Implement double underscore names support in __has_attribute
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151809 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LanguageExtensions.html b/docs/LanguageExtensions.html
index be26d62..23aa4fe 100644
--- a/docs/LanguageExtensions.html
+++ b/docs/LanguageExtensions.html
@@ -257,6 +257,11 @@
</pre>
</blockquote>
+<p>The attribute name can also be specified with a preceding and
+following <code>__</code> (double underscore) to avoid interference from a macro
+with the same name. For instance, <code>__always_inline__</code> can be used
+instead of <code>always_inline</code>.</p>
+
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<h2 id="has_include">Include File Checking Macros</h2>
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