A breakpoint hit reached a WebSocket client as two fields on cpu.stepping: a
reason string and one address. Everything else the hit site knew was formatted
into a log line and dropped.
What was missing per kind:
- exec: hit count, condition, symbol.
- memory: the address actually accessed, read vs write, size, and who did it.
The address that reached the client was the *start of the watched range*, so a
client watching 4KB learned only that something in it was touched.
- register: which register. Entirely - the event carried pc and nothing else.
There's now a BreakpointHit captured where the hit happens and carried through
Core_Break() on the stepping reason, rendered as a "hit" object on cpu.stepping.
It's absent rather than empty when the break wasn't a breakpoint (a pause, a
savestate load, an exception), so presence is the test. relatedAddress keeps
reporting the range start for compatibility; hit.address is the accurate one.
The formatter is shared with the new event below, so the two can't drift.
And a new cpu.breakpoint.hit broadcast fires on *every* hit whose condition
passes, whether or not it stops the CPU. That's the part that makes log-only
breakpoints usable for automation: until now their only trace was a line in the
log stream, so a client couldn't count hits, or react to one, without scraping
text. Same "hit" object, plus a sequence number.
Volume needed handling, since a log-only breakpoint in a hot loop produces
events far faster than a connection drains them - measured 13719 hits in three
seconds of one homebrew's draw function. The per-connection queue is capped and
drops rather than growing without bound, and the sequence number is what makes
that honest: a gap tells a client exactly how many it missed. Clients that don't
want the traffic at all can disallow the new "breakpoint" broadcast category.
Building the hit record is skipped entirely when no debugger is connected, which
is one relaxed atomic load on that path.
Verified against a running game, all three kinds. The memory case shows why the
address/range split matters - accessed address 200540160 against a watched range
starting at 200941120, with source "ThreadFillStack" identifying the HLE call
responsible.
libretro gets stubs: it builds Core.cpp and Breakpoints.cpp but not
Core/Debugger/WebSocket.cpp.
pspautotests 314/314, UnitTest 55/55.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZq8ZtJmFY7bkX5FVkr3P9
The struct and its API only handle GPR indices today, but the naming
should stay general since this is expected to grow to cover other
register files too (e.g. FPU registers like $f10). Pure rename - no
behavior change:
- Core/Debugger/Breakpoints.{h,cpp}: RegBreakpoint struct, all
BreakpointManager Add/Remove/Change/Get/Exec/Has/Find*RegBreakpoint*
methods, regBreakpoints_/regBreakpointMask_ members.
- Core/Core.{h,cpp}: BreakReason::RegBreakpoint, "cpu.regBreakpoint"
break-reason string.
- Core/Debugger/WebSocket/BreakpointSubscriber.{h,cpp}: WebSocket
events cpu.gprBreakpoint.* -> cpu.regBreakpoint.*, matching
Add/Update/Remove/List handlers and params struct.
- Core/MIPS/MIPSTables.cpp: local variable names in the interpreter's
per-instruction breakpoint check.
- docs/WebSocketDebugger.md updated to match.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZq8ZtJmFY7bkX5FVkr3P9
New debugging primitive: break whenever any instruction writes to a
given general-purpose register (0-31), regardless of which address
executes the write. Requested for continuing the reboot.bin trace,
where the actual blocker is "what sets $s3 to this bad value", not
"what happens at a specific address" - existing address/memory
breakpoints can't express that directly.
- GPRBreakpoint (Core/Debugger/Breakpoints.h) mirrors the existing
BreakPoint/MemCheck shape (result/condition/logFormat/hit count),
keyed by register index instead of address/range.
- BreakpointManager keeps a u32 bitmask (bit i = register i has an
active breakpoint) alongside the GPRBreakpoint vector, so the
interpreter loop can test "would this write trip anything" with a
single shift+and against a value already cached in a local.
- RunUntilDowncountZeroWithChecks (Core/MIPS/MIPSTables.cpp) computes
the about-to-be-written register from the current instruction's
OUT_RT/OUT_RD/OUT_RA flags (GetGPRWriteTarget()) and checks it
against the mask, same convention as the existing memcheck handling
right above it (checked before the instruction executes, bails via
CORE_STEPPING_CPU without running it if tripped).
- New BreakReason::GPRBreakpoint ("cpu.gprBreakpoint") for Core_Break.
- WebSocket API: cpu.gprBreakpoint.add/update/remove/list, accepting
either a 0-31 'register' index or a case-insensitive 'name' (e.g.
"s3"), documented in docs/WebSocketDebugger.md.
Interpreter-only for now, deliberately.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZq8ZtJmFY7bkX5FVkr3P9
