Pass kind argument to add_hw_watchpoint

[bet4it]

Currently, when we add watchpoint, kind is ignored:

gdbstub/src/gdbstub_impl/ext/breakpoints.rs

Lines 19 to 32 in a33bbae

	let addr =
	<T::Arch as Arch>::Usize::from_be_bytes(cmd.addr).ok_or(Error::TargetMismatch)?;
	let kind =
	<T::Arch as Arch>::BreakpointKind::from_usize(cmd.kind).ok_or(Error::TargetMismatch)?;
	let handler_status = match cmd_kind {
	CmdKind::Add => {
	use crate::target::ext::breakpoints::WatchKind::*;
	let supported = match cmd.type_ {
	0 => (ops.sw_breakpoint()).map(|op| op.add_sw_breakpoint(addr, kind)),
	1 => (ops.hw_breakpoint()).map(|op| op.add_hw_breakpoint(addr, kind)),
	2 => (ops.hw_watchpoint()).map(|op| op.add_hw_watchpoint(addr, Write)),
	3 => (ops.hw_watchpoint()).map(|op| op.add_hw_watchpoint(addr, Read)),
	4 => (ops.hw_watchpoint()).map(|op| op.add_hw_watchpoint(addr, ReadWrite)),

But according to gdb rsp doc, kind when set watchpoint means number of bytes to watch, which is not meaningless:

‘Z2,addr,kind’
    Insert (‘Z2’) or remove (‘z2’) a write watchpoint at addr. The number of bytes to watch is specified by kind. 

We need also pass kind as an argument to add_hw_watchpoint.

[daniel5151]

Well, this is embarrassing 😳
I'm surprised that I didn't catch this when I plumbed-through BreakpointKind support to software/hardware watchpoints... Oops.

In any case, thanks for reporting this discrepancy!
I'll land a fix in the dev/0.6 branch that updates the add_hw_watchpoint function signature appropriately (hopefully sometime this weekend).

Since this will require an API breaking change, it will also require a breaking gdbstub release. That's not too bad, as there've been enough breaking changes trickling into the dev/0.6 branch that I'll probably end up publishing 0.6 sometime relatively soon-ish. I don't have an exact timeline yet, but I'd wager 0.6 will be up on crates.io sometime in the next few weeks.

[daniel5151]

I've pushed a fix to the dev/0.6 branch.