chore(3p/abseil_cpp): unvendor abseil_cpp r/3786

we weren't actually using these sources anymore, okay?

Change-Id: If701571d9716de308d3512e1eb22c35db0877a66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

16 files changed, 0 insertions, 3119 deletions

diff --git a/third_party/abseil_cpp/absl/flags/internal/commandlineflag.cc b/third_party/abseil_cpp/absl/flags/internal/commandlineflag.cc
deleted file mode 100644
index 4482955c4cb6..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/commandlineflag.cc
+++ /dev/null
@@ -1,26 +0,0 @@
-//
-// Copyright 2020 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/commandlineflag.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-FlagStateInterface::~FlagStateInterface() {}
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
diff --git a/third_party/abseil_cpp/absl/flags/internal/commandlineflag.h b/third_party/abseil_cpp/absl/flags/internal/commandlineflag.h
deleted file mode 100644
index cb46fe2e979d..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/commandlineflag.h
+++ /dev/null
@@ -1,68 +0,0 @@
-//
-// Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
-#define ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
-
-#include "absl/base/config.h"
-#include "absl/base/internal/fast_type_id.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// An alias for flag fast type id. This value identifies the flag value type
-// simialarly to typeid(T), without relying on RTTI being available. In most
-// cases this id is enough to uniquely identify the flag's value type. In a few
-// cases we'll have to resort to using actual RTTI implementation if it is
-// available.
-using FlagFastTypeId = absl::base_internal::FastTypeIdType;
-
-// Options that control SetCommandLineOptionWithMode.
-enum FlagSettingMode {
-  // update the flag's value unconditionally (can call this multiple times).
-  SET_FLAGS_VALUE,
-  // update the flag's value, but *only if* it has not yet been updated
-  // with SET_FLAGS_VALUE, SET_FLAG_IF_DEFAULT, or "FLAGS_xxx = nondef".
-  SET_FLAG_IF_DEFAULT,
-  // set the flag's default value to this.  If the flag has not been updated
-  // yet (via SET_FLAGS_VALUE, SET_FLAG_IF_DEFAULT, or "FLAGS_xxx = nondef")
-  // change the flag's current value to the new default value as well.
-  SET_FLAGS_DEFAULT
-};
-
-// Options that control ParseFrom: Source of a value.
-enum ValueSource {
-  // Flag is being set by value specified on a command line.
-  kCommandLine,
-  // Flag is being set by value specified in the code.
-  kProgrammaticChange,
-};
-
-// Handle to FlagState objects. Specific flag state objects will restore state
-// of a flag produced this flag state from method CommandLineFlag::SaveState().
-class FlagStateInterface {
- public:
-  virtual ~FlagStateInterface();
-
-  // Restores the flag originated this object to the saved state.
-  virtual void Restore() const = 0;
-};
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/flag.cc b/third_party/abseil_cpp/absl/flags/internal/flag.cc
deleted file mode 100644
index 1502e7f11d36..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/flag.cc
+++ /dev/null
@@ -1,568 +0,0 @@
-//
-// Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/flag.h"
-
-#include <assert.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include <array>
-#include <atomic>
-#include <memory>
-#include <new>
-#include <string>
-#include <typeinfo>
-
-#include "absl/base/call_once.h"
-#include "absl/base/casts.h"
-#include "absl/base/config.h"
-#include "absl/base/optimization.h"
-#include "absl/flags/config.h"
-#include "absl/flags/internal/commandlineflag.h"
-#include "absl/flags/usage_config.h"
-#include "absl/memory/memory.h"
-#include "absl/strings/str_cat.h"
-#include "absl/strings/string_view.h"
-#include "absl/synchronization/mutex.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// The help message indicating that the commandline flag has been
-// 'stripped'. It will not show up when doing "-help" and its
-// variants. The flag is stripped if ABSL_FLAGS_STRIP_HELP is set to 1
-// before including absl/flags/flag.h
-const char kStrippedFlagHelp[] = "\001\002\003\004 (unknown) \004\003\002\001";
-
-namespace {
-
-// Currently we only validate flag values for user-defined flag types.
-bool ShouldValidateFlagValue(FlagFastTypeId flag_type_id) {
-#define DONT_VALIDATE(T, _) \
-  if (flag_type_id == base_internal::FastTypeId<T>()) return false;
-  ABSL_FLAGS_INTERNAL_SUPPORTED_TYPES(DONT_VALIDATE)
-#undef DONT_VALIDATE
-
-  return true;
-}
-
-// RAII helper used to temporarily unlock and relock `absl::Mutex`.
-// This is used when we need to ensure that locks are released while
-// invoking user supplied callbacks and then reacquired, since callbacks may
-// need to acquire these locks themselves.
-class MutexRelock {
- public:
-  explicit MutexRelock(absl::Mutex& mu) : mu_(mu) { mu_.Unlock(); }
-  ~MutexRelock() { mu_.Lock(); }
-
-  MutexRelock(const MutexRelock&) = delete;
-  MutexRelock& operator=(const MutexRelock&) = delete;
-
- private:
-  absl::Mutex& mu_;
-};
-
-}  // namespace
-
-///////////////////////////////////////////////////////////////////////////////
-// Persistent state of the flag data.
-
-class FlagImpl;
-
-class FlagState : public flags_internal::FlagStateInterface {
- public:
-  template <typename V>
-  FlagState(FlagImpl& flag_impl, const V& v, bool modified,
-            bool on_command_line, int64_t counter)
-      : flag_impl_(flag_impl),
-        value_(v),
-        modified_(modified),
-        on_command_line_(on_command_line),
-        counter_(counter) {}
-
-  ~FlagState() override {
-    if (flag_impl_.ValueStorageKind() != FlagValueStorageKind::kAlignedBuffer)
-      return;
-    flags_internal::Delete(flag_impl_.op_, value_.heap_allocated);
-  }
-
- private:
-  friend class FlagImpl;
-
-  // Restores the flag to the saved state.
-  void Restore() const override {
-    if (!flag_impl_.RestoreState(*this)) return;
-
-    ABSL_INTERNAL_LOG(INFO,
-                      absl::StrCat("Restore saved value of ", flag_impl_.Name(),
-                                   " to: ", flag_impl_.CurrentValue()));
-  }
-
-  // Flag and saved flag data.
-  FlagImpl& flag_impl_;
-  union SavedValue {
-    explicit SavedValue(void* v) : heap_allocated(v) {}
-    explicit SavedValue(int64_t v) : one_word(v) {}
-    explicit SavedValue(flags_internal::AlignedTwoWords v) : two_words(v) {}
-
-    void* heap_allocated;
-    int64_t one_word;
-    flags_internal::AlignedTwoWords two_words;
-  } value_;
-  bool modified_;
-  bool on_command_line_;
-  int64_t counter_;
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag implementation, which does not depend on flag value type.
-
-DynValueDeleter::DynValueDeleter(FlagOpFn op_arg) : op(op_arg) {}
-
-void DynValueDeleter::operator()(void* ptr) const {
-  if (op == nullptr) return;
-
-  Delete(op, ptr);
-}
-
-void FlagImpl::Init() {
-  new (&data_guard_) absl::Mutex;
-
-  auto def_kind = static_cast<FlagDefaultKind>(def_kind_);
-
-  switch (ValueStorageKind()) {
-    case FlagValueStorageKind::kAlignedBuffer:
-      // For this storage kind the default_value_ always points to gen_func
-      // during initialization.
-      assert(def_kind == FlagDefaultKind::kGenFunc);
-      (*default_value_.gen_func)(AlignedBufferValue());
-      break;
-    case FlagValueStorageKind::kOneWordAtomic: {
-      alignas(int64_t) std::array<char, sizeof(int64_t)> buf{};
-      if (def_kind == FlagDefaultKind::kGenFunc) {
-        (*default_value_.gen_func)(buf.data());
-      } else {
-        assert(def_kind != FlagDefaultKind::kDynamicValue);
-        std::memcpy(buf.data(), &default_value_, Sizeof(op_));
-      }
-      OneWordValue().store(absl::bit_cast<int64_t>(buf),
-                           std::memory_order_release);
-      break;
-    }
-    case FlagValueStorageKind::kTwoWordsAtomic: {
-      // For this storage kind the default_value_ always points to gen_func
-      // during initialization.
-      assert(def_kind == FlagDefaultKind::kGenFunc);
-      alignas(AlignedTwoWords) std::array<char, sizeof(AlignedTwoWords)> buf{};
-      (*default_value_.gen_func)(buf.data());
-      auto atomic_value = absl::bit_cast<AlignedTwoWords>(buf);
-      TwoWordsValue().store(atomic_value, std::memory_order_release);
-      break;
-    }
-  }
-}
-
-absl::Mutex* FlagImpl::DataGuard() const {
-  absl::call_once(const_cast<FlagImpl*>(this)->init_control_, &FlagImpl::Init,
-                  const_cast<FlagImpl*>(this));
-
-  // data_guard_ is initialized inside Init.
-  return reinterpret_cast<absl::Mutex*>(&data_guard_);
-}
-
-void FlagImpl::AssertValidType(FlagFastTypeId rhs_type_id,
-                               const std::type_info* (*gen_rtti)()) const {
-  FlagFastTypeId lhs_type_id = flags_internal::FastTypeId(op_);
-
-  // `rhs_type_id` is the fast type id corresponding to the declaration
-  // visibile at the call site. `lhs_type_id` is the fast type id
-  // corresponding to the type specified in flag definition. They must match
-  //  for this operation to be well-defined.
-  if (ABSL_PREDICT_TRUE(lhs_type_id == rhs_type_id)) return;
-
-  const std::type_info* lhs_runtime_type_id =
-      flags_internal::RuntimeTypeId(op_);
-  const std::type_info* rhs_runtime_type_id = (*gen_rtti)();
-
-  if (lhs_runtime_type_id == rhs_runtime_type_id) return;
-
-#if defined(ABSL_FLAGS_INTERNAL_HAS_RTTI)
-  if (*lhs_runtime_type_id == *rhs_runtime_type_id) return;
-#endif
-
-  ABSL_INTERNAL_LOG(
-      FATAL, absl::StrCat("Flag '", Name(),
-                          "' is defined as one type and declared as another"));
-}
-
-std::unique_ptr<void, DynValueDeleter> FlagImpl::MakeInitValue() const {
-  void* res = nullptr;
-  switch (DefaultKind()) {
-    case FlagDefaultKind::kDynamicValue:
-      res = flags_internal::Clone(op_, default_value_.dynamic_value);
-      break;
-    case FlagDefaultKind::kGenFunc:
-      res = flags_internal::Alloc(op_);
-      (*default_value_.gen_func)(res);
-      break;
-    default:
-      res = flags_internal::Clone(op_, &default_value_);
-      break;
-  }
-  return {res, DynValueDeleter{op_}};
-}
-
-void FlagImpl::StoreValue(const void* src) {
-  switch (ValueStorageKind()) {
-    case FlagValueStorageKind::kAlignedBuffer:
-      Copy(op_, src, AlignedBufferValue());
-      break;
-    case FlagValueStorageKind::kOneWordAtomic: {
-      int64_t one_word_val = 0;
-      std::memcpy(&one_word_val, src, Sizeof(op_));
-      OneWordValue().store(one_word_val, std::memory_order_release);
-      break;
-    }
-    case FlagValueStorageKind::kTwoWordsAtomic: {
-      AlignedTwoWords two_words_val{0, 0};
-      std::memcpy(&two_words_val, src, Sizeof(op_));
-      TwoWordsValue().store(two_words_val, std::memory_order_release);
-      break;
-    }
-  }
-
-  modified_ = true;
-  ++counter_;
-  InvokeCallback();
-}
-
-absl::string_view FlagImpl::Name() const { return name_; }
-
-std::string FlagImpl::Filename() const {
-  return flags_internal::GetUsageConfig().normalize_filename(filename_);
-}
-
-std::string FlagImpl::Help() const {
-  return HelpSourceKind() == FlagHelpKind::kLiteral ? help_.literal
-                                                    : help_.gen_func();
-}
-
-FlagFastTypeId FlagImpl::TypeId() const {
-  return flags_internal::FastTypeId(op_);
-}
-
-bool FlagImpl::IsSpecifiedOnCommandLine() const {
-  absl::MutexLock l(DataGuard());
-  return on_command_line_;
-}
-
-std::string FlagImpl::DefaultValue() const {
-  absl::MutexLock l(DataGuard());
-
-  auto obj = MakeInitValue();
-  return flags_internal::Unparse(op_, obj.get());
-}
-
-std::string FlagImpl::CurrentValue() const {
-  auto* guard = DataGuard();  // Make sure flag initialized
-  switch (ValueStorageKind()) {
-    case FlagValueStorageKind::kAlignedBuffer: {
-      absl::MutexLock l(guard);
-      return flags_internal::Unparse(op_, AlignedBufferValue());
-    }
-    case FlagValueStorageKind::kOneWordAtomic: {
-      const auto one_word_val =
-          absl::bit_cast<std::array<char, sizeof(int64_t)>>(
-              OneWordValue().load(std::memory_order_acquire));
-      return flags_internal::Unparse(op_, one_word_val.data());
-    }
-    case FlagValueStorageKind::kTwoWordsAtomic: {
-      const auto two_words_val =
-          absl::bit_cast<std::array<char, sizeof(AlignedTwoWords)>>(
-              TwoWordsValue().load(std::memory_order_acquire));
-      return flags_internal::Unparse(op_, two_words_val.data());
-    }
-  }
-
-  return "";
-}
-
-void FlagImpl::SetCallback(const FlagCallbackFunc mutation_callback) {
-  absl::MutexLock l(DataGuard());
-
-  if (callback_ == nullptr) {
-    callback_ = new FlagCallback;
-  }
-  callback_->func = mutation_callback;
-
-  InvokeCallback();
-}
-
-void FlagImpl::InvokeCallback() const {
-  if (!callback_) return;
-
-  // Make a copy of the C-style function pointer that we are about to invoke
-  // before we release the lock guarding it.
