[chromium-reviews] Add Compact Language Detection (CLD) library to Chrome. This works in Windows...

third_party/cld/base/logging.h

Index: third_party/cld/base/logging.h
===================================================================
--- third_party/cld/base/logging.h	(revision 0)
+++ third_party/cld/base/logging.h	(revision 0)
@@ -0,0 +1,1403 @@
+// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef _LOGGING_H_
+#define _LOGGING_H_
+
+#include <errno.h>
+#include <string.h>
+#include <time.h>
+#include <string>
+#include <strstream>
+#include <vector>
+
+#ifndef COMPILER_MSVC
+#include <unistd.h>   // for _exit()
+#endif
+
+#include "base/port.h"
+#include "base/basictypes.h"
+#include "third_party/cld/base/commandlineflags.h"
+#include "third_party/cld/base/crash.h"
+#include "third_party/cld/base/dynamic_annotations.h"
+#include "third_party/cld/base/macros.h"
+#include "third_party/cld/base/scoped_ptr.h"
+#include "third_party/cld/base/stl_decl.h"
+#include "third_party/cld/base/log_severity.h"
+#include "third_party/cld/base/vlog_is_on.h"
+#include "third_party/cld/base/global_strip_options.h"
+
+// Make a bunch of macros for logging.  The way to log things is to stream
+// things to LOG(<a particular severity level>).  E.g.,
+//
+//   LOG(INFO) << "Found " << num_cookies << " cookies";
+//
+// You can capture log messages in a string, rather than reporting them
+// immediately:
+//
+//   vector<string> errors;
+//   LOG_STRING(ERROR, &errors) << "Couldn't parse cookie #" << cookie_num;
+//
+// This pushes back the new error onto 'errors'; if given a NULL pointer,
+// it reports the error via LOG(ERROR).
+//
+// You can also do conditional logging:
+//
+//   LOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
+//
+// You can also do occasional logging (log every n'th occurrence of an
+// event):
+//
+//   LOG_EVERY_N(INFO, 10) << "Got the " << COUNTER << "th cookie";
+//
+// The above will cause log messages to be output on the 1st, 11th, 21st, ...
+// times it is executed.  Note that the special COUNTER value is used to
+// identify which repetition is happening.
+//
+// You can also do occasional conditional logging (log every n'th
+// occurrence of an event, when condition is satisfied):
+//
+//   LOG_IF_EVERY_N(INFO, (size > 1024), 10) << "Got the " << COUNTER
+//                                           << "th big cookie";
+//
+// You can log messages the first N times your code executes a line. E.g.
+//
+//   LOG_FIRST_N(INFO, 20) << "Got the " << COUNTER << "th cookie";
+//
+// Outputs log messages for the first 20 times it is executed.
+//
+// Analogous SYSLOG, SYSLOG_IF, and SYSLOG_EVERY_N macros are available.
+// These log to syslog as well as to the normal logs.  If you use these at
+// all, you need to be aware that syslog can drastically reduce performance,
+// especially if it is configured for remote logging!  Don't use these
+// unless you fully understand this and have a concrete need to use them.
+// Even then, try to minimize your use of them.
+//
+// There are also "debug mode" logging macros like the ones above:
+//
+//   DLOG(INFO) << "Found cookies";
+//
+//   DLOG_IF(INFO, num_cookies > 10) << "Got lots of cookies";
+//
+//   DLOG_EVERY_N(INFO, 10) << "Got the " << COUNTER << "th cookie";
+//
+// All "debug mode" logging is compiled away to nothing for non-debug mode
+// compiles.
+//
+// We also have
+//
+//   LOG_ASSERT(assertion);
+//   DLOG_ASSERT(assertion);
+//
+// which is syntactic sugar for {,D}LOG_IF(FATAL, assert fails) << assertion;
+//
+// We also override the standard 'assert' to use 'DLOG_ASSERT'.
+//
+// There are "verbose level" logging macros.  They look like
+//
+//   VLOG(1) << "I'm printed when you run the program with --v=1 or more";
+//   VLOG(2) << "I'm printed when you run the program with --v=2 or more";
+//
+// These always log at the INFO log level (when they log at all).
+// The verbose logging can also be turned on module-by-module.  For instance,
+//    --vmodule=recordio=2,file=1,gfs*=3 --v=0
+// will cause:
+//   a. VLOG(2) and lower messages to be printed from recordio.{h,cc}
+//   b. VLOG(1) and lower messages to be printed from google2file
+//   c. VLOG(3) and lower messages to be printed from files prefixed with "gfs"
+//   d. VLOG(0) and lower messages to be printed from elsewhere
+//
+// The wildcarding functionality shown by (c) supports both '*' (match
+// 0 or more characters) and '?' (match any single character) wildcards.
+//
+// There's also VLOG_IS_ON(n) "verbose level" condition macro. To be used as
+//
+//   if (VLOG_IS_ON(2)) {
+//     // do some logging preparation and logging
+//     // that can't be accomplished with just VLOG(2) << ...;
+//   }
+//
+// There are also VLOG_IF, VLOG_EVERY_N and VLOG_IF_EVERY_N "verbose level"
+// condition macros for sample cases, when some extra computation and
+// preparation for logs is not needed.
+//   VLOG_IF(1, (size > 1024))
+//      << "I'm printed when size is more than 1024 and when you run the "
+//         "program with --v=1 or more";
+//   VLOG_EVERY_N(1, 10)
+//      << "I'm printed every 10th occurrence, and when you run the program "
+//         "with --v=1 or more. Present occurence is " << COUNTER;
+//   VLOG_IF_EVERY_N(1, (size > 1024), 10)
+//      << "I'm printed on every 10th occurence of case when size is more "
+//         " than 1024, when you run the program with --v=1 or more. ";
+//         "Present occurence is " << COUNTER;
+//
+// [MLOG is OBSOLETE - use the more convenient VLOG(n) macros]
+// There is also an MLOG option that enables module-level logging.  MLOG
+// is associated with a specific flag by defining a MODULE_FLAG macro.
+// Other than this, it behaves like VLOG.  Example:
+//    DEFINE_int32(dnsverbose, 0, "Verbose level for DNS module");
+//    #define MODULE_FLAG FLAGS_dnsverbose
+//    MLOG(1) << "I'm printed when you run with --dnsverbose=1 or more";
+//
+// The supported severity levels for macros that allow you to specify one
+// are (in increasing order of severity) INFO, WARNING, ERROR, and FATAL.
+// Note that messages of a given severity are logged not only in the
+// logfile for that severity, but also in all logfiles of lower severity.
+// E.g., a message of severity FATAL will be logged to the logfiles of
+// severity FATAL, ERROR, WARNING, and INFO.
+//
+// There is also the special severity of DFATAL, which logs FATAL in
+// debug mode, ERROR in normal mode.
+//
+// Very important: logging a message at the FATAL severity level causes
+// the program to terminate (after the message is logged).
+//
+// Unless otherwise specified, logs will be written to the filename
+// "<program name>.<hostname>.<user name>.log.<severity level>.", followed
+// by the date, time, and pid (you can't prevent the date, time, and pid
+// from being in the filename).
+//
+// The logging code takes two flags:
+//     --v=#           set the verbose level
+//     --logtostderr   log all the messages to stderr instead of to logfiles
+
+// LOG LINE PREFIX FORMAT
+//
+// Log lines have this form:
+//
+//     Lmmdd hh:mm:ss.uuuuuu threadid file:line] msg...
