diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
new file mode 100644
index 0000000..baaab33
--- /dev/null
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -0,0 +1,1585 @@
+use rustc_ast::{self as ast, NodeId};
+use rustc_feature::is_builtin_attr_name;
+use rustc_hir::def::{DefKind, Namespace, NonMacroAttrKind, PartialRes, PerNS};
+use rustc_hir::PrimTy;
+use rustc_middle::bug;
+use rustc_middle::ty;
+use rustc_session::lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK;
+use rustc_session::lint::BuiltinLintDiagnostics;
+use rustc_span::edition::Edition;
+use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext};
+use rustc_span::symbol::{kw, Ident};
+use rustc_span::{Span, DUMMY_SP};
+
+use std::ptr;
+
+use crate::late::{ConstantItemKind, HasGenericParams, PathSource, Rib, RibKind};
+use crate::macros::{sub_namespace_match, MacroRulesScope};
+use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, Determinacy, Finalize};
+use crate::{ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot};
+use crate::{NameBinding, NameBindingKind, ParentScope, PathResult, PrivacyError, Res};
+use crate::{ResolutionError, Resolver, Scope, ScopeSet, Segment, ToNameBinding, Weak};
+
+use Determinacy::*;
+use Namespace::*;
+use RibKind::*;
+
+impl<'a> Resolver<'a> {
+    /// A generic scope visitor.
+    /// Visits scopes in order to resolve some identifier in them or perform other actions.
+    /// If the callback returns `Some` result, we stop visiting scopes and return it.
+    crate fn visit_scopes<T>(
+        &mut self,
+        scope_set: ScopeSet<'a>,
+        parent_scope: &ParentScope<'a>,
+        ctxt: SyntaxContext,
+        mut visitor: impl FnMut(
+            &mut Self,
+            Scope<'a>,
+            /*use_prelude*/ bool,
+            SyntaxContext,
+        ) -> Option<T>,
+    ) -> Option<T> {
+        // General principles:
+        // 1. Not controlled (user-defined) names should have higher priority than controlled names
+        //    built into the language or standard library. This way we can add new names into the
+        //    language or standard library without breaking user code.
+        // 2. "Closed set" below means new names cannot appear after the current resolution attempt.
+        // Places to search (in order of decreasing priority):
+        // (Type NS)
+        // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet
+        //    (open set, not controlled).
+        // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
+        //    (open, not controlled).
+        // 3. Extern prelude (open, the open part is from macro expansions, not controlled).
+        // 4. Tool modules (closed, controlled right now, but not in the future).
+        // 5. Standard library prelude (de-facto closed, controlled).
+        // 6. Language prelude (closed, controlled).
+        // (Value NS)
+        // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet
+        //    (open set, not controlled).
+        // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
+        //    (open, not controlled).
+        // 3. Standard library prelude (de-facto closed, controlled).
+        // (Macro NS)
+        // 1-3. Derive helpers (open, not controlled). All ambiguities with other names
+        //    are currently reported as errors. They should be higher in priority than preludes
+        //    and probably even names in modules according to the "general principles" above. They
+        //    also should be subject to restricted shadowing because are effectively produced by
+        //    derives (you need to resolve the derive first to add helpers into scope), but they
+        //    should be available before the derive is expanded for compatibility.
+        //    It's mess in general, so we are being conservative for now.
+        // 1-3. `macro_rules` (open, not controlled), loop through `macro_rules` scopes. Have higher
+        //    priority than prelude macros, but create ambiguities with macros in modules.
+        // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
+        //    (open, not controlled). Have higher priority than prelude macros, but create
+        //    ambiguities with `macro_rules`.
+        // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled).
+        // 4a. User-defined prelude from macro-use
+        //    (open, the open part is from macro expansions, not controlled).
+        // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled).
+        // 4c. Standard library prelude (de-facto closed, controlled).
+        // 6. Language prelude: builtin attributes (closed, controlled).
+
+        let rust_2015 = ctxt.edition() == Edition::Edition2015;
+        let (ns, macro_kind, is_absolute_path) = match scope_set {
+            ScopeSet::All(ns, _) => (ns, None, false),
+            ScopeSet::AbsolutePath(ns) => (ns, None, true),
+            ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
+            ScopeSet::Late(ns, ..) => (ns, None, false),
+        };
+        let module = match scope_set {
+            // Start with the specified module.
+            ScopeSet::Late(_, module, _) => module,
+            // Jump out of trait or enum modules, they do not act as scopes.
+            _ => parent_scope.module.nearest_item_scope(),
+        };
+        let mut scope = match ns {
+            _ if is_absolute_path => Scope::CrateRoot,
+            TypeNS | ValueNS => Scope::Module(module, None),
+            MacroNS => Scope::DeriveHelpers(parent_scope.expansion),
+        };
+        let mut ctxt = ctxt.normalize_to_macros_2_0();
+        let mut use_prelude = !module.no_implicit_prelude;
+
+        loop {
+            let visit = match scope {
+                // Derive helpers are not in scope when resolving derives in the same container.
+                Scope::DeriveHelpers(expn_id) => {
+                    !(expn_id == parent_scope.expansion && macro_kind == Some(MacroKind::Derive))
+                }
+                Scope::DeriveHelpersCompat => true,
+                Scope::MacroRules(macro_rules_scope) => {
+                    // Use "path compression" on `macro_rules` scope chains. This is an optimization
+                    // used to avoid long scope chains, see the comments on `MacroRulesScopeRef`.
+                    // As another consequence of this optimization visitors never observe invocation
+                    // scopes for macros that were already expanded.
+                    while let MacroRulesScope::Invocation(invoc_id) = macro_rules_scope.get() {
+                        if let Some(next_scope) = self.output_macro_rules_scopes.get(&invoc_id) {
+                            macro_rules_scope.set(next_scope.get());
+                        } else {
+                            break;
+                        }
+                    }
+                    true
+                }
+                Scope::CrateRoot => true,
+                Scope::Module(..) => true,
+                Scope::RegisteredAttrs => use_prelude,
+                Scope::MacroUsePrelude => use_prelude || rust_2015,
+                Scope::BuiltinAttrs => true,
+                Scope::ExternPrelude => use_prelude || is_absolute_path,
+                Scope::ToolPrelude => use_prelude,
+                Scope::StdLibPrelude => use_prelude || ns == MacroNS,
+                Scope::BuiltinTypes => true,
+            };
+
+            if visit {
+                if let break_result @ Some(..) = visitor(self, scope, use_prelude, ctxt) {
+                    return break_result;
+                }
+            }
+
+            scope = match scope {
+                Scope::DeriveHelpers(LocalExpnId::ROOT) => Scope::DeriveHelpersCompat,
+                Scope::DeriveHelpers(expn_id) => {
+                    // Derive helpers are not visible to code generated by bang or derive macros.
