gscanner.c

嵌入式下基于MiniGUI的Web Browser

      scanner->value = scanner->next_value;
      scanner->line = scanner->next_line;
      scanner->position = scanner->next_position;
      scanner->next_token = G_TOKEN_NONE;
    }
  else
    g_scanner_get_token_i (scanner,
			   &scanner->token,
			   &scanner->value,
			   &scanner->line,
			   &scanner->position);
  
  return scanner->token;
}

GTokenType
g_scanner_cur_token (GScanner *scanner)
{
  g_return_val_if_fail (scanner != NULL, G_TOKEN_EOF);
  
  return scanner->token;
}

GTokenValue
g_scanner_cur_value (GScanner *scanner)
{
  GTokenValue v;
  
  v.v_int = 0;
  
  g_return_val_if_fail (scanner != NULL, v);

  /* MSC isn't capable of handling return scanner->value; ? */

  v = scanner->value;

  return v;
}

guint
g_scanner_cur_line (GScanner *scanner)
{
  g_return_val_if_fail (scanner != NULL, 0);
  
  return scanner->line;
}

guint
g_scanner_cur_position (GScanner *scanner)
{
  g_return_val_if_fail (scanner != NULL, 0);
  
  return scanner->position;
}

gboolean
g_scanner_eof (GScanner	*scanner)
{
  g_return_val_if_fail (scanner != NULL, TRUE);
  
  return scanner->token == G_TOKEN_EOF || scanner->token == G_TOKEN_ERROR;
}

void
g_scanner_input_file (GScanner *scanner,
		      gint	input_fd)
{
  g_return_if_fail (scanner != NULL);
  g_return_if_fail (input_fd >= 0);

  if (scanner->input_fd >= 0)
    g_scanner_sync_file_offset (scanner);

  scanner->token = G_TOKEN_NONE;
  scanner->value.v_int = 0;
  scanner->line = 1;
  scanner->position = 0;
  scanner->next_token = G_TOKEN_NONE;

  scanner->input_fd = input_fd;
  scanner->text = NULL;
  scanner->text_end = NULL;

  if (!scanner->buffer)
    scanner->buffer = g_new (gchar, READ_BUFFER_SIZE + 1);
}

void
g_scanner_input_text (GScanner	  *scanner,
		      const gchar *text,
		      guint	   text_len)
{
  g_return_if_fail (scanner != NULL);
  if (text_len)
    g_return_if_fail (text != NULL);
  else
    text = NULL;

  if (scanner->input_fd >= 0)
    g_scanner_sync_file_offset (scanner);

  scanner->token = G_TOKEN_NONE;
  scanner->value.v_int = 0;
  scanner->line = 1;
  scanner->position = 0;
  scanner->next_token = G_TOKEN_NONE;

  scanner->input_fd = -1;
  scanner->text = text;
  scanner->text_end = text + text_len;

  if (scanner->buffer)
    {
      g_free (scanner->buffer);
      scanner->buffer = NULL;
    }
}

static guchar
g_scanner_peek_next_char (GScanner *scanner)
{
  if (scanner->text < scanner->text_end)
    {
      return *scanner->text;
    }
  else if (scanner->input_fd >= 0)
    {
      gint count;
      gchar *buffer;

      buffer = scanner->buffer;
      do
	{
	  count = read (scanner->input_fd, buffer, READ_BUFFER_SIZE);
	}
      while (count == -1 && (errno == EINTR || errno == EAGAIN));

      if (count < 1)
	{
	  scanner->input_fd = -1;

	  return 0;
	}
      else
	{
	  scanner->text = buffer;
	  scanner->text_end = buffer + count;

	  return *buffer;
	}
    }
  else
    return 0;
}

void
g_scanner_sync_file_offset (GScanner *scanner)
{
  g_return_if_fail (scanner != NULL);

