Re: [RFC - Python] New ObjFile event

Kevin Pouget
2011-03-30T11:32:19Z

> Really nice patch!

thanks :)

> This is the ChangeLog for GDB code, so things in gdb/ and python/ code
> related files have ChangeLog entries here.
> ...
> But the entries below belong in the testsuite/ChangeLog and without the
> preceding "testsuite" in the log.
> ...
> I don't see a documentation entry.  Similarly documentation entries are
> added in the doc/ChangeLog

oh, now it makes sense, I couldn't grep any 'gdb.texinfo'
modification in gdb/ChangeLog, which was somehow strange, that's why I
didn't write anything about this file; that should be fixed now :

From 9e219b36244625880b085f853383a8ed2e6f0759 Mon Sep 17 00:00:00 2001
From: Kevin Pouget <kevin.pouget@st.com>
Date: Wed, 30 Mar 2011 13:23:19 -0400
Subject: [PATCH] Allow Python notification of new object-file loadings

Signed-off-by: Kevin Pouget <kevin.pouget@st.com>
---
gdb/ChangeLog | 21 +++++++++++
gdb/Makefile.in | 10 ++++-
gdb/doc/ChangeLog | 6 +++
gdb/doc/gdb.texinfo | 14 +++++--
gdb/python/py-event.h | 1 +
gdb/python/py-events.h | 1 +
gdb/python/py-evts.c | 3 ++
gdb/python/py-inferior.c | 27 ++++++++++++++
gdb/python/py-newobjfileevent.c | 53 ++++++++++++++++++++++++++++
gdb/python/python-internal.h | 2 +
gdb/python/python.c | 6 ++-
gdb/testsuite/ChangeLog | 9 +++++
gdb/testsuite/gdb.python/py-events-shlib.c | 20 ++++++++++
gdb/testsuite/gdb.python/py-events.c | 3 ++
gdb/testsuite/gdb.python/py-events.exp | 32 ++++++++++++++---
gdb/testsuite/gdb.python/py-events.py | 20 ++++++++++
16 files changed, 215 insertions(+), 13 deletions(-)
create mode 100644 gdb/python/py-newobjfileevent.c
create mode 100644 gdb/testsuite/gdb.python/py-events-shlib.c

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 03885dd..880781a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,24 @@
+2011-03-29 Kevin Pouget <kevin.pouget@st.com>
+
+ Allow Python notification of new object-file loadings.
+ * Makefile.in (SUBDIR_PYTHON_SRCS): Add py-newobjfilevent.c.
+ (SUBDIR_PYTHON_OBS): Add py-newobjfileevent.o.
+ Add build rule for this file.
+ * python/py-event.h (emit_new_objfile_event): New prototype.
+ (newobjfile): New Python event emitter.
+ * python/py-evts.c (gdbpy_initialize_py_events): Add newobjfile to
+ Python event registry.
+ * python/py-inferior.c: Include objfiles.h
+ (python_new_objfile): New function.
+ (gdbpy_initialize_inferior): Add python_new_objfile to the new objfile
+ observers.
+ * python/py-newobjfileevent.c: New file.
+ * python-internal.h (gdbpy_initialize_new_objfile_event): New
+ prototype.
+ (gdbpy_current_objfile): New global variable.
+ * python/python.c (gdbpy_current_objfile): Make global.
+ (_initialize_python): Add gdbpy_initialize_new_objfile_event call.
+
2011-03-28 Jan Kratochvil <jan.kratochvil@redhat.com>

Support resolution of STT_GNU_IFUNC via breakpoints.
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 489b1e9..c15b566 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -296,7 +296,8 @@ SUBDIR_PYTHON_OBS = \
py-threadevent.o \
py-type.o \
py-utils.o \
- py-value.o
+ py-value.o \
+ py-newobjfileevent.o

SUBDIR_PYTHON_SRCS = \
python/python.c \
@@ -326,7 +327,8 @@ SUBDIR_PYTHON_SRCS = \
python/py-threadevent.c \
python/py-type.c \
python/py-utils.c \
- python/py-value.c
+ python/py-value.c \
+ python/py-newobjfileevent.c
SUBDIR_PYTHON_DEPS =
SUBDIR_PYTHON_LDFLAGS=
SUBDIR_PYTHON_CFLAGS=
@@ -2110,6 +2112,10 @@ py-value.o: $(srcdir)/python/py-value.c
$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-value.c
$(POSTCOMPILE)