+                    let expn_data = expn_id.expn_data();
+                    match expn_data.kind {
+                        ExpnKind::Root
+                        | ExpnKind::Macro(MacroKind::Bang | MacroKind::Derive, _) => {
+                            Scope::DeriveHelpersCompat
+                        }
+                        _ => Scope::DeriveHelpers(expn_data.parent.expect_local()),
+                    }
+                }
+                Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.macro_rules),
+                Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() {
+                    MacroRulesScope::Binding(binding) => {
+                        Scope::MacroRules(binding.parent_macro_rules_scope)
+                    }
+                    MacroRulesScope::Invocation(invoc_id) => {
+                        Scope::MacroRules(self.invocation_parent_scopes[&invoc_id].macro_rules)
+                    }
+                    MacroRulesScope::Empty => Scope::Module(module, None),
+                },
+                Scope::CrateRoot => match ns {
+                    TypeNS => {
+                        ctxt.adjust(ExpnId::root());
+                        Scope::ExternPrelude
+                    }
+                    ValueNS | MacroNS => break,
+                },
+                Scope::Module(module, prev_lint_id) => {
+                    use_prelude = !module.no_implicit_prelude;
+                    let derive_fallback_lint_id = match scope_set {
+                        ScopeSet::Late(.., lint_id) => lint_id,
+                        _ => None,
+                    };
+                    match self.hygienic_lexical_parent(module, &mut ctxt, derive_fallback_lint_id) {
+                        Some((parent_module, lint_id)) => {
+                            Scope::Module(parent_module, lint_id.or(prev_lint_id))
+                        }
+                        None => {
+                            ctxt.adjust(ExpnId::root());
+                            match ns {
+                                TypeNS => Scope::ExternPrelude,
+                                ValueNS => Scope::StdLibPrelude,
+                                MacroNS => Scope::RegisteredAttrs,
+                            }
+                        }
+                    }
+                }
+                Scope::RegisteredAttrs => Scope::MacroUsePrelude,
+                Scope::MacroUsePrelude => Scope::StdLibPrelude,
+                Scope::BuiltinAttrs => break, // nowhere else to search
+                Scope::ExternPrelude if is_absolute_path => break,
+                Scope::ExternPrelude => Scope::ToolPrelude,
+                Scope::ToolPrelude => Scope::StdLibPrelude,
+                Scope::StdLibPrelude => match ns {
+                    TypeNS => Scope::BuiltinTypes,
+                    ValueNS => break, // nowhere else to search
+                    MacroNS => Scope::BuiltinAttrs,
+                },
+                Scope::BuiltinTypes => break, // nowhere else to search
+            };
+        }
+
+        None
+    }
+
+    fn hygienic_lexical_parent(
+        &mut self,
+        module: Module<'a>,
+        ctxt: &mut SyntaxContext,
+        derive_fallback_lint_id: Option<NodeId>,
+    ) -> Option<(Module<'a>, Option<NodeId>)> {
+        if !module.expansion.outer_expn_is_descendant_of(*ctxt) {
+            return Some((self.expn_def_scope(ctxt.remove_mark()), None));
+        }
+
+        if let ModuleKind::Block(..) = module.kind {
+            return Some((module.parent.unwrap().nearest_item_scope(), None));
+        }
+
+        // We need to support the next case under a deprecation warning
+        // ```
+        // struct MyStruct;
+        // ---- begin: this comes from a proc macro derive
+        // mod implementation_details {
+        //     // Note that `MyStruct` is not in scope here.
+        //     impl SomeTrait for MyStruct { ... }
+        // }
+        // ---- end
+        // ```
+        // So we have to fall back to the module's parent during lexical resolution in this case.
+        if derive_fallback_lint_id.is_some() {
+            if let Some(parent) = module.parent {
+                // Inner module is inside the macro, parent module is outside of the macro.
+                if module.expansion != parent.expansion
+                    && module.expansion.is_descendant_of(parent.expansion)
+                {
+                    // The macro is a proc macro derive
+                    if let Some(def_id) = module.expansion.expn_data().macro_def_id {
+                        let ext = self.get_macro_by_def_id(def_id);
+                        if ext.builtin_name.is_none()
+                            && ext.macro_kind() == MacroKind::Derive
+                            && parent.expansion.outer_expn_is_descendant_of(*ctxt)
+                        {
+                            return Some((parent, derive_fallback_lint_id));
+                        }
+                    }
+                }
+            }
+        }
+
+        None
+    }
+
+    /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
+    /// More specifically, we proceed up the hierarchy of scopes and return the binding for
+    /// `ident` in the first scope that defines it (or None if no scopes define it).
+    ///
+    /// A block's items are above its local variables in the scope hierarchy, regardless of where
+    /// the items are defined in the block. For example,
+    /// ```rust
+    /// fn f() {
+    ///    g(); // Since there are no local variables in scope yet, this resolves to the item.
+    ///    let g = || {};
+    ///    fn g() {}
+    ///    g(); // This resolves to the local variable `g` since it shadows the item.
+    /// }
+    /// ```
+    ///
+    /// Invariant: This must only be called during main resolution, not during
+    /// import resolution.
+    #[tracing::instrument(level = "debug", skip(self, ribs))]
+    crate fn resolve_ident_in_lexical_scope(
+        &mut self,
+        mut ident: Ident,
+        ns: Namespace,
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        ribs: &[Rib<'a>],
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> Option<LexicalScopeBinding<'a>> {
+        assert!(ns == TypeNS || ns == ValueNS);
+        let orig_ident = ident;
+        if ident.name == kw::Empty {
+            return Some(LexicalScopeBinding::Res(Res::Err));
+        }
+        let (general_span, normalized_span) = if ident.name == kw::SelfUpper {
+            // FIXME(jseyfried) improve `Self` hygiene
+            let empty_span = ident.span.with_ctxt(SyntaxContext::root());
+            (empty_span, empty_span)
+        } else if ns == TypeNS {
+            let normalized_span = ident.span.normalize_to_macros_2_0();
+            (normalized_span, normalized_span)
+        } else {
+            (ident.span.normalize_to_macro_rules(), ident.span.normalize_to_macros_2_0())
+        };
+        ident.span = general_span;
+        let normalized_ident = Ident { span: normalized_span, ..ident };
+
+        // Walk backwards up the ribs in scope.
+        let mut module = self.graph_root;
+        for i in (0..ribs.len()).rev() {
+            debug!("walk rib\n{:?}", ribs[i].bindings);
+            // Use the rib kind to determine whether we are resolving parameters
+            // (macro 2.0 hygiene) or local variables (`macro_rules` hygiene).
+            let rib_ident = if ribs[i].kind.contains_params() { normalized_ident } else { ident };
+            if let Some((original_rib_ident_def, res)) = ribs[i].bindings.get_key_value(&rib_ident)
+            {
+                // The ident resolves to a type parameter or local variable.
+                return Some(LexicalScopeBinding::Res(self.validate_res_from_ribs(
+                    i,
+                    rib_ident,
+                    *res,
+                    finalize.map(|finalize| finalize.path_span),
+                    *original_rib_ident_def,
+                    ribs,
+                )));
+            }
+
+            module = match ribs[i].kind {
+                ModuleRibKind(module) => module,
+                MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
+                    // If an invocation of this macro created `ident`, give up on `ident`
+                    // and switch to `ident`'s source from the macro definition.
+                    ident.span.remove_mark();
+                    continue;
+                }
+                _ => continue,
+            };
+
+            match module.kind {
+                ModuleKind::Block(..) => {} // We can see through blocks
+                _ => break,
+            }
+
+            let item = self.resolve_ident_in_module_unadjusted(
+                ModuleOrUniformRoot::Module(module),
+                ident,
+                ns,
+                parent_scope,
+                finalize,
+                ignore_binding,
+            );
+            if let Ok(binding) = item {
+                // The ident resolves to an item.
