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[140.114.89.60]) by smtp.gmail.com with ESMTPSA id h9-20020a05600c350900b003b492338f45sm1525224wmq.39.2022.09.22.22.43.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Sep 2022 22:43:14 -0700 (PDT) From: Johnson Sun To: BrunoLarsen , gdb-patches@sourceware.org Cc: j3.soon777@gmail.com Subject: [PATCH v2] [PR python/18655] Fix deletion of FinishBreakpoints Date: Fri, 23 Sep 2022 13:41:24 +0800 Message-Id: <20220923054123.78393-1-j3.soon777@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220920172426.90659-1-j3.soon777@gmail.com> References: <20220920172426.90659-1-j3.soon777@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-10.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Sep 2022 05:43:19 -0000 This commit fixes the deletion of FinishBreakpoints by setting the disposition to disp_del_at_next_stop instead, which gets cleaned up in breakpoint_auto_delete. The original code fails since it does not correctly delete the temporary FinishBreakpoints in `gdb/python/py-finishbreakpoint.c': /* Can't delete it here, but it will be removed at the next stop. */ disable_breakpoint (bp_obj->bp); gdb_assert (bp_obj->bp->disposition == disp_del); The code above aims to delete the breakpoint on the next hit by setting the disposition to `disp_del'. However, the FinishBreakpoint is disabled, so it will never be hit (thus never be deleted before the program stops). The fix only consists of a single line, setting the disposition to `disp_del_at_next_stop': bp_obj->bp->disposition = disp_del_at_next_stop; The code above allows the breakpoint to be deleted in `breakpoint_auto_delete': for (breakpoint *b : all_breakpoints_safe ()) if (b->disposition == disp_del_at_next_stop) delete_breakpoint (b); A minimal test is added to verify this issue. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=18655 --- gdb/python/py-finishbreakpoint.c | 1 + .../py-finish-breakpoint-deletion.c | 31 +++++++++++++ .../py-finish-breakpoint-deletion.exp | 43 +++++++++++++++++++ .../py-finish-breakpoint-deletion.py | 33 ++++++++++++++ 4 files changed, 108 insertions(+) create mode 100644 gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.c create mode 100644 gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.exp create mode 100644 gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.py diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c index c80096f6810..a219bc82f15 100644 --- a/gdb/python/py-finishbreakpoint.c +++ b/gdb/python/py-finishbreakpoint.c @@ -146,6 +146,7 @@ bpfinishpy_post_stop_hook (struct gdbpy_breakpoint_object *bp_obj) /* Can't delete it here, but it will be removed at the next stop. */ disable_breakpoint (bp_obj->bp); gdb_assert (bp_obj->bp->disposition == disp_del); + bp_obj->bp->disposition = disp_del_at_next_stop; } catch (const gdb_exception &except) { diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.c b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.c new file mode 100644 index 00000000000..258c8dc3861 --- /dev/null +++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.c @@ -0,0 +1,31 @@ +/* This testcase is part of GDB, the GNU debugger. + + 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 . */ + +int +subroutine (int a) +{ + return a; +} + +int +main () +{ + int i; + for (i = 0; i < 5; i++) + subroutine(i); + return 0; +} diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.exp b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.exp new file mode 100644 index 00000000000..bcf697266a1 --- /dev/null +++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.exp @@ -0,0 +1,43 @@ +# 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 . + +# This file is part of the GDB testsuite. It checks FinishBreakpoints +# are deleted after used. + +load_lib gdb-python.exp + +standard_testfile + +if {[prepare_for_testing "failed to prepare" $testfile $srcfile]} { + return -1 +} + +# Skip all tests if Python scripting is not enabled. +if { [skip_python_tests] } { continue } + +if ![runto_main] then { + return 0 +} + +# +# Check FinishBreakpoints are deleted after used +# + +gdb_test "python print (len(gdb.breakpoints()))" "1" "check default BP count" +gdb_test "source ${srcdir}/${subdir}/${testfile}.py" ".*Python script imported.*" \ + "import python scripts" +gdb_test "python print (len(gdb.breakpoints()))" "2" "check modified BP count" +gdb_test "continue" "Breakpoint.*at.*" "run until FinishBreakpoint stops" +gdb_test "python print (len(gdb.breakpoints()))" "2" "check BP count" diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.py b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.py new file mode 100644 index 00000000000..f207d0bd2bf --- /dev/null +++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.py @@ -0,0 +1,33 @@ +# 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 . + +# This file is part of the GDB testsuite. It checks FinishBreakpoints +# are deleted after used. + + +class MyFinishBreakpoint(gdb.FinishBreakpoint): + def stop(self): + print("stopped at MyFinishBreakpoint") + return self.return_value == 4 + +class MyBreakpoint(gdb.Breakpoint): + def stop(self): + print("stopped at MyBreakpoint") + MyFinishBreakpoint() + return False + +MyBreakpoint("subroutine", internal=True) + +print("Python script imported") -- 2.34.1 base-commit: c99b2113a478a075e8d8f7c3848a92f1ce73f847