Re: [PATCH] run > file for win32

[Pierre Muller <muller@cerbere.u-strasbg.fr>]

> >To sort the events and only handles those of the process that you want
> >to debug you use saw_create variable.
>
>IMO, the right way to handle this is to inspect the name of each process
>as it is created.  That presents some interesting difficulties, however.
>It means that gdb has to understand how the shell will find the executable,
>however.
>
>Alternatively, gdb could detect the transition from shell -> program where
>the pid stays the same.  Hmm.  I think that would be the most foolproof.

But that is not the case... the windows pid does change when you pass from the 
shell to the debuggee. My patch is even based on that change.

>I'll try to come up with some kind of solution to this that uses your method
>plus the above.  It will probably take a couple of days, though.

As the win32 API clearly says that the lpImageName field of the
CREATE_PROCESS_DEBUG_EVENT can be null,
this is not an option.

May I suggest using GetFileInformationByHandle
function?

  If you open the file in the child_create_inferior function
and leave it open until the program is killed or exits,
then the nFileIndexHigh,nFileIndexLow and dwVolumeSerialNumber
identifies uniquely the file.
Using the handle given by the CREATE_PROCESS_DEBUG_EVENT
and calling again GetFileInformationByHandle
should be able to check if the correct file is used.

Remarks:
   -- if a different file (in some other dir) is found,
it will need to be handled somehow...

   -- Even with my patch, there is still a 
problem: the shell does not exit (because 
there is one more ContinueDebugEvent needed to 
the shell exit also, that is at least the feeling I had...)
So after runnig the same program 10 times, you have got 10 zomby shells.

  -- I don't know if this is a problem with my configuration,
but the getenv("SHELL") returns NULL in _initialize_inftarg 
while I do have SHELL=/bin/bash
in the bash that I use as shell...

  --  This reminds me of one more question:
do all shells accept  "exec" command and -c option ?
  
   -- We need to be very careful about the different handles that I given
by the different events, failing to close some might 
result in problems later.

  Finally, wouldn't it be wise to set the default value of useshell to 0
until this problem is fixed?
Currently the variable is set to 1 in _initialize_inftarg
if a shell is found.



Pierre Muller
Institut Charles Sadron
6,rue Boussingault
F 67083 STRASBOURG CEDEX (France)
mailto:muller@ics.u-strasbg.fr
Phone : (33)-3-88-41-40-07  Fax : (33)-3-88-41-40-99