Patchwork [Fortran] PR 47377 reject nonpointer expr data-target in pointer assignment>

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Submitter Tobias Burnus
Date Jan. 20, 2011, 10:01 p.m.
Message ID <4D38B0A2.8070408@net-b.de>
Download mbox | patch
Permalink /patch/79773/
State New
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Comments

Tobias Burnus - Jan. 20, 2011, 10:01 p.m.
A rather obvious patch for an ICE occurring for invalid code:

   ptr => f()

requires that "f()" returns a pointer. Currently, gfortran first happily 
accepts "f()" if the result variable has the target attribute - and then 
it ICEs. (Cf. PR for the quotes from the standard.)

Build on x86-64-linux and currently regtesting (so far successfully).
OK for the trunk?

Tobias
Steve Kargl - Jan. 20, 2011, 10:16 p.m.
On Thu, Jan 20, 2011 at 11:01:06PM +0100, Tobias Burnus wrote:
> A rather obvious patch for an ICE occurring for invalid code:
> 
>   ptr => f()
> 
> requires that "f()" returns a pointer. Currently, gfortran first happily 
> accepts "f()" if the result variable has the target attribute - and then 
> it ICEs. (Cf. PR for the quotes from the standard.)
> 
> Build on x86-64-linux and currently regtesting (so far successfully).
> OK for the trunk?
> 

OK.

I'll suggest a slight wording change in the error message.
Currently, you have "Pointer assignment target expression"
which I find a little awkward.  Perhaps,
 
+      gfc_error ("Target expression in pointer assignment "
+                "at %L must deliver a pointer result",
+                &rvalue->where);

Whatever you decide to commit is fine with me.

Patch

2011-01-20  Tobias Burnus  <burnus@net-b.de>

	PR fortran/47377
	* expr.c (gfc_check_pointer_assign): Reject expr data-targets
	without pointer attribute.

2011-01-20  Tobias Burnus  <burnus@net-b.de>

	PR fortran/47377
	* gfortran.dg/pointer_target_4.f90: New.

diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 3f1141a..a4e48c8 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -3507,6 +3507,15 @@  gfc_check_pointer_assign (gfc_expr *lvalue, gfc_expr *rvalue)
     lvalue->symtree->n.sym->attr.subref_array_pointer = 1;
 
   attr = gfc_expr_attr (rvalue);
+
+  if (rvalue->expr_type == EXPR_FUNCTION && !attr.pointer)
+    {
+      gfc_error ("Pointer assignment target expression "
+		 "at %L must deliver a pointer result",
+		 &rvalue->where);
+      return FAILURE;
+    }
+
   if (!attr.target && !attr.pointer)
     {
       gfc_error ("Pointer assignment target is neither TARGET "
diff --git a/gcc/testsuite/gfortran.dg/pointer_target_4.f90 b/gcc/testsuite/gfortran.dg/pointer_target_4.f90
new file mode 100644
index 0000000..cda3453
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pointer_target_4.f90
@@ -0,0 +1,15 @@ 
+! { dg-do compile }
+!
+! PR fortran/47377
+!
+! Contributed by <thenlich@users.sourceforge.net>
+!
+program testgferr
+    real, pointer :: y
+    y => f()  ! { dg-error "must deliver a pointer result" }
+contains
+    function f()
+      real :: f
+      f = 5
+    end function f
+end program testgferr