2010-10-26 12:00:54 -07:00
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/* -*- Mode: c++; c-basic-offset: 4; tab-width: 40; indent-tabs-mode: nil -*- */
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/* vim: set ts=40 sw=4 et tw=99: */
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/* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is the Mozilla SpiderMonkey bytecode analysis
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*
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* The Initial Developer of the Original Code is
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* Mozilla Foundation
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* Portions created by the Initial Developer are Copyright (C) 2010
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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* Brian Hackett <bhackett@mozilla.com>
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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#include "jsanalyze.h"
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#include "jsautooplen.h"
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#include "jscompartment.h"
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#include "jscntxt.h"
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2011-04-05 18:12:03 -07:00
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#include "jsinferinlines.h"
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#include "jsobjinlines.h"
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2010-10-26 12:00:54 -07:00
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namespace js {
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namespace analyze {
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/////////////////////////////////////////////////////////////////////
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// Script
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/////////////////////////////////////////////////////////////////////
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2010-12-28 11:53:50 -08:00
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Script::Script()
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{
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PodZero(this);
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}
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Script::~Script()
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2010-10-26 12:00:54 -07:00
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{
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JS_FinishArenaPool(&pool);
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}
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/////////////////////////////////////////////////////////////////////
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// Bytecode
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/////////////////////////////////////////////////////////////////////
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bool
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2010-10-29 08:05:55 -07:00
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Bytecode::mergeDefines(JSContext *cx, Script *script, bool initial,
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2010-12-28 11:53:50 -08:00
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unsigned newDepth, uint32 *newArray, unsigned newCount)
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2010-10-26 12:00:54 -07:00
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{
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if (initial) {
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/*
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* Haven't handled any incoming edges to this bytecode before.
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* Define arrays are copy on write, so just reuse the array for this bytecode.
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*/
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stackDepth = newDepth;
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defineArray = newArray;
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defineCount = newCount;
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return true;
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}
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/*
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* This bytecode has multiple incoming edges, intersect the new array with any
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* variables known to be defined along other incoming edges.
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*/
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if (analyzed) {
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#ifdef DEBUG
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/*
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* Once analyzed, a bytecode has its full set of definitions. There are two
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* properties we depend on to ensure this. First, bytecode for a function
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* is emitted in topological order, and since we analyze bytecodes in the
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* order they were emitted we will have seen all incoming jumps except
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* for any loop back edges. Second, javascript has structured control flow,
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* so loop heads dominate their bodies; the set of variables defined
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* on a back edge will be at least as large as at the head of the loop,
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* so no intersection or further analysis needs to be done.
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*/
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JS_ASSERT(stackDepth == newDepth);
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for (unsigned i = 0; i < defineCount; i++) {
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bool found = false;
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for (unsigned j = 0; j < newCount; j++) {
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if (newArray[j] == defineArray[i])
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found = true;
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}
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JS_ASSERT(found);
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}
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#endif
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} else {
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JS_ASSERT(stackDepth == newDepth);
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bool owned = false;
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for (unsigned i = 0; i < defineCount; i++) {
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bool found = false;
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for (unsigned j = 0; j < newCount; j++) {
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if (newArray[j] == defineArray[i])
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found = true;
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}
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if (!found) {
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/*
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* Get a mutable copy of the defines. This can end up making
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* several copies for a bytecode if it has many incoming edges
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* with progressively smaller sets of defined variables.
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*/
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if (!owned) {
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uint32 *reallocArray = ArenaArray<uint32>(script->pool, defineCount);
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if (!reallocArray) {
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script->setOOM(cx);
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return false;
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}
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memcpy(reallocArray, defineArray, defineCount * sizeof(uint32));
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defineArray = reallocArray;
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owned = true;
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}
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/* Swap with the last element and pop the array. */
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defineArray[i--] = defineArray[--defineCount];
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}
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}
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}
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return true;
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}
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/////////////////////////////////////////////////////////////////////
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// Analysis
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/////////////////////////////////////////////////////////////////////
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inline bool
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Script::addJump(JSContext *cx, unsigned offset,
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unsigned *currentOffset, unsigned *forwardJump,
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2010-12-28 11:53:50 -08:00
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unsigned stackDepth, uint32 *defineArray, unsigned defineCount)
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2010-10-26 12:00:54 -07:00
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{
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JS_ASSERT(offset < script->length);
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2010-10-29 08:05:55 -07:00
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Bytecode *&code = codeArray[offset];
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bool initial = (code == NULL);
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2010-10-26 12:00:54 -07:00
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if (initial) {
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2011-03-03 14:07:48 -08:00
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code = ArenaNew<Bytecode>(pool);
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2010-10-29 08:05:55 -07:00
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if (!code) {
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2010-10-26 12:00:54 -07:00
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setOOM(cx);
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return false;
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}
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}
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2010-12-28 11:53:50 -08:00
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if (!code->mergeDefines(cx, this, initial, stackDepth, defineArray, defineCount))
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2010-10-26 12:00:54 -07:00
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return false;
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2010-10-29 08:05:55 -07:00
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code->jumpTarget = true;
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2010-10-26 12:00:54 -07:00
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if (offset < *currentOffset) {
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2011-03-26 19:07:13 -07:00
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/* Scripts containing loops are never inlined. */
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isInlineable = false;
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2010-10-26 12:00:54 -07:00
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/* Don't follow back edges to bytecode which has already been analyzed. */
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2010-10-29 08:05:55 -07:00
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if (!code->analyzed) {
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2010-10-26 12:00:54 -07:00
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if (*forwardJump == 0)
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*forwardJump = *currentOffset;
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*currentOffset = offset;
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}
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} else if (offset > *forwardJump) {
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*forwardJump = offset;
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}
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return true;
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}
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inline void
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Script::setLocal(uint32 local, uint32 offset)
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{
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JS_ASSERT(local < localCount());
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JS_ASSERT(offset != LOCAL_CONDITIONALLY_DEFINED);
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/*
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* It isn't possible to change the point when a variable becomes unconditionally
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* defined, or to mark it as unconditionally defined after it has already been
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* marked as having a use before def. It *is* possible to mark it as having
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* a use before def after marking it as unconditionally defined. In a loop such as:
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*
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* while ((a = b) != 0) { x = a; }
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*
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* When walking through the body of this loop, we will first analyze the test
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* (which comes after the body in the bytecode stream) as unconditional code,
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* and mark a as definitely defined. a is not in the define array when taking
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* the loop's back edge, so it is treated as possibly undefined when written to x.
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*/
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JS_ASSERT(locals[local] == LOCAL_CONDITIONALLY_DEFINED ||
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locals[local] == offset || offset == LOCAL_USE_BEFORE_DEF);
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locals[local] = offset;
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}
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static inline ptrdiff_t
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GetJumpOffset(jsbytecode *pc, jsbytecode *pc2)
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{
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uint32 type = JOF_OPTYPE(*pc);
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if (JOF_TYPE_IS_EXTENDED_JUMP(type))
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return GET_JUMPX_OFFSET(pc2);
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return GET_JUMP_OFFSET(pc2);
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}
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// return whether op bytecodes do not fallthrough (they may do a jump).
