3 files changed, 14 insertions, 0 deletions
diff --git a/libcxxabi/src/demangle/ItaniumDemangle.h b/libcxxabi/src/demangle/ItaniumDemangle.h
index 9a54ff5d80d..f35c062cd6d 100644
--- a/libcxxabi/src/demangle/ItaniumDemangle.h
+++ b/libcxxabi/src/demangle/ItaniumDemangle.h
@@ -2480,6 +2480,12 @@ AbstractManglingParser<Derived, Alloc>::parseUnnamedTypeName(NameState *) {
       return nullptr;
     return make<ClosureTypeName>(Params, Count);
   }
+  if (consumeIf("Ub")) {
+    (void)parseNumber();
+    if (!consumeIf('_'))
+      return nullptr;
+    return make<NameType>("'block-literal'");
+  }
   return nullptr;
 }
 
diff --git a/libcxxabi/test/test_demangle.pass.cpp b/libcxxabi/test/test_demangle.pass.cpp
index 09ba0434841..be0b7b0fde8 100644
--- a/libcxxabi/test/test_demangle.pass.cpp
+++ b/libcxxabi/test/test_demangle.pass.cpp
@@ -29759,6 +29759,8 @@ const char* cases[][2] =
     // Darwin adds leading underscores to symbols, just demangle them anyways.
     {"____Z3foo_block_invoke.25", "invocation function for block in foo"},
     {"__Z1fv", "f()"},
+
+    {"_Z2tfIZUb_E1SEiv", "int tf<'block-literal'::S>()"}
 };
 
 const unsigned N = sizeof(cases) / sizeof(cases[0]);
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index 9a54ff5d80d..f35c062cd6d 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -2480,6 +2480,12 @@ AbstractManglingParser<Derived, Alloc>::parseUnnamedTypeName(NameState *) {
       return nullptr;
     return make<ClosureTypeName>(Params, Count);
   }
+  if (consumeIf("Ub")) {
+    (void)parseNumber();
+    if (!consumeIf('_'))
+      return nullptr;
+    return make<NameType>("'block-literal'");
+  }
   return nullptr;
 }