Re: gdb Digest 26 Mar 2003 19:03:48 -0000 Issue 1129

[Jim Ingham <jingham@apple.com>]

Andrew,

Addressing this problem - driven by the needs of C++ developers - is 
something I was lobbying for time to do during this release cycle.  But 
it got put off in favor of solving performance issues in gdb instead.  
However, for the next one (starting post June) release cycle I will 
probably get more time to look at this.

I don't think we can just hide the physical breakpoints from the user 
however.  It would be very useful to be able to say

(gdb) break FileFullOfTemplates.cc:27

then decide that "no you weren't interested in the int specialization 
only the double one", or whatever...  So being able to peer into the 
contents of the user-lever breakpoint is a good thing.  OTOH, I should 
certainly be able to disable this breakpoint and not hit it for any 
variant...

Jim

On Wednesday, March 26, 2003, at 11:03  AM, 
gdb-digest-help@sources.redhat.com wrote:

>
> (Put simply, the things you learn when reading a book explaining how a 
> debugger should work :-)
>
> The `How Debuggers Work' [rosenberg] book describes a breakpoint 
> implementation broken into two parts:
>
> - high level user breakpoint list
> This is what the user sees.  One entry corresponds to each `break XXX' 
> command.  That high level breakpoint then maps onto 1 or more ...
>
> - low level physical breakpoints (or watchpoints or ...)
> One entry per physical breakpoint.  When a breakpoint is hit, a 
> reverse map back to each high-level breakpoint for the event is done, 
> and then that breakpoint's handler is called.
>
> I might be mistaken, but I don't think GDB implemented things this 
> way.  Instead, it has a single tangled table.
>
> Andrew
>
>
--
Jim Ingham                                   jingham@apple.com
Developer Tools
Apple Computer