Re: [PATCH 4/5] gdb: add inferior parameter to target_find_description

[Simon Marchi <simon.marchi@polymtl.ca>]

> @@ -546,16 +545,22 @@ target_find_description (void)
>    if (!tdesc_info->filename.empty ())
>      tdesc_info->tdesc = file_read_description_xml (tdesc_info->filename.data ());
>  
> +  /* The calls that get the target description from the target depend on INF
> +     being the current inferior, and some targets need a specific thread to
> +     be selected.  */
> +  scoped_restore_current_thread restore_thread;
> +  thread_info *thread = any_thread_of_inferior (inf);
> +  gdb_assert (thread != nullptr);
> +  switch_to_thread (thread);
Sorry, looks like I messed up my testing, this doesn't work when using
the "set tdesc filename" command while there are no threads:


 37 (gdb) set tdesc filename /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.arch/arc-tdesc-cpu/trivial.xml^M
 38 /home/smarchi/src/binutils-gdb/gdb/thread.c:631: internal-error: any_thread_of_inferior: Assertion `inf->pid != 0' failed.^M
 39 A problem internal to GDB has been detected,^M
 40 further debugging may prove unreliable.^M
 41 ----- Backtrace -----^M
 42 FAIL: gdb.arch/arc-tdesc-cpu.exp: set tdesc filename /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.arch/arc-tdesc-cpu/trivial.xml (GDB internal error)

I made it this way because the remote target uses inferior_ptid to set
the general thread in remote_target::xfer_partial, regardless of the
object.  For TARGET_OBJECT_AVAILABLE_FEATURES, since target descriptions
are a per-inferior thing (for now), it could look at the current
inferior instead, it doesn't really need a current thread.  This is part
of my larger work that I picked these patches from, so I will have to
re-check the order of the changes.

Simon