  /* for file input, rewind the filedescriptor to the current
   * buffer position and blow the file read ahead buffer. usefull for
   * third party uses of our filedescriptor, which hooks onto the current
   * scanning position.
   */

  if (scanner->input_fd >= 0 && scanner->text_end > scanner->text)
    {
      gint buffered;

      buffered = scanner->text_end - scanner->text;
      if (lseek (scanner->input_fd, - buffered, SEEK_CUR) >= 0)
	{
	  /* we succeeded, blow our buffer's contents now */
	  scanner->text = NULL;
	  scanner->text_end = NULL;
	}
      else
	errno = 0;
    }
}

static guchar
g_scanner_get_char (GScanner	*scanner,
		    guint	*line_p,
		    guint	*position_p)
{
  guchar fchar;

  if (scanner->text < scanner->text_end)
    fchar = *(scanner->text++);
  else if (scanner->input_fd >= 0)
    {
      gint count;
      gchar *buffer;

      buffer = scanner->buffer;
      do
	{
	  count = read (scanner->input_fd, buffer, READ_BUFFER_SIZE);
	}
      while (count == -1 && (errno == EINTR || errno == EAGAIN));

      if (count < 1)
	{
	  scanner->input_fd = -1;
	  fchar = 0;
	}
      else
	{
	  scanner->text = buffer + 1;
	  scanner->text_end = buffer + count;
	  fchar = *buffer;
	  if (!fchar)
	    {
	      g_scanner_sync_file_offset (scanner);
	      scanner->text_end = scanner->text;
	      scanner->input_fd = -1;
	    }
	}
    }
  else
    fchar = 0;
  
  if (fchar == '\n')
    {
      (*position_p) = 0;
      (*line_p)++;
    }
  else if (fchar)
    {
      (*position_p)++;
    }
  
  return fchar;
}

void
g_scanner_unexp_token (GScanner		*scanner,
		       GTokenType	 expected_token,
		       const gchar	*identifier_spec,
		       const gchar	*symbol_spec,
		       const gchar	*symbol_name,
		       const gchar	*message,
		       gint		 is_error)
{
  gchar	*token_string;
  guint	token_string_len;
  gchar	*expected_string;
  guint	expected_string_len;
  gchar	*message_prefix;
  gboolean print_unexp;
  void (*msg_handler)	(GScanner*, const gchar*, ...);
  
  g_return_if_fail (scanner != NULL);
  
  if (is_error)
    msg_handler = g_scanner_error;
  else
    msg_handler = g_scanner_warn;
  
  if (!identifier_spec)
    identifier_spec = "identifier";
  if (!symbol_spec)
    symbol_spec = "symbol";
  
  token_string_len = 56;
  token_string = g_new (gchar, token_string_len + 1);
  expected_string_len = 64;
  expected_string = g_new (gchar, expected_string_len + 1);
  print_unexp = TRUE;
  
  switch (scanner->token)
    {
    case G_TOKEN_EOF:
      g_snprintf (token_string, token_string_len, "end of file");
      break;
      
    default:
      if (scanner->token >= 1 && scanner->token <= 255)
	{
	  if ((scanner->token >= ' ' && scanner->token <= '~') ||
	      strchr (scanner->config->cset_identifier_first, scanner->token) ||
	      strchr (scanner->config->cset_identifier_nth, scanner->token))
	    g_snprintf (token_string, token_string_len, "character `%c'", scanner->token);
	  else
	    g_snprintf (token_string, token_string_len, "character `\\%o'", scanner->token);
	  break;
	}
      else if (!scanner->config->symbol_2_token)
	{
	  g_snprintf (token_string, token_string_len, "(unknown) token <%d>", scanner->token);
	  break;
	}
      /* fall through */
    case G_TOKEN_SYMBOL:
      if (expected_token == G_TOKEN_SYMBOL ||
	  (scanner->config->symbol_2_token &&
	   expected_token > G_TOKEN_LAST))
	print_unexp = FALSE;
      if (symbol_name)
	g_snprintf (token_string,
		    token_string_len,
		    "%s%s `%s'",
		    print_unexp ? "" : "invalid ",
		    symbol_spec,
		    symbol_name);
      else
	g_snprintf (token_string,
		    token_string_len,
		    "%s%s",
		    print_unexp ? "" : "invalid ",
		    symbol_spec);
      break;
      
    case G_TOKEN_ERROR:
      print_unexp = FALSE;
      expected_token = G_TOKEN_NONE;
      switch (scanner->value.v_error)
	{
	case G_ERR_UNEXP_EOF:
	  g_snprintf (token_string, token_string_len, "scanner: unexpected end of file");
	  break;
	  
