gdb/dwarf2/die.h

   1 /* DWARF DIEs
   2
   3    Copyright (C) 2003-2023 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 #include "dwarf2/attribute.h"
  25
  26 /* This data structure holds a complete die structure.  */
  27 struct die_info
  28 {
  29   /* Allocate a new die_info on OBSTACK.  NUM_ATTRS is the number of
  30      attributes that are needed.  */
  31   static die_info *allocate (struct obstack *obstack, int num_attrs);
  32
  33   /* Trivial hash function for die_info: the hash value of a DIE is
  34      its offset in .debug_info for this objfile.  */
  35   static hashval_t hash (const void *item);
  36
  37   /* Trivial comparison function for die_info structures: two DIEs
  38      are equal if they have the same offset.  */
  39   static int eq (const void *item_lhs, const void *item_rhs);
  40
  41   /* Dump this DIE and any children to MAX_LEVEL.  They are written to
  42      gdb_stdlog.  Note this is called from the pdie user command in
  43      gdb-gdb.gdb.  */
  44   void dump (int max_level);
  45
  46   /* Shallowly dump this DIE to gdb_stderr.  */
  47   void error_dump ();
  48
  49   /* Return the named attribute or NULL if not there, but do not
  50      follow DW_AT_specification, etc.  */
  51   struct attribute *attr (dwarf_attribute name)
  52   {
  53     for (unsigned i = 0; i < num_attrs; ++i)
  54       if (attrs[i].name == name)
  55         return &attrs[i];
  56     return NULL;
  57   }
  58
  59   /* Return the address base of the compile unit, which, if exists, is
  60      stored either at the attribute DW_AT_GNU_addr_base, or
  61      DW_AT_addr_base.  */
  62   gdb::optional<ULONGEST> addr_base ()
  63   {
  64     for (unsigned i = 0; i < num_attrs; ++i)
  65       if (attrs[i].name == DW_AT_addr_base
  66            || attrs[i].name == DW_AT_GNU_addr_base)
  67         {
  68           if (attrs[i].form_is_unsigned ())
  69             {
  70               /* If both exist, just use the first one.  */
  71               return attrs[i].as_unsigned ();
  72             }
  73           complaint (_("address base attribute (offset %s) as wrong form"),
  74                      sect_offset_str (sect_off));
  75         }
  76     return gdb::optional<ULONGEST> ();
  77   }
  78
  79   /* Return the base address of the compile unit into the .debug_ranges section,
  80      which, if exists, is stored in the DW_AT_GNU_ranges_base attribute.  This
  81      value is only relevant in pre-DWARF 5 split-unit scenarios.  */
  82   ULONGEST gnu_ranges_base ()
  83   {
  84     for (unsigned i = 0; i < num_attrs; ++i)
  85       if (attrs[i].name == DW_AT_GNU_ranges_base)
  86         {
  87           if (attrs[i].form_is_unsigned ())
  88             return attrs[i].as_unsigned ();
  89
  90           complaint (_("ranges base attribute (offset %s) has wrong form"),
  91                      sect_offset_str (sect_off));
  92         }
  93
  94     return 0;
  95   }
  96
  97   /* Return the rnglists base of the compile unit, which, if exists, is stored
  98      in the DW_AT_rnglists_base attribute.  */
  99   ULONGEST rnglists_base ()
 100   {
 101     for (unsigned i = 0; i < num_attrs; ++i)
 102       if (attrs[i].name == DW_AT_rnglists_base)
 103         {
 104           if (attrs[i].form_is_unsigned ())
 105             return attrs[i].as_unsigned ();
 106
 107           complaint (_("rnglists base attribute (offset %s) has wrong form"),
 108                      sect_offset_str (sect_off));
 109         }
 110
 111     return 0;
 112   }
 113
 114   /* DWARF-2 tag for this DIE.  */
 115   ENUM_BITFIELD(dwarf_tag) tag : 16;
 116
 117   /* Number of attributes */
 118   unsigned char num_attrs;
 119
 120   /* True if we're presently building the full type name for the
 121      type derived from this DIE.  */
 122   unsigned char building_fullname : 1;
 123
 124   /* True if this die is in process.  PR 16581.  */
 125   unsigned char in_process : 1;
 126
 127   /* True if this DIE has children.  */
 128   unsigned char has_children : 1;
 129
 130   /* Abbrev number */
 131   unsigned int abbrev;
 132
 133   /* Offset in .debug_info or .debug_types section.  */
 134   sect_offset sect_off;
 135
 136   /* The dies in a compilation unit form an n-ary tree.  PARENT
 137      points to this die's parent; CHILD points to the first child of
 138      this node; and all the children of a given node are chained
 139      together via their SIBLING fields.  */
 140   struct die_info *child;       /* Its first child, if any.  */
 141   struct die_info *sibling;     /* Its next sibling, if any.  */
 142   struct die_info *parent;      /* Its parent, if any.  */
 143
 144   /* An array of attributes, with NUM_ATTRS elements.  There may be
 145      zero, but it's not common and zero-sized arrays are not
 146      sufficiently portable C.  */
 147   struct attribute attrs[1];
 148 };
 149
 150 #endif /* GDB_DWARF2_DIE_H */