+py-newobjfileevent.o: $(srcdir)/python/py-newobjfileevent.c
+ $(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-newobjfileevent.c
+ $(POSTCOMPILE)
+
#
# Dependency tracking. Most of this is conditional on GNU Make being
# found by configure; if GNU Make is not found, we fall back to a
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 08d6c8c..3ea5068 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,9 @@
+2011-03-29 Kevin Pouget <kevin.pouget@st.com>
+ * gdb.textinfo (Events In Python): Document `gdb.NewObjFileEvent'
+ events emitter.
+ (Objfiles In Python): Indicate that `gdb.current_objfile' is also set
+ during new object-file callbacks.
+
2011-03-28 Tom Tromey <tromey@redhat.com>

* gdb.texinfo (Set Tracepoints): Fix typo.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index a4e976f..360ff51 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -22057,6 +22057,12 @@ Emits @code{gdb.SignalEvent} which extends
@code{gdb.StopEvent}.
This event indicates that the inferior or one of its threads has received as
signal. @code{gdb.SignalEvent} has the following attributes:

+@item events.newobjfile
+Emits @code{gdb.NewObjFileEvent} which indicates that a new object-file has
+been loaded in the inferior.
+
+During the callback, ``current objfile'' will be set to the new object file.
+
@table @code
@defivar SignalEvent stop_signal
A string representing the signal received by the inferior. A list of possible
@@ -22699,10 +22705,10 @@ The following objfile-related functions are
available in the

@findex gdb.current_objfile
@defun current_objfile
-When auto-loading a Python script (@pxref{Auto-loading}), @value{GDBN}
-sets the ``current objfile'' to the corresponding objfile. This
-function returns the current objfile. If there is no current objfile,
-this function returns @code{None}.
+When auto-loading a Python script (@pxref{Auto-loading}) and during new
+object-file callbacks, @value{GDBN} sets the ``current objfile'' to the
+corresponding objfile. This function returns the current objfile. If
+there is no current objfile, this function returns @code{None}.
@end defun

@findex gdb.objfiles
diff --git a/gdb/python/py-event.h b/gdb/python/py-event.h
index bc95521..9a3ba82 100644
--- a/gdb/python/py-event.h
+++ b/gdb/python/py-event.h
@@ -105,6 +105,7 @@ typedef struct

extern int emit_continue_event (ptid_t ptid);
extern int emit_exited_event (LONGEST exit_code);
+extern int emit_new_objfile_event (struct objfile *objfile);

extern int evpy_emit_event (PyObject *event,
eventregistry_object *registry);
diff --git a/gdb/python/py-events.h b/gdb/python/py-events.h
index 6d4dae5..9c42e39 100644
--- a/gdb/python/py-events.h
+++ b/gdb/python/py-events.h
@@ -45,6 +45,7 @@ typedef struct
eventregistry_object *stop;
eventregistry_object *cont;
eventregistry_object *exited;
+ eventregistry_object *newobjfile;

PyObject *module;

diff --git a/gdb/python/py-evts.c b/gdb/python/py-evts.c
index 50c05f3..ee60560 100644
--- a/gdb/python/py-evts.c
+++ b/gdb/python/py-evts.c
@@ -57,6 +57,9 @@ gdbpy_initialize_py_events (void)

if (add_new_registry (&gdb_py_events.exited, "exited") < 0)
goto fail;
+
+ if (add_new_registry (&gdb_py_events.newobjfile, "newobjfile") < 0)
+ goto fail;

Py_INCREF (gdb_py_events.module);
if (PyModule_AddObject (gdb_module,
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index b9df394..ebd2a2a 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -22,6 +22,7 @@
#include "gdbcore.h"
#include "gdbthread.h"
#include "inferior.h"
+#include "objfiles.h"
#include "observer.h"
#include "python-internal.h"
#include "arch-utils.h"
@@ -129,6 +130,31 @@ python_inferior_exit (struct inferior *inf)
do_cleanups (cleanup);
}

