Chris Lattner <clatt...@apple.com> writes:
> On Jan 27, 2009, at 1:10 PM, Ian Lance Taylor wrote:
>
>> Laurent GUERBY <laur...@guerby.net> writes:
>>
>>> Just curious: is there a "portable" way to read from memory
>>> address zero in C code? "portable" here means likely to work
>>> on most compilers without exotic compile flags in 2009.
>>
>> char *my_null_pointer;
>> char fn() { return *my_null_pointer; }
>>
>> It will be quite a while before whole program optimization is good
>> enough to prove that my_null_pointer is not referenced by anything
>> else.
>
> Perhaps in GCC, but this is not a good solution if you care about
> other compilers.
Is LLVM smart enough to optimize that away, even when using shared
libraries?
If necessary, make the global variable volatile.
Ian
