[Bug fortran/38802] New: Seg fault for RESULT with allocatable components

[Bug fortran/38802] New: Seg fault for RESULT with allocatable components

[pault at gcc dot gnu dot org]

Posted on the list by Marco Restelli http://gcc.gnu.org/ml/fortran/2009-01/

$ gfortran test.f90 -o test
$ ./test
Segmentation fault

$ gfortran --version
GNU Fortran (GCC) 4.4.0 20090110 (experimental) [trunk revision 143243]

System:
Linux 2.6.23-gentoo-r6 x86_64 AMD Turion(tm) 64 Mobile Technology
ML-32 AuthenticAMD GNU/Linux


module mod_a
 implicit none
 public :: a_fun, t_1, t_2
 private

 type t_1
  real :: coeff
 end type t_1

 type t_2
  type(t_1), allocatable :: mons(:)
 end type t_2

contains

 function a_fun(r) result(p)
 integer, intent(in) :: r

 type(t_2) :: p(r+1)
 ! Using an allocatable works
 !type(t_2), allocatable :: p(:)
 ! allocate(p(r+1))

 write(*,*) 'shape(p) is ', shape(p)

 end function a_fun

end module mod_a

A workaround is to not use the RESULT variable.  The code shows that the result
is being nullified before its upper bound is established.

Paul  
program test
 use mod_a, only: a_fun, t_1, t_2
 implicit none
 type(t_2) x(1)

 x = a_fun(0)
end program test


-- 
           Summary: Seg fault for RESULT with allocatable components
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pault at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38802

[Bug fortran/38802] Seg fault for RESULT with allocatable components

[dominiq at lps dot ens dot fr]

------- Comment #1 from dominiq at lps dot ens dot fr  2009-01-11 13:26 -------
Confirmed on i686-apple-darwin9 with -m64 or -m32 with optimization -O1 and
above:

Thread 0 Crashed:
0   a.out                               0x00001dec __mod_a_MOD_a_fun + 30
1   a.out                               0x00001daf MAIN__ + 141
2   a.out                               0x00001f98 main + 40
3   a.out                               0x00001cf6 start + 54


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38802

[Bug fortran/38802] Seg fault for RESULT with allocatable components

[pault at gcc dot gnu dot org]

------- Comment #2 from pault at gcc dot gnu dot org  2009-01-12 06:21 -------
This does the job:
Index: gcc/fortran/trans-array.c
===================================================================
--- gcc/fortran/trans-array.c   (revision 143242)
+++ gcc/fortran/trans-array.c   (working copy)
@@ -5733,7 +5733,7 @@
     }

   /* Dummy and use associated variables don't need anything special.  */
-  if (sym->attr.dummy || sym->attr.use_assoc)
+  if (sym->attr.dummy || sym->attr.use_assoc || sym->attr.result)
     {
       gfc_add_expr_to_block (&fnblock, body);

Paul


-- 

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|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-01-12 06:21:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38802

[Bug fortran/38802] Seg fault for RESULT with allocatable components

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2009-04-08 17:28 -------
Commit log went to the wrong PR:

Author: pault
Date: Wed Apr  8 08:59:34 2009
New Revision: 145714

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145714
Log:
2009-04-08  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/38863
        * trans-array.c (gfc_trans_deferred_array): Return if this
        is a result variable.

2009-04-08  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/38863
        * gfortran.dg/alloc_comp_result_1.f90: New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/alloc_comp_result_1.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38802

[Bug fortran/38802] Seg fault for RESULT with allocatable components

[pault at gcc dot gnu dot org]

------- Comment #4 from pault at gcc dot gnu dot org  2009-04-19 15:03 -------
Fixed on trunk.

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=38802