diff --git a/libcxxabi/src/demangle/ItaniumDemangle.h b/libcxxabi/src/demangle/ItaniumDemangle.h
--- a/libcxxabi/src/demangle/ItaniumDemangle.h
+++ b/libcxxabi/src/demangle/ItaniumDemangle.h
@@ -544,6 +544,8 @@
 
   template<typename Fn> void match(Fn F) const { F(Base, Tag); }
 
+  StringView getBaseName() const override { return Base->getBaseName(); }
+
   void printLeft(OutputBuffer &OB) const override {
     Base->printLeft(OB);
     OB += "[abi:";
diff --git a/libcxxabi/test/test_demangle.pass.cpp b/libcxxabi/test/test_demangle.pass.cpp
--- a/libcxxabi/test/test_demangle.pass.cpp
+++ b/libcxxabi/test/test_demangle.pass.cpp
@@ -30112,6 +30112,8 @@
      "::basic_ostream()"},
     {"_ZNSsC1Ev", "std::basic_string<char, std::char_traits<char>,"
      " std::allocator<char>>::basic_string()"},
+    {"_ZN1SB8ctor_tagC2Ev", "S[abi:ctor_tag]::S()"},
+    {"_ZN1SB8ctor_tagD2Ev", "S[abi:ctor_tag]::~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
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -537,6 +537,8 @@
 
   template<typename Fn> void match(Fn F) const { F(Base, Tag); }
 
+  StringView getBaseName() const override { return Base->getBaseName(); }
+
   void printLeft(OutputBuffer &OB) const override {
     Base->printLeft(OB);
     OB += "[abi:";
diff --git a/llvm/test/tools/llvm-cxxfilt/abitag.test b/llvm/test/tools/llvm-cxxfilt/abitag.test
--- a/llvm/test/tools/llvm-cxxfilt/abitag.test
+++ b/llvm/test/tools/llvm-cxxfilt/abitag.test
@@ -1,6 +1,7 @@
-RUN: llvm-cxxfilt -n _Z14returns_stringB5cxx11v _Z6globalB5cxx11 _Z6globalB12a_longer_tag | FileCheck %s
+RUN: llvm-cxxfilt -n _Z14returns_stringB5cxx11v _Z6globalB5cxx11 _Z6globalB12a_longer_tag _ZN6globalB3TagC2Ev _ZN6globalB3TagD2Ev | FileCheck %s
 
 CHECK: returns_string[abi:cxx11]()
 CHECK-NEXT: global[abi:cxx11]
 CHECK-NEXT: global[abi:a_longer_tag]
-
+CHECK-NEXT: global[abi:Tag]::global()
+CHECK-NEXT: global[abi:Tag]::~global()