Re: [patch] libgo - fix build errors and add ARM bits

[Ian Lance Taylor <iant at google dot com>]

On Mon, Dec 3, 2012 at 10:47 PM, Matthias Klose <doko@ubuntu.com> wrote:
> Am 04.12.2012 07:26, schrieb Ian Lance Taylor:
>> On Mon, Nov 19, 2012 at 8:27 AM, Matthias Klose <doko@ubuntu.com> wrote:
>>> libgo-fix-arm.diff: Work around parse error of struct timex_ on ARM (both trunk
>>> and 4.7 branch).
>>>
>>> libgo-hardening.diff: Avoid compiler warnings in libgo with -D_FORTIFY_SOURCE=2,
>>> which let the build fail with -Werror. first chunk for the trunk and 4.7, second
>>> chunk for trunk only.
>>>
>>> libgo-mksysinfo.diff: Fix TIOCNOTTY and TIOCSCTTY definitions, afaicr needed for
>>> ARM as well. for trunk and 4.7.
>>
>> Thanks.  I committed the libgo-hardening and libgo-mksysinfo patches
>> to mainline and 4.7 branch.
>>
>>
>> Can you tell me more about the libgo-fix-arm patch?  The patch adds
>> these lines to mksysinfo.sh:
>>
>> +# ARM
>> +sed -i '/type _timex/s/INVALID-bit-field/int32/g;/type _timex/s,^//
>> ,,' gen-sysinfo.go
>>
>> I don't understand why there would an INVALID-bit-field on ARM.  This
>> struct comes from the <sys/timex.h>, which as far as I can see should
>> be the same on every glibc system.
>>
>> What does struct timex look like in your <sys/timex.h> file?  What
>> does the line look like in gen-sysinfo.go before the sed script above
>> is run?
>
> defined in bits/timex.h
>
> struct timex
> {
>   unsigned int modes;           /* mode selector */
>   __syscall_slong_t offset;     /* time offset (usec) */
>   __syscall_slong_t freq;       /* frequency offset (scaled ppm) */
>   __syscall_slong_t maxerror;   /* maximum error (usec) */
>   __syscall_slong_t esterror;   /* estimated error (usec) */
>   int status;                   /* clock command/status */
>   __syscall_slong_t constant;   /* pll time constant */
>   __syscall_slong_t precision;  /* clock precision (usec) (ro) */
>   __syscall_slong_t tolerance;  /* clock frequency tolerance (ppm) (ro) */
>   struct timeval time;          /* (read only) */
>   __syscall_slong_t tick;       /* (modified) usecs between clock ticks */
>   __syscall_slong_t ppsfreq;    /* pps frequency (scaled ppm) (ro) */
>   __syscall_slong_t jitter;     /* pps jitter (us) (ro) */
>   int shift;                    /* interval duration (s) (shift) (ro) */
>   __syscall_slong_t stabil;     /* pps stability (scaled ppm) (ro) */
>   __syscall_slong_t jitcnt;     /* jitter limit exceeded (ro) */
>   __syscall_slong_t calcnt;     /* calibration intervals (ro) */
>   __syscall_slong_t errcnt;     /* calibration errors (ro) */
>   __syscall_slong_t stbcnt;     /* stability limit exceeded (ro) */
>
>   int tai;                      /* TAI offset (ro) */
>
>   /* ??? */
>   int  :32; int  :32; int  :32; int  :32;
>   int  :32; int  :32; int  :32; int  :32;
>   int  :32; int  :32; int  :32;
> };
>
>
> I'll have to re-run the build with out the patch, but this replaces just the
> 32bit bit fields with an int32.

Thanks.  That's more or less what timex.h looks like on my system, but
I don't see the bitfields.  GCC treats the :32 fields as int32, in
both 32-bit and 64-bit mode.

Ian