From a5c3cb19219a906af6fa942ba79e6efc46136eca Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Tue, 8 Jul 2025 09:32:40 -0700
Subject: [PATCH 1/7] [llvm] define export annotations for Demangle library

---
 llvm/CMakeLists.txt                     |  5 +--
 llvm/include/llvm/Demangle/Visibility.h | 43 +++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 llvm/include/llvm/Demangle/Visibility.h

diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 903461b39902e..20a648dc95baa 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -1078,9 +1078,10 @@ if (LLVM_BUILD_LLVM_DYLIB OR LLVM_BUILD_SHARED_LIBS OR LLVM_ENABLE_PLUGINS)
   set(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS ON)
 endif()
 
-# Because LLVM-C is built into the LLVM library, for now export its symbols
-# whenever LLVM symbols are exported.
+# Because LLVM-C and Demangle libraries are built into the LLVM library, for now
+# we export their symbols if LLVM symbols are exported.
 set(LLVM_ENABLE_LLVM_C_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
+set(LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
 
 set(LLVM_ENABLE_NEW_PASS_MANAGER TRUE CACHE BOOL
   "Enable the new pass manager by default.")
diff --git a/llvm/include/llvm/Demangle/Visibility.h b/llvm/include/llvm/Demangle/Visibility.h
new file mode 100644
index 0000000000000..35ea238b446b6
--- /dev/null
+++ b/llvm/include/llvm/Demangle/Visibility.h
@@ -0,0 +1,43 @@
+/*===-- Demangle/Visibility.h - Visibility macros for Demangle --*- C++ -*-===*\
+|*                                                                            *|
+|* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
+|* Exceptions.                                                                *|
+|* See https://llvm.org/LICENSE.txt for license information.                  *|
+|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* This header defines visibility macros used for the Demangle library. These *|
+|* macros are used to annotate functions that should be exported as part of a *|
+|* shared library or DLL.                                                     *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef LLVM_DEMANGLE_VISIBILITY_H
+#define LLVM_DEMANGLE_VISIBILITY_H
+
+#include "llvm/Config/llvm-config.h"
+#include "llvm/Demangle/DemangleConfig.h"
+
+/// DEMANGLE_ABI is the export/visibility macro used to mark symbols delcared in
+/// llvm/Demangle as exported when built as a shared library.
+
+#if !defined(LLVM_ABI_GENERATING_ANNOTATIONS)
+#if defined(LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS) &&                        \
+    !defined(LLVM_BUILD_STATIC)
+#if defined(_WIN32) && !defined(__MINGW32__)
+#if defined(LLVM_EXPORTS)
+#define DEMANGLE_ABI __declspec(dllexport)
+#else
+#define DEMANGLE_ABI __declspec(dllimport)
+#endif
+#elif __has_attribute(visibility)
+#define DEMANGLE_ABI __attribute__((visibility("default")))
+#endif
+#endif
+#if !defined(DEMANGLE_ABI)
+#define DEMANGLE_ABI
+#endif
+#endif
+
+#endif

From 63cc75b150749d6c1952419249e885de46da0778 Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Tue, 8 Jul 2025 09:35:00 -0700
Subject: [PATCH 2/7] [llvm] auto-annotate Demangle library interface with IDS

---
 llvm/include/llvm/Demangle/Demangle.h         | 49 +++++++--------
 llvm/include/llvm/Demangle/ItaniumDemangle.h  |  3 +-
 .../include/llvm/Demangle/MicrosoftDemangle.h |  7 ++-
 .../llvm/Demangle/MicrosoftDemangleNodes.h    | 59 ++++++++++---------
 4 files changed, 61 insertions(+), 57 deletions(-)

diff --git a/llvm/include/llvm/Demangle/Demangle.h b/llvm/include/llvm/Demangle/Demangle.h
index 21e7457b6336f..77127d993f5f8 100644
--- a/llvm/include/llvm/Demangle/Demangle.h
+++ b/llvm/include/llvm/Demangle/Demangle.h
@@ -9,6 +9,7 @@
 #ifndef LLVM_DEMANGLE_DEMANGLE_H
 #define LLVM_DEMANGLE_DEMANGLE_H
 
+#include "llvm/Demangle/Visibility.h"
 #include <cstddef>
 #include <optional>
 #include <string>
@@ -33,7 +34,7 @@ enum : int {
 /// Returns a non-NULL pointer to a NUL-terminated C style string
 /// that should be explicitly freed, if successful. Otherwise, may return
 /// nullptr if mangled_name is not a valid mangling or is nullptr.
-char *itaniumDemangle(std::string_view mangled_name, bool ParseParams = true);
+DEMANGLE_ABI char *itaniumDemangle(std::string_view mangled_name, bool ParseParams = true);
 
 enum MSDemangleFlags {
   MSDF_None = 0,
@@ -52,26 +53,26 @@ enum MSDemangleFlags {
 /// bytes of the input string were consumed.
 /// status receives one of the demangle_ enum entries above if it's not nullptr.
 /// Flags controls various details of the demangled representation.
-char *microsoftDemangle(std::string_view mangled_name, size_t *n_read,
+DEMANGLE_ABI char *microsoftDemangle(std::string_view mangled_name, size_t *n_read,
                         int *status, MSDemangleFlags Flags = MSDF_None);
 
-std::optional<size_t>
+DEMANGLE_ABI std::optional<size_t>
 getArm64ECInsertionPointInMangledName(std::string_view MangledName);
 
 // Demangles a Rust v0 mangled symbol.
-char *rustDemangle(std::string_view MangledName);
+DEMANGLE_ABI char *rustDemangle(std::string_view MangledName);
 
 // Demangles a D mangled symbol.
-char *dlangDemangle(std::string_view MangledName);
+DEMANGLE_ABI char *dlangDemangle(std::string_view MangledName);
 
