From 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Fri, 19 Apr 2024 03:47:29 +0200
Subject: Adding upstream version 115.8.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 security/sandbox/chromium/base/bind_internal.h | 1050 ++++++++++++++++++++++++
 1 file changed, 1050 insertions(+)
 create mode 100644 security/sandbox/chromium/base/bind_internal.h

(limited to 'security/sandbox/chromium/base/bind_internal.h')

diff --git a/security/sandbox/chromium/base/bind_internal.h b/security/sandbox/chromium/base/bind_internal.h
new file mode 100644
index 0000000000..bed151a8dc
--- /dev/null
+++ b/security/sandbox/chromium/base/bind_internal.h
@@ -0,0 +1,1050 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_BIND_INTERNAL_H_
+#define BASE_BIND_INTERNAL_H_
+
+#include <stddef.h>
+
+#include <functional>
+#include <memory>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/callback_internal.h"
+#include "base/compiler_specific.h"
+#include "base/memory/raw_scoped_refptr_mismatch_checker.h"
+#include "base/memory/weak_ptr.h"
+#include "base/template_util.h"
+#include "build/build_config.h"
+
+#if defined(OS_MACOSX) && !HAS_FEATURE(objc_arc)
+#include "base/mac/scoped_block.h"
+#endif
+
+// See base/callback.h for user documentation.
+//
+//
+// CONCEPTS:
+//  Functor -- A movable type representing something that should be called.
+//             All function pointers and Callback<> are functors even if the
+//             invocation syntax differs.
+//  RunType -- A function type (as opposed to function _pointer_ type) for
+//             a Callback<>::Run().  Usually just a convenience typedef.
+//  (Bound)Args -- A set of types that stores the arguments.
+//
+// Types:
+//  ForceVoidReturn<> -- Helper class for translating function signatures to
+//                       equivalent forms with a "void" return type.
+//  FunctorTraits<> -- Type traits used to determine the correct RunType and
+//                     invocation manner for a Functor.  This is where function
+//                     signature adapters are applied.
+//  InvokeHelper<> -- Take a Functor + arguments and actully invokes it.
+//                    Handle the differing syntaxes needed for WeakPtr<>
+//                    support.  This is separate from Invoker to avoid creating
+//                    multiple version of Invoker<>.
+//  Invoker<> -- Unwraps the curried parameters and executes the Functor.
+//  BindState<> -- Stores the curried parameters, and is the main entry point
+//                 into the Bind() system.
+
+#if defined(OS_WIN)
+namespace Microsoft {
+namespace WRL {
+template <typename>
+class ComPtr;
+}  // namespace WRL
+}  // namespace Microsoft
+#endif
+
+namespace base {
+
+template <typename T>
+struct IsWeakReceiver;
+
+template <typename>
+struct BindUnwrapTraits;
+
+template <typename Functor, typename BoundArgsTuple, typename SFINAE = void>
+struct CallbackCancellationTraits;
+
+namespace internal {
+
+template <typename Functor, typename SFINAE = void>
+struct FunctorTraits;
+
+template <typename T>
+class UnretainedWrapper {
+ public:
+  explicit UnretainedWrapper(T* o) : ptr_(o) {}
+  T* get() const { return ptr_; }
+
+ private:
+  T* ptr_;
+};
+
+template <typename T>
+class RetainedRefWrapper {
+ public:
+  explicit RetainedRefWrapper(T* o) : ptr_(o) {}
+  explicit RetainedRefWrapper(scoped_refptr<T> o) : ptr_(std::move(o)) {}
+  T* get() const { return ptr_.get(); }
+
+ private:
+  scoped_refptr<T> ptr_;
+};
+
+template <typename T>
+struct IgnoreResultHelper {
+  explicit IgnoreResultHelper(T functor) : functor_(std::move(functor)) {}
+  explicit operator bool() const { return !!functor_; }
+
+  T functor_;
+};
+
+template <typename T, typename Deleter = std::default_delete<T>>
+class OwnedWrapper {
+ public:
+  explicit OwnedWrapper(T* o) : ptr_(o) {}
+  explicit OwnedWrapper(std::unique_ptr<T, Deleter>&& ptr)
+      : ptr_(std::move(ptr)) {}
+  T* get() const { return ptr_.get(); }
+
+ private:
+  std::unique_ptr<T, Deleter> ptr_;
+};
+
+// PassedWrapper is a copyable adapter for a scoper that ignores const.
+//
+// It is needed to get around the fact that Bind() takes a const reference to
+// all its arguments.  Because Bind() takes a const reference to avoid
+// unnecessary copies, it is incompatible with movable-but-not-copyable
+// types; doing a destructive "move" of the type into Bind() would violate
+// the const correctness.
+//
+// This conundrum cannot be solved without either C++11 rvalue references or
+// a O(2^n) blowup of Bind() templates to handle each combination of regular
+// types and movable-but-not-copyable types.  Thus we introduce a wrapper type
+// that is copyable to transmit the correct type information down into
+// BindState<>. Ignoring const in this type makes sense because it is only
+// created when we are explicitly trying to do a destructive move.
+//
+// Two notes:
+//  1) PassedWrapper supports any type that has a move constructor, however
+//     the type will need to be specifically whitelisted in order for it to be
+//     bound to a Callback. We guard this explicitly at the call of Passed()
+//     to make for clear errors. Things not given to Passed() will be forwarded
+//     and stored by value which will not work for general move-only types.
