mirror of
https://github.com/rust-lang/rust
synced 2024-09-19 16:32:34 +00:00
On borrow return type, suggest borrowing from arg or owned return type
When we encounter a function with a return type that has an anonymous
lifetime with no argument to borrow from, besides suggesting the
`'static` lifetime we now also suggest changing the arguments to be
borrows or changing the return type to be an owned type.
```
error[E0106]: missing lifetime specifier
--> $DIR/variadic-ffi-6.rs:7:6
|
LL | ) -> &usize {
| ^ expected named lifetime parameter
|
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
LL | ) -> &'static usize {
| +++++++
help: instead, you are more likely to want to change one of the arguments to be borrowed...
|
LL | x: &usize,
| +
help: ...or alternatively, to want to return an owned value
|
LL - ) -> &usize {
LL + ) -> usize {
|
```
Fix #85843.
This commit is contained in:
Esteban Küber
parent
3a85a5cfe7
commit
b7a23bc08b
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@ -8,7 +8,7 @@
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use rustc_hir::def::Namespace::{self, *};
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use rustc_ast::ptr::P;
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use rustc_ast::visit::{FnCtxt, FnKind, LifetimeCtxt};
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use rustc_ast::visit::{walk_ty, FnCtxt, FnKind, LifetimeCtxt, Visitor};
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use rustc_ast::{
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self as ast, AssocItemKind, Expr, ExprKind, GenericParam, GenericParamKind, Item, ItemKind,
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MethodCall, NodeId, Path, Ty, TyKind, DUMMY_NODE_ID,
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@ -2811,6 +2811,7 @@ fn add_missing_lifetime_specifiers_label(
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.collect();
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debug!(?in_scope_lifetimes);
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let mut maybe_static = false;
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debug!(?function_param_lifetimes);
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if let Some((param_lifetimes, params)) = &function_param_lifetimes {
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let elided_len = param_lifetimes.len();
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@ -2849,9 +2850,10 @@ fn add_missing_lifetime_specifiers_label(
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if num_params == 0 {
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err.help(
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"this function's return type contains a borrowed value, \
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but there is no value for it to be borrowed from",
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"this function's return type contains a borrowed value, but there is no value \
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for it to be borrowed from",
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);
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maybe_static = true;
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if in_scope_lifetimes.is_empty() {
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in_scope_lifetimes = vec![(
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Ident::with_dummy_span(kw::StaticLifetime),
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@ -2860,10 +2862,10 @@ fn add_missing_lifetime_specifiers_label(
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}
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} else if elided_len == 0 {
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err.help(
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"this function's return type contains a borrowed value with \
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an elided lifetime, but the lifetime cannot be derived from \
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the arguments",
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"this function's return type contains a borrowed value with an elided \
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lifetime, but the lifetime cannot be derived from the arguments",
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);
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maybe_static = true;
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if in_scope_lifetimes.is_empty() {
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in_scope_lifetimes = vec![(
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Ident::with_dummy_span(kw::StaticLifetime),
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@ -2872,13 +2874,13 @@ fn add_missing_lifetime_specifiers_label(
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}
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} else if num_params == 1 {
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err.help(format!(
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"this function's return type contains a borrowed value, \
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but the signature does not say which {m} it is borrowed from"
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"this function's return type contains a borrowed value, but the signature does \
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not say which {m} it is borrowed from",
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));
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} else {
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err.help(format!(
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"this function's return type contains a borrowed value, \
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but the signature does not say whether it is borrowed from {m}"
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"this function's return type contains a borrowed value, but the signature does \
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not say whether it is borrowed from {m}",
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));
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}
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}
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@ -2943,11 +2945,107 @@ fn add_missing_lifetime_specifiers_label(
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);
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}
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1 => {
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let post = if maybe_static {
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let owned = if let [lt] = &lifetime_refs[..]
