use RibKind::*;
use crate::{path_names_to_string, BindingError, CrateLint, LexicalScopeBinding};
-use crate::{Module, ModuleOrUniformRoot, NameBinding, NameBindingKind, ParentScope, PathResult};
+use crate::{Module, ModuleOrUniformRoot, NameBindingKind, ParentScope, PathResult};
use crate::{ResolutionError, Resolver, Segment, UseError};
use log::debug;
use rustc::hir::def::Namespace::{self, *};
use rustc::hir::def_id::{DefId, CRATE_DEF_INDEX};
use rustc::hir::TraitCandidate;
-use rustc::util::nodemap::FxHashMap;
+use rustc::util::nodemap::{FxHashMap, FxHashSet};
use smallvec::{smallvec, SmallVec};
use syntax::{unwrap_or, walk_list};
use syntax::ast::*;
type Res = def::Res<NodeId>;
+type IdentMap<T> = FxHashMap<Ident, T>;
+
/// Map from the name in a pattern to its binding mode.
-type BindingMap = FxHashMap<Ident, BindingInfo>;
+type BindingMap = IdentMap<BindingInfo>;
#[derive(Copy, Clone, Debug)]
struct BindingInfo {
}
}
+/// Denotes whether the context for the set of already bound bindings is a `Product`
+/// or `Or` context. This is used in e.g., `fresh_binding` and `resolve_pattern_inner`.
+/// See those functions for more information.
+enum PatBoundCtx {
+ /// A product pattern context, e.g., `Variant(a, b)`.
+ Product,
+ /// An or-pattern context, e.g., `p_0 | ... | p_n`.
+ Or,
+}
+
/// The rib kind restricts certain accesses,
/// e.g. to a `Res::Local` of an outer item.
#[derive(Copy, Clone, Debug)]
/// resolving, the name is looked up from inside out.
#[derive(Debug)]
crate struct Rib<'a, R = Res> {
- pub bindings: FxHashMap<Ident, R>,
+ pub bindings: IdentMap<R>,
pub kind: RibKind<'a>,
}
ValueNS => "method or associated constant",
MacroNS => bug!("associated macro"),
},
- PathSource::Expr(parent) => match parent.map(|p| &p.node) {
+ PathSource::Expr(parent) => match parent.map(|p| &p.kind) {
// "function" here means "anything callable" rather than `DefKind::Fn`,
// this is not precise but usually more helpful than just "value".
Some(&ExprKind::Call(..)) => "function",
}
fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
- __diagnostic_used!(E0404);
- __diagnostic_used!(E0405);
- __diagnostic_used!(E0412);
- __diagnostic_used!(E0422);
- __diagnostic_used!(E0423);
- __diagnostic_used!(E0425);
- __diagnostic_used!(E0531);
- __diagnostic_used!(E0532);
- __diagnostic_used!(E0573);
- __diagnostic_used!(E0574);
- __diagnostic_used!(E0575);
- __diagnostic_used!(E0576);
+ syntax::diagnostic_used!(E0404);
+ syntax::diagnostic_used!(E0405);
+ syntax::diagnostic_used!(E0412);
+ syntax::diagnostic_used!(E0422);
+ syntax::diagnostic_used!(E0423);
+ syntax::diagnostic_used!(E0425);
+ syntax::diagnostic_used!(E0531);
+ syntax::diagnostic_used!(E0532);
+ syntax::diagnostic_used!(E0573);
+ syntax::diagnostic_used!(E0574);
+ syntax::diagnostic_used!(E0575);
+ syntax::diagnostic_used!(E0576);
match (self, has_unexpected_resolution) {
(PathSource::Trait(_), true) => "E0404",
(PathSource::Trait(_), false) => "E0405",
self.resolve_local(local);
}
fn visit_ty(&mut self, ty: &'tcx Ty) {
- match ty.node {
+ match ty.kind {
TyKind::Path(ref qself, ref path) => {
self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
}
visit::walk_foreign_item(this, foreign_item);
});
}
- fn visit_fn(&mut self,
- function_kind: FnKind<'tcx>,
- declaration: &'tcx FnDecl,
- _: Span,
- _: NodeId)
- {
+ fn visit_fn(&mut self, fn_kind: FnKind<'tcx>, declaration: &'tcx FnDecl, _: Span, _: NodeId) {
debug!("(resolving function) entering function");
- let rib_kind = match function_kind {
+ let rib_kind = match fn_kind {
FnKind::ItemFn(..) => FnItemRibKind,
FnKind::Method(..) | FnKind::Closure(_) => NormalRibKind,
};
// Create a value rib for the function.
- self.ribs[ValueNS].push(Rib::new(rib_kind));
-
- // Create a label rib for the function.
- self.label_ribs.push(Rib::new(rib_kind));
-
- // Add each argument to the rib.
- self.resolve_params(&declaration.inputs);
-
- visit::walk_fn_ret_ty(self, &declaration.output);
-
- // Resolve the function body, potentially inside the body of an async closure
- match function_kind {
- FnKind::ItemFn(.., body) |
- FnKind::Method(.., body) => {
- self.visit_block(body);
- }
- FnKind::Closure(body) => {
- self.visit_expr(body);
- }
- };
-
- debug!("(resolving function) leaving function");
-
- self.label_ribs.pop();
- self.ribs[ValueNS].pop();
+ self.with_rib(ValueNS, rib_kind, |this| {
+ // Create a label rib for the function.
