[Bug fortran/48360] New: ICE on array assignment statement with allocatable LHS

[Bug fortran/48360] New: ICE on array assignment statement with allocatable LHS

[krefson at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

           Summary: ICE on array assignment statement with allocatable LHS
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: krefson@googlemail.com


Created attachment 23816
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23816
Fortran 95 source which gives ICE on compilation attempt.

The attached code gives an ICE when compiled with gfortran 4.6.0 

$ gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/gcc-4.6/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-4.6-source/gcc-4.6-20110312/configure
--enable-languages=c,c++,fortran --enable-checking=release --disable-bootstrap
--disable-libmudflap --enable-libgomp --enable-lto --enable-gold
--with-plugin-ld=/usr/bin/gold --prefix=/usr/local/gcc-4.6
Thread model: posix
gcc version 4.6.0 20110312 (experimental) (GCC) 

$ gfortran -c gf46-ice.f90
gf46-ice.f90: In function ‘assignit’:
gf46-ice.f90:19:0: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Fine with 4.4.3 and 4.5

Disabling the possibility of "allocate-on-assignment" by changing

   hmat = mmv%h0

to
   hmat(:,:) = mmv%h0

compiles correctly.

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
                 CC|                            |burnus at gcc dot gnu.org,
                   |                            |pault at gcc dot gnu.org
   Target Milestone|---                         |4.6.1
            Summary|ICE on array assignment     |[4.6/4.7 Regression] ICE on
                   |statement with allocatable  |array assignment statement
                   |LHS                         |with allocatable LHS

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-03-30 11:55:51 UTC ---
(In reply to comment #0)
> Disabling the possibility of "allocate-on-assignment" by changing
[...]

Or simply use: -fno-realloc-lhs


With my - admittedly not clean - tree, that gives the following valgrind
output:

Invalid read of size 8
    at 0x56B13A: get_std_lbound (trans-array.c:6825)
    by 0x573E88: gfc_alloc_allocatable_for_assignment (trans-array.c:7083)
    by 0x58EBDB: gfc_trans_assignment_1 (trans-expr.c:6186)

That's the lines:

6822      else if (expr->expr_type == EXPR_VARIABLE)
6823        {
6824          tmp = TREE_TYPE (expr->symtree->n.sym->backend_decl);
6825          return GFC_TYPE_ARRAY_LBOUND(tmp, dim);

The issue is that
  TYPE_LANG_SPECIFIC (tmp) == tmp->type.lang_specific == NULL
and, thus, accessing TYPE_LANG_SPECIFIC(node)->lbound[dim]  gives an ICE.

The issue is that for "mmv%h0" the proper backend is not:
  expr->symtree->n.sym->backend_decl
but rather
  expr->ref->u.c->component->backend_decl

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
                 CC|                            |jakub at gcc dot gnu.org

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[jvdelisle at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

Jerry DeLisle <jvdelisle at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jvdelisle at gcc dot
                   |                            |gnu.org

--- Comment #2 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> 2011-03-31 13:05:01 UTC ---
I am a little suspicious of this:

 static int count_arglist;

+/* Pointer to an array of gfc_expr ** we operate on, plus its size
+   and counter.  */
+
+static gfc_expr ***expr_array;
+static int expr_size, expr_count;


It could be getting walked on or optimized away by the optimizers.  Is there
another way to do this that is less indirect or relies less on static.

Just seems too tricky.  I am not looking further on this one.

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[jvdelisle at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

--- Comment #3 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> 2011-03-31 13:06:06 UTC ---
Disregard 2, wrong PR

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[jvdelisle at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

--- Comment #4 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> 2011-04-01 17:54:06 UTC ---
This regression was caused by r167220.

Revision 167220 - (view) (download) (annotate) - [select for diffs]
Modified Sun Nov 28 13:47:26 2010 UTC (4 months ago) by pault

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.04.08 04:16:46
     Ever Confirmed|0                           |1

--- Comment #5 from Paul Thomas <pault at gcc dot gnu.org> 2011-04-08 04:16:46 UTC ---
This is obviously mine :-)

This fixes it but I suspect that a few more conditions (no ARRAY_ELEMENT for
example) will be needed for it to be correct.

Index: gcc/fortran/trans-array.c
===================================================================
*** gcc/fortran/trans-array.c    (revision 171573)
--- gcc/fortran/trans-array.c    (working copy)
*************** get_std_lbound (gfc_expr *expr, tree des
*** 6707,6712 ****
--- 6707,6713 ----
    tree stride;
    tree cond, cond1, cond3, cond4;
    tree tmp;
+   gfc_ref *ref;
    if (GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (desc)))
      {
        tmp = gfc_rank_cst[dim];
*************** get_std_lbound (gfc_expr *expr, tree des
*** 6740,6745 ****
--- 6741,6752 ----
    else if (expr->expr_type == EXPR_VARIABLE)
      {
        tmp = TREE_TYPE (expr->symtree->n.sym->backend_decl);
+       for (ref = expr->ref; ref; ref = ref->next)
+     {
+       if (ref->type == REF_COMPONENT
+         && ref->u.c.component->as)
+         tmp = TREE_TYPE (ref->u.c.component->backend_decl);
+     }
        return GFC_TYPE_ARRAY_LBOUND(tmp, dim);
      }
    else if (expr->expr_type == EXPR_FUNCTION)

Paul

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

--- Comment #6 from Paul Thomas <pault at gcc dot gnu.org> 2011-04-12 19:14:52 UTC ---
Author: pault
Date: Tue Apr 12 19:14:49 2011
New Revision: 172339

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=172339
Log:
2011-04-12  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/48360
    PR fortran/48456
    * trans-array.c (get_std_lbound): For derived type variables
    return array valued component lbound.

2011-04-12  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/48360
    PR fortran/48456
    * gfortran.dg/realloc_on_assign_6.f03: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/realloc_on_assign_6.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

--- Comment #7 from Paul Thomas <pault at gcc dot gnu.org> 2011-04-13 18:38:21 UTC ---
Author: pault
Date: Wed Apr 13 18:38:17 2011
New Revision: 172390

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=172390
Log:
2011-04-13  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/48360
    PR fortran/48456
    * trans-array.c (get_std_lbound): For derived type variables
    return array valued component lbound.

2011-04-13  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/48360
    PR fortran/48456
    * gfortran.dg/realloc_on_assign_6.f03: New test.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/gfortran.dg/realloc_on_assign_6.f03
Modified:
    branches/gcc-4_6-branch/gcc/fortran/ChangeLog
    branches/gcc-4_6-branch/gcc/fortran/trans-array.c
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog

[Bug fortran/48360] [4.6/4.7 Regression] ICE on array assignment statement with allocatable LHS

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48360

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

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

--- Comment #8 from Paul Thomas <pault at gcc dot gnu.org> 2011-04-13 19:20:12 UTC ---
Fixed on trunk and 4.6.

Thanks for the report

Paul