diff --git a/src/doc/unstable-book/src/SUMMARY.md b/src/doc/unstable-book/src/SUMMARY.md index a9796fdf01e0d..42af79b8bb07f 100644 --- a/src/doc/unstable-book/src/SUMMARY.md +++ b/src/doc/unstable-book/src/SUMMARY.md @@ -114,6 +114,7 @@ - [lookup_host](lookup-host.md) - [loop_break_value](loop-break-value.md) - [macro_reexport](macro-reexport.md) +- [macro_vis_matcher](macro-vis-matcher.md) - [main](main.md) - [manually_drop](manually-drop.md) - [map_entry_recover_keys](map-entry-recover-keys.md) diff --git a/src/doc/unstable-book/src/macro-vis-matcher.md b/src/doc/unstable-book/src/macro-vis-matcher.md new file mode 100644 index 0000000000000..7918a35684329 --- /dev/null +++ b/src/doc/unstable-book/src/macro-vis-matcher.md @@ -0,0 +1,14 @@ +# `macro_vis_matcher` + +The tracking issue for this feature is: [#41022] + +With this feature gate enabled, the [list of fragment specifiers][frags] gains one more entry: + +* `vis`: a visibility qualifier. Examples: nothing (default visibility); `pub`; `pub(crate)`. + +A `vis` variable may be followed by a comma, ident, type, or path. + +[#41022]: https://github.com/rust-lang/rust/issues/41022 +[frags]: ../book/first-edition/macros.html#syntactic-requirements + +------------------------ diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs index 80f853778c744..c797c151de67c 100644 --- a/src/librustc_resolve/build_reduced_graph.rs +++ b/src/librustc_resolve/build_reduced_graph.rs @@ -521,7 +521,9 @@ impl<'a> Resolver<'a> { LoadedMacro::ProcMacro(ext) => return ext, }; - let ext = Rc::new(macro_rules::compile(&self.session.parse_sess, ¯o_def)); + let ext = Rc::new(macro_rules::compile(&self.session.parse_sess, + &self.session.features, + ¯o_def)); self.macro_map.insert(def_id, ext.clone()); ext } diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs index 966cb7ee8d8d8..030e3936de994 100644 --- a/src/librustc_resolve/macros.rs +++ b/src/librustc_resolve/macros.rs @@ -671,7 +671,9 @@ impl<'a> Resolver<'a> { } let def_id = self.definitions.local_def_id(item.id); - let ext = Rc::new(macro_rules::compile(&self.session.parse_sess, item)); + let ext = Rc::new(macro_rules::compile(&self.session.parse_sess, + &self.session.features, + item)); self.macro_map.insert(def_id, ext); *legacy_scope = LegacyScope::Binding(self.arenas.alloc_legacy_binding(LegacyBinding { parent: Cell::new(*legacy_scope), name: ident.name, def_id: def_id, span: item.span, diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs index 6cd1fea2e75e2..eb0b7c29f8d9a 100644 --- a/src/libsyntax/ext/tt/macro_parser.rs +++ b/src/libsyntax/ext/tt/macro_parser.rs @@ -529,6 +529,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal { token::NtPath(panictry!(p.parse_path(PathStyle::Type))) }, "meta" => token::NtMeta(panictry!(p.parse_meta_item())), + "vis" => token::NtVis(panictry!(p.parse_visibility(true))), // this is not supposed to happen, since it has been checked // when compiling the macro. _ => p.span_bug(sp, "invalid fragment specifier") diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs index 93348c8f08376..be979960725a9 100644 --- a/src/libsyntax/ext/tt/macro_rules.rs +++ b/src/libsyntax/ext/tt/macro_rules.rs @@ -18,6 +18,7 @@ use ext::tt::macro_parser::{MatchedSeq, MatchedNonterminal}; use ext::tt::macro_parser::{parse, parse_failure_msg}; use ext::tt::quoted; use ext::tt::transcribe::transcribe; +use feature_gate::{self, emit_feature_err, Features, GateIssue}; use parse::{Directory, ParseSess}; use parse::parser::Parser; use parse::token::{self, NtTT}; @@ -25,6 +26,7 @@ use parse::token::Token::*; use symbol::Symbol; use tokenstream::{TokenStream, TokenTree}; +use std::cell::RefCell; use std::collections::{HashMap}; use std::collections::hash_map::{Entry}; use std::rc::Rc; @@ -154,7 +156,7 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt, // Holy self-referential! /// Converts a `macro_rules!