+ this.with_label_rib(rib_kind, |this| {
+ // Add each argument to the rib.
+ this.resolve_params(&declaration.inputs);
+
+ visit::walk_fn_ret_ty(this, &declaration.output);
+
+ // Resolve the function body, potentially inside the body of an async closure
+ match fn_kind {
+ FnKind::ItemFn(.., body) |
+ FnKind::Method(.., body) => this.visit_block(body),
+ FnKind::Closure(body) => this.visit_expr(body),
+ };
+
+ debug!("(resolving function) leaving function");
+ })
+ });
}
fn visit_generics(&mut self, generics: &'tcx Generics) {
// although it may be useful to track other components as well for diagnostics.
let graph_root = resolver.graph_root;
let parent_scope = ParentScope::module(graph_root);
+ let start_rib_kind = ModuleRibKind(graph_root);
LateResolutionVisitor {
r: resolver,
parent_scope,
ribs: PerNS {
- value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
- type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
- macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
+ value_ns: vec![Rib::new(start_rib_kind)],
+ type_ns: vec![Rib::new(start_rib_kind)],
+ macro_ns: vec![Rib::new(start_rib_kind)],
},
label_ribs: Vec::new(),
current_trait_ref: None,
// generate a fake "implementation scope" containing all the
// implementations thus found, for compatibility with old resolve pass.
- fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>) -> T
- {
+ /// Do some `work` within a new innermost rib of the given `kind` in the given namespace (`ns`).
+ fn with_rib<T>(
+ &mut self,
+ ns: Namespace,
+ kind: RibKind<'a>,
+ work: impl FnOnce(&mut Self) -> T,
+ ) -> T {
+ self.ribs[ns].push(Rib::new(kind));
+ let ret = work(self);
+ self.ribs[ns].pop();
+ ret
+ }
+
+ fn with_scope<T>(&mut self, id: NodeId, f: impl FnOnce(&mut Self) -> T) -> T {
let id = self.r.definitions.local_def_id(id);
let module = self.r.module_map.get(&id).cloned(); // clones a reference
if let Some(module) = module {
// Move down in the graph.
let orig_module = replace(&mut self.parent_scope.module, module);
- self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
- self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
-
- let ret = f(self);
-
- self.parent_scope.module = orig_module;
- self.ribs[ValueNS].pop();
- self.ribs[TypeNS].pop();
- ret
+ self.with_rib(ValueNS, ModuleRibKind(module), |this| {
+ this.with_rib(TypeNS, ModuleRibKind(module), |this| {
+ let ret = f(this);
+ this.parent_scope.module = orig_module;
+ ret
+ })
+ })
} else {
f(self)
}
fn resolve_item(&mut self, item: &Item) {
let name = item.ident.name;
- debug!("(resolving item) resolving {} ({:?})", name, item.node);
+ debug!("(resolving item) resolving {} ({:?})", name, item.kind);
- match item.node {
+ match item.kind {
ItemKind::TyAlias(_, ref generics) |
ItemKind::OpaqueTy(_, ref generics) |
ItemKind::Fn(_, _, ref generics, _) => {
AssocItemRibKind,
);
this.with_generic_param_rib(generic_params, |this| {
- match trait_item.node {
+ match trait_item.kind {
TraitItemKind::Const(ref ty, ref default) => {
this.visit_ty(ty);
}
fn with_generic_param_rib<'c, F>(&'c mut self, generic_params: GenericParameters<'a, 'c>, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
+ where F: FnOnce(&mut Self)
{
debug!("with_generic_param_rib");
match generic_params {
}
}
- fn with_label_rib<F>(&mut self, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
- {
- self.label_ribs.push(Rib::new(NormalRibKind));
+ fn with_label_rib(&mut self, kind: RibKind<'a>, f: impl FnOnce(&mut Self)) {
+ self.label_ribs.push(Rib::new(kind));
f(self);
self.label_ribs.pop();
}
- fn with_item_rib<F>(&mut self, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
- {
- self.ribs[ValueNS].push(Rib::new(ItemRibKind));
- self.ribs[TypeNS].push(Rib::new(ItemRibKind));
- f(self);
- self.ribs[TypeNS].pop();
- self.ribs[ValueNS].pop();
+ fn with_item_rib(&mut self, f: impl FnOnce(&mut Self)) {
+ self.with_rib(ValueNS, ItemRibKind, |this| this.with_rib(TypeNS, ItemRibKind, f))
}
- fn with_constant_rib<F>(&mut self, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
- {
+ fn with_constant_rib(&mut self, f: impl FnOnce(&mut Self)) {
debug!("with_constant_rib");
- self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
- self.label_ribs.push(Rib::new(ConstantItemRibKind));
- f(self);
- self.label_ribs.pop();
- self.ribs[ValueNS].pop();
+ self.with_rib(ValueNS, ConstantItemRibKind, |this| {
+ this.with_label_rib(ConstantItemRibKind, f);
+ });
}
- fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>) -> T
- {
+ fn with_current_self_type<T>(&mut self, self_type: &Ty, f: impl FnOnce(&mut Self) -> T) -> T {
// Handle nested impls (inside fn bodies)
let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
let result = f(self);
result
}
- fn with_current_self_item<T, F>(&mut self, self_item: &Item, f: F) -> T
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>) -> T
- {
+ fn with_current_self_item<T>(&mut self, self_item: &Item, f: impl FnOnce(&mut Self) -> T) -> T {
let previous_value = replace(&mut self.current_self_item, Some(self_item.id));
let result = f(self);
self.current_self_item = previous_value;
}
/// When evaluating a `trait` use its associated types' idents for suggestionsa in E0412.
