kdelibs/kjs/nodes.cpp

/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
 *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
 *  Copyright (C) 2003, 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 *  Copyright (C) 2007 Maksim Orlovich (maksim@kde.org)
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 */

#include "nodes.h"
#include <config-kjs.h>
#include "scriptfunction.h"
#include "CompileState.h"

#include <math.h>
#include <stdio.h>
#ifdef KJS_DEBUG_MEM
#include <typeinfo>
#endif

//#include <iostream>

#include "debugger.h"
#include "function_object.h"
#include "lexer.h"
#include "operations.h"
#include "package.h"
#include "PropertyNameArray.h"
#include <wtf/AlwaysInline.h>
#include <wtf/Assertions.h>
#include <wtf/HashSet.h>
#include <wtf/HashCountedSet.h>
#include <wtf/MathExtras.h>

#include "bytecode/machine.h"

namespace KJS {

// ------------------------------ Node -----------------------------------------


#ifndef NDEBUG
struct NodeCounter {
    static unsigned count;
    ~NodeCounter()
    {
        if (count)
            fprintf(stderr, "LEAK: %d KJS::Node\n", count);
    }
};
unsigned NodeCounter::count = 0;
static NodeCounter nodeCounter;
#endif

static HashSet<Node*>* newNodes;
static HashCountedSet<Node*>* nodeExtraRefCounts;

Node::Node()
{
#ifndef NDEBUG
    ++NodeCounter::count;
#endif
  m_line = lexer().lineNo();
  if (!newNodes)
      newNodes = new HashSet<Node*>;
  newNodes->add(this);
}

Node::~Node()
{
#ifndef NDEBUG
    --NodeCounter::count;
#endif
}

void Node::ref()
{
    // bumping from 0 to 1 is just removing from the new nodes set
    if (newNodes) {
        HashSet<Node*>::iterator it = newNodes->find(this);
        if (it != newNodes->end()) {
            newNodes->remove(it);
            ASSERT(!nodeExtraRefCounts || !nodeExtraRefCounts->contains(this));
            return;
        }
    }

    ASSERT(!newNodes || !newNodes->contains(this));

    if (!nodeExtraRefCounts)
        nodeExtraRefCounts = new HashCountedSet<Node*>;
    nodeExtraRefCounts->add(this);
}

void Node::deref()
{
    ASSERT(!newNodes || !newNodes->contains(this));

    if (!nodeExtraRefCounts) {
        delete this;
        return;
    }

    HashCountedSet<Node*>::iterator it = nodeExtraRefCounts->find(this);
    if (it == nodeExtraRefCounts->end())
        delete this;
    else
        nodeExtraRefCounts->remove(it);
}

unsigned Node::refcount()
{
    if (newNodes && newNodes->contains(this)) {
        ASSERT(!nodeExtraRefCounts || !nodeExtraRefCounts->contains(this));
        return 0;
    }

    ASSERT(!newNodes || !newNodes->contains(this));

    if (!nodeExtraRefCounts)
        return 1;

    return 1 + nodeExtraRefCounts->count(this);
}

void Node::clearNewNodes()
{
    if (!newNodes)
        return;

#ifndef NDEBUG
    HashSet<Node*>::iterator end = newNodes->end();
    for (HashSet<Node*>::iterator it = newNodes->begin(); it != end; ++it)
        ASSERT(!nodeExtraRefCounts || !nodeExtraRefCounts->contains(*it));
#endif
    deleteAllValues(*newNodes);
    delete newNodes;
    newNodes = 0;
}

static void substitute(UString &string, const UString &substring)
{
    int position = string.find("%s");
    assert(position != -1);
    UString newString = string.substr(0, position);
    newString.append(substring);
    newString.append(string.substr(position + 2));
    string = newString;
}

static inline int currentSourceId(ExecState* exec)
{
    return exec->currentBody()->sourceId();
}

static inline const UString& currentSourceURL(ExecState* exec)
{
    return exec->currentBody()->sourceURL();
}

JSValue* Node::throwError(ExecState* exec, ErrorType e, const UString& msg)
{
    return KJS::throwError(exec, e, msg, lineNo(), currentSourceId(exec), currentSourceURL(exec));
}

