libxl: include <ctype.h> and introduce CTYPE helper macro

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 95c34f3753..b35421f7b7 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -33,6 +33,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <ctype.h>
 
 #include <sys/mman.h>
 #include <sys/poll.h>
@@ -1469,6 +1470,25 @@ static inline void libxl__ctx_unlock(libxl_ctx *ctx) {
     } while(0)
 
 
+/*
+ * int CTYPE(ISFOO, char c);
+ * int CTYPE(toupper, char c);
+ * int CTYPE(tolower, char c);
+ *
+ * This is necessary because passing a simple char to a ctype.h
+ * is forbidden.  ctype.h macros take ints derived from _unsigned_ chars.
+ *
+ * If you have a char which might be EOF then you should already have
+ * it in an int representing an unsigned char, and you can use the
+ * <ctype.h> macros directly.  This generally happens only with values
+ * from fgetc et al.
+ *
+ * For any value known to be a character (eg, anything that came from
+ * a char[]), use CTYPE.
+ */
+#define CTYPE(isfoo,c) (isfoo((unsigned char)(c)))
+
+
 #endif
 
 /*