xref: /netbsd-src/external/gpl3/gdb/dist/gdb/dwarf2/die.h (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
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 
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 */
130