[Bug fortran/20363] New: interface body has incorrect scope

[Bug fortran/20363] New: interface body has incorrect scope

[paulthomas2 at wanadoo dot fr]

 

-- 
           Summary: interface body has incorrect scope
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: paulthomas2 at wanadoo dot fr
                CC: dave dot offiler at metoffice dot gov dot uk,gcc-bugs at
                    gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[paulthomas2 at wanadoo dot fr]

------- Additional Comments From paulthomas2 at wanadoo dot fr  2005-03-07 18:40 -------
(In reply to comment #0)
> Sorry about that I was adding Michael Metcalf to the cc and it, well, went.

$ cat snafu.f90
module snafu
  interface foo
    subroutine really_snafu (foo)        
      integer, intent (inout)  :: foo
    end subroutine really_snafu
  end interface foo
end module snafu
PaulThomas@Paul /cygdrive/d/gfortran
$ d:/irun/bin/gfortran  -c snafu.f90
 In file snafu.f90:4

      integer, intent (inout)  :: foo
                                    1
Error: Symbol 'foo' at (1) cannot have a type

This is incorrect because the interface body is a new separate scope(thanks 
Michael).


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-12 17:29 -------
Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |rejects-valid
   Last reconfirmed|0000-00-00 00:00:00         |2005-03-12 17:29:31
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[tobi at gcc dot gnu dot org]

------- Additional Comments From tobi at gcc dot gnu dot org  2005-07-10 15:37 -------
Erik has posted a patch for this bug here:
http://gcc.gnu.org/ml/fortran/2005-07/msg00081.html

i'm looking into it, but I haven't yet understood how this changes something,
and I'm currently rebuilding the compiler, so I can't look at this in the
debugger, so review will have to wait a few hours.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tobi at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[paulthomas2 at wanadoo dot fr]

------- Additional Comments From paulthomas2 at wanadoo dot fr  2005-07-10 16:57 -------
Subject: Re:  interface body has incorrect scope

tobi at gcc dot gnu dot org wrote:

>------- Additional Comments From tobi at gcc dot gnu dot org  2005-07-10 15:37 -------
>Erik has posted a patch for this bug here:
>http://gcc.gnu.org/ml/fortran/2005-07/msg00081.html
>
>i'm looking into it, but I haven't yet understood how this changes something,
>and I'm currently rebuilding the compiler, so I can't look at this in the
>debugger, so review will have to wait a few hours.
>
>  
>
Erik,

Have you checked the parse tree for this?  It looks OK, from a very 
casual look, but the parse tree would be the clincher.

Paul T




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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[erik dot edelmann at iki dot fi]

------- Additional Comments From erik dot edelmann at iki dot fi  2005-07-11 19:52 -------

> Erik,
> 
> Have you checked the parse tree for this?  It looks OK, from a very 
> casual look, but the parse tree would be the clincher.

After comments from Tobi I posted a new patch here: 
http://gcc.gnu.org/ml/fortran/2005-07/msg00135.html

With that patch, the parse tree for the snafu module is


        Namespace: A-H: (REAL 4) I-N: (INTEGER 4) O-Z: (REAL 4)
        procedure name = snafu
        symtree: foo  Ambig 0
        symbol foo (UNKNOWN 0)(PROCEDURE UNKNOWN-INTENT UNKNOWN-ACCESS
UNKNOWN-PROC SUBROUTINE)
        Generic interfaces: really_snafu

        symtree: snafu  Ambig 0
        symbol snafu (UNKNOWN 0)(MODULE UNKNOWN-INTENT UNKNOWN-ACCESS UNKNOWN-PROC)

        symtree: really_snafu  Ambig 0
        symbol really_snafu (UNKNOWN 0)(PROCEDURE UNKNOWN-INTENT UNKNOWN-ACCESS
MODULE-PROC SUBROUTINE)
        Formal arglist: foo
        Formal namespace
          Namespace: A-H: (REAL 4) I-N: (INTEGER 4) O-Z: (REAL 4)
          procedure name = really_snafu
          symtree: foo  Ambig 0
          symbol foo (INTEGER 4)(VARIABLE INOUT UNKNOWN-ACCESS UNKNOWN-PROC DUMMY)

          symtree: really_snafu  Ambig 0 from namespace snafu



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[paulthomas2 at wanadoo dot fr]

------- Additional Comments From paulthomas2 at wanadoo dot fr  2005-07-11 20:02 -------
Subject: Re:  interface body has incorrect scope

That seems to be as good as one could want!