+//
+// where the fields are defined as follows:
+//
+//   L                A single character, representing the log level
+//                    (eg 'I' for INFO)
+//   mm               The month (zero padded; ie May is '05')
+//   dd               The day (zero padded)
+//   hh:mm:ss.uuuuuu  Time in hours, minutes and fractional seconds
+//   threadid         The space-padded thread ID as returned by GetTID()
+//                    (this matches the PID on Linux)
+//   file             The file name
+//   line             The line number
+//   msg              The user-supplied message
+//
+// Example:
+//
+//   I1103 11:57:31.739339 24395 google.cc:2341] Command line: ./some_prog
+//   I1103 11:57:31.739403 24395 google.cc:2342] Process id 24395
+//
+// NOTE: although the microseconds are useful for comparing events on
+// a single machine, clocks on different machines may not be well
+// synchronized.  Hence, use caution when comparing the low bits of
+// timestamps from different machines.
+
+// Set whether log messages go to stderr instead of logfiles
+DECLARE_bool(logtostderr);
+
+// Set whether log messages go to stderr in addition to logfiles.
+DECLARE_bool(alsologtostderr);
+
+// Log messages at a level >= this flag are automatically sent to
+// stderr in addition to log files.
+DECLARE_int32(stderrthreshold);
+
+// Set whether the log prefix should be prepended to each line of output.
+DECLARE_bool(log_prefix);
+
+// Log messages at a level <= this flag are buffered.
+// Log messages at a higher level are flushed immediately.
+DECLARE_int32(logbuflevel);
+
+// Sets the maximum number of seconds which logs may be buffered for.
+DECLARE_int32(logbufsecs);
+
+// Should Google1 logging be turned on?
+DECLARE_bool(logging);
+
+// Log suppression level: messages logged at a lower level than this
+// are suppressed.
+DECLARE_int32(minloglevel);
+
+// If specified, logfiles are written into this directory instead of the
+// default logging directory.
+DECLARE_string(log_dir);
+
+// Sets the path of the directory into which to put additional links
+// to the log files.
+DECLARE_string(log_link);
+
+// Sets the maximum log file size (in MB).
+DECLARE_int32(max_log_size);
+
+// Should log IO be directed to a background thread?  This flag has no
+// effect unless //thread/logger:logger is linked into the binary.
+DECLARE_bool(threaded_logging);
+
+// Set to cause StatusMessage() to write status to ./STATUS file.
+DECLARE_bool(status_messages_to_status_file);
+
+// Sets whether to avoid logging to the disk if the disk is full.
+DECLARE_bool(stop_logging_if_full_disk);
+
+// Log messages below the STRIP_LOG level will be compiled away for
+// security reasons. See LOG(severtiy) below. STRIP_LOG is defined in
+// //base/global_strip_log.h
+
+// A few definitions of macros that don't generate much code.  Since
+// LOG(INFO) and its ilk are used all over our code, it's
+// better to have compact code for these operations.
+
+#if STRIP_LOG == 0
+#define COMPACT_GOOGLE_LOG_INFO LogMessage(__FILE__, __LINE__)
+#define LOG_TO_STRING_INFO(message) LogMessage(__FILE__, __LINE__, INFO, \
+                                               message)
+#else
+#define COMPACT_GOOGLE_LOG_INFO NullStream()
+#define LOG_TO_STRING_INFO(message) NullStream()
+#endif
+
+#if STRIP_LOG <= 1
+#define COMPACT_GOOGLE_LOG_WARNING LogMessage(__FILE__, __LINE__, WARNING)
+#define LOG_TO_STRING_WARNING(message) LogMessage(__FILE__, __LINE__, \
+                                                  WARNING, message)
+#else
+#define COMPACT_GOOGLE_LOG_WARNING NullStream()
+#define LOG_TO_STRING_WARNING(message) NullStream()
+#endif
+
+#if STRIP_LOG <= 2
+#define COMPACT_GOOGLE_LOG_ERROR LogMessage(__FILE__, __LINE__, ERROR)
+#define LOG_TO_STRING_ERROR(message) LogMessage(__FILE__, __LINE__, ERROR, \
+                                                message)
+#else
+#define COMPACT_GOOGLE_LOG_ERROR NullStream()
+#define LOG_TO_STRING_ERROR(message) NullStream()
+#endif
+
+#if STRIP_LOG <= 3
+#define COMPACT_GOOGLE_LOG_FATAL LogMessageFatal(__FILE__, __LINE__)
+#define COMPACT_GOOGLE_LOG_QFATAL LogMessageQuietlyFatal(__FILE__, __LINE__)
+#define LOG_TO_STRING_FATAL(message) LogMessage(__FILE__, __LINE__, FATAL, \
+                                                message)
+#else
+#define COMPACT_GOOGLE_LOG_FATAL NullStreamFatal()
+#define COMPACT_GOOGLE_LOG_QFATAL NullStreamFatal()
+#define LOG_TO_STRING_FATAL(message) NullStreamFatal()
+#endif
+
+// For DFATAL, we want to use LogMessage (as opposed to
+// LogMessageFatal), to be consistent with the original behavior.
+#ifdef NDEBUG
+#define COMPACT_GOOGLE_LOG_DFATAL COMPACT_GOOGLE_LOG_ERROR
+#elif STRIP_LOG <= 3
+#define COMPACT_GOOGLE_LOG_DFATAL LogMessage(__FILE__, __LINE__, FATAL)
+#else
+#define COMPACT_GOOGLE_LOG_DFATAL NullStreamFatal()
+#endif
+
+#define GOOGLE_LOG_INFO(counter) \
+  LogMessage(__FILE__, __LINE__, INFO, counter, &LogMessage::SendToLog)
+#define SYSLOG_INFO(counter) \
+  LogMessage(__FILE__, __LINE__, INFO, counter, \
+  &LogMessage::SendToSyslogAndLog)
+#define GOOGLE_LOG_WARNING(counter)  \
+  LogMessage(__FILE__, __LINE__, WARNING, counter, &LogMessage::SendToLog)
+#define SYSLOG_WARNING(counter)  \
+  LogMessage(__FILE__, __LINE__, WARNING, counter, \
+  &LogMessage::SendToSyslogAndLog)
+#define GOOGLE_LOG_ERROR(counter)  \
+  LogMessage(__FILE__, __LINE__, ERROR, counter, &LogMessage::SendToLog)
+#define SYSLOG_ERROR(counter)  \
+  LogMessage(__FILE__, __LINE__, ERROR, counter, \
+  &LogMessage::SendToSyslogAndLog)
+#define GOOGLE_LOG_FATAL(counter) \
+  LogMessage(__FILE__, __LINE__, FATAL, counter, &LogMessage::SendToLog)
+#define SYSLOG_FATAL(counter) \
+  LogMessage(__FILE__, __LINE__, FATAL, counter, \
+  &LogMessage::SendToSyslogAndLog)
+#define GOOGLE_LOG_DFATAL(counter) \
+  LogMessage(__FILE__, __LINE__, DFATAL_LEVEL, counter, &LogMessage::SendToLog)
+#define SYSLOG_DFATAL(counter) \
+  LogMessage(__FILE__, __LINE__, DFATAL_LEVEL, counter, \
+  &LogMessage::SendToSyslogAndLog)
+
+#ifdef OS_WINDOWS
+// A very useful logging macro to log windows errors:
+#define LOG_SYSRESULT(result) \
+  if (FAILED(result)) { \
+    LPTSTR message = NULL; \
+    LPTSTR msg = reinterpret_cast<LPTSTR>(&message); \
+    DWORD message_length = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | \
+                         FORMAT_MESSAGE_FROM_SYSTEM, \
+                         0, result, 0, msg, 100, NULL); \
+    if (message_length > 0) { \
+      LogMessage(__FILE__, __LINE__, ERROR, 0, \
+                 &LogMessage::SendToLog).stream() << message; \
+      LocalFree(message); \
+    } \
+  }
+#endif
+
+// We use the preprocessor's merging operator, "##", so that, e.g.,
+// LOG(INFO) becomes the token GOOGLE_LOG_INFO.  There's some funny
+// subtle difference between ostream member streaming functions (e.g.,
+// ostream::operator<<(int) and ostream non-member streaming functions
+// (e.g., ::operator<<(ostream&, string&): it turns out that it's
+// impossible to stream something like a string directly to an unnamed
+// ostream. We employ a neat hack by calling the stream() member
+// function of LogMessage which seems to avoid the problem.