 /// Attempt to demangle a string using different demangling schemes.
 /// The function uses heuristics to determine which demangling scheme to use.
 /// \param MangledName - reference to string to demangle.
 /// \returns - the demangled string, or a copy of the input string if no
 /// demangling occurred.
-std::string demangle(std::string_view MangledName);
+DEMANGLE_ABI std::string demangle(std::string_view MangledName);
 
-bool nonMicrosoftDemangle(std::string_view MangledName, std::string &Result,
+DEMANGLE_ABI bool nonMicrosoftDemangle(std::string_view MangledName, std::string &Result,
                           bool CanHaveLeadingDot = true,
                           bool ParseParams = true);
 
@@ -79,60 +80,60 @@ bool nonMicrosoftDemangle(std::string_view MangledName, std::string &Result,
 /// (typically an intermediate stage in itaniumDemangle) and querying certain
 /// properties or partially printing the demangled name.
 struct ItaniumPartialDemangler {
-  ItaniumPartialDemangler();
+  DEMANGLE_ABI ItaniumPartialDemangler();
 
-  ItaniumPartialDemangler(ItaniumPartialDemangler &&Other);
-  ItaniumPartialDemangler &operator=(ItaniumPartialDemangler &&Other);
+  DEMANGLE_ABI ItaniumPartialDemangler(ItaniumPartialDemangler &&Other);
+  DEMANGLE_ABI ItaniumPartialDemangler &operator=(ItaniumPartialDemangler &&Other);
 
   /// Demangle into an AST. Subsequent calls to the rest of the member functions
   /// implicitly operate on the AST this produces.
   /// \return true on error, false otherwise
-  bool partialDemangle(const char *MangledName);
+  DEMANGLE_ABI bool partialDemangle(const char *MangledName);
 
   /// Just print the entire mangled name into Buf. Buf and N behave like the
   /// second and third parameters to __cxa_demangle.
-  char *finishDemangle(char *Buf, size_t *N) const;
+  DEMANGLE_ABI char *finishDemangle(char *Buf, size_t *N) const;
 
   /// See \ref finishDemangle
   ///
   /// \param[in] OB A llvm::itanium_demangle::OutputBuffer that the demangled
   /// name will be printed into.
   ///
-  char *finishDemangle(void *OB) const;
+  DEMANGLE_ABI char *finishDemangle(void *OB) const;
 
   /// Get the base name of a function. This doesn't include trailing template
   /// arguments, ie for "a::b<int>" this function returns "b".
-  char *getFunctionBaseName(char *Buf, size_t *N) const;
+  DEMANGLE_ABI char *getFunctionBaseName(char *Buf, size_t *N) const;
 
   /// Get the context name for a function. For "a::b::c", this function returns
   /// "a::b".
-  char *getFunctionDeclContextName(char *Buf, size_t *N) const;
+  DEMANGLE_ABI char *getFunctionDeclContextName(char *Buf, size_t *N) const;
 
   /// Get the entire name of this function.
-  char *getFunctionName(char *Buf, size_t *N) const;
+  DEMANGLE_ABI char *getFunctionName(char *Buf, size_t *N) const;
 
   /// Get the parameters for this function.
-  char *getFunctionParameters(char *Buf, size_t *N) const;
-  char *getFunctionReturnType(char *Buf, size_t *N) const;
+  DEMANGLE_ABI char *getFunctionParameters(char *Buf, size_t *N) const;
+  DEMANGLE_ABI char *getFunctionReturnType(char *Buf, size_t *N) const;
 
   /// If this function has any cv or reference qualifiers. These imply that
   /// the function is a non-static member function.
-  bool hasFunctionQualifiers() const;
+  DEMANGLE_ABI bool hasFunctionQualifiers() const;
 
   /// If this symbol describes a constructor or destructor.
-  bool isCtorOrDtor() const;
+  DEMANGLE_ABI bool isCtorOrDtor() const;
 
   /// If this symbol describes a function.
-  bool isFunction() const;
+  DEMANGLE_ABI bool isFunction() const;
 
   /// If this symbol describes a variable.
-  bool isData() const;
+  DEMANGLE_ABI bool isData() const;
 
   /// If this symbol is a <special-name>. These are generally implicitly
   /// generated by the implementation, such as vtables and typeinfo names.
-  bool isSpecialName() const;
+  DEMANGLE_ABI bool isSpecialName() const;
 
-  ~ItaniumPartialDemangler();
+  DEMANGLE_ABI ~ItaniumPartialDemangler();
 
 private:
   void *RootNode;
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index 5533652736dc8..dfa5839d12a5a 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -16,6 +16,7 @@
 #ifndef DEMANGLE_ITANIUMDEMANGLE_H
 #define DEMANGLE_ITANIUMDEMANGLE_H
 
+#include "llvm/Demangle/Visibility.h"
 #include "DemangleConfig.h"
 #include "StringViewExtras.h"
 #include "Utility.h"
@@ -3049,7 +3050,7 @@ template <typename Derived, typename Alloc> struct AbstractManglingParser {
   Node *parse(bool ParseParams = true);
 };
 
-const char* parse_discriminator(const char* first, const char* last);
+DEMANGLE_ABI const char* parse_discriminator(const char* first, const char* last);
 
 // <name> ::= <nested-name> // N
 //        ::= <local-name> # See Scope Encoding below  // Z
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangle.h b/llvm/include/llvm/Demangle/MicrosoftDemangle.h
index b9a25e361eec0..60a0ccab438b3 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangle.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangle.h
@@ -9,6 +9,7 @@
 #ifndef LLVM_DEMANGLE_MICROSOFTDEMANGLE_H
 #define LLVM_DEMANGLE_MICROSOFTDEMANGLE_H
 
