function.cpp

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// -*- c-basic-offset: 2 -*-
/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2002 Harri Porten ([e-mail])
 *  Copyright (C) 2001,2003 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., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, 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>
#include <math.h>
#include <ctype.h>

using namespace KJS;

// ------------------------- URI handling functions ---------------------------

// ECMA 15.1.3
UString encodeURI(ExecState *exec, UString string, UString unescapedSet)
{
  char hexdigits[] = "0123456789ABCDEF";
  int encbufAlloc = 2;
  UChar *encbuf = (UChar*)malloc(encbufAlloc*sizeof(UChar));
  int encbufLen = 0;

  for (int k = 0; k < string.size(); k++) {

    UChar C = string[k];
    if (unescapedSet.find(C) >= 0) {
      if (encbufLen+1 >= encbufAlloc)
	encbuf = (UChar*)realloc(encbuf,(encbufAlloc *= 2)*sizeof(UChar));
      encbuf[encbufLen++] = C;
    }
    else {
      unsigned char octets[4];
      int octets_len = 0;
      if (C.uc <= 0x007F) {
	unsigned short zzzzzzz = C.uc;
	octets[0] = zzzzzzz;
	octets_len = 1;
      }
      else if (C.uc <= 0x07FF) {
	unsigned short zzzzzz = C.uc & 0x3F;
	unsigned short yyyyy = (C.uc >> 6) & 0x1F;
	octets[0] = 0xC0 | yyyyy;
	octets[1] = 0x80 | zzzzzz;
	octets_len = 2;
      }
      else if (C.uc >= 0xD800 && C.uc <= 0xDBFF) {

        // we need two chars
	if (k + 1 >= string.size()) {
	  Object err = Error::create(exec,URIError);
	  exec->setException(err);
	  free(encbuf);
	  return UString();
	}

	unsigned short Cnext = UChar(string[++k]).uc;

	if (Cnext < 0xDC00 || Cnext > 0xDFFF) {
	  Object err = Error::create(exec,URIError);
	  exec->setException(err);
	  free(encbuf);
	  return UString();
	}

	unsigned short zzzzzz = Cnext & 0x3F;
	unsigned short yyyy = (Cnext >> 6) & 0x0F;
	unsigned short xx = C.uc & 0x03;
	unsigned short wwww = (C.uc >> 2) & 0x0F;
	unsigned short vvvv = (C.uc >> 6) & 0x0F;
	unsigned short uuuuu = vvvv+1;
	octets[0] = 0xF0 | (uuuuu >> 2);
	octets[1] = 0x80 | ((uuuuu & 0x03) << 4) | wwww;
	octets[2] = 0x80 | (xx << 4) | yyyy;
	octets[3] = 0x80 | zzzzzz;
	octets_len = 4;
      }
      else if (C.uc >= 0xDC00 && C.uc <= 0xDFFF) {
	Object err = Error::create(exec,URIError);
	exec->setException(err);
	free(encbuf);
	return UString();
      }
      else {
	// 0x0800 - 0xD7FF or 0xE000 - 0xFFFF
	unsigned short zzzzzz = C.uc & 0x3F;
	unsigned short yyyyyy = (C.uc >> 6) & 0x3F;
	unsigned short xxxx = (C.uc >> 12) & 0x0F;
	octets[0] = 0xE0 | xxxx;
	octets[1] = 0x80 | yyyyyy;
	octets[2] = 0x80 | zzzzzz;
	octets_len = 3;
      }

      while (encbufLen+3*octets_len >= encbufAlloc)
	encbuf = (UChar*)realloc(encbuf,(encbufAlloc *= 2)*sizeof(UChar));

      for (int j = 0; j < octets_len; j++) {
	encbuf[encbufLen++] = '%';
	encbuf[encbufLen++] = hexdigits[octets[j] >> 4];
	encbuf[encbufLen++] = hexdigits[octets[j] & 0x0F];
      }
    }
  }

