[clang][Attr] Remove 'literal label' form of AsmLabelAttr (#151858)

This was added purely for the needs of LLDB. However, starting with
#151355 and
#148877 we no longer create
literal AsmLabels in LLDB either. So this is unused and we can get rid
of it.

In the near future LLDB will want to add special support for mangling
`AsmLabel`s (specifically
#149827).

Author: Michael137

clang/include/clang/Basic/Attr.td

@@ -1059,22 +1059,13 @@ def AVRSignal : InheritableAttr, TargetSpecificAttr<TargetAVR> {
 def AsmLabel : InheritableAttr {
   let Spellings = [CustomKeyword<"asm">, CustomKeyword<"__asm__">];
   let Args = [
-    // Label specifies the mangled name for the decl.
-    StringArgument<"Label">,
-
-    // IsLiteralLabel specifies whether the label is literal (i.e. suppresses
-    // the global C symbol prefix) or not. If not, the mangle-suppression prefix
-    // ('\01') is omitted from the decl name at the LLVM IR level.
-    //
-    // Non-literal labels are used by some external AST sources like LLDB.
-    BoolArgument<"IsLiteralLabel", /*optional=*/0, /*fake=*/1>
-  ];
+      // Label specifies the mangled name for the decl.
+      StringArgument<"Label">, ];
   let SemaHandler = 0;
   let Documentation = [AsmLabelDocs];
-  let AdditionalMembers =
-[{
+  let AdditionalMembers = [{
 bool isEquivalent(AsmLabelAttr *Other) const {
-  return getLabel() == Other->getLabel() && getIsLiteralLabel() == Other->getIsLiteralLabel();
+  return getLabel() == Other->getLabel();
 }
 }];
 }

clang/lib/AST/Mangle.cpp

@@ -161,9 +161,9 @@ void MangleContext::mangleName(GlobalDecl GD, raw_ostream &Out) {
   if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
     // If we have an asm name, then we use it as the mangling.
 
-    // If the label isn't literal, or if this is an alias for an LLVM intrinsic,
+    // If the label is an alias for an LLVM intrinsic,
     // do not add a "\01" prefix.
-    if (!ALA->getIsLiteralLabel() || ALA->getLabel().starts_with("llvm.")) {
+    if (ALA->getLabel().starts_with("llvm.")) {
       Out << ALA->getLabel();
       return;
     }

clang/lib/Sema/SemaDecl.cpp

@@ -8113,9 +8113,7 @@ NamedDecl *Sema::ActOnVariableDeclarator(
       }
     }
 
-    NewVD->addAttr(AsmLabelAttr::Create(Context, Label,
-                                        /*IsLiteralLabel=*/true,
-                                        SE->getStrTokenLoc(0)));
+    NewVD->addAttr(AsmLabelAttr::Create(Context, Label, SE->getStrTokenLoc(0)));
   } else if (!ExtnameUndeclaredIdentifiers.empty()) {
     llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
       ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
@@ -10345,9 +10343,8 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
   if (Expr *E = D.getAsmLabel()) {
     // The parser guarantees this is a string.
     StringLiteral *SE = cast<StringLiteral>(E);
-    NewFD->addAttr(AsmLabelAttr::Create(Context, SE->getString(),
-                                        /*IsLiteralLabel=*/true,
-                                        SE->getStrTokenLoc(0)));
+    NewFD->addAttr(
+        AsmLabelAttr::Create(Context, SE->getString(), SE->getStrTokenLoc(0)));
   } else if (!ExtnameUndeclaredIdentifiers.empty()) {
     llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
       ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
@@ -20598,8 +20595,8 @@ void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name,
                                          LookupOrdinaryName);
   AttributeCommonInfo Info(AliasName, SourceRange(AliasNameLoc),
                            AttributeCommonInfo::Form::Pragma());
-  AsmLabelAttr *Attr = AsmLabelAttr::CreateImplicit(
-      Context, AliasName->getName(), /*IsLiteralLabel=*/true, Info);
+  AsmLabelAttr *Attr =
+      AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), Info);
 
   // If a declaration that:
   // 1) declares a function or a variable

clang/unittests/AST/DeclTest.cpp

@@ -74,7 +74,6 @@ TEST(Decl, AsmLabelAttr) {
   StringRef Code = R"(
     struct S {
       void f() {}
-      void g() {}
     };
   )";
   auto AST =
@@ -87,26 +86,20 @@ TEST(Decl, AsmLabelAttr) {
   const auto *DeclS =
       selectFirst<CXXRecordDecl>("d", match(cxxRecordDecl().bind("d"), Ctx));
   NamedDecl *DeclF = *DeclS->method_begin();
-  NamedDecl *DeclG = *(++DeclS->method_begin());
 
-  // Attach asm labels to the decls: one literal, and one not.
-  DeclF->addAttr(AsmLabelAttr::Create(Ctx, "foo", /*LiteralLabel=*/true));
-  DeclG->addAttr(AsmLabelAttr::Create(Ctx, "goo", /*LiteralLabel=*/false));
+  DeclF->addAttr(AsmLabelAttr::Create(Ctx, "foo"));
 
   // Mangle the decl names.
   std::string MangleF, MangleG;
   std::unique_ptr<ItaniumMangleContext> MC(
       ItaniumMangleContext::create(Ctx, Diags));
   {
     llvm::raw_string_ostream OS_F(MangleF);
-    llvm::raw_string_ostream OS_G(MangleG);
     MC->mangleName(DeclF, OS_F);
-    MC->mangleName(DeclG, OS_G);
   }
 
   ASSERT_EQ(MangleF, "\x01"
                      "foo");
-  ASSERT_EQ(MangleG, "goo");
 }
 
 TEST(Decl, MangleDependentSizedArray) {

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp

@@ -2184,8 +2184,7 @@ FunctionDecl *TypeSystemClang::CreateFunctionDeclaration(
   // This is done separately for member functions in
   // AddMethodToCXXRecordType.
   if (!asm_label.empty())
-    func_decl->addAttr(clang::AsmLabelAttr::CreateImplicit(ast, asm_label,
-                                                           /*literal=*/true));
+    func_decl->addAttr(clang::AsmLabelAttr::CreateImplicit(ast, asm_label));
 
   SetOwningModule(func_decl, owning_module);
   decl_ctx->addDecl(func_decl);
@@ -7824,8 +7823,8 @@ clang::CXXMethodDecl *TypeSystemClang::AddMethodToCXXRecordType(
     cxx_method_decl->addAttr(clang::UsedAttr::CreateImplicit(getASTContext()));
 
   if (!asm_label.empty())
-    cxx_method_decl->addAttr(clang::AsmLabelAttr::CreateImplicit(
-        getASTContext(), asm_label, /*literal=*/true));
+    cxx_method_decl->addAttr(
+        clang::AsmLabelAttr::CreateImplicit(getASTContext(), asm_label));
 
   // Parameters on member function declarations in DWARF generally don't
   // have names, so we omit them when creating the ParmVarDecls.