| // Copyright 2012-2014 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Support for parsing unsupported, old syntaxes, for the purpose of reporting errors. Parsing of |
| //! these syntaxes is tested by compile-test/obsolete-syntax.rs. |
| //! |
| //! Obsolete syntax that becomes too hard to parse can be removed. |
| |
| use syntax_pos::Span; |
| use parse::parser; |
| |
| /// The specific types of unsupported syntax |
| #[derive(Copy, Clone, PartialEq, Eq, Hash)] |
| pub enum ObsoleteSyntax { |
| ClosureKind, |
| ExternCrateString, |
| } |
| |
| pub trait ParserObsoleteMethods { |
| /// Reports an obsolete syntax non-fatal error. |
| fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax); |
| fn report(&mut self, |
| sp: Span, |
| kind: ObsoleteSyntax, |
| kind_str: &str, |
| desc: &str, |
| error: bool); |
| } |
| |
| impl<'a> ParserObsoleteMethods for parser::Parser<'a> { |
| /// Reports an obsolete syntax non-fatal error. |
| fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax) { |
| let (kind_str, desc, error) = match kind { |
| ObsoleteSyntax::ClosureKind => ( |
| "`:`, `&mut:`, or `&:`", |
| "rely on inference instead", |
| true, |
| ), |
| ObsoleteSyntax::ExternCrateString => ( |
| "\"crate-name\"", |
| "use an identifier not in quotes instead", |
| false, // warning for now |
| ), |
| }; |
| |
| self.report(sp, kind, kind_str, desc, error); |
| } |
| |
| fn report(&mut self, |
| sp: Span, |
| kind: ObsoleteSyntax, |
| kind_str: &str, |
| desc: &str, |
| error: bool) { |
| let mut err = if error { |
| self.diagnostic().struct_span_err(sp, &format!("obsolete syntax: {}", kind_str)) |
| } else { |
| self.diagnostic().struct_span_warn(sp, &format!("obsolete syntax: {}", kind_str)) |
| }; |
| |
| if !self.obsolete_set.contains(&kind) && |
| (error || self.sess.span_diagnostic.can_emit_warnings) { |
| err.note(&format!("{}", desc)); |
| self.obsolete_set.insert(kind); |
| } |
| err.emit(); |
| } |
| } |