Robert Dewar - Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!) (original) (raw)

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• From: Robert Dewar
• To: Mike Stump
• Cc: Richard Earnshaw , Dave Korn , Ian Lance Taylor , gcc mailing list
• Date: Mon, 28 Nov 2005 14:05:40 -0500
• Subject: Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
• References: <SERRANO6qCvOeyYHeFu00000084@SERRANO.CAM.ARTIMI.COM> <1132674761.27134.177.camel@pc960.cambridge.arm.com> <8C2BE826-8925-45CA-AAE7-EF2F673B2819@apple.com> <1133175654.32658.11.camel@pc960.cambridge.arm.com> <438AE644.7000704@adacore.com> <11FD84E7-060B-44C3-BBD9-07BDA71C8301@apple.com>

Mike Stump wrote:

gcc is not just an Ada compiler. Clearly, the answer has to be yes to support GNU C.

Right, I agree, I was answering whether this can ever be done legitimately, and the answer is really no, it is undefined in C, and if you manage to do it in Ada, which you can if you really try by unchecked conversion of pointer types etc, then it is erroneous there too.

So I don't see that the compiler has to allow for this in any explicit manner, given that its effect is undefined in C.

• Follow-Ups:
  • Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Mike Stump
• References:
  • RE: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Dave Korn
  • RE: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Richard Earnshaw
  • Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Mike Stump
  • Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Richard Earnshaw
  • Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Robert Dewar
  • Re: Why doesn't combine like volatiles? (volatile_ok again, sorry!)
    * From: Mike Stump