| // 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 <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. |
| |
| // force-host |
| |
| #![feature(plugin_registrar, rustc_private)] |
| |
| extern crate syntax; |
| extern crate syntax_ext; |
| extern crate rustc_plugin; |
| |
| use syntax_ext::deriving; |
| use deriving::generic::*; |
| use deriving::generic::ty::*; |
| |
| use rustc_plugin::Registry; |
| use syntax::ast::*; |
| use syntax::codemap::Span; |
| use syntax::ext::base::*; |
| use syntax::ext::build::AstBuilder; |
| use syntax::symbol::Symbol; |
| use syntax::ptr::P; |
| |
| #[plugin_registrar] |
| pub fn plugin_registrar(reg: &mut Registry) { |
| reg.register_syntax_extension(Symbol::intern("derive_CustomPartialEq"), |
| MultiDecorator(Box::new(expand_deriving_partial_eq))); |
| } |
| |
| fn expand_deriving_partial_eq(cx: &mut ExtCtxt, span: Span, mitem: &MetaItem, item: &Annotatable, |
| push: &mut FnMut(Annotatable)) { |
| // structures are equal if all fields are equal, and non equal, if |
| // any fields are not equal or if the enum variants are different |
| fn cs_eq(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> P<Expr> { |
| cs_fold(true, |
| |cx, span, subexpr, self_f, other_fs| { |
| let other_f = (other_fs.len(), other_fs.get(0)).1.unwrap(); |
| let eq = cx.expr_binary(span, BinOpKind::Eq, self_f, other_f.clone()); |
| cx.expr_binary(span, BinOpKind::And, subexpr, eq) |
| }, |
| cx.expr_bool(span, true), |
| Box::new(|cx, span, _, _| cx.expr_bool(span, false)), |
| cx, |
| span, |
| substr) |
| } |
| |
| let inline = cx.meta_word(span, Symbol::intern("inline")); |
| let attrs = vec![cx.attribute(span, inline)]; |
| let methods = vec![MethodDef { |
| name: "eq", |
| generics: LifetimeBounds::empty(), |
| explicit_self: borrowed_explicit_self(), |
| args: vec![(borrowed_self(), "other")], |
| ret_ty: Literal(deriving::generic::ty::Path::new_local("bool")), |
| attributes: attrs, |
| is_unsafe: false, |
| unify_fieldless_variants: true, |
| combine_substructure: combine_substructure(Box::new(cs_eq)), |
| }]; |
| |
| let trait_def = TraitDef { |
| span: span, |
| attributes: Vec::new(), |
| path: deriving::generic::ty::Path::new(vec!["cmp", "PartialEq"]), |
| additional_bounds: Vec::new(), |
| generics: LifetimeBounds::empty(), |
| is_unsafe: false, |
| supports_unions: false, |
| methods: methods, |
| associated_types: Vec::new(), |
| }; |
| trait_def.expand(cx, mitem, item, push) |
| } |