JSValue* Node::throwError(ExecState* exec, ErrorType e, const UString& msg, const Identifier& label)
{
    UString message = msg;
    substitute(message, label.ustring());
    return KJS::throwError(exec, e, message, lineNo(), currentSourceId(exec), currentSourceURL(exec));
}

JSValue* Node::throwUndefinedVariableError(ExecState* exec, const Identifier& ident)
{
    return throwError(exec, ReferenceError, "Cannot find variable: %s", ident);
}

Node *Node::nodeInsideAllParens()
{
    return this;
}

class VarDeclVisitor: public NodeVisitor {
  private:
    ExecState* m_exec;
  public:
    VarDeclVisitor(ExecState* exec) : m_exec(exec)
    {}

    virtual Node* visit(Node* node) {
      node->processVarDecl(m_exec);

      //Do not recurse inside function bodies, or things that 
      // syntactically can't contain declarations
      if (!node->scanForDeclarations())
        return 0;

      return NodeVisitor::visit(node);
    }
};

class FuncDeclVisitor: public NodeVisitor {
  private:
    ExecState* m_exec;
  public:
    FuncDeclVisitor(ExecState* exec) : m_exec(exec)
    {}

    virtual Node* visit(Node* node) {
      node->processFuncDecl(m_exec);

      if (!node->scanForDeclarations())
        return 0;

      return NodeVisitor::visit(node);
    }
};

void Node::processDecls(ExecState *exec) {
  VarDeclVisitor vVisit(exec);
  vVisit.visit(this);

  FuncDeclVisitor fVisit(exec);
  fVisit.visit(this);
}

void Node::processVarDecl (ExecState*)
{}

void Node::processFuncDecl(ExecState*)
{}

// ------------------------------ NodeVisitor ----------------------------------
Node* NodeVisitor::visit(Node *node) {
  node->recurseVisit(this);
  return 0;
}

// ------------------------------ StatementNode --------------------------------

StatementNode::StatementNode()
    : m_lastLine(-1)
{
    m_line = -1;
}

void StatementNode::setLoc(int firstLine, int lastLine) const
{
    m_line = firstLine;
    m_lastLine = lastLine;
}

void StatementNode::hitStatement(ExecState* exec)
{
  // The debugger is always non-zero here, since otherwise this won't be involved
  exec->dynamicInterpreter()->debugger()->reportAtStatement(exec, currentSourceId(exec), firstLine(), lastLine());
}

// ------------------------------ GroupNode ------------------------------------

Node *GroupNode::nodeInsideAllParens()
{
    Node *n = this;
    do
        n = static_cast<GroupNode *>(n)->group.get();
    while (n->isGroupNode());
    return n;
}

void GroupNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, group);
}


// ------------------------------ ElementNode ----------------------------------

void ElementNode::breakCycle()
{
    next = 0;
}

void ElementNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, next);
    recurseVisitLink(visitor, node);
}


// ------------------------------ ArrayNode ------------------------------------

void ArrayNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, element);
}

// ------------------------------ ObjectLiteralNode ----------------------------

void ObjectLiteralNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, list);
}

// ------------------------------ PropertyListNode -----------------------------

void PropertyListNode::breakCycle()
{
    next = 0;
}

void PropertyListNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, node);
    recurseVisitLink(visitor, next);
}

// ------------------------------ PropertyNode -----------------------------
void PropertyNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, name);
    recurseVisitLink(visitor, assign);
}

// ------------------------------ BracketAccessorNode --------------------------------

void BracketAccessorNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr1);
  recurseVisitLink(visitor, expr2);
}

// ------------------------------ DotAccessorNode --------------------------------

void DotAccessorNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, expr);
}

// ------------------------------ ArgumentListNode -----------------------------

void ArgumentListNode::breakCycle()
{
    next = 0;
}

void ArgumentListNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, next);
    recurseVisitLink(visitor, expr);
}

// ------------------------------ ArgumentsNode --------------------------------

void ArgumentsNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, list);
}

// ------------------------------ NewExprNode ----------------------------------

void NewExprNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, expr);
    recurseVisitLink(visitor, args);
}

