src/location.c

   1 /* Locations for Bison
   2
   3    Copyright (C) 2002, 2005-2013 Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   6
   7    This program is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include <config.h>
  21 #include "system.h"
  22
  23 #include <mbswidth.h>
  24 #include <quotearg.h>
  25
  26 #include "complain.h"
  27 #include "location.h"
  28
  29 location const empty_location = EMPTY_LOCATION_INIT;
  30
  31 /* If BUF is null, add BUFSIZE (which in this case must be less than
  32    INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
  33    COLUMN.  If an overflow occurs, or might occur but is undetectable,
  34    return INT_MAX.  Assume COLUMN is nonnegative.  */
  35
  36 static inline int
  37 add_column_width (int column, char const *buf, size_t bufsize)
  38 {
  39   size_t width;
  40   unsigned int remaining_columns = INT_MAX - column;
  41
  42   if (buf)
  43     {
  44       if (INT_MAX / 2 <= bufsize)
  45         return INT_MAX;
  46       width = mbsnwidth (buf, bufsize, 0);
  47     }
  48   else
  49     width = bufsize;
  50
  51   return width <= remaining_columns ? column + width : INT_MAX;
  52 }
  53
  54 /* Set *LOC and adjust scanner cursor to account for token TOKEN of
  55    size SIZE.  */
  56
  57 void
  58 location_compute (location *loc, boundary *cur, char const *token, size_t size)
  59 {
  60   int line = cur->line;
  61   int column = cur->column;
  62   char const *p0 = token;
  63   char const *p = token;
  64   char const *lim = token + size;
  65
  66   loc->start = *cur;
  67
  68   for (p = token; p < lim; p++)
  69     switch (*p)
  70       {
  71       case '\n':
  72         line += line < INT_MAX;
  73         column = 1;
  74         p0 = p + 1;
  75         break;
  76
  77       case '\t':
  78         column = add_column_width (column, p0, p - p0);
  79         column = add_column_width (column, NULL, 8 - ((column - 1) & 7));
  80         p0 = p + 1;
  81         break;
  82
  83       default:
  84         break;
  85       }
  86
  87   cur->line = line;
  88   cur->column = column = add_column_width (column, p0, p - p0);
  89
  90   loc->end = *cur;
  91
  92   if (line == INT_MAX && loc->start.line != INT_MAX)
  93     complain (loc, Wother, _("line number overflow"));
  94   if (column == INT_MAX && loc->start.column != INT_MAX)
  95     complain (loc, Wother, _("column number overflow"));
  96 }
  97
  98
  99 /* Output to OUT the location LOC.
 100    Warning: it uses quotearg's slot 3.  */
 101 unsigned
 102 location_print (location loc, FILE *out)
 103 {
 104   unsigned res = 0;
 105   int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
 106   res += fprintf (out, "%s",
 107                   quotearg_n_style (3, escape_quoting_style, loc.start.file));
 108   if (0 <= loc.start.line)
 109     {
 110       res += fprintf (out, ":%d", loc.start.line);
 111       if (0 <= loc.start.column)
 112         res += fprintf (out, ".%d", loc.start.column);
 113     }
 114   if (loc.start.file != loc.end.file)
 115     {
 116       res += fprintf (out, "-%s",
 117                       quotearg_n_style (3, escape_quoting_style,
 118                                         loc.end.file));
 119       if (0 <= loc.end.line)
 120         {
 121           res += fprintf (out, ":%d", loc.end.line);
 122           if (0 <= end_col)
 123             res += fprintf (out, ".%d", end_col);
 124         }
 125     }
 126   else if (0 <= loc.end.line)
 127     {
 128       if (loc.start.line < loc.end.line)
 129         {
 130           res += fprintf (out, "-%d", loc.end.line);
 131           if (0 <= end_col)
 132             res += fprintf (out, ".%d", end_col);
 133         }
 134       else if (0 <= end_col && loc.start.column < end_col)
 135         res += fprintf (out, "-%d", end_col);
 136     }
 137
 138   return res;
 139 }
 140
 141
 142 /* Persistant data used by location_caret to avoid reopening and rereading the
 143    same file all over for each error.  */
 144 struct caret_info
 145 {
 146   FILE *source;
 147   size_t line;
 148   size_t offset;
 149 };
 150
 151 static struct caret_info caret_info = { NULL, 1, 0 };
 152
 153 void
 154 cleanup_caret ()
 155 {
 156   if (caret_info.source)
 157     fclose (caret_info.source);
 158   caret_info.source = NULL;
 159   caret_info.line = 1;
 160   caret_info.offset = 0;
 161 }
 162
 163 void
 164 location_caret (location loc, FILE *out)
 165 {
 166   /* FIXME: find a way to support multifile locations, and only open once each
 167      file. That would make the procedure future-proof.  */
 168   if (! (caret_info.source
 169          || (caret_info.source = fopen (loc.start.file, "r")))
 170       || loc.start.column == -1 || loc.start.line == -1)
 171     return;
 172
 173   /* If the line we want to quote is seekable (the same line as the previous
 174      location), just seek it. If it was a previous line, we lost track of it,
 175      so return to the start of file.  */
 176   if (caret_info.line <= loc.start.line)
 177     fseek (caret_info.source, caret_info.offset, SEEK_SET);
 178   else
 179     {
 180       caret_info.line = 1;
 181       caret_info.offset = 0;
 182       fseek (caret_info.source, caret_info.offset, SEEK_SET);
 183     }
 184
 185   /* Advance to the line's position, keeping track of the offset.  */
 186   while (caret_info.line < loc.start.line)
 187     caret_info.line += getc (caret_info.source) == '\n';
 188   caret_info.offset = ftell (caret_info.source);
 189
 190   /* Read the actual line.  Don't update the offset, so that we keep a pointer
 191      to the start of the line.  */
 192   {
 193     char c = getc (caret_info.source);
 194     if (c != EOF)
 195       {
 196         /* Quote the file, indent by a single column.  */
 197         putc (' ', out);
 198         do
 199           putc (c, out);
 200         while ((c = getc (caret_info.source)) != EOF && c != '\n');
 201         putc ('\n', out);
 202
 203         {
 204           /* The caret of a multiline location ends with the first line.  */
 205           size_t len = loc.start.line != loc.end.line
 206             ? ftell (caret_info.source) - caret_info.offset
 207             : loc.end.column;
 208           int i;
 209
 210           /* Print the carets (at least one), with the same indent as above.*/
 211           fprintf (out, " %*s", loc.start.column - 1, "");
 212           for (i = loc.start.column; i == loc.start.column || i < len; ++i)
 213             putc ('^', out);
 214           }
 215         putc ('\n', out);
 216       }
 217   }
 218 }
 219
 220 void
 221 boundary_set_from_string (boundary *bound, char *loc_str)
 222 {
 223   /* Must search in reverse since the file name field may
 224    * contain `.' or `:'.  */
 225   char *delim = strrchr (loc_str, '.');
 226   aver (delim);
 227   *delim = '\0';
 228   bound->column = atoi (delim+1);
 229   delim = strrchr (loc_str, ':');
 230   aver (delim);
 231   *delim = '\0';
 232   bound->line = atoi (delim+1);
 233   bound->file = uniqstr_new (loc_str);
 234 }