| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * 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 |
| * |
| * http://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 LIBTEXTCLASSIFIER_UTIL_BASE_LOGGING_H_ |
| #define LIBTEXTCLASSIFIER_UTIL_BASE_LOGGING_H_ |
| |
| #include <cassert> |
| #include <string> |
| |
| #include "util/base/logging_levels.h" |
| #include "util/base/port.h" |
| |
| |
| namespace libtextclassifier2 { |
| namespace logging { |
| |
| // A tiny code footprint string stream for assembling log messages. |
| struct LoggingStringStream { |
| LoggingStringStream() {} |
| LoggingStringStream &stream() { return *this; } |
| // Needed for invocation in TC_CHECK macro. |
| explicit operator bool() const { return true; } |
| |
| std::string message; |
| }; |
| |
| template <typename T> |
| inline LoggingStringStream &operator<<(LoggingStringStream &stream, |
| const T &entry) { |
| stream.message.append(std::to_string(entry)); |
| return stream; |
| } |
| |
| inline LoggingStringStream &operator<<(LoggingStringStream &stream, |
| const char *message) { |
| stream.message.append(message); |
| return stream; |
| } |
| |
| #if defined(HAS_GLOBAL_STRING) |
| inline LoggingStringStream &operator<<(LoggingStringStream &stream, |
| const ::string &message) { |
| stream.message.append(message); |
| return stream; |
| } |
| #endif |
| |
| inline LoggingStringStream &operator<<(LoggingStringStream &stream, |
| const std::string &message) { |
| stream.message.append(message); |
| return stream; |
| } |
| |
| // The class that does all the work behind our TC_LOG(severity) macros. Each |
| // TC_LOG(severity) << obj1 << obj2 << ...; logging statement creates a |
| // LogMessage temporary object containing a stringstream. Each operator<< adds |
| // info to that stringstream and the LogMessage destructor performs the actual |
| // logging. The reason this works is that in C++, "all temporary objects are |
| // destroyed as the last step in evaluating the full-expression that (lexically) |
| // contains the point where they were created." For more info, see |
| // http://en.cppreference.com/w/cpp/language/lifetime. Hence, the destructor is |
| // invoked after the last << from that logging statement. |
| class LogMessage { |
| public: |
| LogMessage(LogSeverity severity, const char *file_name, |
| int line_number) TC_ATTRIBUTE_NOINLINE; |
| |
| ~LogMessage() TC_ATTRIBUTE_NOINLINE; |
| |
| // Returns the stream associated with the logger object. |
| LoggingStringStream &stream() { return stream_; } |
| |
| private: |
| const LogSeverity severity_; |
| |
| // Stream that "prints" all info into a string (not to a file). We construct |
| // here the entire logging message and next print it in one operation. |
| LoggingStringStream stream_; |
| }; |
| |
| // Pseudo-stream that "eats" the tokens <<-pumped into it, without printing |
| // anything. |
| class NullStream { |
| public: |
| NullStream() {} |
| NullStream &stream() { return *this; } |
| }; |
| template <typename T> |
| inline NullStream &operator<<(NullStream &str, const T &) { |
| return str; |
| } |
| |
| } // namespace logging |
| } // namespace libtextclassifier2 |
| |
| #define TC_LOG(severity) \ |
| ::libtextclassifier2::logging::LogMessage( \ |
| ::libtextclassifier2::logging::severity, __FILE__, __LINE__) \ |
| .stream() |
| |
| // If condition x is true, does nothing. Otherwise, crashes the program (liek |
| // LOG(FATAL)) with an informative message. Can be continued with extra |
| // messages, via <<, like any logging macro, e.g., |
| // |
| // TC_CHECK(my_cond) << "I think we hit a problem"; |
| #define TC_CHECK(x) \ |
| (x) || TC_LOG(FATAL) << __FILE__ << ":" << __LINE__ << ": check failed: \"" \ |
| << #x |
| |
| #define TC_CHECK_EQ(x, y) TC_CHECK((x) == (y)) |
| #define TC_CHECK_LT(x, y) TC_CHECK((x) < (y)) |
| #define TC_CHECK_GT(x, y) TC_CHECK((x) > (y)) |
| #define TC_CHECK_LE(x, y) TC_CHECK((x) <= (y)) |
| #define TC_CHECK_GE(x, y) TC_CHECK((x) >= (y)) |
| #define TC_CHECK_NE(x, y) TC_CHECK((x) != (y)) |
| |
| #define TC_NULLSTREAM ::libtextclassifier2::logging::NullStream().stream() |
| |
| // Debug checks: a TC_DCHECK<suffix> macro should behave like TC_CHECK<suffix> |
| // in debug mode an don't check / don't print anything in non-debug mode. |
| #ifdef NDEBUG |
| |
| #define TC_DCHECK(x) TC_NULLSTREAM |
| #define TC_DCHECK_EQ(x, y) TC_NULLSTREAM |
| #define TC_DCHECK_LT(x, y) TC_NULLSTREAM |
| #define TC_DCHECK_GT(x, y) TC_NULLSTREAM |
| #define TC_DCHECK_LE(x, y) TC_NULLSTREAM |
| #define TC_DCHECK_GE(x, y) TC_NULLSTREAM |
| #define TC_DCHECK_NE(x, y) TC_NULLSTREAM |
| |
| #else // NDEBUG |
| |
| // In debug mode, each TC_DCHECK<suffix> is equivalent to TC_CHECK<suffix>, |
| // i.e., a real check that crashes when the condition is not true. |
| #define TC_DCHECK(x) TC_CHECK(x) |
| #define TC_DCHECK_EQ(x, y) TC_CHECK_EQ(x, y) |
| #define TC_DCHECK_LT(x, y) TC_CHECK_LT(x, y) |
| #define TC_DCHECK_GT(x, y) TC_CHECK_GT(x, y) |
| #define TC_DCHECK_LE(x, y) TC_CHECK_LE(x, y) |
| #define TC_DCHECK_GE(x, y) TC_CHECK_GE(x, y) |
| #define TC_DCHECK_NE(x, y) TC_CHECK_NE(x, y) |
| |
| #endif // NDEBUG |
| |
| #ifdef LIBTEXTCLASSIFIER_VLOG |
| #define TC_VLOG(severity) \ |
| ::libtextclassifier2::logging::LogMessage( \ |
| ::libtextclassifier2::logging::INFO, __FILE__, __LINE__) \ |
| .stream() |
| #else |
| #define TC_VLOG(severity) TC_NULLSTREAM |
| #endif |
| |
| #endif // LIBTEXTCLASSIFIER_UTIL_BASE_LOGGING_H_ |