rustc: don't visit lifetime parameters through visit_lifetime.

This commit is contained in:
Eduard-Mihai Burtescu 2018-05-30 14:36:53 +03:00
parent a1433f2f88
commit 5c76b64546
8 changed files with 102 additions and 89 deletions

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@ -580,8 +580,8 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
walk_list!(visitor, visit_ty, tuple_element_types); walk_list!(visitor, visit_ty, tuple_element_types);
} }
TyBareFn(ref function_declaration) => { TyBareFn(ref function_declaration) => {
visitor.visit_fn_decl(&function_declaration.decl);
walk_list!(visitor, visit_generic_param, &function_declaration.generic_params); walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
visitor.visit_fn_decl(&function_declaration.decl);
} }
TyPath(ref qpath) => { TyPath(ref qpath) => {
visitor.visit_qpath(qpath, typ.id, typ.span); visitor.visit_qpath(qpath, typ.id, typ.span);
@ -733,7 +733,16 @@ pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v TyPar
pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam) { pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam) {
match *param { match *param {
GenericParam::Lifetime(ref ld) => { GenericParam::Lifetime(ref ld) => {
visitor.visit_lifetime(&ld.lifetime); visitor.visit_id(ld.lifetime.id);
match ld.lifetime.name {
LifetimeName::Name(name) => {
visitor.visit_name(ld.lifetime.span, name);
}
LifetimeName::Fresh(_) |
LifetimeName::Static |
LifetimeName::Implicit |
LifetimeName::Underscore => {}
}
walk_list!(visitor, visit_lifetime, &ld.bounds); walk_list!(visitor, visit_lifetime, &ld.bounds);
} }
GenericParam::Type(ref ty_param) => { GenericParam::Type(ref ty_param) => {

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@ -1214,7 +1214,13 @@ impl<'a> LoweringContext<'a> {
if let &hir::Ty_::TyBareFn(_) = &t.node { if let &hir::Ty_::TyBareFn(_) = &t.node {
let old_collect_elided_lifetimes = self.collect_elided_lifetimes; let old_collect_elided_lifetimes = self.collect_elided_lifetimes;
self.collect_elided_lifetimes = false; self.collect_elided_lifetimes = false;
// Record the "stack height" of `for<'a>` lifetime bindings
// to be able to later fully undo their introduction.
let old_len = self.currently_bound_lifetimes.len();
hir::intravisit::walk_ty(self, t); hir::intravisit::walk_ty(self, t);
self.currently_bound_lifetimes.truncate(old_len);
self.collect_elided_lifetimes = old_collect_elided_lifetimes; self.collect_elided_lifetimes = old_collect_elided_lifetimes;
} else { } else {
hir::intravisit::walk_ty(self, t); hir::intravisit::walk_ty(self, t);
@ -1223,28 +1229,25 @@ impl<'a> LoweringContext<'a> {
fn visit_poly_trait_ref( fn visit_poly_trait_ref(
&mut self, &mut self,
polytr: &'v hir::PolyTraitRef, trait_ref: &'v hir::PolyTraitRef,
_: hir::TraitBoundModifier, modifier: hir::TraitBoundModifier,
) { ) {
// Record the "stack height" of `for<'a>` lifetime bindings
// to be able to later fully undo their introduction.
let old_len = self.currently_bound_lifetimes.len(); let old_len = self.currently_bound_lifetimes.len();
hir::intravisit::walk_poly_trait_ref(self, trait_ref, modifier);
self.currently_bound_lifetimes.truncate(old_len);
}
fn visit_generic_param(&mut self, param: &'v hir::GenericParam) {
// Record the introduction of 'a in `for<'a> ...` // Record the introduction of 'a in `for<'a> ...`
for param in &polytr.bound_generic_params { if let hir::GenericParam::Lifetime(ref lt_def) = *param {
if let hir::GenericParam::Lifetime(ref lt_def) = *param { // Introduce lifetimes one at a time so that we can handle
// Introduce lifetimes one at a time so that we can handle // cases like `fn foo<'d>() -> impl for<'a, 'b: 'a, 'c: 'b + 'd>`
// cases like `fn foo<'d>() -> impl for<'a, 'b: 'a, 'c: 'b + 'd>` self.currently_bound_lifetimes.push(lt_def.lifetime.name);
self.currently_bound_lifetimes.push(lt_def.lifetime.name);
// Visit the lifetime bounds
for lt_bound in &lt_def.bounds {
self.visit_lifetime(&lt_bound);
}
}
} }
hir::intravisit::walk_trait_ref(self, &polytr.trait_ref); hir::intravisit::walk_generic_param(self, param);
self.currently_bound_lifetimes.truncate(old_len);
} }
fn visit_lifetime(&mut self, lifetime: &'v hir::Lifetime) { fn visit_lifetime(&mut self, lifetime: &'v hir::Lifetime) {

