Implement resolution, parse use<Self>

Author: compiler-errors

compiler/rustc_parse/src/parser/ty.rs

@@ -694,7 +694,13 @@ impl<'a> Parser<'a> {
                 &TokenKind::Gt,
                 SeqSep::trailing_allowed(token::Comma),
                 |self_| {
-                    if self_.check_ident() {
+                    if self_.check_keyword(kw::SelfUpper) {
+                        self_.bump();
+                        Ok(PreciseCapturingArg::Arg(
+                            self_.prev_token.ident().unwrap().0,
+                            DUMMY_NODE_ID,
+                        ))
+                    } else if self_.check_ident() {
                         Ok(PreciseCapturingArg::Arg(self_.parse_ident().unwrap(), DUMMY_NODE_ID))
                     } else if self_.check_lifetime() {
                         Ok(PreciseCapturingArg::Lifetime(self_.expect_lifetime()))

compiler/rustc_resolve/src/late.rs

@@ -1055,8 +1055,28 @@ impl<'a: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast,
     fn visit_precise_capturing_arg(&mut self, arg: &'ast PreciseCapturingArg) {
         match arg {
             PreciseCapturingArg::Lifetime(_) => visit::walk_precise_capturing_arg(self, arg),
-            PreciseCapturingArg::Arg(ident, _) => {
-                todo!("cannot resolve args yet: {ident}");
+            PreciseCapturingArg::Arg(ident, node_id) => {
+                let ident = ident.normalize_to_macros_2_0();
+                'found: {
+                    for (rib_t, rib_v) in
+                        std::iter::zip(&self.ribs.type_ns, &self.ribs.value_ns).rev()
+                    {
+                        if let Some(res) = rib_t.bindings.get(&ident).or(rib_v.bindings.get(&ident))
+                        {
+                            self.r.record_partial_res(*node_id, PartialRes::new(*res));
+                            break 'found;
+                        }
+                    }
+                    self.report_error(
+                        ident.span,
+                        ResolutionError::FailedToResolve {
+                            segment: Some(ident.name),
+                            label: "could not find type or const parameter".to_string(),
+                            suggestion: None,
+                            module: None,
+                        },
+                    );
+                }
             }
         }
     }