[Bug fortran/113883] New: allocatable length parameter used but is undefined

[Bug fortran/113883] New: allocatable length parameter used but is undefined

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113883

            Bug ID: 113883
           Summary: allocatable length parameter used but is undefined
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kargl at gcc dot gnu.org
  Target Milestone: ---

All,

I stumbled across the following issue with my code.  Consider, 

! { dg-do compile }
! { dg-options "-Werror -Wall" }
module foo
   contains
      subroutine bar 
         character(len=:), allocatable :: s(:)
         call bah(s)
      end subroutine bar
end module foo

Currently, if this compiled with '-Werror -Wall' the result is

% gfcx -Wall -Werror -c gcc/testsuite/gfortran.dg/allocatable_length.f90
gcc/testsuite/gfortran.dg/allocatable_length.f90:6:46:

    6 |          character(len=:), allocatable :: s(:)
      |                                              ^
Error: '.s' is used uninitialized [-Werror=uninitialized]
gcc/testsuite/gfortran.dg/allocatable_length.f90:5:20:

    5 |       subroutine bar
      |                    ^
note: '.s' was declared here
f951: all warnings being treated as errors

I tracked down the location where the issue occurs and Mikael suggested
the patch that ultimately fixes the issue.  I'll attach it in a follow-up.

[Bug fortran/113883] allocatable length parameter used but is undefined

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113883

--- Comment #1 from kargl at gcc dot gnu.org ---
Created attachment 57389
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57389&action=edit
patch to fix bug

This is the patch and testcase.  I have successfully bootstrapped
and run the Fortran regression tests without issues.

[Bug fortran/113883] allocatable length parameter used but is undefined

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113883

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2024-02-12
             Status|UNCONFIRMED                 |NEW
           Priority|P3                          |P4

[Bug fortran/113883] allocatable length parameter used but is undefined

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113883

Jerry DeLisle <jvdelisle at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jvdelisle at gcc dot gnu.org

--- Comment #2 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
I should be able to commit this. The patch looks good.  I have one other thing
to do in front of this.

[Bug fortran/113883] allocatable length parameter used but is undefined

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113883

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Jerry DeLisle <jvdelisle@gcc.gnu.org>:

https://gcc.gnu.org/g:6caec7d9ec37e60e718a12934c85bac9c12757ac

commit r14-8947-g6caec7d9ec37e60e718a12934c85bac9c12757ac
Author: Steve Kargl <kargl@gcc.gnu.org>
Date:   Mon Feb 12 20:41:02 2024 -0800

    Fortran: Set the length of an allocatable character

            PR fortran/113883

    gcc/fortran/ChangeLog:

            * trans-array.cc (gfc_trans_deferred_array): Set length to zero,
            avoiding extraneous diagnostics.

    gcc/testsuite/ChangeLog:

            * gfortran.dg/allocatable_length.f90: New test.

[Bug fortran/113883] allocatable length parameter used but is undefined

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113883

--- Comment #4 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Tue, Feb 13, 2024 at 04:51:02AM +0000, cvs-commit at gcc dot gnu.org wrote:
> The trunk branch has been updated by Jerry DeLisle <jvdelisle@gcc.gnu.org>:
> 
> https://gcc.gnu.org/g:6caec7d9ec37e60e718a12934c85bac9c12757ac
> 

Thanks, Jerry.