  UString encoded(encbuf,encbufLen);
  free(encbuf);
  return encoded;
}

static bool decodeHex(UChar hi, UChar lo, unsigned short *val)
{
  *val = 0;
  if (hi.uc >= '0' && hi.uc <= '9')
    *val = (hi.uc-'0') << 4;
  else if (hi.uc >= 'a' && hi.uc <= 'f')
    *val = 10+(hi.uc-'a') << 4;
  else if (hi.uc >= 'A' && hi.uc <= 'F')
    *val = 10+(hi.uc-'A') << 4;
  else
    return false;

  if (lo.uc >= '0' && lo.uc <= '9')
    *val |= (lo.uc-'0');
  else if (lo.uc >= 'a' && lo.uc <= 'f')
    *val |= 10+(lo.uc-'a');
  else if (lo.uc >= 'A' && lo.uc <= 'F')
    *val |= 10+(lo.uc-'A');
  else
    return false;

  return true;
}

UString decodeURI(ExecState *exec, UString string, UString reservedSet)
{
  int decbufAlloc = 2;
  UChar *decbuf = (UChar*)malloc(decbufAlloc*sizeof(UChar));
  int decbufLen = 0;

  for (int k = 0; k < string.size(); k++) {
    UChar C = string[k];

    if (C != UChar('%')) {
      // Normal unescaped character
      if (decbufLen+1 >= decbufAlloc)
	decbuf = (UChar*)realloc(decbuf,(decbufAlloc *= 2)*sizeof(UChar));
      decbuf[decbufLen++] = C;
      continue;
    }

    // We have % escape sequence... expect at least 2 more characters
    int start = k;
    if (k+2 >= string.size()) {
      Object err = Error::create(exec,URIError);
      exec->setException(err);
      free(decbuf);
      return UString();
    }

    unsigned short B;
    if (!decodeHex(string[k+1],string[k+2],&B)) {
      Object err = Error::create(exec,URIError);
      exec->setException(err);
      free(decbuf);
      return UString();
    }

    k += 2;

    if (decbufLen+2 >= decbufAlloc)
        decbuf = (UChar*)realloc(decbuf,(decbufAlloc *= 2)*sizeof(UChar));

    if ((B & 0x80) == 0) {
      // Single-byte character
      C = B;
    }
    else {
      // Multi-byte character
      int n = 0;
      while (((B << n) & 0x80) != 0)
	n++;

      if (n < 2 || n > 4) {
	Object err = Error::create(exec,URIError);
	exec->setException(err);
	free(decbuf);
	return UString();
      }

      if (k+3*(n-1) >= string.size()) {
	Object err = Error::create(exec,URIError);
	exec->setException(err);
	free(decbuf);
	return UString();
      }

      unsigned short octets[4];
      octets[0] = B;
      for (int j = 1; j < n; j++) {
	k++;
	if ((UChar(string[k]) != UChar('%')) ||
	    !decodeHex(string[k+1],string[k+2],&B) ||
	    ((B & 0xC0) != 0x80)) {
	  Object err = Error::create(exec,URIError);
	  exec->setException(err);
	  free(decbuf);
	  return UString();
	}

	k += 2;
	octets[j] = B;
      }

      // UTF-8 transform
      unsigned long V;
      if (n == 2) {
	unsigned long yyyyy = octets[0] & 0x1F;
	unsigned long zzzzzz = octets[1] & 0x3F;
	V = (yyyyy << 6) | zzzzzz;
	C = UChar((unsigned short)V);
      }
      else if (n == 3) {
	unsigned long xxxx = octets[0] & 0x0F;
	unsigned long yyyyyy = octets[1] & 0x3F;
	unsigned long zzzzzz = octets[2] & 0x3F;
	V = (xxxx << 12) | (yyyyyy << 6) | zzzzzz;
	C = UChar((unsigned short)V);
      }
      else {
	assert(n == 4);
	unsigned long uuuuu = ((octets[0] & 0x07) << 2) | ((octets[1] >> 4) & 0x03);
	unsigned long vvvv = uuuuu-1;
	if (vvvv > 0x0F) {
          Object err = Error::create(exec,URIError);
	  exec->setException(err);
	  free(decbuf);
	  return UString();
	}        
	unsigned long wwww = octets[1] & 0x0F;
	unsigned long xx = (octets[2] >> 4) & 0x03;
	unsigned long yyyy = octets[2] & 0x0F;
	unsigned long zzzzzz = octets[3] & 0x3F;
	unsigned short H = 0xD800 | (vvvv << 6) | (wwww << 2) | xx;
	unsigned short L = 0xDC00 | (yyyy << 6) | zzzzzz;
	decbuf[decbufLen++] = UChar(H);
	decbuf[decbufLen++] = UChar(L);
	continue;
      }
    }

