gdb/dwarf2/abbrev.h

   1 /* DWARF abbrev table
   2
   3    Copyright (C) 1994-2023 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 #include "hashtab.h"
  31
  32 struct attr_abbrev
  33 {
  34   ENUM_BITFIELD(dwarf_attribute) name : 16;
  35   ENUM_BITFIELD(dwarf_form) form : 16;
  36
  37   /* It is valid only if FORM is DW_FORM_implicit_const.  */
  38   LONGEST implicit_const;
  39 };
  40
  41 /* This data structure holds the information of an abbrev.  */
  42 struct abbrev_info
  43 {
  44   /* Number identifying abbrev.  */
  45   unsigned int number;
  46   /* DWARF tag.  */
  47   ENUM_BITFIELD (dwarf_tag) tag : 16;
  48   /* True if the DIE has children.  */
  49   bool has_children;
  50   bool interesting;
  51   unsigned short size_if_constant;
  52   unsigned short sibling_offset;
  53   /* Number of attributes.  */
  54   unsigned short num_attrs;
  55   /* An array of attribute descriptions, allocated using the struct
  56      hack.  */
  57   struct attr_abbrev attrs[1];
  58 };
  59
  60 struct abbrev_table;
  61 typedef std::unique_ptr<struct abbrev_table> abbrev_table_up;
  62
  63 /* Top level data structure to contain an abbreviation table.  */
  64
  65 struct abbrev_table
  66 {
  67   /* Read an abbrev table from the indicated section, at the given
  68      offset.  The caller is responsible for ensuring that the section
  69      has already been read.  */
  70
  71   static abbrev_table_up read (struct dwarf2_section_info *section,
  72                                sect_offset sect_off);
  73
  74   /* Look up an abbrev in the table.
  75      Returns NULL if the abbrev is not found.  */
  76
  77   const struct abbrev_info *lookup_abbrev (unsigned int abbrev_number) const
  78   {
  79     struct abbrev_info search;
  80     search.number = abbrev_number;
  81
  82     return (struct abbrev_info *) htab_find_with_hash (m_abbrevs.get (),
  83                                                        &search,
  84                                                        abbrev_number);
  85   }
  86
  87   /* Where the abbrev table came from.
  88      This is used as a sanity check when the table is used.  */
  89   const sect_offset sect_off;
  90
  91   struct dwarf2_section_info *section;
  92
  93 private:
  94
  95   abbrev_table (sect_offset off, struct dwarf2_section_info *sect);
  96
  97   DISABLE_COPY_AND_ASSIGN (abbrev_table);
  98
  99   /* Add an abbreviation to the table.  */
 100   void add_abbrev (struct abbrev_info *abbrev);
 101
 102   /* Hash table of abbrevs.  */
 103   htab_up m_abbrevs;
 104
 105   /* Storage for the abbrev table.  */
 106   auto_obstack m_abbrev_obstack;
 107 };
 108
 109 #endif /* GDB_DWARF2_ABBREV_H */