- fn with_trait_items<T, F>(&mut self, trait_items: &Vec<TraitItem>, f: F) -> T
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>) -> T
- {
+ fn with_trait_items<T>(
+ &mut self,
+ trait_items: &Vec<TraitItem>,
+ f: impl FnOnce(&mut Self) -> T,
+ ) -> T {
let trait_assoc_types = replace(
&mut self.current_trait_assoc_types,
- trait_items.iter().filter_map(|item| match &item.node {
+ trait_items.iter().filter_map(|item| match &item.kind {
TraitItemKind::Type(bounds, _) if bounds.len() == 0 => Some(item.ident),
_ => None,
}).collect(),
}
/// This is called to resolve a trait reference from an `impl` (i.e., `impl Trait for Foo`).
- fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>, Option<DefId>) -> T
- {
+ fn with_optional_trait_ref<T>(
+ &mut self,
+ opt_trait_ref: Option<&TraitRef>,
+ f: impl FnOnce(&mut Self, Option<DefId>) -> T
+ ) -> T {
let mut new_val = None;
let mut new_id = None;
if let Some(trait_ref) = opt_trait_ref {
result
}
- fn with_self_rib<F>(&mut self, self_res: Res, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
- {
+ fn with_self_rib_ns(&mut self, ns: Namespace, self_res: Res, f: impl FnOnce(&mut Self)) {
let mut self_type_rib = Rib::new(NormalRibKind);
// Plain insert (no renaming, since types are not currently hygienic)
self_type_rib.bindings.insert(Ident::with_dummy_span(kw::SelfUpper), self_res);
- self.ribs[TypeNS].push(self_type_rib);
+ self.ribs[ns].push(self_type_rib);
f(self);
- self.ribs[TypeNS].pop();
+ self.ribs[ns].pop();
}
- fn with_self_struct_ctor_rib<F>(&mut self, impl_id: DefId, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
- {
- let self_res = Res::SelfCtor(impl_id);
- let mut self_type_rib = Rib::new(NormalRibKind);
- self_type_rib.bindings.insert(Ident::with_dummy_span(kw::SelfUpper), self_res);
- self.ribs[ValueNS].push(self_type_rib);
- f(self);
- self.ribs[ValueNS].pop();
+ fn with_self_rib(&mut self, self_res: Res, f: impl FnOnce(&mut Self)) {
+ self.with_self_rib_ns(TypeNS, self_res, f)
}
fn resolve_implementation(&mut self,
this.visit_generics(generics);
// Resolve the items within the impl.
this.with_current_self_type(self_type, |this| {
- this.with_self_struct_ctor_rib(item_def_id, |this| {
- debug!("resolve_implementation with_self_struct_ctor_rib");
+ this.with_self_rib_ns(ValueNS, Res::SelfCtor(item_def_id), |this| {
+ debug!("resolve_implementation with_self_rib_ns(ValueNS, ...)");
for impl_item in impl_items {
// We also need a new scope for the impl item type parameters.
let generic_params = HasGenericParams(&impl_item.generics,
AssocItemRibKind);
this.with_generic_param_rib(generic_params, |this| {
use crate::ResolutionError::*;
- match impl_item.node {
+ match impl_item.kind {
ImplItemKind::Const(..) => {
debug!(
"resolve_implementation ImplItemKind::Const",
}
}
- fn resolve_params(&mut self, params: &[Arg]) {
- let mut bindings_list = FxHashMap::default();
- for param in params {
- self.resolve_pattern(¶m.pat, PatternSource::FnParam, &mut bindings_list);
- self.visit_ty(¶m.ty);
+ fn resolve_params(&mut self, params: &[Param]) {
+ let mut bindings = smallvec![(PatBoundCtx::Product, Default::default())];
+ for Param { pat, ty, .. } in params {
+ self.resolve_pattern(pat, PatternSource::FnParam, &mut bindings);
+ self.visit_ty(ty);
debug!("(resolving function / closure) recorded parameter");
}
}
walk_list!(self, visit_expr, &local.init);
// Resolve the pattern.
- self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap::default());
+ self.resolve_pattern_top(&local.pat, PatternSource::Let);
}
- // build a map from pattern identifiers to binding-info's.
- // this is done hygienically. This could arise for a macro
- // that expands into an or-pattern where one 'x' was from the
- // user and one 'x' came from the macro.
+ /// build a map from pattern identifiers to binding-info's.
+ /// this is done hygienically. This could arise for a macro
+ /// that expands into an or-pattern where one 'x' was from the
+ /// user and one 'x' came from the macro.
fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
let mut binding_map = FxHashMap::default();
pat.walk(&mut |pat| {
- if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
- if sub_pat.is_some() || match self.r.partial_res_map.get(&pat.id)
- .map(|res| res.base_res()) {
- Some(Res::Local(..)) => true,
- _ => false,
- } {
- let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
- binding_map.insert(ident, binding_info);
+ match pat.kind {
+ PatKind::Ident(binding_mode, ident, ref sub_pat)
+ if sub_pat.is_some() || self.is_base_res_local(pat.id) =>
+ {
+ binding_map.insert(ident, BindingInfo { span: ident.span, binding_mode });
+ }
+ PatKind::Or(ref ps) => {
+ // Check the consistency of this or-pattern and
+ // then add all bindings to the larger map.
+ for bm in self.check_consistent_bindings(ps) {
+ binding_map.extend(bm);
+ }
+ return false;
}
+ _ => {}
}
+
true
});
binding_map
}
- // Checks that all of the arms in an or-pattern have exactly the
- // same set of bindings, with the same binding modes for each.
- fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
+ fn is_base_res_local(&self, nid: NodeId) -> bool {
+ match self.r.partial_res_map.get(&nid).map(|res| res.base_res()) {
+ Some(Res::Local(..)) => true,
+ _ => false,
+ }
+ }
+
+ /// Checks that all of the arms in an or-pattern have exactly the
+ /// same set of bindings, with the same binding modes for each.
+ fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) -> Vec<BindingMap> {
let mut missing_vars = FxHashMap::default();
let mut inconsistent_vars = FxHashMap::default();
- for pat_outer in pats.iter() {
- let map_outer = self.binding_mode_map(&pat_outer);
-
- for pat_inner in pats.iter().filter(|pat| pat.id != pat_outer.id) {
- let map_inner = self.binding_mode_map(&pat_inner);
-
- for (&key_inner, &binding_inner) in map_inner.iter() {
- match map_outer.get(&key_inner) {
- None => { // missing binding
- let binding_error = missing_vars
- .entry(key_inner.name)
- .or_insert(BindingError {
- name: key_inner.name,
- origin: BTreeSet::new(),
- target: BTreeSet::new(),
- could_be_path:
- key_inner.name.as_str().starts_with(char::is_uppercase)
- });
- binding_error.origin.insert(binding_inner.span);
- binding_error.target.insert(pat_outer.span);
- }
- Some(binding_outer) => { // check consistent binding
- if binding_outer.binding_mode != binding_inner.binding_mode {
- inconsistent_vars
- .entry(key_inner.name)
- .or_insert((binding_inner.span, binding_outer.span));
- }
+ // 1) Compute the binding maps of all arms.
+ let maps = pats.iter()
+ .map(|pat| self.binding_mode_map(pat))
+ .collect::<Vec<_>>();
+
+ // 2) Record any missing bindings or binding mode inconsistencies.
+ for (map_outer, pat_outer) in pats.iter().enumerate().map(|(idx, pat)| (&maps[idx], pat)) {
+ // Check against all arms except for the same pattern which is always self-consistent.
+ let inners = pats.iter().enumerate()
+ .filter(|(_, pat)| pat.id != pat_outer.id)
+ .flat_map(|(idx, _)| maps[idx].iter())
+ .map(|(key, binding)| (key.name, map_outer.get(&key), binding));
+
+ for (name, info, &binding_inner) in inners {
+ match info {
+ None => { // The inner binding is missing in the outer.
+ let binding_error = missing_vars
+ .entry(name)
+ .or_insert_with(|| BindingError {
+ name,
+ origin: BTreeSet::new(),
+ target: BTreeSet::new(),
+ could_be_path: name.as_str().starts_with(char::is_uppercase),
+ });
+ binding_error.origin.insert(binding_inner.span);
+ binding_error.target.insert(pat_outer.span);
+ }
+ Some(binding_outer) => {
+ if binding_outer.binding_mode != binding_inner.binding_mode {
+ // The binding modes in the outer and inner bindings differ.
+ inconsistent_vars
+ .entry(name)
+ .or_insert((binding_inner.span, binding_outer.span));
}
}
}
}
}
+ // 3) Report all missing variables we found.
let mut missing_vars = missing_vars.iter_mut().collect::<Vec<_>>();
missing_vars.sort();
for (name, mut v) in missing_vars {
ResolutionError::VariableNotBoundInPattern(v));
}
+ // 4) Report all inconsistencies in binding modes we found.
let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
inconsistent_vars.sort();
for (name, v) in inconsistent_vars {
self.r.report_error(v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
}
- }
- fn resolve_arm(&mut self, arm: &Arm) {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
-
- self.resolve_pats(&arm.pats, PatternSource::Match);
-
- if let Some(ref expr) = arm.guard {
- self.visit_expr(expr)
- }
- self.visit_expr(&arm.body);
-
- self.ribs[ValueNS].pop();
+ // 5) Finally bubble up all the binding maps.
+ maps
}
- /// Arising from `source`, resolve a sequence of patterns (top level or-patterns).
- fn resolve_pats(&mut self, pats: &[P<Pat>], source: PatternSource) {
- let mut bindings_list = FxHashMap::default();
- for pat in pats {
- self.resolve_pattern(pat, source, &mut bindings_list);
- }
- // This has to happen *after* we determine which pat_idents are variants
- if pats.len() > 1 {
- self.check_consistent_bindings(pats);
- }
+ /// Check the consistency of the outermost or-patterns.
+ fn check_consistent_bindings_top(&mut self, pat: &Pat) {
+ pat.walk(&mut |pat| match pat.kind {
+ PatKind::Or(ref ps) => {
+ self.check_consistent_bindings(ps);
+ false
+ },
+ _ => true,
+ })
}
- fn resolve_block(&mut self, block: &Block) {
- debug!("(resolving block) entering block");
- // Move down in the graph, if there's an anonymous module rooted here.
- let orig_module = self.parent_scope.module;
- let anonymous_module = self.r.block_map.get(&block.id).cloned(); // clones a reference
-
- let mut num_macro_definition_ribs = 0;
- if let Some(anonymous_module) = anonymous_module {
- debug!("(resolving block) found anonymous module, moving down");
- self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
- self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
- self.parent_scope.module = anonymous_module;
- } else {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- }
-
- // Descend into the block.
- for stmt in &block.stmts {
- if let StmtKind::Item(ref item) = stmt.node {
- if let ItemKind::MacroDef(..) = item.node {
- num_macro_definition_ribs += 1;
- let res = self.r.definitions.local_def_id(item.id);
- self.ribs[ValueNS].push(Rib::new(MacroDefinition(res)));
- self.label_ribs.push(Rib::new(MacroDefinition(res)));
- }
- }
-
- self.visit_stmt(stmt);
- }
-
- // Move back up.
- self.parent_scope.module = orig_module;
- for _ in 0 .. num_macro_definition_ribs {
- self.ribs[ValueNS].pop();
- self.label_ribs.pop();
- }
- self.ribs[ValueNS].pop();
- if anonymous_module.is_some() {
- self.ribs[TypeNS].pop();
- }
- debug!("(resolving block) leaving block");
+ fn resolve_arm(&mut self, arm: &Arm) {
+ self.with_rib(ValueNS, NormalRibKind, |this| {
+ this.resolve_pattern_top(&arm.pat, PatternSource::Match);
+ walk_list!(this, visit_expr, &arm.guard);
+ this.visit_expr(&arm.body);
+ });
}
- fn fresh_binding(&mut self,
- ident: Ident,
- pat_id: NodeId,
- outer_pat_id: NodeId,
- pat_src: PatternSource,
- bindings: &mut FxHashMap<Ident, NodeId>)
- -> Res {
- // Add the binding to the local ribs, if it
- // doesn't already exist in the bindings map. (We
- // must not add it if it's in the bindings map
- // because that breaks the assumptions later
- // passes make about or-patterns.)
- let ident = ident.modern_and_legacy();
- let mut res = Res::Local(pat_id);
- match bindings.get(&ident).cloned() {
- Some(id) if id == outer_pat_id => {
- // `Variant(a, a)`, error
- self.r.report_error(
- ident.span,
- ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
- &ident.as_str())
- );
- }
- Some(..) if pat_src == PatternSource::FnParam => {
- // `fn f(a: u8, a: u8)`, error
- self.r.report_error(
- ident.span,
- ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
- &ident.as_str())
- );
- }
- Some(..) if pat_src == PatternSource::Match ||
- pat_src == PatternSource::Let => {
- // `Variant1(a) | Variant2(a)`, ok
- // Reuse definition from the first `a`.
- res = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
- }
- Some(..) => {
- span_bug!(ident.span, "two bindings with the same name from \
- unexpected pattern source {:?}", pat_src);
- }
- None => {
- // A completely fresh binding, add to the lists if it's valid.
- if ident.name != kw::Invalid {
- bindings.insert(ident, outer_pat_id);
- self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, res);
- }
- }
- }
+ /// Arising from `source`, resolve a top level pattern.
+ fn resolve_pattern_top(&mut self, pat: &Pat, pat_src: PatternSource) {
+ let mut bindings = smallvec![(PatBoundCtx::Product, Default::default())];
+ self.resolve_pattern(pat, pat_src, &mut bindings);
+ }
- res
+ fn resolve_pattern(
+ &mut self,
+ pat: &Pat,
+ pat_src: PatternSource,
+ bindings: &mut SmallVec<[(PatBoundCtx, FxHashSet<Ident>); 1]>,
+ ) {
+ self.resolve_pattern_inner(pat, pat_src, bindings);
+ // This has to happen *after* we determine which pat_idents are variants:
+ self.check_consistent_bindings_top(pat);
+ visit::walk_pat(self, pat);
}
- fn resolve_pattern(&mut self,
- pat: &Pat,
- pat_src: PatternSource,
- // Maps idents to the node ID for the
- // outermost pattern that binds them.
- bindings: &mut FxHashMap<Ident, NodeId>) {
+ /// Resolve bindings in a pattern. This is a helper to `resolve_pattern`.
+ ///
+ /// ### `bindings`
+ ///
+ /// A stack of sets of bindings accumulated.
+ ///
+ /// In each set, `PatBoundCtx::Product` denotes that a found binding in it should
+ /// be interpreted as re-binding an already bound binding. This results in an error.
+ /// Meanwhile, `PatBound::Or` denotes that a found binding in the set should result
+ /// in reusing this binding rather than creating a fresh one.
+ ///
+ /// When called at the top level, the stack must have a single element
+ /// with `PatBound::Product`. Otherwise, pushing to the stack happens as
+ /// or-patterns (`p_0 | ... | p_n`) are encountered and the context needs
+ /// to be switched to `PatBoundCtx::Or` and then `PatBoundCtx::Product` for each `p_i`.
+ /// When each `p_i` has been dealt with, the top set is merged with its parent.
+ /// When a whole or-pattern has been dealt with, the thing happens.
+ ///
+ /// See the implementation and `fresh_binding` for more details.
+ fn resolve_pattern_inner(
+ &mut self,
+ pat: &Pat,
+ pat_src: PatternSource,
+ bindings: &mut SmallVec<[(PatBoundCtx, FxHashSet<Ident>); 1]>,
+ ) {
// Visit all direct subpatterns of this pattern.
- let outer_pat_id = pat.id;
pat.walk(&mut |pat| {
- debug!("resolve_pattern pat={:?} node={:?}", pat, pat.node);
- match pat.node {
- PatKind::Ident(bmode, ident, ref opt_pat) => {
- // First try to resolve the identifier as some existing
- // entity, then fall back to a fresh binding.
- let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
- None, pat.span)
- .and_then(LexicalScopeBinding::item);
- let res = binding.map(NameBinding::res).and_then(|res| {
- let is_syntactic_ambiguity = opt_pat.is_none() &&
- bmode == BindingMode::ByValue(Mutability::Immutable);
- match res {
- Res::Def(DefKind::Ctor(_, CtorKind::Const), _) |
- Res::Def(DefKind::Const, _) if is_syntactic_ambiguity => {
- // Disambiguate in favor of a unit struct/variant
- // or constant pattern.
- self.r.record_use(ident, ValueNS, binding.unwrap(), false);
- Some(res)
- }
- Res::Def(DefKind::Ctor(..), _)
- | Res::Def(DefKind::Const, _)
- | Res::Def(DefKind::Static, _) => {
- // This is unambiguously a fresh binding, either syntactically
- // (e.g., `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
- // to something unusable as a pattern (e.g., constructor function),
- // but we still conservatively report an error, see
- // issues/33118#issuecomment-233962221 for one reason why.
- self.r.report_error(
- ident.span,
- ResolutionError::BindingShadowsSomethingUnacceptable(
- pat_src.descr(), ident.name, binding.unwrap())
- );
- None
- }
- Res::Def(DefKind::Fn, _) | Res::Err => {
- // These entities are explicitly allowed
- // to be shadowed by fresh bindings.
- None
- }
- res => {
- span_bug!(ident.span, "unexpected resolution for an \
- identifier in pattern: {:?}", res);
- }
- }
- }).unwrap_or_else(|| {
- self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
- });
-
+ debug!("resolve_pattern pat={:?} node={:?}", pat, pat.kind);
+ match pat.kind {
+ PatKind::Ident(bmode, ident, ref sub) => {
+ // First try to resolve the identifier as some existing entity,
+ // then fall back to a fresh binding.
+ let has_sub = sub.is_some();
+ let res = self.try_resolve_as_non_binding(pat_src, pat, bmode, ident, has_sub)
+ .unwrap_or_else(|| self.fresh_binding(ident, pat.id, pat_src, bindings));
self.r.record_partial_res(pat.id, PartialRes::new(res));
}
-
PatKind::TupleStruct(ref path, ..) => {
self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
}
-
PatKind::Path(ref qself, ref path) => {
self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
}
-
PatKind::Struct(ref path, ..) => {
self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
}
-
+ PatKind::Or(ref ps) => {
+ // Add a new set of bindings to the stack. `Or` here records that when a
+ // binding already exists in this set, it should not result in an error because
+ // `V1(a) | V2(a)` must be allowed and are checked for consistency later.
+ bindings.push((PatBoundCtx::Or, Default::default()));
+ for p in ps {
+ // Now we need to switch back to a product context so that each
+ // part of the or-pattern internally rejects already bound names.
+ // For example, `V1(a) | V2(a, a)` and `V1(a, a) | V2(a)` are bad.
+ bindings.push((PatBoundCtx::Product, Default::default()));
+ self.resolve_pattern_inner(p, pat_src, bindings);
+ // Move up the non-overlapping bindings to the or-pattern.
+ // Existing bindings just get "merged".
+ let collected = bindings.pop().unwrap().1;
+ bindings.last_mut().unwrap().1.extend(collected);
+ }
+ // This or-pattern itself can itself be part of a product,
+ // e.g. `(V1(a) | V2(a), a)` or `(a, V1(a) | V2(a))`.
+ // Both cases bind `a` again in a product pattern and must be rejected.
+ let collected = bindings.pop().unwrap().1;
+ bindings.last_mut().unwrap().1.extend(collected);
+
+ // Prevent visiting `ps` as we've already done so above.
