diff --git a/llvm/lib/Demangle/ItaniumDemangle.cpp b/llvm/lib/Demangle/ItaniumDemangle.cpp
diff --git a/llvm/lib/Demangle/LLVMBuild.txt b/llvm/lib/Demangle/LLVMBuild.txt
@@ -0,0 +1,21 @@
+;===- ./lib/Support/LLVMBuild.txt ------------------------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = Demangle
+parent = Libraries
diff --git a/llvm/lib/LLVMBuild.txt b/llvm/lib/LLVMBuild.txt
@@ -22,6 +22,7 @@ subdirectories =
  Bitcode
  CodeGen
  DebugInfo
+ Demangle
  ExecutionEngine
  LibDriver
  LineEditor

diff --git a/llvm/lib/Support/LLVMBuild.txt b/llvm/lib/Support/LLVMBuild.txt
@@ -19,3 +19,4 @@
 type = Library
 name = Support
 parent = Libraries
+required_libraries = Demangle
diff --git a/llvm/lib/Support/Unix/Signals.inc b/llvm/lib/Support/Unix/Signals.inc
@@ -14,6 +14,7 @@
 
 #include "Unix.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/Demangle/Demangle.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FileUtilities.h"
@@ -33,9 +34,6 @@
 #if HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
-#if HAVE_CXXABI_H
-#include <cxxabi.h>
-#endif
 #if HAVE_DLFCN_H
 #include <dlfcn.h>
 #endif
@@ -443,12 +441,8 @@ void llvm::sys::PrintStackTrace(raw_ostream &OS) {
 
     if (dlinfo.dli_sname != nullptr) {
       OS << ' ';
-#  if HAVE_CXXABI_H
       int res;
-      char* d = abi::__cxa_demangle(dlinfo.dli_sname, nullptr, nullptr, &res);
-#  else
-      char* d = NULL;
-#  endif
+      char* d = itaniumDemangle(dlinfo.dli_sname, nullptr, nullptr, &res);
       if (!d) OS << dlinfo.dli_sname;
       else    OS << d;
       free(d);

diff --git a/llvm/test/CMakeLists.txt b/llvm/test/CMakeLists.txt
@@ -32,6 +32,7 @@ set(LLVM_TEST_DEPENDS
           llvm-as
           llvm-bcanalyzer
           llvm-c-test
+          llvm-cxxfilt
           llvm-config
           llvm-cov
           llvm-cxxdump

diff --git a/llvm/test/Demangle/lit.local.cfg b/llvm/test/Demangle/lit.local.cfg
@@ -0,0 +1 @@
+config.suffixes = ['.test']
diff --git a/llvm/test/Demangle/simple.test b/llvm/test/Demangle/simple.test
@@ -0,0 +1,4 @@
+RUN: llvm-cxxfilt _Z1fi abc | FileCheck %s
+
+CHECK: f(int)
+CHECK-NEXT: abc
diff --git a/llvm/test/lit.cfg b/llvm/test/lit.cfg
@@ -309,6 +309,7 @@ for pattern in [r"\bbugpoint\b(?!-)",
                 r"\bllvm-split\b",
                 r"\bllvm-tblgen\b",
                 r"\bllvm-c-test\b",
+                r"\bllvm-cxxfilt\b",
                 NOJUNK + r"\bllvm-symbolizer\b",
                 NOJUNK + r"\bopt\b",
                 r"\bFileCheck\b",

diff --git a/llvm/test/tools/llvm-objdump/X86/macho-symbolized-disassembly.test b/llvm/test/tools/llvm-objdump/X86/macho-symbolized-disassembly.test
@@ -31,10 +31,7 @@ ObjC-EXE: 0000000100000f1b	movq	0x10e(%rip), %rsi       ## Objc selector ref: da
 ObjC-EXE: 0000000100000f25	callq	0x100000f4a             ## Objc message: +[NSDate date]
 ObjC-EXE: 0000000100000f33	callq	0x100000f44             ## symbol stub for: _NSLog
 
-CXX-EXE: 00000001000014cb	callq	__ZNSt3__116__pad_and_outputIcNS_11char_traitsIcEEEENS_19ostreambuf_iteratorIT_T0_EES6_PKS4_S8_S8_RNS_8ios_baseES4_
-
-// FIXME: Demangler depends on host's <cxxabi.h>.
-// std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char)
+CXX-EXE: 00000001000014cb	callq	__ZNSt3__116__pad_and_outputIcNS_11char_traitsIcEEEENS_19ostreambuf_iteratorIT_T0_EES6_PKS4_S8_S8_RNS_8ios_baseES4_ ## std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char)
 
