diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs index a1363168f01..afb5f23db5b 100644 --- a/src/librustc/hir/lowering.rs +++ b/src/librustc/hir/lowering.rs @@ -1147,7 +1147,7 @@ impl<'a> LoweringContext<'a> { TyKind::Slice(ref ty) => hir::TyKind::Slice(self.lower_ty(ty, itctx)), TyKind::Ptr(ref mt) => hir::TyKind::Ptr(self.lower_mt(mt, itctx)), TyKind::Rptr(ref region, ref mt) => { - let span = t.span.shrink_to_lo(); + let span = self.sess.source_map().next_point(t.span.shrink_to_lo()); let lifetime = match *region { Some(ref lt) => self.lower_lifetime(lt), None => self.elided_ref_lifetime(span), diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs index 98e80d333c1..361abb16896 100644 --- a/src/librustc/middle/resolve_lifetime.rs +++ b/src/librustc/middle/resolve_lifetime.rs @@ -2235,21 +2235,46 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { }; let mut err = report_missing_lifetime_specifiers(self.tcx.sess, span, lifetime_refs.len()); + let mut add_label = true; if let Some(params) = error { if lifetime_refs.len() == 1 { - self.report_elision_failure(&mut err, params); + add_label = add_label && self.report_elision_failure(&mut err, params, span); } } + if add_label { + add_missing_lifetime_specifiers_label(&mut err, span, lifetime_refs.len()); + } err.emit(); } + fn suggest_lifetime(&self, db: &mut DiagnosticBuilder<'_>, span: Span, msg: &str) -> bool { + match self.tcx.sess.source_map().span_to_snippet(span) { + Ok(ref snippet) => { + let (sugg, applicability) = if snippet == "&" { + ("&'static ".to_owned(), Applicability::MachineApplicable) + } else if snippet == "'_" { + ("'static".to_owned(), Applicability::MachineApplicable) + } else { + (format!("{} + 'static", snippet), Applicability::MaybeIncorrect) + }; + db.span_suggestion_with_applicability(span, msg, sugg, applicability); + false + } + Err(_) => { + db.help(msg); + true + } + } + } + fn report_elision_failure( &mut self, db: &mut DiagnosticBuilder<'_>, params: &[ElisionFailureInfo], - ) { + span: Span, + ) -> bool { let mut m = String::new(); let len = params.len(); @@ -2304,7 +2329,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { "this function's return type contains a borrowed value, but \ there is no value for it to be borrowed from" ); - help!(db, "consider giving it a 'static lifetime"); + self.suggest_lifetime(db, span, "consider giving it a 'static lifetime") } else if elided_len == 0 { help!( db, @@ -2312,11 +2337,8 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { an elided lifetime, but the lifetime cannot be derived from \ the arguments" ); - help!( - db, - "consider giving it an explicit bounded or 'static \ - lifetime" - ); + let msg = "consider giving it an explicit bounded or 'static lifetime"; + self.suggest_lifetime(db, span, msg) } else if elided_len == 1 { help!( db, @@ -2324,6 +2346,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { the signature does not say which {} it is borrowed from", m ); + true } else { help!( db, @@ -2331,6 +2354,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { the signature does not say whether it is borrowed from {}", m ); + true } } @@ -2744,26 +2768,28 @@ fn insert_late_bound_lifetimes( } } -pub fn report_missing_lifetime_specifiers( +fn report_missing_lifetime_specifiers( sess: &Session, span: Span, count: usize, ) -> DiagnosticBuilder<'_> { - let mut err = struct_span_err!( + struct_span_err!( sess, span, E0106, "missing lifetime specifier{}", if count > 1 { "s" } else { "" } - ); - - let msg: Cow<'static, str> = if count > 1 { - format!("expected {} lifetime parameters", count).into() - } else { - "expected lifetime parameter".into() - }; - - err.span_label(span, msg); - - err + ) +} + +fn add_missing_lifetime_specifiers_label( + err: &mut DiagnosticBuilder<'_>, + span: Span, + count: usize, +) { + if count > 1 { + err.span_label(span, format!