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static inline bool
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BytecodeNoFallThrough(JSOp op)
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{
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switch (op) {
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case JSOP_GOTO:
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case JSOP_GOTOX:
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case JSOP_DEFAULT:
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case JSOP_DEFAULTX:
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case JSOP_RETURN:
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case JSOP_STOP:
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case JSOP_RETRVAL:
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case JSOP_THROW:
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case JSOP_TABLESWITCH:
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case JSOP_TABLESWITCHX:
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case JSOP_LOOKUPSWITCH:
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case JSOP_LOOKUPSWITCHX:
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case JSOP_FILTER:
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return true;
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case JSOP_GOSUB:
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case JSOP_GOSUBX:
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// these fall through indirectly, after executing a 'finally'.
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return false;
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default:
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return false;
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}
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}
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2010-10-29 08:05:55 -07:00
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void
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2010-12-28 11:53:50 -08:00
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Script::analyze(JSContext *cx, JSScript *script)
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2010-10-29 08:05:55 -07:00
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{
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2011-03-26 19:07:13 -07:00
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JS_InitArenaPool(&pool, "script_analyze", 256, 8, NULL);
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2010-10-29 08:05:55 -07:00
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JS_ASSERT(script && !codeArray && !locals);
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2010-12-28 11:53:50 -08:00
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this->script = script;
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2010-10-26 12:00:54 -07:00
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unsigned length = script->length;
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2011-03-20 08:23:27 -07:00
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unsigned nargs = script->fun ? script->fun->nargs : 0;
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2010-10-26 12:00:54 -07:00
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unsigned nfixed = localCount();
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2010-10-29 08:05:55 -07:00
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codeArray = ArenaArray<Bytecode*>(pool, length);
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2010-10-26 12:00:54 -07:00
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locals = ArenaArray<uint32>(pool, nfixed);
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2011-03-20 08:23:27 -07:00
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closedArgs = ArenaArray<JSPackedBool>(pool, nargs);
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closedVars = ArenaArray<JSPackedBool>(pool, nfixed);
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2010-10-26 12:00:54 -07:00
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2011-03-20 08:23:27 -07:00
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if (!codeArray || !locals || !closedArgs || !closedVars) {
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2010-10-26 12:00:54 -07:00
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setOOM(cx);
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return;
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}
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2010-10-29 08:05:55 -07:00
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PodZero(codeArray, length);
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2010-10-26 12:00:54 -07:00
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for (unsigned i = 0; i < nfixed; i++)
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locals[i] = LOCAL_CONDITIONALLY_DEFINED;
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2011-03-20 08:23:27 -07:00
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PodZero(closedArgs, nargs);
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for (uint32 i = 0; i < script->nClosedArgs; i++) {
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unsigned arg = script->getClosedArg(i);
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JS_ASSERT(arg < nargs);
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closedArgs[arg] = true;
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}
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PodZero(closedVars, nfixed);
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for (uint32 i = 0; i < script->nClosedVars; i++) {
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unsigned local = script->getClosedVar(i);
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if (local < nfixed)
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closedVars[local] = true;
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}
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2010-10-26 12:00:54 -07:00
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/*
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* Treat locals as having a possible use-before-def if they could be accessed
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* by debug code or by eval, or if they could be accessed by an inner script.
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*/
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if (script->usesEval || cx->compartment->debugMode) {
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for (uint32 i = 0; i < nfixed; i++)
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setLocal(i, LOCAL_USE_BEFORE_DEF);
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}
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for (uint32 i = 0; i < script->nClosedVars; i++) {
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uint32 slot = script->getClosedVar(i);
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if (slot < nfixed)
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setLocal(slot, LOCAL_USE_BEFORE_DEF);
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}
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2010-11-08 09:28:12 -08:00
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/*
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* If the script is in debug mode, JS_SetFrameReturnValue can be called at
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* any safe point.
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*/
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if (cx->compartment->debugMode)
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usesRval = true;
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2011-03-26 19:07:13 -07:00
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isInlineable = true;
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2011-04-08 17:57:58 -07:00
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if (script->nClosedArgs || script->nClosedVars || script->nfixed >= LOCAL_LIMIT ||
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2011-03-29 06:39:09 -07:00
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(script->fun && script->fun->isHeavyweight()) ||
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2011-03-26 19:07:13 -07:00
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script->usesEval || script->usesArguments || cx->compartment->debugMode) {
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isInlineable = false;
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}
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2010-10-26 12:00:54 -07:00
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/*
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* If we are in the middle of one or more jumps, the offset of the highest
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* target jumping over this bytecode. Includes implicit jumps from
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* try/catch/finally blocks.
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*/
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unsigned forwardJump = 0;
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/*
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* If we are in the middle of a try block, the offset of the highest
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* catch/finally/enditer.
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*/
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unsigned forwardCatch = 0;
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/* Fill in stack depth and definitions at initial bytecode. */
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2011-03-03 14:07:48 -08:00
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Bytecode *startcode = ArenaNew<Bytecode>(pool);
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2010-10-26 12:00:54 -07:00
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if (!startcode) {
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setOOM(cx);
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return;
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}
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startcode->stackDepth = 0;
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2010-10-29 08:05:55 -07:00
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codeArray[0] = startcode;
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2010-10-26 12:00:54 -07:00
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unsigned offset, nextOffset = 0;
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while (nextOffset < length) {
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|
offset = nextOffset;
|
|
|
|
|
|
|
|
JS_ASSERT(forwardCatch <= forwardJump);
|
|
|
|
|
|
|
|
/* Check if the current forward jump/try-block has finished. */
|
|
|
|
if (forwardJump && forwardJump == offset)
|
|
|
|
forwardJump = 0;
|
|
|
|
if (forwardCatch && forwardCatch == offset)
|
|
|
|
forwardCatch = 0;
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
Bytecode *code = maybeCode(offset);
|
2010-10-26 12:00:54 -07:00
|
|
|
jsbytecode *pc = script->code + offset;
|
|
|
|
|
|
|
|
UntrapOpcode untrap(cx, script, pc);
|
|
|
|
|
|
|
|
JSOp op = (JSOp)*pc;
|
|
|
|
JS_ASSERT(op < JSOP_LIMIT);
|
|
|
|
|
|
|
|
/* Immediate successor of this bytecode. */
|
|
|
|
unsigned successorOffset = offset + GetBytecodeLength(pc);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Next bytecode to analyze. This is either the successor, or is an
|
|
|
|
* earlier bytecode if this bytecode has a loop backedge.
|
|
|
|
*/
|
|
|
|
nextOffset = successorOffset;
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
if (!code) {
|
2010-10-26 12:00:54 -07:00
|
|
|
/* Haven't found a path by which this bytecode is reachable. */
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
if (code->analyzed) {
|
2010-10-26 12:00:54 -07:00
|
|
|
/* No need to reanalyze, see Bytecode::mergeDefines. */
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
code->analyzed = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
|
|
|
|
if (forwardCatch)
|
2010-10-29 08:05:55 -07:00
|
|
|
code->inTryBlock = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
|
2011-03-26 19:07:13 -07:00
|
|
|
if (untrap.trap) {
|
2010-12-20 09:06:43 -08:00
|
|
|
code->safePoint = true;
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
|
|
|
}
|
2010-12-20 09:06:43 -08:00
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
unsigned stackDepth = code->stackDepth;
|
|
|
|
uint32 *defineArray = code->defineArray;
|
|
|
|
unsigned defineCount = code->defineCount;
|
2010-10-26 12:00:54 -07:00
|
|
|
|
|
|
|
if (!forwardJump) {
|
|
|
|
/*
|
|
|
|
* There is no jump over this bytecode, nor a containing try block.