` invocation into a syntax extension. -pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension { +pub fn compile(sess: &ParseSess, features: &RefCell, def: &ast::Item) -> SyntaxExtension { let lhs_nm = ast::Ident::with_empty_ctxt(Symbol::gensym("lhs")); let rhs_nm = ast::Ident::with_empty_ctxt(Symbol::gensym("rhs")); @@ -208,7 +210,7 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension { if let MatchedNonterminal(ref nt) = **m { if let NtTT(ref tt) = **nt { let tt = quoted::parse(tt.clone().into(), true, sess).pop().unwrap(); - valid &= check_lhs_nt_follows(sess, &tt); + valid &= check_lhs_nt_follows(sess, features, &tt); return tt; } } @@ -251,11 +253,13 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension { NormalTT(exp, Some(def.span), attr::contains_name(&def.attrs, "allow_internal_unstable")) } -fn check_lhs_nt_follows(sess: &ParseSess, lhs: "ed::TokenTree) -> bool { +fn check_lhs_nt_follows(sess: &ParseSess, + features: &RefCell, + lhs: "ed::TokenTree) -> bool { // lhs is going to be like TokenTree::Delimited(...), where the // entire lhs is those tts. Or, it can be a "bare sequence", not wrapped in parens. match lhs { - "ed::TokenTree::Delimited(_, ref tts) => check_matcher(sess, &tts.tts), + "ed::TokenTree::Delimited(_, ref tts) => check_matcher(sess, features, &tts.tts), _ => { let msg = "invalid macro matcher; matchers must be contained in balanced delimiters"; sess.span_diagnostic.span_err(lhs.span(), msg); @@ -307,11 +311,13 @@ fn check_rhs(sess: &ParseSess, rhs: "ed::TokenTree) -> bool { false } -fn check_matcher(sess: &ParseSess, matcher: &[quoted::TokenTree]) -> bool { +fn check_matcher(sess: &ParseSess, + features: &RefCell, + matcher: &[quoted::TokenTree]) -> bool { let first_sets = FirstSets::new(matcher); let empty_suffix = TokenSet::empty(); let err = sess.span_diagnostic.err_count(); - check_matcher_core(sess, &first_sets, matcher, &empty_suffix); + check_matcher_core(sess, features, &first_sets, matcher, &empty_suffix); err == sess.span_diagnostic.err_count() } @@ -553,6 +559,7 @@ impl TokenSet { // Requires that `first_sets` is pre-computed for `matcher`; // see `FirstSets::new`. fn check_matcher_core(sess: &ParseSess, + features: &RefCell, first_sets: &FirstSets, matcher: &[quoted::TokenTree], follow: &TokenSet) -> TokenSet { @@ -583,12 +590,11 @@ fn check_matcher_core(sess: &ParseSess, match *token { TokenTree::Token(..) | TokenTree::MetaVarDecl(..) => { let can_be_followed_by_any; - if let Err(bad_frag) = has_legal_fragment_specifier(token) { + if let Err(bad_frag) = has_legal_fragment_specifier(sess, features, token) { let msg = format!("invalid fragment specifier `{}`", bad_frag); sess.span_diagnostic.struct_span_err(token.span(), &msg) - .help("valid fragment specifiers are `ident`, `block`, \ - `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \ - and `item`") + .help("valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, \ + `pat`, `ty`, `path`, `meta`, `tt`, `item` and `vis`") .emit(); // (This eliminates false positives and duplicates // from error messages.) @@ -610,7 +616,7 @@ fn check_matcher_core(sess: &ParseSess, } TokenTree::Delimited(span, ref d) => { let my_suffix = TokenSet::singleton(d.close_tt(span)); - check_matcher_core(sess, first_sets, &d.tts, &my_suffix); + check_matcher_core(sess, features, first_sets, &d.tts, &my_suffix); // don't track non NT tokens last.replace_with_irrelevant(); @@ -642,7 +648,7 @@ fn check_matcher_core(sess: &ParseSess, // At this point, `suffix_first` is built, and // `my_suffix` is some TokenSet that we can use // for checking the interior of `seq_rep`. - let next = check_matcher_core(sess, first_sets, &seq_rep.tts, my_suffix); + let next = check_matcher_core(sess, features, first_sets, &seq_rep.tts, my_suffix); if next.maybe_empty { last.add_all(&next); } else { @@ -790,30 +796,61 @@ fn is_in_follow(tok: "ed::TokenTree, frag: &str) -> Result { + // Explicitly disallow `priv`, on the off chance it comes back. + match *tok { + TokenTree::Token(_, ref tok) => match *tok { + Comma => Ok(true), + Ident(i) if i.name != "priv" => Ok(true), + ref tok => Ok(tok.can_begin_type()) + }, + TokenTree::MetaVarDecl(_, _, frag) if frag.name == "ident" + || frag.name == "ty" + || frag.name == "path" => Ok(true), + _ => Ok(false) + } + }, "" => Ok(true), // keywords::Invalid _ => Err((format!("invalid fragment specifier `{}`", frag), "valid fragment specifiers are `ident`, `block`, \ - `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \ - and `item`")) + `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt`, \ + `item` and `vis`")) } } } -fn has_legal_fragment_specifier(tok: "ed::TokenTree) -> Result<(), String> { +fn has_legal_fragment_specifier(sess: &ParseSess, + features: &RefCell, + tok: "ed::TokenTree) -> Result<(), String> { debug!("has_legal_fragment_specifier({:?})", tok); - if let quoted::TokenTree::MetaVarDecl(_, _, frag_spec) = *tok { - let s = &frag_spec.name.as_str(); - if !is_legal_fragment_specifier(s) { - return Err(s.to_string()); + if let quoted::TokenTree::MetaVarDecl(_, _, ref frag_spec) = *tok { + let frag_name = frag_spec.name.as_str(); + let frag_span = tok.span(); + if !is_legal_fragment_specifier(sess, features, &frag_name, frag_span) { + return Err(frag_name.to_string()); } } Ok(()) } -fn is_legal_fragment_specifier(frag: &str) -> bool { - match frag { +fn is_legal_fragment_specifier(sess: &ParseSess, + features: &RefCell, + frag_name: &str, + frag_span: Span) -> bool { + match frag_name { "item" | "block" | "stmt" | "expr" | "pat" | "path" | "ty" | "ident" | "meta" | "tt" | "" => true, + "vis" => { + if !features.borrow().macro_vis_matcher { + let explain = feature_gate::EXPLAIN_VIS_MATCHER; + emit_feature_err(sess, + "macro_vis_matcher", + frag_span, + GateIssue::Language, + explain); + } + true + }, _ => false, } } diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index 6e455234196d4..129674b74769c 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -352,6 +352,9 @@ declare_features! ( // Allows overlapping impls of marker traits (active, overlapping_marker_traits, "1.18.0", Some(29864)), + + // Allows use of the :vis macro fragment specifier + (active, macro_vis_matcher, "1.18.0", Some(41022)), ); declare_features! ( @@ -1012,6 +1015,9 @@ pub const EXPLAIN_DEPR_CUSTOM_DERIVE: &'static str = pub const EXPLAIN_DERIVE_UNDERSCORE: &'static str = "attributes of the form `#[derive_*]` are reserved for the compiler"; +pub const EXPLAIN_VIS_MATCHER: &'static str = + ":vis fragment specifier is experimental and subject to change"; + pub const EXPLAIN_PLACEMENT_IN: &'static str = "placement-in expression syntax is experimental and subject to change."; diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs index a6ab8e10d9f91..f39399a62e856 100644 --- a/src/libsyntax/fold.rs +++ b/src/libsyntax/fold.rs @@ -636,6 +636,7 @@ pub fn noop_fold_interpolated(nt: token::Nonterminal, fld: &mut T) token::NtWhereClause(where_clause) => token::NtWhereClause(fld.fold_where_clause(where_clause)), token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)), + token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)), } } diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 3b928ea93c78a..31669e1bbe3a7 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -5056,7 +5056,9 @@ impl<'a> Parser<'a> { /// and `pub(super)` for `pub(in super)`. If the following element can't be a tuple (i.e. it's /// a function definition, it's not a tuple struct field) and the contents within the parens /// isn't valid, emit a proper diagnostic. - fn parse_visibility(&mut self, can_take_tuple: bool) -> PResult<'a, Visibility> { + pub fn parse_visibility(&mut self, can_take_tuple: bool) -> PResult<'a, Visibility> { + maybe_whole!