+#include "llvm/Demangle/Visibility.h"
 #include "llvm/Demangle/Demangle.h"
 #include "llvm/Demangle/MicrosoftDemangleNodes.h"
 
@@ -151,14 +152,14 @@ class Demangler {
 
   // You are supposed to call parse() first and then check if error is true.  If
   // it is false, call output() to write the formatted name to the given stream.
-  SymbolNode *parse(std::string_view &MangledName);
+  DEMANGLE_ABI SymbolNode *parse(std::string_view &MangledName);
 
-  TagTypeNode *parseTagUniqueName(std::string_view &MangledName);
+  DEMANGLE_ABI TagTypeNode *parseTagUniqueName(std::string_view &MangledName);
 
   // True if an error occurred.
   bool Error = false;
 
-  void dumpBackReferences();
+  DEMANGLE_ABI void dumpBackReferences();
 
 private:
   SymbolNode *demangleEncodedSymbol(std::string_view &MangledName,
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
index a9cfe726a73d3..4ac18d31ceeff 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
@@ -13,6 +13,7 @@
 #ifndef LLVM_DEMANGLE_MICROSOFTDEMANGLENODES_H
 #define LLVM_DEMANGLE_MICROSOFTDEMANGLENODES_H
 
+#include "llvm/Demangle/Visibility.h"
 #include <array>
 #include <cstdint>
 #include <string>
@@ -281,7 +282,7 @@ struct Node {
 
   virtual void output(OutputBuffer &OB, OutputFlags Flags) const = 0;
 
-  std::string toString(OutputFlags Flags = OF_Default) const;
+  DEMANGLE_ABI std::string toString(OutputFlags Flags = OF_Default) const;
 
 private:
   NodeKind Kind;
@@ -332,7 +333,7 @@ struct TypeNode : public Node {
   Qualifiers Quals = Q_None;
 };
 
-struct PrimitiveTypeNode : public TypeNode {
+struct DEMANGLE_ABI PrimitiveTypeNode : public TypeNode {
   explicit PrimitiveTypeNode(PrimitiveKind K)
       : TypeNode(NodeKind::PrimitiveType), PrimKind(K) {}
 
@@ -346,7 +347,7 @@ struct PrimitiveTypeNode : public TypeNode {
   PrimitiveKind PrimKind;
 };
 
-struct FunctionSignatureNode : public TypeNode {
+struct DEMANGLE_ABI FunctionSignatureNode : public TypeNode {
   explicit FunctionSignatureNode(NodeKind K) : TypeNode(K) {}
   FunctionSignatureNode() : TypeNode(NodeKind::FunctionSignature) {}
 
@@ -394,10 +395,10 @@ struct IdentifierNode : public Node {
   NodeArrayNode *TemplateParams = nullptr;
 
 protected:
-  void outputTemplateParameters(OutputBuffer &OB, OutputFlags Flags) const;
+  DEMANGLE_ABI void outputTemplateParameters(OutputBuffer &OB, OutputFlags Flags) const;
 };
 
-struct VcallThunkIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI VcallThunkIdentifierNode : public IdentifierNode {
   VcallThunkIdentifierNode() : IdentifierNode(NodeKind::VcallThunkIdentifier) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -409,7 +410,7 @@ struct VcallThunkIdentifierNode : public IdentifierNode {
   uint64_t OffsetInVTable = 0;
 };
 
-struct DynamicStructorIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI DynamicStructorIdentifierNode : public IdentifierNode {
   DynamicStructorIdentifierNode()
       : IdentifierNode(NodeKind::DynamicStructorIdentifier) {}
 
@@ -424,7 +425,7 @@ struct DynamicStructorIdentifierNode : public IdentifierNode {
   bool IsDestructor = false;
 };
 
-struct NamedIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI NamedIdentifierNode : public IdentifierNode {
   NamedIdentifierNode() : IdentifierNode(NodeKind::NamedIdentifier) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -436,7 +437,7 @@ struct NamedIdentifierNode : public IdentifierNode {
   std::string_view Name;
 };
 
-struct IntrinsicFunctionIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI IntrinsicFunctionIdentifierNode : public IdentifierNode {
   explicit IntrinsicFunctionIdentifierNode(IntrinsicFunctionKind Operator)
       : IdentifierNode(NodeKind::IntrinsicFunctionIdentifier),
         Operator(Operator) {}
@@ -450,7 +451,7 @@ struct IntrinsicFunctionIdentifierNode : public IdentifierNode {
   IntrinsicFunctionKind Operator;
 };
 
-struct LiteralOperatorIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI LiteralOperatorIdentifierNode : public IdentifierNode {
   LiteralOperatorIdentifierNode()
       : IdentifierNode(NodeKind::LiteralOperatorIdentifier) {}
 
@@ -463,7 +464,7 @@ struct LiteralOperatorIdentifierNode : public IdentifierNode {
   std::string_view Name;
 };
 
-struct LocalStaticGuardIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI LocalStaticGuardIdentifierNode : public IdentifierNode {
   LocalStaticGuardIdentifierNode()
       : IdentifierNode(NodeKind::LocalStaticGuardIdentifier) {}
 
@@ -477,7 +478,7 @@ struct LocalStaticGuardIdentifierNode : public IdentifierNode {
   uint32_t ScopeIndex = 0;
 };
 
-struct ConversionOperatorIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI ConversionOperatorIdentifierNode : public IdentifierNode {
   ConversionOperatorIdentifierNode()
       : IdentifierNode(NodeKind::ConversionOperatorIdentifier) {}
 
@@ -491,7 +492,7 @@ struct ConversionOperatorIdentifierNode : public IdentifierNode {
   TypeNode *TargetType = nullptr;
 };
 