|
|
|
|
* Either this bytecode will definitely be executed, or an exception
|
|
|
|
* will be thrown which the script does not catch. Either way,
|
|
|
|
* any variables definitely defined at this bytecode will stay
|
|
|
|
* defined throughout the rest of the script. We just need to
|
|
|
|
* remember the offset where the variable became unconditionally
|
|
|
|
* defined, rather than continue to maintain it in define arrays.
|
|
|
|
*/
|
|
|
|
for (unsigned i = 0; i < defineCount; i++) {
|
|
|
|
uint32 local = defineArray[i];
|
|
|
|
JS_ASSERT_IF(locals[local] != LOCAL_CONDITIONALLY_DEFINED &&
|
|
|
|
locals[local] != LOCAL_USE_BEFORE_DEF,
|
|
|
|
locals[local] <= offset);
|
|
|
|
if (locals[local] == LOCAL_CONDITIONALLY_DEFINED)
|
|
|
|
setLocal(local, offset);
|
|
|
|
}
|
2011-03-09 09:58:49 -08:00
|
|
|
defineArray = code->defineArray = NULL;
|
|
|
|
defineCount = code->defineCount = 0;
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
unsigned nuses = GetUseCount(script, offset);
|
|
|
|
unsigned ndefs = GetDefCount(script, offset);
|
2010-10-26 12:00:54 -07:00
|
|
|
|
|
|
|
JS_ASSERT(stackDepth >= nuses);
|
|
|
|
stackDepth -= nuses;
|
|
|
|
stackDepth += ndefs;
|
|
|
|
|
|
|
|
switch (op) {
|
|
|
|
|
|
|
|
case JSOP_SETRVAL:
|
|
|
|
case JSOP_POPV:
|
|
|
|
usesRval = true;
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
2010-10-26 12:00:54 -07:00
|
|
|
break;
|
|
|
|
|
|
|
|
case JSOP_NAME:
|
|
|
|
case JSOP_CALLNAME:
|
|
|
|
case JSOP_BINDNAME:
|
|
|
|
case JSOP_SETNAME:
|
|
|
|
case JSOP_DELNAME:
|
|
|
|
case JSOP_INCNAME:
|
|
|
|
case JSOP_DECNAME:
|
|
|
|
case JSOP_NAMEINC:
|
|
|
|
case JSOP_NAMEDEC:
|
|
|
|
case JSOP_FORNAME:
|
|
|
|
usesScope = true;
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case JSOP_THIS:
|
|
|
|
usesThis = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
break;
|
|
|
|
|
2011-03-27 07:48:03 -07:00
|
|
|
case JSOP_CALL:
|
|
|
|
case JSOP_NEW:
|
|
|
|
/* Only consider potentially inlineable calls here. */
|
|
|
|
hasCalls = true;
|
|
|
|
break;
|
|
|
|
|
2010-11-24 17:41:52 -08:00
|
|
|
case JSOP_TABLESWITCH:
|
|
|
|
case JSOP_TABLESWITCHX: {
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
2010-10-26 12:00:54 -07:00
|
|
|
jsbytecode *pc2 = pc;
|
2010-11-24 17:41:52 -08:00
|
|
|
unsigned jmplen = (op == JSOP_TABLESWITCH) ? JUMP_OFFSET_LEN : JUMPX_OFFSET_LEN;
|
2010-10-26 12:00:54 -07:00
|
|
|
unsigned defaultOffset = offset + GetJumpOffset(pc, pc2);
|
2010-11-24 17:41:52 -08:00
|
|
|
pc2 += jmplen;
|
2010-10-26 12:00:54 -07:00
|
|
|
jsint low = GET_JUMP_OFFSET(pc2);
|
|
|
|
pc2 += JUMP_OFFSET_LEN;
|
|
|
|
jsint high = GET_JUMP_OFFSET(pc2);
|
|
|
|
pc2 += JUMP_OFFSET_LEN;
|
|
|
|
|
|
|
|
if (!addJump(cx, defaultOffset, &nextOffset, &forwardJump,
|
2010-12-28 11:53:50 -08:00
|
|
|
stackDepth, defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
getCode(defaultOffset).switchTarget = true;
|
2010-12-20 09:06:43 -08:00
|
|
|
getCode(defaultOffset).safePoint = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
|
|
|
|
for (jsint i = low; i <= high; i++) {
|
|
|
|
unsigned targetOffset = offset + GetJumpOffset(pc, pc2);
|
|
|
|
if (targetOffset != offset) {
|
|
|
|
if (!addJump(cx, targetOffset, &nextOffset, &forwardJump,
|
2010-12-28 11:53:50 -08:00
|
|
|
stackDepth, defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
getCode(targetOffset).switchTarget = true;
|
2010-12-20 09:06:43 -08:00
|
|
|
getCode(targetOffset).safePoint = true;
|
2010-11-24 17:41:52 -08:00
|
|
|
pc2 += jmplen;
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2010-11-24 17:41:52 -08:00
|
|
|
case JSOP_LOOKUPSWITCH:
|
|
|
|
case JSOP_LOOKUPSWITCHX: {
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
2010-10-26 12:00:54 -07:00
|
|
|
jsbytecode *pc2 = pc;
|
2010-11-24 17:41:52 -08:00
|
|
|
unsigned jmplen = (op == JSOP_LOOKUPSWITCH) ? JUMP_OFFSET_LEN : JUMPX_OFFSET_LEN;
|
2010-10-26 12:00:54 -07:00
|
|
|
unsigned defaultOffset = offset + GetJumpOffset(pc, pc2);
|
2010-11-24 17:41:52 -08:00
|
|
|
pc2 += jmplen;
|
2010-10-26 12:00:54 -07:00
|
|
|
unsigned npairs = GET_UINT16(pc2);
|
|
|
|
pc2 += UINT16_LEN;
|
|
|
|
|
|
|
|
if (!addJump(cx, defaultOffset, &nextOffset, &forwardJump,
|
2010-12-28 11:53:50 -08:00
|
|
|
stackDepth, defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
getCode(defaultOffset).switchTarget = true;
|
2010-12-20 09:06:43 -08:00
|
|
|
getCode(defaultOffset).safePoint = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
|
|
|
|
while (npairs) {
|
|
|
|
pc2 += INDEX_LEN;
|
|
|
|
unsigned targetOffset = offset + GetJumpOffset(pc, pc2);
|
|
|
|
if (!addJump(cx, targetOffset, &nextOffset, &forwardJump,
|
2010-12-28 11:53:50 -08:00
|
|
|
stackDepth, defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
getCode(targetOffset).switchTarget = true;
|
2010-12-20 09:06:43 -08:00
|
|
|
getCode(targetOffset).safePoint = true;
|
2010-11-24 17:41:52 -08:00
|
|
|
pc2 += jmplen;
|
2010-10-26 12:00:54 -07:00
|
|
|
npairs--;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_TRY: {
|
|
|
|
/*
|
|
|
|
* Everything between a try and corresponding catch or finally is conditional.