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&& lt.kind != MissingLifetimeKind::Ampersand
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{
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", or if you will only have owned values"
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} else {
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""
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};
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format!(
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", but this is uncommon unless you're returning a borrowed value from a \
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`const` or a `static`{owned}",
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)
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} else {
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String::new()
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};
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err.multipart_suggestion_verbose(
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format!("consider using the `{existing_name}` lifetime"),
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format!("consider using the `{existing_name}` lifetime{post}"),
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spans_suggs,
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Applicability::MaybeIncorrect,
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);
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if maybe_static {
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// FIXME: what follows are general suggestions, but we'd want to perform some
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// minimal flow analysis to provide more accurate suggestions. For example, if
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// we identified that the return expression references only one argument, we
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// would suggest borrowing only that argument, and we'd skip the prior
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// "use `'static`" suggestion entirely.
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if let [lt] = &lifetime_refs[..] && lt.kind == MissingLifetimeKind::Ampersand {
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let pre = if let Some((kind, _span)) =
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self.diagnostic_metadata.current_function
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&& let FnKind::Fn(_, _, sig, _, _, _) = kind
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&& !sig.decl.inputs.is_empty()
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&& let sugg = sig
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.decl
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.inputs
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.iter()
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.filter_map(|param| {
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if param.ty.span.contains(lt.span) {
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// We don't want to suggest `fn elision(_: &fn() -> &i32)`
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// when we have `fn elision(_: fn() -> &i32)`
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None
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} else if let TyKind::CVarArgs = param.ty.kind {
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// Don't suggest `&...` for ffi fn with varargs
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None
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} else {
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Some((param.ty.span.shrink_to_lo(), "&".to_string()))
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}
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})
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.collect::<Vec<_>>()
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&& !sugg.is_empty()
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{
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let (the, s) = if sig.decl.inputs.len() == 1 {
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("the", "")
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} else {
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("one of the", "s")
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};
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err.multipart_suggestion_verbose(
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format!(
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"instead, you are more likely to want to change {the} \
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argument{s} to be borrowed...",
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),
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sugg,
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Applicability::MaybeIncorrect,
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);
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"...or alternatively,"
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} else {
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"instead, you are more likely"
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};
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let mut sugg = vec![(lt.span, String::new())];
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if let Some((kind, _span)) =
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self.diagnostic_metadata.current_function
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&& let FnKind::Fn(_, _, sig, _, _, _) = kind
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&& let ast::FnRetTy::Ty(ty) = &sig.decl.output
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{
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let mut lt_finder = LifetimeFinder { lifetime: lt.span, found: None };
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lt_finder.visit_ty(&ty);
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if let Some(ty) = lt_finder.found {
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if let TyKind::Path(None, Path { segments, .. }) = &ty.kind
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&& segments.len() == 1
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&& segments[0].ident.name == sym::str
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{
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// Don't suggest `-> str`, suggest `-> String`.
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sugg = vec![(lt.span.with_hi(ty.span.hi()), "String".to_string())];
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}
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if let TyKind::Slice(inner_ty) = &ty.kind {
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// Don't suggest `-> [T]`, suggest `-> Vec<T>`.
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sugg = vec![
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(lt.span.with_hi(inner_ty.span.lo()), "Vec<".to_string()),
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(ty.span.with_lo(inner_ty.span.hi()), ">".to_string()),
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];
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}
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}
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};
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err.multipart_suggestion_verbose(
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format!("{pre} to want to return an owned value"),
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sugg,
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Applicability::MaybeIncorrect,
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);
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}
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}
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// Record as using the suggested resolution.
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let (_, (_, res)) = in_scope_lifetimes[0];
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@ -2977,7 +3075,7 @@ fn add_missing_lifetime_specifiers_label(
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fn mk_where_bound_predicate(
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path: &Path,
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poly_trait_ref: &ast::PolyTraitRef,
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ty: &ast::Ty,
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ty: &Ty,
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) -> Option<ast::WhereBoundPredicate> {
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use rustc_span::DUMMY_SP;
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let modified_segments = {
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@ -3054,6 +3152,22 @@ pub(super) fn signal_lifetime_shadowing(sess: &Session, orig: Ident, shadower: I
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err.emit();
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}
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struct LifetimeFinder<'ast> {
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lifetime: Span,
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found: Option<&'ast Ty>,
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}
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impl<'ast> Visitor<'ast> for LifetimeFinder<'ast> {
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fn visit_ty(&mut self, t: &'ast Ty) {
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if t.span.lo() == self.lifetime.lo()
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&& let TyKind::Ref(_, mut_ty) = &t.kind
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{
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self.found = Some(&mut_ty.ty);
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}
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walk_ty(self, t)
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}
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}
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/// Shadowing involving a label is only a warning for historical reasons.
