[Darwin] Patch, take 2: enable linkonce support for Darwin

[Jason Merrill]

On Mon, 2 Feb 2004 14:55:52 -0800, Matt Austern <austern@apple.com> wrote:

> On Feb 2, 2004, at 2:39 PM, Mike Stump wrote:
>
>> On Monday, February 2, 2004, at 11:00 AM, Matt Austern wrote:
>>> OK!  As you may have noticed, version 3 of my patch avoids COMMON
>>> on all platforms where ONE_ONLY is available.
>>
>> I can't help but wonder if this results in larger .o files (ls -l type
>> sizes), or slower compiles...  and how big of an effect it is.
>
> Slower compile, I can't think of any reason to wonder that.  Larger .o
> files...  Conceivably it could increase or decrease the size of the .o
> files, but the effect is almost certainly negligible.  The compiler
> currently uses COMMON for C++ vague linkage only in a few pretty rare
> cases.  Changing it from "used in a few corner cases" to "not used" isn't a
> big deal, pretty much by definition.

And it should just change from .common to .bss, which doesn't take up any
more space in .o files.

Jason