Re: [PATCH v3 0/1] PR20684, preserve user selected context when invoking MI commands

[Jan Vrany <jan.vrany@labware.com>]

Polite ping. 

Jan

On Thu, 2022-01-27 at 14:50 +0000, Jan Vrany wrote:
> This is a next version of the patch fixing some regression
> 
> Changes since previous iteration [1]:
> 
> * updates to accomodate new C++ification of MI commands pushed in
> December last year.
> * updates to handle cases pointed out by Simon
> * add testcase
> 
> Changes since v1:
> 
> * address Simon's comments [2]
> * add more tests for -stack-select-frame
> 
> Changes since v2:
> 
> Fix regression in mi-nonstop.exp and mi-nsthrexec.exp. This
> was caused by extra user selected thread notification being sent
> when resuming a thread like:
> 
>  -exec-continue --thread 2
> 
> The culprit was this part of mi_excecute_command ():
> 
>          else if (inferior_ptid != null_ptid)
>            {
>              struct thread_info *ti = inferior_thread ();
> 
>              report_change = (ti->global_num != command->thread);
>            }
> 
> This "else" is only executed when command specifies --thread.
> 
> Imagine currently selected thread is thread 1 and -exec-continue --thread 2
> is issued.
> 
> BEFORE applying this patch, no change would be reported because mi_cmd_execute ()
> would switch the thread to thread 2 so `ti->global_num != command->thread` would
> be false.
> 
> AFTER appling this patch, mi_cmd_execute () would switch the thread *and then restore*
> back so `ti->global_num != command->thread` would be true.
> 
> Therefore I removed this whole `else if` branch: since mi_cmd_execute () now restores
> the thread if --thread is passed (except few limited commands that notify themselves),
> this condition would hold each time thread passed to --thread is different than current
> thread. Removing it preserves the behavior.
> 
> Removing that "else if" branch allowed me to merge two nested ifs into one to (hopefully)
> make the code simpler.
> 
> Thanks!
> 
> Jan
> 
> 
> [1]: https://sourceware.org/pipermail/gdb-patches/2021-February/175897.html
> 
> 
> Jan Vrany (1):
>   gdb/mi: PR20684, preserve user selected thread and frame when invoking
>     MI commands
> 
>  gdb/mi/mi-cmds.h                             |  12 ++
>  gdb/mi/mi-main.c                             |  54 ++++---
>  gdb/testsuite/gdb.mi/mi-cmd-user-context.exp | 155 +++++++++++++++++++
>  3 files changed, 198 insertions(+), 23 deletions(-)
>  create mode 100644 gdb/testsuite/gdb.mi/mi-cmd-user-context.exp
>