-struct StructorIdentifierNode : public IdentifierNode {
+struct DEMANGLE_ABI StructorIdentifierNode : public IdentifierNode {
   StructorIdentifierNode() : IdentifierNode(NodeKind::StructorIdentifier) {}
   explicit StructorIdentifierNode(bool IsDestructor)
       : IdentifierNode(NodeKind::StructorIdentifier),
@@ -508,7 +509,7 @@ struct StructorIdentifierNode : public IdentifierNode {
   bool IsDestructor = false;
 };
 
-struct ThunkSignatureNode : public FunctionSignatureNode {
+struct DEMANGLE_ABI ThunkSignatureNode : public FunctionSignatureNode {
   ThunkSignatureNode() : FunctionSignatureNode(NodeKind::ThunkSignature) {}
 
   void outputPre(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -528,7 +529,7 @@ struct ThunkSignatureNode : public FunctionSignatureNode {
   ThisAdjustor ThisAdjust;
 };
 
-struct PointerTypeNode : public TypeNode {
+struct DEMANGLE_ABI PointerTypeNode : public TypeNode {
   PointerTypeNode() : TypeNode(NodeKind::PointerType) {}
   void outputPre(OutputBuffer &OB, OutputFlags Flags) const override;
   void outputPost(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -550,7 +551,7 @@ struct PointerTypeNode : public TypeNode {
   TypeNode *Pointee = nullptr;
 };
 
-struct TagTypeNode : public TypeNode {
+struct DEMANGLE_ABI TagTypeNode : public TypeNode {
   explicit TagTypeNode(TagKind Tag) : TypeNode(NodeKind::TagType), Tag(Tag) {}
 
   void outputPre(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -562,7 +563,7 @@ struct TagTypeNode : public TypeNode {
   TagKind Tag;
 };
 
-struct ArrayTypeNode : public TypeNode {
+struct DEMANGLE_ABI ArrayTypeNode : public TypeNode {
   ArrayTypeNode() : TypeNode(NodeKind::ArrayType) {}
 
   void outputPre(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -591,7 +592,7 @@ struct IntrinsicNode : public TypeNode {
   }
 };
 
-struct CustomTypeNode : public TypeNode {
+struct DEMANGLE_ABI CustomTypeNode : public TypeNode {
   CustomTypeNode() : TypeNode(NodeKind::Custom) {}
 
   void outputPre(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -602,7 +603,7 @@ struct CustomTypeNode : public TypeNode {
   IdentifierNode *Identifier = nullptr;
 };
 
-struct NodeArrayNode : public Node {
+struct DEMANGLE_ABI NodeArrayNode : public Node {
   NodeArrayNode() : Node(NodeKind::NodeArray) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -618,7 +619,7 @@ struct NodeArrayNode : public Node {
   size_t Count = 0;
 };
 
-struct QualifiedNameNode : public Node {
+struct DEMANGLE_ABI QualifiedNameNode : public Node {
   QualifiedNameNode() : Node(NodeKind::QualifiedName) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -635,7 +636,7 @@ struct QualifiedNameNode : public Node {
   }
 };
 
-struct TemplateParameterReferenceNode : public Node {
+struct DEMANGLE_ABI TemplateParameterReferenceNode : public Node {
   TemplateParameterReferenceNode()
       : Node(NodeKind::TemplateParameterReference) {}
 
@@ -653,7 +654,7 @@ struct TemplateParameterReferenceNode : public Node {
   bool IsMemberPointer = false;
 };
 
-struct IntegerLiteralNode : public Node {
+struct DEMANGLE_ABI IntegerLiteralNode : public Node {
   IntegerLiteralNode() : Node(NodeKind::IntegerLiteral) {}
   IntegerLiteralNode(uint64_t Value, bool IsNegative)
       : Node(NodeKind::IntegerLiteral), Value(Value), IsNegative(IsNegative) {}
@@ -668,7 +669,7 @@ struct IntegerLiteralNode : public Node {
   bool IsNegative = false;
 };
 
-struct RttiBaseClassDescriptorNode : public IdentifierNode {
+struct DEMANGLE_ABI RttiBaseClassDescriptorNode : public IdentifierNode {
   RttiBaseClassDescriptorNode()
       : IdentifierNode(NodeKind::RttiBaseClassDescriptor) {}
 
@@ -684,7 +685,7 @@ struct RttiBaseClassDescriptorNode : public IdentifierNode {
   uint32_t Flags = 0;
 };
 
-struct SymbolNode : public Node {
+struct DEMANGLE_ABI SymbolNode : public Node {
   explicit SymbolNode(NodeKind K) : Node(K) {}
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
 
@@ -696,7 +697,7 @@ struct SymbolNode : public Node {
   QualifiedNameNode *Name = nullptr;
 };
 
-struct SpecialTableSymbolNode : public SymbolNode {
+struct DEMANGLE_ABI SpecialTableSymbolNode : public SymbolNode {
   explicit SpecialTableSymbolNode()
       : SymbolNode(NodeKind::SpecialTableSymbol) {}
 
@@ -710,7 +711,7 @@ struct SpecialTableSymbolNode : public SymbolNode {
   Qualifiers Quals = Qualifiers::Q_None;
 };
 
-struct LocalStaticGuardVariableNode : public SymbolNode {
+struct DEMANGLE_ABI LocalStaticGuardVariableNode : public SymbolNode {
   LocalStaticGuardVariableNode()
       : SymbolNode(NodeKind::LocalStaticGuardVariable) {}
 
@@ -723,7 +724,7 @@ struct LocalStaticGuardVariableNode : public SymbolNode {
   bool IsVisible = false;
 };
 
-struct EncodedStringLiteralNode : public SymbolNode {
+struct DEMANGLE_ABI EncodedStringLiteralNode : public SymbolNode {
   EncodedStringLiteralNode() : SymbolNode(NodeKind::EncodedStringLiteral) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -737,7 +738,7 @@ struct EncodedStringLiteralNode : public SymbolNode {
   CharKind Char = CharKind::Char;
 };
 
