1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5// Logging and checks. Avoids a dependency on base. 6// 7// LOG(tag) prints messages. Tags are INFO, WARNING, ERROR and FATAL. 8// INFO prints to stdout, the others to stderr. FATAL aborts after printing. 9// 10// LOG_IF(tag, predicate) logs if predicate evaluates to true, else silent. 11// 12// VLOG(level) logs INFO messages where level is less than or equal to the 13// verbosity level set with SetVerbose(). 14// 15// VLOG_IF(level, predicate) logs INFO if predicate evaluates to true, 16// else silent. 17// 18// CHECK(predicate) logs a FATAL error if predicate is false. 19// NOTREACHED() always aborts. 20// Log streams can be changed with SetStreams(). Logging is not thread-safe. 21// 22 23#ifndef TOOLS_RELOCATION_PACKER_SRC_DEBUG_H_ 24#define TOOLS_RELOCATION_PACKER_SRC_DEBUG_H_ 25 26#include <limits.h> 27#include <ostream> 28#include <sstream> 29 30namespace relocation_packer { 31 32class Logger { 33 public: 34 enum Severity {INFO = 0, WARNING, ERROR, FATAL}; 35 36 // Construct a new message logger. Prints if level is less than or 37 // equal to the level set with SetVerbose() and predicate is true. 38 // |severity| is an enumerated severity. 39 // |level| is the verbosity level. 40 // |predicate| controls if the logger prints or is silent. 41 Logger(Severity severity, int level, bool predicate); 42 43 // On destruction, flush and print the strings accumulated in stream_. 44 ~Logger(); 45 46 // Return the stream for this logger. 47 std::ostream& GetStream() { return stream_; } 48 49 // Set verbosity level. Messages with a level less than or equal to 50 // this level are printed, others are discarded. Static, not thread-safe. 51 static void SetVerbose(int level) { max_level_ = level; } 52 53 // Set info and error logging streams. Static, not thread-safe. 54 static void SetStreams(std::ostream* info_stream, 55 std::ostream* error_stream) { 56 info_stream_ = info_stream; 57 error_stream_ = error_stream; 58 } 59 60 // Reset to initial state. 61 static void Reset(); 62 63 private: 64 // Message severity, verbosity level, and predicate. 65 Severity severity_; 66 int level_; 67 bool predicate_; 68 69 // String stream, accumulates message text. 70 std::ostringstream stream_; 71 72 // Verbosity for INFO messages. Not thread-safe. 73 static int max_level_; 74 75 // Logging streams. Not thread-safe. 76 static std::ostream* info_stream_; 77 static std::ostream* error_stream_; 78}; 79 80} // namespace relocation_packer 81 82// Make logging severities visible globally. 83typedef relocation_packer::Logger::Severity LogSeverity; 84const LogSeverity INFO = relocation_packer::Logger::INFO; 85const LogSeverity WARNING = relocation_packer::Logger::WARNING; 86const LogSeverity ERROR = relocation_packer::Logger::ERROR; 87const LogSeverity FATAL = relocation_packer::Logger::FATAL; 88 89// LOG(severity) prints a message with the given severity, and aborts if 90// severity is FATAL. LOG_IF(severity, predicate) does the same but only if 91// predicate is true. INT_MIN is guaranteed to be less than or equal to 92// any verbosity level. 93#define LOG(severity) \ 94 (relocation_packer::Logger(severity, INT_MIN, true).GetStream()) 95#define LOG_IF(severity, predicate) \ 96 (relocation_packer::Logger(severity, INT_MIN, (predicate)).GetStream()) 97 98// VLOG(level) prints its message as INFO if level is less than or equal to 99// the current verbosity level. 100#define VLOG(level) \ 101 (relocation_packer::Logger(INFO, (level), true).GetStream()) 102#define VLOG_IF(level, predicate) \ 103 (relocation_packer::Logger(INFO, (level), (predicate)).GetStream()) 104 105// CHECK(predicate) fails with a FATAL log message if predicate is false. 106#define CHECK(predicate) (LOG_IF(FATAL, !(predicate)) \ 107 << __FILE__ << ":" << __LINE__ << ": " \ 108 << __FUNCTION__ << ": CHECK '" #predicate "' failed") 109 110// NOTREACHED() always fails with a FATAL log message. 111#define NOTREACHED(_) (LOG(FATAL) \ 112 << __FILE__ << ":" << __LINE__ << ": " \ 113 << __FUNCTION__ << ": NOTREACHED() hit") 114 115#endif // TOOLS_RELOCATION_PACKER_SRC_DEBUG_H_ 116