Feature gating *declarations* => new crate rustc_feature

Cargo.lock

@@ -3199,6 +3199,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
+ "rustc_feature",
  "rustc_fs_util",
  "rustc_index",
  "rustc_macros",
@@ -3607,6 +3608,13 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "rustc_feature"
+version = "0.0.0"
+dependencies = [
+ "syntax_pos",
+]
+
 [[package]]
 name = "rustc_fs_util"
 version = "0.0.0"
@@ -3682,6 +3690,7 @@ dependencies = [
  "rustc",
  "rustc_data_structures",
  "rustc_error_codes",
+ "rustc_feature",
  "rustc_index",
  "rustc_target",
  "syntax",
@@ -3786,6 +3795,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
+ "rustc_feature",
  "rustc_lexer",
  "rustc_target",
  "smallvec 1.0.0",
@@ -3802,6 +3812,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
+ "rustc_feature",
  "rustc_index",
  "rustc_parse",
  "rustc_target",
@@ -4442,6 +4453,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
+ "rustc_feature",
  "rustc_index",
  "rustc_lexer",
  "rustc_macros",
@@ -4458,6 +4470,7 @@ dependencies = [
  "log",
  "rustc_data_structures",
  "rustc_errors",
+ "rustc_feature",
  "rustc_lexer",
  "rustc_parse",
  "serialize",
@@ -4475,6 +4488,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_error_codes",
  "rustc_errors",
+ "rustc_feature",
  "rustc_parse",
  "rustc_target",
  "smallvec 1.0.0",

src/librustc/Cargo.toml

@@ -22,6 +22,7 @@ rustc-rayon = "0.3.0"
 rustc-rayon-core = "0.3.0"
 polonius-engine = "0.10.0"
 rustc_apfloat = { path = "../librustc_apfloat" }
+rustc_feature = { path = "../librustc_feature" }
 rustc_target = { path = "../librustc_target" }
 rustc_macros = { path = "../librustc_macros" }
 rustc_data_structures = { path = "../librustc_data_structures" }

src/librustc/arena.rs

@@ -100,7 +100,7 @@ macro_rules! arena_types {
  [few] resolve_lifetimes: rustc::middle::resolve_lifetime::ResolveLifetimes,
  [few] lint_levels: rustc::lint::LintLevelMap,
  [few] stability_index: rustc::middle::stability::Index<'tcx>,
- [few] features: syntax::feature_gate::Features,
+ [few] features: rustc_feature::Features,
  [few] all_traits: Vec<rustc::hir::def_id::DefId>,
  [few] privacy_access_levels: rustc::middle::privacy::AccessLevels,
  [few] target_features_whitelist: rustc_data_structures::fx::FxHashMap<

src/librustc/ich/impls_syntax.rs

@@ -4,7 +4,6 @@
 use crate::ich::StableHashingContext;
 
 use syntax::ast;
-use syntax::feature_gate;
 use syntax_pos::SourceFile;
 
 use crate::hir::def_id::{DefId, CrateNum, CRATE_DEF_INDEX};
@@ -156,7 +155,7 @@ fn stable_normalized_pos(np: ::syntax_pos::NormalizedPos,
 }
 
 
-impl<'tcx> HashStable<StableHashingContext<'tcx>> for feature_gate::Features {
+impl<'tcx> HashStable<StableHashingContext<'tcx>> for rustc_feature::Features {
  fn hash_stable(&self, hcx: &mut StableHashingContext<'tcx>, hasher: &mut StableHasher) {
  // Unfortunately we cannot exhaustively list fields here, since the
  // struct is macro generated.

src/librustc/query/mod.rs

@@ -1130,7 +1130,7 @@ rustc_queries! {
  desc { |tcx| "estimating size for `{}`", tcx.def_path_str(def.def_id()) }
  }
 
- query features_query(_: CrateNum) -> &'tcx feature_gate::Features {
+ query features_query(_: CrateNum) -> &'tcx rustc_feature::Features {
  eval_always
  desc { "looking up enabled feature gates" }
  }

src/librustc/session/mod.rs

@@ -21,7 +21,6 @@ use errors::emitter::{Emitter, EmitterWriter};
 use errors::emitter::HumanReadableErrorType;
 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
 use syntax::edition::Edition;
-use syntax::feature_gate;
 use errors::json::JsonEmitter;
 use syntax::source_map;
 use syntax::sess::ParseSess;
@@ -86,7 +85,7 @@ pub struct Session {
  /// `rustc_codegen_llvm::back::symbol_names` module for more information.
  pub crate_disambiguator: Once<CrateDisambiguator>,
 
- features: Once<feature_gate::Features>,
+ features: Once<rustc_feature::Features>,
 
  /// The maximum recursion limit for potentially infinitely recursive
  /// operations such as auto-dereference and monomorphization.
@@ -473,11 +472,11 @@ impl Session {
  /// DO NOT USE THIS METHOD if there is a TyCtxt available, as it circumvents
  /// dependency tracking. Use tcx.features() instead.
  #[inline]
- pub fn features_untracked(&self) -> &feature_gate::Features {
+ pub fn features_untracked(&self) -> &rustc_feature::Features {
  self.features.get()
  }
 
