diff options
Diffstat (limited to 'absl/flags/internal/commandlineflag.h')
| -rw-r--r-- | absl/flags/internal/commandlineflag.h | 76 |
1 files changed, 47 insertions, 29 deletions
diff --git a/absl/flags/internal/commandlineflag.h b/absl/flags/internal/commandlineflag.h index 4815cdc7c9a2..d82443a7760e 100644 --- a/absl/flags/internal/commandlineflag.h +++ b/absl/flags/internal/commandlineflag.h @@ -69,11 +69,15 @@ using HelpGenFunc = std::string (*)(); // based on default value supplied in flag's definition) using InitialValGenFunc = void* (*)(); +struct CommandLineFlagInfo; + // Signature for the mutation callback used by watched Flags // The callback is noexcept. // TODO(rogeeff): add noexcept after C++17 support is added. using FlagCallback = void (*)(); +using FlagValidator = bool (*)(); + extern const char kStrippedFlagHelp[]; // The per-type function @@ -217,6 +221,9 @@ struct CommandLineFlag { atomic(kAtomicInit), locks(nullptr) {} + // Revert the init routine. + void Destroy() const; + // Not copyable/assignable. CommandLineFlag(const CommandLineFlag&) = delete; CommandLineFlag& operator=(const CommandLineFlag&) = delete; @@ -224,7 +231,9 @@ struct CommandLineFlag { absl::string_view Name() const { return name; } std::string Help() const { return help.GetHelpText(); } bool IsRetired() const { return this->retired; } - bool IsSpecifiedOnCommandLine() const { return on_command_line; } + bool IsModified() const; + void SetModified(bool is_modified); + bool IsSpecifiedOnCommandLine() const; // Returns true iff this is a handle to an Abseil Flag. bool IsAbseilFlag() const { // Set to null for V1 flags @@ -236,6 +245,10 @@ struct CommandLineFlag { std::string DefaultValue() const; std::string CurrentValue() const; + bool HasValidatorFn() const; + bool SetValidatorFn(FlagValidator fn); + bool InvokeValidator(const void* value) const; + // Return true iff flag has type T. template <typename T> inline bool IsOfType() const { @@ -245,7 +258,7 @@ struct CommandLineFlag { // Attempts to retrieve the flag value. Returns value on success, // absl::nullopt otherwise. template <typename T> - absl::optional<T> Get() { + absl::optional<T> Get() const { if (IsRetired() || flags_internal::FlagOps<T> != this->op) return absl::nullopt; @@ -256,6 +269,7 @@ struct CommandLineFlag { } void SetCallback(const flags_internal::FlagCallback mutation_callback); + void InvokeCallback(); // Sets the value of the flag based on specified std::string `value`. If the flag // was successfully set to new value, it returns true. Otherwise, sets `error` @@ -269,27 +283,35 @@ struct CommandLineFlag { flags_internal::FlagSettingMode set_mode, flags_internal::ValueSource source, std::string* error); + void StoreAtomic(size_t size); + + void CheckDefaultValueParsingRoundtrip() const; + // Invoke the flag validators for old flags. + // TODO(rogeeff): implement proper validators for Abseil Flags + bool ValidateDefaultValue() const; + bool ValidateInputValue(absl::string_view value) const; + // Constant configuration for a particular flag. private: const char* const name; const HelpText help; const char* const filename; - public: - const FlagOpFn op; // Type-specific handler + protected: + const FlagOpFn op; // Type-specific handler const FlagMarshallingOpFn marshalling_op; // Marshalling ops handler const InitialValGenFunc make_init_value; // Makes initial value for the flag - const bool retired; // Is the flag retired? - std::atomic<bool> inited; // fields have been lazily initialized + const bool retired; // Is the flag retired? + std::atomic<bool> inited; // fields have been lazily initialized // Mutable state (guarded by locks->primary_mu). - bool modified; // Has flag value been modified? - bool on_command_line; // Specified on command line. - bool (*validator)(); // Validator function, or nullptr - FlagCallback callback; // Mutation callback, or nullptr - void* def; // Lazily initialized pointer to default value - void* cur; // Lazily initialized pointer to current value - int64_t counter; // Mutation counter + bool modified; // Has flag value been modified? + bool on_command_line; // Specified on command line. + FlagValidator validator; // Validator function, or nullptr + FlagCallback callback; // Mutation callback, or nullptr + void* def; // Lazily initialized pointer to default value + void* cur; // Lazily initialized pointer to current value + int64_t counter; // Mutation counter // For some types, a copy of the current value is kept in an atomically // accessible field. @@ -302,24 +324,26 @@ struct CommandLineFlag { // TODO(rogeeff): fix it once Mutex has constexpr constructor struct CommandLineFlagLocks* locks; // locks, laziliy allocated. + // Ensure that the lazily initialized fields of *flag have been initialized, + // and return the lock which should be locked when flag's state is mutated. + absl::Mutex* InitFlagIfNecessary() const; + // copy construct new value of flag's type in a memory referenced by dst // based on current flag's value void Read(void* dst, const flags_internal::FlagOpFn dst_op) const; // updates flag's value to *src (locked) void Write(const void* src, const flags_internal::FlagOpFn src_op); - ABSL_DEPRECATED( - "temporary until FlagName call sites are migrated and validator API is " - "changed") - const char* NameAsCString() const { return name; } - - private: friend class FlagRegistry; + friend class FlagPtrMap; + friend class FlagSaverImpl; + friend void FillCommandLineFlagInfo(CommandLineFlag* flag, + CommandLineFlagInfo* result); + friend bool TryParseLocked(CommandLineFlag* flag, void* dst, + absl::string_view value, std::string* err); + friend absl::Mutex* InitFlag(CommandLineFlag* flag); }; -// Ensure that the lazily initialized fields of *flag have been initialized, -// and return &flag->locks->primary_mu. -absl::Mutex* InitFlagIfNecessary(CommandLineFlag* flag); // Update any copy of the flag value that is stored in an atomic word. // In addition if flag has a mutation callback this function invokes it. While // callback is being invoked the primary flag's mutex is unlocked and it is @@ -332,15 +356,9 @@ absl::Mutex* InitFlagIfNecessary(CommandLineFlag* flag); // different by the time the callback invocation is completed. // Requires that *primary_lock be held in exclusive mode; it may be released // and reacquired by the implementation. -void UpdateCopy(CommandLineFlag* flag, absl::Mutex* primary_lock); +void UpdateCopy(CommandLineFlag* flag); // Return true iff flag value was changed via direct-access. bool ChangedDirectly(CommandLineFlag* flag, const void* a, const void* b); -// Direct-access flags can be modified without going through the -// flag API. Detect such changes and updated the modified bit. -void UpdateModifiedBit(CommandLineFlag* flag); -// Invoke the flag validators for old flags. -// TODO(rogeeff): implement proper validators for Abseil Flags -bool Validate(CommandLineFlag* flag, const void* value); // This macro is the "source of truth" for the list of supported flag types we // expect to perform lock free operations on. Specifically it generates code, |