jiff/
logging.rs

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1// Some feature combinations result in some of these macros never being used.
2// Which is fine. Just squash the warnings.
3#![allow(dead_code, unused_macros)]
4
5macro_rules! log {
6    ($($tt:tt)*) => {
7        #[cfg(feature = "logging")]
8        {
9            $($tt)*
10        }
11    }
12}
13
14macro_rules! error {
15    ($($tt:tt)*) => { log!(log::error!($($tt)*)) }
16}
17
18macro_rules! warn {
19    ($($tt:tt)*) => { log!(log::warn!($($tt)*)) }
20}
21
22macro_rules! info {
23    ($($tt:tt)*) => { log!(log::info!($($tt)*)) }
24}
25
26macro_rules! debug {
27    ($($tt:tt)*) => { log!(log::debug!($($tt)*)) }
28}
29
30macro_rules! trace {
31    ($($tt:tt)*) => { log!(log::trace!($($tt)*)) }
32}
33
34/// A copy of std's `dbg!` macro that doesn't do pretty printing.
35///
36/// This is nice because we usually want more compact output in this crate.
37/// Also, because we don't import std's prelude, we have to use `std::dbg!`.
38/// This macro definition makes it available as `dbg!`.
39#[cfg(feature = "std")]
40macro_rules! dbg {
41    () => {
42        std::eprintln!(
43            "[{}:{}:{}]",
44            $crate::file!(),
45            $crate::line!(),
46            $crate::column!(),
47        )
48    };
49    ($val:expr $(,)?) => {
50        match $val {
51            tmp => {
52                std::eprintln!(
53                    "[{}:{}:{}] {} = {:?}",
54                    std::file!(),
55                    std::line!(),
56                    std::column!(),
57                    std::stringify!($val),
58                    &tmp,
59                );
60                tmp
61            }
62        }
63    };
64    ($($val:expr),+ $(,)?) => {
65        ($(dbg!($val)),+,)
66    };
67}
68
69/// The simplest possible logger that logs to stderr.
70///
71/// This logger does no filtering. Instead, it relies on the `log` crates
72/// filtering via its global max_level setting.
73///
74/// This provides a super simple logger that works with the `log` crate.
75/// We don't need anything fancy; just basic log levels and the ability to
76/// print to stderr. We therefore avoid bringing in extra dependencies just
77/// for this functionality.
78#[cfg(all(test))]
79#[derive(Debug)]
80pub(crate) struct Logger(());
81
82#[cfg(all(test, feature = "std", feature = "logging"))]
83const LOGGER: &'static Logger = &Logger(());
84
85#[cfg(all(test))]
86impl Logger {
87    /// Create a new logger that logs to stderr and initialize it as the
88    /// global logger. If there was a problem setting the logger, then an
89    /// error is returned.
90    pub(crate) fn init() -> Result<(), crate::Error> {
91        #[cfg(all(feature = "std", feature = "logging"))]
92        {
93            log::set_logger(LOGGER).map_err(crate::Error::adhoc)?;
94            log::set_max_level(log::LevelFilter::Trace);
95            Ok(())
96        }
97        #[cfg(not(all(feature = "std", feature = "logging")))]
98        {
99            Ok(())
100        }
101    }
102}
103
104#[cfg(all(test, feature = "std", feature = "logging"))]
105impl log::Log for Logger {
106    fn enabled(&self, _: &log::Metadata<'_>) -> bool {
107        // We set the log level via log::set_max_level, so we don't need to
108        // implement filtering here.
109        true
110    }
111
112    fn log(&self, record: &log::Record<'_>) {
113        match (record.file(), record.line()) {
114            (Some(file), Some(line)) => {
115                std::eprintln!(
116                    "{}|{}|{}:{}: {}",
117                    record.level(),
118                    record.target(),
119                    file,
120                    line,
121                    record.args()
122                );
123            }
124            (Some(file), None) => {
125                std::eprintln!(
126                    "{}|{}|{}: {}",
127                    record.level(),
128                    record.target(),
129                    file,
130                    record.args()
131                );
132            }
133            _ => {
134                std::eprintln!(
135                    "{}|{}: {}",
136                    record.level(),
137                    record.target(),
138                    record.args()
139                );
140            }
141        }
142    }
143
144    fn flush(&self) {
145        // We use eprintln! which is flushed on every call.
146    }
147}
jiff/logging.rs

jiff/
logging.rs
