rust/compiler/rustc_span/src/profiling.rs
Rémy Rakic 215b377cc3 extend EventArgRecorder into span-aware SpannedEventArgRecorder
The self-profiler's `EventArgRecorder` is general-purpose in its ability to record Strings (and `rustc_span` depends on the crate its defined in, `rustc_data_structure`).

Some generic activities could use recording locations where they happen in the user's code: to allow e.g. to track macro expansions and diagnose performance issues there.

This adds a `SpannedEventArgRecorder` that can record an argument given as a span, rather than a String, since turning spans into Strings can be tricky if you're not happy with its default Debug output. This way the recorder can have a `record_arg_spanned` method which will do that.
2022-04-22 18:06:21 +02:00

36 lines
1.3 KiB
Rust

use std::borrow::Borrow;
use rustc_data_structures::profiling::EventArgRecorder;
/// Extension trait for self-profiling purposes: allows to record spans within a generic activity's
/// event arguments.
pub trait SpannedEventArgRecorder {
/// Records the following event arguments within the current generic activity being profiled:
/// - the provided `event_arg`
/// - a string representation of the provided `span`
///
/// Note: when self-profiling with costly event arguments, at least one argument
/// needs to be recorded. A panic will be triggered if that doesn't happen.
fn record_arg_with_span<A>(&mut self, event_arg: A, span: crate::Span)
where
A: Borrow<str> + Into<String>;
}
impl SpannedEventArgRecorder for EventArgRecorder<'_> {
fn record_arg_with_span<A>(&mut self, event_arg: A, span: crate::Span)
where
A: Borrow<str> + Into<String>,
{
self.record_arg(event_arg);
let span_arg = crate::with_session_globals(|session_globals| {
if let Some(source_map) = &*session_globals.source_map.borrow() {
source_map.span_to_embeddable_string(span)
} else {
format!("{:?}", span)
}
});
self.record_arg(span_arg);
}
}