Re: [PATCH] Disable get_ptrace_pid for NetBSD

[Simon Marchi <simark@simark.ca>]

On 2020-03-18 12:29 p.m., Kamil Rytarowski wrote:
> Unlike most other Operating Systems, NetBSD tracks both pid and lwp.
> The process id on NetBSD is stored always in the pid field of ptid.
> 
> gdb/ChangeLog:
> 
> 	* inf-ptrace.h: Disable get_ptrace_pid on NetBSD.
> 	* inf-ptrace.c: Likewise.
> 	* (inf_ptrace_target::resume): Update.
> 	* (inf_ptrace_target::xfer_partial): Likewise.
> ---
>  gdb/ChangeLog    |  7 +++++++
>  gdb/inf-ptrace.c | 19 +++++++++++++++++--
>  gdb/inf-ptrace.h |  2 ++
>  3 files changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 84964dc00ac..36e333ec8ba 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,10 @@
> +2020-03-18  Kamil Rytarowski  <n54@gmx.com>
> +
> +	* inf-ptrace.h: Disable get_ptrace_pid on NetBSD.
> +	* inf-ptrace.c: Likewise.
> +	* (inf_ptrace_target::resume): Update.
> +	* (inf_ptrace_target::xfer_partial): Likewise.
> +
>  2020-03-17  Kamil Rytarowski  <n54@gmx.com>
> 
>  	* regformats/regdef.h: Put reg in gdb namespace.
> diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
> index db17a76d946..e8bf66ed45f 100644
> --- a/gdb/inf-ptrace.c
> +++ b/gdb/inf-ptrace.c
> @@ -313,8 +313,12 @@ inf_ptrace_target::kill ()
>    target_mourn_inferior (inferior_ptid);
>  }
> 
> +#ifndef __NetBSD__
>  /* Return which PID to pass to ptrace in order to observe/control the
> -   tracee identified by PTID.  */
> +   tracee identified by PTID.
> +
> +   Unlike most other Operating Systems, NetBSD tracks both pid and lwp
> +   and avoids this function.  */
> 
>  pid_t
>  get_ptrace_pid (ptid_t ptid)
> @@ -328,6 +332,7 @@ get_ptrace_pid (ptid_t ptid)
>      pid = ptid.pid ();
>    return pid;
>  }
> +#endif
> 
>  /* Resume execution of thread PTID, or all threads if PTID is -1.  If
>     STEP is nonzero, single-step it.  If SIGNAL is nonzero, give it
> @@ -344,7 +349,13 @@ inf_ptrace_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
>         single-threaded processes, so simply resume the inferior.  */
>      pid = inferior_ptid.pid ();
>    else
> -    pid = get_ptrace_pid (ptid);
> +    {
> +#ifdef __NetBSD__
> +      pid = ptid. pid();
> +#else
> +      pid = get_ptrace_pid (ptid);
> +#endif
> +    }

To avoid the ifdefs in this more complex code, can't you use a gdb_ptrace function like in
the other patches?  This time, it would look like:

static int
gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr,
	    PTRACE_TYPE_ARG4 data)
{
#ifdef __NetBSD__
  return ptrace (request, ptid.pid (), addr, data);
#else
  pid_t pid = get_ptrace_pid (ptid);
  return ptrace (request, pid, addr, data);
#endif
}

Simon