Re: [RFC][PATCH 0/6] Step program considering the source column information

[Pedro Alves <palves@redhat.com>]

Hi,

Cool!  A few years back, Antoine Tremblay prototyped this
as well, but it only worked with Clang, because back then
GCC didn't output column information.  I complained about it
to Jakub Jelinek, who in his usual awesomeness quickly implemented
GCC support.  :-)  Quite nice that we're finally getting closer to
actually making use of it in GDB.

You can still find Antoine's prototype here:

 https://github.com/hexa00/binutils-gdb/commits/statement-stepping

It would likely be interesting if you could take a look and compare
approaches.  You should be able to borrow any code you find useful, since
he was working for Ericsson at the time, and had a copyright assignment.

On the name of the new commands -- for a user, thinking in terms
"step until next column" doesn't make sense IMO.  What the user really wants
is "step until next statement".  Column information in the debug
info enables this, but it's an implementation detail.
In Antoine's version, he thus had "nexts" instead of "nextc", which
sounds better to me:

  add_com ("nexts", class_run, nexts_command, _("\
Step program by statement, proceeding through subroutine calls.\n\
Usage: nexts [N]\n\
Unlike \"steps\", if the current source line calls a subroutine,\n\
this command does not enter the subroutine, but instead steps over\n\
the call, in effect treating it as a single statement."));
  add_com_alias ("ns", "nexts", class_run, 1);

Thanks,
Pedro Alves