+                return Some(LexicalScopeBinding::Item(binding));
+            }
+        }
+        self.early_resolve_ident_in_lexical_scope(
+            orig_ident,
+            ScopeSet::Late(ns, module, finalize.map(|finalize| finalize.node_id)),
+            parent_scope,
+            finalize,
+            finalize.is_some(),
+            ignore_binding,
+        )
+        .ok()
+        .map(LexicalScopeBinding::Item)
+    }
+
+    /// Resolve an identifier in lexical scope.
+    /// This is a variation of `fn resolve_ident_in_lexical_scope` that can be run during
+    /// expansion and import resolution (perhaps they can be merged in the future).
+    /// The function is used for resolving initial segments of macro paths (e.g., `foo` in
+    /// `foo::bar!(); or `foo!();`) and also for import paths on 2018 edition.
+    #[tracing::instrument(level = "debug", skip(self, scope_set))]
+    crate fn early_resolve_ident_in_lexical_scope(
+        &mut self,
+        orig_ident: Ident,
+        scope_set: ScopeSet<'a>,
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        force: bool,
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> Result<&'a NameBinding<'a>, Determinacy> {
+        bitflags::bitflags! {
+            struct Flags: u8 {
+                const MACRO_RULES          = 1 << 0;
+                const MODULE               = 1 << 1;
+                const MISC_SUGGEST_CRATE   = 1 << 2;
+                const MISC_SUGGEST_SELF    = 1 << 3;
+                const MISC_FROM_PRELUDE    = 1 << 4;
+            }
+        }
+
+        assert!(force || !finalize.is_some()); // `finalize` implies `force`
+
+        // Make sure `self`, `super` etc produce an error when passed to here.
+        if orig_ident.is_path_segment_keyword() {
+            return Err(Determinacy::Determined);
+        }
+
+        let (ns, macro_kind, is_import) = match scope_set {
+            ScopeSet::All(ns, is_import) => (ns, None, is_import),
+            ScopeSet::AbsolutePath(ns) => (ns, None, false),
+            ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
+            ScopeSet::Late(ns, ..) => (ns, None, false),
+        };
+
+        // This is *the* result, resolution from the scope closest to the resolved identifier.
+        // However, sometimes this result is "weak" because it comes from a glob import or
+        // a macro expansion, and in this case it cannot shadow names from outer scopes, e.g.
+        // mod m { ... } // solution in outer scope
+        // {
+        //     use prefix::*; // imports another `m` - innermost solution
+        //                    // weak, cannot shadow the outer `m`, need to report ambiguity error
+        //     m::mac!();
+        // }
+        // So we have to save the innermost solution and continue searching in outer scopes
+        // to detect potential ambiguities.
+        let mut innermost_result: Option<(&NameBinding<'_>, Flags)> = None;
+        let mut determinacy = Determinacy::Determined;
+
+        // Go through all the scopes and try to resolve the name.
+        let break_result = self.visit_scopes(
+            scope_set,
+            parent_scope,
+            orig_ident.span.ctxt(),
+            |this, scope, use_prelude, ctxt| {
+                let ident = Ident::new(orig_ident.name, orig_ident.span.with_ctxt(ctxt));
+                let ok = |res, span, arenas| {
+                    Ok((
+                        (res, ty::Visibility::Public, span, LocalExpnId::ROOT)
+                            .to_name_binding(arenas),
+                        Flags::empty(),
+                    ))
+                };
+                let result = match scope {
+                    Scope::DeriveHelpers(expn_id) => {
+                        if let Some(attr) = this
+                            .helper_attrs
+                            .get(&expn_id)
+                            .and_then(|attrs| attrs.iter().rfind(|i| ident == **i))
+                        {
+                            let binding = (
+                                Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper),
+                                ty::Visibility::Public,
+                                attr.span,
+                                expn_id,
+                            )
+                                .to_name_binding(this.arenas);
+                            Ok((binding, Flags::empty()))
+                        } else {
+                            Err(Determinacy::Determined)
+                        }
+                    }
+                    Scope::DeriveHelpersCompat => {
+                        let mut result = Err(Determinacy::Determined);
+                        for derive in parent_scope.derives {
+                            let parent_scope = &ParentScope { derives: &[], ..*parent_scope };
+                            match this.resolve_macro_path(
+                                derive,
+                                Some(MacroKind::Derive),
+                                parent_scope,
+                                true,
+                                force,
+                            ) {
+                                Ok((Some(ext), _)) => {
+                                    if ext.helper_attrs.contains(&ident.name) {
+                                        result = ok(
+                                            Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat),
+                                            derive.span,
+                                            this.arenas,
+                                        );
+                                        break;
+                                    }
+                                }
+                                Ok(_) | Err(Determinacy::Determined) => {}
+                                Err(Determinacy::Undetermined) => {
+                                    result = Err(Determinacy::Undetermined)
+                                }
+                            }
+                        }
+                        result
+                    }
+                    Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() {
+                        MacroRulesScope::Binding(macro_rules_binding)
+                            if ident == macro_rules_binding.ident =>
+                        {
+                            Ok((macro_rules_binding.binding, Flags::MACRO_RULES))
+                        }
+                        MacroRulesScope::Invocation(_) => Err(Determinacy::Undetermined),
+                        _ => Err(Determinacy::Determined),
+                    },
+                    Scope::CrateRoot => {
+                        let root_ident = Ident::new(kw::PathRoot, ident.span);
+                        let root_module = this.resolve_crate_root(root_ident);
+                        let binding = this.resolve_ident_in_module_ext(
+                            ModuleOrUniformRoot::Module(root_module),
+                            ident,
+                            ns,
+                            parent_scope,
+                            finalize,
+                            ignore_binding,
+                        );
+                        match binding {
+                            Ok(binding) => Ok((binding, Flags::MODULE | Flags::MISC_SUGGEST_CRATE)),
+                            Err((Determinacy::Undetermined, Weak::No)) => {
+                                return Some(Err(Determinacy::determined(force)));
+                            }
+                            Err((Determinacy::Undetermined, Weak::Yes)) => {
+                                Err(Determinacy::Undetermined)
+                            }
+                            Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
+                        }
+                    }
+                    Scope::Module(module, derive_fallback_lint_id) => {
+                        let adjusted_parent_scope = &ParentScope { module, ..*parent_scope };
+                        let binding = this.resolve_ident_in_module_unadjusted_ext(
+                            ModuleOrUniformRoot::Module(module),
+                            ident,
+                            ns,
+                            adjusted_parent_scope,
+                            !matches!(scope_set, ScopeSet::Late(..)),
+                            finalize,
+                            ignore_binding,
+                        );
+                        match binding {
+                            Ok(binding) => {
+                                if let Some(lint_id) = derive_fallback_lint_id {
+                                    this.lint_buffer.buffer_lint_with_diagnostic(
+                                        PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
+                                        lint_id,
+                                        orig_ident.span,
+                                        &format!(
+                                            "cannot find {} `{}` in this scope",
+                                            ns.descr(),
+                                            ident
+                                        ),
+                                        BuiltinLintDiagnostics::ProcMacroDeriveResolutionFallback(
+                                            orig_ident.span,
+                                        ),
+                                    );
+                                }
+                                let misc_flags = if ptr::eq(module, this.graph_root) {