+#define LOG(severity) COMPACT_GOOGLE_LOG_ ## severity.stream()
+#define SYSLOG(severity) SYSLOG_ ## severity(0).stream()
+
+// A convenient shorthand
+#define LG LOG(INFO)
+
+class LogSink;  // defined below
+
+// If a non-NULL sink pointer is given, we push this message to that sink.
+// For LOG_TO_SINK we then do normal LOG(severity) logging as well.
+// This is useful for capturing messages and passing/storing them
+// somewhere more specific than the global log of the process.
+// Argument types:
+//   LogSink* sink;
+//   LogSeverity severity;
+// The cast is to disambiguate NULL arguments.
+#define LOG_TO_SINK(sink, severity) \
+  LogMessage(__FILE__, __LINE__, severity, \
+             static_cast<LogSink*>(sink), true).stream()
+#define LOG_TO_SINK_BUT_NOT_TO_LOGFILE(sink, severity) \
+  LogMessage(__FILE__, __LINE__, severity, \
+             static_cast<LogSink*>(sink), false).stream()
+
+// If a non-NULL string pointer is given, we write this message to that string.
+// We then do normal LOG(severity) logging as well.
+// This is useful for capturing messages and storing them somewhere more
+// specific than the global log of the process.
+// Argument types:
+//   string* message;
+//   LogSeverity severity;
+// The cast is to disambiguate NULL arguments.
+// NOTE: LOG(severity) expands to LogMessage().stream() for the specified
+// severity.
+#define LOG_TO_STRING(severity, message) \
+  LOG_TO_STRING_##severity(static_cast<string*>(message)).stream()
+
+// If a non-NULL pointer is given, we push the message onto the end
+// of a vector of strings; otherwise, we report it with LOG(severity).
+// This is handy for capturing messages and perhaps passing them back
+// to the caller, rather than reporting them immediately.
+// Argument types:
+//   LogSeverity severity;
+//   vector<string> *outvec;
+// The cast is to disambiguate NULL arguments.
+#define LOG_STRING(severity, outvec) \
+  LOG_TO_STRING_##severity(static_cast<vector<string>*>(outvec)).stream()
+
+#define LOG_IF(severity, condition) \
+  !(condition) ? (void) 0 : LogMessageVoidify() & LOG(severity)
+#define SYSLOG_IF(severity, condition) \
+  !(condition) ? (void) 0 : LogMessageVoidify() & SYSLOG(severity)
+
+#define LOG_ASSERT(condition)  \
+  LOG_IF(FATAL, !(condition)) << "Assert failed: " #condition
+#define SYSLOG_ASSERT(condition) \
+  SYSLOG_IF(FATAL, !(condition)) << "Assert failed: " #condition
+
+// CHECK dies with a fatal error if condition is not true.  It is *not*
+// controlled by NDEBUG, so the check will be executed regardless of
+// compilation mode.  Therefore, it is safe to do things like:
+//    CHECK(fp->Write(x) == 4)
+#define CHECK(condition)  \
+      LOG_IF(FATAL, PREDICT_FALSE(!(condition))) \
+             << "Check failed: " #condition " "
+
+// QCHECK is a quiet version of CHECK. It has all of the same properties,
+// except that when it dies it simply prints out this message and doesn't
+// dump a giant stack trace, etc. This is good for tests like sanity-checking
+// user inputs, where your own failure message is really the only thing you
+// need or want to display.
+#define QCHECK(condition)  \
+      LOG_IF(QFATAL, PREDICT_FALSE(!(condition))) \
+             << "Check failed: " #condition " "
+
+// A container for a string pointer which can be evaluated to a bool -
+// true iff the pointer is NULL.
+struct CheckOpString {
+  CheckOpString(string* str) : str_(str) { }
+  // No destructor: if str_ is non-NULL, we're about to LOG(FATAL),
+  // so there's no point in cleaning up str_.
+  operator bool() const { return PREDICT_FALSE(str_ != NULL); }
+  string* str_;
+};
+
+// Function is overloaded for integral types to allow static const
+// integrals declared in classes and not defined to be used as arguments to
+// CHECK* macros. It's not encouraged though.
+template <class T>
+inline const T&       GetReferenceableValue(const T&           t) { return t; }
+inline char           GetReferenceableValue(char               t) { return t; }
+inline unsigned char  GetReferenceableValue(unsigned char      t) { return t; }
+inline signed char    GetReferenceableValue(signed char        t) { return t; }
+inline short          GetReferenceableValue(short              t) { return t; }
+inline unsigned short GetReferenceableValue(unsigned short     t) { return t; }
+inline int            GetReferenceableValue(int                t) { return t; }
+inline unsigned int   GetReferenceableValue(unsigned int       t) { return t; }
+inline long           GetReferenceableValue(long               t) { return t; }
+inline unsigned long  GetReferenceableValue(unsigned long      t) { return t; }
+inline long long      GetReferenceableValue(long long          t) { return t; }
+inline unsigned long long GetReferenceableValue(unsigned long long t) {
+  return t;
+}
+
+// Build the error message string.
+template<class t1, class t2>
+string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) {
+  strstream ss;
+  ss << names << " (" << v1 << " vs. " << v2 << ")";
+  return new string(ss.str(), ss.pcount());
+}
+
+// Helper functions for CHECK_OP macro.
+// The (int, int) specialization works around the issue that the compiler
+// will not instantiate the template version of the function on values of
+// unnamed enum type - see comment below.
+#define DEFINE_CHECK_OP_IMPL(name, op) \
+  template <class t1, class t2> \
+  inline string* Check##name##Impl(const t1& v1, const t2& v2, \
+                                   const char* names) { \
+    if (v1 op v2) return NULL; \
+    else return MakeCheckOpString(v1, v2, names); \
+  } \
+  inline string* Check##name##Impl(int v1, int v2, const char* names) { \
+    return Check##name##Impl<int, int>(v1, v2, names); \
+  }
+
+// Use _EQ, _NE, _LE, etc. in case the file including base/logging.h
+// provides its own #defines for the simpler names EQ, NE, LE, etc.
+// This happens if, for example, those are used as token names in a
+// yacc grammar.
+DEFINE_CHECK_OP_IMPL(_EQ, ==)
+DEFINE_CHECK_OP_IMPL(_NE, !=)
+DEFINE_CHECK_OP_IMPL(_LE, <=)
+DEFINE_CHECK_OP_IMPL(_LT, < )
+DEFINE_CHECK_OP_IMPL(_GE, >=)
+DEFINE_CHECK_OP_IMPL(_GT, > )
+#undef DEFINE_CHECK_OP_IMPL
+
+// Helper macro for binary operators.
+// Don't use this macro directly in your code, use CHECK_EQ et al below.
+
+#if defined(STATIC_ANALYSIS)
+// Only for static analysis tool to know that it is equivalent to assert
+#define CHECK_OP_LOG(name, op, val1, val2, log) CHECK((val1) op (val2))
+#elif !defined(NDEBUG)
+// In debug mode, avoid constructing CheckOpStrings if possible,
+// to reduce the overhead of CHECK statments by 2x.
+// Real DCHECK-heavy tests have seen 1.5x speedups.
+
+// The meaning of "string" might be different between now and
+// when this macro gets invoked (e.g., if someone is experimenting
+// with other string implementations that get defined after this
+// file is included).  Save the current meaning now and use it
+// in the macro.
+typedef string _Check_string;
+#define CHECK_OP_LOG(name, op, val1, val2, log) \
+  while (_Check_string* _result = \
+         Check##name##Impl(GetReferenceableValue(val1), \
+                           GetReferenceableValue(val2), \
+                           #val1 " " #op " " #val2)) \
+    log(__FILE__, __LINE__, CheckOpString(_result)).stream()
+#else
+// In optimized mode, use CheckOpString to hint to compiler that
+// the while condition is unlikely.