|
|
|
|
* Note that there is no problem with code which is skipped by a thrown
|
|
|
|
* exception but is not caught by a later handler in the same function:
|
|
|
|
* no more code will execute, and it does not matter what is defined.
|
|
|
|
*/
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
2010-10-26 12:00:54 -07:00
|
|
|
JSTryNote *tn = script->trynotes()->vector;
|
|
|
|
JSTryNote *tnlimit = tn + script->trynotes()->length;
|
|
|
|
for (; tn < tnlimit; tn++) {
|
|
|
|
unsigned startOffset = script->main - script->code + tn->start;
|
|
|
|
if (startOffset == offset + 1) {
|
|
|
|
unsigned catchOffset = startOffset + tn->length;
|
|
|
|
|
|
|
|
/* This will overestimate try block code, for multiple catch/finally. */
|
|
|
|
if (catchOffset > forwardCatch)
|
|
|
|
forwardCatch = catchOffset;
|
|
|
|
|
|
|
|
if (tn->kind != JSTRY_ITER) {
|
|
|
|
if (!addJump(cx, catchOffset, &nextOffset, &forwardJump,
|
2010-12-28 11:53:50 -08:00
|
|
|
stackDepth, defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
|
|
|
}
|
2010-10-29 08:05:55 -07:00
|
|
|
getCode(catchOffset).exceptionEntry = true;
|
2010-12-20 09:06:43 -08:00
|
|
|
getCode(catchOffset).safePoint = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_GETLOCAL:
|
|
|
|
/*
|
|
|
|
* Watch for uses of variables not known to be defined, and mark
|
|
|
|
* them as having possible uses before definitions. Ignore GETLOCAL
|
|
|
|
* followed by a POP, these are generated for, e.g. 'var x;'
|
|
|
|
*/
|
|
|
|
if (pc[JSOP_GETLOCAL_LENGTH] != JSOP_POP) {
|
|
|
|
uint32 local = GET_SLOTNO(pc);
|
2011-03-26 19:07:13 -07:00
|
|
|
if (local < nfixed && !localDefined(local, offset)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
setLocal(local, LOCAL_USE_BEFORE_DEF);
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
|
|
|
}
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case JSOP_CALLLOCAL:
|
|
|
|
case JSOP_INCLOCAL:
|
|
|
|
case JSOP_DECLOCAL:
|
|
|
|
case JSOP_LOCALINC:
|
2011-03-03 14:07:48 -08:00
|
|
|
case JSOP_LOCALDEC: {
|
2010-10-26 12:00:54 -07:00
|
|
|
uint32 local = GET_SLOTNO(pc);
|
2011-03-26 19:07:13 -07:00
|
|
|
if (local < nfixed && !localDefined(local, offset)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
setLocal(local, LOCAL_USE_BEFORE_DEF);
|
2011-03-26 19:07:13 -07:00
|
|
|
isInlineable = false;
|
|
|
|
}
|
2010-10-26 12:00:54 -07:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_SETLOCAL:
|
|
|
|
case JSOP_FORLOCAL: {
|
|
|
|
uint32 local = GET_SLOTNO(pc);
|
2010-11-11 17:21:14 -08:00
|
|
|
|
|
|
|
/*
|
|
|
|
* The local variable may already have been marked as unconditionally
|
|
|
|
* defined at a later point in the script, if that definition was in the
|
|
|
|
* condition for a loop which then jumped back here. In such cases we
|
|
|
|
* will not treat the variable as ever being defined in the loop body
|
|
|
|
* (see setLocal).
|
|
|
|
*/
|
2010-10-26 12:00:54 -07:00
|
|
|
if (local < nfixed && locals[local] == LOCAL_CONDITIONALLY_DEFINED) {
|
|
|
|
if (forwardJump) {
|
|
|
|
/* Add this local to the variables defined after this bytecode. */
|
|
|
|
uint32 *newArray = ArenaArray<uint32>(pool, defineCount + 1);
|
|
|
|
if (!newArray) {
|
|
|
|
setOOM(cx);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
if (defineCount)
|
|
|
|
memcpy(newArray, defineArray, defineCount * sizeof(uint32));
|
|
|
|
defineArray = newArray;
|
|
|
|
defineArray[defineCount++] = local;
|
|
|
|
} else {
|
|
|
|
/* This local is unconditionally defined by this bytecode. */
|
|
|
|
setLocal(local, offset);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2011-03-26 19:07:13 -07:00
|
|
|
/* Additional opcodes which can be compiled but which can't be inlined. */
|
|
|
|
case JSOP_ARGUMENTS:
|
|
|
|
case JSOP_EVAL:
|
|
|
|
case JSOP_FORARG:
|
|
|
|
case JSOP_SETARG:
|
|
|
|
case JSOP_INCARG:
|
|
|
|
case JSOP_DECARG:
|
|
|
|
case JSOP_ARGINC:
|
|
|
|
case JSOP_ARGDEC:
|
|
|
|
case JSOP_THROW:
|
|
|
|
case JSOP_EXCEPTION:
|
|
|
|
case JSOP_DEFFUN:
|
|
|
|
case JSOP_DEFVAR:
|
|
|
|
case JSOP_DEFCONST:
|
|
|
|
case JSOP_SETCONST:
|
|
|
|
case JSOP_DEFLOCALFUN:
|
|
|
|
case JSOP_DEFLOCALFUN_FC:
|
|
|
|
case JSOP_LAMBDA:
|
|
|
|
case JSOP_LAMBDA_FC:
|
|
|
|
case JSOP_GETFCSLOT:
|
|
|
|
case JSOP_CALLFCSLOT:
|
|
|
|
case JSOP_ARGSUB:
|
|
|
|
case JSOP_ARGCNT:
|
|
|
|
case JSOP_DEBUGGER:
|
|
|
|
case JSOP_ENTERBLOCK:
|
|
|
|
case JSOP_LEAVEBLOCK:
|
|
|
|
case JSOP_FUNCALL:
|
|
|
|
case JSOP_FUNAPPLY:
|
|
|
|
isInlineable = false;
|
|
|
|
break;
|
|
|
|
|
2010-10-26 12:00:54 -07:00
|
|
|
default:
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
uint32 type = JOF_TYPE(js_CodeSpec[op].format);
|
|
|
|
|
|
|
|
/* Check basic jump opcodes, which may or may not have a fallthrough. */
|
|
|
|
if (type == JOF_JUMP || type == JOF_JUMPX) {
|
|
|
|
/* Some opcodes behave differently on their branching path. */
|
2010-10-29 08:05:55 -07:00
|
|
|
unsigned newStackDepth = stackDepth;
|
2010-10-26 12:00:54 -07:00
|
|
|
|
|
|
|
switch (op) {
|
|
|
|
case JSOP_OR:
|
|
|
|
case JSOP_AND:
|
|
|
|
case JSOP_ORX:
|
|
|
|
case JSOP_ANDX:
|
2010-10-29 08:05:55 -07:00
|
|
|
/*
|
|
|
|
* OR/AND instructions push the operation result when branching.
|
|
|
|
* We accounted for this in GetDefCount, so subtract the pushed value
|
|
|
|
* for the fallthrough case.
