jsparse.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=99:
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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* decision by deleting the provisions above and replace them with the notice
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* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* 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 jsparse.h).
* After tree construction, it rewrites trees to fold constants and evaluate
* compile-time expressions. Finally, it calls js_EmitTree (see jsemit.h) to
* generate bytecode.
*
* This parser attempts no error recovery.
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "jstypes.h"
#include "jsstdint.h"
#include "jsarena.h"
#include "jsutil.h"
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsversion.h"
#include "jsemit.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsgcmark.h"
#include "jsinterp.h"
#include "jsiter.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsparse.h"
#include "jsprobes.h"
#include "jsscan.h"
#include "jsscope.h"
#include "jsscript.h"
#include "jsstr.h"
#include "jsstaticcheck.h"
#include "jslibmath.h"
#include "jsvector.h"
#if JS_HAS_XML_SUPPORT
#include "jsxml.h"
#endif
#if JS_HAS_DESTRUCTURING
#include "jsdhash.h"
#endif
#include "jsatominlines.h"
#include "jsinferinlines.h"
#include "jsobjinlines.h"
#include "jsregexpinlines.h"
#include "jsscriptinlines.h"
#include "frontend/ParseMaps-inl.h"
// Grr, windows.h or something under it #defines CONST...
#ifdef CONST
#undef CONST
#endif
using namespace js;
using namespace js::gc;
/*
* Asserts to verify assumptions behind pn_ macros.
*/
#define pn_offsetof(m) offsetof(JSParseNode, m)
JS_STATIC_ASSERT(pn_offsetof(pn_link) == pn_offsetof(dn_uses));
JS_STATIC_ASSERT(pn_offsetof(pn_u.name.atom) == pn_offsetof(pn_u.apair.atom));
#undef pn_offsetof
/*
* 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) { \
reportErrorNumber(NULL, JSREPORT_ERROR, errno); \
return NULL; \
} \
JS_END_MACRO
#define MUST_MATCH_TOKEN(tt, errno) MUST_MATCH_TOKEN_WITH_FLAGS(tt, errno, 0)
void
JSParseNode::become(JSParseNode *pn2)
{
JS_ASSERT(!pn_defn);
JS_ASSERT(!pn2->isDefn());
JS_ASSERT(!pn_used);
if (pn2->isUsed()) {
JSParseNode **pnup = &pn2->pn_lexdef->dn_uses;
while (*pnup != pn2)
pnup = &(*pnup)->pn_link;
*pnup = this;
pn_link = pn2->pn_link;
pn_used = true;
pn2->pn_link = NULL;
pn2->pn_used = false;
}
pn_type = pn2->pn_type;
pn_op = pn2->pn_op;
pn_arity = pn2->pn_arity;
pn_parens = pn2->pn_parens;
pn_u = pn2->pn_u;
/*
* If any pointers are pointing to pn2, change them to point to this
* instead, since pn2 will be cleared and probably recycled.
*/
if (this->isKind(TOK_FUNCTION) && isArity(PN_FUNC)) {
/* Function node: fix up the pn_funbox->node back-pointer. */
JS_ASSERT(pn_funbox->node == pn2);
pn_funbox->node = this;
} else if (pn_arity == PN_LIST && !pn_head) {
/* Empty list: fix up the pn_tail pointer. */
JS_ASSERT(pn_count == 0);
JS_ASSERT(pn_tail == &pn2->pn_head);
pn_tail = &pn_head;
}
pn2->clear();
}
void
JSParseNode::clear()
{
pn_type = TOK_EOF;
setOp(JSOP_NOP);
pn_used = pn_defn = false;
pn_arity = PN_NULLARY;
pn_parens = false;
}
Parser::Parser(JSContext *cx, JSPrincipals *prin, StackFrame *cfp, bool foldConstants)
: js::AutoGCRooter(cx, PARSER),
context(cx),
tokenStream(cx),
principals(NULL),
callerFrame(cfp),
callerVarObj(cfp ? &cfp->varObj() : NULL),
nodeList(NULL),
functionCount(0),
traceListHead(NULL),
tc(NULL),
keepAtoms(cx->runtime),
foldConstants(foldConstants)
{
cx->activeCompilations++;
js::PodArrayZero(tempFreeList);
setPrincipals(prin);
JS_ASSERT_IF(cfp, cfp->isScriptFrame());
}
bool
Parser::init(const jschar *base, size_t length, const char *filename, uintN lineno,
JSVersion version)
{
JSContext *cx = context;
if (!cx->ensureParseMapPool())
return false;
tempPoolMark = JS_ARENA_MARK(&cx->tempPool);
if (!tokenStream.init(base, length, filename, lineno, version)) {
JS_ARENA_RELEASE(&cx->tempPool, tempPoolMark);
return false;
}
return true;
}
Parser::~Parser()
{
JSContext *cx = context;
if (principals)
JSPRINCIPALS_DROP(cx, principals);
JS_ARENA_RELEASE(&cx->tempPool, tempPoolMark);
cx->activeCompilations--;
}
void
Parser::setPrincipals(JSPrincipals *prin)
{
JS_ASSERT(!principals);
if (prin)
JSPRINCIPALS_HOLD(context, prin);
principals = prin;
}
JSObjectBox *
Parser::newObjectBox(JSObject *obj)
{
JS_ASSERT(obj);
/*
* We use JSContext.tempPool to allocate parsed objects and place them on
* a list in this Parser to ensure GC safety. Thus the tempPool 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.
*/
JSObjectBox *objbox;
JS_ARENA_ALLOCATE_TYPE(objbox, JSObjectBox, &context->tempPool);
if (!objbox) {
js_ReportOutOfMemory(context);
return NULL;
}
objbox->traceLink = traceListHead;
traceListHead = objbox;
objbox->emitLink = NULL;
objbox->object = obj;
objbox->isFunctionBox = false;
return objbox;
}
JSFunctionBox *
Parser::newFunctionBox(JSObject *obj, JSParseNode *fn, JSTreeContext *tc)
{
JS_ASSERT(obj);
JS_ASSERT(obj->isFunction());
/*
* We use JSContext.tempPool to allocate parsed objects and place them on
* a list in this Parser to ensure GC safety. Thus the tempPool 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.
*/
JSFunctionBox *funbox;
JS_ARENA_ALLOCATE_TYPE(funbox, JSFunctionBox, &context->tempPool);
if (!funbox) {
js_ReportOutOfMemory(context);
return NULL;
}
funbox->traceLink = traceListHead;
traceListHead = funbox;
funbox->emitLink = NULL;
funbox->object = obj;
funbox->isFunctionBox = true;
funbox->node = fn;
funbox->siblings = tc->functionList;
tc->functionList = funbox;
++tc->parser->functionCount;
funbox->kids = NULL;
funbox->parent = tc->funbox;
funbox->methods = NULL;
new (&funbox->bindings) Bindings(context);
funbox->queued = false;
funbox->inLoop = false;
for (JSStmtInfo *stmt = tc->topStmt; stmt; stmt = stmt->down) {
if (STMT_IS_LOOP(stmt)) {
funbox->inLoop = true;
break;
}
}
funbox->level = tc->staticLevel;
funbox->tcflags = (TCF_IN_FUNCTION | (tc->flags & (TCF_COMPILE_N_GO | TCF_STRICT_MODE_CODE)));
if (tc->innermostWith)
funbox->tcflags |= TCF_IN_WITH;
return funbox;
}
bool
JSFunctionBox::joinable() const
{
return function()->isNullClosure() &&
(tcflags & (TCF_FUN_USES_ARGUMENTS |
TCF_FUN_USES_OWN_NAME |
TCF_COMPILE_N_GO)) == TCF_COMPILE_N_GO;
}
bool
JSFunctionBox::inAnyDynamicScope() const
{
for (const JSFunctionBox *funbox = this; funbox; funbox = funbox->parent) {
if (funbox->tcflags & (TCF_IN_WITH | TCF_FUN_EXTENSIBLE_SCOPE))
return true;
}
return false;
}
bool
JSFunctionBox::scopeIsExtensible() const
{
return tcflags & TCF_FUN_EXTENSIBLE_SCOPE;
}
bool
JSFunctionBox::shouldUnbrand(uintN methods, uintN slowMethods) const
{
if (slowMethods != 0) {
for (const JSFunctionBox *funbox = this; funbox; funbox = funbox->parent) {
if (!(funbox->tcflags & TCF_FUN_MODULE_PATTERN))
return true;
if (funbox->inLoop)
return true;
}
}
return false;
}
void
Parser::trace(JSTracer *trc)
{
JSObjectBox *objbox = traceListHead;
while (objbox) {
MarkObject(trc, *objbox->object, "parser.object");
if (objbox->isFunctionBox)
static_cast<JSFunctionBox *>(objbox)->bindings.trace(trc);
objbox = objbox->traceLink;
}
for (JSTreeContext *tc = this->tc; tc; tc = tc->parent)
tc->trace(trc);
}
/* Add |node| to |parser|'s free node list. */
static inline void
AddNodeToFreeList(JSParseNode *pn, js::Parser *parser)
{
/* Catch back-to-back dup recycles. */
JS_ASSERT(pn != parser->nodeList);
/*
* It's too hard to clear these nodes from the AtomDefnMaps, etc. that
* hold references to them, so we never free them. It's our caller's job to
* recognize and process these, since their children do need to be dealt
* with.
*/
JS_ASSERT(!pn->isUsed());
JS_ASSERT(!pn->isDefn());
if (pn->isArity(PN_NAMESET) && pn->pn_names.hasMap())
pn->pn_names.releaseMap(parser->context);
#ifdef DEBUG
/* Poison the node, to catch attempts to use it without initializing it. */
memset(pn, 0xab, sizeof(*pn));
#endif
pn->pn_next = parser->nodeList;
parser->nodeList = pn;
}
/* Add |node| to |tc|'s parser's free node list. */
static inline void
AddNodeToFreeList(JSParseNode *pn, JSTreeContext *tc)
{
AddNodeToFreeList(pn, tc->parser);
}
/*
* Walk the function box list at |*funboxHead|, removing boxes for deleted
* functions and cleaning up method lists. We do this once, before
* performing function analysis, to avoid traversing possibly long function
* lists repeatedly when recycling nodes.
*
* There are actually three possible states for function boxes and their
* nodes:
*
* - Live: funbox->node points to the node, and funbox->node->pn_funbox
* points back to the funbox.
*
* - Recycled: funbox->node points to the node, but funbox->node->pn_funbox
* is NULL. When a function node is part of a tree that gets recycled, we
* must avoid corrupting any method list the node is on, so we leave the
* function node unrecycled until we call cleanFunctionList. At recycle
* time, we clear such nodes' pn_funbox pointers to indicate that they
* are deleted and should be recycled once we get here.
*
* - Mutated: funbox->node is NULL; the contents of the node itself could
* be anything. When we mutate a function node into some other kind of
* node, we lose all indication that the node was ever part of the
* function box tree; it could later be recycled, reallocated, and turned
* into anything at all. (Fortunately, method list members never get
* mutated, so we don't have to worry about that case.)
* PrepareNodeForMutation clears the node's function box's node pointer,
* disconnecting it entirely from the function box tree, and marking the
* function box to be trimmed out.
*/
void
Parser::cleanFunctionList(JSFunctionBox **funboxHead)
{
JSFunctionBox **link = funboxHead;
while (JSFunctionBox *box = *link) {
if (!box->node) {
/*
* This funbox's parse node was mutated into something else. Drop the box,
* and stay at the same link.
*/
*link = box->siblings;
} else if (!box->node->pn_funbox) {
/*
* This funbox's parse node is ready to be recycled. Drop the box, recycle
* the node, and stay at the same link.
*/
*link = box->siblings;
AddNodeToFreeList(box->node, this);
} else {
/* The function is still live. */
/* First, remove nodes for deleted functions from our methods list. */
{
JSParseNode **methodLink = &box->methods;
while (JSParseNode *method = *methodLink) {
/* Method nodes are never rewritten in place to be other kinds of nodes. */
JS_ASSERT(method->isArity(PN_FUNC));
if (!method->pn_funbox) {
/* Deleted: drop the node, and stay on this link. */
*methodLink = method->pn_link;
} else {
/* Live: keep the node, and move to the next link. */
methodLink = &method->pn_link;
}
}
}
/* Second, remove boxes for deleted functions from our kids list. */
cleanFunctionList(&box->kids);
/* Keep the box on the list, and move to the next link. */
link = &box->siblings;
}
}
}
namespace js {
/*
* A work pool of JSParseNodes. The work pool is a stack, chained together
* by nodes' pn_next fields. We use this to avoid creating deep C++ stacks
* when recycling deep parse trees.
*
* Since parse nodes are probably allocated in something close to the order
* they appear in a depth-first traversal of the tree, making the work pool
* a stack should give us pretty good locality.
*/
class NodeStack {
public:
NodeStack() : top(NULL) { }
bool empty() { return top == NULL; }
void push(JSParseNode *pn) {
pn->pn_next = top;
top = pn;
}
void pushUnlessNull(JSParseNode *pn) { if (pn) push(pn); }
/* Push the children of the PN_LIST node |pn| on the stack. */
void pushList(JSParseNode *pn) {
/* This clobbers pn->pn_head if the list is empty; should be okay. */
*pn->pn_tail = top;
top = pn->pn_head;
}
JSParseNode *pop() {
JS_ASSERT(!empty());
JSParseNode *hold = top; /* my kingdom for a prog1 */
top = top->pn_next;
return hold;
}
private:
JSParseNode *top;
};
} /* namespace js */
/*
* Push the children of |pn| on |stack|. Return true if |pn| itself could be
* safely recycled, or false if it must be cleaned later (pn_used and pn_defn
* nodes, and all function nodes; see comments for
* js::Parser::cleanFunctionList). Some callers want to free |pn|; others
* (PrepareNodeForMutation) don't care about |pn|, and just need to take care of
* its children.
*/
static bool
PushNodeChildren(JSParseNode *pn, NodeStack *stack)
{
switch (pn->getArity()) {
case PN_FUNC:
/*
* Function nodes are linked into the function box tree, and may
* appear on method lists. Both of those lists are singly-linked,
* so trying to update them now could result in quadratic behavior
* when recycling trees containing many functions; and the lists
* can be very long. So we put off cleaning the lists up until just
* before function analysis, when we call
* js::Parser::cleanFunctionList.
*
* In fact, we can't recycle the parse node yet, either: it may
* appear on a method list, and reusing the node would corrupt
* that. Instead, we clear its pn_funbox pointer to mark it as
* deleted; js::Parser::cleanFunctionList recycles it as well.
*
* We do recycle the nodes around it, though, so we must clear
* pointers to them to avoid leaving dangling references where
* someone can find them.
*/
pn->pn_funbox = NULL;
stack->pushUnlessNull(pn->pn_body);
pn->pn_body = NULL;
return false;
case PN_NAME:
/*
* Because used/defn nodes appear in AtomDefnMaps and elsewhere, we
* don't recycle them. (We'll recover their storage when we free
* the temporary arena.) However, we do recycle the nodes around
* them, so clean up the pointers to avoid dangling references. The
* top-level decls table carries references to them that later
* iterations through the compileScript loop may find, so they need
* to be neat.
*
* pn_expr and pn_lexdef share storage; the latter isn't an owning
* reference.
*/
if (!pn->isUsed()) {
stack->pushUnlessNull(pn->pn_expr);
pn->pn_expr = NULL;
}
return !pn->isUsed() && !pn->isDefn();
case PN_LIST:
stack->pushList(pn);
break;
case PN_TERNARY:
stack->pushUnlessNull(pn->pn_kid1);
stack->pushUnlessNull(pn->pn_kid2);
stack->pushUnlessNull(pn->pn_kid3);
break;
case PN_BINARY:
if (pn->pn_left != pn->pn_right)
stack->pushUnlessNull(pn->pn_left);
stack->pushUnlessNull(pn->pn_right);
break;
case PN_UNARY:
stack->pushUnlessNull(pn->pn_kid);
break;
case PN_NULLARY:
/*
* E4X function namespace nodes are PN_NULLARY, but can appear on use
* lists.
*/
return !pn->isUsed() && !pn->isDefn();
default:
;
}
return true;
}
/*
* Prepare |pn| to be mutated in place into a new kind of node. Recycle all
* |pn|'s recyclable children (but not |pn| itself!), and disconnect it from
* metadata structures (the function box tree).
*/
static void
PrepareNodeForMutation(JSParseNode *pn, JSTreeContext *tc)
{
if (!pn->isArity(PN_NULLARY)) {
if (pn->isArity(PN_FUNC)) {
/*
* Since this node could be turned into anything, we can't
* ensure it won't be subsequently recycled, so we must
* disconnect it from the funbox tree entirely.
*
* Note that pn_funbox may legitimately be NULL. functionDef
* applies MakeDefIntoUse to definition nodes, which can come
* from prior iterations of the big loop in compileScript. In
* such cases, the defn nodes have been visited by the recycler
* (but not actually recycled!), and their funbox pointers
* cleared. But it's fine to mutate them into uses of some new
* definition.
*/
if (pn->pn_funbox)
pn->pn_funbox->node = NULL;
}
/* Put |pn|'s children (but not |pn| itself) on a work stack. */
NodeStack stack;
PushNodeChildren(pn, &stack);
/*
* For each node on the work stack, push its children on the work stack,
* and free the node if we can.
*/
while (!stack.empty()) {
pn = stack.pop();
if (PushNodeChildren(pn, &stack))
AddNodeToFreeList(pn, tc);
}
}
}
/*
* Return the nodes in the subtree |pn| to the parser's free node list, for
* reallocation.
*
* Note that all functions in |pn| that are not enclosed by other functions
* in |pn| must be direct children of |tc|, because we only clean up |tc|'s
* function and method lists. You must not reach into a function and
* recycle some part of it (unless you've updated |tc|->functionList, the
* way js_FoldConstants does).
*/
static JSParseNode *
RecycleTree(JSParseNode *pn, JSTreeContext *tc)
{
if (!pn)
return NULL;
JSParseNode *savedNext = pn->pn_next;
NodeStack stack;
for (;;) {
if (PushNodeChildren(pn, &stack))
AddNodeToFreeList(pn, tc);
if (stack.empty())
break;
pn = stack.pop();
}
return savedNext;
}
/*
* Allocate a JSParseNode from tc's node freelist or, failing that, from
* cx's temporary arena.
*/
static JSParseNode *
NewOrRecycledNode(JSTreeContext *tc)
{
JSParseNode *pn;
pn = tc->parser->nodeList;
if (!pn) {
JSContext *cx = tc->parser->context;
JS_ARENA_ALLOCATE_TYPE(pn, JSParseNode, &cx->tempPool);
if (!pn)
js_ReportOutOfMemory(cx);
} else {
tc->parser->nodeList = pn->pn_next;
}
if (pn) {
pn->setUsed(false);
pn->setDefn(false);
memset(&pn->pn_u, 0, sizeof pn->pn_u);
pn->pn_next = NULL;
}
return pn;
}
/* used only by static create methods of subclasses */
JSParseNode *
JSParseNode::create(JSParseNodeArity arity, JSTreeContext *tc)
{
const Token &tok = tc->parser->tokenStream.currentToken();
return create(arity, tok.type, JSOP_NOP, tok.pos, tc);
}
JSParseNode *
JSParseNode::create(JSParseNodeArity arity, TokenKind type, JSOp op, const TokenPos &pos,
JSTreeContext *tc)
{
JSParseNode *pn = NewOrRecycledNode(tc);
if (!pn)
return NULL;
pn->init(type, op, arity);
pn->pn_pos = pos;
return pn;
}
JSParseNode *
JSParseNode::newBinaryOrAppend(TokenKind tt, JSOp op, JSParseNode *left, JSParseNode *right,
JSTreeContext *tc)
{
JSParseNode *pn, *pn1, *pn2;
if (!left || !right)
return NULL;
/*
* Flatten a left-associative (left-heavy) tree of a given operator into
* a list, to reduce js_FoldConstants and js_EmitTree recursion.
*/
if (left->isKind(tt) &&
left->isOp(op) &&
(js_CodeSpec[op].format & JOF_LEFTASSOC)) {
if (left->pn_arity != PN_LIST) {
pn1 = left->pn_left, pn2 = left->pn_right;
left->setArity(PN_LIST);
left->pn_parens = false;
left->initList(pn1);
left->append(pn2);
if (tt == TOK_PLUS) {
if (pn1->isKind(TOK_STRING))
left->pn_xflags |= PNX_STRCAT;
else if (!pn1->isKind(TOK_NUMBER))
left->pn_xflags |= PNX_CANTFOLD;
if (pn2->isKind(TOK_STRING))
left->pn_xflags |= PNX_STRCAT;
else if (!pn2->isKind(TOK_NUMBER))
left->pn_xflags |= PNX_CANTFOLD;
}
}
left->append(right);
left->pn_pos.end = right->pn_pos.end;
if (tt == TOK_PLUS) {
if (right->isKind(TOK_STRING))
left->pn_xflags |= PNX_STRCAT;
else if (!right->isKind(TOK_NUMBER))
left->pn_xflags |= PNX_CANTFOLD;
}
return left;
}
/*
* Fold constant addition immediately, to conserve node space and, what's
* more, so js_FoldConstants never sees mixed addition and concatenation
* operations with more than one leading non-string operand in a PN_LIST
* generated for expressions such as 1 + 2 + "pt" (which should evaluate
* to "3pt", not "12pt").
*/
if (tt == TOK_PLUS &&
left->isKind(TOK_NUMBER) &&
right->isKind(TOK_NUMBER) &&
tc->parser->foldConstants) {
left->pn_dval += right->pn_dval;
left->pn_pos.end = right->pn_pos.end;
RecycleTree(right, tc);
return left;
}
pn = NewOrRecycledNode(tc);
if (!pn)
return NULL;
pn->init(tt, op, PN_BINARY);
pn->pn_pos.begin = left->pn_pos.begin;
pn->pn_pos.end = right->pn_pos.end;
pn->pn_left = left;
pn->pn_right = right;
return pn;
}
namespace js {
inline void
NameNode::initCommon(JSTreeContext *tc)
{
pn_expr = NULL;
pn_cookie.makeFree();
pn_dflags = (!tc->topStmt || tc->topStmt->type == STMT_BLOCK)
? PND_BLOCKCHILD
: 0;
pn_blockid = tc->blockid();
}
NameNode *
NameNode::create(JSAtom *atom, JSTreeContext *tc)
{
JSParseNode *pn;
pn = JSParseNode::create(PN_NAME, tc);
if (pn) {
pn->pn_atom = atom;
((NameNode *)pn)->initCommon(tc);
}
return (NameNode *)pn;
}
} /* namespace js */
static bool
GenerateBlockId(JSTreeContext *tc, uint32& blockid)
{
if (tc->blockidGen == JS_BIT(20)) {
JS_ReportErrorNumber(tc->parser->context, js_GetErrorMessage, NULL,
JSMSG_NEED_DIET, "program");
return false;
}
blockid = tc->blockidGen++;
return true;
}
static bool
GenerateBlockIdForStmtNode(JSParseNode *pn, JSTreeContext *tc)
{
JS_ASSERT(tc->topStmt);
JS_ASSERT(STMT_MAYBE_SCOPE(tc->topStmt));
JS_ASSERT(pn->isKind(TOK_LC) || pn->isKind(TOK_LEXICALSCOPE));
if (!GenerateBlockId(tc, tc->topStmt->blockid))
return false;
pn->pn_blockid = tc->topStmt->blockid;
return true;
}
/*
* Parse a top-level JS script.
*/
JSParseNode *
Parser::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.
*/
JSTreeContext globaltc(this);
if (!globaltc.init(context))
return NULL;
globaltc.setScopeChain(chain);
if (!GenerateBlockId(&globaltc, globaltc.bodyid))
return NULL;
JSParseNode *pn = statements();
if (pn) {
if (!tokenStream.matchToken(TOK_EOF)) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
pn = NULL;
} else if (foldConstants) {
if (!js_FoldConstants(context, pn, &globaltc))
pn = NULL;
}
}
return pn;
}
JS_STATIC_ASSERT(UpvarCookie::FREE_LEVEL == JS_BITMASK(JSFB_LEVEL_BITS));
static inline bool
SetStaticLevel(JSTreeContext *tc, uintN staticLevel)
{
/*
* This is a lot simpler than error-checking every UpvarCookie::set, and
* practically speaking it leaves more than enough room for upvars.
*/
if (UpvarCookie::isLevelReserved(staticLevel)) {
JS_ReportErrorNumber(tc->parser->context, js_GetErrorMessage, NULL,
JSMSG_TOO_DEEP, js_function_str);
return false;
}
tc->staticLevel = staticLevel;
return true;
}
/*
* Compile a top-level script.
*/
Compiler::Compiler(JSContext *cx, JSPrincipals *prin, StackFrame *cfp)
: parser(cx, prin, cfp), globalScope(NULL)
{}
JSScript *
Compiler::compileScript(JSContext *cx, JSObject *scopeChain, StackFrame *callerFrame,
JSPrincipals *principals, uint32 tcflags,
const jschar *chars, size_t length,
const char *filename, uintN lineno, JSVersion version,
JSString *source /* = NULL */,
uintN staticLevel /* = 0 */)
{
TokenKind tt;
JSParseNode *pn;
JSScript *script;
bool inDirectivePrologue;
JS_ASSERT(!(tcflags & ~(TCF_COMPILE_N_GO | TCF_NO_SCRIPT_RVAL | TCF_NEED_MUTABLE_SCRIPT |
TCF_COMPILE_FOR_EVAL | TCF_NEED_SCRIPT_OBJECT)));
/*
* The scripted callerFrame can only be given for compile-and-go scripts
* and non-zero static level requires callerFrame.
*/
JS_ASSERT_IF(callerFrame, tcflags & TCF_COMPILE_N_GO);
JS_ASSERT_IF(staticLevel != 0, callerFrame);
Compiler compiler(cx, principals, callerFrame);
if (!compiler.init(chars, length, filename, lineno, version))
return NULL;
Parser &parser = compiler.parser;
TokenStream &tokenStream = parser.tokenStream;
JSCodeGenerator cg(&parser, tokenStream.getLineno());
if (!cg.init(cx, JSTreeContext::USED_AS_TREE_CONTEXT))
return NULL;
Probes::compileScriptBegin(cx, filename, lineno);
MUST_FLOW_THROUGH("out");
// We can specialize a bit for the given scope chain if that scope chain is the global object.
JSObject *globalObj = scopeChain && scopeChain == scopeChain->getGlobal()
? scopeChain->getGlobal()
: NULL;
JS_ASSERT_IF(globalObj, globalObj->isNative());
JS_ASSERT_IF(globalObj, (globalObj->getClass()->flags & JSCLASS_GLOBAL_FLAGS) ==
JSCLASS_GLOBAL_FLAGS);
/* Null script early in case of error, to reduce our code footprint. */
script = NULL;
GlobalScope globalScope(cx, globalObj, &cg);
cg.flags |= tcflags;
cg.setScopeChain(scopeChain);
compiler.globalScope = &globalScope;
if (!SetStaticLevel(&cg, staticLevel))
goto out;
/* If this is a direct call to eval, inherit the caller's strictness. */
if (callerFrame &&
callerFrame->isScriptFrame() &&
callerFrame->script()->strictModeCode) {
cg.flags |= TCF_STRICT_MODE_CODE;
tokenStream.setStrictMode();
}
#ifdef DEBUG
bool savedCallerFun;
savedCallerFun = false;
#endif
if (tcflags & TCF_COMPILE_N_GO) {
if (source) {
/*
* Save eval program source in script->atoms[0] for the
* eval cache (see EvalCacheLookup in jsobj.cpp).
*/
JSAtom *atom = js_AtomizeString(cx, source);
jsatomid _;
if (!atom || !cg.makeAtomIndex(atom, &_))
goto out;
}
if (callerFrame && callerFrame->isFunctionFrame()) {
/*
* An eval script in a caller frame needs to have its enclosing
* function captured in case it refers to an upvar, and someone
* wishes to decompile it while it's running.
*/
JSObjectBox *funbox = parser.newObjectBox(callerFrame->fun());
if (!funbox)
goto out;
funbox->emitLink = cg.objectList.lastbox;
cg.objectList.lastbox = funbox;
cg.objectList.length++;
#ifdef DEBUG
savedCallerFun = true;
#endif
}
}
/*
* Inline this->statements to emit as we go to save AST space. We must
* generate our script-body blockid since we aren't calling Statements.
*/
uint32 bodyid;
if (!GenerateBlockId(&cg, bodyid))
goto out;
cg.bodyid = bodyid;
#if JS_HAS_XML_SUPPORT
pn = NULL;
bool onlyXML;
onlyXML = true;
#endif
inDirectivePrologue = true;
tokenStream.setOctalCharacterEscape(false);
for (;;) {
tt = tokenStream.peekToken(TSF_OPERAND);
if (tt <= TOK_EOF) {
if (tt == TOK_EOF)
break;
JS_ASSERT(tt == TOK_ERROR);
goto out;
}
pn = parser.statement();
if (!pn)
goto out;
JS_ASSERT(!cg.blockNode);
if (inDirectivePrologue && !parser.recognizeDirectivePrologue(pn, &inDirectivePrologue))
goto out;
if (!js_FoldConstants(cx, pn, &cg))
goto out;
if (!parser.analyzeFunctions(&cg))
goto out;
cg.functionList = NULL;
if (!js_EmitTree(cx, &cg, pn))
goto out;
#if JS_HAS_XML_SUPPORT
if (!pn->isKind(TOK_SEMI) || !pn->pn_kid || !TreeTypeIsXML(pn->pn_kid->getKind()))
onlyXML = false;
#endif
RecycleTree(pn, &cg);
}
#if JS_HAS_XML_SUPPORT
/*
* Prevent XML data theft via <script src="http://victim.com/foo.xml">.
* For background, see:
*
* https://bugzilla.mozilla.org/show_bug.cgi?id=336551
*/
if (pn && onlyXML && !callerFrame) {
parser.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_XML_WHOLE_PROGRAM);
goto out;
}
#endif
/*
* Global variables (gvars) share the atom index space with locals. Due to
* incremental code generation we need to patch the bytecode to adjust the
* local references to skip the globals.
*/
if (cg.hasSharps()) {
jsbytecode *code, *end;
JSOp op;
const JSCodeSpec *cs;
uintN len, slot;
code = CG_BASE(&cg);
for (end = code + CG_OFFSET(&cg); code != end; code += len) {
JS_ASSERT(code < end);
op = (JSOp) *code;
cs = &js_CodeSpec[op];
len = (cs->length > 0)
? (uintN) cs->length
: js_GetVariableBytecodeLength(code);
if ((cs->format & JOF_SHARPSLOT) ||
JOF_TYPE(cs->format) == JOF_LOCAL ||
(JOF_TYPE(cs->format) == JOF_SLOTATOM)) {
JS_ASSERT_IF(!(cs->format & JOF_SHARPSLOT),
JOF_TYPE(cs->format) != JOF_SLOTATOM);
slot = GET_SLOTNO(code);
if (!(cs->format & JOF_SHARPSLOT))
slot += cg.sharpSlots();
if (slot >= SLOTNO_LIMIT)
goto too_many_slots;
SET_SLOTNO(code, slot);
}
}
}
/*
* Nowadays the threaded interpreter needs a stop instruction, so we
* do have to emit that here.
*/
if (js_Emit1(cx, &cg, JSOP_STOP) < 0)
goto out;
JS_ASSERT(cg.version() == version);
script = JSScript::NewScriptFromCG(cx, &cg);
if (!script)
goto out;
JS_ASSERT(script->savedCallerFun == savedCallerFun);
if (!defineGlobals(cx, globalScope, script))
script = NULL;
out:
Probes::compileScriptEnd(cx, script, filename, lineno);
return script;
too_many_slots:
parser.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_TOO_MANY_LOCALS);
script = NULL;
goto out;
}
bool
Compiler::defineGlobals(JSContext *cx, GlobalScope &globalScope, JSScript *script)
{
JSObject *globalObj = globalScope.globalObj;
/* Define and update global properties. */
for (size_t i = 0; i < globalScope.defs.length(); i++) {
GlobalScope::GlobalDef &def = globalScope.defs[i];
/* Names that could be resolved ahead of time can be skipped. */
if (!def.atom)
continue;
jsid id = ATOM_TO_JSID(def.atom);
Value rval;
if (def.funbox) {
JSFunction *fun = def.funbox->function();
/*
* No need to check for redeclarations or anything, global
* optimizations only take place if the property is not defined.
*/
rval.setObject(*fun);
types::AddTypePropertyId(cx, globalObj, id, rval);
} else {
rval.setUndefined();
}
/*
* Don't update the type information when defining the property for the
* global object, per the consistency rules for type properties. If the
* property is only undefined before it is ever written, we can check
* the global directly during compilation and avoid having to emit type
* checks every time it is accessed in the script.
*/
const Shape *shape =
DefineNativeProperty(cx, globalObj, id, rval, JS_PropertyStub, JS_StrictPropertyStub,
JSPROP_ENUMERATE | JSPROP_PERMANENT, 0, 0, DNP_SKIP_TYPE);
if (!shape)
return false;
def.knownSlot = shape->slot;
}
js::Vector<JSScript *, 16> worklist(cx);
if (!worklist.append(script))
return false;
/*
* Recursively walk through all scripts we just compiled. For each script,
* go through all global uses. Each global use indexes into globalScope->defs.
* Use this information to repoint each use to the correct slot in the global
* object.
*/
while (worklist.length()) {
JSScript *outer = worklist.back();
worklist.popBack();
if (JSScript::isValidOffset(outer->objectsOffset)) {
JSObjectArray *arr = outer->objects();
/*
* If this is an eval script, don't treat the saved caller function
* stored in the first object slot as an inner function.
*/
size_t start = outer->savedCallerFun ? 1 : 0;
for (size_t i = start; i < arr->length; i++) {
JSObject *obj = arr->vector[i];
if (!obj->isFunction())
continue;
JSFunction *fun = obj->getFunctionPrivate();
JS_ASSERT(fun->isInterpreted());
JSScript *inner = fun->script();
if (outer->isHeavyweightFunction) {
outer->isOuterFunction = true;
inner->isInnerFunction = true;
}
if (!JSScript::isValidOffset(inner->globalsOffset) &&
!JSScript::isValidOffset(inner->objectsOffset)) {
continue;
}
if (!worklist.append(inner))
return false;
}
}
if (!JSScript::isValidOffset(outer->globalsOffset))
continue;
GlobalSlotArray *globalUses = outer->globals();
uint32 nGlobalUses = globalUses->length;
for (uint32 i = 0; i < nGlobalUses; i++) {
uint32 index = globalUses->vector[i].slot;
JS_ASSERT(index < globalScope.defs.length());
globalUses->vector[i].slot = globalScope.defs[index].knownSlot;
}
}
return true;
}
/*
* 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.
