[Bug fortran/38471] New: [4.3/4.4 Regression] ICE on pointer assignment of nested derived-type component

[Bug fortran/38471] New: [4.3/4.4 Regression] ICE on pointer assignment of nested derived-type component

[burnus at gcc dot gnu dot org]

Reported at
http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/bf908dba87ce677a


Valgrind shows:
==10280== Invalid read of size 8
==10280==    at 0x4B67E2: gfc_trans_pointer_assignment (trans-expr.c:4076)
==10280==    by 0x4956AF: gfc_trans_code (trans.c:1111)
==10280==    by 0x4AD5FB: gfc_generate_function_code (trans-decl.c:3887)


trans-expr.c is:
  4066            if (expr1->symtree->n.sym->attr.subref_array_pointer)
  4067              {
  4068                decl = expr1->symtree->n.sym->backend_decl;
  4069                gfc_init_se (&rse, NULL);
  4070                rse.descriptor_only = 1;
  4071                gfc_conv_expr (&rse, expr2);
  4072                tmp = gfc_get_element_type (TREE_TYPE (rse.expr));
  4073                tmp = fold_convert (gfc_array_index_type, size_in_bytes
(tmp));
  4074                if (!INTEGER_CST_P (tmp))
  4075                  gfc_add_block_to_block (&lse.post, &rse.pre);
  4076                gfc_add_modify (&lse.post, GFC_DECL_SPAN(decl), tmp);
  4077              }



module test
  implicit none
  !===================================================
  type b
    integer :: j
  end type b
  !===================================================
  type a
    type(b), dimension(4) :: i
  end type a
  !===================================================
contains
  !===================================================
  subroutine test_sub(sorb,ipn)
    type(a), intent(in), target :: sorb
    integer, dimension(:), pointer :: ipn

    ipn=>sorb%i%j
  end subroutine test_sub
  !===================================================
end module test


-- 
           Summary: [4.3/4.4 Regression] ICE on pointer assignment of nested
                    derived-type component
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org
OtherBugsDependingO 32834
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE on pointer assignment of nested derived-type component

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE on pointer assignment of nested derived-type component

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2008-12-10 15:35 -------
More information. The problem is:
  GFC_DECL_SPAN(decl)
which accesses
  DECL_LANG_SPECIFIC(node)->span
however, DECL_LANG_SPECIFIC(node) == NULL as can be seen below.

(gdb) p decl->decl_common.lang_specific
$15 = (struct lang_decl *) 0x0
(gdb) pt decl->decl_common.lang_specific
type = struct lang_decl {
    tree saved_descriptor;
    tree stringlen;
    tree addr;
    tree span;
} *


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2008-12-10 18:08 -------
Paul, do you have an idea?

span is set in trans-decl.c's gfc_get_symbol_decl:

  if (sym->attr.subref_array_pointer)
    {
      [...]
      GFC_DECL_SPAN (decl) = span;

I wondered whether in gfc_check_pointer_assign the attr.subref_array_pointer is
set, but I indeed see:
(gdb) p lvalue->symtree->n.sym->attr.subref_array_pointer
$7 = 1


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pault at gcc dot gnu dot org
            Summary|[4.3/4.4 Regression] ICE on |[4.3/4.4 Regression] ICE
                   |pointer assignment of nested|with subreference pointer
                   |derived-type component      |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer where pointer is a DUMMY argument

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2008-12-10 18:25 -------
OK. I found it, though I'm not sure yet how to solve it best (maybe something
else needs to be moved up as well?) - and I won't have time to work on this the
next day(s?).

gfc_get_symbol_decl (gfc_symbol * sym)
[...]
  if ((sym->attr.dummy && ! sym->attr.function) || (sym->attr.result && byref))
    {
      // We enter here as the POINTER is a DUMMY
      [...]
      return sym->backend_decl;
    }
[...]
  if (sym->attr.subref_array_pointer)
    {
      tree span;


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.3/4.4 Regression] ICE    |[4.3/4.4 Regression] ICE
                   |with subreference pointer   |with subreference pointer
                   |                            |where pointer is a DUMMY
                   |                            |argument


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[burnus at gcc dot gnu dot org]

------- Comment #4 from burnus at gcc dot gnu dot org  2008-12-11 10:12 -------
    integer, dimension(:), pointer :: ipn
    ipn=>sorb%i%j

I tried it with ipn being no dummy argument and it crashes as well.

