs = assignExpr();
if (!rhs)
return null();
return handler.newBinaryOrAppend(kind, lhs, rhs, pc, op);
}
template <> bool
Parser<FullParseHandler>::setLvalKid(ParseNode *pn, ParseNode *kid, const char *name)
{
if (!kid->isKind(PNK_NAME) &&
!kid->isKind(PNK_DOT) &&
(!kid->isKind(PNK_CALL) ||
(!kid->isOp(JSOP_CALL) && !kid->isOp(JSOP_EVAL) &&
!kid->isOp(JSOP_FUNCALL) && !kid->isOp(JSOP_FUNAPPLY))) &&
!kid->isKind(PNK_ELEM))
{
report(ParseError, false, null(), JSMSG_BAD_OPERAND, name);
return false;
}
if (!checkStrictAssignment(kid))
return false;
pn->pn_kid = kid;
return true;
}
static const char incop_name_str[][10] = {"increment", "decrement"};
template <>
bool
Parser<FullParseHandler>::setIncOpKid(ParseNode *pn, ParseNode *kid, TokenKind tt, bool preorder)
{
if (!setLvalKid(pn, kid, incop_name_str[tt == TOK_DEC]))
return false;
switch (kid->getKind()) {
case PNK_NAME:
kid->markAsAssigned();
break;
case PNK_CALL:
if (!makeSetCall(kid, JSMSG_BAD_INCOP_OPERAND))
return false;
break;
case PNK_DOT:
case PNK_ELEM:
break;
default:
JS_ASSERT(0);
}
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::setIncOpKid(Node pn, Node kid, TokenKind tt, bool preorder)
{
return setAssignmentLhsOps(kid, JSOP_NOP);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::unaryOpExpr(ParseNodeKind kind, JSOp op, uint32_t begin)
{
Node kid = unaryExpr();
if (!kid)
return null();
return handler.newUnary(kind, op, begin, kid);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::unaryExpr()
{
Node pn, pn2;
JS_CHECK_RECURSION(context, return null());
TokenKind tt = tokenStream.getToken(TSF_OPERAND);
uint32_t begin = pos().begin;
switch (tt) {
case TOK_TYPEOF:
return unaryOpExpr(PNK_TYPEOF, JSOP_TYPEOF, begin);
case TOK_VOID:
return unaryOpExpr(PNK_VOID, JSOP_VOID, begin);
case TOK_NOT:
return unaryOpExpr(PNK_NOT, JSOP_NOT, begin);
case TOK_BITNOT:
return unaryOpExpr(PNK_BITNOT, JSOP_BITNOT, begin);
case TOK_PLUS:
return unaryOpExpr(PNK_POS, JSOP_POS, begin);
case TOK_MINUS:
return unaryOpExpr(PNK_NEG, JSOP_NEG, begin);
case TOK_INC:
case TOK_DEC:
{
TokenKind tt2 = tokenStream.getToken(TSF_OPERAND);
pn2 = memberExpr(tt2, true);
if (!pn2)
return null();
pn = handler.newUnary((tt == TOK_INC) ? PNK_PREINCREMENT : PNK_PREDECREMENT,
JSOP_NOP,
begin,
pn2);
if (!pn)
return null();
if (!setIncOpKid(pn, pn2, tt, true))
return null();
break;
}
case TOK_DELETE: {
Node expr = unaryExpr();
if (!expr)
return null();
// Per spec, deleting any unary expression is valid -- it simply returns
// true -- except for a few cases that are illegal in strict mode.
if (foldConstants && !FoldConstants(context, &expr, this))
return null();
if (handler.isName(expr)) {
if (!report(ParseStrictError, pc->sc->strict, expr, JSMSG_DEPRECATED_DELETE_OPERAND))
return null();
pc->sc->setBindingsAccessedDynamically();
}
return handler.newDelete(begin, expr);
}
case TOK_ERROR:
return null();
default:
pn = memberExpr(tt, true);
if (!pn)
return null();
/* Don't look across a newline boundary for a postfix incop. */
tt = tokenStream.peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_INC || tt == TOK_DEC) {
tokenStream.consumeKnownToken(tt);
pn2 = handler.newUnary((tt == TOK_INC) ? PNK_POSTINCREMENT : PNK_POSTDECREMENT,
JSOP_NOP,
begin,
pn);
if (!pn2)
return null();
if (!setIncOpKid(pn2, pn, tt, false))
return null();
pn = pn2;
}
break;
}
return pn;
}
#if JS_HAS_GENERATORS
/*
* A dedicated helper for transplanting the comprehension expression E in
*
* [E for (V in I)] // array comprehension
* (E for (V in I)) // 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 generator expression desugars like so:
*
* (E for (V in I)) => (function () { for (var V in I) yield E; })()
*
* so the transplanter must adjust static level as well as blockid. 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 CompExprTransplanter
{
ParseNode *root;
Parser<FullParseHandler> *parser;
ParseContext<FullParseHandler> *outerpc;
bool genexp;
unsigned adjust;
HashSet<Definition *> visitedImplicitArguments;
public:
CompExprTransplanter(ParseNode *pn, Parser<FullParseHandler> *parser,
ParseContext<FullParseHandler> *outerpc,
bool ge, unsigned adj)
: root(pn), parser(parser), outerpc(outerpc), genexp(ge), adjust(adj),
visitedImplicitArguments(parser->context)
{}
bool init() {
return visitedImplicitArguments.init();
}
bool transplant(ParseNode *pn);
};
/*
* A helper for lazily checking for the presence of illegal |yield| or |arguments|
* tokens inside of generator expressions. This must be done lazily since we don't
* know whether we're in a generator expression until we see the "for" token after
* we've already parsed the body expression.
