From a75f72d45a1c1399adab0e123acdb76582a360ae Mon Sep 17 00:00:00 2001 From: Philipp Brüschweiler Date: Mon, 2 Dec 2013 21:47:57 +0100 Subject: Add a macro to check if logging at a given label is enabled This is useful when the information that is needed to do useful logging is expensive to produce. --- src/libstd/logging.rs | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) (limited to 'src/libstd') diff --git a/src/libstd/logging.rs b/src/libstd/logging.rs index 1b540823f17..1605dcebf1a 100644 --- a/src/libstd/logging.rs +++ b/src/libstd/logging.rs @@ -20,14 +20,20 @@ There are five macros that the logging subsystem uses: * `log!(level, ...)` - the generic logging macro, takes a level as a u32 and any related `format!` arguments -* `debug!(...)` - a macro hard-wired to the log level of 4 -* `info!(...)` - a macro hard-wired to the log level of 3 -* `warn!(...)` - a macro hard-wired to the log level of 2 -* `error!(...)` - a macro hard-wired to the log level of 1 +* `debug!(...)` - a macro hard-wired to the log level of `DEBUG` +* `info!(...)` - a macro hard-wired to the log level of `INFO` +* `warn!(...)` - a macro hard-wired to the log level of `WARN` +* `error!(...)` - a macro hard-wired to the log level of `ERROR` All of these macros use the same style of syntax as the `format!` syntax extension. Details about the syntax can be found in the documentation of -`std::fmt` along with the Rust tutorial/manual +`std::fmt` along with the Rust tutorial/manual. + +If you want to check at runtime if a given logging level is enabled (e.g. if the +information you would want to log is expensive to produce), you can use the +following macro: + +* `log_enabled!(level)` - returns true if logging of the given level is enabled ## Enabling logging @@ -95,6 +101,15 @@ use rt::local::Local; use rt::logging::{Logger, StdErrLogger}; use rt::task::Task; +/// Debug log level +pub static DEBUG: u32 = 4; +/// Info log level +pub static INFO: u32 = 3; +/// Warn log level +pub static WARN: u32 = 2; +/// Error log level +pub static ERROR: u32 = 1; + /// This function is called directly by the compiler when using the logging /// macros. This function does not take into account whether the log level /// specified is active or not, it will always log something if this method is -- cgit 1.4.1-3-g733a5