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author | 2020-09-18 15:55:15 -0700 | |
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committer | 2020-09-24 13:47:15 -0400 | |
commit | b56cbdd23834a65682c0b46f367f8679e83bc894 (patch) | |
tree | dacab9a64dd1a9e9668737e511d1a5420ff96001 /absl/flags/reflection.h | |
parent | b832dce8489ef7b6231384909fd9b68d5a5ff2b7 (diff) |
Abseil LTS 2020092320200923
What's New:
* `absl::StatusOr<T>` has been released. See our [blog
post](https://abseil.io/blog/2020-091021-status) for more
information.
* Abseil Flags reflection interfaces have been released.
* Abseil Flags memory usage has been significantly optimized.
* Abseil now supports a "hardened" build mode. This build mode enables
runtime checks that guard against programming errors that may lead
to security vulnerabilities.
Notable Fixes:
* Sanitizer dynamic annotations like `AnnotateRWLockCreate` that are
also defined by the compiler sanitizer implementation are no longer
also defined by Abseil.
* Sanitizer macros are now prefixed with `ABSL_` to avoid naming collisions.
* Sanitizer usage is now automatically detected and no longer requires
macros like `ADDRESS_SANITIZER` to be defined on the command line.
Breaking Changes:
* Abseil no longer contains a `dynamic_annotations` library. Users
using a supported build system (Bazel or CMake) are unaffected by
this, but users manually specifying link libraries may get an error
about a missing linker input.
Baseline: 7680a5f8efe32de4753baadbd63e74e59d95bac1
Cherry picks: None
Diffstat (limited to 'absl/flags/reflection.h')
-rw-r--r-- | absl/flags/reflection.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/absl/flags/reflection.h b/absl/flags/reflection.h new file mode 100644 index 00000000..4ce0ab6c --- /dev/null +++ b/absl/flags/reflection.h @@ -0,0 +1,90 @@ +// +// 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. +// +// ----------------------------------------------------------------------------- +// File: reflection.h +// ----------------------------------------------------------------------------- +// +// This file defines the routines to access and operate on an Abseil Flag's +// reflection handle. + +#ifndef ABSL_FLAGS_REFLECTION_H_ +#define ABSL_FLAGS_REFLECTION_H_ + +#include <string> + +#include "absl/base/config.h" +#include "absl/container/flat_hash_map.h" +#include "absl/flags/commandlineflag.h" +#include "absl/flags/internal/commandlineflag.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace flags_internal { +class FlagSaverImpl; +} // namespace flags_internal + +// FindCommandLineFlag() +// +// Returns the reflection handle of an Abseil flag of the specified name, or +// `nullptr` if not found. This function will emit a warning if the name of a +// 'retired' flag is specified. +absl::CommandLineFlag* FindCommandLineFlag(absl::string_view name); + +// Returns current state of the Flags registry in a form of mapping from flag +// name to a flag reflection handle. +absl::flat_hash_map<absl::string_view, absl::CommandLineFlag*> GetAllFlags(); + +//------------------------------------------------------------------------------ +// FlagSaver +//------------------------------------------------------------------------------ +// +// A FlagSaver object stores the state of flags in the scope where the FlagSaver +// is defined, allowing modification of those flags within that scope and +// automatic restoration of the flags to their previous state upon leaving the +// scope. +// +// A FlagSaver can be used within tests to temporarily change the test +// environment and restore the test case to its previous state. +// +// Example: +// +// void MyFunc() { +// absl::FlagSaver fs; +// ... +// absl::SetFlag(FLAGS_myFlag, otherValue); +// ... +// } // scope of FlagSaver left, flags return to previous state +// +// This class is thread-safe. + +class FlagSaver { + public: + FlagSaver(); + ~FlagSaver(); + + FlagSaver(const FlagSaver&) = delete; + void operator=(const FlagSaver&) = delete; + + private: + flags_internal::FlagSaverImpl* impl_; +}; + +//----------------------------------------------------------------------------- + +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_FLAGS_REFLECTION_H_ |