Paul T




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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[Tobias dot Schlueter at physik dot uni-muenchen dot de]

------- Additional Comments From Tobias dot Schlueter at physik dot uni-muenchen dot de  2005-07-11 20:12 -------
Subject: Re:  interface body has incorrect scope

paulthomas2 at wanadoo dot fr wrote:
> ------- Additional Comments From paulthomas2 at wanadoo dot fr  2005-07-11 20:02 -------
> Subject: Re:  interface body has incorrect scope
> 
> That seems to be as good as one could want!

Paul, do you have any idea what find_special could be intended for?  It seems
obvious that it does the wrong thing in the case of this PR, and I can't see
any case where it would be needed, but I would be surprised if there's no
intent behind it, and in another compiler the function is still present, does
the same thing, and is called in the same places.  Are there maybe any other
changes in symbol handling compensating for this?

Erik, I'll give this some more thought before I commit your patch, so don't
worry if I take a few days.

- Tobi


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[paulthomas2 at wanadoo dot fr]

------- Additional Comments From paulthomas2 at wanadoo dot fr  2005-07-12 07:16 -------
Subject: Re:  interface body has incorrect scope

>
>
>Paul, do you have any idea what find_special could be intended for?  It seems
>obvious that it does the wrong thing in the case of this PR, and I can't see
>  
>
Tobi,

I do not know.  I wondered the same, when Erik could apparently excise 
the lot without breaking anything.

I am just about to return to modules and all that, so I'll put it on my 
list of things to contemplate.






-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[tobi at gcc dot gnu dot org]

------- Additional Comments From tobi at gcc dot gnu dot org  2005-07-12 11:47 -------
(In reply to comment #8)
> I do not know.  I wondered the same, when Erik could apparently excise 
> the lot without breaking anything.

I'm specifically worried that because of the known bad state of generic
interfaces, this might be something which is simply not tested in the testsuite.
 Well, Erik's away for a few days, so we can contemplate this for a while
without alienating him :-)

> I am just about to return to modules and all that, so I'll put it on my 
> list of things to contemplate.

Great.  I'll see if can come up with a testcase that is broken by this change.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[erik dot edelmann at iki dot fi]

------- Additional Comments From erik dot edelmann at iki dot fi  2005-07-27 13:00 -------
(In reply to comment #7)
> Subject: Re:  interface body has incorrect scope
> 
> Paul, do you have any idea what find_special could be intended for?  It seems
> obvious that it does the wrong thing in the case of this PR, and I can't see
> any case where it would be needed, but I would be surprised if there's no
> intent behind it, and in another compiler the function is still present, does
> the same thing, and is called in the same places.  Are there maybe any other
> changes in symbol handling compensating for this?

I've taken a look at "another compiler" (i.e. g95).  The difference is in 
(gfc|g95)_match_interface().  While we do

    case INTERFACE_GENERIC:
      
          <...>

          current_interface.sym = gfc_new_block = sym;

g95 does:

    case INTERFACE_GENERIC:    

        <...>

        g95_new_block = NULL;

The result of this is that in find_special(), when we get to the point

    if (s->state != COMP_INTERFACE || s->sym == NULL)
        goto normal;   /* Nameless interface */