+                                    Flags::MISC_SUGGEST_CRATE
+                                } else if module.is_normal() {
+                                    Flags::MISC_SUGGEST_SELF
+                                } else {
+                                    Flags::empty()
+                                };
+                                Ok((binding, Flags::MODULE | misc_flags))
+                            }
+                            Err((Determinacy::Undetermined, Weak::No)) => {
+                                return Some(Err(Determinacy::determined(force)));
+                            }
+                            Err((Determinacy::Undetermined, Weak::Yes)) => {
+                                Err(Determinacy::Undetermined)
+                            }
+                            Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
+                        }
+                    }
+                    Scope::RegisteredAttrs => match this.registered_attrs.get(&ident).cloned() {
+                        Some(ident) => ok(
+                            Res::NonMacroAttr(NonMacroAttrKind::Registered),
+                            ident.span,
+                            this.arenas,
+                        ),
+                        None => Err(Determinacy::Determined),
+                    },
+                    Scope::MacroUsePrelude => {
+                        match this.macro_use_prelude.get(&ident.name).cloned() {
+                            Some(binding) => Ok((binding, Flags::MISC_FROM_PRELUDE)),
+                            None => Err(Determinacy::determined(
+                                this.graph_root.unexpanded_invocations.borrow().is_empty(),
+                            )),
+                        }
+                    }
+                    Scope::BuiltinAttrs => {
+                        if is_builtin_attr_name(ident.name) {
+                            ok(
+                                Res::NonMacroAttr(NonMacroAttrKind::Builtin(ident.name)),
+                                DUMMY_SP,
+                                this.arenas,
+                            )
+                        } else {
+                            Err(Determinacy::Determined)
+                        }
+                    }
+                    Scope::ExternPrelude => {
+                        match this.extern_prelude_get(ident, finalize.is_some()) {
+                            Some(binding) => Ok((binding, Flags::empty())),
+                            None => Err(Determinacy::determined(
+                                this.graph_root.unexpanded_invocations.borrow().is_empty(),
+                            )),
+                        }
+                    }
+                    Scope::ToolPrelude => match this.registered_tools.get(&ident).cloned() {
+                        Some(ident) => ok(Res::ToolMod, ident.span, this.arenas),
+                        None => Err(Determinacy::Determined),
+                    },
+                    Scope::StdLibPrelude => {
+                        let mut result = Err(Determinacy::Determined);
+                        if let Some(prelude) = this.prelude {
+                            if let Ok(binding) = this.resolve_ident_in_module_unadjusted(
+                                ModuleOrUniformRoot::Module(prelude),
+                                ident,
+                                ns,
+                                parent_scope,
+                                None,
+                                ignore_binding,
+                            ) {
+                                if use_prelude || this.is_builtin_macro(binding.res()) {
+                                    result = Ok((binding, Flags::MISC_FROM_PRELUDE));
+                                }
+                            }
+                        }
+                        result
+                    }
+                    Scope::BuiltinTypes => match PrimTy::from_name(ident.name) {
+                        Some(prim_ty) => ok(Res::PrimTy(prim_ty), DUMMY_SP, this.arenas),
+                        None => Err(Determinacy::Determined),
+                    },
+                };
+
+                match result {
+                    Ok((binding, flags))
+                        if sub_namespace_match(binding.macro_kind(), macro_kind) =>
+                    {
+                        if finalize.is_none() || matches!(scope_set, ScopeSet::Late(..)) {
+                            return Some(Ok(binding));
+                        }
+
+                        if let Some((innermost_binding, innermost_flags)) = innermost_result {
+                            // Found another solution, if the first one was "weak", report an error.
+                            let (res, innermost_res) = (binding.res(), innermost_binding.res());
+                            if res != innermost_res {
+                                let is_builtin = |res| {
+                                    matches!(res, Res::NonMacroAttr(NonMacroAttrKind::Builtin(..)))
+                                };
+                                let derive_helper =
+                                    Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
+                                let derive_helper_compat =
+                                    Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat);
+
+                                let ambiguity_error_kind = if is_import {
+                                    Some(AmbiguityKind::Import)
+                                } else if is_builtin(innermost_res) || is_builtin(res) {
+                                    Some(AmbiguityKind::BuiltinAttr)
+                                } else if innermost_res == derive_helper_compat
+                                    || res == derive_helper_compat && innermost_res != derive_helper
+                                {
+                                    Some(AmbiguityKind::DeriveHelper)
+                                } else if innermost_flags.contains(Flags::MACRO_RULES)
+                                    && flags.contains(Flags::MODULE)
+                                    && !this.disambiguate_macro_rules_vs_modularized(
+                                        innermost_binding,
+                                        binding,
+                                    )
+                                    || flags.contains(Flags::MACRO_RULES)
+                                        && innermost_flags.contains(Flags::MODULE)
+                                        && !this.disambiguate_macro_rules_vs_modularized(
+                                            binding,
+                                            innermost_binding,
+                                        )
+                                {
+                                    Some(AmbiguityKind::MacroRulesVsModularized)
+                                } else if innermost_binding.is_glob_import() {
+                                    Some(AmbiguityKind::GlobVsOuter)
+                                } else if innermost_binding
+                                    .may_appear_after(parent_scope.expansion, binding)
+                                {
+                                    Some(AmbiguityKind::MoreExpandedVsOuter)
+                                } else {
+                                    None
+                                };
+                                if let Some(kind) = ambiguity_error_kind {
+                                    let misc = |f: Flags| {
+                                        if f.contains(Flags::MISC_SUGGEST_CRATE) {
+                                            AmbiguityErrorMisc::SuggestCrate
+                                        } else if f.contains(Flags::MISC_SUGGEST_SELF) {
+                                            AmbiguityErrorMisc::SuggestSelf
+                                        } else if f.contains(Flags::MISC_FROM_PRELUDE) {
+                                            AmbiguityErrorMisc::FromPrelude
+                                        } else {
+                                            AmbiguityErrorMisc::None
+                                        }
+                                    };
+                                    this.ambiguity_errors.push(AmbiguityError {
+                                        kind,
+                                        ident: orig_ident,
+                                        b1: innermost_binding,
+                                        b2: binding,
+                                        misc1: misc(innermost_flags),
+                                        misc2: misc(flags),
+                                    });
+                                    return Some(Ok(innermost_binding));
+                                }
+                            }
+                        } else {
+                            // Found the first solution.
+                            innermost_result = Some((binding, flags));
+                        }
+                    }
+                    Ok(..) | Err(Determinacy::Determined) => {}
+                    Err(Determinacy::Undetermined) => determinacy = Determinacy::Undetermined,
+                }
+
+                None
+            },
+        );
+
+        if let Some(break_result) = break_result {
+            return break_result;
+        }
+
+        // The first found solution was the only one, return it.
