Move builtin attribute logic to new rustc_attr crate.

For now, this is all the crate contains, but more
attribute logic & types will be moved there over time.

Cargo.lock

@@ -3093,6 +3093,7 @@ dependencies = [
  "rustc-rayon",
  "rustc-rayon-core",
  "rustc_apfloat",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -3374,6 +3375,7 @@ name = "rustc_ast_passes"
 version = "0.0.0"
 dependencies = [
  "log",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -3383,12 +3385,28 @@ dependencies = [
  "syntax",
 ]
 
+[[package]]
+name = "rustc_attr"
+version = "0.0.0"
+dependencies = [
+ "rustc_data_structures",
+ "rustc_errors",
+ "rustc_feature",
+ "rustc_macros",
+ "rustc_session",
+ "rustc_span",
+ "serialize",
+ "smallvec 1.0.0",
+ "syntax",
+]
+
 [[package]]
 name = "rustc_builtin_macros"
 version = "0.0.0"
 dependencies = [
  "fmt_macros",
  "log",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_expand",
@@ -3411,6 +3429,7 @@ dependencies = [
  "log",
  "rustc",
  "rustc-demangle",
+ "rustc_attr",
  "rustc_codegen_ssa",
  "rustc_codegen_utils",
  "rustc_data_structures",
@@ -3442,6 +3461,7 @@ dependencies = [
  "num_cpus",
  "rustc",
  "rustc_apfloat",
+ "rustc_attr",
  "rustc_codegen_utils",
  "rustc_data_structures",
  "rustc_errors",
@@ -3552,6 +3572,7 @@ version = "0.0.0"
 dependencies = [
  "log",
  "rustc_ast_passes",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -3628,6 +3649,7 @@ dependencies = [
  "rustc-rayon",
  "rustc_ast_lowering",
  "rustc_ast_passes",
+ "rustc_attr",
  "rustc_builtin_macros",
  "rustc_codegen_llvm",
  "rustc_codegen_ssa",
@@ -3672,6 +3694,7 @@ version = "0.0.0"
 dependencies = [
  "log",
  "rustc",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -3712,6 +3735,7 @@ dependencies = [
  "log",
  "memmap",
  "rustc",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_expand",
@@ -3739,6 +3763,7 @@ dependencies = [
  "polonius-engine",
  "rustc",
  "rustc_apfloat",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",
@@ -3761,6 +3786,7 @@ dependencies = [
  "log",
  "rustc",
  "rustc_apfloat",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",
@@ -3780,6 +3806,7 @@ version = "0.0.0"
 dependencies = [
  "bitflags",
  "log",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -3797,6 +3824,7 @@ version = "0.0.0"
 dependencies = [
  "log",
  "rustc",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_feature",
@@ -3827,6 +3855,7 @@ version = "0.0.0"
 dependencies = [
  "log",
  "rustc",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",
@@ -3844,6 +3873,7 @@ dependencies = [
  "log",
  "rustc",
  "rustc_ast_lowering",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_expand",
@@ -3961,6 +3991,7 @@ dependencies = [
  "arena",
  "log",
  "rustc",
+ "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",

src/librustc/Cargo.toml

@@ -21,6 +21,7 @@ rustc-rayon = "0.3.0"
 rustc-rayon-core = "0.3.0"
 polonius-engine = "0.11.0"
 rustc_apfloat = { path = "../librustc_apfloat" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_feature = { path = "../librustc_feature" }
 rustc_hir = { path = "../librustc_hir" }
 rustc_target = { path = "../librustc_target" }

src/librustc/ich/impls_hir.rs

@@ -3,12 +3,12 @@
 
 use crate::hir::map::DefPathHash;
 use crate::ich::{Fingerprint, NodeIdHashingMode, StableHashingContext};
+use rustc_attr as attr;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
 use rustc_hir as hir;
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX};
 use smallvec::SmallVec;
 use std::mem;
-use syntax::attr;
 
 impl<'ctx> rustc_hir::HashStableContext for StableHashingContext<'ctx> {
     #[inline]

src/librustc/middle/codegen_fn_attrs.rs

@@ -1,6 +1,6 @@
 use crate::mir::mono::Linkage;
+use rustc_attr::{InlineAttr, OptimizeAttr};
 use rustc_span::symbol::Symbol;
-use syntax::attr::{InlineAttr, OptimizeAttr};
 
