Index: clang/include/clang/Basic/Attr.td
===================================================================
--- clang/include/clang/Basic/Attr.td
+++ clang/include/clang/Basic/Attr.td
@@ -722,7 +722,7 @@
 
 def AsmLabel : InheritableAttr {
   let Spellings = [Keyword<"asm">, Keyword<"__asm__">];
-  let Args = [StringArgument<"Label">];
+  let Args = [StringArgument<"Label">, BoolArgument<"LiteralLabel">];
   let SemaHandler = 0;
   let Documentation = [Undocumented];
 }
Index: clang/lib/AST/Mangle.cpp
===================================================================
--- clang/lib/AST/Mangle.cpp
+++ clang/lib/AST/Mangle.cpp
@@ -127,10 +127,11 @@
     // tricks normally used for producing aliases (PR9177). Fortunately the
     // llvm mangler on ELF is a nop, so we can just avoid adding the \01
     // marker.  We also avoid adding the marker if this is an alias for an
-    // LLVM intrinsic.
+    // LLVM intrinsic, or if label has a literal label.
     char GlobalPrefix =
         getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix();
-    if (GlobalPrefix && !ALA->getLabel().startswith("llvm."))
+    if (GlobalPrefix && !ALA->getLabel().startswith("llvm.") &&
+        !ALA->getLiteralLabel())
       Out << '\01'; // LLVM IR Marker for __asm("foo")
 
     Out << ALA->getLabel();
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -2766,6 +2766,8 @@
 
   if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
     if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
+      assert(OldA->getLiteralLabel() == NewA->getLiteralLabel() &&
+             "Redeclaration of asm label changes label kind");
       if (OldA->getLabel() != NewA->getLabel()) {
         // This redeclaration changes __asm__ label.
         Diag(New->getLocation(), diag::err_different_asm_label);
@@ -6983,8 +6985,8 @@
       }
     }
 
-    NewVD->addAttr(::new (Context)
-                       AsmLabelAttr(Context, SE->getStrTokenLoc(0), Label));
+    NewVD->addAttr(::new (Context) AsmLabelAttr(Context, SE->getStrTokenLoc(0),
+                                                Label, /*LiteralLabel=*/false));
   } else if (!ExtnameUndeclaredIdentifiers.empty()) {
     llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
       ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
@@ -8882,8 +8884,9 @@
   if (Expr *E = (Expr*) D.getAsmLabel()) {
     // The parser guarantees this is a string.
     StringLiteral *SE = cast<StringLiteral>(E);
-    NewFD->addAttr(::new (Context) AsmLabelAttr(Context, SE->getStrTokenLoc(0),
-                                                SE->getString()));
+    NewFD->addAttr(::new (Context)
+                       AsmLabelAttr(Context, SE->getStrTokenLoc(0),
+                                    SE->getString(), /*LiteralLabel=*/false));
   } else if (!ExtnameUndeclaredIdentifiers.empty()) {
     llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
       ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
@@ -17555,8 +17558,8 @@
                                          LookupOrdinaryName);
   AttributeCommonInfo Info(AliasName, SourceRange(AliasNameLoc),
                            AttributeCommonInfo::AS_Pragma);
-  AsmLabelAttr *Attr =
-      AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), Info);
+  AsmLabelAttr *Attr = AsmLabelAttr::CreateImplicit(
+      Context, AliasName->getName(), /*LiteralLabel=*/false, Info);
 
   // If a declaration that:
   // 1) declares a function or a variable
Index: clang/unittests/AST/DeclTest.cpp
===================================================================
--- clang/unittests/AST/DeclTest.cpp
+++ clang/unittests/AST/DeclTest.cpp
@@ -10,12 +10,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Mangle.h"
+#include "clang/Basic/LLVM.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/Tooling/Tooling.h"
 #include "gtest/gtest.h"
 
 using namespace clang::ast_matchers;
 using namespace clang::tooling;
+using namespace clang;
 
 TEST(Decl, CleansUpAPValues) {
   MatchFinder Finder;
@@ -56,3 +60,49 @@
       "constexpr _Complex __uint128_t c = 0xffffffffffffffff;",
       Args));
 }
+
+TEST(Decl, AsmLabelAttr) {
+  // Create two method decls: `f` and `g`.
+  StringRef Code = R"(
+    struct S {
+      void f() {}
+      void g() {}
+    };
+  )";
+  auto AST =
+      tooling::buildASTFromCodeWithArgs(Code, {"-target", "i386-apple-darwin"});
+  ASTContext &Ctx = AST->getASTContext();
+  DiagnosticsEngine &Diags = AST->getDiagnostics();
+  SourceManager &SM = AST->getSourceManager();
+  FileID MainFileID = SM.getMainFileID();
+
+  // Find the method decls within the AST.
+  SmallVector<Decl *, 1> Decls;
+  AST->findFileRegionDecls(MainFileID, Code.find('{'), 0, Decls);
+  ASSERT_TRUE(Decls.size() == 1);
+  CXXRecordDecl *DeclS = cast<CXXRecordDecl>(Decls[0]);
+  NamedDecl *DeclF = *DeclS->method_begin();
+  NamedDecl *DeclG = *(++DeclS->method_begin());
+
+  // Attach asm labels to the decls: one literal, and one subject to global
+  // prefixing.
+  DeclF->addAttr(::new (Ctx) AsmLabelAttr(Ctx, SourceLocation(), "foo",
+                                          /*LiteralLabel=*/true));
+  DeclG->addAttr(::new (Ctx) AsmLabelAttr(Ctx, SourceLocation(), "goo",
+                                          /*LiteralLabel=*/false));
+
+  // Mangle the decl names.
+  std::string MangleF, MangleG;
+  MangleContext *MC = ItaniumMangleContext::create(Ctx, Diags);
+  {
+    llvm::raw_string_ostream OS(MangleF);
+    MC->mangleName(DeclF, OS);
+  }
+  {
+    llvm::raw_string_ostream OS(MangleG);
+    MC->mangleName(DeclG, OS);
+  }
+
+  ASSERT_TRUE(0 == MangleF.compare("foo"));
+  ASSERT_TRUE(0 == MangleG.compare("\x01goo"));
+}
Index: lldb/source/Symbol/ClangASTContext.cpp
===================================================================
--- lldb/source/Symbol/ClangASTContext.cpp
+++ lldb/source/Symbol/ClangASTContext.cpp
@@ -8300,8 +8300,8 @@
     cxx_method_decl->addAttr(clang::UsedAttr::CreateImplicit(*getASTContext()));
 
   if (mangled_name != nullptr) {
-    cxx_method_decl->addAttr(
-        clang::AsmLabelAttr::CreateImplicit(*getASTContext(), mangled_name));
+    cxx_method_decl->addAttr(clang::AsmLabelAttr::CreateImplicit(
+        *getASTContext(), mangled_name, /*literal=*/true));
   }
 
   // Populate the method decl with parameter decls