From: Michael Weghorn <m.weghorn@posteo.de>
To: gdb-patches@sourceware.org
Cc: Michael Weghorn <m.weghorn@posteo.de>
Subject: [PATCH v2] gdb: Change init order so pretty printers are set in new_objfile event
Date: Thu, 11 Feb 2021 12:22:17 +0100 [thread overview]
Message-ID: <20210211112217.44646-1-m.weghorn@posteo.de> (raw)
In-Reply-To: <20210210154053.82927-1-m.weghorn@posteo.de>
The observers attached to the 'gdb::observers::new_objfile' observable
are notified in the order in which they have been attached (s. class
'observable' in gdbsupport/observable.h).
The new_objfile observer callback to auto-load scripts is attached in
'_initialize_auto_load'.
The new_objfile observer callback that propagates the new_objfile event
to the Python side is attached in 'gdbpy_initialize_inferior', which is
called via '_initialize_python'.
With the previous initialization order, '_initialize_python' happened
before '_initialize_auto_load', with the consequence that the
new_objfile event was emitted on the Python side before autoloaded
scripts had been executed when a new objfile was loaded.
As a result, trying to access the objfile's pretty printers (defined in
the autoloaded script) from a handler for the Python-side
'new_objfile' event would fail. Those would only be initialized later on
(when the 'auto_load_new_objfile' callback was called).
To make sure that the objfile passed to the Python event handler
is properly initialized (including its 'pretty_printers' member), change
the initialization order so that autoloading happens before the
propagation of the 'new_objfile' event to the Python side.
The initialization happens in 'initialize_all_files' in 'gdb/init.c'
which is autogenerated by Makefile 'gdb/Makefile.in', so change the
order there accordingly by moving the 'CONFIG_OBS' part (which includes
the Python part) after the 'COMMON_SFILES' one (which includes the
autoload part).
Add a corresponding testcase that involves a test library with an autoloaded
Python script and a handler for the Python 'new_objfile' event.
(The real world use case where I came across this was in an attempt to
extend handling for GDB pretty printers for dynamically loaded
objfiles in the Qt Creator IDE, s. [1] and [2] for more background.)
[1] https://bugreports.qt.io/browse/QTCREATORBUG-25339
[2] https://codereview.qt-project.org/c/qt-creator/qt-creator/+/333857/1
Tested on x86_64-linux (Debian testing).
gdb/ChangeLog:
* Makefile.in: Change order so initialization for 'CONFIG_OBS'
happens after 'COMMON_SFILES' so e.g. autoloaded Python pretty
printers are available in handler for Python new_objfile event handler.
gdb/testsuite/ChangeLog:
* gdb.python/libpy-autoloaded-pretty-printers-in-newobjfile-event.so-gdb.py: New test.
* gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.cc: New test.
* gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.h: New test.
* gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-main.cc: New test.
* gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.exp: New test.
* gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.py: New test.
---
gdb/Makefile.in | 3 +-
...tty-printers-in-newobjfile-event.so-gdb.py | 44 +++++++++
...pretty-printers-in-newobjfile-event-lib.cc | 26 +++++
...-pretty-printers-in-newobjfile-event-lib.h | 31 ++++++
...retty-printers-in-newobjfile-event-main.cc | 23 +++++
...ed-pretty-printers-in-newobjfile-event.exp | 96 +++++++++++++++++++
...ded-pretty-printers-in-newobjfile-event.py | 34 +++++++
7 files changed, 256 insertions(+), 1 deletion(-)
create mode 100644 gdb/testsuite/gdb.python/libpy-autoloaded-pretty-printers-in-newobjfile-event.so-gdb.py
create mode 100644 gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.cc
create mode 100644 gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.h
create mode 100644 gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-main.cc
create mode 100644 gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.exp
create mode 100644 gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.py
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 36ef45d4559..2c34714b66d 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1573,11 +1573,12 @@ TAGFILES_NO_SRCDIR = $(SFILES) $(HFILES_NO_SRCDIR) $(ALLDEPFILES) \
$(CONFIG_SRCS)
TAGFILES_WITH_SRCDIR = $(HFILES_WITH_SRCDIR)
-COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
+COMMON_OBS = $(DEPFILES) $(YYOBJ) \
mi/mi-common.o \
version.o \
xml-builtin.o \
$(patsubst %.c,%.o,$(COMMON_SFILES)) \
+ $(CONFIG_OBS) \
$(SUBDIR_CLI_OBS) \
$(SUBDIR_TARGET_OBS) \
$(SUBDIR_GCC_COMPILE_OBS)
diff --git a/gdb/testsuite/gdb.python/libpy-autoloaded-pretty-printers-in-newobjfile-event.so-gdb.py b/gdb/testsuite/gdb.python/libpy-autoloaded-pretty-printers-in-newobjfile-event.so-gdb.py
new file mode 100644
index 00000000000..2327e4a7384
--- /dev/null
+++ b/gdb/testsuite/gdb.python/libpy-autoloaded-pretty-printers-in-newobjfile-event.so-gdb.py
@@ -0,0 +1,44 @@
+# Copyright (C) 2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the GDB testsuite. It tests that python pretty
+# printers defined in a python script that is autoloaded have been
+# registered when a custom event handler for the new_objfile event
+# is called.