 #[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
 pub struct CodegenFnAttrs {

src/librustc/middle/stability.rs

@@ -5,6 +5,7 @@ pub use self::StabilityLevel::*;
 
 use crate::session::{DiagnosticMessageId, Session};
 use crate::ty::{self, TyCtxt};
+use rustc_attr::{self as attr, ConstStability, Deprecation, RustcDeprecation, Stability};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_feature::GateIssue;
@@ -16,7 +17,6 @@ use rustc_session::lint::{self, BuiltinLintDiagnostics, Lint, LintBuffer};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{MultiSpan, Span};
 use syntax::ast::CRATE_NODE_ID;
-use syntax::attr::{self, ConstStability, Deprecation, RustcDeprecation, Stability};
 use syntax::sess::feature_err_issue;
 
 use std::num::NonZeroU32;

src/librustc/mir/mono.rs

@@ -3,6 +3,7 @@ use crate::ich::{Fingerprint, NodeIdHashingMode, StableHashingContext};
 use crate::session::config::OptLevel;
 use crate::ty::print::obsolete::DefPathBasedNames;
 use crate::ty::{subst::InternalSubsts, Instance, InstanceDef, SymbolName, TyCtxt};
+use rustc_attr::InlineAttr;
 use rustc_data_structures::base_n;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
@@ -12,7 +13,6 @@ use rustc_span::source_map::Span;
 use rustc_span::symbol::Symbol;
 use std::fmt;
 use std::hash::Hash;
-use syntax::attr::InlineAttr;
 
 /// Describes how a monomorphization will be instantiated in object files.
 #[derive(PartialEq)]

src/librustc/traits/on_unimplemented.rs

@@ -3,13 +3,13 @@ use fmt_macros::{Parser, Piece, Position};
 use crate::ty::{self, GenericParamDefKind, TyCtxt};
 use crate::util::common::ErrorReported;
 
+use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::struct_span_err;
 use rustc_hir::def_id::DefId;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 use syntax::ast::{MetaItem, NestedMetaItem};
-use syntax::attr;
 
 #[derive(Clone, Debug)]
 pub struct OnUnimplementedFormatString(Symbol);

src/librustc/ty/context.rs

@@ -51,6 +51,7 @@ use rustc_session::config::CrateType;
 use rustc_session::config::{BorrowckMode, OutputFilenames};
 use rustc_session::Session;
 
+use rustc_attr as attr;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::sharded::{IntoPointer, ShardedHashMap};
@@ -79,7 +80,6 @@ use std::mem;
 use std::ops::{Bound, Deref};
 use std::sync::Arc;
 use syntax::ast;
-use syntax::attr;
 use syntax::expand::allocator::AllocatorKind;
 
 type InternedSet<'tcx, T> = ShardedHashMap<Interned<'tcx, T>, ()>;

src/librustc/ty/layout.rs

@@ -1,9 +1,9 @@
 use crate::session::{self, DataTypeKind};
 use crate::ty::{self, subst::SubstsRef, ReprOptions, Ty, TyCtxt, TypeFoldable};
 