- pub fn init_features(&self, features: feature_gate::Features) {
+ pub fn init_features(&self, features: rustc_feature::Features) {
  self.features.set(features);
  }
 

src/librustc/ty/context.rs

@@ -72,7 +72,6 @@ use rustc_macros::HashStable;
 use syntax::ast;
 use syntax::attr;
 use syntax::source_map::MultiSpan;
-use syntax::feature_gate;
 use syntax::symbol::{Symbol, kw, sym};
 use syntax_pos::Span;
 use syntax::expand::allocator::AllocatorKind;
@@ -1315,7 +1314,7 @@ impl<'tcx> TyCtxt<'tcx> {
  self.cstore.allocator_kind()
  }
 
- pub fn features(self) -> &'tcx feature_gate::Features {
+ pub fn features(self) -> &'tcx rustc_feature::Features {
  self.features_query(LOCAL_CRATE)
  }
 

src/librustc/ty/query/mod.rs

@@ -56,7 +56,6 @@ use std::any::type_name;
 use syntax_pos::{Span, DUMMY_SP};
 use syntax::attr;
 use syntax::ast;
-use syntax::feature_gate;
 use syntax::symbol::Symbol;
 
 #[macro_use]

src/librustc_driver/lib.rs

@@ -62,9 +62,9 @@ use std::time::Instant;
 
 use syntax::ast;
 use syntax::source_map::FileLoader;
-use syntax::feature_gate::{GatedCfg, UnstableFeatures};
-use syntax::symbol::sym;
-use syntax_pos::{DUMMY_SP, FileName};
+use syntax::feature_gate::{find_gated_cfg, UnstableFeatures};
+use syntax_pos::symbol::sym;
+use syntax_pos::FileName;
 
 pub mod pretty;
 mod args;
@@ -677,12 +677,6 @@ impl RustcDefaultCalls {
  .is_nightly_build();
 
  let mut cfgs = sess.parse_sess.config.iter().filter_map(|&(name, ref value)| {
- let gated_cfg = GatedCfg::gate(&ast::MetaItem {
- path: ast::Path::from_ident(ast::Ident::with_dummy_span(name)),
- kind: ast::MetaItemKind::Word,
- span: DUMMY_SP,
- });
-
  // Note that crt-static is a specially recognized cfg
  // directive that's printed out here as part of
  // rust-lang/rust#37406, but in general the
@@ -693,10 +687,11 @@ impl RustcDefaultCalls {
  // through to build scripts.
  let value = value.as_ref().map(|s| s.as_str());
  let value = value.as_ref().map(|s| s.as_ref());
- if name != sym::target_feature || value != Some("crt-static") {
- if !allow_unstable_cfg && gated_cfg.is_some() {
- return None
- }
+ if (name != sym::target_feature || value != Some("crt-static"))
+ && !allow_unstable_cfg
+ && find_gated_cfg(|cfg_sym| cfg_sym == name).is_some()
+ {
+ return None;
  }
 
  if let Some(value) = value {

src/librustc_feature/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+authors = ["The Rust Project Developers"]
+name = "rustc_feature"
+version = "0.0.0"
+edition = "2018"
+
+[lib]
+name = "rustc_feature"
+path = "lib.rs"
+doctest = false
+
+[dependencies]
+syntax_pos = { path = "../libsyntax_pos" }

src/libsyntax/feature_gate/accepted.rs → src/librustc_feature/accepted.rs

@@ -1,7 +1,7 @@
 //! List of the accepted feature gates.
 
-use crate::symbol::sym;
 use super::{State, Feature};
+use syntax_pos::symbol::sym;
 
 macro_rules! declare_features {
  ($(

src/libsyntax/feature_gate/active.rs → src/librustc_feature/active.rs

@@ -2,10 +2,9 @@
 
 use super::{State, Feature};
 
-use crate::edition::Edition;
-use crate::symbol::{Symbol, sym};
-
+use syntax_pos::edition::Edition;
 use syntax_pos::Span;
+use syntax_pos::symbol::{Symbol, sym};
 
 macro_rules! set {
  ($field: ident) => {{

src/libsyntax/feature_gate/mod.rs → src/librustc_feature/lib.rs

@@ -15,13 +15,10 @@
 mod accepted;
 mod removed;
 mod active;
-mod builtin_attrs;
-mod check;
 
-use crate::{edition::Edition, symbol::Symbol};
 use std::fmt;
 use std::num::NonZeroU32;
-use syntax_pos::Span;
+use syntax_pos::{Span, edition::Edition, symbol::Symbol};
 
 #[derive(Clone, Copy)]
 pub enum State {
@@ -44,28 +41,29 @@ impl fmt::Debug for State {
 
