diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs
index a9da92a768fe6..6f40e17855a78 100644
--- a/src/librustc/middle/resolve_lifetime.rs
+++ b/src/librustc/middle/resolve_lifetime.rs
@@ -24,6 +24,7 @@ use middle::region;
use middle::subst;
use middle::ty;
use std::fmt;
+use std::mem::replace;
use syntax::ast;
use syntax::codemap::Span;
use syntax::parse::token::special_idents;
@@ -70,6 +71,9 @@ struct LifetimeContext<'a> {
// I'm sorry.
trait_ref_hack: bool,
+
+ // List of labels in the function/method currently under analysis.
+ labels_in_fn: Vec<(ast::Ident, Span)>,
}
enum ScopeChain<'a> {
@@ -97,6 +101,7 @@ pub fn krate(sess: &Session, krate: &ast::Crate, def_map: &DefMap) -> NamedRegio
scope: &ROOT_SCOPE,
def_map: def_map,
trait_ref_hack: false,
+ labels_in_fn: vec![],
}, krate);
sess.abort_if_errors();
named_region_map
@@ -104,6 +109,10 @@ pub fn krate(sess: &Session, krate: &ast::Crate, def_map: &DefMap) -> NamedRegio
impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
fn visit_item(&mut self, item: &ast::Item) {
+ // Items save/restore the set of labels. This way innner items
+ // can freely reuse names, be they loop labels or lifetimes.
+ let saved = replace(&mut self.labels_in_fn, vec![]);
+
// Items always introduce a new root scope
self.with(RootScope, |_, this| {
match item.node {
@@ -137,6 +146,9 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
}
}
});
+
+ // Done traversing the item; restore saved set of labels.
+ replace(&mut self.labels_in_fn, saved);
}
fn visit_fn(&mut self, fk: visit::FnKind<'v>, fd: &'v ast::FnDecl,
@@ -144,16 +156,16 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
match fk {
visit::FkItemFn(_, generics, _, _, _) => {
self.visit_early_late(subst::FnSpace, generics, |this| {
- visit::walk_fn(this, fk, fd, b, s)
+ this.walk_fn(fk, fd, b, s)
})
}
visit::FkMethod(_, sig, _) => {
self.visit_early_late(subst::FnSpace, &sig.generics, |this| {
- visit::walk_fn(this, fk, fd, b, s)
+ this.walk_fn(fk, fd, b, s)
})
}
visit::FkFnBlock(..) => {
- visit::walk_fn(self, fk, fd, b, s)
+ self.walk_fn(fk, fd, b, s)
}
}
}
@@ -190,6 +202,10 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
}
fn visit_trait_item(&mut self, trait_item: &ast::TraitItem) {
+ // We reset the labels on every trait item, so that different
+ // methods in an impl can reuse label names.
+ let saved = replace(&mut self.labels_in_fn, vec![]);
+
if let ast::MethodTraitItem(ref sig, None) = trait_item.node {
self.visit_early_late(
subst::FnSpace, &sig.generics,
@@ -197,6 +213,8 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
} else {
visit::walk_trait_item(self, trait_item);
}
+
+ replace(&mut self.labels_in_fn, saved);
}
fn visit_block(&mut self, b: &ast::Block) {
@@ -286,7 +304,170 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> {
}
}
+#[derive(Copy, Clone, PartialEq)]
+enum ShadowKind { Label, Lifetime }
+struct Original { kind: ShadowKind, span: Span }
+struct Shadower { kind: ShadowKind, span: Span }
+
+fn original_label(span: Span) -> Original {
+ Original { kind: ShadowKind::Label, span: span }
+}
+fn shadower_label(span: Span) -> Shadower {
+ Shadower { kind: ShadowKind::Label, span: span }
+}
+fn original_lifetime(l: &ast::Lifetime) -> Original {
+ Original { kind: ShadowKind::Lifetime, span: l.span }
+}
+fn shadower_lifetime(l: &ast::Lifetime) -> Shadower {
+ Shadower { kind: ShadowKind::Lifetime, span: l.span }
+}
+
+impl ShadowKind {
+ fn desc(&self) -> &'static str {
+ match *self {
+ ShadowKind::Label => "label",
+ ShadowKind::Lifetime => "lifetime",
+ }
+ }
+}
+
+fn signal_shadowing_problem(
+ sess: &Session, name: ast::Name, orig: Original, shadower: Shadower) {
+ if let (ShadowKind::Lifetime, ShadowKind::Lifetime) = (orig.kind, shadower.kind) {
+ // lifetime/lifetime shadowing is an error
+ sess.span_err(shadower.span,
+ &format!("{} name `{}` shadows a \
+ {} name that is already in scope",
+ shadower.kind.desc(), name, orig.kind.desc()));
+ } else {
+ // shadowing involving a label is only a warning, due to issues with
+ // labels and lifetimes not being macro-hygienic.