+use rustc_attr as attr;
 use rustc_span::DUMMY_SP;
 use syntax::ast::{self, Ident, IntTy, UintTy};
-use syntax::attr;
 
 use std::cmp;
 use std::fmt;

src/librustc/ty/mod.rs

@@ -26,6 +26,7 @@ use crate::ty::layout::VariantIdx;
 use crate::ty::subst::{InternalSubsts, Subst, SubstsRef};
 use crate::ty::util::{Discr, IntTypeExt};
 use crate::ty::walk::TypeWalker;
+use rustc_attr as attr;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::fx::FxIndexMap;
@@ -53,7 +54,6 @@ use std::ops::Range;
 use std::slice;
 use std::{mem, ptr};
 use syntax::ast::{self, Constness, Ident, Name, NodeId};
-use syntax::attr;
 
 pub use self::sty::BoundRegion::*;
 pub use self::sty::InferTy::*;

src/librustc/ty/print/pretty.rs

@@ -11,10 +11,10 @@ use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 
 use rustc_apfloat::ieee::{Double, Single};
 use rustc_apfloat::Float;
+use rustc_attr::{SignedInt, UnsignedInt};
 use rustc_span::symbol::{kw, Symbol};
 use rustc_target::spec::abi::Abi;
 use syntax::ast;
-use syntax::attr::{SignedInt, UnsignedInt};
 
 use std::cell::Cell;
 use std::collections::BTreeMap;

src/librustc/ty/query/mod.rs

@@ -49,6 +49,7 @@ use rustc_hir::{HirIdSet, ItemLocalId, TraitCandidate};
 use rustc_index::vec::IndexVec;
 use rustc_target::spec::PanicStrategy;
 
+use rustc_attr as attr;
 use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 use std::any::type_name;
@@ -56,7 +57,6 @@ use std::borrow::Cow;
 use std::ops::Deref;
 use std::sync::Arc;
 use syntax::ast;
-use syntax::attr;
 
 #[macro_use]
 mod plumbing;

src/librustc/ty/util.rs

@@ -10,6 +10,7 @@ use crate::ty::TyKind::*;
 use crate::ty::{self, DefIdTree, GenericParamDefKind, Ty, TyCtxt, TypeFoldable};
 use crate::util::common::ErrorReported;
 use rustc_apfloat::Float as _;
+use rustc_attr::{self as attr, SignedInt, UnsignedInt};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_hir as hir;
@@ -19,7 +20,6 @@ use rustc_macros::HashStable;
 use rustc_span::Span;
 use std::{cmp, fmt};
 use syntax::ast;
-use syntax::attr::{self, SignedInt, UnsignedInt};
 
 #[derive(Copy, Clone, Debug)]
 pub struct Discr<'tcx> {

src/librustc_ast_passes/Cargo.toml

@@ -10,6 +10,7 @@ path = "lib.rs"
 
 [dependencies]
 log = "0.4"
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_feature = { path = "../librustc_feature" }

src/librustc_ast_passes/ast_validation.rs

@@ -331,7 +331,7 @@ impl<'a> AstValidator<'a> {
             .flat_map(|i| i.attrs.as_ref())
             .filter(|attr| {
                 let arr = [sym::allow, sym::cfg, sym::cfg_attr, sym::deny, sym::forbid, sym::warn];
-                !arr.contains(&attr.name_or_empty()) && attr::is_builtin_attr(attr)
+                !arr.contains(&attr.name_or_empty()) && rustc_attr::is_builtin_attr(attr)
             })
             .for_each(|attr| {
                 if attr.is_doc_comment() {

src/librustc_attr/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+authors = ["The Rust Project Developers"]
+name = "rustc_attr"
+version = "0.0.0"
+edition = "2018"
+
+[lib]
+name = "rustc_attr"
+path = "lib.rs"
+doctest = false
+
+[dependencies]
+rustc_serialize = { path = "../libserialize", package = "serialize" }
+rustc_errors = { path = "../librustc_errors" }
+rustc_span = { path = "../librustc_span" }
+rustc_data_structures = { path = "../librustc_data_structures" }
+rustc_feature = { path = "../librustc_feature" }
+rustc_macros = { path = "../librustc_macros" }
+smallvec = { version = "1.0", features = ["union", "may_dangle"] }
+rustc_session = { path = "../librustc_session" }
+syntax = { path = "../libsyntax" }

