[Bug fortran/104391] New: Gfortran 9 regression with bind(C) and allocatable or pointer attribute

[Bug fortran/104391] New: Gfortran 9 regression with bind(C) and allocatable or pointer attribute

[michael at scivision dot dev]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

            Bug ID: 104391
           Summary: Gfortran 9 regression with bind(C) and allocatable or
                    pointer attribute
           Product: gcc
           Version: 9.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: michael at scivision dot dev
  Target Milestone: ---

The `bind(C)` on a procedure appears to break `pointer` and `allocatable`
attributes of a variable with regard to index start. Specifically, on exiting a
procedure with `bind(c)`, the variable(s) have their indices shifted to
zero-based.

example that works with GCC <= 8.5 and GCC 12 (broken for GCC 9, 10, 11).

```
program test_bounds
use iso_fortran_env, only : error_unit
implicit none

real, allocatable :: a(:)
integer :: L1,L2, U1,U2
allocate(a(1:2))

L1 = lbound(a,1)
U1 = ubound(a,1)
call c_bounder(a)
L2 = lbound(a,1)
U2 = ubound(a,1)

if (L1 /= L2 .or. U1 /= U2) then
  write(error_unit, '(a,2i2,a,2i2)') 'FAIL: bounds changed before/after
lower:', L1,L2, " upper: ", U1,U2
  error stop
endif

print '(a)', "bounds check OK"

contains

subroutine c_bounder(a) bind(c)
real,  intent(inout) :: a(:)
end subroutine c_bounder

end program
```

[Bug fortran/104391] [9/10/11 Regression] bind(C) and allocatable or pointer attribute don't work

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |9.5
           Keywords|                            |needs-bisection, wrong-code
            Summary|Gfortran [9,10,11]          |[9/10/11 Regression]
                   |regression with bind(C) and |bind(C) and allocatable or
                   |allocatable or pointer      |pointer attribute don't
                   |attribute                   |work

[Bug fortran/104391] [9/10/11 Regression] bind(C) and allocatable or pointer attribute don't work

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=92189

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Maybe PR 92189.

[Bug fortran/104391] [9/10/11 Regression] bind(C) and allocatable or pointer attribute don't work

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4

[Bug fortran/104391] [9/10/11 Regression] bind(C) and allocatable or pointer attribute don't work

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-02-22
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |burnus at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org,
                   |                            |pault at gcc dot gnu.org

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Fixed on master with r12-2511-g0cbf03689e3e7d9d, started with
r9-5372-gbbf18dc5d248a79a.

[Bug fortran/104391] [10/11 Regression] bind(C) and allocatable or pointer attribute don't work

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug fortran/104391] [10/11 Regression] bind(C) and allocatable or pointer attribute don't work

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug fortran/104391] [11 Regression] bind(C) and allocatable or pointer attribute don't work

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.

[Bug fortran/104391] [11 Regression] bind(C) and allocatable or pointer attribute don't work

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104391

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #6 from Paul Thomas <pault at gcc dot gnu.org> ---
(In reply to Martin Liška from comment #2)
> Fixed on master with r12-2511-g0cbf03689e3e7d9d, started with
> r9-5372-gbbf18dc5d248a79a.

Yes, indeed.

Thanks, Martin.