("expected {} lifetime parameters", count)); + } else { + err.span_label(span, "expected lifetime parameter"); + }; } diff --git a/src/test/ui/associated-types/bound-lifetime-in-binding-only.elision.stderr b/src/test/ui/associated-types/bound-lifetime-in-binding-only.elision.stderr index 0a12aa76a78..6b9d4ebb298 100644 --- a/src/test/ui/associated-types/bound-lifetime-in-binding-only.elision.stderr +++ b/src/test/ui/associated-types/bound-lifetime-in-binding-only.elision.stderr @@ -2,10 +2,9 @@ error[E0106]: missing lifetime specifier --> $DIR/bound-lifetime-in-binding-only.rs:62:23 | LL | fn elision &i32>() { - | ^ expected lifetime parameter + | ^ help: consider giving it a 'static lifetime: `&'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error: aborting due to previous error diff --git a/src/test/ui/associated-types/bound-lifetime-in-return-only.elision.stderr b/src/test/ui/associated-types/bound-lifetime-in-return-only.elision.stderr index 8fefdfd4d19..7906f0a30e4 100644 --- a/src/test/ui/associated-types/bound-lifetime-in-return-only.elision.stderr +++ b/src/test/ui/associated-types/bound-lifetime-in-return-only.elision.stderr @@ -2,10 +2,9 @@ error[E0106]: missing lifetime specifier --> $DIR/bound-lifetime-in-return-only.rs:44:23 | LL | fn elision(_: fn() -> &i32) { - | ^ expected lifetime parameter + | ^ help: consider giving it a 'static lifetime: `&'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error: aborting due to previous error diff --git a/src/test/ui/foreign-fn-return-lifetime.fixed b/src/test/ui/foreign-fn-return-lifetime.fixed new file mode 100644 index 00000000000..9fc35eae705 --- /dev/null +++ b/src/test/ui/foreign-fn-return-lifetime.fixed @@ -0,0 +1,18 @@ +// Copyright 2017 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// run-rustfix + +extern "C" { + pub fn g(_: &u8) -> &u8; // OK + pub fn f() -> &'static u8; //~ ERROR missing lifetime specifier +} + +fn main() {} diff --git a/src/test/ui/foreign-fn-return-lifetime.rs b/src/test/ui/foreign-fn-return-lifetime.rs index da77066150c..941e7e05a36 100644 --- a/src/test/ui/foreign-fn-return-lifetime.rs +++ b/src/test/ui/foreign-fn-return-lifetime.rs @@ -8,9 +8,11 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. +// run-rustfix + extern "C" { - fn g(_: &u8) -> &u8; // OK - fn f() -> &u8; //~ ERROR missing lifetime specifier + pub fn g(_: &u8) -> &u8; // OK + pub fn f() -> &u8; //~ ERROR missing lifetime specifier } fn main() {} diff --git a/src/test/ui/foreign-fn-return-lifetime.stderr b/src/test/ui/foreign-fn-return-lifetime.stderr index ea15897b3d6..583487656f2 100644 --- a/src/test/ui/foreign-fn-return-lifetime.stderr +++ b/src/test/ui/foreign-fn-return-lifetime.stderr @@ -1,11 +1,10 @@ error[E0106]: missing lifetime specifier - --> $DIR/foreign-fn-return-lifetime.rs:13:15 + --> $DIR/foreign-fn-return-lifetime.rs:15:19 | -LL | fn f() -> &u8; //~ ERROR missing lifetime specifier - | ^ expected lifetime parameter +LL | pub fn f() -> &u8; //~ ERROR missing lifetime specifier + | ^ help: consider giving it a 'static lifetime: `&'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error: aborting due to previous error diff --git a/src/test/ui/issues/issue-13497.stderr b/src/test/ui/issues/issue-13497.stderr index ab6d041bd48..e592452b899 100644 --- a/src/test/ui/issues/issue-13497.stderr +++ b/src/test/ui/issues/issue-13497.stderr @@ -2,10 +2,9 @@ error[E0106]: missing lifetime specifier --> $DIR/issue-13497.rs:12:5 | LL | &str //~ ERROR missing lifetime specifier - | ^ expected lifetime parameter + | ^ help: consider giving it a 'static lifetime: `&'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error: aborting due to previous error diff --git a/src/test/ui/issues/issue-26638.stderr b/src/test/ui/issues/issue-26638.stderr index cf6fcd9f01c..0ac6316f0dc 100644 --- a/src/test/ui/issues/issue-26638.stderr +++ b/src/test/ui/issues/issue-26638.stderr @@ -10,19 +10,17 @@ error[E0106]: missing lifetime specifier --> $DIR/issue-26638.rs:14:40 | LL | fn parse_type_2(iter: fn(&u8)->&u8) -> &str { iter() } - | ^ expected lifetime parameter + | ^ help: consider giving it an explicit bounded or 'static lifetime: `&'static` | = 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 giving it an explicit bounded or 'static lifetime error[E0106]: missing lifetime specifier --> $DIR/issue-26638.rs:17:22 | LL | fn parse_type_3() -> &str { unimplemented!