cp-lex.c

早期freebsd实现

	case '\r':
	case '\v':
	case '\b':
	  do
	    c = getch ();
	  while (c == ' ' || c == '\t');
	  break;

	case '\\':
	  c = getch ();
	  if (c == '\n')
	    lineno++;
	  else
	    error ("stray '\\' in program");
	  c = getch ();
	  break;

	default:
	  return (c);
	}
    }
}



/* Make the token buffer longer, preserving the data in it.
   P should point to just beyond the last valid character in the old buffer.
   The value we return is a pointer to the new buffer
   at a place corresponding to P.  */

static char *
extend_token_buffer (p)
     char *p;
{
  int offset = p - token_buffer;

  maxtoken = maxtoken * 2 + 10;
  token_buffer = (char *) xrealloc (token_buffer, maxtoken + 2);

  return token_buffer + offset;
}

static int
get_last_nonwhite_on_line ()
{
  register int c;

  /* Is this the last nonwhite stuff on the line?  */
  if (nextchar >= 0)
    c = nextchar, nextchar = -1;
  else
    c = getch ();

  while (c == ' ' || c == '\t')
    c = getch ();
  return c;
}

/* At the beginning of a line, increment the line number
   and process any #-directive on this line.
   If the line is a #-directive, read the entire line and return a newline.
   Otherwise, return the line's first non-whitespace character.  */

int
check_newline ()
{
  register int c;
  register int token;

  lineno++;

  /* Read first nonwhite char on the line.  */

  do
    c = getch ();
  while (c == ' ' || c == '\t');

  if (c != '#')
    {
      /* If not #, return it so caller will use it.  */
      return c;
    }

  /* Read first nonwhite char after the `#'.  */

  do
    c = getch ();
  while (c == ' ' || c == '\t');

  /* If a letter follows, then if the word here is `line', skip
     it and ignore it; otherwise, ignore the line, with an error
     if the word isn't `pragma'.  */

  if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
    {
      if (c == 'p')
	{
	  if (getch () == 'r'
	      && getch () == 'a'
	      && getch () == 'g'
	      && getch () == 'm'
	      && getch () == 'a')
	    {
	      /* Read first nonwhite char after the `#pragma'.  */

	      do
		c = getch ();
	      while (c == ' ' || c == '\t');

	      if (c == 'v'
		  && getch () == 't'
		  && getch () == 'a'
		  && getch () == 'b'
		  && getch () == 'l'
		  && getch () == 'e'
		  && ((c = getch ()) == ' ' || c == '\t' || c == '\n'))
		{
		  extern tree pending_vtables;

		  /* More follows: it must be a string constant (class name).  */
		  token = real_yylex ();
		  if (token != STRING || TREE_CODE (yylval.ttype) != STRING_CST)
		    {
		      error ("invalid #pragma vtable");
		      goto skipline;
		    }
		  if (write_virtuals != 2)
		    {
		      warning ("use `+e2' option to enable #pragma vtable");
		      goto skipline;
		    }
		  pending_vtables = perm_tree_cons (NULL_TREE, get_identifier (TREE_STRING_POINTER (yylval.ttype)), pending_vtables);
		  if (nextchar < 0)
		    nextchar = getch ();
		  c = nextchar;
		  if (c != '\n')
		    warning ("trailing characters ignored");
		}
	      else if (c == 'u'
		       && getch () == 'n'
		       && getch () == 'i'
		       && getch () == 't'
		       && ((c = getch ()) == ' ' || c == '\t' || c == '\n'))
		{
		  /* More follows: it must be a string constant (unit name).  */
		  token = real_yylex ();
		  if (token != STRING || TREE_CODE (yylval.ttype) != STRING_CST)
		    {
		      error ("invalid #pragma unit");
		      goto skipline;
		    }
		  current_unit_name = get_identifier (TREE_STRING_POINTER (yylval.ttype));
		  current_unit_language = current_lang_name;
		  if (nextchar < 0)
		    nextchar = getch ();
		  c = nextchar;
		  if (c != '\n')
		    warning ("trailing characters ignored");
		}
	      else if (c == 'i')
		{
		  tree fileinfo = IDENTIFIER_CLASS_VALUE (get_time_identifier (input_filename));
		  c = getch ();

		  if (c == 'n'
		      && getch () == 't'
		      && getch () == 'e'
		      && getch () == 'r'
		      && getch () == 'f'
		      && getch () == 'a'
		      && getch () == 'c'
		      && getch () == 'e'
		      && ((c = getch ()) == ' ' || c == '\t' || c == '\n'))
		    {
		      /* read to newline.  */
		      while (c != '\n')
			c = getch ();

		      write_virtuals = 3;

		      if (impl_file_chain == 0)
			{
			  char *filename;
			  tree fi;

