diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/flags/reflection.cc')
-rw-r--r-- | third_party/abseil_cpp/absl/flags/reflection.cc | 337 |
1 files changed, 0 insertions, 337 deletions
diff --git a/third_party/abseil_cpp/absl/flags/reflection.cc b/third_party/abseil_cpp/absl/flags/reflection.cc deleted file mode 100644 index c976d4679601..000000000000 --- a/third_party/abseil_cpp/absl/flags/reflection.cc +++ /dev/null @@ -1,337 +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/reflection.h" - -#include <assert.h> - -#include <atomic> -#include <map> -#include <string> - -#include "absl/base/config.h" -#include "absl/base/thread_annotations.h" -#include "absl/flags/commandlineflag.h" -#include "absl/flags/internal/private_handle_accessor.h" -#include "absl/flags/internal/registry.h" -#include "absl/flags/usage_config.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 { - -// -------------------------------------------------------------------- -// FlagRegistry -// A FlagRegistry singleton object holds all flag objects indexed by their -// names so that if you know a flag's name, you can access or set it. If the -// function is named FooLocked(), you must own the registry lock before -// calling the function; otherwise, you should *not* hold the lock, and the -// function will acquire it itself if needed. -// -------------------------------------------------------------------- - -class FlagRegistry { - public: - FlagRegistry() = default; - ~FlagRegistry() = default; - - // Store a flag in this registry. Takes ownership of *flag. - void RegisterFlag(CommandLineFlag& flag); - - void Lock() ABSL_EXCLUSIVE_LOCK_FUNCTION(lock_) { lock_.Lock(); } - void Unlock() ABSL_UNLOCK_FUNCTION(lock_) { lock_.Unlock(); } - - // Returns the flag object for the specified name, or nullptr if not found. - // Will emit a warning if a 'retired' flag is specified. - CommandLineFlag* FindFlag(absl::string_view name); - - static FlagRegistry& GlobalRegistry(); // returns a singleton registry - - private: - friend class flags_internal::FlagSaverImpl; // reads all the flags in order - // to copy them - friend void ForEachFlag(std::function<void(CommandLineFlag&)> visitor); - friend void FinalizeRegistry(); - - // The map from name to flag, for FindFlag(). - using FlagMap = std::map<absl::string_view, CommandLineFlag*>; - using FlagIterator = FlagMap::iterator; - using FlagConstIterator = FlagMap::const_iterator; - FlagMap flags_; - std::vector<CommandLineFlag*> flat_flags_; - std::atomic<bool> finalized_flags_{false}; - - absl::Mutex lock_; - - // Disallow - FlagRegistry(const FlagRegistry&); - FlagRegistry& operator=(const FlagRegistry&); -}; - -namespace { - -class FlagRegistryLock { - public: - explicit FlagRegistryLock(FlagRegistry& fr) : fr_(fr) { fr_.Lock(); } - ~FlagRegistryLock() { fr_.Unlock(); } - - private: - FlagRegistry& fr_; -}; - -} // namespace - -CommandLineFlag* FlagRegistry::FindFlag(absl::string_view name) { - if (finalized_flags_.load(std::memory_order_acquire)) { - // We could save some gcus here if we make `Name()` be non-virtual. - // We could move the `const char*` name to the base class. - auto it = std::partition_point( - flat_flags_.begin(), flat_flags_.end(), - [=](CommandLineFlag* f) { return f->Name() < name; }); - if (it != flat_flags_.end() && (*it)->Name() == name) return *it; - } - - FlagRegistryLock frl(*this); - auto it = flags_.find(name); - return it != flags_.end() ? it->second : nullptr; -} - -void FlagRegistry::RegisterFlag(CommandLineFlag& flag) { - FlagRegistryLock registry_lock(*this); - - std::pair<FlagIterator, bool> ins = - flags_.insert(FlagMap::value_type(flag.Name(), &flag)); - if (ins.second == false) { // means the name was already in the map - CommandLineFlag& old_flag = *ins.first->second; - if (flag.IsRetired() != old_flag.IsRetired()) { - // All registrations must agree on the 'retired' flag. - flags_internal::ReportUsageError( - absl::StrCat( - "Retired flag '", flag.Name(), "' was defined normally in file '", - (flag.IsRetired() ? old_flag.Filename() : flag.Filename()), "'."), - true); - } else if (flags_internal::PrivateHandleAccessor::TypeId(flag) != - flags_internal::PrivateHandleAccessor::TypeId(old_flag)) { - flags_internal::ReportUsageError( - absl::StrCat("Flag '", flag.Name(), - "' was defined more than once but with " - "differing types. Defined in files '", - old_flag.Filename(), "' and '", flag.Filename(), "'."), - true); - } else if (old_flag.IsRetired()) { - return; - } else if (old_flag.Filename() != flag.Filename()) { - flags_internal::ReportUsageError( - absl::StrCat("Flag '", flag.Name(), - "' was defined more than once (in files '", - old_flag.Filename(), "' and '", flag.Filename(), "')."), - true); - } else { - flags_internal::ReportUsageError( - absl::StrCat( - "Something is wrong with flag '", flag.Name(), "' in file '", - flag.Filename(), "'. One possibility: file '", flag.Filename(), - "' is being linked both statically and dynamically into this " - "executable. e.g. some files listed as srcs to a test and also " - "listed as srcs of some shared lib deps of the same test."), - true); - } - // All cases above