*/
#define ENDS_IN_OTHER 0
#define ENDS_IN_RETURN 1
#define ENDS_IN_BREAK 2
static int
HasFinalReturn(JSParseNode *pn)
{
JSParseNode *pn2, *pn3;
uintN rv, rv2, hasDefault;
switch (pn->getKind()) {
case TOK_LC:
if (!pn->pn_head)
return ENDS_IN_OTHER;
return HasFinalReturn(pn->last());
case TOK_IF:
if (!pn->pn_kid3)
return ENDS_IN_OTHER;
return HasFinalReturn(pn->pn_kid2) & HasFinalReturn(pn->pn_kid3);
case TOK_WHILE:
pn2 = pn->pn_left;
if (pn2->isKind(TOK_PRIMARY) && pn2->isOp(JSOP_TRUE))
return ENDS_IN_RETURN;
if (pn2->isKind(TOK_NUMBER) && pn2->pn_dval)
return ENDS_IN_RETURN;
return ENDS_IN_OTHER;
case TOK_DO:
pn2 = pn->pn_right;
if (pn2->isKind(TOK_PRIMARY)) {
if (pn2->isOp(JSOP_FALSE))
return HasFinalReturn(pn->pn_left);
if (pn2->isOp(JSOP_TRUE))
return ENDS_IN_RETURN;
}
if (pn2->isKind(TOK_NUMBER)) {
if (pn2->pn_dval == 0)
return HasFinalReturn(pn->pn_left);
return ENDS_IN_RETURN;
}
return ENDS_IN_OTHER;
case TOK_FOR:
pn2 = pn->pn_left;
if (pn2->isArity(PN_TERNARY) && !pn2->pn_kid2)
return ENDS_IN_RETURN;
return ENDS_IN_OTHER;
case TOK_SWITCH:
rv = ENDS_IN_RETURN;
hasDefault = ENDS_IN_OTHER;
pn2 = pn->pn_right;
if (pn2->isKind(TOK_LEXICALSCOPE))
pn2 = pn2->expr();
for (pn2 = pn2->pn_head; rv && pn2; pn2 = pn2->pn_next) {
if (pn2->isKind(TOK_DEFAULT))
hasDefault = ENDS_IN_RETURN;
pn3 = pn2->pn_right;
JS_ASSERT(pn3->isKind(TOK_LC));
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 TOK_BREAK:
return ENDS_IN_BREAK;
case TOK_WITH:
return HasFinalReturn(pn->pn_right);
case TOK_RETURN:
return ENDS_IN_RETURN;
case TOK_COLON:
case TOK_LEXICALSCOPE:
return HasFinalReturn(pn->expr());
case TOK_THROW:
return ENDS_IN_RETURN;
case TOK_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 TOK_CATCH:
/* Check this catch block's body. */
return HasFinalReturn(pn->pn_kid3);
case TOK_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 JSBool
ReportBadReturn(JSContext *cx, JSTreeContext *tc, JSParseNode *pn, uintN flags, uintN errnum,
uintN anonerrnum)
{
JSAutoByteString name;
if (tc->fun()->atom) {
if (!js_AtomToPrintableString(cx, tc->fun()->atom, &name))
return false;
} else {
errnum = anonerrnum;
}
return ReportCompileErrorNumber(cx, TS(tc->parser), pn, flags, errnum, name.ptr());
}
static JSBool
CheckFinalReturn(JSContext *cx, JSTreeContext *tc, JSParseNode *pn)
{
JS_ASSERT(tc->inFunction());
return HasFinalReturn(pn) == ENDS_IN_RETURN ||
ReportBadReturn(cx, tc, pn, JSREPORT_WARNING | JSREPORT_STRICT,
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'.
*/
bool
CheckStrictAssignment(JSContext *cx, JSTreeContext *tc, JSParseNode *lhs)
{
if (tc->needStrictChecks() && lhs->isKind(TOK_NAME)) {
JSAtom *atom = lhs->pn_atom;
JSAtomState *atomState = &cx->runtime->atomState;
if (atom == atomState->evalAtom || atom == atomState->argumentsAtom) {
JSAutoByteString name;
if (!js_AtomToPrintableString(cx, atom, &name) ||
!ReportStrictModeError(cx, TS(tc->parser), tc, 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
* tc's token stream if pn is NULL.
*/
bool
CheckStrictBinding(JSContext *cx, JSTreeContext *tc, JSAtom *atom, JSParseNode *pn)
{
if (!tc->needStrictChecks())
return true;
JSAtomState *atomState = &cx->runtime->atomState;
if (atom == atomState->evalAtom ||
atom == atomState->argumentsAtom ||
FindKeyword(atom->charsZ(), atom->length()))
{
JSAutoByteString name;
if (!js_AtomToPrintableString(cx, atom, &name))
return false;
return ReportStrictModeError(cx, TS(tc->parser), tc, pn, JSMSG_BAD_BINDING, name.ptr());
}
return true;
}
static bool
ReportBadParameter(JSContext *cx, JSTreeContext *tc, JSAtom *name, uintN errorNumber)
{
JSDefinition *dn = tc->decls.lookupFirst(name);
JSAutoByteString bytes;
return js_AtomToPrintableString(cx, name, &bytes) &&
ReportStrictModeError(cx, TS(tc->parser), tc, dn, errorNumber, bytes.ptr());
}
/*
* In strict mode code, all parameter names must be distinct, must not be
* strict mode reserved keywords, and must not be 'eval' or 'arguments'. We
* must perform these checks here, and not eagerly during parsing, because a
* function's body may turn on strict mode for the function head.
*/
static bool
CheckStrictParameters(JSContext *cx, JSTreeContext *tc)
{
JS_ASSERT(tc->inFunction());
if (!tc->needStrictChecks() || tc->bindings.countArgs() == 0)
return true;
JSAtom *argumentsAtom = cx->runtime->atomState.argumentsAtom;
JSAtom *evalAtom = cx->runtime->atomState.evalAtom;
/* name => whether we've warned about the name already */
HashMap<JSAtom *, bool> parameters(cx);
if (!parameters.init(tc->bindings.countArgs()))
return false;
/* Start with lastVariable(), not lastArgument(), for destructuring. */
for (Shape::Range r = tc->bindings.lastVariable(); !r.empty(); r.popFront()) {
jsid id = r.front().propid;
if (!JSID_IS_ATOM(id))
continue;
JSAtom *name = JSID_TO_ATOM(id);
if (name == argumentsAtom || name == evalAtom) {
if (!ReportBadParameter(cx, tc, name, JSMSG_BAD_BINDING))
return false;
}
if (tc->inStrictMode() && FindKeyword(name->charsZ(), name->length())) {
/*
* JSOPTION_STRICT is supposed to warn about future keywords, too,
* but we took care of that in the scanner.
*/
JS_ALWAYS_TRUE(!ReportBadParameter(cx, tc, name, JSMSG_RESERVED_ID));
return false;
}
/*
* Check for a duplicate parameter: warn or report an error exactly
* once for each duplicated parameter.
*/
if (HashMap<JSAtom *, bool>::AddPtr p = parameters.lookupForAdd(name)) {
if (!p->value && !ReportBadParameter(cx, tc, name, JSMSG_DUPLICATE_FORMAL))
return false;
p->value = true;
} else {
if (!parameters.add(p, name, false))
return false;
}
}
return true;
}
JSParseNode *
Parser::functionBody()
{
JS_ASSERT(tc->inFunction());
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_BLOCK, -1);
stmtInfo.flags = SIF_BODY_BLOCK;
uintN oldflags = tc->flags;
tc->flags &= ~(TCF_RETURN_EXPR | TCF_RETURN_VOID);
JSParseNode *pn;
#if JS_HAS_EXPR_CLOSURES
if (tokenStream.currentToken().type == TOK_LC) {
pn = statements();
} else {
pn = UnaryNode::create(tc);
if (pn) {
pn->pn_kid = assignExpr();
if (!pn->pn_kid) {
pn = NULL;
} else {
if (tc->flags & TCF_FUN_IS_GENERATOR) {
ReportBadReturn(context, tc, pn, JSREPORT_ERROR,
JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
pn = NULL;
} else {
pn->setKind(TOK_RETURN);
pn->setOp(JSOP_RETURN);
pn->pn_pos.end = pn->pn_kid->pn_pos.end;
}
}
}
}
#else
pn = statements();
#endif
if (pn) {
JS_ASSERT(!(tc->topStmt->flags & SIF_SCOPE));
js_PopStatement(tc);
/* Check for falling off the end of a function that returns a value. */
if (context->hasStrictOption() && (tc->flags & TCF_RETURN_EXPR) &&
!CheckFinalReturn(context, tc, pn)) {
pn = NULL;
}
}
tc->flags = oldflags | (tc->flags & TCF_FUN_FLAGS);
return pn;
}
/* Create a placeholder JSDefinition node for |atom|. */
static JSDefinition *
MakePlaceholder(JSParseNode *pn, JSTreeContext *tc)
{
JSDefinition *dn = (JSDefinition *) NameNode::create(pn->pn_atom, tc);
if (!dn)
return NULL;
dn->setKind(TOK_NAME);
dn->setOp(JSOP_NOP);
dn->setDefn(true);
dn->pn_dflags |= PND_PLACEHOLDER;
return dn;
}
static bool
Define(JSParseNode *pn, JSAtom *atom, JSTreeContext *tc, bool let = false)
{
JS_ASSERT(!pn->isUsed());
JS_ASSERT_IF(pn->isDefn(), pn->isPlaceholder());
bool foundLexdep = false;
JSDefinition *dn = NULL;
if (let)
dn = tc->decls.lookupFirst(atom);
if (!dn) {
dn = tc->lexdeps.lookupDefn(atom);
foundLexdep = !!dn;
}
if (dn && dn != pn) {
JSParseNode **pnup = &dn->dn_uses;
JSParseNode *pnu;
uintN start = let ? pn->pn_blockid : tc->bodyid;
while ((pnu = *pnup) != NULL && pnu->pn_blockid >= start) {
JS_ASSERT(pnu->isUsed());
pnu->pn_lexdef = (JSDefinition *) pn;
pn->pn_dflags |= pnu->pn_dflags & PND_USE2DEF_FLAGS;
pnup = &pnu->pn_link;
}
if (pnu != dn->dn_uses) {
*pnup = pn->dn_uses;
pn->dn_uses = dn->dn_uses;
dn->dn_uses = pnu;
if ((!pnu || pnu->pn_blockid < tc->bodyid) && foundLexdep)
tc->lexdeps->remove(atom);
}
}
JSDefinition *toAdd = (JSDefinition *) pn;
bool ok = let ? tc->decls.addShadow(atom, toAdd) : tc->decls.addUnique(atom, toAdd);
if (!ok)
return false;
pn->setDefn(true);
pn->pn_dflags &= ~PND_PLACEHOLDER;
if (!tc->parent)
pn->pn_dflags |= PND_TOPLEVEL;
return true;
}
static void
LinkUseToDef(JSParseNode *pn, JSDefinition *dn, JSTreeContext *tc)
{
JS_ASSERT(!pn->isUsed());
JS_ASSERT(!pn->isDefn());
JS_ASSERT(pn != dn->dn_uses);
pn->pn_link = dn->dn_uses;
dn->dn_uses = pn;
dn->pn_dflags |= pn->pn_dflags & PND_USE2DEF_FLAGS;
pn->setUsed(true);
pn->pn_lexdef = dn;
}
static void
ForgetUse(JSParseNode *pn)
{
if (!pn->isUsed()) {
JS_ASSERT(!pn->isDefn());
return;
}
JSParseNode **pnup = &pn->lexdef()->dn_uses;
JSParseNode *pnu;
while ((pnu = *pnup) != pn)
pnup = &pnu->pn_link;
*pnup = pn->pn_link;
pn->setUsed(false);
}
static JSParseNode *
MakeAssignment(JSParseNode *pn, JSParseNode *rhs, JSTreeContext *tc)
{
JSParseNode *lhs = NewOrRecycledNode(tc);
if (!lhs)
return NULL;
*lhs = *pn;
if (pn->isUsed()) {
JSDefinition *dn = pn->pn_lexdef;
JSParseNode **pnup = &dn->dn_uses;
while (*pnup != pn)
pnup = &(*pnup)->pn_link;
*pnup = lhs;
lhs->pn_link = pn->pn_link;
pn->pn_link = NULL;
}
pn->setKind(TOK_ASSIGN);
pn->setOp(JSOP_NOP);
pn->setArity(PN_BINARY);
pn->setInParens(false);
pn->setUsed(false);
pn->setDefn(false);
pn->pn_left = lhs;
pn->pn_right = rhs;
return lhs;
}
static JSParseNode *
MakeDefIntoUse(JSDefinition *dn, JSParseNode *pn, JSAtom *atom, JSTreeContext *tc)
{
/*
* 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->isBindingForm()) {
JSParseNode *rhs = dn->expr();
if (rhs) {
JSParseNode *lhs = MakeAssignment(dn, rhs, tc);
if (!lhs)
return NULL;
//pn->dn_uses = lhs;
dn = (JSDefinition *) lhs;
}
dn->setOp((js_CodeSpec[dn->getOp()].format & JOF_SET) ? JSOP_SETNAME : JSOP_NAME);
} else if (dn->kind() == JSDefinition::FUNCTION) {
JS_ASSERT(dn->isOp(JSOP_NOP));
PrepareNodeForMutation(dn, tc);
dn->setKind(TOK_NAME);
dn->setArity(PN_NAME);
dn->pn_atom = atom;
}
/* Now make dn no longer a definition, rather a use of pn. */
JS_ASSERT(dn->isKind(TOK_NAME));
JS_ASSERT(dn->isArity(PN_NAME));
JS_ASSERT(dn->pn_atom == atom);
for (JSParseNode *pnu = dn->dn_uses; pnu; pnu = pnu->pn_link) {
JS_ASSERT(pnu->isUsed());
JS_ASSERT(!pnu->isDefn());
pnu->pn_lexdef = (JSDefinition *) pn;
pn->pn_dflags |= pnu->pn_dflags & PND_USE2DEF_FLAGS;
}
pn->pn_dflags |= dn->pn_dflags & PND_USE2DEF_FLAGS;
pn->dn_uses = dn;
dn->setDefn(false);
dn->setUsed(true);
dn->pn_lexdef = (JSDefinition *) pn;
dn->pn_cookie.makeFree();
dn->pn_dflags &= ~PND_BOUND;
return dn;
}
static bool
DefineArg(JSParseNode *pn, JSAtom *atom, uintN i, JSTreeContext *tc)
{
JSParseNode *argpn, *argsbody;
/* Flag tc so we don't have to lookup arguments on every use. */
if (atom == tc->parser->context->runtime->atomState.argumentsAtom)
tc->flags |= TCF_FUN_PARAM_ARGUMENTS;
/*
* Make an argument definition node, distinguished by being in tc->decls
* but having TOK_NAME type and JSOP_NOP op. Insert it in a TOK_ARGSBODY
* list node returned via pn->pn_body.
*/
argpn = NameNode::create(atom, tc);
if (!argpn)
return false;
JS_ASSERT(argpn->isKind(TOK_NAME) && argpn->isOp(JSOP_NOP));
/* Arguments are initialized by definition. */
argpn->pn_dflags |= PND_INITIALIZED;
if (!Define(argpn, atom, tc))
return false;
argsbody = pn->pn_body;
if (!argsbody) {
argsbody = ListNode::create(tc);
if (!argsbody)
return false;
argsbody->setKind(TOK_ARGSBODY);
argsbody->setOp(JSOP_NOP);
argsbody->makeEmpty();
pn->pn_body = argsbody;
}
argsbody->append(argpn);
argpn->setOp(JSOP_GETARG);
argpn->pn_cookie.set(tc->staticLevel, i);
argpn->pn_dflags |= PND_BOUND;
return true;
}
/*
* Compile a JS function body, which might appear as the value of an event
* handler attribute in an HTML <INPUT> tag.
*/
bool
Compiler::compileFunctionBody(JSContext *cx, JSFunction *fun, JSPrincipals *principals,
Bindings *bindings, const jschar *chars, size_t length,
const char *filename, uintN lineno, JSVersion version)
{
Compiler compiler(cx, principals);
if (!compiler.init(chars, length, filename, lineno, version))
return false;
Parser &parser = compiler.parser;
TokenStream &tokenStream = parser.tokenStream;
JSCodeGenerator funcg(&parser, tokenStream.getLineno());
if (!funcg.init(cx, JSTreeContext::USED_AS_TREE_CONTEXT))
return false;
funcg.flags |= TCF_IN_FUNCTION;
funcg.setFunction(fun);
funcg.bindings.transfer(cx, bindings);
fun->setArgCount(funcg.bindings.countArgs());
if (!GenerateBlockId(&funcg, funcg.bodyid))
return false;
/* FIXME: make Function format the source for a function definition. */
tokenStream.mungeCurrentToken(TOK_NAME);
JSParseNode *fn = FunctionNode::create(&funcg);
if (fn) {
fn->pn_body = NULL;
fn->pn_cookie.makeFree();
uintN nargs = fun->nargs;
if (nargs) {
/*
* NB: do not use AutoLocalNameArray because it will release space
* allocated from cx->tempPool by DefineArg.
*/
Vector<JSAtom *> names(cx);
if (!funcg.bindings.getLocalNameArray(cx, &names)) {
fn = NULL;
} else {
for (uintN i = 0; i < nargs; i++) {
if (!DefineArg(fn, names[i], i, &funcg)) {
fn = NULL;
break;
}
}
}
}
}
/*
* Farble the body so that it looks like a block statement to js_EmitTree,
* which is called from js_EmitFunctionBody (see jsemit.cpp). After we're
* done parsing, we must fold constants, analyze any nested functions, and
* generate code for this function, including a stop opcode at the end.
*/
tokenStream.mungeCurrentToken(TOK_LC);
JSParseNode *pn = fn ? parser.functionBody() : NULL;
if (pn) {
if (!CheckStrictParameters(cx, &funcg)) {
pn = NULL;
} else if (!tokenStream.matchToken(TOK_EOF)) {
parser.reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
pn = NULL;
} else if (!js_FoldConstants(cx, pn, &funcg)) {
/* js_FoldConstants reported the error already. */
pn = NULL;
} else if (!parser.analyzeFunctions(&funcg)) {
pn = NULL;
} else {
if (fn->pn_body) {
JS_ASSERT(fn->pn_body->isKind(TOK_ARGSBODY));
fn->pn_body->append(pn);
fn->pn_body->pn_pos = pn->pn_pos;
pn = fn->pn_body;
}
if (!js_EmitFunctionScript(cx, &funcg, pn))
pn = NULL;
}
}
return pn != NULL;
}
/*
* 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.
*/
typedef JSBool
(*Binder)(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc);
struct BindData {
BindData() : fresh(true) {}
JSParseNode *pn; /* name node for definition processing and
error source coordinates */
JSOp op; /* prolog bytecode or nop */
Binder binder; /* binder, discriminates u */
union {
struct {
uintN overflow;
} let;
};
bool fresh;
};
static bool
BindLocalVariable(JSContext *cx, JSTreeContext *tc, JSParseNode *pn, BindingKind kind)
{
JS_ASSERT(kind == VARIABLE || kind == CONSTANT);
/* 'arguments' can be bound as a local only via a destructuring formal parameter. */
JS_ASSERT_IF(pn->pn_atom == cx->runtime->atomState.argumentsAtom, kind == VARIABLE);
uintN index = tc->bindings.countVars();
if (!tc->bindings.add(cx, pn->pn_atom, kind))
return false;
pn->pn_cookie.set(tc->staticLevel, index);
pn->pn_dflags |= PND_BOUND;
return true;
}
#if JS_HAS_DESTRUCTURING
static JSBool
BindDestructuringArg(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
{
/* Flag tc so we don't have to lookup arguments on every use. */
if (atom == tc->parser->context->runtime->atomState.argumentsAtom)
tc->flags |= TCF_FUN_PARAM_ARGUMENTS;
JS_ASSERT(tc->inFunction());
/*
* NB: Check tc->decls rather than tc->bindings, because destructuring
* bindings aren't added to tc->bindings until after all arguments have
* been parsed.
*/
if (tc->decls.lookupFirst(atom)) {
ReportCompileErrorNumber(cx, TS(tc->parser), NULL, JSREPORT_ERROR,
JSMSG_DESTRUCT_DUP_ARG);
return JS_FALSE;
}
JSParseNode *pn = data->pn;
/*
* Distinguish destructured-to binding nodes as vars, not args, by setting
* pn_op to JSOP_SETLOCAL. Parser::functionDef checks for this pn_op value
* when processing the destructuring-assignment AST prelude induced by such
* destructuring args in Parser::functionArguments.
*
* We must set the PND_BOUND flag too to prevent pn_op from being reset to
* JSOP_SETNAME by BindDestructuringVar. The only field not initialized is
* pn_cookie; it gets set in functionDef in the first "if (prelude)" block.
* We have to wait to set the cookie until we can call JSFunction::addLocal
* with kind = JSLOCAL_VAR, after all JSLOCAL_ARG locals have been added.
*
* Thus a destructuring formal parameter binds an ARG (as in arguments[i]
* element) with a null atom name for the object or array passed in to be
* destructured, and zero or more VARs (as in named local variables) for
* the destructured-to identifiers in the property value positions within
* the object or array destructuring pattern, and all ARGs for the formal
* parameter list bound as locals before any VAR for a destructured name.
*/
pn->setOp(JSOP_SETLOCAL);
pn->pn_dflags |= PND_BOUND;
return Define(pn, atom, tc);
}
#endif /* JS_HAS_DESTRUCTURING */
JSFunction *
Parser::newFunction(JSTreeContext *tc, JSAtom *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 tc->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 (tc->parent)
tc = tc->parent;
JSObject *parent = tc->inFunction() ? NULL : tc->scopeChain();
JSFunction *fun =
js_NewFunction(context, NULL, NULL, 0,
JSFUN_INTERPRETED | (kind == Expression ? JSFUN_LAMBDA : 0),
parent, atom);
if (fun && !tc->compileAndGo()) {
fun->clearParent();
fun->clearType();
}
return fun;
}
static JSBool
MatchOrInsertSemicolon(JSContext *cx, TokenStream *ts)
{
TokenKind tt = ts->peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_ERROR)
return JS_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);
ReportCompileErrorNumber(cx, ts, NULL, JSREPORT_ERROR, JSMSG_SEMI_BEFORE_STMNT);
return JS_FALSE;
}
(void) ts->matchToken(TOK_SEMI);
return JS_TRUE;
}
bool
Parser::analyzeFunctions(JSTreeContext *tc)
{
cleanFunctionList(&tc->functionList);
if (!tc->functionList)
return true;
if (!markFunArgs(tc->functionList))
return false;
markExtensibleScopeDescendants(tc->functionList, false);
setFunctionKinds(tc->functionList, &tc->flags);
return true;
}
/*
* Mark as funargs any functions that reach up to one or more upvars across an
* already-known funarg. The parser will flag the o_m lambda as a funarg in:
*
* function f(o, p) {
* o.m = function o_m(a) {
* function g() { return p; }
* function h() { return a; }
* return g() + h();
* }
* }
*
* but without this extra marking phase, function g will not be marked as a
* funarg since it is called from within its parent scope. But g reaches up to
* f's parameter p, so if o_m escapes f's activation scope, g does too and
* cannot assume that p's stack slot is still alive. In contast function h
* neither escapes nor uses an upvar "above" o_m's level.
*
* If function g itself contained lambdas that contained non-lambdas that reach
* up above its level, then those non-lambdas would have to be marked too. This
* process is potentially exponential in the number of functions, but generally
* not so complex. But it can't be done during a single recursive traversal of
* the funbox tree, so we must use a work queue.
*
* Return the minimal "skipmin" for funbox and its siblings. This is the delta
* between the static level of the bodies of funbox and its peers (which must
* be funbox->level + 1), and the static level of the nearest upvar among all
* the upvars contained by funbox and its peers. If there are no upvars, return
* FREE_STATIC_LEVEL. Thus this function never returns 0.
*/
static uintN
FindFunArgs(JSFunctionBox *funbox, int level, JSFunctionBoxQueue *queue)
{
uintN allskipmin = UpvarCookie::FREE_LEVEL;
do {
JSParseNode *fn = funbox->node;
JS_ASSERT(fn->isArity(PN_FUNC));
JSFunction *fun = funbox->function();
int fnlevel = level;
/*
* An eval can leak funbox, functions along its ancestor line, and its
* immediate kids. Since FindFunArgs uses DFS and the parser propagates
* TCF_FUN_HEAVYWEIGHT bottom up, funbox's ancestor function nodes have
* already been marked as funargs by this point. Therefore we have to
* flag only funbox->node and funbox->kids' nodes here.
*
* Generators need to be treated in the same way. Even if the value
* of a generator function doesn't escape, anything defined or referred
* to inside the generator can escape through a call to the generator.
* We could imagine doing static analysis to track the calls and see
* if any iterators or values returned by iterators escape, but that
* would be hard, so instead we just assume everything might escape.
*/
if (funbox->tcflags & (TCF_FUN_HEAVYWEIGHT | TCF_FUN_IS_GENERATOR)) {
fn->setFunArg();
for (JSFunctionBox *kid = funbox->kids; kid; kid = kid->siblings)
kid->node->setFunArg();
}
/*
* Compute in skipmin the least distance from fun's static level up to
* an upvar, whether used directly by fun, or indirectly by a function
* nested in fun.
*/
uintN skipmin = UpvarCookie::FREE_LEVEL;
JSParseNode *pn = fn->pn_body;
if (pn->isKind(TOK_UPVARS)) {
AtomDefnMapPtr &upvars = pn->pn_names;
JS_ASSERT(upvars->count() != 0);
for (AtomDefnRange r = upvars->all(); !r.empty(); r.popFront()) {
JSDefinition *defn = r.front().value();
JSDefinition *lexdep = defn->resolve();
if (!lexdep->isFreeVar()) {
uintN upvarLevel = lexdep->frameLevel();
if (int(upvarLevel) <= fnlevel)
fn->setFunArg();
uintN skip = (funbox->level + 1) - upvarLevel;
if (skip < skipmin)
skipmin = skip;
}
}
}
/*
* If this function escapes, whether directly (the parser detects such
* escapes) or indirectly (because this non-escaping function uses an
* upvar that reaches across an outer function boundary where the outer
* function escapes), enqueue it for further analysis, and bump fnlevel
* to trap any non-escaping children.
*/
if (fn->isFunArg()) {
queue->push(funbox);
fnlevel = int(funbox->level);
}
/*
* Now process the current function's children, and recalibrate their
* cumulative skipmin to be relative to the current static level.
*/
if (funbox->kids) {
uintN kidskipmin = FindFunArgs(funbox->kids, fnlevel, queue);
JS_ASSERT(kidskipmin != 0);
if (kidskipmin != UpvarCookie::FREE_LEVEL) {
--kidskipmin;
if (kidskipmin != 0 && kidskipmin < skipmin)
skipmin = kidskipmin;
}
}
/*
* Finally, after we've traversed all of the current function's kids,
* minimize fun's skipmin against our accumulated skipmin. Do likewise
* with allskipmin, but minimize across funbox and all of its siblings,
* to compute our return value.
*/
if (skipmin != UpvarCookie::FREE_LEVEL) {
fun->u.i.skipmin = skipmin;
if (skipmin < allskipmin)
allskipmin = skipmin;
}
} while ((funbox = funbox->siblings) != NULL);
return allskipmin;
}
bool
Parser::markFunArgs(JSFunctionBox *funbox)
{
JSFunctionBoxQueue queue;
if (!queue.init(functionCount)) {
js_ReportOutOfMemory(context);
return false;
}
FindFunArgs(funbox, -1, &queue);
while ((funbox = queue.pull()) != NULL) {
JSParseNode *fn = funbox->node;
JS_ASSERT(fn->isFunArg());
JSParseNode *pn = fn->pn_body;
if (pn->isKind(TOK_UPVARS)) {
AtomDefnMapPtr upvars = pn->pn_names;
JS_ASSERT(!upvars->empty());
for (AtomDefnRange r = upvars->all(); !r.empty(); r.popFront()) {
JSDefinition *defn = r.front().value();
JSDefinition *lexdep = defn->resolve();
if (!lexdep->isFreeVar() &&
!lexdep->isFunArg() &&
(lexdep->kind() == JSDefinition::FUNCTION ||
lexdep->isOp(JSOP_CALLEE))) {
/*
* Mark this formerly-Algol-like function as an escaping
* function (i.e., as a funarg), because it is used from
* another funarg.
*
* Progress is guaranteed because we set the funarg flag
* here, which suppresses revisiting this function (thanks
* to the !lexdep->isFunArg() test just above).
*/
lexdep->setFunArg();
JSFunctionBox *afunbox;
if (lexdep->isOp(JSOP_CALLEE)) {
/*
* A named function expression will not appear to be a
* funarg if it is immediately applied. However, if its
* name is used in an escaping function nested within
* it, then it must become flagged as a funarg again.
* See bug 545980.
*/
afunbox = funbox;
uintN calleeLevel = lexdep->pn_cookie.level();
uintN staticLevel = afunbox->level + 1U;
while (staticLevel != calleeLevel) {
afunbox = afunbox->parent;
--staticLevel;
}
JS_ASSERT(afunbox->level + 1U == calleeLevel);
afunbox->node->setFunArg();
} else {
afunbox = lexdep->pn_funbox;
}
queue.push(afunbox);
/*
* Walk over nested functions again, now that we have
* changed the level across which it is unsafe to access
* upvars using the runtime dynamic link (frame chain).
*/
if (afunbox->kids)
FindFunArgs(afunbox->kids, afunbox->level, &queue);
}
}
}
}
return true;
}
static uint32
MinBlockId(JSParseNode *fn, uint32 id)
{
if (fn->pn_blockid < id)
return false;
if (fn->isDefn()) {
for (JSParseNode *pn = fn->dn_uses; pn; pn = pn->pn_link) {
if (pn->pn_blockid < id)
return false;
}
}
return true;
}
static inline bool
CanFlattenUpvar(JSDefinition *dn, JSFunctionBox *funbox, uint32 tcflags)
{
/*
* Consider the current function (the lambda, innermost below) using a var
* x defined two static levels up:
*
* function f() {
* // z = g();
* var x = 42;
* function g() {
* return function () { return x; };
* }
* return g();
* }
*
* So long as (1) the initialization in 'var x = 42' dominates all uses of
* g and (2) x is not reassigned, it is safe to optimize the lambda to a
* flat closure. Uncommenting the early call to g makes this optimization
* unsafe (z could name a global setter that calls its argument).
*/
JSFunctionBox *afunbox = funbox;
uintN dnLevel = dn->frameLevel();
JS_ASSERT(dnLevel <= funbox->level);
while (afunbox->level != dnLevel) {
afunbox = afunbox->parent;
/*
* NB: afunbox can't be null because we are sure to find a function box
* whose level == dnLevel before we would try to walk above the root of
* the funbox tree. See bug 493260 comments 16-18.
*
* Assert but check anyway, to protect future changes that bind eval
* upvars in the parser.
*/
JS_ASSERT(afunbox);
/*
* If this function is reaching up across an enclosing funarg, then we
* cannot copy dn's value into a flat closure slot. The flat closure
* code assumes the upvars to be copied are in frames still on the
* stack.
*/
if (!afunbox || afunbox->node->isFunArg())
return false;
/*
* Reaching up for dn across a generator also means we can't flatten,
* since the generator iterator does not run until later, in general.
* See bug 563034.
*/
if (afunbox->tcflags & TCF_FUN_IS_GENERATOR)
return false;
}
/*
* If afunbox's function (which is at the same level as dn) is in a loop,
* pessimistically assume the variable initializer may be in the same loop.
* A flat closure would then be unsafe, as the captured variable could be
* assigned after the closure is created. See bug 493232.
*/
if (afunbox->inLoop)
return false;
/*
* |with| and eval used as an operator defeat lexical scoping: they can be
* used to assign to any in-scope variable. Therefore they must disable
* flat closures that use such upvars. The parser detects these as special
* forms and marks the function heavyweight.
*/
if ((afunbox->parent ? afunbox->parent->tcflags : tcflags) & TCF_FUN_HEAVYWEIGHT)
return false;
/*
* If afunbox's function is not a lambda, it will be hoisted, so it could
* capture the undefined value that by default initializes var, let, and
* const bindings. And if dn is a function that comes at (meaning a
* function refers to its own name) or strictly after afunbox, we also
* defeat the flat closure optimization for this dn.
*/
JSFunction *afun = afunbox->function();
if (!(afun->flags & JSFUN_LAMBDA)) {
if (dn->isBindingForm() || dn->pn_pos >= afunbox->node->pn_pos)
return false;
}
if (!dn->isInitialized())
return false;
JSDefinition::Kind dnKind = dn->kind();
if (dnKind != JSDefinition::CONST) {
if (dn->isAssigned())
return false;
/*
* Any formal could be mutated behind our back via the arguments
* object, so deoptimize if the outer function uses arguments.
*
* In a Function constructor call where the final argument -- the body
* source for the function to create -- contains a nested function
* definition or expression, afunbox->parent will be null. The body
* source might use |arguments| outside of any nested functions it may
* contain, so we have to check the tcflags parameter that was passed
* in from Compiler::compileFunctionBody.
*/
if (dnKind == JSDefinition::ARG &&
((afunbox->parent ? afunbox->parent->tcflags : tcflags) & TCF_FUN_USES_ARGUMENTS)) {
return false;
}
}
/*
* Check quick-and-dirty dominance relation. Function definitions dominate
* their uses thanks to hoisting. Other binding forms hoist as undefined,
* of course, so check forward-reference and blockid relations.
*/
if (dnKind != JSDefinition::FUNCTION) {
/*
* Watch out for code such as
*
* (function () {
* ...
* var jQuery = ... = function (...) {
* return new jQuery.foo.bar(baz);
* }
* ...
* })();
*
* where the jQuery variable is not reassigned, but of course is not
* initialized at the time that the would-be-flat closure containing
* the jQuery upvar is formed.
