1 files changed, 429 insertions, 0 deletions
diff --git a/third_party/llvm-project/include/llvm/ADT/Optional.h b/third_party/llvm-project/include/llvm/ADT/Optional.h
new file mode 100644
index 000000000..b45a74002
--- /dev/null
+++ b/third_party/llvm-project/include/llvm/ADT/Optional.h
@@ -0,0 +1,429 @@
+//===- Optional.h - Simple variant for passing optional values --*- 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 provides Optional, a template class modeled in the spirit of
+//  OCaml's 'opt' variant.  The idea is to strongly type whether or not
+//  a value can be optional.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_OPTIONAL_H
+#define LLVM_ADT_OPTIONAL_H
+
+#include "llvm/ADT/None.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/type_traits.h"
+#include <cassert>
+#include <memory>
+#include <new>
+#include <utility>
+
+namespace llvm {
+
+class raw_ostream;
+
+namespace optional_detail {
+
+struct in_place_t {};
+
+/// Storage for any type.
+template <typename T, bool = is_trivially_copyable<T>::value>
+class OptionalStorage {
+  union {
+    char empty;
+    T value;
+  };
+  bool hasVal;
+
+public:
+  ~OptionalStorage() { reset(); }
+
+  OptionalStorage() noexcept : empty(), hasVal(false) {}
+
+  OptionalStorage(OptionalStorage const &other) : OptionalStorage() {
+    if (other.hasValue()) {
+      emplace(other.value);
+    }
+  }
+  OptionalStorage(OptionalStorage &&other) : OptionalStorage() {
+    if (other.hasValue()) {
+      emplace(std::move(other.value));
+    }
+  }
+
+  template <class... Args>
+  explicit OptionalStorage(in_place_t, Args &&... args)
+      : value(std::forward<Args>(args)...), hasVal(true) {}
+
+  void reset() noexcept {
+    if (hasVal) {
+      value.~T();
+      hasVal = false;
+    }
+  }
+
+  bool hasValue() const noexcept { return hasVal; }
+
+  T &getValue() LLVM_LVALUE_FUNCTION noexcept {
+    assert(hasVal);
+    return value;
+  }
+  T const &getValue() const LLVM_LVALUE_FUNCTION noexcept {
+    assert(hasVal);
+    return value;
+  }
+#if LLVM_HAS_RVALUE_REFERENCE_THIS
+  T &&getValue() && noexcept {
+    assert(hasVal);
+    return std::move(value);
+  }
+#endif
+
+  template <class... Args> void emplace(Args &&... args) {
+    reset();
+    ::new ((void *)std::addressof(value)) T(std::forward<Args>(args)...);
+    hasVal = true;
+  }
+
+  OptionalStorage &operator=(T const &y) {
+    if (hasValue()) {
+      value = y;
+    } else {
+      ::new ((void *)std::addressof(value)) T(y);
+      hasVal = true;
+    }
+    return *this;
+  }
+  OptionalStorage &operator=(T &&y) {
+    if (hasValue()) {
+      value = std::move(y);
+    } else {
+      ::new ((void *)std::addressof(value)) T(std::move(y));
+      hasVal = true;
+    }
+    return *this;
+  }
+
+  OptionalStorage &operator=(OptionalStorage const &other) {
+    if (other.hasValue()) {
+      if (hasValue()) {
+        value = other.value;
+      } else {
+        ::new ((void *)std::addressof(value)) T(other.value);
+        hasVal = true;
+      }
+    } else {
+      reset();
+    }
+    return *this;
+  }
+
+  OptionalStorage &operator=(OptionalStorage &&other) {
+    if (other.hasValue()) {
+      if (hasValue()) {
+        value = std::move(other.value);
+      } else {
+        ::new ((void *)std::addressof(value)) T(std::move(other.value));
+        hasVal = true;
+      }
+    } else {
+      reset();
+    }
+    return *this;
+  }
+};
+
+template <typename T> class OptionalStorage<T, true> {
+  union {
+    char empty;
+    T value;
+  };
+  bool hasVal = false;
+
+public:
+  ~OptionalStorage() = default;
+
+  OptionalStorage() noexcept : empty{} {}
