debug!(?param_span, ?use_span, ?deletion_span);
db.span_label(param_span, "this lifetime...");
db.span_label(use_span, "...is used only here");
- let msg = "elide the single-use lifetime";
- let (use_span, replace_lt) = if elide {
- let use_span = sess.source_map().span_extend_while(
- use_span,
- char::is_whitespace,
- ).unwrap_or(use_span);
- (use_span, String::new())
- } else {
- (use_span, "'_".to_owned())
- };
- db.multipart_suggestion(
- msg,
- vec![(deletion_span, String::new()), (use_span, replace_lt)],
- Applicability::MachineApplicable,
- );
+ if let Some(deletion_span) = deletion_span {
+ let msg = "elide the single-use lifetime";
+ let (use_span, replace_lt) = if elide {
+ let use_span = sess.source_map().span_extend_while(
+ use_span,
+ char::is_whitespace,
+ ).unwrap_or(use_span);
+ (use_span, String::new())
+ } else {
+ (use_span, "'_".to_owned())
+ };
+ debug!(?deletion_span, ?use_span);
+ db.multipart_suggestion(
+ msg,
+ vec![(deletion_span, String::new()), (use_span, replace_lt)],
+ Applicability::MachineApplicable,
+ );
+ }
},
BuiltinLintDiagnostics::SingleUseLifetime {
param_span: _,
deletion_span,
} => {
debug!(?deletion_span);
- db.span_suggestion(
- deletion_span,
- "elide the unused lifetime",
- "",
- Applicability::MachineApplicable,
- );
+ if let Some(deletion_span) = deletion_span {
+ db.span_suggestion(
+ deletion_span,
+ "elide the unused lifetime",
+ "",
+ Applicability::MachineApplicable,
+ );
+ }
},
BuiltinLintDiagnostics::NamedArgumentUsedPositionally{ position_sp_to_replace, position_sp_for_msg, named_arg_sp, named_arg_name, is_formatting_arg} => {
db.span_label(named_arg_sp, "this named argument is referred to by position in formatting string");
param_span: Span,
/// Span of the code that should be removed when eliding this lifetime.
/// This span should include leading or trailing comma.
- deletion_span: Span,
+ deletion_span: Option<Span>,
/// Span of the single use, or None if the lifetime is never used.
/// If true, the lifetime will be fully elided.
use_span: Option<(Span, bool)>,
let deletion_span = || {
if params.len() == 1 {
// if sole lifetime, remove the entire `<>` brackets
- generics_span
+ Some(generics_span)
} else if param_index == 0 {
// if removing within `<>` brackets, we also want to
// delete a leading or trailing comma as appropriate
- param.span().to(params[param_index + 1].span().shrink_to_lo())
+ match (
+ param.span().find_ancestor_inside(generics_span),
+ params[param_index + 1].span().find_ancestor_inside(generics_span),
+ ) {
+ (Some(param_span), Some(next_param_span)) => {
+ Some(param_span.to(next_param_span.shrink_to_lo()))
+ }
+ _ => None,
+ }
} else {
// if removing within `<>` brackets, we also want to
// delete a leading or trailing comma as appropriate
- params[param_index - 1].span().shrink_to_hi().to(param.span())
+ match (
+ param.span().find_ancestor_inside(generics_span),
+ params[param_index - 1].span().find_ancestor_inside(generics_span),
+ ) {
