Document the LLVM "thunk" attribute added back in r226708

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231181 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/LangRef.rst b/docs/LangRef.rst
index 97b2784a6914fa62750c22edc46d77718cdba66d..cc815e1a4e9f3e260c39bb1a5d27583da877ed62 100644 (file)
--- a/docs/LangRef.rst
+++ b/docs/LangRef.rst
@@ -1369,6 +1369,11 @@ example:
     If a function that has an ``sspstrong`` attribute is inlined into a
     function that doesn't have an ``sspstrong`` attribute, then the
     resulting function will have an ``sspstrong`` attribute.
+``"thunk"``
+    This attribute indicates that the function will delegate to some other
+    function with a tail call. The prototype of a thunk should not be used for
+    optimization purposes. The caller is expected to cast the thunk prototype to
+    match the thunk target prototype.
 ``uwtable``
     This attribute indicates that the ABI being targeted requires that
     an unwind table entry be produce for this function even if we can