[Patch, Fortran] PR fortran/36746: Fix IMPLICIT typing of derived types

[Daniel Kraft <d at domob dot eu>]

Hi,

so here's my second attempt at this bug, this time with a more 
conservative patch as promised :)

All I did is moving the logic that gives a symbol it's IMPLICIT derived 
type if a component reference is found from gfc_match_rvalue to 
gfc_match_varspec, so that an array-reference inbetween does not confuse 
the parser.  In addition I added a new test to check for the behaviour 
we agreed upon in the discussion of my last attempt, it succeeds by default.

I've added the reduced test from the PR to the test-suite and also 
checked that the original test (long) works with my patch.  I'm at the 
moment regression-testing on GNU/Linux-x86-32.  Is this patch ok if 
there are no regressions?

Cheers,
Daniel

--
Done:     Arc-Bar-Cav-Sam-Val-Wiz, Dwa-Elf-Gno-Hum-Orc, Law-Neu-Cha, Fem-Mal
To go:    Hea-Kni-Mon-Pri-Ran-Rog-Tou

2008-08-05  Daniel Kraft  <d@domob.eu>

	PR fortran/36746
	* primary.c (gfc_match_rvalue): Removed logic to handle implicit
	typing to a derived-type if a component reference is found.
	(gfc_match_varspec): Moved it here.

2008-08-05  Daniel Kraft  <d@domob.eu>

	PR fortran/36746
	* gfortran.dg/implicit_derived_type_1.f90: New test.
	* gfortran.dg/used_before_typed_5.f90: New test.

Index: gcc/fortran/primary.c
===================================================================
--- gcc/fortran/primary.c	(revision 139985)
+++ gcc/fortran/primary.c	(working copy)
@@ -1745,6 +1745,10 @@ gfc_match_varspec (gfc_expr *primary, in
   if (equiv_flag)
     return MATCH_YES;
 
+  if (sym->ts.type == BT_UNKNOWN && gfc_peek_ascii_char () == '%'
+      && gfc_get_default_type (sym, sym->ns)->type == BT_DERIVED)
+    gfc_set_default_type (sym, 0, sym->ns);
+
   if (sym->ts.type != BT_DERIVED || gfc_match_char ('%') != MATCH_YES)
     goto check_substring;
 
@@ -2434,10 +2438,6 @@ gfc_match_rvalue (gfc_expr **result)
     {
     case FL_VARIABLE:
     variable:
-      if (sym->ts.type == BT_UNKNOWN && gfc_peek_ascii_char () == '%'
-	  && gfc_get_default_type (sym, sym->ns)->type == BT_DERIVED)
-	gfc_set_default_type (sym, 0, sym->ns);
-
       e = gfc_get_expr ();
 
       e->expr_type = EXPR_VARIABLE;
Index: gcc/testsuite/gfortran.dg/implicit_derived_type_1.f90
===================================================================
--- gcc/testsuite/gfortran.dg/implicit_derived_type_1.f90	(revision 0)
+++ gcc/testsuite/gfortran.dg/implicit_derived_type_1.f90	(revision 0)
@@ -0,0 +1,20 @@
+! { dg-do compile }
+
+! PR fortran/36746
+! Check that parsing of component references for symbols with IMPLICIT
+! derived-type works.
+
+! Reduced test from the PR.
+! Contributed by Tobias Burnus <burnus@gcc.gnu.org>
+
+module m
+  type t
+    integer :: i
+  end type t
+contains
+  subroutine s(x)
+    implicit type(t)(x)
+    dimension x(:)
+    print *, x(1)%i
+  end subroutine s
+end module m
Index: gcc/testsuite/gfortran.dg/used_before_typed_5.f90
===================================================================
--- gcc/testsuite/gfortran.dg/used_before_typed_5.f90	(revision 0)
+++ gcc/testsuite/gfortran.dg/used_before_typed_5.f90	(revision 0)
@@ -0,0 +1,19 @@
+! { dg-do compile }
+! { dg-options "-pedantic -std=f95" }
+
+! Check that DIMENSION/POINTER/ALLOCATABLE/INTENT statements *do* allow
+! symbols to be typed later.
+
+SUBROUTINE test (a)
+  IMPLICIT REAL (a-z)
+
+  ! Those should *not* IMPLICIT-type the symbols:
+  INTENT(IN) :: a
+  DIMENSION :: b(:)
+  POINTER :: c
+  ALLOCATABLE :: b
+
+  ! So this is ok:
+  INTEGER :: a, b, c
+
+END SUBROUTINE test