|
|
|
|
*/
|
|
|
|
stackDepth--;
|
2010-10-26 12:00:54 -07:00
|
|
|
break;
|
|
|
|
|
|
|
|
case JSOP_CASE:
|
|
|
|
case JSOP_CASEX:
|
|
|
|
/* Case instructions do not push the lvalue back when branching. */
|
2010-10-29 08:05:55 -07:00
|
|
|
newStackDepth--;
|
2010-10-26 12:00:54 -07:00
|
|
|
break;
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
default:;
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
unsigned targetOffset = offset + GetJumpOffset(pc, pc);
|
|
|
|
if (!addJump(cx, targetOffset, &nextOffset, &forwardJump,
|
2010-12-28 11:53:50 -08:00
|
|
|
newStackDepth, defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Handle any fallthrough from this opcode. */
|
|
|
|
if (!BytecodeNoFallThrough(op)) {
|
|
|
|
JS_ASSERT(successorOffset < script->length);
|
|
|
|
|
2010-10-29 08:05:55 -07:00
|
|
|
Bytecode *&nextcode = codeArray[successorOffset];
|
2010-10-26 12:00:54 -07:00
|
|
|
bool initial = (nextcode == NULL);
|
|
|
|
|
|
|
|
if (initial) {
|
2011-03-03 14:07:48 -08:00
|
|
|
nextcode = ArenaNew<Bytecode>(pool);
|
2010-10-26 12:00:54 -07:00
|
|
|
if (!nextcode) {
|
|
|
|
setOOM(cx);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
if (type == JOF_JUMP || type == JOF_JUMPX)
|
|
|
|
nextcode->jumpFallthrough = true;
|
|
|
|
|
2010-12-28 11:53:50 -08:00
|
|
|
if (!nextcode->mergeDefines(cx, this, initial, stackDepth,
|
2010-10-29 08:05:55 -07:00
|
|
|
defineArray, defineCount)) {
|
2010-10-26 12:00:54 -07:00
|
|
|
return;
|
2010-10-29 08:05:55 -07:00
|
|
|
}
|
2010-11-12 06:25:52 -08:00
|
|
|
|
|
|
|
/* Treat the fallthrough of a branch instruction as a jump target. */
|
|
|
|
if (type == JOF_JUMP || type == JOF_JUMPX)
|
|
|
|
nextcode->jumpTarget = true;
|
|
|
|
else
|
|
|
|
nextcode->fallthrough = true;
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
JS_ASSERT(!failed());
|
|
|
|
JS_ASSERT(forwardJump == 0 && forwardCatch == 0);
|
2010-12-06 11:53:53 -08:00
|
|
|
}
|
|
|
|
|
2011-04-16 06:54:01 -07:00
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
// Stack Analysis
|
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
|
|
bool
|
|
|
|
StackAnalysis::analyze(JSArenaPool &pool, JSScript *script,
|
|
|
|
uint32 start, uint32 length, Script *analysis)
|
|
|
|
{
|
|
|
|
this->script = script;
|
|
|
|
this->start = start;
|
|
|
|
this->length = length;
|
|
|
|
|
|
|
|
poppedArray = ArenaArray<PoppedValue*>(pool, length);
|
|
|
|
if (!poppedArray)
|
|
|
|
return false;
|
|
|
|
PodZero(poppedArray, length);
|
|
|
|
|
|
|
|
PoppedValue *stack = ArenaArray<PoppedValue>(pool, script->nslots - script->nfixed);
|
|
|
|
if (!stack)
|
|
|
|
return false;
|
|
|
|
|
|
|
|
unsigned depth = analysis->getCode(start).stackDepth;
|
|
|
|
for (unsigned i = 0; i < depth; i++)
|
|
|
|
stack[i].reset();
|
|
|
|
|
|
|
|
unsigned offset = start;
|
|
|
|
while (offset < start + length) {
|
|
|
|
jsbytecode *pc = script->code + offset;
|
|
|
|
uint32 successorOffset = offset + GetBytecodeLength(pc);
|
|
|
|
|
|
|
|
Bytecode *code = analysis->maybeCode(pc);
|
|
|
|
if (!code) {
|
|
|
|
offset = successorOffset;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (unsigned i = depth; i < code->stackDepth; i++)
|
|
|
|
stack[i].reset();
|
|
|
|
depth = code->stackDepth;
|
|
|
|
|
|
|
|
if (code->jumpTarget) {
|
|
|
|
for (unsigned i = 0; i < depth; i++)
|
|
|
|
stack[i].reset();
|
|
|
|
}
|
|
|
|
|
|
|
|
unsigned nuses = GetUseCount(script, offset);
|
|
|
|
unsigned ndefs = GetDefCount(script, offset);
|
|
|
|
|
|
|
|
if (nuses) {
|
|
|
|
PoppedValue *popped = ArenaArray<PoppedValue>(pool, nuses);
|
|
|
|
if (!popped)
|
|
|
|
return false;
|
|
|
|
for (unsigned i = 0; i < nuses; i++)
|
|
|
|
popped[i] = stack[depth - 1 - i];
|
|
|
|
poppedArray[offset - start] = popped;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (unsigned i = 0; i < ndefs; i++) {
|
|
|
|
PoppedValue &value = stack[depth - nuses + i];
|
|
|
|
value.offset = offset;
|
|
|
|
value.which = i;
|
|
|
|
}
|
|
|
|
|
|
|
|
depth -= nuses;
|
|
|
|
depth += ndefs;
|
|
|
|
|
|
|
|
offset = successorOffset;
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
// Live Range Analysis
|
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
|
|
LifetimeScript::LifetimeScript()
|
|
|
|
{
|
2011-03-20 08:23:27 -07:00
|
|
|
PodZero(this);
|
2010-12-06 11:53:53 -08:00
|
|
|
}
|
|
|
|
|
|
|
|
LifetimeScript::~LifetimeScript()
|
|
|
|
{
|
|
|
|
JS_FinishArenaPool(&pool);
|
|
|
|
}
|
|
|
|
|
|
|
|
bool
|
2011-03-26 19:07:13 -07:00
|
|
|
LifetimeScript::analyze(JSContext *cx, analyze::Script *analysis, JSScript *script)
|
2010-12-06 11:53:53 -08:00
|
|
|
{
|
|
|
|
JS_ASSERT(analysis->hasAnalyzed() && !analysis->failed());
|
|
|
|
|
2011-03-26 19:07:13 -07:00
|
|
|
JS_InitArenaPool(&pool, "script_liverange", 256, 8, NULL);
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
this->analysis = analysis;
|
|
|
|
this->script = script;
|
|
|
|
|
|
|
|
codeArray = ArenaArray<LifetimeBytecode>(pool, script->length);
|
|
|
|
if (!codeArray)
|
|
|
|
return false;
|
|
|
|
PodZero(codeArray, script->length);
|
|
|
|
|
2011-03-20 08:23:27 -07:00
|
|
|
unsigned nfixed = analysis->localCount();
|
2011-03-26 19:07:13 -07:00
|
|
|
unsigned nargs = script->fun ? script->fun->nargs : 0;
|
2011-04-05 18:12:03 -07:00
|
|
|
|
|
|
|
nLifetimes = 2 + nargs + nfixed;
|
|
|
|
lifetimes = ArenaArray<LifetimeVariable>(pool, nLifetimes);
|
|
|
|
if (!lifetimes)
|
2011-03-20 08:23:27 -07:00
|
|
|
return false;
|
2011-04-05 18:12:03 -07:00
|
|
|
PodZero(lifetimes, nLifetimes);
|
2010-12-06 11:53:53 -08:00
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
LifetimeVariable *thisVar = lifetimes + 1;
|
|
|
|
LifetimeVariable *args = lifetimes + 2;
|
|
|
|
LifetimeVariable *locals = lifetimes + 2 + nargs;
|
2010-12-06 11:53:53 -08:00
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
saved = ArenaArray<LifetimeVariable*>(pool, nLifetimes);
|
2011-03-03 14:07:48 -08:00
|
|
|
if (!saved)
|
|
|
|
return false;
|
2010-12-06 11:53:53 -08:00
|
|
|
savedCount = 0;
|
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
LifetimeLoop *loop = NULL;
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
uint32 offset = script->length - 1;
|
|
|
|
while (offset < script->length) {
|
|
|
|
Bytecode *code = analysis->maybeCode(offset);
|
|
|
|
if (!code) {
|
|
|
|
offset--;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
if (loop && code->safePoint)
|
|
|
|
loop->hasSafePoints = true;
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
UntrapOpcode untrap(cx, script, script->code + offset);
|
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
if (codeArray[offset].loop) {
|
2010-12-06 11:53:53 -08:00
|
|
|
/*
|
|
|
|
* This is the head of a loop, we need to go and make sure that any
|
|
|
|
* variables live at the head are live at the backedge and points prior.