+ sess.span_warn(shadower.span,
+ &format!("{} name `{}` shadows a \
+ {} name that is already in scope",
+ shadower.kind.desc(), name, orig.kind.desc()));
+ }
+ sess.span_note(orig.span,
+ &format!("shadowed {} `{}` declared here",
+ orig.kind.desc(), name));
+}
+
+// Adds all labels in `b` to `ctxt.labels_in_fn`, signalling a warning
+// if one of the label shadows a lifetime or another label.
+fn extract_labels<'v, 'a>(ctxt: &mut LifetimeContext<'a>, b: &'v ast::Block) {
+
+ struct GatherLabels<'a> {
+ sess: &'a Session,
+ scope: Scope<'a>,
+ labels_in_fn: &'a mut Vec<(ast::Ident, Span)>,
+ }
+
+ let mut gather = GatherLabels {
+ sess: ctxt.sess,
+ scope: ctxt.scope,
+ labels_in_fn: &mut ctxt.labels_in_fn,
+ };
+ gather.visit_block(b);
+ return;
+
+ impl<'v, 'a> Visitor<'v> for GatherLabels<'a> {
+ fn visit_expr(&mut self, ex: &'v ast::Expr) {
+ if let Some(label) = expression_label(ex) {
+ for &(prior, prior_span) in &self.labels_in_fn[..] {
+ // FIXME (#24278): non-hygienic comparision
+ if label.name == prior.name {
+ signal_shadowing_problem(self.sess,
+ label.name,
+ original_label(prior_span),
+ shadower_label(ex.span));
+ }
+ }
+
+ check_if_label_shadows_lifetime(self.sess,
+ self.scope,
+ label,
+ ex.span);
+
+ self.labels_in_fn.push((label, ex.span));
+ }
+ visit::walk_expr(self, ex)
+ }
+
+ fn visit_item(&mut self, _: &ast::Item) {
+ // do not recurse into items defined in the block
+ }
+ }
+
+ fn expression_label(ex: &ast::Expr) -> Option<ast::Ident> {
+ match ex.node {
+ ast::ExprWhile(_, _, Some(label)) |
+ ast::ExprWhileLet(_, _, _, Some(label)) |
+ ast::ExprForLoop(_, _, _, Some(label)) |
+ ast::ExprLoop(_, Some(label)) => Some(label),
+ _ => None,
+ }
+ }
+
+ fn check_if_label_shadows_lifetime<'a>(sess: &'a Session,
+ mut scope: Scope<'a>,
+ label: ast::Ident,
+ label_span: Span) {
+ loop {
+ match *scope {
+ BlockScope(_, s) => { scope = s; }
+ RootScope => { return; }
+
+ EarlyScope(_, lifetimes, s) |
+ LateScope(lifetimes, s) => {
+ for lifetime_def in lifetimes {
+ // FIXME (#24278): non-hygienic comparision
+ if label.name == lifetime_def.lifetime.name {
+ signal_shadowing_problem(
+ sess,
+ label.name,
+ original_lifetime(&lifetime_def.lifetime),
+ shadower_label(label_span));
+ return;
+ }
+ }
+ scope = s;
+ }
+ }
+ }
+ }
+}
+
impl<'a> LifetimeContext<'a> {
+ // This is just like visit::walk_fn, except that it extracts the
+ // labels of the function body and swaps them in before visiting
+ // the function body itself.
