Re: [Nasm-devel] clang patches

[Daniel L. <da...@ma...>]

> On 13 Oct 2016, at 23:07, hp...@zy... wrote:
> 
> On October 13, 2016 1:55:04 PM PDT, Daniel Lundqvist <da...@ma...> wrote:
>> 
>>> On 8 Oct 2016, at 06:35, H. Peter Anvin <hp...@zy...> wrote:
>>> 
>>> On 10/07/16 06:46, Daniel Lundqvist wrote:
>>>> 
>>>> Unfortunately clang does not realise that 'again' will never be
>> false
>>>> for non-glibc. How do you want that fixed? Is it OK to just
>>>> initialise f to NULL or do you prefer something else?
>>>> 
>>> 
>>> Setting f to NULL is fine.
>>> 
>>> From fd764d58a7ada29f5121e275ee6b1c050c5f219f Mon Sep 17 00:00:00
>> 2001
>>> From: Daniel Lundqvist <da...@ma...>
>>> Date: Fri, 7 Oct 2016 15:41:24 +0200
>>> Subject: [PATCH] include/compiler.h: Adapt 'malloc' attributes for
>> clang.
>>> 
>>> As clang does not support alloc_size attribute, don't try to use it.
>>> 
>>> Signed-off-by: Daniel Lundqvist <da...@ma...>
>>> 
>>> What happens if you do, given that it defined __GNUC__ and therefore
>>> claims to be compatible with gcc?
>>> 
>>> 	-hpa
>> 
>> It gives an 'unknown attribute' warning. IIRC, clang defining __GNUC__
>> does not mean 100% compatibility, rather it means gcc-like. I remember
>> reading about it, but can't find a source right now. I don't know how
>> viable it is to use __has_attribute, at least recent versions of both
>> gcc and clang support it.
> 
> __has_attribute() sounds promising... do we have a presence test for that?


Yes, if __has_attribute is defined. Same mechanism for __has_feature. See http://clang.llvm.org/docs/LanguageExtensions.html#has-attribute <http://clang.llvm.org/docs/LanguageExtensions.html#has-attribute> and http://clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension <http://clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension> for typical usage.

-- 
daniel