+
+import gdb.printing
+
+
+class MyClassTestLibPrinter(object):
+ "Print a MyClassTestLib"
+
+ def __init__(self, val):
+ self.val = val
+
+ def to_string(self):
+ return "MyClassTestLib object, id: {}".format(self.val['id'])
+
+ def display_hint(self):
+ return "string"
+
+
+def build_pretty_printer():
+ pp = gdb.printing.RegexpCollectionPrettyPrinter(
+ "my_library")
+ pp.add_printer("MyClassTestLib", "^MyClassTestLib$", MyClassTestLibPrinter)
+ return pp
+
+
+gdb.printing.register_pretty_printer(gdb.current_objfile(), build_pretty_printer())
diff --git a/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.cc b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.cc
new file mode 100644
index 00000000000..7e06cf3903f
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.cc
@@ -0,0 +1,26 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2021 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 "py-autoloaded-pretty-printers-in-newobjfile-event-lib.h"
+
+MyClassTestLib::MyClassTestLib(int theId) {
+ id = theId;
+}
+
+int MyClassTestLib::getId() {
+ return id;
+}
diff --git a/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.h b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.h
new file mode 100644
index 00000000000..fa2501bf6de
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-lib.h
@@ -0,0 +1,31 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2021 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/>. */
+
+#ifndef TESTLIBRARY_H
+#define TESTLIBRARY_H
+
+class MyClassTestLib {
+
+public:
+ explicit MyClassTestLib(int theId);
+ int getId();
+
+private:
+ int id;
+};
+
+#endif // TESTLIBRARY_H
diff --git a/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-main.cc b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-main.cc
new file mode 100644
index 00000000000..6e66bbe3d43
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event-main.cc
@@ -0,0 +1,23 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2021 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 "py-autoloaded-pretty-printers-in-newobjfile-event-lib.h"
+
+int main() {
+ MyClassTestLib test(1);
+ return 0; /* break to inspect */
+}
diff --git a/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.exp b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.exp
new file mode 100644
index 00000000000..ed1c3230835
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.exp
@@ -0,0 +1,96 @@
+# Copyright (C) 2021 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/>.
+
+# This file is part of the GDB testsuite. It tests that python pretty
+# printers defined in a python script that is autoloaded have been
+# registered when a custom event handler for the new_objfile event
+# is called.
+
+if [use_gdb_stub] {
+ return 0
+}
+
+load_lib gdb-python.exp
+
+set test "py-autoloaded-pretty-printers-in-newobjfile-event"
+set srcfile_main "${test}-main.cc"
+set executable_main ${test}-test
+set binfile_main [standard_output_file ${executable_main}]
+set srcfile_lib "${test}-lib.cc"
+set libname "lib${test}"
+set pyscriptfile_lib "${libname}.so-gdb.py"
+set binfile_lib [standard_output_file ${libname}.so]
+
+
+# Start with a fresh gdb.
+gdb_exit
+gdb_start
+
+# Skip all tests if Python scripting is not enabled.
+if { [skip_python_tests] } { continue }
+
+if {[gdb_compile_shlib ${srcdir}/${subdir}/${srcfile_lib} ${binfile_lib} \
+ [list debug c++ -Wl,-soname,${libname}.so]] != ""} {
+ return -1
+}
+
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile_main}" "${binfile_main}.o" \
+ object [list debug c++]] != ""} {
+ return -1
+}
+
+set testobjdir [standard_output_file {}]
+if {[gdb_compile "${binfile_main}.o" "${binfile_main}" executable \
+ [list debug "additional_flags=-L$testobjdir -l${test} \
+ -Wl,-rpath=$testobjdir"]] != ""} {
+ return -1
+}
+
+# Start with a fresh gdb.