			  /* If this is zero at this point, then we are
			     auto-implementing.  */
			  if (main_input_filename == 0)
			    main_input_filename = input_filename;

			  filename = FILE_NAME_NONDIRECTORY (main_input_filename);
			  fi = get_time_identifier (filename);
			  fi = IDENTIFIER_CLASS_VALUE (fi);
			  TREE_INT_CST_LOW (fi) = 0;
			  TREE_INT_CST_HIGH (fi) = 1;
			  /* Get default.  */
			  impl_file_chain = (struct impl_files *)permalloc (sizeof (struct impl_files));
			  impl_file_chain->filename = filename;
			  impl_file_chain->next = 0;
			}

		      interface_only = interface_strcmp (input_filename);
		      interface_unknown = 0;
		      TREE_INT_CST_LOW (fileinfo) = interface_only;
		      TREE_INT_CST_HIGH (fileinfo) = interface_unknown;
		    }
		  else if (c == 'm'
			   && getch () == 'p'
			   && getch () == 'l'
			   && getch () == 'e'
			   && getch () == 'm'
			   && getch () == 'e'
			   && getch () == 'n'
			   && getch () == 't'
			   && getch () == 'a'
			   && getch () == 't'
			   && getch () == 'i'
			   && getch () == 'o'
			   && getch () == 'n'
			   && ((c = getch ()) == ' ' || c == '\t' || c == '\n'))
		    {
		      char *main_filename = main_input_filename ? main_input_filename : input_filename;

		      while (c == ' ' || c == '\t')
			c = getch ();
		      if (c != '\n')
			{
			  put_back (c);
			  token = real_yylex ();
			  if (token != STRING
			      || TREE_CODE (yylval.ttype) != STRING_CST)
			    {
			      error ("invalid `#pragma implementation'");
			      goto skipline;
			    }
			  main_filename = TREE_STRING_POINTER (yylval.ttype);
			}
		      main_filename = FILE_NAME_NONDIRECTORY (main_filename);

		      /* read to newline.  */
		      while (c != '\n')
			c = getch ();

		      if (write_virtuals == 3)
			{
			  struct impl_files *ifiles = impl_file_chain;
			  while (ifiles)
			    {
			      if (! strcmp (ifiles->filename, main_filename))
				break;
			      ifiles = ifiles->next;
			    }
			  if (ifiles == 0)
			    {
			      ifiles = (struct impl_files*) permalloc (sizeof (struct impl_files));
			      ifiles->filename = main_filename;
			      ifiles->next = impl_file_chain;
			      impl_file_chain = ifiles;
			    }
			}
		      else if ((main_input_filename != 0
				&& ! strcmp (main_input_filename, input_filename))
			       || ! strcmp (input_filename, main_filename))
			{
			  write_virtuals = 3;
			  if (impl_file_chain == 0)
			    {
			      impl_file_chain = (struct impl_files*) permalloc (sizeof (struct impl_files));
			      impl_file_chain->filename = main_filename;
			      impl_file_chain->next = 0;
			    }
			}
		      else
			error ("`#pragma implementation' can only appear at top-level");
		      interface_only = 0;
		      /* We make this non-zero so that we infer decl linkage
			 in the impl file only for variables first declared
			 in the interface file.  */
		      interface_unknown = 1;
		      TREE_INT_CST_LOW (fileinfo) = interface_only;
		      TREE_INT_CST_HIGH (fileinfo) = interface_unknown;
		    }
		}
	    }
	  goto skipline;
	}
      else if (c == 'd')
	{
	  if (getch () == 'e'
	      && getch () == 'f'
	      && getch () == 'i'
	      && getch () == 'n'
	      && getch () == 'e'
	      && ((c = getch ()) == ' ' || c == '\t' || c == '\n'))
	    {
#ifdef DWARF_DEBUGGING_INFO
	      if ((debug_info_level == DINFO_LEVEL_VERBOSE)
		  && (write_symbols == DWARF_DEBUG))
	        dwarfout_define (lineno, get_directive_line (finput));
#endif /* DWARF_DEBUGGING_INFO */
	      goto skipline;
	    }
	}
      else if (c == 'u')
	{
	  if (getch () == 'n'
	      && getch () == 'd'
	      && getch () == 'e'
	      && getch () == 'f'
	      && ((c = getch ()) == ' ' || c == '\t' || c == '\n'))
	    {
#ifdef DWARF_DEBUGGING_INFO
	      if ((debug_info_level == DINFO_LEVEL_VERBOSE)
		  && (write_symbols == DWARF_DEBUG))
	        dwarfout_undef (lineno, get_directive_line (finput));
#endif /* DWARF_DEBUGGING_INFO */
	      goto skipline;
	    }
	}
      else if (c == 'l')
	{
	  if (getch () == 'i'
	      && getch () == 'n'
	      && getch () == 'e'
	      && ((c = getch ()) == ' ' || c == '\t'))
	    goto linenum;
	}
      else if (c == 'i')
	{
	  if (getch () == 'd'
	      && getch () == 'e'
	      && getch () == 'n'
	      && getch () == 't'
	      && ((c = getch ()) == ' ' || c == '\t'))
	    {
#ifdef ASM_OUTPUT_IDENT
              extern FILE *asm_out_file;
#endif
	      /* #ident.  The pedantic warning is now in cccp.c.  */

