binutils-gdb/gdb/dwarf2/index-cache.h
Simon Marchi e5afccc7e4 gdb/dwarf2: cleanup includes
Cleanup includes in dwarf2/*.

 1. Add the necessary includes so that clangd reports no errors when
    opening header files.  This ensures that header files include what
    they use.

 2. Remove all includes reported as unused by clangd (except
    gdb-safe-ctype.h, which I think does some magic that affects what
    follows).

Built-tested --enable-threading at "yes" and "no", since there are some
portions of code gated by `#ifdef CXX_STD_THREAD`.

Change-Id: I21debffcd7c2caf90f08e1e0fbba3ce30422d042
Approved-By: Tom Tromey <tom@tromey.com>
2024-08-30 13:57:11 -04:00

139 lines
3.7 KiB
C++

/* Caching of GDB/DWARF index files.
Copyright (C) 2018-2024 Free Software Foundation, Inc.
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 DWARF_INDEX_CACHE_H
#define DWARF_INDEX_CACHE_H
#include "gdbsupport/array-view.h"
class dwarf2_per_bfd;
class index_cache;
/* Base of the classes used to hold the resources of the indices loaded from
the cache (e.g. mmapped files). */
struct index_cache_resource
{
virtual ~index_cache_resource () = 0;
};
/* Information to be captured in the main thread, and to be used by worker
threads during store (). */
struct index_cache_store_context
{
index_cache_store_context (const index_cache &ic, dwarf2_per_bfd *per_bfd);
/* Store the index in the cache. */
void store () const;
private:
/* Captured value of enabled (). */
bool m_enabled;
/* Captured value of index cache directory. */
std::string m_dir;
/* The per-bfd object that we're caching. */
dwarf2_per_bfd *m_per_bfd;
/* Captured value of build id. */
std::string m_build_id_str;
/* Captured value of dwz build id. */
std::optional<std::string> m_dwz_build_id_str;
};
/* Class to manage the access to the DWARF index cache. */
class index_cache
{
friend struct index_cache_store_context;
public:
/* Change the directory used to save/load index files. */
void set_directory (std::string dir);
/* Return true if the usage of the cache is enabled. */
bool enabled () const
{
return m_enabled;
}
/* Enable the cache. */
void enable ();
/* Disable the cache. */
void disable ();
/* Look for an index file matching BUILD_ID. If found, return the contents
as an array_view and store the underlying resources (allocated memory,
mapped file, etc) in RESOURCE. The returned array_view is valid as long
as RESOURCE is not destroyed.
If no matching index file is found, return an empty array view. */
gdb::array_view<const gdb_byte>
lookup_gdb_index (const bfd_build_id *build_id,
std::unique_ptr<index_cache_resource> *resource);
/* Return the number of cache hits. */
unsigned int n_hits () const
{ return m_n_hits; }
/* Record a cache hit. */
void hit ()
{
if (enabled ())
m_n_hits++;
}
/* Return the number of cache misses. */
unsigned int n_misses () const
{ return m_n_misses; }
/* Record a cache miss. */
void miss ()
{
if (enabled ())
m_n_misses++;
}
private:
/* Compute the absolute filename where the index of the objfile with build
id BUILD_ID will be stored. SUFFIX is appended at the end of the
filename. */
std::string make_index_filename (const bfd_build_id *build_id,
const char *suffix) const;
/* The base directory where we are storing and looking up index files. */
std::string m_dir;
/* Whether the cache is enabled. */
bool m_enabled = false;
/* Number of cache hits and misses during this GDB session. */
unsigned int m_n_hits = 0;
unsigned int m_n_misses = 0;
};
/* The global instance of the index cache. */
extern index_cache global_index_cache;
#endif /* DWARF_INDEX_CACHE_H */