re PR lto/83954 (LTO: Bogus -Wlto-type-mismatch warning for array of pointer to incomplete type)

	PR lto/83954
	* lto-symtab.c (warn_type_compatibility_p): Do not recurse into the
	component type of array types with non-aliased component.

From-SVN: r257343

gcc/lto/ChangeLog

+2018-02-02  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR lto/83954
+	* lto-symtab.c (warn_type_compatibility_p): Do not recurse into the
+	component type of array types with non-aliased component.
+
 2018-01-30  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR lto/83954

gcc/lto/lto-symtab.c

@@ -288,9 +288,12 @@ warn_type_compatibility_p (tree prevailing_type, tree type,
 	{
           tree t1 = type, t2 = prevailing_type;
 
-	  /* Alias sets of arrays are the same as alias sets of the inner
-	     types.  */
-	  while (TREE_CODE (t1) == ARRAY_TYPE && TREE_CODE (t2) == ARRAY_TYPE)
+	  /* Alias sets of arrays with aliased components are the same as alias
+	     sets of the inner types.  */
+	  while (TREE_CODE (t1) == ARRAY_TYPE
+		 && !TYPE_NONALIASED_COMPONENT (t1)
+		 && TREE_CODE (t2) == ARRAY_TYPE
+		 && !TYPE_NONALIASED_COMPONENT (t2))
 	    {
 	      t1 = TREE_TYPE (t1);
 	      t2 = TREE_TYPE (t2);