[PATCH] [gdb/testsuite] Fix gdb.cp/non-trivial-retval.exp on arm-linux with gcc 13

[Tom de Vries]

On 1/19/25 21:06, Alexandra Petlanova Hajkova wrote:
> 
> 
> On Fri, Jan 17, 2025 at 1:08 PM Tom de Vries <tdevries@suse.de 
> <mailto:tdevries@suse.de>> wrote:
> 
>     On arm-linux, with target board unix/-mthumb, we get:
>     ...
>     (gdb) PASS: gdb.cp/non-trivial-retval.exp: continue to breakpoint:
>     Break here
>     p f1 (i1, i2)^M
>     $1 = {a = -136274256}^M
>     (gdb) FAIL: gdb.cp/non-trivial-retval.exp: gdb-command<p f1 (i1, i2)>
>     ...
> 
>     This is not a problem with the inferior call, which works fine:
>     ...
>     (gdb) p f1 (23, 100)
>     $3 = {a = 123}
>     ...
>     but instead it's a problem with the location information:
>     ...
>     (gdb) p i1
>     $1 = -136274356
>     (gdb) p i2
>     $2 = 100
>     ...
>     which tells us to find the value of i1 in (DW_OP_fbreg: -12).
> 
>     The test-case passes if we drop -fvar-tracking, in which case the
>     debug info
>     tells us to find the value of i1 in (DW_OP_fbreg: -20).
> 
>     This is with gcc 13.3.0 on Ubuntu 24.04.  With gcc 14.2.0 on Debian
>     testing,
>     the code is the same, but -fvar-tracking does use the correct
>     '(DW_OP_fbreg: -20)'.
> 
>     There seems to be some bugfix in -fvar-tracking for gcc 14.
> 
>     Workaround the bug by using constants 23 and 100 instead of i1 and
>     i2 when
>     using -fvar-tracking and gcc < 14.
> 
>     Tested on arm-linux.
> 
>     PR testsuite/32549
>     Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32549 <https://
>     sourceware.org/bugzilla/show_bug.cgi?id=32549>
> 
> Hi,
> 
> neat fix. I can confirm this brings no regressions for Fedora 42 aarch64.

Hi Alexandra,

thanks for checking.

I've pushed this now.

Thanks,
- Tom