rust/compiler/stable_mir/src/crate_def.rs

70 lines
2.2 KiB
Rust

//! Module that define a common trait for things that represent a crate definition,
//! such as, a function, a trait, an enum, and any other definitions.
use crate::ty::Span;
use crate::{with, Crate, Symbol};
/// A unique identification number for each item accessible for the current compilation unit.
#[derive(Clone, Copy, PartialEq, Eq, Hash)]
pub struct DefId(pub(crate) usize);
/// A trait for retrieving information about a particular definition.
///
/// Implementors must provide the implementation of `def_id` which will be used to retrieve
/// information about a crate's definition.
pub trait CrateDef {
/// Retrieve the unique identifier for the current definition.
fn def_id(&self) -> DefId;
/// Return the fully qualified name of the current definition.
fn name(&self) -> Symbol {
let def_id = self.def_id();
with(|cx| cx.def_name(def_id, false))
}
/// Return a trimmed name of this definition.
///
/// This can be used to print more user friendly diagnostic messages.
///
/// If a symbol name can only be imported from one place for a type, and as
/// long as it was not glob-imported anywhere in the current crate, we trim its
/// path and print only the name.
///
/// For example, this function may shorten `std::vec::Vec` to just `Vec`,
/// as long as there is no other `Vec` importable anywhere.
fn trimmed_name(&self) -> Symbol {
let def_id = self.def_id();
with(|cx| cx.def_name(def_id, true))
}
/// Return information about the crate where this definition is declared.
///
/// This will return the crate number and its name.
fn krate(&self) -> Crate {
let def_id = self.def_id();
with(|cx| cx.krate(def_id))
}
/// Return the span of this definition.
fn span(&self) -> Span {
let def_id = self.def_id();
with(|cx| cx.span_of_an_item(def_id))
}
}
macro_rules! crate_def {
( $(#[$attr:meta])*
$vis:vis $name:ident $(;)?
) => {
$(#[$attr])*
#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
$vis struct $name(pub DefId);
impl CrateDef for $name {
fn def_id(&self) -> DefId {
self.0
}
}
};
}