Auto merge of #36316 - jseyfried:custom_derive_internal_unstable, r=eddyb

Avoid instaiblity errors in code generated by `syntax_ext::deriving::call_intrinsic()`

r? @eddyb
This commit is contained in:
bors 2016-09-08 01:44:51 -07:00 committed by GitHub
commit 0b02ae02bb
3 changed files with 113 additions and 1 deletions

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@ -338,10 +338,19 @@ fn hygienic_type_parameter(item: &Annotatable, base: &str) -> String {
/// Constructs an expression that calls an intrinsic
fn call_intrinsic(cx: &ExtCtxt,
span: Span,
mut span: Span,
intrinsic: &str,
args: Vec<P<ast::Expr>>)
-> P<ast::Expr> {
span.expn_id = cx.codemap().record_expansion(codemap::ExpnInfo {
call_site: span,
callee: codemap::NameAndSpan {
format: codemap::MacroAttribute(intern("derive")),
span: Some(span),
allow_internal_unstable: true,
},
});
let path = cx.std_path(&["intrinsics", intrinsic]);
let call = cx.expr_call_global(span, path, args);

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@ -0,0 +1,81 @@
// 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, item_like_imports)]
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::parse::token::{intern, InternedString};
use syntax::ptr::P;
#[plugin_registrar]
pub fn plugin_registrar(reg: &mut Registry) {
reg.register_syntax_extension(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, InternedString::new("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()),
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!["std", "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)
}

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@ -0,0 +1,22 @@
// 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.
// aux-build:custom_derive_partial_eq.rs
// ignore-stage1
// ignore-pretty : (#23623) problems when ending with // comments
#![feature(plugin, custom_derive)]
#![plugin(custom_derive_partial_eq)]
#![allow(unused)]
#[derive(CustomPartialEq)] // Check that this is not a stability error.
enum E { V1, V2 }
fn main() {}