gdb/dwarf2/abbrev.h

   1 /* DWARF abbrev table
   2
   3    Copyright (C) 1994-2020 Free Software Foundation, Inc.
   4
   5    Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
   6    Inc.  with support from Florida State University (under contract
   7    with the Ada Joint Program Office), and Silicon Graphics, Inc.
   8    Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
   9    based on Fred Fish's (Cygnus Support) implementation of DWARF 1
  10    support.
  11
  12    This file is part of GDB.
  13
  14    This program is free software; you can redistribute it and/or modify
  15    it under the terms of the GNU General Public License as published by
  16    the Free Software Foundation; either version 3 of the License, or
  17    (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22    GNU General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  26
  27 #ifndef GDB_DWARF2_ABBREV_H
  28 #define GDB_DWARF2_ABBREV_H
  29
  30 /* This data structure holds the information of an abbrev.  */
  31 struct abbrev_info
  32   {
  33     unsigned int number;        /* number identifying abbrev */
  34     enum dwarf_tag tag;         /* dwarf tag */
  35     unsigned short has_children;                /* boolean */
  36     unsigned short num_attrs;   /* number of attributes */
  37     struct attr_abbrev *attrs;  /* an array of attribute descriptions */
  38     struct abbrev_info *next;   /* next in chain */
  39   };
  40
  41 struct attr_abbrev
  42   {
  43     ENUM_BITFIELD(dwarf_attribute) name : 16;
  44     ENUM_BITFIELD(dwarf_form) form : 16;
  45
  46     /* It is valid only if FORM is DW_FORM_implicit_const.  */
  47     LONGEST implicit_const;
  48   };
  49
  50 /* Size of abbrev_table.abbrev_hash_table.  */
  51 #define ABBREV_HASH_SIZE 121
  52
  53 /* Top level data structure to contain an abbreviation table.  */
  54
  55 struct abbrev_table
  56 {
  57   explicit abbrev_table (sect_offset off)
  58     : sect_off (off)
  59   {
  60     m_abbrevs =
  61       XOBNEWVEC (&abbrev_obstack, struct abbrev_info *, ABBREV_HASH_SIZE);
  62     memset (m_abbrevs, 0, ABBREV_HASH_SIZE * sizeof (struct abbrev_info *));
  63   }
  64
  65   DISABLE_COPY_AND_ASSIGN (abbrev_table);
  66
  67   /* Allocate space for a struct abbrev_info object in
  68      ABBREV_TABLE.  */
  69   struct abbrev_info *alloc_abbrev ();
  70
  71   /* Add an abbreviation to the table.  */
  72   void add_abbrev (unsigned int abbrev_number, struct abbrev_info *abbrev);
  73
  74   /* Look up an abbrev in the table.
  75      Returns NULL if the abbrev is not found.  */
  76
  77   struct abbrev_info *lookup_abbrev (unsigned int abbrev_number);
  78
  79
  80   /* Where the abbrev table came from.
  81      This is used as a sanity check when the table is used.  */
  82   const sect_offset sect_off;
  83
  84   /* Storage for the abbrev table.  */
  85   auto_obstack abbrev_obstack;
  86
  87 private:
  88
  89   /* Hash table of abbrevs.
  90      This is an array of size ABBREV_HASH_SIZE allocated in abbrev_obstack.
  91      It could be statically allocated, but the previous code didn't so we
  92      don't either.  */
  93   struct abbrev_info **m_abbrevs;
  94 };
  95
  96 typedef std::unique_ptr<struct abbrev_table> abbrev_table_up;
  97
  98 extern abbrev_table_up abbrev_table_read_table
  99   (struct objfile *objfile,
 100    struct dwarf2_section_info *section,
 101    sect_offset sect_off);
 102
 103 #endif /* GDB_DWARF2_ABBREV_H */