    if (reservedSet.find(C) < 0) {
        decbuf[decbufLen++] = C;
    }
    else {
      while (decbufLen+k-start >= decbufAlloc)
	decbuf = (UChar*)realloc(decbuf,(decbufAlloc *= 2)*sizeof(UChar));
      for (int p = start; p < k; p++)
	decbuf[decbufLen++] = string[p];
    }
  }

  UString decoded(decbuf,decbufLen);
  free(decbuf);
  return decoded;
}

static UString uriReserved = ";/?:@&=+$,";
static UString uriAlpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
static UString DecimalDigit = "0123456789";
static UString uriMark = "-_.!~*'()";
static UString uriUnescaped = uriAlpha+DecimalDigit+uriMark;

// ----------------------------- 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), line0(-1), line1(-1), sid(-1)
{
  //fprintf(stderr,"FunctionImp::FunctionImp this=%p\n");
  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();

  // enter a new execution context
  ContextImp ctx(globalObj, exec->dynamicInterpreter()->imp(), thisObj, sid, 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);

  ctx.setLines(line0,line0);
  Debugger *dbg = exec->interpreter()->imp()->debugger();
  if (dbg) {
    if (!dbg->enterContext(&newExec)) {
      // debugger requested we stop execution
      dbg->imp()->abort();
      return Undefined();
    }
  }

  Completion comp = execute(&newExec);

  ctx.setLines(line1,line1);
  if (dbg) {
    Object func(this);
    // ### lineno is inaccurate - we really want the end of the function _body_ here
    // line1 is suppoed to be the end of the function start, just before the body
    if (!dbg->exitContext(&newExec,comp)) {
      // debugger requested we stop execution
      dbg->imp()->abort();
      return Undefined();
    }
  }

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

#ifdef KJS_VERBOSE
  CString n = ident.isEmpty() ? CString("(internal)") : ident.ustring().cstring();
  if (comp.complType() == Throw) {
    n += " throws";
    printInfo(exec, n.c_str(), comp.value());
  } else if (comp.complType() == ReturnValue) {
    n += " returns";
    printInfo(exec, n.c_str(), comp.value());
  } else
    fprintf(stderr, "%s returns: undefined\n", n.c_str());
#endif

  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);
}

Identifier FunctionImp::parameterProperty(int index) const
{
  // Find the property name corresponding to the given parameter
  int pos = 0;
  Parameter *p;
  for (p = param; p && pos < index; p = p->next)
    pos++;

  if (!p)
    return Identifier::null();

  // Are there any subsequent parameters with the same name?
  Identifier name = p->name;
  for (p = p->next; p; p = p->next)
    if (p->name == name)
      return Identifier::null();

  return name;
}

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) {
// delme
        ContextImp *context = exec->context().imp();
// fixme
//         ContextImp *context = exec->_context;
        while (context) {
            if (context->function() == this)
                return static_cast<ActivationImp *>
                    (context->activationObject())->get(exec, propertyName);
            context = context->callingContext();
        }
        return Null();
    }

    // Compute length of parameters.
    if (propertyName == lengthPropertyName) {
        const Parameter * p = param;
        int count = 0;
        while (p) {
            ++count;
            p = p->next;
        }
        return Number(count);