*
* Use in any context which may turn out to be inside a generator expression. This
* includes parenthesized expressions and argument lists, and it includes the tail
* of generator expressions.
*
* The guard will keep track of any |yield| or |arguments| tokens that occur while
* parsing the body. As soon as the parser reaches the end of the body expression,
* call endBody() to reset the context's state, and then immediately call:
*
* - checkValidBody() if this *did* turn out to be a generator expression
* - maybeNoteGenerator() if this *did not* turn out to be a generator expression
*/
template <typename ParseHandler>
class GenexpGuard
{
Parser<ParseHandler> *parser;
uint32_t startYieldCount;
typedef typename ParseHandler::Node Node;
public:
explicit GenexpGuard(Parser<ParseHandler> *parser)
: parser(parser)
{
ParseContext<ParseHandler> *pc = parser->pc;
if (pc->parenDepth == 0) {
pc->yieldCount = 0;
pc->yieldOffset = 0;
}
startYieldCount = pc->yieldCount;
pc->parenDepth++;
}
void endBody();
bool checkValidBody(Node pn, unsigned err = JSMSG_BAD_GENEXP_BODY);
bool maybeNoteGenerator(Node pn);
};
template <typename ParseHandler>
void
GenexpGuard<ParseHandler>::endBody()
{
parser->pc->parenDepth--;
}
/*
* Check whether a |yield| or |arguments| token has been encountered in the
* body expression, and if so, report an error.
*
* Call this after endBody() when determining that the body *was* in a
* generator expression.
*/
template <typename ParseHandler>
bool
GenexpGuard<ParseHandler>::checkValidBody(Node pn, unsigned err)
{
ParseContext<ParseHandler> *pc = parser->pc;
if (pc->yieldCount > startYieldCount) {
uint32_t offset = pc->yieldOffset
? pc->yieldOffset
: (pn ? parser->handler.getPosition(pn)
: parser->pos()).begin;
parser->reportWithOffset(ParseError, false, offset, err, js_yield_str);
return false;
}
return true;
}
/*
* Check whether a |yield| token has been encountered in the body expression,
* and if so, note that the current function is a generator function.
*
* Call this after endBody() when determining that the body *was not* in a
* generator expression.
*/
template <typename ParseHandler>
bool
GenexpGuard<ParseHandler>::maybeNoteGenerator(Node pn)
{
ParseContext<ParseHandler> *pc = parser->pc;
if (pc->yieldCount > 0) {
if (!pc->sc->isFunctionBox()) {
parser->report(ParseError, false, ParseHandler::null(),
JSMSG_BAD_RETURN_OR_YIELD, js_yield_str);
return false;
}
pc->sc->asFunctionBox()->setIsGenerator();
if (pc->funHasReturnExpr) {
/* At the time we saw the yield, we might not have set isGenerator yet. */
parser->reportBadReturn(pn, ParseError,
JSMSG_BAD_GENERATOR_RETURN, JSMSG_BAD_ANON_GENERATOR_RETURN);
return false;
}
}
return true;
}
/*
* Any definitions nested within the comprehension expression of a generator
* expression must move "down" one static level, which of course increases the
* upvar-frame-skip count.
*/
template <typename ParseHandler>
static bool
BumpStaticLevel(ParseNode *pn, ParseContext<ParseHandler> *pc)
{
if (pn->pn_cookie.isFree())
return true;
unsigned level = unsigned(pn->pn_cookie.level()) + 1;
JS_ASSERT(level >= pc->staticLevel);
return pn->pn_cookie.set(pc->sc->context, level, pn->pn_cookie.slot());
}
template <typename ParseHandler>
static bool
AdjustBlockId(ParseNode *pn, unsigned adjust, ParseContext<ParseHandler> *pc)
{
JS_ASSERT(pn->isArity(PN_LIST) || pn->isArity(PN_CODE) || pn->isArity(PN_NAME));
if (JS_BIT(20) - pn->pn_blockid <= adjust + 1) {
JS_ReportErrorNumber(pc->sc->context, js_GetErrorMessage, NULL, JSMSG_NEED_DIET, "program");
return false;
}
pn->pn_blockid += adjust;
if (pn->pn_blockid >= pc->blockidGen)
pc->blockidGen = pn->pn_blockid + 1;
return true;
}
bool
CompExprTransplanter::transplant(ParseNode *pn)
{
ParseContext<FullParseHandler> *pc = parser->pc;
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) {
if (!AdjustBlockId(pn, adjust, pc))
return false;
}
break;
case PN_TERNARY:
if (!transplant(pn->pn_kid1) ||
!transplant(pn->pn_kid2) ||
!transplant(pn->pn_kid3))
return false;
break;
case PN_BINARY:
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->isDefn()) {
if (genexp && !BumpStaticLevel(pn, pc))
return false;
} else if (pn->isUsed()) {
JS_ASSERT(pn->pn_cookie.isFree());
Definition *dn = pn->pn_lexdef;
JS_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 comprehension expression (to avoid adjusting the blockid
* multiple times).