-struct VariableSymbolNode : public SymbolNode {
+struct DEMANGLE_ABI VariableSymbolNode : public SymbolNode {
   VariableSymbolNode() : SymbolNode(NodeKind::VariableSymbol) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -750,7 +751,7 @@ struct VariableSymbolNode : public SymbolNode {
   TypeNode *Type = nullptr;
 };
 
-struct FunctionSymbolNode : public SymbolNode {
+struct DEMANGLE_ABI FunctionSymbolNode : public SymbolNode {
   FunctionSymbolNode() : SymbolNode(NodeKind::FunctionSymbol) {}
 
   void output(OutputBuffer &OB, OutputFlags Flags) const override;
@@ -762,7 +763,7 @@ struct FunctionSymbolNode : public SymbolNode {
   FunctionSignatureNode *Signature = nullptr;
 };
 
-struct PointerAuthQualifierNode : public Node {
+struct DEMANGLE_ABI PointerAuthQualifierNode : public Node {
   PointerAuthQualifierNode() : Node(NodeKind::PointerAuthQualifier) {}
 
   // __ptrauth takes three arguments:

From 4e068ff3bf3e6249a16b03f3d05bec19fe03a0f7 Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Tue, 8 Jul 2025 09:37:33 -0700
Subject: [PATCH 3/7] [llvm] manual fix-ups to Demangle library code-mod

---
 llvm/include/llvm/Demangle/Demangle.h               | 2 +-
 llvm/include/llvm/Demangle/ItaniumDemangle.h        | 2 +-
 llvm/include/llvm/Demangle/MicrosoftDemangle.h      | 2 +-
 llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/llvm/include/llvm/Demangle/Demangle.h b/llvm/include/llvm/Demangle/Demangle.h
index 77127d993f5f8..cd6f49883bae7 100644
--- a/llvm/include/llvm/Demangle/Demangle.h
+++ b/llvm/include/llvm/Demangle/Demangle.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_DEMANGLE_DEMANGLE_H
 #define LLVM_DEMANGLE_DEMANGLE_H
 
-#include "llvm/Demangle/Visibility.h"
+#include "Visibility.h"
 #include <cstddef>
 #include <optional>
 #include <string>
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index dfa5839d12a5a..f9e8dade4fd83 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -16,10 +16,10 @@
 #ifndef DEMANGLE_ITANIUMDEMANGLE_H
 #define DEMANGLE_ITANIUMDEMANGLE_H
 
-#include "llvm/Demangle/Visibility.h"
 #include "DemangleConfig.h"
 #include "StringViewExtras.h"
 #include "Utility.h"
+#include "Visibility.h"
 #include <algorithm>
 #include <cctype>
 #include <cstdint>
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangle.h b/llvm/include/llvm/Demangle/MicrosoftDemangle.h
index 60a0ccab438b3..4e1baf05dd886 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangle.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangle.h
@@ -9,9 +9,9 @@
 #ifndef LLVM_DEMANGLE_MICROSOFTDEMANGLE_H
 #define LLVM_DEMANGLE_MICROSOFTDEMANGLE_H
 
-#include "llvm/Demangle/Visibility.h"
 #include "llvm/Demangle/Demangle.h"
 #include "llvm/Demangle/MicrosoftDemangleNodes.h"
+#include "llvm/Demangle/Visibility.h"
 
 #include <cassert>
 #include <string_view>
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
index 4ac18d31ceeff..48e4271a0cc4e 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
@@ -13,7 +13,7 @@
 #ifndef LLVM_DEMANGLE_MICROSOFTDEMANGLENODES_H
 #define LLVM_DEMANGLE_MICROSOFTDEMANGLENODES_H
 
-#include "llvm/Demangle/Visibility.h"
+#include "Visibility.h"
 #include <array>
 #include <cstdint>
 #include <string>

From a7f70abef1b174e7a89e7bf6f20db197a3335adb Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Tue, 8 Jul 2025 09:41:11 -0700
Subject: [PATCH 4/7] [llvm] clang format changes

---
 llvm/include/llvm/Demangle/Demangle.h          | 18 +++++++++++-------
 llvm/include/llvm/Demangle/ItaniumDemangle.h   |  3 ++-
 .../llvm/Demangle/MicrosoftDemangleNodes.h     |  3 ++-
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/llvm/include/llvm/Demangle/Demangle.h b/llvm/include/llvm/Demangle/Demangle.h
index cd6f49883bae7..24fd9ba8b2fe4 100644
--- a/llvm/include/llvm/Demangle/Demangle.h
+++ b/llvm/include/llvm/Demangle/Demangle.h
@@ -34,7 +34,8 @@ enum : int {
 /// Returns a non-NULL pointer to a NUL-terminated C style string
 /// that should be explicitly freed, if successful. Otherwise, may return
 /// nullptr if mangled_name is not a valid mangling or is nullptr.
-DEMANGLE_ABI char *itaniumDemangle(std::string_view mangled_name, bool ParseParams = true);
+DEMANGLE_ABI char *itaniumDemangle(std::string_view mangled_name,
+                                   bool ParseParams = true);
 
 enum MSDemangleFlags {
   MSDF_None = 0,
@@ -53,8 +54,9 @@ enum MSDemangleFlags {
 /// bytes of the input string were consumed.
 /// status receives one of the demangle_ enum entries above if it's not nullptr.
 /// Flags controls various details of the demangled representation.
-DEMANGLE_ABI char *microsoftDemangle(std::string_view mangled_name, size_t *n_read,
-                        int *status, MSDemangleFlags Flags = MSDF_None);
+DEMANGLE_ABI char *microsoftDemangle(std::string_view mangled_name,
+                                     size_t *n_read, int *status,
+                                     MSDemangleFlags Flags = MSDF_None);
 
