libcpp/include/line-map.h

   1 /* Map logical line numbers to (source file, line number) pairs.
   2    Copyright (C) 2001, 2003, 2004, 2007, 2008, 2009
   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 3, 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; see the file COPYING3.  If not see
  17 <http://www.gnu.org/licenses/>.
  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 #ifndef LIBCPP_LINE_MAP_H
  24 #define LIBCPP_LINE_MAP_H
  25
  26 #ifndef GTY
  27 #define GTY(x) /* nothing */
  28 #endif
  29
  30 /* Reason for adding a line change with add_line_map ().  LC_ENTER is
  31    when including a new file, e.g. a #include directive in C.
  32    LC_LEAVE is when reaching a file's end.  LC_RENAME is when a file
  33    name or line number changes for neither of the above reasons
  34    (e.g. a #line directive in C); LC_RENAME_VERBATIM is like LC_RENAME
  35    but a filename of "" is not specially interpreted as standard input.  */
  36 enum lc_reason {LC_ENTER = 0, LC_LEAVE, LC_RENAME, LC_RENAME_VERBATIM};
  37
  38 /* The type of line numbers.  */
  39 typedef unsigned int linenum_type;
  40
  41 /* A logical line/column number, i.e. an "index" into a line_map.  */
  42 /* Long-term, we want to use this to replace struct location_s (in input.h),
  43    and effectively typedef source_location location_t.  */
  44 typedef unsigned int source_location;
  45
  46 /* Memory allocation function typedef.  Works like xrealloc.  */
  47 typedef void *(*line_map_realloc) (void *, size_t);
  48
  49 /* Physical source file TO_FILE at line TO_LINE at column 0 is represented
  50    by the logical START_LOCATION.  TO_LINE+L at column C is represented by
  51    START_LOCATION+(L*(1<<column_bits))+C, as long as C<(1<<column_bits),
  52    and the result_location is less than the next line_map's start_location.
  53    (The top line is line 1 and the leftmost column is column 1; line/column 0
  54    means "entire file/line" or "unknown line/column" or "not applicable".)
  55    INCLUDED_FROM is an index into the set that gives the line mapping
  56    at whose end the current one was included.  File(s) at the bottom
  57    of the include stack have this set to -1.  REASON is the reason for
  58    creation of this line map, SYSP is one for a system header, two for
  59    a C system header file that therefore needs to be extern "C"
  60    protected in C++, and zero otherwise.  */
  61 struct GTY(()) line_map {
  62   const char *to_file;
  63   linenum_type to_line;
  64   source_location start_location;
  65   int included_from;
  66   ENUM_BITFIELD (lc_reason) reason : CHAR_BIT;
  67   /* The sysp field isn't really needed now that it's in cpp_buffer.  */
  68   unsigned char sysp;
  69   /* Number of the low-order source_location bits used for a column number.  */
  70   unsigned int column_bits : 8;
  71 };
  72
  73 /* A set of chronological line_map structures.  */
  74 struct GTY(()) line_maps {
  75   struct line_map * GTY ((length ("%h.used"))) maps;
  76   unsigned int allocated;
  77   unsigned int used;
  78
  79   unsigned int cache;
  80
  81   /* The most recently listed include stack, if any, starts with
  82      LAST_LISTED as the topmost including file.  -1 indicates nothing
  83      has been listed yet.  */
  84   int last_listed;
  85
  86   /* Depth of the include stack, including the current file.  */
  87   unsigned int depth;
  88
  89   /* If true, prints an include trace a la -H.  */
  90   bool trace_includes;
  91
  92   /* Highest source_location "given out".  */
  93   source_location highest_location;
  94
  95   /* Start of line of highest source_location "given out".  */
  96   source_location highest_line;
  97
  98   /* The maximum column number we can quickly allocate.  Higher numbers
  99      may require allocating a new line_map.  */
 100   unsigned int max_column_hint;
 101
 102   /* If non-null, the allocator to use when resizing 'maps'.  If null,
 103      xrealloc is used.  */
 104   line_map_realloc reallocator;
 105 };
 106
 107 /* Initialize a line map set.  */
 108 extern void linemap_init (struct line_maps *);
 109
 110 /* Free a line map set.  */
 111 extern void linemap_free (struct line_maps *);
 112
 113 /* Check for and warn about line_maps entered but not exited.  */
 114
 115 extern void linemap_check_files_exited (struct line_maps *);
 116
 117 /* Return a source_location for the start (i.e. column==0) of
 118    (physical) line TO_LINE in the current source file (as in the
 119    most recent linemap_add).   MAX_COLUMN_HINT is the highest column
 120    number we expect to use in this line (but it does not change
 121    the highest_location).  */
 122
 123 extern source_location linemap_line_start
 124 (struct line_maps *set, linenum_type to_line,  unsigned int max_column_hint);
 125
 126 /* Add a mapping of logical source line to physical source file and
 127    line number.