*/
if (dn->pn_pos.end >= afunbox->node->pn_pos.end)
return false;
if (!MinBlockId(afunbox->node, dn->pn_blockid))
return false;
}
return true;
}
static void
FlagHeavyweights(JSDefinition *dn, JSFunctionBox *funbox, uint32 *tcflags)
{
uintN dnLevel = dn->frameLevel();
while ((funbox = funbox->parent) != NULL) {
/*
* Notice that funbox->level is the static level of the definition or
* expression of the function parsed into funbox, not the static level
* of its body. Therefore we must add 1 to match dn's level to find the
* funbox whose body contains the dn definition.
*/
if (funbox->level + 1U == dnLevel || (dnLevel == 0 && dn->isLet())) {
funbox->tcflags |= TCF_FUN_HEAVYWEIGHT;
break;
}
funbox->tcflags |= TCF_FUN_ENTRAINS_SCOPES;
}
if (!funbox && (*tcflags & TCF_IN_FUNCTION))
*tcflags |= TCF_FUN_HEAVYWEIGHT;
}
static bool
DeoptimizeUsesWithin(JSDefinition *dn, const TokenPos &pos)
{
uintN ndeoptimized = 0;
for (JSParseNode *pnu = dn->dn_uses; pnu; pnu = pnu->pn_link) {
JS_ASSERT(pnu->isUsed());
JS_ASSERT(!pnu->isDefn());
if (pnu->pn_pos.begin >= pos.begin && pnu->pn_pos.end <= pos.end) {
pnu->pn_dflags |= PND_DEOPTIMIZED;
++ndeoptimized;
}
}
return ndeoptimized != 0;
}
static void
ConsiderUnbranding(JSFunctionBox *funbox)
{
/*
* We've already recursively set our kids' kinds, which also classifies
* enclosing functions holding upvars referenced in those descendants'
* bodies. So now we can check our "methods".
*
* Despecialize from branded method-identity-based shape to shape- or
* slot-based shape if this function smells like a constructor and too many
* of its methods are *not* joinable null closures (i.e., they have one or
* more upvars fetched via the display).
*/
bool returnsExpr = !!(funbox->tcflags & TCF_RETURN_EXPR);
#if JS_HAS_EXPR_CLOSURES
{
JSParseNode *pn2 = funbox->node->pn_body;
if (pn2->isKind(TOK_UPVARS))
pn2 = pn2->pn_tree;
if (pn2->isKind(TOK_ARGSBODY))
pn2 = pn2->last();
if (!pn2->isKind(TOK_LC))
returnsExpr = true;
}
#endif
if (!returnsExpr) {
uintN methodSets = 0, slowMethodSets = 0;
for (JSParseNode *method = funbox->methods; method; method = method->pn_link) {
JS_ASSERT(method->isOp(JSOP_LAMBDA) || method->isOp(JSOP_LAMBDA_FC));
++methodSets;
if (!method->pn_funbox->joinable())
++slowMethodSets;
}
if (funbox->shouldUnbrand(methodSets, slowMethodSets))
funbox->tcflags |= TCF_FUN_UNBRAND_THIS;
}
}
void
Parser::setFunctionKinds(JSFunctionBox *funbox, uint32 *tcflags)
{
for (; funbox; funbox = funbox->siblings) {
JSParseNode *fn = funbox->node;
JSParseNode *pn = fn->pn_body;
if (funbox->kids) {
setFunctionKinds(funbox->kids, tcflags);
ConsiderUnbranding(funbox);
}
JSFunction *fun = funbox->function();
JS_ASSERT(fun->kind() == JSFUN_INTERPRETED);
if (funbox->tcflags & TCF_FUN_HEAVYWEIGHT) {
/* nothing to do */
} else if (callerFrame || funbox->inAnyDynamicScope()) {
/*
* Either we are in a with-block or a function scope that is
* subject to direct eval; or we are compiling strict direct eval
* code.
*
* In either case, fun may reference names that are not bound but
* are not necessarily global either. (In the strict direct eval
* case, we could bind them, but currently do not bother; see
* the comment about strict mode code in BindTopLevelVar.)
*/
JS_ASSERT(!fun->isNullClosure());
} else {
bool hasUpvars = false;
bool canFlatten = true;
if (pn->isKind(TOK_UPVARS)) {
AtomDefnMapPtr upvars = pn->pn_names;
JS_ASSERT(!upvars->empty());
/*
* For each lexical dependency from this closure to an outer
* binding, analyze whether it is safe to copy the binding's
* value into a flat closure slot when the closure is formed.
*/
for (AtomDefnRange r = upvars->all(); !r.empty(); r.popFront()) {
JSDefinition *defn = r.front().value();
JSDefinition *lexdep = defn->resolve();
if (!lexdep->isFreeVar()) {
hasUpvars = true;
if (!CanFlattenUpvar(lexdep, funbox, *tcflags)) {
/*
* Can't flatten. Enclosing functions holding
* variables used by this function will be flagged
* heavyweight below. FIXME bug 545759: re-enable
* partial flat closures.
*/
canFlatten = false;
break;
}
}
}
}
if (!hasUpvars) {
/* No lexical dependencies => null closure, for best performance. */
fun->setKind(JSFUN_NULL_CLOSURE);
} else if (canFlatten) {
fun->setKind(JSFUN_FLAT_CLOSURE);
switch (fn->getOp()) {
case JSOP_DEFFUN:
fn->setOp(JSOP_DEFFUN_FC);
break;
case JSOP_DEFLOCALFUN:
fn->setOp(JSOP_DEFLOCALFUN_FC);
break;
case JSOP_LAMBDA:
fn->setOp(JSOP_LAMBDA_FC);
break;
default:
/* js_EmitTree's case TOK_FUNCTION: will select op. */
JS_ASSERT(fn->isOp(JSOP_NOP));
}
}
}
if (fun->kind() == JSFUN_INTERPRETED && pn->isKind(TOK_UPVARS)) {
/*
* One or more upvars cannot be safely snapshot into a flat
* closure's non-reserved slot (see JSOP_GETFCSLOT), so we loop
* again over all upvars, and for each non-free upvar, ensure that
* its containing function has been flagged as heavyweight.
*
* The emitter must see TCF_FUN_HEAVYWEIGHT accurately before
* generating any code for a tree of nested functions.
*/
AtomDefnMapPtr upvars = pn->pn_names;
JS_ASSERT(!upvars->empty());
for (AtomDefnRange r = upvars->all(); !r.empty(); r.popFront()) {
JSDefinition *defn = r.front().value();
JSDefinition *lexdep = defn->resolve();
if (!lexdep->isFreeVar())
FlagHeavyweights(lexdep, funbox, tcflags);
}
}
if (funbox->joinable())
fun->setJoinable();
}
}
/*
* Walk the JSFunctionBox tree looking for functions whose call objects may
* acquire new bindings as they execute: non-strict functions that call eval,
* and functions that contain function statements (definitions not appearing
* within the top statement list, which don't take effect unless they are
* evaluated). Such call objects may acquire bindings that shadow variables
* defined in enclosing scopes, so any enclosed functions must have their
* bindings' extensibleParents flags set, and enclosed compiler-created blocks
* must have their OWN_SHAPE flags set; the comments for
* js::Bindings::extensibleParents explain why.
*/
void
Parser::markExtensibleScopeDescendants(JSFunctionBox *funbox, bool hasExtensibleParent)
{
for (; funbox; funbox = funbox->siblings) {
/*
* It would be nice to use fun->kind() here to recognize functions
* that will never consult their parent chains, and thus don't need
* their 'extensible parents' flag set. Filed as bug 619750.
*/
JS_ASSERT(!funbox->bindings.extensibleParents());
if (hasExtensibleParent)
funbox->bindings.setExtensibleParents();
if (funbox->kids) {
markExtensibleScopeDescendants(funbox->kids,
hasExtensibleParent || funbox->scopeIsExtensible());
}
}
}
const char js_argument_str[] = "argument";
const char js_variable_str[] = "variable";
const char js_unknown_str[] = "unknown";
const char *
JSDefinition::kindString(Kind kind)
{
static const char *table[] = {
js_var_str, js_const_str, js_let_str,
js_function_str, js_argument_str, js_unknown_str
};
JS_ASSERT(unsigned(kind) <= unsigned(ARG));
return table[kind];
}
static JSFunctionBox *
EnterFunction(JSParseNode *fn, JSTreeContext *funtc, JSAtom *funAtom = NULL,
FunctionSyntaxKind kind = Expression)
{
JSTreeContext *tc = funtc->parent;
JSFunction *fun = tc->parser->newFunction(tc, funAtom, kind);
if (!fun)
return NULL;
/* Create box for fun->object early to protect against last-ditch GC. */
JSFunctionBox *funbox = tc->parser->newFunctionBox(fun, fn, tc);
if (!funbox)
return NULL;
/* Initialize non-default members of funtc. */
funtc->flags |= funbox->tcflags;
funtc->blockidGen = tc->blockidGen;
if (!GenerateBlockId(funtc, funtc->bodyid))
return NULL;
funtc->setFunction(fun);
funtc->funbox = funbox;
if (!SetStaticLevel(funtc, tc->staticLevel + 1))
return NULL;
return funbox;
}
static bool
LeaveFunction(JSParseNode *fn, JSTreeContext *funtc, JSAtom *funAtom = NULL,
FunctionSyntaxKind kind = Expression)
{
JSTreeContext *tc = funtc->parent;
tc->blockidGen = funtc->blockidGen;
JSFunctionBox *funbox = fn->pn_funbox;
funbox->tcflags |= funtc->flags & (TCF_FUN_FLAGS | TCF_COMPILE_N_GO | TCF_RETURN_EXPR);
fn->pn_dflags |= PND_INITIALIZED;
if (!tc->topStmt || tc->topStmt->type == STMT_BLOCK)
fn->pn_dflags |= PND_BLOCKCHILD;
/*
* Propagate unresolved lexical names up to tc->lexdeps, and save a copy
* of funtc->lexdeps in a TOK_UPVARS node wrapping the function's formal
* params and body. We do this only if there are lexical dependencies not
* satisfied by the function's declarations, to avoid penalizing functions
* that use only their arguments and other local bindings.
*/
if (funtc->lexdeps->count()) {
int foundCallee = 0;
for (AtomDefnRange r = funtc->lexdeps->all(); !r.empty(); r.popFront()) {
JSAtom *atom = r.front().key();
JSDefinition *dn = r.front().value();
JS_ASSERT(dn->isPlaceholder());
if (atom == funAtom && kind == Expression) {
dn->setOp(JSOP_CALLEE);
dn->pn_cookie.set(funtc->staticLevel, UpvarCookie::CALLEE_SLOT);
dn->pn_dflags |= PND_BOUND;
/*
* If this named function expression uses its own name other
* than to call itself, flag this function specially.
*/
if (dn->isFunArg())
funbox->tcflags |= TCF_FUN_USES_OWN_NAME;
foundCallee = 1;
continue;
}
if (!(funbox->tcflags & TCF_FUN_SETS_OUTER_NAME) &&
dn->isAssigned()) {
/*
* Make sure we do not fail to set TCF_FUN_SETS_OUTER_NAME if
* any use of dn in funtc assigns. See NoteLValue for the easy
* backward-reference case; this is the hard forward-reference
* case where we pay a higher price.
*/
for (JSParseNode *pnu = dn->dn_uses; pnu; pnu = pnu->pn_link) {
if (pnu->isAssigned() && pnu->pn_blockid >= funtc->bodyid) {
funbox->tcflags |= TCF_FUN_SETS_OUTER_NAME;
break;
}
}
}
JSDefinition *outer_dn = tc->decls.lookupFirst(atom);
/*
* Make sure to deoptimize lexical dependencies that are polluted
* by eval or with, to safely bind globals (see bug 561923).
*/
if (funtc->callsEval() ||
(outer_dn && tc->innermostWith &&
outer_dn->pn_pos < tc->innermostWith->pn_pos)) {
DeoptimizeUsesWithin(dn, fn->pn_pos);
}
if (!outer_dn) {
AtomDefnAddPtr p = tc->lexdeps->lookupForAdd(atom);
if (p) {
outer_dn = p.value();
} else {
/*
* 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 = MakePlaceholder(dn, tc);
if (!outer_dn || !tc->lexdeps->add(p, atom, 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_FUNC/PN_NAME
* case), and nowhere else, currently.
*/
if (dn != outer_dn) {
JSParseNode **pnup = &dn->dn_uses;
JSParseNode *pnu;
while ((pnu = *pnup) != NULL) {
pnu->pn_lexdef = outer_dn;
pnup = &pnu->pn_link;
}
/*
* Make dn be a use that redirects to outer_dn, because we
* can't replace dn with outer_dn in all the pn_namesets in
* the AST where it may be. Instead we make it forward to
* outer_dn. See JSDefinition::resolve.
*/
*pnup = outer_dn->dn_uses;
outer_dn->dn_uses = dn;
outer_dn->pn_dflags |= dn->pn_dflags & ~PND_PLACEHOLDER;
dn->setDefn(false);
dn->setUsed(true);
dn->pn_lexdef = outer_dn;
}
/* Mark the outer dn as escaping. */
outer_dn->pn_dflags |= PND_CLOSED;
}
if (funtc->lexdeps->count() - foundCallee != 0) {
JSParseNode *body = fn->pn_body;
fn->pn_body = NameSetNode::create(tc);
if (!fn->pn_body)
return false;
fn->pn_body->setKind(TOK_UPVARS);
fn->pn_body->pn_pos = body->pn_pos;
if (foundCallee)
funtc->lexdeps->remove(funAtom);
/* Transfer ownership of the lexdep map to the parse node. */
fn->pn_body->pn_names = funtc->lexdeps;
funtc->lexdeps.clearMap();
fn->pn_body->pn_tree = body;
} else {
funtc->lexdeps.releaseMap(funtc->parser->context);
}
}
/*
* 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 (funtc->inStrictMode() && funbox->object->getFunctionPrivate()->nargs > 0) {
AtomDeclsIter iter(&funtc->decls);
JSDefinition *dn;
while ((dn = iter()) != NULL) {
if (dn->kind() == JSDefinition::ARG && dn->isAssigned()) {
funbox->tcflags |= TCF_FUN_MUTATES_PARAMETER;
break;
}
}
}
funbox->bindings.transfer(funtc->parser->context, &funtc->bindings);
return true;
}
static bool
DefineGlobal(JSParseNode *pn, JSCodeGenerator *cg, JSAtom *atom);
/*
* FIXME? this Parser method was factored from Parser::functionDef with minimal
* change, hence the funtc ref param and funbox. It probably should match
* functionBody, etc., and use tc and tc->funbox instead of taking explicit
* parameters.
*/
bool
Parser::functionArguments(JSTreeContext &funtc, JSFunctionBox *funbox, JSParseNode **listp)
{
if (tokenStream.getToken() != TOK_LP) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_PAREN_BEFORE_FORMAL);
return false;
}
if (!tokenStream.matchToken(TOK_RP)) {
#if JS_HAS_DESTRUCTURING
JSAtom *duplicatedArg = NULL;
bool destructuringArg = false;
JSParseNode *list = NULL;
#endif
do {
switch (TokenKind tt = tokenStream.getToken()) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
{
/* See comment below in the TOK_NAME case. */
if (duplicatedArg)
goto report_dup_and_destructuring;
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 data;
data.pn = NULL;
data.op = JSOP_DEFVAR;
data.binder = BindDestructuringArg;
JSParseNode *lhs = destructuringExpr(&data, tt);
if (!lhs)
return false;
/*
* Adjust fun->nargs to count the single anonymous positional
* parameter that is to be destructured.
*/
uint16 slot;
if (!funtc.bindings.addDestructuring(context, &slot))
return false;
/*
* Synthesize a destructuring assignment from the single
* anonymous positional parameter into the destructuring
* left-hand-side expression and accumulate it in list.
*/
JSParseNode *rhs = NameNode::create(context->runtime->atomState.emptyAtom, &funtc);
if (!rhs)
return false;
rhs->setKind(TOK_NAME);
rhs->setOp(JSOP_GETARG);
rhs->pn_cookie.set(funtc.staticLevel, slot);
rhs->pn_dflags |= PND_BOUND;
JSParseNode *item =
JSParseNode::newBinaryOrAppend(TOK_ASSIGN, JSOP_NOP, lhs, rhs, &funtc);
if (!item)
return false;
if (!list) {
list = ListNode::create(&funtc);
if (!list)
return false;
list->setKind(TOK_VAR);
list->makeEmpty();
*listp = list;
}
list->append(item);
break;
}
#endif /* JS_HAS_DESTRUCTURING */
case TOK_NAME:
{
JSAtom *atom = tokenStream.currentToken().t_atom;
#ifdef JS_HAS_DESTRUCTURING
/*
* ECMA-262 requires us to support duplicate parameter names,
* but if the parameter list includes destructuring, we
* consider the code to have "opted in" to higher standards and
* forbid duplicates. We may see a destructuring parameter
* later, so always note duplicates now.
*
* Duplicates are warned about (strict option) or cause errors
* (strict mode code), but we do those tests in one place
* below, after having parsed the body in case it begins with a
* "use strict"; directive.
*
* NB: Check funtc.decls rather than funtc.bindings, because
* destructuring bindings aren't added to funtc.bindings
* until after all arguments have been parsed.
*/
if (funtc.decls.lookupFirst(atom)) {
duplicatedArg = atom;
if (destructuringArg)
goto report_dup_and_destructuring;
}
#endif
uint16 slot;
if (!funtc.bindings.addArgument(context, atom, &slot))
return false;
if (!DefineArg(funbox->node, atom, slot, &funtc))
return false;
break;
}
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_MISSING_FORMAL);
/* FALL THROUGH */
case TOK_ERROR:
return false;
#if JS_HAS_DESTRUCTURING
report_dup_and_destructuring:
JSDefinition *dn = funtc.decls.lookupFirst(duplicatedArg);
reportErrorNumber(dn, JSREPORT_ERROR, JSMSG_DESTRUCT_DUP_ARG);
return false;
#endif
}
} while (tokenStream.matchToken(TOK_COMMA));
if (tokenStream.getToken() != TOK_RP) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_PAREN_AFTER_FORMAL);
return false;
}
}
return true;
}
JSParseNode *
Parser::functionDef(JSAtom *funAtom, FunctionType type, FunctionSyntaxKind kind)
{
JS_ASSERT_IF(kind == Statement, funAtom);
/* Make a TOK_FUNCTION node. */
tokenStream.mungeCurrentToken(TOK_FUNCTION, JSOP_NOP);
JSParseNode *pn = FunctionNode::create(tc);
if (!pn)
return NULL;
pn->pn_body = NULL;
pn->pn_cookie.makeFree();
/*
* If this is a function expression, mark this function as escaping (as a
* "funarg") unless it is immediately applied (we clear PND_FUNARG if so --
* see memberExpr).
*
* Treat function sub-statements (those not at body level of a function or
* program) as escaping funargs, since we can't statically analyze their
* definitions and uses.
*/
bool bodyLevel = tc->atBodyLevel();
pn->pn_dflags = (kind == Expression || !bodyLevel) ? PND_FUNARG : 0;
/*
* Record names for function statements in tc->decls so we know when to
* avoid optimizing variable references that might name a function.
*/
if (kind == Statement) {
if (JSDefinition *dn = tc->decls.lookupFirst(funAtom)) {
JSDefinition::Kind dn_kind = dn->kind();
JS_ASSERT(!dn->isUsed());
JS_ASSERT(dn->isDefn());
if (context->hasStrictOption() || dn_kind == JSDefinition::CONST) {
JSAutoByteString name;
if (!js_AtomToPrintableString(context, funAtom, &name) ||
!reportErrorNumber(NULL,
(dn_kind != JSDefinition::CONST)
? JSREPORT_WARNING | JSREPORT_STRICT
: JSREPORT_ERROR,
JSMSG_REDECLARED_VAR,
JSDefinition::kindString(dn_kind),
name.ptr())) {
return NULL;
}
}
if (bodyLevel) {
tc->decls.updateFirst(funAtom, (JSDefinition *) pn);
pn->setDefn(true);
pn->dn_uses = dn; /* dn->dn_uses is now pn_link */
if (!MakeDefIntoUse(dn, pn, funAtom, tc))
return NULL;
}
} 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 tc->lexdeps on first forward reference, and recycle pn.
*/
if (JSDefinition *fn = tc->lexdeps.lookupDefn(funAtom)) {
JS_ASSERT(fn->isDefn());
fn->setKind(TOK_FUNCTION);
fn->setArity(PN_FUNC);
fn->pn_pos.begin = pn->pn_pos.begin;
/*
* Set fn->pn_pos.end too, in case of error before we parse the
* closing brace. See bug 640075.
*/
fn->pn_pos.end = pn->pn_pos.end;
fn->pn_body = NULL;
fn->pn_cookie.makeFree();
tc->lexdeps->remove(funAtom);
RecycleTree(pn, tc);
pn = fn;
}
if (!Define(pn, funAtom, tc))
return NULL;
}
/*
* A function directly inside another's body needs only a local
* variable to bind its name to its value, and not an activation object
* property (it might also need the activation property, if the outer
* function contains with statements, e.g., but the stack slot wins
* when jsemit.cpp's BindNameToSlot can optimize a JSOP_NAME into a
* JSOP_GETLOCAL bytecode).
*/
if (bodyLevel && tc->inFunction()) {
/*
* Define a local in the outer function so that BindNameToSlot
* can properly optimize accesses. Note that we need a local
* variable, not an argument, for the function statement. Thus
* we add a variable even if a parameter with the given name
* already exists.
*/
uintN index;
switch (tc->bindings.lookup(context, funAtom, &index)) {
case NONE:
case ARGUMENT:
index = tc->bindings.countVars();
if (!tc->bindings.addVariable(context, funAtom))
return NULL;
/* FALL THROUGH */
case VARIABLE:
pn->pn_cookie.set(tc->staticLevel, index);
pn->pn_dflags |= PND_BOUND;
break;
default:;
}
}
}
JSTreeContext *outertc = tc;
/* Initialize early for possible flags mutation via destructuringExpr. */
JSTreeContext funtc(tc->parser);
if (!funtc.init(context))
return NULL;
JSFunctionBox *funbox = EnterFunction(pn, &funtc, funAtom, kind);
if (!funbox)
return NULL;
JSFunction *fun = funbox->function();
/* Now parse formal argument list and compute fun->nargs. */
JSParseNode *prelude = NULL;
if (!functionArguments(funtc, funbox, &prelude))
return NULL;
fun->setArgCount(funtc.bindings.countArgs());
#if JS_HAS_DESTRUCTURING
/*
* If there were destructuring formal parameters, bind the destructured-to
* local variables now that we've parsed all the regular and destructuring
* formal parameters. Because js::Bindings::add must be called first for
* all ARGUMENTs, then all VARIABLEs and CONSTANTs, and finally all UPVARs,
* we can't bind vars induced by formal parameter destructuring until after
* Parser::functionArguments has returned.
*/
if (prelude) {
AtomDeclsIter iter(&funtc.decls);
while (JSDefinition *apn = iter()) {
/* Filter based on pn_op -- see BindDestructuringArg, above. */
if (!apn->isOp(JSOP_SETLOCAL))
continue;
if (!BindLocalVariable(context, &funtc, apn, VARIABLE))
return NULL;
}
}
#endif
if (type == Getter && fun->nargs > 0) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_ACCESSOR_WRONG_ARGS,
"getter", "no", "s");
return NULL;
}
if (type == Setter && fun->nargs != 1) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_ACCESSOR_WRONG_ARGS,
"setter", "one", "");
return NULL;
}
#if JS_HAS_EXPR_CLOSURES
TokenKind tt = tokenStream.getToken(TSF_OPERAND);
if (tt != TOK_LC) {
tokenStream.ungetToken();
fun->flags |= JSFUN_EXPR_CLOSURE;
}
#else
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_BODY);
#endif
JSParseNode *body = functionBody();
if (!body)
return NULL;
if (funAtom && !CheckStrictBinding(context, &funtc, funAtom, pn))
return NULL;
if (!CheckStrictParameters(context, &funtc))
return NULL;
#if JS_HAS_EXPR_CLOSURES
if (tt == TOK_LC)
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_BODY);
else if (kind == Statement && !MatchOrInsertSemicolon(context, &tokenStream))
return NULL;
#else
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_BODY);
#endif
pn->pn_pos.end = tokenStream.currentToken().pos.end;
/*
* Fruit of the poisonous tree: if a closure calls eval, we consider the
* parent to call eval. We need this for two reasons: (1) the Jaegermonkey
* optimizations really need to know if eval is called transitively, and
* (2) in strict mode, eval called transitively requires eager argument
* creation in strict mode parent functions.
*
* For the latter, we really only need to propagate callsEval if both
* functions are strict mode, but we don't lose much by always propagating.
* The only optimization we lose this way is in the case where a function
* is strict, does not mutate arguments, does not call eval directly, but
* calls eval transitively.
*/
if (funtc.callsEval())
outertc->noteCallsEval();
#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 TOK_SEQ node, to prepend the destructuring
* code without bracing the decompilation of the function body.
*/
if (prelude) {
if (!body->isArity(PN_LIST)) {
JSParseNode *block;
block = ListNode::create(outertc);
if (!block)
return NULL;
block->setKind(TOK_SEQ);
block->pn_pos = body->pn_pos;
block->initList(body);
body = block;
}
JSParseNode *item = UnaryNode::create(outertc);
if (!item)
return NULL;
item->setKind(TOK_SEMI);
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
/*
* If we collected flags that indicate nested heavyweight functions, or
* this function contains heavyweight-making statements (with statement,
* visible eval call, or assignment to 'arguments'), flag the function as
* heavyweight (requiring a call object per invocation).
*/
if (funtc.flags & TCF_FUN_HEAVYWEIGHT) {
fun->flags |= JSFUN_HEAVYWEIGHT;
outertc->flags |= TCF_FUN_HEAVYWEIGHT;
} else {
/*
* If this function is not at body level of a program or function (i.e.
* it is a function statement that is not a direct child of a program
* or function), then our enclosing function, if any, must be
* heavyweight.
*/
if (!bodyLevel && kind == Statement)
outertc->flags |= TCF_FUN_HEAVYWEIGHT;
}
JSOp op = JSOP_NOP;
if (kind == Expression) {
op = JSOP_LAMBDA;
} else {
if (!bodyLevel) {
/*
* Extension: in non-strict mode code, a function statement not at
* the top level of a function body or whole program, e.g., in a
* compound statement such as the "then" part of an "if" statement,
* binds a closure only if control reaches that sub-statement.
*/
JS_ASSERT(!outertc->inStrictMode());
op = JSOP_DEFFUN;
outertc->noteMightAliasLocals();
}
}
funbox->kids = funtc.functionList;
pn->pn_funbox = funbox;
pn->setOp(op);
if (pn->pn_body) {
pn->pn_body->append(body);
pn->pn_body->pn_pos = body->pn_pos;
} else {
pn->pn_body = body;
}
if (!outertc->inFunction() && bodyLevel && kind == Statement && outertc->compiling()) {
JS_ASSERT(pn->pn_cookie.isFree());
if (!DefineGlobal(pn, outertc->asCodeGenerator(), funAtom))
return NULL;
}
pn->pn_blockid = outertc->blockid();
if (!LeaveFunction(pn, &funtc, funAtom, kind))
return NULL;
/* If the surrounding function is not strict code, reset the lexer. */
if (!outertc->inStrictMode())
tokenStream.setStrictMode(false);
return pn;
}
JSParseNode *
Parser::functionStmt()
{
JSAtom *name = NULL;
if (tokenStream.getToken(TSF_KEYWORD_IS_NAME) == TOK_NAME) {
name = tokenStream.currentToken().t_atom;
} else {
/* Unnamed function expressions are forbidden in statement context. */
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_UNNAMED_FUNCTION_STMT);
return NULL;
}
/* We forbid function statements in strict mode code. */
if (!tc->atBodyLevel() && tc->inStrictMode()) {
reportErrorNumber(NULL, JSREPORT_STRICT_MODE_ERROR, JSMSG_STRICT_FUNCTION_STATEMENT);
return NULL;
}
return functionDef(name, Normal, Statement);
}
JSParseNode *
Parser::functionExpr()
{
JSAtom *name = NULL;
if (tokenStream.getToken(TSF_KEYWORD_IS_NAME) == TOK_NAME)
name = tokenStream.currentToken().t_atom;
else
tokenStream.ungetToken();
return functionDef(name, Normal, Expression);
}
/*
* Recognize Directive Prologue members and directives. Assuming |pn| is a
* candidate for membership in a directive prologue, recognize directives and
* set |tc|'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.
*/
bool
Parser::recognizeDirectivePrologue(JSParseNode *pn, bool *isDirectivePrologueMember)
{
*isDirectivePrologueMember = pn->isStringExprStatement();
if (!*isDirectivePrologueMember)
return true;
JSParseNode *kid = pn->pn_kid;
if (kid->isEscapeFreeStringLiteral()) {
/*
* Mark this statement as being a possibly legitimate part of a
* directive prologue, so the byte code 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.
*/
pn->pn_prologue = true;
JSAtom *directive = kid->pn_atom;
if (directive == context->runtime->atomState.useStrictAtom) {
/*
* Unfortunately, Directive Prologue members in general may contain
* escapes, even while "use strict" directives may not. Therefore
* we must check whether an octal character escape has been seen in
* any previous directives whenever we encounter a "use strict"
* directive, so that the octal escape is properly treated as a
* syntax error. An example of this case:
*
* function error()
* {
* "\145"; // octal escape
* "use strict"; // retroactively makes "\145" a syntax error
* }
*/
if (tokenStream.hasOctalCharacterEscape()) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_DEPRECATED_OCTAL);
return false;
}
tc->flags |= TCF_STRICT_MODE_CODE;
tokenStream.setStrictMode();
}
}
return true;
}
/*
* Parse the statements in a block, creating a TOK_LC node that lists the
* statements' trees. If called from block-parsing code, the caller must
* match { before and } after.
*/
JSParseNode *
Parser::statements()
{
JSParseNode *pn, *pn2, *saveBlock;
TokenKind tt;
JS_CHECK_RECURSION(context, return NULL);
pn = ListNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_LC);
pn->makeEmpty();
pn->pn_blockid = tc->blockid();
saveBlock = tc->blockNode;
tc->blockNode = pn;
bool inDirectivePrologue = tc->atBodyLevel();
tokenStream.setOctalCharacterEscape(false);
for (;;) {
tt = tokenStream.peekToken(TSF_OPERAND);
if (tt <= TOK_EOF || tt == TOK_RC) {
if (tt == TOK_ERROR) {
if (tokenStream.isEOF())
tokenStream.setUnexpectedEOF();
return NULL;
}
break;
}
pn2 = statement();
if (!pn2) {
if (tokenStream.isEOF())
tokenStream.setUnexpectedEOF();
return NULL;
}
if (inDirectivePrologue && !recognizeDirectivePrologue(pn2, &inDirectivePrologue))
return NULL;
if (pn2->isKind(TOK_FUNCTION)) {
/*
* PNX_FUNCDEFS notifies the emitter that the block contains body-
* level function definitions that should be processed before the
* rest of nodes.
*
* TCF_HAS_FUNCTION_STMT is for the TOK_LC case in Statement. It
* is relevant only for function definitions not at body-level,
* which we call function statements.
*/
if (tc->atBodyLevel()) {
pn->pn_xflags |= PNX_FUNCDEFS;
} else {
tc->flags |= TCF_HAS_FUNCTION_STMT;
/* Function statements extend the Call object at runtime. */
tc->noteHasExtensibleScope();
}
}
pn->append(pn2);
}
/*
* Handle the case where there was a let declaration under this block. If
* it replaced tc->blockNode with a new block node then we must refresh pn
* and then restore tc->blockNode.
*/
if (tc->blockNode != pn)
pn = tc->blockNode;
tc->blockNode = saveBlock;
pn->pn_pos.end = tokenStream.currentToken().pos.end;
return pn;
}
JSParseNode *
Parser::condition()
{
JSParseNode *pn;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_COND);
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 (pn->isKind(TOK_ASSIGN) &&
pn->isOp(JSOP_NOP) &&
!pn->isInParens() &&
!reportErrorNumber(NULL, JSREPORT_WARNING | JSREPORT_STRICT, JSMSG_EQUAL_AS_ASSIGN, "")) {
return NULL;
}
return pn;
}
static JSBool
MatchLabel(JSContext *cx, TokenStream *ts, JSParseNode *pn)
{
JSAtom *label;
TokenKind tt;
tt = ts->peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_ERROR)
return JS_FALSE;
if (tt == TOK_NAME) {
(void) ts->getToken();
label = ts->currentToken().t_atom;
} else {
label = NULL;
}
pn->pn_atom = label;
return JS_TRUE;
}
/*
* Define a let-variable in a block, let-expression, or comprehension scope. tc
* 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, tc->blockChain();
* populate data->pn->pn_{op,cookie,defn,dflags}; and stash a pointer to
* data->pn in a slot of the block object.
*/
static JSBool
BindLet(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
{
JSParseNode *pn;
JSObject *blockObj;
jsint n;
/*
* Body-level 'let' is the same as 'var' currently -- this may change in a
* successor standard to ES5 that specifies 'let'.
*/
JS_ASSERT(!tc->atBodyLevel());
pn = data->pn;
if (!CheckStrictBinding(cx, tc, atom, pn))
return false;
blockObj = tc->blockChain();
JSDefinition *dn = tc->decls.lookupFirst(atom);
if (dn && dn->pn_blockid == tc->blockid()) {
JSAutoByteString name;
if (js_AtomToPrintableString(cx, atom, &name)) {
ReportCompileErrorNumber(cx, TS(tc->parser), pn,
JSREPORT_ERROR, JSMSG_REDECLARED_VAR,
dn->isConst() ? js_const_str : js_variable_str,
name.ptr());
}
return false;
}
n = OBJ_BLOCK_COUNT(cx, blockObj);
if (n == JS_BIT(16)) {
ReportCompileErrorNumber(cx, TS(tc->parser), pn,
JSREPORT_ERROR, data->let.overflow);
return false;
}
/*
* Pass push = true to Define so it pushes an ale ahead of any outer scope.
* This is balanced by PopStatement, defined immediately below.
*/
if (!Define(pn, atom, tc, true))
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, Compiler::compileScript will adjust the slot again to
* include script->nfixed.
*/
pn->setOp(JSOP_GETLOCAL);
pn->pn_cookie.set(tc->staticLevel, uint16(n));
pn->pn_dflags |= PND_LET | PND_BOUND;
/*
* Define the let binding's property before storing pn in the the binding's
* slot indexed by n off the class-reserved slot base.