|
|
|
|
* For each such variable, look for the last lifetime segment in the body
|
|
|
|
* and extend it to the end of the loop.
|
|
|
|
*/
|
2011-04-06 14:04:24 -07:00
|
|
|
JS_ASSERT(loop == codeArray[offset].loop);
|
2011-04-05 18:12:03 -07:00
|
|
|
unsigned backedge = codeArray[offset].loop->backedge;
|
2011-03-20 08:23:27 -07:00
|
|
|
for (unsigned i = 0; i < nfixed; i++) {
|
2010-12-06 11:53:53 -08:00
|
|
|
if (locals[i].lifetime && !extendVariable(cx, locals[i], offset, backedge))
|
|
|
|
return false;
|
|
|
|
}
|
2011-03-20 08:23:27 -07:00
|
|
|
for (unsigned i = 0; i < nargs; i++) {
|
2010-12-06 11:53:53 -08:00
|
|
|
if (args[i].lifetime && !extendVariable(cx, args[i], offset, backedge))
|
|
|
|
return false;
|
|
|
|
}
|
2011-04-05 18:12:03 -07:00
|
|
|
|
2011-04-06 14:04:24 -07:00
|
|
|
loop = loop->parent;
|
|
|
|
JS_ASSERT_IF(loop, loop->head < offset);
|
2010-12-06 11:53:53 -08:00
|
|
|
}
|
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
/* Find the last jump target in the loop, other than the initial entry point. */
|
|
|
|
if (loop && code->jumpTarget && offset != loop->entry && offset > loop->lastBlock)
|
|
|
|
loop->lastBlock = offset;
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
jsbytecode *pc = script->code + offset;
|
|
|
|
JSOp op = (JSOp) *pc;
|
|
|
|
|
|
|
|
switch (op) {
|
|
|
|
case JSOP_GETARG:
|
2011-04-19 15:24:09 -07:00
|
|
|
case JSOP_CALLARG: {
|
2010-12-06 11:53:53 -08:00
|
|
|
unsigned arg = GET_ARGNO(pc);
|
|
|
|
if (!analysis->argEscapes(arg)) {
|
|
|
|
if (!addVariable(cx, args[arg], offset))
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_SETARG: {
|
|
|
|
unsigned arg = GET_ARGNO(pc);
|
2011-04-05 18:12:03 -07:00
|
|
|
if (!analysis->argEscapes(arg)) {
|
|
|
|
if (!killVariable(cx, args[arg], offset))
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_INCARG:
|
|
|
|
case JSOP_DECARG:
|
|
|
|
case JSOP_ARGINC:
|
|
|
|
case JSOP_ARGDEC: {
|
|
|
|
unsigned arg = GET_ARGNO(pc);
|
|
|
|
if (!analysis->argEscapes(arg)) {
|
|
|
|
if (!killVariable(cx, args[arg], offset))
|
|
|
|
return false;
|
|
|
|
if (!addVariable(cx, args[arg], offset))
|
|
|
|
return false;
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_GETLOCAL:
|
2011-04-19 15:24:09 -07:00
|
|
|
case JSOP_CALLLOCAL: {
|
2010-12-06 11:53:53 -08:00
|
|
|
unsigned local = GET_SLOTNO(pc);
|
|
|
|
if (!analysis->localEscapes(local)) {
|
2011-03-20 08:23:27 -07:00
|
|
|
JS_ASSERT(local < nfixed);
|
2010-12-06 11:53:53 -08:00
|
|
|
if (!addVariable(cx, locals[local], offset))
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_SETLOCAL:
|
2010-12-28 11:53:50 -08:00
|
|
|
case JSOP_SETLOCALPOP:
|
|
|
|
case JSOP_DEFLOCALFUN: {
|
2010-12-06 11:53:53 -08:00
|
|
|
unsigned local = GET_SLOTNO(pc);
|
2011-03-20 08:23:27 -07:00
|
|
|
if (!analysis->localEscapes(local)) {
|
|
|
|
JS_ASSERT(local < nfixed);
|
2011-04-05 18:12:03 -07:00
|
|
|
if (!killVariable(cx, locals[local], offset))
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_INCLOCAL:
|
|
|
|
case JSOP_DECLOCAL:
|
|
|
|
case JSOP_LOCALINC:
|
|
|
|
case JSOP_LOCALDEC: {
|
|
|
|
unsigned local = GET_SLOTNO(pc);
|
|
|
|
if (!analysis->localEscapes(local)) {
|
|
|
|
if (!killVariable(cx, locals[local], offset))
|
|
|
|
return false;
|
|
|
|
if (!addVariable(cx, locals[local], offset))
|
|
|
|
return false;
|
2011-03-20 08:23:27 -07:00
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_THIS:
|
2011-04-05 18:12:03 -07:00
|
|
|
if (!addVariable(cx, *thisVar, offset))
|
2010-12-06 11:53:53 -08:00
|
|
|
return false;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case JSOP_IFEQ:
|
|
|
|
case JSOP_IFEQX:
|
|
|
|
case JSOP_IFNE:
|
|
|
|
case JSOP_IFNEX:
|
|
|
|
case JSOP_OR:
|
|
|
|
case JSOP_ORX:
|
|
|
|
case JSOP_AND:
|
|
|
|
case JSOP_ANDX:
|
|
|
|
case JSOP_GOTO:
|
|
|
|
case JSOP_GOTOX: {
|
2011-04-05 18:12:03 -07:00
|
|
|
/*
|
|
|
|
* Forward jumps need to pull in all variables which are live at
|
|
|
|
* their target offset --- the variables live before the jump are
|
|
|
|
* the union of those live at the fallthrough and at the target.
