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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
// 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 `Level` and `format!`
/// based argument list.
///
/// # Examples
///
/// ```edition2018
/// use log::{log, Level};
///
/// # fn main() {
/// let data = (42, "Forty-two");
/// let private_data = "private";
///
/// log!(Level::Error, "Received errors: {}, {}", data.0, data.1);
/// log!(target: "app_events", Level::Warn, "App warning: {}, {}, {}",
///     data.0, data.1, private_data);
/// # }
/// ```
#[macro_export(local_inner_macros)]
macro_rules! log {
    (target: $target:expr, $lvl:expr, $message:expr) => ({
        let lvl = $lvl;
        if lvl <= $crate::STATIC_MAX_LEVEL && lvl <= $crate::max_level() {
            // ensure that $message is a valid format string literal
            let _ = __log_format_args!($message);
            $crate::__private_api_log_lit(
                $message,
                lvl,
                &($target, __log_module_path!(), __log_file!(), __log_line!()),
            );
        }
    });
    (target: $target:expr, $lvl:expr, $($arg:tt)+) => ({
        let lvl = $lvl;
        if lvl <= $crate::STATIC_MAX_LEVEL && lvl <= $crate::max_level() {
            $crate::__private_api_log(
                __log_format_args!($($arg)+),
                lvl,
                &($target, __log_module_path!(), __log_file!(), __log_line!()),
            );
        }
    });
    ($lvl:expr, $($arg:tt)+) => (log!(target: __log_module_path!(), $lvl, $($arg)+))
}

/// Logs a message at the error level.
///
/// # Examples
///
/// ```edition2018
/// use log::error;
///
/// # fn main() {
/// let (err_info, port) = ("No connection", 22);
///
/// error!("Error: {} on port {}", err_info, port);
/// error!(target: "app_events", "App Error: {}, Port: {}", err_info, 22);
/// # }
/// ```
#[macro_export(local_inner_macros)]
macro_rules! error {
    (target: $target:expr, $($arg:tt)+) => (
        log!(target: $target, $crate::Level::Error, $($arg)+);
    );
    ($($arg:tt)+) => (
        log!($crate::Level::Error, $($arg)+);
    )
}

/// Logs a message at the warn level.
///
/// # Examples
///
/// ```edition2018
/// use log::warn;
///
/// # fn main() {
/// let warn_description = "Invalid Input";
///
/// warn!("Warning! {}!", warn_description);
/// warn!(target: "input_events", "App received warning: {}", warn_description);
/// # }
/// ```
#[macro_export(local_inner_macros)]
macro_rules! warn {
    (target: $target:expr, $($arg:tt)+) => (
        log!(target: $target, $crate::Level::Warn, $($arg)+);
    );
    ($($arg:tt)+) => (
        log!($crate::Level::Warn, $($arg)+);
    )
}

/// Logs a message at the info level.
///
/// # Examples
///
/// ```edition2018
/// use log::info;
///
/// # fn main() {
/// # struct Connection { port: u32, speed: f32 }
/// let conn_info = Connection { port: 40, speed: 3.20 };
///
/// info!("Connected to port {} at {} Mb/s", conn_info.port, conn_info.speed);
/// info!(target: "connection_events", "Successfull connection, port: {}, speed: {}",
///       conn_info.port, conn_info.speed);
/// # }
/// ```
#[macro_export(local_inner_macros)]
macro_rules! info {
    (target: $target:expr, $($arg:tt)+) => (
        log!(target: $target, $crate::Level::Info, $($arg)+);
    );
    ($($arg:tt)+) => (
        log!($crate::Level::Info, $($arg)+);
    )
}

/// Logs a message at the debug level.
///
/// # Examples
///
/// ```edition2018
/// use log::debug;
///
/// # fn main() {
/// # struct Position { x: f32, y: f32 }
/// let pos = Position { x: 3.234, y: -1.223 };
///
/// debug!("New position: x: {}, y: {}", pos.x, pos.y);
/// debug!(target: "app_events", "New position: x: {}, y: {}", pos.x, pos.y);
/// # }
/// ```
#[macro_export(local_inner_macros)]
macro_rules! debug {
    (target: $target:expr, $($arg:tt)+) => (
        log!(target: $target, $crate::Level::Debug, $($arg)+);
    );
    ($($arg:tt)+) => (
        log!($crate::Level::Debug, $($arg)+);
    )
}

/// Logs a message at the trace level.
///
/// # Examples
///
/// ```edition2018
/// use log::trace;
///
/// # fn main() {
/// # struct Position { x: f32, y: f32 }
/// let pos = Position { x: 3.234, y: -1.223 };
///
/// trace!("Position is: x: {}, y: {}", pos.x, pos.y);
/// trace!(target: "app_events", "x is {} and y is {}",
///        if pos.x >= 0.0 { "positive" } else { "negative" },
///        if pos.y >= 0.0 { "positive" } else { "negative" });
/// # }
/// ```
#[macro_export(local_inner_macros)]
macro_rules! trace {
    (target: $target:expr, $($arg:tt)+) => (
        log!(target: $target, $crate::Level::Trace, $($arg)+);
    );
    ($($arg:tt)+) => (
        log!($crate::Level::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
///
/// ```edition2018
/// use log::Level::Debug;
/// use log::{debug, log_enabled};
///
/// # fn foo() {
/// if log_enabled!(Debug) {
///     let data = expensive_call();
///     debug!("expensive debug data: {} {}", data.x, data.y);
/// }
/// if log_enabled!(target: "Global", Debug) {
///    let data = expensive_call();
///    debug!(target: "Global", "expensive debug data: {} {}", data.x, data.y);
/// }
/// # }
/// # struct Data { x: u32, y: u32 }
/// # fn expensive_call() -> Data { Data { x: 0, y: 0 } }
/// # fn main() {}
/// ```
#[macro_export(local_inner_macros)]
macro_rules! log_enabled {
    (target: $target:expr, $lvl:expr) => {{
        let lvl = $lvl;
        lvl <= $crate::STATIC_MAX_LEVEL
            && lvl <= $crate::max_level()
            && $crate::__private_api_enabled(lvl, $target)
    }};
    ($lvl:expr) => {
        log_enabled!(target: __log_module_path!(), $lvl)
    };
}

// The log macro above cannot invoke format_args directly because it uses
// local_inner_macros. A format_args invocation there would resolve to
// $crate::format_args which does not exist. Instead invoke format_args here
// outside of local_inner_macros so that it resolves (probably) to
// core::format_args or std::format_args. Same for the several macros that
// follow.
//
// This is a workaround until we drop support for pre-1.30 compilers. At that
// point we can remove use of local_inner_macros, use $crate:: when invoking
// local macros, and invoke format_args directly.
#[doc(hidden)]
#[macro_export]
macro_rules! __log_format_args {
    ($($args:tt)*) => {
        format_args!($($args)*)
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! __log_module_path {
    () => {
        module_path!()
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! __log_file {
    () => {
        file!()
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! __log_line {
    () => {
        line!()
    };
}