-  FlagCallbackFunc cb = callback_->func;
-
-  // If the flag has a mutation callback this function invokes it. While the
-  // callback is being invoked the primary flag's mutex is unlocked and it is
-  // re-locked back after call to callback is completed. Callback invocation is
-  // guarded by flag's secondary mutex instead which prevents concurrent
-  // callback invocation. Note that it is possible for other thread to grab the
-  // primary lock and update flag's value at any time during the callback
-  // invocation. This is by design. Callback can get a value of the flag if
-  // necessary, but it might be different from the value initiated the callback
-  // and it also can be different by the time the callback invocation is
-  // completed. Requires that *primary_lock be held in exclusive mode; it may be
-  // released and reacquired by the implementation.
-  MutexRelock relock(*DataGuard());
-  absl::MutexLock lock(&callback_->guard);
-  cb();
-}
-
-std::unique_ptr<FlagStateInterface> FlagImpl::SaveState() {
-  absl::MutexLock l(DataGuard());
-
-  bool modified = modified_;
-  bool on_command_line = on_command_line_;
-  switch (ValueStorageKind()) {
-    case FlagValueStorageKind::kAlignedBuffer: {
-      return absl::make_unique<FlagState>(
-          *this, flags_internal::Clone(op_, AlignedBufferValue()), modified,
-          on_command_line, counter_);
-    }
-    case FlagValueStorageKind::kOneWordAtomic: {
-      return absl::make_unique<FlagState>(
-          *this, OneWordValue().load(std::memory_order_acquire), modified,
-          on_command_line, counter_);
-    }
-    case FlagValueStorageKind::kTwoWordsAtomic: {
-      return absl::make_unique<FlagState>(
-          *this, TwoWordsValue().load(std::memory_order_acquire), modified,
-          on_command_line, counter_);
-    }
-  }
-  return nullptr;
-}
-
-bool FlagImpl::RestoreState(const FlagState& flag_state) {
-  absl::MutexLock l(DataGuard());
-
-  if (flag_state.counter_ == counter_) {
-    return false;
-  }
-
-  switch (ValueStorageKind()) {
-    case FlagValueStorageKind::kAlignedBuffer:
-      StoreValue(flag_state.value_.heap_allocated);
-      break;
-    case FlagValueStorageKind::kOneWordAtomic:
-      StoreValue(&flag_state.value_.one_word);
-      break;
-    case FlagValueStorageKind::kTwoWordsAtomic:
-      StoreValue(&flag_state.value_.two_words);
-      break;
-  }
-
-  modified_ = flag_state.modified_;
-  on_command_line_ = flag_state.on_command_line_;
-
-  return true;
-}
-
-template <typename StorageT>
-StorageT* FlagImpl::OffsetValue() const {
-  char* p = reinterpret_cast<char*>(const_cast<FlagImpl*>(this));
-  // The offset is deduced via Flag value type specific op_.
-  size_t offset = flags_internal::ValueOffset(op_);
-
-  return reinterpret_cast<StorageT*>(p + offset);
-}
-
-void* FlagImpl::AlignedBufferValue() const {
-  assert(ValueStorageKind() == FlagValueStorageKind::kAlignedBuffer);
-  return OffsetValue<void>();
-}
-
-std::atomic<int64_t>& FlagImpl::OneWordValue() const {
-  assert(ValueStorageKind() == FlagValueStorageKind::kOneWordAtomic);
-  return OffsetValue<FlagOneWordValue>()->value;
-}
-
-std::atomic<AlignedTwoWords>& FlagImpl::TwoWordsValue() const {
-  assert(ValueStorageKind() == FlagValueStorageKind::kTwoWordsAtomic);
-  return OffsetValue<FlagTwoWordsValue>()->value;
-}
-
-// Attempts to parse supplied `value` string using parsing routine in the `flag`
-// argument. If parsing successful, this function replaces the dst with newly
-// parsed value. In case if any error is encountered in either step, the error
-// message is stored in 'err'
-std::unique_ptr<void, DynValueDeleter> FlagImpl::TryParse(
-    absl::string_view value, std::string& err) const {
-  std::unique_ptr<void, DynValueDeleter> tentative_value = MakeInitValue();
-
-  std::string parse_err;
-  if (!flags_internal::Parse(op_, value, tentative_value.get(), &parse_err)) {
-    absl::string_view err_sep = parse_err.empty() ? "" : "; ";
-    err = absl::StrCat("Illegal value '", value, "' specified for flag '",
-                       Name(), "'", err_sep, parse_err);
-    return nullptr;
-  }
-
-  return tentative_value;
-}
-
-void FlagImpl::Read(void* dst) const {
-  auto* guard = DataGuard();  // Make sure flag initialized
-  switch (ValueStorageKind()) {
-    case FlagValueStorageKind::kAlignedBuffer: {
-      absl::MutexLock l(guard);
-      flags_internal::CopyConstruct(op_, AlignedBufferValue(), dst);
-      break;
-    }
-    case FlagValueStorageKind::kOneWordAtomic: {
-      const int64_t one_word_val =
-          OneWordValue().load(std::memory_order_acquire);
-      std::memcpy(dst, &one_word_val, Sizeof(op_));
-      break;
-    }
-    case FlagValueStorageKind::kTwoWordsAtomic: {
-      const AlignedTwoWords two_words_val =
-          TwoWordsValue().load(std::memory_order_acquire);
-      std::memcpy(dst, &two_words_val, Sizeof(op_));
-      break;
-    }
-  }
-}
-
-void FlagImpl::Write(const void* src) {
-  absl::MutexLock l(DataGuard());
-
-  if (ShouldValidateFlagValue(flags_internal::FastTypeId(op_))) {
-    std::unique_ptr<void, DynValueDeleter> obj{flags_internal::Clone(op_, src),
-                                               DynValueDeleter{op_}};
-    std::string ignored_error;
-    std::string src_as_str = flags_internal::Unparse(op_, src);
-    if (!flags_internal::Parse(op_, src_as_str, obj.get(), &ignored_error)) {
-      ABSL_INTERNAL_LOG(ERROR, absl::StrCat("Attempt to set flag '", Name(),
-                                            "' to invalid value ", src_as_str));
-    }
-  }
-
-  StoreValue(src);
-}
-
-// Sets the value of the flag based on specified string `value`. If the flag
-// was successfully set to new value, it returns true. Otherwise, sets `err`
-// to indicate the error, leaves the flag unchanged, and returns false. There
-// are three ways to set the flag's value:
-//  * Update the current flag value
-//  * Update the flag's default value
-//  * Update the current flag value if it was never set before
-// The mode is selected based on 'set_mode' parameter.
-bool FlagImpl::ParseFrom(absl::string_view value, FlagSettingMode set_mode,
-                         ValueSource source, std::string& err) {
-  absl::MutexLock l(DataGuard());
-
-  switch (set_mode) {
-    case SET_FLAGS_VALUE: {
-      // set or modify the flag's value
-      auto tentative_value = TryParse(value, err);
-      if (!tentative_value) return false;
-
-      StoreValue(tentative_value.get());
-
-      if (source == kCommandLine) {
-        on_command_line_ = true;
-      }
-      break;
-    }
-    case SET_FLAG_IF_DEFAULT: {
-      // set the flag's value, but only if it hasn't been set by someone else
-      if (modified_) {
-        // TODO(rogeeff): review and fix this semantic. Currently we do not fail
-        // in this case if flag is modified. This is misleading since the flag's
-        // value is not updated even though we return true.
-        // *err = absl::StrCat(Name(), " is already set to ",
-        //                     CurrentValue(), "\n");
-        // return false;
-        return true;
-      }
-      auto tentative_value = TryParse(value, err);
-      if (!tentative_value) return false;
-
-      StoreValue(tentative_value.get());
-      break;
-    }
-    case SET_FLAGS_DEFAULT: {
-      auto tentative_value = TryParse(value, err);
-      if (!tentative_value) return false;
-
-      if (DefaultKind() == FlagDefaultKind::kDynamicValue) {
-        void* old_value = default_value_.dynamic_value;
-        default_value_.dynamic_value = tentative_value.release();
-        tentative_value.reset(old_value);
-      } else {
-        default_value_.dynamic_value = tentative_value.release();
-        def_kind_ = static_cast<uint8_t>(FlagDefaultKind::kDynamicValue);
-      }
-
-      if (!modified_) {
-        // Need to set both default value *and* current, in this case.
-        StoreValue(default_value_.dynamic_value);
-        modified_ = false;
-      }
-      break;
-    }
-  }
-
-  return true;
-}
-
-void FlagImpl::CheckDefaultValueParsingRoundtrip() const {
-  std::string v = DefaultValue();
-
-  absl::MutexLock lock(DataGuard());
-
-  auto dst = MakeInitValue();
-  std::string error;
-  if (!flags_internal::Parse(op_, v, dst.get(), &error)) {
-    ABSL_INTERNAL_LOG(
-        FATAL,
-        absl::StrCat("Flag ", Name(), " (from ", Filename(),
-                     "): string form of default value '", v,
-                     "' could not be parsed; error=", error));
-  }
-
-  // We do not compare dst to def since parsing/unparsing may make
-  // small changes, e.g., precision loss for floating point types.
-}
-
-bool FlagImpl::ValidateInputValue(absl::string_view value) const {
-  absl::MutexLock l(DataGuard());
-
-  auto obj = MakeInitValue();
-  std::string ignored_error;
-  return flags_internal::Parse(op_, value, obj.get(), &ignored_error);
-}
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
diff --git a/third_party/abseil_cpp/absl/flags/internal/flag.h b/third_party/abseil_cpp/absl/flags/internal/flag.h
deleted file mode 100644
index 370d8a02ef04..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/flag.h
+++ /dev/null
@@ -1,775 +0,0 @@
-//
-// Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_FLAG_H_
-#define ABSL_FLAGS_INTERNAL_FLAG_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <atomic>
-#include <cstring>
-#include <memory>
-#include <new>
-#include <string>
-#include <type_traits>
-#include <typeinfo>
-
-#include "absl/base/attributes.h"
-#include "absl/base/call_once.h"
-#include "absl/base/config.h"
-#include "absl/base/optimization.h"
-#include "absl/base/thread_annotations.h"
-#include "absl/flags/commandlineflag.h"
-#include "absl/flags/config.h"
-#include "absl/flags/internal/commandlineflag.h"
-#include "absl/flags/internal/registry.h"
-#include "absl/flags/marshalling.h"
-#include "absl/meta/type_traits.h"
-#include "absl/strings/string_view.h"
-#include "absl/synchronization/mutex.h"
-#include "absl/utility/utility.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-
-///////////////////////////////////////////////////////////////////////////////
-// Forward declaration of absl::Flag<T> public API.
