Re: svn commit: r1936828 - in apr/apr-util/branches/1.6.x: . crypto

[Rainer Jung]

Hi Eric and all,

Am 03.08.26 um 15:45 schrieb cove...@apache.org:
Author: covener
Date: Mon Aug  3 13:45:25 2026
New Revision: 1936828
Log:
Merge r1936827 from aprutil 1.7.x:

hide __has_attribute on traditional xlc platforms

The backport of 1917748 omitted this in apr.h on purpose,
but this is a new/narrow usage and not in a header
where it would taint anyones use of __has_attribute.

Modified:
    apr/apr-util/branches/1.6.x/   (props changed)
    apr/apr-util/branches/1.6.x/crypto/   (props changed)
    apr/apr-util/branches/1.6.x/crypto/apr_passwd.c

Modified: apr/apr-util/branches/1.6.x/crypto/apr_passwd.c
==============================================================================
--- apr/apr-util/branches/1.6.x/crypto/apr_passwd.c     Mon Aug  3 13:44:19 
2026        (r1936827)
+++ apr/apr-util/branches/1.6.x/crypto/apr_passwd.c     Mon Aug  3 13:45:25 
2026        (r1936828)
@@ -64,6 +64,12 @@ static volatile const apr_uint32_t optbl
   * Paper:
   *   https://cr.yp.to/papers/cryptoint-20250424.pdf
   */
+#if (defined(__xlc__) && !defined(__GNUC__))
+#ifndef __has_attribute
+#define __has_attribute(__x)    0
+#endif
+#endif
+
  #if __has_attribute(always_inline)
  __attribute__((always_inline))
  #endif
I also get compilation errors due to __has_attribute() when compiling 
with older gcc compilers. Due to

https://gcc.gnu.org/onlinedocs/cpp/_005f_005fhas_005fattribute.html

I would suggest a more general check like this:

--- crypto/apr_passwd.c 2026-08-03 15:45:25.000000000 +0200
+++ crypto/apr_passwd.c 2026-08-09 20:56:18.478871355 +0200
...
-#if (defined(__xlc__) && !defined(__GNUC__))
 #ifndef __has_attribute
 #define __has_attribute(__x)    0
 #endif
-#endif
 ...


Would that be OK for your xlc environment as well?

I would then also apply this to crypto/apr_crypto.c which contains 
another copy of test_nonzero_timingsafe() and thus also uses 
__has_attribute().

Thanks and regards,

Rainer