From 0588bcadf81ef7ac88914c0f8dd2bbfbb164f09c Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Fri, 11 May 2018 09:14:23 -0700 Subject: [PATCH] rustc: Allow an edition's feature on that edition This commit fixes a hard error where the `#![feature(rust_2018_preview)]` feature was forbidden to be mentioned when the `--edition 2018` flag was passed. This instead silently accepts that feature gate despite it not being necessary. It's intended that this will help ease the transition into the 2018 edition as users will, for the time being, start off with the `rust_2018_preview` feature and no longer immediately need to remove it. Closes #50662 --- src/libsyntax/feature_gate.rs | 87 +++++++++++---------- src/test/compile-fail/edition-feature-ok.rs | 16 ++++ 2 files changed, 62 insertions(+), 41 deletions(-) create mode 100644 src/test/compile-fail/edition-feature-ok.rs diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index a137faf689fb7..b27568a61f85c 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -1861,56 +1861,61 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute], continue } - match attr.meta_item_list() { + let list = match attr.meta_item_list() { + Some(list) => list, None => { span_err!(span_handler, attr.span, E0555, "malformed feature attribute, expected #![feature(...)]"); + continue + } + }; + + for mi in list { + let name = if let Some(word) = mi.word() { + word.name() + } else { + span_err!(span_handler, mi.span, E0556, + "malformed feature, expected just one word"); + continue + }; + + if let Some((.., set)) = ACTIVE_FEATURES.iter().find(|f| name == f.0) { + set(&mut features, mi.span); + feature_checker.collect(&features, mi.span); + continue } - Some(list) => { - for mi in list { - let name = if let Some(word) = mi.word() { - word.name() - } else { - span_err!(span_handler, mi.span, E0556, - "malformed feature, expected just one word"); - continue - }; - - if let Some(&(_, _, _, _, set)) = ACTIVE_FEATURES.iter() - .find(|& &(n, ..)| name == n) { - set(&mut features, mi.span); - feature_checker.collect(&features, mi.span); - } - else if let Some(&(.., reason)) = REMOVED_FEATURES.iter() - .find(|& &(n, ..)| name == n) - .or_else(|| STABLE_REMOVED_FEATURES.iter() - .find(|& &(n, ..)| name == n)) { - feature_removed(span_handler, mi.span, reason); - } - else if let Some(&(..)) = ACCEPTED_FEATURES.iter() - .find(|& &(n, ..)| name == n) { - features.declared_stable_lang_features.push((name, mi.span)); - } else if let Some(&edition) = ALL_EDITIONS.iter() - .find(|e| name == e.feature_name()) { - if edition <= crate_edition { - feature_removed(span_handler, mi.span, None); - } else { - for &(.., f_edition, set) in ACTIVE_FEATURES.iter() { - if let Some(f_edition) = f_edition { - if edition >= f_edition { - // FIXME(Manishearth) there is currently no way to set - // lib features by edition - set(&mut features, DUMMY_SP); - } - } - } + let removed = REMOVED_FEATURES.iter().find(|f| name == f.0); + let stable_removed = STABLE_REMOVED_FEATURES.iter().find(|f| name == f.0); + if let Some((.., reason)) = removed.or(stable_removed) { + feature_removed(span_handler, mi.span, *reason); + continue + } + + if ACCEPTED_FEATURES.iter().any(|f| name == f.0) { + features.declared_stable_lang_features.push((name, mi.span)); + continue + } + + if let Some(edition) = ALL_EDITIONS.iter().find(|e| name == e.feature_name()) { + if *edition <= crate_edition { + continue + } + + for &(.., f_edition, set) in ACTIVE_FEATURES.iter() { + if let Some(f_edition) = f_edition { + if *edition >= f_edition { + // FIXME(Manishearth) there is currently no way to set + // lib features by edition + set(&mut features, DUMMY_SP); } - } else { - features.declared_lib_features.push((name, mi.span)); } } + + continue } + + features.declared_lib_features.push((name, mi.span)); } } diff --git a/src/test/compile-fail/edition-feature-ok.rs b/src/test/compile-fail/edition-feature-ok.rs new file mode 100644 index 0000000000000..3a3a6ff95f97e --- /dev/null +++ b/src/test/compile-fail/edition-feature-ok.rs @@ -0,0 +1,16 @@ +// Copyright 2018 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. + +// compile-flags:--edition 2018 +// compile-pass + +#![feature(rust_2018_preview)] + +fn main() {}