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[PATCH(es)] PR fortran/77391 -- RFC vote on which you prefer

Message ID 20160827000605.GA3601@troutmask.apl.washington.edu
State New
Headers show

Commit Message

Steve Kargl Aug. 27, 2016, 12:06 a.m. UTC 
On Fri, Aug 26, 2016 at 10:28:25PM +0200, Mikael Morin wrote:
> Hello,
> 
> Le 26/08/2016 à 20:27, Steve Kargl a écrit :
> > Here are two possible patches for PR fortran/77391.  The first
> > patch treats the invalid code as a GNU Fortran extension as
> > gfortran current accepts the invalid code.  The second patch
> > enforces the standard.  As I think gfortran should encourage
> > standard conformance, I am inclined to commit the second patch.
> > I will however commit the most popular of the two patches tomorrow.
> > Voting starts now and will remain open for 24 hours (give or take
> > a few hours depend on when I awaken).
> >
> 
> I don't think it's sufficient to check current_attr because of this case:
> 
>        character(:) :: a
>        pointer :: a
>        end
> 
> The statement should be accepted, and the check be postponed at a time 
> after the symbol has been initialised, at resolution time for example.
> 

So, I've come up the following.  We now need to debate whether
Dominiq's observations mean that C402 does not apply to named
constant.

2016-08-26  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/77391
	* resolve.c (deferred_requirements): New function to check F2008:C402.
	(resolve_fl_variable,resolve_fl_parameter): Use it.
 
2016-08-26  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/77391
	* gfortran.dg/pr77391.f90: New test.

Comments

Jerry DeLisle Aug. 27, 2016, 12:51 p.m. UTC | #1 
On 08/26/2016 05:06 PM, Steve Kargl wrote:
--- snip ---
>
> So, I've come up the following.  We now need to debate whether
> Dominiq's observations mean that C402 does not apply to named
> constant.
>

See my comment in the PR. The standard gives the explicit way to accomplish what 
the user wants to do by use of the asterisk.

C402 Holds

Jerry
diff mbox

Patch

Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(revision 239762)
+++ gcc/fortran/resolve.c	(working copy)
@@ -11402,6 +11402,27 @@  resolve_fl_variable_derived (gfc_symbol 
 }
 
 
+/* F2008, C402 (R401):  A colon shall not be used as a type-param-value
+   except in the declaration of an entity or component that has the POINTER
+   or ALLOCATABLE attribute.  */
+
+static bool
+deferred_requirements (gfc_symbol *sym)
+{
+  if (sym->ts.deferred
+      && !(sym->attr.pointer
+	   || sym->attr.allocatable
+	   || sym->attr.omp_udr_artificial_var))
+    {
+      gfc_error ("Entity %qs at %L has a deferred type parameter and "
+		 "requires either the POINTER or ALLOCATABLE attribute",
+		 sym->name, &sym->declared_at);
+      return false;
+    }
+  return true;
+}
+
+
 /* Resolve symbols with flavor variable.  */
 
 static bool
@@ -11441,17 +11462,8 @@  resolve_fl_variable (gfc_symbol *sym, in
     }
 
   /* Constraints on deferred type parameter.  */
-  if (sym->ts.deferred
-      && !(sym->attr.pointer
-	   || sym->attr.allocatable
-	   || sym->attr.omp_udr_artificial_var))
-    {
-      gfc_error ("Entity %qs at %L has a deferred type parameter and "
-		 "requires either the pointer or allocatable attribute",
-		     sym->name, &sym->declared_at);
-      specification_expr = saved_specification_expr;
-      return false;
-    }
+  if (!deferred_requirements (sym))
+    return false;
 
   if (sym->ts.type == BT_CHARACTER)
     {
@@ -13570,6 +13582,10 @@  resolve_fl_parameter (gfc_symbol *sym)
       return false;
     }
 
+  /* Constraints on deferred type parameter.  */
+  if (!deferred_requirements (sym))
+    return false;
+
   /* Make sure a parameter that has been implicitly typed still
      matches the implicit type, since PARAMETER statements can precede
      IMPLICIT statements.  */
Index: gcc/testsuite/gfortran.dg/pr77391.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr77391.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr77391.f90	(working copy)
@@ -0,0 +1,7 @@ 
+! { dg-do compile }
+program picky
+character(len=:), parameter :: a="whoops" ! { dg-error "POINTER or ALLOCATABLE" }
+character(len=:) :: b="whoops" ! { dg-error "POINTER or ALLOCATABLE" }
+character(len=:) :: good
+pointer good
+end program picky