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//FIXME: make this a proper lint.
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pub(super) fn signal_label_shadowing(sess: &Session, orig: Span, shadower: Ident) {
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@ -11,7 +11,7 @@
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const ENTRY_LIMIT: usize = 900;
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// FIXME: The following limits should be reduced eventually.
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const ISSUES_ENTRY_LIMIT: usize = 1852;
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const ROOT_ENTRY_LIMIT: usize = 867;
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const ROOT_ENTRY_LIMIT: usize = 866;
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const EXPECTED_TEST_FILE_EXTENSIONS: &[&str] = &[
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"rs", // test source files
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@ -5,10 +5,15 @@ LL | fn elision<T: Fn() -> &i32>() {
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| ^ expected named lifetime parameter
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|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
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help: consider using the `'static` lifetime
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
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|
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LL | fn elision<T: Fn() -> &'static i32>() {
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| +++++++
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help: instead, you are more likely to want to return an owned value
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|
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LL - fn elision<T: Fn() -> &i32>() {
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LL + fn elision<T: Fn() -> i32>() {
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error: aborting due to previous error
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|
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@ -5,10 +5,15 @@ LL | fn elision(_: fn() -> &i32) {
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| ^ expected named lifetime parameter
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|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
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help: consider using the `'static` lifetime
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
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|
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LL | fn elision(_: fn() -> &'static i32) {
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| +++++++
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help: instead, you are more likely to want to return an owned value
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|
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LL - fn elision(_: fn() -> &i32) {
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LL + fn elision(_: fn() -> i32) {
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|
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error: aborting due to previous error
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|
|
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@ -5,10 +5,19 @@ LL | ) -> &usize {
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| ^ expected named lifetime parameter
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|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
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help: consider using the `'static` lifetime
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
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|
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LL | ) -> &'static usize {
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| +++++++
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help: instead, you are more likely to want to change one of the arguments to be borrowed...
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|
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LL | x: &usize,
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| +
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help: ...or alternatively, to want to return an owned value
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|
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LL - ) -> &usize {
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LL + ) -> usize {
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|
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error: aborting due to previous error
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|
|
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@ -1,8 +0,0 @@
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// run-rustfix
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extern "C" {
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pub fn g(_: &u8) -> &u8; // OK
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pub fn f() -> &'static u8; //~ ERROR missing lifetime specifier
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}
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fn main() {}
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@ -1,5 +1,3 @@
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// run-rustfix
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extern "C" {
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pub fn g(_: &u8) -> &u8; // OK
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pub fn f() -> &u8; //~ ERROR missing lifetime specifier
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|
|
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|
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@ -1,14 +1,19 @@
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error[E0106]: missing lifetime specifier
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--> $DIR/foreign-fn-return-lifetime.rs:5:19
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--> $DIR/foreign-fn-return-lifetime.rs:3:19
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|
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LL | pub fn f() -> &u8;
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| ^ expected named lifetime parameter
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|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
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help: consider using the `'static` lifetime
|