-namespace flags_internal {
-template <typename T>
-class Flag;
-}  // namespace flags_internal
-
-#if defined(_MSC_VER) && !defined(__clang__)
-template <typename T>
-class Flag;
-#else
-template <typename T>
-using Flag = flags_internal::Flag<T>;
-#endif
-
-template <typename T>
-ABSL_MUST_USE_RESULT T GetFlag(const absl::Flag<T>& flag);
-
-template <typename T>
-void SetFlag(absl::Flag<T>* flag, const T& v);
-
-template <typename T, typename V>
-void SetFlag(absl::Flag<T>* flag, const V& v);
-
-template <typename U>
-const CommandLineFlag& GetFlagReflectionHandle(const absl::Flag<U>& f);
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag value type operations, eg., parsing, copying, etc. are provided
-// by function specific to that type with a signature matching FlagOpFn.
-
-namespace flags_internal {
-
-enum class FlagOp {
-  kAlloc,
-  kDelete,
-  kCopy,
-  kCopyConstruct,
-  kSizeof,
-  kFastTypeId,
-  kRuntimeTypeId,
-  kParse,
-  kUnparse,
-  kValueOffset,
-};
-using FlagOpFn = void* (*)(FlagOp, const void*, void*, void*);
-
-// Forward declaration for Flag value specific operations.
-template <typename T>
-void* FlagOps(FlagOp op, const void* v1, void* v2, void* v3);
-
-// Allocate aligned memory for a flag value.
-inline void* Alloc(FlagOpFn op) {
-  return op(FlagOp::kAlloc, nullptr, nullptr, nullptr);
-}
-// Deletes memory interpreting obj as flag value type pointer.
-inline void Delete(FlagOpFn op, void* obj) {
-  op(FlagOp::kDelete, nullptr, obj, nullptr);
-}
-// Copies src to dst interpreting as flag value type pointers.
-inline void Copy(FlagOpFn op, const void* src, void* dst) {
-  op(FlagOp::kCopy, src, dst, nullptr);
-}
-// Construct a copy of flag value in a location pointed by dst
-// based on src - pointer to the flag's value.
-inline void CopyConstruct(FlagOpFn op, const void* src, void* dst) {
-  op(FlagOp::kCopyConstruct, src, dst, nullptr);
-}
-// Makes a copy of flag value pointed by obj.
-inline void* Clone(FlagOpFn op, const void* obj) {
-  void* res = flags_internal::Alloc(op);
-  flags_internal::CopyConstruct(op, obj, res);
-  return res;
-}
-// Returns true if parsing of input text is successfull.
-inline bool Parse(FlagOpFn op, absl::string_view text, void* dst,
-                  std::string* error) {
-  return op(FlagOp::kParse, &text, dst, error) != nullptr;
-}
-// Returns string representing supplied value.
-inline std::string Unparse(FlagOpFn op, const void* val) {
-  std::string result;
-  op(FlagOp::kUnparse, val, &result, nullptr);
-  return result;
-}
-// Returns size of flag value type.
-inline size_t Sizeof(FlagOpFn op) {
-  // This sequence of casts reverses the sequence from
-  // `flags_internal::FlagOps()`
-  return static_cast<size_t>(reinterpret_cast<intptr_t>(
-      op(FlagOp::kSizeof, nullptr, nullptr, nullptr)));
-}
-// Returns fast type id coresponding to the value type.
-inline FlagFastTypeId FastTypeId(FlagOpFn op) {
-  return reinterpret_cast<FlagFastTypeId>(
-      op(FlagOp::kFastTypeId, nullptr, nullptr, nullptr));
-}
-// Returns fast type id coresponding to the value type.
-inline const std::type_info* RuntimeTypeId(FlagOpFn op) {
-  return reinterpret_cast<const std::type_info*>(
-      op(FlagOp::kRuntimeTypeId, nullptr, nullptr, nullptr));
-}
-// Returns offset of the field value_ from the field impl_ inside of
-// absl::Flag<T> data. Given FlagImpl pointer p you can get the
-// location of the corresponding value as:
-//      reinterpret_cast<char*>(p) + ValueOffset().
-inline ptrdiff_t ValueOffset(FlagOpFn op) {
-  // This sequence of casts reverses the sequence from
-  // `flags_internal::FlagOps()`
-  return static_cast<ptrdiff_t>(reinterpret_cast<intptr_t>(
-      op(FlagOp::kValueOffset, nullptr, nullptr, nullptr)));
-}
-
-// Returns an address of RTTI's typeid(T).
-template <typename T>
-inline const std::type_info* GenRuntimeTypeId() {
-#if defined(ABSL_FLAGS_INTERNAL_HAS_RTTI)
-  return &typeid(T);
-#else
-  return nullptr;
-#endif
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag help auxiliary structs.
-
-// This is help argument for absl::Flag encapsulating the string literal pointer
-// or pointer to function generating it as well as enum descriminating two
-// cases.
-using HelpGenFunc = std::string (*)();
-
-template <size_t N>
-struct FixedCharArray {
-  char value[N];
-
-  template <size_t... I>
-  static constexpr FixedCharArray<N> FromLiteralString(
-      absl::string_view str, absl::index_sequence<I...>) {
-    return (void)str, FixedCharArray<N>({{str[I]..., '\0'}});
-  }
-};
-
-template <typename Gen, size_t N = Gen::Value().size()>
-constexpr FixedCharArray<N + 1> HelpStringAsArray(int) {
-  return FixedCharArray<N + 1>::FromLiteralString(
-      Gen::Value(), absl::make_index_sequence<N>{});
-}
-
-template <typename Gen>
-constexpr std::false_type HelpStringAsArray(char) {
-  return std::false_type{};
-}
-
-union FlagHelpMsg {
-  constexpr explicit FlagHelpMsg(const char* help_msg) : literal(help_msg) {}
-  constexpr explicit FlagHelpMsg(HelpGenFunc help_gen) : gen_func(help_gen) {}
-
-  const char* literal;
-  HelpGenFunc gen_func;
-};
-
-enum class FlagHelpKind : uint8_t { kLiteral = 0, kGenFunc = 1 };
-
-struct FlagHelpArg {
-  FlagHelpMsg source;
-  FlagHelpKind kind;
-};
-
-extern const char kStrippedFlagHelp[];
-
-// These two HelpArg overloads allows us to select at compile time one of two
-// way to pass Help argument to absl::Flag. We'll be passing
-// AbslFlagHelpGenFor##name as Gen and integer 0 as a single argument to prefer
-// first overload if possible. If help message is evaluatable on constexpr
-// context We'll be able to make FixedCharArray out of it and we'll choose first
-// overload. In this case the help message expression is immediately evaluated
-// and is used to construct the absl::Flag. No additionl code is generated by
-// ABSL_FLAG Otherwise SFINAE kicks in and first overload is dropped from the
-// consideration, in which case the second overload will be used. The second
-// overload does not attempt to evaluate the help message expression
-// immediately and instead delays the evaluation by returing the function
-// pointer (&T::NonConst) genering the help message when necessary. This is
-// evaluatable in constexpr context, but the cost is an extra function being
-// generated in the ABSL_FLAG code.
-template <typename Gen, size_t N>
-constexpr FlagHelpArg HelpArg(const FixedCharArray<N>& value) {
-  return {FlagHelpMsg(value.value), FlagHelpKind::kLiteral};
-}
-
-template <typename Gen>
-constexpr FlagHelpArg HelpArg(std::false_type) {
-  return {FlagHelpMsg(&Gen::NonConst), FlagHelpKind::kGenFunc};
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag default value auxiliary structs.
-
-// Signature for the function generating the initial flag value (usually
-// based on default value supplied in flag's definition)
-using FlagDfltGenFunc = void (*)(void*);
-
-union FlagDefaultSrc {
-  constexpr explicit FlagDefaultSrc(FlagDfltGenFunc gen_func_arg)
-      : gen_func(gen_func_arg) {}
-
-#define ABSL_FLAGS_INTERNAL_DFLT_FOR_TYPE(T, name) \
-  T name##_value;                                  \
-  constexpr explicit FlagDefaultSrc(T value) : name##_value(value) {}  // NOLINT
-  ABSL_FLAGS_INTERNAL_BUILTIN_TYPES(ABSL_FLAGS_INTERNAL_DFLT_FOR_TYPE)
-#undef ABSL_FLAGS_INTERNAL_DFLT_FOR_TYPE
-
-  void* dynamic_value;
-  FlagDfltGenFunc gen_func;
-};
-
-enum class FlagDefaultKind : uint8_t {
-  kDynamicValue = 0,
-  kGenFunc = 1,
-  kOneWord = 2  // for default values UP to one word in size
-};
-
-struct FlagDefaultArg {
-  FlagDefaultSrc source;
-  FlagDefaultKind kind;
-};
-
-// This struct and corresponding overload to InitDefaultValue are used to
-// facilitate usage of {} as default value in ABSL_FLAG macro.
-// TODO(rogeeff): Fix handling types with explicit constructors.
-struct EmptyBraces {};
-
-template <typename T>
-constexpr T InitDefaultValue(T t) {
-  return t;
-}
-
-template <typename T>
-constexpr T InitDefaultValue(EmptyBraces) {
-  return T{};
-}
-
-template <typename ValueT, typename GenT,
-          typename std::enable_if<std::is_integral<ValueT>::value, int>::type =
-              (GenT{}, 0)>
-constexpr FlagDefaultArg DefaultArg(int) {
-  return {FlagDefaultSrc(GenT{}.value), FlagDefaultKind::kOneWord};
-}
-
-template <typename ValueT, typename GenT>
-constexpr FlagDefaultArg DefaultArg(char) {
-  return {FlagDefaultSrc(&GenT::Gen), FlagDefaultKind::kGenFunc};
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag current value auxiliary structs.
-
-constexpr int64_t UninitializedFlagValue() { return 0xababababababababll; }
-
-template <typename T>
-using FlagUseOneWordStorage = std::integral_constant<
-    bool, absl::type_traits_internal::is_trivially_copyable<T>::value &&
-              (sizeof(T) <= 8)>;
-
-#if defined(ABSL_FLAGS_INTERNAL_ATOMIC_DOUBLE_WORD)
-// Clang does not always produce cmpxchg16b instruction when alignment of a 16
-// bytes type is not 16.
-struct alignas(16) AlignedTwoWords {
-  int64_t first;
-  int64_t second;
-
-  bool IsInitialized() const {
-    return first != flags_internal::UninitializedFlagValue();
-  }
-};
-
-template <typename T>
-using FlagUseTwoWordsStorage = std::integral_constant<
-    bool, absl::type_traits_internal::is_trivially_copyable<T>::value &&
-              (sizeof(T) > 8) && (sizeof(T) <= 16)>;
-#else
-// This is actually unused and only here to avoid ifdefs in other palces.
-struct AlignedTwoWords {
-  constexpr AlignedTwoWords() noexcept : dummy() {}
-  constexpr AlignedTwoWords(int64_t, int64_t) noexcept : dummy() {}
-  char dummy;
-
-  bool IsInitialized() const {
-    std::abort();
-    return true;
-  }
-};
-
-// This trait should be type dependent, otherwise SFINAE below will fail
-template <typename T>
-using FlagUseTwoWordsStorage =
-    std::integral_constant<bool, sizeof(T) != sizeof(T)>;
-#endif
-
-template <typename T>
-using FlagUseBufferStorage =
-    std::integral_constant<bool, !FlagUseOneWordStorage<T>::value &&
-                                     !FlagUseTwoWordsStorage<T>::value>;
-
-enum class FlagValueStorageKind : uint8_t {
-  kAlignedBuffer = 0,
-  kOneWordAtomic = 1,
-  kTwoWordsAtomic = 2
-};
-
-template <typename T>
-static constexpr FlagValueStorageKind StorageKind() {
-  return FlagUseBufferStorage<T>::value
-             ? FlagValueStorageKind::kAlignedBuffer
-             : FlagUseOneWordStorage<T>::value
-                   ? FlagValueStorageKind::kOneWordAtomic
-                   : FlagValueStorageKind::kTwoWordsAtomic;
-}
-
-struct FlagOneWordValue {
-  constexpr FlagOneWordValue() : value(UninitializedFlagValue()) {}
-
-  std::atomic<int64_t> value;
-};
-
-struct FlagTwoWordsValue {
-  constexpr FlagTwoWordsValue()
-      : value(AlignedTwoWords{UninitializedFlagValue(), 0}) {}
-
-  std::atomic<AlignedTwoWords> value;
-};
-
-template <typename T,
-          FlagValueStorageKind Kind = flags_internal::StorageKind<T>()>
-struct FlagValue;
-
-template <typename T>
-struct FlagValue<T, FlagValueStorageKind::kAlignedBuffer> {
-  bool Get(T&) const { return false; }
-
-  alignas(T) char value[sizeof(T)];
-};
-
-template <typename T>
-struct FlagValue<T, FlagValueStorageKind::kOneWordAtomic> : FlagOneWordValue {
-  bool Get(T& dst) const {
-    int64_t one_word_val = value.load(std::memory_order_acquire);
-    if (ABSL_PREDICT_FALSE(one_word_val == UninitializedFlagValue())) {
-      return false;
-    }
-    std::memcpy(&dst, static_cast<const void*>(&one_word_val), sizeof(T));
-    return true;
-  }
-};
-
-template <typename T>
-struct FlagValue<T, FlagValueStorageKind::kTwoWordsAtomic> : FlagTwoWordsValue {
-  bool Get(T& dst) const {
-    AlignedTwoWords two_words_val = value.load(std::memory_order_acquire);
-    if (ABSL_PREDICT_FALSE(!two_words_val.IsInitialized())) {
-      return false;
-    }
-    std::memcpy(&dst, static_cast<const void*>(&two_words_val), sizeof(T));
-    return true;
-  }
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag callback auxiliary structs.