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+
+# Make the -gdb.py script available to gdb, it is automatically loaded by
+# gdb if it is put in the same directory as the library.
+set remote_python_file_autoload [gdb_remote_download host \
+ ${srcdir}/${subdir}/${pyscriptfile_lib}]
+
+gdb_test_no_output "set auto-load safe-path ${remote_python_file_autoload}" \
+ "set auto-load safe-path"
+
+# load the python file that defines a handler for the new_objfile event,
+# which will generate the output to check later
+# (prints information on available pretty-printers for objfile)
+set remote_python_file [gdb_remote_download host \
+ ${srcdir}/${subdir}/${test}.py]
+gdb_test_no_output "source ${remote_python_file}" "load python file"
+
+gdb_load ${binfile_main}
+
+gdb_test_no_output "set print pretty on"
+
+gdb_breakpoint [gdb_get_line_number "break to inspect" ${srcfile_main}]
+
+# check that the handler prints output when test library is loaded
+# and that the pretty printer from autoloaded python file has been registered
+gdb_test "run" "new_objfile event for test library.*
+.*number of pretty printers: 1.*
+.*name of the first pretty printer: my_library.*"
+
+# check that pretty printer actually works
+gdb_test "print test" " .*MyClassTestLib object, id: 1.*"
+
+gdb_continue_to_end
diff --git a/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.py b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.py
new file mode 100644
index 00000000000..924f304fd33
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-autoloaded-pretty-printers-in-newobjfile-event.py
@@ -0,0 +1,34 @@
+# Copyright (C) 2021 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/>.
+
+# This file is part of the GDB testsuite. It tests that python pretty
+# printers defined in a python script that is autoloaded have been
+# registered when a custom event handler for the new_objfile event
+# is called.
+
+import gdb
+import os
+
+
+def new_objfile_handler(event):
+ assert(isinstance(event, gdb.NewObjFileEvent))
+ # only observe the custom test library
+ if os.path.basename(event.new_objfile.filename).find("libpy-autoloaded-pretty-printers-in-newobjfile-event") == 0:
+ print("new_objfile event for test library")
+ assert(len(event.new_objfile.pretty_printers) == 1)
+ print("number of pretty printers: {}".format(len(event.new_objfile.pretty_printers)))
+ print("name of the first pretty printer: {}".format(event.new_objfile.pretty_printers[0].name))
+
+gdb.events.new_objfile.connect(new_objfile_handler)
--
2.30.0
next prev parent reply other threads:[~2021-02-11 11:22 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 15:40 [PATCH] " Michael Weghorn
2021-02-11 9:42 ` Andrew Burgess
2021-02-11 11:23 ` Michael Weghorn
2021-03-02 7:18 ` Michael Weghorn
2021-03-23 18:55 ` Simon Marchi
2021-03-24 9:45 ` Andrew Burgess
2021-03-24 13:51 ` Simon Marchi
2021-03-26 8:33 ` Michael Weghorn
2021-02-11 11:22 ` Michael Weghorn [this message]
2021-03-23 8:01 ` [PING] [PATCH v2] " Michael Weghorn
2021-03-26 8:29 ` [PATCH v3] gdb: Do autoload before notifying Python side " Michael Weghorn
2021-04-12 13:37 ` [PING] " Michael Weghorn
2021-04-20 11:38 ` [PING 2] " Michael Weghorn
2021-04-20 21:57 ` Simon Marchi
2021-04-22 15:46 ` Michael Weghorn
2021-04-22 16:06 ` Simon Marchi
2021-04-23 6:41 ` Michael Weghorn
2021-04-23 10:48 ` Simon Marchi
2021-04-22 15:44 ` [PATCH v4 0/2] Make sure autoload happens " Michael Weghorn
2021-04-22 15:44 ` [PATCH v4 1/2] gdbsupport: Allow to specify dependencies between observers Michael Weghorn
2021-04-22 15:44 ` [PATCH v4 2/2] gdb: Do autoload before notifying Python side in new_objfile event Michael Weghorn
2021-04-25 1:46 ` [PATCH v4 0/2] Make sure autoload happens " Simon Marchi
2021-04-26 8:18 ` Michael Weghorn
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