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externals/demangle/llvm/Demangle/Demangle.h

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+//===--- Demangle.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-FileCopyrightText: Part of the LLVM Project
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEMANGLE_DEMANGLE_H
+#define LLVM_DEMANGLE_DEMANGLE_H
+
+#include <cstddef>
+#include <string>
+#include <string_view>
+
+namespace llvm {
+/// This is a llvm local version of __cxa_demangle. Other than the name and
+/// being in the llvm namespace it is identical.
+///
+/// The mangled_name is demangled into buf and returned. If the buffer is not
+/// large enough, realloc is used to expand it.
+///
+/// The *status will be set to a value from the following enumeration
+enum : int {
+  demangle_unknown_error = -4,
+  demangle_invalid_args = -3,
+  demangle_invalid_mangled_name = -2,
+  demangle_memory_alloc_failure = -1,
+  demangle_success = 0,
+};
+
+/// 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);
+
+enum MSDemangleFlags {
+  MSDF_None = 0,
+  MSDF_DumpBackrefs = 1 << 0,
+  MSDF_NoAccessSpecifier = 1 << 1,
+  MSDF_NoCallingConvention = 1 << 2,
+  MSDF_NoReturnType = 1 << 3,
+  MSDF_NoMemberType = 1 << 4,
+  MSDF_NoVariableType = 1 << 5,
+};
+
+/// Demangles the Microsoft symbol pointed at by mangled_name and returns it.
+/// Returns a pointer to the start of a null-terminated demangled string on
+/// success, or nullptr on error.
+/// If n_read is non-null and demangling was successful, it receives how many
+/// 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,
+                        int *status, MSDemangleFlags Flags = MSDF_None);
+
+// Demangles a Rust v0 mangled symbol.
+char *rustDemangle(std::string_view MangledName);
+
+// Demangles a D mangled symbol.
+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);
+
+bool nonMicrosoftDemangle(std::string_view MangledName, std::string &Result);
+
+/// "Partial" demangler. This supports demangling a string into an AST
+/// (typically an intermediate stage in itaniumDemangle) and querying certain
+/// properties or partially printing the demangled name.
+struct ItaniumPartialDemangler {
+  ItaniumPartialDemangler();
+
+  ItaniumPartialDemangler(ItaniumPartialDemangler &&Other);
+  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);
+
+  /// 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;
+
+  /// 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;
+
+  /// Get the context name for a function. For "a::b::c", this function returns
+  /// "a::b".
+  char *getFunctionDeclContextName(char *Buf, size_t *N) const;
+
+  /// Get the entire name of this function.
+  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;
+
+  /// If this function has any any cv or reference qualifiers. These imply that
+  /// the function is a non-static member function.
+  bool hasFunctionQualifiers() const;
+
+  /// If this symbol describes a constructor or destructor.
+  bool isCtorOrDtor() const;
+
+  /// If this symbol describes a function.
+  bool isFunction() const;
+
+  /// If this symbol describes a variable.
+  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;
+
+  ~ItaniumPartialDemangler();
+
+private:
+  void *RootNode;
+  void *Context;
+};
+} // namespace llvm
+
+#endif

