rollup merge of #24162: pnkfelix/fsk-detect-duplicate-loop-labels
Check for duplicate loop labels in function bodies. See also: http://internals.rust-lang.org/t/psa-rejecting-duplicate-loop-labels/1833 The change, which we are putting in as future-proofing in preparation for future potential additions to the language (namely labeling arbitrary blocks and using those labels in borrow expressions), means that code like this will start emitting warnings: ```rust fn main() { { 'a: loop { break; } } { 'a: loop { break; } } } ``` To make the above code compile without warnings, write this instead: ```rust fn main() { { 'a: loop { break; } } { 'b: loop { break; } } } ``` Since this change is only introducing a new warnings, this change is non-breaking. Fix #21633
This commit is contained in:
Alex Crichton
commit
75f35657b3
|
|
@ -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;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -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
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -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();
|
||||
}
|
||||
|
|
@ -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();
|
||||
}
|
||||
|
|
@ -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();
|
||||
}
|
||||
|
|
@ -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();
|
||||
}
|
||||
|
|
@ -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
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -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) => {
|
||||
// $e shouldn't be able to interact with this 'x
|
||||
|
|
|
|||
|
|
@ -8,6 +8,11 @@
|
|||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
// Test that labels injected by macros do not break hygiene.
|
||||
|
||||
// Issue #24278: The label/lifetime shadowing checker from #24162
|
||||
// conservatively ignores hygiene, and thus issues warnings that are
|
||||
// both true- and false-positives for this test.
|
||||
|
||||
macro_rules! loop_x {
|
||||
($e: expr) => {
|
||||
|
|
|
|||
Loading…
Reference in New Issue