+//  2) is_valid_ is distinct from NULL because it is valid to bind a "NULL"
+//     scoper to a Callback and allow the Callback to execute once.
+template <typename T>
+class PassedWrapper {
+ public:
+  explicit PassedWrapper(T&& scoper)
+      : is_valid_(true), scoper_(std::move(scoper)) {}
+  PassedWrapper(PassedWrapper&& other)
+      : is_valid_(other.is_valid_), scoper_(std::move(other.scoper_)) {}
+  T Take() const {
+    CHECK(is_valid_);
+    is_valid_ = false;
+    return std::move(scoper_);
+  }
+
+ private:
+  mutable bool is_valid_;
+  mutable T scoper_;
+};
+
+template <typename T>
+using Unwrapper = BindUnwrapTraits<std::decay_t<T>>;
+
+template <typename T>
+decltype(auto) Unwrap(T&& o) {
+  return Unwrapper<T>::Unwrap(std::forward<T>(o));
+}
+
+// IsWeakMethod is a helper that determine if we are binding a WeakPtr<> to a
+// method.  It is used internally by Bind() to select the correct
+// InvokeHelper that will no-op itself in the event the WeakPtr<> for
+// the target object is invalidated.
+//
+// The first argument should be the type of the object that will be received by
+// the method.
+template <bool is_method, typename... Args>
+struct IsWeakMethod : std::false_type {};
+
+template <typename T, typename... Args>
+struct IsWeakMethod<true, T, Args...> : IsWeakReceiver<T> {};
+
+// Packs a list of types to hold them in a single type.
+template <typename... Types>
+struct TypeList {};
+
+// Used for DropTypeListItem implementation.
+template <size_t n, typename List>
+struct DropTypeListItemImpl;
+
+// Do not use enable_if and SFINAE here to avoid MSVC2013 compile failure.
+template <size_t n, typename T, typename... List>
+struct DropTypeListItemImpl<n, TypeList<T, List...>>
+    : DropTypeListItemImpl<n - 1, TypeList<List...>> {};
+
+template <typename T, typename... List>
+struct DropTypeListItemImpl<0, TypeList<T, List...>> {
+  using Type = TypeList<T, List...>;
+};
+
+template <>
+struct DropTypeListItemImpl<0, TypeList<>> {
+  using Type = TypeList<>;
+};
+
+// A type-level function that drops |n| list item from given TypeList.
+template <size_t n, typename List>
+using DropTypeListItem = typename DropTypeListItemImpl<n, List>::Type;
+
+// Used for TakeTypeListItem implementation.
+template <size_t n, typename List, typename... Accum>
+struct TakeTypeListItemImpl;
+
+// Do not use enable_if and SFINAE here to avoid MSVC2013 compile failure.
+template <size_t n, typename T, typename... List, typename... Accum>
+struct TakeTypeListItemImpl<n, TypeList<T, List...>, Accum...>
+    : TakeTypeListItemImpl<n - 1, TypeList<List...>, Accum..., T> {};
+
+template <typename T, typename... List, typename... Accum>
+struct TakeTypeListItemImpl<0, TypeList<T, List...>, Accum...> {
+  using Type = TypeList<Accum...>;
+};
+
+template <typename... Accum>
+struct TakeTypeListItemImpl<0, TypeList<>, Accum...> {
+  using Type = TypeList<Accum...>;
+};
+
+// A type-level function that takes first |n| list item from given TypeList.
+// E.g. TakeTypeListItem<3, TypeList<A, B, C, D>> is evaluated to
+// TypeList<A, B, C>.
+template <size_t n, typename List>
+using TakeTypeListItem = typename TakeTypeListItemImpl<n, List>::Type;
+
+// Used for ConcatTypeLists implementation.
+template <typename List1, typename List2>
+struct ConcatTypeListsImpl;
+
+template <typename... Types1, typename... Types2>
+struct ConcatTypeListsImpl<TypeList<Types1...>, TypeList<Types2...>> {
+  using Type = TypeList<Types1..., Types2...>;
+};
+
+// A type-level function that concats two TypeLists.
+template <typename List1, typename List2>
+using ConcatTypeLists = typename ConcatTypeListsImpl<List1, List2>::Type;
+
+// Used for MakeFunctionType implementation.
+template <typename R, typename ArgList>
+struct MakeFunctionTypeImpl;
+
+template <typename R, typename... Args>
+struct MakeFunctionTypeImpl<R, TypeList<Args...>> {
+  // MSVC 2013 doesn't support Type Alias of function types.
+  // Revisit this after we update it to newer version.
+  typedef R Type(Args...);
+};
+
+// A type-level function that constructs a function type that has |R| as its
+// return type and has TypeLists items as its arguments.
+template <typename R, typename ArgList>
+using MakeFunctionType = typename MakeFunctionTypeImpl<R, ArgList>::Type;
+
+// Used for ExtractArgs and ExtractReturnType.
+template <typename Signature>
+struct ExtractArgsImpl;
+
+template <typename R, typename... Args>
+struct ExtractArgsImpl<R(Args...)> {
+  using ReturnType = R;
+  using ArgsList = TypeList<Args...>;
+};
+
+// A type-level function that extracts function arguments into a TypeList.