+/* Callback used to notify Python listeners about new objfiles loaded in the
+ inferior. Python global variable 'gdb.current_objfile ()' will be set
+ during the notifications.
+ */
+
+static void
+python_new_objfile (struct objfile *objfile)
+{
+ struct cleanup *cleanup;
+
+ /* Will be NULL when clearing the symtab. */
+ if (objfile)
+ cleanup = ensure_python_env (get_objfile_arch (objfile), current_language);
+ else
+ cleanup = ensure_python_env (get_current_arch (), current_language);
+
+ gdbpy_current_objfile = objfile;
+
+ if (emit_new_objfile_event (objfile) < 0)
+ gdbpy_print_stack ();
+
+ do_cleanups (cleanup);
+ gdbpy_current_objfile = NULL;
+}
+
/* Return a borrowed reference to the Python object of type Inferior
representing INFERIOR. If the object has already been created,
return it, otherwise, create it. Return NULL on failure. */
@@ -669,6 +695,7 @@ gdbpy_initialize_inferior (void)
observer_attach_normal_stop (python_on_normal_stop);
observer_attach_target_resumed (python_on_resume);
observer_attach_inferior_exit (python_inferior_exit);
+ observer_attach_new_objfile (python_new_objfile);

if (PyType_Ready (&membuf_object_type) < 0)
return;
diff --git a/gdb/python/py-newobjfileevent.c b/gdb/python/py-newobjfileevent.c
new file mode 100644
index 0000000..20e2b31
--- /dev/null
+++ b/gdb/python/py-newobjfileevent.c
@@ -0,0 +1,53 @@
+/* Python interface to new object file loading events.
+
+ Copyright (C) 2011 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 "py-event.h"
+
+static PyTypeObject new_objfile_event_object_type;
+
+PyObject *
+create_new_objfile_event_object (void)
+{
+ return create_event_object (&new_objfile_event_object_type);
+}
+
+/* Callback function which notifies observers when a new objfile event occurs.
+ This function will create a new Python new_objfile event object.
+ Return -1 if emit fails. */
+
+int
+emit_new_objfile_event (struct objfile *objfile)
+{
+ PyObject *event;
+
+ if (evregpy_no_listeners_p (gdb_py_events.newobjfile))
+ return 0;
+
+ event = create_new_objfile_event_object ();
+ if (event)
+ return evpy_emit_event (event, gdb_py_events.newobjfile);
+ return -1;
+}
+
+GDBPY_NEW_EVENT_TYPE (new_objfile,
+ "gdb.NewObjFileEvent",
+ "NewObjFileEvent",
+ "GDB new object file event object",
+ event_object_type,
+ static);
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index d3cb788..cc9108f 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -207,6 +207,7 @@ void gdbpy_initialize_breakpoint_event (void);
void gdbpy_initialize_continue_event (void);
void gdbpy_initialize_exited_event (void);
void gdbpy_initialize_thread_event (void);
+void gdbpy_initialize_new_objfile_event (void);

struct cleanup *make_cleanup_py_decref (PyObject *py);

@@ -215,6 +216,7 @@ struct cleanup *ensure_python_env (struct gdbarch *gdbarch,

extern struct gdbarch *python_gdbarch;
extern const struct language_defn *python_language;
+extern struct objfile *gdbpy_current_objfile;

/* 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 90d5dc8..df883ef 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -811,8 +811,9 @@ gdbpy_progspaces (PyObject *unused1, PyObject *unused2)

/* The "current" objfile. This is set when gdb detects that a new
objfile has been loaded. It is only set for the duration of a call to
- source_python_script_for_objfile; it is NULL at other times. */
-static struct objfile *gdbpy_current_objfile;
+ source_python_script_for_objfile and new_objfile callbacks; it is NULL at
+ other times. */
+struct objfile *gdbpy_current_objfile;

/* Set the current objfile to OBJFILE and then read STREAM,FILE as
Python code. */
@@ -1074,6 +1075,7 @@ Enables or disables printing of Python stack traces."),
gdbpy_initialize_continue_event ();
gdbpy_initialize_exited_event ();
gdbpy_initialize_thread_event ();
+ gdbpy_initialize_new_objfile_event () ;

PyRun_SimpleString ("import gdb");
PyRun_SimpleString ("gdb.pretty_printers = []");
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index fa575d0..bc48a56 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2011-03-29 Kevin Pouget <kevin.pouget@st.com>
+ * testsuite/gdb.python/py-events-shlib.c: New file.
+ * testsuite/gdb.python/py-events.c (do_nothing): New global.
+ (main): Add call to shared library.
+ * testsuite/gdb.python/py-events.exp: Link the execfile to a shared
+ library and check newobjfile event notification.
+ * testsuite/gdb.python/py-events.py (new_objfile_handler): New Class.
+ (test_newobj_events): New class.
+
2011-03-28 Jan Kratochvil <jan.kratochvil@redhat.com>

