--- /dev/null
+//
+// 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 <map>
+#include <string>
+
+#include "absl/base/macros.h"
+#include "absl/flags/internal/commandlineflag.h"
+
+// --------------------------------------------------------------------
+// Global flags registry API.
+
+namespace absl {
+namespace flags_internal {
+
+// CommandLineFlagInfo holds all information for a flag.
+struct CommandLineFlagInfo {
+ std::string name; // the name of the flag
+ std::string type; // DO NOT use. Use flag->IsOfType<T>() instead.
+ std::string description; // the "help text" associated with the flag
+ std::string current_value; // the current value, as a std::string
+ std::string default_value; // the default value, as a std::string
+ std::string filename; // 'cleaned' version of filename holding the flag
+ bool has_validator_fn; // true if RegisterFlagValidator called on this flag
+
+ bool is_default; // true if the flag has the default value and
+ // has not been set explicitly from the cmdline
+ // or via SetCommandLineOption.
+
+ // nullptr for ABSL_FLAG. A pointer to the flag's current value
+ // otherwise. E.g., for DEFINE_int32(foo, ...), flag_ptr will be
+ // &FLAGS_foo.
+ const void* flag_ptr;
+};
+
+//-----------------------------------------------------------------------------
+
+void FillCommandLineFlagInfo(CommandLineFlag* flag,
+ CommandLineFlagInfo* result);
+
+//-----------------------------------------------------------------------------
+
+CommandLineFlag* FindCommandLineFlag(absl::string_view name);
+CommandLineFlag* FindCommandLineV1Flag(const void* flag_ptr);
+CommandLineFlag* FindRetiredFlag(absl::string_view name);
+
+// Executes specified visitor for each non-retired flag in the registry.
+// Requires the caller hold the registry lock.
+void ForEachFlagUnlocked(std::function<void(CommandLineFlag*)> visitor);
+// 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);
+
+//-----------------------------------------------------------------------------
+
+// Store the list of all flags in *OUTPUT, sorted by file.
+void GetAllFlags(std::vector<CommandLineFlagInfo>* OUTPUT);
+
+//-----------------------------------------------------------------------------
+
+bool RegisterCommandLineFlag(CommandLineFlag*, const void* ptr = nullptr);
+
+//-----------------------------------------------------------------------------
+// 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.
+//
+// Returns bool to enable use in namespace-scope initializers.
+// For example:
+//
+// static const bool dummy = base::RetiredFlag<int32_t>("myflag");
+//
+// Or to declare several at once:
+//
+// static bool dummies[] = {
+// base::RetiredFlag<std::string>("some_string_flag"),
+// base::RetiredFlag<double>("some_double_flag"),
+// base::RetiredFlag<int32_t>("some_int32_flag")
+// };
+
+// Retire flag with name "name" and type indicated by ops.
+bool Retire(FlagOpFn ops, FlagMarshallingOpFn marshalling_ops,
+ const char* name);
+
+// Registered a retired flag with name 'flag_name' and type 'T'.
+template <typename T>
+inline bool RetiredFlag(const char* flag_name) {
+ return flags_internal::Retire(flags_internal::FlagOps<T>,
+ flags_internal::FlagMarshallingOps<T>,
+ flag_name);
+}
+
+// If the flag is retired, returns true and indicates in |*type_is_bool|
+// whether the type of the retired flag is a bool.
+// Only to be called by code that needs to explicitly ignore retired flags.
+bool IsRetiredFlag(absl::string_view name, bool* type_is_bool);
+
+//-----------------------------------------------------------------------------
+// Saves the states (value, default value, whether the user has set
+// the flag, registered validators, etc) of all flags, and restores
+// them when the FlagSaver is destroyed.
+//
+// This class is thread-safe. However, its destructor writes to
+// exactly the set of flags that have changed value during its
+// lifetime, so concurrent _direct_ access to those flags
+// (i.e. FLAGS_foo instead of {Get,Set}CommandLineOption()) is unsafe.
+
+class FlagSaver {
+ public:
+ FlagSaver();
+ ~FlagSaver();
+
+ FlagSaver(const FlagSaver&) = delete;
+ void operator=(const FlagSaver&) = delete;
+
+ // Prevents saver from restoring the saved state of flags.
+ void Ignore();
+
+ private:
+ class FlagSaverImpl* impl_; // we use pimpl here to keep API steady
+};
+
+} // namespace flags_internal
+} // namespace absl
+
+#endif // ABSL_FLAGS_INTERNAL_REGISTRY_H_
git://repos.xcallymotion.com / motion2.git / blobdiff