[libunwind] Ensure test/libunwind_01.pass is not completely inlined
By adding noinline and calling fprintf before returning we ensure that
every function will have a distinct call frame and that the return address
will always be saved instead of saving the target in main as the result.
Before this change all backtraces were always backtrace -> main -> _start,
i.e. always exactly three entries. This happenend because all calls were
inlined in main() and the test just happenend to pass because there is at
least _start before main.
I found this while fixing some bugs in libunwind for CHERI and noticed that
the test was passing even though the code was completely broken.
Obtained from: https://github.com/CTSRD-CHERI/llvm-project
Reviewed By: #libunwind, ldionne, MaskRay
Differential Revision: https://reviews.llvm.org/D126611
GitOrigin-RevId: 8df257a6d0b0b32e05e89874eff4c8ddd2a2a2a9
1 file changed
