libclang: document the purpose of createNull()

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174195 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/tools/libclang/CXString.h b/tools/libclang/CXString.h
index 0495ee9616689e17c6efce7b5a4898123638ce96..06887124fa5c7000fd296c6ce681037e032661e1 100644 (file)
--- a/tools/libclang/CXString.h
+++ b/tools/libclang/CXString.h
@@ -29,6 +29,8 @@ struct CXStringBuf;
 CXString createEmpty();
 
 /// \brief Create a CXString object for an NULL string.
+///
+/// A NULL string should be used as an "invalid" value in case of errors.
 CXString createNull();
 
 /// \brief Create a CXString object from a C string.