*/
const Shape *shape = blockObj->defineBlockVariable(cx, ATOM_TO_JSID(atom), n);
if (!shape)
return false;
/*
* Store pn temporarily in what would be shape-mapped slots in a cloned
* block object (once the prototype's final population is known, after all
* 'let' bindings for this block have been parsed). We free these slots in
* jsemit.cpp:EmitEnterBlock so they don't tie up unused space in the so-
* called "static" prototype Block.
*/
blockObj->setSlot(shape->slot, PrivateValue(pn));
return true;
}
static void
PopStatement(JSTreeContext *tc)
{
JSStmtInfo *stmt = tc->topStmt;
if (stmt->flags & SIF_SCOPE) {
JSObject *obj = stmt->blockBox->object;
JS_ASSERT(!obj->isClonedBlock());
for (Shape::Range r = obj->lastProperty()->all(); !r.empty(); r.popFront()) {
JSAtom *atom = JSID_TO_ATOM(r.front().propid);
/* Beware the empty destructuring dummy. */
if (atom == tc->parser->context->runtime->atomState.emptyAtom)
continue;
tc->decls.remove(atom);
}
}
js_PopStatement(tc);
}
static inline bool
OuterLet(JSTreeContext *tc, JSStmtInfo *stmt, JSAtom *atom)
{
while (stmt->downScope) {
stmt = js_LexicalLookup(tc, atom, NULL, stmt->downScope);
if (!stmt)
return false;
if (stmt->type == STMT_BLOCK)
return true;
}
return false;
}
/*
* If we are generating global or eval-called-from-global code, bind a "gvar"
* here, as soon as possible. The JSOP_GETGVAR, etc., ops speed up interpreted
* global variable access by memoizing name-to-slot mappings during execution
* of the script prolog (via JSOP_DEFVAR/JSOP_DEFCONST). If the memoization
* can't be done due to a pre-existing property of the same name as the var or
* const but incompatible attributes/getter/setter/etc, these ops devolve to
* JSOP_NAME, etc.
*
* For now, don't try to lookup eval frame variables at compile time. This is
* sub-optimal: we could handle eval-called-from-global-code gvars since eval
* gets its own script and frame. The eval-from-function-code case is harder,
* since functions do not atomize gvars and then reserve their atom indexes as
* stack frame slots.
*/
static bool
DefineGlobal(JSParseNode *pn, JSCodeGenerator *cg, JSAtom *atom)
{
GlobalScope *globalScope = cg->compiler()->globalScope;
JSObject *globalObj = globalScope->globalObj;
if (!cg->compileAndGo() || !globalObj || cg->compilingForEval())
return true;
AtomIndexAddPtr p = globalScope->names.lookupForAdd(atom);
if (!p) {
JSContext *cx = cg->parser->context;
JSObject *holder;
JSProperty *prop;
if (!globalObj->lookupProperty(cx, ATOM_TO_JSID(atom), &holder, &prop))
return false;
JSFunctionBox *funbox = pn->isKind(TOK_FUNCTION) ? pn->pn_funbox : NULL;
GlobalScope::GlobalDef def;
if (prop) {
/*
* A few cases where we don't bother aggressively caching:
* 1) Function value changes.
* 2) Configurable properties.
* 3) Properties without slots, or with getters/setters.
*/
const Shape *shape = (const Shape *)prop;
if (funbox ||
globalObj != holder ||
shape->configurable() ||
!shape->hasSlot() ||
!shape->hasDefaultGetterOrIsMethod() ||
!shape->hasDefaultSetter()) {
return true;
}
def = GlobalScope::GlobalDef(shape->slot);
} else {
def = GlobalScope::GlobalDef(atom, funbox);
}
if (!globalScope->defs.append(def))
return false;
jsatomid index = globalScope->names.count();
if (!globalScope->names.add(p, atom, index))
return false;
JS_ASSERT(index == globalScope->defs.length() - 1);
} else {
/*
* Functions can be redeclared, and the last one takes effect. Check
* for this and make sure to rewrite the definition.
*
* Note: This could overwrite an existing variable declaration, for
* example:
* var c = []
* function c() { }
*
* This rewrite is allowed because the function will be statically
* hoisted to the top of the script, and the |c = []| will just
* overwrite it at runtime.
*/
if (pn->isKind(TOK_FUNCTION)) {
JS_ASSERT(pn->isArity(PN_FUNC));
jsatomid index = p.value();
globalScope->defs[index].funbox = pn->pn_funbox;
}
}
pn->pn_dflags |= PND_GVAR;
return true;
}
static bool
BindTopLevelVar(JSContext *cx, BindData *data, JSParseNode *pn, JSTreeContext *tc)
{
JS_ASSERT(pn->isOp(JSOP_NAME));
JS_ASSERT(!tc->inFunction());
/* There's no need to optimize bindings if we're not compiling code. */
if (!tc->compiling())
return true;
/*
* Bindings at top level in eval code aren't like bindings at top level in
* regular code, and we must handle them specially.
*/
if (tc->parser->callerFrame) {
/*
* If the eval code is not strict mode code, such bindings are created
* from scratch in the the caller's environment (if the eval is direct)
* or in the global environment (if the eval is indirect) -- and they
* can be deleted. Therefore we can't bind early.
*/
if (!tc->inStrictMode())
return true;
/*
* But if the eval code is strict mode code, bindings are added to a
* new environment specifically for that eval code's compilation, and
* they can't be deleted. Thus strict mode eval code does not affect
* the caller's environment, and we can bind such names early. (But
* note: strict mode eval code can still affect the global environment
* by performing an indirect eval of non-strict mode code.)
*
* However, optimizing such bindings requires either precarious
* type-punning or, ideally, a new kind of Call object specifically for
* strict mode eval frames. Further, strict mode eval is not (yet)
* common. So for now (until we rewrite the scope chain to not use
* objects?) just disable optimizations for top-level names in eval
* code.
*/
return true;
}
if (pn->pn_dflags & PND_CONST)
return true;
/*
* If this is a global variable, we're compile-and-go, and a global object
* is present, try to bake in either an already available slot or a
* predicted slot that will be defined after compiling is completed.
*/
return DefineGlobal(pn, tc->asCodeGenerator(), pn->pn_atom);
}
static bool
BindFunctionLocal(JSContext *cx, BindData *data, MultiDeclRange &mdl, JSTreeContext *tc)
{
JS_ASSERT(tc->inFunction());
JSParseNode *pn = data->pn;
JSAtom *name = pn->pn_atom;
/*
* Don't create a local variable with the name 'arguments', per ECMA-262.
* Instead, 'var arguments' always restates that predefined binding of the
* lexical environment for function activations. Assignments to arguments
* must be handled specially -- see NoteLValue.
*/
if (name == cx->runtime->atomState.argumentsAtom) {
pn->setOp(JSOP_ARGUMENTS);
pn->pn_dflags |= PND_BOUND;
return true;
}
BindingKind kind = tc->bindings.lookup(cx, name, NULL);
if (kind == NONE) {
/*
* Property not found in current variable scope: we have not seen this
* variable before, so bind a new local variable for it. Any locals
* declared in a with statement body are handled at runtime, by script
* prolog JSOP_DEFVAR opcodes generated for global and heavyweight-
* function-local vars.
*/
kind = (data->op == JSOP_DEFCONST) ? CONSTANT : VARIABLE;
if (!BindLocalVariable(cx, tc, pn, kind))
return false;
pn->setOp(JSOP_GETLOCAL);
return true;
}
if (kind == ARGUMENT) {
JS_ASSERT(tc->inFunction());
JS_ASSERT(!mdl.empty() && mdl.front()->kind() == JSDefinition::ARG);
} else {
JS_ASSERT(kind == VARIABLE || kind == CONSTANT);
}
return true;
}
static JSBool
BindVarOrConst(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
{
JSParseNode *pn = data->pn;
/* Default best op for pn is JSOP_NAME; we'll try to improve below. */
pn->setOp(JSOP_NAME);
if (!CheckStrictBinding(cx, tc, atom, pn))
return false;
JSStmtInfo *stmt = js_LexicalLookup(tc, atom, NULL);
if (stmt && stmt->type == STMT_WITH) {
data->fresh = false;
pn->pn_dflags |= PND_DEOPTIMIZED;
tc->noteMightAliasLocals();
return true;
}
MultiDeclRange mdl = tc->decls.lookupMulti(atom);
JSOp op = data->op;
if (stmt || !mdl.empty()) {
JSDefinition *dn = mdl.empty() ? NULL : mdl.front();
JSDefinition::Kind dn_kind = dn ? dn->kind() : JSDefinition::VAR;
if (dn_kind == JSDefinition::ARG) {
JSAutoByteString name;
if (!js_AtomToPrintableString(cx, atom, &name))
return JS_FALSE;
if (op == JSOP_DEFCONST) {
ReportCompileErrorNumber(cx, TS(tc->parser), pn,
JSREPORT_ERROR, JSMSG_REDECLARED_PARAM,
name.ptr());
return JS_FALSE;
}
if (!ReportCompileErrorNumber(cx, TS(tc->parser), pn,
JSREPORT_WARNING | JSREPORT_STRICT,
JSMSG_VAR_HIDES_ARG, name.ptr())) {
return JS_FALSE;
}
} else {
bool error = (op == JSOP_DEFCONST ||
dn_kind == JSDefinition::CONST ||
(dn_kind == JSDefinition::LET &&
(stmt->type != STMT_CATCH || OuterLet(tc, stmt, atom))));
if (cx->hasStrictOption()
? op != JSOP_DEFVAR || dn_kind != JSDefinition::VAR
: error) {
JSAutoByteString name;
if (!js_AtomToPrintableString(cx, atom, &name) ||
!ReportCompileErrorNumber(cx, TS(tc->parser), pn,
!error
? JSREPORT_WARNING | JSREPORT_STRICT
: JSREPORT_ERROR,
JSMSG_REDECLARED_VAR,
JSDefinition::kindString(dn_kind),
name.ptr())) {
return JS_FALSE;
}
}
}
}
if (mdl.empty()) {
if (!Define(pn, atom, tc))
return JS_FALSE;
} else {
/*
* A var declaration never recreates an existing binding, it restates
* it and possibly reinitializes its value. Beware that if pn becomes a
* use of |mdl.defn()|, and if we have an initializer for this var or
* const (typically a const would ;-), then pn must be rewritten into a
* TOK_ASSIGN node. See Variables, further below.
*
* A case such as let (x = 1) { var x = 2; print(x); } is even harder.
* There the x definition is hoisted but the x = 2 assignment mutates
* the block-local binding of x.
*/
JSDefinition *dn = mdl.front();
data->fresh = false;
if (!pn->isUsed()) {
/* Make pnu be a fresh name node that uses dn. */
JSParseNode *pnu = pn;
if (pn->isDefn()) {
pnu = NameNode::create(atom, tc);
if (!pnu)
return JS_FALSE;
}
LinkUseToDef(pnu, dn, tc);
pnu->setOp(JSOP_NAME);
}
/* Find the first non-let binding of this atom. */
while (dn->kind() == JSDefinition::LET) {
mdl.popFront();
if (mdl.empty())
break;
dn = mdl.front();
}
if (dn) {
JS_ASSERT_IF(data->op == JSOP_DEFCONST,
dn->kind() == JSDefinition::CONST);
return JS_TRUE;
}
/*
* A var or const that is shadowed by one or more let bindings of the
* same name, but that has not been declared until this point, must be
* hoisted above the let bindings.
*/
if (!pn->isDefn()) {
if (tc->lexdeps->lookup(atom)) {
tc->lexdeps->remove(atom);
} else {
JSParseNode *pn2 = NameNode::create(atom, tc);
if (!pn2)
return JS_FALSE;
/* The token stream may be past the location for pn. */
pn2->setKind(TOK_NAME);
pn2->pn_pos = pn->pn_pos;
pn = pn2;
}
pn->setOp(JSOP_NAME);
}
if (!tc->decls.addHoist(atom, (JSDefinition *) pn))
return JS_FALSE;
pn->setDefn(true);
pn->pn_dflags &= ~PND_PLACEHOLDER;
}
if (data->op == JSOP_DEFCONST)
pn->pn_dflags |= PND_CONST;
if (tc->inFunction())
return BindFunctionLocal(cx, data, mdl, tc);
return BindTopLevelVar(cx, data, pn, tc);
}
static bool
MakeSetCall(JSContext *cx, JSParseNode *pn, JSTreeContext *tc, uintN msg)
{
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 (!ReportStrictModeError(cx, TS(tc->parser), tc, pn, msg))
return false;
JSParseNode *pn2 = pn->pn_head;
if (pn2->isKind(TOK_FUNCTION) && (pn2->pn_funbox->tcflags & TCF_GENEXP_LAMBDA)) {
ReportCompileErrorNumber(cx, TS(tc->parser), pn, JSREPORT_ERROR, msg);
return false;
}
pn->pn_xflags |= PNX_SETCALL;
return true;
}
static void
NoteLValue(JSContext *cx, JSParseNode *pn, JSTreeContext *tc, uintN dflag = PND_ASSIGNED)
{
if (pn->isUsed()) {
JSDefinition *dn = pn->pn_lexdef;
/*
* Save the win of PND_INITIALIZED if we can prove 'var x;' and 'x = y'
* occur as direct kids of the same block with no forward refs to x.
*/
if (!(dn->pn_dflags & (PND_INITIALIZED | PND_CONST | PND_PLACEHOLDER)) &&
dn->isBlockChild() &&
pn->isBlockChild() &&
dn->pn_blockid == pn->pn_blockid &&
dn->pn_pos.end <= pn->pn_pos.begin &&
dn->dn_uses == pn) {
dflag = PND_INITIALIZED;
}
dn->pn_dflags |= dflag;
if (dn->pn_cookie.isFree() || dn->frameLevel() < tc->staticLevel)
tc->flags |= TCF_FUN_SETS_OUTER_NAME;
}
pn->pn_dflags |= dflag;
/*
* Both arguments and the enclosing function's name are immutable bindings
* in ES5, so assignments to them must do nothing or throw a TypeError
* depending on code strictness. Assignment to arguments is a syntax error
* in strict mode and thus cannot happen. Outside strict mode, we optimize
* away assignment to the function name. For assignment to function name
* to fail in strict mode, we must have a binding for it in the scope
* chain; we ensure this happens by making such functions heavyweight.
*/
JSAtom *lname = pn->pn_atom;
if (lname == cx->runtime->atomState.argumentsAtom) {
tc->flags |= TCF_FUN_HEAVYWEIGHT;
tc->countArgumentsUse(pn);
} else if (tc->inFunction() && lname == tc->fun()->atom) {
tc->flags |= TCF_FUN_HEAVYWEIGHT;
}
}
#if JS_HAS_DESTRUCTURING
static JSBool
BindDestructuringVar(JSContext *cx, BindData *data, JSParseNode *pn,
JSTreeContext *tc)
{
JSAtom *atom;
/*
* Destructuring is a form of assignment, so just as for an initialized
* simple variable, we must check for assignment to 'arguments' and flag
* the enclosing function (if any) as heavyweight.
*/
JS_ASSERT(pn->isKind(TOK_NAME));
atom = pn->pn_atom;
if (atom == cx->runtime->atomState.argumentsAtom)
tc->flags |= TCF_FUN_HEAVYWEIGHT;
data->pn = pn;
if (!data->binder(cx, data, atom, tc))
return JS_FALSE;
/*
* Select the appropriate name-setting opcode, respecting eager selection
* done by the data->binder function.
*/
if (pn->pn_dflags & PND_BOUND) {
JS_ASSERT(!(pn->pn_dflags & PND_GVAR));
pn->setOp(pn->isOp(JSOP_ARGUMENTS) ? JSOP_SETNAME : JSOP_SETLOCAL);
} else {
pn->setOp((data->op == JSOP_DEFCONST) ? JSOP_SETCONST : JSOP_SETNAME);
}
if (data->op == JSOP_DEFCONST)
pn->pn_dflags |= PND_CONST;
NoteLValue(cx, pn, tc, PND_INITIALIZED);
return JS_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.
*/
static JSBool
BindDestructuringLHS(JSContext *cx, JSParseNode *pn, JSTreeContext *tc)
{
switch (pn->getKind()) {
case TOK_NAME:
NoteLValue(cx, pn, tc);
/* FALL THROUGH */
case TOK_DOT:
case TOK_LB:
/*
* 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 TOK_LP:
if (!MakeSetCall(cx, pn, tc, JSMSG_BAD_LEFTSIDE_OF_ASS))
return JS_FALSE;
break;
#if JS_HAS_XML_SUPPORT
case TOK_UNARYOP:
if (pn->isOp(JSOP_XMLNAME)) {
pn->setOp(JSOP_BINDXMLNAME);
break;
}
/* FALL THROUGH */
#endif
default:
ReportCompileErrorNumber(cx, TS(tc->parser), pn,
JSREPORT_ERROR, JSMSG_BAD_LEFTSIDE_OF_ASS);
return JS_FALSE;
}
return JS_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 the
* TCF_DECL_DESTRUCTURING flag 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
* TCF_DECL_DESTRUCTURING 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.
*
* See also UndominateInitializers, immediately below. If you change
* either of these functions, you might have to change the other to
* match.
*/
static bool
CheckDestructuring(JSContext *cx, BindData *data, JSParseNode *left, JSTreeContext *tc)
{
bool ok;
if (left->isKind(TOK_ARRAYCOMP)) {
ReportCompileErrorNumber(cx, TS(tc->parser), left, JSREPORT_ERROR,
JSMSG_ARRAY_COMP_LEFTSIDE);
return false;
}
if (left->isKind(TOK_RB)) {
for (JSParseNode *pn = left->pn_head; pn; pn = pn->pn_next) {
/* Nullary comma is an elision; binary comma is an expression.*/
if (!pn->isKind(TOK_COMMA) || !pn->isArity(PN_NULLARY)) {
if (pn->isKind(TOK_RB) || pn->isKind(TOK_RC)) {
ok = CheckDestructuring(cx, data, pn, tc);
} else {
if (data) {
if (!pn->isKind(TOK_NAME)) {
ReportCompileErrorNumber(cx, TS(tc->parser), pn, JSREPORT_ERROR,
JSMSG_NO_VARIABLE_NAME);
return false;
}
ok = BindDestructuringVar(cx, data, pn, tc);
} else {
ok = BindDestructuringLHS(cx, pn, tc);
}
}
if (!ok)
return false;
}
}
} else {
JS_ASSERT(left->isKind(TOK_RC));
for (JSParseNode *pair = left->pn_head; pair; pair = pair->pn_next) {
JS_ASSERT(pair->isKind(TOK_COLON));
JSParseNode *pn = pair->pn_right;
if (pn->isKind(TOK_RB) || pn->isKind(TOK_RC)) {
ok = CheckDestructuring(cx, data, pn, tc);
} else if (data) {
if (!pn->isKind(TOK_NAME)) {
ReportCompileErrorNumber(cx, TS(tc->parser), pn, JSREPORT_ERROR,
JSMSG_NO_VARIABLE_NAME);
return false;
}
ok = BindDestructuringVar(cx, data, pn, tc);
} else {
ok = BindDestructuringLHS(cx, pn, tc);
}
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. To satisfy it we add an empty property to such
* blocks so that OBJ_BLOCK_COUNT(cx, blockObj), which gives the number of
* slots, would be always positive.
*
* Note that we add such a property even if the block has locals due to
* later let declarations in it. We optimize for code simplicity here,
* not the fastest runtime performance with empty [] or {}.
*/
if (data &&
data->binder == BindLet &&
OBJ_BLOCK_COUNT(cx, tc->blockChain()) == 0 &&
!DefineNativeProperty(cx, tc->blockChain(),
ATOM_TO_JSID(cx->runtime->atomState.emptyAtom),
UndefinedValue(), NULL, NULL,
JSPROP_ENUMERATE | JSPROP_PERMANENT,
Shape::HAS_SHORTID, 0)) {
return false;
}
return true;
}
/*
* Extend the pn_pos.end source coordinate of each name in a destructuring
* binding such as
*
* var [x, y] = [function () y, 42];
*
* to cover the entire initializer, so that the initialized bindings do not
* appear to dominate any closures in the initializer. See bug 496134.
*
* The quick-and-dirty dominance computation in Parser::setFunctionKinds is not
* very precise. With one-pass SSA construction from structured source code
* (see "Single-Pass Generation of Static Single Assignment Form for Structured
* Languages", Brandis and Mössenböck), we could do much better.
*
* See CheckDestructuring, immediately above. If you change either of these
* functions, you might have to change the other to match.
*/
static void
UndominateInitializers(JSParseNode *left, const TokenPtr &end, JSTreeContext *tc)
{
if (left->isKind(TOK_RB)) {
for (JSParseNode *pn = left->pn_head; pn; pn = pn->pn_next) {
/* Nullary comma is an elision; binary comma is an expression.*/
if (!pn->isKind(TOK_COMMA) || !pn->isArity(PN_NULLARY)) {
if (pn->isKind(TOK_RB) || pn->isKind(TOK_RC))
UndominateInitializers(pn, end, tc);
else
pn->pn_pos.end = end;
}
}
} else {
JS_ASSERT(left->isKind(TOK_RC));
for (JSParseNode *pair = left->pn_head; pair; pair = pair->pn_next) {
JS_ASSERT(pair->isKind(TOK_COLON));
JSParseNode *pn = pair->pn_right;
if (pn->isKind(TOK_RB) || pn->isKind(TOK_RC))
UndominateInitializers(pn, end, tc);
else
pn->pn_pos.end = end;
}
}
}
JSParseNode *
Parser::destructuringExpr(BindData *data, TokenKind tt)
{
JSParseNode *pn;
tc->flags |= TCF_DECL_DESTRUCTURING;
pn = primaryExpr(tt, JS_FALSE);
tc->flags &= ~TCF_DECL_DESTRUCTURING;
if (!pn)
return NULL;
if (!CheckDestructuring(context, data, pn, tc))
return NULL;
return pn;
}
/*
* Currently used only #if JS_HAS_DESTRUCTURING, in Statement's TOK_FOR case.
* This function assumes the cloned tree is for use in the same statement and
* binding context as the original tree.
*/
static JSParseNode *
CloneParseTree(JSParseNode *opn, JSTreeContext *tc)
{
JS_CHECK_RECURSION(tc->parser->context, return NULL);
JSParseNode *pn, *pn2, *opn2;
pn = NewOrRecycledNode(tc);
if (!pn)
return NULL;
pn->setKind(opn->getKind());
pn->setOp(opn->getOp());
pn->setUsed(opn->isUsed());
pn->setDefn(opn->isDefn());
pn->setArity(opn->getArity());
pn->setInParens(opn->isInParens());
pn->pn_pos = opn->pn_pos;
switch (pn->getArity()) {
#define NULLCHECK(e) JS_BEGIN_MACRO if (!(e)) return NULL; JS_END_MACRO
case PN_FUNC:
NULLCHECK(pn->pn_funbox =
tc->parser->newFunctionBox(opn->pn_funbox->object, pn, tc));
NULLCHECK(pn->pn_body = CloneParseTree(opn->pn_body, tc));
pn->pn_cookie = opn->pn_cookie;
pn->pn_dflags = opn->pn_dflags;
pn->pn_blockid = opn->pn_blockid;
break;
case PN_LIST:
pn->makeEmpty();
for (opn2 = opn->pn_head; opn2; opn2 = opn2->pn_next) {
NULLCHECK(pn2 = CloneParseTree(opn2, tc));
pn->append(pn2);
}
pn->pn_xflags = opn->pn_xflags;
break;
case PN_TERNARY:
NULLCHECK(pn->pn_kid1 = CloneParseTree(opn->pn_kid1, tc));
NULLCHECK(pn->pn_kid2 = CloneParseTree(opn->pn_kid2, tc));
NULLCHECK(pn->pn_kid3 = CloneParseTree(opn->pn_kid3, tc));
break;
case PN_BINARY:
NULLCHECK(pn->pn_left = CloneParseTree(opn->pn_left, tc));
if (opn->pn_right != opn->pn_left)
NULLCHECK(pn->pn_right = CloneParseTree(opn->pn_right, tc));
else
pn->pn_right = pn->pn_left;
pn->pn_pval = opn->pn_pval;
pn->pn_iflags = opn->pn_iflags;
break;
case PN_UNARY:
NULLCHECK(pn->pn_kid = CloneParseTree(opn->pn_kid, tc));
pn->pn_num = opn->pn_num;
pn->pn_hidden = opn->pn_hidden;
break;
case PN_NAME:
// PN_NAME could mean several arms in pn_u, so copy the whole thing.
pn->pn_u = opn->pn_u;
if (opn->isUsed()) {
/*
* The old name is a use of its pn_lexdef. Make the clone also be a
* use of that definition.
*/
JSDefinition *dn = pn->pn_lexdef;
pn->pn_link = dn->dn_uses;
dn->dn_uses = pn;
} else if (opn->pn_expr) {
NULLCHECK(pn->pn_expr = CloneParseTree(opn->pn_expr, tc));
/*
* If the old name is a definition, the new one has pn_defn set.
* Make the old name a use of the new node.
*/
if (opn->isDefn()) {
opn->setDefn(false);
LinkUseToDef(opn, (JSDefinition *) pn, tc);
}
}
break;
case PN_NAMESET:
pn->pn_names = opn->pn_names;
NULLCHECK(pn->pn_tree = CloneParseTree(opn->pn_tree, tc));
break;
case PN_NULLARY:
// Even PN_NULLARY may have data (apair for E4X -- what a botch).
pn->pn_u = opn->pn_u;
break;
#undef NULLCHECK
}
return pn;
}
#endif /* JS_HAS_DESTRUCTURING */
static JSParseNode *
ContainsStmt(JSParseNode *pn, TokenKind tt)
{
JSParseNode *pn2, *pnt;
if (!pn)
return NULL;
if (pn->isKind(tt))
return pn;
switch (pn->getArity()) {
case PN_LIST:
for (pn2 = pn->pn_head; pn2; pn2 = pn2->pn_next) {
pnt = ContainsStmt(pn2, tt);
if (pnt)
return pnt;
}
break;
case PN_TERNARY:
pnt = ContainsStmt(pn->pn_kid1, tt);
if (pnt)
return pnt;
pnt = ContainsStmt(pn->pn_kid2, tt);
if (pnt)
return pnt;
return ContainsStmt(pn->pn_kid3, tt);
case PN_BINARY:
/*
* Limit recursion if pn is a binary expression, which can't contain a
* var statement.
*/
if (!pn->isOp(JSOP_NOP))
return NULL;
pnt = ContainsStmt(pn->pn_left, tt);
if (pnt)
return pnt;
return ContainsStmt(pn->pn_right, tt);
case PN_UNARY:
if (!pn->isOp(JSOP_NOP))
return NULL;
return ContainsStmt(pn->pn_kid, tt);
case PN_NAME:
return ContainsStmt(pn->maybeExpr(), tt);
case PN_NAMESET:
return ContainsStmt(pn->pn_tree, tt);
default:;
}
return NULL;
}
JSParseNode *
Parser::returnOrYield(bool useAssignExpr)
{
TokenKind tt, tt2;
JSParseNode *pn, *pn2;
tt = tokenStream.currentToken().type;
if (!tc->inFunction()) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_RETURN_OR_YIELD,
(tt == TOK_RETURN) ? js_return_str : js_yield_str);
return NULL;
}
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
#if JS_HAS_GENERATORS
if (tt == TOK_YIELD) {
/*
* 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 (tc->parenDepth == 0) {
tc->flags |= TCF_FUN_IS_GENERATOR;
} else {
tc->yieldCount++;
tc->yieldNode = pn;
}
}
#endif
/* This is ugly, but we don't want to require a semicolon. */
tt2 = tokenStream.peekTokenSameLine(TSF_OPERAND);
if (tt2 == TOK_ERROR)
return NULL;
if (tt2 != TOK_EOF && tt2 != TOK_EOL && tt2 != TOK_SEMI && tt2 != TOK_RC
#if JS_HAS_GENERATORS
&& (tt != TOK_YIELD ||
(tt2 != tt && tt2 != TOK_RB && tt2 != TOK_RP &&
tt2 != TOK_COLON && tt2 != TOK_COMMA))
#endif
) {
pn2 = useAssignExpr ? assignExpr() : expr();
if (!pn2)
return NULL;
#if JS_HAS_GENERATORS
if (tt == TOK_RETURN)
#endif
tc->flags |= TCF_RETURN_EXPR;
pn->pn_pos.end = pn2->pn_pos.end;
pn->pn_kid = pn2;
} else {
#if JS_HAS_GENERATORS
if (tt == TOK_RETURN)
#endif
tc->flags |= TCF_RETURN_VOID;
}
if ((~tc->flags & (TCF_RETURN_EXPR | TCF_FUN_IS_GENERATOR)) == 0) {
/* As in Python (see PEP-255), disallow return v; in generators. */
ReportBadReturn(context, tc, pn, JSREPORT_ERROR,
JSMSG_BAD_GENERATOR_RETURN,
JSMSG_BAD_ANON_GENERATOR_RETURN);
return NULL;
}
if (context->hasStrictOption() &&
(~tc->flags & (TCF_RETURN_EXPR | TCF_RETURN_VOID)) == 0 &&
!ReportBadReturn(context, tc, pn, JSREPORT_WARNING | JSREPORT_STRICT,
JSMSG_NO_RETURN_VALUE,
JSMSG_ANON_NO_RETURN_VALUE)) {
return NULL;
}
return pn;
}
static JSParseNode *
PushLexicalScope(JSContext *cx, TokenStream *ts, JSTreeContext *tc,
JSStmtInfo *stmt)
{
JSParseNode *pn;
JSObject *obj;
JSObjectBox *blockbox;
pn = LexicalScopeNode::create(tc);
if (!pn)
return NULL;
obj = js_NewBlockObject(cx);
if (!obj)
return NULL;
blockbox = tc->parser->newObjectBox(obj);
if (!blockbox)
return NULL;
js_PushBlockScope(tc, stmt, blockbox, -1);
pn->setKind(TOK_LEXICALSCOPE);
pn->setOp(JSOP_LEAVEBLOCK);
pn->pn_objbox = blockbox;
pn->pn_cookie.makeFree();
pn->pn_dflags = 0;
if (!GenerateBlockId(tc, stmt->blockid))
return NULL;
pn->pn_blockid = stmt->blockid;
return pn;
}
#if JS_HAS_BLOCK_SCOPE
JSParseNode *
Parser::letBlock(JSBool statement)
{
JSParseNode *pn, *pnblock, *pnlet;
JSStmtInfo stmtInfo;
JS_ASSERT(tokenStream.currentToken().type == TOK_LET);
/* Create the let binary node. */
pnlet = BinaryNode::create(tc);
if (!pnlet)
return NULL;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_LET);
/* This is a let block or expression of the form: let (a, b, c) .... */
pnblock = PushLexicalScope(context, &tokenStream, tc, &stmtInfo);
if (!pnblock)
return NULL;
pn = pnblock;
pn->pn_expr = pnlet;
pnlet->pn_left = variables(true);
if (!pnlet->pn_left)
return NULL;
pnlet->pn_left->pn_xflags = PNX_POPVAR;
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_LET);
if (statement && !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 (!ReportStrictModeError(context, &tokenStream, tc, 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 TOK_LET node in a TOK_SEMI node so that we pop
* the return value of the expression.
*/
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_SEMI);
pn->pn_num = -1;
pn->pn_kid = pnblock;
statement = JS_FALSE;
}
if (statement) {
pnlet->pn_right = statements();
if (!pnlet->pn_right)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_LET);
} else {
/*
* Change pnblock's opcode to the variant that propagates the last
* result down after popping the block, and clear statement.
*/
pnblock->setOp(JSOP_LEAVEBLOCKEXPR);
pnlet->pn_right = assignExpr();
if (!pnlet->pn_right)
return NULL;
}
PopStatement(tc);
return pn;
}
#endif /* JS_HAS_BLOCK_SCOPE */
static bool
PushBlocklikeStatement(JSStmtInfo *stmt, JSStmtType type, JSTreeContext *tc)
{
js_PushStatement(tc, stmt, type, -1);
return GenerateBlockId(tc, stmt->blockid);
}
static JSParseNode *
NewBindingNode(JSAtom *atom, JSTreeContext *tc, bool let = false)
{
JSParseNode *pn;
AtomDefnPtr removal;
if ((pn = tc->decls.lookupFirst(atom))) {
JS_ASSERT(!pn->isPlaceholder());
} else {
removal = tc->lexdeps->lookup(atom);
pn = removal ? removal.value() : NULL;
JS_ASSERT_IF(pn, pn->isPlaceholder());
}
if (pn) {
JS_ASSERT(pn->isDefn());
/*
* A let binding at top level becomes a var before we get here, so if
* pn and tc have the same blockid then that id must not be the bodyid.
* If pn is a forward placeholder definition from the same or a higher
* block then we claim it.
*/
JS_ASSERT_IF(let && pn->pn_blockid == tc->blockid(),
pn->pn_blockid != tc->bodyid);
if (pn->isPlaceholder() && pn->pn_blockid >= (let ? tc->blockid() : tc->bodyid)) {
if (let)
pn->pn_blockid = tc->blockid();
tc->lexdeps->remove(removal);
return pn;
}
}
/* Make a new node for this declarator name (or destructuring pattern). */
pn = NameNode::create(atom, tc);
if (!pn)
return NULL;
if (atom == tc->parser->context->runtime->atomState.argumentsAtom)
tc->countArgumentsUse(pn);
return pn;
}
JSParseNode *
Parser::switchStatement()
{
JSParseNode *pn5, *saveBlock;
JSBool seenDefault = JS_FALSE;
JSParseNode *pn = BinaryNode::create(tc);
if (!pn)
return NULL;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_SWITCH);
/* pn1 points to the switch's discriminant. */
JSParseNode *pn1 = parenExpr();
if (!pn1)
return NULL;
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_SWITCH);
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_SWITCH);
/*
* NB: we must push stmtInfo before calling GenerateBlockIdForStmtNode
* because that function states tc->topStmt->blockid.