*
* Non-placeholder definitions within the comprehension expression
* will be visited further below.
*/
if (dn->isPlaceholder() && dn->pn_pos >= root->pn_pos && dn->dn_uses == pn) {
if (genexp && !BumpStaticLevel(dn, pc))
return false;
if (!AdjustBlockId(dn, adjust, pc))
return false;
}
RootedAtom atom(parser->context, pn->pn_atom);
#ifdef DEBUG
StmtInfoPC *stmt = LexicalLookup(pc, atom, NULL, (StmtInfoPC *)NULL);
JS_ASSERT(!stmt || stmt != pc->topStmt);
#endif
if (genexp && !dn->isOp(JSOP_CALLEE)) {
JS_ASSERT(!pc->decls().lookupFirst(atom));
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 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->inBlock(), 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) != NULL && 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 = NULL;
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 (genexp && !visitedImplicitArguments.has(dn)) {
if (!BumpStaticLevel(dn, pc))
return false;
if (!AdjustBlockId(dn, adjust, pc))
return false;
if (!visitedImplicitArguments.put(dn))
return false;
}
}
}
}
if (pn->pn_pos >= root->pn_pos) {
if (!AdjustBlockId(pn, adjust, pc))
return false;
}
break;
case PN_NULLARY:
/* Nothing. */
break;
}
return true;
}
/*
* 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>::comprehensionTail(ParseNode *kid, unsigned blockid, bool isGenexp,
ParseContext<FullParseHandler> *outerpc,
ParseNodeKind kind, JSOp op)
{
/*
* 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 NULL;
}
unsigned adjust;
ParseNode *pn, *pn2, *pn3, **pnp;
StmtInfoPC stmtInfo(context);
BindData<FullParseHandler> data(context);
TokenKind tt;
JS_ASSERT(tokenStream.currentToken().type == TOK_FOR);
if (kind == PNK_SEMI) {
/*
* Generator expression desugars to an immediately applied lambda that
* yields the next value from a for-in loop (possibly nested, and with
* optional if guard). Make pn be the TOK_LC body node.
*/
pn = pushLexicalScope(&stmtInfo);
if (!pn)
return null();
adjust = pn->pn_blockid - blockid;
} else {
JS_ASSERT(kind == PNK_ARRAYPUSH);
/*
* Make a parse-node and literal object representing the block scope of
* this array comprehension. Our caller in primaryExpr, the TOK_LB case
* aka the array initialiser case, has passed the blockid to claim for
* the comprehension's block scope. We allocate that id or one above it
* here, by calling PushLexicalScope.
*
* In the case of a comprehension expression that has nested blocks
* (e.g., let expressions), we will allocate a higher blockid but then
* slide all blocks "to the right" to make room for the comprehension's
* block scope.
*/
adjust = pc->blockid();
pn = pushLexicalScope(&stmtInfo);
if (!pn)
return null();
JS_ASSERT(blockid <= pn->pn_blockid);
JS_ASSERT(blockid < pc->blockidGen);
JS_ASSERT(pc->bodyid < blockid);
pn->pn_blockid = stmtInfo.blockid = blockid;
JS_ASSERT(adjust < blockid);
adjust = blockid - adjust;
}
pnp = &pn->pn_expr;
CompExprTransplanter transplanter(kid, this, outerpc, kind == PNK_SEMI, adjust);
if (!transplanter.init())
return null();
if (!transplanter.transplant(kid))
return null();
JS_ASSERT(pc->blockChain && pc->blockChain == pn->pn_objbox->object);
data.initLet(HoistVars, *pc->blockChain, JSMSG_ARRAY_INIT_TOO_BIG);
do {
/*
* FOR node is binary, left is loop control and right is body. Use
* index to count each block-local let-variable on the left-hand side
* of the in/of.
