Re: Wrong class export/visibility setting for shared libs in many Boost libs

From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2021-02-02 13:30:19

On 2/2/21 4:23 PM, Mathias Gaunard wrote:
> On Tue, 2 Feb 2021 at 11:59, Andrey Semashev via Boost
> <boost_at_[hidden]> wrote:
>>
>> On 2/2/21 2:51 PM, Andrey Semashev wrote:
>>> On 2/2/21 11:35 AM, Alexander Grund via Boost wrote:
> 
>> PPS: I forgot to add that recent gcc versions don't need RTTI to be
>> publicly visible to be able to catch exceptions or compare type_info, as
>> they now perform deep string comparison instead of address comparison.
>> However, older compiler versions are still susceptible to this, and I'm
>> not sure if the deep comparison behavior is used on all platforms.
> 
> That sounds like a step backwards.
> Do you have more information about this change and the motivation behind it?

Some motivation is given in the sources:

https://github.com/gcc-mirror/gcc/blob/13d8be91218950707bf38bdb1c554cf1605e4501/libstdc%2B%2B-v3/libsupc%2B%2B/typeinfo#L48