*/
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_SWITCH, -1);
/* pn2 is a list of case nodes. The default case has pn_left == NULL */
JSParseNode *pn2 = ListNode::create(tc);
if (!pn2)
return NULL;
pn2->makeEmpty();
if (!GenerateBlockIdForStmtNode(pn2, tc))
return NULL;
saveBlock = tc->blockNode;
tc->blockNode = pn2;
TokenKind tt;
while ((tt = tokenStream.getToken()) != TOK_RC) {
JSParseNode *pn3;
switch (tt) {
case TOK_DEFAULT:
if (seenDefault) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_TOO_MANY_DEFAULTS);
return NULL;
}
seenDefault = JS_TRUE;
/* FALL THROUGH */
case TOK_CASE:
{
pn3 = BinaryNode::create(tc);
if (!pn3)
return NULL;
if (tt == TOK_CASE) {
pn3->pn_left = expr();
if (!pn3->pn_left)
return NULL;
}
pn2->append(pn3);
if (pn2->pn_count == JS_BIT(16)) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_TOO_MANY_CASES);
return NULL;
}
break;
}
case TOK_ERROR:
return NULL;
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_SWITCH);
return NULL;
}
MUST_MATCH_TOKEN(TOK_COLON, JSMSG_COLON_AFTER_CASE);
JSParseNode *pn4 = ListNode::create(tc);
if (!pn4)
return NULL;
pn4->setKind(TOK_LC);
pn4->makeEmpty();
while ((tt = tokenStream.peekToken(TSF_OPERAND)) != TOK_RC &&
tt != TOK_CASE && tt != TOK_DEFAULT) {
if (tt == TOK_ERROR)
return NULL;
pn5 = statement();
if (!pn5)
return NULL;
pn4->pn_pos.end = pn5->pn_pos.end;
pn4->append(pn5);
}
/* Fix the PN_LIST so it doesn't begin at the TOK_COLON. */
if (pn4->pn_head)
pn4->pn_pos.begin = pn4->pn_head->pn_pos.begin;
pn3->pn_pos.end = pn4->pn_pos.end;
pn3->pn_right = pn4;
}
/*
* 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
* tc->blockNode with a new block node then we must refresh pn2 and
* then restore tc->blockNode.
*/
if (tc->blockNode != pn2)
pn2 = tc->blockNode;
tc->blockNode = saveBlock;
PopStatement(tc);
pn->pn_pos.end = pn2->pn_pos.end = tokenStream.currentToken().pos.end;
pn->pn_left = pn1;
pn->pn_right = pn2;
return pn;
}
/*
* Used by Parser::forStatement and comprehensionTail to clone the TARGET in
* for (var/const/let TARGET in EXPR)
*
* opn must be the pn_head of a node produced by Parser::variables, so its form
* is known to be LHS = NAME | [LHS] | {id:LHS}.
*
* The cloned tree is for use only in the same statement and binding context as
* the original tree.
*/
static JSParseNode *
CloneLeftHandSide(JSParseNode *opn, JSTreeContext *tc)
{
JSParseNode *pn = NewOrRecycledNode(tc);
if (!pn)
return NULL;
pn->setKind(opn->getKind());
pn->setOp(opn->getOp());
pn->setUsed(opn->isUsed());
pn->setDefn(opn->isDefn());
pn->setArity(opn->getArity());
pn->setInParens(opn->isInParens());
pn->pn_pos = opn->pn_pos;
#if JS_HAS_DESTRUCTURING
if (opn->isArity(PN_LIST)) {
JS_ASSERT(opn->isKind(TOK_RB) || opn->isKind(TOK_RC));
pn->makeEmpty();
for (JSParseNode *opn2 = opn->pn_head; opn2; opn2 = opn2->pn_next) {
JSParseNode *pn2;
if (opn->isKind(TOK_RC)) {
JS_ASSERT(opn2->isArity(PN_BINARY));
JS_ASSERT(opn2->isKind(TOK_COLON));
JSParseNode *tag = CloneParseTree(opn2->pn_left, tc);
if (!tag)
return NULL;
JSParseNode *target = CloneLeftHandSide(opn2->pn_right, tc);
if (!target)
return NULL;
pn2 = BinaryNode::create(TOK_COLON, JSOP_INITPROP, opn2->pn_pos, tag, target, tc);
} else if (opn2->isArity(PN_NULLARY)) {
JS_ASSERT(opn2->isKind(TOK_COMMA));
pn2 = CloneParseTree(opn2, tc);
} else {
pn2 = CloneLeftHandSide(opn2, tc);
}
if (!pn2)
return NULL;
pn->append(pn2);
}
pn->pn_xflags = opn->pn_xflags;
return pn;
}
#endif
JS_ASSERT(opn->isArity(PN_NAME));
JS_ASSERT(opn->isKind(TOK_NAME));
/* If opn is a definition or use, make pn a use. */
pn->pn_u.name = opn->pn_u.name;
pn->setOp(JSOP_SETNAME);
if (opn->isUsed()) {
JSDefinition *dn = pn->pn_lexdef;
pn->pn_link = dn->dn_uses;
dn->dn_uses = pn;
} else {
pn->pn_expr = NULL;
if (opn->isDefn()) {
/* We copied some definition-specific state into pn. Clear it out. */
pn->pn_cookie.makeFree();
pn->pn_dflags &= ~PND_BOUND;
pn->setDefn(false);
LinkUseToDef(pn, (JSDefinition *) opn, tc);
}
}
return pn;
}
JSParseNode *
Parser::forStatement()
{
JSParseNode *pnseq = NULL;
#if JS_HAS_BLOCK_SCOPE
JSParseNode *pnlet = NULL;
JSStmtInfo blockInfo;
#endif
/* A FOR node is binary, left is loop control and right is the body. */
JSParseNode *pn = BinaryNode::create(tc);
if (!pn)
return NULL;
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_FOR_LOOP, -1);
pn->setOp(JSOP_ITER);
pn->pn_iflags = 0;
if (tokenStream.matchToken(TOK_NAME)) {
if (tokenStream.currentToken().t_atom == context->runtime->atomState.eachAtom)
pn->pn_iflags = JSITER_FOREACH;
else
tokenStream.ungetToken();
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
TokenKind tt = tokenStream.peekToken(TSF_OPERAND);
#if JS_HAS_BLOCK_SCOPE
bool let = false;
#endif
JSParseNode *pn1;
if (tt == TOK_SEMI) {
if (pn->pn_iflags & JSITER_FOREACH) {
reportErrorNumber(pn, JSREPORT_ERROR, JSMSG_BAD_FOR_EACH_LOOP);
return NULL;
}
/* No initializer -- set first kid of left sub-node to null. */
pn1 = NULL;
} else {
/*
* Set pn1 to a var list or an initializing expression.
*
* Set the TCF_IN_FOR_INIT 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.
*/
tc->flags |= TCF_IN_FOR_INIT;
if (tt == TOK_VAR) {
(void) tokenStream.getToken();
pn1 = variables(false);
#if JS_HAS_BLOCK_SCOPE
} else if (tt == TOK_LET) {
let = true;
(void) tokenStream.getToken();
if (tokenStream.peekToken() == TOK_LP) {
pn1 = letBlock(JS_FALSE);
tt = TOK_LEXICALSCOPE;
} else {
pnlet = PushLexicalScope(context, &tokenStream, tc, &blockInfo);
if (!pnlet)
return NULL;
blockInfo.flags |= SIF_FOR_BLOCK;
pn1 = variables(false);
}
#endif
} else {
pn1 = expr();
}
tc->flags &= ~TCF_IN_FOR_INIT;
if (!pn1)
return 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
* the TCF_IN_FOR_INIT flag in our JSTreeContext.
*/
JSParseNode *pn2, *pn3;
JSParseNode *pn4 = TernaryNode::create(tc);
if (!pn4)
return NULL;
if (pn1 && tokenStream.matchToken(TOK_IN)) {
/*
* Parse the rest of the for/in head.
*
* Here pn1 is everything to the left of 'in'. 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'.
*/
pn->pn_iflags |= JSITER_ENUMERATE;
stmtInfo.type = STMT_FOR_IN_LOOP;
/* Check that the left side of the 'in' is valid. */
JS_ASSERT(!TokenKindIsDecl(tt) || pn1->isKind(tt));
if (TokenKindIsDecl(tt)
? (pn1->pn_count > 1 || pn1->isOp(JSOP_DEFCONST)
#if JS_HAS_DESTRUCTURING
|| (versionNumber() == JSVERSION_1_7 &&
pn->isOp(JSOP_ITER) &&
!(pn->pn_iflags & JSITER_FOREACH) &&
(pn1->pn_head->isKind(TOK_RC) ||
(pn1->pn_head->isKind(TOK_RB) &&
pn1->pn_head->pn_count != 2) ||
(pn1->pn_head->isKind(TOK_ASSIGN) &&
(!pn1->pn_head->pn_left->isKind(TOK_RB) ||
pn1->pn_head->pn_left->pn_count != 2))))
#endif
)
: (!pn1->isKind(TOK_NAME) &&
!pn1->isKind(TOK_DOT) &&
#if JS_HAS_DESTRUCTURING
((versionNumber() == JSVERSION_1_7 &&
pn->isOp(JSOP_ITER) &&
!(pn->pn_iflags & JSITER_FOREACH))
? (!pn1->isKind(TOK_RB) || pn1->pn_count != 2)
: (!pn1->isKind(TOK_RB) && !pn1->isKind(TOK_RC))) &&
#endif
!pn1->isKind(TOK_LP) &&
#if JS_HAS_XML_SUPPORT
(!pn1->isKind(TOK_UNARYOP) ||
!pn1->isOp(JSOP_XMLNAME)) &&
#endif
!pn1->isKind(TOK_LB))) {
reportErrorNumber(pn1, JSREPORT_ERROR, 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.
*/
pn2 = NULL;
uintN dflag = PND_ASSIGNED;
if (TokenKindIsDecl(tt)) {
/* Tell EmitVariables that pn1 is part of a for/in. */
pn1->pn_xflags |= PNX_FORINVAR;
pn2 = pn1->pn_head;
if ((pn2->isKind(TOK_NAME) && pn2->maybeExpr())
#if JS_HAS_DESTRUCTURING
|| pn2->isKind(TOK_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. TOK_VAR is the type for both 'var' and 'const'.
*/
#if JS_HAS_BLOCK_SCOPE
if (tt == TOK_LET) {
reportErrorNumber(pn2, JSREPORT_ERROR, JSMSG_INVALID_FOR_IN_INIT);
return NULL;
}
#endif /* JS_HAS_BLOCK_SCOPE */
pnseq = ListNode::create(tc);
if (!pnseq)
return NULL;
pnseq->setKind(TOK_SEQ);
pnseq->pn_pos.begin = pn->pn_pos.begin;
dflag = PND_INITIALIZED;
/*
* All of 'var x = i' is hoisted above 'for (x in o)',
* so clear PNX_FORINVAR.
*
* 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_FORINVAR;
pn1->pn_xflags |= PNX_POPVAR;
pnseq->initList(pn1);
#if JS_HAS_DESTRUCTURING
if (pn2->isKind(TOK_ASSIGN)) {
pn2 = pn2->pn_left;
JS_ASSERT(pn2->isKind(TOK_RB) || pn2->isKind(TOK_RC) ||
pn2->isKind(TOK_NAME));
}
#endif
pn1 = NULL;
}
/*
* pn2 is part of a declaration. Make a copy that can be passed to
* EmitAssignment.
*/
pn2 = CloneLeftHandSide(pn2, tc);
if (!pn2)
return NULL;
} else {
/* Not a declaration. */
pn2 = pn1;
pn1 = NULL;
if (!setAssignmentLhsOps(pn2, JSOP_NOP))
return NULL;
}
switch (pn2->getKind()) {
case TOK_NAME:
/* Beware 'for (arguments in ...)' with or without a 'var'. */
NoteLValue(context, pn2, tc, dflag);
break;
#if JS_HAS_DESTRUCTURING
case TOK_ASSIGN:
JS_NOT_REACHED("forStatement TOK_ASSIGN");
break;
case TOK_RB:
case TOK_RC:
if (versionNumber() == JSVERSION_1_7) {
/*
* Destructuring for-in requires [key, value] enumeration
* in JS1.7.
*/
JS_ASSERT(pn->isOp(JSOP_ITER));
if (!(pn->pn_iflags & JSITER_FOREACH))
pn->pn_iflags |= JSITER_FOREACH | JSITER_KEYVALUE;
}
break;
#endif
default:;
}
/*
* Parse the object expression as the right operand of 'in', first
* removing the top statement from the statement-stack if this is a
* 'for (let x in y)' loop.
*/
#if JS_HAS_BLOCK_SCOPE
JSStmtInfo *save = tc->topStmt;
if (let)
tc->topStmt = save->down;
#endif
pn3 = expr();
if (!pn3)
return NULL;
#if JS_HAS_BLOCK_SCOPE
if (let)
tc->topStmt = save;
#endif
pn4->setKind(TOK_IN);
} else {
if (pn->pn_iflags & JSITER_FOREACH) {
reportErrorNumber(pn, JSREPORT_ERROR, JSMSG_BAD_FOR_EACH_LOOP);
return NULL;
}
pn->setOp(JSOP_NOP);
/* Parse the loop condition or null into pn2. */
MUST_MATCH_TOKEN(TOK_SEMI, JSMSG_SEMI_AFTER_FOR_INIT);
tt = tokenStream.peekToken(TSF_OPERAND);
if (tt == 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);
tt = tokenStream.peekToken(TSF_OPERAND);
if (tt == TOK_RP) {
pn3 = NULL;
} else {
pn3 = expr();
if (!pn3)
return NULL;
}
pn4->setKind(TOK_FORHEAD);
}
pn4->setOp(JSOP_NOP);
pn4->pn_kid1 = pn1;
pn4->pn_kid2 = pn2;
pn4->pn_kid3 = pn3;
pn->pn_left = pn4;
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_FOR_CTRL);
/* Parse the loop body into pn->pn_right. */
pn2 = statement();
if (!pn2)
return NULL;
pn->pn_right = pn2;
/* Record the absolute line number for source note emission. */
pn->pn_pos.end = pn2->pn_pos.end;
#if JS_HAS_BLOCK_SCOPE
if (pnlet) {
PopStatement(tc);
pnlet->pn_expr = pn;
pn = pnlet;
}
#endif
if (pnseq) {
pnseq->pn_pos.end = pn->pn_pos.end;
pnseq->append(pn);
pn = pnseq;
}
PopStatement(tc);
return pn;
}
JSParseNode *
Parser::tryStatement()
{
JSParseNode *catchList, *lastCatch;
/*
* 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.
*/
JSParseNode *pn = TernaryNode::create(tc);
if (!pn)
return NULL;
pn->setOp(JSOP_NOP);
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_TRY);
JSStmtInfo stmtInfo;
if (!PushBlocklikeStatement(&stmtInfo, STMT_TRY, tc))
return NULL;
pn->pn_kid1 = statements();
if (!pn->pn_kid1)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_TRY);
PopStatement(tc);
catchList = NULL;
TokenKind tt = tokenStream.getToken();
if (tt == TOK_CATCH) {
catchList = ListNode::create(tc);
if (!catchList)
return NULL;
catchList->setKind(TOK_RESERVED);
catchList->makeEmpty();
lastCatch = NULL;
do {
JSParseNode *pnblock;
BindData data;
/* Check for another catch after unconditional catch. */
if (lastCatch && !lastCatch->pn_kid2) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_CATCH_AFTER_GENERAL);
return NULL;
}
/*
* Create a lexical scope node around the whole catch clause,
* including the head.
*/
pnblock = PushLexicalScope(context, &tokenStream, tc, &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)
*/
JSParseNode *pn2 = TernaryNode::create(tc);
if (!pn2)
return NULL;
pnblock->pn_expr = pn2;
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.pn = NULL;
data.op = JSOP_NOP;
data.binder = BindLet;
data.let.overflow = JSMSG_TOO_MANY_CATCH_VARS;
tt = tokenStream.getToken();
JSParseNode *pn3;
switch (tt) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
pn3 = destructuringExpr(&data, tt);
if (!pn3)
return NULL;
break;
#endif
case TOK_NAME:
{
JSAtom *label = tokenStream.currentToken().t_atom;
pn3 = NewBindingNode(label, tc, true);
if (!pn3)
return NULL;
data.pn = pn3;
if (!data.binder(context, &data, label, tc))
return NULL;
break;
}
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_CATCH_IDENTIFIER);
return NULL;
}
pn2->pn_kid1 = pn3;
#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)) {
pn2->pn_kid2 = expr();
if (!pn2->pn_kid2)
return NULL;
}
#endif
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_CATCH);
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_CATCH);
pn2->pn_kid3 = statements();
if (!pn2->pn_kid3)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_CATCH);
PopStatement(tc);
catchList->append(pnblock);
lastCatch = pn2;
tt = tokenStream.getToken(TSF_OPERAND);
} while (tt == TOK_CATCH);
}
pn->pn_kid2 = catchList;
if (tt == TOK_FINALLY) {
MUST_MATCH_TOKEN(TOK_LC, JSMSG_CURLY_BEFORE_FINALLY);
if (!PushBlocklikeStatement(&stmtInfo, STMT_FINALLY, tc))
return NULL;
pn->pn_kid3 = statements();
if (!pn->pn_kid3)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_AFTER_FINALLY);
PopStatement(tc);
} else {
tokenStream.ungetToken();
}
if (!catchList && !pn->pn_kid3) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_CATCH_OR_FINALLY);
return NULL;
}
return pn;
}
JSParseNode *
Parser::withStatement()
{
/*
* In most cases, we want the constructs forbidden in strict mode
* code to be a subset of those that JSOPTION_STRICT 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_STRICT. See
* https://bugzilla.mozilla.org/show_bug.cgi?id=514576#c1.
*/
if (tc->flags & TCF_STRICT_MODE_CODE) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_STRICT_CODE_WITH);
return NULL;
}
JSParseNode *pn = BinaryNode::create(tc);
if (!pn)
return NULL;
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_BEFORE_WITH);
JSParseNode *pn2 = parenExpr();
if (!pn2)
return NULL;
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_AFTER_WITH);
pn->pn_left = pn2;
JSParseNode *oldWith = tc->innermostWith;
tc->innermostWith = pn;
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_WITH, -1);
pn2 = statement();
if (!pn2)
return NULL;
PopStatement(tc);
pn->pn_pos.end = pn2->pn_pos.end;
pn->pn_right = pn2;
tc->flags |= TCF_FUN_HEAVYWEIGHT;
tc->innermostWith = oldWith;
/*
* Make sure to deoptimize lexical dependencies inside the |with|
* to safely optimize binding globals (see bug 561923).
*/
for (AtomDefnRange r = tc->lexdeps->all(); !r.empty(); r.popFront()) {
JSDefinition *defn = r.front().value();
JSDefinition *lexdep = defn->resolve();
DeoptimizeUsesWithin(lexdep, pn->pn_pos);
}
return pn;
}
#if JS_HAS_BLOCK_SCOPE
JSParseNode *
Parser::letStatement()
{
JSObjectBox *blockbox;
JSParseNode *pn;
do {
/* Check for a let statement or let expression. */
if (tokenStream.peekToken() == TOK_LP) {
pn = letBlock(JS_TRUE);
if (!pn || pn->isOp(JSOP_LEAVEBLOCK))
return pn;
/* Let expressions require automatic semicolon insertion. */
JS_ASSERT(pn->isKind(TOK_SEMI) || pn->isOp(JSOP_LEAVEBLOCKEXPR));
break;
}
/*
* 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
* JSStmtInfo 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 JSStmtInfo isn't yet a scope statement) then
* we also need to set tc->blockNode to be our TOK_LEXICALSCOPE.
*/
JSStmtInfo *stmt = tc->topStmt;
if (stmt &&
(!STMT_MAYBE_SCOPE(stmt) || (stmt->flags & SIF_FOR_BLOCK))) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_LET_DECL_NOT_IN_BLOCK);
return NULL;
}
if (stmt && (stmt->flags & SIF_SCOPE)) {
JS_ASSERT(tc->blockChainBox == stmt->blockBox);
} else {
if (!stmt || (stmt->flags & SIF_BODY_BLOCK)) {
/*
* ES4 specifies that let at top level and at body-block scope
* does not shadow var, so convert back to var.
*/
tokenStream.mungeCurrentToken(TOK_VAR, JSOP_DEFVAR);
pn = variables(false);
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->flags & SIF_SCOPE));
JS_ASSERT(stmt != tc->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. */
JSObject *obj = js_NewBlockObject(tc->parser->context);
if (!obj)
return NULL;
blockbox = tc->parser->newObjectBox(obj);
if (!blockbox)
return NULL;
/*
* Insert stmt on the tc->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->flags |= SIF_SCOPE;
stmt->downScope = tc->topScopeStmt;
tc->topScopeStmt = stmt;
obj->setParent(tc->blockChain());
blockbox->parent = tc->blockChainBox;
tc->blockChainBox = blockbox;
stmt->blockBox = blockbox;
#ifdef DEBUG
JSParseNode *tmp = tc->blockNode;
JS_ASSERT(!tmp || !tmp->isKind(TOK_LEXICALSCOPE));
#endif
/* Create a new lexical scope node for these statements. */
JSParseNode *pn1 = LexicalScopeNode::create(tc);
if (!pn1)
return NULL;
pn1->setKind(TOK_LEXICALSCOPE);
pn1->setOp(JSOP_LEAVEBLOCK);
pn1->pn_pos = tc->blockNode->pn_pos;
pn1->pn_objbox = blockbox;
pn1->pn_expr = tc->blockNode;
pn1->pn_blockid = tc->blockNode->pn_blockid;
tc->blockNode = pn1;
}
pn = variables(false);
if (!pn)
return NULL;
pn->pn_xflags = PNX_POPVAR;
} while (0);
/* Check termination of this primitive statement. */
return MatchOrInsertSemicolon(context, &tokenStream) ? pn : NULL;
}
#endif
JSParseNode *
Parser::expressionStatement()
{
tokenStream.ungetToken();
JSParseNode *pn2 = expr();
if (!pn2)
return NULL;
if (tokenStream.peekToken() == TOK_COLON) {
if (!pn2->isKind(TOK_NAME)) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_LABEL);
return NULL;
}
JSAtom *label = pn2->pn_atom;
for (JSStmtInfo *stmt = tc->topStmt; stmt; stmt = stmt->down) {
if (stmt->type == STMT_LABEL && stmt->label == label) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_DUPLICATE_LABEL);
return NULL;
}
}
ForgetUse(pn2);
(void) tokenStream.getToken();
/* Push a label struct and parse the statement. */
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_LABEL, -1);
stmtInfo.label = label;
JSParseNode *pn = statement();
if (!pn)
return NULL;
/* Normalize empty statement to empty block for the decompiler. */
if (pn->isKind(TOK_SEMI) && !pn->pn_kid) {
pn->setKind(TOK_LC);
pn->setArity(PN_LIST);
pn->makeEmpty();
}
/* Pop the label, set pn_expr, and return early. */
PopStatement(tc);
pn2->setKind(TOK_COLON);
pn2->pn_pos.end = pn->pn_pos.end;
pn2->pn_expr = pn;
return pn2;
}
JSParseNode *pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_SEMI);
pn->pn_pos = pn2->pn_pos;
pn->pn_kid = pn2;
switch (pn2->getKind()) {
case TOK_LP:
/*
* Flag lambdas immediately applied as statements as instances of
* the JS "module pattern". See CheckForImmediatelyAppliedLambda.
*/
if (pn2->pn_head->isKind(TOK_FUNCTION) &&
!pn2->pn_head->pn_funbox->node->isFunArg()) {
pn2->pn_head->pn_funbox->tcflags |= TCF_FUN_MODULE_PATTERN;
}
break;
case TOK_ASSIGN:
/*
* Keep track of all apparent methods created by assignments such
* as this.foo = function (...) {...} in a function that could end
* up a constructor function. See Parser::setFunctionKinds.
*/
if (tc->funbox &&
pn2->isOp(JSOP_NOP) &&
pn2->pn_left->isOp(JSOP_SETPROP) &&
pn2->pn_left->pn_expr->isOp(JSOP_THIS) &&
pn2->pn_right->isOp(JSOP_LAMBDA)) {
JS_ASSERT(!pn2->isDefn());
JS_ASSERT(!pn2->isUsed());
pn2->pn_right->pn_link = tc->funbox->methods;
tc->funbox->methods = pn2->pn_right;
}
break;
default:;
}
/* Check termination of this primitive statement. */
return MatchOrInsertSemicolon(context, &tokenStream) ? pn : NULL;
}
JSParseNode *
Parser::statement()
{
JSParseNode *pn;
JS_CHECK_RECURSION(context, return NULL);
switch (tokenStream.getToken(TSF_OPERAND)) {
case TOK_FUNCTION:
{
#if JS_HAS_XML_SUPPORT
TokenKind tt = tokenStream.peekToken(TSF_KEYWORD_IS_NAME);
if (tt == TOK_DBLCOLON)
goto expression;
#endif
return functionStmt();
}
case TOK_IF:
{
/* An IF node has three kids: condition, then, and optional else. */
pn = TernaryNode::create(tc);
if (!pn)
return NULL;
JSParseNode *pn1 = condition();
if (!pn1)
return NULL;
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_IF, -1);
JSParseNode *pn2 = statement();
if (!pn2)
return NULL;
JSParseNode *pn3;
if (tokenStream.matchToken(TOK_ELSE, TSF_OPERAND)) {
stmtInfo.type = STMT_ELSE;
pn3 = statement();
if (!pn3)
return NULL;
pn->pn_pos.end = pn3->pn_pos.end;
} else {
pn3 = NULL;
pn->pn_pos.end = pn2->pn_pos.end;
}
PopStatement(tc);
pn->pn_kid1 = pn1;
pn->pn_kid2 = pn2;
pn->pn_kid3 = pn3;
return pn;
}
case TOK_SWITCH:
return switchStatement();
case TOK_WHILE:
{
pn = BinaryNode::create(tc);
if (!pn)
return NULL;
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_WHILE_LOOP, -1);
JSParseNode *pn2 = condition();
if (!pn2)
return NULL;
pn->pn_left = pn2;
JSParseNode *pn3 = statement();
if (!pn3)
return NULL;
PopStatement(tc);
pn->pn_pos.end = pn3->pn_pos.end;
pn->pn_right = pn3;
return pn;
}
case TOK_DO:
{
pn = BinaryNode::create(tc);
if (!pn)
return NULL;
JSStmtInfo stmtInfo;
js_PushStatement(tc, &stmtInfo, STMT_DO_LOOP, -1);
JSParseNode *pn2 = statement();
if (!pn2)
return NULL;
pn->pn_left = pn2;
MUST_MATCH_TOKEN(TOK_WHILE, JSMSG_WHILE_AFTER_DO);
JSParseNode *pn3 = condition();
if (!pn3)
return NULL;
PopStatement(tc);
pn->pn_pos.end = pn3->pn_pos.end;
pn->pn_right = pn3;
if (versionNumber() != JSVERSION_ECMA_3) {
/*
* All legacy and extended versions must do automatic semicolon
* insertion after do-while. See the testcase and discussion in
* http://bugzilla.mozilla.org/show_bug.cgi?id=238945.
*/
(void) tokenStream.matchToken(TOK_SEMI);
return pn;
}
break;
}
case TOK_FOR:
return forStatement();
case TOK_TRY:
return tryStatement();
case TOK_THROW:
{
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
/* 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) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
return NULL;
}
JSParseNode *pn2 = expr();
if (!pn2)
return NULL;
pn->pn_pos.end = pn2->pn_pos.end;
pn->setOp(JSOP_THROW);
pn->pn_kid = pn2;
break;
}
/* TOK_CATCH and TOK_FINALLY are both handled in the TOK_TRY case */
case TOK_CATCH:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_CATCH_WITHOUT_TRY);
return NULL;
case TOK_FINALLY:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_FINALLY_WITHOUT_TRY);
return NULL;
case TOK_BREAK:
{
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
if (!MatchLabel(context, &tokenStream, pn))
return NULL;
JSStmtInfo *stmt = tc->topStmt;
JSAtom *label = pn->pn_atom;
if (label) {
for (; ; stmt = stmt->down) {
if (!stmt) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_LABEL_NOT_FOUND);
return NULL;
}
if (stmt->type == STMT_LABEL && stmt->label == label)
break;
}
} else {
for (; ; stmt = stmt->down) {
if (!stmt) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_TOUGH_BREAK);
return NULL;
}
if (STMT_IS_LOOP(stmt) || stmt->type == STMT_SWITCH)
break;
}
}
if (label)
pn->pn_pos.end = tokenStream.currentToken().pos.end;
break;
}
case TOK_CONTINUE:
{
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
if (!MatchLabel(context, &tokenStream, pn))
return NULL;
JSStmtInfo *stmt = tc->topStmt;
JSAtom *label = pn->pn_atom;
if (label) {
for (JSStmtInfo *stmt2 = NULL; ; stmt = stmt->down) {
if (!stmt) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_LABEL_NOT_FOUND);
return NULL;
}
if (stmt->type == STMT_LABEL) {
if (stmt->label == label) {
if (!stmt2 || !STMT_IS_LOOP(stmt2)) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_CONTINUE);
return NULL;
}
break;
}
} else {
stmt2 = stmt;
}
}
} else {
for (; ; stmt = stmt->down) {
if (!stmt) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_CONTINUE);
return NULL;
}
if (STMT_IS_LOOP(stmt))
break;
}
}
if (label)
pn->pn_pos.end = tokenStream.currentToken().pos.end;
break;
}
case TOK_WITH:
return withStatement();
case TOK_VAR:
pn = variables(false);
if (!pn)
return NULL;
/* Tell js_EmitTree to generate a final POP. */
pn->pn_xflags |= PNX_POPVAR;
break;
#if JS_HAS_BLOCK_SCOPE
case TOK_LET:
return letStatement();
#endif /* JS_HAS_BLOCK_SCOPE */
case TOK_RETURN:
pn = returnOrYield(false);
if (!pn)
return NULL;
break;
case TOK_LC:
{
uintN oldflags;
oldflags = tc->flags;
tc->flags = oldflags & ~TCF_HAS_FUNCTION_STMT;
JSStmtInfo stmtInfo;
if (!PushBlocklikeStatement(&stmtInfo, STMT_BLOCK, tc))
return NULL;
pn = statements();
if (!pn)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_IN_COMPOUND);
PopStatement(tc);
/*
* If we contain a function statement and our container is top-level
* or another block, flag pn to preserve braces when decompiling.
*/
if ((tc->flags & TCF_HAS_FUNCTION_STMT) &&
(!tc->topStmt || tc->topStmt->type == STMT_BLOCK)) {
pn->pn_xflags |= PNX_NEEDBRACES;
}
tc->flags = oldflags | (tc->flags & (TCF_FUN_FLAGS | TCF_RETURN_FLAGS));
return pn;
}
case TOK_SEMI:
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_SEMI);
return pn;
case TOK_DEBUGGER:
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_DEBUGGER);
tc->flags |= TCF_FUN_HEAVYWEIGHT;
break;
#if JS_HAS_XML_SUPPORT
case TOK_DEFAULT:
{
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
if (!tokenStream.matchToken(TOK_NAME) ||
tokenStream.currentToken().t_atom != context->runtime->atomState.xmlAtom ||
!tokenStream.matchToken(TOK_NAME) ||
tokenStream.currentToken().t_atom != context->runtime->atomState.namespaceAtom ||
!tokenStream.matchToken(TOK_ASSIGN) ||
tokenStream.currentToken().t_op != JSOP_NOP) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_DEFAULT_XML_NAMESPACE);
return NULL;
}
/* Is this an E4X dagger I see before me? */
tc->flags |= TCF_FUN_HEAVYWEIGHT;
JSParseNode *pn2 = expr();
if (!pn2)
return NULL;
pn->setOp(JSOP_DEFXMLNS);
pn->pn_pos.end = pn2->pn_pos.end;
pn->pn_kid = pn2;
break;
}
#endif
case TOK_ERROR:
return NULL;
default:
#if JS_HAS_XML_SUPPORT
expression:
#endif
return expressionStatement();
}
/* Check termination of this primitive statement. */
return MatchOrInsertSemicolon(context, &tokenStream) ? pn : NULL;
}
JSParseNode *
Parser::variables(bool inLetHead)
{
TokenKind tt;
bool let;
JSStmtInfo *scopeStmt;
BindData data;
JSParseNode *pn, *pn2;
JSAtom *atom;
/*
* The three options here are:
* - TOK_LET: We are parsing a let declaration.
* - TOK_LP: We are parsing the head of a let block.
* - Otherwise, we're parsing var declarations.
*/
tt = tokenStream.currentToken().type;
let = (tt == TOK_LET || tt == TOK_LP);
JS_ASSERT(let || tt == TOK_VAR);
#if JS_HAS_BLOCK_SCOPE
bool popScope = (inLetHead || (let && (tc->flags & TCF_IN_FOR_INIT)));
JSStmtInfo *save = tc->topStmt, *saveScope = tc->topScopeStmt;
#endif
/* Make sure that statement set up the tree context correctly. */
scopeStmt = tc->topScopeStmt;
if (let) {
while (scopeStmt && !(scopeStmt->flags & SIF_SCOPE)) {
JS_ASSERT(!STMT_MAYBE_SCOPE(scopeStmt));
scopeStmt = scopeStmt->downScope;
}
JS_ASSERT(scopeStmt);
}
data.op = let ? JSOP_NOP : tokenStream.currentToken().t_op;
pn = ListNode::create(tc);
if (!pn)
return NULL;
pn->setOp(data.op);
pn->makeEmpty();
/*
* 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.
