log

A. call

1. Assertions.h LOGL

#define LOG(channel, ...) WTFLog(&JOIN_LOG_CHANNEL_WITH_PREFIX(LOG_CHANNEL_PREFIX, channel), __VA_ARGS__)

//convert a string to a channel variable

#define JOIN_LOG_CHANNEL_WITH_PREFIX(prefix, channel) JOIN_LOG_CHANNEL_WITH_PREFIX_LEVEL_2(prefix, channel)

#define JOIN_LOG_CHANNEL_WITH_PREFIX_LEVEL_2(prefix, channel) prefix ## channel

2. Assertions.cpp WTFLog

B. define

WTFLogChannel WebKitLogTextInput = { 0x00000010, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogTiming = { 0x00000020, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogLoading = { 0x00000040, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogFontCache = { 0x00000100, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogFontSubstitution = { 0x00000200, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogDownload = { 0x00000800, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogDocumentLoad = { 0x00001000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogPlugins = { 0x00002000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogEvents = { 0x00010000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogView = { 0x00020000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogRedirect = { 0x00040000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogPageCache = { 0x00080000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogCacheSizes = { 0x00100000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogFormDelegate = { 0x00200000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogFileDatabaseActivity = { 0x00400000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogHistory = { 0x00800000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogBindings = { 0x01000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogFontSelection = { 0x02000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogEncoding = { 0x04000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogLiveConnect = { 0x08000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogBackForward = { 0x10000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogProgress = { 0x20000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogPluginEvents = { 0x40000000, "WebKitLogLevel", WTFLogChannelOff };

WTFLogChannel WebKitLogIconDatabase = { 0x80000000, "WebKitLogLevel", WTFLogChannelOff };

Logging.cpp
http://blog.csdn.net/bluepath/article/details/7029215