+
+  OptionalStorage(OptionalStorage const &other) = default;
+  OptionalStorage(OptionalStorage &&other) = default;
+
+  OptionalStorage &operator=(OptionalStorage const &other) = default;
+  OptionalStorage &operator=(OptionalStorage &&other) = default;
+
+  template <class... Args>
+  explicit OptionalStorage(in_place_t, Args &&... args)
+      : value(std::forward<Args>(args)...), hasVal(true) {}
+
+  void reset() noexcept {
+    if (hasVal) {
+      value.~T();
+      hasVal = false;
+    }
+  }
+
+  bool hasValue() const noexcept { return hasVal; }
+
+  T &getValue() LLVM_LVALUE_FUNCTION noexcept {
+    assert(hasVal);
+    return value;
+  }
+  T const &getValue() const LLVM_LVALUE_FUNCTION noexcept {
+    assert(hasVal);
+    return value;
+  }
+#if LLVM_HAS_RVALUE_REFERENCE_THIS
+  T &&getValue() && noexcept {
+    assert(hasVal);
+    return std::move(value);
+  }
+#endif
+
+  template <class... Args> void emplace(Args &&... args) {
+    reset();
+    ::new ((void *)std::addressof(value)) T(std::forward<Args>(args)...);
+    hasVal = true;
+  }
+
+  OptionalStorage &operator=(T const &y) {
+    if (hasValue()) {
+      value = y;
+    } else {
+      ::new ((void *)std::addressof(value)) T(y);
+      hasVal = true;
+    }
+    return *this;
+  }
+  OptionalStorage &operator=(T &&y) {
+    if (hasValue()) {
+      value = std::move(y);
+    } else {
+      ::new ((void *)std::addressof(value)) T(std::move(y));
+      hasVal = true;
+    }
+    return *this;
+  }
+};
+
+} // namespace optional_detail
+
+template <typename T> class Optional {
+  optional_detail::OptionalStorage<T> Storage;
+
+public:
+  using value_type = T;
+
+  constexpr Optional() {}
+  constexpr Optional(NoneType) {}
+
+  Optional(const T &y) : Storage(optional_detail::in_place_t{}, y) {}
+  Optional(const Optional &O) = default;
+
+  Optional(T &&y) : Storage(optional_detail::in_place_t{}, std::move(y)) {}
+  Optional(Optional &&O) = default;
+
+  Optional &operator=(T &&y) {
+    Storage = std::move(y);
+    return *this;
+  }
+  Optional &operator=(Optional &&O) = default;
+
+  /// Create a new object by constructing it in place with the given arguments.
+  template <typename... ArgTypes> void emplace(ArgTypes &&... Args) {
+    Storage.emplace(std::forward<ArgTypes>(Args)...);
+  }
+
+  static inline Optional create(const T *y) {
+    return y ? Optional(*y) : Optional();
+  }
+
+  Optional &operator=(const T &y) {
+    Storage = y;
+    return *this;
+  }
+  Optional &operator=(const Optional &O) = default;
+
+  void reset() { Storage.reset(); }
+
+  const T *getPointer() const { return &Storage.getValue(); }
+  T *getPointer() { return &Storage.getValue(); }
+  const T &getValue() const LLVM_LVALUE_FUNCTION { return Storage.getValue(); }
+  T &getValue() LLVM_LVALUE_FUNCTION { return Storage.getValue(); }
+
+  explicit operator bool() const { return hasValue(); }
+  bool hasValue() const { return Storage.hasValue(); }
+  const T *operator->() const { return getPointer(); }
+  T *operator->() { return getPointer(); }
+  const T &operator*() const LLVM_LVALUE_FUNCTION { return getValue(); }
+  T &operator*() LLVM_LVALUE_FUNCTION { return getValue(); }
+
+  template <typename U>
+  constexpr T getValueOr(U &&value) const LLVM_LVALUE_FUNCTION {
+    return hasValue() ? getValue() : std::forward<U>(value);
+  }
+
+#if LLVM_HAS_RVALUE_REFERENCE_THIS
+  T &&getValue() && { return std::move(Storage.getValue()); }
+  T &&operator*() && { return std::move(Storage.getValue()); }
+
+  template <typename U>
+  T getValueOr(U &&value) && {
+    return hasValue() ? std::move(getValue()) : std::forward<U>(value);
