avutil/tile: check clock_gettime at runtime for apple platforms
authorWang Bin <wbsecg1@gmail.com>
Mon, 9 Jan 2017 03:52:06 +0000 (11:52 +0800)
committerSteven Liu <lq@chinaffmpeg.org>
Mon, 9 Jan 2017 03:52:06 +0000 (11:52 +0800)
commit0e8b68a2c4031e25082603ad88711be12210d41f
treec7917f042d9ef6b64791c509c07a757796511e94
parentb53b3a4f6abcc97d4cdcc1f025ef803fcfab18c6
avutil/tile: check clock_gettime at runtime for apple platforms

clock_gettime is avalible since macOS 10.12 and iOS 10.0. Because of
weak linking, clock_gettime can be build without error with new
macOS/iOS sdk, but the symbol may not exist on the target system.
Explicitly checking the symbol is required.
https://developer.apple.com/library/content/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/WeakLinking.html

Signed-off-by: Wang Bin <wbsecg1@gmail.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
libavutil/time.c