[PATCH] Fix Fortran serial loop iterators sharing (PR fortran/43339)

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

While OpenMP 2.5 has been pretty vague here and I don't remember
getting any OpenMP response for
http://openmp.org/pipermail/omp/2005/000353.html
(for more details see also
http://gcc.gnu.org/ml/gcc-patches/2005-10/msg01150.html )
OpenMP 3.0 seems to be pretty clear that only the innermost task region
is affected.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
committed to trunk, will commit to 4.5/4.4 tomorrow after
bootstrapping/regtesting there.

2010-04-19  Jakub Jelinek  <jakub@redhat.com>

	PR fortran/43339
	* openmp.c (gfc_resolve_do_iterator): Only make iteration vars for
	sequential loops private in the innermost containing task region.

	* gfortran.dg/gomp/sharing-2.f90: Adjust for iteration vars
	of sequential loops being private only in the innermost containing
	task region.

--- gcc/fortran/openmp.c.jj	2009-08-19 17:46:03.000000000 +0200
+++ gcc/fortran/openmp.c	2010-04-19 19:31:06.000000000 +0200
@@ -1,5 +1,5 @@
 /* OpenMP directive matching and resolving.
-   Copyright (C) 2005, 2006, 2007, 2008
+   Copyright (C) 2005, 2006, 2007, 2008, 2010
    Free Software Foundation, Inc.
    Contributed by Jakub Jelinek
 
@@ -1367,7 +1367,6 @@ gfc_resolve_omp_parallel_blocks (gfc_cod
 void
 gfc_resolve_do_iterator (gfc_code *code, gfc_symbol *sym)
 {
-  struct omp_context *ctx;
   int i = omp_current_do_collapse;
   gfc_code *c = omp_current_do_code;
 
@@ -1386,21 +1385,21 @@ gfc_resolve_do_iterator (gfc_code *code,
       c = c->block->next;
     }
 
-  for (ctx = omp_current_ctx; ctx; ctx = ctx->previous)
-    {
-      if (pointer_set_contains (ctx->sharing_clauses, sym))
-	continue;
+  if (omp_current_ctx == NULL)
+    return;
 
-      if (! pointer_set_insert (ctx->private_iterators, sym))
-	{
-	  gfc_omp_clauses *omp_clauses = ctx->code->ext.omp_clauses;
-	  gfc_namelist *p;
+  if (pointer_set_contains (omp_current_ctx->sharing_clauses, sym))
+    return;
 
-	  p = gfc_get_namelist ();
-	  p->sym = sym;
-	  p->next = omp_clauses->lists[OMP_LIST_PRIVATE];
-	  omp_clauses->lists[OMP_LIST_PRIVATE] = p;
-	}
+  if (! pointer_set_insert (omp_current_ctx->private_iterators, sym))
+    {
+      gfc_omp_clauses *omp_clauses = omp_current_ctx->code->ext.omp_clauses;
+      gfc_namelist *p;
+
+      p = gfc_get_namelist ();
+      p->sym = sym;
+      p->next = omp_clauses->lists[OMP_LIST_PRIVATE];
+      omp_clauses->lists[OMP_LIST_PRIVATE] = p;
     }
 }
 
--- gcc/testsuite/gfortran.dg/gomp/sharing-2.f90.jj	2008-09-05 12:55:10.000000000 +0200
+++ gcc/testsuite/gfortran.dg/gomp/sharing-2.f90	2010-04-19 20:51:32.000000000 +0200
@@ -28,10 +28,10 @@
   end do
 !$omp end single
 !$omp end parallel
-!$omp parallel default (none) shared (a)
-  i = 1
-  j = 1
-  k = 1
+!$omp parallel default (none) shared (a) ! { dg-error "enclosing parallel" }
+  i = 1		! { dg-error "not specified in" }
+  j = 1		! { dg-error "not specified in" }
+  k = 1		! { dg-error "not specified in" }
 !$omp parallel default (none) shared (a)
   i = 1
   j = 1
@@ -68,8 +68,8 @@
     a(i, 1) = i + 1
   end do
 !$omp end parallel
-!$omp parallel default (none) shared (a)
-  i = 1
+!$omp parallel default (none) shared (a) ! { dg-error "enclosing parallel" }
+  i = 1		! { dg-error "not specified in" }
 !$omp parallel default (none) shared (a, i)
   i = 2
 !$omp parallel default (none) shared (a)

	Jakub