 DEMANGLE_ABI std::optional<size_t>
 getArm64ECInsertionPointInMangledName(std::string_view MangledName);
@@ -72,9 +74,10 @@ DEMANGLE_ABI char *dlangDemangle(std::string_view MangledName);
 /// demangling occurred.
 DEMANGLE_ABI std::string demangle(std::string_view MangledName);
 
-DEMANGLE_ABI bool nonMicrosoftDemangle(std::string_view MangledName, std::string &Result,
-                          bool CanHaveLeadingDot = true,
-                          bool ParseParams = true);
+DEMANGLE_ABI bool nonMicrosoftDemangle(std::string_view MangledName,
+                                       std::string &Result,
+                                       bool CanHaveLeadingDot = true,
+                                       bool ParseParams = true);
 
 /// "Partial" demangler. This supports demangling a string into an AST
 /// (typically an intermediate stage in itaniumDemangle) and querying certain
@@ -83,7 +86,8 @@ struct ItaniumPartialDemangler {
   DEMANGLE_ABI ItaniumPartialDemangler();
 
   DEMANGLE_ABI ItaniumPartialDemangler(ItaniumPartialDemangler &&Other);
-  DEMANGLE_ABI ItaniumPartialDemangler &operator=(ItaniumPartialDemangler &&Other);
+  DEMANGLE_ABI ItaniumPartialDemangler &
+  operator=(ItaniumPartialDemangler &&Other);
 
   /// Demangle into an AST. Subsequent calls to the rest of the member functions
   /// implicitly operate on the AST this produces.
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index f9e8dade4fd83..802802a978a4a 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -3050,7 +3050,8 @@ template <typename Derived, typename Alloc> struct AbstractManglingParser {
   Node *parse(bool ParseParams = true);
 };
 
-DEMANGLE_ABI const char* parse_discriminator(const char* first, const char* last);
+DEMANGLE_ABI const char *parse_discriminator(const char *first,
+                                             const char *last);
 
 // <name> ::= <nested-name> // N
 //        ::= <local-name> # See Scope Encoding below  // Z
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
index 48e4271a0cc4e..611fcdf7999b2 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
@@ -395,7 +395,8 @@ struct IdentifierNode : public Node {
   NodeArrayNode *TemplateParams = nullptr;
 
 protected:
-  DEMANGLE_ABI void outputTemplateParameters(OutputBuffer &OB, OutputFlags Flags) const;
+  DEMANGLE_ABI void outputTemplateParameters(OutputBuffer &OB,
+                                             OutputFlags Flags) const;
 };
 
 struct DEMANGLE_ABI VcallThunkIdentifierNode : public IdentifierNode {

From 918b17b0b1875efdaf10c94f9480fda8267f30e3 Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Tue, 8 Jul 2025 12:39:01 -0700
Subject: [PATCH 5/7] fix test failures

---
 libcxxabi/src/demangle/ItaniumDemangle.h |  4 +++-
 libcxxabi/src/demangle/Visibility.h      | 18 ++++++++++++++++++
 libcxxabi/src/demangle/cp-to-llvm.sh     |  5 +++--
 3 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 libcxxabi/src/demangle/Visibility.h

diff --git a/libcxxabi/src/demangle/ItaniumDemangle.h b/libcxxabi/src/demangle/ItaniumDemangle.h
index b306b2013445c..ed73b1aaf4363 100644
--- a/libcxxabi/src/demangle/ItaniumDemangle.h
+++ b/libcxxabi/src/demangle/ItaniumDemangle.h
@@ -19,6 +19,7 @@
 #include "DemangleConfig.h"
 #include "StringViewExtras.h"
 #include "Utility.h"
+#include "Visibility.h"
 #include <algorithm>
 #include <cctype>
 #include <cstdint>
@@ -3049,7 +3050,8 @@ template <typename Derived, typename Alloc> struct AbstractManglingParser {
   Node *parse(bool ParseParams = true);
 };
 
-const char* parse_discriminator(const char* first, const char* last);
+DEMANGLE_ABI const char *parse_discriminator(const char *first,
+                                             const char *last);
 
 // <name> ::= <nested-name> // N
 //        ::= <local-name> # See Scope Encoding below  // Z
diff --git a/libcxxabi/src/demangle/Visibility.h b/libcxxabi/src/demangle/Visibility.h
new file mode 100644
index 0000000000000..90ca0e5e87335
--- /dev/null
+++ b/libcxxabi/src/demangle/Visibility.h
@@ -0,0 +1,18 @@
+//===--- Visibility.h -------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// This file is contains noop definitions of the DEMANGLE_ABI macro defined in
+// llvm/include/llvm/Demangle/Visibility.h.
+//===----------------------------------------------------------------------===//
+
+#ifndef LIBCXXABI_DEMANGLE_VISIBILITY_H
+#define LIBCXXABI_DEMANGLE_VISIBILITY_H
+
+// The DEMANGLE_ABI macro resovles to nothing when building libcxxabi. Only
+// the llvm copy defines DEMANGLE_ABI as a visibility attribute.
+#define DEMANGLE_ABI
+
+#endif
diff --git a/libcxxabi/src/demangle/cp-to-llvm.sh b/libcxxabi/src/demangle/cp-to-llvm.sh
index f773dff9f0a8b..30bcd42191175 100755
--- a/libcxxabi/src/demangle/cp-to-llvm.sh
+++ b/libcxxabi/src/demangle/cp-to-llvm.sh
@@ -1,7 +1,8 @@
 #!/bin/bash
 
-# Copies the 'demangle' library, excluding 'DemangleConfig.h', to llvm. If no
-# llvm directory is specified, then assume a monorepo layout.
+# Copies the 'demangle' library, excluding 'DemangleConfig.h' and
+# 'Visibility.h', to llvm. If no llvm directory is specified, then assume a
+# monorepo layout.
 