externals/demangle/llvm/Demangle/DemangleConfig.h

@@ -0,0 +1,93 @@
+//===--- DemangleConfig.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-FileCopyrightText: Part of the LLVM Project
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a variety of feature test macros copied from
+// include/llvm/Support/Compiler.h so that LLVMDemangle does not need to take
+// a dependency on LLVMSupport.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEMANGLE_DEMANGLECONFIG_H
+#define LLVM_DEMANGLE_DEMANGLECONFIG_H
+
+#ifndef __has_feature
+#define __has_feature(x) 0
+#endif
+
+#ifndef __has_cpp_attribute
+#define __has_cpp_attribute(x) 0
+#endif
+
+#ifndef __has_attribute
+#define __has_attribute(x) 0
+#endif
+
+#ifndef __has_builtin
+#define __has_builtin(x) 0
+#endif
+
+#ifndef DEMANGLE_GNUC_PREREQ
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+#define DEMANGLE_GNUC_PREREQ(maj, min, patch)                           \
+  ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >=          \
+   ((maj) << 20) + ((min) << 10) + (patch))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+#define DEMANGLE_GNUC_PREREQ(maj, min, patch)                           \
+  ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10))
+#else
+#define DEMANGLE_GNUC_PREREQ(maj, min, patch) 0
+#endif
+#endif
+
+#if __has_attribute(used) || DEMANGLE_GNUC_PREREQ(3, 1, 0)
+#define DEMANGLE_ATTRIBUTE_USED __attribute__((__used__))
+#else
+#define DEMANGLE_ATTRIBUTE_USED
+#endif
+
+#if __has_builtin(__builtin_unreachable) || DEMANGLE_GNUC_PREREQ(4, 5, 0)
+#define DEMANGLE_UNREACHABLE __builtin_unreachable()
+#elif defined(_MSC_VER)
+#define DEMANGLE_UNREACHABLE __assume(false)
+#else
+#define DEMANGLE_UNREACHABLE
+#endif
+
+#if __has_attribute(noinline) || DEMANGLE_GNUC_PREREQ(3, 4, 0)
+#define DEMANGLE_ATTRIBUTE_NOINLINE __attribute__((noinline))
+#elif defined(_MSC_VER)
+#define DEMANGLE_ATTRIBUTE_NOINLINE __declspec(noinline)
+#else
+#define DEMANGLE_ATTRIBUTE_NOINLINE
+#endif
+
+#if !defined(NDEBUG)
+#define DEMANGLE_DUMP_METHOD DEMANGLE_ATTRIBUTE_NOINLINE DEMANGLE_ATTRIBUTE_USED
+#else
+#define DEMANGLE_DUMP_METHOD DEMANGLE_ATTRIBUTE_NOINLINE
+#endif
+
+#if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
+#define DEMANGLE_FALLTHROUGH [[fallthrough]]
+#elif __has_cpp_attribute(gnu::fallthrough)
+#define DEMANGLE_FALLTHROUGH [[gnu::fallthrough]]
+#elif !__cplusplus
+// Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious
+// error when __has_cpp_attribute is given a scoped attribute in C mode.
+#define DEMANGLE_FALLTHROUGH
+#elif __has_cpp_attribute(clang::fallthrough)
+#define DEMANGLE_FALLTHROUGH [[clang::fallthrough]]
+#else
+#define DEMANGLE_FALLTHROUGH
+#endif
+
+#define DEMANGLE_NAMESPACE_BEGIN namespace llvm { namespace itanium_demangle {
+#define DEMANGLE_NAMESPACE_END } }
+
+#endif

externals/demangle/llvm/Demangle/ItaniumNodes.def

@@ -0,0 +1,96 @@
+//===--- ItaniumNodes.def ------------*- mode:c++;eval:(read-only-mode) -*-===//
+//       Do not edit! See README.txt.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-FileCopyrightText: Part of the LLVM Project
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Define the demangler's node names
+
+#ifndef NODE
+#error Define NODE to handle nodes
+#endif
+
+NODE(NodeArrayNode)
+NODE(DotSuffix)
+NODE(VendorExtQualType)
+NODE(QualType)
+NODE(ConversionOperatorType)
+NODE(PostfixQualifiedType)
+NODE(ElaboratedTypeSpefType)
+NODE(NameType)
+NODE(AbiTagAttr)
+NODE(EnableIfAttr)
+NODE(ObjCProtoName)
+NODE(PointerType)
+NODE(ReferenceType)
+NODE(PointerToMemberType)
+NODE(ArrayType)
+NODE(FunctionType)
+NODE(NoexceptSpec)
+NODE(DynamicExceptionSpec)
+NODE(FunctionEncoding)
+NODE(LiteralOperator)
+NODE(SpecialName)
+NODE(CtorVtableSpecialName)
+NODE(QualifiedName)
+NODE(NestedName)
+NODE(LocalName)
+NODE(ModuleName)
+NODE(ModuleEntity)
+NODE(VectorType)
+NODE(PixelVectorType)
+NODE(BinaryFPType)
+NODE(BitIntType)
+NODE(SyntheticTemplateParamName)
+NODE(TypeTemplateParamDecl)
+NODE(NonTypeTemplateParamDecl)
+NODE(TemplateTemplateParamDecl)
+NODE(TemplateParamPackDecl)
+NODE(ParameterPack)
+NODE(TemplateArgumentPack)
+NODE(ParameterPackExpansion)
+NODE(TemplateArgs)
+NODE(ForwardTemplateReference)
+NODE(NameWithTemplateArgs)
+NODE(GlobalQualifiedName)
+NODE(ExpandedSpecialSubstitution)
+NODE(SpecialSubstitution)
+NODE(CtorDtorName)
+NODE(DtorName)
+NODE(UnnamedTypeName)
+NODE(ClosureTypeName)
+NODE(StructuredBindingName)
+NODE(BinaryExpr)
+NODE(ArraySubscriptExpr)
+NODE(PostfixExpr)
+NODE(ConditionalExpr)
+NODE(MemberExpr)
+NODE(SubobjectExpr)
+NODE(EnclosingExpr)
+NODE(CastExpr)
+NODE(SizeofParamPackExpr)
+NODE(CallExpr)
+NODE(NewExpr)
+NODE(DeleteExpr)
+NODE(PrefixExpr)
+NODE(FunctionParam)
+NODE(ConversionExpr)
+NODE(PointerToMemberConversionExpr)
+NODE(InitListExpr)
+NODE(FoldExpr)
+NODE(ThrowExpr)
+NODE(BoolExpr)
+NODE(StringLiteral)
+NODE(LambdaExpr)
+NODE(EnumLiteral)
+NODE(IntegerLiteral)
+NODE(FloatLiteral)
+NODE(DoubleLiteral)
+NODE(LongDoubleLiteral)
+NODE(BracedExpr)
+NODE(BracedRangeExpr)
+
+#undef NODE

