// Copyright 2017 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_BASE_LOG_SEVERITY_H_ #define ABSL_BASE_LOG_SEVERITY_H_ #include <array> #include <ostream> #include "absl/base/attributes.h" #include "absl/base/config.h" namespace absl { ABSL_NAMESPACE_BEGIN // absl::LogSeverity // // Four severity levels are defined. Logging APIs should terminate the program // when a message is logged at severity `kFatal`; the other levels have no // special semantics. // // Values other than the four defined levels (e.g. produced by `static_cast`) // are valid, but their semantics when passed to a function, macro, or flag // depend on the function, macro, or flag. The usual behavior is to normalize // such values to a defined severity level, however in some cases values other // than the defined levels are useful for comparison. // // Example: // // // Effectively disables all logging: // SetMinLogLevel(static_cast<absl::LogSeverity>(100)); // // Abseil flags may be defined with type `LogSeverity`. Dependency layering // constraints require that the `AbslParseFlag()` overload be declared and // defined in the flags library itself rather than here. The `AbslUnparseFlag()` // overload is defined there as well for consistency. // // absl::LogSeverity Flag String Representation // // An `absl::LogSeverity` has a string representation used for parsing // command-line flags based on the enumerator name (e.g. `kFatal`) or // its unprefixed name (without the `k`) in any case-insensitive form. (E.g. // "FATAL", "fatal" or "Fatal" are all valid.) Unparsing such flags produces an // unprefixed string representation in all caps (e.g. "FATAL") or an integer. // // Additionally, the parser accepts arbitrary integers (as if the type were // `int`). // // Examples: // // --my_log_level=kInfo // --my_log_level=INFO // --my_log_level=info // --my_log_level=0 // // Unparsing a flag produces the same result as `absl::LogSeverityName()` for // the standard levels and a base-ten integer otherwise. enum class LogSeverity : int { kInfo = 0, kWarning = 1, kError = 2, kFatal = 3, }; // LogSeverities() // // Returns an iterable of all standard `absl::LogSeverity` values, ordered from // least to most severe. constexpr std::array<absl::LogSeverity, 4> LogSeverities() { return {{absl::LogSeverity::kInfo, absl::LogSeverity::kWarning, absl::LogSeverity::kError, absl::LogSeverity::kFatal}}; } // LogSeverityName() // // Returns the all-caps string representation (e.g. "INFO") of the specified // severity level if it is one of the standard levels and "UNKNOWN" otherwise. constexpr const char* LogSeverityName(absl::LogSeverity s) { return s == absl::LogSeverity::kInfo ? "INFO" : s == absl::LogSeverity::kWarning ? "WARNING" : s == absl::LogSeverity::kError ? "ERROR" : s == absl::LogSeverity::kFatal ? "FATAL" : "UNKNOWN"; } // NormalizeLogSeverity() // // Values less than `kInfo` normalize to `kInfo`; values greater than `kFatal` // normalize to `kError` (**NOT** `kFatal`). constexpr absl::LogSeverity NormalizeLogSeverity(absl::LogSeverity s) { return s < absl::LogSeverity::kInfo ? absl::LogSeverity::kInfo : s > absl::LogSeverity::kFatal ? absl::LogSeverity::kError : s; } constexpr absl::LogSeverity NormalizeLogSeverity(int s) { return absl::NormalizeLogSeverity(static_cast<absl::LogSeverity>(s)); } // operator<< // // The exact representation of a streamed `absl::LogSeverity` is deliberately // unspecified; do not rely on it. std::ostream& operator<<(std::ostream& os, absl::LogSeverity s); ABSL_NAMESPACE_END } // namespace absl #endif // ABSL_BASE_LOG_SEVERITY_H_