+        if let Some((binding, _)) = innermost_result {
+            return Ok(binding);
+        }
+
+        Err(Determinacy::determined(determinacy == Determinacy::Determined || force))
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    crate fn maybe_resolve_ident_in_module(
+        &mut self,
+        module: ModuleOrUniformRoot<'a>,
+        ident: Ident,
+        ns: Namespace,
+        parent_scope: &ParentScope<'a>,
+    ) -> Result<&'a NameBinding<'a>, Determinacy> {
+        self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, None, None)
+            .map_err(|(determinacy, _)| determinacy)
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    crate fn resolve_ident_in_module(
+        &mut self,
+        module: ModuleOrUniformRoot<'a>,
+        ident: Ident,
+        ns: Namespace,
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> Result<&'a NameBinding<'a>, Determinacy> {
+        self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, finalize, ignore_binding)
+            .map_err(|(determinacy, _)| determinacy)
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    fn resolve_ident_in_module_ext(
+        &mut self,
+        module: ModuleOrUniformRoot<'a>,
+        mut ident: Ident,
+        ns: Namespace,
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> {
+        let tmp_parent_scope;
+        let mut adjusted_parent_scope = parent_scope;
+        match module {
+            ModuleOrUniformRoot::Module(m) => {
+                if let Some(def) = ident.span.normalize_to_macros_2_0_and_adjust(m.expansion) {
+                    tmp_parent_scope =
+                        ParentScope { module: self.expn_def_scope(def), ..*parent_scope };
+                    adjusted_parent_scope = &tmp_parent_scope;
+                }
+            }
+            ModuleOrUniformRoot::ExternPrelude => {
+                ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root());
+            }
+            ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => {
+                // No adjustments
+            }
+        }
+        self.resolve_ident_in_module_unadjusted_ext(
+            module,
+            ident,
+            ns,
+            adjusted_parent_scope,
+            false,
+            finalize,
+            ignore_binding,
+        )
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    fn resolve_ident_in_module_unadjusted(
+        &mut self,
+        module: ModuleOrUniformRoot<'a>,
+        ident: Ident,
+        ns: Namespace,
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> Result<&'a NameBinding<'a>, Determinacy> {
+        self.resolve_ident_in_module_unadjusted_ext(
+            module,
+            ident,
+            ns,
+            parent_scope,
+            false,
+            finalize,
+            ignore_binding,
+        )
+        .map_err(|(determinacy, _)| determinacy)
+    }
+
+    /// Attempts to resolve `ident` in namespaces `ns` of `module`.
+    /// Invariant: if `finalize` is `Some`, expansion and import resolution must be complete.
+    #[tracing::instrument(level = "debug", skip(self))]
+    fn resolve_ident_in_module_unadjusted_ext(
+        &mut self,
+        module: ModuleOrUniformRoot<'a>,
+        ident: Ident,
+        ns: Namespace,
+        parent_scope: &ParentScope<'a>,
+        restricted_shadowing: bool,
+        finalize: Option<Finalize>,
+        // This binding should be ignored during in-module resolution, so that we don't get
+        // "self-confirming" import resolutions during import validation and checking.
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> {
+        let module = match module {
+            ModuleOrUniformRoot::Module(module) => module,
+            ModuleOrUniformRoot::CrateRootAndExternPrelude => {
+                assert!(!restricted_shadowing);
+                let binding = self.early_resolve_ident_in_lexical_scope(
+                    ident,
+                    ScopeSet::AbsolutePath(ns),
+                    parent_scope,
+                    finalize,
+                    finalize.is_some(),
+                    ignore_binding,
+                );
+                return binding.map_err(|determinacy| (determinacy, Weak::No));
+            }
+            ModuleOrUniformRoot::ExternPrelude => {
+                assert!(!restricted_shadowing);
+                return if ns != TypeNS {
+                    Err((Determined, Weak::No))
+                } else if let Some(binding) = self.extern_prelude_get(ident, finalize.is_some()) {
+                    Ok(binding)
+                } else if !self.graph_root.unexpanded_invocations.borrow().is_empty() {
+                    // Macro-expanded `extern crate` items can add names to extern prelude.
+                    Err((Undetermined, Weak::No))
+                } else {
+                    Err((Determined, Weak::No))
+                };
+            }
+            ModuleOrUniformRoot::CurrentScope => {
+                assert!(!restricted_shadowing);
+                if ns == TypeNS {
+                    if ident.name == kw::Crate || ident.name == kw::DollarCrate {
+                        let module = self.resolve_crate_root(ident);
+                        let binding =
+                            (module, ty::Visibility::Public, module.span, LocalExpnId::ROOT)
+                                .to_name_binding(self.arenas);
+                        return Ok(binding);
+                    } else if ident.name == kw::Super || ident.name == kw::SelfLower {
+                        // FIXME: Implement these with renaming requirements so that e.g.
+                        // `use super;` doesn't work, but `use super as name;` does.
+                        // Fall through here to get an error from `early_resolve_...`.
+                    }
+                }
+
+                let scopes = ScopeSet::All(ns, true);
+                let binding = self.early_resolve_ident_in_lexical_scope(
+                    ident,
+                    scopes,
+                    parent_scope,
+                    finalize,
+                    finalize.is_some(),
+                    ignore_binding,
+                );
+                return binding.map_err(|determinacy| (determinacy, Weak::No));
+            }
+        };
+
+        let key = self.new_key(ident, ns);
+        let resolution =
+            self.resolution(module, key).try_borrow_mut().map_err(|_| (Determined, Weak::No))?; // This happens when there is a cycle of imports.
+
+        if let Some(Finalize { path_span, report_private, .. }) = finalize {
+            // If the primary binding is unusable, search further and return the shadowed glob
+            // binding if it exists. What we really want here is having two separate scopes in
+            // a module - one for non-globs and one for globs, but until that's done use this
+            // hack to avoid inconsistent resolution ICEs during import validation.
+            let binding = [resolution.binding, resolution.shadowed_glob]
+                .into_iter()
+                .filter_map(|binding| match (binding, ignore_binding) {
+                    (Some(binding), Some(ignored)) if ptr::eq(binding, ignored) => None,
+                    _ => binding,
+                })
+                .next();
+            let Some(binding) = binding else {
+                return Err((Determined, Weak::No));
+            };
+
+            if !self.is_accessible_from(binding.vis, parent_scope.module) {
+                if report_private {
+                    self.privacy_errors.push(PrivacyError {
+                        ident,
+                        binding,
+                        dedup_span: path_span,
+                    });
+                } else {
+                    return Err((Determined, Weak::No));
+                }
+            }
+
+            // Forbid expanded shadowing to avoid time travel.
+            if let Some(shadowed_glob) = resolution.shadowed_glob
+                && restricted_shadowing
+                && binding.expansion != LocalExpnId::ROOT
+                && binding.res() != shadowed_glob.res()
+            {
+                self.ambiguity_errors.push(AmbiguityError {
+                    kind: AmbiguityKind::GlobVsExpanded,
+                    ident,
+                    b1: binding,
+                    b2: shadowed_glob,
+                    misc1: AmbiguityErrorMisc::None,
+                    misc2: AmbiguityErrorMisc::None,
+                });
+            }
+
+            if !restricted_shadowing && binding.expansion != LocalExpnId::ROOT {
+                if let NameBindingKind::Res(_, true) = binding.kind {
+                    self.macro_expanded_macro_export_errors.insert((path_span, binding.span));
+                }
+            }
+
+            self.record_use(ident, binding, restricted_shadowing);
+            return Ok(binding);
+        }
+
+        let check_usable = |this: &mut Self, binding: &'a NameBinding<'a>| {
+            if let Some(ignored) = ignore_binding && ptr::eq(binding, ignored) {
+                return Err((Determined, Weak::No));
+            }
+            let usable = this.is_accessible_from(binding.vis, parent_scope.module);
+            if usable { Ok(binding) } else { Err((Determined, Weak::No)) }
+        };
+
+        // Items and single imports are not shadowable, if we have one, then it's determined.
