libclang: document the purpose of createNull()

llvm-svn: 174195

diff --git a/clang/tools/libclang/CXString.h b/clang/tools/libclang/CXString.h
index 0495ee9..0688712 100644 (file)
--- a/clang/tools/libclang/CXString.h
+++ b/clang/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.