C:\FPC\SVN\fpc_2.6.4\rtl\win\wininc\defines.inc

line 5669 (in 3.6.4)
{ our own invention }

      FLAG_TRACE_BIT = $100;

This is only there for 32 bit and wince, but not for win64.

But the problem is finding out what it actually means. All googling has not brought any definition to it.

From usage in old code in fpdebug, it is given as flag to

   Context^.EFlags := Context^.EFlags or FLAG_TRACE_BIT;
   if not SetThreadContext(Handle, Context^)

An ideas?

http://en.wikipedia.org/wiki/FLAGS_register

It's a trap (single-step) flag. to stop after each instruction. (IIRC with some exceptions).
I'd think it should be AMD64 compatible.

thanks,
Dmitry

To add to that.

*nixes are using ptrace() function and PTRACE_SINGLESTEP request. I do believe that setting EFlag (FLAG_TRACE_BIT for x86 machines) would work for *nix systems (didn't try myself), but respecting defined API is always a better approach.

thanks,
Dmitry

On Mon, Mar 31, 2014 at 9:58 PM, Dmitry Boyarintsev <

I was mainly about win64.
I had mainly googled it as an argument to the windows API (which was where I had found it in fpdebug code), and I found nothing on msdn.

Anyway, If it exists for 64 bits, should/can it be added to rtl\win\wininc\defines.inc same as it is for 32 bit?

1) it's not part of originating Windows headers (if these are used as part of RTL definitions) - keep the base header as small as possible.
2) The flag itself is very debugging specific. Thus the declaration should go with either separate debugging package or more specific CPU definition header (not necessarily debugging related).

The idea here is to be as "component" as possible, rather than put everything into a single ready for anything RTL (that would bloat it a lot).

thanks,
Dmitry