rust/crates/hir-def/src/nameres/proc_macro.rs

92 lines
3.1 KiB
Rust

//! Nameres-specific procedural macro data and helpers.
use hir_expand::name::{AsName, Name};
use crate::attr::Attrs;
use crate::tt::{Leaf, TokenTree};
#[derive(Debug, PartialEq, Eq)]
pub struct ProcMacroDef {
pub name: Name,
pub kind: ProcMacroKind,
}
#[derive(Debug, PartialEq, Eq)]
pub enum ProcMacroKind {
CustomDerive { helpers: Box<[Name]> },
FnLike,
Attr,
}
impl ProcMacroKind {
pub(super) fn to_basedb_kind(&self) -> hir_expand::proc_macro::ProcMacroKind {
match self {
ProcMacroKind::CustomDerive { .. } => {
hir_expand::proc_macro::ProcMacroKind::CustomDerive
}
ProcMacroKind::FnLike => hir_expand::proc_macro::ProcMacroKind::FuncLike,
ProcMacroKind::Attr => hir_expand::proc_macro::ProcMacroKind::Attr,
}
}
}
impl Attrs {
#[rustfmt::skip]
pub fn parse_proc_macro_decl(&self, func_name: &Name) -> Option<ProcMacroDef> {
if self.is_proc_macro() {
Some(ProcMacroDef { name: func_name.clone(), kind: ProcMacroKind::FnLike })
} else if self.is_proc_macro_attribute() {
Some(ProcMacroDef { name: func_name.clone(), kind: ProcMacroKind::Attr })
} else if self.by_key("proc_macro_derive").exists() {
let derive = self.by_key("proc_macro_derive").tt_values().next()?;
let def = parse_macro_name_and_helper_attrs(&derive.token_trees)
.map(|(name, helpers)| ProcMacroDef { name, kind: ProcMacroKind::CustomDerive { helpers } });
if def.is_none() {
tracing::trace!("malformed `#[proc_macro_derive]`: {}", derive);
}
def
} else {
None
}
}
}
// This fn is intended for `#[proc_macro_derive(..)]` and `#[rustc_builtin_macro(..)]`, which have
// the same structure.
#[rustfmt::skip]
pub(crate) fn parse_macro_name_and_helper_attrs(tt: &[TokenTree]) -> Option<(Name, Box<[Name]>)> {
match tt {
// `#[proc_macro_derive(Trait)]`
// `#[rustc_builtin_macro(Trait)]`
[TokenTree::Leaf(Leaf::Ident(trait_name))] => Some((trait_name.as_name(), Box::new([]))),
// `#[proc_macro_derive(Trait, attributes(helper1, helper2, ...))]`
// `#[rustc_builtin_macro(Trait, attributes(helper1, helper2, ...))]`
[
TokenTree::Leaf(Leaf::Ident(trait_name)),
TokenTree::Leaf(Leaf::Punct(comma)),
TokenTree::Leaf(Leaf::Ident(attributes)),
TokenTree::Subtree(helpers)
] if comma.char == ',' && attributes.text == "attributes" =>
{
let helpers = helpers
.token_trees
.iter()
.filter(
|tt| !matches!(tt, TokenTree::Leaf(Leaf::Punct(comma)) if comma.char == ','),
)
.map(|tt| match tt {
TokenTree::Leaf(Leaf::Ident(helper)) => Some(helper.as_name()),
_ => None,
})
.collect::<Option<Box<[_]>>>()?;
Some((trait_name.as_name(), helpers))
}
_ => None,
}
}