+// E.g. ExtractArgs<R(A, B, C)> is evaluated to TypeList<A, B, C>.
+template <typename Signature>
+using ExtractArgs = typename ExtractArgsImpl<Signature>::ArgsList;
+
+// A type-level function that extracts the return type of a function.
+// E.g. ExtractReturnType<R(A, B, C)> is evaluated to R.
+template <typename Signature>
+using ExtractReturnType = typename ExtractArgsImpl<Signature>::ReturnType;
+
+template <typename Callable,
+          typename Signature = decltype(&Callable::operator())>
+struct ExtractCallableRunTypeImpl;
+
+template <typename Callable, typename R, typename... Args>
+struct ExtractCallableRunTypeImpl<Callable, R (Callable::*)(Args...)> {
+  using Type = R(Args...);
+};
+
+template <typename Callable, typename R, typename... Args>
+struct ExtractCallableRunTypeImpl<Callable, R (Callable::*)(Args...) const> {
+  using Type = R(Args...);
+};
+
+// Evaluated to RunType of the given callable type.
+// Example:
+//   auto f = [](int, char*) { return 0.1; };
+//   ExtractCallableRunType<decltype(f)>
+//   is evaluated to
+//   double(int, char*);
+template <typename Callable>
+using ExtractCallableRunType =
+    typename ExtractCallableRunTypeImpl<Callable>::Type;
+
+// IsCallableObject<Functor> is std::true_type if |Functor| has operator().
+// Otherwise, it's std::false_type.
+// Example:
+//   IsCallableObject<void(*)()>::value is false.
+//
+//   struct Foo {};
+//   IsCallableObject<void(Foo::*)()>::value is false.
+//
+//   int i = 0;
+//   auto f = [i]() {};
+//   IsCallableObject<decltype(f)>::value is false.
+template <typename Functor, typename SFINAE = void>
+struct IsCallableObject : std::false_type {};
+
+template <typename Callable>
+struct IsCallableObject<Callable, void_t<decltype(&Callable::operator())>>
+    : std::true_type {};
+
+// HasRefCountedTypeAsRawPtr selects true_type when any of the |Args| is a raw
+// pointer to a RefCounted type.
+// Implementation note: This non-specialized case handles zero-arity case only.
+// Non-zero-arity cases should be handled by the specialization below.
+template <typename... Args>
+struct HasRefCountedTypeAsRawPtr : std::false_type {};
+
+// Implementation note: Select true_type if the first parameter is a raw pointer
+// to a RefCounted type. Otherwise, skip the first parameter and check rest of
+// parameters recursively.
+template <typename T, typename... Args>
+struct HasRefCountedTypeAsRawPtr<T, Args...>
+    : std::conditional_t<NeedsScopedRefptrButGetsRawPtr<T>::value,
+                         std::true_type,
+                         HasRefCountedTypeAsRawPtr<Args...>> {};
+
+// ForceVoidReturn<>
+//
+// Set of templates that support forcing the function return type to void.
+template <typename Sig>
+struct ForceVoidReturn;
+
+template <typename R, typename... Args>
+struct ForceVoidReturn<R(Args...)> {
+  using RunType = void(Args...);
+};
+
+// FunctorTraits<>
+//
+// See description at top of file.
+template <typename Functor, typename SFINAE>
+struct FunctorTraits;
+
+// For empty callable types.
+// This specialization is intended to allow binding captureless lambdas, based
+// on the fact that captureless lambdas are empty while capturing lambdas are
+// not. This also allows any functors as far as it's an empty class.
+// Example:
+//
+//   // Captureless lambdas are allowed.
+//   []() {return 42;};
+//
+//   // Capturing lambdas are *not* allowed.
+//   int x;
+//   [x]() {return x;};
+//
+//   // Any empty class with operator() is allowed.
+//   struct Foo {
+//     void operator()() const {}
+//     // No non-static member variable and no virtual functions.
+//   };
+template <typename Functor>
+struct FunctorTraits<Functor,
+                     std::enable_if_t<IsCallableObject<Functor>::value &&
+                                      std::is_empty<Functor>::value>> {
+  using RunType = ExtractCallableRunType<Functor>;
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = false;
+
+  template <typename RunFunctor, typename... RunArgs>
+  static ExtractReturnType<RunType> Invoke(RunFunctor&& functor,
+                                           RunArgs&&... args) {
+    return std::forward<RunFunctor>(functor)(std::forward<RunArgs>(args)...);
+  }
+};
+
+// For functions.
+template <typename R, typename... Args>
+struct FunctorTraits<R (*)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename Function, typename... RunArgs>
+  static R Invoke(Function&& function, RunArgs&&... args) {
+    return std::forward<Function>(function)(std::forward<RunArgs>(args)...);
+  }
+};
+
+#if defined(OS_WIN) && !defined(ARCH_CPU_64_BITS)
+
+// For functions.
+template <typename R, typename... Args>
+struct FunctorTraits<R(__stdcall*)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename... RunArgs>
+  static R Invoke(R(__stdcall* function)(Args...), RunArgs&&... args) {
+    return function(std::forward<RunArgs>(args)...);
+  }
+};
+
+// For functions.