-
-// Signature for the mutation callback used by watched Flags
-// The callback is noexcept.
-// TODO(rogeeff): add noexcept after C++17 support is added.
-using FlagCallbackFunc = void (*)();
-
-struct FlagCallback {
-  FlagCallbackFunc func;
-  absl::Mutex guard;  // Guard for concurrent callback invocations.
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// Flag implementation, which does not depend on flag value type.
-// The class encapsulates the Flag's data and access to it.
-
-struct DynValueDeleter {
-  explicit DynValueDeleter(FlagOpFn op_arg = nullptr);
-  void operator()(void* ptr) const;
-
-  FlagOpFn op;
-};
-
-class FlagState;
-
-class FlagImpl final : public CommandLineFlag {
- public:
-  constexpr FlagImpl(const char* name, const char* filename, FlagOpFn op,
-                     FlagHelpArg help, FlagValueStorageKind value_kind,
-                     FlagDefaultArg default_arg)
-      : name_(name),
-        filename_(filename),
-        op_(op),
-        help_(help.source),
-        help_source_kind_(static_cast<uint8_t>(help.kind)),
-        value_storage_kind_(static_cast<uint8_t>(value_kind)),
-        def_kind_(static_cast<uint8_t>(default_arg.kind)),
-        modified_(false),
-        on_command_line_(false),
-        counter_(0),
-        callback_(nullptr),
-        default_value_(default_arg.source),
-        data_guard_{} {}
-
-  // Constant access methods
-  void Read(void* dst) const override ABSL_LOCKS_EXCLUDED(*DataGuard());
-
-  // Mutating access methods
-  void Write(const void* src) ABSL_LOCKS_EXCLUDED(*DataGuard());
-
-  // Interfaces to operate on callbacks.
-  void SetCallback(const FlagCallbackFunc mutation_callback)
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-  void InvokeCallback() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
-
-  // Used in read/write operations to validate source/target has correct type.
-  // For example if flag is declared as absl::Flag<int> FLAGS_foo, a call to
-  // absl::GetFlag(FLAGS_foo) validates that the type of FLAGS_foo is indeed
-  // int. To do that we pass the "assumed" type id (which is deduced from type
-  // int) as an argument `type_id`, which is in turn is validated against the
-  // type id stored in flag object by flag definition statement.
-  void AssertValidType(FlagFastTypeId type_id,
-                       const std::type_info* (*gen_rtti)()) const;
-
- private:
-  template <typename T>
-  friend class Flag;
-  friend class FlagState;
-
-  // Ensures that `data_guard_` is initialized and returns it.
-  absl::Mutex* DataGuard() const
-      ABSL_LOCK_RETURNED(reinterpret_cast<absl::Mutex*>(data_guard_));
-  // Returns heap allocated value of type T initialized with default value.
-  std::unique_ptr<void, DynValueDeleter> MakeInitValue() const
-      ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
-  // Flag initialization called via absl::call_once.
-  void Init();
-
-  // Offset value access methods. One per storage kind. These methods to not
-  // respect const correctness, so be very carefull using them.
-
-  // This is a shared helper routine which encapsulates most of the magic. Since
-  // it is only used inside the three routines below, which are defined in
-  // flag.cc, we can define it in that file as well.
-  template <typename StorageT>
-  StorageT* OffsetValue() const;
-  // This is an accessor for a value stored in an aligned buffer storage.
-  // Returns a mutable pointer to the start of a buffer.
-  void* AlignedBufferValue() const;
-  // This is an accessor for a value stored as one word atomic. Returns a
-  // mutable reference to an atomic value.
-  std::atomic<int64_t>& OneWordValue() const;
-  // This is an accessor for a value stored as two words atomic. Returns a
-  // mutable reference to an atomic value.
-  std::atomic<AlignedTwoWords>& TwoWordsValue() const;
-
-  // Attempts to parse supplied `value` string. If parsing is successful,
-  // returns new value. Otherwise returns nullptr.
-  std::unique_ptr<void, DynValueDeleter> TryParse(absl::string_view value,
-                                                  std::string& err) const
-      ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
-  // Stores the flag value based on the pointer to the source.
-  void StoreValue(const void* src) ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
-
-  FlagHelpKind HelpSourceKind() const {
-    return static_cast<FlagHelpKind>(help_source_kind_);
-  }
-  FlagValueStorageKind ValueStorageKind() const {
-    return static_cast<FlagValueStorageKind>(value_storage_kind_);
-  }
-  FlagDefaultKind DefaultKind() const
-      ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard()) {
-    return static_cast<FlagDefaultKind>(def_kind_);
-  }
-
-  // CommandLineFlag interface implementation
-  absl::string_view Name() const override;
-  std::string Filename() const override;
-  std::string Help() const override;
-  FlagFastTypeId TypeId() const override;
-  bool IsSpecifiedOnCommandLine() const override
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-  std::string DefaultValue() const override ABSL_LOCKS_EXCLUDED(*DataGuard());
-  std::string CurrentValue() const override ABSL_LOCKS_EXCLUDED(*DataGuard());
-  bool ValidateInputValue(absl::string_view value) const override
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-  void CheckDefaultValueParsingRoundtrip() const override
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-
-  // Interfaces to save and restore flags to/from persistent state.
-  // Returns current flag state or nullptr if flag does not support
-  // saving and restoring a state.
-  std::unique_ptr<FlagStateInterface> SaveState() override
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-
-  // Restores the flag state to the supplied state object. If there is
-  // nothing to restore returns false. Otherwise returns true.
-  bool RestoreState(const FlagState& flag_state)
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-
-  bool ParseFrom(absl::string_view value, FlagSettingMode set_mode,
-                 ValueSource source, std::string& error) override
-      ABSL_LOCKS_EXCLUDED(*DataGuard());
-
-  // Immutable flag's state.
-
-  // Flags name passed to ABSL_FLAG as second arg.
-  const char* const name_;
-  // The file name where ABSL_FLAG resides.
-  const char* const filename_;
-  // Type-specific operations "vtable".
-  const FlagOpFn op_;
-  // Help message literal or function to generate it.
-  const FlagHelpMsg help_;
-  // Indicates if help message was supplied as literal or generator func.
-  const uint8_t help_source_kind_ : 1;
-  // Kind of storage this flag is using for the flag's value.
-  const uint8_t value_storage_kind_ : 2;
-
-  uint8_t : 0;  // The bytes containing the const bitfields must not be
-                // shared with bytes containing the mutable bitfields.
-
-  // Mutable flag's state (guarded by `data_guard_`).
-
-  // def_kind_ is not guard by DataGuard() since it is accessed in Init without
-  // locks.
-  uint8_t def_kind_ : 2;
-  // Has this flag's value been modified?
-  bool modified_ : 1 ABSL_GUARDED_BY(*DataGuard());
-  // Has this flag been specified on command line.
-  bool on_command_line_ : 1 ABSL_GUARDED_BY(*DataGuard());
-
-  // Unique tag for absl::call_once call to initialize this flag.
-  absl::once_flag init_control_;
-
-  // Mutation counter
-  int64_t counter_ ABSL_GUARDED_BY(*DataGuard());
-  // Optional flag's callback and absl::Mutex to guard the invocations.
-  FlagCallback* callback_ ABSL_GUARDED_BY(*DataGuard());
-  // Either a pointer to the function generating the default value based on the
-  // value specified in ABSL_FLAG or pointer to the dynamically set default
-  // value via SetCommandLineOptionWithMode. def_kind_ is used to distinguish
-  // these two cases.
-  FlagDefaultSrc default_value_;
-
-  // This is reserved space for an absl::Mutex to guard flag data. It will be
-  // initialized in FlagImpl::Init via placement new.
-  // We can't use "absl::Mutex data_guard_", since this class is not literal.
-  // We do not want to use "absl::Mutex* data_guard_", since this would require
-  // heap allocation during initialization, which is both slows program startup
-  // and can fail. Using reserved space + placement new allows us to avoid both
-  // problems.
-  alignas(absl::Mutex) mutable char data_guard_[sizeof(absl::Mutex)];
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// The Flag object parameterized by the flag's value type. This class implements
-// flag reflection handle interface.
-
-template <typename T>
-class Flag {
- public:
-  constexpr Flag(const char* name, const char* filename, FlagHelpArg help,
-                 const FlagDefaultArg default_arg)
-      : impl_(name, filename, &FlagOps<T>, help,
-              flags_internal::StorageKind<T>(), default_arg),
-        value_() {}
-
-  // CommandLineFlag interface
-  absl::string_view Name() const { return impl_.Name(); }
-  std::string Filename() const { return impl_.Filename(); }
-  std::string Help() const { return impl_.Help(); }
-  // Do not use. To be removed.
-  bool IsSpecifiedOnCommandLine() const {
-    return impl_.IsSpecifiedOnCommandLine();
-  }
-  std::string DefaultValue() const { return impl_.DefaultValue(); }
-  std::string CurrentValue() const { return impl_.CurrentValue(); }
-
- private:
-  template <typename, bool>
-  friend class FlagRegistrar;
-  friend class FlagImplPeer;
-
-  T Get() const {
-    // See implementation notes in CommandLineFlag::Get().
-    union U {
-      T value;
-      U() {}
-      ~U() { value.~T(); }
-    };
-    U u;
-
-#if !defined(NDEBUG)
-    impl_.AssertValidType(base_internal::FastTypeId<T>(), &GenRuntimeTypeId<T>);
-#endif
-
-    if (!value_.Get(u.value)) impl_.Read(&u.value);
-    return std::move(u.value);
-  }
-  void Set(const T& v) {
-    impl_.AssertValidType(base_internal::FastTypeId<T>(), &GenRuntimeTypeId<T>);
-    impl_.Write(&v);
-  }
-
-  // Access to the reflection.
-  const CommandLineFlag& Reflect() const { return impl_; }
-
-  // Flag's data
-  // The implementation depends on value_ field to be placed exactly after the
-  // impl_ field, so that impl_ can figure out the offset to the value and
-  // access it.
-  FlagImpl impl_;
-  FlagValue<T> value_;
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// Trampoline for friend access
-
-class FlagImplPeer {
- public:
-  template <typename T, typename FlagType>
-  static T InvokeGet(const FlagType& flag) {
-    return flag.Get();
-  }
-  template <typename FlagType, typename T>
-  static void InvokeSet(FlagType& flag, const T& v) {
-    flag.Set(v);
-  }
-  template <typename FlagType>
-  static const CommandLineFlag& InvokeReflect(const FlagType& f) {
-    return f.Reflect();
-  }
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// Implementation of Flag value specific operations routine.
