From d349e87d61745d402f6e38727beb62a6525a2153 Mon Sep 17 00:00:00 2001 From: Vadim Petrochenkov Date: Wed, 22 Feb 2017 23:59:40 +0300 Subject: [PATCH] Parse trait object types starting with a lifetime bound --- src/libsyntax/parse/parser.rs | 4 +-- .../trait-object-macro-matcher.rs | 2 ++ .../trait-object-vs-lifetime-2.rs | 23 +++++++++++++++ .../compile-fail/trait-object-vs-lifetime.rs | 29 +++++++++++++++++++ .../run-pass/trait-object-lifetime-first.rs | 22 ++++++++++++++ 5 files changed, 78 insertions(+), 2 deletions(-) create mode 100644 src/test/compile-fail/trait-object-vs-lifetime-2.rs create mode 100644 src/test/compile-fail/trait-object-vs-lifetime.rs create mode 100644 src/test/run-pass/trait-object-lifetime-first.rs diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 1baf0d1b54c..c7f4512301c 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -1451,9 +1451,9 @@ impl<'a> Parser<'a> { } else if self.eat_keyword(keywords::Impl) { // FIXME: figure out priority of `+` in `impl Trait1 + Trait2` (#34511). TyKind::ImplTrait(self.parse_ty_param_bounds()?) - } else if self.check(&token::Question) { + } else if self.check(&token::Question) || + self.check_lifetime() && self.look_ahead(1, |t| t == &token::BinOp(token::Plus)){ // Bound list (trait object type) - // Bound lists starting with `'lt` are not currently supported (#40043) TyKind::TraitObject(self.parse_ty_param_bounds_common(allow_plus)?) } else { let msg = format!("expected type, found {}", self.this_token_descr()); diff --git a/src/test/compile-fail/trait-object-macro-matcher.rs b/src/test/compile-fail/trait-object-macro-matcher.rs index de80b04b865..8497a699e97 100644 --- a/src/test/compile-fail/trait-object-macro-matcher.rs +++ b/src/test/compile-fail/trait-object-macro-matcher.rs @@ -16,4 +16,6 @@ macro_rules! m { fn main() { m!(Copy + Send + 'static); //~ ERROR the trait `std::marker::Copy` cannot be made into an object + m!('static + Send); + m!('static +); //~ ERROR at least one non-builtin trait is required for an object type } diff --git a/src/test/compile-fail/trait-object-vs-lifetime-2.rs b/src/test/compile-fail/trait-object-vs-lifetime-2.rs new file mode 100644 index 00000000000..9801cac4714 --- /dev/null +++ b/src/test/compile-fail/trait-object-vs-lifetime-2.rs @@ -0,0 +1,23 @@ +// 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. + +// A few contrived examples where lifetime should (or should not) be parsed as an object type. +// Lifetimes parsed as types are still rejected later by semantic checks. + +// compile-flags: -Z continue-parse-after-error + +// `'static` is a lifetime, `'static +` is a type, `'a` is a type +fn g() where + 'static: 'static, + 'static +: 'static + Copy, + //~^ ERROR at least one non-builtin trait is required for an object type +{} + +fn main() {} diff --git a/src/test/compile-fail/trait-object-vs-lifetime.rs b/src/test/compile-fail/trait-object-vs-lifetime.rs new file mode 100644 index 00000000000..a70141edc29 --- /dev/null +++ b/src/test/compile-fail/trait-object-vs-lifetime.rs @@ -0,0 +1,29 @@ +// 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. + +// A few contrived examples where lifetime should (or should not) be parsed as an object type. +// Lifetimes parsed as types are still rejected later by semantic checks. + +// compile-flags: -Z continue-parse-after-error + +struct S<'a, T>(&'a u8, T); + +fn main() { + // `'static` is a lifetime argument, `'static +` is a type argument + let _: S<'static, u8>; + let _: S<'static, 'static +>; + //~^ at least one non-builtin trait is required for an object type + let _: S<'static, 'static>; + //~^ ERROR wrong number of lifetime parameters: expected 1, found 2 + //~| ERROR wrong number of type arguments: expected 1, found 0 + let _: S<'static +, 'static>; + //~^ ERROR lifetime parameters must be declared prior to type parameters + //~| ERROR at least one non-builtin trait is required for an object type +} diff --git a/src/test/run-pass/trait-object-lifetime-first.rs b/src/test/run-pass/trait-object-lifetime-first.rs new file mode 100644 index 00000000000..f269fe90d4b --- /dev/null +++ b/src/test/run-pass/trait-object-lifetime-first.rs @@ -0,0 +1,22 @@ +// 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. + +use std::fmt::Display; + +static BYTE: u8 = 33; + +fn main() { + let x: &('static + Display) = &BYTE; + let y: Box<'static + Display> = Box::new(BYTE); + let xstr = format!("{}", x); + let ystr = format!("{}", y); + assert_eq!(xstr, "33"); + assert_eq!(ystr, "33"); +}