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
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|
|
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LL | pub fn f() -> &'static u8;
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| +++++++
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help: instead, you are more likely to want to return an owned value
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|
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LL - pub fn f() -> &u8;
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LL + pub fn f() -> u8;
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|
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error: aborting due to previous error
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|
|
|
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|
|
@ -11,7 +11,7 @@ LL | fn create_doc() -> impl Document<Cursor<'_> = DocCursorImpl<'_>> {
|
|||
| ^^ expected named lifetime parameter
|
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|
|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
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|
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LL | fn create_doc() -> impl Document<Cursor<'_> = DocCursorImpl<'static>> {
|
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| ~~~~~~~
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|
|
|
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|
|
@ -5,7 +5,7 @@ LL | fn d() -> impl Fn() -> (impl Debug + '_) {
|
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| ^^ expected named lifetime parameter
|
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|
|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
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|
|
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LL | fn d() -> impl Fn() -> (impl Debug + 'static) {
|
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| ~~~~~~~
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|
|
|
|||
|
|
@ -5,10 +5,14 @@ LL | &str
|
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| ^ expected named lifetime parameter
|
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|
|
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= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
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help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
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LL | &'static str
|
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| +++++++
|
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help: instead, you are more likely to want to return an owned value
|
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|
|
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LL | String
|
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| ~~~~~~
|
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|
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error: aborting due to previous error
|
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|
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|
|
|
|||
|
|
@ -17,10 +17,18 @@ LL | fn parse_type_2(iter: fn(&u8)->&u8) -> &str { iter() }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn parse_type_2(iter: fn(&u8)->&u8) -> &'static str { iter() }
|
||||
| +++++++
|
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help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn parse_type_2(iter: &fn(&u8)->&u8) -> &str { iter() }
|
||||
| +
|
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help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL | fn parse_type_2(iter: fn(&u8)->&u8) -> String { iter() }
|
||||
| ~~~~~~
|
||||
|
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error[E0106]: missing lifetime specifier
|
||||
--> $DIR/issue-26638.rs:10:22
|
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|
|
@ -29,10 +37,14 @@ LL | fn parse_type_3() -> &str { unimplemented!() }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn parse_type_3() -> &'static str { unimplemented!() }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to return an owned value
|
||||
|
|
||||
LL | fn parse_type_3() -> String { unimplemented!() }
|
||||
| ~~~~~~
|
||||
|
||||
error[E0308]: mismatched types
|
||||
--> $DIR/issue-26638.rs:1:69
|
||||
|
|
|
|||
|
|
@ -5,10 +5,15 @@ LL | fn f() -> &isize {
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn f() -> &'static isize {
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to return an owned value
|
||||
|
|
||||
LL - fn f() -> &isize {
|
||||
LL + fn f() -> isize {
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:7:33
|
||||
|
|
@ -41,10 +46,19 @@ LL | fn i(_x: isize) -> &isize {
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn i(_x: isize) -> &'static isize {
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn i(_x: &isize) -> &isize {
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn i(_x: isize) -> &isize {
|
||||
LL + fn i(_x: isize) -> isize {
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:34:24
|
||||
|
|
@ -53,10 +67,19 @@ LL | fn j(_x: StaticStr) -> &isize {
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn j(_x: StaticStr) -> &'static isize {
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn j(_x: &StaticStr) -> &isize {
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn j(_x: StaticStr) -> &isize {
|
||||
LL + fn j(_x: StaticStr) -> isize {
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:40:49
|
||||
|
|
@ -65,10 +88,19 @@ LL | fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> &isize {
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'a` lifetime
|
||||
help: consider using the `'a` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> &'a isize {
|
||||
| ++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn k<'a, T: WithLifetime<'a>>(_x: &T::Output) -> &isize {
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> &isize {
|
||||
LL + fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> isize {
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:45:37
|
||||
|
|
@ -77,10 +109,18 @@ LL | fn l<'a>(_: &'a str, _: &'a str) -> &str { "" }
|
|||
| ------- ------- ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value with an elided lifetime, but the lifetime cannot be derived from the arguments
|
||||
help: consider using the `'a` lifetime
|
||||
help: consider using the `'a` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn l<'a>(_: &'a str, _: &'a str) -> &'a str { "" }
|
||||
| ++
|
||||
help: instead, you are more likely to want to change one of the arguments to be borrowed...
