diff --git a/clang-tools-extra/pseudo/lib/cxx.bnf b/clang-tools-extra/pseudo/lib/cxx.bnf
--- a/clang-tools-extra/pseudo/lib/cxx.bnf
+++ b/clang-tools-extra/pseudo/lib/cxx.bnf
@@ -750,3 +750,8 @@
 #! split it into two tokens to make the GLR parser aware of the nested-template
 #! case.
 greatergreater := > >
+
+#! C++ predefined identifier, __func__ [dcl.fct.def.general] p8
+#! FIXME: add other (MSVC, GNU extension) predefined identifiers.
+primary-expression := predefined-expression
+predefined-expression := __FUNC__
diff --git a/clang-tools-extra/pseudo/test/cxx/predefined-identifier.cpp b/clang-tools-extra/pseudo/test/cxx/predefined-identifier.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/pseudo/test/cxx/predefined-identifier.cpp
@@ -0,0 +1,5 @@
+// RUN: clang-pseudo -grammar=%cxx-bnf-file -source=%s --print-forest | FileCheck %s
+void s() {
+  __func__;
+  // CHECK: expression~__FUNC__ := tok[5]
+}