Re: [pushed] [gdb/testsuite] Fix gdb.opt/solib-intra-step.exp for powerpc64le

[Carl Love <cel@us.ibm.com>]

Tom:

On Mon, 2022-11-28 at 14:23 +0100, Tom de Vries wrote:
> On powerpc64le-linux, I run into:
> ...
> (gdb) PASS: gdb.opt/solib-intra-step.exp: first-hit
> step^M
> 28      { /* first-retry */^M
> (gdb) FAIL: gdb.opt/solib-intra-step.exp: second-hit
> ...
> 
> It's a bit easier to understand what happens if we do a full stepping
> session:
> ...
> Temporary breakpoint 1, main ()
>     at solib-intra-step-main.c:23
> 23        shlib_first ();
> (gdb) step
> shlib_first () at solib-intra-step-lib.c:29
> 29        shlib_second (0); /* first-hit */
> (gdb) step
> 28      { /* first-retry */
> (gdb) step
> 29        shlib_second (0); /* first-hit */
> (gdb) step
> shlib_second (dummy=0)
>     at solib-intra-step-lib.c:23
> 23        abort (); /* second-hit */
> ...
> and compare that to the line info:
> ...
> CU: solib-intra-step-lib.c:
> File name                    Line number    Starting
> address    View    Stmt
> solib-intra-step-
> lib.c                22               0x710               x
> solib-intra-step-
> lib.c                23               0x724               x
> solib-intra-step-
> lib.c                28               0x740               x
> solib-intra-step-
> lib.c                29               0x74c               x
> solib-intra-step-
> lib.c                28               0x750               x
> solib-intra-step-
> lib.c                29               0x758               x
> solib-intra-step-
> lib.c                30               0x760               x
> solib-intra-step-lib.c                 -               0x77c
> ...
> 
> So we step from line 29 to line 28, and back to line 29, which is
> behaviour
> that matches the line table.  The peculiar order is due to using
> optimization.
> The problem is that the test-case doesn't expect this order.
> 
> Fix this by allowing this order in the test-case.
> 
> Tested on powerpc64le-linux.
> 
> PR testsuite/29792
> Bug: 
> https://sourceware.org/bugzilla/show_bug.cgi?id=29792
>  
> ---
>  gdb/testsuite/gdb.opt/solib-intra-step.exp | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/gdb/testsuite/gdb.opt/solib-intra-step.exp
> b/gdb/testsuite/gdb.opt/solib-intra-step.exp
> index 0acda6594c5..e803a7db14d 100644
> --- a/gdb/testsuite/gdb.opt/solib-intra-step.exp
> +++ b/gdb/testsuite/gdb.opt/solib-intra-step.exp
> @@ -58,16 +58,35 @@ gdb_test_multiple "step" $test {
>      }
>  }
>  
> +set in_second 0
>  set test "second-hit"
>  gdb_test_multiple "step" $test {
> +    -re -wrap " first-retry .*" {
> +	if { $in_second } {
> +	    fail $gdb_test_name
> +	} else {
> +	    send_gdb "step\n"
> +	    exp_continue
> +	}
> +    }
> +    -re -wrap " first-hit .*" {
> +	if { $in_second } {
> +	    fail $gdb_test_name
> +	} else {
> +	    send_gdb "step\n"
> +	    exp_continue
> +	}
> +    }
>      -re -wrap " second-hit .*" {
>  	pass $gdb_test_name
>      }
>      -re -wrap " second-retry .*" {
> +	set in_second 1
>  	send_gdb "step\n"
>  	exp_continue
>      }
>      -re -wrap "get_pc_thunk.*" {
> +	set in_second 1
>  	send_gdb "step\n"
>  	exp_continue
>      }
> 
> base-commit: ddff2a2dea5261789e1f281f3ee1b33dd5fd8892

I ran the test with and without the commit on my Power 10 and Power 9
systems.  I did not see the issue on either system before or after the
fix.  I am guessing there is probably a system configuration difference
between my systems and yours.  The fix looks fine to me in that it
doesn't break anything on my systems.  But I am unable to reproduce the
reported failure.

Power 10 system:  Fedora release 36 (Thirty Six),  gcc (GCC) 12.2.1
20220819 (Red Hat 12.2.1-2)

Power 9 system:   Ubuntu 20.04.5 LTS,  gcc (Ubuntu 9.4.0-
1ubuntu1~20.04.1) 9.4.0

                     Carl