-template <typename T>
-void* FlagOps(FlagOp op, const void* v1, void* v2, void* v3) {
-  switch (op) {
-    case FlagOp::kAlloc: {
-      std::allocator<T> alloc;
-      return std::allocator_traits<std::allocator<T>>::allocate(alloc, 1);
-    }
-    case FlagOp::kDelete: {
-      T* p = static_cast<T*>(v2);
-      p->~T();
-      std::allocator<T> alloc;
-      std::allocator_traits<std::allocator<T>>::deallocate(alloc, p, 1);
-      return nullptr;
-    }
-    case FlagOp::kCopy:
-      *static_cast<T*>(v2) = *static_cast<const T*>(v1);
-      return nullptr;
-    case FlagOp::kCopyConstruct:
-      new (v2) T(*static_cast<const T*>(v1));
-      return nullptr;
-    case FlagOp::kSizeof:
-      return reinterpret_cast<void*>(static_cast<uintptr_t>(sizeof(T)));
-    case FlagOp::kFastTypeId:
-      return const_cast<void*>(base_internal::FastTypeId<T>());
-    case FlagOp::kRuntimeTypeId:
-      return const_cast<std::type_info*>(GenRuntimeTypeId<T>());
-    case FlagOp::kParse: {
-      // Initialize the temporary instance of type T based on current value in
-      // destination (which is going to be flag's default value).
-      T temp(*static_cast<T*>(v2));
-      if (!absl::ParseFlag<T>(*static_cast<const absl::string_view*>(v1), &temp,
-                              static_cast<std::string*>(v3))) {
-        return nullptr;
-      }
-      *static_cast<T*>(v2) = std::move(temp);
-      return v2;
-    }
-    case FlagOp::kUnparse:
-      *static_cast<std::string*>(v2) =
-          absl::UnparseFlag<T>(*static_cast<const T*>(v1));
-      return nullptr;
-    case FlagOp::kValueOffset: {
-      // Round sizeof(FlagImp) to a multiple of alignof(FlagValue<T>) to get the
-      // offset of the data.
-      ptrdiff_t round_to = alignof(FlagValue<T>);
-      ptrdiff_t offset =
-          (sizeof(FlagImpl) + round_to - 1) / round_to * round_to;
-      return reinterpret_cast<void*>(offset);
-    }
-  }
-  return nullptr;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// This class facilitates Flag object registration and tail expression-based
-// flag definition, for example:
-// ABSL_FLAG(int, foo, 42, "Foo help").OnUpdate(NotifyFooWatcher);
-struct FlagRegistrarEmpty {};
-template <typename T, bool do_register>
-class FlagRegistrar {
- public:
-  explicit FlagRegistrar(Flag<T>& flag) : flag_(flag) {
-    if (do_register) flags_internal::RegisterCommandLineFlag(flag_.impl_);
-  }
-
-  FlagRegistrar OnUpdate(FlagCallbackFunc cb) && {
-    flag_.impl_.SetCallback(cb);
-    return *this;
-  }
-
-  // Make the registrar "die" gracefully as an empty struct on a line where
-  // registration happens. Registrar objects are intended to live only as
-  // temporary.
-  operator FlagRegistrarEmpty() const { return {}; }  // NOLINT
-
- private:
-  Flag<T>& flag_;  // Flag being registered (not owned).
-};
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_FLAG_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/parse.h b/third_party/abseil_cpp/absl/flags/internal/parse.h
deleted file mode 100644
index de706c898470..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/parse.h
+++ /dev/null
@@ -1,59 +0,0 @@
-//
-// Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_PARSE_H_
-#define ABSL_FLAGS_INTERNAL_PARSE_H_
-
-#include <string>
-#include <vector>
-
-#include "absl/base/config.h"
-#include "absl/flags/declare.h"
-#include "absl/strings/string_view.h"
-
-ABSL_DECLARE_FLAG(std::vector<std::string>, flagfile);
-ABSL_DECLARE_FLAG(std::vector<std::string>, fromenv);
-ABSL_DECLARE_FLAG(std::vector<std::string>, tryfromenv);
-ABSL_DECLARE_FLAG(std::vector<std::string>, undefok);
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-enum class ArgvListAction { kRemoveParsedArgs, kKeepParsedArgs };
-enum class UsageFlagsAction { kHandleUsage, kIgnoreUsage };
-enum class OnUndefinedFlag {
-  kIgnoreUndefined,
-  kReportUndefined,
-  kAbortIfUndefined
-};
-
-std::vector<char*> ParseCommandLineImpl(int argc, char* argv[],
-                                        ArgvListAction arg_list_act,
-                                        UsageFlagsAction usage_flag_act,
-                                        OnUndefinedFlag on_undef_flag);
-
-// --------------------------------------------------------------------
-// Inspect original command line
-
-// Returns true if flag with specified name was either present on the original
-// command line or specified in flag file present on the original command line.
-bool WasPresentOnCommandLine(absl::string_view flag_name);
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_PARSE_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/path_util.h b/third_party/abseil_cpp/absl/flags/internal/path_util.h
deleted file mode 100644
index a6594d3347e1..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/path_util.h
+++ /dev/null
@@ -1,62 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_PATH_UTIL_H_
-#define ABSL_FLAGS_INTERNAL_PATH_UTIL_H_
-
-#include "absl/base/config.h"
-#include "absl/strings/string_view.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// A portable interface that returns the basename of the filename passed as an
-// argument. It is similar to basename(3)
-// <https://linux.die.net/man/3/basename>.
-// For example:
-//     flags_internal::Basename("a/b/prog/file.cc")
-// returns "file.cc"
-//     flags_internal::Basename("file.cc")
-// returns "file.cc"
-inline absl::string_view Basename(absl::string_view filename) {
-  auto last_slash_pos = filename.find_last_of("/\\");
-
-  return last_slash_pos == absl::string_view::npos
-             ? filename
-             : filename.substr(last_slash_pos + 1);
-}
-
-// A portable interface that returns the directory name of the filename
-// passed as an argument, including the trailing slash.
-// Returns the empty string if a slash is not found in the input file name.
-// For example:
-//      flags_internal::Package("a/b/prog/file.cc")
-// returns "a/b/prog/"
-//      flags_internal::Package("file.cc")
-// returns ""
-inline absl::string_view Package(absl::string_view filename) {
-  auto last_slash_pos = filename.find_last_of("/\\");
-
-  return last_slash_pos == absl::string_view::npos
-             ? absl::string_view()
-             : filename.substr(0, last_slash_pos + 1);
-}
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_PATH_UTIL_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/path_util_test.cc b/third_party/abseil_cpp/absl/flags/internal/path_util_test.cc
deleted file mode 100644
index 2091373c88ea..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/path_util_test.cc
+++ /dev/null
@@ -1,46 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/path_util.h"
-
-#include "gtest/gtest.h"
-
-namespace {
-
-namespace flags = absl::flags_internal;
-
-TEST(FlagsPathUtilTest, TestBasename) {
-  EXPECT_EQ(flags::Basename(""), "");
-  EXPECT_EQ(flags::Basename("a.cc"), "a.cc");
-  EXPECT_EQ(flags::Basename("dir/a.cc"), "a.cc");
-  EXPECT_EQ(flags::Basename("dir1/dir2/a.cc"), "a.cc");
-  EXPECT_EQ(flags::Basename("../dir1/dir2/a.cc"), "a.cc");
-  EXPECT_EQ(flags::Basename("/dir1/dir2/a.cc"), "a.cc");
-  EXPECT_EQ(flags::Basename("/dir1/dir2/../dir3/a.cc"), "a.cc");
-}
-
-// --------------------------------------------------------------------
-
-TEST(FlagsPathUtilTest, TestPackage) {
-  EXPECT_EQ(flags::Package(""), "");
-  EXPECT_EQ(flags::Package("a.cc"), "");
-  EXPECT_EQ(flags::Package("dir/a.cc"), "dir/");
-  EXPECT_EQ(flags::Package("dir1/dir2/a.cc"), "dir1/dir2/");
-  EXPECT_EQ(flags::Package("../dir1/dir2/a.cc"), "../dir1/dir2/");
-  EXPECT_EQ(flags::Package("/dir1/dir2/a.cc"), "/dir1/dir2/");
-  EXPECT_EQ(flags::Package("/dir1/dir2/../dir3/a.cc"), "/dir1/dir2/../dir3/");
-}
-
-}  // namespace
diff --git a/third_party/abseil_cpp/absl/flags/internal/private_handle_accessor.cc b/third_party/abseil_cpp/absl/flags/internal/private_handle_accessor.cc
deleted file mode 100644
index a7eb58b6d45f..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/private_handle_accessor.cc
+++ /dev/null
@@ -1,65 +0,0 @@
-//
-// Copyright 2020 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/private_handle_accessor.h"
-
-#include <memory>
-#include <string>
-
-#include "absl/base/config.h"
-#include "absl/flags/commandlineflag.h"
-#include "absl/flags/internal/commandlineflag.h"
-#include "absl/strings/string_view.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-FlagFastTypeId PrivateHandleAccessor::TypeId(const CommandLineFlag& flag) {
-  return flag.TypeId();
-}
-
-std::unique_ptr<FlagStateInterface> PrivateHandleAccessor::SaveState(
-    CommandLineFlag& flag) {
-  return flag.SaveState();
-}
-
-bool PrivateHandleAccessor::IsSpecifiedOnCommandLine(
-    const CommandLineFlag& flag) {
-  return flag.IsSpecifiedOnCommandLine();
-}
-
-bool PrivateHandleAccessor::ValidateInputValue(const CommandLineFlag& flag,
-                                               absl::string_view value) {
-  return flag.ValidateInputValue(value);
-}
-
-void PrivateHandleAccessor::CheckDefaultValueParsingRoundtrip(
-    const CommandLineFlag& flag) {
-  flag.CheckDefaultValueParsingRoundtrip();
-}
-
-bool PrivateHandleAccessor::ParseFrom(CommandLineFlag& flag,
-                                      absl::string_view value,
-                                      flags_internal::FlagSettingMode set_mode,
-                                      flags_internal::ValueSource source,
-                                      std::string& error) {
-  return flag.ParseFrom(value, set_mode, source, error);
-}
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
diff --git a/third_party/abseil_cpp/absl/flags/internal/private_handle_accessor.h b/third_party/abseil_cpp/absl/flags/internal/private_handle_accessor.h
deleted file mode 100644
index c64435cd6199..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/private_handle_accessor.h
+++ /dev/null
@@ -1,61 +0,0 @@
-//
-// Copyright 2020 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_PRIVATE_HANDLE_ACCESSOR_H_
-#define ABSL_FLAGS_INTERNAL_PRIVATE_HANDLE_ACCESSOR_H_
-
-#include <memory>
-#include <string>
-
-#include "absl/base/config.h"
-#include "absl/flags/commandlineflag.h"
-#include "absl/flags/internal/commandlineflag.h"
-#include "absl/strings/string_view.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// This class serves as a trampoline to access private methods of
-// CommandLineFlag. This class is intended for use exclusively internally inside
-// of the Abseil Flags implementation.
-class PrivateHandleAccessor {
- public:
-  // Access to CommandLineFlag::TypeId.
-  static FlagFastTypeId TypeId(const CommandLineFlag& flag);
-
-  // Access to CommandLineFlag::SaveState.
-  static std::unique_ptr<FlagStateInterface> SaveState(CommandLineFlag& flag);
-
-  // Access to CommandLineFlag::IsSpecifiedOnCommandLine.
-  static bool IsSpecifiedOnCommandLine(const CommandLineFlag& flag);
-
-  // Access to CommandLineFlag::ValidateInputValue.
-  static bool ValidateInputValue(const CommandLineFlag& flag,
-                                 absl::string_view value);
-
-  // Access to CommandLineFlag::CheckDefaultValueParsingRoundtrip.