+#define CHECK_OP_LOG(name, op, val1, val2, log) \
+  while (CheckOpString _result = \
+         Check##name##Impl(GetReferenceableValue(val1), \
+                           GetReferenceableValue(val2), \
+                           #val1 " " #op " " #val2)) \
+    log(__FILE__, __LINE__, _result).stream()
+#endif  // STATIC_ANALYSIS, !NDEBUG
+
+#if STRIP_LOG <= 3
+#define CHECK_OP(name, op, val1, val2) \
+  CHECK_OP_LOG(name, op, val1, val2, LogMessageFatal)
+#else
+#define CHECK_OP(name, op, val1, val2) \
+  CHECK_OP_LOG(name, op, val1, val2, NullStreamFatal)
+#endif // STRIP_LOG <= 3
+#define QCHECK_OP(name, op, val1, val2) \
+  CHECK_OP_LOG(name, op, val1, val2, LogMessageQuietlyFatal)
+
+// Equality/Inequality checks - compare two values, and log a FATAL message
+// including the two values when the result is not as expected.  The values
+// must have operator<<(ostream, ...) defined.
+//
+// You may append to the error message like so:
+//   CHECK_NE(1, 2) << ": The world must be ending!";
+//
+// We are very careful to ensure that each argument is evaluated exactly
+// once, and that anything which is legal to pass as a function argument is
+// legal here.  In particular, the arguments may be temporary expressions
+// which will end up being destroyed at the end of the apparent statement,
+// for example:
+//   CHECK_EQ(string("abc")[1], 'b');
+//
+// WARNING: These don't compile correctly if one of the arguments is a pointer
+// and the other is NULL. To work around this, simply static_cast NULL to the
+// type of the desired pointer.
+
+#define CHECK_EQ(val1, val2) CHECK_OP(_EQ, ==, val1, val2)
+#define CHECK_NE(val1, val2) CHECK_OP(_NE, !=, val1, val2)
+#define CHECK_LE(val1, val2) CHECK_OP(_LE, <=, val1, val2)
+#define CHECK_LT(val1, val2) CHECK_OP(_LT, < , val1, val2)
+#define CHECK_GE(val1, val2) CHECK_OP(_GE, >=, val1, val2)
+#define CHECK_GT(val1, val2) CHECK_OP(_GT, > , val1, val2)
+
+#define QCHECK_EQ(val1, val2) QCHECK_OP(_EQ, ==, val1, val2)
+#define QCHECK_NE(val1, val2) QCHECK_OP(_NE, !=, val1, val2)
+#define QCHECK_LE(val1, val2) QCHECK_OP(_LE, <=, val1, val2)
+#define QCHECK_LT(val1, val2) QCHECK_OP(_LT, < , val1, val2)
+#define QCHECK_GE(val1, val2) QCHECK_OP(_GE, >=, val1, val2)
+#define QCHECK_GT(val1, val2) QCHECK_OP(_GT, > , val1, val2)
+
+
+// Check that the input is non NULL.  This very useful in constructor
+// initializer lists.
+
+#define CHECK_NOTNULL(val) \
+  CheckNotNull(__FILE__, __LINE__, "'" #val "' Must be non NULL", (val))
+
+// Helper functions for string comparisons.
+// To avoid bloat, the definitions are in logging.cc.
+#define DECLARE_CHECK_STROP_IMPL(func, expected) \
+  string* Check##func##expected##Impl(const char* s1, const char* s2, \
+                                      const char* names);
+DECLARE_CHECK_STROP_IMPL(strcmp, true)
+DECLARE_CHECK_STROP_IMPL(strcmp, false)
+DECLARE_CHECK_STROP_IMPL(strcasecmp, true)
+DECLARE_CHECK_STROP_IMPL(strcasecmp, false)
+#undef DECLARE_CHECK_STROP_IMPL
+
+// Helper macro for string comparisons.
+// Don't use this macro directly in your code, use CHECK_STREQ et al below.
+#define CHECK_STROP(func, op, expected, s1, s2) \
+  while (CheckOpString _result = \
+         Check##func##expected##Impl((s1), (s2), \
+                                     #s1 " " #op " " #s2)) \
+    LOG(FATAL) << *_result.str_
+#define QCHECK_STROP(func, op, expected, s1, s2) \
+  while (CheckOpString _result = \
+         Check##func##expected##Impl((s1), (s2), \
+                                     #s1 " " #op " " #s2)) \
+    LOG(QFATAL) << *_result.str_
+
+
+// String (char*) equality/inequality checks.
+// CASE versions are case-insensitive.
+//
+// Note that "s1" and "s2" may be temporary strings which are destroyed
+// by the compiler at the end of the current "full expression"
+// (e.g. CHECK_STREQ(Foo().c_str(), Bar().c_str())).
+
+#define CHECK_STREQ(s1, s2) CHECK_STROP(strcmp, ==, true, s1, s2)
+#define CHECK_STRNE(s1, s2) CHECK_STROP(strcmp, !=, false, s1, s2)
+#define CHECK_STRCASEEQ(s1, s2) CHECK_STROP(strcasecmp, ==, true, s1, s2)
+#define CHECK_STRCASENE(s1, s2) CHECK_STROP(strcasecmp, !=, false, s1, s2)
+
+#define CHECK_INDEX(I,A) CHECK(I < (sizeof(A)/sizeof(A[0])))
+#define CHECK_BOUND(B,A) CHECK(B <= (sizeof(A)/sizeof(A[0])))
+
+#define QCHECK_STREQ(s1, s2) QCHECK_STROP(strcmp, ==, true, s1, s2)
+#define QCHECK_STRNE(s1, s2) QCHECK_STROP(strcmp, !=, false, s1, s2)
+#define QCHECK_STRCASEEQ(s1, s2) QCHECK_STROP(strcasecmp, ==, true, s1, s2)
+#define QCHECK_STRCASENE(s1, s2) QCHECK_STROP(strcasecmp, !=, false, s1, s2)
+
+#define QCHECK_INDEX(I,A) QCHECK(I < (sizeof(A)/sizeof(A[0])))
+#define QCHECK_BOUND(B,A) QCHECK(B <= (sizeof(A)/sizeof(A[0])))
+
+// Likely to be deprecated; instead use
+//   CHECK(MathUtil::NearByMargin(x, y))
+// (or another similar function from util/math/mathutil.h).
+#define CHECK_DOUBLE_EQ(val1, val2)              \
+  do {                                           \
+    CHECK_LE((val1), (val2)+0.000000000000001L); \
+    CHECK_GE((val1), (val2)-0.000000000000001L); \
+  } while (0)
+
+// Likely to be deprecated; instead use
+//   CHECK(MathUtil::WithinMargin(x, y, margin))
+// (or another similar function from util/math/mathutil.h).
+#define CHECK_NEAR(val1, val2, margin)           \
+  do {                                           \
+    CHECK_LE((val1), (val2)+(margin));           \
+    CHECK_GE((val1), (val2)-(margin));           \
+  } while (0)
+
+// perror()..googly style!
+//
+// PLOG() and PLOG_IF() and PCHECK() behave exactly like their LOG* and
+// CHECK equivalents with the addition that they postpend a description
+// of the current state of errno to their output lines.
+
+#define PLOG(severity) GOOGLE_PLOG(severity, 0).stream()
+
+#define GOOGLE_PLOG(severity, counter)  \
+  ErrnoLogMessage(__FILE__, __LINE__, severity, counter, \
+                  &LogMessage::SendToLog)
+
+#define PLOG_IF(severity, condition) \
+  !(condition) ? (void) 0 : LogMessageVoidify() & PLOG(severity)
+
+// A CHECK() macro that postpends errno if the condition is false. E.g.
