PR c++/27210

[pf3gnuchains/gcc-fork.git] / gcc / cp / init.c

diff --git a/gcc/cp/init.c b/gcc/cp/init.c
index e9528f2..533f9fb 100644 (file)
--- a/gcc/cp/init.c
+++ b/gcc/cp/init.c
@@ -2088,9 +2088,22 @@ build_new (tree placement, tree type, tree nelts, tree init,
     {
       if (!build_expr_type_conversion (WANT_INT | WANT_ENUM, nelts, false))
        pedwarn ("size in array new must have integral type");
-      nelts = save_expr (cp_convert (sizetype, nelts));
-      if (nelts == integer_zero_node)
-       warning (0, "zero size array reserves no space");
+      nelts = cp_save_expr (cp_convert (sizetype, nelts));
+      /* It is valid to allocate a zero-element array:
+
+          [expr.new]
+
+          When the value of the expression in a direct-new-declarator
+          is zero, the allocation function is called to allocate an
+          array with no elements.  The pointer returned by the
+          new-expression is non-null.  [Note: If the library allocation
+          function is called, the pointer returned is distinct from the
+          pointer to any other object.]  
+
+        However, that is not generally useful, so we issue a
+        warning.  */
+      if (integer_zerop (nelts))
+       warning (0, "allocating zero-element array");
     }
 
   /* ``A reference cannot be created by the new operator.  A reference