|
||||
|
|
||||
LL | fn l<'a>(_: &&'a str, _: &&'a str) -> &str { "" }
|
||||
| + +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL | fn l<'a>(_: &'a str, _: &'a str) -> String { "" }
|
||||
| ~~~~~~
|
||||
|
||||
error: aborting due to 7 previous errors
|
||||
|
||||
|
|
|
|||
|
|
@ -21,10 +21,19 @@ LL | fn wrap(self: Wrap<{ fn bar(&self) {} }>) -> &() {
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn wrap(self: Wrap<{ fn bar(&self) {} }>) -> &'static () {
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn wrap(self: &Wrap<{ fn bar(&self) {} }>) -> &() {
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn wrap(self: Wrap<{ fn bar(&self) {} }>) -> &() {
|
||||
LL + fn wrap(self: Wrap<{ fn bar(&self) {} }>) -> () {
|
||||
|
|
||||
|
||||
error[E0412]: cannot find type `Wrap` in this scope
|
||||
--> $DIR/nested-item.rs:5:15
|
||||
|
|
|
|||
|
|
@ -5,10 +5,19 @@ LL | fn g(mut x: impl Iterator<Item = &()>) -> Option<&()> { x.next() }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn g(mut x: impl Iterator<Item = &()>) -> Option<&'static ()> { x.next() }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn g(mut x: &impl Iterator<Item = &()>) -> Option<&()> { x.next() }
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn g(mut x: impl Iterator<Item = &()>) -> Option<&()> { x.next() }
|
||||
LL + fn g(mut x: impl Iterator<Item = &()>) -> Option<()> { x.next() }
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/impl-trait-missing-lifetime-gated.rs:19:60
|
||||
|
|
@ -17,10 +26,19 @@ LL | async fn i(mut x: impl Iterator<Item = &()>) -> Option<&()> { x.next()
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | async fn i(mut x: impl Iterator<Item = &()>) -> Option<&'static ()> { x.next() }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | async fn i(mut x: &impl Iterator<Item = &()>) -> Option<&()> { x.next() }
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - async fn i(mut x: impl Iterator<Item = &()>) -> Option<&()> { x.next() }
|
||||
LL + async fn i(mut x: impl Iterator<Item = &()>) -> Option<()> { x.next() }
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/impl-trait-missing-lifetime-gated.rs:27:58
|
||||
|
|
@ -29,7 +47,7 @@ LL | fn g(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()> { x.next()
|
|||
| ^^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | fn g(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'static ()> { x.next() }
|
||||
| ~~~~~~~
|
||||
|
|
@ -41,7 +59,7 @@ LL | async fn i(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()> { x.n
|
|||
| ^^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | async fn i(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'static ()> { x.next() }
|
||||
| ~~~~~~~
|
||||
|
|
@ -53,10 +71,19 @@ LL | fn g(mut x: impl Foo) -> Option<&()> { x.next() }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn g(mut x: impl Foo) -> Option<&'static ()> { x.next() }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn g(mut x: &impl Foo) -> Option<&()> { x.next() }
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn g(mut x: impl Foo) -> Option<&()> { x.next() }
|
||||
LL + fn g(mut x: impl Foo) -> Option<()> { x.next() }
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/impl-trait-missing-lifetime-gated.rs:58:41
|
||||
|
|
@ -65,10 +92,19 @@ LL | fn g(mut x: impl Foo<()>) -> Option<&()> { x.next() }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn g(mut x: impl Foo<()>) -> Option<&'static ()> { x.next() }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change the argument to be borrowed...
|
||||
|
|
||||
LL | fn g(mut x: &impl Foo<()>) -> Option<&()> { x.next() }
|
||||
| +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn g(mut x: impl Foo<()>) -> Option<&()> { x.next() }
|
||||
LL + fn g(mut x: impl Foo<()>) -> Option<()> { x.next() }
|
||||
|
|
||||
|
||||
error[E0658]: anonymous lifetimes in `impl Trait` are unstable
|
||||
--> $DIR/impl-trait-missing-lifetime-gated.rs:6:35
|
||||
|
|
|
|||
|
|
@ -5,7 +5,7 @@ LL | fn g(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()> { x.next() }
|
|||
| ^^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | fn g(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'static ()> { x.next() }
|
||||
| ~~~~~~~