externals/demangle/llvm/Demangle/StringView.h

@@ -0,0 +1,123 @@
+//===--- StringView.h ----------------*- mode:c++;eval:(read-only-mode) -*-===//
+//       Do not edit! See README.txt.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-FileCopyrightText: Part of the LLVM Project
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// FIXME: Use std::string_view instead when we support C++17.
+// There are two copies of this file in the source tree.  The one under
+// libcxxabi is the original and the one under llvm is the copy.  Use
+// cp-to-llvm.sh to update the copy.  See README.txt for more details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef DEMANGLE_STRINGVIEW_H
+#define DEMANGLE_STRINGVIEW_H
+
+#include "DemangleConfig.h"
+#include <cassert>
+#include <cstring>
+
+DEMANGLE_NAMESPACE_BEGIN
+
+class StringView {
+  const char *First;
+  const char *Last;
+
+public:
+  static const size_t npos = ~size_t(0);
+
+  template <size_t N>
+  StringView(const char (&Str)[N]) : First(Str), Last(Str + N - 1) {}
+  StringView(const char *First_, const char *Last_)
+      : First(First_), Last(Last_) {}
+  StringView(const char *First_, size_t Len)
+      : First(First_), Last(First_ + Len) {}
+  StringView(const char *Str) : First(Str), Last(Str + std::strlen(Str)) {}
+  StringView() : First(nullptr), Last(nullptr) {}
+
+  StringView substr(size_t Pos, size_t Len = npos) const {
+    assert(Pos <= size());
+    if (Len > size() - Pos)
+      Len = size() - Pos;
+    return StringView(begin() + Pos, Len);
+  }
+
+  size_t find(char C, size_t From = 0) const {
+    // Avoid calling memchr with nullptr.
+    if (From < size()) {
+      // Just forward to memchr, which is faster than a hand-rolled loop.
+      if (const void *P = ::memchr(First + From, C, size() - From))
+        return size_t(static_cast<const char *>(P) - First);
+    }
+    return npos;
+  }
+
+  StringView dropFront(size_t N = 1) const {
+    if (N >= size())
+      N = size();
+    return StringView(First + N, Last);
+  }
+
+  StringView dropBack(size_t N = 1) const {
+    if (N >= size())
+      N = size();
+    return StringView(First, Last - N);
+  }
+
+  char front() const {
+    assert(!empty());
+    return *begin();
+  }
+
+  char back() const {
+    assert(!empty());
+    return *(end() - 1);
+  }
+
+  char popFront() {
+    assert(!empty());
+    return *First++;
+  }
+
+  bool consumeFront(char C) {
+    if (!startsWith(C))
+      return false;
+    *this = dropFront(1);
+    return true;
+  }
+
+  bool consumeFront(StringView S) {
+    if (!startsWith(S))
+      return false;
+    *this = dropFront(S.size());
+    return true;
+  }
+
+  bool startsWith(char C) const { return !empty() && *begin() == C; }
+
+  bool startsWith(StringView Str) const {
+    if (Str.size() > size())
+      return false;
+    return std::strncmp(Str.begin(), begin(), Str.size()) == 0;
+  }
+
+  const char &operator[](size_t Idx) const { return *(begin() + Idx); }
+
+  const char *begin() const { return First; }
+  const char *end() const { return Last; }
+  size_t size() const { return static_cast<size_t>(Last - First); }
+  bool empty() const { return First == Last; }
+};
+
+inline bool operator==(const StringView &LHS, const StringView &RHS) {
+  return LHS.size() == RHS.size() &&
+         std::strncmp(LHS.begin(), RHS.begin(), LHS.size()) == 0;
+}
+
+DEMANGLE_NAMESPACE_END
+
+#endif

