[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2010-08-19 09:47:08         |2013-03-29
                 CC|                            |Joost.VandeVondele at mat
                   |                            |dot ethz.ch

--- Comment #12 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> 2013-03-29 09:27:23 UTC ---
comment #11 still fails on 4.9 trunk.

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[markeggleston at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

markeggleston at gcc dot gnu.org changed:

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

--- Comment #13 from markeggleston at gcc dot gnu.org ---
Regarding patch in comment 7 and test case in comment 11.

It seems to me that it is only necessary to to check for the dummy attribute:

diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 223dcccce91..730d11105bd 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -12918,8 +12918,7 @@ resolve_fl_variable (gfc_symbol *sym, int mp_flag)
       else if (sym->attr.external)
        gfc_error ("External %qs at %L cannot have an initializer",
                   sym->name, &sym->declared_at);
-      else if (sym->attr.dummy
-       && !(sym->ts.type == BT_DERIVED && sym->attr.intent == INTENT_OUT))
+      else if (sym->attr.dummy)
        gfc_error ("Dummy %qs at %L cannot have an initializer",
                   sym->name, &sym->declared_at);
       else if (sym->attr.intrinsic)


For the test case from comment 1:

pr45337_1.f90:3:20:

    3 | subroutine lengthX(x, i)
      |                    1
Error: Dummy 'x' at (1) cannot have an initializer
pr45337_1.f90:14:7:

   14 |   use ptrmod
      |       1
Fatal Error: Cannot open module file 'ptrmod.mod' for reading at (1): No such
file or directory
compilation terminated.


and for the test case from comment 11:

pr45337_2.f90:7:16:

    7 |   subroutine x(a, b, c)
      |                1
Error: Dummy 'a' at (1) cannot have an initializer
pr45337_2.f90:7:19:

    7 |   subroutine x(a, b, c)
      |                   1
Error: Dummy 'b' at (1) cannot have an initializer


Regarding comments 8, 9 and 10.  I think the the error messages are sufficient
as is.

No additional test failures encountered when running make check-fortran.

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

--- Comment #14 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Mark Eggleston
<markeggleston@gcc.gnu.org>:

https://gcc.gnu.org/g:bae66e0f04323ba9d5daf60fcb997de925100e3e

commit r11-2065-gbae66e0f04323ba9d5daf60fcb997de925100e3e
Author: Mark Eggleston <markeggleston@gcc.gnu.org>
Date:   Wed Jun 10 07:22:50 2020 +0100

    Fortran  : accepts pointer initialization of DT dummy args PR45337

    Initialisation of a variable results in an implicit save attribute
    being added to the variable.  The save attribute is not allowed for
    variables with the dummy attribute set.  Initialisation should be
    rejected for dummy variables.

    2020-07-13  Mark Eggleston  <markeggleston@gcc.gnu.org>

    gcc/fortran/

            PR fortran/45337
            * resolve.c (resolve_fl_variable): Remove type and intent
            checks from the check for dummy.

    2020-07-13  Mark Eggleston  <markeggleston@gcc.gnu.org>

    gcc/testsuite/

            PR fortran/45337
            * gfortran.dg/pr45337_1.f90: New test.
            * gfortran.dg/pr45337_2.f90: New test.

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[markeggleston at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

markeggleston at gcc dot gnu.org changed:

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

--- Comment #15 from markeggleston at gcc dot gnu.org ---
Committed to master.

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[burnus at gcc dot gnu dot org]

------- Comment #11 from burnus at gcc dot gnu dot org  2010-08-20 22:28 -------
(In reply to comment #7)
> Untested patch:

The patch is not sufficient as the following example shows for which no warning
is printed:

type t
end type t
type t2
  integer :: j = 7
end type t2
contains
  subroutine x(a, b, c)
    type(t) ,intent(OUT) :: a = t() ! Wrong
    type(t2) ,intent(OUT) :: b = t2() ! Wrong
    type(t2) ,intent(OUT) :: c ! OK, default initializer
end subroutine x
end


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[jv244 at cam dot ac dot uk]

------- Comment #10 from jv244 at cam dot ac dot uk  2010-08-20 08:57 -------
(In reply to comment #9)
> (In reply to comment #8)
> > Error: Dummy 'x' at (1) cannot have an initializer
>
> Do you have a suggestion?
>
Error: Dummy argument 'x' at (1) cannot have the save attribute which is
implied by initialization.

