bison/src/location.c

/* Locations for Bison

   Copyright (C) 2002, 2005, 2006, 2007, 2008, 2009, 2010 Free
   Software Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>
#include "system.h"

#include <mbswidth.h>
#include <quotearg.h>

#include "complain.h"
#include "location.h"

location const empty_location = EMPTY_LOCATION_INIT;

/* If BUF is null, add BUFSIZE (which in this case must be less than
   INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
   COLUMN.  If an overflow occurs, or might occur but is undetectable,
   return INT_MAX.  Assume COLUMN is nonnegative.  */

static inline int
add_column_width (int column, char const *buf, size_t bufsize)
{
  size_t width;
  unsigned int remaining_columns = INT_MAX - column;

  if (buf)
    {
      if (INT_MAX / 2 <= bufsize)
	return INT_MAX;
      width = mbsnwidth (buf, bufsize, 0);
    }
  else
    width = bufsize;

  return width <= remaining_columns ? column + width : INT_MAX;
}

/* Set *LOC and adjust scanner cursor to account for token TOKEN of
   size SIZE.  */

void
location_compute (location *loc, boundary *cur, char const *token, size_t size)
{
  int line = cur->line;
  int column = cur->column;
  char const *p0 = token;
  char const *p = token;
  char const *lim = token + size;

  loc->start = *cur;

  for (p = token; p < lim; p++)
    switch (*p)
      {
      case '\n':
	line += line < INT_MAX;
	column = 1;
	p0 = p + 1;
	break;

      case '\t':
	column = add_column_width (column, p0, p - p0);
	column = add_column_width (column, NULL, 8 - ((column - 1) & 7));
	p0 = p + 1;
	break;

      default:
	break;
      }

  cur->line = line;
  cur->column = column = add_column_width (column, p0, p - p0);

  loc->end = *cur;

  if (line == INT_MAX && loc->start.line != INT_MAX)
    warn_at (*loc, _("line number overflow"));
  if (column == INT_MAX && loc->start.column != INT_MAX)
    warn_at (*loc, _("column number overflow"));
}


/* Output to OUT the location LOC.
   Warning: it uses quotearg's slot 3.  */
void
location_print (FILE *out, location loc)
{
  int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
  fprintf (out, "%s",
           quotearg_n_style (3, escape_quoting_style, loc.start.file));
  if (0 <= loc.start.line)
    {
      fprintf(out, ":%d", loc.start.line);
      if (0 <= loc.start.column)
        fprintf (out, ".%d", loc.start.column);
    }
  if (loc.start.file != loc.end.file)
    {
      fprintf (out, "-%s",
               quotearg_n_style (3, escape_quoting_style, loc.end.file));
      if (0 <= loc.end.line)
        {
          fprintf(out, ":%d", loc.end.line);
          if (0 <= end_col)
            fprintf (out, ".%d", end_col);
        }
    }
  else if (0 <= loc.end.line)
    {
      if (loc.start.line < loc.end.line)
        {
          fprintf (out, "-%d", loc.end.line);
          if (0 <= end_col)
            fprintf (out, ".%d", end_col);
        }
      else if (0 <= end_col && loc.start.column < end_col)
        fprintf (out, "-%d", end_col);
    }
}

void
boundary_set_from_string (boundary *bound, char *loc_str)
{
  /* Must search in reverse since the file name field may
   * contain `.' or `:'.  */
  char *delim = strrchr (loc_str, '.');
  aver (delim);
  *delim = '\0';
  bound->column = atoi (delim+1);
  delim = strrchr (loc_str, ':');
  aver (delim);
  *delim = '\0';
  bound->line = atoi (delim+1);
  bound->file = uniqstr_new (loc_str);
}