 #[derive(Debug, Clone)]
 pub struct Feature {
- state: State,
- name: Symbol,
- since: &'static str,
+ pub state: State,
+ pub name: Symbol,
+ pub since: &'static str,
  issue: Option<u32>, // FIXME: once #58732 is done make this an Option<NonZeroU32>
- edition: Option<Edition>,
+ pub edition: Option<Edition>,
  description: &'static str,
 }
 
 impl Feature {
- fn issue(&self) -> Option<NonZeroU32> {
+ // FIXME(Centril): privatize again.
+ pub fn issue(&self) -> Option<NonZeroU32> {
  self.issue.and_then(|i| NonZeroU32::new(i))
  }
 }
 
-pub use active::{Features, INCOMPLETE_FEATURES};
-pub use builtin_attrs::{
- AttributeGate, AttributeType, GatedCfg,
- BuiltinAttribute, BUILTIN_ATTRIBUTES, BUILTIN_ATTRIBUTE_MAP,
- deprecated_attributes, is_builtin_attr, is_builtin_attr_name,
-};
-pub use check::{
- check_crate, check_attribute, get_features, feature_err, emit_feature_err,
- Stability, GateIssue, UnstableFeatures,
- EXPLAIN_STMT_ATTR_SYNTAX, EXPLAIN_UNSIZED_TUPLE_COERCION,
-};
+#[derive(Copy, Clone, Debug)]
+pub enum Stability {
+ Unstable,
+ // First argument is tracking issue link; second argument is an optional
+ // help message, which defaults to "remove this attribute".
+ Deprecated(&'static str, Option<&'static str>),
+}
+
+pub use accepted::ACCEPTED_FEATURES;
+pub use active::{ACTIVE_FEATURES, Features, INCOMPLETE_FEATURES};
+pub use removed::{REMOVED_FEATURES, STABLE_REMOVED_FEATURES};

src/libsyntax/feature_gate/removed.rs → src/librustc_feature/removed.rs

@@ -1,7 +1,7 @@
 //! List of the removed feature gates.
 
-use crate::symbol::sym;
 use super::{State, Feature};
+use syntax_pos::symbol::sym;
 
 macro_rules! declare_features {
  ($(

src/librustc_lint/Cargo.toml

@@ -15,5 +15,6 @@ rustc_target = { path = "../librustc_target" }
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }
 rustc_data_structures = { path = "../librustc_data_structures" }
+rustc_feature = { path = "../librustc_feature" }
 rustc_index = { path = "../librustc_index" }
 rustc_error_codes = { path = "../librustc_error_codes" }

src/librustc_lint/builtin.rs

@@ -34,15 +34,16 @@ use lint::{LateContext, LintContext, LintArray};
 use lint::{LintPass, LateLintPass, EarlyLintPass, EarlyContext};
 
 use rustc::util::nodemap::FxHashSet;
+use rustc_feature::Stability;
 
 use syntax::tokenstream::{TokenTree, TokenStream};
 use syntax::ast::{self, Expr};
 use syntax::ptr::P;
-use syntax::attr::{self, HasAttrs, AttributeTemplate};
+use syntax::attr::{self, HasAttrs};
 use syntax::source_map::Spanned;
 use syntax::edition::Edition;
-use syntax::feature_gate::{self, AttributeGate, AttributeType};
-use syntax::feature_gate::{Stability, deprecated_attributes};
+use syntax::feature_gate::{AttributeGate, AttributeTemplate, AttributeType};
+use syntax::feature_gate::deprecated_attributes;
 use syntax_pos::{BytePos, Span};
 use syntax::symbol::{Symbol, kw, sym};
 use syntax::errors::{Applicability, DiagnosticBuilder};
@@ -1850,7 +1851,7 @@ impl EarlyLintPass for IncompleteFeatures {
  features.declared_lang_features
  .iter().map(|(name, span, _)| (name, span))
  .chain(features.declared_lib_features.iter().map(|(name, span)| (name, span)))
- .filter(|(name, _)| feature_gate::INCOMPLETE_FEATURES.iter().any(|f| name == &f))
+ .filter(|(name, _)| rustc_feature::INCOMPLETE_FEATURES.iter().any(|f| name == &f))
  .for_each(|(name, &span)| {
  cx.struct_span_lint(
  INCOMPLETE_FEATURES,

src/librustc_parse/Cargo.toml

@@ -16,6 +16,7 @@ syntax_pos = { path = "../libsyntax_pos" }
 syntax = { path = "../libsyntax" }
 errors = { path = "../librustc_errors", package = "rustc_errors" }
 rustc_data_structures = { path = "../librustc_data_structures" }
+rustc_feature = { path = "../librustc_feature" }
 rustc_lexer = { path = "../librustc_lexer" }
 rustc_target = { path = "../librustc_target" }
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }

src/librustc_parse/config.rs

@@ -9,11 +9,11 @@
 //! [#64197]: https://github.com/rust-lang/rust/issues/64197
 
 use crate::validate_attr;
+use rustc_feature::Features;
 use syntax::attr::HasAttrs;
 use syntax::feature_gate::{
  feature_err,
  EXPLAIN_STMT_ATTR_SYNTAX,
- Features,
  get_features,
  GateIssue,
 };