// ------------------------------ FunctionCallValueNode ------------------------

void FunctionCallValueNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, expr);
    recurseVisitLink(visitor, args);
}

// ------------------------------ FunctionCallRerefenceNode --------------------

void FunctionCallReferenceNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, expr);
    recurseVisitLink(visitor, args);
}

// ------------------------------ PostfixNode ----------------------------------

void PostfixNode::recurseVisit(NodeVisitor *visitor)
{
   Node::recurseVisitLink(visitor, m_loc);
}

// ------------------------------ DeleteReferenceNode -------------------------------

void DeleteReferenceNode::recurseVisit(NodeVisitor *visitor)
{
   Node::recurseVisitLink(visitor, loc);
}

// ------------------------------ DeleteValueNode -----------------------------------

void DeleteValueNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, m_expr);
}

// ------------------------------ VoidNode -------------------------------------

void VoidNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ TypeOfVarNode -----------------------------------

void TypeOfVarNode::recurseVisit(NodeVisitor *visitor)
{
   Node::recurseVisitLink(visitor, loc);
}

// ------------------------------ TypeOfValueNode -----------------------------------

void TypeOfValueNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, m_expr);
}

// ------------------------------ PrefixNode ----------------------------------------

void PrefixNode::recurseVisit(NodeVisitor *visitor)
{
   Node::recurseVisitLink(visitor, m_loc);
}

// ------------------------------ UnaryPlusNode --------------------------------

void UnaryPlusNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ NegateNode -----------------------------------

void NegateNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ BitwiseNotNode -------------------------------

void BitwiseNotNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ LogicalNotNode -------------------------------

void LogicalNotNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------ BinaryOperatorNode -------------------------------

void BinaryOperatorNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr1);
  recurseVisitLink(visitor, expr2);
}

// ------------------------------ BinaryLogicalNode ----------------------------

void BinaryLogicalNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr1);
  recurseVisitLink(visitor, expr2);
}

// ------------------------------ ConditionalNode ------------------------------

void ConditionalNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, logical);
  recurseVisitLink(visitor, expr1);
  recurseVisitLink(visitor, expr2);
}

// ------------------------------ AssignNode -----------------------------------

void AssignNode::recurseVisit(NodeVisitor *visitor)
{
   Node::recurseVisitLink(visitor, m_loc);
   Node::recurseVisitLink(visitor, m_right);
}

// ------------------------------ CommaNode ------------------------------------

void CommaNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr1);
  recurseVisitLink(visitor, expr2);
}

// ------------------------------ AssignExprNode -------------------------------

void AssignExprNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ VarDeclNode ----------------------------------

VarDeclNode::VarDeclNode(const Identifier &id, AssignExprNode *in, Type t)
    : varType(t), ident(id), init(in)
{
}

#if 0
// ECMA 12.2
JSValue *VarDeclNode::evaluate(ExecState *exec)
{
  JSObject* variable = exec->variableObject();

  JSValue* val;
  if (init) {
      val = init->evaluate(exec);
      KJS_CHECKEXCEPTIONVALUE
  } else {
      // already declared? - check with getDirect so you can override
      // built-in properties of the global object with var declarations.
      // Also check for 'arguments' property. The 'arguments' cannot be found with
      // getDirect, because it's created lazily by
      // ActivationImp::getOwnPropertySlot.
      // Since variable declarations are always in function scope, 'variable'
      // will always contain instance of ActivationImp and ActivationImp will
      // always have 'arguments' property
      if (variable->getDirect(ident) || ident == exec->propertyNames().arguments)
          return 0;
      val = jsUndefined();
  }

#ifdef KJS_VERBOSE
  printInfo(exec,(UString("new variable ")+ident.ustring()).cstring().c_str(),val);
#endif
  // We use Internal to bypass all checks in derived objects, e.g. so that
  // "var location" creates a dynamic property instead of activating window.location.
  int flags = Internal;
  if (exec->codeType() != EvalCode)
    flags |= DontDelete;
  if (varType == VarDeclNode::Constant)
    flags |= ReadOnly;
  variable->put(exec, ident, val, flags);

  return 0; //No useful value, not a true expr
}
#endif

void VarDeclNode::processVarDecl(ExecState *exec)
{
  JSObject* variable = exec->variableObject();

