+/**
+ * STR_MAX_CHARS - Maximum possible size of numeric string for this type.
+ * @type_or_expr: a pointer or integer type or expression.
+ *
+ * This provides enough space for a nul-terminated string which represents the
+ * largest possible value for the type or expression.
+ *
+ * Note: The implementation adds extra space so hex values or negative
+ * values will fit (eg. sprintf(... "%p"). )
+ *
+ * Example:
+ * char str[STR_MAX_CHARS(int)];
+ *
+ * sprintf(str, "%i", 7);
+ */
+#define STR_MAX_CHARS(type_or_expr) \
+ ((sizeof(type_or_expr) * CHAR_BIT + 8) / 9 * 3 + 2 \
+ + STR_MAX_CHARS_TCHECK_(type_or_expr))
+
+#if HAVE_TYPEOF
+/* Only a simple type can have 0 assigned, so test that. */
+#define STR_MAX_CHARS_TCHECK_(type_or_expr) \
+ ({ typeof(type_or_expr) x = 0; (void)x; 0; })
+#else
+#define STR_MAX_CHARS_TCHECK_(type_or_expr) 0
+#endif
+
+/**
+ * cisalnum - isalnum() which takes a char (and doesn't accept EOF)
+ * @c: a character
+ *
+ * Surprisingly, the standard ctype.h isalnum() takes an int, which
+ * must have the value of EOF (-1) or an unsigned char. This variant
+ * takes a real char, and doesn't accept EOF.
+ */
+static inline bool cisalnum(char c)
+{
+ return isalnum((unsigned char)c);
+}
+static inline bool cisalpha(char c)
+{
+ return isalpha((unsigned char)c);
+}
+static inline bool cisascii(char c)
+{
+ return isascii((unsigned char)c);
+}
+#if HAVE_ISBLANK
+static inline bool cisblank(char c)
+{
+ return isblank((unsigned char)c);
+}
+#endif
+static inline bool ciscntrl(char c)
+{
+ return iscntrl((unsigned char)c);
+}
+static inline bool cisdigit(char c)
+{
+ return isdigit((unsigned char)c);
+}
+static inline bool cisgraph(char c)
+{
+ return isgraph((unsigned char)c);
+}
+static inline bool cislower(char c)
+{
+ return islower((unsigned char)c);
+}
+static inline bool cisprint(char c)
+{
+ return isprint((unsigned char)c);
+}
+static inline bool cispunct(char c)
+{
+ return ispunct((unsigned char)c);
+}
+static inline bool cisspace(char c)
+{
+ return isspace((unsigned char)c);
+}
+static inline bool cisupper(char c)
+{
+ return isupper((unsigned char)c);
+}
+static inline bool cisxdigit(char c)
+{
+ return isxdigit((unsigned char)c);
+}
+