+template <typename R, typename... Args>
+struct FunctorTraits<R(__fastcall*)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename... RunArgs>
+  static R Invoke(R(__fastcall* function)(Args...), RunArgs&&... args) {
+    return function(std::forward<RunArgs>(args)...);
+  }
+};
+
+#endif  // defined(OS_WIN) && !defined(ARCH_CPU_64_BITS)
+
+#if defined(OS_MACOSX)
+
+// Support for Objective-C blocks. There are two implementation depending
+// on whether Automated Reference Counting (ARC) is enabled. When ARC is
+// enabled, then the block itself can be bound as the compiler will ensure
+// its lifetime will be correctly managed. Otherwise, require the block to
+// be wrapped in a base::mac::ScopedBlock (via base::RetainBlock) that will
+// correctly manage the block lifetime.
+//
+// The two implementation ensure that the One Definition Rule (ODR) is not
+// broken (it is not possible to write a template base::RetainBlock that would
+// work correctly both with ARC enabled and disabled).
+
+#if HAS_FEATURE(objc_arc)
+
+template <typename R, typename... Args>
+struct FunctorTraits<R (^)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename BlockType, typename... RunArgs>
+  static R Invoke(BlockType&& block, RunArgs&&... args) {
+    // According to LLVM documentation (§ 6.3), "local variables of automatic
+    // storage duration do not have precise lifetime." Use objc_precise_lifetime
+    // to ensure that the Objective-C block is not deallocated until it has
+    // finished executing even if the Callback<> is destroyed during the block
+    // execution.
+    // https://clang.llvm.org/docs/AutomaticReferenceCounting.html#precise-lifetime-semantics
+    __attribute__((objc_precise_lifetime)) R (^scoped_block)(Args...) = block;
+    return scoped_block(std::forward<RunArgs>(args)...);
+  }
+};
+
+#else  // HAS_FEATURE(objc_arc)
+
+template <typename R, typename... Args>
+struct FunctorTraits<base::mac::ScopedBlock<R (^)(Args...)>> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename BlockType, typename... RunArgs>
+  static R Invoke(BlockType&& block, RunArgs&&... args) {
+    // Copy the block to ensure that the Objective-C block is not deallocated
+    // until it has finished executing even if the Callback<> is destroyed
+    // during the block execution.
+    base::mac::ScopedBlock<R (^)(Args...)> scoped_block(block);
+    return scoped_block.get()(std::forward<RunArgs>(args)...);
+  }
+};
+
+#endif  // HAS_FEATURE(objc_arc)
+#endif  // defined(OS_MACOSX)
+
+// For methods.
+template <typename R, typename Receiver, typename... Args>
+struct FunctorTraits<R (Receiver::*)(Args...)> {
+  using RunType = R(Receiver*, Args...);
+  static constexpr bool is_method = true;
+  static constexpr bool is_nullable = true;
+
+  template <typename Method, typename ReceiverPtr, typename... RunArgs>
+  static R Invoke(Method method,
+                  ReceiverPtr&& receiver_ptr,
+                  RunArgs&&... args) {
+    return ((*receiver_ptr).*method)(std::forward<RunArgs>(args)...);
+  }
+};
+
+// For const methods.
+template <typename R, typename Receiver, typename... Args>
+struct FunctorTraits<R (Receiver::*)(Args...) const> {
+  using RunType = R(const Receiver*, Args...);
+  static constexpr bool is_method = true;
+  static constexpr bool is_nullable = true;
+
+  template <typename Method, typename ReceiverPtr, typename... RunArgs>
+  static R Invoke(Method method,
+                  ReceiverPtr&& receiver_ptr,
+                  RunArgs&&... args) {
+    return ((*receiver_ptr).*method)(std::forward<RunArgs>(args)...);
+  }
+};
+
+#ifdef __cpp_noexcept_function_type
+// noexcept makes a distinct function type in C++17.
+// I.e. `void(*)()` and `void(*)() noexcept` are same in pre-C++17, and
+// different in C++17.
+template <typename R, typename... Args>
+struct FunctorTraits<R (*)(Args...) noexcept> : FunctorTraits<R (*)(Args...)> {
+};
+
+template <typename R, typename Receiver, typename... Args>
+struct FunctorTraits<R (Receiver::*)(Args...) noexcept>
+    : FunctorTraits<R (Receiver::*)(Args...)> {};
+
+template <typename R, typename Receiver, typename... Args>
+struct FunctorTraits<R (Receiver::*)(Args...) const noexcept>
+    : FunctorTraits<R (Receiver::*)(Args...) const> {};
+#endif
+
+// For IgnoreResults.
+template <typename T>
+struct FunctorTraits<IgnoreResultHelper<T>> : FunctorTraits<T> {
+  using RunType =
+      typename ForceVoidReturn<typename FunctorTraits<T>::RunType>::RunType;
+
+  template <typename IgnoreResultType, typename... RunArgs>
+  static void Invoke(IgnoreResultType&& ignore_result_helper,
+                     RunArgs&&... args) {
+    FunctorTraits<T>::Invoke(
+        std::forward<IgnoreResultType>(ignore_result_helper).functor_,
+        std::forward<RunArgs>(args)...);
+  }
+};
+
+// For OnceCallbacks.
