Best way to check whether the "sim" is running standalone or by GDB

Best way to check whether the "sim" is running standalone or by GDB

[William Tambe]

What is the best way to check whether the "sim" is running standalone
or by GDB ?

Re: Best way to check whether the "sim" is running standalone or by GDB

[William Tambe]

To clarify further my question, I would like to be able to issue the
following only when the sim is being run by GDB:
sim_engine_halt (sim_stopped, SIM_SIGTRAP);

On Wed, Aug 28, 2019 at 9:15 PM William Tambe <tambewilliam@gmail.com> wrote:
>
> What is the best way to check whether the "sim" is running standalone
> or by GDB ?

Re: Best way to check whether the "sim" is running standalone or by GDB

[Nick Clifton]

Hi William,

>> What is the best way to check whether the "sim" is running standalone
>> or by GDB ?

Possibly not the best way, but one way is to use a global variable to 
indicate the presence of the standalone driver.  eg:

  int running_standalone = 0;

  ...
    if (! running_standalone)
      sim_engine_halt (sim_stopped, SIM_SIGTRAP);

Then in your standalone code, initialise the variable to non-zero.

Cheers
  Nick

Re: Best way to check whether the "sim" is running standalone or by GDB

[William Tambe]

On Fri, Aug 30, 2019 at 4:54 AM Nick Clifton <nickc@redhat.com> wrote:
>
> Hi William,
>
> >> What is the best way to check whether the "sim" is running standalone
> >> or by GDB ?
>
> Possibly not the best way, but one way is to use a global variable to
> indicate the presence of the standalone driver.  eg:
>
>   int running_standalone = 0;
>
>   ...
>     if (! running_standalone)
>       sim_engine_halt (sim_stopped, SIM_SIGTRAP);
>
> Then in your standalone code, initialise the variable to non-zero.

What constitute the standalone code ?

in fact, to port the simulator, I only had to implement the following:
sim_engine_run ()
sim_open ()
sim_create_inferior ()

All the above functions are both used when the sim is running
"standalone" or by "GDB".

Is there another function I can define that will only be used when the
sim is running "standalone" ?

>
> Cheers
>   Nick
>
>
>
>

Re: Best way to check whether the "sim" is running standalone or by GDB

[Nick Clifton]

Hi William,

> What constitute the standalone code ?> 
> in fact, to port the simulator, I only had to implement the following:
> sim_engine_run ()
> sim_open ()
> sim_create_inferior ()
> 
> All the above functions are both used when the sim is running
> "standalone" or by "GDB".
> 
> Is there another function I can define that will only be used when the
> sim is running "standalone" ?

Presumably you are using a Makefile.in like the other simulators.
In there you define SIM_RUN_OBJS to contain the object files that
are only part of the standalone simulator.  So you could use a 
function in one of those object files.  main() would be the obvious
choice, if you are using your own.  Or else something called from
the main() defined in common/nrun.c.

Cheers
  Nick

Re: Best way to check whether the "sim" is running standalone or by GDB

[Mike Frysinger]

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On 28 Aug 2019 21:15, William Tambe wrote:
> What is the best way to check whether the "sim" is running standalone
> or by GDB ?

this is the point of SIM_OPEN_KIND.  it is set to SIM_OPEN_DEBUG when
gdb (a debugger) is used, and SIM_OPEN_STANDALONE when it's not.
-mike

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Re: Best way to check whether the "sim" is running standalone or by GDB

[Michael Morrell]

William,

> What is the best way to check whether the "sim" is running standalone or by GDB ?

In sim_open, the first parameter is "SIM_OPEN_KIND kind".  When sim_open is called in standalone (i.e., from nrun.c), this parameter is SIM_OPEN_STANDALONE) and when called from GDB, it is SIM_OPEN_DEBUG.  This can be saved and checked later.

A typical call in sim_open is:

SIM_DESC sd = sim_state_alloc(kind, callback);

which saves kind in the sd structure.  You can use STATE_OPEN_KIND(sd) to examine it in any function that receives an "sd".

Hope this helps.

   Michael