From fe96c11aba8ef34de187551572a8943d89ae26ac Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Mon, 16 Jan 2023 21:06:34 +0900 Subject: [PATCH] fix #104440 --- compiler/rustc_lint/src/context.rs | 47 ++++---- compiler/rustc_lint_defs/src/lib.rs | 2 +- .../rustc_resolve/src/late/diagnostics.rs | 22 +++- tests/ui/single-use-lifetime/issue-104440.rs | 100 ++++++++++++++++++ .../single-use-lifetime/issue-104440.stderr | 28 +++++ 5 files changed, 174 insertions(+), 25 deletions(-) create mode 100644 tests/ui/single-use-lifetime/issue-104440.rs create mode 100644 tests/ui/single-use-lifetime/issue-104440.stderr diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs index c9b9a62257148..8046cc21cea58 100644 --- a/compiler/rustc_lint/src/context.rs +++ b/compiler/rustc_lint/src/context.rs @@ -825,21 +825,24 @@ pub trait LintContext: Sized { 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: _, @@ -847,12 +850,14 @@ pub trait LintContext: Sized { 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"); diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs index f4b4c5168bfd6..45e2467340bab 100644 --- a/compiler/rustc_lint_defs/src/lib.rs +++ b/compiler/rustc_lint_defs/src/lib.rs @@ -502,7 +502,7 @@ pub enum BuiltinLintDiagnostics { 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 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)>, diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index d92b046d0b9f2..6d448433ee6db 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -2188,15 +2188,31 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { 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 { diff --git a/tests/ui/single-use-lifetime/issue-104440.rs b/tests/ui/single-use-lifetime/issue-104440.rs new file mode 100644 index 0000000000000..0795e95303a1e --- /dev/null +++ b/tests/ui/single-use-lifetime/issue-104440.rs @@ -0,0 +1,100 @@ +#![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(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(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(t1: [(); $C], t2: [(); C]) -> ([(); $C], [(); C]) { + (t1, t2) + } + } + + #[rustc_macro_transparency = "semitransparent"] + macro n($C:ident) { + fn g(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) { + (t1, t2) + } + fn h(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) { + (t1, t2) + } + } + + #[rustc_macro_transparency = "transparent"] + macro p($C:ident) { + fn j(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) { + (t1, t2) + } + fn k(t1: [(); $C], t2: [(); C]) -> ([(); C], [(); $C]) { + (t1, t2) + } + } + + m!(C); + n!(C); + p!(C); +} + +fn main() {} diff --git a/tests/ui/single-use-lifetime/issue-104440.stderr b/tests/ui/single-use-lifetime/issue-104440.stderr new file mode 100644 index 0000000000000..54ded31dcbe89 --- /dev/null +++ b/tests/ui/single-use-lifetime/issue-104440.stderr @@ -0,0 +1,28 @@ +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 +