* [PATCH] Add gdb.free_objfile event registry
@ 2022-06-20 17:36 Tom Tromey
2022-06-20 18:21 ` Eli Zaretskii
2022-06-20 18:36 ` Lancelot SIX
0 siblings, 2 replies; 4+ messages in thread
From: Tom Tromey @ 2022-06-20 17:36 UTC (permalink / raw)
To: gdb-patches; +Cc: Tom Tromey
Currently, Python code can use event registries to detect when gdb
loads a new objfile, and when gdb clears the objfile list. However,
there's no way to detect the removal of an objfile, say when the
inferior calls dlclose.
This patch adds a gdb.free_objfile event registry and arranges for an
event to be emitted in this case.
---
gdb/doc/python.texi | 11 ++++
gdb/python/py-all-events.def | 1 +
gdb/python/py-event-types.def | 5 ++
gdb/python/py-event.h | 1 +
gdb/python/py-inferior.c | 15 +++++
gdb/python/py-newobjfileevent.c | 36 ++++++++++++
gdb/testsuite/gdb.python/py-event-load.c | 42 ++++++++++++++
gdb/testsuite/gdb.python/py-event-load.exp | 67 ++++++++++++++++++++++
gdb/testsuite/gdb.python/py-event-load.py | 30 ++++++++++
9 files changed, 208 insertions(+)
create mode 100644 gdb/testsuite/gdb.python/py-event-load.c
create mode 100644 gdb/testsuite/gdb.python/py-event-load.exp
create mode 100644 gdb/testsuite/gdb.python/py-event-load.py
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 9e2e97b1e74..7d2c6e323a1 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -3470,6 +3470,17 @@ A reference to the object file (@code{gdb.Objfile}) which has been loaded.
@xref{Objfiles In Python}, for details of the @code{gdb.Objfile} object.
@end defvar
+@item events.free_objfile
+Emits @code{gdb.FreeObjFileEvent} which indicates that an object file
+is about to be removed from @value{GDBN}. One reason this can happen
+is when the inferior calls @code{dlclose}.
+@code{gdb.FreeObjFileEvent} has one attribute:
+
+@defvar NewObjFileEvent.objfile
+A reference to the object file (@code{gdb.Objfile}) which will be unloaded.
+@xref{Objfiles In Python}, for details of the @code{gdb.Objfile} object.
+@end defvar
+
@item events.clear_objfiles
Emits @code{gdb.ClearObjFilesEvent} which indicates that the list of object
files for a program space has been reset.
diff --git a/gdb/python/py-all-events.def b/gdb/python/py-all-events.def
index 7db8efa1390..e8ae9066875 100644
--- a/gdb/python/py-all-events.def
+++ b/gdb/python/py-all-events.def
@@ -27,6 +27,7 @@ GDB_PY_DEFINE_EVENT(stop)
GDB_PY_DEFINE_EVENT(cont)
GDB_PY_DEFINE_EVENT(exited)
GDB_PY_DEFINE_EVENT(new_objfile)
+GDB_PY_DEFINE_EVENT(free_objfile)
GDB_PY_DEFINE_EVENT(clear_objfiles)
GDB_PY_DEFINE_EVENT(new_inferior)
GDB_PY_DEFINE_EVENT(inferior_deleted)
diff --git a/gdb/python/py-event-types.def b/gdb/python/py-event-types.def
index 596e68a852a..e613e6949d3 100644
--- a/gdb/python/py-event-types.def
+++ b/gdb/python/py-event-types.def
@@ -86,6 +86,11 @@ GDB_PY_DEFINE_EVENT_TYPE (new_objfile,
"GDB new object file event object",
event_object_type);
+GDB_PY_DEFINE_EVENT_TYPE (free_objfile,
+ "FreeObjFileEvent",
+ "GDB free object file event object",
+ event_object_type);
+
GDB_PY_DEFINE_EVENT_TYPE (clear_objfiles,
"ClearObjFilesEvent",
"GDB clear object files event object",
diff --git a/gdb/python/py-event.h b/gdb/python/py-event.h
index 831dd10fc85..220af1f7b12 100644
--- a/gdb/python/py-event.h
+++ b/gdb/python/py-event.h
@@ -74,6 +74,7 @@ extern gdbpy_ref<> create_thread_event_object (PyTypeObject *py_type,
PyObject *thread);
extern int emit_new_objfile_event (struct objfile *objfile);
+extern int emit_free_objfile_event (struct objfile *objfile);
extern int emit_clear_objfiles_event (void);
extern void evpy_dealloc (PyObject *self);
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index ebcd5b0a70f..61ed342d1c1 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -197,6 +197,20 @@ python_new_objfile (struct objfile *objfile)
}
}
+/* Emit a Python event when an objfile is about to be removed. */
+
+static void
+python_free_objfile (struct objfile *objfile)
+{
+ if (!gdb_python_initialized)
+ return;
+
+ gdbpy_enter enter_py (objfile->arch ());
+
+ if (emit_free_objfile_event (objfile) < 0)
+ gdbpy_print_stack ();
+}
+
/* 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.
