EIC code displayed by LXR master/​include/​absl/​flags/​internal/​registry.h	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2025-01-30 09:31:43

 //
 // 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&, const char* filename);
 
 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_

This page was automatically generated by the 2.3.7 LXR engine. The LXR team