maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Document the weak-linking behavior of the availability attribute 

llvm-svn: 152543
This commit is contained in:
Douglas Gregor 2012-03-11 17:21:03 +00:00
parent 71b197306e
commit c683e4a8e9
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
clang/docs/LanguageExtensions.html
View File

@ -665,6 +665,12 @@ void f(void) __attribute__((availability(macosx,introduced=10.4,deprecated=10.6,
<dd>Apple's Mac OS X operating system. The minimum deployment target is specified by the <code>-mmacosx-version-min=<i>version</i></code> command-line argument.</dd>
</dl>
<p>A declaration can be used even when deploying back to a platform
version prior to when the declaration was introduced. When this
happens, the declaration is <a
href="https://developer.apple.com/library/mac/#documentation/MacOSX/Conceptual/BPFrameworks/Concepts/WeakLinking.html">weakly
linked</a>, as if the <code>weak_import</code> attribute were added to the declaration. A weakly-linked declaration may or may not be present a run-time, and a program can determine whether the declaration is present by checking whether the address of that declaration is non-NULL.</p>
<!-- ======================================================================= -->
<h2 id="checking_language_features">Checks for Standard Language Features</h2>
<!-- ======================================================================= -->