*/
pn2 = BinaryNode::create(PNK_FOR, &handler);
if (!pn2)
return null();
pn2->setOp(JSOP_ITER);
pn2->pn_iflags = JSITER_ENUMERATE;
if (allowsForEachIn() && tokenStream.matchToken(TOK_NAME)) {
if (tokenStream.currentToken().name() == context->names().each)
pn2->pn_iflags |= JSITER_FOREACH;
else
tokenStream.ungetToken();
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
GenexpGuard<FullParseHandler> guard(this);
RootedPropertyName name(context);
tt = tokenStream.getToken();
switch (tt) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
pc->inDeclDestructuring = true;
pn3 = primaryExpr(tt);
pc->inDeclDestructuring = false;
if (!pn3)
return null();
break;
#endif
case TOK_NAME:
name = tokenStream.currentToken().name();
/*
* Create a name node with pn_op JSOP_NAME. 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);
case TOK_ERROR:
return null();
}
bool isForOf;
if (!matchInOrOf(&isForOf)) {
report(ParseError, false, null(), JSMSG_IN_AFTER_FOR_NAME);
return null();
}
if (isForOf) {
if (pn2->pn_iflags != JSITER_ENUMERATE) {
JS_ASSERT(pn2->pn_iflags == (JSITER_FOREACH | JSITER_ENUMERATE));
report(ParseError, false, null(), JSMSG_BAD_FOR_EACH_LOOP);
return null();
}
pn2->pn_iflags = JSITER_FOR_OF;
}
ParseNode *pn4 = expr();
if (!pn4)
return null();
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_FOR_CTRL);
guard.endBody();
if (isGenexp) {
if (!guard.checkValidBody(pn2))
return null();
} else {
if (!guard.maybeNoteGenerator(pn2))
return null();
}
switch (tt) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
if (!checkDestructuring(&data, pn3))
return null();
if (versionNumber() == JSVERSION_1_7 &&
!(pn2->pn_iflags & JSITER_FOREACH) &&
!isForOf)
{
/* Destructuring requires [key, value] enumeration in JS1.7. */
if (!pn3->isKind(PNK_ARRAY) || pn3->pn_count != 2) {
report(ParseError, false, null(), JSMSG_BAD_FOR_LEFTSIDE);
return null();
}
JS_ASSERT(pn2->isOp(JSOP_ITER));
JS_ASSERT(pn2->pn_iflags & JSITER_ENUMERATE);
pn2->pn_iflags |= JSITER_FOREACH | JSITER_KEYVALUE;
}
break;
#endif
case TOK_NAME:
data.pn = pn3;
if (!data.binder(context, &data, name, this))
return null();
break;
default:;
}
/*
* Synthesize a declaration. Every definition must appear in the parse
* tree in order for ComprehensionTranslator to work.
*/
ParseNode *vars = ListNode::create(PNK_VAR, &handler);
if (!vars)
return null();
vars->setOp(JSOP_NOP);
vars->pn_pos = pn3->pn_pos;
vars->makeEmpty();
vars->append(pn3);
/* Definitions can't be passed directly to EmitAssignment as lhs. */
pn3 = cloneLeftHandSide(pn3);
if (!pn3)
return null();
pn2->pn_left = handler.newTernary(PNK_FORIN, vars, pn3, pn4);
if (!pn2->pn_left)
return null();
*pnp = pn2;
pnp = &pn2->pn_right;
} while (tokenStream.matchToken(TOK_FOR));
if (tokenStream.matchToken(TOK_IF)) {
pn2 = TernaryNode::create(PNK_IF, &handler);
if (!pn2)
return null();
pn2->pn_kid1 = condition();
if (!pn2->pn_kid1)
return null();
*pnp = pn2;
pnp = &pn2->pn_kid2;
}
pn2 = UnaryNode::create(kind, &handler);
if (!pn2)
return null();
pn2->setOp(op);
pn2->pn_kid = kid;
*pnp = pn2;
PopStatementPC(context, pc);
return pn;
}
template <>
bool
Parser<FullParseHandler>::arrayInitializerComprehensionTail(ParseNode *pn)
{
/* Relabel pn as an array comprehension node. */
pn->setKind(PNK_ARRAYCOMP);
/*
* Remove the comprehension expression from pn's linked list
* and save it via pnexp. We'll re-install it underneath the
* ARRAYPUSH node after we parse the rest of the comprehension.
*/
ParseNode *pnexp = pn->last();
JS_ASSERT(pn->pn_count == 1);
pn->pn_count = 0;
pn->pn_tail = &pn->pn_head;
*pn->pn_tail = NULL;
ParseNode *pntop = comprehensionTail(pnexp, pn->pn_blockid, false, NULL,
PNK_ARRAYPUSH, JSOP_ARRAYPUSH);
if (!pntop)
return false;
pn->append(pntop);
return true;
}
template <>
bool
Parser<SyntaxParseHandler>::arrayInitializerComprehensionTail(Node pn)
{
return abortIfSyntaxParser();
}
#if JS_HAS_GENERATOR_EXPRS
/*
* Starting from a |for| keyword after an expression, parse the comprehension
* tail completing this generator expression. Wrap the expression at kid in a
* generator function that is immediately called to evaluate to the generator
* iterator that is the value of this generator expression.
*
* |kid| 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 |kid| as the operand of a |yield| expression as the
* innermost loop body.
