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Diffstat (limited to 'absl/flags/internal/registry.cc')
| -rw-r--r-- | absl/flags/internal/registry.cc | 350 |
1 files changed, 0 insertions, 350 deletions
diff --git a/absl/flags/internal/registry.cc b/absl/flags/internal/registry.cc deleted file mode 100644 index 3b941f04c2..0000000000 --- a/absl/flags/internal/registry.cc +++ /dev/null @@ -1,350 +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/registry.h" - -#include <assert.h> -#include <stdlib.h> - -#include <functional> -#include <map> -#include <memory> -#include <string> -#include <utility> -#include <vector> - -#include "absl/base/config.h" -#include "absl/base/internal/raw_logging.h" -#include "absl/base/thread_annotations.h" -#include "absl/flags/internal/commandlineflag.h" -#include "absl/flags/internal/private_handle_accessor.h" -#include "absl/flags/usage_config.h" -#include "absl/strings/str_cat.h" -#include "absl/strings/string_view.h" -#include "absl/synchronization/mutex.h" - -// -------------------------------------------------------------------- -// FlagRegistry implementation -// A FlagRegistry holds all flag objects indexed -// by their names so that if you know a flag's name you can access or -// set it. - -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 (as a C -// string), 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* FindFlagLocked(absl::string_view name); - - // Returns the retired flag object for the specified name, or nullptr if not - // found or not retired. Does not emit a warning. - CommandLineFlag* FindRetiredFlagLocked(absl::string_view name); - - static FlagRegistry* GlobalRegistry(); // returns a singleton registry - - private: - friend class FlagSaverImpl; // reads all the flags in order to copy them - friend void ForEachFlagUnlocked( - std::function<void(CommandLineFlag*)> visitor); - - // The map from name to flag, for FindFlagLocked(). - using FlagMap = std::map<absl::string_view, CommandLineFlag*>; - using FlagIterator = FlagMap::iterator; - using FlagConstIterator = FlagMap::const_iterator; - FlagMap flags_; - - absl::Mutex lock_; - - // Disallow - FlagRegistry(const FlagRegistry&); - FlagRegistry& operator=(const FlagRegistry&); -}; - -FlagRegistry* FlagRegistry::GlobalRegistry() { - static FlagRegistry* global_registry = new FlagRegistry; - return global_registry; -} - -namespace { - -class FlagRegistryLock { - public: - explicit FlagRegistryLock(FlagRegistry* fr) : fr_(fr) { fr_->Lock(); } - ~FlagRegistryLock() { fr_->Unlock(); } - - private: - FlagRegistry* const fr_; -}; - -void DestroyRetiredFlag(CommandLineFlag* flag); -} // namespace - -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()) { - // Retired flag can just be deleted. - DestroyRetiredFlag(flag); - 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 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); - } -} - -CommandLineFlag* FlagRegistry::FindFlagLocked(absl::string_view name) { - FlagConstIterator i = flags_.find(name); - if (i == flags_.end()) { - return nullptr; - } - - if (i->second->IsRetired()) { - flags_internal::ReportUsageError( - absl::StrCat("Accessing retired flag '", name, "'"), false); - } - - return i->second; -} - -CommandLineFlag* FlagRegistry::FindRetiredFlagLocked(absl::string_view name) { - FlagConstIterator i = flags_.find(name); - if (i == flags_.end() || !i->second->IsRetired()) { - return nullptr; - } - - return i->second; -} - -// -------------------------------------------------------------------- -// FlagSaver -// FlagSaverImpl -// This class stores the states of all flags at construct time, -// and restores all flags to that state at destruct time. -// Its major implementation challenge is that it never modifies -// pointers in the 'main' registry, so global FLAG_* vars always -// point to the right place. -// -------------------------------------------------------------------- - -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([&](flags_internal::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_; -}; - -FlagSaver::FlagSaver() : impl_(new FlagSaverImpl) { impl_->SaveFromRegistry(); } - -void FlagSaver::Ignore() { - delete impl_; - impl_ = nullptr; -} - -FlagSaver::~FlagSaver() { - if (!impl_) return; - - impl_->RestoreToRegistry(); - delete impl_; -} - -// -------------------------------------------------------------------- - -CommandLineFlag* FindCommandLineFlag(absl::string_view name) { - if (name.empty()) return nullptr; - FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); - FlagRegistryLock frl(registry); - - return registry->FindFlagLocked(name); -} - -CommandLineFlag* FindRetiredFlag(absl::string_view name) { - FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); - FlagRegistryLock frl(registry); - - return registry->FindRetiredFlagLocked(name); -} - -// -------------------------------------------------------------------- - -void ForEachFlagUnlocked(std::function<void(CommandLineFlag*)> visitor) { - FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); - for (FlagRegistry::FlagConstIterator i = registry->flags_.begin(); - i != registry->flags_.end(); ++i) { - visitor(i->second); - } -} - -void ForEachFlag(std::function<void(CommandLineFlag*)> visitor) { - FlagRegistry* const registry = FlagRegistry::GlobalRegistry(); - FlagRegistryLock frl(registry); - ForEachFlagUnlocked(visitor); -} - -// -------------------------------------------------------------------- - -bool RegisterCommandLineFlag(CommandLineFlag* flag) { - FlagRegistry::GlobalRegistry()->RegisterFlag(flag); - return true; -} - -// -------------------------------------------------------------------- - -namespace { - -class RetiredFlagObj final : public flags_internal::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 { return "RETIRED"; } - FlagFastTypeId TypeId() const override { return type_id_; } - std::string Help() const override { return ""; } - bool IsRetired() const override { return true; } - bool IsSpecifiedOnCommandLine() const override { return false; } - std::string DefaultValue() const override { return ""; } - std::string CurrentValue() const override { return ""; } - - // Any input is valid - bool ValidateInputValue(absl::string_view) const override { 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 { - return false; - } - - void CheckDefaultValueParsingRoundtrip() const override {} - - void Read(void*) const override {} - - // Data members - const char* const name_; - const FlagFastTypeId type_id_; -}; - -void DestroyRetiredFlag(flags_internal::CommandLineFlag* flag) { - assert(flag->IsRetired()); - delete static_cast<RetiredFlagObj*>(flag); -} - -} // namespace - -bool Retire(const char* name, FlagFastTypeId type_id) { - auto* flag = new flags_internal::RetiredFlagObj(name, type_id); - FlagRegistry::GlobalRegistry()->RegisterFlag(flag); - return true; -} - -// -------------------------------------------------------------------- - -bool IsRetiredFlag(absl::string_view name, bool* type_is_bool) { - assert(!name.empty()); - CommandLineFlag* flag = flags_internal::FindRetiredFlag(name); - if (flag == nullptr) { - return false; - } - assert(type_is_bool); - *type_is_bool = flag->IsOfType<bool>(); - return true; -} - -} // namespace flags_internal -ABSL_NAMESPACE_END -} // namespace absl |