+//
+// if (poll(fds, nfds, timeout) == -1) { PCHECK(errno == EINTR); ... }
+#define PCHECK(condition)  \
+      PLOG_IF(FATAL, PREDICT_FALSE(!(condition))) \
+              << "Check failed: " #condition " "
+
+// A CHECK() macro that lets you assert the success of a function that
+// returns -1 and sets errno in case of an error. E.g.
+//
+// CHECK_ERR(mkdir(path, 0700));
+//
+// or
+//
+// int fd = open(filename, flags); CHECK_ERR(fd) << ": open " << filename;
+#define CHECK_ERR(invocation)                                          \
+PLOG_IF(FATAL, PREDICT_FALSE((invocation) == -1)) << #invocation
+
+// Use macro expansion to create, for each use of LOG_EVERY_N(), static
+// variables with the __LINE__ expansion as part of the variable name.
+#define LOG_EVERY_N_VARNAME(base, line) LOG_EVERY_N_VARNAME_CONCAT(base, line)
+#define LOG_EVERY_N_VARNAME_CONCAT(base, line) base ## line
+
+#define LOG_OCCURRENCES LOG_EVERY_N_VARNAME(occurrences_, __LINE__)
+#define LOG_OCCURRENCES_MOD_N LOG_EVERY_N_VARNAME(occurrences_mod_n_, __LINE__)
+
+#define SOME_KIND_OF_LOG_EVERY_N(severity, n, what_to_do) \
+  static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
+  ++LOG_OCCURRENCES; \
+  if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
+  if (LOG_OCCURRENCES_MOD_N == 1) \
+    LogMessage(__FILE__, __LINE__, severity, LOG_OCCURRENCES, \
+               &what_to_do).stream()
+
+#define SOME_KIND_OF_LOG_IF_EVERY_N(severity, condition, n, what_to_do) \
+  static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
+  ANNOTATE_BENIGN_RACE(&LOG_OCCURRENCES, "logging"); \
+  ANNOTATE_BENIGN_RACE(&LOG_OCCURRENCES_MOD_N, "logging"); \
+  ++LOG_OCCURRENCES; \
+  if (condition && \
+      ((LOG_OCCURRENCES_MOD_N=(LOG_OCCURRENCES_MOD_N + 1) % n) == (1 % n))) \
+    LogMessage(__FILE__, __LINE__, severity, LOG_OCCURRENCES, \
+                 &what_to_do).stream()
+
+#define SOME_KIND_OF_PLOG_EVERY_N(severity, n, what_to_do) \
+  static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
+  ANNOTATE_BENIGN_RACE(&LOG_OCCURRENCES, "logging"); \
+  ANNOTATE_BENIGN_RACE(&LOG_OCCURRENCES_MOD_N, "logging"); \
+  ++LOG_OCCURRENCES; \
+  if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
+  if (LOG_OCCURRENCES_MOD_N == 1) \
+    ErrnoLogMessage(__FILE__, __LINE__, severity, LOG_OCCURRENCES, \
+                    &what_to_do).stream()
+
+#define SOME_KIND_OF_LOG_FIRST_N(severity, n, what_to_do) \
+  static int LOG_OCCURRENCES = 0; \
+  ANNOTATE_BENIGN_RACE(&LOG_OCCURRENCES, "logging"); \
+  if (LOG_OCCURRENCES <= n) \
+    ++LOG_OCCURRENCES; \
+  if (LOG_OCCURRENCES <= n) \
+    LogMessage(__FILE__, __LINE__, severity, LOG_OCCURRENCES, \
+               &what_to_do).stream()
+
+#define LOG_EVERY_N(severity, n) \
+  COMPILE_ASSERT(severity < NUM_SEVERITIES, \
+                 INVALID_REQUESTED_LOG_SEVERITY); \
+  SOME_KIND_OF_LOG_EVERY_N(severity, (n), LogMessage::SendToLog)
+
+#define SYSLOG_EVERY_N(severity, n) \
+  SOME_KIND_OF_LOG_EVERY_N(severity, (n), LogMessage::SendToSyslogAndLog)
+
+#define PLOG_EVERY_N(severity, n) \
+  SOME_KIND_OF_PLOG_EVERY_N(severity, (n), LogMessage::SendToLog)
+
+#define LOG_FIRST_N(severity, n) \
+  SOME_KIND_OF_LOG_FIRST_N(severity, (n), LogMessage::SendToLog)
+
+#define LOG_IF_EVERY_N(severity, condition, n) \
+  SOME_KIND_OF_LOG_IF_EVERY_N(severity, (condition), (n), LogMessage::SendToLog)
+
+// We want the special COUNTER value available for LOG_EVERY_X()'ed messages
+enum PRIVATE_Counter {COUNTER};
+
+
+// Plus some debug-logging macros that get compiled to nothing for production
+
+#ifndef NDEBUG
+
+#define DLOG(severity) LOG(severity)
+#define DVLOG(verboselevel) VLOG(verboselevel)
+#define DLOG_IF(severity, condition) LOG_IF(severity, condition)
+#define DLOG_EVERY_N(severity, n) LOG_EVERY_N(severity, n)
+#define DLOG_IF_EVERY_N(severity, condition, n) \
+  LOG_IF_EVERY_N(severity, condition, n)
+#define DLOG_ASSERT(condition) LOG_ASSERT(condition)
+
+// debug-only checking.  not executed in NDEBUG mode.
+#define DCHECK(condition) CHECK(condition)
+#define DCHECK_EQ(val1, val2) CHECK_EQ(val1, val2)
+#define DCHECK_NE(val1, val2) CHECK_NE(val1, val2)
+#define DCHECK_LE(val1, val2) CHECK_LE(val1, val2)
+#define DCHECK_LT(val1, val2) CHECK_LT(val1, val2)
+#define DCHECK_GE(val1, val2) CHECK_GE(val1, val2)
+#define DCHECK_GT(val1, val2) CHECK_GT(val1, val2)
+#define DCHECK_STREQ(str1, str2) CHECK_STREQ(str1, str2)
+#define DCHECK_STRCASEEQ(str1, str2) CHECK_STRCASEEQ(str1, str2)
+#define DCHECK_STRNE(str1, str2) CHECK_STRNE(str1, str2)
+#define DCHECK_STRCASENE(str1, str2) CHECK_STRCASENE(str1, str2)
+
+#else  // NDEBUG
+
+#define DLOG(severity) \
+  true ? (void) 0 : LogMessageVoidify() & LOG(severity)
+
+#define DVLOG(verboselevel) \
+  (true || !VLOG_IS_ON(verboselevel)) ?\
+    (void) 0 : LogMessageVoidify() & LOG(INFO)
+
+#define DLOG_IF(severity, condition) \
+  (true || !(condition)) ? (void) 0 : LogMessageVoidify() & LOG(severity)
+
+#define DLOG_EVERY_N(severity, n) \
+  true ? (void) 0 : LogMessageVoidify() & LOG(severity)
+
+#define DLOG_IF_EVERY_N(severity, condition, n) \
+  (true || !(condition))? (void) 0 : LogMessageVoidify() & LOG(severity)
+
+#define DLOG_ASSERT(condition) \
+  true ? (void) 0 : LOG_ASSERT(condition)
+
+#define DCHECK(condition) \
+  while (false) \
+    CHECK(condition)
+
+#define DCHECK_EQ(val1, val2) \
+  while (false) \
+    CHECK_EQ(val1, val2)
+
+#define DCHECK_NE(val1, val2) \
+  while (false) \
+    CHECK_NE(val1, val2)
+
+#define DCHECK_LE(val1, val2) \
+  while (false) \
+    CHECK_LE(val1, val2)
+
+#define DCHECK_LT(val1, val2) \
+  while (false) \
+    CHECK_LT(val1, val2)
+
+#define DCHECK_GE(val1, val2) \
+  while (false) \
+    CHECK_GE(val1, val2)
+
+#define DCHECK_GT(val1, val2) \
+  while (false) \
+    CHECK_GT(val1, val2)
+
+#define DCHECK_STREQ(str1, str2) \
+  while (false) \
+    CHECK_STREQ(str1, str2)
+
+#define DCHECK_STRCASEEQ(str1, str2) \
+  while (false) \
+    CHECK_STRCASEEQ(str1, str2)
+
+#define DCHECK_STRNE(str1, str2) \
+  while (false) \
+    CHECK_STRNE(str1, str2)
+
+#define DCHECK_STRCASENE(str1, str2) \
+  while (false) \
+    CHECK_STRCASENE(str1, str2)
+
+
+#endif  // NDEBUG
+
+// Log only in verbose mode.
