[cfe-dev] Odd piece of Clang 2.1 behaviour

[Dallman, John]

> FWIW,  llvm-gcc provides the same source compatibility as
> gcc (including -fpermissive), since it's the same front end.

Indeed, but for the customers that need looking after carefully,
just getting them off Mac OS X 10.5 onto something modern is a
big win, and making that path as smooth as possible this time
round is helpful.

> ... and it's worth noting that GCC/LLVM-GCC/Clang all implement
> the same ABI, so different parts of a program can be compiled
> with different compilers.

Oh, I know. Without that, I would not be attempting to go up to
Clang myself.

thanks,

--
John Dallman

-----Original Message-----
From: Douglas Gregor [mailto:dgregor at apple.com]
Sent: 12 October 2011 15:34
To: Dallman, John
Cc: Chris Lattner; Eli Friedman; clang-dev Developers
Subject: Re: [cfe-dev] Odd piece of Clang 2.1 behaviour


On Oct 12, 2011, at 3:04 AM, Dallman, John wrote:

> Eli Friedman wrote:
>>> It's a bug; IIRC, it's already fixed in clang trunk.
>
> Chris Lattner wrote:
>
>> For what it's worth, Xcode 4.2 includes a vastly updated version
>> of Clang (branded "Apple LLVM Compiler 3.0" instead of "2.1" by
>> the apple marketing people).  It recently came out of Beta.  I
>> recommend upgrading to it if you can.
>
> But I have customers who aren't switching to Clang immediately, because
> their code (which requires "permissive" with GCC) won't compile with Clang,
> until they do some extra work, and they are nervous about Clang.

FWIW,  llvm-gcc provides the same source compatibility as gcc (including -fpermissive), since it's the same front end.

> So staying
> on a Clang that definitely has a corresponding conventional GCC is going
> to be good for their peace of mind.


... and it's worth noting that GCC/LLVM-GCC/Clang all implement the same ABI, so different parts of a program can be compiled with different compilers.

        - Doug