1 // This file is automatically generated from src/glog/vlog_is_on.h.in
2 // using src/windows/preprocess.sh.
5 // Copyright 1999, 2007 Google Inc. All Rights Reserved.
6 // Author: Ray Sidney and many others
8 // Defines the VLOG_IS_ON macro that controls the variable-verbosity
9 // conditional logging.
11 // It's used by VLOG and VLOG_IF in logging.h
12 // and by RAW_VLOG in raw_logging.h to trigger the logging.
14 // It can also be used directly e.g. like this:
15 // if (VLOG_IS_ON(2)) {
16 // // do some logging preparation and logging
17 // // that can't be accomplished e.g. via just VLOG(2) << ...;
20 // The truth value that VLOG_IS_ON(level) returns is determined by
21 // the three verbosity level flags:
22 // --v=<n> Gives the default maximal active V-logging level;
24 // Normally positive values are used for V-logging levels.
25 // --vmodule=<str> Gives the per-module maximal V-logging levels to override
26 // the value given by --v.
27 // E.g. "my_module=2,foo*=3" would change the logging level
28 // for all code in source files "my_module.*" and "foo*.*"
29 // ("-inl" suffixes are also disregarded for this matching).
31 // SetVLOGLevel helper function is provided to do limited dynamic control over
32 // V-logging by overriding the per-module settings given via --vmodule flag.
34 // CAVEAT: --vmodule functionality is not available in non gcc compilers.
37 #ifndef BASE_VLOG_IS_ON_H_
38 #define BASE_VLOG_IS_ON_H_
40 #include "glog/log_severity.h"
42 // Annoying stuff for windows -- makes sure clients can import these functions
43 #ifndef GOOGLE_GLOG_DLL_DECL
45 # define GOOGLE_GLOG_DLL_DECL __declspec(dllimport)
47 # define GOOGLE_GLOG_DLL_DECL
52 // We emit an anonymous static int* variable at every VLOG_IS_ON(n) site.
53 // (Normally) the first time every VLOG_IS_ON(n) site is hit,
54 // we determine what variable will dynamically control logging at this site:
55 // it's either FLAGS_v or an appropriate internal variable
56 // matching the current source file that represents results of
57 // parsing of --vmodule flag and/or SetVLOGLevel calls.
58 #define VLOG_IS_ON(verboselevel) \
59 ({ static google::int32* vlocal__ = &google::kLogSiteUninitialized; \
60 google::int32 verbose_level__ = (verboselevel); \
61 (*vlocal__ >= verbose_level__) && \
62 ((vlocal__ != &google::kLogSiteUninitialized) || \
63 (google::InitVLOG3__(&vlocal__, &FLAGS_v, \
64 __FILE__, verbose_level__))); })
66 // GNU extensions not available, so we do not support --vmodule.
67 // Dynamic value of FLAGS_v always controls the logging level.
68 #define VLOG_IS_ON(verboselevel) (FLAGS_v >= (verboselevel))
71 // Set VLOG(_IS_ON) level for module_pattern to log_level.
72 // This lets us dynamically control what is normally set by the --vmodule flag.
73 // Returns the level that previously applied to module_pattern.
74 // NOTE: To change the log level for VLOG(_IS_ON) sites
75 // that have already executed after/during InitGoogleLogging,
76 // one needs to supply the exact --vmodule pattern that applied to them.
77 // (If no --vmodule pattern applied to them
78 // the value of FLAGS_v will continue to control them.)
79 extern GOOGLE_GLOG_DLL_DECL int SetVLOGLevel(const char* module_pattern,
82 // Various declarations needed for VLOG_IS_ON above: =========================
84 // Special value used to indicate that a VLOG_IS_ON site has not been
85 // initialized. We make this a large value, so the common-case check
86 // of "*vlocal__ >= verbose_level__" in VLOG_IS_ON definition
87 // passes in such cases and InitVLOG3__ is then triggered.
88 extern google::int32 kLogSiteUninitialized;
90 // Helper routine which determines the logging info for a particalur VLOG site.
91 // site_flag is the address of the site-local pointer to the controlling
93 // site_default is the default to use for *site_flag
94 // fname is the current source file name
95 // verbose_level is the argument to VLOG_IS_ON
96 // We will return the return value for VLOG_IS_ON
97 // and if possible set *site_flag appropriately.
98 extern GOOGLE_GLOG_DLL_DECL bool InitVLOG3__(
99 google::int32** site_flag,
100 google::int32* site_default,
102 google::int32 verbose_level);
104 #endif // BASE_VLOG_IS_ON_H_