+
+#define VLOG(verboselevel) LOG_IF(INFO, VLOG_IS_ON(verboselevel))
+
+#define VLOG_IF(verboselevel, condition) \
+  LOG_IF(INFO, (condition) && VLOG_IS_ON(verboselevel))
+
+#define VLOG_EVERY_N(verboselevel, n) \
+  LOG_IF_EVERY_N(INFO, VLOG_IS_ON(verboselevel), n)
+
+#define VLOG_IF_EVERY_N(verboselevel, condition, n) \
+  LOG_IF_EVERY_N(INFO, (condition) && VLOG_IS_ON(verboselevel), n)
+
+
+// [MLOG is OBSOLETE - use the more convenient VLOG(n) macros]
+// Log only when a module-specific value (MODULE_FLAG) has a specific
+// value.  MODULE_FLAG must be a macro that evaluates to the name of
+// the flag that you wish to use.  You should '#define MODULE_FLAG
+// <variable name>' before using this macro.  (For example:
+//       #define MODULE_FLAG FLAGS_dnsverbose
+#define MLOG(verboselevel) LOG_IF(INFO, MODULE_FLAG >= (verboselevel))
+
+// Redefine the standard assert to use our nice log files
+#undef assert
+#define assert(x) DLOG_ASSERT(x)
+
+//
+// This class more or less represents a particular log message.  You
+// create an instance of LogMessage and then stream stuff to it.
+// When you finish streaming to it, ~LogMessage is called and the
+// full message gets streamed to the appropriate destination.
+//
+// You shouldn't actually use LogMessage's constructor to log things,
+// though.  You should use the LOG() macro (and variants thereof)
+// above.
+class LogMessage {
+public:
+  enum {
+    // Passing kNoLogPrefix for the line number disables the
+    // log-message prefix. Useful for using the LogMessage
+    // infrastructure as a printing utility. See also the --log_prefix
+    // flag for controlling the log-message prefix on an
+    // application-wide basis.
+    kNoLogPrefix = -1
+  };
+
+  class LogStream : public ostrstream {
+  public:
+    LogStream(char *buf, int len, int ctr)
+      : ostrstream(buf, len),
+        ctr_(ctr) {
+      self_ = this;
+    }
+
+    int ctr() const { return ctr_; }
+    void set_ctr(int ctr) { ctr_ = ctr; }
+    LogStream* self() const { return self_; }
+
+  private:
+    int ctr_;  // Counter hack (for the LOG_EVERY_X() macro)
+    LogStream *self_;  // Consistency check hack
+  };
+
+public:
+  // icc 8 requires this typedef to avoid an internal compiler error.
+  typedef void (LogMessage::*SendMethod)();
+
+  LogMessage(const char* file, int line, LogSeverity severity, int ctr,
+             SendMethod send_method);
+
+  // Two special constructors that generate reduced amounts of code at
+  // LOG call sites for common cases.
+
+  // Used for LOG(INFO): Implied are:
+  // severity = INFO, ctr = 0, send_method = &LogMessage::SendToLog.
+  //
+  // Using this constructor instead of the more complex constructor above
+  // saves 19 bytes per call site.
+  LogMessage(const char* file, int line);
+
+  // Used for LOG(severity) where severity != INFO.  Implied
+  // are: ctr = 0, send_method = &LogMessage::SendToLog
+  //
+  // Using this constructor instead of the more complex constructor above
+  // saves 17 bytes per call site.
+  LogMessage(const char* file, int line, LogSeverity severity);
+
+  // Constructor to log this message to a specified sink (if not NULL).
+  // Implied are: ctr = 0, send_method = &LogMessage::SendToSinkAndLog if
+  // also_send_to_log is true, send_method = &LogMessage::SendToSink otherwise.
+  LogMessage(const char* file, int line, LogSeverity severity, LogSink* sink,
+             bool also_send_to_log);
+
+  // Constructor where we also give a vector<string> pointer
+  // for storing the messages (if the pointer is not NULL).
+  // Implied are: ctr = 0, send_method = &LogMessage::SaveOrSendToLog.
+  LogMessage(const char* file, int line, LogSeverity severity,
+             vector<string>* outvec);
+
+  // Constructor where we also give a string pointer for storing the
+  // message (if the pointer is not NULL).  Implied are: ctr = 0,
+  // send_method = &LogMessage::WriteToStringAndLog.
+  LogMessage(const char* file, int line, LogSeverity severity,
+             string* message);
+
+  // A special constructor used for check failures
+  LogMessage(const char* file, int line, const CheckOpString& result);
+
+  ~LogMessage();
+
+  // Flush a buffered message to the sink set in the constructor.  Always
+  // called by the destructor, it may also be called from elsewhere if
+  // needed.  Only the first call is actioned; any later ones are ignored.
+  void Flush();
+
+  // An arbitrary limit on the length of a single log message.  This
+  // is so that streaming can be done more efficiently.
+  static const size_t kMaxLogMessageLen;
+
+  // Theses should not be called directly outside of logging.*,
+  // only passed as SendMethod arguments to other LogMessage methods:
+  void SendToLog();  // Actually dispatch to the logs
+  void SendToSyslogAndLog();  // Actually dispatch to syslog and the logs
+
+  // Call abort() or similar to perform LOG(FATAL) crash.
+  // Writes current stack trace to stderr.
+  static void Fail() ATTRIBUTE_NORETURN;
+
+  // Same as Fail(), but without writing out the stack trace.
+  // It is assumed that the caller has already generated and
+  // written the trace as appropriate.
+  static void FailWithoutStackTrace() ATTRIBUTE_NORETURN;
+
+  // Similar to FailWithoutStackTrace(), but without abort()ing.
+  // Terminates the process with error exit code.
+  static void FailQuietly() ATTRIBUTE_NORETURN;
+
+  ostream& stream() { return *(data_->stream_); }
+
+  int preserved_errno() const { return data_->preserved_errno_; }
+
+  // Must be called without the log_mutex held.  (L < log_mutex)
+  static int64 num_messages(int severity);
+
+private:
+  // Fully internal SendMethod cases:
+  void SendToSinkAndLog();  // Send to sink if provided and dispatch to the logs
+  void SendToSink();  // Send to sink if provided, do nothing otherwise.
+
+  // Write to string if provided and dispatch to the logs.
+  void WriteToStringAndLog();
+
+  void SaveOrSendToLog();  // Save to stringvec if provided, else to logs
+
+  void Init(const char* file, int line, LogSeverity severity,
+            void (LogMessage::*send_method)());
+
+  // Used to fill in crash information during LOG(FATAL) failures.
+  void RecordCrashReason(base::CrashReason* reason);
+
+  // Counts of messages sent at each priority:
+  static int64 num_messages_[NUM_SEVERITIES];  // under log_mutex
+
+  // We keep the data in a separate struct so that each instance of
+  // LogMessage uses less stack space.
+  struct LogMessageData {
+    LogMessageData() {};
+
+    int preserved_errno_;         // errno at Init() time
+    scoped_array<char> buf_;      // buffer space for non FATAL messages
+    char* message_text_;          // Complete message text
+    scoped_ptr<LogStream> stream_alloc_;
+    LogStream* stream_;
+    char severity_;               // level of LogMessage (ex. I, W, E, F)
+    int line_;                    // line number of file that called LOG
+    void (LogMessage::*send_method_)();  // Call this in destructor to send
+    union {  // At most one of these is used: union to keep the size low.