  // First, determine which flags we want to use..
  int flags = DontDelete;
  if (varType == VarDeclNode::Constant)
    flags |= ReadOnly;

  // Are we inside a function? If so, we fill in the symbol table
  switch (exec->codeType()) {
    case FunctionCode:
      // Inside a function, we're just computing static information.
      // so, just fill in the symbol table.
      exec->currentBody()->addVarDecl(ident, flags, exec);
      return;
    case EvalCode:
      // eval-injected variables can be deleted..
      flags &= ~DontDelete;

      // If a variable by this name already exists, don't clobber it -
      // eval may be trying to inject a variable that already exists..
      if (!variable->hasProperty(exec, ident)) {
        variable->put(exec, ident, jsUndefined(), flags);
        // eval injected a new local into scope! Better mark that down,
        // so that NonLocalResolver stops skipping the local scope
        variable->setLocalInjected();
      }
      break;
    case GlobalCode:
      // If a variable by this name already exists, don't clobber it -
      // ### I am not sue this is needed for GlobalCode
      if (!variable->hasProperty(exec, ident))
        variable->put(exec, ident, jsUndefined(), flags);
  };
}

void VarDeclNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, init);
}

// ------------------------------ VarDeclListNode ------------------------------

void VarDeclListNode::breakCycle()
{
    next = 0;
}

void VarDeclListNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, var);
  recurseVisitLink(visitor, next);
}

// ------------------------------ VarStatementNode -----------------------------

void VarStatementNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, next);
}

// ------------------------------ BlockNode ------------------------------------

BlockNode::BlockNode(SourceElementsNode *s)
{
  if (s) {
    source = s->next.release();
    Parser::removeNodeCycle(source.get());
    setLoc(s->firstLine(), s->lastLine());
  } else {
    source = 0;
  }
}

void BlockNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, source);
}

// ------------------------------ ExprStatementNode ----------------------------

void ExprStatementNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ IfNode ---------------------------------------

void IfNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, statement1);
  recurseVisitLink(visitor, statement2);
}

// ------------------------------ DoWhileNode ----------------------------------

void DoWhileNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, statement);
}

// ------------------------------ WhileNode ------------------------------------

void WhileNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, statement);
}

// ------------------------------ ForNode --------------------------------------

void ForNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr1);
  recurseVisitLink(visitor, expr2);
  recurseVisitLink(visitor, expr3);
  recurseVisitLink(visitor, statement);
}

// ------------------------------ ForInNode ------------------------------------

ForInNode::ForInNode(Node *l, Node *e, StatementNode *s)
  : init(0L), lexpr(l), expr(e), varDecl(0L), statement(s)
{
}

ForInNode::ForInNode(const Identifier &i, AssignExprNode *in, Node *e, StatementNode *s)
  : ident(i), init(in), expr(e), statement(s)
{
  // for( var foo = bar in baz )
  varDecl = new VarDeclNode(ident, init.get(), VarDeclNode::Variable);
  lexpr   = new VarAccessNode(ident);
}

void ForInNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, init);
  recurseVisitLink(visitor, lexpr);
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, varDecl);
  recurseVisitLink(visitor, statement);
}

// ------------------------------ ReturnNode -----------------------------------

void ReturnNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, value);
}

// ------------------------------ WithNode -------------------------------------

void WithNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, statement);
}

// ------------------------------ CaseClauseNode -------------------------------

void CaseClauseNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, source);
}

// ------------------------------ ClauseListNode -------------------------------

void ClauseListNode::breakCycle()
{
    next = 0;
}

void ClauseListNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, clause);
  recurseVisitLink(visitor, next);
}

