[MacPorts] #55441: libcxx, libcxxabi: also install into the SDKs

[MacPorts]

#55441: libcxx, libcxxabi: also install into the SDKs
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  Reporter:  ryandesign         |      Owner:  jeremyhu
      Type:  enhancement        |     Status:  new
  Priority:  Normal             |  Milestone:
 Component:  ports              |    Version:
Resolution:                     |   Keywords:  snowleopard haspatch
      Port:  libcxx, libcxxabi  |
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Comment (by ryandesign):

 Replying to [comment:8 mojca]:
 > Ticktet from long time ago: #44125

 Oh boy, yes I remember all that, thanks for the pointer. I was sure this
 had come up in previous tickets but couldn't find it.

 > I support installing libc++ to the SDK.
 >
 > Not sure about what to do for 10.5

 libcxx doesn't currently build on 10.5 unless you change `universal_archs`
 from `ppc i386` to `i386 x86_64`. It doesn't build at all on 10.4 and the
 port prevents the build attempt. So on 10.5, if the port installs at all,
 it's reasonable to copy libc++ into the 10.5 SDK only and not into the
 10.4u SDK.

 On 10.6, which includes the 10.5 SDK if using Xcode 3 (but not if using
 Xcode 4), the question is whether to put it in the 10.6 SDK only or also
 into the 10.5 SDK.

 > or what to do with SDK for 10.6 on Lion where the location of that SDK
 is not even fixed, but depends on the Xcode version. (Maybe nothing for
 now?)

 That's a good point. Xcode 4.1 through 4.3.x ran on Lion and included both
 the 10.6 and 10.7 SDK. The port currently does nothing on those systems
 other than install a readme. It probably makes sense to keep it that way,
 and therefore to match the behavior on 10.6 and not install into the 10.5
 SDK there. I'll update the attachment.

 It seems unlikely that someone would want to use libc++ while running on
 10.6 but want to use the 10.5 SDK, or while running on 10.7 and want to
 use the 10.6 SDK. Apple recommends using the latest SDK, even when
 targeting old systems. Modern code wanting to use libc++ is more likely to
 accommodate that recommendation. The only time I think you might need to
 use an old SDK is to build really old and not-so-well-made software that
 was built at the time that old SDK was current, and such old software
 won't be using C++11.

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Ticket URL: <https://trac.macports.org/ticket/55441#comment:9>
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