[1/3,gdb/testsuite] Add gdb.python/py-finish-breakpoint-deletion.exp for Bug 18655

  This adds a minimal test that will fail (KFAIL) due to not deleting Python FinishBreakpoints.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=18655
---
 .../py-finish-breakpoint-deletion.c           | 28 +++++++++++
 .../py-finish-breakpoint-deletion.exp         | 47 +++++++++++++++++++
 .../py-finish-breakpoint-deletion.py          | 33 +++++++++++++
 3 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
  

On 20/09/2022 19:24, Johnson Sun via Gdb-patches wrote:
> This adds a minimal test that will fail (KFAIL) due to not deleting Python FinishBreakpoints.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=18655

Hi Johnson!

Thanks for working on this!

In general, I think it is better to add the testcase in the same patch 
that fixes the behavior, so I think you can squash this commit into the 
next one. I also have some comments on code styling, which have been 
inlined.

> ---
>   .../py-finish-breakpoint-deletion.c           | 28 +++++++++++
>   .../py-finish-breakpoint-deletion.exp         | 47 +++++++++++++++++++
>   .../py-finish-breakpoint-deletion.py          | 33 +++++++++++++
>   3 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/testsuite/gdb.python/py-finish-breakpoint-deletion.c b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.c
> new file mode 100644
> index 00000000000..d2e6783799c
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.c
> @@ -0,0 +1,28 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> +   Copyright 2011-2022 Free Software Foundation, Inc.
Since the file is only being added in 2022, you can remove the range and 
just leave 2022 here. Goes for all copyright blurbs.
> +
> +   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/>.  */
> +
> +int subroutine(int a) {
> +  return a;
> +}

Even for tests, whenever possible, code should follow the GNU coding 
style, so this function should look like:

int

subroutine (int a)

{

   return a;

}

Same goes for the main function.

> +
> +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..778b53fbeda
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.exp
> @@ -0,0 +1,47 @@
> +# Copyright (C) 2011-2022 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/>.
> +
> +# This file is part of the GDB testsuite.  It tests the mechanism
> +# exposing values to Python.

The description of the test here seems a bit off, is it a copy-paste 
mistake?

I think the "check FinishBreakpoints (...)" comment can be used here 
instead.

> +
> +load_lib gdb-python.exp
> +
> +standard_testfile
> +
> +if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug c++}]} {
is there a specific reason you decided to compile the testcase as C++ 
when the code is pure C?
> +    return -1
> +}
> +
> +# Skip all tests if Python scripting is not enabled.
> +if { [skip_python_tests] } { continue }
> +
> +if ![runto_main] then {
> +    return 0
> +}
> +
> +set pyfile [gdb_remote_download host \
> +		${srcdir}/${subdir}/${testfile}.py]
This looks unnecessary, I think you can just "source 
${srcdir}/${subdir}/${testfile}.py" down below.
> +
> +#
> +# Check FinishBreakpoints are deleted after used
> +#
> +
> +gdb_test "python print (len(gdb.breakpoints()))" "1" "check default BP count"
> +gdb_test "source $pyfile" ".*Python script imported.*" \
> +         "import python scripts"

change the 8 spaces here for a tab.

Cheers,
Bruno


> +gdb_test "python print (len(gdb.breakpoints()))" "2" "check modified BP count"
> +gdb_test "continue" "Breakpoint.*at.*" "run until FinishBreakpoint stops"
> +setup_kfail "gdb/18655" "*-*-*"
> +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..8146940d41f
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.py
> @@ -0,0 +1,33 @@
> +# Copyright (C) 2011-2022 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/>.
> +
> +# This file is part of the GDB testsuite.  It tests python Finish
> +# Breakpoints.
> +
> +
> +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")
  

Hi Bruno,

Thanks for reviewing this!  I revised the patch and 
will send version 2 shortly.

Cheers,
Johnson