+template <typename R, typename... Args>
+struct FunctorTraits<OnceCallback<R(Args...)>> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename CallbackType, typename... RunArgs>
+  static R Invoke(CallbackType&& callback, RunArgs&&... args) {
+    DCHECK(!callback.is_null());
+    return std::forward<CallbackType>(callback).Run(
+        std::forward<RunArgs>(args)...);
+  }
+};
+
+// For RepeatingCallbacks.
+template <typename R, typename... Args>
+struct FunctorTraits<RepeatingCallback<R(Args...)>> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename CallbackType, typename... RunArgs>
+  static R Invoke(CallbackType&& callback, RunArgs&&... args) {
+    DCHECK(!callback.is_null());
+    return std::forward<CallbackType>(callback).Run(
+        std::forward<RunArgs>(args)...);
+  }
+};
+
+template <typename Functor>
+using MakeFunctorTraits = FunctorTraits<std::decay_t<Functor>>;
+
+// InvokeHelper<>
+//
+// There are 2 logical InvokeHelper<> specializations: normal, WeakCalls.
+//
+// The normal type just calls the underlying runnable.
+//
+// WeakCalls need special syntax that is applied to the first argument to check
+// if they should no-op themselves.
+template <bool is_weak_call, typename ReturnType>
+struct InvokeHelper;
+
+template <typename ReturnType>
+struct InvokeHelper<false, ReturnType> {
+  template <typename Functor, typename... RunArgs>
+  static inline ReturnType MakeItSo(Functor&& functor, RunArgs&&... args) {
+    using Traits = MakeFunctorTraits<Functor>;
+    return Traits::Invoke(std::forward<Functor>(functor),
+                          std::forward<RunArgs>(args)...);
+  }
+};
+
+template <typename ReturnType>
+struct InvokeHelper<true, ReturnType> {
+  // WeakCalls are only supported for functions with a void return type.
+  // Otherwise, the function result would be undefined if the the WeakPtr<>
+  // is invalidated.
+  static_assert(std::is_void<ReturnType>::value,
+                "weak_ptrs can only bind to methods without return values");
+
+  template <typename Functor, typename BoundWeakPtr, typename... RunArgs>
+  static inline void MakeItSo(Functor&& functor,
+                              BoundWeakPtr&& weak_ptr,
+                              RunArgs&&... args) {
+    if (!weak_ptr)
+      return;
+    using Traits = MakeFunctorTraits<Functor>;
+    Traits::Invoke(std::forward<Functor>(functor),
+                   std::forward<BoundWeakPtr>(weak_ptr),
+                   std::forward<RunArgs>(args)...);
+  }
+};
+
+// Invoker<>
+//
+// See description at the top of the file.
+template <typename StorageType, typename UnboundRunType>
+struct Invoker;
+
+template <typename StorageType, typename R, typename... UnboundArgs>
+struct Invoker<StorageType, R(UnboundArgs...)> {
+  static R RunOnce(BindStateBase* base,
+                   PassingType<UnboundArgs>... unbound_args) {
+    // Local references to make debugger stepping easier. If in a debugger,
+    // you really want to warp ahead and step through the
+    // InvokeHelper<>::MakeItSo() call below.
+    StorageType* storage = static_cast<StorageType*>(base);
+    static constexpr size_t num_bound_args =
+        std::tuple_size<decltype(storage->bound_args_)>::value;
+    return RunImpl(std::move(storage->functor_),
+                   std::move(storage->bound_args_),
+                   std::make_index_sequence<num_bound_args>(),
+                   std::forward<UnboundArgs>(unbound_args)...);
+  }
+
+  static R Run(BindStateBase* base, PassingType<UnboundArgs>... unbound_args) {
+    // Local references to make debugger stepping easier. If in a debugger,
+    // you really want to warp ahead and step through the
+    // InvokeHelper<>::MakeItSo() call below.
+    const StorageType* storage = static_cast<StorageType*>(base);
+    static constexpr size_t num_bound_args =
+        std::tuple_size<decltype(storage->bound_args_)>::value;
+    return RunImpl(storage->functor_, storage->bound_args_,
+                   std::make_index_sequence<num_bound_args>(),
+                   std::forward<UnboundArgs>(unbound_args)...);
+  }
+
+ private:
+  template <typename Functor, typename BoundArgsTuple, size_t... indices>
+  static inline R RunImpl(Functor&& functor,
+                          BoundArgsTuple&& bound,
+                          std::index_sequence<indices...>,
+                          UnboundArgs&&... unbound_args) {
+    static constexpr bool is_method = MakeFunctorTraits<Functor>::is_method;
+
+    using DecayedArgsTuple = std::decay_t<BoundArgsTuple>;
+    static constexpr bool is_weak_call =
+        IsWeakMethod<is_method,
+                     std::tuple_element_t<indices, DecayedArgsTuple>...>();
+
+    return InvokeHelper<is_weak_call, R>::MakeItSo(
+        std::forward<Functor>(functor),
+        Unwrap(std::get<indices>(std::forward<BoundArgsTuple>(bound)))...,
+        std::forward<UnboundArgs>(unbound_args)...);
+  }
+};
+
+// Extracts necessary type info from Functor and BoundArgs.
+// Used to implement MakeUnboundRunType, BindOnce and BindRepeating.