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@ -346,12 +346,16 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
}); });
} }
fn visit_generics(&mut self, generics: &'hir Generics) { fn visit_generic_param(&mut self, param: &'hir GenericParam) {
for ty_param in generics.ty_params() { match *param {
self.insert(ty_param.id, NodeTyParam(ty_param)); GenericParam::Lifetime(ref ld) => {
self.insert(ld.lifetime.id, NodeLifetime(&ld.lifetime));
}
GenericParam::Type(ref ty_param) => {
self.insert(ty_param.id, NodeTyParam(ty_param));
}
} }
intravisit::walk_generic_param(self, param);
intravisit::walk_generics(self, generics);
} }
fn visit_trait_item(&mut self, ti: &'hir TraitItem) { fn visit_trait_item(&mut self, ti: &'hir TraitItem) {

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@ -1928,10 +1928,10 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
} }
fn visit_generic_param(&mut self, param: &hir::GenericParam) { fn visit_generic_param(&mut self, param: &hir::GenericParam) {
if let hir::GenericParam::Lifetime(ref lifetime_def) = *param { if let hir::GenericParam::Lifetime(_) = *param {
for l in &lifetime_def.bounds { // FIXME(eddyb) Do we want this? It only makes a difference
self.visit_lifetime(l); // if this `for<'a>` lifetime parameter is never used.
} self.have_bound_regions = true;
} }
intravisit::walk_generic_param(self, param); intravisit::walk_generic_param(self, param);
@ -2144,28 +2144,26 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
fn check_lifetime_params(&mut self, old_scope: ScopeRef, params: &'tcx [hir::GenericParam]) { fn check_lifetime_params(&mut self, old_scope: ScopeRef, params: &'tcx [hir::GenericParam]) {
for (i, lifetime_i) in params.lifetimes().enumerate() { for (i, lifetime_i) in params.lifetimes().enumerate() {
for lifetime in params.lifetimes() { match lifetime_i.lifetime.name {
match lifetime.lifetime.name { hir::LifetimeName::Static | hir::LifetimeName::Underscore => {
hir::LifetimeName::Static | hir::LifetimeName::Underscore => { let lifetime = lifetime_i.lifetime;
let lifetime = lifetime.lifetime; let name = lifetime.name.name();
let name = lifetime.name.name(); let mut err = struct_span_err!(
let mut err = struct_span_err!( self.tcx.sess,
self.tcx.sess, lifetime.span,
lifetime.span, E0262,
E0262, "invalid lifetime parameter name: `{}`",
"invalid lifetime parameter name: `{}`", name
name );
); err.span_label(
err.span_label( lifetime.span,
lifetime.span, format!("{} is a reserved lifetime name", name),
format!("{} is a reserved lifetime name", name), );
); err.emit();
err.emit();
}
hir::LifetimeName::Fresh(_)
| hir::LifetimeName::Implicit
| hir::LifetimeName::Name(_) => {}
} }
hir::LifetimeName::Fresh(_)
| hir::LifetimeName::Implicit
| hir::LifetimeName::Name(_) => {}
} }
// It is a hard error to shadow a lifetime within the same scope. // It is a hard error to shadow a lifetime within the same scope.
@ -2347,31 +2345,18 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
| Region::LateBound(_, def_id, _) | Region::LateBound(_, def_id, _)
| Region::EarlyBound(_, def_id, _) => { | Region::EarlyBound(_, def_id, _) => {
// A lifetime declared by the user. // A lifetime declared by the user.
let def_local_id = self.tcx.hir.as_local_node_id(def_id).unwrap(); let track_lifetime_uses = self.track_lifetime_uses();
if def_local_id == lifetime_ref.id { debug!(
// This is weird. Because the HIR defines a "insert_lifetime: track_lifetime_uses={}",
// lifetime *definition* as wrapping a Lifetime, track_lifetime_uses
// we wind up invoking this method also for the );
// definitions in some cases (notably if track_lifetime_uses && !self.lifetime_uses.contains_key(&def_id) {
// higher-ranked types). This means that a debug!("insert_lifetime: first use of {:?}", def_id);
// lifetime with one use (e.g., `for<'a> fn(&'a self.lifetime_uses
// u32)`) wind up being counted as two uses. To .insert(def_id, LifetimeUseSet::One(lifetime_ref));
// avoid that, we just ignore the lifetime that
// corresponds to the definition.
} else { } else {
let track_lifetime_uses = self.track_lifetime_uses(); debug!("insert_lifetime: many uses of {:?}", def_id);
debug!( self.lifetime_uses.insert(def_id, LifetimeUseSet::Many);
"insert_lifetime: track_lifetime_uses={}",
track_lifetime_uses
);
if track_lifetime_uses && !self.lifetime_uses.contains_key(&def_id) {
debug!("insert_lifetime: first use of {:?}", def_id);
self.lifetime_uses
.insert(def_id, LifetimeUseSet::One(lifetime_ref));
} else {
debug!("insert_lifetime: many uses of {:?}", def_id);
self.lifetime_uses.insert(def_id, LifetimeUseSet::Many);
}
} }
} }
} }
@ -2424,31 +2409,20 @@ fn insert_late_bound_lifetimes(
let mut appears_in_where_clause = AllCollector { let mut appears_in_where_clause = AllCollector {
regions: FxHashSet(), regions: FxHashSet(),
}; };
appears_in_where_clause.visit_generics(generics);
for param in &generics.params { for param in &generics.params {
match *param { match *param {
hir::GenericParam::Lifetime(ref lifetime_def) => { hir::GenericParam::Lifetime(ref lifetime_def) => {
if !lifetime_def.bounds.is_empty() { if !lifetime_def.bounds.is_empty() {
// `'a: 'b` means both `'a` and `'b` are referenced // `'a: 'b` means both `'a` and `'b` are referenced
appears_in_where_clause.visit_generic_param(param); appears_in_where_clause.regions.insert(lifetime_def.lifetime.name);
} }
} }
hir::GenericParam::Type(ref ty_param) => { hir::GenericParam::Type(_) => {}
walk_list!(
&mut appears_in_where_clause,
visit_ty_param_bound,
&ty_param.bounds
);
}
} }
} }
walk_list!(
&mut appears_in_where_clause,
visit_where_predicate,
&generics.where_clause.predicates
);
debug!( debug!(
"insert_late_bound_lifetimes: appears_in_where_clause={:?}", "insert_late_bound_lifetimes: appears_in_where_clause={:?}",
appears_in_where_clause.regions appears_in_where_clause.regions

