breakpoint insert API (was: A patch for ia32 hardware watchpoint.)

[Andrew Cagney]

"J.T. Conklin" wrote:

> Todd> So I would have to argue that the singlestep logic must either
> Todd> happen at a really low level (this guarantees it will patch last
> Todd> and un-patch first) or must go through the real breakpoint logic
> Todd> which can do duplicate detection.
> 
> The SOFTWARE_SINGLE_STEP() macro is called at a low enough level that
> it inserts and remove trap instructions without effecting GDB's high-
> level breakpoints.  So I think we're OK.  As a result, I wouldn't be
> suprised if steping into a breakpoint didn't behave the same as on a
> machine with hardware single-step.

Its got long-term problems.

The code assumes that it is going to retain control, blocked on the
target, while the actual step is performed.
This doesn't work well within a pure event model where control is ment
to return to the event-loop when ever the target is resumed.

	enjoy,
		Andrew