// ------------------------------ CaseBlockNode --------------------------------

CaseBlockNode::CaseBlockNode(ClauseListNode *l1, CaseClauseNode *d,
                             ClauseListNode *l2)
{
  if (l1) {
    list1 = l1->next.release();
    Parser::removeNodeCycle(list1.get());
  } else {
    list1 = 0;
  }

  def = d;

  if (l2) {
    list2 = l2->next.release();
    Parser::removeNodeCycle(list2.get());
  } else {
    list2 = 0;
  }
}

void CaseBlockNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, list1);
  recurseVisitLink(visitor, def);
  recurseVisitLink(visitor, list2);
}

// ------------------------------ SwitchNode -----------------------------------

void SwitchNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
  recurseVisitLink(visitor, block);
}

// ------------------------------ LabelNode ------------------------------------

void LabelNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, statement);
}

// ------------------------------ ThrowNode ------------------------------------

void ThrowNode::recurseVisit(NodeVisitor *visitor)
{
  recurseVisitLink(visitor, expr);
}

// ------------------------------ TryNode --------------------------------------

void TryNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, tryBlock);
    recurseVisitLink(visitor, catchBlock);
    recurseVisitLink(visitor, finallyBlock);
}

// ------------------------------ ParameterNode --------------------------------

void ParameterNode::breakCycle()
{
    next = 0;
}

void ParameterNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, next);
}

// ------------------------------ FunctionBodyNode -----------------------------

FunctionBodyNode::FunctionBodyNode(SourceElementsNode *s)
    : BlockNode(s)
    , m_sourceURL(lexer().sourceURL())
    , m_sourceId(parser().sourceId())
    , m_compType(NotCompiled)
    , m_flags(parser().popFunctionContext())
{
  setLoc(-1, -1);
}


void FunctionBodyNode::addVarDecl(const Identifier& ident, int attr, ExecState* exec)
{
  // There is one nasty special case: ignore a 'var' declaration of 'arguments';
  // it effectively doesn't do anything since the magic 'arguments' is already
  // in scope anyway, and if we allocated a local, we would have to worry about
  // keeping track of whether it was initialized or not on what is supposed to be the
  // fast path. So we just make this go through the property map instead.
  // Note that this does not matter for parameters or function declarations,
  // since those overwrite the magic 'arguments' anyway.
  if (ident == exec->propertyNames().arguments)
    return;

  (void)addSymbol(ident, attr);
}

void FunctionBodyNode::addFunDecl(const Identifier& ident, int attr, FuncDeclNode* funcDecl)
{
  m_functionLocals.append(addSymbol(ident, attr, funcDecl));
}

void FunctionBodyNode::reserveSlot(size_t id, bool shouldMark)
{
  ASSERT(id == m_symbolList.size());
  m_symbolList.append(SymbolInfo(shouldMark ? 0 : DontMark, 0));
}

size_t FunctionBodyNode::addSymbol(const Identifier& ident, int flags, FuncDeclNode* funcDecl)
{
  // We get symbols in the order specified in 10.1.3, but sometimes
  // the later ones are supposed to lose. This -mostly- does not
  // matter for us --- we primarily concern ourselves with name/ID
  // mapping, but there is an issue of attributes and funcDecl's.
  // However, the only flag that matters here is ReadOnly --
  // everything else just has DontDelete set; and it's from const,
  // so we can just ignore it on repetitions, since var/const should lose
  // and are at the end.
  //
  // And for funcDecl, since functions win over everything, we always set it if non-zero
  size_t oldId = m_symbolTable.get(ident.ustring().rep());
  if (oldId != missingSymbolMarker()) {
    if (funcDecl)
      m_symbolList[oldId].funcDecl = funcDecl;
    return oldId;
  }

  size_t id = m_symbolList.size();         //First entry gets 0, etc.
  m_symbolTable.set(ident.ustring().rep(), id);
  m_symbolList.append(SymbolInfo(flags, funcDecl));
  return id;
}

void FunctionBodyNode::addSymbolOverwriteID(size_t id, const Identifier& ident, int flags)
{
  ASSERT(id == m_symbolList.size());

  // Remove previous one, if any
  size_t oldId = m_symbolTable.get(ident.ustring().rep());
  if (oldId != missingSymbolMarker())
      m_symbolList[oldId].attr = DontMark;