*
* Note how 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>::generatorExpr(ParseNode *kid)
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_FOR));
/* Create a |yield| node for |kid|. */
ParseNode *pn = UnaryNode::create(PNK_YIELD, &handler);
if (!pn)
return null();
pn->setOp(JSOP_YIELD);
pn->setInParens(true);
pn->pn_pos = kid->pn_pos;
pn->pn_kid = kid;
pn->pn_hidden = true;
/* Make a new node for the desugared generator function. */
ParseNode *genfn = CodeNode::create(PNK_FUNCTION, &handler);
if (!genfn)
return null();
genfn->setOp(JSOP_LAMBDA);
JS_ASSERT(!genfn->pn_body);
genfn->pn_dflags = 0;
{
ParseContext<FullParseHandler> *outerpc = pc;
RootedFunction fun(context, newFunction(outerpc, /* atom = */ NullPtr(), Expression));
if (!fun)
return null();
/* Create box for fun->object early to protect against last-ditch GC. */
FunctionBox *genFunbox = newFunctionBox(fun, outerpc, outerpc->sc->strict);
if (!genFunbox)
return null();
ParseContext<FullParseHandler> genpc(this, outerpc, genFunbox,
outerpc->staticLevel + 1, outerpc->blockidGen);
if (!genpc.init())
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;
genFunbox->setIsGenerator();
genFunbox->inGenexpLambda = true;
genfn->pn_funbox = genFunbox;
genfn->pn_blockid = genpc.bodyid;
ParseNode *body = comprehensionTail(pn, outerpc->blockid(), true, outerpc);
if (!body)
return null();
JS_ASSERT(!genfn->pn_body);
genfn->pn_body = body;
genfn->pn_pos.begin = body->pn_pos.begin = kid->pn_pos.begin;
genfn->pn_pos.end = body->pn_pos.end = pos().end;
RootedPropertyName funName(context);
if (!leaveFunction(genfn, funName, outerpc))
return null();
}
/*
* Our result is a call expression that invokes the anonymous generator
* function object.
*/
ParseNode *result = ListNode::create(PNK_GENEXP, &handler);
if (!result)
return null();
result->setOp(JSOP_CALL);
result->pn_pos.begin = genfn->pn_pos.begin;
result->initList(genfn);
return result;
}
template <>
SyntaxParseHandler::Node
Parser<SyntaxParseHandler>::generatorExpr(Node kid)
{
JS_ALWAYS_FALSE(abortIfSyntaxParser());
return SyntaxParseHandler::NodeFailure;
}
static const char js_generator_str[] = "generator";
#endif /* JS_HAS_GENERATOR_EXPRS */
#endif /* JS_HAS_GENERATORS */
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::assignExprWithoutYield(unsigned msg)
{
#ifdef JS_HAS_GENERATORS
GenexpGuard<ParseHandler> yieldGuard(this);
#endif
Node res = assignExpr();
yieldGuard.endBody();
if (res) {
#ifdef JS_HAS_GENERATORS
if (!yieldGuard.checkValidBody(res, msg))
return null();
#endif
}
return res;
}
template <typename ParseHandler>
bool
Parser<ParseHandler>::argumentList(Node listNode)
{
if (tokenStream.matchToken(TOK_RP, TSF_OPERAND))
return true;
GenexpGuard<ParseHandler> guard(this);
bool arg0 = true;
do {
Node argNode = assignExpr();
if (!argNode)
return false;
if (arg0)
guard.endBody();
#if JS_HAS_GENERATORS
if (handler.isOperationWithoutParens(argNode, PNK_YIELD) &&
tokenStream.peekToken() == TOK_COMMA) {
report(ParseError, false, argNode, JSMSG_BAD_GENERATOR_SYNTAX, js_yield_str);
return false;
}
#endif
#if JS_HAS_GENERATOR_EXPRS
if (tokenStream.matchToken(TOK_FOR)) {
if (!guard.checkValidBody(argNode))
return false;
argNode = generatorExpr(argNode);
if (!argNode)
return false;
if (!arg0 || tokenStream.peekToken() == TOK_COMMA) {
report(ParseError, false, argNode, JSMSG_BAD_GENERATOR_SYNTAX, js_generator_str);
return false;
}
} else
#endif
if (arg0 && !guard.maybeNoteGenerator(argNode))
return false;
arg0 = false;
handler.addList(listNode, argNode);
} while (tokenStream.matchToken(TOK_COMMA));
if (tokenStream.getToken() != TOK_RP) {
report(ParseError, false, null(), JSMSG_PAREN_AFTER_ARGS);
return false;
}
return true;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::memberExpr(TokenKind tt, bool allowCallSyntax)
{
JS_ASSERT(tokenStream.isCurrentTokenType(tt));
Node lhs;
JS_CHECK_RECURSION(context, return null());
/* Check for new expression first. */
if (tt == TOK_NEW) {
lhs = handler.newList(PNK_NEW, null(), JSOP_NEW);
if (!lhs)
return null();
tt = tokenStream.getToken(TSF_OPERAND);
Node ctorExpr = memberExpr(tt, false);
if (!ctorExpr)
return null();
handler.addList(lhs, ctorExpr);
if (tokenStream.matchToken(TOK_LP) && !argumentList(lhs))
return null();
} else {
lhs = primaryExpr(tt);
if (!lhs)
return null();
}
while ((tt = tokenStream.getToken()) > TOK_EOF) {
Node nextMember;
if (tt == TOK_DOT) {
tt = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
if (tt == TOK_ERROR)
return null();
if (tt == TOK_NAME) {
PropertyName *field = tokenStream.currentToken().name();
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();
if (!propExpr)
return null();
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_IN_INDEX);
/*
* Do folding so we don't have roundtrip changes for cases like:
* function (obj) { return obj["a" + "b"] }
*/
if (foldConstants && !FoldConstants(context, &propExpr, this))
return null();
nextMember = handler.newPropertyByValue(lhs, propExpr, pos().end);
if (!nextMember)
return null();
} else if (allowCallSyntax && tt == TOK_LP) {
nextMember = handler.newList(PNK_CALL, null(), JSOP_CALL);
if (!nextMember)
return null();
if (JSAtom *atom = handler.isName(lhs)) {
if (atom == context->names().eval) {
/* Select JSOP_EVAL and flag pc as heavyweight. */
handler.setOp(nextMember, JSOP_EVAL);
pc->sc->setBindingsAccessedDynamically();
/*
* 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();
}
} else if (JSAtom *atom = handler.isGetProp(lhs)) {
/* Select JSOP_FUNAPPLY given foo.apply(...). */
if (atom == context->names().apply) {
handler.setOp(nextMember, JSOP_FUNAPPLY);
if (pc->sc->isFunctionBox())
pc->sc->asFunctionBox()->usesApply = true;
} else if (atom == context->names().call) {
handler.setOp(nextMember, JSOP_FUNCALL);
}
}
handler.setBeginPosition(nextMember, lhs);
handler.addList(nextMember, lhs);
if (!argumentList(nextMember))
return null();
} else {
tokenStream.ungetToken();
return lhs;
}
lhs = nextMember;
}
if (tt == TOK_ERROR)
return null();
return lhs;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::bracketedExpr()
{
/*
* Always accept the 'in' operator in a parenthesized expression,
* where it's unambiguous, even if we might be parsing the init of a
* for statement.
