[RFA,v2,23/24] Use gdb_argv in Python

  This changes one spot in the Python code to use gdb_argv.  This
removes the last cleanup from the Python layer.

ChangeLog
2017-07-25  Tom Tromey  <tom@tromey.com>

	* python/py-param.c (compute_enum_values): Use gdb_argv.
---
 gdb/ChangeLog         |  4 ++++
 gdb/python/py-param.c | 24 +++++++-----------------
 2 files changed, 11 insertions(+), 17 deletions(-)
  

On 2017-07-25 19:21, Tom Tromey wrote:
> This changes one spot in the Python code to use gdb_argv.  This
> removes the last cleanup from the Python layer.
> 
> ChangeLog
> 2017-07-25  Tom Tromey  <tom@tromey.com>
> 
> 	* python/py-param.c (compute_enum_values): Use gdb_argv.
> ---
>  gdb/ChangeLog         |  4 ++++
>  gdb/python/py-param.c | 24 +++++++-----------------
>  2 files changed, 11 insertions(+), 17 deletions(-)
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 7dcc95e..4168f39 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,5 +1,9 @@
>  2017-07-25  Tom Tromey  <tom@tromey.com>
> 
> +	* python/py-param.c (compute_enum_values): Use gdb_argv.
> +
> +2017-07-25  Tom Tromey  <tom@tromey.com>
> +
>  	* utils.h (struct gdb_argv_deleter): New.
>  	(gdb_argv): New class.
>  	* utils.c (gdb_argv::reset): New method.
> diff --git a/gdb/python/py-param.c b/gdb/python/py-param.c
> index f0d3423..455c99e 100644
> --- a/gdb/python/py-param.c
> +++ b/gdb/python/py-param.c
> @@ -555,7 +555,6 @@ static int
>  compute_enum_values (parmpy_object *self, PyObject *enum_values)
>  {
>    Py_ssize_t size, i;
> -  struct cleanup *back_to;
> 
>    if (! enum_values)
>      {
> @@ -581,36 +580,27 @@ compute_enum_values (parmpy_object *self,
> PyObject *enum_values)
>        return 0;
>      }
> 
> -  self->enumeration = XCNEWVEC (const char *, size + 1);
> -  back_to = make_cleanup (free_current_contents, &self->enumeration);
> +  gdb_argv holder (XCNEWVEC (char *, size + 1));
> +  char **enumeration = holder.get ();
> 
>    for (i = 0; i < size; ++i)
>      {
>        gdbpy_ref<> item (PySequence_GetItem (enum_values, i));
> 
>        if (item == NULL)
> -	{
> -	  do_cleanups (back_to);
> -	  return 0;
> -	}
> +	return 0;
>        if (! gdbpy_is_string (item.get ()))
>  	{
> -	  do_cleanups (back_to);
>  	  PyErr_SetString (PyExc_RuntimeError,
>  			   _("The enumeration item not a string."));
>  	  return 0;
>  	}
> -      self->enumeration[i]
> -	= python_string_to_host_string (item.get ()).release ();
> -      if (self->enumeration[i] == NULL)
> -	{
> -	  do_cleanups (back_to);
> -	  return 0;
> -	}
> -      make_cleanup (xfree, (char *) self->enumeration[i]);
> +      enumeration[i] = python_string_to_host_string (item.get 
> ()).release ();
> +      if (enumeration[i] == NULL)
> +	return 0;
>      }
> 
> -  discard_cleanups (back_to);
> +  self->enumeration = const_cast<const char**> (holder.release ());
>    return 1;
>  }

LGTM.