	      /* Here we have just seen `#ident '.
		 A string constant should follow.  */

	      while (c == ' ' || c == '\t')
		c = getch ();

	      /* If no argument, ignore the line.  */
	      if (c == '\n')
		return c;

	      put_back (c);
	      token = real_yylex ();
	      if (token != STRING
		  || TREE_CODE (yylval.ttype) != STRING_CST)
		{
		  error ("invalid #ident");
		  goto skipline;
		}

	      if (! flag_no_ident)
		{
#ifdef ASM_OUTPUT_IDENT
		  ASM_OUTPUT_IDENT (asm_out_file,
				    TREE_STRING_POINTER (yylval.ttype));
#endif
		}

	      /* Skip the rest of this line.  */
	      goto skipline;
	    }
	}
      else if (c == 'n')
	{
	  if (getch () == 'e'
	      && getch () == 'w'
	      && getch () == 'w'
	      && getch () == 'o'
	      && getch () == 'r'
	      && getch () == 'l'
	      && getch () == 'd'
	      && ((c = getch ()) == ' ' || c == '\t'))
	    {
	      /* Used to test incremental compilation.  */
	      sorry ("#pragma newworld");
	      goto skipline;
	    }
	}
      error ("undefined or invalid # directive");
      goto skipline;
    }

linenum:
  /* Here we have either `#line' or `# <nonletter>'.
     In either case, it should be a line number; a digit should follow.  */

  while (c == ' ' || c == '\t')
    c = getch ();

  /* If the # is the only nonwhite char on the line,
     just ignore it.  Check the new newline.  */
  if (c == '\n')
    return c;

  /* Something follows the #; read a token.  */

  put_back (c);
  token = real_yylex ();

  if (token == CONSTANT
      && TREE_CODE (yylval.ttype) == INTEGER_CST)
    {
      int old_lineno = lineno;
      int used_up = 0;
      /* subtract one, because it is the following line that
	 gets the specified number */

      int l = TREE_INT_CST_LOW (yylval.ttype) - 1;
      c = get_last_nonwhite_on_line ();
      if (c == '\n')
	{
	  /* No more: store the line number and check following line.  */
	  lineno = l;
	  return c;
	}
      put_back (c);

      /* More follows: it must be a string constant (filename).  */

      /* Read the string constant, but don't treat \ as special.  */
      ignore_escape_flag = 1;
      token = real_yylex ();
      ignore_escape_flag = 0;

      if (token != STRING || TREE_CODE (yylval.ttype) != STRING_CST)
	{
	  error ("invalid #line");
	  goto skipline;
	}

      /* Changing files again.  This means currently collected