Re: [PATCH] gdb/testsuite: Fix gdb.rocm/displaced-stepping.exp

[Simon Marchi <simark@simark.ca>]

On 10/21/26 9:39 AM, Lancelot SIX wrote:
> The gdb.rocm/displaced-stepping.exp testcase currently fails with:
> 
>   with debug displaced on -- stepi
>   Unhandled dwarf expression opcode 0xe9
>   (gdb) FAIL: gdb.rocm/displaced-stepping.exp: with debug displaced on -- stepi
> 
> This is because when doing the stepi, GDB computes the current frame ID
> in set_step_info.  This will go and evaluate the CFA for the current
> frame, which reads AMDGPU debug info, which is not supported by GDB
> currently.
> 
> Current AMDGPU DWARF requires changes expected to be available in the
> future DWARF-6 standard (address space support), as well as llvm private
> opcodes (DW_OP_LLVM_user DW_OP_LLVM_form_aspace_address):
> 
>     $ llvm-dwarfdump --debug-frame displaced-stepping.0.hip-amdgcn-amd-amdhsa--gfx1031
>     [...]
>     00000014 00000018 00000018 FDE cie=00000000 pc=00001a00...00001b64
>       Format:       DWARF32
>       DW_CFA_def_cfa_expression: DW_OP_lit0, DW_OP_lit6, DW_OP_LLVM_user DW_OP_LLVM_form_aspace_address
> 
> At this point, there is no way to support this in GDB, so instead this
> patch proposes to fix the failure by instructing the compiler to not
> produce any unwind table.
> 
> Tested on x86_64-linux + AMDGPU-gfx1031.
> 
> Change-Id: I2e62270f39c9e96324ae01d401bafb46cfff596c

I suppose something changed in the compiler since the test was merged,
since it used to pass.  Did it not emit those tables before?

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon