From 3a9b7be10b8e32d014008f9fde276cd032aa4e4a Mon Sep 17 00:00:00 2001 From: "Felix S. Klock II" Date: Mon, 11 Jul 2016 18:29:45 +0200 Subject: [PATCH] Added tests and fixed corner case for trailing attributes with no attached binding in generics. --- src/libsyntax/parse/parser.rs | 17 +++++++++++- .../attrs-with-no-formal-in-generics-1.rs | 26 +++++++++++++++++++ .../attrs-with-no-formal-in-generics-2.rs | 26 +++++++++++++++++++ .../attrs-with-no-formal-in-generics-3.rs | 26 +++++++++++++++++++ 4 files changed, 94 insertions(+), 1 deletion(-) create mode 100644 src/test/compile-fail/attrs-with-no-formal-in-generics-1.rs create mode 100644 src/test/compile-fail/attrs-with-no-formal-in-generics-2.rs create mode 100644 src/test/compile-fail/attrs-with-no-formal-in-generics-3.rs diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index fe5ff5c47b248..3c561780085b8 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -1958,7 +1958,7 @@ impl<'a> Parser<'a> { assert!(recv.is_empty()); *recv = attrs; } else { - let msg = "encountered trailing attributes after lifetime parameters"; + let msg = "trailing attribute after lifetime parameters"; return Err(self.fatal(msg)); } debug!("parse_lifetime_defs ret {:?}", res); @@ -4294,12 +4294,21 @@ impl<'a> Parser<'a> { let span_lo = self.span.lo; if self.eat(&token::Lt) { + // Upon encountering attribute in generics list, we do not + // know if it is attached to lifetime or to type param. + // + // Solution: 1. eagerly parse attributes in tandem with + // lifetime defs, 2. store last set of parsed (and unused) + // attributes in `attrs`, and 3. pass in those attributes + // when parsing formal type param after lifetime defs. let mut attrs = vec![]; let lifetime_defs = self.parse_lifetime_defs(Some(&mut attrs))?; let mut seen_default = false; let mut post_lifetime_attrs = Some(attrs); let ty_params = self.parse_seq_to_gt(Some(token::Comma), |p| { p.forbid_lifetime()?; + // Move out of `post_lifetime_attrs` if present. O/w + // not first type param: parse attributes anew. let attrs = match post_lifetime_attrs.as_mut() { None => p.parse_outer_attributes()?, Some(attrs) => mem::replace(attrs, vec![]), @@ -4315,6 +4324,12 @@ impl<'a> Parser<'a> { } Ok(ty_param) })?; + if let Some(attrs) = post_lifetime_attrs { + if !attrs.is_empty() { + self.span_err(attrs[0].span, + "trailing attribute after lifetime parameters"); + } + } Ok(ast::Generics { lifetimes: lifetime_defs, ty_params: ty_params, diff --git a/src/test/compile-fail/attrs-with-no-formal-in-generics-1.rs b/src/test/compile-fail/attrs-with-no-formal-in-generics-1.rs new file mode 100644 index 0000000000000..53e287cda208a --- /dev/null +++ b/src/test/compile-fail/attrs-with-no-formal-in-generics-1.rs @@ -0,0 +1,26 @@ +// Copyright 2016 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. + +// This test checks variations on `<#[attr] 'a, #[oops]>`, where +// `#[oops]` is left dangling (that is, it is unattached, with no +// formal binding following it). + +#![feature(generic_param_attrs, rustc_attrs)] +#![allow(dead_code)] + +struct RefIntPair<'a, 'b>(&'a u32, &'b u32); + +impl<#[rustc_1] 'a, 'b, #[oops]> RefIntPair<'a, 'b> { + //~^ ERROR trailing attribute after lifetime parameters +} + +fn main() { + +} diff --git a/src/test/compile-fail/attrs-with-no-formal-in-generics-2.rs b/src/test/compile-fail/attrs-with-no-formal-in-generics-2.rs new file mode 100644 index 0000000000000..a38a7bfb93785 --- /dev/null +++ b/src/test/compile-fail/attrs-with-no-formal-in-generics-2.rs @@ -0,0 +1,26 @@ +// Copyright 2016 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. + +// This test checks variations on `<#[attr] 'a, #[oops]>`, where +// `#[oops]` is left dangling (that is, it is unattached, with no +// formal binding following it). + +#![feature(generic_param_attrs, rustc_attrs)] +#![allow(dead_code)] + +struct RefAny<'a, T>(&'a T); + +impl<#[rustc_1] 'a, #[rustc_2] T, #[oops]> RefAny<'a, T> { + //~^ ERROR expected identifier, found `>` +} + +fn main() { + +} diff --git a/src/test/compile-fail/attrs-with-no-formal-in-generics-3.rs b/src/test/compile-fail/attrs-with-no-formal-in-generics-3.rs new file mode 100644 index 0000000000000..e7d5b94d24226 --- /dev/null +++ b/src/test/compile-fail/attrs-with-no-formal-in-generics-3.rs @@ -0,0 +1,26 @@ +// Copyright 2016 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. + +// This test checks variations on `<#[attr] 'a, #[oops]>`, where +// `#[oops]` is left dangling (that is, it is unattached, with no +// formal binding following it). + +struct RefIntPair<'a, 'b>(&'a u32, &'b u32); + +fn hof_lt(_: Q) + where Q: for <#[rustc_1] 'a, 'b, #[oops]> Fn(RefIntPair<'a,'b>) -> &'b u32 + //~^ ERROR trailing attribute after lifetime parameters +{ + +} + +fn main() { + +}