+/* True if N * S would overflow in a size_t calculation,
+ or would generate a value larger than PTRDIFF_MAX.
+ This expands to a constant expression if N and S are both constants.
+ By gnulib convention, SIZE_MAX represents overflow in size
+ calculations, so the conservative size_t-based dividend to use here
+ is SIZE_MAX - 1. */
+#define __xalloc_oversized(n, s) \
+ ((size_t) (PTRDIFF_MAX < SIZE_MAX ? PTRDIFF_MAX : SIZE_MAX - 1) / (s) < (n))
+
+#if PTRDIFF_MAX < SIZE_MAX
+typedef ptrdiff_t __xalloc_count_type;
+#else
+typedef size_t __xalloc_count_type;