(or corresponding point in gfortran source code), g95 will 'goto normal', while
we continue. In other words; g95 treats generic interfaces as nameless
interfaces.  This brings me to a question: what is a "named interface"?  I had
assumed that it would the same thing as a generic interface, but in g95 code it
is apperantly not.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[Tobias dot Schlueter at physik dot uni-muenchen dot de]

------- Additional Comments From Tobias dot Schlueter at physik dot uni-muenchen dot de  2005-07-27 13:21 -------
Subject: Re:  interface body has incorrect scope

Quoting erik dot edelmann at iki dot fi <gcc-bugzilla@gcc.gnu.org>:
> I've taken a look at "another compiler" (i.e. g95).  The difference is in
> (gfc|g95)_match_interface().  While we do
>
>     case INTERFACE_GENERIC:
>
>           <...>
>
>           current_interface.sym = gfc_new_block = sym;
>
> g95 does:
>
>     case INTERFACE_GENERIC:
>
>         <...>
>
>         g95_new_block = NULL;
>
> The result of this is that in find_special(), when we get to the point
>
>     if (s->state != COMP_INTERFACE || s->sym == NULL)
>         goto normal;   /* Nameless interface */
>
> (or corresponding point in gfortran source code), g95 will 'goto normal',
> while
> we continue. In other words; g95 treats generic interfaces as nameless
> interfaces.  This brings me to a question: what is a "named interface"?  I
> had
> assumed that it would the same thing as a generic interface, but in g95 code
> it
> is apperantly not.

(I'm at the office so wrapping is weird, my e-mail address is weird and I don't
have the standard nor the source handy)

IIRC in g95 generic interface names are not part of the usual symbol tree, but
instead they're stored completely apart, so that the symbol doesn't get in the
way as it does in our case, and therefore the check in find_special can remain
the same.  Therefore it's unfortunately not clear if the behavior with your
patch is equivalent to g95's.

I couldn't think of anything that breaks with your patch, which leaves us with
either the option of applying your patch (and then having to remember reverting
your change if someone finds time to overhaul symbol handling) or overhauling
symbol handling right away :-(



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[paulthomas2 at wanadoo dot fr]

------- Additional Comments From paulthomas2 at wanadoo dot fr  2005-07-27 16:21 -------
> > interfaces.  This brings me to a question: what is a "named interface"?  I

This is a nameless interface, isn't it?

module snafu
  interface
    subroutine really_snafu (foo)        
      integer, intent (inout)  :: foo
    end subroutine really_snafu
  end interface
end module snafu

This compiles correctly with gfc.  A named interface, therefore, is the same
thing but with a name.  I don't know what this does for us.  A generic
interface, is a named interface that contains variants for different types.

> I couldn't think of anything that breaks with your patch, which leaves us with
> either the option of applying your patch (and then having to remember revertin

I would go along with that - we will need to remember, though....

> your change if someone finds time to overhaul symbol handling) or overhauling
> symbol handling right away :-(

I am not entirely sure that symbol handling should be overhauled but maybe I
have not understood your reasons for wanting to do that?

Anyway, my invlovement with the library is taking longer than intended; having
taken a foray into the scalarizer etc., in order to do the right thing with
internal units.  As soon as I am done, I will return to these matters.

Cheers

Paul

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[erik dot edelmann at iki dot fi]

------- Additional Comments From erik dot edelmann at iki dot fi  2005-07-28 09:06 -------
(In reply to comment #12)
> > > interfaces.  This brings me to a question: what is a "named interface"?  I
> 
> This is a nameless interface, isn't it?
> 
> module snafu
>   interface
>     subroutine really_snafu (foo)        
>       integer, intent (inout)  :: foo
>     end subroutine really_snafu
>   end interface
> end module snafu
> 
> This compiles correctly with gfc.  A named interface, therefore, is the same
> thing but with a name.  I don't know what this does for us.  A generic
> interface, is a named interface that contains variants for different types.

I did som checking ...

The (draft) f2k standard apperantly considers interfaces with names to be
generic interfaces, even when the interface block contains only one procedure.

