* gcc-interface/trans.c (return_value_ok_for_nrv_p): Add sanity check.

From-SVN: r245701

gcc/ada/ChangeLog

 2017-02-24  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* gcc-interface/trans.c (return_value_ok_for_nrv_p): Add sanity check.
+
+2017-02-24  Eric Botcazou  <ebotcazou@adacore.com>
+
 	* gcc-interface/decl.c: Include demangle.h.
 	(is_cplusplus_method): Return again true for a primitive operation
 	only if it is dispatching.  For a subprogram with an interface name,

gcc/ada/gcc-interface/trans.c

@@ -3614,9 +3614,16 @@ return_value_ok_for_nrv_p (tree ret_obj, tree ret_val)
   if (TREE_ADDRESSABLE (ret_val))
     return false;
 
+  /* For the constrained case, test for overalignment.  */
   if (ret_obj && DECL_ALIGN (ret_val) > DECL_ALIGN (ret_obj))
     return false;
 
+  /* For the unconstrained case, test for bogus initialization.  */
+  if (!ret_obj
+      && DECL_INITIAL (ret_val)
+      && TREE_CODE (DECL_INITIAL (ret_val)) == NULL_EXPR)
+    return false;
+
   return true;
 }
 

gcc/testsuite/ChangeLog

 2017-02-24  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* gnat.dg/opt63.adb: New test.
+
+2017-02-24  Eric Botcazou  <ebotcazou@adacore.com>
+
 	* gnat.dg/discr47.adb: New test.
 
 2017-02-24  Richard Biener  <rguenther@suse.de>

gcc/testsuite/gnat.dg/opt63.adb

+-- { dg-do compile }
+-- { dg-options "-O -gnatws" }
+
+procedure Opt63 is
+
+   type T_MOD is mod 2**32;
+   subtype T_INDEX is T_MOD range 3_000_000_000 .. 4_000_000_000;
+   type T_ARRAY is array(T_INDEX range <>) of INTEGER;
+
+   function Build_Crash(First : T_INDEX; Length : NATURAL) return T_ARRAY is
+      R : T_ARRAY(First .. T_Index'Val (T_Index'Pos (First) + Length))
+             := (others => -1); -- Crash here
+   begin
+      return R;
+   end;
+
+begin
+   null;
+end;