[Bug fortran/34079] New: Bind(C): Don't pass the string length as argument (for STDCALL)

[Bug fortran/34079] New: Bind(C): Don't pass the string length as argument (for STDCALL)

[burnus at gcc dot gnu dot org]

Using STDCALL, not the callee but the called procedure pops the arguments from
the stack. The problem is that gfortran currently also for BIND(C) passes the
string lengths as arguments.

See also:
http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/19d77dfc75f8be58


-- 
           Summary: Bind(C): Don't pass the string length as argument (for
                    STDCALL)
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Don't pass the string length as argument (for STDCALL)

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2007-11-13 14:39 -------
Example:

interface
  subroutine subiso(x) bind(c)
    use iso_c_binding
    character(kind=c_char,len=1), dimension(*) :: x
  end subroutine subiso
  subroutine subiso2(x) bind(c) ! { dg-warning "may not be C interoperable" }
    character(len=1), dimension(*) :: x
  end subroutine subiso2
  subroutine sub(x)
    use iso_c_binding
    character(kind=c_char,len=1), dimension(*) :: x
  end subroutine sub
end interface
call sub    ("abcdef")
call subiso ("ABCDEF")
call subiso2("AbCdEf")
end

Dumped tree should look like:
  sub (&"abcdef"[1]{lb: 1 sz: 1}, 6);
  subiso (&"ABCDEF"[1]{lb: 1 sz: 1});
  subiso2 (&"ABCDEF"[1]{lb: 1 sz: 1});


Draft of a patch:

Index: gcc/fortran/trans-expr.c
===================================================================
--- gcc/fortran/trans-expr.c    (Revision 130131)
+++ gcc/fortran/trans-expr.c    (Arbeitskopie)
@@ -2390,8 +2390,8 @@ gfc_conv_function_call (gfc_se * se, gfc
         }

       /* Character strings are passed as two parameters, a length and a
-         pointer.  */
-      if (parmse.string_length != NULL_TREE)
+         pointer - except for Bind(c) which only passes the pointer.  */
+      if (parmse.string_length != NULL_TREE && !sym->attr.is_bind_c)
         stringargs = gfc_chainon_list (stringargs, parmse.string_length);

       arglist = gfc_chainon_list (arglist, parmse.expr);


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Don't pass the string length as argument (for STDCALL)

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2007-11-13 20:02 -------
Note: The patch above works, one only needs to check whether there is a memory
leak or something else which affects the generated tree.

Index: gcc/testsuite/gfortran.dg/bind_c_vars_2.f03
===================================================================
--- gcc/testsuite/gfortran.dg/bind_c_vars_2.f03 (revision 0)
+++ gcc/testsuite/gfortran.dg/bind_c_vars_2.f03 (revision 0)
@@ -0,0 +1,29 @@
+! { dg-do compile }
+! { dg-options "-fdump-tree-original" }
+!
+! PR fortran/34079
+! Character bind(c) arguments shall not pass the length as additional argument
+!
+implicit none
+interface
+  subroutine subiso(x) bind(c)
+    use iso_c_binding
+    character(kind=c_char,len=1), dimension(*) :: x
+  end subroutine subiso
+  subroutine subiso2(x) bind(c) ! { dg-warning "may not be C interoperable" }
+    character(len=1), dimension(*) :: x
+  end subroutine subiso2
+  subroutine sub(x)
+    use iso_c_binding
+    character(kind=c_char,len=1), dimension(*) :: x
+  end subroutine sub
+end interface
+call sub    ("abc")
+call subiso ("ABCDEF")
+call subiso2("AbCdEfGhIj")
+end
+
+! { dg-final { scan-tree-dump-times "{lb: 1 sz: 1}, 3" 1 "original" } }
+! { dg-final { scan-tree-dump-times "{lb: 1 sz: 1}, 6" 0 "original" } }
+! { dg-final { scan-tree-dump-times "{lb: 1 sz: 1}, 10" 0 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch, wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Don't pass the string length as argument (for STDCALL)

[patchapp at dberlin dot org]

------- Comment #4 from patchapp at dberlin dot org  2007-11-15 15:10 -------
Subject: Bug number PR34079

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-11/msg00851.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Don't pass the string length as argument (for STDCALL)

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2007-11-15 15:10 -------
See also:
  http://gcc.gnu.org/ml/fortran/2007-11/msg00074.html
and for the patch:
  http://gcc.gnu.org/ml/fortran/2007-11/msg00093.html