*/
if (let) {
JS_ASSERT(tc->blockChainBox == scopeStmt->blockBox);
data.binder = BindLet;
data.let.overflow = JSMSG_TOO_MANY_LOCALS;
} else {
data.binder = BindVarOrConst;
}
do {
tt = tokenStream.getToken();
#if JS_HAS_DESTRUCTURING
if (tt == TOK_LB || tt == TOK_LC) {
tc->flags |= TCF_DECL_DESTRUCTURING;
pn2 = primaryExpr(tt, JS_FALSE);
tc->flags &= ~TCF_DECL_DESTRUCTURING;
if (!pn2)
return NULL;
if (!CheckDestructuring(context, &data, pn2, tc))
return NULL;
if ((tc->flags & TCF_IN_FOR_INIT) && tokenStream.peekToken() == TOK_IN) {
pn->append(pn2);
continue;
}
MUST_MATCH_TOKEN(TOK_ASSIGN, JSMSG_BAD_DESTRUCT_DECL);
if (tokenStream.currentToken().t_op != JSOP_NOP)
goto bad_var_init;
#if JS_HAS_BLOCK_SCOPE
if (popScope) {
tc->topStmt = save->down;
tc->topScopeStmt = saveScope->downScope;
}
#endif
JSParseNode *init = assignExpr();
#if JS_HAS_BLOCK_SCOPE
if (popScope) {
tc->topStmt = save;
tc->topScopeStmt = saveScope;
}
#endif
if (!init)
return NULL;
UndominateInitializers(pn2, init->pn_pos.end, tc);
pn2 = JSParseNode::newBinaryOrAppend(TOK_ASSIGN, JSOP_NOP, pn2, init, tc);
if (!pn2)
return NULL;
pn->append(pn2);
continue;
}
#endif /* JS_HAS_DESTRUCTURING */
if (tt != TOK_NAME) {
if (tt != TOK_ERROR)
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_NO_VARIABLE_NAME);
return NULL;
}
atom = tokenStream.currentToken().t_atom;
pn2 = NewBindingNode(atom, tc, let);
if (!pn2)
return NULL;
if (data.op == JSOP_DEFCONST)
pn2->pn_dflags |= PND_CONST;
data.pn = pn2;
if (!data.binder(context, &data, atom, tc))
return NULL;
pn->append(pn2);
if (tokenStream.matchToken(TOK_ASSIGN)) {
if (tokenStream.currentToken().t_op != JSOP_NOP)
goto bad_var_init;
#if JS_HAS_BLOCK_SCOPE
if (popScope) {
tc->topStmt = save->down;
tc->topScopeStmt = saveScope->downScope;
}
#endif
JSParseNode *init = assignExpr();
#if JS_HAS_BLOCK_SCOPE
if (popScope) {
tc->topStmt = save;
tc->topScopeStmt = saveScope;
}
#endif
if (!init)
return NULL;
if (pn2->isUsed()) {
pn2 = MakeAssignment(pn2, init, tc);
if (!pn2)
return NULL;
} else {
pn2->pn_expr = init;
}
JS_ASSERT_IF(pn2->pn_dflags & PND_GVAR, !(pn2->pn_dflags & PND_BOUND));
pn2->setOp(pn2->isOp(JSOP_ARGUMENTS)
? JSOP_SETNAME
: (pn2->pn_dflags & PND_BOUND)
? JSOP_SETLOCAL
: (data.op == JSOP_DEFCONST)
? JSOP_SETCONST
: JSOP_SETNAME);
NoteLValue(context, pn2, tc, data.fresh ? PND_INITIALIZED : PND_ASSIGNED);
/* The declarator's position must include the initializer. */
pn2->pn_pos.end = init->pn_pos.end;
if (tc->inFunction() &&
atom == context->runtime->atomState.argumentsAtom) {
tc->noteArgumentsUse(pn2);
if (!let)
tc->flags |= TCF_FUN_HEAVYWEIGHT;
}
}
} while (tokenStream.matchToken(TOK_COMMA));
pn->pn_pos.end = pn->last()->pn_pos.end;
return pn;
bad_var_init:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_VAR_INIT);
return NULL;
}
JSParseNode *
Parser::expr()
{
JSParseNode *pn = assignExpr();
if (pn && tokenStream.matchToken(TOK_COMMA)) {
JSParseNode *pn2 = ListNode::create(tc);
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(TOK_YIELD) && !pn2->isInParens()) {
reportErrorNumber(pn2, JSREPORT_ERROR, 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;
}
/*
* For a number of the expression parsers we define an always-inlined version
* and a never-inlined version (which just calls the always-inlined version).
* Using the always-inlined version in the hot call-sites givs a ~5% parsing
* speedup. These macros help avoid some boilerplate code.
*/
#define BEGIN_EXPR_PARSER(name) \
JS_ALWAYS_INLINE JSParseNode * \
Parser::name##i()
#define END_EXPR_PARSER(name) \
JS_NEVER_INLINE JSParseNode * \
Parser::name##n() { \
return name##i(); \
}
BEGIN_EXPR_PARSER(mulExpr1)
{
TokenKind tt;
JSParseNode *pn = unaryExpr();
/*
* Note: unlike addExpr1() et al, we use getToken() here instead of
* isCurrentTokenType() because unaryExpr() doesn't leave the TokenStream
* state one past the end of the unary expression.
*/
while (pn && ((tt = tokenStream.getToken()) == TOK_STAR || tt == TOK_DIVOP)) {
tt = tokenStream.currentToken().type;
JSOp op = tokenStream.currentToken().t_op;
pn = JSParseNode::newBinaryOrAppend(tt, op, pn, unaryExpr(), tc);
}
return pn;
}
END_EXPR_PARSER(mulExpr1)
BEGIN_EXPR_PARSER(addExpr1)
{
JSParseNode *pn = mulExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_PLUS, TOK_MINUS)) {
TokenKind tt = tokenStream.currentToken().type;
JSOp op = (tt == TOK_PLUS) ? JSOP_ADD : JSOP_SUB;
pn = JSParseNode::newBinaryOrAppend(tt, op, pn, mulExpr1n(), tc);
}
return pn;
}
END_EXPR_PARSER(addExpr1)
BEGIN_EXPR_PARSER(shiftExpr1)
{
JSParseNode *pn = addExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_SHOP)) {
JSOp op = tokenStream.currentToken().t_op;
pn = JSParseNode::newBinaryOrAppend(TOK_SHOP, op, pn, addExpr1n(), tc);
}
return pn;
}
END_EXPR_PARSER(shiftExpr1)
BEGIN_EXPR_PARSER(relExpr1)
{
uintN inForInitFlag = tc->flags & TCF_IN_FOR_INIT;
/*
* Uses of the in operator in shiftExprs are always unambiguous,
* so unset the flag that prohibits recognizing it.
*/
tc->flags &= ~TCF_IN_FOR_INIT;
JSParseNode *pn = shiftExpr1i();
while (pn &&
(tokenStream.isCurrentTokenType(TOK_RELOP) ||
/*
* Recognize the 'in' token as an operator only if we're not
* currently in the init expr of a for loop.
*/
(inForInitFlag == 0 && tokenStream.isCurrentTokenType(TOK_IN)) ||
tokenStream.isCurrentTokenType(TOK_INSTANCEOF))) {
TokenKind tt = tokenStream.currentToken().type;
JSOp op = tokenStream.currentToken().t_op;
pn = JSParseNode::newBinaryOrAppend(tt, op, pn, shiftExpr1n(), tc);
}
/* Restore previous state of inForInit flag. */
tc->flags |= inForInitFlag;
return pn;
}
END_EXPR_PARSER(relExpr1)
BEGIN_EXPR_PARSER(eqExpr1)
{
JSParseNode *pn = relExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_EQOP)) {
JSOp op = tokenStream.currentToken().t_op;
pn = JSParseNode::newBinaryOrAppend(TOK_EQOP, op, pn, relExpr1n(), tc);
}
return pn;
}
END_EXPR_PARSER(eqExpr1)
BEGIN_EXPR_PARSER(bitAndExpr1)
{
JSParseNode *pn = eqExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_BITAND))
pn = JSParseNode::newBinaryOrAppend(TOK_BITAND, JSOP_BITAND, pn, eqExpr1n(), tc);
return pn;
}
END_EXPR_PARSER(bitAndExpr1)
BEGIN_EXPR_PARSER(bitXorExpr1)
{
JSParseNode *pn = bitAndExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_BITXOR))
pn = JSParseNode::newBinaryOrAppend(TOK_BITXOR, JSOP_BITXOR, pn, bitAndExpr1n(), tc);
return pn;
}
END_EXPR_PARSER(bitXorExpr1)
BEGIN_EXPR_PARSER(bitOrExpr1)
{
JSParseNode *pn = bitXorExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_BITOR))
pn = JSParseNode::newBinaryOrAppend(TOK_BITOR, JSOP_BITOR, pn, bitXorExpr1n(), tc);
return pn;
}
END_EXPR_PARSER(bitOrExpr1)
BEGIN_EXPR_PARSER(andExpr1)
{
JSParseNode *pn = bitOrExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_AND))
pn = JSParseNode::newBinaryOrAppend(TOK_AND, JSOP_AND, pn, bitOrExpr1n(), tc);
return pn;
}
END_EXPR_PARSER(andExpr1)
JS_ALWAYS_INLINE JSParseNode *
Parser::orExpr1()
{
JSParseNode *pn = andExpr1i();
while (pn && tokenStream.isCurrentTokenType(TOK_OR))
pn = JSParseNode::newBinaryOrAppend(TOK_OR, JSOP_OR, pn, andExpr1n(), tc);
return pn;
}
JS_ALWAYS_INLINE JSParseNode *
Parser::condExpr1()
{
JSParseNode *pn = orExpr1();
if (pn && tokenStream.isCurrentTokenType(TOK_HOOK)) {
JSParseNode *pn1 = pn;
pn = TernaryNode::create(tc);
if (!pn)
return NULL;
/*
* 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.
*/
uintN oldflags = tc->flags;
tc->flags &= ~TCF_IN_FOR_INIT;
JSParseNode *pn2 = assignExpr();
tc->flags = oldflags | (tc->flags & TCF_FUN_FLAGS);
if (!pn2)
return NULL;
MUST_MATCH_TOKEN(TOK_COLON, JSMSG_COLON_IN_COND);
JSParseNode *pn3 = assignExpr();
if (!pn3)
return NULL;
pn->pn_pos.begin = pn1->pn_pos.begin;
pn->pn_pos.end = pn3->pn_pos.end;
pn->pn_kid1 = pn1;
pn->pn_kid2 = pn2;
pn->pn_kid3 = pn3;
tokenStream.getToken(); /* need to read one token past the end */
}
return pn;
}
bool
Parser::setAssignmentLhsOps(JSParseNode *pn, JSOp op)
{
switch (pn->getKind()) {
case TOK_NAME:
if (!CheckStrictAssignment(context, tc, pn))
return false;
pn->setOp(pn->isOp(JSOP_GETLOCAL) ? JSOP_SETLOCAL : JSOP_SETNAME);
NoteLValue(context, pn, tc);
break;
case TOK_DOT:
pn->setOp(JSOP_SETPROP);
break;
case TOK_LB:
pn->setOp(JSOP_SETELEM);
break;
#if JS_HAS_DESTRUCTURING
case TOK_RB:
case TOK_RC:
if (op != JSOP_NOP) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_DESTRUCT_ASS);
return false;
}
if (!CheckDestructuring(context, NULL, pn, tc))
return false;
break;
#endif
case TOK_LP:
if (!MakeSetCall(context, pn, tc, JSMSG_BAD_LEFTSIDE_OF_ASS))
return false;
break;
#if JS_HAS_XML_SUPPORT
case TOK_UNARYOP:
if (pn->isOp(JSOP_XMLNAME)) {
pn->setOp(JSOP_SETXMLNAME);
break;
}
/* FALL THROUGH */
#endif
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_LEFTSIDE_OF_ASS);
return false;
}
return true;
}
JSParseNode *
Parser::assignExpr()
{
JS_CHECK_RECURSION(context, return NULL);
#if JS_HAS_GENERATORS
if (tokenStream.matchToken(TOK_YIELD, TSF_OPERAND))
return returnOrYield(true);
#endif
JSParseNode *pn = condExpr1();
if (!pn)
return NULL;
if (!tokenStream.isCurrentTokenType(TOK_ASSIGN)) {
tokenStream.ungetToken();
return pn;
}
JSOp op = tokenStream.currentToken().t_op;
if (!setAssignmentLhsOps(pn, op))
return NULL;
JSParseNode *rhs = assignExpr();
if (!rhs)
return NULL;
if (pn->isKind(TOK_NAME) && pn->isUsed()) {
JSDefinition *dn = pn->pn_lexdef;
/*
* If the definition is not flagged as assigned, we must have imputed
* the initialized flag to it, to optimize for flat closures. But that
* optimization uses source coordinates to check dominance relations,
* so we must extend the end of the definition to cover the right-hand
* side of this assignment, i.e., the initializer.
*/
if (!dn->isAssigned()) {
JS_ASSERT(dn->isInitialized());
dn->pn_pos.end = rhs->pn_pos.end;
}
}
return JSParseNode::newBinaryOrAppend(TOK_ASSIGN, op, pn, rhs, tc);
}
static JSParseNode *
SetLvalKid(JSContext *cx, TokenStream *ts, JSTreeContext *tc,
JSParseNode *pn, JSParseNode *kid, const char *name)
{
if (!kid->isKind(TOK_NAME) &&
!kid->isKind(TOK_DOT) &&
(!kid->isKind(TOK_LP) ||
(!kid->isOp(JSOP_CALL) && !kid->isOp(JSOP_EVAL) &&
!kid->isOp(JSOP_FUNCALL) && !kid->isOp(JSOP_FUNAPPLY))) &&
#if JS_HAS_XML_SUPPORT
(!kid->isKind(TOK_UNARYOP) || !kid->isOp(JSOP_XMLNAME)) &&
#endif
!kid->isKind(TOK_LB)) {
ReportCompileErrorNumber(cx, ts, NULL, JSREPORT_ERROR, JSMSG_BAD_OPERAND, name);
return NULL;
}
if (!CheckStrictAssignment(cx, tc, kid))
return NULL;
pn->pn_kid = kid;
return kid;
}
static const char incop_name_str[][10] = {"increment", "decrement"};
static JSBool
SetIncOpKid(JSContext *cx, TokenStream *ts, JSTreeContext *tc,
JSParseNode *pn, JSParseNode *kid,
TokenKind tt, JSBool preorder)
{
JSOp op;
kid = SetLvalKid(cx, ts, tc, pn, kid, incop_name_str[tt == TOK_DEC]);
if (!kid)
return JS_FALSE;
switch (kid->getKind()) {
case TOK_NAME:
op = (tt == TOK_INC)
? (preorder ? JSOP_INCNAME : JSOP_NAMEINC)
: (preorder ? JSOP_DECNAME : JSOP_NAMEDEC);
NoteLValue(cx, kid, tc);
break;
case TOK_DOT:
op = (tt == TOK_INC)
? (preorder ? JSOP_INCPROP : JSOP_PROPINC)
: (preorder ? JSOP_DECPROP : JSOP_PROPDEC);
break;
case TOK_LP:
if (!MakeSetCall(cx, kid, tc, JSMSG_BAD_INCOP_OPERAND))
return JS_FALSE;
/* FALL THROUGH */
#if JS_HAS_XML_SUPPORT
case TOK_UNARYOP:
if (kid->isOp(JSOP_XMLNAME))
kid->setOp(JSOP_SETXMLNAME);
/* FALL THROUGH */
#endif
case TOK_LB:
op = (tt == TOK_INC)
? (preorder ? JSOP_INCELEM : JSOP_ELEMINC)
: (preorder ? JSOP_DECELEM : JSOP_ELEMDEC);
break;
default:
JS_ASSERT(0);
op = JSOP_NOP;
}
pn->setOp(op);
return JS_TRUE;
}
JSParseNode *
Parser::unaryExpr()
{
JSParseNode *pn, *pn2;
JS_CHECK_RECURSION(context, return NULL);
TokenKind tt = tokenStream.getToken(TSF_OPERAND);
switch (tt) {
case TOK_UNARYOP:
case TOK_PLUS:
case TOK_MINUS:
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_UNARYOP); /* PLUS and MINUS are binary */
pn->setOp(tokenStream.currentToken().t_op);
pn2 = unaryExpr();
if (!pn2)
return NULL;
pn->pn_pos.end = pn2->pn_pos.end;
pn->pn_kid = pn2;
break;
case TOK_INC:
case TOK_DEC:
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn2 = memberExpr(JS_TRUE);
if (!pn2)
return NULL;
if (!SetIncOpKid(context, &tokenStream, tc, pn, pn2, tt, JS_TRUE))
return NULL;
pn->pn_pos.end = pn2->pn_pos.end;
break;
case TOK_DELETE:
{
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn2 = unaryExpr();
if (!pn2)
return NULL;
pn->pn_pos.end = pn2->pn_pos.end;
/*
* Under ECMA3, deleting any unary expression is valid -- it simply
* returns true. Here we fold constants before checking for a call
* expression, in order to rule out delete of a generator expression.
*/
if (foldConstants && !js_FoldConstants(context, pn2, tc))
return NULL;
switch (pn2->getKind()) {
case TOK_LP:
if (!(pn2->pn_xflags & PNX_SETCALL)) {
/*
* Call MakeSetCall to check for errors, but clear PNX_SETCALL
* because the optimizer will eliminate the useless delete.
*/
if (!MakeSetCall(context, pn2, tc, JSMSG_BAD_DELETE_OPERAND))
return NULL;
pn2->pn_xflags &= ~PNX_SETCALL;
}
break;
case TOK_NAME:
if (!ReportStrictModeError(context, &tokenStream, tc, pn,
JSMSG_DEPRECATED_DELETE_OPERAND)) {
return NULL;
}
pn2->setOp(JSOP_DELNAME);
if (pn2->pn_atom == context->runtime->atomState.argumentsAtom) {
tc->flags |= TCF_FUN_HEAVYWEIGHT;
tc->countArgumentsUse(pn2);
}
break;
default:;
}
pn->pn_kid = pn2;
break;
}
case TOK_ERROR:
return NULL;
default:
tokenStream.ungetToken();
pn = memberExpr(JS_TRUE);
if (!pn)
return NULL;
/* Don't look across a newline boundary for a postfix incop. */
if (tokenStream.onCurrentLine(pn->pn_pos)) {
tt = tokenStream.peekTokenSameLine(TSF_OPERAND);
if (tt == TOK_INC || tt == TOK_DEC) {
(void) tokenStream.getToken();
pn2 = UnaryNode::create(tc);
if (!pn2)
return NULL;
if (!SetIncOpKid(context, &tokenStream, tc, pn2, pn, tt, JS_FALSE))
return NULL;
pn2->pn_pos.begin = pn->pn_pos.begin;
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 {
JSParseNode *root;
JSTreeContext *tc;
bool genexp;
uintN adjust;
uintN funcLevel;
public:
CompExprTransplanter(JSParseNode *pn, JSTreeContext *tc, bool ge, uintN adj)
: root(pn), tc(tc), genexp(ge), adjust(adj), funcLevel(0)
{
}
bool transplant(JSParseNode *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
*/
class GenexpGuard {
JSTreeContext *tc;
uint32 startYieldCount;
uint32 startArgumentsCount;
public:
explicit GenexpGuard(JSTreeContext *tc)
: tc(tc)
{
if (tc->parenDepth == 0) {
tc->yieldCount = tc->argumentsCount = 0;
tc->yieldNode = tc->argumentsNode = NULL;
}
startYieldCount = tc->yieldCount;
startArgumentsCount = tc->argumentsCount;
tc->parenDepth++;
}
void endBody();
bool checkValidBody(JSParseNode *pn);
bool maybeNoteGenerator(JSParseNode *pn);
};
void
GenexpGuard::endBody()
{
tc->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.
*/
bool
GenexpGuard::checkValidBody(JSParseNode *pn)
{
if (tc->yieldCount > startYieldCount) {
JSParseNode *errorNode = tc->yieldNode;
if (!errorNode)
errorNode = pn;
tc->parser->reportErrorNumber(errorNode, JSREPORT_ERROR, JSMSG_BAD_GENEXP_BODY, js_yield_str);
return false;
}
if (tc->argumentsCount > startArgumentsCount) {
JSParseNode *errorNode = tc->argumentsNode;
if (!errorNode)
errorNode = pn;
tc->parser->reportErrorNumber(errorNode, JSREPORT_ERROR, JSMSG_BAD_GENEXP_BODY, js_arguments_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.
*/
bool
GenexpGuard::maybeNoteGenerator(JSParseNode *pn)
{
if (tc->yieldCount > 0) {
tc->flags |= TCF_FUN_IS_GENERATOR;
if (!tc->inFunction()) {
tc->parser->reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_RETURN_OR_YIELD,
js_yield_str);
return false;
}
if (tc->flags & TCF_RETURN_EXPR) {
/* At the time we saw the yield, we might not have set TCF_FUN_IS_GENERATOR yet. */
ReportBadReturn(tc->parser->context, tc, pn, JSREPORT_ERROR,
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.
*/
static bool
BumpStaticLevel(JSParseNode *pn, JSTreeContext *tc)
{
if (!pn->pn_cookie.isFree()) {
uintN level = pn->pn_cookie.level() + 1;
JS_ASSERT(level >= tc->staticLevel);
if (level >= UpvarCookie::FREE_LEVEL) {
JS_ReportErrorNumber(tc->parser->context, js_GetErrorMessage, NULL,
JSMSG_TOO_DEEP, js_function_str);
return false;
}
pn->pn_cookie.set(level, pn->pn_cookie.slot());
}
return true;
}
static void
AdjustBlockId(JSParseNode *pn, uintN adjust, JSTreeContext *tc)
{
JS_ASSERT(pn->isArity(PN_LIST) || pn->isArity(PN_FUNC) || pn->isArity(PN_NAME));
pn->pn_blockid += adjust;
if (pn->pn_blockid >= tc->blockidGen)
tc->blockidGen = pn->pn_blockid + 1;
}
bool
CompExprTransplanter::transplant(JSParseNode *pn)
{
if (!pn)
return true;
switch (pn->getArity()) {
case PN_LIST:
for (JSParseNode *pn2 = pn->pn_head; pn2; pn2 = pn2->pn_next) {
if (!transplant(pn2))
return false;
}
if (pn->pn_pos >= root->pn_pos)
AdjustBlockId(pn, adjust, tc);
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_FUNC:
{
/*
* Only the first level of transplant recursion through functions needs
* to reparent the funbox, since all descendant functions are correctly
* linked under the top-most funbox. But every visit to this case needs
* to update funbox->level.
*
* Recall that funbox->level is the static level of the code containing
* the definition or expression of the function and not the static level
* of the function's body.
*/
JSFunctionBox *funbox = pn->pn_funbox;
funbox->level = tc->staticLevel + funcLevel;
if (++funcLevel == 1 && genexp) {
JSFunctionBox *parent = tc->funbox;
JSFunctionBox **funboxp = &tc->parent->functionList;
while (*funboxp != funbox)
funboxp = &(*funboxp)->siblings;
*funboxp = funbox->siblings;
funbox->parent = parent;
funbox->siblings = parent->kids;
parent->kids = funbox;
funbox->level = tc->staticLevel;
}
/* FALL THROUGH */
}
case PN_NAME:
if (!transplant(pn->maybeExpr()))
return false;
if (pn->isArity(PN_FUNC))
--funcLevel;
if (pn->isDefn()) {
if (genexp && !BumpStaticLevel(pn, tc))
return false;
} else if (pn->isUsed()) {
JS_ASSERT(!pn->isOp(JSOP_NOP));
JS_ASSERT(pn->pn_cookie.isFree());
JSDefinition *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, tc))
return false;
AdjustBlockId(dn, adjust, tc);
}
JSAtom *atom = pn->pn_atom;
#ifdef DEBUG
JSStmtInfo *stmt = js_LexicalLookup(tc, atom, NULL);
JS_ASSERT(!stmt || stmt != tc->topStmt);
#endif
if (genexp && !dn->isOp(JSOP_CALLEE)) {
JS_ASSERT(!tc->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.
*/
JSDefinition *dn2 = MakePlaceholder(pn, tc);
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.
*/
JSParseNode **pnup = &dn->dn_uses;
JSParseNode *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;
if (!tc->lexdeps->put(atom, dn2))
return false;
} 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.
*/
tc->parent->lexdeps->remove(atom);
if (!tc->lexdeps->put(atom, dn))
return false;
}
}
}
if (pn->pn_pos >= root->pn_pos)
AdjustBlockId(pn, adjust, tc);
break;
case PN_NAMESET:
if (!transplant(pn->pn_tree))
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 |type, op, kid|.
*/
JSParseNode *
Parser::comprehensionTail(JSParseNode *kid, uintN blockid, bool isGenexp,
TokenKind type, JSOp op)
{
uintN adjust;
JSParseNode *pn, *pn2, *pn3, **pnp;
JSStmtInfo stmtInfo;
BindData data;
TokenKind tt;
JSAtom *atom;
JS_ASSERT(tokenStream.currentToken().type == TOK_FOR);
if (type == TOK_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(context, &tokenStream, tc, &stmtInfo);
if (!pn)
return NULL;
adjust = pn->pn_blockid - blockid;
} else {
JS_ASSERT(type == TOK_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 js_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 = tc->blockid();
pn = PushLexicalScope(context, &tokenStream, tc, &stmtInfo);
if (!pn)
return NULL;
JS_ASSERT(blockid <= pn->pn_blockid);
JS_ASSERT(blockid < tc->blockidGen);
JS_ASSERT(tc->bodyid < blockid);
pn->pn_blockid = stmtInfo.blockid = blockid;
JS_ASSERT(adjust < blockid);
adjust = blockid - adjust;
}
pnp = &pn->pn_expr;
CompExprTransplanter transplanter(kid, tc, type == TOK_SEMI, adjust);
transplanter.transplant(kid);
data.pn = NULL;
data.op = JSOP_NOP;
data.binder = BindLet;
data.let.overflow = 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.
*/
pn2 = BinaryNode::create(tc);
if (!pn2)
return NULL;
pn2->setOp(JSOP_ITER);
pn2->pn_iflags = JSITER_ENUMERATE;
if (tokenStream.matchToken(TOK_NAME)) {
if (tokenStream.currentToken().t_atom == context->runtime->atomState.eachAtom)
pn2->pn_iflags |= JSITER_FOREACH;
else
tokenStream.ungetToken();
}
MUST_MATCH_TOKEN(TOK_LP, JSMSG_PAREN_AFTER_FOR);
GenexpGuard guard(tc);
atom = NULL;
tt = tokenStream.getToken();
switch (tt) {
#if JS_HAS_DESTRUCTURING
case TOK_LB:
case TOK_LC:
tc->flags |= TCF_DECL_DESTRUCTURING;
pn3 = primaryExpr(tt, JS_FALSE);
tc->flags &= ~TCF_DECL_DESTRUCTURING;
if (!pn3)
return NULL;
break;
#endif
case TOK_NAME:
atom = tokenStream.currentToken().t_atom;
/*
* 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(atom, tc, true);
if (!pn3)
return NULL;
break;
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_NO_VARIABLE_NAME);
case TOK_ERROR:
return NULL;
}
MUST_MATCH_TOKEN(TOK_IN, JSMSG_IN_AFTER_FOR_NAME);
JSParseNode *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(context, &data, pn3, tc))
return NULL;
if (versionNumber() == JSVERSION_1_7) {
/* Destructuring requires [key, value] enumeration in JS1.7. */
if (!pn3->isKind(TOK_RB) || pn3->pn_count != 2) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_FOR_LEFTSIDE);
return NULL;
}
JS_ASSERT(pn2->isOp(JSOP_ITER));
JS_ASSERT(pn2->pn_iflags & JSITER_ENUMERATE);
if (!(pn2->pn_iflags & JSITER_FOREACH))
pn2->pn_iflags |= JSITER_FOREACH | JSITER_KEYVALUE;
}
break;
#endif
case TOK_NAME:
data.pn = pn3;
if (!data.binder(context, &data, atom, tc))
return NULL;
break;
default:;
}
/*
* Synthesize a declaration. Every definition must appear in the parse
* tree in order for ComprehensionTranslator to work.
*/
JSParseNode *vars = ListNode::create(tc);
if (!vars)
return NULL;
vars->setOp(JSOP_NOP);
vars->setKind(TOK_VAR);
vars->pn_pos = pn3->pn_pos;
vars->makeEmpty();
vars->append(pn3);
vars->pn_xflags |= PNX_FORINVAR;
/* Definitions can't be passed directly to EmitAssignment as lhs. */
pn3 = CloneLeftHandSide(pn3, tc);
if (!pn3)
return NULL;
pn2->pn_left = TernaryNode::create(TOK_IN, JSOP_NOP, vars, pn3, pn4, tc);
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(tc);
if (!pn2)
return NULL;
pn2->pn_kid1 = condition();
if (!pn2->pn_kid1)
return NULL;
*pnp = pn2;
pnp = &pn2->pn_kid2;
}
pn2 = UnaryNode::create(tc);
if (!pn2)
return NULL;
pn2->setKind(type);
pn2->setOp(op);
pn2->pn_kid = kid;
*pnp = pn2;
PopStatement(tc);
return pn;
}
#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.
*/
JSParseNode *
Parser::generatorExpr(JSParseNode *kid)
{
/* Create a |yield| node for |kid|. */
JSParseNode *pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_YIELD);
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. */
JSParseNode *genfn = FunctionNode::create(tc);
if (!genfn)
return NULL;
genfn->setKind(TOK_FUNCTION);
genfn->setOp(JSOP_LAMBDA);
JS_ASSERT(!genfn->pn_body);
genfn->pn_dflags = PND_FUNARG;
{
JSTreeContext *outertc = tc;
JSTreeContext gentc(tc->parser);
if (!gentc.init(context))
return NULL;
JSFunctionBox *funbox = EnterFunction(genfn, &gentc);
if (!funbox)
return NULL;
/*
* We have to dance around a bit to propagate sharp variables from
* outertc to gentc before setting TCF_HAS_SHARPS implicitly by
* propagating all of outertc's TCF_FUN_FLAGS flags. As below, we have
* to be conservative by leaving TCF_HAS_SHARPS set in outertc if we
* do propagate to gentc.
*/
if (outertc->flags & TCF_HAS_SHARPS) {
gentc.flags |= TCF_IN_FUNCTION;
if (!gentc.ensureSharpSlots())
return NULL;
}
/*
* We assume conservatively that any deoptimization flag in tc->flags
* besides TCF_FUN_PARAM_ARGUMENTS can 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 tc->flags.
*/
gentc.flags |= TCF_FUN_IS_GENERATOR | TCF_GENEXP_LAMBDA |
(outertc->flags & (TCF_FUN_FLAGS & ~TCF_FUN_PARAM_ARGUMENTS));
funbox->tcflags |= gentc.flags;
genfn->pn_funbox = funbox;
genfn->pn_blockid = gentc.bodyid;
JSParseNode *body = comprehensionTail(pn, outertc->blockid(), true);
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 = tokenStream.currentToken().pos.end;
if (!LeaveFunction(genfn, &gentc))
return NULL;
}
/*
* Our result is a call expression that invokes the anonymous generator
* function object.
*/
JSParseNode *result = ListNode::create(tc);
if (!result)
return NULL;
result->setKind(TOK_LP);
result->setOp(JSOP_CALL);
result->pn_pos.begin = genfn->pn_pos.begin;
result->initList(genfn);
return result;
}
static const char js_generator_str[] = "generator";
#endif /* JS_HAS_GENERATOR_EXPRS */
#endif /* JS_HAS_GENERATORS */
JSBool
Parser::argumentList(JSParseNode *listNode)
{
if (tokenStream.matchToken(TOK_RP, TSF_OPERAND))
return JS_TRUE;
GenexpGuard guard(tc);
bool arg0 = true;
do {
JSParseNode *argNode = assignExpr();
if (!argNode)
return JS_FALSE;
if (arg0)
guard.endBody();
#if JS_HAS_GENERATORS
if (argNode->isKind(TOK_YIELD) &&
!argNode->isInParens() &&
tokenStream.peekToken() == TOK_COMMA) {
reportErrorNumber(argNode, JSREPORT_ERROR, JSMSG_BAD_GENERATOR_SYNTAX, js_yield_str);
return JS_FALSE;
}
#endif
#if JS_HAS_GENERATOR_EXPRS
if (tokenStream.matchToken(TOK_FOR)) {
if (!guard.checkValidBody(argNode))
return JS_FALSE;
argNode = generatorExpr(argNode);
if (!argNode)
return JS_FALSE;
if (listNode->pn_count > 1 ||
tokenStream.peekToken() == TOK_COMMA) {
reportErrorNumber(argNode, JSREPORT_ERROR, JSMSG_BAD_GENERATOR_SYNTAX,
js_generator_str);
return JS_FALSE;
}
} else
#endif
if (arg0 && !guard.maybeNoteGenerator(argNode))
return JS_FALSE;
arg0 = false;
listNode->append(argNode);
} while (tokenStream.matchToken(TOK_COMMA));
if (tokenStream.getToken() != TOK_RP) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_PAREN_AFTER_ARGS);
return JS_FALSE;
}
return JS_TRUE;
}
/* Check for an immediately-applied (new'ed) lambda and clear PND_FUNARG. */
static JSParseNode *
CheckForImmediatelyAppliedLambda(JSParseNode *pn)
{
if (pn->isKind(TOK_FUNCTION)) {
JS_ASSERT(pn->isArity(PN_FUNC));
JSFunctionBox *funbox = pn->pn_funbox;
JS_ASSERT((funbox->function())->flags & JSFUN_LAMBDA);
if (!(funbox->tcflags & (TCF_FUN_USES_ARGUMENTS | TCF_FUN_USES_OWN_NAME)))
pn->pn_dflags &= ~PND_FUNARG;
}
return pn;
}
JSParseNode *
Parser::memberExpr(JSBool allowCallSyntax)
{
JSParseNode *pn, *pn2, *pn3;
JS_CHECK_RECURSION(context, return NULL);
/* Check for new expression first. */
TokenKind tt = tokenStream.getToken(TSF_OPERAND);
if (tt == TOK_NEW) {
pn = ListNode::create(tc);
if (!pn)
return NULL;
pn2 = memberExpr(JS_FALSE);
if (!pn2)
return NULL;
pn2 = CheckForImmediatelyAppliedLambda(pn2);
pn->setOp(JSOP_NEW);
pn->initList(pn2);
pn->pn_pos.begin = pn2->pn_pos.begin;
if (tokenStream.matchToken(TOK_LP) && !argumentList(pn))
return NULL;
if (pn->pn_count > ARGC_LIMIT) {
JS_ReportErrorNumber(context, js_GetErrorMessage, NULL,
JSMSG_TOO_MANY_CON_ARGS);
return NULL;
}
pn->pn_pos.end = pn->last()->pn_pos.end;
} else {
pn = primaryExpr(tt, JS_FALSE);
if (!pn)
return NULL;
if (pn->isKind(TOK_ANYNAME) || pn->isKind(TOK_AT) || pn->isKind(TOK_DBLCOLON)) {
pn2 = NewOrRecycledNode(tc);
if (!pn2)
return NULL;
pn2->setKind(TOK_UNARYOP);
pn2->pn_pos = pn->pn_pos;
pn2->setOp(JSOP_XMLNAME);
pn2->setArity(PN_UNARY);
pn2->setInParens(false);
pn2->pn_kid = pn;
pn = pn2;
}
}
while ((tt = tokenStream.getToken()) > TOK_EOF) {
if (tt == TOK_DOT) {
pn2 = NameNode::create(NULL, tc);
if (!pn2)
return NULL;
#if JS_HAS_XML_SUPPORT
tt = tokenStream.getToken(TSF_OPERAND | TSF_KEYWORD_IS_NAME);
/* Treat filters as 'with' statements for name deoptimization. */
JSParseNode *oldWith = tc->innermostWith;
JSStmtInfo stmtInfo;
if (tt == TOK_LP) {
tc->innermostWith = pn;
js_PushStatement(tc, &stmtInfo, STMT_WITH, -1);
}
pn3 = primaryExpr(tt, JS_TRUE);
if (!pn3)
return NULL;
if (tt == TOK_LP) {
tc->innermostWith = oldWith;
PopStatement(tc);
}
/* Check both tt and pn_type, to distinguish |x.(y)| and |x.y::z| from |x.y|. */
if (tt == TOK_NAME && pn3->isKind(TOK_NAME)) {
pn2->setOp(JSOP_GETPROP);
pn2->pn_expr = pn;
pn2->pn_atom = pn3->pn_atom;
RecycleTree(pn3, tc);
} else {
if (tt == TOK_LP) {
pn2->setKind(TOK_FILTER);
pn2->setOp(JSOP_FILTER);
/* A filtering predicate is like a with statement. */
tc->flags |= TCF_FUN_HEAVYWEIGHT;
} else if (TokenKindIsXML(pn3->getKind())) {
pn2->setKind(TOK_LB);
pn2->setOp(JSOP_GETELEM);
} else {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_NAME_AFTER_DOT);
return NULL;
}
pn2->setArity(PN_BINARY);
pn2->pn_left = pn;
pn2->pn_right = pn3;
}
#else
MUST_MATCH_TOKEN_WITH_FLAGS(TOK_NAME, JSMSG_NAME_AFTER_DOT, TSF_KEYWORD_IS_NAME);
pn2->setOp(JSOP_GETPROP);
pn2->pn_expr = pn;
pn2->pn_atom = tokenStream.currentToken().t_atom;
#endif
pn2->pn_pos.begin = pn->pn_pos.begin;
pn2->pn_pos.end = tokenStream.currentToken().pos.end;
#if JS_HAS_XML_SUPPORT
} else if (tt == TOK_DBLDOT) {
pn2 = BinaryNode::create(tc);
if (!pn2)
return NULL;
tt = tokenStream.getToken(TSF_OPERAND | TSF_KEYWORD_IS_NAME);
pn3 = primaryExpr(tt, JS_TRUE);
if (!pn3)
return NULL;
tt = pn3->getKind();
if (tt == TOK_NAME && !pn3->isInParens()) {
pn3->setKind(TOK_STRING);
pn3->setArity(PN_NULLARY);
pn3->setOp(JSOP_QNAMEPART);
} else if (!TokenKindIsXML(tt)) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_NAME_AFTER_DOT);
return NULL;
}
pn2->setOp(JSOP_DESCENDANTS);
pn2->pn_left = pn;
pn2->pn_right = pn3;
pn2->pn_pos.begin = pn->pn_pos.begin;
pn2->pn_pos.end = tokenStream.currentToken().pos.end;
#endif
} else if (tt == TOK_LB) {
pn2 = BinaryNode::create(tc);
if (!pn2)
return NULL;
pn3 = expr();
if (!pn3)
return NULL;
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_IN_INDEX);
pn2->pn_pos.begin = pn->pn_pos.begin;
pn2->pn_pos.end = tokenStream.currentToken().pos.end;
/*
* Optimize o['p'] to o.p by rewriting pn2, but avoid rewriting
* o['0'] to use JSOP_GETPROP, to keep fast indexing disjoint in
* the interpreter from fast property access. However, if the
* bracketed string is a uint32, we rewrite pn3 to be a number
* instead of a string.
