Guard unwind test against old OS X versions

[btj]

tests/unwind crashes on OS X 10.8. This fixes that by only running the test if a sufficiently new version of ld is present on the system.

[gasche]

I merged in trunk ( 17e5435 ) and in 4.03 ( 7a16f2f ).

[gasche]

So this patch breaks our CI infrastructure because the bash-only matching is not supported everywhere.

I tried to rewrite it in a more portable way in dd5dc84 , which I pushed in trunk to get some feedback from the CI infrastructure. @btj , would you mind looking at it to confirm that it has the intended semantics?

@damiendoligez : apoligies for the hasty merge in the release branch. In the future I'll merge in trunk first and wait for CI report, even for stuff that we want in 4.03 and "obviously doesn't break anything". I can revert the commit if you think it's best, but I hope that the trunk CI will look good and my plan is to merge dd5dc84 directly.

[gasche]

The patch seems to fix the CI on non-mac machines, so I also pushed it into 4.03 to help people currently testing the branch: 1d9c4a0 . I would still be interested in a confirmation that it also solves the original issue on OSX 10.8 (this CI machine is disabled currently).

[btj]

I don't think this does the right thing: the output of ld -v 2>&1 is as follows on my machine:

@(#)PROGRAM:ld  PROJECT:ld64-241.9
configured to support archs: armv6 armv7 armv7s arm64 i386 x86_64 x86_64h armv6m armv7m armv7em
LTO support using: LLVM version 3.5svn

Notice that 1) the version does not appear at the start of the line, and 2) the output consists of 3 lines.

[gasche]

@btj thanks for the quick reaction; would 1d6e092 (in my local fork) do the job?

(I tested with your ld output and it seemed to work.)

[btj]

Yes, except that you do need the 2>&1: ld -v writes to stderr, not stdout.

[gasche]

Of course; I used a literal string for testing, then put back the wrong thing, sorry. The fixed commit is 8dcb687 , and I'm going to sit on it for a dozen of minutes to make sure I haven't forgotten about something, and then push it to 4.03 and trunk.

[btj]

This works on my machine (OS X 10.10.1).

[gasche]

I pushed them ( 8dcb687 in trunk; 6151d4c in 4.03 ). Thanks!

[damiendoligez]

@gasche

@damiendoligez : apoligies for the hasty merge in the release branch. In the future I'll merge in trunk first and wait for CI report, even for stuff that we want in 4.03 and "obviously doesn't break anything".

No need to apologize, I've done my fair share of "obviously doesn't break anything" myself...