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.

1 files changed, 99 insertions, 0 deletions

diff --git a/gdb/observable.c b/gdb/observable.c
new file mode 100644
index 0000000..5539b98
--- /dev/null
+++ b/gdb/observable.c
@@ -0,0 +1,99 @@
+/* GDB Notifications to Observers.
+
+   Copyright (C) 2003-2018 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/>.  */
+
+#include "defs.h"
+#include "observable.h"
+#include "command.h"
+#include "gdbcmd.h"
+
+namespace gdb
+{
+
+namespace observers
+{
+
+unsigned int observer_debug;
+
+#define DEFINE_OBSERVABLE(name) decltype (name) name (# name)
+
+DEFINE_OBSERVABLE (normal_stop);
+DEFINE_OBSERVABLE (signal_received);
+DEFINE_OBSERVABLE (end_stepping_range);
+DEFINE_OBSERVABLE (signal_exited);
+DEFINE_OBSERVABLE (exited);
+DEFINE_OBSERVABLE (no_history);
+DEFINE_OBSERVABLE (sync_execution_done);
+DEFINE_OBSERVABLE (command_error);
+DEFINE_OBSERVABLE (target_changed);
+DEFINE_OBSERVABLE (executable_changed);
+DEFINE_OBSERVABLE (inferior_created);
+DEFINE_OBSERVABLE (record_changed);
+DEFINE_OBSERVABLE (solib_loaded);
+DEFINE_OBSERVABLE (solib_unloaded);
+DEFINE_OBSERVABLE (new_objfile);
+DEFINE_OBSERVABLE (free_objfile);
+DEFINE_OBSERVABLE (new_thread);
+DEFINE_OBSERVABLE (thread_exit);
+DEFINE_OBSERVABLE (thread_stop_requested);
+DEFINE_OBSERVABLE (target_resumed);
+DEFINE_OBSERVABLE (about_to_proceed);
+DEFINE_OBSERVABLE (breakpoint_created);
+DEFINE_OBSERVABLE (breakpoint_deleted);
+DEFINE_OBSERVABLE (breakpoint_modified);
+DEFINE_OBSERVABLE (traceframe_changed);
+DEFINE_OBSERVABLE (architecture_changed);
+DEFINE_OBSERVABLE (thread_ptid_changed);
+DEFINE_OBSERVABLE (inferior_added);
+DEFINE_OBSERVABLE (inferior_appeared);
+DEFINE_OBSERVABLE (inferior_exit);
+DEFINE_OBSERVABLE (inferior_removed);
+DEFINE_OBSERVABLE (memory_changed);
+DEFINE_OBSERVABLE (before_prompt);
+DEFINE_OBSERVABLE (gdb_datadir_changed);
+DEFINE_OBSERVABLE (command_param_changed);
+DEFINE_OBSERVABLE (tsv_created);
+DEFINE_OBSERVABLE (tsv_deleted);
+DEFINE_OBSERVABLE (tsv_modified);
+DEFINE_OBSERVABLE (inferior_call_pre);
+DEFINE_OBSERVABLE (inferior_call_post);
+DEFINE_OBSERVABLE (register_changed);
+DEFINE_OBSERVABLE (user_selected_context_changed);
+
+} /* namespace observers */
+} /* namespace gdb */
+
+static void
+show_observer_debug (struct ui_file *file, int from_tty,
+		     struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file, _("Observer debugging is %s.\n"), value);
+}
+
+void
+_initialize_observer (void)
+{
+  add_setshow_zuinteger_cmd ("observer", class_maintenance,
+			     &gdb::observers::observer_debug, _("\
+Set observer debugging."), _("\
+Show observer debugging."), _("\
+When non-zero, observer debugging is enabled."),
+			     NULL,
+			     show_observer_debug,
+			     &setdebuglist, &showdebuglist);
+}