-  static void CheckDefaultValueParsingRoundtrip(const CommandLineFlag& flag);
-
-  static bool ParseFrom(CommandLineFlag& flag, absl::string_view value,
-                        flags_internal::FlagSettingMode set_mode,
-                        flags_internal::ValueSource source, std::string& error);
-};
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_PRIVATE_HANDLE_ACCESSOR_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/program_name.cc b/third_party/abseil_cpp/absl/flags/internal/program_name.cc
deleted file mode 100644
index 51d698da8b31..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/program_name.cc
+++ /dev/null
@@ -1,60 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/program_name.h"
-
-#include <string>
-
-#include "absl/base/attributes.h"
-#include "absl/base/config.h"
-#include "absl/base/const_init.h"
-#include "absl/base/thread_annotations.h"
-#include "absl/flags/internal/path_util.h"
-#include "absl/strings/string_view.h"
-#include "absl/synchronization/mutex.h"
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-ABSL_CONST_INIT static absl::Mutex program_name_guard(absl::kConstInit);
-ABSL_CONST_INIT static std::string* program_name
-    ABSL_GUARDED_BY(program_name_guard) = nullptr;
-
-std::string ProgramInvocationName() {
-  absl::MutexLock l(&program_name_guard);
-
-  return program_name ? *program_name : "UNKNOWN";
-}
-
-std::string ShortProgramInvocationName() {
-  absl::MutexLock l(&program_name_guard);
-
-  return program_name ? std::string(flags_internal::Basename(*program_name))
-                      : "UNKNOWN";
-}
-
-void SetProgramInvocationName(absl::string_view prog_name_str) {
-  absl::MutexLock l(&program_name_guard);
-
-  if (!program_name)
-    program_name = new std::string(prog_name_str);
-  else
-    program_name->assign(prog_name_str.data(), prog_name_str.size());
-}
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
diff --git a/third_party/abseil_cpp/absl/flags/internal/program_name.h b/third_party/abseil_cpp/absl/flags/internal/program_name.h
deleted file mode 100644
index b99b94fe18ab..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/program_name.h
+++ /dev/null
@@ -1,50 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_PROGRAM_NAME_H_
-#define ABSL_FLAGS_INTERNAL_PROGRAM_NAME_H_
-
-#include <string>
-
-#include "absl/base/config.h"
-#include "absl/strings/string_view.h"
-
-// --------------------------------------------------------------------
-// Program name
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// Returns program invocation name or "UNKNOWN" if `SetProgramInvocationName()`
-// is never called. At the moment this is always set to argv[0] as part of
-// library initialization.
-std::string ProgramInvocationName();
-
-// Returns base name for program invocation name. For example, if
-//   ProgramInvocationName() == "a/b/mybinary"
-// then
-//   ShortProgramInvocationName() == "mybinary"
-std::string ShortProgramInvocationName();
-
-// Sets program invocation name to a new value. Should only be called once
-// during program initialization, before any threads are spawned.
-void SetProgramInvocationName(absl::string_view prog_name_str);
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_PROGRAM_NAME_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/program_name_test.cc b/third_party/abseil_cpp/absl/flags/internal/program_name_test.cc
deleted file mode 100644
index aff9f6315e4e..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/program_name_test.cc
+++ /dev/null
@@ -1,61 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/program_name.h"
-
-#include <string>
-
-#include "gtest/gtest.h"
-#include "absl/strings/match.h"
-#include "absl/strings/string_view.h"
-
-namespace {
-
-namespace flags = absl::flags_internal;
-
-TEST(FlagsPathUtilTest, TestProgamNameInterfaces) {
-  flags::SetProgramInvocationName("absl/flags/program_name_test");
-  std::string program_name = flags::ProgramInvocationName();
-  for (char& c : program_name)
-    if (c == '\\') c = '/';
-
-#if !defined(__wasm__) && !defined(__asmjs__)
-  const std::string expect_name = "absl/flags/program_name_test";
-  const std::string expect_basename = "program_name_test";
-#else
-  // For targets that generate javascript or webassembly the invocation name
-  // has the special value below.
-  const std::string expect_name = "this.program";
-  const std::string expect_basename = "this.program";
-#endif
-
-  EXPECT_TRUE(absl::EndsWith(program_name, expect_name)) << program_name;
-  EXPECT_EQ(flags::ShortProgramInvocationName(), expect_basename);
-
-  flags::SetProgramInvocationName("a/my_test");
-
-  EXPECT_EQ(flags::ProgramInvocationName(), "a/my_test");
-  EXPECT_EQ(flags::ShortProgramInvocationName(), "my_test");
-
-  absl::string_view not_null_terminated("absl/aaa/bbb");
-  not_null_terminated = not_null_terminated.substr(1, 10);
-
-  flags::SetProgramInvocationName(not_null_terminated);
-
-  EXPECT_EQ(flags::ProgramInvocationName(), "bsl/aaa/bb");
-  EXPECT_EQ(flags::ShortProgramInvocationName(), "bb");
-}
-
-}  // namespace
diff --git a/third_party/abseil_cpp/absl/flags/internal/registry.h b/third_party/abseil_cpp/absl/flags/internal/registry.h
deleted file mode 100644
index a8d9eb9cb0bb..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/registry.h
+++ /dev/null
@@ -1,97 +0,0 @@
-//
-// Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_REGISTRY_H_
-#define ABSL_FLAGS_INTERNAL_REGISTRY_H_
-
-#include <functional>
-
-#include "absl/base/config.h"
-#include "absl/flags/commandlineflag.h"
-#include "absl/flags/internal/commandlineflag.h"
-#include "absl/strings/string_view.h"
-
-// --------------------------------------------------------------------
-// Global flags registry API.
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// Executes specified visitor for each non-retired flag in the registry. While
-// callback are executed, the registry is locked and can't be changed.
-void ForEachFlag(std::function<void(CommandLineFlag&)> visitor);
-
-//-----------------------------------------------------------------------------
-
-bool RegisterCommandLineFlag(CommandLineFlag&);
-
-void FinalizeRegistry();
-
-//-----------------------------------------------------------------------------
-// Retired registrations:
-//
-// Retired flag registrations are treated specially. A 'retired' flag is
-// provided only for compatibility with automated invocations that still
-// name it.  A 'retired' flag:
-//   - is not bound to a C++ FLAGS_ reference.
-//   - has a type and a value, but that value is intentionally inaccessible.
-//   - does not appear in --help messages.
-//   - is fully supported by _all_ flag parsing routines.
-//   - consumes args normally, and complains about type mismatches in its
-//     argument.
-//   - emits a complaint but does not die (e.g. LOG(ERROR)) if it is
-//     accessed by name through the flags API for parsing or otherwise.
-//
-// The registrations for a flag happen in an unspecified order as the
-// initializers for the namespace-scope objects of a program are run.
-// Any number of weak registrations for a flag can weakly define the flag.
-// One non-weak registration will upgrade the flag from weak to non-weak.
-// Further weak registrations of a non-weak flag are ignored.
-//
-// This mechanism is designed to support moving dead flags into a
-// 'graveyard' library.  An example migration:
-//
-//   0: Remove references to this FLAGS_flagname in the C++ codebase.
-//   1: Register as 'retired' in old_lib.
-//   2: Make old_lib depend on graveyard.
-//   3: Add a redundant 'retired' registration to graveyard.
-//   4: Remove the old_lib 'retired' registration.
-//   5: Eventually delete the graveyard registration entirely.
-//
-
-// Retire flag with name "name" and type indicated by ops.
-void Retire(const char* name, FlagFastTypeId type_id, char* buf);
-
-constexpr size_t kRetiredFlagObjSize = 3 * sizeof(void*);
-constexpr size_t kRetiredFlagObjAlignment = alignof(void*);
-
-// Registered a retired flag with name 'flag_name' and type 'T'.
-template <typename T>
-class RetiredFlag {
- public:
-  void Retire(const char* flag_name) {
-    flags_internal::Retire(flag_name, base_internal::FastTypeId<T>(), buf_);
-  }
-
- private:
-  alignas(kRetiredFlagObjAlignment) char buf_[kRetiredFlagObjSize];
-};
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_REGISTRY_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/usage.cc b/third_party/abseil_cpp/absl/flags/internal/usage.cc
deleted file mode 100644
index f29d7c9b48f0..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/usage.cc
+++ /dev/null
@@ -1,524 +0,0 @@
-//
-// Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/usage.h"
-
-#include <stdint.h>
-
-#include <functional>
-#include <map>
-#include <ostream>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "absl/base/config.h"
-#include "absl/flags/commandlineflag.h"
-#include "absl/flags/flag.h"
-#include "absl/flags/internal/flag.h"
-#include "absl/flags/internal/path_util.h"
-#include "absl/flags/internal/private_handle_accessor.h"
-#include "absl/flags/internal/program_name.h"
-#include "absl/flags/internal/registry.h"
-#include "absl/flags/usage_config.h"
-#include "absl/strings/str_cat.h"
-#include "absl/strings/str_split.h"
-#include "absl/strings/string_view.h"
-
-// Dummy global variables to prevent anyone else defining these.
-bool FLAGS_help = false;
-bool FLAGS_helpfull = false;
-bool FLAGS_helpshort = false;
-bool FLAGS_helppackage = false;
-bool FLAGS_version = false;
-bool FLAGS_only_check_args = false;
-bool FLAGS_helpon = false;
-bool FLAGS_helpmatch = false;
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-namespace {
-
-using PerFlagFilter = std::function<bool(const absl::CommandLineFlag&)>;
-
-// Maximum length size in a human readable format.
-constexpr size_t kHrfMaxLineLength = 80;
-
-// This class is used to emit an XML element with `tag` and `text`.
-// It adds opening and closing tags and escapes special characters in the text.
-// For example:
-// std::cout << XMLElement("title", "Milk & Cookies");
-// prints "<title>Milk &amp; Cookies</title>"
-class XMLElement {
- public:
-  XMLElement(absl::string_view tag, absl::string_view txt)
-      : tag_(tag), txt_(txt) {}
-
-  friend std::ostream& operator<<(std::ostream& out,
-                                  const XMLElement& xml_elem) {
-    out << "<" << xml_elem.tag_ << ">";
-
-    for (auto c : xml_elem.txt_) {
-      switch (c) {
-        case '"':
-          out << "&quot;";
-          break;
-        case '\'':
-          out << "&apos;";
-          break;
-        case '&':
-          out << "&amp;";
-          break;
-        case '<':
-          out << "&lt;";
-          break;
-        case '>':
-          out << "&gt;";
-          break;
-        default:
-          out << c;
-          break;
-      }
-    }
-
-    return out << "</" << xml_elem.tag_ << ">";
-  }
-
- private:
-  absl::string_view tag_;
-  absl::string_view txt_;
-};
-
-// --------------------------------------------------------------------
-// Helper class to pretty-print info about a flag.
-
-class FlagHelpPrettyPrinter {
- public:
-  // Pretty printer holds on to the std::ostream& reference to direct an output
-  // to that stream.
-  FlagHelpPrettyPrinter(size_t max_line_len, size_t min_line_len,
-                        size_t wrapped_line_indent, std::ostream& out)
-      : out_(out),
-        max_line_len_(max_line_len),
-        min_line_len_(min_line_len),
-        wrapped_line_indent_(wrapped_line_indent),
-        line_len_(0),
-        first_line_(true) {}
-
-  void Write(absl::string_view str, bool wrap_line = false) {
-    // Empty string - do nothing.
-    if (str.empty()) return;
-
-    std::vector<absl::string_view> tokens;
-    if (wrap_line) {
-      for (auto line : absl::StrSplit(str, absl::ByAnyChar("\n\r"))) {
-        if (!tokens.empty()) {
-          // Keep line separators in the input string.
-          tokens.push_back("\n");
-        }
-        for (auto token :
-             absl::StrSplit(line, absl::ByAnyChar(" \t"), absl::SkipEmpty())) {
-          tokens.push_back(token);
-        }
-      }
-    } else {
-      tokens.push_back(str);
-    }
-
-    for (auto token : tokens) {
-      bool new_line = (line_len_ == 0);
-
-      // Respect line separators in the input string.
-      if (token == "\n") {
-        EndLine();
-        continue;
-      }
-
-      // Write the token, ending the string first if necessary/possible.
-      if (!new_line &&
-          (line_len_ + static_cast<int>(token.size()) >= max_line_len_)) {
-        EndLine();
-        new_line = true;
-      }
-
-      if (new_line) {
-        StartLine();
-      } else {
-        out_ << ' ';
-        ++line_len_;
-      }
-
-      out_ << token;
-      line_len_ += token.size();
-    }
-  }
-
-  void StartLine() {
-    if (first_line_) {
-      line_len_ = min_line_len_;
-      first_line_ = false;
-    } else {
-      line_len_ = min_line_len_ + wrapped_line_indent_;
-    }
-    out_ << std::string(line_len_, ' ');
-  }
-  void EndLine() {
-    out_ << '\n';
-    line_len_ = 0;
-  }
-
- private:
-  std::ostream& out_;
-  const size_t max_line_len_;
-  const size_t min_line_len_;
-  const size_t wrapped_line_indent_;
-  size_t line_len_;
-  bool first_line_;
-};
-
-void FlagHelpHumanReadable(const CommandLineFlag& flag, std::ostream& out) {
-  FlagHelpPrettyPrinter printer(kHrfMaxLineLength, 4, 2, out);
-
-  // Flag name.
-  printer.Write(absl::StrCat("--", flag.Name()));
-
-  // Flag help.
