Re: boot-time: straighten code

[Po Lu]

Bruno Haible <bruno@clisp.org> writes:

> Po Lu wrote:
>> During the automated build of the Android port, the following errors
>> were encountered with the Android NDK r10b and __ANDROID_API__ set to 8
>> (which is the oldest configuration Emacs supports.)
>> ...
>> boot-time.c: In function 'get_boot_time_uncached':
>> boot-time.c:111:26: error: 'BOOT_TIME' undeclared (first use in this 
>> function)
>>        if (ut->ut_type == BOOT_TIME)
>>                           ^
>
> Unlike USER_PROCESS, which is defined in all versions of Android's <utmp.h>,
> BOOT_TIME is only defined in newer versions.
>
> When compiling against an older version, we need to use the value from the
> newer versions — otherwise a binary built against an older version might
> not work right when running on a newer Android.
>
> This patch does it.
>
>
> 2023-08-13  Bruno Haible  <bruno@clisp.org>
>
>       readutmp, boot-time: Fix compilation error on old Android.
>       Reported by Po Lu in
>       <https://lists.gnu.org/archive/html/bug-gnulib/2023-08/msg00108.html>.
>       * lib/readutmp.h (BOOT_TIME): Add fallback.
>
> diff --git a/lib/readutmp.h b/lib/readutmp.h
> index 1cf588d265..f7cad36d44 100644
> --- a/lib/readutmp.h
> +++ b/lib/readutmp.h
> @@ -249,6 +249,13 @@ struct utmpx32
>  # define WTMP_FILE "/etc/wtmp"
>  #endif
>  
> +/* In early versions of Android, <utmp.h> did not define BOOT_TIME, only
> +   USER_PROCESS.  We need to use the value that is defined in newer versions
> +   of Android.  */
> +#if defined __ANDROID__ && !defined BOOT_TIME
> +# define BOOT_TIME 2
> +#endif
> +
>  /* Some platforms, such as OpenBSD, don't have an ut_type field and don't 
> have
>     the BOOT_TIME and USER_PROCESS macros.  But we want to support them in
>     'struct gl_utmp'.  */

Both of your patches appear to work.
Thanks.