-#define PTRDIFF_MIN (~(ptrdiff_t)0 << (sizeof(ptrdiff_t)*CHAR_BIT-1))
-#define PTRDIFF_MAX (~PTRDIFF_MIN)
-
-/* This may be wrong... */
-#define SIG_ATOMIC_MIN 0
-#define SIG_ATOMIC_MAX 127
-
-#ifndef SIZE_MAX /* SIZE_MAX may also be defined in config.h. */
-# define SIZE_MAX ((size_t)~(size_t)0)
-#endif
-
-/* wchar_t limits already defined in <stddef.h>. */
-/* wint_t limits already defined in <wchar.h>. */
-
-#endif
+/* ptrdiff_t limits */
+#undef PTRDIFF_MIN
+#undef PTRDIFF_MAX
+#define PTRDIFF_MIN \
+ _STDINT_MIN (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+#define PTRDIFF_MAX \
+ _STDINT_MAX (1, @BITSIZEOF_PTRDIFF_T@, 0@PTRDIFF_T_SUFFIX@)
+
+/* sig_atomic_t limits */
+#undef SIG_ATOMIC_MIN
+#undef SIG_ATOMIC_MAX
+#define SIG_ATOMIC_MIN \
+ _STDINT_MIN (@HAVE_SIGNED_SIG_ATOMIC_T@, @BITSIZEOF_SIG_ATOMIC_T@, \
+ 0@SIG_ATOMIC_T_SUFFIX@)
+#define SIG_ATOMIC_MAX \
+ _STDINT_MAX (@HAVE_SIGNED_SIG_ATOMIC_T@, @BITSIZEOF_SIG_ATOMIC_T@, \
+ 0@SIG_ATOMIC_T_SUFFIX@)
+
+
+/* size_t limit */
+#undef SIZE_MAX
+#define SIZE_MAX _STDINT_MAX (0, @BITSIZEOF_SIZE_T@, 0@SIZE_T_SUFFIX@)
+
+/* wchar_t limits */
+#undef WCHAR_MIN
+#undef WCHAR_MAX
+#define WCHAR_MIN \
+ _STDINT_MIN (@HAVE_SIGNED_WCHAR_T@, @BITSIZEOF_WCHAR_T@, 0@WCHAR_T_SUFFIX@)
+#define WCHAR_MAX \
+ _STDINT_MAX (@HAVE_SIGNED_WCHAR_T@, @BITSIZEOF_WCHAR_T@, 0@WCHAR_T_SUFFIX@)
+
+/* wint_t limits */
+#undef WINT_MIN
+#undef WINT_MAX
+#define WINT_MIN \
+ _STDINT_MIN (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, 0@WINT_T_SUFFIX@)
+#define WINT_MAX \
+ _STDINT_MAX (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, 0@WINT_T_SUFFIX@)
+
+#endif /* !defined __cplusplus || defined __STDC_LIMIT_MACROS */