-  printer.Write(absl::StrCat("(", flag.Help(), ");"), /*wrap_line=*/true);
-
-  // The listed default value will be the actual default from the flag
-  // definition in the originating source file, unless the value has
-  // subsequently been modified using SetCommandLineOption() with mode
-  // SET_FLAGS_DEFAULT.
-  std::string dflt_val = flag.DefaultValue();
-  std::string curr_val = flag.CurrentValue();
-  bool is_modified = curr_val != dflt_val;
-
-  if (flag.IsOfType<std::string>()) {
-    dflt_val = absl::StrCat("\"", dflt_val, "\"");
-  }
-  printer.Write(absl::StrCat("default: ", dflt_val, ";"));
-
-  if (is_modified) {
-    if (flag.IsOfType<std::string>()) {
-      curr_val = absl::StrCat("\"", curr_val, "\"");
-    }
-    printer.Write(absl::StrCat("currently: ", curr_val, ";"));
-  }
-
-  printer.EndLine();
-}
-
-// Shows help for every filename which matches any of the filters
-// If filters are empty, shows help for every file.
-// If a flag's help message has been stripped (e.g. by adding '#define
-// STRIP_FLAG_HELP 1' then this flag will not be displayed by '--help'
-// and its variants.
-void FlagsHelpImpl(std::ostream& out, PerFlagFilter filter_cb,
-                   HelpFormat format, absl::string_view program_usage_message) {
-  if (format == HelpFormat::kHumanReadable) {
-    out << flags_internal::ShortProgramInvocationName() << ": "
-        << program_usage_message << "\n\n";
-  } else {
-    // XML schema is not a part of our public API for now.
-    out << "<?xml version=\"1.0\"?>\n"
-        << "<!-- This output should be used with care. We do not report type "
-           "names for flags with user defined types -->\n"
-        << "<!-- Prefer flag only_check_args for validating flag inputs -->\n"
-        // The document.
-        << "<AllFlags>\n"
-        // The program name and usage.
-        << XMLElement("program", flags_internal::ShortProgramInvocationName())
-        << '\n'
-        << XMLElement("usage", program_usage_message) << '\n';
-  }
-
-  // Map of package name to
-  //   map of file name to
-  //     vector of flags in the file.
-  // This map is used to output matching flags grouped by package and file
-  // name.
-  std::map<std::string,
-           std::map<std::string, std::vector<const absl::CommandLineFlag*>>>
-      matching_flags;
-
-  flags_internal::ForEachFlag([&](absl::CommandLineFlag& flag) {
-    // Ignore retired flags.
-    if (flag.IsRetired()) return;
-
-    // If the flag has been stripped, pretend that it doesn't exist.
-    if (flag.Help() == flags_internal::kStrippedFlagHelp) return;
-
-    // Make sure flag satisfies the filter
-    if (!filter_cb(flag)) return;
-
-    std::string flag_filename = flag.Filename();
-
-    matching_flags[std::string(flags_internal::Package(flag_filename))]
-                  [flag_filename]
-                      .push_back(&flag);
-  });
-
-  absl::string_view package_separator;  // controls blank lines between packages
-  absl::string_view file_separator;     // controls blank lines between files
-  for (const auto& package : matching_flags) {
-    if (format == HelpFormat::kHumanReadable) {
-      out << package_separator;
-      package_separator = "\n\n";
-    }
-
-    file_separator = "";
-    for (const auto& flags_in_file : package.second) {
-      if (format == HelpFormat::kHumanReadable) {
-        out << file_separator << "  Flags from " << flags_in_file.first
-            << ":\n";
-        file_separator = "\n";
-      }
-
-      for (const auto* flag : flags_in_file.second) {
-        flags_internal::FlagHelp(out, *flag, format);
-      }
-    }
-  }
-
-  if (format == HelpFormat::kHumanReadable) {
-    FlagHelpPrettyPrinter printer(kHrfMaxLineLength, 0, 0, out);
-
-    if (filter_cb && matching_flags.empty()) {
-      printer.Write("No flags matched.\n", true);
-    }
-    printer.EndLine();
-    printer.Write(
-        "Try --helpfull to get a list of all flags or --help=substring "
-        "shows help for flags which include specified substring in either "
-        "in the name, or description or path.\n",
-        true);
-  } else {
-    // The end of the document.
-    out << "</AllFlags>\n";
-  }
-}
-
-void FlagsHelpImpl(std::ostream& out,
-                   flags_internal::FlagKindFilter filename_filter_cb,
-                   HelpFormat format, absl::string_view program_usage_message) {
-  FlagsHelpImpl(
-      out,
-      [&](const absl::CommandLineFlag& flag) {
-        return filename_filter_cb && filename_filter_cb(flag.Filename());
-      },
-      format, program_usage_message);
-}
-
-}  // namespace
-
-// --------------------------------------------------------------------
-// Produces the help message describing specific flag.
-void FlagHelp(std::ostream& out, const CommandLineFlag& flag,
-              HelpFormat format) {
-  if (format == HelpFormat::kHumanReadable)
-    flags_internal::FlagHelpHumanReadable(flag, out);
-}
-
-// --------------------------------------------------------------------
-// Produces the help messages for all flags matching the filename filter.
-// If filter is empty produces help messages for all flags.
-void FlagsHelp(std::ostream& out, absl::string_view filter, HelpFormat format,
-               absl::string_view program_usage_message) {
-  flags_internal::FlagKindFilter filter_cb = [&](absl::string_view filename) {
-    return filter.empty() || filename.find(filter) != absl::string_view::npos;
-  };
-  flags_internal::FlagsHelpImpl(out, filter_cb, format, program_usage_message);
-}
-
-// --------------------------------------------------------------------
-// Checks all the 'usage' command line flags to see if any have been set.
-// If so, handles them appropriately.
-int HandleUsageFlags(std::ostream& out,
-                     absl::string_view program_usage_message) {
-  switch (GetFlagsHelpMode()) {
-    case HelpMode::kNone:
-      break;
-    case HelpMode::kImportant:
-      flags_internal::FlagsHelpImpl(
-          out, flags_internal::GetUsageConfig().contains_help_flags,
-          GetFlagsHelpFormat(), program_usage_message);
-      return 1;
-
-    case HelpMode::kShort:
-      flags_internal::FlagsHelpImpl(
-          out, flags_internal::GetUsageConfig().contains_helpshort_flags,
-          GetFlagsHelpFormat(), program_usage_message);
-      return 1;
-
-    case HelpMode::kFull:
-      flags_internal::FlagsHelp(out, "", GetFlagsHelpFormat(),
-                                program_usage_message);
-      return 1;
-
-    case HelpMode::kPackage:
-      flags_internal::FlagsHelpImpl(
-          out, flags_internal::GetUsageConfig().contains_helppackage_flags,
-          GetFlagsHelpFormat(), program_usage_message);
-
-      return 1;
-
-    case HelpMode::kMatch: {
-      std::string substr = GetFlagsHelpMatchSubstr();
-      if (substr.empty()) {
-        // show all options
-        flags_internal::FlagsHelp(out, substr, GetFlagsHelpFormat(),
-                                  program_usage_message);
-      } else {
-        auto filter_cb = [&substr](const absl::CommandLineFlag& flag) {
-          if (absl::StrContains(flag.Name(), substr)) return true;
-          if (absl::StrContains(flag.Filename(), substr)) return true;
-          if (absl::StrContains(flag.Help(), substr)) return true;
-
-          return false;
-        };
-        flags_internal::FlagsHelpImpl(
-            out, filter_cb, HelpFormat::kHumanReadable, program_usage_message);
-      }
-
-      return 1;
-    }
-    case HelpMode::kVersion:
-      if (flags_internal::GetUsageConfig().version_string)
-        out << flags_internal::GetUsageConfig().version_string();
-      // Unlike help, we may be asking for version in a script, so return 0
-      return 0;
-
-    case HelpMode::kOnlyCheckArgs:
-      return 0;
-  }
-
-  return -1;
-}
-
-// --------------------------------------------------------------------
-// Globals representing usage reporting flags
-
-namespace {
-
-ABSL_CONST_INIT absl::Mutex help_attributes_guard(absl::kConstInit);
-ABSL_CONST_INIT std::string* match_substr
-    ABSL_GUARDED_BY(help_attributes_guard) = nullptr;
-ABSL_CONST_INIT HelpMode help_mode ABSL_GUARDED_BY(help_attributes_guard) =
-    HelpMode::kNone;
-ABSL_CONST_INIT HelpFormat help_format ABSL_GUARDED_BY(help_attributes_guard) =
-    HelpFormat::kHumanReadable;
-
-}  // namespace
-
-std::string GetFlagsHelpMatchSubstr() {
-  absl::MutexLock l(&help_attributes_guard);
-  if (match_substr == nullptr) return "";
-  return *match_substr;
-}
-
-void SetFlagsHelpMatchSubstr(absl::string_view substr) {
-  absl::MutexLock l(&help_attributes_guard);
-  if (match_substr == nullptr) match_substr = new std::string;
-  match_substr->assign(substr.data(), substr.size());
-}
-
-HelpMode GetFlagsHelpMode() {
-  absl::MutexLock l(&help_attributes_guard);
-  // Refer to dummy variales to prevent linker dropping them
-  if (FLAGS_help || FLAGS_helpfull || FLAGS_helpshort || FLAGS_helppackage ||
-      FLAGS_version || FLAGS_only_check_args || FLAGS_helpon ||
-      FLAGS_helpmatch) {
-    help_mode = HelpMode::kNone;
-  }
-  return help_mode;
-}
-
-void SetFlagsHelpMode(HelpMode mode) {
-  absl::MutexLock l(&help_attributes_guard);
-  help_mode = mode;
-}
-
-HelpFormat GetFlagsHelpFormat() {
-  absl::MutexLock l(&help_attributes_guard);
-  return help_format;
-}
-
-void SetFlagsHelpFormat(HelpFormat format) {
-  absl::MutexLock l(&help_attributes_guard);
-  help_format = format;
-}
-
-// Deduces usage flags from the input argument in a form --name=value or
-// --name. argument is already split into name and value before we call this
-// function.
-bool DeduceUsageFlags(absl::string_view name, absl::string_view value) {
-  if (absl::ConsumePrefix(&name, "help")) {
-    if (name == "") {
-      if (value.empty()) {
-        SetFlagsHelpMode(HelpMode::kImportant);
-      } else {
-        SetFlagsHelpMode(HelpMode::kMatch);
-        SetFlagsHelpMatchSubstr(value);
-      }
-      return true;
-    }
-
-    if (name == "match") {
-      SetFlagsHelpMode(HelpMode::kMatch);
-      SetFlagsHelpMatchSubstr(value);
-      return true;
-    }
-
-    if (name == "on") {
-      SetFlagsHelpMode(HelpMode::kMatch);
-      SetFlagsHelpMatchSubstr(absl::StrCat("/", value, "."));
-      return true;
-    }
-
-    if (name == "full") {
-      SetFlagsHelpMode(HelpMode::kFull);
-      return true;
-    }
-
-    if (name == "short") {
-      SetFlagsHelpMode(HelpMode::kShort);
-      return true;
-    }
-
-    if (name == "package") {
-      SetFlagsHelpMode(HelpMode::kPackage);
-      return true;
-    }
-
-    return false;
-  }
-
-  if (name == "version") {
-    SetFlagsHelpMode(HelpMode::kVersion);
-    return true;
-  }
-
-  if (name == "only_check_args") {
-    SetFlagsHelpMode(HelpMode::kOnlyCheckArgs);
-    return true;
-  }
-
-  return false;
-}
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
diff --git a/third_party/abseil_cpp/absl/flags/internal/usage.h b/third_party/abseil_cpp/absl/flags/internal/usage.h
deleted file mode 100644
index c0bcac57628a..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/usage.h
+++ /dev/null
@@ -1,104 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef ABSL_FLAGS_INTERNAL_USAGE_H_
-#define ABSL_FLAGS_INTERNAL_USAGE_H_
-
-#include <iosfwd>
-#include <string>
-
-#include "absl/base/config.h"
-#include "absl/flags/commandlineflag.h"
-#include "absl/flags/declare.h"
-#include "absl/strings/string_view.h"
-
-// --------------------------------------------------------------------
-// Usage reporting interfaces
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace flags_internal {
-
-// The format to report the help messages in.
