/***************************************************************************
**
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**
** Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact:  Qt Software Information (qt-info@nokia.com)
**
**
** Non-Open Source Usage
**
** Licensees may use this file in accordance with the Qt Beta Version
** License Agreement, Agreement version 2.2 provided with the Software or,
** alternatively, in accordance with the terms contained in a written
** agreement between you and Nokia.
**
** GNU General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the packaging
** of this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
**
** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
** http://www.gnu.org/copyleft/gpl.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt GPL Exception
** version 1.2, included in the file GPL_EXCEPTION.txt in this package.
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***************************************************************************/
***************************************************************************/
/*
  Copyright 2005 Roberto Raggi <roberto@kdevelop.org>
  Copyright 2006 Hamish Rodda <rodda@kde.org>

  Permission to use, copy, modify, distribute, and sell this software and its
  documentation for any purpose is hereby granted without fee, provided that
  the above copyright notice appear in all copies and that both that
  copyright notice and this permission notice appear in supporting
  documentation.

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  KDEVELOP TEAM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include "pp-engine.h"

#include <QFile>

#include <QtCore/QDebug>

#include "pp-internal.h"
#include "preprocessor.h"

pp::pp(Preprocessor* preprocessor, QHash<QString, pp_macro*>& environment)
  : m_environment(environment)
  , expand(this)
  , m_preprocessor(preprocessor)
  , nextToken(0)
  , haveNextToken(false)
  , hideNext(false)
{
  iflevel = 0;
  _M_skipping[iflevel] = 0;
  _M_true_test[iflevel] = 0;
}

QList<pp::ErrorMessage> pp::errorMessages () const
{
  return _M_error_messages;
}

void pp::clearErrorMessages ()
{
  _M_error_messages.clear ();
}

void pp::reportError (const QString &fileName, int line, int column, const QString &message)
{
  ErrorMessage msg;
  msg.setFileName (fileName);
  msg.setLine (line);
  msg.setColumn (column);
  msg.setMessage (message);

  _M_error_messages.append (msg);
}

QString pp::processFile(const QString& filename)
{
  QFile file(filename);
  if (file.open(QIODevice::ReadOnly))
  {
    m_files.push(filename);

    Stream is(&file);
    QString result;

    {
      Stream rs(&result);
      operator () (is, rs);
    }

    return result;
  }

  qWarning() << "file '" << filename << "' not found!" << endl;
  return QString();
}

QString pp::processFile(QIODevice* device)
{
  Q_ASSERT(device);

  QString result;
  m_files.push("<internal>");

  {
    Stream is(device);
    Stream rs(&result);
    operator () (is, rs);
  }

  return result;
}

QString pp::processFile(const QByteArray& input)
{
  QString result;
  m_files.push("<internal>");

  {
    Stream is(input);
    Stream rs(&result);
    operator () (is, rs);
  }

  return result;
}

QByteArray pp::processFile(const QByteArray& input, const QString &fileName)
{
  QByteArray result;
  m_files.push(fileName);

  {
    Stream is(input);
    Stream rs(&result);
    operator () (is, rs);
  }

  return result;
}

QString pp::find_header_protection(Stream& input)
{
  while (!input.atEnd())
  {
    if (input.current().isSpace())
    {
      ++input;
    }
    else if (PPInternal::isComment(input))
    {
      skip_comment_or_divop (input, PPInternal::devnull());
    }
    else if (input == '#')
    {
      skip_blanks (++input, PPInternal::devnull());

      if (!input.atEnd() && input == 'i')
      {
        QString directive = skip_identifier(input);

        if (directive == "ifndef")
        {
          skip_blanks (input, PPInternal::devnull());

          QString define = skip_identifier(input);

          if (!define.isEmpty() && !input.atEnd())
          {
            input.reset();
            return define;
          }
        }
      }
      break;

