rustc_errors/
timings.rs

1use std::time::Instant;
2
3use crate::DiagCtxtHandle;
4
5/// A high-level section of the compilation process.
6#[derive(Copy, Clone, Debug)]
7pub enum TimingSection {
8    /// Time spent linking.
9    Linking,
10}
11
12/// Section with attached timestamp
13#[derive(Copy, Clone, Debug)]
14pub struct TimingRecord {
15    pub section: TimingSection,
16    /// Microseconds elapsed since some predetermined point in time (~start of the rustc process).
17    pub timestamp: u128,
18}
19
20impl TimingRecord {
21    fn from_origin(origin: Instant, section: TimingSection) -> Self {
22        Self { section, timestamp: Instant::now().duration_since(origin).as_micros() }
23    }
24
25    pub fn section(&self) -> TimingSection {
26        self.section
27    }
28
29    pub fn timestamp(&self) -> u128 {
30        self.timestamp
31    }
32}
33
34/// Manages emission of start/end section timings, enabled through `--json=timings`.
35pub struct TimingSectionHandler {
36    /// Time when the compilation session started.
37    /// If `None`, timing is disabled.
38    origin: Option<Instant>,
39}
40
41impl TimingSectionHandler {
42    pub fn new(enabled: bool) -> Self {
43        let origin = if enabled { Some(Instant::now()) } else { None };
44        Self { origin }
45    }
46
47    /// Returns a RAII guard that will immediately emit a start the provided section, and then emit
48    /// its end when it is dropped.
49    pub fn start_section<'a>(
50        &self,
51        diag_ctxt: DiagCtxtHandle<'a>,
52        section: TimingSection,
53    ) -> TimingSectionGuard<'a> {
54        TimingSectionGuard::create(diag_ctxt, section, self.origin)
55    }
56}
57
58/// RAII wrapper for starting and ending section timings.
59pub struct TimingSectionGuard<'a> {
60    dcx: DiagCtxtHandle<'a>,
61    section: TimingSection,
62    origin: Option<Instant>,
63}
64
65impl<'a> TimingSectionGuard<'a> {
66    fn create(dcx: DiagCtxtHandle<'a>, section: TimingSection, origin: Option<Instant>) -> Self {
67        if let Some(origin) = origin {
68            dcx.emit_timing_section_start(TimingRecord::from_origin(origin, section));
69        }
70        Self { dcx, section, origin }
71    }
72}
73
74impl<'a> Drop for TimingSectionGuard<'a> {
75    fn drop(&mut self) {
76        if let Some(origin) = self.origin {
77            self.dcx.emit_timing_section_end(TimingRecord::from_origin(origin, self.section));
78        }
79    }
80}
rustc_errors/timings.rs

rustc_errors/
timings.rs
