[PATCH] libstdc++: testsuite: don't test for __unused

[Jonathan Wakely]

On Sun, 25 Jan 2026 at 19:28, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>
>
>
> On Sun, 25 Jan 2026, 16:06 Xi Ruoyao, <xry111@xry111.site> wrote:
>>
>> x86_64 glibc has started to use it since the 2.43 release.
>
>
> The correct fix is to #undef it for glibc then. That way it's still defined (and tested) for other targets.

Like this:

--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -303,8 +303,8 @@
#if defined (__linux__) || defined (__gnu_hurd__)
#if __has_include(<features.h>)
#include <features.h>
-#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 19
-// Glibc defines this prior to 2.19
+#if __GLIBC__ == 2 && (__GLIBC_MINOR__ < 19 || __GLIBC_MINOR__ >= 43)
+// Glibc defines this prior to 2.19 and since 2.43
#undef __unused
#endif
#endif

The change to badnames.cc is OK though.





>
>
>
>>
>> Link: https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=b9579342c68b#patch67
>> ---
>>  libstdc++-v3/testsuite/17_intro/badnames.cc | 2 +-
>>  libstdc++-v3/testsuite/17_intro/names.cc    | 2 +-
>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/libstdc++-v3/testsuite/17_intro/badnames.cc b/libstdc++-v3/testsuite/17_intro/badnames.cc
>> index ff590fcdf4d..de4d94faf14 100644
>> --- a/libstdc++-v3/testsuite/17_intro/badnames.cc
>> +++ b/libstdc++-v3/testsuite/17_intro/badnames.cc
>> @@ -67,7 +67,7 @@
>>
>>  // BSD adds:
>>  #define __used         __used is a BADNAME
>> -#define __unused       __unused is a BADNAME
>> +        // __unused    (glibc uses this so can't test here)
>>          // __inline    (glibc uses this so can't test here)
>>          // _Complex    (glibc uses this so can't test here)
>>  #define __istype       __istype is a BADNAME
>> diff --git a/libstdc++-v3/testsuite/17_intro/names.cc b/libstdc++-v3/testsuite/17_intro/names.cc
>> index 106acfa641b..2249735baae 100644
>> --- a/libstdc++-v3/testsuite/17_intro/names.cc
>> +++ b/libstdc++-v3/testsuite/17_intro/names.cc
>> @@ -150,7 +150,7 @@
>>  # define __lockable            cannot be used as an identifier
>>  # define __null_sentinel       cannot be used as an identifier
>>  # define __packed              cannot be used as an identifier
>> -# define __unused              cannot be used as an identifier
>> +      // __unused              (glibc uses this so can't test here)
>>  # define __used                        cannot be used as an identifier
>>
>>  #ifndef __APPLE__
>> --
>> 2.52.0
>>