Index: llvm/trunk/docs/CommandGuide/llvm-symbolizer.rst
===================================================================
--- llvm/trunk/docs/CommandGuide/llvm-symbolizer.rst
+++ llvm/trunk/docs/CommandGuide/llvm-symbolizer.rst
@@ -87,6 +87,10 @@
 
  Print demangled function names. Defaults to true.
 
+.. option:: -no-demangle
+
+ Don't print demangled function names.
+
 .. option:: -inlining 
 
  If a source code location is in an inlined function, prints all the
Index: llvm/trunk/test/DebugInfo/llvm-symbolizer.test
===================================================================
--- llvm/trunk/test/DebugInfo/llvm-symbolizer.test
+++ llvm/trunk/test/DebugInfo/llvm-symbolizer.test
@@ -214,3 +214,16 @@
 RUN:    | FileCheck %s --check-prefix=SHORT_FUNCTION_NAME
 
 SHORT_FUNCTION_NAME-NOT: _Z1cv
+
+; Check that the last of --demangle and --no-demangle wins.
+RUN: llvm-symbolizer --demangle < %t.input7 \
+RUN:    | FileCheck %s --check-prefix=DEMANGLED_FUNCTION_NAME
+RUN: llvm-symbolizer --no-demangle < %t.input7 \
+RUN:    | FileCheck %s --check-prefix=MANGLED_FUNCTION_NAME
+RUN: llvm-symbolizer --demangle --no-demangle < %t.input7 \
+RUN:    | FileCheck %s --check-prefix=MANGLED_FUNCTION_NAME
+RUN: llvm-symbolizer --no-demangle --demangle < %t.input7 \
+RUN:    | FileCheck %s --check-prefix=DEMANGLED_FUNCTION_NAME
+
+MANGLED_FUNCTION_NAME: _Z1cv
+DEMANGLED_FUNCTION_NAME: c()
Index: llvm/trunk/tools/llvm-symbolizer/llvm-symbolizer.cpp
===================================================================
--- llvm/trunk/tools/llvm-symbolizer/llvm-symbolizer.cpp
+++ llvm/trunk/tools/llvm-symbolizer/llvm-symbolizer.cpp
@@ -54,12 +54,15 @@
     ClPrintInlining("inlining", cl::init(true),
                     cl::desc("Print all inlined frames for a given address"));
 
-// -demangle, -C
+// -demangle, -C, -no-demangle
 static cl::opt<bool>
 ClDemangle("demangle", cl::init(true), cl::desc("Demangle function names"));
 static cl::alias
 ClDemangleShort("C", cl::desc("Alias for -demangle"),
                 cl::NotHidden, cl::aliasopt(ClDemangle));
+static cl::opt<bool>
+ClNoDemangle("no-demangle", cl::init(false),
+             cl::desc("Don't demangle function names"));
 
 static cl::opt<std::string> ClDefaultArch("default-arch", cl::init(""),
                                           cl::desc("Default architecture "
@@ -200,8 +203,12 @@
   InitLLVM X(argc, argv);
 
   llvm::sys::InitializeCOMRAII COM(llvm::sys::COMThreadingMode::MultiThreaded);
-
   cl::ParseCommandLineOptions(argc, argv, "llvm-symbolizer\n");
+
+  // If both --demangle and --no-demangle are specified then pick the last one.
+  if (ClNoDemangle.getPosition() > ClDemangle.getPosition())
+    ClDemangle = !ClNoDemangle;
+
   LLVMSymbolizer::Options Opts(ClPrintFunctions, ClUseSymbolTable, ClDemangle,
                                ClUseRelativeAddress, ClDefaultArch);