[Bug fortran/50933] New: Wrongly regards BIND(C) types as incompatible

[Bug fortran/50933] New: Wrongly regards BIND(C) types as incompatible

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50933

             Bug #: 50933
           Summary: Wrongly regards BIND(C) types as incompatible
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org


gfortran fails to compile the program below. I think the program is valid as
the derived type uses BIND(C). Works if one uses SEQUENCE instead of BIND(C)

Taken from
http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/887251d8cd64eb02
(Richard Maine's example). For some reason, only the part of the issues raised
in the thread were fixed in PR 45211; cf. also PR 37829.

gfortran compilation fails with:

  write (*,*) liter_cb(link_info)
                       1
Error: Type mismatch in argument 'link_info' at (1); passed TYPE(info_t) to
TYPE(info_t)


MODULE liter_cb_mod
USE ISO_C_BINDING
CONTAINS
   FUNCTION liter_cb(link_info) bind(C)
     USE ISO_C_BINDING
     IMPLICIT NONE

     INTEGER(c_int) liter_cb

     TYPE, bind(C) :: info_t
        INTEGER(c_int) :: type
     END TYPE info_t

     TYPE(info_t) :: link_info

     liter_cb = 0

   END FUNCTION liter_cb

END MODULE liter_cb_mod

PROGRAM main
     USE ISO_C_BINDING
   interface
   FUNCTION liter_cb(link_info) bind(C)
     USE ISO_C_BINDING
     IMPLICIT NONE
     INTEGER(c_int) liter_cb
     TYPE, bind(C) :: info_t
        INTEGER(c_int) :: type
     END TYPE info_t
     TYPE(info_t) :: link_info
   END FUNCTION liter_cb
   end interface

      TYPE, bind(C) :: info_t
        INTEGER(c_int) :: type
     END TYPE info_t  
  type(info_t) :: link_info

  write (*,*) liter_cb(link_info)

END PROGRAM main

[Bug fortran/50933] Wrongly regards BIND(C) types as incompatible

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50933

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-11-02 08:30:20 UTC ---
Untested patch:

--- a/gcc/fortran/interface.c
+++ b/gcc/fortran/interface.c
@@ -405,7 +405,7 @@ gfc_compare_derived_types (gfc_symbol *derived1, gfc_symbol
*derived2)
     return 1;

   /* Compare type via the rules of the standard.  Both types must have
-     the SEQUENCE attribute to be equal.  */
+     the SEQUENCE or BIND(C) attribute to be equal.  */

   if (strcmp (derived1->name, derived2->name))
     return 0;
@@ -414,7 +414,8 @@ gfc_compare_derived_types (gfc_symbol *derived1, gfc_symbol
*derived2)
       || derived2->component_access == ACCESS_PRIVATE)
     return 0;

-  if (derived1->attr.sequence == 0 || derived2->attr.sequence == 0)
+  if (!(derived1->attr.sequence && derived2->attr.sequence)
+      && !(derived1->attr.is_bind_c && derived2->attr.is_bind_c))
     return 0;

   dt1 = derived1->components;

[Bug fortran/50933] Wrongly regards BIND(C) types as incompatible

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50933

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-11-03 22:36:19 UTC ---
Author: burnus
Date: Thu Nov  3 22:36:11 2011
New Revision: 180879

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=180879
Log:
2011-11-03  Tobias Burnus  <burnus@net-b.de>

        PR fortran/50933
        * interface.c (gfc_compare_derived_types): Fix check for
        * BIND(C).

2011-11-03  Tobias Burnus  <burnus@net-b.de>

        PR fortran/50933
        * gfortran.dg/bind_c_dts_5.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/bind_c_dts_5.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/50933] Wrongly regards BIND(C) types as incompatible

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50933

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

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

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-11-03 22:43:46 UTC ---
FIXED on the 4.7 trunk.