+      LogSink* sink_;             // NULL or sink to send message to
+      vector<string>* outvec_;    // NULL or vector to push message onto
+      string* message_;           // NULL or string to write message into
+    };
+    time_t timestamp_;            // Time of creation of LogMessage
+    struct tm tm_time_;           // Time of creation of LogMessage
+    size_t num_prefix_chars_;     // # of chars of prefix in this message
+    size_t num_chars_to_log_;     // # of chars of msg to send to log
+    size_t num_chars_to_syslog_;  // # of chars of msg to send to syslog
+    const char* basename_;        // basename of file that called LOG
+    const char* fullname_;        // fullname of file that called LOG
+    bool has_been_flushed_;       // false => data has not been flushed
+    bool first_fatal_;            // true => this was first fatal msg
+
+   private:
+    DISALLOW_EVIL_CONSTRUCTORS(LogMessageData);
+  };
+
+  static LogMessageData fatal_msg_data_exclusive_;
+  static LogMessageData fatal_msg_data_shared_;
+
+  scoped_ptr<LogMessageData> allocated_;
+  LogMessageData* data_;
+
+  friend class LogDestination;
+
+  DISALLOW_EVIL_CONSTRUCTORS(LogMessage);
+
+protected:
+  // Default false; if true, all failures should be as quiet as possible. This
+  // is stored in LogMessage, rather than LogMessageData, because all FATAL-
+  // level handlers share the same LogMessageData for signal safety reasons.
+  bool fail_quietly_;
+};
+
+// This class happens to be thread-hostile because all instances share
+// a single data buffer, but since it can only be created just before
+// the process dies, we don't worry so much.
+class LogMessageFatal : public LogMessage {
+ public:
+  LogMessageFatal(const char* file, int line);
+  LogMessageFatal(const char* file, int line, const CheckOpString& result);
+  ~LogMessageFatal() ATTRIBUTE_NORETURN;
+};
+
+class LogMessageQuietlyFatal : public LogMessage {
+ public:
+  LogMessageQuietlyFatal(const char* file, int line);
+  LogMessageQuietlyFatal(const char* file, int line,
+                         const CheckOpString& result);
+  ~LogMessageQuietlyFatal() ATTRIBUTE_NORETURN;
+};
+
+// A non-macro interface to the log facility; (useful
+// when the logging level is not a compile-time constant).
+inline void LogAtLevel(int const severity, string const &msg) {
+  LogMessage(__FILE__, __LINE__, severity).stream() << msg;
+}
+
+// A macro alternative of LogAtLevel. New code may want to use this
+// version since there are two advantages: 1. this version outputs the
+// file name and the line number where this macro is put like other
+// LOG macros, 2. this macro can be used as C++ stream.
+#define LOG_AT_LEVEL(severity) LogMessage(__FILE__, __LINE__, severity).stream()
+
+// Helpers for CHECK_NOTNULL(). Two are necessary to support both raw pointers
+// and smart pointers.
+template <typename T>
+T* CheckNotNull(const char *file, int line, const char *names, T* t) {
+  return CheckNotNullCommon(file, line, names, t);
+}
+
+template <typename T>
+T& CheckNotNull(const char *file, int line, const char *names, T& t) {
+  return CheckNotNullCommon(file, line, names, t);
+}
+
+template <typename T>
+T& CheckNotNullCommon(const char *file, int line, const char *names, T& t) {
+  if (t == NULL) {
+    LogMessageFatal(file, line, new string(names));
+  }
+  return t;
+}
+
+// Allow folks to put a counter in the LOG_EVERY_X()'ed messages. This
+// only works if ostream is a LogStream. If the ostream is not a
+// LogStream you'll get an assert saying as much at runtime.
+ostream& operator<<(ostream &os, const PRIVATE_Counter&);
+
+
+// We need to be able to stream DocIds.  But if DocIds are the same as
+// a built-in type, don't try to redefine things that are already
+// defined!
+#ifndef NDEBUG
+inline ostream& operator<<(ostream& o, const DocId& d) {
+  return (o << DocidForPrintf(d));
+}
+
+inline ostream& operator<<(ostream& o, const DocId32Bit& d) {
+  return (o << Docid32BitForPrintf(d));
+}
+#endif  // NDEBUG
+
+
+// Derived class for PLOG*() above.
+class ErrnoLogMessage : public LogMessage {
+ public:
+
+  ErrnoLogMessage(const char* file, int line, LogSeverity severity, int ctr,
+                  void (LogMessage::*send_method)());
+
+  // Postpends ": strerror(errno) [errno]".
+  ~ErrnoLogMessage();
+
+ private:
+
+  DISALLOW_EVIL_CONSTRUCTORS(ErrnoLogMessage);
+};
+
+
+// This class is used to explicitly ignore values in the conditional
+// logging macros.  This avoids compiler warnings like "value computed
+// is not used" and "statement has no effect".
+
+class LogMessageVoidify {
+ public:
+  LogMessageVoidify() { }
+  // This has to be an operator with a precedence lower than << but
+  // higher than ?:
+  void operator&(ostream&) { }
+};
+
+
+// Flushes all log files that contains messages that are at least of
+// the specified severity level.  Thread-safe.
+void FlushLogFiles(LogSeverity min_severity);
+
+// Flushes all log files that contains messages that are at least of
+// the specified severity level. Thread-hostile because it ignores
+// locking -- used for catastrophic failures.
+void FlushLogFilesUnsafe(LogSeverity min_severity);
+
+//
+// Set the destination to which a particular severity level of log
+// messages is sent.  If base_filename is "", it means "don't log this
+// severity".  Thread-safe.
+//
+void SetLogDestination(LogSeverity severity, const char* base_filename);
+
+//
+// Set the basename of the symlink to the latest log file at a given
+// severity.  If symlink_basename is empty, do not make a symlink.  If
+// you don't call this function, the symlink basename is the
+// invocation name of the program.  Thread-safe.
+//
+void SetLogSymlink(LogSeverity severity, const char* symlink_basename);
+
+//
+// Used to send logs to some other kind of destination
+// Users should subclass LogSink and override send to do whatever they want.
+// Implementations must be thread-safe because a shared instance will
+// be called from whichever thread ran the LOG(XXX) line.
+class LogSink {
+ public:
+  virtual ~LogSink();
+
+  // Sink's logging logic (message_len is such as to exclude '\n' at the end).
+  // This method can't use LOG() or CHECK() as logging system mutex(s) are held
+  // during this call.
+  virtual void send(LogSeverity severity, const char* full_filename,
+                    const char* base_filename, int line,
+                    const struct tm* tm_time,
+                    const char* message, size_t message_len) = 0;
+
+  // Redefine this to implement waiting for
+  // the sink's logging logic to complete.
+  // It will be called after each send() returns,
+  // but before that LogMessage exits or crashes.
+  // By default this function does nothing.
+  // Using this function one can implement complex logic for send()
+  // that itself involves logging; and do all this w/o causing deadlocks and
+  // inconsistent rearrangement of log messages.
+  // E.g. if a LogSink has thread-specific actions, the send() method
+  // can simply add the message to a queue and wake up another thread that
+  // handles real logging while itself making some LOG() calls;
+  // WaitTillSent() can be implemented to wait for that logic to complete.
+  // See our unittest for an example.
+  virtual void WaitTillSent();
+
+  // Returns the normal text output of the log message.
+  // Can be useful to implement send().
+  static string ToString(LogSeverity severity, const char* file, int line,
+                         const struct tm* tm_time,
+                         const char* message, size_t message_len);
+};
+
+// Add or remove a LogSink as a consumer of logging data.  Thread-safe.
