Support dead-stripping in ELF objects

[Shankar Easwaran]

On 4/4/2013 4:51 PM, Robinson, Paul wrote:
> From: Nick Kledzik [mailto:kledzik at apple.com]
>>> On Apr 2, 2013, at 6:23 PM, Michael Spencer <bigcheesegs at gmail.com> wrote:
>>>    * If a relocation in this section has a target symbol which is in a
>>> section with this flag set, r_addend must be less than st_size.
>> I assume you mean the st_size of the target symbol.  But that would disallow
>> valid C code.  You can write:
>>
>>        char* x = &foo + 100;
>> or
>>        char* y = &foo - 50;
>>
>> where 100 > sizeof(foo).
> Actually this isn't valid C code, computing a pointer that lies outside
> the allocated size of an object/array is undefined.
> [6.5.6 Additive Operators, p8: If both the pointer
> operand and the result point to elements of the same array object, or one past the last
> element of the array object, the evaluation shall not produce an overflow; otherwise, the
> behavior is undefined.]
Why is it not valid, its valid C code which would may/maynot run.

Thanks

Shankar Easwaran

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