1305738 - Fix our clock_gettime detection with XCode 8

Status: RESOLVED DUPLICATE of bug 1303212

(Firefox Build System :: General, defect)

Description

[(no longer active)]

OSX 10.12 now has clock_gettime(), and building with XCode 8 makes us believe that we can use this function, but the problem is that we're using AC_TRY_LINK.  This symbol is resolved as a weak symbol so the linking succeeds, but if you try to run the resulting binary, you get something like this:

$ ./conftest
dyld: lazy symbol binding failed: Symbol not found: _clock_gettime
  Referenced from: /Users/ehsan/src/spidernode/./conftest (which was built for Mac OS X 10.12)
  Expected in: /usr/lib/libSystem.B.dylib

dyld: Symbol not found: _clock_gettime
  Referenced from: /Users/ehsan/src/spidernode/./conftest (which was built for Mac OS X 10.12)
  Expected in: /usr/lib/libSystem.B.dylib

Trace/BPT trap: 5

Using AC_TRY_RUN enables us to correctly detect the availability of this symbol.

Comment 1

[(no longer active)]

Attachment: Do not get tricked into believing that clock_gettime is available when building with XCode 8 on OSX 10.11 and lower

Comment 2

[(not currently active) Ted Mielczarek]

Is this not just a dupe of bug 1303212?

Comment 3

[(no longer active)]

It is...  Bugzilla search apparently ignored all comments.  :(

Comment 4

[Gregory Szorc [:gps]]

Comment on attachment 8795337 [details] [diff] [review]
Do not get tricked into believing that clock_gettime is available when building with XCode 8 on OSX 10.11 and lower

Bug marked as dupe.