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// Copyright 1999, 2007 Google Inc. All Rights Reserved.
// Author: Ray Sidney and many others
// Defines the VLOG_IS_ON macro that controls the variable-verbosity
// conditional logging.
// It's used by VLOG and VLOG_IF in logging.h
// and by RAW_VLOG in raw_logging.h to trigger the logging.
// It can also be used directly e.g. like this:
// if (VLOG_IS_ON(2)) {
// // do some logging preparation and logging
// // that can't be accomplished e.g. via just VLOG(2) << ...;
// }
// The truth value that VLOG_IS_ON(level) returns is determined by
// the three verbosity level flags:
// --v=<n> Gives the default maximal active V-logging level;
// 0 is the default.
// Normally positive values are used for V-logging levels.
// --vmodule=<str> Gives the per-module maximal V-logging levels to override
// the value given by --v.
// E.g. "my_module=2,foo*=3" would change the logging level
// for all code in source files "my_module.*" and "foo*.*"
// ("-inl" suffixes are also disregarded for this matching).
// SetVLOGLevel helper function is provided to do limited dynamic control over
// V-logging by overriding the per-module settings given via --vmodule flag.
// CAVEAT: --vmodule functionality is not available in non gcc compilers.
#ifndef BASE_VLOG_IS_ON_H_
#define BASE_VLOG_IS_ON_H_
#include "glog/log_severity.h"
#if defined(__GNUC__)
// We emit an anonymous static int* variable at every VLOG_IS_ON(n) site.
// (Normally) the first time every VLOG_IS_ON(n) site is hit,
// we determine what variable will dynamically control logging at this site:
// it's either FLAGS_v or an appropriate internal variable
// matching the current source file that represents results of
// parsing of --vmodule flag and/or SetVLOGLevel calls.
#define VLOG_IS_ON(verboselevel) \
({ static @ac_google_namespace@::int32* vlocal__ = &@ac_google_namespace@::kLogSiteUninitialized; \
@ac_google_namespace@::int32 verbose_level__ = (verboselevel); \
(*vlocal__ >= verbose_level__) && \
((vlocal__ != &@ac_google_namespace@::kLogSiteUninitialized) || \
(@ac_google_namespace@::InitVLOG3__(&vlocal__, &FLAGS_v, \
__FILE__, verbose_level__))); })
// GNU extensions not available, so we do not support --vmodule.
// Dynamic value of FLAGS_v always controls the logging level.
#define VLOG_IS_ON(verboselevel) (FLAGS_v >= (verboselevel))
// Set VLOG(_IS_ON) level for module_pattern to log_level.
// This lets us dynamically control what is normally set by the --vmodule flag.
// Returns the level that previously applied to module_pattern.
// NOTE: To change the log level for VLOG(_IS_ON) sites
// that have already executed after/during InitGoogleLogging,
// one needs to supply the exact --vmodule pattern that applied to them.
// (If no --vmodule pattern applied to them
// the value of FLAGS_v will continue to control them.)
extern int SetVLOGLevel(const char* module_pattern, int log_level);
// Various declarations needed for VLOG_IS_ON above: =========================
// Special value used to indicate that a VLOG_IS_ON site has not been
// initialized. We make this a large value, so the common-case check
// of "*vlocal__ >= verbose_level__" in VLOG_IS_ON definition
// passes in such cases and InitVLOG3__ is then triggered.
extern @ac_google_namespace@::int32 kLogSiteUninitialized;
// Helper routine which determines the logging info for a particalur VLOG site.
// site_flag is the address of the site-local pointer to the controlling
// verbosity level
// site_default is the default to use for *site_flag
// fname is the current source file name
// verbose_level is the argument to VLOG_IS_ON
// We will return the return value for VLOG_IS_ON
// and if possible set *site_flag appropriately.
extern bool InitVLOG3__(@ac_google_namespace@::int32** site_flag,
@ac_google_namespace@::int32* site_default,
const char* fname,
@ac_google_namespace@::int32 verbose_level);
#endif // BASE_VLOG_IS_ON_H_