	case G_ERR_UNEXP_EOF_IN_STRING:
	  g_snprintf (token_string, token_string_len, "scanner: unterminated string constant");
	  break;
	  
	case G_ERR_UNEXP_EOF_IN_COMMENT:
	  g_snprintf (token_string, token_string_len, "scanner: unterminated comment");
	  break;
	  
	case G_ERR_NON_DIGIT_IN_CONST:
	  g_snprintf (token_string, token_string_len, "scanner: non digit in constant");
	  break;
	  
	case G_ERR_FLOAT_RADIX:
	  g_snprintf (token_string, token_string_len, "scanner: invalid radix for floating constant");
	  break;
	  
	case G_ERR_FLOAT_MALFORMED:
	  g_snprintf (token_string, token_string_len, "scanner: malformed floating constant");
	  break;
	  
	case G_ERR_DIGIT_RADIX:
	  g_snprintf (token_string, token_string_len, "scanner: digit is beyond radix");
	  break;
	  
	case G_ERR_UNKNOWN:
	default:
	  g_snprintf (token_string, token_string_len, "scanner: unknown error");
	  break;
	}
      break;
      
    case G_TOKEN_CHAR:
      g_snprintf (token_string, token_string_len, "character `%c'", scanner->value.v_char);
      break;
      
    case G_TOKEN_IDENTIFIER:
    case G_TOKEN_IDENTIFIER_NULL:
      if (expected_token == G_TOKEN_IDENTIFIER ||
	  expected_token == G_TOKEN_IDENTIFIER_NULL)
	print_unexp = FALSE;
      g_snprintf (token_string,
		  token_string_len,
		  "%s%s `%s'",
		  print_unexp ? "" : "invalid ",
		  identifier_spec,
		  scanner->token == G_TOKEN_IDENTIFIER ? scanner->value.v_string : "null");
      break;
      
    case G_TOKEN_BINARY:
    case G_TOKEN_OCTAL:
    case G_TOKEN_INT:
    case G_TOKEN_HEX:
      g_snprintf (token_string, token_string_len, "number `%lu'", scanner->value.v_int);
      break;
      
    case G_TOKEN_FLOAT:
      g_snprintf (token_string, token_string_len, "number `%.3f'", scanner->value.v_float);
      break;
      
    case G_TOKEN_STRING:
      if (expected_token == G_TOKEN_STRING)
	print_unexp = FALSE;
      g_snprintf (token_string,
		  token_string_len,
		  "%s%sstring constant \"%s\"",
		  print_unexp ? "" : "invalid ",
		  scanner->value.v_string[0] == 0 ? "empty " : "",
		  scanner->value.v_string);
      token_string[token_string_len - 2] = '"';
      token_string[token_string_len - 1] = 0;
      break;
      
    case G_TOKEN_COMMENT_SINGLE:
    case G_TOKEN_COMMENT_MULTI:
      g_snprintf (token_string, token_string_len, "comment");
      break;
      
    case G_TOKEN_NONE:
      /* somehow the user's parsing code is screwed, there isn't much
       * we can do about it.
       * Note, a common case to trigger this is
       * g_scanner_peek_next_token(); g_scanner_unexp_token();
       * without an intermediate g_scanner_get_next_token().
       */
      g_assert_not_reached ();
      break;
    }
  
