Horizontal Scrolling not working in TUI Regs window

Hello GDB maintainers and users,



I’m writing to clarify the intended behavior of the TUI “registers” window
and to ask whether horizontal scrolling (or another way to view full wide
registers) can be supported.



Context

-------

• Environment:

  - GDB version: GNU gdb (AOMP_23.0-1) 16.3

  - Binary Alias: rocgdb <http://github.com/ROCm/ROCgdb>

  - OS/Terminal: Ubuntu 24.04.3 LTS

  - Target/ISA : AMDGPU / ROCm toolchain, or CPU with wide SIMD/Vector regs

  - Invocation: `gdb -tui <prog>` → `layout regs` → `focus regs`



• What I see:

  - Very wide registers (e.g., V4, V7 on my target) are displayed as a
shortened sequence with

    “<repeats N times>” and/or are visually truncated in the TUI registers
window.

  - Left/Right arrow keys don’t reveal additional content even with `focus
regs`. The window appears

    to not support horizontal scrolling for registers. Increasing terminal
width helps only to a

    point, but content still gets truncated for long vectors.



• What I expected:

  - Either (A) horizontal scrolling in the registers window (like other TUI
windows that support

    Left/Right scrolling), or (B) an alternate built‑in command/pane to
expand a single register

    (vector/SIMD/GPU) fully in a scrollable view, without truncation.



• What I’ve tried:

  - Ensured `focus regs` are active, tested arrow keys and custom Readline
mappings.

  - Verified this isn't a terminal line‑wrap (disabling wrap does not make
the regs pane scroll).

  - Used `info register <name>` as a workaround, which prints the full
value, but it’s not as fluid as an interactive view when inspecting
multiple wide registers.



Questions

---------

1) Is the lack of horizontal scrolling in the TUI “registers” window
intentional (by design), or is it considered a missing feature/bug?



2) If this is by design, would the project consider an enhancement to:

   - Enable horizontal scrolling for the registers window; or

   - Provide a dedicated “expanded register” TUI window (or command) that
shows the selected register in a scrollable region?



3) Is there a recommended workflow today (beyond `info register` and
widening the terminal) for interactively viewing full wide register
contents in TUI?



Repro (minimal)

---------------

1) Start GDB TUI → `tui enable`, `layout regs`, `focus regs`

2) Stop at a point where wide vector/GPU registers hold many elements

3) Observe truncation and the absence of horizontal scroll in the registers
pane



If helpful, Below is the attached screenshot.


[image: image.png]

Motivation

----------

For modern targets (e.g., GPUs, RISC‑V RVV, AArch64 SVE/SVE2, wide SIMD),
register contents can be

much wider than a terminal line. Having an interactive, scrollable view for
full register values

would significantly improve TUI usability in these workflows.



Thanks & Regards

Amit



Thanks for your time—and for GDB!