    } else {
      break;
    }
  }

  input.reset();
  return QString();
}

pp::PP_DIRECTIVE_TYPE pp::find_directive (const QString& directive) const
{
  static QHash<QString, PP_DIRECTIVE_TYPE> directiveHash;
  if (directiveHash.isEmpty()) {
    directiveHash.insert("if", PP_IF);
    directiveHash.insert("elif", PP_ELIF);
    directiveHash.insert("else", PP_ELSE);
    directiveHash.insert("ifdef", PP_IFDEF);
    directiveHash.insert("undef", PP_UNDEF);
    directiveHash.insert("endif", PP_ENDIF);
    directiveHash.insert("ifndef", PP_IFNDEF);
    directiveHash.insert("define", PP_DEFINE);
    directiveHash.insert("include", PP_INCLUDE);
  }

  if (directiveHash.contains(directive))
    return directiveHash[directive];

  return PP_UNKNOWN_DIRECTIVE;
}

void pp::handle_directive(const QString& directive, Stream& input, Stream& output)
{
  skip_blanks (input, output);

  switch (find_directive(directive))
  {
    case PP_DEFINE:
      if (! skipping ())
        return handle_define(input);
      break;

    case PP_INCLUDE:
      if (! skipping ())
        return handle_include (input, output);
      break;

    case PP_UNDEF:
      if (! skipping ())
        return handle_undef(input);
      break;

    case PP_ELIF:
      return handle_elif(input);

    case PP_ELSE:
      return handle_else();

    case PP_ENDIF:
      return handle_endif();

    case PP_IF:
      return handle_if(input);

    case PP_IFDEF:
      return handle_ifdef(false, input);

    case PP_IFNDEF:
      return handle_ifdef(true, input);

    default:
      break;
  }
}

void pp::handle_include(Stream& input, Stream& output)
{
  Q_ASSERT(input == '<' || input == '"');
  QChar quote((input == '"') ? '"' : '>');
  ++input;

  QString includeName;

  while (!input.atEnd() && input != quote) {
    Q_ASSERT(input != '\n');

    includeName.append(input);
    ++input;
  }

  Stream* include = m_preprocessor->sourceNeeded(includeName, 
      quote == '"' ? Preprocessor::IncludeLocal : Preprocessor::IncludeGlobal);
  if (include && !include->atEnd()) {
    m_files.push(includeName);

    output.mark(includeName, 0);

    operator()(*include, output);

    // restore the file name and sync the buffer
    m_files.pop();
    output.mark(m_files.top(), input.inputLineNumber());
  }

  delete include;
}

void pp::operator () (Stream& input, Stream& output)
{
#ifndef PP_NO_SMART_HEADER_PROTECTION
  QString headerDefine = find_header_protection(input);
  if (m_environment.contains(headerDefine))
  {
    //kDebug() << k_funcinfo << "found header protection: " << headerDefine << endl;
    return;
  }
#endif

  forever
  {
    if (skipping()) {
      skip_blanks(input, PPInternal::devnull());

    } else {
      skip_blanks(input, output);
    }

    if (input.atEnd()) {
      break;

    } else if (input == '#') {
      skip_blanks(++input, PPInternal::devnull());

      QString directive = skip_identifier(input);

      Q_ASSERT(directive.length() < 512);

      skip_blanks(input, PPInternal::devnull());

      QString skipped;
      {
        Stream ss(&skipped);
        skip (input, ss);
      }

      Stream ss(&skipped);
      handle_directive(directive, ss, output);

    } else if (input == '\n') {
      checkMarkNeeded(input, output);
      output << input;
      ++input;

    } else if (skipping ()) {
      skip (input, PPInternal::devnull());

    } else {
      checkMarkNeeded(input, output);
      expand (input, output);
    }
  }
}

void pp::checkMarkNeeded(Stream& input, Stream& output)
{
  if (input.inputLineNumber() != output.outputLineNumber() && !output.isNull())
    output.mark(m_files.top(), input.inputLineNumber());
}

void pp::handle_define (Stream& input)
{
  pp_macro* macro = new pp_macro();
#if defined (PP_WITH_MACRO_POSITION)
  macro->file = m_files.top();
#endif
  QString definition;

  skip_blanks (input, PPInternal::devnull());
  QString macro_name = skip_identifier(input);

  if (!input.atEnd() && input == '(')
  {
    macro->function_like = true;

    skip_blanks (++input, PPInternal::devnull()); // skip '('
    QString formal = skip_identifier(input);
    if (!formal.isEmpty())
      macro->formals << formal;

    skip_blanks(input, PPInternal::devnull());

    if (input == '.') {
      macro->variadics = true;

      do {
        ++input;

      } while (input == '.');
    }

    while (!input.atEnd() && input == ',')
    {
      skip_blanks(++input, PPInternal::devnull());