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |burnus at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-11-15 15:10:33
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #5 from burnus at gcc dot gnu dot org  2007-11-17 08:08 -------
Additional problems, spotted by FX:

subroutine foo(x) bind(c)
   character(len=1) :: x

function bar(x) bind(c)
   character(len=1) :: x, bar

These generates:
  foo (x, _x)
  bar (__result, .__result, x, _x)

Instead of
   void foo(char *x)
and
  char bar(char *x)


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |crickett at lanl dot gov
OtherBugsDependingO|                            |32630
              nThis|                            |
            Summary|Bind(C): Don't pass the     |Bind(C): Character
                   |string length as argument   |argument/return value
                   |(for STDCALL)               |problems


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #6 from burnus at gcc dot gnu dot org  2007-11-17 13:49 -------
More fun with ENTRY:

a) gfortran does not match the BIND(C) suffix for ENTRY,
   "R1235 entry-stmt is ENTRY entry-name [ ( [ dummy-arg-list ] ) [ suffix ] ]"
   cf. decl.c: gfc_match_function_decl and gfc_match_entry

b) As entry and procedure do not need to be both bind(c), the master function
should always be called with the string length.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #7 from burnus at gcc dot gnu dot org  2007-11-19 12:30 -------
Subject: Bug 34079

Author: burnus
Date: Mon Nov 19 12:30:17 2007
New Revision: 130288

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130288
Log:
2007-11-19  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * decl.c (gfc_match_entry): Support BIND(C).
        (gfc_match_subroutine): Fix comment typo.

2007-11-19  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * gfortran.dg/bind_c_usage_10_c.c: New.
        * gfortran.dg/bind_c_usage_10.f03: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_10.f03
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_10_c.c
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/decl.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[patchapp at dberlin dot org]

------- Comment #8 from patchapp at dberlin dot org  2007-11-20 05:04 -------
Subject: Bug number PR34079

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-11/msg00980.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #9 from burnus at gcc dot gnu dot org  2007-11-22 09:56 -------
Subject: Bug 34079

Author: burnus
Date: Thu Nov 22 09:55:47 2007
New Revision: 130346

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130346
Log:
2007-11-22  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * trans-expr.c (gfc_conv_function_call): Do not append
        string length arguments when calling bind(c) procedures.
        * trans-decl.c (create_function_arglist): Do not append
        string length arguments when declaring bind(c) procedures.

2007-11-22  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * gfortran.dg/bind_c_usage_10.f03: Remove .mod file afterwards.
        * gfortran.dg/bind_c_usage_13.f03: New.
        * gfortran.dg/bind_c_usage_14.f03: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_13.f03
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_14.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-decl.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_10.f03


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[patchapp at dberlin dot org]

------- Comment #10 from patchapp at dberlin dot org  2007-11-22 19:01 -------
Subject: Bug number PR34079

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-11/msg01109.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[patchapp at dberlin dot org]

------- Comment #11 from patchapp at dberlin dot org  2007-11-24 13:05 -------
Subject: Bug number PR34079

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-11/msg01275.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #12 from burnus at gcc dot gnu dot org  2007-11-25 22:03 -------
Subject: Bug 34079

Author: burnus
Date: Sun Nov 25 22:02:53 2007
New Revision: 130414

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130414
Log:
2007-11-25  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * trans-types.c (gfc_return_by_reference,
        gfc_get_function_type): Do not return result of
        character-returning bind(C) functions as argument.
        * trans-expr.c (gfc_conv_function_call): Ditto.

2007-11-25  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * gfortran.dg/bind_c_usage_10_c.c: Fix comment.
        * gfortran.dg/bind_c_usage_16.f03: New.
        * gfortran.dg/bind_c_usage_16_c.c: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_16.f03
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_16_c.c
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/fortran/trans-types.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/bind_c_usage_10_c.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #13 from burnus at gcc dot gnu dot org  2007-11-25 22:15 -------
Subject: Bug 34079

Author: burnus
Date: Sun Nov 25 22:15:47 2007
New Revision: 130417

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130417
Log:
Forgot trans-expr.c in previous commit:

2007-11-25  Tobias Burnus  <burnus@net-b.de>

        PR fortran/34079
        * trans-types.c (gfc_return_by_reference,
        gfc_get_function_type): Do not return result of
        character-returning bind(C) functions as argument.
        * trans-expr.c (gfc_conv_function_call): Ditto.

Modified:
    trunk/gcc/fortran/trans-expr.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079

[Bug fortran/34079] Bind(C): Character argument/return value problems

[burnus at gcc dot gnu dot org]

------- Comment #14 from burnus at gcc dot gnu dot org  2007-11-25 22:18 -------
FIXED on the trunk (4.3.0) [there is no bind(C) support in 4.2.x].


-- 

burnus at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34079