binutils-gdb/gdb/common/observable.h
Tom Tromey 76727919ce Convert observers to C++
This converts observers from using a special source-generating script
to be plain C++.  This version of the patch takes advantage of C++11
by using std::function and variadic templates; incorporates Pedro's
patches; and renames the header file to "observable.h" (this change
eliminates the need for a clean rebuild).

Note that Pedro's patches used a template lambda in tui-hooks.c, but
this failed to compile on some buildbot instances (presumably due to
differing C++ versions); I replaced this with an ordinary template
function.

Regression tested on the buildbot.

gdb/ChangeLog
2018-03-19  Pedro Alves  <palves@redhat.com>
	    Tom Tromey  <tom@tromey.com>

	* unittests/observable-selftests.c: New file.
	* common/observable.h: New file.
	* observable.h: New file.
	* ada-lang.c, ada-tasks.c, agent.c, aix-thread.c, annotate.c,
	arm-tdep.c, auto-load.c, auxv.c, break-catch-syscall.c,
	breakpoint.c, bsd-uthread.c, cli/cli-interp.c, cli/cli-setshow.c,
	corefile.c, dummy-frame.c, event-loop.c, event-top.c, exec.c,
	extension.c, frame.c, gdbarch.c, guile/scm-breakpoint.c,
	infcall.c, infcmd.c, inferior.c, inflow.c, infrun.c, jit.c,
	linux-tdep.c, linux-thread-db.c, m68klinux-tdep.c,
	mi/mi-cmd-break.c, mi/mi-interp.c, mi/mi-main.c, objfiles.c,
	ppc-linux-nat.c, ppc-linux-tdep.c, printcmd.c, procfs.c,
	python/py-breakpoint.c, python/py-finishbreakpoint.c,
	python/py-inferior.c, python/py-unwind.c, ravenscar-thread.c,
	record-btrace.c, record-full.c, record.c, regcache.c, remote.c,
	riscv-tdep.c, sol-thread.c, solib-aix.c, solib-spu.c, solib.c,
	spu-multiarch.c, spu-tdep.c, stack.c, symfile-mem.c, symfile.c,
	symtab.c, thread.c, top.c, tracepoint.c, tui/tui-hooks.c,
	tui/tui-interp.c, valops.c: Update all users.
	* tui/tui-hooks.c (tui_bp_created_observer)
	(tui_bp_deleted_observer, tui_bp_modified_observer)
	(tui_inferior_exit_observer, tui_before_prompt_observer)
	(tui_normal_stop_observer, tui_register_changed_observer):
	Remove.
	(tui_observers_token): New global.
	(attach_or_detach, tui_attach_detach_observers): New functions.
	(tui_install_hooks, tui_remove_hooks): Use
	tui_attach_detach_observers.
	* record-btrace.c (record_btrace_thread_observer): Remove.
	(record_btrace_thread_observer_token): New global.
	* observer.sh: Remove.
	* observer.c: Rename to observable.c.
	* observable.c (namespace gdb_observers): Define new objects.
	(observer_debug): Move into gdb_observers namespace.
	(struct observer, struct observer_list, xalloc_observer_list_node)
	(xfree_observer_list_node, generic_observer_attach)
	(generic_observer_detach, generic_observer_notify): Remove.
	(_initialize_observer): Update.
	Don't include observer.inc.
	* Makefile.in (generated_files): Remove observer.h, observer.inc.
	(clean mostlyclean): Likewise.
	(observer.h, observer.inc): Remove targets.
	(SUBDIR_UNITTESTS_SRCS): Add observable-selftests.c.
	(COMMON_SFILES): Use observable.c, not observer.c.
	* .gitignore: Remove observer.h.

gdb/doc/ChangeLog
2018-03-19  Tom Tromey  <tom@tromey.com>

	* observer.texi: Remove.

gdb/testsuite/ChangeLog
2018-03-19  Tom Tromey  <tom@tromey.com>

	* gdb.gdb/observer.exp: Remove.
2018-03-19 09:37:49 -06:00

120 lines
3.1 KiB
C++

/* Observers
Copyright (C) 2016-2018 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/>. */
#if !defined (GDB_COMMON_OBSERVABLE_H)
#define GDB_COMMON_OBSERVABLE_H
#include <algorithm>
#include <functional>
#include <vector>
namespace gdb
{
namespace observers
{
extern unsigned int observer_debug;
/* An observer is an entity which is interested in being notified
when GDB reaches certain states, or certain events occur in GDB.
The entity being observed is called the observable. To receive
notifications, the observer attaches a callback to the observable.
One observable can have several observers.
The observer implementation is also currently not reentrant. In
particular, it is therefore not possible to call the attach or
detach routines during a notification. */
/* The type of a key that can be passed to attach, which can be passed
to detach to remove associated observers. Tokens have address
identity, and are thus usually const globals. */
struct token
{
token () = default;
DISABLE_COPY_AND_ASSIGN (token);
};
template<typename... T>
class observable
{
public:
typedef std::function<void (T...)> func_type;
explicit observable (const char *name)
: m_name (name)
{
}
DISABLE_COPY_AND_ASSIGN (observable);
/* Attach F as an observer to this observable. F cannot be
detached. */
void attach (const func_type &f)
{
m_observers.emplace_back (nullptr, f);
}
/* Attach F as an observer to this observable. T is a reference to
a token that can be used to later remove F. */
void attach (const func_type &f, const token &t)
{
m_observers.emplace_back (&t, f);
}
/* Remove observers associated with T from this observable. T is
the token that was previously passed to any number of "attach"
calls. */
void detach (const token &t)
{
auto iter = std::remove_if (m_observers.begin (),
m_observers.end (),
[&] (const std::pair<const token *,
func_type> &e)
{
return e.first == &t;
});
m_observers.erase (iter, m_observers.end ());
}
/* Notify all observers that are attached to this observable. */
void notify (T... args) const
{
if (observer_debug)
fprintf_unfiltered (gdb_stdlog, "observable %s notify() called\n",
m_name);
for (auto &&e : m_observers)
e.second (args...);
}
private:
std::vector<std::pair<const token *, func_type>> m_observers;
const char *m_name;
};
} /* namespace observers */
} /* namespace gdb */
#endif /* GDB_COMMON_OBSERVABLE_H */