Re: [petsc-users] Compile issue

[Sanjay Govindjee via petsc-users]

Thanks Mark. It dawned on me to Gemini my problem just after I posted it. I switched to .F90 and the problem resolved itself.  -sanjay Sent from my iPhone On May 8, 2026, at 4:52 AM, Mark Adams <mfad...@lbl.gov> wrote:  Result from (cut and paste into) Claude:  ## Diagnosis The compile error is caused by **fixed-form Fortran line truncation at column 72**. Your file `parstop.F` uses the `.F` extension, which tells `gfortran` to use **fixed-form** parsing (72-column limit by default). In PETSc 3.25, the [`PetscObjectIsNull`](include/petsc/finclude/petscsysbase.h:132) macro expanded significantly. It is now defined as: ```fortran #define PetscObjectIsNull(obj) (obj%v == 0 .or. obj%v == PETSC_FORTRAN_TYPE_INITIALIZE .or. obj%v == -3) ``` When the preprocessor expands `PetscObjectIsNull(Mdiag)`, the resulting line is far longer than 72 characters and gets truncated mid-_expression_, producing the syntax error. The compiler warnings confirm this: ``` parstop.F:64:72: Warning: Line truncated at (1) [-Wline-truncation] ``` ## Solution: Rename `.F` to `.F90` **Rename `parstop.F` → `parstop.F90`** (and do the same for any other `.F` files that use `PetscObjectIsNull`). Your code is already written in free-form Fortran style (`!` comments, `::` declarations, `implicit none`), so the `.F` extension is misleading. The `.F90` extension will: 1. Invoke the C preprocessor (uppercase `F` is preserved) 2. Use **free-form** parsing (132-column default limit) 3. Work with your existing `-ffree-line-length-none` flag, which removes the line length limit entirely This is the cleanest fix and requires no code changes — only a file rename. ### Alternative: Keep `.F` and add a compiler flag If renaming is not feasible, add `-ffixed-line-length-none` to your `mpif90` flags to remove the 72-column truncation for fixed-form files. On Thu, May 7, 2026 at 6:26 PM Sanjay Govindjee via petsc-users <petsc-users@mcs.anl.gov> wrote: I am trying to update our code to petsc 3.25.1.  We were previously on 3.22.4.  I am running into a compile error that I can not understand.  I went through the release notes but can not see what is wrong.  Any suggestions will be appreciated. -sanjay /Users/sg/petsc/gnu/bin/mpif90 -o parstop.o -c -fPIC -Wall -ffree-line-length-none -ffree-line-length-0 -Wno-lto-type-mismatch -Wno-unused-dummy-argument -g -O   -I/Users/sg/petsc/include -I/Users/sg/petsc/gnu/include -I/opt/X11/include -I/Users/sg/Feap/ver87/include -I/Users/sg/Feap/ver87/modules -I/usr/local/include -J/Users/sg/Feap/ver87/modules       parstop.F parstop.F:64:72:    64 |       if(.not.PetscObjectIsNull(Mdiag)) then       |                                                                        1 Warning: Line truncated at (1) [-Wline-truncation] parstop.F:64:70:    64 |       if(.not.PetscObjectIsNull(Mdiag)) then       |                                                                      1 Error: Syntax error in IF-clause after (1) parstop.F:66:9:    66 |       endif       |         1 Error: Expecting END SUBROUTINE statement at (1) parstop.F:68:72:    68 |       if(.not.PetscObjectIsNull(Msqrt)) then       |                                                                        1 Warning: Line truncated at (1) [-Wline-truncation] parstop.F:68:70:    68 |       if(.not.PetscObjectIsNull(Msqrt)) then       |                                                                      1 Error: Syntax error in IF-clause after (1) parstop.F:70:9:    70 |       endif       |         1 Error: Expecting END SUBROUTINE statement at (1) The subroutine is super simple: #     include   <petsc/finclude/petscksp.h>       use                       petscksp       use                       pfeapc       implicit   none #     include   "pfeapb.h"       PetscErrorCode ierr       logical     :: eflag       save !     Close out PETSc matrices       if(.not.PetscObjectIsNull(Kmat)) then         call MatDestroy(Kmat, ierr)       endif       if(.not.PetscObjectIsNull(Pmat)) then         call MatDestroy(Pmat, ierr)       endif       if(.not.PetscObjectIsNull(Mmat)) then         call MatDestroy(Mmat, ierr)       endif       if(pfeap_dstr) then         call KSPDestroy(kspsol, ierr)       endif !     Close out PETSc vectors       if(.not.PetscObjectIsNull(Mdiag)) then         call VecDestroy(Mdiag, ierr)       endif       if(.not.PetscObjectIsNull(Msqrt)) then         call VecDestroy(Msqrt, ierr)       endif The custom module pfeapc contains the objects:       module pfeapc #     include   <petsc/finclude/petscksp.h>       use                       petscksp       implicit none       Vec          :: rhs, sol, xvec       Vec          :: yvec, zvec       Vec          :: Mdiag, Msqrt       Mat          :: Kmat, Mmat, Pmat       KSP          :: kspsol       end module pfeapc ------