2009-01-10 Paul Thomas <pault@gcc.gnu.org>

[pf3gnuchains/gcc-fork.git] / gcc / fortran / dependency.c

diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c
index cd768be..265cf20 100644 (file)
--- a/gcc/fortran/dependency.c
+++ b/gcc/fortran/dependency.c
@@ -1,5 +1,5 @@
 /* Dependency analysis
-   Copyright (C) 2000, 2001, 2002, 2005, 2006, 2007, 2008
+   Copyright (C) 2000, 2001, 2002, 2005, 2006, 2007, 2008, 2009
    Free Software Foundation, Inc.
    Contributed by Paul Brook <paul@nowt.org>
 
@@ -422,6 +422,28 @@ gfc_ref_needs_temporary_p (gfc_ref *ref)
 }
 
 
+int
+gfc_is_data_pointer (gfc_expr *e)
+{
+  gfc_ref *ref;
+
+  if (e->expr_type != EXPR_VARIABLE && e->expr_type != EXPR_FUNCTION)
+    return 0;
+
+  /* No subreference if it is a function  */
+  gcc_assert (e->expr_type == EXPR_VARIABLE || !e->ref);
+
+  if (e->symtree->n.sym->attr.pointer)
+    return 1;
+
+  for (ref = e->ref; ref; ref = ref->next)
+    if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer)
+      return 1;
+
+  return 0;
+}
+
+
 /* Return true if array variable VAR could be passed to the same function
    as argument EXPR without interfering with EXPR.  INTENT is the intent
    of VAR.
@@ -449,19 +471,23 @@ gfc_check_argument_var_dependency (gfc_expr *var, sym_intent intent,
        {
          if (elemental == ELEM_DONT_CHECK_VARIABLE)
            {
-             /* Elemental procedures forbid unspecified intents, 
-                and we don't check dependencies for INTENT_IN args.  */
-             gcc_assert (intent == INTENT_OUT || intent == INTENT_INOUT);
-
-             /* We are told not to check dependencies. 
-                We do it, however, and issue a warning in case we find one. 
-                If a dependency is found in the case 
-                elemental == ELEM_CHECK_VARIABLE, we will generate
-                a temporary, so we don't need to bother the user.  */
-             gfc_warning ("INTENT(%s) actual argument at %L might interfere "
-                          "with actual argument at %L.", 
-                          intent == INTENT_OUT ? "OUT" : "INOUT", 
-                          &var->where, &expr->where);
+             /* Too many false positive with pointers.  */
+             if (!gfc_is_data_pointer (var) && !gfc_is_data_pointer (expr))
+               {
+                 /* Elemental procedures forbid unspecified intents, 
+                    and we don't check dependencies for INTENT_IN args.  */
+                 gcc_assert (intent == INTENT_OUT || intent == INTENT_INOUT);
+
+                 /* We are told not to check dependencies. 
+                    We do it, however, and issue a warning in case we find one.
+                    If a dependency is found in the case 
+                    elemental == ELEM_CHECK_VARIABLE, we will generate
+                    a temporary, so we don't need to bother the user.  */
+                 gfc_warning ("INTENT(%s) actual argument at %L might "
+                              "interfere with actual argument at %L.", 
+                              intent == INTENT_OUT ? "OUT" : "INOUT", 
+                              &var->where, &expr->where);
+               }
              return 0;
            }
          else
@@ -664,7 +690,6 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical)
 {
   gfc_actual_arglist *actual;
   gfc_constructor *c;
-  gfc_ref *ref;
   int n;
 
   gcc_assert (expr1->expr_type == EXPR_VARIABLE);
@@ -700,17 +725,8 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical)
 
          /* If either variable is a pointer, assume the worst.  */
          /* TODO: -fassume-no-pointer-aliasing */
-         if (expr1->symtree->n.sym->attr.pointer)
-           return 1;
-         for (ref = expr1->ref; ref; ref = ref->next)
-           if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer)
-             return 1;
-
-         if (expr2->symtree->n.sym->attr.pointer)
+         if (gfc_is_data_pointer (expr1) || gfc_is_data_pointer (expr2))
            return 1;
-         for (ref = expr2->ref; ref; ref = ref->next)
-           if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer)
-             return 1;
 
          /* Otherwise distinct symbols have no dependencies.  */
          return 0;