[go: up one dir, main page]

log 0.3.0

A lightweight logging facade for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145

// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/// The standard logging macro.
///
/// This macro will generically log with the specified `LogLevel` and `format!`
/// based argument list.
///
/// The `log_level` cfg can be used to statically disable logging at various
/// levels.
#[macro_export]
macro_rules! log {
    (target: $target:expr, $lvl:expr, $($arg:tt)+) => ({
        static LOC: $crate::LogLocation = $crate::LogLocation {
            __line: line!(),
            __file: file!(),
            __module_path: module_path!(),
        };
        let lvl = $lvl;
        if !cfg!(log_level = "off") &&
                (lvl <= $crate::LogLevel::Error || !cfg!(log_level = "error")) &&
                (lvl <= $crate::LogLevel::Warn || !cfg!(log_level = "warn")) &&
                (lvl <= $crate::LogLevel::Debug || !cfg!(log_level = "debug")) &&
                (lvl <= $crate::LogLevel::Info || !cfg!(log_level = "info")) &&
                lvl <= $crate::max_log_level() {
            $crate::__log(lvl, $target, &LOC, format_args!($($arg)+))
        }
    });
    ($lvl:expr, $($arg:tt)+) => (log!(target: module_path!(), $lvl, $($arg)+))
}

/// Logs a message at the error level.
///
/// Logging at this level is disabled if the `log_level = "off"` cfg is
/// present.
#[macro_export]
macro_rules! error {
    (target: $target:expr, $($arg:tt)*) => (
        log!(target: $target, $crate::LogLevel::Error, $($arg)*);
    );
    ($($arg:tt)*) => (
        log!($crate::LogLevel::Error, $($arg)*);
    )
}

/// Logs a message at the warn level.
///
/// Logging at this level is disabled if any of the following cfgs are present:
/// `log_level = "off"` or `log_level = "error"`.
#[macro_export]
macro_rules! warn {
    (target: $target:expr, $($arg:tt)*) => (
        log!(target: $target, $crate::LogLevel::Warn, $($arg)*);
    );
    ($($arg:tt)*) => (
        log!($crate::LogLevel::Warn, $($arg)*);
    )
}

/// Logs a message at the info level.
///
/// Logging at this level is disabled if any of the following cfgs are present:
/// `log_level = "off"`, `log_level = "error"`, or
/// `log_level = "warn"`.
#[macro_export]
macro_rules! info {
    (target: $target:expr, $($arg:tt)*) => (
        log!(target: $target, $crate::LogLevel::Info, $($arg)*);
    );
    ($($arg:tt)*) => (
        log!($crate::LogLevel::Info, $($arg)*);
    )
}

/// Logs a message at the debug level.
///
/// Logging at this level is disabled if any of the following cfgs are present:
/// `log_level = "off"`, `log_level = "error"`, `log_level = "warn"`,
/// or `log_level = "info"`.
#[macro_export]
macro_rules! debug {
    (target: $target:expr, $($arg:tt)*) => (
        log!(target: $target, $crate::LogLevel::Debug, $($arg)*);
    );
    ($($arg:tt)*) => (
        log!($crate::LogLevel::Debug, $($arg)*);
    )
}

/// Logs a message at the trace level.
///
/// Logging at this level is disabled if any of the following cfgs are present:
/// `log_level = "off"`, `log_level = "error"`, `log_level = "warn"`,
/// `log_level = "info"`, or `log_level = "debug"`.
#[macro_export]
macro_rules! trace {
    (target: $target:expr, $($arg:tt)*) => (
        log!(target: $target, $crate::LogLevel::Trace, $($arg)*);
    );
    ($($arg:tt)*) => (
        log!($crate::LogLevel::Trace, $($arg)*);
    )
}

/// Determines if a message logged at the specified level in that module will
/// be logged.
///
/// This can be used to avoid expensive computation of log message arguments if
/// the message would be ignored anyway.
///
/// # Examples
///
/// ```rust
/// # #[macro_use]
/// # extern crate log;
/// use log::LogLevel::Debug;
///
/// # fn foo() {
/// if log_enabled!(Debug) {
///     debug!("expensive debug data: {}", expensive_call());
/// }
/// # }
/// # fn expensive_call() -> u32 { 0 }
/// # fn main() {}
/// ```
#[macro_export]
macro_rules! log_enabled {
    (target: $target:expr, $lvl:expr) => ({
        let lvl = $lvl;
        !cfg!(log_level = "off") &&
            (lvl <= $crate::LogLevel::Error || !cfg!(log_level = "error")) &&
            (lvl <= $crate::LogLevel::Warn || !cfg!(log_level = "warn")) &&
            (lvl <= $crate::LogLevel::Debug || !cfg!(log_level = "debug")) &&
            (lvl <= $crate::LogLevel::Info || !cfg!(log_level = "info")) &&
            lvl <= $crate::max_log_level() &&
            $crate::__enabled(lvl, $target)
    });
    ($lvl:expr) => (log_enabled!(target: module_path!(), $lvl))
}