From 8e817061976910fd1ac7bb8f689dbd96123ea593 Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Fri, 1 Jun 2018 09:36:05 -0700 Subject: [PATCH] inadvertent language switch during breakpoint_re_set_one Trying to insert a breakpoint using *FUNC'address with an Ada program and then running the program until reaching that breakpoint currently yields the following behavior: (gdb) break *a'address Breakpoint 1 at 0x40240c: file a.adb, line 1. (gdb) run [1] + 27222 suspended (tty output) /[...]/gdb -q simple_main Unsuspending GDB then shows it was suspended trying to report the following error: Starting program: /home/takamaka.a/brobecke/ex/simple/a Error in re-setting breakpoint 1: Unmatched single quote. Error in re-setting breakpoint 1: Unmatched single quote. Error in re-setting breakpoint 1: Unmatched single quote. [Inferior 1 (process 32470) exited normally] The "a'address" is Ada speak for function A's address ("A" by itself means the result of calling A with no arguments). The transcript above shows that we're having problems trying to parse the breakpoint location while re-setting it. As a result, we also fail to stop at the breakpoint. Normally, breakpoint locations are evaluated with the current_language being set to the language of the breakpoint. But, unfortunately for us, what happened in this case is that parse_exp_in_context_1 calls get_selected_block which eventually leads to a call to select_frame because the current_frame hadn't been set yet. select_frame then finds that our language_mode is auto, and therefore changes the current_language to match the language of the frame we just selected. In our case, the language chosen was 'c', which of course is not able to parse an Ada expression, hence the error. This patch prevents this by forcing the language_mode to manual before we call breakpoint_re_set_one. gdb/ChangeLog: * breakpoint.c (breakpoint_re_set): Temporarily force language_mode to language_mode_manual while calling breakpoint_re_set_one. gdb/testsuite/ChangeLog: * gdb.ada/bp_fun_addr: New testcase. Tested on x86_64-linux. --- gdb/ChangeLog | 5 ++++ gdb/breakpoint.c | 13 +++++++++ gdb/testsuite/ChangeLog | 4 +++ gdb/testsuite/gdb.ada/bp_fun_addr.exp | 35 +++++++++++++++++++++++++ gdb/testsuite/gdb.ada/bp_fun_addr/a.adb | 19 ++++++++++++++ 5 files changed, 76 insertions(+) create mode 100644 gdb/testsuite/gdb.ada/bp_fun_addr.exp create mode 100644 gdb/testsuite/gdb.ada/bp_fun_addr/a.adb diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 01f4c009b22..082a435de9c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2018-06-01 Joel Brobecker + + * breakpoint.c (breakpoint_re_set): Temporarily force language_mode + to language_mode_manual while calling breakpoint_re_set_one. + 2018-06-01 Tom Tromey * valops.c (value_cast_structs, destructor_name_p): Update. diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index f3101af96fb..00c538e989e 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -13868,6 +13868,19 @@ breakpoint_re_set (void) scoped_restore save_input_radix = make_scoped_restore (&input_radix); scoped_restore_current_pspace_and_thread restore_pspace_thread; + /* breakpoint_re_set_one sets the current_language to the language + of the breakpoint it is resetting (see prepare_re_set_context) + before re-evaluating the breakpoint's location. This change can + unfortunately get undone by accident if the language_mode is set + to auto, and we either switch frames, or more likely in this context, + we select the current frame. + + We prevent this by temporarily turning the language_mode to + language_mode_manual. We restore it once all breakpoints + have been reset. */ + scoped_restore save_language_mode = make_scoped_restore (&language_mode); + language_mode = language_mode_manual; + /* Note: we must not try to insert locations until after all breakpoints have been re-set. Otherwise, e.g., when re-setting breakpoint 1, we'd insert the locations of breakpoint 2, which diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 9fb10b5a23c..8cef172a26d 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2018-06-01 Joel Brobecker + + * gdb.ada/bp_fun_addr: New testcase. + 2018-06-01 Tom Tromey * gdb.xml/tdesc-regs.exp (load_description): Update expected diff --git a/gdb/testsuite/gdb.ada/bp_fun_addr.exp b/gdb/testsuite/gdb.ada/bp_fun_addr.exp new file mode 100644 index 00000000000..b037d435383 --- /dev/null +++ b/gdb/testsuite/gdb.ada/bp_fun_addr.exp @@ -0,0 +1,35 @@ +# Copyright 2016-2018 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 . + +load_lib "ada.exp" + +if { [skip_ada_tests] } { return -1 } + +standard_ada_testfile a + +if {[gdb_compile_ada "${srcfile}" "${binfile}" executable {debug}] != ""} { + return -1 +} + +clean_restart ${testfile} + +gdb_test "break *a'address" \ + "Breakpoint \[0-9\]+ at.*: file .*a.adb, line \[0-9\]+." + +gdb_run_cmd +gdb_test "" \ + "Breakpoint $decimal, a \\(\\).*" \ + "run until breakpoint at a'address" + diff --git a/gdb/testsuite/gdb.ada/bp_fun_addr/a.adb b/gdb/testsuite/gdb.ada/bp_fun_addr/a.adb new file mode 100644 index 00000000000..00e2e863554 --- /dev/null +++ b/gdb/testsuite/gdb.ada/bp_fun_addr/a.adb @@ -0,0 +1,19 @@ +-- Copyright 2016-2018 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 . + +procedure A is +begin + null; +end A; -- 2.30.2