[gambit-list] How do you use "___print_ctrl_flow_history" in GDB - where do you get the ___ps from?

Marc Feeley feeley at iro.umontreal.ca
Wed Jan 20 17:35:24 EST 2016


In gdb you need to do

call log_ctrl_flow_history

to generate the control-flow history in the gambit.log file.

However, you have to configure Gambit with --enable-debug so that the code keeps track of the control flow history.

To get the processor state with gdb, it all depends on how Gambit was built.  With --enable-multiple-threaded-vms and/or --enable-multiple-vms there can be more than one processor state.  But if those options aren’t used (the default), then the only processor state will be at the head of the only virtual machine state structure, which is at the head of the global state structure (accessible with ___gstate0).  I’ve never tried it before, but this is what I got:

% gdb gsi
...
(gdb) run
Gambit v4.8.3

> 
Program received signal SIGINT, Interrupt.
0x00007fff950e1176 in select$DARWIN_EXTSN ()
   from /usr/lib/system/libsystem_kernel.dylib
(gdb) print ___gstate0
$1 = 18939960

Marc

> On Jan 20, 2016, at 4:46 PM, Adam <adam.mlmb at gmail.com> wrote:
> 
> Dear Marc,
> 
> How do I actually run "___print_ctrl_flow_history" from a GDB prompt such as the one below?
> 
> I have access to global vars, can I pick up the needed ___ps argument from there, or do I need to make an own facility for knowing what ___ps value to use here?
> 
> E.g. "call ___print_ctrl_flow_history(123456 )"
> 
> Thanks!
> 
> $ gdb ./gsc/gsc
> GNU gdb (GDB) 7.4.1-debian
> Copyright (C) 2012 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> Reading symbols from /tmp/gambit/gsc/gsc...done.
> (gdb) run
> Starting program: /tmp/gambit/gsc/gsc
> Gambit v4.8.3
> 
> > 1 2 3
> 1
> > 2
> > 3
> >
> Program received signal SIGINT, Interrupt.
> 0x00007ffff6f81433 in select () from /lib/x86_64-linux-gnu/libc.so.6
> (gdb)
> 




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