libcpp/line-map.c

   1 /* Map logical line numbers to (source file, line number) pairs.
   2    Copyright (C) 2001, 2003, 2004
   3    Free Software Foundation, Inc.
   4
   5 This program is free software; you can redistribute it and/or modify it
   6 under the terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option) any
   8 later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19  In other words, you are welcome to use, share and improve this program.
  20  You are forbidden to forbid anyone else to use, share and improve
  21  what you give them.   Help stamp out software-hoarding!  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "line-map.h"
  26
  27 static void trace_include (const struct line_maps *, const struct line_map *);
  28
  29 /* Initialize a line map set.  */
  30
  31 void
  32 linemap_init (struct line_maps *set)
  33 {
  34   set->maps = NULL;
  35   set->allocated = 0;
  36   set->used = 0;
  37   set->last_listed = -1;
  38   set->trace_includes = false;
  39   set->depth = 0;
  40   set->cache = 0;
  41   set->highest_location = 0;
  42   set->highest_line = 0;
  43   set->max_column_hint = 0;
  44 }
  45
  46 /* Check for and warn about line_maps entered but not exited.  */
  47
  48 void
  49 linemap_check_files_exited (struct line_maps *set)
  50 {
  51   struct line_map *map;
  52   /* Depending upon whether we are handling preprocessed input or
  53      not, this can be a user error or an ICE.  */
  54   for (map = &set->maps[set->used - 1]; ! MAIN_FILE_P (map);
  55        map = INCLUDED_FROM (set, map))
  56     fprintf (stderr, "line-map.c: file \"%s\" entered but not left\n",
  57              map->to_file);
  58 }
  59
  60 /* Free a line map set.  */
  61
  62 void
  63 linemap_free (struct line_maps *set)
  64 {
  65   if (set->maps)
  66     {
  67       linemap_check_files_exited (set);
  68
  69       free (set->maps);
  70     }
  71 }
  72
  73 /* Add a mapping of logical source line to physical source file and
  74    line number.
  75
  76    The text pointed to by TO_FILE must have a lifetime
  77    at least as long as the final call to lookup_line ().  An empty
  78    TO_FILE means standard input.  If reason is LC_LEAVE, and
  79    TO_FILE is NULL, then TO_FILE, TO_LINE and SYSP are given their
  80    natural values considering the file we are returning to.
  81
  82    FROM_LINE should be monotonic increasing across calls to this
  83    function.  A call to this function can relocate the previous set of
  84    A call to this function can relocate the previous set of
  85    maps, so any stored line_map pointers should not be used.  */
  86
  87 const struct line_map *
  88 linemap_add (struct line_maps *set, enum lc_reason reason,
  89              unsigned int sysp, const char *to_file, unsigned int to_line)
  90 {
  91   struct line_map *map;
  92   source_location start_location = set->highest_location + 1;
  93
  94   if (set->used && start_location < set->maps[set->used - 1].start_location)
  95     abort ();
  96
  97   if (set->used == set->allocated)
  98     {
  99       set->allocated = 2 * set->allocated + 256;
 100       set->maps = xrealloc (set->maps, set->allocated * sizeof (struct line_map));
 101     }
 102
 103   map = &set->maps[set->used];
 104
 105   if (to_file && *to_file == '\0')
 106     to_file = "<stdin>";
 107
 108   /* If we don't keep our line maps consistent, we can easily
 109      segfault.  Don't rely on the client to do it for us.  */
 110   if (set->depth == 0)
 111     reason = LC_ENTER;
 112   else if (reason == LC_LEAVE)
 113     {
 114       struct line_map *from;
 115       bool error;
 116
 117       if (MAIN_FILE_P (map - 1))
 118         {
 119           if (to_file == NULL)
 120             {
 121               set->depth--;
 122               return NULL;
 123             }
 124           error = true;
 125           reason = LC_RENAME;
 126           from = map - 1;
 127         }
 128       else
 129         {
 130           from = INCLUDED_FROM (set, map - 1);
 131           error = to_file && strcmp (from->to_file, to_file);
 132         }
 133
 134       /* Depending upon whether we are handling preprocessed input or
 135          not, this can be a user error or an ICE.  */
 136       if (error)
 137         fprintf (stderr, "line-map.c: file \"%s\" left but not entered\n",
 138                  to_file);
 139
 140       /* A TO_FILE of NULL is special - we use the natural values.  */
 141       if (error || to_file == NULL)
 142         {
 143           to_file = from->to_file;
 144           to_line = SOURCE_LINE (from, from[1].start_location);
 145           sysp = from->sysp;
 146         }
 147     }
 148
 149   map->reason = reason;
 150   map->sysp = sysp;
 151   map->start_location = start_location;
 152   map->to_file = to_file;
 153   map->to_line = to_line;
 154   set->cache = set->used++;
 155   map->column_bits = 0;
 156   set->highest_location = start_location;
 157   set->highest_line = start_location;
 158   set->max_column_hint = 0;
 159
 160   if (reason == LC_ENTER)
 161     {
 162       map->included_from = set->depth == 0 ? -1 : (int) (set->used - 2);
 163       set->depth++;
 164       if (set->trace_includes)
 165         trace_include (set, map);
 166     }
 167   else if (reason == LC_RENAME)
 168     map->included_from = map[-1].included_from;
 169   else if (reason == LC_LEAVE)
 170     {
 171       set->depth--;
 172       map->included_from = INCLUDED_FROM (set, map - 1)->included_from;
 173     }
 174
 175   return map;
 176 }
 177
 178 source_location