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@ -441,6 +441,13 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
visit::walk_generics(self, g) visit::walk_generics(self, g)
} }
fn visit_generic_param(&mut self, param: &'a GenericParam) {
if let GenericParam::Lifetime(ref ld) = *param {
self.check_lifetime(ld.lifetime.ident);
}
visit::walk_generic_param(self, param);
}
fn visit_pat(&mut self, pat: &'a Pat) { fn visit_pat(&mut self, pat: &'a Pat) {
match pat.node { match pat.node {
PatKind::Lit(ref expr) => { PatKind::Lit(ref expr) => {

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@ -318,8 +318,8 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
walk_list!(visitor, visit_ty, tuple_element_types); walk_list!(visitor, visit_ty, tuple_element_types);
} }
TyKind::BareFn(ref function_declaration) => { TyKind::BareFn(ref function_declaration) => {
walk_fn_decl(visitor, &function_declaration.decl);
walk_list!(visitor, visit_generic_param, &function_declaration.generic_params); walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
walk_fn_decl(visitor, &function_declaration.decl);
} }
TyKind::Path(ref maybe_qself, ref path) => { TyKind::Path(ref maybe_qself, ref path) => {
if let Some(ref qself) = *maybe_qself { if let Some(ref qself) = *maybe_qself {
@ -485,7 +485,7 @@ pub fn walk_ty_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a TyPar
pub fn walk_generic_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a GenericParam) { pub fn walk_generic_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a GenericParam) {
match *param { match *param {
GenericParam::Lifetime(ref l) => { GenericParam::Lifetime(ref l) => {
visitor.visit_lifetime(&l.lifetime); visitor.visit_ident(l.lifetime.ident);
walk_list!(visitor, visit_lifetime, &l.bounds); walk_list!(visitor, visit_lifetime, &l.bounds);
walk_list!(visitor, visit_attribute, &*l.attrs); walk_list!(visitor, visit_attribute, &*l.attrs);
} }

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@ -23,7 +23,6 @@ impl<'a> Meh<'a> for u8 {}
fn meh() -> Box<for<'_> Meh<'_>> //~ ERROR invalid lifetime parameter name: `'_` fn meh() -> Box<for<'_> Meh<'_>> //~ ERROR invalid lifetime parameter name: `'_`
//~^ ERROR missing lifetime specifier //~^ ERROR missing lifetime specifier
//~^^ ERROR missing lifetime specifier
{ {
Box::new(5u8) Box::new(5u8)
} }

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@ -0,0 +1,17 @@
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
fn foo() -> impl Into<for<'a> fn(&'a ())> {
(|_| {}) as for<'a> fn(&'a ())
}
fn main() {
foo().into()(&());
}