+template <typename Functor, typename... BoundArgs>
+struct BindTypeHelper {
+  static constexpr size_t num_bounds = sizeof...(BoundArgs);
+  using FunctorTraits = MakeFunctorTraits<Functor>;
+
+  // Example:
+  //   When Functor is `double (Foo::*)(int, const std::string&)`, and BoundArgs
+  //   is a template pack of `Foo*` and `int16_t`:
+  //    - RunType is `double(Foo*, int, const std::string&)`,
+  //    - ReturnType is `double`,
+  //    - RunParamsList is `TypeList<Foo*, int, const std::string&>`,
+  //    - BoundParamsList is `TypeList<Foo*, int>`,
+  //    - UnboundParamsList is `TypeList<const std::string&>`,
+  //    - BoundArgsList is `TypeList<Foo*, int16_t>`,
+  //    - UnboundRunType is `double(const std::string&)`.
+  using RunType = typename FunctorTraits::RunType;
+  using ReturnType = ExtractReturnType<RunType>;
+
+  using RunParamsList = ExtractArgs<RunType>;
+  using BoundParamsList = TakeTypeListItem<num_bounds, RunParamsList>;
+  using UnboundParamsList = DropTypeListItem<num_bounds, RunParamsList>;
+
+  using BoundArgsList = TypeList<BoundArgs...>;
+
+  using UnboundRunType = MakeFunctionType<ReturnType, UnboundParamsList>;
+};
+
+template <typename Functor>
+std::enable_if_t<FunctorTraits<Functor>::is_nullable, bool> IsNull(
+    const Functor& functor) {
+  return !functor;
+}
+
+template <typename Functor>
+std::enable_if_t<!FunctorTraits<Functor>::is_nullable, bool> IsNull(
+    const Functor&) {
+  return false;
+}
+
+// Used by QueryCancellationTraits below.
+template <typename Functor, typename BoundArgsTuple, size_t... indices>
+bool QueryCancellationTraitsImpl(BindStateBase::CancellationQueryMode mode,
+                                 const Functor& functor,
+                                 const BoundArgsTuple& bound_args,
+                                 std::index_sequence<indices...>) {
+  switch (mode) {
+    case BindStateBase::IS_CANCELLED:
+      return CallbackCancellationTraits<Functor, BoundArgsTuple>::IsCancelled(
+          functor, std::get<indices>(bound_args)...);
+    case BindStateBase::MAYBE_VALID:
+      return CallbackCancellationTraits<Functor, BoundArgsTuple>::MaybeValid(
+          functor, std::get<indices>(bound_args)...);
+  }
+  NOTREACHED();
+}
+
+// Relays |base| to corresponding CallbackCancellationTraits<>::Run(). Returns
+// true if the callback |base| represents is canceled.
+template <typename BindStateType>
+bool QueryCancellationTraits(const BindStateBase* base,
+                             BindStateBase::CancellationQueryMode mode) {
+  const BindStateType* storage = static_cast<const BindStateType*>(base);
+  static constexpr size_t num_bound_args =
+      std::tuple_size<decltype(storage->bound_args_)>::value;
+  return QueryCancellationTraitsImpl(
+      mode, storage->functor_, storage->bound_args_,
+      std::make_index_sequence<num_bound_args>());
+}
+
+// The base case of BanUnconstructedRefCountedReceiver that checks nothing.
+template <typename Functor, typename Receiver, typename... Unused>
+std::enable_if_t<
+    !(MakeFunctorTraits<Functor>::is_method &&
+      std::is_pointer<std::decay_t<Receiver>>::value &&
+      IsRefCountedType<std::remove_pointer_t<std::decay_t<Receiver>>>::value)>
+BanUnconstructedRefCountedReceiver(const Receiver& receiver, Unused&&...) {}
+
+template <typename Functor>
+void BanUnconstructedRefCountedReceiver() {}
+
+// Asserts that Callback is not the first owner of a ref-counted receiver.
+template <typename Functor, typename Receiver, typename... Unused>
+std::enable_if_t<
+    MakeFunctorTraits<Functor>::is_method &&
+    std::is_pointer<std::decay_t<Receiver>>::value &&
+    IsRefCountedType<std::remove_pointer_t<std::decay_t<Receiver>>>::value>
+BanUnconstructedRefCountedReceiver(const Receiver& receiver, Unused&&...) {
+  DCHECK(receiver);
+
+  // It's error prone to make the implicit first reference to ref-counted types.
+  // In the example below, base::BindOnce() makes the implicit first reference
+  // to the ref-counted Foo. If PostTask() failed or the posted task ran fast
+  // enough, the newly created instance can be destroyed before |oo| makes
+  // another reference.
+  //   Foo::Foo() {
+  //     base::PostTask(FROM_HERE, base::BindOnce(&Foo::Bar, this));
+  //   }
+  //
+  //   scoped_refptr<Foo> oo = new Foo();
+  //
+  // Instead of doing like above, please consider adding a static constructor,
+  // and keep the first reference alive explicitly.