*/
do {
if (pn3->isKind(TOK_STRING)) {
jsuint index;
if (!js_IdIsIndex(ATOM_TO_JSID(pn3->pn_atom), &index)) {
pn2->setKind(TOK_DOT);
pn2->setOp(JSOP_GETPROP);
pn2->setArity(PN_NAME);
pn2->pn_expr = pn;
pn2->pn_atom = pn3->pn_atom;
break;
}
pn3->setKind(TOK_NUMBER);
pn3->setOp(JSOP_DOUBLE);
pn3->pn_dval = index;
}
pn2->setOp(JSOP_GETELEM);
pn2->pn_left = pn;
pn2->pn_right = pn3;
} while (0);
} else if (allowCallSyntax && tt == TOK_LP) {
pn2 = ListNode::create(tc);
if (!pn2)
return NULL;
pn2->setOp(JSOP_CALL);
pn = CheckForImmediatelyAppliedLambda(pn);
if (pn->isOp(JSOP_NAME)) {
if (pn->pn_atom == context->runtime->atomState.evalAtom) {
/* Select JSOP_EVAL and flag tc as heavyweight. */
pn2->setOp(JSOP_EVAL);
tc->noteCallsEval();
tc->flags |= TCF_FUN_HEAVYWEIGHT;
/*
* In non-strict mode code, direct calls to eval can add
* variables to the call object.
*/
if (!tc->inStrictMode())
tc->noteHasExtensibleScope();
}
} else if (pn->isOp(JSOP_GETPROP)) {
/* Select JSOP_FUNAPPLY given foo.apply(...). */
if (pn->pn_atom == context->runtime->atomState.applyAtom)
pn2->setOp(JSOP_FUNAPPLY);
else if (pn->pn_atom == context->runtime->atomState.callAtom)
pn2->setOp(JSOP_FUNCALL);
}
pn2->initList(pn);
pn2->pn_pos.begin = pn->pn_pos.begin;
if (!argumentList(pn2))
return NULL;
if (pn2->pn_count > ARGC_LIMIT) {
JS_ReportErrorNumber(context, js_GetErrorMessage, NULL,
JSMSG_TOO_MANY_FUN_ARGS);
return NULL;
}
pn2->pn_pos.end = tokenStream.currentToken().pos.end;
} else {
tokenStream.ungetToken();
return pn;
}
pn = pn2;
}
if (tt == TOK_ERROR)
return NULL;
return pn;
}
JSParseNode *
Parser::bracketedExpr()
{
uintN oldflags;
JSParseNode *pn;
/*
* 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.
*/
oldflags = tc->flags;
tc->flags &= ~TCF_IN_FOR_INIT;
pn = expr();
tc->flags = oldflags | (tc->flags & TCF_FUN_FLAGS);
return pn;
}
#if JS_HAS_XML_SUPPORT
JSParseNode *
Parser::endBracketedExpr()
{
JSParseNode *pn;
pn = bracketedExpr();
if (!pn)
return NULL;
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_AFTER_ATTR_EXPR);
return pn;
}
/*
* From the ECMA-357 grammar in 11.1.1 and 11.1.2:
*
* AttributeIdentifier:
* @ PropertySelector
* @ QualifiedIdentifier
* @ [ Expression ]
*
* PropertySelector:
* Identifier
* *
*
* QualifiedIdentifier:
* PropertySelector :: PropertySelector
* PropertySelector :: [ Expression ]
*
* We adapt AttributeIdentifier and QualifiedIdentier to be LL(1), like so:
*
* AttributeIdentifier:
* @ QualifiedIdentifier
* @ [ Expression ]
*
* PropertySelector:
* Identifier
* *
*
* QualifiedIdentifier:
* PropertySelector :: PropertySelector
* PropertySelector :: [ Expression ]
* PropertySelector
*
* As PrimaryExpression: Identifier is in ECMA-262 and we want the semantics
* for that rule to result in a name node, but ECMA-357 extends the grammar
* to include PrimaryExpression: QualifiedIdentifier, we must factor further:
*
* QualifiedIdentifier:
* PropertySelector QualifiedSuffix
*
* QualifiedSuffix:
* :: PropertySelector
* :: [ Expression ]
* /nothing/
*
* And use this production instead of PrimaryExpression: QualifiedIdentifier:
*
* PrimaryExpression:
* Identifier QualifiedSuffix
*
* We hoist the :: match into callers of QualifiedSuffix, in order to tweak
* PropertySelector vs. Identifier pn_arity, pn_op, and other members.
*/
JSParseNode *
Parser::propertySelector()
{
JSParseNode *pn;
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
if (pn->isKind(TOK_STAR)) {
pn->setKind(TOK_ANYNAME);
pn->setOp(JSOP_ANYNAME);
pn->pn_atom = context->runtime->atomState.starAtom;
} else {
JS_ASSERT(pn->isKind(TOK_NAME));
pn->setOp(JSOP_QNAMEPART);
pn->setArity(PN_NAME);
pn->pn_atom = tokenStream.currentToken().t_atom;
pn->pn_cookie.makeFree();
}
return pn;
}
JSParseNode *
Parser::qualifiedSuffix(JSParseNode *pn)
{
JSParseNode *pn2, *pn3;
TokenKind tt;
JS_ASSERT(tokenStream.currentToken().type == TOK_DBLCOLON);
pn2 = NameNode::create(NULL, tc);
if (!pn2)
return NULL;
/* Left operand of :: must be evaluated if it is an identifier. */
if (pn->isOp(JSOP_QNAMEPART))
pn->setOp(JSOP_NAME);
tt = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
if (tt == TOK_STAR || tt == TOK_NAME) {
/* Inline and specialize propertySelector for JSOP_QNAMECONST. */
pn2->setOp(JSOP_QNAMECONST);
pn2->pn_pos.begin = pn->pn_pos.begin;
pn2->pn_atom = (tt == TOK_STAR)
? context->runtime->atomState.starAtom
: tokenStream.currentToken().t_atom;
pn2->pn_expr = pn;
pn2->pn_cookie.makeFree();
return pn2;
}
if (tt != TOK_LB) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
return NULL;
}
pn3 = endBracketedExpr();
if (!pn3)
return NULL;
pn2->setOp(JSOP_QNAME);
pn2->setArity(PN_BINARY);
pn2->pn_pos.begin = pn->pn_pos.begin;
pn2->pn_pos.end = pn3->pn_pos.end;
pn2->pn_left = pn;
pn2->pn_right = pn3;
return pn2;
}
JSParseNode *
Parser::qualifiedIdentifier()
{
JSParseNode *pn;
pn = propertySelector();
if (!pn)
return NULL;
if (tokenStream.matchToken(TOK_DBLCOLON)) {
/* Hack for bug 496316. Slowing down E4X won't make it go away, alas. */
tc->flags |= TCF_FUN_HEAVYWEIGHT;
pn = qualifiedSuffix(pn);
}
return pn;
}
JSParseNode *
Parser::attributeIdentifier()
{
JSParseNode *pn, *pn2;
TokenKind tt;
JS_ASSERT(tokenStream.currentToken().type == TOK_AT);
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->setOp(JSOP_TOATTRNAME);
tt = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
if (tt == TOK_STAR || tt == TOK_NAME) {
pn2 = qualifiedIdentifier();
} else if (tt == TOK_LB) {
pn2 = endBracketedExpr();
} else {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
return NULL;
}
if (!pn2)
return NULL;
pn->pn_kid = pn2;
return pn;
}
/*
* Make a TOK_LC unary node whose pn_kid is an expression.
*/
JSParseNode *
Parser::xmlExpr(JSBool inTag)
{
JSParseNode *pn, *pn2;
JS_ASSERT(tokenStream.currentToken().type == TOK_LC);
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
/*
* Turn off XML tag mode. We save the old value of the flag because it may
* already be off: XMLExpr is called both from within a tag, and from
* within text contained in an element, but outside of any start, end, or
* point tag.
*/
bool oldflag = tokenStream.isXMLTagMode();
tokenStream.setXMLTagMode(false);
pn2 = expr();
if (!pn2)
return NULL;
MUST_MATCH_TOKEN(TOK_RC, JSMSG_CURLY_IN_XML_EXPR);
tokenStream.setXMLTagMode(oldflag);
pn->pn_kid = pn2;
pn->setOp(inTag ? JSOP_XMLTAGEXPR : JSOP_XMLELTEXPR);
return pn;
}
/*
* Make a terminal node for one of TOK_XMLNAME, TOK_XMLATTR, TOK_XMLSPACE,
* TOK_XMLTEXT, TOK_XMLCDATA, TOK_XMLCOMMENT, or TOK_XMLPI. When converting
* parse tree to XML, we preserve a TOK_XMLSPACE node only if it's the sole
* child of a container tag.
*/
JSParseNode *
Parser::xmlAtomNode()
{
JSParseNode *pn = NullaryNode::create(tc);
if (!pn)
return NULL;
const Token &tok = tokenStream.currentToken();
pn->setOp(tok.t_op);
pn->pn_atom = tok.t_atom;
if (tok.type == TOK_XMLPI)
pn->pn_atom2 = tok.t_atom2;
return pn;
}
/*
* Parse the productions:
*
* XMLNameExpr:
* XMLName XMLNameExpr?
* { Expr } XMLNameExpr?
*
* Return a PN_LIST, PN_UNARY, or PN_NULLARY according as XMLNameExpr produces
* a list of names and/or expressions, a single expression, or a single name.
* If PN_LIST or PN_NULLARY, pn_type will be TOK_XMLNAME; if PN_UNARY, pn_type
* will be TOK_LC.
*/
JSParseNode *
Parser::xmlNameExpr()
{
JSParseNode *pn, *pn2, *list;
TokenKind tt;
pn = list = NULL;
do {
tt = tokenStream.currentToken().type;
if (tt == TOK_LC) {
pn2 = xmlExpr(JS_TRUE);
if (!pn2)
return NULL;
} else {
JS_ASSERT(tt == TOK_XMLNAME);
pn2 = xmlAtomNode();
if (!pn2)
return NULL;
}
if (!pn) {
pn = pn2;
} else {
if (!list) {
list = ListNode::create(tc);
if (!list)
return NULL;
list->setKind(TOK_XMLNAME);
list->pn_pos.begin = pn->pn_pos.begin;
list->initList(pn);
list->pn_xflags = PNX_CANTFOLD;
pn = list;
}
pn->pn_pos.end = pn2->pn_pos.end;
pn->append(pn2);
}
} while ((tt = tokenStream.getToken()) == TOK_XMLNAME || tt == TOK_LC);
tokenStream.ungetToken();
return pn;
}
/*
* Macro to test whether an XMLNameExpr or XMLTagContent node can be folded
* at compile time into a JSXML tree.
*/
#define XML_FOLDABLE(pn) ((pn)->isArity(PN_LIST) \
? ((pn)->pn_xflags & PNX_CANTFOLD) == 0 \
: !(pn)->isKind(TOK_LC))
/*
* Parse the productions:
*
* XMLTagContent:
* XMLNameExpr
* XMLTagContent S XMLNameExpr S? = S? XMLAttr
* XMLTagContent S XMLNameExpr S? = S? { Expr }
*
* Return a PN_LIST, PN_UNARY, or PN_NULLARY according to how XMLTagContent
* produces a list of name and attribute values and/or braced expressions, a
* single expression, or a single name.
*
* If PN_LIST or PN_NULLARY, pn_type will be TOK_XMLNAME for the case where
* XMLTagContent: XMLNameExpr. If pn_type is not TOK_XMLNAME but pn_arity is
* PN_LIST, pn_type will be tagtype. If PN_UNARY, pn_type will be TOK_LC and
* we parsed exactly one expression.
*/
JSParseNode *
Parser::xmlTagContent(TokenKind tagtype, JSAtom **namep)
{
JSParseNode *pn, *pn2, *list;
TokenKind tt;
pn = xmlNameExpr();
if (!pn)
return NULL;
*namep = (pn->isArity(PN_NULLARY)) ? pn->pn_atom : NULL;
list = NULL;
while (tokenStream.matchToken(TOK_XMLSPACE)) {
tt = tokenStream.getToken();
if (tt != TOK_XMLNAME && tt != TOK_LC) {
tokenStream.ungetToken();
break;
}
pn2 = xmlNameExpr();
if (!pn2)
return NULL;
if (!list) {
list = ListNode::create(tc);
if (!list)
return NULL;
list->setKind(tagtype);
list->pn_pos.begin = pn->pn_pos.begin;
list->initList(pn);
pn = list;
}
pn->append(pn2);
if (!XML_FOLDABLE(pn2))
pn->pn_xflags |= PNX_CANTFOLD;
tokenStream.matchToken(TOK_XMLSPACE);
MUST_MATCH_TOKEN(TOK_ASSIGN, JSMSG_NO_ASSIGN_IN_XML_ATTR);
tokenStream.matchToken(TOK_XMLSPACE);
tt = tokenStream.getToken();
if (tt == TOK_XMLATTR) {
pn2 = xmlAtomNode();
} else if (tt == TOK_LC) {
pn2 = xmlExpr(JS_TRUE);
pn->pn_xflags |= PNX_CANTFOLD;
} else {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_XML_ATTR_VALUE);
return NULL;
}
if (!pn2)
return NULL;
pn->pn_pos.end = pn2->pn_pos.end;
pn->append(pn2);
}
return pn;
}
#define XML_CHECK_FOR_ERROR_AND_EOF(tt,result) \
JS_BEGIN_MACRO \
if ((tt) <= TOK_EOF) { \
if ((tt) == TOK_EOF) { \
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_END_OF_XML_SOURCE); \
} \
return result; \
} \
JS_END_MACRO
/*
* Consume XML element tag content, including the TOK_XMLETAGO (</) sequence
* that opens the end tag for the container.
*/
JSBool
Parser::xmlElementContent(JSParseNode *pn)
{
tokenStream.setXMLTagMode(false);
for (;;) {
TokenKind tt = tokenStream.getToken(TSF_XMLTEXTMODE);
XML_CHECK_FOR_ERROR_AND_EOF(tt, JS_FALSE);
JS_ASSERT(tt == TOK_XMLSPACE || tt == TOK_XMLTEXT);
JSAtom *textAtom = tokenStream.currentToken().t_atom;
if (textAtom) {
/* Non-zero-length XML text scanned. */
JSParseNode *pn2 = xmlAtomNode();
if (!pn2)
return JS_FALSE;
pn->pn_pos.end = pn2->pn_pos.end;
pn->append(pn2);
}
tt = tokenStream.getToken(TSF_OPERAND);
XML_CHECK_FOR_ERROR_AND_EOF(tt, JS_FALSE);
if (tt == TOK_XMLETAGO)
break;
JSParseNode *pn2;
if (tt == TOK_LC) {
pn2 = xmlExpr(JS_FALSE);
pn->pn_xflags |= PNX_CANTFOLD;
} else if (tt == TOK_XMLSTAGO) {
pn2 = xmlElementOrList(JS_FALSE);
if (pn2) {
pn2->pn_xflags &= ~PNX_XMLROOT;
pn->pn_xflags |= pn2->pn_xflags;
}
} else {
JS_ASSERT(tt == TOK_XMLCDATA || tt == TOK_XMLCOMMENT ||
tt == TOK_XMLPI);
pn2 = xmlAtomNode();
}
if (!pn2)
return JS_FALSE;
pn->pn_pos.end = pn2->pn_pos.end;
pn->append(pn2);
}
tokenStream.setXMLTagMode(true);
JS_ASSERT(tokenStream.currentToken().type == TOK_XMLETAGO);
return JS_TRUE;
}
/*
* Return a PN_LIST node containing an XML or XMLList Initialiser.
*/
JSParseNode *
Parser::xmlElementOrList(JSBool allowList)
{
JSParseNode *pn, *pn2, *list;
TokenKind tt;
JSAtom *startAtom, *endAtom;
JS_CHECK_RECURSION(context, return NULL);
JS_ASSERT(tokenStream.currentToken().type == TOK_XMLSTAGO);
pn = ListNode::create(tc);
if (!pn)
return NULL;
tokenStream.setXMLTagMode(true);
tt = tokenStream.getToken();
if (tt == TOK_ERROR)
return NULL;
if (tt == TOK_XMLNAME || tt == TOK_LC) {
/*
* XMLElement. Append the tag and its contents, if any, to pn.
*/
pn2 = xmlTagContent(TOK_XMLSTAGO, &startAtom);
if (!pn2)
return NULL;
tokenStream.matchToken(TOK_XMLSPACE);
tt = tokenStream.getToken();
if (tt == TOK_XMLPTAGC) {
/* Point tag (/>): recycle pn if pn2 is a list of tag contents. */
if (pn2->isKind(TOK_XMLSTAGO)) {
pn->makeEmpty();
RecycleTree(pn, tc);
pn = pn2;
} else {
JS_ASSERT(pn2->isKind(TOK_XMLNAME) ||
pn2->isKind(TOK_LC));
pn->initList(pn2);
if (!XML_FOLDABLE(pn2))
pn->pn_xflags |= PNX_CANTFOLD;
}
pn->setKind(TOK_XMLPTAGC);
pn->pn_xflags |= PNX_XMLROOT;
} else {
/* We had better have a tag-close (>) at this point. */
if (tt != TOK_XMLTAGC) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_XML_TAG_SYNTAX);
return NULL;
}
pn2->pn_pos.end = tokenStream.currentToken().pos.end;
/* Make sure pn2 is a TOK_XMLSTAGO list containing tag contents. */
if (!pn2->isKind(TOK_XMLSTAGO)) {
pn->initList(pn2);
if (!XML_FOLDABLE(pn2))
pn->pn_xflags |= PNX_CANTFOLD;
pn2 = pn;
pn = ListNode::create(tc);
if (!pn)
return NULL;
}
/* Now make pn a nominal-root TOK_XMLELEM list containing pn2. */
pn->setKind(TOK_XMLELEM);
pn->pn_pos.begin = pn2->pn_pos.begin;
pn->initList(pn2);
if (!XML_FOLDABLE(pn2))
pn->pn_xflags |= PNX_CANTFOLD;
pn->pn_xflags |= PNX_XMLROOT;
/* Get element contents and delimiting end-tag-open sequence. */
if (!xmlElementContent(pn))
return NULL;
tt = tokenStream.getToken();
XML_CHECK_FOR_ERROR_AND_EOF(tt, NULL);
if (tt != TOK_XMLNAME && tt != TOK_LC) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_XML_TAG_SYNTAX);
return NULL;
}
/* Parse end tag; check mismatch at compile-time if we can. */
pn2 = xmlTagContent(TOK_XMLETAGO, &endAtom);
if (!pn2)
return NULL;
if (pn2->isKind(TOK_XMLETAGO)) {
/* Oops, end tag has attributes! */
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_XML_TAG_SYNTAX);
return NULL;
}
if (endAtom && startAtom && endAtom != startAtom) {
/* End vs. start tag name mismatch: point to the tag name. */
reportErrorNumber(pn2, JSREPORT_UC | JSREPORT_ERROR, JSMSG_XML_TAG_NAME_MISMATCH,
startAtom->chars());
return NULL;
}
/* Make a TOK_XMLETAGO list with pn2 as its single child. */
JS_ASSERT(pn2->isKind(TOK_XMLNAME) || pn2->isKind(TOK_LC));
list = ListNode::create(tc);
if (!list)
return NULL;
list->setKind(TOK_XMLETAGO);
list->initList(pn2);
pn->append(list);
if (!XML_FOLDABLE(pn2)) {
list->pn_xflags |= PNX_CANTFOLD;
pn->pn_xflags |= PNX_CANTFOLD;
}
tokenStream.matchToken(TOK_XMLSPACE);
MUST_MATCH_TOKEN(TOK_XMLTAGC, JSMSG_BAD_XML_TAG_SYNTAX);
}
/* Set pn_op now that pn has been updated to its final value. */
pn->setOp(JSOP_TOXML);
} else if (allowList && tt == TOK_XMLTAGC) {
/* XMLList Initialiser. */
pn->setKind(TOK_XMLLIST);
pn->setOp(JSOP_TOXMLLIST);
pn->makeEmpty();
pn->pn_xflags |= PNX_XMLROOT;
if (!xmlElementContent(pn))
return NULL;
MUST_MATCH_TOKEN(TOK_XMLTAGC, JSMSG_BAD_XML_LIST_SYNTAX);
} else {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_XML_NAME_SYNTAX);
return NULL;
}
tokenStream.setXMLTagMode(false);
pn->pn_pos.end = tokenStream.currentToken().pos.end;
return pn;
}
JSParseNode *
Parser::xmlElementOrListRoot(JSBool allowList)
{
/*
* Force XML support to be enabled so that comments and CDATA literals
* are recognized, instead of <! followed by -- starting an HTML comment
* to end of line (used in script tags to hide content from old browsers
* that don't recognize <script>).
*/
bool hadXML = tokenStream.hasXML();
tokenStream.setXML(true);
JSParseNode *pn = xmlElementOrList(allowList);
tokenStream.setXML(hadXML);
return pn;
}
JSParseNode *
Parser::parseXMLText(JSObject *chain, bool allowList)
{
/*
* Push a compiler frame if we have no frames, or if the top frame is a
* lightweight function activation, or if its scope chain doesn't match
* the one passed to us.
*/
JSTreeContext xmltc(this);
if (!xmltc.init(context))
return NULL;
xmltc.setScopeChain(chain);
/* Set XML-only mode to turn off special treatment of {expr} in XML. */
tokenStream.setXMLOnlyMode();
TokenKind tt = tokenStream.getToken(TSF_OPERAND);
JSParseNode *pn;
if (tt != TOK_XMLSTAGO) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_XML_MARKUP);
pn = NULL;
} else {
pn = xmlElementOrListRoot(allowList);
}
tokenStream.setXMLOnlyMode(false);
return pn;
}
#endif /* JS_HAS_XMLSUPPORT */
#if JS_HAS_BLOCK_SCOPE
/*
* Check whether blockid is an active scoping statement in tc. This code is
* necessary to qualify tc->decls.lookup() hits in primaryExpr's TOK_NAME case
* (below) where the hits come from Scheme-ish let bindings in for loop heads
* and let blocks and expressions (not let declarations).
*
* Unlike let declarations ("let as the new var"), which is a kind of letrec
* due to hoisting, let in a for loop head, let block, or let expression acts
* like Scheme's let: initializers are evaluated without the new let bindings
* being in scope.
*
* Name binding analysis is eager with fixups, rather than multi-pass, and let
* bindings push on the front of the tc->decls AtomDecls (either the singular
* list or on a hash chain -- see JSAtomMultiList::add*) in order to shadow
* outer scope bindings of the same name.
*
* This simplifies binding lookup code at the price of a linear search here,
* but only if code uses let (var predominates), and even then this function's
* loop iterates more than once only in crazy cases.
*/
static inline bool
BlockIdInScope(uintN blockid, JSTreeContext *tc)
{
if (blockid > tc->blockid())
return false;
for (JSStmtInfo *stmt = tc->topScopeStmt; stmt; stmt = stmt->downScope) {
if (stmt->blockid == blockid)
return true;
}
return false;
}
#endif
bool
JSParseNode::isConstant()
{
switch (pn_type) {
case TOK_NUMBER:
case TOK_STRING:
return true;
case TOK_PRIMARY:
switch (pn_op) {
case JSOP_NULL:
case JSOP_FALSE:
case JSOP_TRUE:
return true;
default:
return false;
}
case TOK_RB:
case TOK_RC:
return isOp(JSOP_NEWINIT) && !(pn_xflags & PNX_NONCONST);
default:
return false;
}
}
JSParseNode *
Parser::primaryExpr(TokenKind tt, JSBool afterDot)
{
JSParseNode *pn, *pn2, *pn3;
JSOp op;
JS_CHECK_RECURSION(context, return NULL);
switch (tt) {
case TOK_FUNCTION:
#if JS_HAS_XML_SUPPORT
if (tokenStream.matchToken(TOK_DBLCOLON, TSF_KEYWORD_IS_NAME)) {
pn2 = NullaryNode::create(tc);
if (!pn2)
return NULL;
pn2->setKind(TOK_FUNCTION);
pn = qualifiedSuffix(pn2);
if (!pn)
return NULL;
break;
}
#endif
pn = functionExpr();
if (!pn)
return NULL;
break;
case TOK_LB:
{
JSBool matched;
jsuint index;
pn = ListNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_RB);
pn->setOp(JSOP_NEWINIT);
pn->makeEmpty();
#if JS_HAS_GENERATORS
pn->pn_blockid = tc->blockidGen;
#endif
matched = tokenStream.matchToken(TOK_RB, TSF_OPERAND);
if (!matched) {
for (index = 0; ; index++) {
if (index == StackSpace::ARGS_LENGTH_MAX) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_ARRAY_INIT_TOO_BIG);
return NULL;
}
tt = tokenStream.peekToken(TSF_OPERAND);
if (tt == TOK_RB) {
pn->pn_xflags |= PNX_ENDCOMMA;
break;
}
if (tt == TOK_COMMA) {
/* So CURRENT_TOKEN gets TOK_COMMA and not TOK_LB. */
tokenStream.matchToken(TOK_COMMA);
pn2 = NullaryNode::create(tc);
pn->pn_xflags |= PNX_HOLEY | PNX_NONCONST;
} else {
pn2 = assignExpr();
if (pn2 && !pn2->isConstant())
pn->pn_xflags |= PNX_NONCONST;
}
if (!pn2)
return NULL;
pn->append(pn2);
if (tt != TOK_COMMA) {
/* If we didn't already match TOK_COMMA in above case. */
if (!tokenStream.matchToken(TOK_COMMA))
break;
}
}
#if JS_HAS_GENERATORS
/*
* At this point, (index == 0 && pn->pn_count != 0) 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_ARRAYCOMP <array>,
* where <array> is the index of array's stack slot.
*/
if (index == 0 && pn->pn_count != 0 && tokenStream.matchToken(TOK_FOR)) {
JSParseNode *pnexp, *pntop;
/* Relabel pn as an array comprehension node. */
pn->setKind(TOK_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.
*/
pnexp = pn->last();
JS_ASSERT(pn->pn_count == 1);
pn->pn_count = 0;
pn->pn_tail = &pn->pn_head;
*pn->pn_tail = NULL;
pntop = comprehensionTail(pnexp, pn->pn_blockid, false,
TOK_ARRAYPUSH, JSOP_ARRAYPUSH);
if (!pntop)
return NULL;
pn->append(pntop);
}
#endif /* JS_HAS_GENERATORS */
MUST_MATCH_TOKEN(TOK_RB, JSMSG_BRACKET_AFTER_LIST);
}
pn->pn_pos.end = tokenStream.currentToken().pos.end;
return pn;
}
case TOK_LC:
{
JSParseNode *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(context);
enum AssignmentType {
GET = 0x1,
SET = 0x2,
VALUE = 0x4 | GET | SET
};
pn = ListNode::create(tc);
if (!pn)
return NULL;
pn->setKind(TOK_RC);
pn->setOp(JSOP_NEWINIT);
pn->makeEmpty();
for (;;) {
JSAtom *atom;
tt = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
switch (tt) {
case TOK_NUMBER:
pn3 = NullaryNode::create(tc);
if (!pn3)
return NULL;
pn3->pn_dval = tokenStream.currentToken().t_dval;
if (!js_ValueToAtom(context, DoubleValue(pn3->pn_dval), &atom))
return NULL;
break;
case TOK_NAME:
{
atom = tokenStream.currentToken().t_atom;
if (atom == context->runtime->atomState.getAtom)
op = JSOP_GETTER;
else if (atom == context->runtime->atomState.setAtom)
op = JSOP_SETTER;
else
goto property_name;
tt = tokenStream.getToken(TSF_KEYWORD_IS_NAME);
if (tt == TOK_NAME || tt == TOK_STRING) {
atom = tokenStream.currentToken().t_atom;
pn3 = NameNode::create(atom, tc);
if (!pn3)
return NULL;
} else if (tt == TOK_NUMBER) {
pn3 = NullaryNode::create(tc);
if (!pn3)
return NULL;
pn3->pn_dval = tokenStream.currentToken().t_dval;
if (!js_ValueToAtom(context, DoubleValue(pn3->pn_dval), &atom))
return NULL;
} else {
tokenStream.ungetToken();
goto property_name;
}
pn->pn_xflags |= PNX_NONCONST;
/* NB: Getter function in { get x(){} } is unnamed. */
pn2 = functionDef(NULL, op == JSOP_GETTER ? Getter : Setter, Expression);
pn2 = JSParseNode::newBinaryOrAppend(TOK_COLON, op, pn3, pn2, tc);
goto skip;
}
property_name:
case TOK_STRING:
atom = tokenStream.currentToken().t_atom;
pn3 = NullaryNode::create(tc);
if (!pn3)
return NULL;
pn3->pn_atom = atom;
break;
case TOK_RC:
goto end_obj_init;
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_PROP_ID);
return NULL;
}
op = JSOP_INITPROP;
tt = tokenStream.getToken();
if (tt == TOK_COLON) {
pnval = assignExpr();
/*
* Treat initializers which mutate __proto__ as non-constant,
* so that we can later assume singleton objects delegate to
* the default Object.prototype.
*/
if ((pnval && !pnval->isConstant()) ||
atom == context->runtime->atomState.protoAtom) {
pn->pn_xflags |= PNX_NONCONST;
}
} else {
#if JS_HAS_DESTRUCTURING_SHORTHAND
if (tt != TOK_COMMA && tt != TOK_RC) {
#endif
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_COLON_AFTER_ID);
return NULL;
#if JS_HAS_DESTRUCTURING_SHORTHAND
}
/*
* Support, e.g., |var {x, y} = o| as destructuring shorthand
* for |var {x: x, y: y} = o|, per proposed JS2/ES4 for JS1.8.