*/
bool oldParsingForInit = pc->parsingForInit;
pc->parsingForInit = false;
Node pn = expr();
pc->parsingForInit = oldParsingForInit;
return pn;
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newName(PropertyName *name)
{
return handler.newName(name, pc->inBlock(), pc->blockid(), pos());
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::identifierName()
{
JS_ASSERT(tokenStream.isCurrentTokenType(TOK_NAME));
RootedPropertyName name(context, tokenStream.currentToken().name());
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()
{
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 handler.newStringLiteral(atom, pos());
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::newRegExp()
{
// Create the regexp even when doing a syntax parse, to check the regexp's syntax.
size_t length = tokenStream.getTokenbuf().length();
const StableCharPtr chars(tokenStream.getTokenbuf().begin(), length);
RegExpFlag flags = tokenStream.currentToken().regExpFlags();
Rooted<RegExpObject*> reobj(context);
if (RegExpStatics *res = context->regExpStatics())
reobj = RegExpObject::create(context, res, chars.get(), length, flags, &tokenStream);
else
reobj = RegExpObject::createNoStatics(context, chars.get(), length, flags, &tokenStream);
if (!reobj)
return null();
return handler.newRegExp(reobj, pos(), *this);
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::primaryExpr(TokenKind tt)
{
JS_ASSERT(tokenStream.isCurrentTokenType(tt));
Node pn, pn2, pn3;
JSOp op;
JS_CHECK_RECURSION(context, return null());
switch (tt) {
case TOK_FUNCTION:
return functionExpr();
case TOK_LB:
{
pn = handler.newList(PNK_ARRAY, null(), JSOP_NEWINIT);
if (!pn)
return null();
#if JS_HAS_GENERATORS
handler.setBlockId(pn, pc->blockidGen);
#endif
if (tokenStream.matchToken(TOK_RB, TSF_OPERAND)) {
/*
* Mark empty arrays as non-constant, since we cannot easily
* determine their type.
*/
handler.setListFlag(pn, PNX_NONCONST);
} else {
bool spread = false, missingTrailingComma = false;
unsigned index = 0;
for (; ; index++) {
if (index == JSObject::NELEMENTS_LIMIT) {
report(ParseError, false, null(), JSMSG_ARRAY_INIT_TOO_BIG);
return null();
}
tt = tokenStream.peekToken(TSF_OPERAND);
if (tt == TOK_RB)
break;
if (tt == TOK_COMMA) {
tokenStream.consumeKnownToken(TOK_COMMA);
pn2 = handler.newElision();
if (!pn2)
return null();
handler.setListFlag(pn, PNX_SPECIALARRAYINIT | PNX_NONCONST);
} else if (tt == TOK_TRIPLEDOT) {
spread = true;
handler.setListFlag(pn, PNX_SPECIALARRAYINIT | PNX_NONCONST);
tokenStream.consumeKnownToken(TOK_TRIPLEDOT);
uint32_t begin = pos().begin;
Node inner = assignExpr();
if (!inner)
return null();
pn2 = handler.newUnary(PNK_SPREAD, JSOP_NOP, begin, inner);
if (!pn2)
return null();
} else {
pn2 = assignExpr();
if (!pn2)
return null();
if (foldConstants && !FoldConstants(context, &pn2, this))
return null();
if (!handler.isConstant(pn2))
handler.setListFlag(pn, PNX_NONCONST);
}
handler.addList(pn, pn2);
if (tt != TOK_COMMA) {
/* If we didn't already match TOK_COMMA in above case. */
if (!tokenStream.matchToken(TOK_COMMA)) {
missingTrailingComma = true;
break;
}
}
}
#if JS_HAS_GENERATORS
/*
* At this point, (index == 0 && missingTrailingComma) implies one
* element initialiser was parsed.
*
* An array comprehension of the form:
*
* [i * j for (i in o) for (j in p) if (i != j)]
*
* translates to roughly the following let expression:
*
* 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.
* An array comprehension opens exactly one block scope, no matter
* how many for heads it contains.