src/librustc_attr/builtin.rs

@@ -1,16 +1,16 @@
 //! Parsing and validation of builtin attributes
 
-use super::{mark_used, MetaItemKind};
+use super::mark_used;
-use crate::ast::{self, Attribute, MetaItem, NestedMetaItem};
-use crate::print::pprust;
-use crate::sess::{feature_err, ParseSess};
 
 use rustc_errors::{struct_span_err, Applicability, Handler};
 use rustc_feature::{find_gated_cfg, is_builtin_attr_name, Features, GatedCfg};
 use rustc_macros::HashStable_Generic;
+use rustc_session::parse::{feature_err, ParseSess};
 use rustc_span::hygiene::Transparency;
 use rustc_span::{symbol::sym, symbol::Symbol, Span};
 use std::num::NonZeroU32;
+use syntax::ast::{self, Attribute, MetaItem, MetaItemKind, NestedMetaItem};
+use syntax::print::pprust;
 
 pub fn is_builtin_attr(attr: &Attribute) -> bool {
     attr.is_doc_comment() || attr.ident().filter(|ident| is_builtin_attr_name(ident.name)).is_some()

src/librustc_attr/lib.rs

@@ -0,0 +1,16 @@
+//! Functions and types dealing with attributes and meta items.
+//!
+//! FIXME(Centril): For now being, much of the logic is still in `syntax::attr`.
+//! The goal is to move the definition of `MetaItem` and things that don't need to be in `syntax`
+//! to this crate.
+
+mod builtin;
+
+pub use builtin::*;
+pub use IntType::*;
+pub use ReprAttr::*;
+pub use StabilityLevel::*;
+
+pub use syntax::attr::*;
+
+pub(crate) use syntax::HashStableContext;

src/librustc_builtin_macros/Cargo.toml

@@ -12,6 +12,7 @@ doctest = false
 [dependencies]
 fmt_macros = { path = "../libfmt_macros" }
 log = "0.4"
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_feature = { path = "../librustc_feature" }

src/librustc_builtin_macros/cfg.rs

@@ -2,11 +2,11 @@
 //! a literal `true` or `false` based on whether the given cfg matches the
 //! current compilation environment.
 
+use rustc_attr as attr;
 use rustc_errors::DiagnosticBuilder;
 use rustc_expand::base::{self, *};
 use rustc_span::Span;
 use syntax::ast;
-use syntax::attr;
 use syntax::token;
 use syntax::tokenstream::TokenStream;
 

src/librustc_builtin_macros/deriving/generic/mod.rs

@@ -181,13 +181,13 @@ use std::cell::RefCell;
 use std::iter;
 use std::vec;
 
+use rustc_attr as attr;
 use rustc_expand::base::{Annotatable, ExtCtxt};
 use rustc_span::source_map::respan;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 use syntax::ast::{self, BinOpKind, EnumDef, Expr, Generics, Ident, PatKind};
 use syntax::ast::{GenericArg, GenericParamKind, VariantData};
-use syntax::attr;
 use syntax::ptr::P;
 use syntax::sess::ParseSess;
 use syntax::util::map_in_place::MapInPlace;

src/librustc_codegen_llvm/Cargo.toml

@@ -17,6 +17,7 @@ libc = "0.2"
 log = "0.4"
 rustc = { path = "../librustc" }
 rustc-demangle = "0.1"
+rustc_attr = { path = "../librustc_attr" }
 rustc_codegen_ssa = { path = "../librustc_codegen_ssa" }
 rustc_codegen_utils = { path = "../librustc_codegen_utils" }
 rustc_data_structures = { path = "../librustc_data_structures" }

src/librustc_codegen_llvm/attributes.rs

@@ -21,7 +21,7 @@ use crate::attributes;
 use crate::llvm::AttributePlace::Function;
 use crate::llvm::{self, Attribute};
 use crate::llvm_util;
-pub use syntax::attr::{self, InlineAttr, OptimizeAttr};
+pub use rustc_attr::{self as attr, InlineAttr, OptimizeAttr};
 
 use crate::context::CodegenCx;
 use crate::value::Value;