?? 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[burnus at gcc dot gnu dot org]

------- Comment #9 from burnus at gcc dot gnu dot org  2010-08-20 08:45 -------
(In reply to comment #8)
> Error: Dummy 'x' at (1) cannot have an initializer
> 
> I think this is easy to understand, an additional short message about why it
> can't have an initializer will be better.

Do you have a suggestion?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[linuxl4 at sohu dot com]

------- Comment #8 from linuxl4 at sohu dot com  2010-08-20 06:50 -------
Error: Dummy 'x' at (1) cannot have an initializer

I think this is easy to understand, an additional short message about why it
can't have an initializer will be better.

> 
>   It helps if you already state (a) the error message and (b) what you expect
> in the first
>   description.
> 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[burnus at gcc dot gnu dot org]

------- Comment #7 from burnus at gcc dot gnu dot org  2010-08-19 09:56 -------
Untested patch:

Index: resolve.c
===================================================================
--- resolve.c   (revision 163368)
+++ resolve.c   (working copy)
@@ -9724,7 +9724,8 @@ resolve_fl_variable (gfc_symbol *sym, in
        gfc_error ("External '%s' at %L cannot have an initializer",
                   sym->name, &sym->declared_at);
       else if (sym->attr.dummy
-       && !(sym->ts.type == BT_DERIVED && sym->attr.intent == INTENT_OUT))
+       && !(sym->ts.type == BT_DERIVED && sym->attr.intent == INTENT_OUT
+            && !sym->attr.pointer))
        gfc_error ("Dummy '%s' at %L cannot have an initializer",
                   sym->name, &sym->declared_at);
       else if (sym->attr.intrinsic)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[burnus at gcc dot gnu dot org]

------- Comment #6 from burnus at gcc dot gnu dot org  2010-08-19 09:47 -------
(In reply to comment #5)
  It should read: program in comment 3 (not in comment 2).

To macius bat:
  Thanks for the bug report!

  It helps if you already state (a) the error message and (b) what you expect
in the first
  description.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
  GCC build triplet|x86_64 - redhat - linux     |
   GCC host triplet|x86_64 - redhat - linux     |
 GCC target triplet|x86_64 - redhat - linux     |
   Last reconfirmed|0000-00-00 00:00:00         |2010-08-19 09:47:08
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337

[Bug fortran/45337] gfortran accepts pointer initialization of DT dummy arguments w/ INTENT(OUT)

[burnus at gcc dot gnu dot org]

------- Comment #5 from burnus at gcc dot gnu dot org  2010-08-19 09:40 -------
(In reply to comment #2)
> Intents for pointers is fine, but not Fortran95 (2003/2008?)

Intents for pointers is Fortran 2003; it applies to the pointer association
status and not to the value.


The programs in comment 0 and comment 2 are both invalid.

  type(inde), pointer :: indexx(:)=>null()

means that "indexx" is initialized - which is only possible for variables which
are in static memory ("SAVE"; the assignment implies the SAVE). That's OK for
the line above, but not for dummy arguments to subroutines.

Note: In C  "int a = 5;" and "int a; a = 5;" have the same meaning. In Fortran
not! "integer :: a = 5" means that "a" is in static memory ("SAVE") and will
only be initialized once at program start. Whereas for "integer :: a; a = 5" 
the assignment happens every time the line is subroutine is called.

 * * *

Regarding the accepts invalid bug:

While for the program in comment 0, gfortran prints the error
  Error: Dummy 'x' at (1) cannot have an initializer
it compiles the program in comment 2.

Note: If one removes the INTENT(OUT) or has (as in comment 0) no derived-type
dummy, the error is printed.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
           Keywords|                            |accepts-invalid
         Resolution|INVALID                     |
            Summary|intent(out) and pointer =>  |gfortran accepts pointer
                   |null()                      |initialization of DT dummy
                   |                            |arguments w/ INTENT(OUT)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45337