(self, NtVis, |x| x); + if !self.eat_keyword(keywords::Pub) { return Ok(Visibility::Inherited) } diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs index 74aa3984a9a42..25cabef70c15b 100644 --- a/src/libsyntax/parse/token.rs +++ b/src/libsyntax/parse/token.rs @@ -363,6 +363,7 @@ pub enum Nonterminal { /// Stuff inside brackets for attributes NtMeta(ast::MetaItem), NtPath(ast::Path), + NtVis(ast::Visibility), NtTT(TokenTree), // These are not exposed to macros, but are used by quasiquote. NtArm(ast::Arm), @@ -392,6 +393,7 @@ impl fmt::Debug for Nonterminal { NtGenerics(..) => f.pad("NtGenerics(..)"), NtWhereClause(..) => f.pad("NtWhereClause(..)"), NtArg(..) => f.pad("NtArg(..)"), + NtVis(..) => f.pad("NtVis(..)"), } } } diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs index 433ba3d3693f1..be1d26f8fe487 100644 --- a/src/libsyntax/print/pprust.rs +++ b/src/libsyntax/print/pprust.rs @@ -293,6 +293,7 @@ pub fn token_to_string(tok: &Token) -> String { token::NtGenerics(ref e) => generics_to_string(&e), token::NtWhereClause(ref e) => where_clause_to_string(&e), token::NtArg(ref e) => arg_to_string(&e), + token::NtVis(ref e) => vis_to_string(&e), } } } @@ -373,6 +374,10 @@ pub fn ident_to_string(id: ast::Ident) -> String { to_string(|s| s.print_ident(id)) } +pub fn vis_to_string(v: &ast::Visibility) -> String { + to_string(|s| s.print_visibility(v)) +} + pub fn fun_to_string(decl: &ast::FnDecl, unsafety: ast::Unsafety, constness: ast::Constness, @@ -427,13 +432,7 @@ pub fn mac_to_string(arg: &ast::Mac) -> String { } pub fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String { - match *vis { - ast::Visibility::Public => format!("pub {}", s), - ast::Visibility::Crate(_) => format!("pub(crate) {}", s), - ast::Visibility::Restricted { ref path, .. } => - format!("pub({}) {}", to_string(|s| s.print_path(path, false, 0, true)), s), - ast::Visibility::Inherited => s.to_string() - } + format!("{}{}", to_string(|s| s.print_visibility(vis)), s) } fn needs_parentheses(expr: &ast::Expr) -> bool { @@ -1468,7 +1467,11 @@ impl<'a> State<'a> { ast::Visibility::Crate(_) => self.word_nbsp("pub(crate)"), ast::Visibility::Restricted { ref path, .. } => { let path = to_string(|s| s.print_path(path, false, 0, true)); - self.word_nbsp(&format!("pub({})", path)) + if path == "self" || path == "super" { + self.word_nbsp(&format!("pub({})", path)) + } else { + self.word_nbsp(&format!("pub(in {})", path)) + } } ast::Visibility::Inherited => Ok(()) } diff --git a/src/test/compile-fail/feature-gate-macro-vis-matcher.rs b/src/test/compile-fail/feature-gate-macro-vis-matcher.rs new file mode 100644 index 0000000000000..5d6f2acea83ce --- /dev/null +++ b/src/test/compile-fail/feature-gate-macro-vis-matcher.rs @@ -0,0 +1,19 @@ +// Copyright 2017 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. + +// Test that the MSP430 interrupt ABI cannot be used when msp430_interrupt +// feature gate is not used. + +macro_rules! m { ($v:vis) => {} } +//~^ ERROR :vis fragment specifier is experimental and subject to change + +fn main() { + m!