diff options
Diffstat (limited to 'compiler/stable_mir/src/crate_def.rs')
-rw-r--r-- | compiler/stable_mir/src/crate_def.rs | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/compiler/stable_mir/src/crate_def.rs b/compiler/stable_mir/src/crate_def.rs new file mode 100644 index 000000000..70ca9e682 --- /dev/null +++ b/compiler/stable_mir/src/crate_def.rs @@ -0,0 +1,69 @@ +//! 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 + } + } + }; +} |