|
|
|
|
*/
|
2010-12-06 11:53:53 -08:00
|
|
|
uint32 targetOffset = offset + GetJumpOffset(pc, pc);
|
|
|
|
if (targetOffset < offset) {
|
|
|
|
JSOp nop = JSOp(script->code[targetOffset]);
|
|
|
|
if (nop == JSOP_GOTO || nop == JSOP_GOTOX) {
|
|
|
|
/* This is a continue, short circuit the backwards goto. */
|
|
|
|
jsbytecode *target = script->code + targetOffset;
|
|
|
|
targetOffset = targetOffset + GetJumpOffset(target, target);
|
2011-04-05 18:12:03 -07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Unless this is continuing an outer loop, it is a jump to
|
|
|
|
* the entry offset separate from the initial jump.
|
|
|
|
* Prune the last block in the loop.
|
|
|
|
*/
|
|
|
|
JS_ASSERT(loop);
|
|
|
|
if (loop->entry == targetOffset && loop->entry > loop->lastBlock)
|
|
|
|
loop->lastBlock = loop->entry;
|
2010-12-06 11:53:53 -08:00
|
|
|
} else {
|
|
|
|
/* This is a loop back edge, no lifetime to pull in yet. */
|
2010-12-06 15:54:16 -08:00
|
|
|
JS_ASSERT(nop == JSOP_TRACE || nop == JSOP_NOTRACE);
|
2011-04-05 18:12:03 -07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If we already have a loop, it is an outer loop and we
|
|
|
|
* need to prune the last block in the loop --- we do not
|
|
|
|
* track 'continue' statements for outer loops.
|
|
|
|
*/
|
|
|
|
if (loop && loop->entry > loop->lastBlock)
|
|
|
|
loop->lastBlock = loop->entry;
|
|
|
|
|
2011-04-06 14:04:24 -07:00
|
|
|
LifetimeLoop *nloop = ArenaNew<LifetimeLoop>(pool);
|
|
|
|
if (!nloop)
|
2011-04-05 18:12:03 -07:00
|
|
|
return false;
|
2011-04-06 14:04:24 -07:00
|
|
|
PodZero(nloop);
|
|
|
|
|
2011-04-07 16:12:37 -07:00
|
|
|
if (loop)
|
|
|
|
loop->hasCallsLoops = true;
|
|
|
|
|
2011-04-06 14:04:24 -07:00
|
|
|
nloop->parent = loop;
|
|
|
|
loop = nloop;
|
2011-04-05 18:12:03 -07:00
|
|
|
|
|
|
|
codeArray[targetOffset].loop = loop;
|
|
|
|
loop->head = targetOffset;
|
|
|
|
loop->backedge = offset;
|
|
|
|
loop->lastBlock = loop->head;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Find the entry jump, which will be a GOTO for 'for' or
|
2011-04-19 06:39:49 -07:00
|
|
|
* 'while' loops or a fallthrough for 'do while' loops.
|
2011-04-05 18:12:03 -07:00
|
|
|
*/
|
|
|
|
uint32 entry = targetOffset;
|
|
|
|
if (entry) {
|
|
|
|
do {
|
|
|
|
entry--;
|
|
|
|
} while (!analysis->maybeCode(entry));
|
|
|
|
|
|
|
|
jsbytecode *entrypc = script->code + entry;
|
|
|
|
if (JSOp(*entrypc) == JSOP_GOTO || JSOp(*entrypc) == JSOP_GOTOX)
|
|
|
|
loop->entry = entry + GetJumpOffset(entrypc, entrypc);
|
|
|
|
else
|
|
|
|
loop->entry = targetOffset;
|
|
|
|
} else {
|
|
|
|
/* Do-while loop at the start of the script. */
|
|
|
|
loop->entry = targetOffset;
|
|
|
|
}
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
for (unsigned i = 0; i < savedCount; i++) {
|
2010-12-06 17:23:19 -08:00
|
|
|
LifetimeVariable &var = *saved[i];
|
|
|
|
JS_ASSERT(!var.lifetime && var.saved);
|
|
|
|
if (var.live(targetOffset)) {
|
2010-12-06 11:53:53 -08:00
|
|
|
/*
|
|
|
|
* Jumping to a place where this variable is live. Make a new
|
|
|
|
* lifetime segment for the variable.
|
|
|
|
*/
|
2011-04-19 06:39:49 -07:00
|
|
|
var.lifetime = ArenaNew<Lifetime>(pool, offset, var.savedEnd, var.saved);
|
2010-12-06 17:23:19 -08:00
|
|
|
if (!var.lifetime)
|
2010-12-06 11:53:53 -08:00
|
|
|
return false;
|
2010-12-06 17:23:19 -08:00
|
|
|
var.saved = NULL;
|
|
|
|
saved[i--] = saved[--savedCount];
|
2011-04-19 06:39:49 -07:00
|
|
|
} else if (loop && !var.savedEnd) {
|
|
|
|
/*
|
|
|
|
* This jump precedes the basic block which killed the variable,
|
|
|
|
* remember it and use it for the end of the next lifetime
|
|
|
|
* segment should the variable become live again. This is needed
|
|
|
|
* for loops, as if we wrap liveness around the loop the isLive
|
|
|
|
* test below may have given the wrong answer.