-enum class HelpFormat {
-  kHumanReadable,
-};
-
-// Streams the help message describing `flag` to `out`.
-// The default value for `flag` is included in the output.
-void FlagHelp(std::ostream& out, const CommandLineFlag& flag,
-              HelpFormat format = HelpFormat::kHumanReadable);
-
-// Produces the help messages for all flags matching the filter. A flag matches
-// the filter if it is defined in a file with a filename which includes
-// filter string as a substring. You can use '/' and '.' to restrict the
-// matching to a specific file names. For example:
-//   FlagsHelp(out, "/path/to/file.");
-// restricts help to only flags which resides in files named like:
-//  .../path/to/file.<ext>
-// for any extension 'ext'. If the filter is empty this function produces help
-// messages for all flags.
-void FlagsHelp(std::ostream& out, absl::string_view filter,
-               HelpFormat format, absl::string_view program_usage_message);
-
-// --------------------------------------------------------------------
-
-// If any of the 'usage' related command line flags (listed on the bottom of
-// this file) has been set this routine produces corresponding help message in
-// the specified output stream and returns:
-//  0 - if "version" or "only_check_flags" flags were set and handled.
-//  1 - if some other 'usage' related flag was set and handled.
-// -1 - if no usage flags were set on a commmand line.
-// Non negative return values are expected to be used as an exit code for a
-// binary.
-int HandleUsageFlags(std::ostream& out,
-                     absl::string_view program_usage_message);
-
-// --------------------------------------------------------------------
-// Globals representing usage reporting flags
-
-enum class HelpMode {
-  kNone,
-  kImportant,
-  kShort,
-  kFull,
-  kPackage,
-  kMatch,
-  kVersion,
-  kOnlyCheckArgs
-};
-
-// Returns substring to filter help output (--help=substr argument)
-std::string GetFlagsHelpMatchSubstr();
-// Returns the requested help mode.
-HelpMode GetFlagsHelpMode();
-// Returns the requested help format.
-HelpFormat GetFlagsHelpFormat();
-
-// These are corresponding setters to the attributes above.
-void SetFlagsHelpMatchSubstr(absl::string_view);
-void SetFlagsHelpMode(HelpMode);
-void SetFlagsHelpFormat(HelpFormat);
-
-// Deduces usage flags from the input argument in a form --name=value or
-// --name. argument is already split into name and value before we call this
-// function.
-bool DeduceUsageFlags(absl::string_view name, absl::string_view value);
-
-}  // namespace flags_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_FLAGS_INTERNAL_USAGE_H_
diff --git a/third_party/abseil_cpp/absl/flags/internal/usage_test.cc b/third_party/abseil_cpp/absl/flags/internal/usage_test.cc
deleted file mode 100644
index b5c2487da577..000000000000
--- a/third_party/abseil_cpp/absl/flags/internal/usage_test.cc
+++ /dev/null
@@ -1,493 +0,0 @@
-//
-//  Copyright 2019 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/flags/internal/usage.h"
-
-#include <stdint.h>
-
-#include <sstream>
-#include <string>
-
-#include "gtest/gtest.h"
-#include "absl/flags/flag.h"
-#include "absl/flags/internal/parse.h"
-#include "absl/flags/internal/path_util.h"
-#include "absl/flags/internal/program_name.h"
-#include "absl/flags/reflection.h"
-#include "absl/flags/usage.h"
-#include "absl/flags/usage_config.h"
-#include "absl/strings/match.h"
-#include "absl/strings/string_view.h"
-
-ABSL_FLAG(int, usage_reporting_test_flag_01, 101,
-          "usage_reporting_test_flag_01 help message");
-ABSL_FLAG(bool, usage_reporting_test_flag_02, false,
-          "usage_reporting_test_flag_02 help message");
-ABSL_FLAG(double, usage_reporting_test_flag_03, 1.03,
-          "usage_reporting_test_flag_03 help message");
-ABSL_FLAG(int64_t, usage_reporting_test_flag_04, 1000000000000004L,
-          "usage_reporting_test_flag_04 help message");
-
-static const char kTestUsageMessage[] = "Custom usage message";
-
-struct UDT {
-  UDT() = default;
-  UDT(const UDT&) = default;
-};
-bool AbslParseFlag(absl::string_view, UDT*, std::string*) { return true; }
-std::string AbslUnparseFlag(const UDT&) { return "UDT{}"; }
-
-ABSL_FLAG(UDT, usage_reporting_test_flag_05, {},
-          "usage_reporting_test_flag_05 help message");
-
-ABSL_FLAG(
-    std::string, usage_reporting_test_flag_06, {},
-    "usage_reporting_test_flag_06 help message.\n"
-    "\n"
-    "Some more help.\n"
-    "Even more long long long long long long long long long long long long "
-    "help message.");
-
-namespace {
-
-namespace flags = absl::flags_internal;
-
-static std::string NormalizeFileName(absl::string_view fname) {
-#ifdef _WIN32
-  std::string normalized(fname);
-  std::replace(normalized.begin(), normalized.end(), '\\', '/');
-  fname = normalized;
-#endif
-
-  auto absl_pos = fname.rfind("absl/");
-  if (absl_pos != absl::string_view::npos) {
-    fname = fname.substr(absl_pos);
-  }
-  return std::string(fname);
-}
-
-class UsageReportingTest : public testing::Test {
- protected:
-  UsageReportingTest() {
-    // Install default config for the use on this unit test.
-    // Binary may install a custom config before tests are run.
-    absl::FlagsUsageConfig default_config;
-    default_config.normalize_filename = &NormalizeFileName;
-    absl::SetFlagsUsageConfig(default_config);
-  }
-  ~UsageReportingTest() override {
-    flags::SetFlagsHelpMode(flags::HelpMode::kNone);
-    flags::SetFlagsHelpMatchSubstr("");
-    flags::SetFlagsHelpFormat(flags::HelpFormat::kHumanReadable);
-  }
-
- private:
-  absl::FlagSaver flag_saver_;
-};
-
-// --------------------------------------------------------------------
-
-using UsageReportingDeathTest = UsageReportingTest;
-
-TEST_F(UsageReportingDeathTest, TestSetProgramUsageMessage) {
-  EXPECT_EQ(absl::ProgramUsageMessage(), kTestUsageMessage);
-
-#ifndef _WIN32
-  // TODO(rogeeff): figure out why this does not work on Windows.
-  EXPECT_DEATH_IF_SUPPORTED(
-      absl::SetProgramUsageMessage("custom usage message"),
-      ".*SetProgramUsageMessage\\(\\) called twice.*");
-#endif
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_01) {
-  const auto* flag = absl::FindCommandLineFlag("usage_reporting_test_flag_01");
-  std::stringstream test_buf;
-
-  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
-  EXPECT_EQ(
-      test_buf.str(),
-      R"(    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-)");
-}
-
-TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_02) {
-  const auto* flag = absl::FindCommandLineFlag("usage_reporting_test_flag_02");
-  std::stringstream test_buf;
-
-  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
-  EXPECT_EQ(
-      test_buf.str(),
-      R"(    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-)");
-}
-
-TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_03) {
-  const auto* flag = absl::FindCommandLineFlag("usage_reporting_test_flag_03");
-  std::stringstream test_buf;
-
-  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
-  EXPECT_EQ(
-      test_buf.str(),
-      R"(    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-)");
-}
-
-TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_04) {
-  const auto* flag = absl::FindCommandLineFlag("usage_reporting_test_flag_04");
-  std::stringstream test_buf;
-
-  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
-  EXPECT_EQ(
-      test_buf.str(),
-      R"(    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-)");
-}
-
-TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_05) {
-  const auto* flag = absl::FindCommandLineFlag("usage_reporting_test_flag_05");
-  std::stringstream test_buf;
-
-  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
-  EXPECT_EQ(
-      test_buf.str(),
-      R"(    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-)");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestFlagsHelpHRF) {
-  std::string usage_test_flags_out =
-      R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)";
-
-  std::stringstream test_buf_01;
-  flags::FlagsHelp(test_buf_01, "usage_test.cc",
-                   flags::HelpFormat::kHumanReadable, kTestUsageMessage);
-  EXPECT_EQ(test_buf_01.str(), usage_test_flags_out);
-
-  std::stringstream test_buf_02;
-  flags::FlagsHelp(test_buf_02, "flags/internal/usage_test.cc",
-                   flags::HelpFormat::kHumanReadable, kTestUsageMessage);
-  EXPECT_EQ(test_buf_02.str(), usage_test_flags_out);
-
-  std::stringstream test_buf_03;
-  flags::FlagsHelp(test_buf_03, "usage_test", flags::HelpFormat::kHumanReadable,
-                   kTestUsageMessage);
-  EXPECT_EQ(test_buf_03.str(), usage_test_flags_out);
-
-  std::stringstream test_buf_04;
-  flags::FlagsHelp(test_buf_04, "flags/invalid_file_name.cc",
-                   flags::HelpFormat::kHumanReadable, kTestUsageMessage);
-  EXPECT_EQ(test_buf_04.str(),
-            R"(usage_test: Custom usage message
-
-No flags matched.
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-
-  std::stringstream test_buf_05;
-  flags::FlagsHelp(test_buf_05, "", flags::HelpFormat::kHumanReadable,
-                   kTestUsageMessage);
-  std::string test_out = test_buf_05.str();
-  absl::string_view test_out_str(test_out);
-  EXPECT_TRUE(
-      absl::StartsWith(test_out_str, "usage_test: Custom usage message"));
-  EXPECT_TRUE(absl::StrContains(
-      test_out_str, "Flags from absl/flags/internal/usage_test.cc:"));
-  EXPECT_TRUE(
-      absl::StrContains(test_out_str, "-usage_reporting_test_flag_01 "));
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestNoUsageFlags) {
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), -1);
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_helpshort) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kShort);
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf.str(),
-            R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_help_simple) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kImportant);
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf.str(),
-            R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_help_one_flag) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kMatch);
-  flags::SetFlagsHelpMatchSubstr("usage_reporting_test_flag_06");
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf.str(),
-            R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_help_multiple_flag) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kMatch);
-  flags::SetFlagsHelpMatchSubstr("test_flag");
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf.str(),
-            R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_helppackage) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kPackage);
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf.str(),
-            R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_version) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kVersion);
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 0);
-#ifndef NDEBUG
-  EXPECT_EQ(test_buf.str(), "usage_test\nDebug build (NDEBUG not #defined)\n");
-#else
-  EXPECT_EQ(test_buf.str(), "usage_test\n");
-#endif
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_only_check_args) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kOnlyCheckArgs);
-
-  std::stringstream test_buf;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf, kTestUsageMessage), 0);
-  EXPECT_EQ(test_buf.str(), "");
-}
-
-// --------------------------------------------------------------------
-
-TEST_F(UsageReportingTest, TestUsageFlag_helpon) {
-  flags::SetFlagsHelpMode(flags::HelpMode::kMatch);
-  flags::SetFlagsHelpMatchSubstr("/bla-bla.");
-
-  std::stringstream test_buf_01;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf_01, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf_01.str(),
-            R"(usage_test: Custom usage message
-
-No flags matched.
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-
-  flags::SetFlagsHelpMatchSubstr("/usage_test.");
-
-  std::stringstream test_buf_02;
-  EXPECT_EQ(flags::HandleUsageFlags(test_buf_02, kTestUsageMessage), 1);
-  EXPECT_EQ(test_buf_02.str(),
-            R"(usage_test: Custom usage message
-
-  Flags from absl/flags/internal/usage_test.cc:
-    --usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
-      default: 101;
-    --usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
-      default: false;
-    --usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
-      default: 1.03;
-    --usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
-      default: 1000000000000004;
-    --usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
-      default: UDT{};
-    --usage_reporting_test_flag_06 (usage_reporting_test_flag_06 help message.
-
-      Some more help.
-      Even more long long long long long long long long long long long long help
-      message.); default: "";
-
-Try --helpfull to get a list of all flags or --help=substring shows help for
-flags which include specified substring in either in the name, or description or
-path.
-)");
-}
-
-// --------------------------------------------------------------------
-
-}  // namespace
-
-int main(int argc, char* argv[]) {
-  (void)absl::GetFlag(FLAGS_undefok);  // Force linking of parse.cc
-  flags::SetProgramInvocationName("usage_test");
-  absl::SetProgramUsageMessage(kTestUsageMessage);
-  ::testing::InitGoogleTest(&argc, argv);
-
-  return RUN_ALL_TESTS();
-}