[Bug fortran/47523] New: Wrong length in I/O deferred allocatable scalar character

[Bug fortran/47523] New: Wrong length in I/O deferred allocatable scalar character

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

           Summary: Wrong length in I/O deferred allocatable scalar
                    character
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: tkoenig@gcc.gnu.org
                CC: pault@gcc.gnu.org


Hi Paul,

sorry to be the first one to find a bug in your really cool
deferred length allocatable scalars.

Test case:

ig25@linux-fd1f:~/Krempel/Char-alloc> cat foo.f90
program main
  implicit none
  character(:), allocatable :: a, b
  a = 'a'
  print '(A)', a
  a = a // 'x'
  print '(A,A)',a
  print *,len(a)
end program main
ig25@linux-fd1f:~/Krempel/Char-alloc> gfortran foo.f90
ig25@linux-fd1f:~/Krempel/Char-alloc> ./a.out
a
a
           2

Output should be

a
ax
           2

The last line shows the length is correct, maybe it's just the
interaction with the library.  I will investigate a bit more.

[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

Thomas Koenig <tkoenig at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Wrong length in I/O         |Concatenation with deferred
                   |deferred allocatable scalar |length character with lhs
                   |character                   |variable

--- Comment #1 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2011-01-28 20:58:49 UTC ---
Actually, it isn't a wrong length, the problem was an
invisible nul character in the output.

Look at this:

program main
  implicit none
  integer :: i
  character(:), allocatable :: a, b, c
  a = 'a'
  a = a // 'x'
  b = 'b'
  c = b // 'x'
  write (*,*) 'a is:'
  do i=1,len(a)
    write (*,*) ichar(a(i:i))
  end do

  write (*,*) 'c is:'
  do i=1,len(c)
     write (*,*) ichar(c(i:i))
  end do
end program main
ig25@linux-fd1f:~/Krempel/Char-alloc> gfortran bar.f90
ig25@linux-fd1f:~/Krempel/Char-alloc> ./a.out
 a is:
          97
           0
 c is:
          98
         120

The expression a = a // 'x' gets the wrong value for x.

[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-01-28 21:04:40 UTC ---
I think I/O is OK - the issue is probably the same as PR 47519: Mishandling of
intrinsic operations. Though, this case looks a bit different than the other
PR.

void
concat_string (gfc_charlen_type destlen, CHARTYPE * dest,
               gfc_charlen_type len1, const CHARTYPE * s1,
               gfc_charlen_type len2, const CHARTYPE * s2)

But for   a = a // 'x'


        if (a != 0B) goto L.3;
        L.3:;
        a = (character(kind=1)[1:.a] *) __builtin_realloc ((void *) a,
(<unnamed-unsigned:64>) (.a + 1));
        L.4:;
        .a = .a + 1;
        D.1536 = (.a + 1) * 64;
        D.1537 = (void * restrict) __builtin_malloc (MAX_EXPR
<(<unnamed-unsigned:64>) D.1536, 1>);
        pstr.0 = (character(kind=1)[1:] *) D.1537;
        _gfortran_concat_string (.a + 1, pstr.0, .a, a, 1, &"x"[1]{lb: 1 sz:
1});

Thus, one first allocates "a", increments the length and then uses as "s1"
argument to the intrinsic. That cannot work ...

[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.01.29 14:58:37
         AssignedTo|unassigned at gcc dot       |pault at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #3 from Paul Thomas <pault at gcc dot gnu.org> 2011-01-29 14:58:37 UTC ---
I have a patch cooking - thanks for the report Thomas!

Paul

[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

--- Comment #4 from Paul Thomas <pault at gcc dot gnu.org> 2011-01-30 17:50:07 UTC ---
Author: pault
Date: Sun Jan 30 17:50:01 2011
New Revision: 169413

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169413
Log:
2011-01-30  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/47523
    * trans-expr.c (gfc_trans_assignment_1): If the rhs is an op
    expr and is assigned to a deferred character length scalar,
    make sure that the function is called before reallocation,
    so that the length is available. Include procedure pointer
    and procedure pointer component rhs as well.

2011-01-30  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/47523
    * trans-expr.c (gfc_trans_assignment_1): If the rhs is an op
    expr and is assigned to a deferred character length scalar,
    make sure that the function is called before reallocation,
    so that the length is available. Include procedure pointer
    and procedure pointer component rhs as well.

    PR fortran/45170
    PR fortran/35810
    PR fortran/47350
    * gfortran.dg/allocatable_function_5.f90: New test not added by
    mistake on 2011-01-28.



Added:
    trunk/gcc/testsuite/gfortran.dg/allocatable_function_5.f90
    trunk/gcc/testsuite/gfortran.dg/realloc_on_assign_5.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

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

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

--- Comment #5 from Paul Thomas <pault at gcc dot gnu.org> 2011-01-30 17:56:22 UTC ---
Fixed on trunk.

Thanks, Thomas :-)

Cheers

Paul

[Bug fortran/47523] Concatenation with deferred length character with lhs variable

[dnovillo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47523

--- Comment #6 from Diego Novillo <dnovillo at gcc dot gnu.org> 2011-02-02 18:04:31 UTC ---
Author: dnovillo
Date: Wed Feb  2 18:04:21 2011
New Revision: 169697

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169697
Log:
2011-01-30  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/47523
    * trans-expr.c (gfc_trans_assignment_1): If the rhs is an op
    expr and is assigned to a deferred character length scalar,
    make sure that the function is called before reallocation,
    so that the length is available. Include procedure pointer
    and procedure pointer component rhs as well.

2011-01-30  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/47523
    * trans-expr.c (gfc_trans_assignment_1): If the rhs is an op
    expr and is assigned to a deferred character length scalar,
    make sure that the function is called before reallocation,
    so that the length is available. Include procedure pointer
    and procedure pointer component rhs as well.

    PR fortran/45170
    PR fortran/35810
    PR fortran/47350
    * gfortran.dg/allocatable_function_5.f90: New test not added by
    mistake on 2011-01-28.

Added:
   
branches/google/integration/gcc/testsuite/gfortran.dg/allocatable_function_5.f90
   
branches/google/integration/gcc/testsuite/gfortran.dg/realloc_on_assign_5.f03
Modified:
    branches/google/integration/gcc/fortran/ChangeLog
    branches/google/integration/gcc/fortran/trans-expr.c
    branches/google/integration/gcc/testsuite/ChangeLog