src/librustc_codegen_ssa/Cargo.toml

@@ -24,6 +24,7 @@ syntax = { path = "../libsyntax" }
 rustc_span = { path = "../librustc_span" }
 rustc = { path = "../librustc" }
 rustc_apfloat = { path = "../librustc_apfloat" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_codegen_utils = { path = "../librustc_codegen_utils" }
 rustc_data_structures = { path = "../librustc_data_structures"}
 rustc_errors = { path = "../librustc_errors" }

src/librustc_codegen_ssa/back/link.rs

@@ -1719,7 +1719,7 @@ pub fn add_upstream_native_libraries(
 
 pub fn relevant_lib(sess: &Session, lib: &NativeLibrary) -> bool {
     match lib.cfg {
-        Some(ref cfg) => syntax::attr::cfg_matches(cfg, &sess.parse_sess, None),
+        Some(ref cfg) => rustc_attr::cfg_matches(cfg, &sess.parse_sess, None),
         None => true,
     }
 }

src/librustc_codegen_ssa/base.rs

@@ -37,6 +37,7 @@ use rustc::ty::layout::{self, Align, HasTyCtxt, LayoutOf, TyLayout, VariantIdx};
 use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
 use rustc::ty::query::Providers;
 use rustc::ty::{self, Instance, Ty, TyCtxt};
+use rustc_attr as attr;
 use rustc_codegen_utils::{check_for_rustc_errors_attr, symbol_names_test};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::profiling::print_time_passes_entry;
@@ -46,7 +47,6 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_index::vec::Idx;
 use rustc_session::cgu_reuse_tracker::CguReuse;
 use rustc_span::Span;
-use syntax::attr;
 
 use std::cmp;
 use std::ops::{Deref, DerefMut};

src/librustc_expand/Cargo.toml

@@ -15,6 +15,7 @@ rustc_serialize = { path = "../libserialize", package = "serialize" }
 log = "0.4"
 rustc_span = { path = "../librustc_span" }
 rustc_ast_passes = { path = "../librustc_ast_passes" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_feature = { path = "../librustc_feature" }

src/librustc_expand/base.rs

@@ -1,5 +1,6 @@
 use crate::expand::{self, AstFragment, Invocation};
 
+use rustc_attr::{self as attr, Deprecation, HasAttrs, Stability};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::{self, Lrc};
 use rustc_errors::{DiagnosticBuilder, DiagnosticId};
@@ -11,7 +12,6 @@ use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{FileName, MultiSpan, Span, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 use syntax::ast::{self, Attribute, Name, NodeId, PatKind};
-use syntax::attr::{self, Deprecation, HasAttrs, Stability};
 use syntax::mut_visit::{self, MutVisitor};
 use syntax::ptr::P;
 use syntax::sess::ParseSess;

src/librustc_expand/expand.rs

@@ -5,6 +5,7 @@ use crate::mbe::macro_rules::annotate_err_with_kind;
 use crate::placeholders::{placeholder, PlaceholderExpander};
 use crate::proc_macro::collect_derives;
 
+use rustc_attr::{self as attr, is_builtin_attr, HasAttrs};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, FatalError, PResult};
 use rustc_feature::Features;
@@ -17,7 +18,6 @@ use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{FileName, Span, DUMMY_SP};
 use syntax::ast::{self, AttrItem, Block, Ident, LitKind, NodeId, PatKind, Path};
 use syntax::ast::{ItemKind, MacArgs, MacStmtStyle, StmtKind};
-use syntax::attr::{self, is_builtin_attr, HasAttrs};
 use syntax::mut_visit::*;
 use syntax::print::pprust;
 use syntax::ptr::P;

src/librustc_expand/mbe/macro_rules.rs

@@ -8,6 +8,7 @@ use crate::mbe::macro_parser::{Error, Failure, Success};
 use crate::mbe::macro_parser::{MatchedNonterminal, MatchedSeq, NamedParseResult};
 use crate::mbe::transcribe::transcribe;
 