 i386-OBJ: 0000002f	calll	_printf
 

diff --git a/llvm/tools/llvm-cxxfilt/CMakeLists.txt b/llvm/tools/llvm-cxxfilt/CMakeLists.txt
@@ -0,0 +1,7 @@
+set(LLVM_LINK_COMPONENTS
+  Demangle
+  )
+
+add_llvm_tool(llvm-cxxfilt
+  llvm-cxxfilt.cpp
+  )
diff --git a/llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp b/llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp
@@ -0,0 +1,29 @@
+//===-- llvm-c++filt.cpp --------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Demangle/Demangle.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+using namespace llvm;
+
+int main(int argc, char **argv) {
+  for (int I = 1; I < argc; ++I) {
+    const char *Mangled = argv[I];
+    int Status;
+    char *Demangled = itaniumDemangle(Mangled, nullptr, nullptr, &Status);
+    if (Demangled)
+      printf("%s\n", Demangled);
+    else
+      printf("%s\n", Mangled);
+    free(Demangled);
+  }
+  return 0;
+}
diff --git a/llvm/tools/llvm-objdump/CMakeLists.txt b/llvm/tools/llvm-objdump/CMakeLists.txt
@@ -6,6 +6,7 @@ set(LLVM_LINK_COMPONENTS
   CodeGen
   DebugInfoDWARF
   DebugInfoPDB
+  Demangle
   MC
   MCDisassembler
   Object

diff --git a/llvm/tools/llvm-objdump/LLVMBuild.txt b/llvm/tools/llvm-objdump/LLVMBuild.txt
@@ -19,4 +19,4 @@
 type = Tool
 name = llvm-objdump
 parent = Tools
-required_libraries = DebugInfoDWARF MC MCDisassembler MCParser Object all-targets
+required_libraries = DebugInfoDWARF MC MCDisassembler MCParser Object all-targets Demangle
diff --git a/llvm/tools/llvm-objdump/MachODump.cpp b/llvm/tools/llvm-objdump/MachODump.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Config/config.h"
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/Demangle/Demangle.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
@@ -48,10 +49,6 @@
 #include <cstring>
 #include <system_error>
 
-#if HAVE_CXXABI_H
-#include <cxxabi.h>
-#endif
-
 #ifdef HAVE_LIBXAR
 extern "C" {
 #include <xar/xar.h>
@@ -6235,11 +6232,9 @@ static const char *GuessLiteralPointer(uint64_t ReferenceValue,
 // Out type and the ReferenceName will also be set which is added as a comment
 // to the disassembled instruction.
 //
-#if HAVE_CXXABI_H
 // If the symbol name is a C++ mangled name then the demangled name is
 // returned through ReferenceName and ReferenceType is set to
 // LLVMDisassembler_ReferenceType_DeMangled_Name .
-#endif
 //
 // When this is called to get a symbol name for a branch target then the
 // ReferenceType will be LLVMDisassembler_ReferenceType_In_Branch and then
@@ -6274,21 +6269,18 @@ static const char *SymbolizerSymbolLookUp(void *DisInfo,
       method_reference(info, ReferenceType, ReferenceName);
       if (*ReferenceType != LLVMDisassembler_ReferenceType_Out_Objc_Message)
         *ReferenceType = LLVMDisassembler_ReferenceType_Out_SymbolStub;
-    } else
-#if HAVE_CXXABI_H
-        if (SymbolName != nullptr && strncmp(SymbolName, "__Z", 3) == 0) {
+    } else if (SymbolName != nullptr && strncmp(SymbolName, "__Z", 3) == 0) {
       if (info->demangled_name != nullptr)
         free(info->demangled_name);
       int status;
       info->demangled_name =
-          abi::__cxa_demangle(SymbolName + 1, nullptr, nullptr, &status);
+          itaniumDemangle(SymbolName + 1, nullptr, nullptr, &status);
       if (info->demangled_name != nullptr) {
         *ReferenceName = info->demangled_name;
         *ReferenceType = LLVMDisassembler_ReferenceType_DeMangled_Name;
       } else
         *ReferenceType = LLVMDisassembler_ReferenceType_InOut_None;
     } else
-#endif
       *ReferenceType = LLVMDisassembler_ReferenceType_InOut_None;
   } else if (*ReferenceType == LLVMDisassembler_ReferenceType_In_PCrel_Load) {
     *ReferenceName =
@@ -6377,20 +6369,17 @@ static const char *SymbolizerSymbolLookUp(void *DisInfo,
         GuessLiteralPointer(ReferenceValue, ReferencePC, ReferenceType, info);
     if (*ReferenceName == nullptr)
       *ReferenceType = LLVMDisassembler_ReferenceType_InOut_None;
-  }
-#if HAVE_CXXABI_H
-  else if (SymbolName != nullptr && strncmp(SymbolName, "__Z", 3) == 0) {
+  } else if (SymbolName != nullptr && strncmp(SymbolName, "__Z", 3) == 0) {
     if (info->demangled_name != nullptr)
       free(info->demangled_name);
     int status;
     info->demangled_name =
-        abi::__cxa_demangle(SymbolName + 1, nullptr, nullptr, &status);
+        itaniumDemangle(SymbolName + 1, nullptr, nullptr, &status);
     if (info->demangled_name != nullptr) {
       *ReferenceName = info->demangled_name;
       *ReferenceType = LLVMDisassembler_ReferenceType_DeMangled_Name;
     }
   }
-#endif
   else {
     *ReferenceName = nullptr;
     *ReferenceType = LLVMDisassembler_ReferenceType_InOut_None;