@@ -853,6 +867,7 @@ gdbpy_initialize_inferior (void)
gdb::observers::new_objfile.attach
(python_new_objfile, "py-inferior",
{ &auto_load_new_objfile_observer_token });
+ gdb::observers::free_objfile.attach (python_free_objfile, "py-inferior");
gdb::observers::inferior_added.attach (python_new_inferior, "py-inferior");
gdb::observers::inferior_removed.attach (python_inferior_deleted,
"py-inferior");
diff --git a/gdb/python/py-newobjfileevent.c b/gdb/python/py-newobjfileevent.c
index dcbd0faf3a8..929d0eaac73 100644
--- a/gdb/python/py-newobjfileevent.c
+++ b/gdb/python/py-newobjfileevent.c
@@ -53,6 +53,42 @@ emit_new_objfile_event (struct objfile *objfile)
return -1;
}
+/* Create an event object representing a to-be-freed objfile. Return
+ nullptr, with the Python exception set, on error. */
+
+static gdbpy_ref<>
+create_free_objfile_event_object (struct objfile *objfile)
+{
+ gdbpy_ref<> objfile_event
+ = create_event_object (&free_objfile_event_object_type);
+ if (objfile_event == nullptr)
+ return nullptr;
+
+ gdbpy_ref<> py_objfile = objfile_to_objfile_object (objfile);
+ if (py_objfile == nullptr
+ || evpy_add_attribute (objfile_event.get (), "objfile",
+ py_objfile.get ()) < 0)
+ return nullptr;
+
+ return objfile_event;
+}
+
+/* Callback function which notifies observers when a free objfile
+ event occurs. This function will create a new Python event object.
+ Return -1 if emit fails. */
+
+int
+emit_free_objfile_event (struct objfile *objfile)
+{
+ if (evregpy_no_listeners_p (gdb_py_events.free_objfile))
+ return 0;
+
+ gdbpy_ref<> event = create_free_objfile_event_object (objfile);
+ if (event == nullptr)
+ return -1;
+ return evpy_emit_event (event.get (), gdb_py_events.free_objfile);
+}
+
\f
/* Subroutine of emit_clear_objfiles_event to simplify it. */
diff --git a/gdb/testsuite/gdb.python/py-event-load.c b/gdb/testsuite/gdb.python/py-event-load.c
new file mode 100644
index 00000000000..515b4b0be08
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-event-load.c
@@ -0,0 +1,42 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2010-2022 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/>. */
+
+#include <unistd.h>
+
+#ifdef __WIN32__
+#include <windows.h>
+#define dlopen(name, mode) LoadLibrary (TEXT (name))
+#define dlclose(handle) FreeLibrary (handle)
+#else
+#include <dlfcn.h>
+#endif
+
+/* This is updated by the .exp file. */
+char *libname = "catch-load-so.so";
+
+int
+main ()
+{
+ void *h;
+
+ h = dlopen (libname, RTLD_LAZY);
+
+ dlclose (h);
+
+ h = NULL; /* final breakpoint here */
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.python/py-event-load.exp b/gdb/testsuite/gdb.python/py-event-load.exp
new file mode 100644
index 00000000000..f7aeb5f33fb
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-event-load.exp
@@ -0,0 +1,67 @@
+# Copyright 2022 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/>.
+#
+
+# Test the Python free_objfile event.
+
+load_lib gdb-python.exp
+
+if {[skip_shlib_tests]} {
+ untested "skipping shared library tests"
+ return -1
+}
+
+if {[get_compiler_info]} {
+ warning "Could not get compiler info"
+ untested "no compiler info"
+ return -1
+}
+
+standard_testfile .c
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
+ executable {debug shlib_load}] != ""} {
+ untested "failed to compile"
+ return -1
+}
+
+set testfile2 py-events-shlib
+set srcfile2 ${testfile2}.c
+set binfile2 [standard_output_file ${testfile2}.so]
+set binfile2_dlopen [shlib_target_file ${testfile2}.so]
+if {[gdb_compile_shlib "${srcdir}/${subdir}/${srcfile2}" \
+ ${binfile2} {debug}] != ""} {
+ untested "failed to compile shared library"
+ return -1
+}
+
+clean_restart $testfile
+
+if {![runto_main]} {
+ return
+}
+
+if { [skip_python_tests] } { return }
+
+gdb_test_no_output "set var libname = \"$binfile2_dlopen\""
+
+set pyfile [gdb_remote_download host ${srcdir}/${subdir}/py-event-load.py]
+gdb_test_no_output "source ${pyfile}" "load python file"
+
+gdb_breakpoint [gdb_get_line_number "final breakpoint here"]
+
+gdb_continue_to_breakpoint "run to final breakpoint"
+
+gdb_test "python print(freed_objfile)" [string_to_regexp $binfile2_dlopen] \
+ "print name of unloaded objfile"
diff --git a/gdb/testsuite/gdb.python/py-event-load.py b/gdb/testsuite/gdb.python/py-event-load.py
new file mode 100644
index 00000000000..9cf56115205
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-event-load.py
@@ -0,0 +1,30 @@
+# Copyright (C) 2022 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/>.