+ return false;
+ }
_ => {}
}
true
});
+ }
- visit::walk_pat(self, pat);
+ fn fresh_binding(
+ &mut self,
+ ident: Ident,
+ pat_id: NodeId,
+ pat_src: PatternSource,
+ bindings: &mut SmallVec<[(PatBoundCtx, FxHashSet<Ident>); 1]>,
+ ) -> Res {
+ // Add the binding to the local ribs, if it doesn't already exist in the bindings map.
+ // (We must not add it if it's in the bindings map because that breaks the assumptions
+ // later passes make about or-patterns.)
+ let ident = ident.modern_and_legacy();
+
+ // Walk outwards the stack of products / or-patterns and
+ // find out if the identifier has been bound in any of these.
+ let mut already_bound_and = false;
+ let mut already_bound_or = false;
+ for (is_sum, set) in bindings.iter_mut().rev() {
+ match (is_sum, set.get(&ident).cloned()) {
+ // Already bound in a product pattern, e.g. `(a, a)` which is not allowed.
+ (PatBoundCtx::Product, Some(..)) => already_bound_and = true,
+ // Already bound in an or-pattern, e.g. `V1(a) | V2(a)`.
+ // This is *required* for consistency which is checked later.
+ (PatBoundCtx::Or, Some(..)) => already_bound_or = true,
+ // Not already bound here.
+ _ => {}
+ }
+ }
+
+ if already_bound_and {
+ // Overlap in a product pattern somewhere; report an error.
+ use ResolutionError::*;
+ let error = match pat_src {
+ // `fn f(a: u8, a: u8)`:
+ PatternSource::FnParam => IdentifierBoundMoreThanOnceInParameterList,
+ // `Variant(a, a)`:
+ _ => IdentifierBoundMoreThanOnceInSamePattern,
+ };
+ self.r.report_error(ident.span, error(&ident.as_str()));
+ }
+
+ // Record as bound if it's valid:
+ let ident_valid = ident.name != kw::Invalid;
+ if ident_valid {
+ bindings.last_mut().unwrap().1.insert(ident);
+ }
+
+ if already_bound_or {
+ // `Variant1(a) | Variant2(a)`, ok
+ // Reuse definition from the first `a`.
+ self.innermost_rib_bindings(ValueNS)[&ident]
+ } else {
+ let res = Res::Local(pat_id);
+ if ident_valid {
+ // A completely fresh binding add to the set if it's valid.
+ self.innermost_rib_bindings(ValueNS).insert(ident, res);
+ }
+ res
+ }
+ }
+
+ fn innermost_rib_bindings(&mut self, ns: Namespace) -> &mut IdentMap<Res> {
+ &mut self.ribs[ns].last_mut().unwrap().bindings
+ }
+
+ fn try_resolve_as_non_binding(
+ &mut self,
+ pat_src: PatternSource,
+ pat: &Pat,
+ bm: BindingMode,
+ ident: Ident,
+ has_sub: bool,
+ ) -> Option<Res> {
+ let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, pat.span)?.item()?;
+ let res = binding.res();
+
+ // An immutable (no `mut`) by-value (no `ref`) binding pattern without
+ // a sub pattern (no `@ $pat`) is syntactically ambiguous as it could
+ // also be interpreted as a path to e.g. a constant, variant, etc.
+ let is_syntactic_ambiguity = !has_sub && bm == BindingMode::ByValue(Mutability::Immutable);
+
+ match res {
+ Res::Def(DefKind::Ctor(_, CtorKind::Const), _) |
+ Res::Def(DefKind::Const, _) if is_syntactic_ambiguity => {
+ // Disambiguate in favor of a unit struct/variant or constant pattern.
+ self.r.record_use(ident, ValueNS, binding, false);
+ Some(res)
+ }
+ Res::Def(DefKind::Ctor(..), _)
+ | Res::Def(DefKind::Const, _)
+ | Res::Def(DefKind::Static, _) => {
+ // This is unambiguously a fresh binding, either syntactically
+ // (e.g., `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
+ // to something unusable as a pattern (e.g., constructor function),
+ // but we still conservatively report an error, see
+ // issues/33118#issuecomment-233962221 for one reason why.
+ self.r.report_error(
+ ident.span,
+ ResolutionError::BindingShadowsSomethingUnacceptable(
+ pat_src.descr(),
+ ident.name,
+ binding,
+ ),
+ );
+ None
+ }
+ Res::Def(DefKind::Fn, _) | Res::Err => {
+ // These entities are explicitly allowed to be shadowed by fresh bindings.
+ None
+ }
+ res => {
+ span_bug!(ident.span, "unexpected resolution for an \
+ identifier in pattern: {:?}", res);
+ }
+ }
}
// High-level and context dependent path resolution routine.
Some(result)
}
- fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
- where F: FnOnce(&mut LateResolutionVisitor<'_, '_>)
- {
+ fn with_resolved_label(&mut self, label: Option<Label>, id: NodeId, f: impl FnOnce(&mut Self)) {
if let Some(label) = label {
self.unused_labels.insert(id, label.ident.span);
- self.with_label_rib(|this| {
+ self.with_label_rib(NormalRibKind, |this| {
let ident = label.ident.modern_and_legacy();
this.label_ribs.last_mut().unwrap().bindings.insert(ident, id);
f(this);
self.with_resolved_label(label, id, |this| this.visit_block(block));
}
+ fn resolve_block(&mut self, block: &Block) {
+ debug!("(resolving block) entering block");
+ // Move down in the graph, if there's an anonymous module rooted here.