+        if let Some(binding) = resolution.binding {
+            if !binding.is_glob_import() {
+                return check_usable(self, binding);
+            }
+        }
+
+        // --- From now on we either have a glob resolution or no resolution. ---
+
+        // Check if one of single imports can still define the name,
+        // if it can then our result is not determined and can be invalidated.
+        for single_import in &resolution.single_imports {
+            if !self.is_accessible_from(single_import.vis.get(), parent_scope.module) {
+                continue;
+            }
+            let Some(module) = single_import.imported_module.get() else {
+                return Err((Undetermined, Weak::No));
+            };
+            let ImportKind::Single { source: ident, .. } = single_import.kind else {
+                unreachable!();
+            };
+            match self.resolve_ident_in_module(
+                module,
+                ident,
+                ns,
+                &single_import.parent_scope,
+                None,
+                ignore_binding,
+            ) {
+                Err(Determined) => continue,
+                Ok(binding)
+                    if !self.is_accessible_from(binding.vis, single_import.parent_scope.module) =>
+                {
+                    continue;
+                }
+                Ok(_) | Err(Undetermined) => return Err((Undetermined, Weak::No)),
+            }
+        }
+
+        // So we have a resolution that's from a glob import. This resolution is determined
+        // if it cannot be shadowed by some new item/import expanded from a macro.
+        // This happens either if there are no unexpanded macros, or expanded names cannot
+        // shadow globs (that happens in macro namespace or with restricted shadowing).
+        //
+        // Additionally, any macro in any module can plant names in the root module if it creates
+        // `macro_export` macros, so the root module effectively has unresolved invocations if any
+        // module has unresolved invocations.
+        // However, it causes resolution/expansion to stuck too often (#53144), so, to make
+        // progress, we have to ignore those potential unresolved invocations from other modules
+        // and prohibit access to macro-expanded `macro_export` macros instead (unless restricted
+        // shadowing is enabled, see `macro_expanded_macro_export_errors`).
+        let unexpanded_macros = !module.unexpanded_invocations.borrow().is_empty();
+        if let Some(binding) = resolution.binding {
+            if !unexpanded_macros || ns == MacroNS || restricted_shadowing {
+                return check_usable(self, binding);
+            } else {
+                return Err((Undetermined, Weak::No));
+            }
+        }
+
+        // --- From now on we have no resolution. ---
+
+        // Now we are in situation when new item/import can appear only from a glob or a macro
+        // expansion. With restricted shadowing names from globs and macro expansions cannot
+        // shadow names from outer scopes, so we can freely fallback from module search to search
+        // in outer scopes. For `early_resolve_ident_in_lexical_scope` to continue search in outer
+        // scopes we return `Undetermined` with `Weak::Yes`.
+
+        // Check if one of unexpanded macros can still define the name,
+        // if it can then our "no resolution" result is not determined and can be invalidated.
+        if unexpanded_macros {
+            return Err((Undetermined, Weak::Yes));
+        }
+
+        // Check if one of glob imports can still define the name,
+        // if it can then our "no resolution" result is not determined and can be invalidated.
+        for glob_import in module.globs.borrow().iter() {
+            if !self.is_accessible_from(glob_import.vis.get(), parent_scope.module) {
+                continue;
+            }
+            let module = match glob_import.imported_module.get() {
+                Some(ModuleOrUniformRoot::Module(module)) => module,
+                Some(_) => continue,
+                None => return Err((Undetermined, Weak::Yes)),
+            };
+            let tmp_parent_scope;
+            let (mut adjusted_parent_scope, mut ident) =
+                (parent_scope, ident.normalize_to_macros_2_0());
+            match ident.span.glob_adjust(module.expansion, glob_import.span) {
+                Some(Some(def)) => {
+                    tmp_parent_scope =
+                        ParentScope { module: self.expn_def_scope(def), ..*parent_scope };
+                    adjusted_parent_scope = &tmp_parent_scope;
+                }
+                Some(None) => {}
+                None => continue,
+            };
+            let result = self.resolve_ident_in_module_unadjusted(
+                ModuleOrUniformRoot::Module(module),
+                ident,
+                ns,
+                adjusted_parent_scope,
+                None,
+                ignore_binding,
+            );
+
+            match result {
+                Err(Determined) => continue,
+                Ok(binding)
+                    if !self.is_accessible_from(binding.vis, glob_import.parent_scope.module) =>
+                {
+                    continue;
+                }
+                Ok(_) | Err(Undetermined) => return Err((Undetermined, Weak::Yes)),
+            }
+        }
+
+        // No resolution and no one else can define the name - determinate error.
+        Err((Determined, Weak::No))
+    }
+
+    /// Validate a local resolution (from ribs).
+    #[tracing::instrument(level = "debug", skip(self, all_ribs))]
+    fn validate_res_from_ribs(
+        &mut self,
+        rib_index: usize,
+        rib_ident: Ident,
+        mut res: Res,
+        finalize: Option<Span>,
+        original_rib_ident_def: Ident,
+        all_ribs: &[Rib<'a>],
+    ) -> Res {
+        const CG_BUG_STR: &str = "min_const_generics resolve check didn't stop compilation";
+        debug!("validate_res_from_ribs({:?})", res);
+        let ribs = &all_ribs[rib_index + 1..];
+
+        // An invalid forward use of a generic parameter from a previous default.
+        if let ForwardGenericParamBanRibKind = all_ribs[rib_index].kind {
+            if let Some(span) = finalize {
+                let res_error = if rib_ident.name == kw::SelfUpper {
+                    ResolutionError::SelfInGenericParamDefault
+                } else {
+                    ResolutionError::ForwardDeclaredGenericParam
+                };
+                self.report_error(span, res_error);
+            }
+            assert_eq!(res, Res::Err);
+            return Res::Err;
+        }
+
+        match res {
+            Res::Local(_) => {
+                use ResolutionError::*;
+                let mut res_err = None;
+
+                for rib in ribs {
+                    match rib.kind {
+                        NormalRibKind
+                        | ClosureOrAsyncRibKind
+                        | ModuleRibKind(..)
+                        | MacroDefinition(..)
+                        | ForwardGenericParamBanRibKind => {
+                            // Nothing to do. Continue.
+                        }
+                        ItemRibKind(_) | FnItemRibKind | AssocItemRibKind => {
+                            // This was an attempt to access an upvar inside a
+                            // named function item. This is not allowed, so we
+                            // report an error.
+                            if let Some(span) = finalize {
+                                // We don't immediately trigger a resolve error, because
+                                // we want certain other resolution errors (namely those
+                                // emitted for `ConstantItemRibKind` below) to take
+                                // precedence.