  // Add a new one
  m_symbolTable.set(ident.ustring().rep(), id);
  m_symbolList.append(SymbolInfo(flags, 0));
}

void FunctionBodyNode::addParam(const Identifier& ident)
{
  m_paramList.append(ident);
}

Completion FunctionBodyNode::execute(ExecState *exec)
{
  CodeType    ctype   = exec->codeType();
  CompileType cmpType = exec->dynamicInterpreter()->debugger() ? Debug : Release;
  compileIfNeeded(ctype, cmpType);
  ASSERT(ctype != FunctionCode);

  LocalStorage*      store = new LocalStorage();
  LocalStorageEntry* regs;

  // Allocate enough space, and make sure to initialize things so we don't mark garbage
  store->resize(m_symbolList.size());
  regs = store->data();
  for (size_t c = 0; c < m_symbolList.size(); ++c) {
    regs[c].val.valueVal = jsUndefined();
    regs[c].attributes   = m_symbolList[c].attr;
  }
  
  exec->initLocalStorage(regs, m_symbolList.size());

  JSValue* val = Machine::runBlock(exec, m_compiledCode);

  Completion result;
  if (exec->hadException())
    result = Completion(Throw, exec->exception());
  else
    result = Completion(Normal, val);

  exec->initLocalStorage(0, 0);
  delete store;
  exec->clearException();

  return result;
}

void FunctionBodyNode::compile(CodeType ctype, CompileType compType)
{
  m_compType = compType;

  CompileState comp(ctype, compType, this, m_symbolList.size());
  generateExecCode(&comp);
  m_tearOffAtEnd = comp.needsClosures();

#if 0
  fprintf(stderr, "\n\n");
  fprintf(stderr, "\n---------------------------------\n\n");
  fprintf(stderr, "%s", toString().ascii());
  fprintf(stderr, "\n---------------------------------\n\n");
  CodeGen::disassembleBlock(m_compiledCode);
  fprintf(stderr, "\n---------------------------------\n\n");
#endif
}


// ------------------------------ FuncDeclNode ---------------------------------

// ECMA 13
void FuncDeclNode::processFuncDecl(ExecState *exec)
{
  // See whether we just need to fill in the symbol table,
  // or actually fiddle with objects.
  int flags = Internal | DontDelete;
  switch (exec->codeType()) {
    case FunctionCode:
      // Inside a function, just need symbol info
      exec->currentBody()->addFunDecl(ident, flags, this);
      return;
    case EvalCode:
      // eval-injected symbols can be deleted...
      flags &= ~DontDelete;

      // eval injected a new local into scope! Better mark that down,
      // so that NonLocalResolver stops skipping the local scope
      exec->variableObject()->setLocalInjected();

      // fallthrough intentional
    case GlobalCode:
      exec->variableObject()->put(exec, ident, makeFunctionObject(exec), flags);
  };
}

void FuncDeclNode::addParams()
{
  for (ParameterNode *p = param.get(); p != 0L; p = p->nextParam())
    body->addParam(p->ident());
}

FunctionImp* FuncDeclNode::makeFunctionObject(ExecState *exec)
{
  // TODO: let this be an object with [[Class]] property "Function"
  FunctionImp *func = new FunctionImp(exec, ident, body.get(), exec->scopeChain());

  JSObject *proto = exec->lexicalInterpreter()->builtinObject()->construct(exec, List::empty());
  proto->put(exec, exec->propertyNames().constructor, func, DontEnum);
  // ECMA Edition 5.1r6 - 15.3.5.2 - [[Writable]]: true, [[Enumerable]]: false, [[Configurable]]: false
  func->put(exec, exec->propertyNames().prototype, proto, Internal|DontDelete|DontEnum);

  func->put(exec, exec->propertyNames().length, jsNumber(body->numParams()), ReadOnly|DontDelete|DontEnum);

  return func;
}

void FuncDeclNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, param);
    recurseVisitLink(visitor, body);
}

// ------------------------------ FuncExprNode ---------------------------------

void FuncExprNode::addParams()
{
  for(ParameterNode *p = param.get(); p != 0L; p = p->nextParam())
    body->addParam(p->ident());
}

void FuncExprNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, param);
    recurseVisitLink(visitor, body);
}