*
* Each let () {...} or for (let ...) ... compiles to:
*
* JSOP_ENTERBLOCK <o> ... JSOP_LEAVEBLOCK <n>
*
* 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, and allocates a slot on the operand stack at
* runtime via JSOP_ENTERBLOCK. 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 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 && tokenStream.matchToken(TOK_FOR) && missingTrailingComma) {
if (!arrayInitializerComprehensionTail(pn))
return null();
}
#endif /* JS_HAS_GENERATORS */
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_AFTER_LIST);
}
handler.setEndPosition(pn, pos().end);
return pn;
}
case TOK_LC:
{
Node pnval;
/*
* A map from property names we've seen thus far to a mask of property
* assignment types, stored and retrieved with ALE_SET_INDEX/ALE_INDEX.
*/
AtomIndexMap seen;
enum AssignmentType {
GET = 0x1,
SET = 0x2,
VALUE = 0x4 | GET | SET
};
pn = handler.newList(PNK_OBJECT, null(), JSOP_NEWINIT);
if (!pn)
return null();
RootedAtom atom(context);
Value tmp;
for (;;) {
TokenKind ltok = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
switch (ltok) {
case TOK_NUMBER:
tmp = DoubleValue(tokenStream.currentToken().number());
atom = ToAtom<CanGC>(context, HandleValue::fromMarkedLocation(&tmp));
if (!atom)
return null();
pn3 = newNumber(tokenStream.currentToken());
break;
case TOK_NAME:
{
atom = tokenStream.currentToken().name();
if (atom == context->names().get) {
op = JSOP_INITPROP_GETTER;
} else if (atom == context->names().set) {
op = JSOP_INITPROP_SETTER;
} else {
pn3 = handler.newIdentifier(atom, pos());
if (!pn3)
return null();
break;
}
tt = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
if (tt == TOK_NAME) {
atom = tokenStream.currentToken().name();
pn3 = newName(atom->asPropertyName());
if (!pn3)
return null();
} else if (tt == TOK_STRING) {
atom = tokenStream.currentToken().atom();
uint32_t index;
if (atom->isIndex(&index)) {
pn3 = handler.newNumber(index, NoDecimal, pos());
if (!pn3)
return null();
tmp = DoubleValue(index);
atom = ToAtom<CanGC>(context, HandleValue::fromMarkedLocation(&tmp));
if (!atom)
return null();
} else {
pn3 = stringLiteral();
if (!pn3)
return null();
}
} else if (tt == TOK_NUMBER) {
double number = tokenStream.currentToken().number();
tmp = DoubleValue(number);
atom = ToAtom<CanGC>(context, HandleValue::fromMarkedLocation(&tmp));
if (!atom)
return null();
pn3 = newNumber(tokenStream.currentToken());
if (!pn3)
return null();
} else {
tokenStream.ungetToken();
pn3 = handler.newIdentifier(atom, pos());
if (!pn3)
return null();
break;
}
JS_ASSERT(op == JSOP_INITPROP_GETTER || op == JSOP_INITPROP_SETTER);
handler.setListFlag(pn, PNX_NONCONST);
/* NB: Getter function in { get x(){} } is unnamed. */
Rooted<PropertyName*> funName(context, NULL);
TokenStream::Position start(keepAtoms);
tokenStream.tell(&start);
pn2 = functionDef(funName, start, tokenStream.positionToOffset(start),
op == JSOP_INITPROP_GETTER ? Getter : Setter,
Expression);
if (!pn2)
return null();
pn2 = handler.newBinary(PNK_COLON, pn3, pn2, op);
goto skip;
}
case TOK_STRING: {
atom = tokenStream.currentToken().atom();
uint32_t index;
if (atom->isIndex(&index)) {
pn3 = handler.newNumber(index, NoDecimal, pos());
if (!pn3)
return null();
} else {
pn3 = stringLiteral();
if (!pn3)
return null();
}
break;
}
case TOK_RC:
goto end_obj_init;
default:
report(ParseError, false, null(), JSMSG_BAD_PROP_ID);
return null();
}
op = JSOP_INITPROP;
tt = tokenStream.getToken();
if (tt == TOK_COLON) {
pnval = assignExpr();
if (!pnval)
return null();
if (foldConstants && !FoldConstants(context, &pnval, this))
return null();
/*
* Treat initializers which mutate __proto__ as non-constant,
* so that we can later assume singleton objects delegate to
* the default Object.prototype.
*/
if (!handler.isConstant(pnval) || atom == context->names().proto)
handler.setListFlag(pn, PNX_NONCONST);
}
#if JS_HAS_DESTRUCTURING_SHORTHAND
else if (ltok == TOK_NAME && (tt == TOK_COMMA || tt == TOK_RC)) {
/*
* Support, e.g., |var {x, y} = o| as destructuring shorthand
* for |var {x: x, y: y} = o|, per proposed JS2/ES4 for JS1.8.