+ fn walk_fn<'b>(&mut self,
+ fk: visit::FnKind,
+ fd: &ast::FnDecl,
+ fb: &'b ast::Block,
+ _span: Span) {
+ match fk {
+ visit::FkItemFn(_, generics, _, _, _) => {
+ visit::walk_fn_decl(self, fd);
+ self.visit_generics(generics);
+ }
+ visit::FkMethod(_, sig, _) => {
+ visit::walk_fn_decl(self, fd);
+ self.visit_generics(&sig.generics);
+ self.visit_explicit_self(&sig.explicit_self);
+ }
+ visit::FkFnBlock(..) => {
+ visit::walk_fn_decl(self, fd);
+ }
+ }
+
+ // After inpsecting the decl, add all labels from the body to
+ // `self.labels_in_fn`.
+ extract_labels(self, fb);
+
+ self.visit_block(fb);
+ }
+
fn with<F>(&mut self, wrap_scope: ScopeChain, f: F) where
F: FnOnce(Scope, &mut LifetimeContext),
{
@@ -297,6 +478,7 @@ impl<'a> LifetimeContext<'a> {
scope: &wrap_scope,
def_map: self.def_map,
trait_ref_hack: self.trait_ref_hack,
+ labels_in_fn: self.labels_in_fn.clone(),
};
debug!("entering scope {:?}", this.scope);
f(self.scope, &mut this);
@@ -494,6 +676,17 @@ impl<'a> LifetimeContext<'a> {
mut old_scope: Scope,
lifetime: &ast::Lifetime)
{
+ for &(label, label_span) in &self.labels_in_fn {
+ // FIXME (#24278): non-hygienic comparision
+ if lifetime.name == label.name {
+ signal_shadowing_problem(self.sess,
+ lifetime.name,
+ original_label(label_span),
+ shadower_lifetime(&lifetime));
+ return;
+ }
+ }
+
loop {
match *old_scope {
BlockScope(_, s) => {
@@ -507,15 +700,11 @@ impl<'a> LifetimeContext<'a> {
EarlyScope(_, lifetimes, s) |
LateScope(lifetimes, s) => {
if let Some((_, lifetime_def)) = search_lifetimes(lifetimes, lifetime) {
- self.sess.span_err(
- lifetime.span,
- &format!("lifetime name `{}` shadows another \
- lifetime name that is already in scope",
- token::get_name(lifetime.name)));
- self.sess.span_note(
- lifetime_def.span,
- &format!("shadowed lifetime `{}` declared here",
- token::get_name(lifetime.name)));
+ signal_shadowing_problem(
+ self.sess,
+ lifetime.name,
+ original_lifetime(&lifetime_def),
+ shadower_lifetime(&lifetime));
return;
}
diff --git a/src/test/compile-fail/loop-labeled-break-value.rs b/src/test/compile-fail/loop-labeled-break-value.rs
index e1ae3ae464f98..f0792c145d2a2 100644
--- a/src/test/compile-fail/loop-labeled-break-value.rs
+++ b/src/test/compile-fail/loop-labeled-break-value.rs
@@ -16,6 +16,6 @@ fn main() {
let _: i32 = 'inner: loop { break 'inner }; //~ ERROR mismatched types
}
loop {
- let _: i32 = 'inner: loop { loop { break 'inner } }; //~ ERROR mismatched types
+ let _: i32 = 'inner2: loop { loop { break 'inner2 } }; //~ ERROR mismatched types
}
}
diff --git a/src/test/compile-fail/loops-reject-duplicate-labels-2.rs b/src/test/compile-fail/loops-reject-duplicate-labels-2.rs
new file mode 100644
index 0000000000000..68627ecaa718f
--- /dev/null
+++ b/src/test/compile-fail/loops-reject-duplicate-labels-2.rs
@@ -0,0 +1,51 @@
+// Copyright 2015 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.
+
+#![feature(rustc_attrs)]
+
+// ignore-tidy-linelength
+
+// Issue #21633: reject duplicate loop labels in function bodies.
