[Bug fortran/46060] New: gfortran crash when referencing procedure pointer

[Bug fortran/46060] New: gfortran crash when referencing procedure pointer

[sjbespa at comcast dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

           Summary: gfortran crash when referencing procedure pointer
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: sjbespa@comcast.net


Created attachment 22072
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22072
module test_1.f90 which is referenced in the bug report

Compiling the module below causes a segmentation fault.

gfortran -c test_1.f90
test_1.f90: In function ‘test_subroutine’:
test_1.f90:20:0: internal compiler error: Segmentation fault

the crash occurs in last week's 4.6 trunk and 4.5.

========

gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/gfortran/libexec/gcc/x86_64-apple-darwin10.3.0/4.5.1/lto-wrapper
Target: x86_64-apple-darwin10.3.0
Configured with: ../gcc-4_5-branch/configure --prefix=/usr/local/gfortran
--enable-languages=c,c++,fortran
--with-gmp=/Users/fx/devel/gcc/ibin45/../irun45 --enable-bootstrap
--with-included-gettext --with-arch=nocona --with-tune=generic
Thread model: posix
gcc version 4.5.1 20100506 (prerelease) (GCC) 

=========

/volumes/dev/gfortran-4.6-trunk/bin/gfortran -v
Using built-in specs.
COLLECT_GCC=/volumes/dev/gfortran-4.6-trunk/bin/gfortran
COLLECT_LTO_WRAPPER=/Volumes/dev/gfortran-4.6-trunk/bin/../libexec/gcc/x86_64-apple-darwin10/4.6.0/lto-wrapper
Target: x86_64-apple-darwin10
Configured with: ../gfortran-4.6-src/configure
--prefix=/volumes/dev/gfortran-4.6-trunk --enable-languages=fortran
--host=x86_64-apple-darwin10 --build=x86_64-apple-darwin10
--target=x86_64-apple-darwin10
Thread model: posix
gcc version 4.6.0 20101013 (experimental) (GCC)

[Bug fortran/46060] gfortran crash when referencing procedure pointer

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org
           Severity|critical                    |normal

--- Comment #1 from kargl at gcc dot gnu.org 2010-10-18 02:17:48 UTC ---
The following patch allows your code to compile, but 
I have no idea if it is the correct fix.

Index: trans-expr.c
===================================================================
--- trans-expr.c        (revision 165533)
+++ trans-expr.c        (working copy)
@@ -5675,7 +5675,7 @@ gfc_trans_assignment_1 (gfc_expr * expr1
   gfc_conv_expr (&rse, expr2);

   /* Stabilize a string length for temporaries.  */
-  if (expr2->ts.type == BT_CHARACTER)
+  if (expr2->ts.type == BT_CHARACTER && rse.string_length)
     string_length = gfc_evaluate_now (rse.string_length, &rse.pre);
   else
     string_length = NULL_TREE;

[Bug fortran/46060] gfortran crash when referencing procedure pointer

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

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

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

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2010-10-18 06:42:42 UTC ---
(In reply to comment #1)
> The following patch allows your code to compile, but 
> I have no idea if it is the correct fix.

I have the feeling that it is not the best fix. The string lengths are known at
the compile time - thus, rse.string_length should be defined. I wonder whether
something goes wrong either in resolve_procedure_interface, or in
add_hidden_procptr_result or in ...?

[Bug fortran/46060] gfortran crash when referencing procedure pointer

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-invalid-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.10.18 09:48:42
     Ever Confirmed|0                           |1

--- Comment #3 from janus at gcc dot gnu.org 2010-10-18 09:48:42 UTC ---
Confirmed. Here is a slightly reduced test case:

implicit none

abstract interface
  function name_func (ivar) result (res)
    integer, intent(in) :: ivar
    character(len=8) :: res
  end function name_func
end interface

type var_type
  procedure(name_func), nopass, pointer :: name
end type var_type

type(var_type) :: vars
character(len=8) name

name = vars%name   ! invalid !!!

end


This, like the original code, is invalid and gives an ICE. Changing the invalid
line to something like

name = vars%name(3)

makes the ICE go away.

[Bug fortran/46060] [F03] procedure pointer component referenced without argument list

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|gfortran crash when         |[F03] procedure pointer
                   |referencing procedure       |component referenced
                   |pointer                     |without argument list

--- Comment #4 from janus at gcc dot gnu.org 2010-10-18 11:44:40 UTC ---
Here is another variation which causes a different ICE:


implicit none

type var_type
  procedure(integer), nopass, pointer :: ppc
end type var_type

type(var_type) :: vars
integer :: i

i = vars%ppc

end



internal compiler error: in fold_convert_loc, at fold-const.c:1899

[Bug fortran/46060] [F03] procedure pointer component referenced without argument list

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |janus at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #5 from janus at gcc dot gnu.org 2010-10-18 20:48:26 UTC ---
Here is a preliminary patch:


Index: gcc/fortran/primary.c
===================================================================
--- gcc/fortran/primary.c       (revision 165600)
+++ gcc/fortran/primary.c       (working copy)
@@ -1883,13 +1883,20 @@ gfc_match_varspec (gfc_expr *primary, int equiv_fl
       if (component->attr.proc_pointer && ppc_arg
          && !gfc_matching_procptr_assignment)
        {
+         /* Procedure pointer component call: Look for argument list.  */
          m = gfc_match_actual_arglist (sub_flag,
                                        &primary->value.compcall.actual);
          if (m == MATCH_ERROR)
            return MATCH_ERROR;
-         if (m == MATCH_YES)
-           primary->expr_type = EXPR_PPC;

+         if (m == MATCH_NO)
+           {
+             gfc_error ("Procedure pointer component '%s' requires an "
+                        "argument list at %C", component->name);
+             return MATCH_ERROR;
+           }
+
+         primary->expr_type = EXPR_PPC;
           break;
        }


It rejects the test cases in comment #0, #3 and #4 with the proper error
message, but is otherwise untested.

[Bug fortran/46060] [F03] procedure pointer component referenced without argument list

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

--- Comment #6 from janus at gcc dot gnu.org 2010-10-21 11:31:58 UTC ---
Author: janus
Date: Thu Oct 21 11:31:55 2010
New Revision: 165769

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=165769
Log:
2010-10-21  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/46060
    * match.h (gfc_matching_ptr_assignment): New global variable to indicate
    we're currently matching a (non-proc-)pointer assignment.
    * decl.c (match_pointer_init): Set it.
    * match.c (gfc_match_pointer_assignment): Ditto.
    * primary.c (matching_actual_arglist): New global variable to indicate
    we're currently matching an actual argument list.
    (gfc_match_actual_arglist): Set it.
    (gfc_match_varspec): Reject procedure pointer component calls with
    missing argument list.


2010-10-21  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/46060
    * gfortran.dg/proc_ptr_comp_25.f90: New.

Added:
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_comp_25.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/decl.c
    trunk/gcc/fortran/match.c
    trunk/gcc/fortran/match.h
    trunk/gcc/fortran/primary.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/46060] [F03] procedure pointer component referenced without argument list

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46060

janus at gcc dot gnu.org changed:

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

--- Comment #7 from janus at gcc dot gnu.org 2010-10-21 11:35:05 UTC ---
Fixed with r165769. Closing.

Thanks for the report, Stephen!