Re: [RFC][patch 3/9] export hooks mechanism to Python

[Thiago Jung Bauermann <bauerman at br dot ibm dot com>]

Zitat von Tom Tromey <tromey@redhat.com>:

> > > > > > "Daniel" == Daniel Jacobowitz <drow@false.org> writes:
>
> Daniel> I won't look at this one, as I believe Tom's rewritten it to use
> Daniel> observers instead.
>
> Yeah, that's right.

Here's the new version.
--
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


gdb/
2008-06-15  Tom Tromey <tromey@redhat.com>

	* Makefile.in (SUBDIR_PYTHON_OBS): Add python-hooks.o.
	(SUBDIR_PYTHON_SRCS): Add python/hooks.c.
	(python-hooks.o): New target.
	* breakpoint.c (mention): Notify observers of created
	breakpoint.
	(delete_breakpoint): Notify observers of deleted
	breakpoint.
	* python/hooks.c: New file.
	* python/python-internal.h (gdbpy_get_hook_function,
	gdbpy_initialize_hooks): Declare.
	* python/python.c (_initialize_python): Call gdbpy_initialize_hooks.

doc/
2008-06-15  Tom Tromey <tromey@redhat.com>

	* observer.texi (Notifications): Document breakpoint_created
	and breakpoint_deleted.

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index b15fa61..45ecfbd 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -257,9 +257,11 @@ SUBDIR_TUI_CFLAGS= \
 #
 # python sub directory definitons
 #
-SUBDIR_PYTHON_OBS =
+SUBDIR_PYTHON_OBS = \
+	python-hooks.o
 SUBDIR_PYTHON_SRCS = \
 	python/python.c \
+	python/hooks.c \
 	python/value.c
 SUBDIR_PYTHON_DEPS =
 SUBDIR_PYTHON_LDFLAGS=
@@ -3413,6 +3415,11 @@ python.o: $(srcdir)/python/python.c $(defs_h) $(python_h) \
 	$(exceptions_h) $(python_internal_h) $(version_h) $(cli_script_h) \
 	$(ui_out_h)
 	$(CC) -c $(INTERNAL_CFLAGS) $(PYTHON_CFLAGS) $(srcdir)/python/python.c
+python-hooks.o: $(srcdir)/python/hooks.c $(defs_h) $(cli_decode_h) \
+	$(charset_h) $(gdb_events_h) $(python_h) $(python_internal_h) \
+	$(observer_h)
+	$(CC) -c $(INTERNAL_CFLAGS) $(PYTHON_CFLAGS) \
+	$(srcdir)/python/hooks.c -o python-hooks.o
 python-value.o: $(srcdir)/python/value.c $(defs_h) $(exceptions_h) \
 	$(python_internal_h) $(value_h)
 	$(CC) -c $(INTERNAL_CFLAGS) $(PYTHON_CFLAGS) \
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 24ef7bf..4c2b1eb 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -4913,6 +4913,7 @@ mention (struct breakpoint *b)
   if (deprecated_create_breakpoint_hook)
     deprecated_create_breakpoint_hook (b);
   breakpoint_create_event (b->number);
+  observer_notify_breakpoint_created (b->number);
 
   if (b->ops != NULL && b->ops->print_mention != NULL)
     b->ops->print_mention (b);
@@ -7141,6 +7142,7 @@ delete_breakpoint (struct breakpoint *bpt)
   if (deprecated_delete_breakpoint_hook)
     deprecated_delete_breakpoint_hook (bpt);
   breakpoint_delete_event (bpt->number);
+  observer_notify_breakpoint_deleted (bpt->number);
 
   if (breakpoint_chain == bpt)
     breakpoint_chain = bpt->next;
diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index 5bcc76c..b6aefab 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -2,7 +2,7 @@
 
 @c This file is part of the GDB manual.
 @c
-@c Copyright (C) 2003, 2004, 2005, 2006
+@c Copyright (C) 2003, 2004, 2005, 2006, 2008
 @c               Free Software Foundation, Inc.
 @c
 @c See the file gdbint.texinfo for copying conditions.
@@ -133,3 +133,13 @@ previously loaded symbol table data has now been invalidated.
 The thread specified by @var{t} has been created.
 @end deftypefun
 
+@deftypefun void breakpoint_created (int @var{bpnum})
+A new breakpoint has been created.  The argument @var{bpnum} is the
+number of the newly-created breakpoint.
+@end deftypefun
+
+@deftypefun void breakpoint_deleted (int @var{bpnum})
+A breakpoint has been destroyed.  The argument @var{bpnum} is the
+number of the newly-destroyed breakpoint.
+@end deftypefun
+
diff --git a/gdb/python/hooks.c b/gdb/python/hooks.c
new file mode 100644
index 0000000..21f3a28
--- /dev/null
+++ b/gdb/python/hooks.c
@@ -0,0 +1,62 @@
+/* Notifications from gdb to Python
+
+   Copyright (C) 2008 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 "cli/cli-decode.h"
+#include "charset.h"
+#include "gdb-events.h"
+#include "python.h"
+#include "python-internal.h"
+#include "observer.h"
+
+PyObject *
+gdbpy_get_hook_function (const char *name)
+{
+  PyObject *hooks;
+  PyObject *result;
+
+  if (! PyObject_HasAttrString (gdb_module, "hooks"))
+    return NULL;
+  hooks = PyObject_GetAttrString (gdb_module, "hooks");
+  if (! hooks)
+    return NULL;
+  /* The cast is because the Python function doesn't declare const argument.
+     This is a problem in Python version 2.4, but not in 2.5.  */
+  if (! PyObject_HasAttrString (hooks, (char *) name))
+    {
+      Py_DECREF (hooks);
+      return NULL;
+    }
+  /* The cast is because the Python function doesn't declare const argument.
+     This is a problem in Python version 2.4, but not in 2.5.  */
+  result = PyObject_GetAttrString (hooks, (char *) name);
+  Py_DECREF (hooks);
+  return result;
+}
+
+void
+gdbpy_initialize_hooks (void)
+{
+  /* If you need to hook into any sort of state change in gdb, do so
+     by adding a new observer to observer.texi, attach to the new
+     observer here, and notify the new observer at the appropriate
+     place.  */
+  observer_attach_breakpoint_created (gdbpy_breakpoint_created);
+  observer_attach_breakpoint_deleted (gdbpy_breakpoint_deleted);
+}
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 0abdfde..1bb2422 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -56,7 +56,10 @@ PyObject *gdb_owned_value_to_value_object (struct value *v);
 
 struct value *value_object_to_value (PyObject *self);
 
+PyObject *gdbpy_get_hook_function (const char *);
+
 void gdbpy_initialize_values (void);
+void gdbpy_initialize_hooks (void);
 
 /* Use this after a TRY_EXCEPT to throw the appropriate Python
    exception.  */
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 5b8b975..2e8db56 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -282,6 +282,7 @@ the end of the command."));
   PyModule_AddStringConstant (gdb_module, "HOST_CONFIG", (char*) host_name);
   PyModule_AddStringConstant (gdb_module, "TARGET_CONFIG", (char*) target_name);
 
+  gdbpy_initialize_hooks ();
   gdbpy_initialize_values ();
 
   PyRun_SimpleString ("import gdb");