*/
tokenStream.ungetToken();
if (!tokenStream.checkForKeyword(atom->charsZ(), atom->length(), NULL, NULL))
return null();
handler.setListFlag(pn, PNX_DESTRUCT | PNX_NONCONST);
PropertyName *name = handler.isName(pn3);
JS_ASSERT(atom);
pn3 = newName(name);
if (!pn3)
return null();
pnval = pn3;
}
#endif
else {
report(ParseError, false, null(), JSMSG_COLON_AFTER_ID);
return null();
}
pn2 = handler.newBinary(PNK_COLON, pn3, pnval, op);
skip:
if (!pn2)
return null();
handler.addList(pn, pn2);
/*
* Check for duplicate property names. Duplicate data properties
* only conflict in strict mode. Duplicate getter or duplicate
* setter halves always conflict. A data property conflicts with
* any part of an accessor property.
*/
AssignmentType assignType;
if (op == JSOP_INITPROP) {
assignType = VALUE;
} else if (op == JSOP_INITPROP_GETTER) {
assignType = GET;
} else if (op == JSOP_INITPROP_SETTER) {
assignType = SET;
} else {
JS_NOT_REACHED("bad opcode in object initializer");
assignType = VALUE; /* try to error early */
}
AtomIndexAddPtr p = seen.lookupForAdd(atom);
if (p) {
jsatomid index = p.value();
AssignmentType oldAssignType = AssignmentType(index);
if ((oldAssignType & assignType) &&
(oldAssignType != VALUE || assignType != VALUE || pc->sc->needStrictChecks()))
{
JSAutoByteString name;
if (!js_AtomToPrintableString(context, atom, &name))
return null();
ParseReportKind reportKind =
(oldAssignType == VALUE && assignType == VALUE && !pc->sc->needStrictChecks())
? ParseWarning
: (pc->sc->needStrictChecks() ? ParseStrictError : ParseError);
if (!report(reportKind, pc->sc->strict, null(),
JSMSG_DUPLICATE_PROPERTY, name.ptr()))
{
return null();
}
}
p.value() = assignType | oldAssignType;
} else {
if (!seen.add(p, atom, assignType))
return null();
}
tt = tokenStream.getToken();
if (tt == TOK_RC)
goto end_obj_init;
if (tt != TOK_COMMA) {
report(ParseError, false, null(), JSMSG_CURLY_AFTER_LIST);
return null();
}
}
end_obj_init:
handler.setEndPosition(pn, pos().end);
return pn;
}
#if JS_HAS_BLOCK_SCOPE
case TOK_LET:
return letBlock(LetExpresion);
#endif
case TOK_LP:
{
bool genexp;
pn = parenExpr(&genexp);
if (!pn)
return null();
pn = handler.setInParens(pn);
if (!genexp)
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_IN_PAREN);
return pn;
}
case TOK_STRING:
return stringLiteral();
case TOK_NAME:
return identifierName();
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:
return handler.newThisLiteral(pos());
case TOK_NULL:
return handler.newNullLiteral(pos());
case TOK_RP:
// Not valid expression syntax, but this is valid in an arrow function
// with no params: `() => body`.
if (tokenStream.peekToken() == TOK_ARROW) {
tokenStream.ungetToken(); // put back right paren
// 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());
}
report(ParseError, false, null(), JSMSG_SYNTAX_ERROR);
return null();
case TOK_TRIPLEDOT:
// Not valid expression syntax, but this is valid in an arrow function
// with a rest param: `(a, b, ...rest) => body`.
if (tokenStream.matchToken(TOK_NAME) &&
tokenStream.matchToken(TOK_RP) &&
tokenStream.peekToken() == TOK_ARROW)
{
tokenStream.ungetToken(); // put back right paren
// Return an arbitrary expression node. See case TOK_RP above.
return handler.newNullLiteral(pos());
}
report(ParseError, false, null(), JSMSG_SYNTAX_ERROR);
return null();
case TOK_ERROR:
/* The scanner or one of its subroutines reported the error. */
return null();
default:
report(ParseError, false, null(), JSMSG_SYNTAX_ERROR);
return null();
}
}
template <typename ParseHandler>
typename ParseHandler::Node
Parser<ParseHandler>::parenExpr(bool *genexp)
{
JS_ASSERT(tokenStream.currentToken().type == TOK_LP);
uint32_t begin = pos().begin;
if (genexp)
*genexp = false;
GenexpGuard<ParseHandler> guard(this);
Node pn = bracketedExpr();
if (!pn)
return null();
guard.endBody();
#if JS_HAS_GENERATOR_EXPRS
if (tokenStream.matchToken(TOK_FOR)) {
if (!guard.checkValidBody(pn))
return null();
if (handler.isOperationWithoutParens(pn, PNK_COMMA)) {
report(ParseError, false, null(),
JSMSG_BAD_GENERATOR_SYNTAX, js_generator_str);
return null();
}
pn = generatorExpr(pn);
if (!pn)
return null();
handler.setBeginPosition(pn, begin);
if (genexp) {
if (tokenStream.getToken() != TOK_RP) {
report(ParseError, false, null(),
JSMSG_BAD_GENERATOR_SYNTAX, js_generator_str);
return null();
}
handler.setEndPosition(pn, pos().end);
*genexp = true;
}
} else
#endif /* JS_HAS_GENERATOR_EXPRS */
if (!guard.maybeNoteGenerator(pn))
return null();
return pn;
}
template class Parser<FullParseHandler>;
template class Parser<SyntaxParseHandler>;
} /* namespace frontend */
} /* namespace js */