[Bug fortran/36526] New: pointer in pure function

[Bug fortran/36526] New: pointer in pure function

[aradi at bccms dot uni-bremen dot de]

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Hi, 

 I discovered a problem with gfortran 4.3.1 when compiling code with pure
function with pointer argument. Inside the pure function, the argument is
passed further to an other function. This seems to work, as long this other
function is an intrinsic function, but seems to fail for user defined pure
functions. The effect is demonstrated by the code below.

  Best regards,

    Bálint

--------------------------------------------------------
module TestPure
  implicit none

  type T1
    character(10) :: str
  end type T1

contains

  pure function getT1Len(self) result(t1len)
    type(T1), pointer :: self
    integer :: t1len

    t1len = getStrLen(self%str)
    !t1len = len_trim(self%str)   ! <- this would work

  end function getT1Len


  pure function getStrLen(str) result(length)
    character(*), intent(in) :: str
    integer :: length

    length = len_trim(str)

  end function getStrLen

end module TestPure


program Test
  use TestPure
  implicit none

  type(T1), pointer :: pT1

  allocate(pT1)
  pT1%str = "test"
  write (*,*) getT1Len(pT1)
  deallocate(pT1)

end program Test
------------------------------------------------------


-- 
           Summary: pointer in pure function
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: aradi at bccms dot uni-bremen dot de
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2008-06-13 17:52 -------
CONFIRM. Works with other compilers. The constraint checked for is:

"C1272 In a pure subprogram any designator with a base object that is in common
or accessed by host or use association, is a dummy argument of a pure function,
is a dummy argument with INTENT (IN) of a pure subroutine, or an object that is
storage associated with any such variable, shall not be used in the following
contexts: [...]
(5) As an actual argument associated with a dummy argument with INTENT (OUT) or
INTENT (INOUT) or with the POINTER attribute." (From F2003.)

At a glance, it seems as if this applies, but as the non-normative note
indicates, C1272 does not apply in this case:

"NOTE 12.45  Pure subroutines are included to allow subroutine calls from pure
procedures in a safe way [...] The constraints for pure subroutines are
based on the same principles as for pure functions, except that side effects to
INTENT (OUT), INTENT (INOUT), and pointer dummy arguments are permitted."

However, I failed to find this in the normative part; I will try a bit more to
figure out why C1272 does not apply.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |rejects-valid
   Last reconfirmed|0000-00-00 00:00:00         |2008-06-13 17:52:34
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[pault at gcc dot gnu dot org]

------- Comment #2 from pault at gcc dot gnu dot org  2008-06-20 10:43 -------
(In reply to comment #1)
This is due to an error in interface.c.  The following fixes the fault,
bootstraps and regtests OK.  I will apply as obvious just as soon as I can.

Paul

Index: gcc/fortran/interface.c
===================================================================
*** gcc/fortran/interface.c     (revision 136870)
--- gcc/fortran/interface.c     (working copy)
*************** check_intents (gfc_formal_arglist *f, gf
*** 2379,2385 ****
              return FAILURE;
            }

!         if (a->expr->symtree->n.sym->attr.pointer)
            {
              gfc_error ("Procedure argument at %L is local to a PURE "
                         "procedure and has the POINTER attribute",
--- 2379,2385 ----
              return FAILURE;
            }

!         if (f->sym->attr.pointer)
            {
              gfc_error ("Procedure argument at %L is local to a PURE "
                         "procedure and has the POINTER attribute",


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pault at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-06-13 17:52:34         |2008-06-20 10:43:30
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[pault at gcc dot gnu dot org]

------- Comment #3 from pault at gcc dot gnu dot org  2008-06-25 23:05 -------
Subject: Bug 36526

Author: pault
Date: Wed Jun 25 23:04:33 2008
New Revision: 137125

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=137125
Log:
2008-06-25  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/36526
        * interface.c (check_intents):  Correct error where the actual
        arg was checked for a pointer argument, rather than the formal.

2008-06-25  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/36526
        * gfortran.dg/proc_formal_proc_2.f90: New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/pure_formal_proc_2.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[jv244 at cam dot ac dot uk]

------- Comment #4 from jv244 at cam dot ac dot uk  2008-08-08 22:23 -------
this bug seems fixed in 4.4.0, should it be closed?


-- 

jv244 at cam dot ac dot uk changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[pault at gcc dot gnu dot org]

------- Comment #5 from pault at gcc dot gnu dot org  2008-11-18 10:01 -------
(In reply to comment #4)
> this bug seems fixed in 4.4.0, should it be closed?
> 

Joost,

I forgot the PR and missed your prompt - I'll apply it to 4.3 and close it.

Thanks

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[pault at gcc dot gnu dot org]

------- Comment #6 from pault at gcc dot gnu dot org  2008-11-27 22:21 -------
Subject: Bug 36526

Author: pault
Date: Thu Nov 27 22:20:27 2008
New Revision: 142248

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=142248
Log:
2008-11-27  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/36526
        * interface.c (check_intents):  Correct error where the actual
        arg was checked for a pointer argument, rather than the formal.

2008-11-27  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/36526
        * gfortran.dg/pure_formal_proc_2.f90: New test.


Added:
    branches/gcc-4_3-branch/gcc/testsuite/gfortran.dg/pure_formal_proc_2.f90
Modified:
    branches/gcc-4_3-branch/gcc/fortran/ChangeLog
    branches/gcc-4_3-branch/gcc/fortran/interface.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526

[Bug fortran/36526] pointer in pure function

[pault at gcc dot gnu dot org]

------- Comment #7 from pault at gcc dot gnu dot org  2008-11-27 22:23 -------
Fixed on trunk and 4.3.

Thanks for the report.

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36526