(pub); +} diff --git a/src/test/run-pass/macro-pub-matcher.rs b/src/test/run-pass/macro-pub-matcher.rs new file mode 100644 index 0000000000000..d79f4b65b69e1 --- /dev/null +++ b/src/test/run-pass/macro-pub-matcher.rs @@ -0,0 +1,115 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![allow(dead_code, unused_imports)] +#![feature(macro_vis_matcher)] + +/** +Ensure that `:vis` matches can be captured in existing positions, and passed +through without the need for reparse tricks. +*/ +macro_rules! vis_passthru { + ($vis:vis const $name:ident: $ty:ty = $e:expr;) => { $vis const $name: $ty = $e; }; + ($vis:vis enum $name:ident {}) => { $vis struct $name {} }; + ($vis:vis extern "C" fn $name:ident() {}) => { $vis extern "C" fn $name() {} }; + ($vis:vis fn $name:ident() {}) => { $vis fn $name() {} }; + ($vis:vis mod $name:ident {}) => { $vis mod $name {} }; + ($vis:vis static $name:ident: $ty:ty = $e:expr;) => { $vis static $name: $ty = $e; }; + ($vis:vis struct $name:ident;) => { $vis struct $name; }; + ($vis:vis trait $name:ident {}) => { $vis trait $name {} }; + ($vis:vis type $name:ident = $ty:ty;) => { $vis type $name = $ty; }; + ($vis:vis use $path:ident as $name:ident;) => { $vis use self::$path as $name; }; +} + +mod with_pub { + vis_passthru! { pub const A: i32 = 0; } + vis_passthru! { pub enum B {} } + vis_passthru! { pub extern "C" fn c() {} } + vis_passthru! { pub mod d {} } + vis_passthru! { pub static E: i32 = 0; } + vis_passthru! { pub struct F; } + vis_passthru! { pub trait G {} } + vis_passthru! { pub type H = i32; } + vis_passthru! { pub use A as I; } +} + +mod without_pub { + vis_passthru! { const A: i32 = 0; } + vis_passthru! { enum B {} } + vis_passthru! { extern "C" fn c() {} } + vis_passthru! { mod d {} } + vis_passthru! { static E: i32 = 0; } + vis_passthru! { struct F; } + vis_passthru! { trait G {} } + vis_passthru! { type H = i32; } + vis_passthru! { use A as I; } +} + +mod with_pub_restricted { + vis_passthru! { pub(crate) const A: i32 = 0; } + vis_passthru! { pub(crate) enum B {} } + vis_passthru! { pub(crate) extern "C" fn c() {} } + vis_passthru! { pub(crate) mod d {} } + vis_passthru! { pub(crate) static E: i32 = 0; } + vis_passthru! { pub(crate) struct F; } + vis_passthru! { pub(crate) trait G {} } + vis_passthru! { pub(crate) type H = i32; } + vis_passthru! { pub(crate) use A as I; } +} + +mod garden { + mod with_pub_restricted_path { + vis_passthru! { pub(in garden) const A: i32 = 0; } + vis_passthru! { pub(in garden) enum B {} } + vis_passthru! { pub(in garden) extern "C" fn c() {} } + vis_passthru! { pub(in garden) mod d {} } + vis_passthru! { pub(in garden) static E: i32 = 0; } + vis_passthru! { pub(in garden) struct F; } + vis_passthru! { pub(in garden) trait G {} } + vis_passthru! { pub(in garden) type H = i32; } + vis_passthru! { pub(in garden) use A as I; } + } +} + +/* +Ensure that the `:vis` matcher works in a more complex situation: parsing a +struct definition. +*/ +macro_rules! vis_parse_struct { + ($(#[$($attrs:tt)*])* $vis:vis struct $name:ident {$($body:tt)*}) => { + vis_parse_struct! { @parse_fields $(#[$($attrs)*])*, $vis, $name, $($body)* } + }; + + ($(#[$($attrs:tt)*])* $vis:vis struct $name:ident ($($body:tt)*);) => { + vis_parse_struct! { @parse_tuple $(#[$($attrs)*])*, $vis, $name, $($body)* } + }; + + (@parse_fields + $(#[$attrs:meta])*, $vis:vis, $name:ident, $($fvis:vis $fname:ident: $fty:ty),* $(,)*) => { + $(#[$attrs])* $vis struct $name { $($fvis $fname: $fty,)* } + }; + + (@parse_tuple + $(#[$attrs:meta])*, $vis:vis, $name:ident, $($fvis:vis $fty:ty),* $(,)*) => { + $(#[$attrs])* $vis struct $name ( $($fvis $fty,)* ); + }; +} + +mod test_struct { + vis_parse_struct! { pub(crate) struct A { pub a: i32, b: i32, pub(crate) c: i32 } } + vis_parse_struct! { pub struct B { a: i32, pub(crate) b: i32, pub c: i32 } } + vis_parse_struct! { struct C { pub(crate) a: i32, pub b: i32, c: i32 } } + + vis_parse_struct! { pub(crate) struct D (pub i32, i32, pub(crate) i32); } + vis_parse_struct! { pub struct E (i32, pub(crate) i32, pub i32); } + vis_parse_struct! { struct F (pub(crate) i32, pub i32, i32); } +} + +fn main() {}