+ let orig_module = self.parent_scope.module;
+ let anonymous_module = self.r.block_map.get(&block.id).cloned(); // clones a reference
+
+ let mut num_macro_definition_ribs = 0;
+ if let Some(anonymous_module) = anonymous_module {
+ debug!("(resolving block) found anonymous module, moving down");
+ self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
+ self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
+ self.parent_scope.module = anonymous_module;
+ } else {
+ self.ribs[ValueNS].push(Rib::new(NormalRibKind));
+ }
+
+ // Descend into the block.
+ for stmt in &block.stmts {
+ if let StmtKind::Item(ref item) = stmt.kind {
+ if let ItemKind::MacroDef(..) = item.kind {
+ num_macro_definition_ribs += 1;
+ let res = self.r.definitions.local_def_id(item.id);
+ self.ribs[ValueNS].push(Rib::new(MacroDefinition(res)));
+ self.label_ribs.push(Rib::new(MacroDefinition(res)));
+ }
+ }
+
+ self.visit_stmt(stmt);
+ }
+
+ // Move back up.
+ self.parent_scope.module = orig_module;
+ for _ in 0 .. num_macro_definition_ribs {
+ self.ribs[ValueNS].pop();
+ self.label_ribs.pop();
+ }
+ self.ribs[ValueNS].pop();
+ if anonymous_module.is_some() {
+ self.ribs[TypeNS].pop();
+ }
+ debug!("(resolving block) leaving block");
+ }
+
fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
// First, record candidate traits for this expression if it could
// result in the invocation of a method call.
self.record_candidate_traits_for_expr_if_necessary(expr);
// Next, resolve the node.
- match expr.node {
+ match expr.kind {
ExprKind::Path(ref qself, ref path) => {
self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
visit::walk_expr(self, expr);
visit::walk_expr(self, expr);
}
- ExprKind::Let(ref pats, ref scrutinee) => {
+ ExprKind::Let(ref pat, ref scrutinee) => {
self.visit_expr(scrutinee);
- self.resolve_pats(pats, PatternSource::Let);
+ self.resolve_pattern_top(pat, PatternSource::Let);
}
ExprKind::If(ref cond, ref then, ref opt_else) => {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- self.visit_expr(cond);
- self.visit_block(then);
- self.ribs[ValueNS].pop();
-
+ self.with_rib(ValueNS, NormalRibKind, |this| {
+ this.visit_expr(cond);
+ this.visit_block(then);
+ });
opt_else.as_ref().map(|expr| self.visit_expr(expr));
}
ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
- ExprKind::While(ref subexpression, ref block, label) => {
+ ExprKind::While(ref cond, ref block, label) => {
self.with_resolved_label(label, expr.id, |this| {
- this.ribs[ValueNS].push(Rib::new(NormalRibKind));
- this.visit_expr(subexpression);
- this.visit_block(block);
- this.ribs[ValueNS].pop();
+ this.with_rib(ValueNS, NormalRibKind, |this| {
+ this.visit_expr(cond);
+ this.visit_block(block);
+ })
});
}
- ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
- self.visit_expr(subexpression);
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap::default());
-
- self.resolve_labeled_block(label, expr.id, block);
-
- self.ribs[ValueNS].pop();
+ ExprKind::ForLoop(ref pat, ref iter_expr, ref block, label) => {
+ self.visit_expr(iter_expr);
+ self.with_rib(ValueNS, NormalRibKind, |this| {
+ this.resolve_pattern_top(pat, PatternSource::For);
+ this.resolve_labeled_block(label, expr.id, block);
+ });
}
ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
// resolve the arguments within the proper scopes so that usages of them inside the
// closure are detected as upvars rather than normal closure arg usages.
ExprKind::Closure(_, IsAsync::Async { .. }, _, ref fn_decl, ref body, _span) => {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- // Resolve arguments:
- self.resolve_params(&fn_decl.inputs);
- // No need to resolve return type --
- // the outer closure return type is `FunctionRetTy::Default`.
-
- // Now resolve the inner closure
- {
- // No need to resolve arguments: the inner closure has none.
- // Resolve the return type:
- visit::walk_fn_ret_ty(self, &fn_decl.output);
- // Resolve the body
- self.visit_expr(body);
- }
- self.ribs[ValueNS].pop();
+ self.with_rib(ValueNS, NormalRibKind, |this| {
+ // Resolve arguments:
+ this.resolve_params(&fn_decl.inputs);
+ // No need to resolve return type --
+ // the outer closure return type is `FunctionRetTy::Default`.
+
+ // Now resolve the inner closure
+ {
+ // No need to resolve arguments: the inner closure has none.
+ // Resolve the return type:
+ visit::walk_fn_ret_ty(this, &fn_decl.output);
+ // Resolve the body
+ this.visit_expr(body);
+ }
+ });
}
_ => {
visit::walk_expr(self, expr);
}
fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
- match expr.node {
+ match expr.kind {
ExprKind::Field(_, ident) => {
// FIXME(#6890): Even though you can't treat a method like a
// field, we need to add any trait methods we find that match
projects / rust.git / blobdiff