 179 linemap_line_start (struct line_maps *set, unsigned int to_line,
 180                     unsigned int max_column_hint)
 181 {
 182   struct line_map *map = &set->maps[set->used - 1];
 183   source_location highest = set->highest_location;
 184   source_location r;
 185   unsigned int last_line = SOURCE_LINE (map, set->highest_line);
 186   int line_delta = to_line - last_line;
 187   bool add_map = false;
 188   if (line_delta < 0
 189       || (line_delta > 10 && line_delta * map->column_bits > 1000)
 190       || (max_column_hint >= (1U << map->column_bits))
 191       || (max_column_hint <= 80 && map->column_bits >= 10))
 192     {
 193       add_map = true;
 194     }
 195   else
 196     max_column_hint = set->max_column_hint;
 197   if (add_map)
 198     {
 199       int column_bits;
 200       if (max_column_hint > 100000 || highest > 0xC0000000)
 201         {
 202           max_column_hint = 0;
 203           if (highest >0xF0000000)
 204             return 0;
 205           column_bits = 0;
 206         }
 207       else
 208         {
 209           column_bits = 7;
 210           while (max_column_hint >= (1U << column_bits))
 211             column_bits++;
 212           max_column_hint = 1U << column_bits;
 213         }
 214       if (line_delta < 0
 215           || last_line != map->to_line
 216           || SOURCE_COLUMN (map, highest) >= (1U << column_bits))
 217         map = (struct line_map*) linemap_add (set, LC_RENAME, map->sysp,
 218                                       map->to_file, to_line);
 219       map->column_bits = column_bits;
 220       r = map->start_location;
 221     }
 222   else
 223     r = highest - SOURCE_COLUMN (map, highest)
 224       + (line_delta << map->column_bits);
 225   set->highest_line = r;
 226   if (r > set->highest_location)
 227     set->highest_location = r;
 228   set->max_column_hint = max_column_hint;
 229   return r;
 230 }
 231
 232 source_location
 233 linemap_position_for_column (struct line_maps *set, unsigned int to_column)
 234 {
 235   source_location r = set->highest_line;
 236   if (to_column >= set->max_column_hint)
 237     {
 238       if (r >= 0xC000000 || to_column > 100000)
 239         {
 240           /* Running low on source_locations - disable column numbers.  */
 241           return r;
 242         }
 243       else
 244         {
 245           struct line_map *map = &set->maps[set->used - 1];
 246           r = linemap_line_start (set, SOURCE_LINE (map, r), to_column + 50);
 247         }
 248     }
 249   r = r + to_column;
 250   if (r >= set->highest_location)
 251     set->highest_location = r;
 252   return r;
 253 }
 254
 255 /* Given a logical line, returns the map from which the corresponding
 256    (source file, line) pair can be deduced.  Since the set is built
 257    chronologically, the logical lines are monotonic increasing, and so
 258    the list is sorted and we can use a binary search.  */
 259
 260 const struct line_map *
 261 linemap_lookup (struct line_maps *set, source_location line)
 262 {
 263   unsigned int md, mn, mx;
 264   const struct line_map *cached;
 265
 266   mn = set->cache;
 267   mx = set->used;
 268
 269   cached = &set->maps[mn];
 270   /* We should get a segfault if no line_maps have been added yet.  */
 271   if (line >= cached->start_location)
 272     {
 273       if (mn + 1 == mx || line < cached[1].start_location)
 274         return cached;
 275     }
 276   else
 277     {
 278       mx = mn;
 279       mn = 0;
 280     }
 281
 282   while (mx - mn > 1)
 283     {
 284       md = (mn + mx) / 2;
 285       if (set->maps[md].start_location > line)
 286         mx = md;
 287       else
 288         mn = md;
 289     }
 290
 291   set->cache = mn;
 292   return &set->maps[mn];
 293 }
 294
 295 /* Print the file names and line numbers of the #include commands
 296    which led to the map MAP, if any, to stderr.  Nothing is output if
 297    the most recently listed stack is the same as the current one.  */
 298
 299 void
 300 linemap_print_containing_files (struct line_maps *set,
 301                                 const struct line_map *map)
 302 {
 303   if (MAIN_FILE_P (map) || set->last_listed == map->included_from)
 304     return;
 305
 306   set->last_listed = map->included_from;
 307   map = INCLUDED_FROM (set, map);
 308
 309   fprintf (stderr,  _("In file included from %s:%u"),
 310            map->to_file, LAST_SOURCE_LINE (map));
 311
 312   while (! MAIN_FILE_P (map))
 313     {
 314       map = INCLUDED_FROM (set, map);
 315       /* Translators note: this message is used in conjunction
 316          with "In file included from %s:%ld" and some other
 317          tricks.  We want something like this:
 318
 319          | In file included from sys/select.h:123,
 320          |                  from sys/types.h:234,
 321          |                  from userfile.c:31:
 322          | bits/select.h:45: <error message here>
 323
 324          with all the "from"s lined up.
 325          The trailing comma is at the beginning of this message,
 326          and the trailing colon is not translated.  */
 327       fprintf (stderr, _(",\n                 from %s:%u"),
 328                map->to_file, LAST_SOURCE_LINE (map));
 329     }
 330
 331   fputs (":\n", stderr);
 332 }
 333
 334 /* Print an include trace, for e.g. the -H option of the preprocessor.  */
 335
 336 static void
 337 trace_include (const struct line_maps *set, const struct line_map *map)
 338 {
 339   unsigned int i = set->depth;
 340
 341   while (--i)
 342     putc ('.', stderr);
 343   fprintf (stderr, " %s\n", map->to_file);
 344 }