+//
+// This is testing the generalization (to the whole function body)
+// discussed here:
+// http://internals.rust-lang.org/t/psa-rejecting-duplicate-loop-labels/1833
+
+pub fn foo() {
+ { 'fl: for _ in 0..10 { break; } } //~ NOTE shadowed label `'fl` declared here
+ { 'fl: loop { break; } } //~ WARN label name `'fl` shadows a label name that is already in scope
+
+ { 'lf: loop { break; } } //~ NOTE shadowed label `'lf` declared here
+ { 'lf: for _ in 0..10 { break; } } //~ WARN label name `'lf` shadows a label name that is already in scope
+
+ { 'wl: while 2 > 1 { break; } } //~ NOTE shadowed label `'wl` declared here
+ { 'wl: loop { break; } } //~ WARN label name `'wl` shadows a label name that is already in scope
+
+ { 'lw: loop { break; } } //~ NOTE shadowed label `'lw` declared here
+ { 'lw: while 2 > 1 { break; } } //~ WARN label name `'lw` shadows a label name that is already in scope
+
+ { 'fw: for _ in 0..10 { break; } } //~ NOTE shadowed label `'fw` declared here
+ { 'fw: while 2 > 1 { break; } } //~ WARN label name `'fw` shadows a label name that is already in scope
+
+ { 'wf: while 2 > 1 { break; } } //~ NOTE shadowed label `'wf` declared here
+ { 'wf: for _ in 0..10 { break; } } //~ WARN label name `'wf` shadows a label name that is already in scope
+
+ { 'tl: while let Some(_) = None::<i32> { break; } } //~ NOTE shadowed label `'tl` declared here
+ { 'tl: loop { break; } } //~ WARN label name `'tl` shadows a label name that is already in scope
+
+ { 'lt: loop { break; } } //~ NOTE shadowed label `'lt` declared here
+ { 'lt: while let Some(_) = None::<i32> { break; } }
+ //~^ WARN label name `'lt` shadows a label name that is already in scope
+}
+
+#[rustc_error]
+pub fn main() { //~ ERROR compilation successful
+ foo();
+}
diff --git a/src/test/compile-fail/loops-reject-duplicate-labels.rs b/src/test/compile-fail/loops-reject-duplicate-labels.rs
new file mode 100644
index 0000000000000..15446bf642d4d
--- /dev/null
+++ b/src/test/compile-fail/loops-reject-duplicate-labels.rs
@@ -0,0 +1,60 @@
+// Copyright 2015 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.
+
+#![feature(rustc_attrs)]
+
+// ignore-tidy-linelength
+
+// Issue #21633: reject duplicate loop labels in function bodies.
+// This is testing the exact cases that are in the issue description.
+
+fn foo() {
+ 'fl: for _ in 0..10 { break; } //~ NOTE shadowed label `'fl` declared here
+ 'fl: loop { break; } //~ WARN label name `'fl` shadows a label name that is already in scope
+
+ 'lf: loop { break; } //~ NOTE shadowed label `'lf` declared here
+ 'lf: for _ in 0..10 { break; } //~ WARN label name `'lf` shadows a label name that is already in scope
+
+ 'wl: while 2 > 1 { break; } //~ NOTE shadowed label `'wl` declared here
+ 'wl: loop { break; } //~ WARN label name `'wl` shadows a label name that is already in scope
+
+ 'lw: loop { break; } //~ NOTE shadowed label `'lw` declared here
+ 'lw: while 2 > 1 { break; } //~ WARN label name `'lw` shadows a label name that is already in scope
+
+ 'fw: for _ in 0..10 { break; } //~ NOTE shadowed label `'fw` declared here
+ 'fw: while 2 > 1 { break; } //~ WARN label name `'fw` shadows a label name that is already in scope
+
+ 'wf: while 2 > 1 { break; } //~ NOTE shadowed label `'wf` declared here
+ 'wf: for _ in 0..10 { break; } //~ WARN label name `'wf` shadows a label name that is already in scope
+
+ 'tl: while let Some(_) = None::<i32> { break; } //~ NOTE shadowed label `'tl` declared here
+ 'tl: loop { break; } //~ WARN label name `'tl` shadows a label name that is already in scope
+
+ 'lt: loop { break; } //~ NOTE shadowed label `'lt` declared here
+ 'lt: while let Some(_) = None::<i32> { break; }
+ //~^ WARN label name `'lt` shadows a label name that is already in scope
+}
+
+// Note however that it is okay for the same label to be reused in
+// different methods of one impl, as illustrated here.
