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-rw-r--r--third_party/abseil_cpp/absl/flags/internal/flag.cc568
1 files changed, 0 insertions, 568 deletions
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