[cfe-dev] [RFC] Bump up clang's __GNUC_MINOR__

Benjamin Kramer benny.kra at googlemail.com
Sat May 12 08:31:04 PDT 2012

On 12.05.2012, at 17:20, PaX Team wrote:

> On 12 May 2012 at 10:18, Rafael EspĂ­ndola wrote:
>> Pretending to be an old gcc protects us from some of the more obscure
>> gcc features used in glibc. test/CodeGen/pr9614.c has some cases that
>> we already have to handle.
> i'd like to add that pretending to be gcc 4.5 or newer will also require support
> for attribute((__cold__)) and "asm goto" stmts that are used in linux extensively
> (and there's possibly more, these are the ones i remember from the code).

For attribute __hot__ and __cold__ we could get away with just dropping the attribute silently, as it has no observable effect except performance. Implementing it in clang should be easy though, we do something similar for static constructors already.

asm goto is crazy and requires backend support, I don't think that will be implemented in llvm any time soon :(

- Ben

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