--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2006-10-10  Bruno Haible  <bruno@clisp.org>
+
+	Make it possible to #define c_isascii to an alias.
+	* lib/c-ctype.h: Don't define the macros if NO_C_CTYPE_MACROS is
+	defined. Undefine the macros before defining them, to avoid gcc
+	warnings.
+	* lib/c-ctype.c: Include config.h. Don't undefine the macros; instead,
+	define NO_C_CTYPE_MACROS early.
+
 2006-10-10  Bruno Haible  <bruno@clisp.org>
 
 	Make it possible to #define set_program_name to an alias.

--- a/lib/c-ctype.c
+++ b/lib/c-ctype.c
@@ -1,6 +1,6 @@
 /* Character handling in C locale.
 
-   Copyright 2000-2003 Free Software Foundation, Inc.
+   Copyright 2000-2003, 2006 Free Software Foundation, Inc.
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -16,24 +16,11 @@
 along with this program; if not, write to the Free Software Foundation,
 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-/* Specification.  */
-#include "c-ctype.h"
+#include <config.h>
 
-#undef c_isalnum
-#undef c_isalpha
-#undef c_isascii
-#undef c_isblank
-#undef c_iscntrl
-#undef c_isdigit
-#undef c_islower
-#undef c_isgraph
-#undef c_isprint
-#undef c_ispunct
-#undef c_isspace
-#undef c_isupper
-#undef c_isxdigit
-#undef c_tolower
-#undef c_toupper
+/* Specification.  */
+#define NO_C_CTYPE_MACROS
+#include "c-ctype.h"
 
 /* The function isascii is not locale dependent. Its use in EBCDIC is
    questionable. */

--- a/lib/c-ctype.h
+++ b/lib/c-ctype.h
@@ -5,7 +5,7 @@
    <ctype.h> functions' behaviour depends on the current locale set via
    setlocale.
 
-   Copyright (C) 2000-2003 Free Software Foundation, Inc.
+   Copyright (C) 2000-2003, 2006 Free Software Foundation, Inc.
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -117,10 +117,11 @@
 extern int c_toupper (int c);
 
 
-#if defined __GNUC__ && defined __OPTIMIZE__ && !defined __OPTIMIZE_SIZE__
+#if defined __GNUC__ && defined __OPTIMIZE__ && !defined __OPTIMIZE_SIZE__ && !defined NO_C_CTYPE_MACROS
 
 /* ASCII optimizations. */
 
+#undef c_isascii
 #define c_isascii(c) \
   ({ int __c = (c); \
      (__c >= 0x00 && __c <= 0x7f); \
@@ -129,12 +130,14 @@
 #if C_CTYPE_CONSECUTIVE_DIGITS \
     && C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE
 #if C_CTYPE_ASCII
+#undef c_isalnum
 #define c_isalnum(c) \
   ({ int __c = (c); \
      ((__c >= '0' && __c <= '9') \
       || ((__c & ~0x20) >= 'A' && (__c & ~0x20) <= 'Z')); \
    })
 #else
+#undef c_isalnum
 #define c_isalnum(c) \
   ({ int __c = (c); \
      ((__c >= '0' && __c <= '9') \
@@ -146,11 +149,13 @@
 
 #if C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE
 #if C_CTYPE_ASCII
+#undef c_isalpha
 #define c_isalpha(c) \
   ({ int __c = (c); \
      ((__c & ~0x20) >= 'A' && (__c & ~0x20) <= 'Z'); \
    })
 #else
+#undef c_isalpha
 #define c_isalpha(c) \
   ({ int __c = (c); \
      ((__c >= 'A' && __c <= 'Z') || (__c >= 'a' && __c <= 'z')); \
@@ -158,12 +163,14 @@
 #endif
 #endif
 
+#undef c_isblank
 #define c_isblank(c) \
   ({ int __c = (c); \
      (__c == ' ' || __c == '\t'); \
    })
 
 #if C_CTYPE_ASCII
+#undef c_iscntrl
 #define c_iscntrl(c) \
   ({ int __c = (c); \
      ((__c & ~0x1f) == 0 || __c == 0x7f); \
@@ -171,6 +178,7 @@
 #endif
 
 #if C_CTYPE_CONSECUTIVE_DIGITS
+#undef c_isdigit
 #define c_isdigit(c) \
   ({ int __c = (c); \
      (__c >= '0' && __c <= '9'); \
@@ -178,6 +186,7 @@
 #endif
 
 #if C_CTYPE_CONSECUTIVE_LOWERCASE
+#undef c_islower
 #define c_islower(c) \
   ({ int __c = (c); \
      (__c >= 'a' && __c <= 'z'); \
@@ -185,6 +194,7 @@
 #endif
 
 #if C_CTYPE_ASCII
+#undef c_isgraph
 #define c_isgraph(c) \
   ({ int __c = (c); \
      (__c >= '!' && __c <= '~'); \
@@ -192,6 +202,7 @@
 #endif
 
 #if C_CTYPE_ASCII
+#undef c_isprint
 #define c_isprint(c) \
   ({ int __c = (c); \
      (__c >= ' ' && __c <= '~'); \
@@ -199,12 +210,14 @@
 #endif
 
 #if C_CTYPE_ASCII
+#undef c_ispunct
 #define c_ispunct(c) \
   ({ int _c = (c); \
      (c_isgraph (_c) && ! c_isalnum (_c)); \
    })
 #endif
 
+#undef c_isspace
 #define c_isspace(c) \
   ({ int __c = (c); \
      (__c == ' ' || __c == '\t' \
@@ -212,6 +225,7 @@
    })
 
 #if C_CTYPE_CONSECUTIVE_UPPERCASE
+#undef c_isupper
 #define c_isupper(c) \
   ({ int __c = (c); \
      (__c >= 'A' && __c <= 'Z'); \
@@ -221,12 +235,14 @@
 #if C_CTYPE_CONSECUTIVE_DIGITS \
     && C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE
 #if C_CTYPE_ASCII
+#undef c_isxdigit
 #define c_isxdigit(c) \
   ({ int __c = (c); \
      ((__c >= '0' && __c <= '9') \
       || ((__c & ~0x20) >= 'A' && (__c & ~0x20) <= 'F')); \
    })
 #else
+#undef c_isxdigit
 #define c_isxdigit(c) \
   ({ int __c = (c); \
      ((__c >= '0' && __c <= '9') \
@@ -237,10 +253,12 @@
 #endif
 
 #if C_CTYPE_CONSECUTIVE_UPPERCASE && C_CTYPE_CONSECUTIVE_LOWERCASE
+#undef c_tolower
 #define c_tolower(c) \
   ({ int __c = (c); \
      (__c >= 'A' && __c <= 'Z' ? __c - 'A' + 'a' : __c); \
    })
+#undef c_toupper
 #define c_toupper(c) \
   ({ int __c = (c); \
      (__c >= 'a' && __c <= 'z' ? __c - 'a' + 'A' : __c); \