+use rustc_attr::{self as attr, TransparencyError};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, DiagnosticBuilder, FatalError};
@@ -19,7 +20,6 @@ use rustc_span::hygiene::Transparency;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 use syntax::ast;
-use syntax::attr::{self, TransparencyError};
 use syntax::print::pprust;
 use syntax::sess::ParseSess;
 use syntax::token::{self, NtTT, Token, TokenKind::*};

src/librustc_interface/Cargo.toml

@@ -14,6 +14,7 @@ log = "0.4"
 rayon = { version = "0.3.0", package = "rustc-rayon" }
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }
 syntax = { path = "../libsyntax" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_builtin_macros = { path = "../librustc_builtin_macros" }
 rustc_expand = { path = "../librustc_expand" }
 rustc_parse = { path = "../librustc_parse" }

src/librustc_interface/util.rs

@@ -32,7 +32,7 @@ use syntax::ast::{AttrVec, BlockCheckMode};
 use syntax::mut_visit::{visit_clobber, MutVisitor, *};
 use syntax::ptr::P;
 use syntax::util::lev_distance::find_best_match_for_name;
-use syntax::{self, ast, attr};
+use syntax::{self, ast};
 
 /// Adds `target_feature = "..."` cfgs for a variety of platform
 /// specific features (SSE, NEON etc.).
@@ -547,7 +547,7 @@ pub fn build_output_filenames(
                 .opts
                 .crate_name
                 .clone()
-                .or_else(|| attr::find_crate_name(attrs).map(|n| n.to_string()))
+                .or_else(|| rustc_attr::find_crate_name(attrs).map(|n| n.to_string()))
                 .unwrap_or_else(|| input.filestem().to_owned());
 
             OutputFilenames::new(

src/librustc_lint/Cargo.toml

@@ -12,6 +12,7 @@ path = "lib.rs"
 log = "0.4"
 unicode-security = "0.0.2"
 rustc = { path = "../librustc" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_hir = { path = "../librustc_hir" }
 rustc_target = { path = "../librustc_target" }

src/librustc_lint/nonstandard_style.rs

@@ -1,5 +1,6 @@
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 use rustc::ty;
+use rustc_attr as attr;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -9,7 +10,6 @@ use rustc_span::symbol::sym;
 use rustc_span::{symbol::Ident, BytePos, Span};
 use rustc_target::spec::abi::Abi;
 use syntax::ast;
-use syntax::attr;
 
 #[derive(PartialEq)]
 pub enum MethodLateContext {

src/librustc_lint/types.rs

@@ -5,6 +5,7 @@ use rustc::mir::interpret::{sign_extend, truncate};
 use rustc::ty::layout::{self, IntegerExt, LayoutOf, SizeSkeleton, VariantIdx};
 use rustc::ty::subst::SubstsRef;
 use rustc::ty::{self, AdtKind, ParamEnv, Ty, TyCtxt};
+use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
@@ -15,7 +16,7 @@ use rustc_span::source_map;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
-use syntax::{ast, attr};
+use syntax::ast;
 
 use log::debug;
 use std::cmp;

src/librustc_metadata/Cargo.toml

@@ -15,6 +15,7 @@ log = "0.4"
 memmap = "0.7"
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }
 rustc = { path = "../librustc" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_hir = { path = "../librustc_hir" }

src/librustc_metadata/native_libs.rs

@@ -2,6 +2,7 @@ use rustc::middle::cstore::{self, NativeLibrary};
 use rustc::session::parse::feature_err;
 use rustc::session::Session;
 use rustc::ty::TyCtxt;
+use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -9,7 +10,6 @@ use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_target::spec::abi::Abi;
-use syntax::attr;
 
 crate fn collect(tcx: TyCtxt<'_>) -> Vec<NativeLibrary> {
     let mut collector = Collector { tcx, libs: Vec::new() };

src/librustc_metadata/rmeta/decoder.rs

@@ -34,6 +34,7 @@ use std::u32;
 
