[asterisk-dev] Compiler feature requirements

[Corey Farrell]

This will definitely break any compilers older than gcc-4.1.2, but no 
major distribution (that I know of) has a supported release with this.  
CentOS 6 is the only major distro that will even use the __sync [1] 
methods. All other major distro's have gcc >= 4.7.0 which implements 
__atomic built-ins.

I tested OSX El Capitain, the configure script detected __atomic 
built-ins so this will not create any new issues for Mac.

[1] https://gist.github.com/coreyfarrell/c096dd335afee5502a6faee2a507b012

On 01/26/2018 03:20 PM, Matt Fredrickson wrote:
> On Wed, Jan 24, 2018 at 3:50 PM, Corey Farrell <git at cfware.com> wrote:
>> I've posted ASTERISK-27619 [1] proposing that we drop support for GCC
>> versions older than 4.1.2.  Specifically we'd be requiring that either
>> __sync or __atomic builtin functions be available (I'm unsure what this will
>> do to clang requirements).  gcc-4.1.2 was released in February 2007 and was
>> the version provided by CentOS 5.  I've posted a PR to the jansson project
>> [2] which will make reference counting thread safe, but I'm getting
>> push-back on the parts needed to provide a replacement function for old
>> compilers.  Since reference counting in jansson was never thread safe before
>> I think they'd rather just leave it as is for old compilers.
>>
>> Obviously this proposal is for Asterisk 16+ only.  Does this matter to any
>> distributions that will be supported beyond this October?
>>
>> [1] https://issues.asterisk.org/jira/browse/ASTERISK-27619
>> [2] https://github.com/akheron/jansson/pull/389
> As long as we don't impact any major, currently supported
> distributions that may use earlier versions than gcc-4.1.2, I'm ok
> with moving things forward as suggested.  Especially since this is
> isolated to master/proposed-16.
>
> Anybody else have any thoughts?
>