*/
tokenStream.ungetToken();
pn->pn_xflags |= PNX_DESTRUCT | PNX_NONCONST;
pnval = pn3;
if (pnval->isKind(TOK_NAME)) {
pnval->setArity(PN_NAME);
((NameNode *)pnval)->initCommon(tc);
}
#endif
}
pn2 = JSParseNode::newBinaryOrAppend(TOK_COLON, op, pn3, pnval, tc);
skip:
if (!pn2)
return NULL;
pn->append(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_GETTER) {
assignType = GET;
} else if (op == JSOP_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 || tc->needStrictChecks()))
{
JSAutoByteString name;
if (!js_AtomToPrintableString(context, atom, &name))
return NULL;
uintN flags = (oldAssignType == VALUE &&
assignType == VALUE &&
!tc->inStrictMode())
? JSREPORT_WARNING
: JSREPORT_ERROR;
if (!ReportCompileErrorNumber(context, &tokenStream, NULL, flags,
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) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_CURLY_AFTER_LIST);
return NULL;
}
}
end_obj_init:
pn->pn_pos.end = tokenStream.currentToken().pos.end;
return pn;
}
#if JS_HAS_BLOCK_SCOPE
case TOK_LET:
pn = letBlock(JS_FALSE);
if (!pn)
return NULL;
break;
#endif
#if JS_HAS_SHARP_VARS
case TOK_DEFSHARP:
pn = UnaryNode::create(tc);
if (!pn)
return NULL;
pn->pn_num = (jsint) tokenStream.currentToken().t_dval;
tt = tokenStream.getToken(TSF_OPERAND);
pn->pn_kid = primaryExpr(tt, JS_FALSE);
if (!pn->pn_kid)
return NULL;
if (pn->pn_kid->isKind(TOK_USESHARP) ||
pn->pn_kid->isKind(TOK_DEFSHARP) ||
pn->pn_kid->isKind(TOK_STRING) ||
pn->pn_kid->isKind(TOK_NUMBER) ||
pn->pn_kid->isKind(TOK_PRIMARY)) {
reportErrorNumber(pn->pn_kid, JSREPORT_ERROR, JSMSG_BAD_SHARP_VAR_DEF);
return NULL;
}
if (!tc->ensureSharpSlots())
return NULL;
break;
case TOK_USESHARP:
/* Check for forward/dangling references at runtime, to allow eval. */
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
if (!tc->ensureSharpSlots())
return NULL;
pn->pn_num = (jsint) tokenStream.currentToken().t_dval;
break;
#endif /* JS_HAS_SHARP_VARS */
case TOK_LP:
{
JSBool genexp;
pn = parenExpr(&genexp);
if (!pn)
return NULL;
pn->setInParens(true);
if (!genexp)
MUST_MATCH_TOKEN(TOK_RP, JSMSG_PAREN_IN_PAREN);
break;
}
#if JS_HAS_XML_SUPPORT
case TOK_STAR:
pn = qualifiedIdentifier();
if (!pn)
return NULL;
break;
case TOK_AT:
pn = attributeIdentifier();
if (!pn)
return NULL;
break;
case TOK_XMLSTAGO:
pn = xmlElementOrListRoot(JS_TRUE);
if (!pn)
return NULL;
break;
#endif /* JS_HAS_XML_SUPPORT */
case TOK_STRING:
#if JS_HAS_SHARP_VARS
/* FALL THROUGH */
#endif
#if JS_HAS_XML_SUPPORT
case TOK_XMLCDATA:
case TOK_XMLCOMMENT:
case TOK_XMLPI:
#endif
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
pn->pn_atom = tokenStream.currentToken().t_atom;
#if JS_HAS_XML_SUPPORT
if (tt == TOK_XMLPI)
pn->pn_atom2 = tokenStream.currentToken().t_atom2;
else
#endif
pn->setOp(tokenStream.currentToken().t_op);
break;
case TOK_NAME:
pn = NameNode::create(tokenStream.currentToken().t_atom, tc);
if (!pn)
return NULL;
JS_ASSERT(tokenStream.currentToken().t_op == JSOP_NAME);
pn->setOp(JSOP_NAME);
if ((tc->flags & (TCF_IN_FUNCTION | TCF_FUN_PARAM_ARGUMENTS)) == TCF_IN_FUNCTION &&
pn->pn_atom == context->runtime->atomState.argumentsAtom) {
/*
* Flag arguments usage so we can avoid unsafe optimizations such
* as formal parameter assignment analysis (because of the hated
* feature whereby arguments alias formals). We do this even for
* a reference of the form foo.arguments, which ancient code may
* still use instead of arguments (more hate).
*/
tc->noteArgumentsUse(pn);
/*
* Bind early to JSOP_ARGUMENTS to relieve later code from having
* to do this work (new rule for the emitter to count on).
*/
if (!afterDot && !(tc->flags & TCF_DECL_DESTRUCTURING)
&& !tc->inStatement(STMT_WITH)) {
pn->setOp(JSOP_ARGUMENTS);
pn->pn_dflags |= PND_BOUND;
}
} else if ((!afterDot
#if JS_HAS_XML_SUPPORT
|| tokenStream.peekToken() == TOK_DBLCOLON
#endif
) && !(tc->flags & TCF_DECL_DESTRUCTURING)) {
/* In case this is a generator expression outside of any function. */
if (!tc->inFunction() &&
pn->pn_atom == context->runtime->atomState.argumentsAtom) {
tc->countArgumentsUse(pn);
}
JSStmtInfo *stmt = js_LexicalLookup(tc, pn->pn_atom, NULL);
MultiDeclRange mdl = tc->decls.lookupMulti(pn->pn_atom);
JSDefinition *dn;
if (!mdl.empty()) {
dn = mdl.front();
#if JS_HAS_BLOCK_SCOPE
/*
* Skip out-of-scope let bindings along an ALE list or hash
* chain. These can happen due to |let (x = x) x| block and
* expression bindings, where the x on the right of = comes
* from an outer scope. See bug 496532.
*/
while (dn->isLet() && !BlockIdInScope(dn->pn_blockid, tc)) {
mdl.popFront();
if (mdl.empty())
break;
dn = mdl.front();
}
#endif
}
if (!mdl.empty()) {
dn = mdl.front();
} else {
AtomDefnAddPtr p = tc->lexdeps->lookupForAdd(pn->pn_atom);
if (p) {
dn = p.value();
} 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 = MakePlaceholder(pn, tc);
if (!dn || !tc->lexdeps->add(p, dn->pn_atom, dn))
return NULL;
/*
* In case this is a forward reference to a function,
* we pessimistically set PND_FUNARG if the next token
* is not a left parenthesis.
*
* If the definition eventually parsed into dn is not a
* function, this flag won't hurt, and if we do parse a
* function with pn's name, then the PND_FUNARG flag is
* necessary for safe context->display-based optimiza-
* tion of the closure's static link.
*/
if (tokenStream.peekToken() != TOK_LP)
dn->pn_dflags |= PND_FUNARG;
}
}
JS_ASSERT(dn->isDefn());
LinkUseToDef(pn, dn, tc);
/* Here we handle the backward function reference case. */
if (tokenStream.peekToken() != TOK_LP)
dn->pn_dflags |= PND_FUNARG;
pn->pn_dflags |= (dn->pn_dflags & PND_FUNARG);
if (stmt && stmt->type == STMT_WITH)
pn->pn_dflags |= PND_DEOPTIMIZED;
}
#if JS_HAS_XML_SUPPORT
if (tokenStream.matchToken(TOK_DBLCOLON)) {
if (afterDot) {
/*
* Here primaryExpr is called after . or .. followed by a name
* followed by ::. This is the only case where a keyword after
* . or .. is not treated as a property name.
*/
const KeywordInfo *ki = FindKeyword(pn->pn_atom->charsZ(), pn->pn_atom->length());
if (ki) {
if (ki->tokentype != TOK_FUNCTION) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_KEYWORD_NOT_NS);
return NULL;
}
pn->setArity(PN_NULLARY);
pn->setKind(TOK_FUNCTION);
}
}
pn = qualifiedSuffix(pn);
if (!pn)
return NULL;
}
#endif
break;
case TOK_REGEXP:
{
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
JSObject *obj;
if (context->hasfp()) {
obj = RegExp::createObject(context, context->regExpStatics(),
tokenStream.getTokenbuf().begin(),
tokenStream.getTokenbuf().length(),
tokenStream.currentToken().t_reflags,
&tokenStream);
} else {
obj = RegExp::createObjectNoStatics(context,
tokenStream.getTokenbuf().begin(),
tokenStream.getTokenbuf().length(),
tokenStream.currentToken().t_reflags,
&tokenStream);
}
if (!obj)
return NULL;
if (!tc->compileAndGo()) {
obj->clearParent();
obj->clearType();
}
pn->pn_objbox = tc->parser->newObjectBox(obj);
if (!pn->pn_objbox)
return NULL;
pn->setOp(JSOP_REGEXP);
break;
}
case TOK_NUMBER:
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
pn->setOp(JSOP_DOUBLE);
pn->pn_dval = tokenStream.currentToken().t_dval;
break;
case TOK_PRIMARY:
pn = NullaryNode::create(tc);
if (!pn)
return NULL;
pn->setOp(tokenStream.currentToken().t_op);
break;
case TOK_ERROR:
/* The scanner or one of its subroutines reported the error. */
return NULL;
default:
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_SYNTAX_ERROR);
return NULL;
}
return pn;
}
JSParseNode *
Parser::parenExpr(JSBool *genexp)
{
TokenPtr begin;
JSParseNode *pn;
JS_ASSERT(tokenStream.currentToken().type == TOK_LP);
begin = tokenStream.currentToken().pos.begin;
if (genexp)
*genexp = JS_FALSE;
GenexpGuard guard(tc);
pn = bracketedExpr();
if (!pn)
return NULL;
guard.endBody();
#if JS_HAS_GENERATOR_EXPRS
if (tokenStream.matchToken(TOK_FOR)) {
if (!guard.checkValidBody(pn))
return NULL;
JS_ASSERT(!pn->isKind(TOK_YIELD));
if (pn->isKind(TOK_COMMA) && !pn->isInParens()) {
reportErrorNumber(pn->last(), JSREPORT_ERROR, JSMSG_BAD_GENERATOR_SYNTAX,
js_generator_str);
return NULL;
}
pn = generatorExpr(pn);
if (!pn)
return NULL;
pn->pn_pos.begin = begin;
if (genexp) {
if (tokenStream.getToken() != TOK_RP) {
reportErrorNumber(NULL, JSREPORT_ERROR, JSMSG_BAD_GENERATOR_SYNTAX,
js_generator_str);
return NULL;
}
pn->pn_pos.end = tokenStream.currentToken().pos.end;
*genexp = JS_TRUE;
}
} else
#endif /* JS_HAS_GENERATOR_EXPRS */
if (!guard.maybeNoteGenerator(pn))
return NULL;
return pn;
}
/*
* Fold from one constant type to another.
* XXX handles only strings and numbers for now
*/
static JSBool
FoldType(JSContext *cx, JSParseNode *pn, TokenKind type)
{
if (!pn->isKind(type)) {
switch (type) {
case TOK_NUMBER:
if (pn->isKind(TOK_STRING)) {
jsdouble d;
if (!ToNumber(cx, StringValue(pn->pn_atom), &d))
return JS_FALSE;
pn->pn_dval = d;
pn->setKind(TOK_NUMBER);
pn->setOp(JSOP_DOUBLE);
}
break;
case TOK_STRING:
if (pn->isKind(TOK_NUMBER)) {
JSString *str = js_NumberToString(cx, pn->pn_dval);
if (!str)
return JS_FALSE;
pn->pn_atom = js_AtomizeString(cx, str);
if (!pn->pn_atom)
return JS_FALSE;
pn->setKind(TOK_STRING);
pn->setOp(JSOP_STRING);
}
break;
default:;
}
}
return JS_TRUE;
}
/*
* Fold two numeric constants. Beware that pn1 and pn2 are recycled, unless
* one of them aliases pn, so you can't safely fetch pn2->pn_next, e.g., after
* a successful call to this function.
*/
static JSBool
FoldBinaryNumeric(JSContext *cx, JSOp op, JSParseNode *pn1, JSParseNode *pn2,
JSParseNode *pn, JSTreeContext *tc)
{
jsdouble d, d2;
int32 i, j;
JS_ASSERT(pn1->isKind(TOK_NUMBER) && pn2->isKind(TOK_NUMBER));
d = pn1->pn_dval;
d2 = pn2->pn_dval;
switch (op) {
case JSOP_LSH:
case JSOP_RSH:
i = js_DoubleToECMAInt32(d);
j = js_DoubleToECMAInt32(d2);
j &= 31;
d = (op == JSOP_LSH) ? i << j : i >> j;
break;
case JSOP_URSH:
j = js_DoubleToECMAInt32(d2);
j &= 31;
d = js_DoubleToECMAUint32(d) >> j;
break;
case JSOP_ADD:
d += d2;
break;
case JSOP_SUB:
d -= d2;
break;
case JSOP_MUL:
d *= d2;
break;
case JSOP_DIV:
if (d2 == 0) {
#if defined(XP_WIN)
/* XXX MSVC miscompiles such that (NaN == 0) */
if (JSDOUBLE_IS_NaN(d2))
d = js_NaN;
else
#endif
if (d == 0 || JSDOUBLE_IS_NaN(d))
d = js_NaN;
else if (JSDOUBLE_IS_NEG(d) != JSDOUBLE_IS_NEG(d2))
d = js_NegativeInfinity;
else
d = js_PositiveInfinity;
} else {
d /= d2;
}
break;
case JSOP_MOD:
if (d2 == 0) {
d = js_NaN;
} else {
d = js_fmod(d, d2);
}
break;
default:;
}
/* Take care to allow pn1 or pn2 to alias pn. */
if (pn1 != pn)
RecycleTree(pn1, tc);
if (pn2 != pn)
RecycleTree(pn2, tc);
pn->setKind(TOK_NUMBER);
pn->setOp(JSOP_DOUBLE);
pn->setArity(PN_NULLARY);
pn->pn_dval = d;
return JS_TRUE;
}
#if JS_HAS_XML_SUPPORT
static JSBool
FoldXMLConstants(JSContext *cx, JSParseNode *pn, JSTreeContext *tc)
{
TokenKind tt;
JSParseNode **pnp, *pn1, *pn2;
JSString *accum, *str;
uint32 i, j;
JS_ASSERT(pn->isArity(PN_LIST));
tt = pn->getKind();
pnp = &pn->pn_head;
pn1 = *pnp;
accum = NULL;
str = NULL;
if ((pn->pn_xflags & PNX_CANTFOLD) == 0) {
if (tt == TOK_XMLETAGO)
accum = cx->runtime->atomState.etagoAtom;
else if (tt == TOK_XMLSTAGO || tt == TOK_XMLPTAGC)
accum = cx->runtime->atomState.stagoAtom;
}
/*
* GC Rooting here is tricky: for most of the loop, |accum| is safe via
* the newborn string root. However, when |pn2->pn_type| is TOK_XMLCDATA,
* TOK_XMLCOMMENT, or TOK_XMLPI it is knocked out of the newborn root.
* Therefore, we have to add additonal protection from GC nesting under
* js_ConcatStrings.
*/
for (pn2 = pn1, i = j = 0; pn2; pn2 = pn2->pn_next, i++) {
/* The parser already rejected end-tags with attributes. */
JS_ASSERT(tt != TOK_XMLETAGO || i == 0);
switch (pn2->getKind()) {
case TOK_XMLATTR:
if (!accum)
goto cantfold;
/* FALL THROUGH */
case TOK_XMLNAME:
case TOK_XMLSPACE:
case TOK_XMLTEXT:
case TOK_STRING:
if (pn2->isArity(PN_LIST))
goto cantfold;
str = pn2->pn_atom;
break;
case TOK_XMLCDATA:
str = js_MakeXMLCDATAString(cx, pn2->pn_atom);
if (!str)
return JS_FALSE;
break;
case TOK_XMLCOMMENT:
str = js_MakeXMLCommentString(cx, pn2->pn_atom);
if (!str)
return JS_FALSE;
break;
case TOK_XMLPI:
str = js_MakeXMLPIString(cx, pn2->pn_atom, pn2->pn_atom2);
if (!str)
return JS_FALSE;
break;
cantfold:
default:
JS_ASSERT(*pnp == pn1);
if ((tt == TOK_XMLSTAGO || tt == TOK_XMLPTAGC) &&
(i & 1) ^ (j & 1)) {
#ifdef DEBUG_brendanXXX
printf("1: %d, %d => ", i, j);
if (accum)
FileEscapedString(stdout, accum, 0);
else
fputs("NULL", stdout);
fputc('\n', stdout);
#endif
} else if (accum && pn1 != pn2) {
while (pn1->pn_next != pn2) {
pn1 = RecycleTree(pn1, tc);
--pn->pn_count;
}
pn1->setKind(TOK_XMLTEXT);
pn1->setOp(JSOP_STRING);
pn1->setArity(PN_NULLARY);
pn1->pn_atom = js_AtomizeString(cx, accum);
if (!pn1->pn_atom)
return JS_FALSE;
JS_ASSERT(pnp != &pn1->pn_next);
*pnp = pn1;
}
pnp = &pn2->pn_next;
pn1 = *pnp;
accum = NULL;
continue;
}
if (accum) {
{
AutoStringRooter tvr(cx, accum);
str = ((tt == TOK_XMLSTAGO || tt == TOK_XMLPTAGC) && i != 0)
? js_AddAttributePart(cx, i & 1, accum, str)
: js_ConcatStrings(cx, accum, str);
}
if (!str)
return JS_FALSE;
#ifdef DEBUG_brendanXXX
printf("2: %d, %d => ", i, j);
FileEscapedString(stdout, str, 0);
printf(" (%u)\n", str->length());
#endif
++j;
}
accum = str;
}
if (accum) {
str = NULL;
if ((pn->pn_xflags & PNX_CANTFOLD) == 0) {
if (tt == TOK_XMLPTAGC)
str = cx->runtime->atomState.ptagcAtom;
else if (tt == TOK_XMLSTAGO || tt == TOK_XMLETAGO)
str = cx->runtime->atomState.tagcAtom;
}
if (str) {
accum = js_ConcatStrings(cx, accum, str);
if (!accum)
return JS_FALSE;
}
JS_ASSERT(*pnp == pn1);
while (pn1->pn_next) {
pn1 = RecycleTree(pn1, tc);
--pn->pn_count;
}
pn1->setKind(TOK_XMLTEXT);
pn1->setOp(JSOP_STRING);
pn1->setArity(PN_NULLARY);
pn1->pn_atom = js_AtomizeString(cx, accum);
if (!pn1->pn_atom)
return JS_FALSE;
JS_ASSERT(pnp != &pn1->pn_next);
*pnp = pn1;
}
if (pn1 && pn->pn_count == 1) {
/*
* Only one node under pn, and it has been folded: move pn1 onto pn
* unless pn is an XML root (in which case we need it to tell the code
* generator to emit a JSOP_TOXML or JSOP_TOXMLLIST op). If pn is an
* XML root *and* it's a point-tag, rewrite it to TOK_XMLELEM to avoid
* extra "<" and "/>" bracketing at runtime.
*/
if (!(pn->pn_xflags & PNX_XMLROOT)) {
pn->become(pn1);
} else if (tt == TOK_XMLPTAGC) {
pn->setKind(TOK_XMLELEM);
pn->setOp(JSOP_TOXML);
}
}
return JS_TRUE;
}
#endif /* JS_HAS_XML_SUPPORT */
static int
Boolish(JSParseNode *pn)
{
switch (pn->getOp()) {
case JSOP_DOUBLE:
return pn->pn_dval != 0 && !JSDOUBLE_IS_NaN(pn->pn_dval);
case JSOP_STRING:
return pn->pn_atom->length() != 0;
#if JS_HAS_GENERATOR_EXPRS
case JSOP_CALL:
{
/*
* A generator expression as an if or loop condition has no effects, it
* simply results in a truthy object reference. This condition folding
* is needed for the decompiler. See bug 442342 and bug 443074.
*/
if (pn->pn_count != 1)
break;
JSParseNode *pn2 = pn->pn_head;
if (!pn2->isKind(TOK_FUNCTION))
break;
if (!(pn2->pn_funbox->tcflags & TCF_GENEXP_LAMBDA))
break;
/* FALL THROUGH */
}
#endif
case JSOP_DEFFUN:
case JSOP_LAMBDA:
case JSOP_TRUE:
return 1;
case JSOP_NULL:
case JSOP_FALSE:
return 0;
default:;
}
return -1;
}
JSBool
js_FoldConstants(JSContext *cx, JSParseNode *pn, JSTreeContext *tc, bool inCond)
{
JSParseNode *pn1 = NULL, *pn2 = NULL, *pn3 = NULL;
JS_CHECK_RECURSION(cx, return JS_FALSE);
switch (pn->getArity()) {
case PN_FUNC:
{
uint32 oldflags = tc->flags;
JSFunctionBox *oldlist = tc->functionList;
tc->flags = pn->pn_funbox->tcflags;
tc->functionList = pn->pn_funbox->kids;
if (!js_FoldConstants(cx, pn->pn_body, tc))
return JS_FALSE;
pn->pn_funbox->kids = tc->functionList;
tc->flags = oldflags;
tc->functionList = oldlist;
break;
}
case PN_LIST:
{
/* Propagate inCond through logical connectives. */
bool cond = inCond && (pn->isKind(TOK_OR) || pn->isKind(TOK_AND));
/* Don't fold a parenthesized call expression. See bug 537673. */
pn1 = pn2 = pn->pn_head;
if ((pn->isKind(TOK_LP) || pn->isKind(TOK_NEW)) && pn2->isInParens())
pn2 = pn2->pn_next;
/* Save the list head in pn1 for later use. */
for (; pn2; pn2 = pn2->pn_next) {
if (!js_FoldConstants(cx, pn2, tc, cond))
return JS_FALSE;
}
break;
}
case PN_TERNARY:
/* Any kid may be null (e.g. for (;;)). */
pn1 = pn->pn_kid1;
pn2 = pn->pn_kid2;
pn3 = pn->pn_kid3;
if (pn1 && !js_FoldConstants(cx, pn1, tc, pn->isKind(TOK_IF)))
return JS_FALSE;
if (pn2) {
if (!js_FoldConstants(cx, pn2, tc, pn->isKind(TOK_FORHEAD)))
return JS_FALSE;
if (pn->isKind(TOK_FORHEAD) && pn2->isOp(JSOP_TRUE)) {
RecycleTree(pn2, tc);
pn->pn_kid2 = NULL;
}
}
if (pn3 && !js_FoldConstants(cx, pn3, tc))
return JS_FALSE;
break;
case PN_BINARY:
pn1 = pn->pn_left;
pn2 = pn->pn_right;
/* Propagate inCond through logical connectives. */
if (pn->isKind(TOK_OR) || pn->isKind(TOK_AND)) {
if (!js_FoldConstants(cx, pn1, tc, inCond))
return JS_FALSE;
if (!js_FoldConstants(cx, pn2, tc, inCond))
return JS_FALSE;
break;
}
/* First kid may be null (for default case in switch). */
if (pn1 && !js_FoldConstants(cx, pn1, tc, pn->isKind(TOK_WHILE)))
return JS_FALSE;
if (!js_FoldConstants(cx, pn2, tc, pn->isKind(TOK_DO)))
return JS_FALSE;
break;
case PN_UNARY:
pn1 = pn->pn_kid;
/*
* Kludge to deal with typeof expressions: because constant folding
* can turn an expression into a name node, we have to check here,
* before folding, to see if we should throw undefined name errors.
*
* NB: We know that if pn->pn_op is JSOP_TYPEOF, pn1 will not be
* null. This assumption does not hold true for other unary
* expressions.
*/
if (pn->isOp(JSOP_TYPEOF) && !pn1->isKind(TOK_NAME))
pn->setOp(JSOP_TYPEOFEXPR);
if (pn1 && !js_FoldConstants(cx, pn1, tc, pn->isOp(JSOP_NOT)))
return JS_FALSE;
break;
case PN_NAME:
/*
* Skip pn1 down along a chain of dotted member expressions to avoid
* excessive recursion. Our only goal here is to fold constants (if
* any) in the primary expression operand to the left of the first
* dot in the chain.
*/
if (!pn->isUsed()) {
pn1 = pn->pn_expr;
while (pn1 && pn1->isArity(PN_NAME) && !pn1->isUsed())
pn1 = pn1->pn_expr;
if (pn1 && !js_FoldConstants(cx, pn1, tc))
return JS_FALSE;
}
break;
case PN_NAMESET:
pn1 = pn->pn_tree;
if (!js_FoldConstants(cx, pn1, tc))
return JS_FALSE;
break;
case PN_NULLARY:
break;
}
switch (pn->getKind()) {
case TOK_IF:
if (ContainsStmt(pn2, TOK_VAR) || ContainsStmt(pn3, TOK_VAR))
break;
/* FALL THROUGH */
case TOK_HOOK:
/* Reduce 'if (C) T; else E' into T for true C, E for false. */
switch (pn1->getKind()) {
case TOK_NUMBER:
if (pn1->pn_dval == 0 || JSDOUBLE_IS_NaN(pn1->pn_dval))
pn2 = pn3;
break;
case TOK_STRING:
if (pn1->pn_atom->length() == 0)
pn2 = pn3;
break;
case TOK_PRIMARY:
if (pn1->isOp(JSOP_TRUE))
break;
if (pn1->isOp(JSOP_FALSE) || pn1->isOp(JSOP_NULL)) {
pn2 = pn3;
break;
}
/* FALL THROUGH */
default:
/* Early return to dodge common code that copies pn2 to pn. */
return JS_TRUE;
}
#if JS_HAS_GENERATOR_EXPRS
/* Don't fold a trailing |if (0)| in a generator expression. */
if (!pn2 && (tc->flags & TCF_GENEXP_LAMBDA))
break;
#endif
if (pn2 && !pn2->isDefn())
pn->become(pn2);
if (!pn2 || (pn->isKind(TOK_SEMI) && !pn->pn_kid)) {
/*
* False condition and no else, or an empty then-statement was
* moved up over pn. Either way, make pn an empty block (not an
* empty statement, which does not decompile, even when labeled).
* NB: pn must be a TOK_IF as TOK_HOOK can never have a null kid
* or an empty statement for a child.
*/
pn->setKind(TOK_LC);
pn->setArity(PN_LIST);
pn->makeEmpty();
}
RecycleTree(pn2, tc);
if (pn3 && pn3 != pn2)
RecycleTree(pn3, tc);
break;
case TOK_OR:
case TOK_AND:
if (inCond) {
if (pn->isArity(PN_LIST)) {
JSParseNode **pnp = &pn->pn_head;
JS_ASSERT(*pnp == pn1);
do {
int cond = Boolish(pn1);
if (cond == pn->isKind(TOK_OR)) {
for (pn2 = pn1->pn_next; pn2; pn2 = pn3) {
pn3 = pn2->pn_next;
RecycleTree(pn2, tc);
--pn->pn_count;
}
pn1->pn_next = NULL;
break;
}
if (cond != -1) {
JS_ASSERT(cond == pn->isKind(TOK_AND));
if (pn->pn_count == 1)
break;
*pnp = pn1->pn_next;
RecycleTree(pn1, tc);
--pn->pn_count;
} else {
pnp = &pn1->pn_next;
}
} while ((pn1 = *pnp) != NULL);
// We may have to change arity from LIST to BINARY.
pn1 = pn->pn_head;
if (pn->pn_count == 2) {
pn2 = pn1->pn_next;
pn1->pn_next = NULL;
JS_ASSERT(!pn2->pn_next);
pn->setArity(PN_BINARY);
pn->pn_left = pn1;
pn->pn_right = pn2;
} else if (pn->pn_count == 1) {
pn->become(pn1);
RecycleTree(pn1, tc);
}
} else {
int cond = Boolish(pn1);
if (cond == pn->isKind(TOK_OR)) {
RecycleTree(pn2, tc);
pn->become(pn1);
} else if (cond != -1) {
JS_ASSERT(cond == pn->isKind(TOK_AND));
RecycleTree(pn1, tc);
pn->become(pn2);
}
}
}
break;
case TOK_ASSIGN:
/*
* Compound operators such as *= should be subject to folding, in case
* the left-hand side is constant, and so that the decompiler produces
* the same string that you get from decompiling a script or function
* compiled from that same string. As with +, += is special.
*/
if (pn->isOp(JSOP_NOP))
break;
if (!pn->isOp(JSOP_ADD))
goto do_binary_op;
/* FALL THROUGH */
case TOK_PLUS:
if (pn->isArity(PN_LIST)) {
/*
* Any string literal term with all others number or string means
* this is a concatenation. If any term is not a string or number
* literal, we can't fold.
*/
JS_ASSERT(pn->pn_count > 2);
if (pn->pn_xflags & PNX_CANTFOLD)
return JS_TRUE;
if (pn->pn_xflags != PNX_STRCAT)
goto do_binary_op;
/* Ok, we're concatenating: convert non-string constant operands. */
size_t length = 0;
for (pn2 = pn1; pn2; pn2 = pn2->pn_next) {
if (!FoldType(cx, pn2, TOK_STRING))
return JS_FALSE;
/* XXX fold only if all operands convert to string */
if (!pn2->isKind(TOK_STRING))
return JS_TRUE;
length += pn2->pn_atom->length();
}
/* Allocate a new buffer and string descriptor for the result. */
jschar *chars = (jschar *) cx->malloc_((length + 1) * sizeof(jschar));
if (!chars)
return JS_FALSE;
chars[length] = 0;
JSString *str = js_NewString(cx, chars, length);
if (!str) {
cx->free_(chars);
return JS_FALSE;
}
/* Fill the buffer, advancing chars and recycling kids as we go. */
for (pn2 = pn1; pn2; pn2 = RecycleTree(pn2, tc)) {
JSAtom *atom = pn2->pn_atom;
size_t length2 = atom->length();
js_strncpy(chars, atom->chars(), length2);
chars += length2;
}
JS_ASSERT(*chars == 0);
/* Atomize the result string and mutate pn to refer to it. */
pn->pn_atom = js_AtomizeString(cx, str);
if (!pn->pn_atom)
return JS_FALSE;
pn->setKind(TOK_STRING);
pn->setOp(JSOP_STRING);
pn->setArity(PN_NULLARY);
break;
}
/* Handle a binary string concatenation. */
JS_ASSERT(pn->isArity(PN_BINARY));
if (pn1->isKind(TOK_STRING) || pn2->isKind(TOK_STRING)) {
JSString *left, *right, *str;
if (!FoldType(cx, !pn1->isKind(TOK_STRING) ? pn1 : pn2, TOK_STRING))
return JS_FALSE;
if (!pn1->isKind(TOK_STRING) || !pn2->isKind(TOK_STRING))
return JS_TRUE;
left = pn1->pn_atom;
right = pn2->pn_atom;
str = js_ConcatStrings(cx, left, right);
if (!str)
return JS_FALSE;
pn->pn_atom = js_AtomizeString(cx, str);
if (!pn->pn_atom)
return JS_FALSE;
pn->setKind(TOK_STRING);
pn->setOp(JSOP_STRING);
pn->setArity(PN_NULLARY);
RecycleTree(pn1, tc);
RecycleTree(pn2, tc);
break;
}
/* Can't concatenate string literals, let's try numbers. */
goto do_binary_op;
case TOK_STAR:
case TOK_SHOP:
case TOK_MINUS:
case TOK_DIVOP:
do_binary_op:
if (pn->isArity(PN_LIST)) {
JS_ASSERT(pn->pn_count > 2);
for (pn2 = pn1; pn2; pn2 = pn2->pn_next) {
if (!FoldType(cx, pn2, TOK_NUMBER))
return JS_FALSE;
}
for (pn2 = pn1; pn2; pn2 = pn2->pn_next) {
/* XXX fold only if all operands convert to number */
if (!pn2->isKind(TOK_NUMBER))
break;
}
if (!pn2) {
JSOp op = pn->getOp();
pn2 = pn1->pn_next;
pn3 = pn2->pn_next;
if (!FoldBinaryNumeric(cx, op, pn1, pn2, pn, tc))
return JS_FALSE;
while ((pn2 = pn3) != NULL) {
pn3 = pn2->pn_next;
if (!FoldBinaryNumeric(cx, op, pn, pn2, pn, tc))
return JS_FALSE;
}
}
} else {
JS_ASSERT(pn->isArity(PN_BINARY));
if (!FoldType(cx, pn1, TOK_NUMBER) ||
!FoldType(cx, pn2, TOK_NUMBER)) {
return JS_FALSE;
}
if (pn1->isKind(TOK_NUMBER) && pn2->isKind(TOK_NUMBER)) {
if (!FoldBinaryNumeric(cx, pn->getOp(), pn1, pn2, pn, tc))
return JS_FALSE;
}
}
break;
case TOK_UNARYOP:
if (pn1->isKind(TOK_NUMBER)) {
jsdouble d;
/* Operate on one numeric constant. */
d = pn1->pn_dval;
switch (pn->getOp()) {
case JSOP_BITNOT:
d = ~js_DoubleToECMAInt32(d);
break;
case JSOP_NEG:
d = -d;
break;
case JSOP_POS:
break;
case JSOP_NOT:
pn->setKind(TOK_PRIMARY);
pn->setOp((d == 0 || JSDOUBLE_IS_NaN(d)) ? JSOP_TRUE : JSOP_FALSE);
pn->setArity(PN_NULLARY);
/* FALL THROUGH */
default:
/* Return early to dodge the common TOK_NUMBER code. */
return JS_TRUE;
}
pn->setKind(TOK_NUMBER);
pn->setOp(JSOP_DOUBLE);
pn->setArity(PN_NULLARY);
pn->pn_dval = d;
RecycleTree(pn1, tc);
} else if (pn1->isKind(TOK_PRIMARY)) {
if (pn->isOp(JSOP_NOT) && (pn1->isOp(JSOP_TRUE) || pn1->isOp(JSOP_FALSE))) {
pn->become(pn1);
pn->setOp(pn->isOp(JSOP_TRUE) ? JSOP_FALSE : JSOP_TRUE);
RecycleTree(pn1, tc);
}
}
break;
#if JS_HAS_XML_SUPPORT
case TOK_XMLELEM:
case TOK_XMLLIST:
case TOK_XMLPTAGC:
case TOK_XMLSTAGO:
case TOK_XMLETAGO:
case TOK_XMLNAME:
if (pn->isArity(PN_LIST)) {
JS_ASSERT(pn->isKind(TOK_XMLLIST) || pn->pn_count != 0);
if (!FoldXMLConstants(cx, pn, tc))
return JS_FALSE;
}
break;
case TOK_AT:
if (pn1->isKind(TOK_XMLNAME)) {
JSObjectBox *xmlbox;
Value v = StringValue(pn1->pn_atom);
if (!js_ToAttributeName(cx, &v))
return JS_FALSE;
JS_ASSERT(v.isObject());
xmlbox = tc->parser->newObjectBox(&v.toObject());
if (!xmlbox)
return JS_FALSE;
pn->setKind(TOK_XMLNAME);
pn->setOp(JSOP_OBJECT);
pn->setArity(PN_NULLARY);
pn->pn_objbox = xmlbox;
RecycleTree(pn1, tc);
}
break;
#endif /* JS_HAS_XML_SUPPORT */
default:;
}
if (inCond) {
int cond = Boolish(pn);
if (cond >= 0) {
/*
* We can turn function nodes into constant nodes here, but mutating function
* nodes is tricky --- in particular, mutating a function node that appears on
* a method list corrupts the method list. However, methods are M's in
* statements of the form 'this.foo = M;', which we never fold, so we're okay.
*/
PrepareNodeForMutation(pn, tc);
pn->setKind(TOK_PRIMARY);
pn->setOp(cond ? JSOP_TRUE : JSOP_FALSE);
pn->setArity(PN_NULLARY);
}
}
return JS_TRUE;
}