externals/demangle/llvm/Demangle/StringViewExtras.h

@@ -0,0 +1,39 @@
+//===--- StringViewExtras.h ----------*- mode:c++;eval:(read-only-mode) -*-===//
+//       Do not edit! See README.txt.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-FileCopyrightText: Part of the LLVM Project
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// There are two copies of this file in the source tree.  The one under
+// libcxxabi is the original and the one under llvm is the copy.  Use
+// cp-to-llvm.sh to update the copy.  See README.txt for more details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef DEMANGLE_STRINGVIEW_H
+#define DEMANGLE_STRINGVIEW_H
+
+#include "DemangleConfig.h"
+
+#include <string_view>
+
+DEMANGLE_NAMESPACE_BEGIN
+
+inline bool starts_with(std::string_view self, char C) noexcept {
+  return !self.empty() && *self.begin() == C;
+}
+
+inline bool starts_with(std::string_view haystack,
+                        std::string_view needle) noexcept {
+  if (needle.size() > haystack.size())
+    return false;
+  haystack.remove_suffix(haystack.size() - needle.size());
+  return haystack == needle;
+}
+
+DEMANGLE_NAMESPACE_END
+
+#endif

externals/demangle/llvm/Demangle/Utility.h

@@ -0,0 +1,206 @@
+//===--- Utility.h -------------------*- mode:c++;eval:(read-only-mode) -*-===//
+//       Do not edit! See README.txt.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-FileCopyrightText: Part of the LLVM Project
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Provide some utility classes for use in the demangler.
+// There are two copies of this file in the source tree.  The one in libcxxabi
+// is the original and the one in llvm is the copy.  Use cp-to-llvm.sh to update
+// the copy.  See README.txt for more details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef DEMANGLE_UTILITY_H
+#define DEMANGLE_UTILITY_H
+
+#include "DemangleConfig.h"
+
+#include <array>
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
+#include <exception>
+#include <limits>
+#include <string_view>
+
+DEMANGLE_NAMESPACE_BEGIN
+
+// Stream that AST nodes write their string representation into after the AST
+// has been parsed.
+class OutputBuffer {
+  char *Buffer = nullptr;
+  size_t CurrentPosition = 0;
+  size_t BufferCapacity = 0;
+
+  // Ensure there are at least N more positions in the buffer.
+  void grow(size_t N) {
+    size_t Need = N + CurrentPosition;
+    if (Need > BufferCapacity) {
+      // Reduce the number of reallocations, with a bit of hysteresis. The
+      // number here is chosen so the first allocation will more-than-likely not
+      // allocate more than 1K.
+      Need += 1024 - 32;
+      BufferCapacity *= 2;
+      if (BufferCapacity < Need)
+        BufferCapacity = Need;
+      Buffer = static_cast<char *>(std::realloc(Buffer, BufferCapacity));
+      if (Buffer == nullptr)
+        std::terminate();
+    }
+  }
+
+  OutputBuffer &writeUnsigned(uint64_t N, bool isNeg = false) {
+    std::array<char, 21> Temp;
+    char *TempPtr = Temp.data() + Temp.size();
+
+    // Output at least one character.
+    do {
+      *--TempPtr = char('0' + N % 10);
+      N /= 10;
+    } while (N);
+
+    // Add negative sign.
+    if (isNeg)
+      *--TempPtr = '-';
+
+    return operator+=(
+        std::string_view(TempPtr, Temp.data() + Temp.size() - TempPtr));
+  }
+
+public:
+  OutputBuffer(char *StartBuf, size_t Size)
+      : Buffer(StartBuf), BufferCapacity(Size) {}
+  OutputBuffer(char *StartBuf, size_t *SizePtr)
+      : OutputBuffer(StartBuf, StartBuf ? *SizePtr : 0) {}
