Re: [PATCH] Fix setting breakpoints or stepping on line 65535

Andrew Burgess
2019-12-01T22:08:25Z

* Bernd Edlinger <bernd.edlinger@hotmail.de> [2019-11-24 11:54:23 +0000]:

> Hi,
>
> this removes code that is present from the very first git revisison
> 7b4ac7e1ed2c4616bce56d1760807798be87ac9e from 1988. It was in the
> gdb/dbxread.c at the time (and makes more sense for dbx line info format
> since line numbers are 16-bit entities in that debug format and debugging
> files with more than 65535 lines would not work anyway) but moved from
> there to gdb/buildsym.c which is used for dwarf line info as well, and
> excluding an arbitrary line number does certainly not make sense nowadays.
>
>
> Thanks
> Bernd.

> From f202ae765b72ad6d17600eb661993a63191309f7 Mon Sep 17 00:00:00 2001
> From: Bernd Edlinger <bernd.edlinger@hotmail.de>
> Date: Sat, 23 Nov 2019 07:37:26 +0100
> Subject: [PATCH 1/2] Fix setting breakpoints or stepping on line 65535
>

Bernd,

Thanks for looking into this, and especially thanks for adding a test!

Normally you should include the git commit message and ChangeLog along
with your patch submission so that these can be reviewed too. 'git
format-patch' and 'git send-email' can be useful for this, if you can
get them setup.

Given the age of the code you're removing I think this change sounds
reasonable. I assume there's no test that covers why this code should
be there, so you see no regressions with this code removed?

I have a couple of minor issues with the test. If you address those
and repost with commit message and ChangeLog this can be approved.

Thanks,
Andrew

> ---
> gdb/buildsym.c | 6 ------
> 1 file changed, 6 deletions(-)
>
> diff --git a/gdb/buildsym.c b/gdb/buildsym.c
> index 79f8305..6c14f3f 100644
> --- a/gdb/buildsym.c
> +++ b/gdb/buildsym.c
> @@ -670,12 +670,6 @@ buildsym_compunit::record_line (struct subfile *subfile, int line,
> {
> struct linetable_entry *e;
>
> - /* Ignore the dummy line number in libg.o */
> - if (line == 0xffff)
> - {
> - return;
> - }
> -
> /* Make sure line vector exists and is big enough. */
> if (!subfile->line_vector)
> {
> --
> 1.9.1
>

> From 54a7631206a2cf54573fb4cc94474cb2f6f99245 Mon Sep 17 00:00:00 2001
> From: Bernd Edlinger <bernd.edlinger@hotmail.de>
> Date: Sun, 24 Nov 2019 09:37:22 +0100
> Subject: [PATCH 2/2] Add a test case for line 65535
>
> ---
> gdb/testsuite/gdb.base/line65535.c | 19 +++++++++++++++++++
> gdb/testsuite/gdb.base/line65535.exp | 26 ++++++++++++++++++++++++++
> 2 files changed, 45 insertions(+)
> create mode 100644 gdb/testsuite/gdb.base/line65535.c
> create mode 100644 gdb/testsuite/gdb.base/line65535.exp
>
> diff --git a/gdb/testsuite/gdb.base/line65535.c b/gdb/testsuite/gdb.base/line65535.c
> new file mode 100644
> index 0000000..d80a294
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/line65535.c
> @@ -0,0 +1,19 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2019 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/>. */
> +
> +#line 65535 "line65535.c"
> +int main() { return 0; }
> diff --git a/gdb/testsuite/gdb.base/line65535.exp b/gdb/testsuite/gdb.base/line65535.exp
> new file mode 100644
> index 0000000..2535ba5
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/line65535.exp
> @@ -0,0 +1,26 @@
> +# Copyright 2019 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/>.
> +

Normally we like to add a short description of what the test is doing
here - for new tests. Many old ones don't have this thought.

> +standard_testfile
> +
> +if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
> + return -1
> +}
> +
> +gdb_test "break $srcfile:65535" \
> + ".*Breakpoint 1 at .*: file $srcfile, line 65535\\..*" \
> + "break at line 65535"
> +
> +return 0

I don't think this return is needed at the end of a test.

> --
> 1.9.1
>