+                                res_err = Some((span, CannotCaptureDynamicEnvironmentInFnItem));
+                            }
+                        }
+                        ConstantItemRibKind(_, item) => {
+                            // Still doesn't deal with upvars
+                            if let Some(span) = finalize {
+                                let (span, resolution_error) =
+                                    if let Some((ident, constant_item_kind)) = item {
+                                        let kind_str = match constant_item_kind {
+                                            ConstantItemKind::Const => "const",
+                                            ConstantItemKind::Static => "static",
+                                        };
+                                        (
+                                            span,
+                                            AttemptToUseNonConstantValueInConstant(
+                                                ident, "let", kind_str,
+                                            ),
+                                        )
+                                    } else {
+                                        (
+                                            rib_ident.span,
+                                            AttemptToUseNonConstantValueInConstant(
+                                                original_rib_ident_def,
+                                                "const",
+                                                "let",
+                                            ),
+                                        )
+                                    };
+                                self.report_error(span, resolution_error);
+                            }
+                            return Res::Err;
+                        }
+                        ConstParamTyRibKind => {
+                            if let Some(span) = finalize {
+                                self.report_error(span, ParamInTyOfConstParam(rib_ident.name));
+                            }
+                            return Res::Err;
+                        }
+                        InlineAsmSymRibKind => {
+                            if let Some(span) = finalize {
+                                self.report_error(span, InvalidAsmSym);
+                            }
+                            return Res::Err;
+                        }
+                    }
+                }
+                if let Some((span, res_err)) = res_err {
+                    self.report_error(span, res_err);
+                    return Res::Err;
+                }
+            }
+            Res::Def(DefKind::TyParam, _) | Res::SelfTy { .. } => {
+                for rib in ribs {
+                    let has_generic_params: HasGenericParams = match rib.kind {
+                        NormalRibKind
+                        | ClosureOrAsyncRibKind
+                        | AssocItemRibKind
+                        | ModuleRibKind(..)
+                        | MacroDefinition(..)
+                        | ForwardGenericParamBanRibKind => {
+                            // Nothing to do. Continue.
+                            continue;
+                        }
+
+                        ConstantItemRibKind(trivial, _) => {
+                            let features = self.session.features_untracked();
+                            // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
+                            if !(trivial == HasGenericParams::Yes || features.generic_const_exprs) {
+                                // HACK(min_const_generics): If we encounter `Self` in an anonymous constant
+                                // we can't easily tell if it's generic at this stage, so we instead remember
+                                // this and then enforce the self type to be concrete later on.
+                                if let Res::SelfTy { trait_, alias_to: Some((def, _)) } = res {
+                                    res = Res::SelfTy { trait_, alias_to: Some((def, true)) }
+                                } else {
+                                    if let Some(span) = finalize {
+                                        self.report_error(
+                                            span,
+                                            ResolutionError::ParamInNonTrivialAnonConst {
+                                                name: rib_ident.name,
+                                                is_type: true,
+                                            },
+                                        );
+                                        self.session.delay_span_bug(span, CG_BUG_STR);
+                                    }
+
+                                    return Res::Err;
+                                }
+                            }
+
+                            continue;
+                        }
+
+                        // This was an attempt to use a type parameter outside its scope.
+                        ItemRibKind(has_generic_params) => has_generic_params,
+                        FnItemRibKind => HasGenericParams::Yes,
+                        ConstParamTyRibKind => {
+                            if let Some(span) = finalize {
+                                self.report_error(
+                                    span,
+                                    ResolutionError::ParamInTyOfConstParam(rib_ident.name),
+                                );
+                            }
+                            return Res::Err;
+                        }
+                        InlineAsmSymRibKind => {
+                            let features = self.session.features_untracked();
+                            if !features.generic_const_exprs {
+                                if let Some(span) = finalize {
+                                    self.report_error(
+                                        span,
+                                        ResolutionError::ParamInNonTrivialAnonConst {
+                                            name: rib_ident.name,
+                                            is_type: true,
+                                        },
+                                    );
+                                }
+                                return Res::Err;
+                            }
+                            continue;
+                        }
+                    };
+
+                    if let Some(span) = finalize {
+                        self.report_error(
+                            span,
+                            ResolutionError::GenericParamsFromOuterFunction(
+                                res,
+                                has_generic_params,
+                            ),
+                        );
+                    }
+                    return Res::Err;
+                }
+            }
+            Res::Def(DefKind::ConstParam, _) => {
+                let mut ribs = ribs.iter().peekable();
+                if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() {
+                    // When declaring const parameters inside function signatures, the first rib
+                    // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
+                    // (spuriously) conflicting with the const param.
+                    ribs.next();
+                }
+
+                for rib in ribs {
+                    let has_generic_params = match rib.kind {
+                        NormalRibKind
+                        | ClosureOrAsyncRibKind
+                        | AssocItemRibKind
+                        | ModuleRibKind(..)
+                        | MacroDefinition(..)
+                        | ForwardGenericParamBanRibKind => continue,
+
+                        ConstantItemRibKind(trivial, _) => {
+                            let features = self.session.features_untracked();
+                            // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
+                            if !(trivial == HasGenericParams::Yes || features.generic_const_exprs) {
+                                if let Some(span) = finalize {
+                                    self.report_error(
+                                        span,
+                                        ResolutionError::ParamInNonTrivialAnonConst {
+                                            name: rib_ident.name,
+                                            is_type: false,
+                                        },
+                                    );
+                                    self.session.delay_span_bug(span, CG_BUG_STR);
+                                }
+
+                                return Res::Err;
+                            }
+
+                            continue;
+                        }
+
+                        ItemRibKind(has_generic_params) => has_generic_params,
+                        FnItemRibKind => HasGenericParams::Yes,
+                        ConstParamTyRibKind => {
+                            if let Some(span) = finalize {
+                                self.report_error(
+                                    span,
+                                    ResolutionError::ParamInTyOfConstParam(rib_ident.name),
+                                );
+                            }
+                            return Res::Err;
+                        }
+                        InlineAsmSymRibKind => {
+                            let features = self.session.features_untracked();
+                            if !features.generic_const_exprs {
+                                if let Some(span) = finalize {
+                                    self.report_error(
+                                        span,
+                                        ResolutionError::ParamInNonTrivialAnonConst {
+                                            name: rib_ident.name,
+                                            is_type: false,
+                                        },
+                                    );
+                                }
+                                return Res::Err;
+                            }
+                            continue;
+                        }
+                    };
+
+                    // This was an attempt to use a const parameter outside its scope.
