Fwd: [PATCH V2 3/4] Work around bootstrap failure in Fortran front end.

[Thomas Koenig]

Hi,

the change looks good to me, OK for master.

Regards

	Thomas
> This arose from work by Sandra on "Unify C and C++ handling of loops and 
> switches"
> 
> Kind regards,
> Toon.
> 
> -------- Forwarded Message --------
> Subject: [PATCH V2 3/4] Work around bootstrap failure in Fortran front end.
> Date: Thu, 13 Aug 2020 10:34:31 -0600
> From: Sandra Loosemore <sandra@codesourcery.com>
> To: gcc-patches@gcc.gnu.org
> 
> Switching the C++ front end to lower loops the same was as the C front
> end triggered this error when bootstrapping the Fortran front end:
> 
> /path/to/gcc/fortran/interface.c:3546:12: error: '*new_arg' may be used 
> uninitialized [-Werror=maybe-uninitialized]
>   3546 |   new_arg[i]->next = NULL;
>        |   ~~~~~~~~~^
> 
> Work around this by adding an assertion, which seems appropriate for
> documentation and good coding practices anyway.
> 
> 2020-08-12  Sandra Loosemore  <sandra@codesourcery.com>
> 
>      gcc/fortran/
>      * interface.c (gfc_compare_actual_formal): Add assertion after
>      main processing loop to silence maybe-uninitialized error.
> ---
>   gcc/fortran/interface.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/gcc/fortran/interface.c b/gcc/fortran/interface.c
> index 7985fc7..9fea94c 100644
> --- a/gcc/fortran/interface.c
> +++ b/gcc/fortran/interface.c
> @@ -3527,6 +3527,10 @@ gfc_compare_actual_formal (gfc_actual_arglist 
> **ap, gfc_formal_arglist *formal,
>       }
>       }
>   +  /* We should have handled the cases where the formal arglist is null
> +     already.  */
> +  gcc_assert (n > 0);
> +
>     /* The argument lists are compatible.  We now relink a new actual
>        argument list with null arguments in the right places.  The head
>        of the list remains the head.  */