This view also agres with the sources of g95 and gfortran; we have 4 different
types of interfaces (defined in gfortran.h):

typedef enum 
{
  INTERFACE_NAMELESS=1,    INTERFACE_GENERIC,
  INTERFACE_INTRINSIC_OP,  INTERFACE_USER_OP
} 
inteface_type; 

The only one of these that can have a name is INTERFACE_GENERIC, which is
treated as "nameless" in find_special() by g95.  This means that either
find_special() is meaningless in g95, or g95 has a bug. In the latter case, we
would most likely introduce the same bug in gfortran with my patch.  I'm,
however, becoming more and more convinced that find_special() is meaningless (in
both compilers) (but I'm not 100 % sure of course).

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[Tobias dot Schlueter at physik dot uni-muenchen dot de]

------- Additional Comments From Tobias dot Schlueter at physik dot uni-muenchen dot de  2005-07-28 10:45 -------
Subject: Re:  interface body has incorrect scope

Quoting erik dot edelmann at iki dot fi <gcc-bugzilla@gcc.gnu.org>:

> The (draft) f2k standard apperantly considers interfaces with names to be
> generic interfaces, even when the interface block contains only one
> procedure.

This is probably so because procedures can later be added to the same generic
name, say
interface a
 module procedure b
end interface
interface a
 module procedure c
end interface

etc.

> The only one of these that can have a name is INTERFACE_GENERIC, which is
> treated as "nameless" in find_special() by g95.  This means that either
> find_special() is meaningless in g95, or g95 has a bug. In the latter case,
> we
> would most likely introduce the same bug in gfortran with my patch.  I'm,
> however, becoming more and more convinced that find_special() is meaningless
> (in
> both compilers) (but I'm not 100 % sure of course).

I think I agree with this, but I'm still not 100% sure I've understood
everything that's relevant.

- Tobi



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-08-25 11:58 -------
Subject: Bug 20363

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	tobi@gcc.gnu.org	2005-08-25 11:57:37

Modified files:
	gcc/fortran    : ChangeLog decl.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gfortran.dg: named_interface.f90 

Log message:
	2005-08-25  Erik Edelmann  <eedelman@acclab.helsinki.fi>
	fortran/
	PR fortran/20363
	* symbol.c (find_special): Remove.
	(build_sym, add_init_expr, attr_decl1): Remove calls to
	find_special in favor of calls to gfc_get_symbol.
	testsuite/
	PR fortran/20363
	* gfortran.dg/named_interface.f90: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fortran/ChangeLog.diff?cvsroot=gcc&r1=1.532&r2=1.533
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fortran/decl.c.diff?cvsroot=gcc&r1=1.40&r2=1.41
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5962&r2=1.5963
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gfortran.dg/named_interface.f90.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-08-25 12:25 -------
Subject: Bug 20363

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-4_0-branch
Changes by:	tobi@gcc.gnu.org	2005-08-25 12:25:37

Modified files:
	gcc/fortran    : ChangeLog decl.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gfortran.dg: named_interface.f90 

Log message:
	2005-08-25  Erik Edelmann  <eedelman@acclab.helsinki.fi>
	fortran/
	PR fortran/20363
	* symbol.c (find_special): Remove.
	(build_sym, add_init_expr, attr_decl1): Remove calls to
	find_special in favor of calls to gfc_get_symbol.
	testsuite/
	PR fortran/20363
	* gfortran.dg/named_interface.f90: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fortran/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.335.2.109&r2=1.335.2.110
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fortran/decl.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.31.2.3&r2=1.31.2.4
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.5084.2.349&r2=1.5084.2.350
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gfortran.dg/named_interface.f90.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=NONE&r2=1.1.2.1



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[tobi at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363

[Bug fortran/20363] interface body has incorrect scope

[tobi at gcc dot gnu dot org]

------- Additional Comments From tobi at gcc dot gnu dot org  2005-08-25 12:27 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20363