[Bug fortran/102885] New: [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto

[Bug fortran/102885] New: [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102885

            Bug ID: 102885
           Summary: [12 Regression] ICE when compiling
                    gfortran.dg/bind_c_char_10.f90 with -flto
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dominiq at lps dot ens.fr
                CC: burnus at gcc dot gnu.org, hubicka at gcc dot gnu.org,
                    iains at gcc dot gnu.org, sandra at gcc dot gnu.org
  Target Milestone: ---

The test gfortran.dg/bind_c_char_10.f90 ICE when compiled with -flto:

lto1: internal compiler error: Segmentation fault: 11
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.
lto-wrapper: fatal error: gfc returned 1 exit status
compilation terminated.
collect2: fatal error: lto-wrapper returned 1 exit status
compilation terminated.

Reduced test:

module m
  use iso_c_binding, only: c_char
  implicit none (type, external)

contains

! Assumed-shape array, nonallocatable/nonpointer

subroutine ar3 (xn, n) bind(C)
  integer :: n
  character(len=n) :: xn(..)
  if (size(xn) /= 6) stop
  if (len(xn) /= 5) stop  
  select rank(xn)
    rank(1)
      xn = ['FDGhf', &
            'hdrhg', &
            'fDgFl', &
            'DFHs3', &
            '4a54G', &
            'hSs6k']
  rank default
    stop
  end select
end

end

program main
  use m
  implicit none (type, external)
  character(kind=c_char, len=5) :: str5a6(6)

  ! assumed rank - with array descriptor

  str5a6 = ['DDGhf', &
            'hdrh$', &
            'fDGSl', &
            'DFHs3', &
            '43grG', &
            'hFG$k']
  call ar3 (str5a6, 5)

end

All the other tests compile with -flto.

[Bug fortran/102885] [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102885

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |11.2.1
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-10-22
   Target Milestone|---                         |12.0

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.

We've streamed an SSA name in the BLOCK part of a function - that's very likely
a missing DECL_EXPR and thus a SSA name in TYPE_SIZE or so.

We may want to add IL verification for this to catch this earlier.

[Bug fortran/102885] [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto since r12-4467-g64f9623765da3306

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102885

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marxin at gcc dot gnu.org
            Summary|[12 Regression] ICE when    |[12 Regression] ICE when
                   |compiling                   |compiling
                   |gfortran.dg/bind_c_char_10. |gfortran.dg/bind_c_char_10.
                   |f90 with -flto              |f90 with -flto since
                   |                            |r12-4467-g64f9623765da3306

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r12-4467-g64f9623765da3306.

[Bug fortran/102885] [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto since r12-4467-g64f9623765da3306

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102885

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Further reduced testcase:

module m
  use iso_c_binding, only: c_char, c_size_t
  implicit none (type, external)
contains
subroutine ar3 (xn, n) bind(C)
  integer(c_size_t), intent(in) :: n
  character(len=n) :: xn(..)
  select rank(xn)
    rank(1)
      xn(1:1) = ['FDGhf']
  end select
end
end

Works if I add "VALUE :: n", i.e. 'n' is passed by value instead of by
reference.

[Bug fortran/102885] [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto since r12-4467-g64f9623765da3306

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102885

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tobias Burnus <burnus@gcc.gnu.org>:

https://gcc.gnu.org/g:a31a3d0421f0cf1f7eefacfec8cbf37e7f91600d

commit r12-4703-ga31a3d0421f0cf1f7eefacfec8cbf37e7f91600d
Author: Tobias Burnus <tobias@codesourcery.com>
Date:   Tue Oct 26 10:53:53 2021 +0200

    Fortran: Fix character(len=cst) dummies with bind(C) [PR102885]

            PR fortran/102885

    gcc/fortran/ChangeLog:

            * trans-decl.c (gfc_conv_cfi_to_gfc): Properly handle nonconstant
            character lenghts.

    gcc/testsuite/ChangeLog:

            * gfortran.dg/lto/bind-c-char_0.f90: New test.

[Bug fortran/102885] [12 Regression] ICE when compiling gfortran.dg/bind_c_char_10.f90 with -flto since r12-4467-g64f9623765da3306

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102885

Tobias Burnus <burnus at gcc dot gnu.org> changed:

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

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> ---
FIXED – thanks all for the report and the help!