+ (Some(param_span), Some(prev_param_span)) => {
+ Some(prev_param_span.shrink_to_hi().to(param_span))
+ }
+ _ => None,
+ }
}
};
match use_set {
--- /dev/null
+#![feature(decl_macro, rustc_attrs)]
+#![deny(single_use_lifetimes)]
+
+mod type_params {
+ macro m($T:ident) {
+ fn f<$T: Clone, T: PartialEq>(t1: $T, t2: T) -> ($T, bool) {
+ (t1.clone(), t2 == t2)
+ }
+ }
+
+ #[rustc_macro_transparency = "semitransparent"]
+ macro n($T:ident) {
+ fn g<$T: Clone>(t1: $T, t2: T) -> (T, $T) {
+ (t1.clone(), t2.clone())
+ }
+ fn h<T: Clone>(t1: $T, t2: T) -> (T, $T) {
+ (t1.clone(), t2.clone())
+ }
+ }
+
+ #[rustc_macro_transparency = "transparent"]
+ macro p($T:ident) {
+ fn j<$T: Clone>(t1: $T, t2: T) -> (T, $T) {
+ (t1.clone(), t2.clone())
+ }
+ fn k<T: Clone>(t1: $T, t2: T) -> (T, $T) {
+ (t1.clone(), t2.clone())
+ }
+ }
+
+ m!(T);
+ n!(T);
+ p!(T);
+}
+
+mod lifetime_params {
+ macro m($a:lifetime) {
+ fn f<'b, 'c, $a: 'b, 'a: 'c>(t1: &$a(), t2: &'a ()) -> (&'b (), &'c ()) { //~ ERROR lifetime parameter `'a` only used once
+ (t1, t2)
+ }
+ }
+
+ #[rustc_macro_transparency = "semitransparent"]
+ macro n($a:lifetime) {
+ fn g<$a>(t1: &$a(), t2: &'a ()) -> (&'a (), &$a ()) {
+ (t1, t2)
+ }
+ fn h<'a>(t1: &$a(), t2: &'a ()) -> (&'a (), &$a ()) {
+ (t1, t2)
+ }
+ }
+
+ #[rustc_macro_transparency = "transparent"]
+ macro p($a:lifetime) {
+ fn j<$a>(t1: &$a(), t2: &'a ()) -> (&'a (), &$a ()) {
+ (t1, t2)
+ }
+ fn k<'a>(t1: &$a(), t2: &'a ()) -> (&'a (), &$a ()) {
+ (t1, t2)
+ }
+ }
+
+ m!('a); //~ ERROR lifetime parameter `'a` only used once
+ n!('a);
+ p!('a);
+}
+
+mod const_params {
+ macro m($C:ident) {
+ fn f<const $C: usize, const C: usize>(t1: [(); $C], t2: [(); C]) -> ([(); $C], [(); C]) {
+ (t1, t2)
+ }
+ }
+
+ #[rustc_macro_transparency = "semitransparent"]
+ macro n($C:ident) {
+ fn g<const $C: usize>(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) {
+ (t1, t2)
+ }
+ fn h<const C: usize>(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) {
+ (t1, t2)
+ }
+ }
+
+ #[rustc_macro_transparency = "transparent"]
+ macro p($C:ident) {
+ fn j<const $C: usize>(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) {
+ (t1, t2)
+ }
+ fn k<const C: usize>(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) {
+ (t1, t2)
+ }
+ }
+
+ m!(C);
+ n!(C);
+ p!(C);
+}
+
+fn main() {}
--- /dev/null
+error: lifetime parameter `'a` only used once
+ --> $DIR/issue-104440.rs:63:8
+ |
+LL | m!('a);
+ | ^^
+ | |
+ | this lifetime...
+ | ...is used only here
+ |
+note: the lint level is defined here
+ --> $DIR/issue-104440.rs:2:9
+ |
+LL | #![deny(single_use_lifetimes)]
+ | ^^^^^^^^^^^^^^^^^^^^
+
+error: lifetime parameter `'a` only used once
+ --> $DIR/issue-104440.rs:38:30
+ |
+LL | fn f<'b, 'c, $a: 'b, 'a: 'c>(t1: &$a(), t2: &'a ()) -> (&'b (), &'c ()) {
+ | ^^ this lifetime... -- ...is used only here
+...
+LL | m!('a);
+ | ------ in this macro invocation
+ |
+ = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 2 previous errors
+
projects / rust.git / commitdiff