+  }
+#endif
+};
+
+template <typename T, typename U>
+bool operator==(const Optional<T> &X, const Optional<U> &Y) {
+  if (X && Y)
+    return *X == *Y;
+  return X.hasValue() == Y.hasValue();
+}
+
+template <typename T, typename U>
+bool operator!=(const Optional<T> &X, const Optional<U> &Y) {
+  return !(X == Y);
+}
+
+template <typename T, typename U>
+bool operator<(const Optional<T> &X, const Optional<U> &Y) {
+  if (X && Y)
+    return *X < *Y;
+  return X.hasValue() < Y.hasValue();
+}
+
+template <typename T, typename U>
+bool operator<=(const Optional<T> &X, const Optional<U> &Y) {
+  return !(Y < X);
+}
+
+template <typename T, typename U>
+bool operator>(const Optional<T> &X, const Optional<U> &Y) {
+  return Y < X;
+}
+
+template <typename T, typename U>
+bool operator>=(const Optional<T> &X, const Optional<U> &Y) {
+  return !(X < Y);
+}
+
+template<typename T>
+bool operator==(const Optional<T> &X, NoneType) {
+  return !X;
+}
+
+template<typename T>
+bool operator==(NoneType, const Optional<T> &X) {
+  return X == None;
+}
+
+template<typename T>
+bool operator!=(const Optional<T> &X, NoneType) {
+  return !(X == None);
+}
+
+template<typename T>
+bool operator!=(NoneType, const Optional<T> &X) {
+  return X != None;
+}
+
+template <typename T> bool operator<(const Optional<T> &X, NoneType) {
+  return false;
+}
+
+template <typename T> bool operator<(NoneType, const Optional<T> &X) {
+  return X.hasValue();
+}
+
+template <typename T> bool operator<=(const Optional<T> &X, NoneType) {
+  return !(None < X);
+}
+
+template <typename T> bool operator<=(NoneType, const Optional<T> &X) {
+  return !(X < None);
+}
+
+template <typename T> bool operator>(const Optional<T> &X, NoneType) {
+  return None < X;
+}
+
+template <typename T> bool operator>(NoneType, const Optional<T> &X) {
+  return X < None;
+}
+
+template <typename T> bool operator>=(const Optional<T> &X, NoneType) {
+  return None <= X;
+}
+
+template <typename T> bool operator>=(NoneType, const Optional<T> &X) {
+  return X <= None;
+}
+
+template <typename T> bool operator==(const Optional<T> &X, const T &Y) {
+  return X && *X == Y;
+}
+
+template <typename T> bool operator==(const T &X, const Optional<T> &Y) {
+  return Y && X == *Y;
+}
+
+template <typename T> bool operator!=(const Optional<T> &X, const T &Y) {
+  return !(X == Y);
+}
+
+template <typename T> bool operator!=(const T &X, const Optional<T> &Y) {
+  return !(X == Y);
+}
+
+template <typename T> bool operator<(const Optional<T> &X, const T &Y) {
+  return !X || *X < Y;
+}
+
+template <typename T> bool operator<(const T &X, const Optional<T> &Y) {
+  return Y && X < *Y;
+}
+
+template <typename T> bool operator<=(const Optional<T> &X, const T &Y) {
+  return !(Y < X);
+}
+
+template <typename T> bool operator<=(const T &X, const Optional<T> &Y) {
+  return !(Y < X);
+}
+
+template <typename T> bool operator>(const Optional<T> &X, const T &Y) {
+  return Y < X;
+}
+
+template <typename T> bool operator>(const T &X, const Optional<T> &Y) {
+  return Y < X;
+}
+
+template <typename T> bool operator>=(const Optional<T> &X, const T &Y) {
+  return !(X < Y);
+}
+
+template <typename T> bool operator>=(const T &X, const Optional<T> &Y) {
+  return !(X < Y);
+}
+
+raw_ostream &operator<<(raw_ostream &OS, NoneType);
+
+template <typename T, typename = decltype(std::declval<raw_ostream &>()
+                                          << std::declval<const T &>())>
+raw_ostream &operator<<(raw_ostream &OS, const Optional<T> &O) {
+  if (O)
+    OS << *O;
+  else
+    OS << None;
+  return OS;
+}
+
+} // end namespace llvm
+
+#endif // LLVM_ADT_OPTIONAL_H