[Bug breakpoints/31403] New: Automatic hardware breakpoints do not count towards hardware-breakpoint-limit

[Bug breakpoints/31403] New: Automatic hardware breakpoints do not count towards hardware-breakpoint-limit

[recursivenomad+sourceware at protonmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=31403

            Bug ID: 31403
           Summary: Automatic hardware breakpoints do not count towards
                    hardware-breakpoint-limit
           Product: gdb
           Version: 13.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: breakpoints
          Assignee: unassigned at sourceware dot org
          Reporter: recursivenomad+sourceware at protonmail dot com
  Target Milestone: ---

I am debugging a Raspberry Pi Pico (RP2040, ARM Cortex-M0+) via a Picoprobe (a
second Pico used as the debug probe), from GDB through OpenOCD.  I have
encountered this bug on Windows 10 with arm-none-eabi-gdb, and on Debian 12
with gdb-multiarch.

I send GDB `set remote hardware-breakpoint-limit 4` at launch.  If I manually
request `hbreak` four times, the limit is successfully reached, and a fifth
`hbreak` request gracefully returns "Hardware breakpoints used exceeds limit".

If I instead request `break` (noting that GDB reports "Note: automatically
using hardware breakpoints for read-only addresses." at launch), I can see that
GDB is successfully sending `Z1` packets; however, these automatic hardware
breakpoints do not appear to count towards the gracefully monitored
hardware-breakpoint-limit.  Listing these breakpoints with `info break` reports
they are of Type "breakpoint" (not "hw breakpoint").

The result of this bug is that requesting more breakpoints than the hardware
supports will result in a fatal error, requiring GDB to restart.

For my development environment, manually submitting `hbreak` is not a graceful
workaround, as my debugging interface (VSCodium/VSCode) automatically submits
`break` when creating breakpoints through the UI.

I am curious if there is a way for GDB to track these automatic hardware
breakpoints the same as those created manually with `hbreak`?

Thank you for your contributions to this project :)

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