 128
 129    The text pointed to by TO_FILE must have a lifetime
 130    at least as long as the final call to lookup_line ().  An empty
 131    TO_FILE means standard input.  If reason is LC_LEAVE, and
 132    TO_FILE is NULL, then TO_FILE, TO_LINE and SYSP are given their
 133    natural values considering the file we are returning to.
 134
 135    A call to this function can relocate the previous set of
 136    maps, so any stored line_map pointers should not be used.  */
 137 extern const struct line_map *linemap_add
 138   (struct line_maps *, enum lc_reason, unsigned int sysp,
 139    const char *to_file, linenum_type to_line);
 140
 141 /* Given a logical line, returns the map from which the corresponding
 142    (source file, line) pair can be deduced.  */
 143 extern const struct line_map *linemap_lookup
 144   (struct line_maps *, source_location);
 145
 146 /* source_location values from 0 to RESERVED_LOCATION_COUNT-1 will
 147    be reserved for libcpp user as special values, no token from libcpp
 148    will contain any of those locations.  */
 149 #define RESERVED_LOCATION_COUNT 2
 150
 151 /* Converts a map and a source_location to source line.  */
 152 #define SOURCE_LINE(MAP, LOC) \
 153   ((((LOC) - (MAP)->start_location) >> (MAP)->column_bits) + (MAP)->to_line)
 154
 155 #define SOURCE_COLUMN(MAP, LOC) \
 156   (((LOC) - (MAP)->start_location) & ((1 << (MAP)->column_bits) - 1))
 157
 158 /* Returns the last source line within a map.  This is the (last) line
 159    of the #include, or other directive, that caused a map change.  */
 160 #define LAST_SOURCE_LINE(MAP) \
 161   SOURCE_LINE (MAP, LAST_SOURCE_LINE_LOCATION (MAP))
 162 #define LAST_SOURCE_COLUMN(MAP) \
 163   SOURCE_COLUMN (MAP, LAST_SOURCE_LINE_LOCATION (MAP))
 164 #define LAST_SOURCE_LINE_LOCATION(MAP) \
 165   ((((MAP)[1].start_location - 1 - (MAP)->start_location) \
 166     & ~((1 << (MAP)->column_bits) - 1))                   \
 167    + (MAP)->start_location)
 168
 169 /* Returns the map a given map was included from.  */
 170 #define INCLUDED_FROM(SET, MAP) (&(SET)->maps[(MAP)->included_from])
 171
 172 /* Nonzero if the map is at the bottom of the include stack.  */
 173 #define MAIN_FILE_P(MAP) ((MAP)->included_from < 0)
 174
 175 /* Set LOC to a source position that is the same line as the most recent
 176    linemap_line_start, but with the specified TO_COLUMN column number.  */
 177
 178 #define LINEMAP_POSITION_FOR_COLUMN(LOC, SET, TO_COLUMN) do { \
 179   unsigned int to_column = (TO_COLUMN); \
 180   struct line_maps *set = (SET); \
 181   if (__builtin_expect (to_column >= set->max_column_hint, 0)) \
 182     (LOC) = linemap_position_for_column (set, to_column); \
 183   else { \
 184     source_location r = set->highest_line; \
 185     r = r + to_column; \
 186     if (r >= set->highest_location) \
 187       set->highest_location = r; \
 188     (LOC) = r;                   \
 189   }} while (0)
 190
 191
 192 extern source_location
 193 linemap_position_for_column (struct line_maps *set, unsigned int to_column);
 194
 195 #endif /* !LIBCPP_LINE_MAP_H  */