() } - | ^ expected lifetime parameter + | ^ help: consider giving it a 'static lifetime: `&'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error: aborting due to 3 previous errors diff --git a/src/test/ui/lifetimes/lifetime-elision-return-type-requires-explicit-lifetime.stderr b/src/test/ui/lifetimes/lifetime-elision-return-type-requires-explicit-lifetime.stderr index 30cff86ed1d..4c7a1b5ea9f 100644 --- a/src/test/ui/lifetimes/lifetime-elision-return-type-requires-explicit-lifetime.stderr +++ b/src/test/ui/lifetimes/lifetime-elision-return-type-requires-explicit-lifetime.stderr @@ -2,10 +2,9 @@ error[E0106]: missing lifetime specifier --> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:12:11 | LL | fn f() -> &isize { //~ ERROR missing lifetime specifier - | ^ expected lifetime parameter + | ^ help: consider giving it a 'static lifetime: `&'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error[E0106]: missing lifetime specifier --> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:17:33 @@ -27,28 +26,25 @@ error[E0106]: missing lifetime specifier --> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:31:20 | LL | fn i(_x: isize) -> &isize { //~ ERROR missing lifetime specifier - | ^ expected lifetime parameter + | ^ help: consider giving it an explicit bounded or 'static lifetime: `&'static` | = 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 giving it an explicit bounded or 'static lifetime error[E0106]: missing lifetime specifier --> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:44:24 | LL | fn j(_x: StaticStr) -> &isize { //~ ERROR missing lifetime specifier - | ^ expected lifetime parameter + | ^ help: consider giving it an explicit bounded or 'static lifetime: `&'static` | = 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 giving it an explicit bounded or 'static lifetime error[E0106]: missing lifetime specifier --> $DIR/lifetime-elision-return-type-requires-explicit-lifetime.rs:50:49 | LL | fn k<'a, T: WithLifetime<'a>>(_x: T::Output) -> &isize { - | ^ expected lifetime parameter + | ^ help: consider giving it an explicit bounded or 'static lifetime: `&'static` | = 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 giving it an explicit bounded or 'static lifetime error: aborting due to 6 previous errors diff --git a/src/test/ui/lifetimes/lifetime-elision-return-type-trait.rs b/src/test/ui/lifetimes/lifetime-elision-return-type-trait.rs new file mode 100644 index 00000000000..eb959bfbcb5 --- /dev/null +++ b/src/test/ui/lifetimes/lifetime-elision-return-type-trait.rs @@ -0,0 +1,12 @@ +trait Future { + type Item; + type Error; +} + +use std::error::Error; + +fn foo() -> impl Future> { + Ok(()) +} + +fn main() {} diff --git a/src/test/ui/lifetimes/lifetime-elision-return-type-trait.stderr b/src/test/ui/lifetimes/lifetime-elision-return-type-trait.stderr new file mode 100644 index 00000000000..b2a3d9a9436 --- /dev/null +++ b/src/test/ui/lifetimes/lifetime-elision-return-type-trait.stderr @@ -0,0 +1,11 @@ +error[E0106]: missing lifetime specifier + --> $DIR/lifetime-elision-return-type-trait.rs:8:44 + | +LL | fn foo() -> impl Future> { + | ^^^^^ help: consider giving it a 'static lifetime: `Error + 'static` + | + = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0106`. diff --git a/src/test/ui/underscore-lifetime/underscore-lifetime-binders.stderr b/src/test/ui/underscore-lifetime/underscore-lifetime-binders.stderr index bccecd60e1c..e56d008d266 100644 --- a/src/test/ui/underscore-lifetime/underscore-lifetime-binders.stderr +++ b/src/test/ui/underscore-lifetime/underscore-lifetime-binders.stderr @@ -20,10 +20,9 @@ error[E0106]: missing lifetime specifier --> $DIR/underscore-lifetime-binders.rs:20:29 | LL | fn meh() -> Box Meh<'_>> //~ ERROR cannot be used here - | ^^ expected lifetime parameter + | ^^ help: consider giving it a 'static lifetime: `'static` | = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from - = help: consider giving it a 'static lifetime error[E0106]: missing lifetime specifier --> $DIR/underscore-lifetime-binders.rs:26:35