// ------------------------------ SourceElementsNode ---------------------------

SourceElementsNode::SourceElementsNode(StatementNode *s1)
  : node(s1), next(this)
{
    Parser::noteNodeCycle(this);
    setLoc(s1->firstLine(), s1->lastLine());
}

SourceElementsNode::SourceElementsNode(SourceElementsNode *s1, StatementNode *s2)
  : node(s2), next(s1->next)
{
  s1->next = this;
  setLoc(s1->firstLine(), s2->lastLine());
}

void SourceElementsNode::breakCycle()
{
    next = 0;
}

void SourceElementsNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, node);
    recurseVisitLink(visitor, next);
}

// ------------------------------ ProgramNode ----------------------------------

ProgramNode::ProgramNode(SourceElementsNode *s) : FunctionBodyNode(s)
{
}

// ------------------------------ PackageNameNode ------------------------------
void PackageNameNode::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, names);
}

Completion PackageNameNode::loadSymbol(ExecState* exec, bool wildcard)
{
    Package* basePackage;
    JSObject* baseObject;
    if (names) {
	PackageObject *pobj = names->resolvePackage(exec);
	if (pobj == 0)
	    return Completion(Normal);
	basePackage = pobj->package();
	baseObject = pobj;
    } else {
	Interpreter* ip = exec->lexicalInterpreter();
	basePackage = ip->globalPackage();
	baseObject = ip->globalObject();
    }

    if (wildcard) {
	// if a .* is specified the last identifier should
	// denote another package name
	PackageObject* pobj = resolvePackage(exec, baseObject, basePackage);
	if (!pobj)
	    return Completion(Normal);
	basePackage = pobj->package();
	baseObject = pobj;
	basePackage->loadAllSymbols(exec, baseObject);
    } else {
	basePackage->loadSymbol(exec, baseObject, id);
    }

    return Completion(Normal);
}

PackageObject* PackageNameNode::resolvePackage(ExecState* exec)
{
    JSObject* baseObject;
    Package* basePackage;
    if (names) {
	PackageObject* basePackageObject = names->resolvePackage(exec);
	if (basePackageObject == 0)
	    return 0;
	baseObject = basePackageObject;
	basePackage = basePackageObject->package();
    } else {
	// first identifier is looked up in global object
	Interpreter* ip = exec->lexicalInterpreter();
	baseObject = ip->globalObject();
	basePackage = ip->globalPackage();
    }

    return resolvePackage(exec, baseObject, basePackage);
}

PackageObject* PackageNameNode::resolvePackage(ExecState* exec,
					       JSObject* baseObject,
					       Package* basePackage)
{
    PackageObject* res = 0;

    // Let's see whether the package was already resolved previously.
    JSValue* v = baseObject->get(exec, id);
    if (v && !v->isUndefined()) {
	if (!v->isObject()) {
	    // Symbol conflict
	    throwError(exec, GeneralError, "Invalid type of package %s", id);
	    return 0;
	}
	res = static_cast<PackageObject*>(v);
    } else {
	UString err;
	Package *newBase = basePackage->loadSubPackage(id, &err);
	if (newBase == 0) {
	    if (err.isEmpty()) {
		throwError(exec, GeneralError, "Package not found");
	    } else {
		throwError(exec, GeneralError, err);
	    }
	    return 0;
	}
	res = new PackageObject(newBase);
	baseObject->put(exec, id, res);
    }

    return res;
}

void ImportStatement::processVarDecl(ExecState* exec)
{
    // error out if package support is not activated
    Package* glob = exec->lexicalInterpreter()->globalPackage();
    if (!glob) {
	throwError(exec, GeneralError,
		   "Package support disabled. Import failed.");
	return;
    }

    // also error out if not used on top-level
    if (exec->codeType() != GlobalCode) {
      throwError(exec, GeneralError,
                  "Package imports may only occur at top level.");
      return;
    }

    name->loadSymbol(exec, wld);
}

void ImportStatement::recurseVisit(NodeVisitor *visitor)
{
    recurseVisitLink(visitor, name);
}

} //namespace KJS