+
+# Test Python free_objfile event.
+
+import gdb
+
+
+freed_objfile = None
+
+
+def free_objfile_handler(event):
+ assert isinstance(event, gdb.FreeObjFileEvent)
+ global freed_objfile
+ freed_objfile = event.objfile.username
+
+
+gdb.events.free_objfile.connect(free_objfile_handler)
--
2.34.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Add gdb.free_objfile event registry
2022-06-20 17:36 [PATCH] Add gdb.free_objfile event registry Tom Tromey
@ 2022-06-20 18:21 ` Eli Zaretskii
2022-06-20 18:36 ` Lancelot SIX
1 sibling, 0 replies; 4+ messages in thread
From: Eli Zaretskii @ 2022-06-20 18:21 UTC (permalink / raw)
To: Tom Tromey; +Cc: gdb-patches
> Date: Mon, 20 Jun 2022 11:36:22 -0600
> From: Tom Tromey via Gdb-patches <gdb-patches@sourceware.org>
> Cc: Tom Tromey <tromey@adacore.com>
>
> Currently, Python code can use event registries to detect when gdb
> loads a new objfile, and when gdb clears the objfile list. However,
> there's no way to detect the removal of an objfile, say when the
> inferior calls dlclose.
>
> This patch adds a gdb.free_objfile event registry and arranges for an
> event to be emitted in this case.
> ---
> gdb/doc/python.texi | 11 ++++
> gdb/python/py-all-events.def | 1 +
> gdb/python/py-event-types.def | 5 ++
> gdb/python/py-event.h | 1 +
> gdb/python/py-inferior.c | 15 +++++
> gdb/python/py-newobjfileevent.c | 36 ++++++++++++
> gdb/testsuite/gdb.python/py-event-load.c | 42 ++++++++++++++
> gdb/testsuite/gdb.python/py-event-load.exp | 67 ++++++++++++++++++++++
> gdb/testsuite/gdb.python/py-event-load.py | 30 ++++++++++
> 9 files changed, 208 insertions(+)
> create mode 100644 gdb/testsuite/gdb.python/py-event-load.c
> create mode 100644 gdb/testsuite/gdb.python/py-event-load.exp
> create mode 100644 gdb/testsuite/gdb.python/py-event-load.py
Thanks, the documentation part is OK.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Add gdb.free_objfile event registry
2022-06-20 17:36 [PATCH] Add gdb.free_objfile event registry Tom Tromey
2022-06-20 18:21 ` Eli Zaretskii
@ 2022-06-20 18:36 ` Lancelot SIX
2022-07-18 17:25 ` Tom Tromey
1 sibling, 1 reply; 4+ messages in thread
From: Lancelot SIX @ 2022-06-20 18:36 UTC (permalink / raw)
To: Tom Tromey; +Cc: gdb-patches
Hi,
I have minor remarks / questions down below.
> diff --git a/gdb/testsuite/gdb.python/py-event-load.c b/gdb/testsuite/gdb.python/py-event-load.c
> new file mode 100644
> index 00000000000..515b4b0be08
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-event-load.c
> @@ -0,0 +1,42 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2010-2022 Free Software Foundation, Inc.
Is the 2010 intentional? It looks that this file is copied from
gdb.base/catch-load.c which is marked 2012-2022.
> +
> + 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 <unistd.h>
> +
> +#ifdef __WIN32__
> +#include <windows.h>
> +#define dlopen(name, mode) LoadLibrary (TEXT (name))
> +#define dlclose(handle) FreeLibrary (handle)
> +#else
> +#include <dlfcn.h>
> +#endif
> +
> +/* This is updated by the .exp file. */
> +char *libname = "catch-load-so.so";
To be "consistent" with other files which uses this pattern, shouldn't
the default libname reflect the test name? Something like
py-event-load-so.so I guess. Later in the test you use
"py-events-shlib.so" as actual libname.