|
||||
|
|
@ -17,7 +17,7 @@ LL | async fn i(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()> { x.next(
|
|||
| ^^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | async fn i(mut x: impl Iterator<Item = &'_ ()>) -> Option<&'static ()> { x.next() }
|
||||
| ~~~~~~~
|
||||
|
|
|
|||
|
|
@ -5,7 +5,7 @@ LL | static a: RefCell<HashMap<i32, Vec<Vec<Foo>>>> = RefCell::new(HashMap::
|
|||
| ^^^ expected 2 lifetime parameters
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | static a: RefCell<HashMap<i32, Vec<Vec<Foo<'static, 'static>>>>> = RefCell::new(HashMap::new());
|
||||
| ++++++++++++++++++
|
||||
|
|
@ -32,7 +32,7 @@ LL | static b: RefCell<HashMap<i32, Vec<Vec<&Bar>>>> = RefCell::new(HashMap:
|
|||
| expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | static b: RefCell<HashMap<i32, Vec<Vec<&'static Bar<'static, 'static>>>>> = RefCell::new(HashMap::new());
|
||||
| +++++++ ++++++++++++++++++
|
||||
|
|
@ -59,7 +59,7 @@ LL | static c: RefCell<HashMap<i32, Vec<Vec<Qux<i32>>>>> = RefCell::new(Hash
|
|||
| ^ expected 2 lifetime parameters
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | static c: RefCell<HashMap<i32, Vec<Vec<Qux<'static, 'static, i32>>>>> = RefCell::new(HashMap::new());
|
||||
| +++++++++++++++++
|
||||
|
|
@ -86,7 +86,7 @@ LL | static d: RefCell<HashMap<i32, Vec<Vec<&Tar<i32>>>>> = RefCell::new(Has
|
|||
| expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | static d: RefCell<HashMap<i32, Vec<Vec<&'static Tar<'static, 'static, i32>>>>> = RefCell::new(HashMap::new());
|
||||
| +++++++ +++++++++++++++++
|
||||
|
|
@ -113,10 +113,15 @@ LL | static f: RefCell<HashMap<i32, Vec<Vec<&Tar<'static, i32>>>>> = RefCell
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | static f: RefCell<HashMap<i32, Vec<Vec<&'static Tar<'static, i32>>>>> = RefCell::new(HashMap::new());
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to return an owned value
|
||||
|
|
||||
LL - static f: RefCell<HashMap<i32, Vec<Vec<&Tar<'static, i32>>>>> = RefCell::new(HashMap::new());
|
||||
LL + static f: RefCell<HashMap<i32, Vec<Vec<Tar<'static, i32>>>>> = RefCell::new(HashMap::new());
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifier
|
||||
--> $DIR/missing-lifetime-specifier.rs:47:44
|
||||
|
|
|
|||
|
|
@ -5,10 +5,15 @@ LL | fn f1() -> &i32 { loop {} }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn f1() -> &'static i32 { loop {} }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to return an owned value
|
||||
|
|
||||
LL - fn f1() -> &i32 { loop {} }
|
||||
LL + fn f1() -> i32 { loop {} }
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifiers
|
||||
--> $DIR/return-elided-lifetime.rs:8:14
|
||||
|
|
@ -19,7 +24,7 @@ LL | fn f1_() -> (&i32, &i32) { loop {} }
|
|||
| expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn f1_() -> (&'static i32, &'static i32) { loop {} }
|
||||
| +++++++ +++++++
|
||||
|
|
@ -31,10 +36,19 @@ LL | fn f2(a: i32, b: i32) -> &i32 { loop {} }
|
|||
| ^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn f2(a: i32, b: i32) -> &'static i32 { loop {} }
|
||||
| +++++++
|
||||
help: instead, you are more likely to want to change one of the arguments to be borrowed...
|
||||
|
|
||||
LL | fn f2(a: &i32, b: &i32) -> &i32 { loop {} }
|
||||
| + +
|
||||
help: ...or alternatively, to want to return an owned value
|
||||
|
|
||||
LL - fn f2(a: i32, b: i32) -> &i32 { loop {} }
|
||||
LL + fn f2(a: i32, b: i32) -> i32 { loop {} }
|
||||
|
|
||||
|
||||
error[E0106]: missing lifetime specifiers
|
||||
--> $DIR/return-elided-lifetime.rs:13:28
|
||||
|
|
@ -45,7 +59,7 @@ LL | fn f2_(a: i32, b: i32) -> (&i32, &i32) { loop {} }
|
|||
| expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
||||
|
|
||||
LL | fn f2_(a: i32, b: i32) -> (&'static i32, &'static i32) { loop {} }
|
||||
| +++++++ +++++++
|
||||
|
|
|
|||
|
|
@ -28,7 +28,7 @@ LL | fn meh() -> Box<dyn for<'_> Meh<'_>>
|
|||
| ^^ expected named lifetime parameter
|
||||
|
|
||||
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
|
||||
help: consider using the `'static` lifetime
|
||||
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
||||
|
|
||||
LL | fn meh() -> Box<dyn for<'_> Meh<'static>>
|
||||
| ~~~~~~~
|
||||
|
|
|
|||
Loading…
Reference in a new issue