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-rw-r--r--absl/flags/internal/commandlineflag.h157
1 files changed, 6 insertions, 151 deletions
diff --git a/absl/flags/internal/commandlineflag.h b/absl/flags/internal/commandlineflag.h
index 6363c661..cb46fe2e 100644
--- a/absl/flags/internal/commandlineflag.h
+++ b/absl/flags/internal/commandlineflag.h
@@ -16,41 +16,19 @@
#ifndef ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
#define ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
-#include <stddef.h>
-#include <stdint.h>
-
-#include <memory>
-#include <string>
-#include <typeinfo>
-
#include "absl/base/config.h"
-#include "absl/base/macros.h"
-#include "absl/flags/config.h"
-#include "absl/flags/marshalling.h"
-#include "absl/strings/string_view.h"
-#include "absl/types/optional.h"
+#include "absl/base/internal/fast_type_id.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace flags_internal {
-// An alias for flag static type id. Values of type identify the flag value type
-// simialarly to typeid(T), but without relying on RTTI being available. In most
+// An alias for flag fast type id. This value identifies the flag value type
+// simialarly to typeid(T), without relying on RTTI being available. In most
// cases this id is enough to uniquely identify the flag's value type. In a few
// cases we'll have to resort to using actual RTTI implementation if it is
// available.
-using FlagStaticTypeId = void* (*)();
-
-// Address of this function template is used in current implementation as a flag
-// static type id.
-template <typename T>
-void* FlagStaticTypeIdGen() {
-#if defined(ABSL_FLAGS_INTERNAL_HAS_RTTI)
- return const_cast<std::type_info*>(&typeid(T));
-#else
- return nullptr;
-#endif
-}
+using FlagFastTypeId = absl::base_internal::FastTypeIdType;
// Options that control SetCommandLineOptionWithMode.
enum FlagSettingMode {
@@ -65,7 +43,7 @@ enum FlagSettingMode {
SET_FLAGS_DEFAULT
};
-// Options that control SetFromString: Source of a value.
+// Options that control ParseFrom: Source of a value.
enum ValueSource {
// Flag is being set by value specified on a command line.
kCommandLine,
@@ -77,135 +55,12 @@ enum ValueSource {
// of a flag produced this flag state from method CommandLineFlag::SaveState().
class FlagStateInterface {
public:
- virtual ~FlagStateInterface() {}
+ virtual ~FlagStateInterface();
// Restores the flag originated this object to the saved state.
virtual void Restore() const = 0;
};
-// Holds all information for a flag.
-class CommandLineFlag {
- public:
- constexpr CommandLineFlag() = default;
-
- // Not copyable/assignable.
- CommandLineFlag(const CommandLineFlag&) = delete;
- CommandLineFlag& operator=(const CommandLineFlag&) = delete;
-
- // Non-polymorphic access methods.
-
- // Return true iff flag has type T.
- template <typename T>
- inline bool IsOfType() const {
- return TypeId() == &flags_internal::FlagStaticTypeIdGen<T>;
- }
-
- // Attempts to retrieve the flag value. Returns value on success,
- // absl::nullopt otherwise.
- template <typename T>
- absl::optional<T> Get() const {
- if (IsRetired() || !IsOfType<T>()) {
- return absl::nullopt;
- }
-
- // Implementation notes:
- //
- // We are wrapping a union around the value of `T` to serve three purposes:
- //
- // 1. `U.value` has correct size and alignment for a value of type `T`
- // 2. The `U.value` constructor is not invoked since U's constructor does
- // not do it explicitly.
- // 3. The `U.value` destructor is invoked since U's destructor does it
- // explicitly. This makes `U` a kind of RAII wrapper around non default
- // constructible value of T, which is destructed when we leave the
- // scope. We do need to destroy U.value, which is constructed by
- // CommandLineFlag::Read even though we left it in a moved-from state
- // after std::move.
- //
- // All of this serves to avoid requiring `T` being default constructible.
- union U {
- T value;
- U() {}
- ~U() { value.~T(); }
- };
- U u;
-
- Read(&u.value);
- return std::move(u.value);
- }
-
- // Polymorphic access methods
-
- // Returns name of this flag.
- virtual absl::string_view Name() const = 0;
- // Returns name of the file where this flag is defined.
- virtual std::string Filename() const = 0;
- // Returns name of the flag's value type for some built-in types or empty
- // std::string.
- virtual absl::string_view Typename() const = 0;
- // Returns help message associated with this flag.
- virtual std::string Help() const = 0;
- // Returns true iff this object corresponds to retired flag.
- virtual bool IsRetired() const { return false; }
- // Returns true iff this is a handle to an Abseil Flag.
- virtual bool IsAbseilFlag() const { return true; }
- // Returns id of the flag's value type.
- virtual FlagStaticTypeId TypeId() const = 0;
- virtual bool IsModified() const = 0;
- virtual bool IsSpecifiedOnCommandLine() const = 0;
- virtual std::string DefaultValue() const = 0;
- virtual std::string CurrentValue() const = 0;
-
- // Interfaces to operate on validators.
- virtual bool ValidateInputValue(absl::string_view value) const = 0;
-
- // Interface to save flag to some persistent state. Returns current flag state
- // or nullptr if flag does not support saving and restoring a state.
- virtual std::unique_ptr<FlagStateInterface> SaveState() = 0;
-
- // 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`
- // to indicate the error, leaves the flag unchanged, and returns false. There
- // are three ways to set the flag's value:
- // * Update the current flag value
- // * Update the flag's default value
- // * Update the current flag value if it was never set before
- // The mode is selected based on `set_mode` parameter.
- virtual bool SetFromString(absl::string_view value,
- flags_internal::FlagSettingMode set_mode,
- flags_internal::ValueSource source,
- std::string* error) = 0;
-
- // Checks that flags default value can be converted to std::string and back to the
- // flag's value type.
- virtual void CheckDefaultValueParsingRoundtrip() const = 0;
-
- protected:
- ~CommandLineFlag() = default;
-
- private:
- // Copy-construct a new value of the flag's type in a memory referenced by
- // the dst based on the current flag's value.
- virtual void Read(void* dst) const = 0;
-};
-
-// This macro is the "source of truth" for the list of supported flag built-in
-// types.
-#define ABSL_FLAGS_INTERNAL_BUILTIN_TYPES(A) \
- A(bool) \
- A(short) \
- A(unsigned short) \
- A(int) \
- A(unsigned int) \
- A(long) \
- A(unsigned long) \
- A(long long) \
- A(unsigned long long) \
- A(double) \
- A(float) \
- A(std::string) \
- A(std::vector<std::string>)
-
} // namespace flags_internal
ABSL_NAMESPACE_END
} // namespace absl