+  //   // static
+  //   scoped_refptr<Foo> Foo::Create() {
+  //     auto foo = base::WrapRefCounted(new Foo());
+  //     base::PostTask(FROM_HERE, base::BindOnce(&Foo::Bar, foo));
+  //     return foo;
+  //   }
+  //
+  //   Foo::Foo() {}
+  //
+  //   scoped_refptr<Foo> oo = Foo::Create();
+  DCHECK(receiver->HasAtLeastOneRef())
+      << "base::Bind{Once,Repeating}() refuses to create the first reference "
+         "to ref-counted objects. That typically happens around PostTask() in "
+         "their constructor, and such objects can be destroyed before `new` "
+         "returns if the task resolves fast enough.";
+}
+
+// BindState<>
+//
+// This stores all the state passed into Bind().
+template <typename Functor, typename... BoundArgs>
+struct BindState final : BindStateBase {
+  using IsCancellable = std::integral_constant<
+      bool,
+      CallbackCancellationTraits<Functor,
+                                 std::tuple<BoundArgs...>>::is_cancellable>;
+
+  template <typename ForwardFunctor, typename... ForwardBoundArgs>
+  static BindState* Create(BindStateBase::InvokeFuncStorage invoke_func,
+                           ForwardFunctor&& functor,
+                           ForwardBoundArgs&&... bound_args) {
+    // Ban ref counted receivers that were not yet fully constructed to avoid
+    // a common pattern of racy situation.
+    BanUnconstructedRefCountedReceiver<ForwardFunctor>(bound_args...);
+
+    // IsCancellable is std::false_type if
+    // CallbackCancellationTraits<>::IsCancelled returns always false.
+    // Otherwise, it's std::true_type.
+    return new BindState(IsCancellable{}, invoke_func,
+                         std::forward<ForwardFunctor>(functor),
+                         std::forward<ForwardBoundArgs>(bound_args)...);
+  }
+
+  Functor functor_;
+  std::tuple<BoundArgs...> bound_args_;
+
+ private:
+  template <typename ForwardFunctor, typename... ForwardBoundArgs>
+  explicit BindState(std::true_type,
+                     BindStateBase::InvokeFuncStorage invoke_func,
+                     ForwardFunctor&& functor,
+                     ForwardBoundArgs&&... bound_args)
+      : BindStateBase(invoke_func,
+                      &Destroy,
+                      &QueryCancellationTraits<BindState>),
+        functor_(std::forward<ForwardFunctor>(functor)),
+        bound_args_(std::forward<ForwardBoundArgs>(bound_args)...) {
+    DCHECK(!IsNull(functor_));
+  }
+
+  template <typename ForwardFunctor, typename... ForwardBoundArgs>
+  explicit BindState(std::false_type,
+                     BindStateBase::InvokeFuncStorage invoke_func,
+                     ForwardFunctor&& functor,
+                     ForwardBoundArgs&&... bound_args)
+      : BindStateBase(invoke_func, &Destroy),
+        functor_(std::forward<ForwardFunctor>(functor)),
+        bound_args_(std::forward<ForwardBoundArgs>(bound_args)...) {
+    DCHECK(!IsNull(functor_));
+  }
+
+  ~BindState() = default;
+
+  static void Destroy(const BindStateBase* self) {
+    delete static_cast<const BindState*>(self);
+  }
+};
+
+// Used to implement MakeBindStateType.
+template <bool is_method, typename Functor, typename... BoundArgs>
+struct MakeBindStateTypeImpl;
+
+template <typename Functor, typename... BoundArgs>
+struct MakeBindStateTypeImpl<false, Functor, BoundArgs...> {
+  static_assert(!HasRefCountedTypeAsRawPtr<std::decay_t<BoundArgs>...>::value,
+                "A parameter is a refcounted type and needs scoped_refptr.");
+  using Type = BindState<std::decay_t<Functor>, std::decay_t<BoundArgs>...>;
+};
+
+template <typename Functor>
+struct MakeBindStateTypeImpl<true, Functor> {
+  using Type = BindState<std::decay_t<Functor>>;
+};
+
+template <typename Functor, typename Receiver, typename... BoundArgs>
+struct MakeBindStateTypeImpl<true, Functor, Receiver, BoundArgs...> {
+ private:
+  using DecayedReceiver = std::decay_t<Receiver>;
+
+  static_assert(!std::is_array<std::remove_reference_t<Receiver>>::value,
+                "First bound argument to a method cannot be an array.");
+  static_assert(
+      !std::is_pointer<DecayedReceiver>::value ||
+          IsRefCountedType<std::remove_pointer_t<DecayedReceiver>>::value,
+      "Receivers may not be raw pointers. If using a raw pointer here is safe"
+      " and has no lifetime concerns, use base::Unretained() and document why"
+      " it's safe.");
+  static_assert(!HasRefCountedTypeAsRawPtr<std::decay_t<BoundArgs>...>::value,
+                "A parameter is a refcounted type and needs scoped_refptr.");
+
+ public:
+  using Type = BindState<
+      std::decay_t<Functor>,
+      std::conditional_t<std::is_pointer<DecayedReceiver>::value,
+                         scoped_refptr<std::remove_pointer_t<DecayedReceiver>>,
+                         DecayedReceiver>,
+      std::decay_t<BoundArgs>...>;
+};
+
+template <typename Functor, typename... BoundArgs>
+using MakeBindStateType =
+    typename MakeBindStateTypeImpl<MakeFunctorTraits<Functor>::is_method,
+                                   Functor,
+                                   BoundArgs...>::Type;
+
+}  // namespace internal
+
+// An injection point to control |this| pointer behavior on a method invocation.
