Why does gcc generate const local array on stack?

Jonathan Wakely jwakely.gcc@gmail.com
Wed Apr 20 17:51:00 GMT 2016

On 20 April 2016 at 18:31, lh_mouse wrote:
> I tend to say clang is wrong here.

If you can't detect the difference then it is a valid transformation.

> Your identifier 'a' has no linkage. Your object designated by 'a' does not have a storage-class specifier.
> So it has automatic storage duration and 6.2.4/7 applies: 'If the scope is entered recursively, a new instance of the object is created each time.'

How do you tell the difference between a const array that is recreated
each time and one that isn't?

> Interesting enough, ISO C doesn't say whether distinct objects should have distinct addresses.
> It is worth noting that this is explicitly forbidden in ISO C++ because distinct complete objects shall have distinct addresses:

If the object's address doesn't escape from the function then I can't
think of a way to tell the difference.

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