function.cpp

khtml在gtk上的移植版本

// -*- c-basic-offset: 2 -*-
/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2002 Harri Porten ([e-mail])
 *  Copyright (C) 2001 Peter Kelly ([e-mail])
 *  Copyright (C) 2003 Apple Computer, Inc.
 *
 *  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., 59 Temple Place - Suite 330,
 *  Boston, MA 02111-1307, USA.
 *
 */

#include "function.h"

#include "internal.h"
#include "function_object.h"
#include "lexer.h"
#include "nodes.h"
#include "operations.h"
#include "debugger.h"
#include "context.h"

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>

using namespace KJS;

// ----------------------------- FunctionImp ----------------------------------

const ClassInfo FunctionImp::info = {"Function", &InternalFunctionImp::info, 0, 0};

namespace KJS {
  class Parameter {
  public:
    Parameter(const Identifier &n) : name(n), next(0L) { }
    ~Parameter() { delete next; }
    Identifier name;
    Parameter *next;
  };
};

FunctionImp::FunctionImp(ExecState *exec, const Identifier &n)
  : InternalFunctionImp(
      static_cast<FunctionPrototypeImp*>(exec->lexicalInterpreter()->builtinFunctionPrototype().imp())
      ), param(0L), ident(n)
{
}

FunctionImp::~FunctionImp()
{
  delete param;
}

bool FunctionImp::implementsCall() const
{
  return true;
}

Value FunctionImp::call(ExecState *exec, Object &thisObj, const List &args)
{
  Object &globalObj = exec->dynamicInterpreter()->globalObject();

  Debugger *dbg = exec->dynamicInterpreter()->imp()->debugger();
  int sid = -1;
  int lineno = -1;
  if (dbg) {
    if (inherits(&DeclaredFunctionImp::info)) {
      sid = static_cast<DeclaredFunctionImp*>(this)->body->sourceId();
      lineno = static_cast<DeclaredFunctionImp*>(this)->body->firstLine();
    }

    Object func(this);
    bool cont = dbg->callEvent(exec,sid,lineno,func,args);
    if (!cont) {
      dbg->imp()->abort();
      return Undefined();
    }
  }

  // enter a new execution context
  ContextImp ctx(globalObj, exec->dynamicInterpreter()->imp(), thisObj, codeType(),
                 exec->context().imp(), this, &args);
  ExecState newExec(exec->dynamicInterpreter(), &ctx);
  newExec.setException(exec->exception()); // could be null

  // assign user supplied arguments to parameters
  processParameters(&newExec, args);
  // add variable declarations (initialized to undefined)
  processVarDecls(&newExec);

  Completion comp = execute(&newExec);

  // if an exception occured, propogate it back to the previous execution object
  if (newExec.hadException())
    exec->setException(newExec.exception());

#ifdef KJS_VERBOSE
  if (comp.complType() == Throw)
    printInfo(exec,"throwing", comp.value());
  else if (comp.complType() == ReturnValue)
    printInfo(exec,"returning", comp.value());
  else
    fprintf(stderr, "returning: undefined\n");
#endif

  if (dbg) {
    Object func(this);
    int cont = dbg->returnEvent(exec,sid,lineno,func);
    if (!cont) {
      dbg->imp()->abort();
      return Undefined();
    }
  }

  if (comp.complType() == Throw) {
    exec->setException(comp.value());
    return comp.value();
  }
  else if (comp.complType() == ReturnValue)
    return comp.value();
  else
    return Undefined();
}

void FunctionImp::addParameter(const Identifier &n)
{
  Parameter **p = &param;
  while (*p)
    p = &(*p)->next;

  *p = new Parameter(n);
}

UString FunctionImp::parameterString() const
{
  UString s;
  const Parameter *p = param;
  while (p) {
    if (!s.isEmpty())
        s += ", ";
    s += p->name.ustring();
    p = p->next;
  }

  return s;
}


// ECMA 10.1.3q
void FunctionImp::processParameters(ExecState *exec, const List &args)
{
  Object variable = exec->context().imp()->variableObject();