> +
> +int
> +main ()
> +{
> + void *h;
> +
> + h = dlopen (libname, RTLD_LAZY);
> +
> + dlclose (h);
> +
> + h = NULL; /* final breakpoint here */
> + return 0;
> +}
> diff --git a/gdb/testsuite/gdb.python/py-event-load.exp b/gdb/testsuite/gdb.python/py-event-load.exp
> new file mode 100644
> index 00000000000..f7aeb5f33fb
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-event-load.exp
> @@ -0,0 +1,67 @@
> +# Copyright 2022 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/>.
> +#
> +
> +# Test the Python free_objfile event.
> +
> +load_lib gdb-python.exp
> +
> +if {[skip_shlib_tests]} {
> + untested "skipping shared library tests"
> + return -1
> +}
> +
> +if {[get_compiler_info]} {
> + warning "Could not get compiler info"
> + untested "no compiler info"
> + return -1
> +}
> +
> +standard_testfile .c
> +if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
> + executable {debug shlib_load}] != ""} {
> + untested "failed to compile"
> + return -1
> +}
> +
> +set testfile2 py-events-shlib
> +set srcfile2 ${testfile2}.c
> +set binfile2 [standard_output_file ${testfile2}.so]
> +set binfile2_dlopen [shlib_target_file ${testfile2}.so]
> +if {[gdb_compile_shlib "${srcdir}/${subdir}/${srcfile2}" \
> + ${binfile2} {debug}] != ""} {
> + untested "failed to compile shared library"
> + return -1
> +}
> +
> +clean_restart $testfile
> +
> +if {![runto_main]} {
> + return
> +}
> +
> +if { [skip_python_tests] } { return }
I guess that this skip check can be moved above (together with the
skip_shlib_tests), so on target which skip python tests we do not bother
compiling the test program. WDYT?
Best,
Lancelot.
> +
> +gdb_test_no_output "set var libname = \"$binfile2_dlopen\""
> +
> +set pyfile [gdb_remote_download host ${srcdir}/${subdir}/py-event-load.py]
> +gdb_test_no_output "source ${pyfile}" "load python file"
> +
> +gdb_breakpoint [gdb_get_line_number "final breakpoint here"]
> +
> +gdb_continue_to_breakpoint "run to final breakpoint"
> +
> +gdb_test "python print(freed_objfile)" [string_to_regexp $binfile2_dlopen] \
> + "print name of unloaded objfile"
> diff --git a/gdb/testsuite/gdb.python/py-event-load.py b/gdb/testsuite/gdb.python/py-event-load.py
> new file mode 100644
> index 00000000000..9cf56115205
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-event-load.py
> @@ -0,0 +1,30 @@
> +# Copyright (C) 2022 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/>.
> +
> +# Test Python free_objfile event.
> +
> +import gdb
> +
> +
> +freed_objfile = None
> +
> +
> +def free_objfile_handler(event):
> + assert isinstance(event, gdb.FreeObjFileEvent)
> + global freed_objfile
> + freed_objfile = event.objfile.username
> +
> +
> +gdb.events.free_objfile.connect(free_objfile_handler)
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Add gdb.free_objfile event registry
2022-06-20 18:36 ` Lancelot SIX
@ 2022-07-18 17:25 ` Tom Tromey
0 siblings, 0 replies; 4+ messages in thread
From: Tom Tromey @ 2022-07-18 17:25 UTC (permalink / raw)
To: Lancelot SIX; +Cc: Tom Tromey, gdb-patches
>> + Copyright 2010-2022 Free Software Foundation, Inc.
Lancelot> Is the 2010 intentional? It looks that this file is copied from
Lancelot> gdb.base/catch-load.c which is marked 2012-2022.
I changed it to just 2022.
>> +/* This is updated by the .exp file. */
>> +char *libname = "catch-load-so.so";
Lancelot> To be "consistent" with other files which uses this pattern, shouldn't
Lancelot> the default libname reflect the test name? Something like
Lancelot> py-event-load-so.so I guess. Later in the test you use
Lancelot> "py-events-shlib.so" as actual libname.
I updated this.
>> +clean_restart $testfile
>> +
>> +if {![runto_main]} {
>> + return
>> +}
>> +
>> +if { [skip_python_tests] } { return }
Lancelot> I guess that this skip check can be moved above (together with the
Lancelot> skip_shlib_tests), so on target which skip python tests we do not bother
Lancelot> compiling the test program. WDYT?
Unfortunately, skip_python_tests requires that gdb already be running.
I'm going to check in the updated patch now.
Tom
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-07-18 17:25 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-20 17:36 [PATCH] Add gdb.free_objfile event registry Tom Tromey
2022-06-20 18:21 ` Eli Zaretskii
2022-06-20 18:36 ` Lancelot SIX
2022-07-18 17:25 ` Tom Tromey
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).