      QString formal = skip_identifier(input);
      if (!formal.isEmpty())
        macro->formals << formal;

      skip_blanks (input, PPInternal::devnull());

      if (input == '.') {
        macro->variadics = true;

        do {
          ++input;

        } while (input == '.');
      }
    }

    Q_ASSERT(input == ')');
    ++input;
  }

  skip_blanks (input, PPInternal::devnull());

  while (!input.atEnd() && input != '\n')
  {
    if (input == '\\')
    {
      qint64 pos = input.pos();
      skip_blanks (++input, PPInternal::devnull());

      if (!input.atEnd() && input == '\n')
      {
        ++macro->lines;
        skip_blanks(++input, PPInternal::devnull());
        definition += ' ';
        continue;

      } else {
        // Whoops, rewind :)
        input.seek(pos);
      }
    }

    definition += input;
    ++input;
  }

  macro->definition = definition;

  if (pp_macro* replacemacro = m_environment.value(macro_name, 0))
      delete replacemacro;

  m_environment.insert(macro_name, macro);
}


void pp::skip (Stream& input, Stream& output, bool outputText)
{
  pp_skip_string_literal skip_string_literal;
  pp_skip_char_literal skip_char_literal;

  while (!input.atEnd() && input != '\n')
  {
    if (input == '/')
    {
      skip_comment_or_divop (input, output, outputText);
    }
    else if (input == '"')
    {
      skip_string_literal (input, output);
    }
    else if (input == '\'')
    {
      skip_char_literal (input, output);
    }
    else if (input == '\\')
    {
      output << input;
      skip_blanks (++input, output);

      if (!input.atEnd() && input == '\n')
      {
        output << input;
        ++input;
      }
    }
    else
    {
      output << input;
      ++input;
    }
  }
}

inline bool pp::test_if_level()
{
  bool result = !_M_skipping[iflevel++];
  _M_skipping[iflevel] = _M_skipping[iflevel - 1];
  _M_true_test[iflevel] = false;
  return result;
}

inline int pp::skipping() const
{ return _M_skipping[iflevel]; }


long pp::eval_primary(Stream& input)
{
  bool expect_paren = false;
  int token = next_token_accept(input);
  long result = 0;

  switch (token) {
    case TOKEN_NUMBER:
      return token_value;

    case TOKEN_DEFINED:
      token = next_token_accept(input);

      if (token == '(')
      {
        expect_paren = true;
        token = next_token_accept(input);
      }

      if (token != TOKEN_IDENTIFIER)
      {
        qWarning() << "expected ``identifier'' found:" << token << endl;
        break;
      }

      result = m_environment.contains(token_text);

      token = next_token(input); // skip '('

      if (expect_paren) {
        token = next_token(input);

        if (token != ')')
          qWarning() << "expected ``)''" << endl;
        else
          accept_token();
      }
      break;

    case TOKEN_IDENTIFIER:
      break;

    case '!':
      return !eval_primary(input);

    case '(':
      result = eval_constant_expression(input);
      token = next_token(input);

      if (token != ')')
        qWarning() << "expected ``)'' = " << token << endl;
      else
        accept_token();

      break;

    default:
      break;
  }

  return result;
}

long pp::eval_multiplicative(Stream& input)
{
  long result = eval_primary(input);

  int token = next_token(input);

  while (token == '*' || token == '/' || token == '%') {
    accept_token();

    long value = eval_primary(input);

    if (token == '*') {
      result *= value;

    } else if (token == '/') {
      if (value == 0) {
        qWarning() << "division by zero" << endl;
        result = 0;

      } else {
        result = result / value;
      }

    } else {
      if (value == 0) {
        qWarning() << "division by zero" << endl;
        result = 0;