  
  switch (expected_token)
    {
      gboolean need_valid;
      gchar *tstring;
    case G_TOKEN_EOF:
      g_snprintf (expected_string, expected_string_len, "end of file");
      break;
    default:
      if (expected_token >= 1 && expected_token <= 255)
	{
	  if ((expected_token >= ' ' && expected_token <= '~') ||
	      strchr (scanner->config->cset_identifier_first, expected_token) ||
	      strchr (scanner->config->cset_identifier_nth, expected_token))
	    g_snprintf (expected_string, expected_string_len, "character `%c'", expected_token);
	  else
	    g_snprintf (expected_string, expected_string_len, "character `\\%o'", expected_token);
	  break;
	}
      else if (!scanner->config->symbol_2_token)
	{
	  g_snprintf (expected_string, expected_string_len, "(unknown) token <%d>", expected_token);
	  break;
	}
      /* fall through */
    case G_TOKEN_SYMBOL:
      need_valid = (scanner->token == G_TOKEN_SYMBOL ||
		    (scanner->config->symbol_2_token &&
		     scanner->token > G_TOKEN_LAST));
      g_snprintf (expected_string,
		  expected_string_len,
		  "%s%s",
		  need_valid ? "valid " : "",
		  symbol_spec);
      /* FIXME: should we attempt to lookup the symbol_name for symbol_2_token? */
      break;
    case G_TOKEN_CHAR:
      g_snprintf (expected_string, expected_string_len, "%scharacter",
		  scanner->token == G_TOKEN_CHAR ? "valid " : "");
      break;
    case G_TOKEN_BINARY:
      tstring = "binary";
      g_snprintf (expected_string, expected_string_len, "%snumber (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_OCTAL:
      tstring = "octal";
      g_snprintf (expected_string, expected_string_len, "%snumber (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_INT:
      tstring = "integer";
      g_snprintf (expected_string, expected_string_len, "%snumber (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_HEX:
      tstring = "hexadecimal";
      g_snprintf (expected_string, expected_string_len, "%snumber (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_FLOAT:
      tstring = "float";
      g_snprintf (expected_string, expected_string_len, "%snumber (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_STRING:
      g_snprintf (expected_string,
		  expected_string_len,
		  "%sstring constant",
		  scanner->token == G_TOKEN_STRING ? "valid " : "");
      break;
    case G_TOKEN_IDENTIFIER:
    case G_TOKEN_IDENTIFIER_NULL:
      need_valid = (scanner->token == G_TOKEN_IDENTIFIER_NULL ||
		    scanner->token == G_TOKEN_IDENTIFIER);
      g_snprintf (expected_string,
		  expected_string_len,
		  "%s%s",
		  need_valid ? "valid " : "",
		  identifier_spec);
      break;
    case G_TOKEN_COMMENT_SINGLE:
      tstring = "single-line";
      g_snprintf (expected_string, expected_string_len, "%scomment (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_COMMENT_MULTI:
      tstring = "multi-line";
      g_snprintf (expected_string, expected_string_len, "%scomment (%s)",
		  scanner->token == expected_token ? "valid " : "", tstring);
      break;
    case G_TOKEN_NONE:
    case G_TOKEN_ERROR:
      /* this is handled upon printout */
      break;
    }
  
  if (message && message[0] != 0)
    message_prefix = " - ";
  else
    {
      message_prefix = "";
      message = "";
    }
  if (expected_token == G_TOKEN_ERROR)
    {
      msg_handler (scanner,
		   "failure around %s%s%s",
		   token_string,
		   message_prefix,
		   message);
    }
  else if (expected_token == G_TOKEN_NONE)
    {
      if (print_unexp)
	msg_handler (scanner,
		     "unexpected %s%s%s",
		     token_string,
		     message_prefix,
		     message);
      else
	msg_handler (scanner,
		     "%s%s%s",
		     token_string,
		     message_prefix,
		     message);
    }
  else
    {
      if (print_unexp)
	msg_handler (scanner,
		     "unexpected %s, expected %s%s%s",
		     token_string,
		     expected_string,
		     message_prefix,
		     message);
      else
	msg_handler (scanner,
		     "%s, expected %s%s%s",
		     token_string,
		     expected_string,
		     message_prefix,
		     message);
    }
  
  g_free (token_string);
  g_free (expected_string);
}

static void
g_scanner_get_token_i (GScanner	*scanner,
		       GTokenType	*token_p,
		       GTokenValue	*value_p,
		       guint		*line_p,
		       guint		*position_p)
{
  do
    {
      g_scanner_free_value (token_p, value_p);
      g_scanner_get_token_ll (scanner, token_p, value_p, line_p, position_p);
    }
  while (((*token_p > 0 && *token_p < 256) &&
	  strchr (scanner->config->cset_skip_characters, *token_p)) ||
	 (*token_p == G_TOKEN_CHAR &&
	  strchr (scanner->config->cset_skip_characters, value_p->v_char)) ||
	 (*token_p == G_TOKEN_COMMENT_MULTI &&
	  scanner->config->skip_comment_multi) ||
	 (*token_p == G_TOKEN_COMMENT_SINGLE &&
	  scanner->config->skip_comment_single));