Don't interfere with a program's definition of __attribute__. * lib/argp.h (__attribute__): Remove definition. (_GL_ATTRIBUTE_FORMAT): New macro. (argp_error, __argp_error, argp_failure, __argp_failure): Use it. * lib/argp-fmtstream.h (__attribute__): Remove definition. (_GL_ATTRIBUTE_FORMAT): New macro. (__argp_fmtstream_printf, argp_fmtstream_printf): Use it. * lib/argp-help.c (hol_entry_long_iterate): Use __attribute__ only for GCC 3 or newer. * lib/error.h (__attribute__): Remove definition. (_GL_ATTRIBUTE_FORMAT): New macro. (error, error_at_line): Use it. * lib/hash.h (__attribute__): Remove definition. (ATTRIBUTE_WUR): Update definition. Define always. * lib/openat.h (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. * lib/sigpipe-die.h (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. * lib/vasnprintf.h (__attribute__): Remove definition. (_GL_ATTRIBUTE_FORMAT): New macro. (asnprintf, vasnprintf): Use it. * lib/xalloc.h (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. (ATTRIBUTE_MALLOC, ATTRIBUTE_ALLOC_SIZE): Define always. * lib/xmemdup0.h (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. * lib/xprintf.h (__attribute__): Remove definition. (_GL_ATTRIBUTE_FORMAT): New macro. (xprintf, xvprintf, xfprintf, xvfprintf): Use it. * lib/xstrtol.h (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. * lib/xvasprintf.h (__attribute__): Remove definition. (_GL_ATTRIBUTE_FORMAT): New macro. (xasprintf, xvasprintf): Use it. * tests/test-argmatch.c (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. * tests/test-exclude.c (__attribute__): Remove definition. (ATTRIBUTE_NORETURN): Update definition. Define always. Reported by Paul Eggert.

--- a/lib/xvasprintf.h
+++ b/lib/xvasprintf.h
@@ -20,16 +20,16 @@
 /* Get va_list.  */
 #include <stdarg.h>
 
-#ifndef __attribute__
 /* The __attribute__ feature is available in gcc versions 2.5 and later.
    The __-protected variants of the attributes 'format' and 'printf' are
    accepted by gcc versions 2.6.4 (effectively 2.7) and later.
-   We enable __attribute__ only if these are supported too, because
+   We enable _GL_ATTRIBUTE_FORMAT only if these are supported too, because
    gnulib and libintl do '#define printf __printf__' when they override
    the 'printf' function.  */
-# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
-#  define __attribute__(Spec)   /* empty */
-# endif
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
+# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
+#else
+# define _GL_ATTRIBUTE_FORMAT(spec) /* empty */
 #endif
 
 #ifdef __cplusplus
@@ -44,9 +44,9 @@
      - [EILSEQ] error during conversion between wide and multibyte characters,
    return NULL.  */
 extern char *xasprintf (const char *format, ...)
-       __attribute__ ((__format__ (__printf__, 1, 2)));
+       _GL_ATTRIBUTE_FORMAT ((__printf__, 1, 2));
 extern char *xvasprintf (const char *format, va_list args)
-       __attribute__ ((__format__ (__printf__, 1, 0)));
+       _GL_ATTRIBUTE_FORMAT ((__printf__, 1, 0));
 
 #ifdef __cplusplus
 }