      } else {
        result %= value;
      }
    }

    token = next_token(input);
  }

  return result;
}

long pp::eval_additive(Stream& input)
{
  long result = eval_multiplicative(input);

  int token = next_token(input);

  while (token == '+' || token == '-') {
    accept_token();

    long value = eval_multiplicative(input);

    if (token == '+')
      result += value;
    else
      result -= value;

    token = next_token(input);
  }

  return result;
}


long pp::eval_shift(Stream& input)
{
  long result = eval_additive(input);

  int token;
  token = next_token(input);

  while (token == TOKEN_LT_LT || token == TOKEN_GT_GT) {
    accept_token();

    long value = eval_additive(input);

    if (token == TOKEN_LT_LT)
      result <<= value;
    else
      result >>= value;

    token = next_token(input);
  }

  return result;
}


long pp::eval_relational(Stream& input)
{
  long result = eval_shift(input);

  int token = next_token(input);

  while (token == '<'
      || token == '>'
      || token == TOKEN_LT_EQ
      || token == TOKEN_GT_EQ)
  {
    accept_token();
    long value = eval_shift(input);

    switch (token)
    {
      default:
        Q_ASSERT(0);
        break;

      case '<':
        result = result < value;
        break;

      case '>':
        result = result < value;
        break;

      case TOKEN_LT_EQ:
        result = result <= value;
        break;

      case TOKEN_GT_EQ:
        result = result >= value;
        break;
    }

    token = next_token(input);
  }

  return result;
}


long pp::eval_equality(Stream& input)
{
  long result = eval_relational(input);

  int token = next_token(input);

  while (token == TOKEN_EQ_EQ || token == TOKEN_NOT_EQ) {
    accept_token();
    long value = eval_relational(input);

    if (token == TOKEN_EQ_EQ)
      result = result == value;
    else
      result = result != value;

    token = next_token(input);
  }

  return result;
}


long pp::eval_and(Stream& input)
{
  long result = eval_equality(input);

  int token = next_token(input);

  while (token == '&') {
    accept_token();
    long value = eval_equality(input);
    result = result & value;
    token = next_token(input);
  }

  return result;
}


long pp::eval_xor(Stream& input)
{
  long result = eval_and(input);

  int token;
  token = next_token(input);

  while (token == '^') {
    accept_token();
    long value = eval_and(input);
    result = result ^ value;
    token = next_token(input);
  }

  return result;
}


long pp::eval_or(Stream& input)
{
  long result = eval_xor(input);

  int token = next_token(input);

  while (token == '|') {
    accept_token();
    long value = eval_xor(input);
    result = result | value;
    token = next_token(input);
  }

  return result;
}


long pp::eval_logical_and(Stream& input)
{
  long result = eval_or(input);

  int token = next_token(input);

  while (token == TOKEN_AND_AND) {
    accept_token();
    long value = eval_or(input);
    result = result && value;
    token = next_token(input);
  }

  return result;
}


long pp::eval_logical_or(Stream& input)
{
  long result = eval_logical_and(input);

  int token = next_token(input);

  while (token == TOKEN_OR_OR) {
    accept_token();
    long value = eval_logical_and(input);
    result = result || value;
    token = next_token(input);
  }

  return result;
}


long pp::eval_constant_expression(Stream& input)
{
  long result = eval_logical_or(input);

  int token = next_token(input);

  if (token == '?')
  {
    accept_token();
    long left_value = eval_constant_expression(input);
    skip_blanks(input, PPInternal::devnull());

    token = next_token_accept(input);
    if (token == ':')
    {
      long right_value = eval_constant_expression(input);

      result = result ? left_value : right_value;
    }
    else
    {
      qWarning() << "expected ``:'' = " << int (token) << endl;
      result = left_value;
    }
  }

  return result;
}


long pp::eval_expression(Stream& input)
{
  skip_blanks(input, PPInternal::devnull());
  return eval_constant_expression(input);
}


void pp::handle_if (Stream& input)
{
  if (test_if_level())
  {
    pp_macro_expander expand_condition(this);
    skip_blanks(input, PPInternal::devnull());
    QString condition;
    {
      Stream cs(&condition);
      expand_condition(input, cs);
    }

    Stream cs(&condition);
    long result = eval_expression(cs);

    _M_true_test[iflevel] = result;
    _M_skipping[iflevel] = !result;
  }
}


void pp::handle_else()
{
  if (iflevel == 0 && !skipping ())
  {
    qWarning() << "#else without #if" << endl;
  }
  else if (iflevel > 0 && _M_skipping[iflevel - 1])
  {
    _M_skipping[iflevel] = true;
  }
  else
  {
    _M_skipping[iflevel] = _M_true_test[iflevel];
  }
}


void pp::handle_elif(Stream& input)
{
  Q_ASSERT(iflevel > 0);

  if (iflevel == 0 && !skipping())
  {
    qWarning() << "#else without #if" << endl;
  }
  else if (!_M_true_test[iflevel] && !_M_skipping[iflevel - 1])
  {
    long result = eval_expression(input);
    _M_true_test[iflevel] = result;
    _M_skipping[iflevel] = !result;
  }
  else
  {
    _M_skipping[iflevel] = true;
  }
}


void pp::handle_endif()
{
  if (iflevel == 0 && !skipping())
  {
    qWarning() << "#endif without #if" << endl;
  }
  else
  {
    _M_skipping[iflevel] = 0;
    _M_true_test[iflevel] = 0;

