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</pre><pre class="rust ">
<span class="comment">// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT</span>
<span class="comment">// file at the top-level directory of this distribution and at</span>
<span class="comment">// http://rust-lang.org/COPYRIGHT.</span>
<span class="comment">//</span>
<span class="comment">// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span>
<span class="comment">// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span>
<span class="comment">// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span>
<span class="comment">// option. This file may not be copied, modified, or distributed</span>
<span class="comment">// except according to those terms.</span>
<span class="doccomment">/// The standard logging macro.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This macro will generically log with the specified `Level` and `format!`</span>
<span class="doccomment">/// based argument list.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// use log::Level;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # fn main() {</span>
<span class="doccomment">/// let data = (42, "Forty-two");</span>
<span class="doccomment">/// let private_data = "private";</span>
<span class="doccomment">///</span>
<span class="doccomment">/// log!(Level::Error, "Received errors: {}, {}", data.0, data.1);</span>
<span class="doccomment">/// log!(target: "app_events", Level::Warn, "App warning: {}, {}, {}",</span>
<span class="doccomment">/// data.0, data.1, private_data);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">log</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="op">+</span>) <span class="op">=></span> ({
<span class="kw">let</span> <span class="ident">lvl</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>;
<span class="kw">if</span> <span class="ident">lvl</span> <span class="op"><=</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">STATIC_MAX_LEVEL</span> <span class="op">&&</span> <span class="ident">lvl</span> <span class="op"><=</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">max_level</span>() {
<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">__private_api_log</span>(
<span class="macro">__log_format_args</span><span class="macro">!</span>($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="op">+</span>),
<span class="ident">lvl</span>,
<span class="kw-2">&</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>, <span class="macro">__log_module_path</span><span class="macro">!</span>(), <span class="macro">__log_file</span><span class="macro">!</span>(), <span class="macro">__log_line</span><span class="macro">!</span>()),
);
}
});
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="op">+</span>) <span class="op">=></span> (<span class="macro">log</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro">__log_module_path</span><span class="macro">!</span>(), <span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="op">+</span>))
}
<span class="doccomment">/// Logs a message at the error level.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// # fn main() {</span>
<span class="doccomment">/// let (err_info, port) = ("No connection", 22);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// error!("Error: {} on port {}", err_info, port);</span>
<span class="doccomment">/// error!(target: "app_events", "App Error: {}, Port: {}", err_info, 22);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">error</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>, <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Error</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
);
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Error</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
)
}
<span class="doccomment">/// Logs a message at the warn level.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// # fn main() {</span>
<span class="doccomment">/// let warn_description = "Invalid Input";</span>
<span class="doccomment">///</span>
<span class="doccomment">/// warn!("Warning! {}!", warn_description);</span>
<span class="doccomment">/// warn!(target: "input_events", "App received warning: {}", warn_description);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">warn</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>, <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Warn</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
);
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Warn</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
)
}
<span class="doccomment">/// Logs a message at the info level.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// # fn main() {</span>
<span class="doccomment">/// # struct Connection { port: u32, speed: f32 }</span>
<span class="doccomment">/// let conn_info = Connection { port: 40, speed: 3.20 };</span>
<span class="doccomment">///</span>
<span class="doccomment">/// info!("Connected to port {} at {} Mb/s", conn_info.port, conn_info.speed);</span>
<span class="doccomment">/// info!(target: "connection_events", "Successfull connection, port: {}, speed: {}",</span>
<span class="doccomment">/// conn_info.port, conn_info.speed);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">info</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>, <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Info</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
);
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Info</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
)
}
<span class="doccomment">/// Logs a message at the debug level.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// # fn main() {</span>
<span class="doccomment">/// # struct Position { x: f32, y: f32 }</span>
<span class="doccomment">/// let pos = Position { x: 3.234, y: -1.223 };</span>
<span class="doccomment">///</span>
<span class="doccomment">/// debug!("New position: x: {}, y: {}", pos.x, pos.y);</span>
