src/location.c

   1 /* Locations for Bison
   2    Copyright (C) 2002, 2005, 2006 Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    Bison is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    Bison is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with Bison; see the file COPYING.  If not, write to
  18    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19    Boston, MA 02110-1301, USA.  */
  20
  21 #include <config.h>
  22 #include "system.h"
  23
  24 #include <mbswidth.h>
  25 #include <quotearg.h>
  26
  27 #include "complain.h"
  28 #include "location.h"
  29
  30 location const empty_location;
  31
  32 /* If BUF is null, add BUFSIZE (which in this case must be less than
  33    INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
  34    COLUMN.  If an overflow occurs, or might occur but is undetectable,
  35    return INT_MAX.  Assume COLUMN is nonnegative.  */
  36
  37 static inline int
  38 add_column_width (int column, char const *buf, size_t bufsize)
  39 {
  40   size_t width;
  41   unsigned int remaining_columns = INT_MAX - column;
  42
  43   if (buf)
  44     {
  45       if (INT_MAX / 2 <= bufsize)
  46         return INT_MAX;
  47       width = mbsnwidth (buf, bufsize, 0);
  48     }
  49   else
  50     width = bufsize;
  51
  52   return width <= remaining_columns ? column + width : INT_MAX;
  53 }
  54
  55 /* Set *LOC and adjust scanner cursor to account for token TOKEN of
  56    size SIZE.  */
  57
  58 void
  59 location_compute (location *loc, boundary *cur, char const *token, size_t size)
  60 {
  61   int line = cur->line;
  62   int column = cur->column;
  63   char const *p0 = token;
  64   char const *p = token;
  65   char const *lim = token + size;
  66
  67   loc->start = *cur;
  68
  69   for (p = token; p < lim; p++)
  70     switch (*p)
  71       {
  72       case '\n':
  73         line += line < INT_MAX;
  74         column = 1;
  75         p0 = p + 1;
  76         break;
  77
  78       case '\t':
  79         column = add_column_width (column, p0, p - p0);
  80         column = add_column_width (column, NULL, 8 - ((column - 1) & 7));
  81         p0 = p + 1;
  82         break;
  83
  84       default:
  85         break;
  86       }
  87
  88   cur->line = line;
  89   cur->column = column = add_column_width (column, p0, p - p0);
  90
  91   loc->end = *cur;
  92
  93   if (line == INT_MAX && loc->start.line != INT_MAX)
  94     warn_at (*loc, _("line number overflow"));
  95   if (column == INT_MAX && loc->start.column != INT_MAX)
  96     warn_at (*loc, _("column number overflow"));
  97 }
  98
  99
 100 /* Output to OUT the location LOC.
 101    Warning: it uses quotearg's slot 3.  */
 102 void
 103 location_print (FILE *out, location loc)
 104 {
 105   int end_col = 0 < loc.end.column ? loc.end.column - 1 : 0;
 106   fprintf (out, "%s:%d.%d",
 107            quotearg_n_style (3, escape_quoting_style, loc.start.file),
 108            loc.start.line, loc.start.column);
 109
 110   if (loc.start.file != loc.end.file)
 111     fprintf (out, "-%s:%d.%d",
 112              quotearg_n_style (3, escape_quoting_style, loc.end.file),
 113              loc.end.line, end_col);
 114   else if (loc.start.line < loc.end.line)
 115     fprintf (out, "-%d.%d", loc.end.line, end_col);
 116   else if (loc.start.column < end_col)
 117     fprintf (out, "-%d", end_col);
 118 }