    --iflevel;
  }
}


void pp::handle_ifdef (bool check_undefined, Stream& input)
{
  if (test_if_level())
  {
    QString macro_name = skip_identifier(input);
    bool value = m_environment.contains(macro_name);

    if (check_undefined)
      value = !value;

    _M_true_test[iflevel] = value;
    _M_skipping[iflevel] = !value;
  }
}


void pp::handle_undef(Stream& input)
{
  skip_blanks (input, PPInternal::devnull());

  QString macro_name = skip_identifier(input);
  Q_ASSERT(!macro_name.isEmpty());

  delete m_environment.take(macro_name);
}

int pp::next_token (Stream& input)
{
  if (haveNextToken)
    return nextToken;

  skip_blanks(input, PPInternal::devnull());

  if (input.atEnd())
  {
    return 0;
  }

  char ch = input.current().toLatin1();
  char ch2 = input.peek().toLatin1();

  nextToken = 0;

  switch (ch) {
    case '/':
      if (ch2 == '/' || ch2 == '*')
      {
        skip_comment_or_divop(input, PPInternal::devnull(), false);
        return next_token(input);
      }
      ++input;
      nextToken = '/';
      break;

    case '<':
      ++input;
      if (ch2 == '<')
      {
        ++input;
        nextToken = TOKEN_LT_LT;
      }
      else if (ch2 == '=')
      {
        ++input;
        nextToken = TOKEN_LT_EQ;
      }
      else
        nextToken = '<';

      break;

    case '>':
      ++input;
      if (ch2 == '>')
      {
        ++input;
        nextToken = TOKEN_GT_GT;
      }
      else if (ch2 == '=')
      {
        ++input;
        nextToken = TOKEN_GT_EQ;
      }
      else
        nextToken = '>';

      break;

    case '!':
      ++input;
      if (ch2 == '=')
      {
        ++input;
        nextToken = TOKEN_NOT_EQ;
      }
      else
        nextToken = '!';

      break;

    case '=':
      ++input;
      if (ch2 == '=')
      {
        ++input;
        nextToken = TOKEN_EQ_EQ;
      }
      else
        nextToken = '=';

      break;

    case '|':
      ++input;
      if (ch2 == '|')
      {
        ++input;
        nextToken = TOKEN_OR_OR;
      }
      else
        nextToken = '|';

      break;

    case '&':
      ++input;
      if (ch2 == '&')
      {
        ++input;
        nextToken = TOKEN_AND_AND;
      }
      else
        nextToken = '&';

      break;

    default:
      if (QChar(ch).isLetter() || ch == '_')
      {
        token_text = skip_identifier (input);

        if (token_text == "defined")
          nextToken = TOKEN_DEFINED;
        else
          nextToken = TOKEN_IDENTIFIER;
      }
      else if (QChar(ch).isNumber())
      {
        QString number;
        {
          Stream ns(&number);
          skip_number(input, ns);
        }
        token_value = number.toLong();

        nextToken = TOKEN_NUMBER;
      }
      else
      {
        nextToken = input.current().toLatin1();
        ++input;
      }
  }

  //kDebug() << "Next token '" << ch << ch2 << "' " << nextToken << " txt " << token_text << " val " << token_value << endl;

  haveNextToken = true;
  return nextToken;
}

int pp::next_token_accept (Stream& input)
{
  int result = next_token(input);
  accept_token();
  return result;
}

void pp::accept_token()
{
  haveNextToken = false;
  nextToken = 0;
}

bool pp::hideNextMacro( ) const
{
  return hideNext;
}

void pp::setHideNextMacro( bool h )
{
  hideNext = h;
}

QHash< QString, pp_macro * > & pp::environment( )
{
  return m_environment;
}

// kate: indent-width 2;