binutils-gdb/gdb/dwarf2/abbrev.h
Simon Marchi cd1a05c76f Convert abbrevs to new hash table
This converts the DWARF abbrevs themselves to use the new hash table.

Change-Id: I0320a733ecefe2cffeb25c068f17322dd3ab23e2
Co-Authored-By: Tom Tromey <tom@tromey.com>
Approved-By: Tom Tromey <tom@tromey.com>
2024-11-25 22:07:04 -05:00

149 lines
4.3 KiB
C++

/* DWARF abbrev table
Copyright (C) 1994-2024 Free Software Foundation, Inc.
Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
Inc. with support from Florida State University (under contract
with the Ada Joint Program Office), and Silicon Graphics, Inc.
Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
based on Fred Fish's (Cygnus Support) implementation of DWARF 1
support.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef GDB_DWARF2_ABBREV_H
#define GDB_DWARF2_ABBREV_H
#include "dwarf2.h"
#include "gdbsupport/gdb_obstack.h"
#include "gdbsupport/unordered_set.h"
#include "types.h"
struct attr_abbrev
{
ENUM_BITFIELD(dwarf_attribute) name : 16;
ENUM_BITFIELD(dwarf_form) form : 16;
/* It is valid only if FORM is DW_FORM_implicit_const. */
LONGEST implicit_const;
};
/* This data structure holds the information of an abbrev. */
struct abbrev_info
{
/* Number identifying abbrev. */
unsigned int number;
/* DWARF tag. */
ENUM_BITFIELD (dwarf_tag) tag : 16;
/* True if the DIE has children. */
bool has_children;
bool interesting;
unsigned short size_if_constant;
unsigned short sibling_offset;
/* Number of attributes. */
unsigned short num_attrs;
/* An array of attribute descriptions, allocated using the struct
hack. */
struct attr_abbrev attrs[1];
};
struct abbrev_table;
typedef std::unique_ptr<struct abbrev_table> abbrev_table_up;
/* Top level data structure to contain an abbreviation table.
In DWARF version 2, the description of the debugging information is
stored in a separate .debug_abbrev section. Before we read any
dies from a section we read in all abbreviations and install them
in a hash table. */
struct abbrev_table
{
/* Read an abbrev table from the indicated section, at the given
offset. The caller is responsible for ensuring that the section
has already been read. */
static abbrev_table_up read (struct dwarf2_section_info *section,
sect_offset sect_off);
/* Look up an abbrev in the table.
Returns NULL if the abbrev is not found. */
const abbrev_info *lookup_abbrev (unsigned int abbrev_number) const
{
if (auto iter = m_abbrevs.find (abbrev_number);
iter != m_abbrevs.end ())
return *iter;
return nullptr;
}
/* Where the abbrev table came from.
This is used as a sanity check when the table is used. */
const sect_offset sect_off;
struct dwarf2_section_info *section;
private:
abbrev_table (sect_offset off, struct dwarf2_section_info *sect)
: sect_off (off),
section (sect)
{}
DISABLE_COPY_AND_ASSIGN (abbrev_table);
/* Add an abbreviation to the table. */
void add_abbrev (const abbrev_info *abbrev)
{ m_abbrevs.emplace (abbrev); }
struct abbrev_info_number_eq
{
using is_transparent = void;
bool operator() (unsigned int number,
const abbrev_info *abbrev) const noexcept
{ return number == abbrev->number; }
bool operator() (const abbrev_info *lhs,
const abbrev_info *rhs) const noexcept
{ return (*this) (lhs->number, rhs); }
};
struct abbrev_info_number_hash
{
using is_transparent = void;
std::size_t operator() (unsigned int number) const noexcept
{ return std::hash<unsigned int> () (number); }
std::size_t operator() (const abbrev_info *abbrev) const noexcept
{ return (*this) (abbrev->number); }
};
/* Hash table of abbrev, identified by their number. */
gdb::unordered_set<const abbrev_info *,
abbrev_info_number_hash,
abbrev_info_number_eq>
m_abbrevs;
/* Storage for the abbrev table. */
auto_obstack m_abbrev_obstack;
};
#endif /* GDB_DWARF2_ABBREV_H */