+  OutputBuffer() = default;
+  // Non-copyable
+  OutputBuffer(const OutputBuffer &) = delete;
+  OutputBuffer &operator=(const OutputBuffer &) = delete;
+
+  operator std::string_view() const {
+    return std::string_view(Buffer, CurrentPosition);
+  }
+
+  /// If a ParameterPackExpansion (or similar type) is encountered, the offset
+  /// into the pack that we're currently printing.
+  unsigned CurrentPackIndex = std::numeric_limits<unsigned>::max();
+  unsigned CurrentPackMax = std::numeric_limits<unsigned>::max();
+
+  /// When zero, we're printing template args and '>' needs to be parenthesized.
+  /// Use a counter so we can simply increment inside parentheses.
+  unsigned GtIsGt = 1;
+
+  bool isGtInsideTemplateArgs() const { return GtIsGt == 0; }
+
+  void printOpen(char Open = '(') {
+    GtIsGt++;
+    *this += Open;
+  }
+  void printClose(char Close = ')') {
+    GtIsGt--;
+    *this += Close;
+  }
+
+  OutputBuffer &operator+=(std::string_view R) {
+    if (size_t Size = R.size()) {
+      grow(Size);
+      std::memcpy(Buffer + CurrentPosition, &*R.begin(), Size);
+      CurrentPosition += Size;
+    }
+    return *this;
+  }
+
+  OutputBuffer &operator+=(char C) {
+    grow(1);
+    Buffer[CurrentPosition++] = C;
+    return *this;
+  }
+
+  OutputBuffer &prepend(std::string_view R) {
+    size_t Size = R.size();
+
+    grow(Size);
+    std::memmove(Buffer + Size, Buffer, CurrentPosition);
+    std::memcpy(Buffer, &*R.begin(), Size);
+    CurrentPosition += Size;
+
+    return *this;
+  }
+
+  OutputBuffer &operator<<(std::string_view R) { return (*this += R); }
+
+  OutputBuffer &operator<<(char C) { return (*this += C); }
+
+  OutputBuffer &operator<<(long long N) {
+    return writeUnsigned(static_cast<unsigned long long>(std::abs(N)), N < 0);
+  }
+
+  OutputBuffer &operator<<(unsigned long long N) {
+    return writeUnsigned(N, false);
+  }
+
+  OutputBuffer &operator<<(long N) {
+    return this->operator<<(static_cast<long long>(N));
+  }
+
+  OutputBuffer &operator<<(unsigned long N) {
+    return this->operator<<(static_cast<unsigned long long>(N));
+  }
+
+  OutputBuffer &operator<<(int N) {
+    return this->operator<<(static_cast<long long>(N));
+  }
+
+  OutputBuffer &operator<<(unsigned int N) {
+    return this->operator<<(static_cast<unsigned long long>(N));
+  }
+
+  void insert(size_t Pos, const char *S, size_t N) {
+    assert(Pos <= CurrentPosition);
+    if (N == 0)
+      return;
+    grow(N);
+    std::memmove(Buffer + Pos + N, Buffer + Pos, CurrentPosition - Pos);
+    std::memcpy(Buffer + Pos, S, N);
+    CurrentPosition += N;
+  }
+
+  size_t getCurrentPosition() const { return CurrentPosition; }
+  void setCurrentPosition(size_t NewPos) { CurrentPosition = NewPos; }
+
+  char back() const {
+    assert(CurrentPosition);
+    return Buffer[CurrentPosition - 1];
+  }
+
+  bool empty() const { return CurrentPosition == 0; }
+
+  char *getBuffer() { return Buffer; }
+  char *getBufferEnd() { return Buffer + CurrentPosition - 1; }
+  size_t getBufferCapacity() const { return BufferCapacity; }
+};
+
+template <class T> class ScopedOverride {
+  T &Loc;
+  T Original;
+
+public:
+  ScopedOverride(T &Loc_) : ScopedOverride(Loc_, Loc_) {}
+
+  ScopedOverride(T &Loc_, T NewVal) : Loc(Loc_), Original(Loc_) {
+    Loc_ = std::move(NewVal);
+  }
+  ~ScopedOverride() { Loc = std::move(Original); }
+
+  ScopedOverride(const ScopedOverride &) = delete;
+  ScopedOverride &operator=(const ScopedOverride &) = delete;
+};
+
+DEMANGLE_NAMESPACE_END
+
+#endif