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Re: [PATCH] prune warn_compact_unwind warnings on darwin
On Sat, Mar 19, 2011 at 08:52:32AM +0000, IainS wrote:
>
> On 19 Mar 2011, at 06:22, Mike Stump wrote:
>
>> On Mar 12, 2011, at 1:01 PM, Jack Howarth wrote:
>>> Xcode 4.0's linker now defaults on...
>>>
>>> -warn_compact_unwind
>>
>> So, if this is a flag, and we can turn the warning off, and we truly
>> don't care about the warnings, why not just use -
>> no_warn_compact_unwind? That would be preferable, I think.
>
>
> 1/
> Hm. AFAIK we set "-no_compact_unwind", when the target is 10.6
>
> #define LINK_GCC_C_SEQUENCE_SPEC \
> "%:version-compare(>= 10.6 mmacosx-version-min= -no_compact_unwind) \
>
> - it would seem to be a tool bug to flag a warning for something
> specifically excluded.
Yes it could be considered a tool bug but we are stuck with it. We might
be able to get that fixed in Xcode 4.1 but I have doubts about 3.2.6 or
even 4.0 getting such a fix. Unfortunately it generates a lot of noise on
the testsuite results with bogus excessive error failures.
Note that Nick said...
Yes. -warn_compact_unwind is on by default in the Xcode4 linker. And there is no
option to turn of the warnings (other than -Wl,-w which suppresses all linker warnings).
>
> 2/
> unless "-no_compact_unwind" is now ignored?
>
> 3/
> maybe we are going to have to follow clang et. al in having a tools
> version runtime flag (this would especially ease the issues in making
> canadians to early Darwin versions). OSX ld and cctools version are
> detectable at runtime for native builds - say: -mmacosx-ld-version= -
> mmacosx-cctools-version= ... so we don't ask people to put this for the
> native case (we can also pick sensible defaults for other systems).
> [trunk clang uses -target-linker-version xx.yy.zz - but that's not
> consistent with our general scheme].
>
> (I know Mike hates additional flags - and tool capabilities can, of
> course, be detected at runtime for native builds - but we also cater -
> by design - for cross-builds to earlier versions of the OS)
>
> cheers
> Iain