+
+struct S;
+impl S {
+ fn m1(&self) { 'okay: loop { break 'okay; } }
+ fn m2(&self) { 'okay: loop { break 'okay; } }
+}
+
+#[rustc_error]
+pub fn main() { //~ ERROR compilation successful
+ let s = S;
+ s.m1();
+ s.m2();
+ foo();
+}
diff --git a/src/test/compile-fail/loops-reject-labels-shadowing-lifetimes.rs b/src/test/compile-fail/loops-reject-labels-shadowing-lifetimes.rs
new file mode 100644
index 0000000000000..bbdd0774ed936
--- /dev/null
+++ b/src/test/compile-fail/loops-reject-labels-shadowing-lifetimes.rs
@@ -0,0 +1,120 @@
+// Copyright 2015 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.
+
+// Issue #21633: reject duplicate loop labels in function bodies.
+// This is testing interaction between lifetime-params and labels.
+
+#![feature(rustc_attrs)]
+
+#![allow(dead_code, unused_variables)]
+
+fn foo() {
+ fn foo<'a>() { //~ NOTE shadowed lifetime `'a` declared here
+ 'a: loop { break 'a; }
+ //~^ WARN label name `'a` shadows a lifetime name that is already in scope
+ }
+
+ struct Struct<'b, 'c> { _f: &'b i8, _g: &'c i8 }
+ enum Enum<'d, 'e> { A(&'d i8), B(&'e i8) }
+
+ impl<'d, 'e> Struct<'d, 'e> {
+ fn meth_okay() {
+ 'a: loop { break 'a; }
+ 'b: loop { break 'b; }
+ 'c: loop { break 'c; }
+ }
+ }
+
+ impl <'d, 'e> Enum<'d, 'e> {
+ fn meth_okay() {
+ 'a: loop { break 'a; }
+ 'b: loop { break 'b; }
+ 'c: loop { break 'c; }
+ }
+ }
+
+ impl<'bad, 'c> Struct<'bad, 'c> { //~ NOTE shadowed lifetime `'bad` declared here
+ fn meth_bad(&self) {
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+
+ impl<'b, 'bad> Struct<'b, 'bad> { //~ NOTE shadowed lifetime `'bad` declared here
+ fn meth_bad2(&self) {
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+
+ impl<'b, 'c> Struct<'b, 'c> {
+ fn meth_bad3<'bad>(x: &'bad i8) { //~ NOTE shadowed lifetime `'bad` declared here
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+
+ fn meth_bad4<'a,'bad>(x: &'a i8, y: &'bad i8) {
+ //~^ NOTE shadowed lifetime `'bad` declared here
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+
+ impl <'bad, 'e> Enum<'bad, 'e> { //~ NOTE shadowed lifetime `'bad` declared here
+ fn meth_bad(&self) {
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+ impl <'d, 'bad> Enum<'d, 'bad> { //~ NOTE shadowed lifetime `'bad` declared here
+ fn meth_bad2(&self) {
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+ impl <'d, 'e> Enum<'d, 'e> {
+ fn meth_bad3<'bad>(x: &'bad i8) { //~ NOTE shadowed lifetime `'bad` declared here
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+
+ fn meth_bad4<'a,'bad>(x: &'bad i8) { //~ NOTE shadowed lifetime `'bad` declared here
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+
+ trait HasDefaultMethod1<'bad> { //~ NOTE shadowed lifetime `'bad` declared here
+ fn meth_okay() {
+ 'c: loop { break 'c; }
+ }
+ fn meth_bad(&self) {
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+ trait HasDefaultMethod2<'a,'bad> { //~ NOTE shadowed lifetime `'bad` declared here
+ fn meth_bad(&self) {
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+ trait HasDefaultMethod3<'a,'b> {
+ fn meth_bad<'bad>(&self) { //~ NOTE shadowed lifetime `'bad` declared here
+ 'bad: loop { break 'bad; }
+ //~^ WARN label name `'bad` shadows a lifetime name that is already in scope
+ }
+ }
+}
+
+#[rustc_error]
+pub fn main() { //~ ERROR compilation successful
+ foo();
+}
diff --git a/src/test/compile-fail/loops-reject-lifetime-shadowing-label.rs b/src/test/compile-fail/loops-reject-lifetime-shadowing-label.rs
new file mode 100644
index 0000000000000..2344d251c9a69
--- /dev/null
+++ b/src/test/compile-fail/loops-reject-lifetime-shadowing-label.rs
@@ -0,0 +1,41 @@
+// Copyright 2015 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.
