From 94c9ea4baee98c1d6579865d0e0d78a45927aa83 Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Thu, 12 Jul 2018 14:04:24 -0700 Subject: [PATCH] rustc: Tweak expansion of #[proc_macro] for 2018 The syntactical expansion of `#[proc_macro]` and related attributes currently contains absolute paths which conflicts with a lint for the 2018 edition, causing issues like #52214. This commit puts a band-aid on the issue by ensuring that procedural macros can also migrate to the 2018 edition for now by tweaking the expansion based on what features are activated. A more long-term solution would probably tweak the edition hygiene of spans, but this should do the trick for now. Closes #52214 --- src/libsyntax_ext/proc_macro_registrar.rs | 11 ++++++--- .../rust-2018/proc-macro-crate-in-paths.rs | 24 +++++++++++++++++++ 2 files changed, 32 insertions(+), 3 deletions(-) create mode 100644 src/test/ui-fulldeps/rust-2018/proc-macro-crate-in-paths.rs diff --git a/src/libsyntax_ext/proc_macro_registrar.rs b/src/libsyntax_ext/proc_macro_registrar.rs index 85aa84acc4221..07852e5714b87 100644 --- a/src/libsyntax_ext/proc_macro_registrar.rs +++ b/src/libsyntax_ext/proc_macro_registrar.rs @@ -23,6 +23,7 @@ use syntax::fold::Folder; use syntax::parse::ParseSess; use syntax::ptr::P; use syntax::symbol::Symbol; +use syntax::symbol::keywords; use syntax::visit::{self, Visitor}; use syntax_pos::{Span, DUMMY_SP}; @@ -385,9 +386,13 @@ fn mk_registrar(cx: &mut ExtCtxt, let register_custom_derive = Ident::from_str("register_custom_derive"); let register_attr_proc_macro = Ident::from_str("register_attr_proc_macro"); let register_bang_proc_macro = Ident::from_str("register_bang_proc_macro"); + let crate_kw = Ident::with_empty_ctxt(keywords::Crate.name()); + let local_path = |cx: &mut ExtCtxt, sp: Span, name: Ident| { + cx.path(sp.with_ctxt(span.ctxt()), vec![crate_kw, name]) + }; let mut stmts = custom_derives.iter().map(|cd| { - let path = cx.path_global(cd.span, vec![cd.function_name]); + let path = local_path(cx, cd.span, cd.function_name); let trait_name = cx.expr_str(cd.span, cd.trait_name); let attrs = cx.expr_vec_slice( span, @@ -404,7 +409,7 @@ fn mk_registrar(cx: &mut ExtCtxt, stmts.extend(custom_attrs.iter().map(|ca| { let name = cx.expr_str(ca.span, ca.function_name.name); - let path = cx.path_global(ca.span, vec![ca.function_name]); + let path = local_path(cx, ca.span, ca.function_name); let registrar = cx.expr_ident(ca.span, registrar); let ufcs_path = cx.path(span, @@ -416,7 +421,7 @@ fn mk_registrar(cx: &mut ExtCtxt, stmts.extend(custom_macros.iter().map(|cm| { let name = cx.expr_str(cm.span, cm.function_name.name); - let path = cx.path_global(cm.span, vec![cm.function_name]); + let path = local_path(cx, cm.span, cm.function_name); let registrar = cx.expr_ident(cm.span, registrar); let ufcs_path = cx.path(span, diff --git a/src/test/ui-fulldeps/rust-2018/proc-macro-crate-in-paths.rs b/src/test/ui-fulldeps/rust-2018/proc-macro-crate-in-paths.rs new file mode 100644 index 0000000000000..1068c05874589 --- /dev/null +++ b/src/test/ui-fulldeps/rust-2018/proc-macro-crate-in-paths.rs @@ -0,0 +1,24 @@ +// 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-pass + +#![crate_type = "proc-macro"] +#![deny(rust_2018_compatibility)] +#![feature(rust_2018_preview)] + +extern crate proc_macro; + +use proc_macro::TokenStream; + +#[proc_macro_derive(Template, attributes(template))] +pub fn derive_template(input: TokenStream) -> TokenStream { + input +}