bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #81236 - estebank:everybody-loop-now, r=oli-obk

Browse source 
Gracefully handle loop labels missing leading `'` in different positions

Fix #81192.

* Account for labels when suggesting `loop` instead of `while true`
* Suggest `'a` when given `a` only when appropriate
* Add loop head span to hir
* Tweak error for invalid `break expr`
* Add more misspelled label tests
* Avoid emitting redundant "unused label" lint
* Parse loop labels missing a leading `'`

Each commit can be reviewed in isolation.
This commit is contained in:
Mara Bos 2021-01-22 14:30:19 +00:00 • committed by GitHub
commit 3682a06dcf
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
33 changed files with 523 additions and 139 deletions
Download patch file Download diff file Expand all files Collapse all files

12
compiler/rustc_lint/src/builtin.rs
View file

@ -96,18 +96,24 @@ fn pierce_parens(mut expr: &ast::Expr) -> &ast::Expr {
impl EarlyLintPass for WhileTrue {
fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
if let ast::ExprKind::While(cond, ..) = &e.kind {
if let ast::ExprKind::While(cond, _, label) = &e.kind {
if let ast::ExprKind::Lit(ref lit) = pierce_parens(cond).kind {
if let ast::LitKind::Bool(true) = lit.kind {
if !lit.span.from_expansion() {
let msg = "denote infinite loops with `loop { ... }`";
let condition_span = cx.sess.source_map().guess_head_span(e.span);
let condition_span = e.span.with_hi(cond.span.hi());
cx.struct_span_lint(WHILE_TRUE, condition_span, |lint| {
lint.build(msg)
.span_suggestion_short(
condition_span,
"use `loop`",
"loop".to_owned(),
format!(
"{}loop",
label.map_or_else(String::new, |label| format!(
"{}: ",
label.ident,
))
),
Applicability::MachineApplicable,
)
.emit();