 set -e
 

From bad677579a24ed8393e8617b3331bdc16bc5592f Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Tue, 15 Jul 2025 11:00:58 -0700
Subject: [PATCH 6/7] Update libcxxabi/src/demangle/Visibility.h

Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
---
 libcxxabi/src/demangle/Visibility.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libcxxabi/src/demangle/Visibility.h b/libcxxabi/src/demangle/Visibility.h
index 90ca0e5e87335..34b10e49f4b8a 100644
--- a/libcxxabi/src/demangle/Visibility.h
+++ b/libcxxabi/src/demangle/Visibility.h
@@ -11,7 +11,7 @@
 #ifndef LIBCXXABI_DEMANGLE_VISIBILITY_H
 #define LIBCXXABI_DEMANGLE_VISIBILITY_H
 
-// The DEMANGLE_ABI macro resovles to nothing when building libcxxabi. Only
+// The DEMANGLE_ABI macro resolves to nothing when building libc++abi. Only
 // the llvm copy defines DEMANGLE_ABI as a visibility attribute.
 #define DEMANGLE_ABI
 

From a122ec67183b177ce7c0dd5e627164c2f95bbde7 Mon Sep 17 00:00:00 2001
From: Andrew Rogers <andrurogerz@gmail.com>
Date: Wed, 23 Jul 2025 08:54:07 -0700
Subject: [PATCH 7/7] remove Demangle dependency on Support

---
 libcxxabi/src/demangle/DemangleConfig.h       |  4 ++
 libcxxabi/src/demangle/ItaniumDemangle.h      |  1 -
 libcxxabi/src/demangle/Visibility.h           | 18 --------
 libcxxabi/src/demangle/cp-to-llvm.sh          |  5 +--
 llvm/CMakeLists.txt                           |  5 +--
 llvm/include/llvm/Demangle/Demangle.h         |  2 +-
 llvm/include/llvm/Demangle/DemangleConfig.h   | 20 +++++++++
 llvm/include/llvm/Demangle/ItaniumDemangle.h  |  1 -
 .../include/llvm/Demangle/MicrosoftDemangle.h |  2 +-
 .../llvm/Demangle/MicrosoftDemangleNodes.h    |  2 +-
 llvm/include/llvm/Demangle/Visibility.h       | 43 -------------------
 11 files changed, 31 insertions(+), 72 deletions(-)
 delete mode 100644 libcxxabi/src/demangle/Visibility.h
 delete mode 100644 llvm/include/llvm/Demangle/Visibility.h

diff --git a/libcxxabi/src/demangle/DemangleConfig.h b/libcxxabi/src/demangle/DemangleConfig.h
index 06fd223f5553f..a88e6ce65d702 100644
--- a/libcxxabi/src/demangle/DemangleConfig.h
+++ b/libcxxabi/src/demangle/DemangleConfig.h
@@ -107,4 +107,8 @@
 #define DEMANGLE_NAMESPACE_BEGIN namespace { namespace itanium_demangle {
 #define DEMANGLE_NAMESPACE_END } }
 
+// The DEMANGLE_ABI macro resolves to nothing when building libc++abi. Only
+// the llvm copy defines DEMANGLE_ABI as a visibility attribute.
+#define DEMANGLE_ABI
+
 #endif // LIBCXXABI_DEMANGLE_DEMANGLE_CONFIG_H
diff --git a/libcxxabi/src/demangle/ItaniumDemangle.h b/libcxxabi/src/demangle/ItaniumDemangle.h
index ed73b1aaf4363..6f27da7b9cadf 100644
--- a/libcxxabi/src/demangle/ItaniumDemangle.h
+++ b/libcxxabi/src/demangle/ItaniumDemangle.h
@@ -19,7 +19,6 @@
 #include "DemangleConfig.h"
 #include "StringViewExtras.h"
 #include "Utility.h"
-#include "Visibility.h"
 #include <algorithm>
 #include <cctype>
 #include <cstdint>
diff --git a/libcxxabi/src/demangle/Visibility.h b/libcxxabi/src/demangle/Visibility.h
deleted file mode 100644
index 34b10e49f4b8a..0000000000000
--- a/libcxxabi/src/demangle/Visibility.h
+++ /dev/null
@@ -1,18 +0,0 @@
-//===--- Visibility.h -------------------------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-// This file is contains noop definitions of the DEMANGLE_ABI macro defined in
-// llvm/include/llvm/Demangle/Visibility.h.
-//===----------------------------------------------------------------------===//
-
-#ifndef LIBCXXABI_DEMANGLE_VISIBILITY_H
-#define LIBCXXABI_DEMANGLE_VISIBILITY_H
-
-// The DEMANGLE_ABI macro resolves to nothing when building libc++abi. Only
-// the llvm copy defines DEMANGLE_ABI as a visibility attribute.
-#define DEMANGLE_ABI
-
-#endif
diff --git a/libcxxabi/src/demangle/cp-to-llvm.sh b/libcxxabi/src/demangle/cp-to-llvm.sh
index 30bcd42191175..f773dff9f0a8b 100755
--- a/libcxxabi/src/demangle/cp-to-llvm.sh
+++ b/libcxxabi/src/demangle/cp-to-llvm.sh
@@ -1,8 +1,7 @@
 #!/bin/bash
 
-# Copies the 'demangle' library, excluding 'DemangleConfig.h' and
-# 'Visibility.h', to llvm. If no llvm directory is specified, then assume a
-# monorepo layout.
+# Copies the 'demangle' library, excluding 'DemangleConfig.h', to llvm. If no
+# llvm directory is specified, then assume a monorepo layout.
 
