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

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

0 files changed, 0 insertions, 0 deletions