<span class="doccomment">/// debug!(target: "app_events", "New position: x: {}, y: {}", pos.x, pos.y);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">debug</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>, <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Debug</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
);
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Debug</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
)
}
<span class="doccomment">/// Logs a message at the trace level.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// # fn main() {</span>
<span class="doccomment">/// # struct Position { x: f32, y: f32 }</span>
<span class="doccomment">/// let pos = Position { x: 3.234, y: -1.223 };</span>
<span class="doccomment">///</span>
<span class="doccomment">/// trace!("Position is: x: {}, y: {}", pos.x, pos.y);</span>
<span class="doccomment">/// trace!(target: "app_events", "x is {} and y is {}",</span>
<span class="doccomment">/// if pos.x >= 0.0 { "positive" } else { "negative" },</span>
<span class="doccomment">/// if pos.y >= 0.0 { "positive" } else { "negative" });</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">trace</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>, <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Trace</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
);
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> (
<span class="macro">log</span><span class="macro">!</span>(<span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">Level</span>::<span class="ident">Trace</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>)<span class="kw-2">*</span>);
)
}
<span class="doccomment">/// Determines if a message logged at the specified level in that module will</span>
<span class="doccomment">/// be logged.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This can be used to avoid expensive computation of log message arguments if</span>
<span class="doccomment">/// the message would be ignored anyway.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// # #[macro_use]</span>
<span class="doccomment">/// # extern crate log;</span>
<span class="doccomment">/// use log::Level::Debug;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # fn foo() {</span>
<span class="doccomment">/// if log_enabled!(Debug) {</span>
<span class="doccomment">/// let data = expensive_call();</span>
<span class="doccomment">/// debug!("expensive debug data: {} {}", data.x, data.y);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// if log_enabled!(target: "Global", Debug) {</span>
<span class="doccomment">/// let data = expensive_call();</span>
<span class="doccomment">/// debug!(target: "Global", "expensive debug data: {} {}", data.x, data.y);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// # struct Data { x: u32, y: u32 }</span>
<span class="doccomment">/// # fn expensive_call() -> Data { Data { x: 0, y: 0 } }</span>
<span class="doccomment">/// # fn main() {}</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">macro_export</span>(<span class="ident">local_inner_macros</span>)]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">log_enabled</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>:<span class="ident">expr</span>) <span class="op">=></span> {{
<span class="kw">let</span> <span class="ident">lvl</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>;
<span class="ident">lvl</span> <span class="op"><=</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">STATIC_MAX_LEVEL</span>
<span class="op">&&</span> <span class="ident">lvl</span> <span class="op"><=</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">max_level</span>()
<span class="op">&&</span> <span class="macro-nonterminal">$</span><span class="kw">crate</span>::<span class="macro-nonterminal">__private_api_enabled</span>(<span class="ident">lvl</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>)
}};
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>:<span class="ident">expr</span>) <span class="op">=></span> {
<span class="macro">log_enabled</span><span class="macro">!</span>(<span class="ident">target</span>: <span class="macro">__log_module_path</span><span class="macro">!</span>(), <span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>)
};
}
<span class="comment">// The log macro above cannot invoke format_args directly because it uses</span>
<span class="comment">// local_inner_macros. A format_args invocation there would resolve to</span>
<span class="comment">// $crate::format_args which does not exist. Instead invoke format_args here</span>
<span class="comment">// outside of local_inner_macros so that it resolves (probably) to</span>
<span class="comment">// core::format_args or std::format_args. Same for the several macros that</span>
<span class="comment">// follow.</span>
<span class="comment">//</span>
<span class="comment">// This is a workaround until we drop support for pre-1.30 compilers. At that</span>
<span class="comment">// point we can remove use of local_inner_macros, use $crate:: when invoking</span>
<span class="comment">// local macros, and invoke format_args directly.</span>
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">__log_format_args</span> {
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">args</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> {
<span class="macro">format_args</span><span class="macro">!</span>($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">args</span>)<span class="kw-2">*</span>)
};
}
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">__log_module_path</span> {
() <span class="op">=></span> {
<span class="macro">module_path</span><span class="macro">!</span>()
};
}
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">__log_file</span> {
() <span class="op">=></span> {
<span class="macro">file</span><span class="macro">!</span>()
};
}
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span>
<span class="attribute">#[<span class="ident">macro_export</span>]</span>
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">__log_line</span> {
() <span class="op">=></span> {
<span class="macro">line</span><span class="macro">!</span>()
};
}
</pre>
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