+                    if let Some(span) = finalize {
+                        self.report_error(
+                            span,
+                            ResolutionError::GenericParamsFromOuterFunction(
+                                res,
+                                has_generic_params,
+                            ),
+                        );
+                    }
+                    return Res::Err;
+                }
+            }
+            _ => {}
+        }
+        res
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    crate fn maybe_resolve_path(
+        &mut self,
+        path: &[Segment],
+        opt_ns: Option<Namespace>, // `None` indicates a module path in import
+        parent_scope: &ParentScope<'a>,
+    ) -> PathResult<'a> {
+        self.resolve_path_with_ribs(path, opt_ns, parent_scope, None, None, None)
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    crate fn resolve_path(
+        &mut self,
+        path: &[Segment],
+        opt_ns: Option<Namespace>, // `None` indicates a module path in import
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> PathResult<'a> {
+        self.resolve_path_with_ribs(path, opt_ns, parent_scope, finalize, None, ignore_binding)
+    }
+
+    crate fn resolve_path_with_ribs(
+        &mut self,
+        path: &[Segment],
+        opt_ns: Option<Namespace>, // `None` indicates a module path in import
+        parent_scope: &ParentScope<'a>,
+        finalize: Option<Finalize>,
+        ribs: Option<&PerNS<Vec<Rib<'a>>>>,
+        ignore_binding: Option<&'a NameBinding<'a>>,
+    ) -> PathResult<'a> {
+        debug!("resolve_path(path={:?}, opt_ns={:?}, finalize={:?})", path, opt_ns, finalize);
+
+        let mut module = None;
+        let mut allow_super = true;
+        let mut second_binding = None;
+
+        for (i, &Segment { ident, id, .. }) in path.iter().enumerate() {
+            debug!("resolve_path ident {} {:?} {:?}", i, ident, id);
+            let record_segment_res = |this: &mut Self, res| {
+                if finalize.is_some() {
+                    if let Some(id) = id {
+                        if !this.partial_res_map.contains_key(&id) {
+                            assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id");
+                            this.record_partial_res(id, PartialRes::new(res));
+                        }
+                    }
+                }
+            };
+
+            let is_last = i == path.len() - 1;
+            let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
+            let name = ident.name;
+
+            allow_super &= ns == TypeNS && (name == kw::SelfLower || name == kw::Super);
+
+            if ns == TypeNS {
+                if allow_super && name == kw::Super {
+                    let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
+                    let self_module = match i {
+                        0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)),
+                        _ => match module {
+                            Some(ModuleOrUniformRoot::Module(module)) => Some(module),
+                            _ => None,
+                        },
+                    };
+                    if let Some(self_module) = self_module {
+                        if let Some(parent) = self_module.parent {
+                            module = Some(ModuleOrUniformRoot::Module(
+                                self.resolve_self(&mut ctxt, parent),
+                            ));
+                            continue;
+                        }
+                    }
+                    return PathResult::failed(ident.span, false, finalize.is_some(), || {
+                        ("there are too many leading `super` keywords".to_string(), None)
+                    });
+                }
+                if i == 0 {
+                    if name == kw::SelfLower {
+                        let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
+                        module = Some(ModuleOrUniformRoot::Module(
+                            self.resolve_self(&mut ctxt, parent_scope.module),
+                        ));
+                        continue;
+                    }
+                    if name == kw::PathRoot && ident.span.rust_2018() {
+                        module = Some(ModuleOrUniformRoot::ExternPrelude);
+                        continue;
+                    }
+                    if name == kw::PathRoot && ident.span.rust_2015() && self.session.rust_2018() {
+                        // `::a::b` from 2015 macro on 2018 global edition
+                        module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude);
+                        continue;
+                    }
+                    if name == kw::PathRoot || name == kw::Crate || name == kw::DollarCrate {
+                        // `::a::b`, `crate::a::b` or `$crate::a::b`
+                        module = Some(ModuleOrUniformRoot::Module(self.resolve_crate_root(ident)));
+                        continue;
+                    }
+                }
+            }
+
+            // Report special messages for path segment keywords in wrong positions.
+            if ident.is_path_segment_keyword() && i != 0 {
+                return PathResult::failed(ident.span, false, finalize.is_some(), || {
+                    let name_str = if name == kw::PathRoot {
+                        "crate root".to_string()
+                    } else {
+                        format!("`{}`", name)
+                    };
+                    let label = if i == 1 && path[0].ident.name == kw::PathRoot {
+                        format!("global paths cannot start with {}", name_str)
+                    } else {
+                        format!("{} in paths can only be used in start position", name_str)
+                    };
+                    (label, None)
+                });
+            }
+
+            enum FindBindingResult<'a> {
+                Binding(Result<&'a NameBinding<'a>, Determinacy>),
+                Res(Res),
+            }
+            let find_binding_in_ns = |this: &mut Self, ns| {
+                let binding = if let Some(module) = module {
+                    this.resolve_ident_in_module(
+                        module,
+                        ident,
+                        ns,
+                        parent_scope,
+                        finalize,
+                        ignore_binding,
+                    )
+                } else if let Some(ribs) = ribs
+                    && let Some(TypeNS | ValueNS) = opt_ns
+                {
+                    match this.resolve_ident_in_lexical_scope(
+                        ident,
+                        ns,
+                        parent_scope,
+                        finalize,
+                        &ribs[ns],
+                        ignore_binding,
+                    ) {
+                        // we found a locally-imported or available item/module
+                        Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
+                        // we found a local variable or type param
+                        Some(LexicalScopeBinding::Res(res)) => return FindBindingResult::Res(res),
+                        _ => Err(Determinacy::determined(finalize.is_some())),
+                    }
+                } else {
+                    let scopes = ScopeSet::All(ns, opt_ns.is_none());
+                    this.early_resolve_ident_in_lexical_scope(
+                        ident,
+                        scopes,
+                        parent_scope,
+                        finalize,
+                        finalize.is_some(),
+                        ignore_binding,
+                    )
+                };
+                FindBindingResult::Binding(binding)
+            };
+            let binding = match find_binding_in_ns(self, ns) {
+                FindBindingResult::Res(res) => {
+                    record_segment_res(self, res);
+                    return PathResult::NonModule(PartialRes::with_unresolved_segments(
+                        res,
+                        path.len() - 1,
+                    ));
+                }
+                FindBindingResult::Binding(binding) => binding,
+            };
+            match binding {
+                Ok(binding) => {
+                    if i == 1 {
+                        second_binding = Some(binding);
+                    }
+                    let res = binding.res();
+                    let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res);
+                    if let Some(next_module) = binding.module() {
+                        module = Some(ModuleOrUniformRoot::Module(next_module));
+                        record_segment_res(self, res);
+                    } else if res == Res::ToolMod && i + 1 != path.len() {
+                        if binding.is_import() {
+                            self.session
+                                .struct_span_err(
+                                    ident.span,
+                                    "cannot use a tool module through an import",
+                                )
+                                .span_note(binding.span, "the tool module imported here")
+                                .emit();
+                        }
+                        let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
+                        return PathResult::NonModule(PartialRes::new(res));
+                    } else if res == Res::Err {
+                        return PathResult::NonModule(PartialRes::new(Res::Err));
+                    } else if opt_ns.is_some() && (is_last || maybe_assoc) {
+                        self.lint_if_path_starts_with_module(finalize, path, second_binding);
+                        return PathResult::NonModule(PartialRes::with_unresolved_segments(
+                            res,
+                            path.len() - i - 1,
+                        ));
+                    } else {
+                        return PathResult::failed(ident.span, is_last, finalize.is_some(), || {
+                            let label = format!(
+                                "`{ident}` is {} {}, not a module",
+                                res.article(),
+                                res.descr()
+                            );
+                            (label, None)
+                        });
+                    }
+                }
+                Err(Undetermined) => return PathResult::Indeterminate,
+                Err(Determined) => {
+                    if let Some(ModuleOrUniformRoot::Module(module)) = module {
+                        if opt_ns.is_some() && !module.is_normal() {
+                            return PathResult::NonModule(PartialRes::with_unresolved_segments(
+                                module.res().unwrap(),
+                                path.len() - i,
+                            ));
+                        }
+                    }
+
+                    return PathResult::failed(ident.span, is_last, finalize.is_some(), || {
+                        self.report_path_resolution_error(
+                            path,
+                            opt_ns,
+                            parent_scope,
+                            ribs,
+                            ignore_binding,
+                            module,
+                            i,
+                            ident,
+                        )
+                    });
+                }
+            }
+        }
+
+        self.lint_if_path_starts_with_module(finalize, path, second_binding);
+
+        PathResult::Module(match module {
+            Some(module) => module,
+            None if path.is_empty() => ModuleOrUniformRoot::CurrentScope,
+            _ => bug!("resolve_path: non-empty path `{:?}` has no module", path),
+        })
+    }
+}