2012-03-29 Basile Starynkevitch <basile@starynkevitch.net>

	MELT branch merged with trunk rev 185951 using svnmerge



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@185952 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 16 insertions, 3 deletions

diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 7eccf672546..b048ac7b3cd 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -151,6 +151,9 @@ change_return_type (tree new_ret, tree fntype)
   tree raises = TYPE_RAISES_EXCEPTIONS (fntype);
   tree attrs = TYPE_ATTRIBUTES (fntype);
 
+  if (new_ret == error_mark_node)
+    return fntype;
+
   if (same_type_p (new_ret, TREE_TYPE (fntype)))
     return fntype;
 
@@ -4281,7 +4284,11 @@ mark_used (tree decl)
   if ((TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
       || DECL_LANG_SPECIFIC (decl) == NULL
       || DECL_THUNK_P (decl))
-    return true;
+    {
+      if (!processing_template_decl && type_uses_auto (TREE_TYPE (decl)))
+	error ("use of %qD before deduction of %<auto%>", decl);
+      return true;
+    }
 
   /* We only want to do this processing once.  We don't need to keep trying
      to instantiate inline templates, because unit-at-a-time will make sure
@@ -4303,10 +4310,13 @@ mark_used (tree decl)
   /* Normally, we can wait until instantiation-time to synthesize DECL.
      However, if DECL is a static data member initialized with a constant
      or a constexpr function, we need it right now because a reference to
-     such a data member or a call to such function is not value-dependent.  */
+     such a data member or a call to such function is not value-dependent.
+     For a function that uses auto in the return type, we need to instantiate
+     it to find out its type.  */
   if ((decl_maybe_constant_var_p (decl)
        || (TREE_CODE (decl) == FUNCTION_DECL
-	   && DECL_DECLARED_CONSTEXPR_P (decl)))
+	   && (DECL_DECLARED_CONSTEXPR_P (decl)
+	       || type_uses_auto (TREE_TYPE (TREE_TYPE (decl))))))
       && DECL_LANG_SPECIFIC (decl)
       && DECL_TEMPLATE_INFO (decl)
       && !uses_template_parms (DECL_TI_ARGS (decl)))
@@ -4321,6 +4331,9 @@ mark_used (tree decl)
       --function_depth;
     }
 
+  if (type_uses_auto (TREE_TYPE (decl)))
+    error ("use of %qD before deduction of %<auto%>", decl);
+
   /* If we don't need a value, then we don't need to synthesize DECL.  */
   if (cp_unevaluated_operand != 0)
     return true;