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Re: [PATCH 1/6] rtc: generic: allow building on all architectures

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Geert Uytterhoeven <geert@linux-m68k.org> writes:

>> +#else
>> +#define generic_rtc_ops *(struct rtc_class_ops*)NULL
>> +#endif
>>
>>  static int __init generic_rtc_probe(struct platform_device *dev)
>>  {
>>         struct rtc_device *rtc;
>> +       const struct rtc_class_ops *ops;
>> +
>> +       ops = dev_get_platdata(&dev->dev);
>> +       if (!ops)
>> +               ops = &generic_rtc_ops;
>
> I hope no compiler version treats "&*(struct rtc_class_ops*)NULL" as
> undefined behavior?

Yes, that is guaranteed, the operations cancel each other (6.5.3.2#3: If
the operand is the result of a unary * operator, neither that operator
nor the & operator is evaluated and the result is as if both were
omitted).

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

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[PATCH 1/6] rtc: generic: allow building on all architectures Arnd Bergmann <arnd@arndb.de> - 2016-03-01 18:10 +0100
  Re: [PATCH 1/6] rtc: generic: allow building on all architectures Geert Uytterhoeven <geert@linux-m68k.org> - 2016-03-02 10:00 +0100
    Re: [PATCH 1/6] rtc: generic: allow building on all architectures Arnd Bergmann <arnd@arndb.de> - 2016-03-02 10:10 +0100
    Re: [PATCH 1/6] rtc: generic: allow building on all architectures Andreas Schwab <schwab@linux-m68k.org> - 2016-03-02 10:30 +0100
      Re: [PATCH 1/6] rtc: generic: allow building on all architectures Geert Uytterhoeven <geert@linux-m68k.org> - 2016-03-02 10:40 +0100

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