And I forgot to write the name of the initial reporter in comment 0. The credit
for finding the bug goes to Sudeep Punnathanam.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.3/4.4 Regression] ICE    |[4.3/4.4 Regression] ICE
                   |with subreference pointer   |with subreference pointer
                   |where pointer is a DUMMY    |assignment
                   |argument                    |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[pault at gcc dot gnu dot org]

------- Comment #5 from pault at gcc dot gnu dot org  2008-12-11 10:52 -------
Tobias,

It's a bit tough to call it a regression, since the earlier versions of
gfortran produced wrong code.

Is this worth fixing for 4.4? If we get the array descriptor business sorted
out, it should go away.

Cheers

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-12-11 10:52:06
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[pault at gcc dot gnu dot org]

------- Comment #6 from pault at gcc dot gnu dot org  2008-12-11 11:21 -------
This cures the ICE and allows correct code within the subroutine.  'span' is
not transferred in the call and so wrong code is produced if the pointer is
subsequently used in the caller.

I can apply it if you like.

Paul

Sorry about the rudimentary diff - the VMware images do not carry much by way
of developer's tools.

trans-decl.c

1012,1030d1011
< 
<       if (sym->attr.subref_array_pointer
<           && DECL_LANG_SPECIFIC (sym->backend_decl) == NULL)
<       gfc_allocate_lang_decl (sym->backend_decl);
< 
<       if (sym->attr.subref_array_pointer
<           && GFC_DECL_SPAN (sym->backend_decl) == NULL)
<       {
<         tree span;
<         GFC_DECL_SUBREF_ARRAY_P (sym->backend_decl) = 1;
<         span = build_decl (VAR_DECL, create_tmp_var_name ("span"),
<                            gfc_array_index_type);
<         gfc_finish_var_decl (span, sym);
<         TREE_STATIC (span) = TREE_STATIC (sym->backend_decl);
<         DECL_ARTIFICIAL (span) = 1;
<         DECL_INITIAL (span) = build_int_cst (gfc_array_index_type, 0);
< 
<         GFC_DECL_SPAN (sym->backend_decl) = span;
<       }


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[burnus at gcc dot gnu dot org]

------- Comment #7 from burnus at gcc dot gnu dot org  2008-12-11 16:18 -------
Created an attachment (id=16885)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16885&action=view)
pointer_assign_7.f90 - a test cae

As fj pointed out: This PR might be a duplicate of PR 34640. The patch looks
quite similar (identical?). The attached test case works when "type b" does not
contain "character :: c" and fails if it does.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[pault at gcc dot gnu dot org]

------- Comment #8 from pault at gcc dot gnu dot org  2008-12-22 21:55 -------
All routes to deal with this are way too invasive for this stage in the
proceedings.  This PR must wait for the array descriptor upgrade, so I am
suspending it for now.

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |SUSPENDED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4 Regression] ICE with subreference pointer assignment

[burnus at gcc dot gnu dot org]

-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.3.3                       |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] [4.3/4.4/4.5 Regression] ICE with subreference pointer assignment

[pault at gcc dot gnu dot org]

-- 

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|SUSPENDED                   |ASSIGNED
   Last reconfirmed|2008-12-11 10:52:06         |2009-04-04 12:49:17
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] ICE with subreference pointer assignment

[pault at gcc dot gnu dot org]

------- Comment #9 from pault at gcc dot gnu dot org  2009-07-10 17:33 -------
I never accepted this to be a regression and now, when it is the only one, I
feel that it is time to register that :-)  It will, of course, be dealt with
once I attack the array descriptor business.  ice-on-invalid-code gives it
quite enough importance.

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.3/4.4/4.5 Regression] ICE|ICE with subreference
                   |with subreference pointer   |pointer assignment
                   |assignment                  |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] ICE with subreference pointer assignment

[rguenth at gcc dot gnu dot org]

------- Comment #10 from rguenth at gcc dot gnu dot org  2010-04-06 11:19 -------
GCC 4.5.0 is being released.  Deferring to 4.5.1.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.5.0                       |4.5.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] ICE with subreference pointer assignment

[dfranke at gcc dot gnu dot org]

------- Comment #11 from dfranke at gcc dot gnu dot org  2010-05-18 22:26 -------
As commented multiple times in PR34640, given the similarity of the testcase,
the identical backtrace and the same assignee ...


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471

[Bug fortran/38471] ICE with subreference pointer assignment

[dfranke at gcc dot gnu dot org]

------- Comment #12 from dfranke at gcc dot gnu dot org  2010-05-18 22:28 -------
(In reply to comment #11)
> As commented multiple times in PR34640, given the similarity of the testcase,
> the identical backtrace and the same assignee ...



*** This bug has been marked as a duplicate of 34640 ***


-- 

dfranke at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38471