[PATCH] Restore terminal state in mi_thread_exit (PR gdb/17627)

[Simon Marchi]

On 2014-11-25 04:59 PM, Sergio Durigan Junior wrote:
> On Tuesday, November 25 2014, Simon Marchi wrote:
> 
>> When a thread exits, the terminal is left in mode "terminal_is_ours"
>> while the target executes. This patch fixes that.
>>
>> From my understanding, a function calling target_terminal_ours expects
>> that the terminal could be in any state at the moment it is called.
>> Therefore, it should be its reponsibility to put back the terminal in
>> whatever state it was before being called.
>>
>> I find that this fits quite well the cleanup model, so I implemented a
>> cleanup for that.
> 
> Thanks for the patch.  A few comments related to the coding style and
> cleanups.
> 
>> gdb/ChangeLog:
>>
>> 2014-11-25  Simon Marchi  <simon.marchi@ericsson.com>
>>
>> 	PR gdb/17627
>> 	* target.c (cleanup_restore_target_terminal): New function.
>> 	(make_cleanup_restore_target_terminal): New function.
>> 	* target.h (make_cleanup_restore_target_terminal): New
>> 	declaration.
>> 	* mi/mi-interp.c (mi_thread_exit): Use the new cleanup.
>>
>> Signed-off-by: Simon Marchi <simon.marchi@ericsson.com>
>> ---
>>  gdb/mi/mi-interp.c |  4 ++++
>>  gdb/target.c       | 30 ++++++++++++++++++++++++++++++
>>  gdb/target.h       |  4 ++++
>>  3 files changed, 38 insertions(+)
>>
>> diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
>> index df2b558..2a62e22 100644
>> --- a/gdb/mi/mi-interp.c
>> +++ b/gdb/mi/mi-interp.c
>> @@ -386,6 +386,7 @@ mi_thread_exit (struct thread_info *t, int silent)
>>  {
>>    struct mi_interp *mi;
>>    struct inferior *inf;
>> +  struct cleanup *old_chain;
>>  
>>    if (silent)
>>      return;
>> @@ -393,11 +394,14 @@ mi_thread_exit (struct thread_info *t, int silent)
>>    inf = find_inferior_pid (ptid_get_pid (t->ptid));
>>  
>>    mi = top_level_interpreter_data ();
>> +  old_chain = make_cleanup_restore_target_terminal();
> 
> Space between function name and ().
> 
>>    target_terminal_ours ();
>>    fprintf_unfiltered (mi->event_channel, 
>>  		      "thread-exited,id=\"%d\",group-id=\"i%d\"",
>>  		      t->num, inf->num);
>>    gdb_flush (mi->event_channel);
>> +
>> +  do_cleanups(old_chain);
> 
> Likewise.
> 
>>  }
>>  
>>  /* Emit notification on changing the state of record.  */
>> diff --git a/gdb/target.c b/gdb/target.c
>> index ab5f2b9..d6a06bd 100644
>> --- a/gdb/target.c
>> +++ b/gdb/target.c
>> @@ -528,6 +528,36 @@ target_supports_terminal_ours (void)
>>    return 0;
>>  }
>>  
>> +static void cleanup_restore_target_terminal (void *arg)
>               ^
> Break the line here.
> 
> New functions should have a comment describing them.
> 
>> +{
>> +  enum terminal_state *previous_state = arg;
>> +
>> +  switch (*previous_state)
>> +  {
>> +    case terminal_is_ours:
>> +      target_terminal_ours();
>> +      break;
>> +    case terminal_is_ours_for_output:
>> +      target_terminal_ours_for_output();
>> +      break;
>> +    case terminal_is_inferior:
>> +      target_terminal_inferior();
>> +      break;
> 
> The "case" should be indented below the "{".
> 
> Missing whitespace between function names and ().
> 
>> +  }
>> +
>> +  xfree(previous_state);
> 
> Likewise.
> 
>> +}
>> +
>> +struct cleanup *
>> +make_cleanup_restore_target_terminal (void)
> 
> Missing function comment.  Since you already described this one on the
> header file, you can just say:
> 
>   /* See definition in target.h.  */
> 
>> +{
>> +  enum terminal_state *ts = xmalloc(sizeof(*ts));
> 
> Whitespace between function name and ().
> 
>> +
>> +  *ts = terminal_state;
>> +
>> +  return make_cleanup (cleanup_restore_target_terminal, ts);
> 
> You should use make_cleanup_dtor here, because "ts" may leak if the
> cleanup is not called.
> 
>> +}
>> +
>>  static void
>>  tcomplain (void)
>>  {
>> diff --git a/gdb/target.h b/gdb/target.h
>> index d363b61..a1c3b7b 100644
>> --- a/gdb/target.h
>> +++ b/gdb/target.h
>> @@ -1413,6 +1413,10 @@ extern void target_terminal_ours (void);
>>  
>>  extern int target_supports_terminal_ours (void);
>>  
>> +/* Make a cleanup that restores the state of the terminal to the current
>> + * value. */
> 
> You just need to use "*" after and before the "/" in comments:
> 
>   /* This is a
>      multi-line
>      comment.  */
> 
> It's also missing two spaces after period.
> 
>> +extern struct cleanup *make_cleanup_restore_target_terminal (void);
>> +
>>  /* Print useful information about our terminal status, if such a thing
>>     exists.  */
>>  
>> -- 
>> 2.1.3

Oops, I had missed your reply. Thanks for the review, I just sent a V2.

Simon