use _GL_ATTRIBUTE_CONST and _GL_ATTRIBUTE_PURE

[gnulib.git] / lib / base64.c

diff --git a/lib/base64.c b/lib/base64.c
index 99fcc57..89e83e6 100644 (file)
--- a/lib/base64.c
+++ b/lib/base64.c
@@ -53,6 +53,14 @@
 
 #include <string.h>
 
+/* The attribute __const__ was added in gcc 2.95.  */
+#undef _GL_ATTRIBUTE_CONST
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
+#else
+# define _GL_ATTRIBUTE_CONST /* empty */
+#endif
+
 /* C89 compliant way to cast 'char' to 'unsigned char'. */
 static inline unsigned char
 to_uchar (char ch)
@@ -295,7 +303,7 @@ static const signed char b64[0x100] = {
 /* Return true if CH is a character from the Base64 alphabet, and
    false otherwise.  Note that '=' is padding and not considered to be
    part of the alphabet.  */
-bool
+bool _GL_ATTRIBUTE_CONST
 isbase64 (char ch)
 {
   return uchar_in_range (to_uchar (ch)) && 0 <= b64[to_uchar (ch)];