rustc_metadata/
eii.rs

1use rustc_data_structures::fx::FxIndexMap;
2use rustc_hir::attrs::{AttributeKind, EiiDecl, EiiImpl, EiiImplResolution};
3use rustc_hir::def_id::DefId;
4use rustc_hir::find_attr;
5use rustc_middle::query::LocalCrate;
6use rustc_middle::ty::TyCtxt;
7
8// basically the map below but flattened out
9pub(crate) type EiiMapEncodedKeyValue = (DefId, (EiiDecl, Vec<(DefId, EiiImpl)>));
10
11pub(crate) type EiiMap = FxIndexMap<
12    DefId, // the defid of the foreign item associated with the eii
13    (
14        // the corresponding declaration
15        EiiDecl,
16        // all the given implementations, indexed by defid.
17        // We expect there to be only one, but collect them all to give errors if there are more
18        // (or if there are none) in the final crate we build.
19        FxIndexMap<DefId, EiiImpl>,
20    ),
21>;
22
23pub(crate) fn collect<'tcx>(tcx: TyCtxt<'tcx>, LocalCrate: LocalCrate) -> EiiMap {
24    let mut eiis = EiiMap::default();
25
26    // iterate over all items in the current crate
27    for id in tcx.hir_crate_items(()).eiis() {
28        for i in
29            find_attr!(tcx.get_all_attrs(id), AttributeKind::EiiImpls(e) => e).into_iter().flatten()
30        {
31            let decl = match i.resolution {
32                EiiImplResolution::Macro(macro_defid) => {
33                    // find the decl for this one if it wasn't in yet (maybe it's from the local crate? not very useful but not illegal)
34                    let Some(decl) = find_attr!(tcx.get_all_attrs(macro_defid), AttributeKind::EiiDeclaration(d) => *d)
35                    else {
36                        // skip if it doesn't have eii_declaration (if we resolved to another macro that's not an EII)
37                        tcx.dcx()
38                            .span_delayed_bug(i.span, "resolved to something that's not an EII");
39                        continue;
40                    };
41                    decl
42                }
43                EiiImplResolution::Known(decl) => decl,
44                EiiImplResolution::Error(_eg) => continue,
45            };
46
47            // FIXME(eii) remove extern target from encoded decl
48            eiis.entry(decl.foreign_item)
49                .or_insert_with(|| (decl, Default::default()))
50                .1
51                .insert(id.into(), *i);
52        }
53
54        // if we find a new declaration, add it to the list without a known implementation
55        if let Some(decl) =
56            find_attr!(tcx.get_all_attrs(id), AttributeKind::EiiDeclaration(d) => *d)
57        {
58            eiis.entry(decl.foreign_item).or_insert((decl, Default::default()));
59        }
60    }
61
62    eiis
63}
rustc_metadata/eii.rs

rustc_metadata/
eii.rs