Test STT_GNU_IFUNC support.
diff --git a/gdb/testsuite/gdb.python/py-events-shlib.c
b/gdb/testsuite/gdb.python/py-events-shlib.c
new file mode 100644
index 0000000..2a17bbf
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-events-shlib.c
@@ -0,0 +1,20 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2011 Free Software Foundation, Inc.
+
+ 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/>. */
+
+
+void do_nothing (void) {}
+
diff --git a/gdb/testsuite/gdb.python/py-events.c
b/gdb/testsuite/gdb.python/py-events.c
index ceb697e..1cf7cc7 100644
--- a/gdb/testsuite/gdb.python/py-events.c
+++ b/gdb/testsuite/gdb.python/py-events.c
@@ -16,6 +16,8 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

+extern void do_nothing (void) ;
+
int second(){
return 12;
}
@@ -25,5 +27,6 @@ int first(){
}

int main (){
+ do_nothing() ;
return first();
}
diff --git a/gdb/testsuite/gdb.python/py-events.exp
b/gdb/testsuite/gdb.python/py-events.exp
index e5d6daf..56e8f86 100644
--- a/gdb/testsuite/gdb.python/py-events.exp
+++ b/gdb/testsuite/gdb.python/py-events.exp
@@ -24,23 +24,45 @@ if $tracelevel then {

load_lib gdb-python.exp

+set libfile "py-events-shlib"
+set libsrc $srcdir/$subdir/$libfile.c
+set lib_sl $objdir/$subdir/$libfile.so
+set lib_opts debug
+
set testfile "py-events"
set srcfile ${testfile}.c
set binfile ${objdir}/${subdir}/${testfile}
+set exec_opts [list debug shlib=$lib_sl]
set pyfile ${srcdir}/${subdir}/${testfile}.py

-if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+if [get_compiler_info ${binfile}] {
+ return -1
+}
+
+if { [gdb_compile_shlib $libsrc $lib_sl $lib_opts] != ""
+ || [gdb_compile $srcdir/$subdir/$srcfile $binfile executable
$exec_opts] != ""} {
+ untested "Could not compile either $libsrc or $srcdir/$subdir/$srcfile."
return -1
}

+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+
if { [skip_python_tests] } { continue }

+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
gdb_test_no_output "python execfile ('${pyfile}')" ""

-if ![runto_main ] then {
- fail "Can't run to main"
- return -1
-}
+gdb_test "Test_Newobj_Events" "New ObjectFile Event tester registered."
+
+gdb_breakpoint "main" {temporary}
+
+gdb_test "run" ".*event type: new_objfile.*
+.*new objfile name.*"

gdb_test "Test_Events" "Event testers registered."

diff --git a/gdb/testsuite/gdb.python/py-events.py
b/gdb/testsuite/gdb.python/py-events.py
index 9f05b9f..12e36e8 100644
--- a/gdb/testsuite/gdb.python/py-events.py
+++ b/gdb/testsuite/gdb.python/py-events.py
@@ -48,6 +48,14 @@ def continue_handler (event):
if ( event.inferior_thread is not None) :
print "thread num: %s" % (event.inferior_thread.num);

+def new_objfile_handler (event):
+ if (isinstance (event, gdb.NewObjFileEvent)):
+ print "event type: new_objfile"
+ if (gdb.current_objfile () is not None):
+ print "new objfile name: %s" % (gdb.current_objfile ().filename)
+ else:
+ print "new objfile is None"
+
class test_events (gdb.Command):
"""Test events."""

@@ -62,3 +70,15 @@ class test_events (gdb.Command):
print "Event testers registered."

test_events ()
+
+class test_newobj_events (gdb.Command):
+ """NewObj events."""
+
+ def __init__ (self):
+ gdb.Command.__init__ (self, "test_newobj_events", gdb.COMMAND_STACK)
+
+ def invoke (self, arg, from_tty):
+ gdb.events.newobjfile.connect (new_objfile_handler)
+ print "New ObjectFile Event tester registered."
+
+test_newobj_events ()
--
1.7.4