+// If IsWeakReceiver<> is true_type for |T| and |T| is used for a receiver of a
+// method, base::Bind cancels the method invocation if the receiver is tested as
+// false.
+// E.g. Foo::bar() is not called:
+//   struct Foo : base::SupportsWeakPtr<Foo> {
+//     void bar() {}
+//   };
+//
+//   WeakPtr<Foo> oo = nullptr;
+//   base::BindOnce(&Foo::bar, oo).Run();
+template <typename T>
+struct IsWeakReceiver : std::false_type {};
+
+template <typename T>
+struct IsWeakReceiver<std::reference_wrapper<T>> : IsWeakReceiver<T> {};
+
+template <typename T>
+struct IsWeakReceiver<WeakPtr<T>> : std::true_type {};
+
+// An injection point to control how bound objects passed to the target
+// function. BindUnwrapTraits<>::Unwrap() is called for each bound objects right
+// before the target function is invoked.
+template <typename>
+struct BindUnwrapTraits {
+  template <typename T>
+  static T&& Unwrap(T&& o) {
+    return std::forward<T>(o);
+  }
+};
+
+template <typename T>
+struct BindUnwrapTraits<internal::UnretainedWrapper<T>> {
+  static T* Unwrap(const internal::UnretainedWrapper<T>& o) { return o.get(); }
+};
+
+template <typename T>
+struct BindUnwrapTraits<std::reference_wrapper<T>> {
+  static T& Unwrap(std::reference_wrapper<T> o) { return o.get(); }
+};
+
+template <typename T>
+struct BindUnwrapTraits<internal::RetainedRefWrapper<T>> {
+  static T* Unwrap(const internal::RetainedRefWrapper<T>& o) { return o.get(); }
+};
+
+template <typename T, typename Deleter>
+struct BindUnwrapTraits<internal::OwnedWrapper<T, Deleter>> {
+  static T* Unwrap(const internal::OwnedWrapper<T, Deleter>& o) {
+    return o.get();
+  }
+};
+
+template <typename T>
+struct BindUnwrapTraits<internal::PassedWrapper<T>> {
+  static T Unwrap(const internal::PassedWrapper<T>& o) { return o.Take(); }
+};
+
+#if defined(OS_WIN)
+template <typename T>
+struct BindUnwrapTraits<Microsoft::WRL::ComPtr<T>> {
+  static T* Unwrap(const Microsoft::WRL::ComPtr<T>& ptr) { return ptr.Get(); }
+};
+#endif
+
+// CallbackCancellationTraits allows customization of Callback's cancellation
+// semantics. By default, callbacks are not cancellable. A specialization should
+// set is_cancellable = true and implement an IsCancelled() that returns if the
+// callback should be cancelled.
+template <typename Functor, typename BoundArgsTuple, typename SFINAE>
+struct CallbackCancellationTraits {
+  static constexpr bool is_cancellable = false;
+};
+
+// Specialization for method bound to weak pointer receiver.
+template <typename Functor, typename... BoundArgs>
+struct CallbackCancellationTraits<
+    Functor,
+    std::tuple<BoundArgs...>,
+    std::enable_if_t<
+        internal::IsWeakMethod<internal::FunctorTraits<Functor>::is_method,
+                               BoundArgs...>::value>> {
+  static constexpr bool is_cancellable = true;
+
+  template <typename Receiver, typename... Args>
+  static bool IsCancelled(const Functor&,
+                          const Receiver& receiver,
+                          const Args&...) {
+    return !receiver;
+  }
+
+  template <typename Receiver, typename... Args>
+  static bool MaybeValid(const Functor&,
+                         const Receiver& receiver,
+                         const Args&...) {
+    return receiver.MaybeValid();
+  }
+};
+
+// Specialization for a nested bind.
+template <typename Signature, typename... BoundArgs>
+struct CallbackCancellationTraits<OnceCallback<Signature>,
+                                  std::tuple<BoundArgs...>> {
+  static constexpr bool is_cancellable = true;
+
+  template <typename Functor>
+  static bool IsCancelled(const Functor& functor, const BoundArgs&...) {
+    return functor.IsCancelled();
+  }
+
+  template <typename Functor>
+  static bool MaybeValid(const Functor& functor, const BoundArgs&...) {
+    return functor.MaybeValid();
+  }
+};
+
+template <typename Signature, typename... BoundArgs>
+struct CallbackCancellationTraits<RepeatingCallback<Signature>,
+                                  std::tuple<BoundArgs...>> {
+  static constexpr bool is_cancellable = true;
+
+  template <typename Functor>
+  static bool IsCancelled(const Functor& functor, const BoundArgs&...) {
+    return functor.IsCancelled();
+  }
+
+  template <typename Functor>
+  static bool MaybeValid(const Functor& functor, const BoundArgs&...) {
+    return functor.MaybeValid();
+  }
+};
+
+// Returns a RunType of bound functor.
+// E.g. MakeUnboundRunType<R(A, B, C), A, B> is evaluated to R(C).
+template <typename Functor, typename... BoundArgs>
+using MakeUnboundRunType =
+    typename internal::BindTypeHelper<Functor, BoundArgs...>::UnboundRunType;
+
+}  // namespace base
+
+#endif  // BASE_BIND_INTERNAL_H_
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