+void AddLogSink(LogSink *destination);
+void RemoveLogSink(LogSink *destination);
+
+//
+// Specify an "extension" added to the filename specified via
+// SetLogDestination.  This applies to all severity levels.  It's
+// often used to append the port we're listening on to the logfile
+// name.  Thread-safe.
+//
+void SetLogFilenameExtension(const char* filename_extension);
+
+//
+// Make it so that all log messages of at least a particular severity
+// are logged to stderr (in addition to logging to the usual log
+// file(s)).  Thread-safe.
+//
+void SetStderrLogging(LogSeverity min_severity);
+
+//
+// Make it so that all log messages go only to stderr.  Thread-safe.
+//
+void LogToStderr();
+
+//
+// Make it so that all log messages of at least a particular severity are
+// logged via email to a list of addresses (in addition to logging to the
+// usual log file(s)).  The list of addresses is just a string containing
+// the email addresses to send to (separated by spaces, say).
+//
+// Beyond thread-hostile.  This function enables email logging,
+// which calls popen() if any log messages are actually mailed.
+// A multi-thread program which calls this function, even in a single thread,
+// will randomly hang if it logs any messages which are mailed.
+void SetEmailLogging(LogSeverity min_severity, const char* addresses);
+
+//
+// Generate a special "status" message.  This will be useful to
+// monitoring scripts that want to know about the progress of
+// a long-running program.  The two supplied arguments should have
+// identical units.  The "done" argument says how much work has
+// been completed, and the "total" argument says how much total
+// work has to be done.  Thread-hostile if
+// FLAGS_status_messages_to_status_file.  Thread-safe otherwise.
+//
+void StatusMessage(int64 done, int64 total);
+
+// Like StatusMessage(), only writes the status to the file ./STATUS
+// Intended to make life easier for processes running on the global
+// work queue, where the standard status message file is ./STATUS.
+// Thread-hostile.
+void GWQStatusMessage(const char* msg);
+
+// A simple function that sends email. dest is a comma-separated
+// list of addressess.
+//
+// Beyond thread-hostile.  This function calls popen().
+// A multi-thread program which calls this function, even in a single thread,
+// will randomly hang.
+bool SendEmail(const char*dest, const char *subject, const char*body);
+
+// Return the set of directories to try generating a log file into.
+// Thread-hostile, but expected to only be called from InitGoogle.
+const vector<string>& GetLoggingDirectories();
+
+// For tests only:  Clear the internal [cached] list of logging directories to
+// force a refresh the next time GetLoggingDirectories is called.
+// Thread-hostile.
+void TestOnly_ClearLoggingDirectoriesList();
+
+// Returns a set of existing temporary directories, which will be a
+// subset of the directories returned by GetLogginDirectories().
+// Thread-safe.
+void GetExistingTempDirectories(vector<string>* list);
+
+// Print any fatal message again -- useful to call from signal handler
+// so that the last thing in the output is the fatal message.
+// Thread-hostile, but a race is unlikely.
+void ReprintFatalMessage();
+
+// Truncate a log file that may be the append-only output of multiple
+// processes and hence can't simply be renamed/reopened (typically a
+// stdout/stderr).  If the file "path" is > "limit" bytes, copy the
+// last "keep" bytes to offset 0 and truncate the rest. Since we could
+// be racing with other writers, this approach has the potential to
+// lose very small amounts of data. For security, only follow symlinks
+// if the path is /proc/self/fd/*
+void TruncateLogFile(const char *path, int64 limit, int64 keep);
+
+// Truncate stdout and stderr if they are over the value specified by
+// --max_log_size; keep the final 1MB.  This function has the same
+// race condition as TruncateLogFile.
+void TruncateStdoutStderr();
+
+// Return the string representation of the provided LogSeverity level.
+// Thread-safe.
+const char* GetLogSeverityName(LogSeverity severity);
+
+// ---------------------------------------------------------------------
+// Implementation details that are not useful to most clients
+// ---------------------------------------------------------------------
+
+// A Logger is the interface used by logging modules (base/logging.cc
+// and file/logging/blog.cc) to emit entries to a log.  A typical
+// implementation will dump formatted data to a sequence of files.  We
+// also provide interfaces that will forward the data to another
+// thread so that the invoker never blocks.  Implementations should be
+// thread-safe since the logging system will write to them from
+// multiple threads.
+
+namespace base {
+
+class Logger {
+ public:
+  virtual ~Logger();
+
+  // Writes "message[0,message_len-1]" corresponding to an event that
+  // occurred at "timestamp".  If "force_flush" is true, the log file
+  // is flushed immediately.
+  //
+  // The input message has already been formatted as deemed
+  // appropriate by the higher level logging facility.  For example,
+  // textual log messages already contain timestamps, and the
+  // file:linenumber header.
+  virtual void Write(bool force_flush,
+                     time_t timestamp,
+                     const char* message,
+                     int message_len) = 0;
+
+  // Flush any buffered messages
+  virtual void Flush() = 0;
+
+  // Get the current LOG file size.
+  // The returned value is approximate since some
+  // logged data may not have been flushed to disk yet.
+  virtual uint32 LogSize() = 0;
+};
+
+// Get the logger for the specified severity level.  The logger
+// remains the property of the logging module and should not be
+// deleted by the caller.  Thread-safe.
+extern Logger* GetLogger(LogSeverity level);
+
+// Set the logger for the specified severity level.  The logger
+// becomes the property of the logging module and should not
+// be deleted by the caller.  Thread-safe.
+extern void SetLogger(LogSeverity level, Logger* logger);
+
+}
+
+// glibc has traditionally implemented two incompatible versions of
+// strerror_r(). There is a poorly defined convention for picking the
+// version that we want, but it is not clear whether it even works with
+// all versions of glibc.
+// So, instead, we provide this wrapper that automatically detects the
+// version that is in use, and then implements POSIX semantics.
+// N.B. In addition to what POSIX says, we also guarantee that "buf" will
+// be set to an empty string, if this function failed. This means, in most
+// cases, you do not need to check the error code and you can directly
+// use the value of "buf". It will never have an undefined value.
+int posix_strerror_r(int err, char *buf, size_t len);
+
+
+// A class for which we define operator<<, which does nothing.
+class NullStream : public LogMessage::LogStream {
+ public:
+  // Initialize the LogStream so the messages can be written somewhere
+  // (they'll never be actually displayed). This will be needed if a
+  // NullStream& is implicitly converted to LogStream&, in which case
+  // the overloaded NullStream::operator<< will not be invoked.
+  NullStream() : LogMessage::LogStream(message_buffer_, 1, 0) { }
+  NullStream(const char* /*file*/, int /*line*/,
+             const CheckOpString& /*result*/) :
+      LogMessage::LogStream(message_buffer_, 1, 0) { }
+  NullStream &stream() { return *this; }
+ private:
+  // A very short buffer for messages (which we discard anyway). This
+  // will be needed if NullStream& converted to LogStream& (e.g. as a
+  // result of a conditional expression).
+  char message_buffer_[2];
+};
+
+// Do nothing. This operator is inline, allowing the message to be
+// compiled away. The message will not be compiled away if we do
+// something like (flag ? LOG(INFO) : LOG(ERROR)) << message; when
+// SKIP_LOG=WARNING. In those cases, NullStream will be implicitly
+// converted to LogStream and the message will be computed and then
+// quietly discarded.
+template<class T>
+inline NullStream& operator<<(NullStream &str, const T &value) { return str; }
+
+// Similar to NullStream, but aborts the program (without stack
+// trace), like LogMessageFatal.
+class NullStreamFatal : public NullStream {
+ public:
+  NullStreamFatal() { }
+  NullStreamFatal(const char* file, int line, const CheckOpString& result) :
+      NullStream(file, line, result) { }
+  ~NullStreamFatal() ATTRIBUTE_NORETURN { _exit(1); }
+};
+
+#endif // _LOGGING_H_
Property changes on: third_party\cld\base\logging.h
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Added: svn:eol-style
   + LF