gdb/dwarf2/die.h

   1 /* DWARF DIEs
   2
   3    Copyright (C) 2003-2021 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   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 #ifndef GDB_DWARF2_DIE_H
  21 #define GDB_DWARF2_DIE_H
  22
  23 #include "complaints.h"
  24
  25 /* This data structure holds a complete die structure.  */
  26 struct die_info
  27 {
  28   /* Return the named attribute or NULL if not there, but do not
  29      follow DW_AT_specification, etc.  */
  30   struct attribute *attr (dwarf_attribute name)
  31   {
  32     for (unsigned i = 0; i < num_attrs; ++i)
  33       if (attrs[i].name == name)
  34         return &attrs[i];
  35     return NULL;
  36   }
  37
  38   /* Return the address base of the compile unit, which, if exists, is
  39      stored either at the attribute DW_AT_GNU_addr_base, or
  40      DW_AT_addr_base.  */
  41   gdb::optional<ULONGEST> addr_base ()
  42   {
  43     for (unsigned i = 0; i < num_attrs; ++i)
  44       if (attrs[i].name == DW_AT_addr_base
  45            || attrs[i].name == DW_AT_GNU_addr_base)
  46         {
  47           if (attrs[i].form_is_unsigned ())
  48             {
  49               /* If both exist, just use the first one.  */
  50               return attrs[i].as_unsigned ();
  51             }
  52           complaint (_("address base attribute (offset %s) as wrong form"),
  53                      sect_offset_str (sect_off));
  54         }
  55     return gdb::optional<ULONGEST> ();
  56   }
  57
  58   /* Return the base address of the compile unit into the .debug_ranges section,
  59      which, if exists, is stored in the DW_AT_GNU_ranges_base attribute.  This
  60      value is only relevant in pre-DWARF 5 split-unit scenarios.  */
  61   ULONGEST gnu_ranges_base ()
  62   {
  63     for (unsigned i = 0; i < num_attrs; ++i)
  64       if (attrs[i].name == DW_AT_GNU_ranges_base)
  65         {
  66           if (attrs[i].form_is_unsigned ())
  67             return attrs[i].as_unsigned ();
  68
  69           complaint (_("ranges base attribute (offset %s) has wrong form"),
  70                      sect_offset_str (sect_off));
  71         }
  72
  73     return 0;
  74   }
  75
  76   /* Return the rnglists base of the compile unit, which, if exists, is stored
  77      in the DW_AT_rnglists_base attribute.  */
  78   ULONGEST rnglists_base ()
  79   {
  80     for (unsigned i = 0; i < num_attrs; ++i)
  81       if (attrs[i].name == DW_AT_rnglists_base)
  82         {
  83           if (attrs[i].form_is_unsigned ())
  84             return attrs[i].as_unsigned ();
  85
  86           complaint (_("rnglists base attribute (offset %s) has wrong form"),
  87                      sect_offset_str (sect_off));
  88         }
  89
  90     return 0;
  91   }
  92
  93   /* DWARF-2 tag for this DIE.  */
  94   ENUM_BITFIELD(dwarf_tag) tag : 16;
  95
  96   /* Number of attributes */
  97   unsigned char num_attrs;
  98
  99   /* True if we're presently building the full type name for the
 100      type derived from this DIE.  */
 101   unsigned char building_fullname : 1;
 102
 103   /* True if this die is in process.  PR 16581.  */
 104   unsigned char in_process : 1;
 105
 106   /* True if this DIE has children.  */
 107   unsigned char has_children : 1;
 108
 109   /* Abbrev number */
 110   unsigned int abbrev;
 111
 112   /* Offset in .debug_info or .debug_types section.  */
 113   sect_offset sect_off;
 114
 115   /* The dies in a compilation unit form an n-ary tree.  PARENT
 116      points to this die's parent; CHILD points to the first child of
 117      this node; and all the children of a given node are chained
 118      together via their SIBLING fields.  */
 119   struct die_info *child;       /* Its first child, if any.  */
 120   struct die_info *sibling;     /* Its next sibling, if any.  */
 121   struct die_info *parent;      /* Its parent, if any.  */
 122
 123   /* An array of attributes, with NUM_ATTRS elements.  There may be
 124      zero, but it's not common and zero-sized arrays are not
 125      sufficiently portable C.  */
 126   struct attribute attrs[1];
 127 };
 128
 129 #endif /* GDB_DWARF2_DIE_H */