#ifdef KJS_VERBOSE
  fprintf(stderr, "---------------------------------------------------\n"
	  "processing parameters for %s call\n",
	  name().isEmpty() ? "(internal)" : name().ascii());
#endif

  if (param) {
    ListIterator it = args.begin();
    Parameter *p = param;
    while (p) {
      if (it != args.end()) {
#ifdef KJS_VERBOSE
	fprintf(stderr, "setting parameter %s ", p->name.ascii());
	printInfo(exec,"to", *it);
#endif
	variable.put(exec, p->name, *it);
	it++;
      } else
	variable.put(exec, p->name, Undefined());
      p = p->next;
    }
  }
#ifdef KJS_VERBOSE
  else {
    for (int i = 0; i < args.size(); i++)
      printInfo(exec,"setting argument", args[i]);
  }
#endif
}

void FunctionImp::processVarDecls(ExecState */*exec*/)
{
}

Value FunctionImp::get(ExecState *exec, const Identifier &propertyName) const
{
    // Find the arguments from the closest context.
    if (propertyName == argumentsPropertyName) {
        ContextImp *context = exec->_context;
        while (context) {
            if (context->function() == this)
                return static_cast<ActivationImp *>
                    (context->activationObject())->get(exec, propertyName);
            context = context->callingContext();
        }
        return Undefined();
    }
    
    // Compute length of parameters.
    if (propertyName == lengthPropertyName) {
        const Parameter * p = param;
        int count = 0;
        while (p) {
            ++count;
            p = p->next;
        }
        return Number(count);
    }
    
    return InternalFunctionImp::get(exec, propertyName);
}

void FunctionImp::put(ExecState *exec, const Identifier &propertyName, const Value &value, int attr)
{
    if (propertyName == argumentsPropertyName || propertyName == lengthPropertyName)
        return;
    InternalFunctionImp::put(exec, propertyName, value, attr);
}

bool FunctionImp::hasProperty(ExecState *exec, const Identifier &propertyName) const
{
    if (propertyName == argumentsPropertyName || propertyName == lengthPropertyName)
        return true;
    return InternalFunctionImp::hasProperty(exec, propertyName);
}

bool FunctionImp::deleteProperty(ExecState *exec, const Identifier &propertyName)
{
    if (propertyName == argumentsPropertyName || propertyName == lengthPropertyName)
        return false;
    return InternalFunctionImp::deleteProperty(exec, propertyName);
}

// ------------------------------ DeclaredFunctionImp --------------------------

// ### is "Function" correct here?
const ClassInfo DeclaredFunctionImp::info = {"Function", &FunctionImp::info, 0, 0};

DeclaredFunctionImp::DeclaredFunctionImp(ExecState *exec, const Identifier &n,
					 FunctionBodyNode *b, const ScopeChain &sc)
  : FunctionImp(exec,n), body(b)
{
  Value protect(this);
  body->ref();
  setScope(sc);
}

DeclaredFunctionImp::~DeclaredFunctionImp()
{
  if ( body->deref() )
    delete body;
}

bool DeclaredFunctionImp::implementsConstruct() const
{
  return true;
}

// ECMA 13.2.2 [[Construct]]
Object DeclaredFunctionImp::construct(ExecState *exec, const List &args)
{
  Object proto;
  Value p = get(exec,prototypePropertyName);
  if (p.type() == ObjectType)
    proto = Object(static_cast<ObjectImp*>(p.imp()));
  else
    proto = exec->lexicalInterpreter()->builtinObjectPrototype();

  Object obj(new ObjectImp(proto));

  Value res = call(exec,obj,args);

  if (res.type() == ObjectType)
    return Object::dynamicCast(res);
  else
    return obj;
}

Completion DeclaredFunctionImp::execute(ExecState *exec)
{
  Completion result = body->execute(exec);

  if (result.complType() == Throw || result.complType() == ReturnValue)
      return result;
  return Completion(Normal, Undefined()); // TODO: or ReturnValue ?
}

void DeclaredFunctionImp::processVarDecls(ExecState *exec)
{
  body->processVarDecls(exec);
}

// ------------------------------ ArgumentsImp ---------------------------------

const ClassInfo ArgumentsImp::info = {"Arguments", 0, 0, 0};

// ECMA 10.1.8
ArgumentsImp::ArgumentsImp(ExecState *exec, FunctionImp *func)