+
+#![feature(rustc_attrs)]
+
+#![allow(dead_code, unused_variables)]
+
+// Issue #21633: reject duplicate loop labels in function bodies.
+//
+// Test rejection of lifetimes in *expressions* that shadow loop labels.
+
+fn foo() {
+ // Reusing lifetime `'a` in function item is okay.
+ fn foo<'a>(x: &'a i8) -> i8 { *x }
+
+ // So is reusing `'a` in struct item
+ struct S1<'a> { x: &'a i8 } impl<'a> S1<'a> { fn m(&self) {} }
+ // and a method item
+ struct S2; impl S2 { fn m<'a>(&self) {} }
+
+ let z = 3_i8;
+
+ 'a: loop { //~ NOTE shadowed label `'a` declared here
+ let b = Box::new(|x: &i8| *x) as Box<for <'a> Fn(&'a i8) -> i8>;
+ //~^ WARN lifetime name `'a` shadows a label name that is already in scope
+ assert_eq!((*b)(&z), z);
+ break 'a;
+ }
+}
+
+#[rustc_error]
+pub fn main() { //~ ERROR compilation successful
+ foo();
+}
diff --git a/src/test/compile-fail/shadowed-lifetime.rs b/src/test/compile-fail/shadowed-lifetime.rs
index 110b1a0d90c22..8cbab5f830809 100644
--- a/src/test/compile-fail/shadowed-lifetime.rs
+++ b/src/test/compile-fail/shadowed-lifetime.rs
@@ -15,14 +15,14 @@ struct Foo<'a>(&'a isize);
impl<'a> Foo<'a> {
//~^ NOTE shadowed lifetime `'a` declared here
fn shadow_in_method<'a>(&'a self) -> &'a isize {
- //~^ ERROR lifetime name `'a` shadows another lifetime name that is already in scope
+ //~^ ERROR lifetime name `'a` shadows a lifetime name that is already in scope
self.0
}
fn shadow_in_type<'b>(&'b self) -> &'b isize {
//~^ NOTE shadowed lifetime `'b` declared here
let x: for<'b> fn(&'b isize) = panic!();
- //~^ ERROR lifetime name `'b` shadows another lifetime name that is already in scope
+ //~^ ERROR lifetime name `'b` shadows a lifetime name that is already in scope
self.0
}
diff --git a/src/test/run-pass/hygienic-labels-in-let.rs b/src/test/run-pass/hygienic-labels-in-let.rs
index 589d6e1581bde..5b45f1e0d3928 100644
--- a/src/test/run-pass/hygienic-labels-in-let.rs
+++ b/src/test/run-pass/hygienic-labels-in-let.rs
@@ -10,6 +10,14 @@
// ignore-pretty: pprust doesn't print hygiene output
+// Test that labels injected by macros do not break hygiene. This
+// checks cases where the macros invocations are under the rhs of a
+// let statement.
+
+// Issue #24278: The label/lifetime shadowing checker from #24162
+// conservatively ignores hygiene, and thus issues warnings that are
+// both true- and false-positives for this test.
+
macro_rules! loop_x {
($e: expr) => {
// $e shouldn't be able to interact with this 'x
diff --git a/src/test/run-pass/hygienic-labels.rs b/src/test/run-pass/hygienic-labels.rs
index df72a5410a2b2..a5882f022920f 100644
--- a/src/test/run-pass/hygienic-labels.rs
+++ b/src/test/run-pass/hygienic-labels.rs
@@ -8,6 +8,11 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
+// Test that labels injected by macros do not break hygiene.
+
+// Issue #24278: The label/lifetime shadowing checker from #24162
+// conservatively ignores hygiene, and thus issues warnings that are
+// both true- and false-positives for this test.
macro_rules! loop_x {
($e: expr) => {