[Bug fortran/45211] New: C interoperable error when compiling BIND(C) function in a module.

[Bug fortran/45211] New: C interoperable error when compiling BIND(C) function in a module.

[brtnfld at hdfgroup dot org]

gfortran (all versions 4.2-4.5) reports the error when trying to compile code
below:

Error: Type 'link_info' at (1) is a parameter to the BIND(C)  procedure
'liter_cb' but is not C interoperable because derived type 'info_t' is not C
interoperable

when I remove the module and compile just the function it compiles fine. info_t
is interoperable with C


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


-- 
           Summary: C interoperable error when compiling BIND(C) function in
                    a module.
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: brtnfld at hdfgroup dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45211

[Bug fortran/45211] C interoperable error when compiling BIND(C) function in a module.

[dominiq at lps dot ens dot fr]

------- Comment #1 from dominiq at lps dot ens dot fr  2010-08-06 17:26 -------
Confirmed also with trunk.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45211

[Bug fortran/45211] C interoperable error when compiling BIND(C) function in a module.

[brtnfld at hdfgroup dot org]

------- Comment #2 from brtnfld at hdfgroup dot org  2010-08-09 15:02 -------
If the type declaration is moved to the module scope the code compiles.

MODULE liter_cb_mod

USE ISO_C_BINDING

TYPE, BIND(C) :: MYFTYPE
  INTEGER(C_INT) :: I, J
  REAL(C_FLOAT) :: S
END TYPE MYFTYPE

CONTAINS

  FUNCTION liter_cb() bind(C)

    USE ISO_C_BINDING
    IMPLICIT NONE

    INTEGER(c_int) liter_cb

    TYPE(MYFTYPE) :: link_info

    liter_cb = 0

  END FUNCTION liter_cb

END MODULE liter_cb_mod

There was a discussion about the matter in comp.lang.fortran under the topic
"BIND(C) functions in a module error" as to the source of the problem. Since
there seems to be a work around I downgraded the severity.


-- 

brtnfld at hdfgroup dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45211

[Bug fortran/45211] C interoperable error when compiling BIND(C) function in a module.

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2010-08-14 16:24 -------
Cf.
http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/887251d8cd64eb02

Lightly tested patch. The ts.is_c_interop is only set when via
verify_bind_c_derived_type, which is called by resolve.c - and thus comes too
late.

I am not sure whether this now allows DT which are not BIND(C) and whether one
thus should add an !attr.resolved, but I assume that incompatibilities between
the BIND(C) attribute for the DT and the actual DT will be found at resolution
time. Thus, the patch should be fine.

Index: gcc/fortran/decl.c
===================================================================
--- gcc/fortran/decl.c  (Revision 163239)
+++ gcc/fortran/decl.c  (Arbeitskopie)
@@ -991,7 +991,7 @@ verify_c_interop_param (gfc_symbol *sym)
              /* Make personalized messages to give better feedback.  */
              if (sym->ts.type == BT_DERIVED)
                gfc_error ("Type '%s' at %L is a parameter to the BIND(C) "
-                          " procedure '%s' but is not C interoperable "
+                          "procedure '%s' but is not C interoperable "
                           "because derived type '%s' is not C interoperable",
                           sym->name, &(sym->declared_at),
                           sym->ns->proc_name->name, 
@@ -3612,7 +3612,8 @@ gfc_try
 verify_c_interop (gfc_typespec *ts)
 {
   if (ts->type == BT_DERIVED && ts->u.derived != NULL)
-    return (ts->u.derived->ts.is_c_interop ? SUCCESS : FAILURE);
+    return (ts->u.derived->ts.is_c_interop || ts->u.derived->attr.is_bind_c)
+          ? SUCCESS : FAILURE;
   else if (ts->is_c_interop != 1)
     return FAILURE;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45211

[Bug fortran/45211] C interoperable error when compiling BIND(C) function in a module.

[burnus at gcc dot gnu dot org]

------- Comment #4 from burnus at gcc dot gnu dot org  2010-08-15 16:21 -------
Subject: Bug 45211

Author: burnus
Date: Sun Aug 15 16:20:56 2010
New Revision: 163264

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=163264
Log:
2010-08-15  Tobias Burnus  <burnus@net-b.de>

        PR fortran/45211
        * decl.c (verify_c_interop_param): Remove superfluous space (" ").
        (verify_c_interop): Handle unresolved DT with bind(C).

2010-08-15  Tobias Burnus  <burnus@net-b.de>

        PR fortran/45211
        * gfortran.dg/bind_c_usage_21.f90: New.
        * gfortran.dg/bind_c_dts_3.f03: Update dg-error.


Added:
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_21.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/decl.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/bind_c_dts_3.f03


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45211

[Bug fortran/45211] C interoperable error when compiling BIND(C) function in a module.

[burnus at gcc dot gnu dot org]

------- Comment #5 from burnus at gcc dot gnu dot org  2010-08-15 16:23 -------
FIXED on the trunk (4.6). Thanks for the bug report!

(I do not intent to backport the patch to the 4.4/4.5 branch; tell me if you
think it should be applied there as well.)


-- 

burnus at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45211