are fatal, except for the retired flags. - std::exit(1); - } -} - -FlagRegistry& FlagRegistry::GlobalRegistry() { - static FlagRegistry* global_registry = new FlagRegistry; - return *global_registry; -} - -// -------------------------------------------------------------------- - -void ForEachFlag(std::function<void(CommandLineFlag&)> visitor) { - FlagRegistry& registry = FlagRegistry::GlobalRegistry(); - - if (registry.finalized_flags_.load(std::memory_order_acquire)) { - for (const auto& i : registry.flat_flags_) visitor(*i); - } - - FlagRegistryLock frl(registry); - for (const auto& i : registry.flags_) visitor(*i.second); -} - -// -------------------------------------------------------------------- - -bool RegisterCommandLineFlag(CommandLineFlag& flag) { - FlagRegistry::GlobalRegistry().RegisterFlag(flag); - return true; -} - -void FinalizeRegistry() { - auto& registry = FlagRegistry::GlobalRegistry(); - FlagRegistryLock frl(registry); - if (registry.finalized_flags_.load(std::memory_order_relaxed)) { - // Was already finalized. Ignore the second time. - return; - } - registry.flat_flags_.reserve(registry.flags_.size()); - for (const auto& f : registry.flags_) { - registry.flat_flags_.push_back(f.second); - } - registry.flags_.clear(); - registry.finalized_flags_.store(true, std::memory_order_release); -} - -// -------------------------------------------------------------------- - -namespace { - -class RetiredFlagObj final : public CommandLineFlag { - public: - constexpr RetiredFlagObj(const char* name, FlagFastTypeId type_id) - : name_(name), type_id_(type_id) {} - - private: - absl::string_view Name() const override { return name_; } - std::string Filename() const override { - OnAccess(); - return "RETIRED"; - } - FlagFastTypeId TypeId() const override { return type_id_; } - std::string Help() const override { - OnAccess(); - return ""; - } - bool IsRetired() const override { return true; } - bool IsSpecifiedOnCommandLine() const override { - OnAccess(); - return false; - } - std::string DefaultValue() const override { - OnAccess(); - return ""; - } - std::string CurrentValue() const override { - OnAccess(); - return ""; - } - - // Any input is valid - bool ValidateInputValue(absl::string_view) const override { - OnAccess(); - return true; - } - - std::unique_ptr<flags_internal::FlagStateInterface> SaveState() override { - return nullptr; - } - - bool ParseFrom(absl::string_view, flags_internal::FlagSettingMode, - flags_internal::ValueSource, std::string&) override { - OnAccess(); - return false; - } - - void CheckDefaultValueParsingRoundtrip() const override { OnAccess(); } - - void Read(void*) const override { OnAccess(); } - - void OnAccess() const { - flags_internal::ReportUsageError( - absl::StrCat("Accessing retired flag '", name_, "'"), false); - } - - // Data members - const char* const name_; - const FlagFastTypeId type_id_; -}; - -} // namespace - -void Retire(const char* name, FlagFastTypeId type_id, char* buf) { - static_assert(sizeof(RetiredFlagObj) == kRetiredFlagObjSize, ""); - static_assert(alignof(RetiredFlagObj) == kRetiredFlagObjAlignment, ""); - auto* flag = ::new (static_cast<void*>(buf)) - flags_internal::RetiredFlagObj(name, type_id); - FlagRegistry::GlobalRegistry().RegisterFlag(*flag); -} - -// -------------------------------------------------------------------- - -class FlagSaverImpl { - public: - FlagSaverImpl() = default; - FlagSaverImpl(const FlagSaverImpl&) = delete; - void operator=(const FlagSaverImpl&) = delete; - - // Saves the flag states from the flag registry into this object. - // It's an error to call this more than once. - void SaveFromRegistry() { - assert(backup_registry_.empty()); // call only once! - flags_internal::ForEachFlag([&](CommandLineFlag& flag) { - if (auto flag_state = - flags_internal::PrivateHandleAccessor::SaveState(flag)) { - backup_registry_.emplace_back(std::move(flag_state)); - } - }); - } - - // Restores the saved flag states into the flag registry. - void RestoreToRegistry() { - for (const auto& flag_state : backup_registry_) { - flag_state->Restore(); - } - } - - private: - std::vector<std::unique_ptr<flags_internal::FlagStateInterface>> - backup_registry_; -}; - -} // namespace flags_internal - -FlagSaver::FlagSaver() : impl_(new flags_internal::FlagSaverImpl) { - impl_->SaveFromRegistry(); -} - -FlagSaver::~FlagSaver() { - if (!impl_) return; - - impl_->RestoreToRegistry(); - delete impl_; -} - -// -------------------------------------------------------------------- - -CommandLineFlag* FindCommandLineFlag(absl::string_view name) { - if (name.empty()) return nullptr; - flags_internal::FlagRegistry& registry = - flags_internal::FlagRegistry::GlobalRegistry(); - return registry.FindFlag(name); -} - -// -------------------------------------------------------------------- - -absl::flat_hash_map<absl::string_view, absl::CommandLineFlag*> GetAllFlags() { - absl::flat_hash_map<absl::string_view, absl::CommandLineFlag*> res; - flags_internal::ForEachFlag([&](CommandLineFlag& flag) { - if (!flag.IsRetired()) res.insert({flag.Name(), &flag}); - }); - return res; -} - -ABSL_NAMESPACE_END -} // namespace absl |