Re: [PATCH][PR cli/22573] Honour 'print pretty' when printing result of finish command

[Pedro Alves <palves at redhat dot com>]

On 06/09/2018 06:07 PM, Tom de Vries wrote:
> Hi,
> 
> this fixes PR22573 - "finish" doesn't respect "set print pretty".
> 
> 
> Consider this testcase:
> ...
> struct s {
>   int a;
>   int b;
> };
> 
> struct s foo ()
> {
>   struct s r;
>   r.a = 1;
>   r.b = 2;
>   return r;
> }
> 
> int
> main (void)
> {
>   struct s v;
>   v = foo ();
>   return v.a + v.b;
> }
> ...
> 
> When we compile it with -g, load the exec with gdb, and run till the end of foo,
> we can print r:
> ...
> (gdb) p r
> $1 = {a = 1, b = 2}
> ...
> 
> and by setting pretty printing to on, we can get the fields of r printed each
> on its own line:
> ...
> (gdb) set print pretty
> (gdb) p r
> $2 = {
>   a = 1, 
>   b = 2
> }
> ...
> 
> However, when we finish foo, the printed function result value is not using
> the pretty printing setting:
> ...
> (gdb) finish
> Run till exit from #0  foo () at test.c:11
> 0x00000000004004c1 in main () at test.c:18
> 18        v = foo ();
> Value returned is $3 = {a = 1, b = 2}
> ...
> 
> This patch fixes that by using get_user_print_options instead of
> get_no_prettyformat_print_options in print_return_value_1, which gives us:
> ...
> (gdb) finish
> Run till exit from #0  foo () at test.c:11
> 0x00000000004004c1 in main () at test.c:18
> 18        v = foo ();
> Value returned is $2 = {
>   a = 1, 
>   b = 2
> }
> ...
> 
> Build & reg-tested on x86_64.
> 
> OK for trunk?
> 
> Thanks,
> - Tom
> 
> [gdb/cli] Honour 'print pretty' when printing result of finish command
> 
> 2018-06-08  Tom de Vries  <tdevries@suse.de>
> 
> 	PR cli/22573
> 	* infcmd.c (print_return_value_1): Use get_user_print_options instead of
> 	get_no_prettyformat_print_options.
> 
> 	* gdb.base/finish-pretty.c: New test.
> 	* gdb.base/finish-pretty.exp: New file.

Just in case, note that gdb/testsuite/ has its own ChangeLog.


> diff --git a/gdb/testsuite/gdb.base/finish-pretty.c b/gdb/testsuite/gdb.base/finish-pretty.c
> new file mode 100644
> index 0000000000..5d30b1c16d
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/finish-pretty.c
> @@ -0,0 +1,24 @@

Please add a copyright header.

> +struct s
> +{
> +  int a;
> +  int b;
> +};
> +
> +static struct s __attribute((noinline, noclone))

Do we need that?  (Tests are built with -O0.)

> +foo (void)
> +{
> +  struct s r;
> +  r.a = 1;
> +  r.b = 2;
> +  return r;
> +}
> +
> +int
> +main (void)
> +{
> +  struct s v;
> +
> +  v = foo ();
> +
> +  return v.a + v.b;
> +}
> diff --git a/gdb/testsuite/gdb.base/finish-pretty.exp b/gdb/testsuite/gdb.base/finish-pretty.exp
> new file mode 100644
> index 0000000000..52852c7bad
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/finish-pretty.exp
> @@ -0,0 +1,34 @@
> +# Copyright 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 <http://www.gnu.org/licenses/>.
> +

Please add small intro comment describing what the testcase is about.

> +if { [prepare_for_testing "failed to prepare" finish-pretty finish-pretty.c] } {
> +    return -1
> +}

Write:

standard_testfile

if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
    return -1
}



> +
> +proc finish_pretty { } {
> +    global gdb_prompt

Not used, AFAICT.

> +
> +    gdb_test "break foo" "Breakpoint \[0123456789\].*" \
> +	"set break on foo"
> +    gdb_test "run" "Breakpoint.* foo.*" \
> +	"run to foo"

Please don't use naked "run" unless required for the testcase.
It won't work when testing against "target remote".

You can try that with:

make check-parallel \
   RUNTESTFLAGS="--target_board=native-gdbserver" TESTS="*/finish-pretty.exp"

Instead, use "runto_main", or better, since you want to run to "foo",
use "runto foo", like:

if ![runto foo] {
  fail "can't run to foo"
  return
}

> +    gdb_test "set print pretty" ".*" \
> +	"pretty printing switched on"

Use gdb_test_no_output.

Please resend a v2 with the issue addressed, and it should be
ready to go.

> +    gdb_test "finish" {.*Value returned is \$1 = \{\r\n  a = 1, \r\n  b = 2\r\n\}} \
> +	"finish foo"
> +}
> +
> +finish_pretty
> +
> 

Thanks,
Pedro Alves