|
|
|
|
*/
|
|
|
|
var.savedEnd = offset;
|
2010-12-06 11:53:53 -08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case JSOP_LOOKUPSWITCH:
|
|
|
|
case JSOP_LOOKUPSWITCHX:
|
|
|
|
case JSOP_TABLESWITCH:
|
|
|
|
case JSOP_TABLESWITCHX:
|
|
|
|
/* Restore all saved variables. :FIXME: maybe do this precisely. */
|
|
|
|
for (unsigned i = 0; i < savedCount; i++) {
|
2010-12-07 09:13:53 -08:00
|
|
|
LifetimeVariable &var = *saved[i];
|
2011-04-19 06:39:49 -07:00
|
|
|
var.lifetime = ArenaNew<Lifetime>(pool, offset, var.savedEnd, var.saved);
|
2010-12-07 09:13:53 -08:00
|
|
|
if (!var.lifetime)
|
2010-12-06 11:53:53 -08:00
|
|
|
return false;
|
2010-12-07 09:13:53 -08:00
|
|
|
var.saved = NULL;
|
|
|
|
saved[i--] = saved[--savedCount];
|
2010-12-06 11:53:53 -08:00
|
|
|
}
|
|
|
|
savedCount = 0;
|
|
|
|
break;
|
|
|
|
|
2011-04-07 16:12:37 -07:00
|
|
|
case JSOP_NEW:
|
|
|
|
case JSOP_CALL:
|
|
|
|
case JSOP_EVAL:
|
|
|
|
case JSOP_FUNAPPLY:
|
|
|
|
case JSOP_FUNCALL:
|
|
|
|
if (loop)
|
|
|
|
loop->hasCallsLoops = true;
|
|
|
|
break;
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
default:;
|
|
|
|
}
|
|
|
|
|
|
|
|
offset--;
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef DEBUG
|
|
|
|
void
|
|
|
|
LifetimeScript::dumpVariable(LifetimeVariable &var)
|
|
|
|
{
|
|
|
|
Lifetime *segment = var.lifetime ? var.lifetime : var.saved;
|
|
|
|
while (segment) {
|
|
|
|
printf(" (%u,%u%s)", segment->start, segment->end, segment->loopTail ? ",tail" : "");
|
|
|
|
segment = segment->next;
|
|
|
|
}
|
|
|
|
printf("\n");
|
|
|
|
}
|
|
|
|
#endif /* DEBUG */
|
|
|
|
|
|
|
|
inline bool
|
|
|
|
LifetimeScript::addVariable(JSContext *cx, LifetimeVariable &var, unsigned offset)
|
|
|
|
{
|
|
|
|
if (var.lifetime) {
|
|
|
|
JS_ASSERT(offset < var.lifetime->start);
|
|
|
|
var.lifetime->start = offset;
|
|
|
|
} else {
|
|
|
|
if (var.saved) {
|
|
|
|
/* Remove from the list of saved entries. */
|
|
|
|
for (unsigned i = 0; i < savedCount; i++) {
|
|
|
|
if (saved[i] == &var) {
|
|
|
|
JS_ASSERT(savedCount);
|
|
|
|
saved[i--] = saved[--savedCount];
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2011-04-19 06:39:49 -07:00
|
|
|
var.lifetime = ArenaNew<Lifetime>(pool, offset, var.savedEnd, var.saved);
|
2010-12-06 11:53:53 -08:00
|
|
|
if (!var.lifetime)
|
|
|
|
return false;
|
|
|
|
var.saved = NULL;
|
|
|
|
}
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2011-04-05 18:12:03 -07:00
|
|
|
inline bool
|
2010-12-06 11:53:53 -08:00
|
|
|
LifetimeScript::killVariable(JSContext *cx, LifetimeVariable &var, unsigned offset)
|
|
|
|
{
|
2011-04-05 18:12:03 -07:00
|
|
|
if (!var.lifetime) {
|
|
|
|
/* Make a point lifetime indicating the write. */
|
2011-04-19 06:39:49 -07:00
|
|
|
if (!var.saved)
|
|
|
|
saved[savedCount++] = &var;
|
|
|
|
var.saved = ArenaNew<Lifetime>(pool, offset, var.savedEnd, var.saved);
|
2011-04-05 18:12:03 -07:00
|
|
|
if (!var.saved)
|
|
|
|
return false;
|
|
|
|
var.saved->write = true;
|
2011-04-19 06:39:49 -07:00
|
|
|
var.savedEnd = 0;
|
2011-04-05 18:12:03 -07:00
|
|
|
return true;
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
JS_ASSERT(offset < var.lifetime->start);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The variable is considered to be live at the bytecode which kills it
|
|
|
|
* (just not at earlier bytecodes). This behavior is needed by downstream
|
|
|
|
* register allocation (see FrameState::bestEvictReg).
|
|
|
|
*/
|
|
|
|
var.lifetime->start = offset;
|
2011-04-05 18:12:03 -07:00
|
|
|
var.lifetime->write = true;
|
2010-12-06 11:53:53 -08:00
|
|
|
|
|
|
|
var.saved = var.lifetime;
|
|
|
|
var.savedEnd = 0;
|
|
|
|
var.lifetime = NULL;
|
|
|
|
|
|
|
|
saved[savedCount++] = &var;
|
2011-04-05 18:12:03 -07:00
|
|
|
|
|
|
|
return true;
|
2010-12-06 11:53:53 -08:00
|
|
|
}
|
|
|
|
|
|
|
|
inline bool
|
|
|
|
LifetimeScript::extendVariable(JSContext *cx, LifetimeVariable &var, unsigned start, unsigned end)
|
|
|
|
{
|
|
|
|
JS_ASSERT(var.lifetime);
|
|
|
|
var.lifetime->start = start;
|
|
|
|
|
2011-04-19 06:39:49 -07:00
|
|
|
/*
|
|
|
|
* When walking backwards through loop bodies, we don't know which vars
|
|
|
|
* are live at the loop's backedge. We save the endpoints for lifetime
|
|
|
|
* segments which we *would* use if the variables were live at the backedge
|
|
|
|
* and extend the variable with new lifetimes if we find the variable is
|
|
|
|
* indeed live at the head of the loop.
|
|
|
|
*
|
|
|
|
* while (...) {
|
|
|
|
* if (x #1) { ... }
|
|
|
|
* ...
|
|
|
|
* if (... #2) { x = 0; #3}
|
|
|
|
* }
|
|
|
|
*
|
|
|
|
* If x is not live after the loop, we treat it as dead in the walk and
|
|
|
|
* make a point lifetime for the write at #3. At the beginning of that
|
|
|
|
* basic block (#2), we save the loop endpoint; if we knew x was live in
|
|
|
|
* the next iteration then a new lifetime would be made here. At #1 we
|
|
|
|
* mark x live again, make a segment between the head of the loop and #1,
|
|
|
|
* and then extend x with loop tail lifetimes from #1 to #2, and from #3
|
|
|
|
* to the back edge.
|
|
|
|
*/
|
|
|
|
|
2010-12-06 11:53:53 -08:00
|
|
|
Lifetime *segment = var.lifetime;
|
2011-04-19 06:39:49 -07:00
|
|
|
while (segment && segment->start < end) {
|
|
|
|
uint32 savedEnd = segment->savedEnd;
|
|
|
|
if (!segment->next || segment->next->start >= end) {
|
|
|
|
/*
|
|
|
|
* savedEnd is only set for variables killed in the middle of the
|
|
|
|
* loop. Make a tail segment connecting the last use with the
|
|
|
|
* back edge.
|
|
|
|
*/
|
|
|
|
if (segment->end >= end) {
|
|
|
|
/* Variable known to be live after the loop finishes. */
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
savedEnd = end;
|
|
|
|
}
|
|
|
|
JS_ASSERT(savedEnd <= end);
|
|
|
|
if (savedEnd > segment->end) {
|
|
|
|
Lifetime *tail = ArenaNew<Lifetime>(pool, savedEnd, 0, segment->next);
|
|
|
|
if (!tail)
|
|
|
|
return false;
|
|
|
|
tail->start = segment->end;
|
|
|
|
tail->loopTail = true;
|
2010-12-06 11:53:53 -08:00
|
|
|
|
2011-04-19 06:39:49 -07:00
|
|
|
/*
|
|
|
|
* Clear the segment's saved end, but preserve in the tail if this
|
|
|
|
* is the last segment in the loop and the variable is killed in an
|
|
|
|
* outer loop before the backedge.
|
|
|
|
*/
|
|
|
|
if (segment->savedEnd > end) {
|
|
|
|
JS_ASSERT(savedEnd == end);
|
|
|
|
tail->savedEnd = segment->savedEnd;
|
|
|
|
}
|
|
|
|
segment->savedEnd = 0;
|
|
|
|
|
|
|
|
segment->next = tail;
|
|
|
|
segment = tail->next;
|
|
|
|
} else {
|
|
|
|
JS_ASSERT(segment->savedEnd == 0);
|
|
|
|
segment = segment->next;
|
|
|
|
}
|
|
|
|
}
|
2010-12-06 11:53:53 -08:00
|
|
|
|
|
|
|
return true;
|
2010-10-26 12:00:54 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
} /* namespace analyze */
|
|
|
|
} /* namespace js */
|