1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
//! Used by `rustc` when compiling a plugin crate.
use rustc_hir as hir;
use rustc_hir::def_id::LocalDefId;
use rustc_hir::itemlikevisit::ItemLikeVisitor;
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::TyCtxt;
use rustc_span::symbol::sym;
use rustc_span::Span;
struct RegistrarFinder<'tcx> {
tcx: TyCtxt<'tcx>,
registrars: Vec<(LocalDefId, Span)>,
}
impl<'v, 'tcx> ItemLikeVisitor<'v> for RegistrarFinder<'tcx> {
fn visit_item(&mut self, item: &hir::Item<'_>) {
if let hir::ItemKind::Fn(..) = item.kind {
let attrs = self.tcx.hir().attrs(item.hir_id());
if self.tcx.sess.contains_name(attrs, sym::plugin_registrar) {
self.registrars.push((item.def_id, item.span));
}
}
}
fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem<'_>) {}
fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {}
fn visit_foreign_item(&mut self, _foreign_item: &hir::ForeignItem<'_>) {}
}
/// Finds the function marked with `#[plugin_registrar]`, if any.
fn plugin_registrar_fn(tcx: TyCtxt<'_>, (): ()) -> Option<LocalDefId> {
let mut finder = RegistrarFinder { tcx, registrars: Vec::new() };
tcx.hir().krate().visit_all_item_likes(&mut finder);
let (def_id, span) = finder.registrars.pop()?;
if !finder.registrars.is_empty() {
let diagnostic = tcx.sess.diagnostic();
let mut e = diagnostic.struct_err("multiple plugin registration functions found");
e.span_note(span, "one is here");
for &(_, span) in &finder.registrars {
e.span_note(span, "one is here");
}
e.emit();
diagnostic.abort_if_errors();
unreachable!();
}
Some(def_id)
}
pub fn provide(providers: &mut Providers) {
*providers = Providers { plugin_registrar_fn, ..*providers };
}
|
