Re: [RFC - Python] New ObjFile event

Kevin Pouget
2011-09-01T11:01:39Z

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On Thu, Sep 1, 2011 at 12:18 PM, Eli Zaretskii <eliz@gnu.org> wrote:
>> From: Kevin Pouget <kevin.pouget@gmail.com>
>> Date: Thu, 1 Sep 2011 11:17:51 +0200
>> Cc: pmuldoon@redhat.com, gdb-patches@sourceware.org
>>
>>  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 by @value{GDBN}.
>> +
>> +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
>> @@ -22949,10 +22955,10 @@ The following objfile-related functions are available in the
>
> The addition doesn't look right: shouldn't it be _after_ the following
> @table line?  events.newobjfile is an attribute of the same object as
> stop_signal, right?

sorry; I moved the paragraph to the right place.

>> +When auto-loading a Python script (@pxref{Auto-loading}) and during new
>> +object-file callbacks, @value{GDBN} sets the ``current objfile'' to the
>
> Why did you use "new" here?  New in relation to what?

"new" here refers to object-file, but I'm not sure I can write "during
new-object-file callbacks", can I?

I also added a label reference to make things clearer here:

> During the callback, ``current objfile'' will be set to the new object file
> (@pxref{Objfiles In Python}).

(I'm not sure why there is no `_' between 'current' and 'objfile', I
copied it from another place --- @value{GDBN} sets the ``current
objfile'' to the
corresponding objfile.)

Many thanks,

Kevin

2011-09-01 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.

2011-09-01 Kevin Pouget <kevin.pouget@st.com>

Allow Python notification of new object-file loadings.
* gdb.texinfo (Events In Python): Document `gdb.NewObjFileEvent'
events emitter.
(Objfiles In Python): Indicate that `gdb.current_objfile' is also set
during new object-file callbacks.

2011-09-01 Kevin Pouget <kevin.pouget@st.com>

Allow Python notification of new object-file loadings.
* gdb.python/py-events.exp: Test newobjfile event.
* gdb.python/py-events.py: Register newobjfile callback.
* gdb.python/py-events.c: Add call to shared library
* gdb.python/py-events-shlib.c: New file.

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From 2bce2763858358b753f1da7b2bb3da0215ed8bfc Mon Sep 17 00:00:00 2001
From: Kevin Pouget <kevin.pouget@st.com>
Date: Thu, 1 Sep 2011 11:08:23 +0200
Subject: [PATCH] New ObjFile event

---
gdb/Makefile.in | 6 +++
gdb/NEWS | 2 +
gdb/doc/gdb.texinfo | 15 ++++++--
gdb/python/py-event.h | 1 +
gdb/python/py-events.h | 1 +
gdb/python/py-evts.c | 3 ++
gdb/python/py-inferior.c | 25 +++++++++++++
gdb/python/py-newobjfileevent.c | 53 ++++++++++++++++++++++++++++
gdb/python/python-internal.h | 2 +
gdb/python/python.c | 6 ++-
gdb/testsuite/gdb.python/py-events-shlib.c | 20 ++++++++++
gdb/testsuite/gdb.python/py-events.c | 3 ++
gdb/testsuite/gdb.python/py-events.exp | 26 +++++++++++---
gdb/testsuite/gdb.python/py-events.py | 20 ++++++++++
14 files changed, 172 insertions(+), 11 deletions(-)
create mode 100644 gdb/python/py-newobjfileevent.c
create mode 100644 gdb/testsuite/gdb.python/py-events-shlib.c

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 826d339..986588b 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -289,6 +289,7 @@ SUBDIR_PYTHON_OBS = \
py-inferior.o \
py-infthread.o \
py-lazy-string.o \
+ py-newobjfileevent.o \
py-objfile.o \
py-param.o \
py-prettyprint.o \
@@ -319,6 +320,7 @@ SUBDIR_PYTHON_SRCS = \
python/py-inferior.c \
python/py-infthread.c \
python/py-lazy-string.c \
+ python/py-newobjfileevent.c \
python/py-objfile.c \
python/py-param.c \
python/py-prettyprint.c \
@@ -2115,6 +2117,10 @@ py-lazy-string.o: $(srcdir)/python/py-lazy-string.c
$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-lazy-string.c
$(POSTCOMPILE)

+py-newobjfileevent.o: $(srcdir)/python/py-newobjfileevent.c
+ $(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-newobjfileevent.c
+ $(POSTCOMPILE)
+
py-objfile.o: $(srcdir)/python/py-objfile.c
$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-objfile.c
$(POSTCOMPILE)
diff --git a/gdb/NEWS b/gdb/NEWS
index 255a22e..bb5795c 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -38,6 +38,8 @@

** Symbols now provide the "type" attribute, the type of the symbol.

+ ** A new event "gdb.newobjfile" has been added.
+
* libthread-db-search-path now supports two special values: $sdir and $pdir.
$sdir specifies the default system locations of shared libraries.
$pdir specifies the directory where the libpthread used by the application
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 23b2a98..056776a 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -22327,6 +22327,13 @@ A reference to the breakpoint that was hit of type @code{gdb.Breakpoint}.
@end defivar
@end table

+@item events.newobjfile
+Emits @code{gdb.NewObjFileEvent} which indicates that a new object-file has
+been loaded by @value{GDBN}.
+
+During the callback, ``current objfile'' will be set to the new object file
+(@pxref{Objfiles In Python}).
+
@end table

@node Threads In Python
@@ -22949,10 +22956,10 @@ 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 f4b3ee2..9069a51 100644
--- a/gdb/python/py-event.h
+++ b/gdb/python/py-event.h
@@ -111,6 +111,7 @@ extern int evpy_emit_event (PyObject *event,

extern PyObject *create_event_object (PyTypeObject *py_type);
extern PyObject *create_thread_event_object (PyTypeObject *py_type);
+extern int emit_new_objfile_event (struct objfile *objfile);

extern void evpy_dealloc (PyObject *self);
extern int evpy_add_attribute (PyObject *event,
diff --git a/gdb/python/py-events.h b/gdb/python/py-events.h
index bd54418..70f45a4 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..c8d1044 100644
--- a/gdb/python/py-evts.c
+++ b/gdb/python/py-evts.c
@@ -58,6 +58,9 @@ 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,
"events",
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index 6add681..63ffc2b 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"
@@ -125,6 +126,29 @@ 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;
+
+ if (objfile == NULL)
+ return;
+
+ cleanup = ensure_python_env (get_objfile_arch (objfile), 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 reference to the Python object of type Inferior
representing INFERIOR. If the object has already been created,
return it and increment the reference count, otherwise, create it.
@@ -701,6 +725,7 @@ 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);

membuf_object_type.tp_new = PyType_GenericNew;
if (PyType_Ready (&membuf_object_type) < 0)
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 996b23b..a64ded2 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -211,6 +211,7 @@ 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);

@@ -219,6 +220,7 @@ 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 03edce9..812fc61 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -891,8 +891,9 @@ 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. */
@@ -1209,6 +1210,7 @@ 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 () ;

observer_attach_before_prompt (before_prompt_hook);

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..5ac72f2 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..11d7e00 100644
--- a/gdb/testsuite/gdb.python/py-events.exp
+++ b/gdb/testsuite/gdb.python/py-events.exp
@@ -24,23 +24,39 @@ 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.
+clean_restart ${testfile}
+
if { [skip_python_tests] } { continue }

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." "Register new objfile event handler"
+
+gdb_breakpoint "main" {temporary}
+
+gdb_test "run" ".*event type: new_objfile.*new objfile name.*" "New objfile notification"

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 ()
--
1.7.6