 set -e
 
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 20a648dc95baa..903461b39902e 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -1078,10 +1078,9 @@ if (LLVM_BUILD_LLVM_DYLIB OR LLVM_BUILD_SHARED_LIBS OR LLVM_ENABLE_PLUGINS)
   set(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS ON)
 endif()
 
-# Because LLVM-C and Demangle libraries are built into the LLVM library, for now
-# we export their symbols if LLVM symbols are exported.
+# Because LLVM-C is built into the LLVM library, for now export its symbols
+# whenever LLVM symbols are exported.
 set(LLVM_ENABLE_LLVM_C_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
-set(LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
 
 set(LLVM_ENABLE_NEW_PASS_MANAGER TRUE CACHE BOOL
   "Enable the new pass manager by default.")
diff --git a/llvm/include/llvm/Demangle/Demangle.h b/llvm/include/llvm/Demangle/Demangle.h
index 24fd9ba8b2fe4..d9b08b2d856dc 100644
--- a/llvm/include/llvm/Demangle/Demangle.h
+++ b/llvm/include/llvm/Demangle/Demangle.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_DEMANGLE_DEMANGLE_H
 #define LLVM_DEMANGLE_DEMANGLE_H
 
-#include "Visibility.h"
+#include "DemangleConfig.h"
 #include <cstddef>
 #include <optional>
 #include <string>
diff --git a/llvm/include/llvm/Demangle/DemangleConfig.h b/llvm/include/llvm/Demangle/DemangleConfig.h
index 30f72ffe0d7ef..8807a0e597a17 100644
--- a/llvm/include/llvm/Demangle/DemangleConfig.h
+++ b/llvm/include/llvm/Demangle/DemangleConfig.h
@@ -94,4 +94,24 @@
 #define DEMANGLE_NAMESPACE_BEGIN namespace llvm { namespace itanium_demangle {
 #define DEMANGLE_NAMESPACE_END } }
 
+/// DEMANGLE_ABI is the export/visibility macro used to mark symbols delcared in
+/// llvm/Demangle as exported when built as a shared library.
+#if defined(LLVM_BUILD_STATIC) || !defined(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS)
+#define DEMANGLE_ABI
+#else
+#if defined(_WIN32)
+#if defined(LLVM_EXPORTS)
+#define DEMANGLE_ABI __declspec(dllexport)
+#else
+#define DEMANGLE_ABI__declspec(dllimport)
+#endif
+#else
+#if __has_attribute(visibility)
+#define DEMANGLE_ABI __attribute__((__visibility__("default")))
+#else
+#define DEMANGLE_ABI
+#endif
+#endif
+#endif
+
 #endif
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index 802802a978a4a..62d427c3966bb 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -19,7 +19,6 @@
 #include "DemangleConfig.h"
 #include "StringViewExtras.h"
 #include "Utility.h"
-#include "Visibility.h"
 #include <algorithm>
 #include <cctype>
 #include <cstdint>
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangle.h b/llvm/include/llvm/Demangle/MicrosoftDemangle.h
index 4e1baf05dd886..a2af87537aa58 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangle.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangle.h
@@ -10,8 +10,8 @@
 #define LLVM_DEMANGLE_MICROSOFTDEMANGLE_H
 
 #include "llvm/Demangle/Demangle.h"
+#include "llvm/Demangle/DemangleConfig.h"
 #include "llvm/Demangle/MicrosoftDemangleNodes.h"
-#include "llvm/Demangle/Visibility.h"
 
 #include <cassert>
 #include <string_view>
diff --git a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
index 611fcdf7999b2..155cfe8dd3a98 100644
--- a/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
+++ b/llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h
@@ -13,7 +13,7 @@
 #ifndef LLVM_DEMANGLE_MICROSOFTDEMANGLENODES_H
 #define LLVM_DEMANGLE_MICROSOFTDEMANGLENODES_H
 
-#include "Visibility.h"
+#include "DemangleConfig.h"
 #include <array>
 #include <cstdint>
 #include <string>
diff --git a/llvm/include/llvm/Demangle/Visibility.h b/llvm/include/llvm/Demangle/Visibility.h
deleted file mode 100644
index 35ea238b446b6..0000000000000
--- a/llvm/include/llvm/Demangle/Visibility.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*===-- Demangle/Visibility.h - Visibility macros for Demangle --*- C++ -*-===*\
-|*                                                                            *|
-|* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
-|* Exceptions.                                                                *|
-|* See https://llvm.org/LICENSE.txt for license information.                  *|
-|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
-|*                                                                            *|
-|*===----------------------------------------------------------------------===*|
-|*                                                                            *|
-|* This header defines visibility macros used for the Demangle library. These *|
-|* macros are used to annotate functions that should be exported as part of a *|
-|* shared library or DLL.                                                     *|
-|*                                                                            *|
-\*===----------------------------------------------------------------------===*/
-
-#ifndef LLVM_DEMANGLE_VISIBILITY_H
-#define LLVM_DEMANGLE_VISIBILITY_H
-
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Demangle/DemangleConfig.h"
-
-/// DEMANGLE_ABI is the export/visibility macro used to mark symbols delcared in
-/// llvm/Demangle as exported when built as a shared library.
-
-#if !defined(LLVM_ABI_GENERATING_ANNOTATIONS)
-#if defined(LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS) &&                        \
-    !defined(LLVM_BUILD_STATIC)
-#if defined(_WIN32) && !defined(__MINGW32__)
-#if defined(LLVM_EXPORTS)
-#define DEMANGLE_ABI __declspec(dllexport)
-#else
-#define DEMANGLE_ABI __declspec(dllimport)
-#endif
-#elif __has_attribute(visibility)
-#define DEMANGLE_ABI __attribute__((visibility("default")))
-#endif
-#endif
-#if !defined(DEMANGLE_ABI)
-#define DEMANGLE_ABI
-#endif
-#endif
-
-#endif