 use log::debug;
 use proc_macro::bridge::client::ProcMacro;
+use rustc_attr as attr;
 use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
 use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, ProcMacroDerive};
 use rustc_serialize::{opaque, Decodable, Decoder, SpecializedDecoder};
@@ -41,7 +42,6 @@ use rustc_span::source_map::{self, respan, Spanned};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{self, hygiene::MacroKind, BytePos, Pos, Span, DUMMY_SP};
 use syntax::ast::{self, Ident};
-use syntax::attr;
 
 pub use cstore_impl::{provide, provide_extern};
 

src/librustc_metadata/rmeta/mod.rs

@@ -10,6 +10,7 @@ use rustc::mir;
 use rustc::session::config::SymbolManglingVersion;
 use rustc::session::CrateDisambiguator;
 use rustc::ty::{self, ReprOptions, Ty};
+use rustc_attr as attr;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::MetadataRef;
 use rustc_hir as hir;
@@ -21,7 +22,7 @@ use rustc_span::edition::Edition;
 use rustc_span::symbol::Symbol;
 use rustc_span::{self, Span};
 use rustc_target::spec::{PanicStrategy, TargetTriple};
-use syntax::{ast, attr};
+use syntax::ast;
 
 use std::marker::PhantomData;
 use std::num::NonZeroUsize;

src/librustc_mir/Cargo.toml

@@ -17,6 +17,7 @@ log = "0.4"
 log_settings = "0.1.1"
 polonius-engine = "0.11.0"
 rustc = { path = "../librustc" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_hir = { path = "../librustc_hir" }

src/librustc_mir/const_eval/fn_queries.rs

@@ -1,11 +1,11 @@
 use rustc::hir::map::blocks::FnLikeNode;
 use rustc::ty::query::Providers;
 use rustc::ty::TyCtxt;
+use rustc_attr as attr;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_span::symbol::Symbol;
 use rustc_target::spec::abi::Abi;
-use syntax::attr;
 
 /// Whether the `def_id` counts as const fn in your current crate, considering all active
 /// feature gates

src/librustc_mir/transform/inline.rs

@@ -16,8 +16,8 @@ use crate::transform::{MirPass, MirSource};
 use std::collections::VecDeque;
 use std::iter;
 
+use rustc_attr as attr;
 use rustc_target::spec::abi::Abi;
-use syntax::attr;
 
 const DEFAULT_THRESHOLD: usize = 50;
 const HINT_THRESHOLD: usize = 100;

src/librustc_mir_build/Cargo.toml

@@ -15,6 +15,7 @@ itertools = "0.8"
 log = "0.4"
 rustc = { path = "../librustc" }
 rustc_apfloat = { path = "../librustc_apfloat" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_index = { path = "../librustc_index" }
 rustc_errors = { path = "../librustc_errors" }

src/librustc_mir_build/build/matches/simplify.rs

@@ -18,8 +18,8 @@ use crate::hair::{self, *};
 use rustc::mir::interpret::truncate;
 use rustc::ty;
 use rustc::ty::layout::{Integer, IntegerExt, Size};
+use rustc_attr::{SignedInt, UnsignedInt};
 use rustc_hir::RangeEnd;
-use syntax::attr::{SignedInt, UnsignedInt};
 
 use std::mem;
 

src/librustc_mir_build/build/mod.rs

@@ -7,6 +7,7 @@ use rustc::middle::region;
 use rustc::mir::*;
 use rustc::ty::subst::Subst;
 use rustc::ty::{self, Ty, TyCtxt};
+use rustc_attr::{self as attr, UnwindAttr};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{GeneratorKind, HirIdMap, Node};
@@ -16,7 +17,6 @@ use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 use rustc_target::spec::PanicStrategy;
 use std::u32;
-use syntax::attr::{self, UnwindAttr};
 
 use super::lints;
 

src/librustc_mir_build/hair/pattern/_match.rs

@@ -245,8 +245,8 @@ use rustc::mir::interpret::{truncate, AllocId, ConstValue, Pointer, Scalar};
 use rustc::mir::Field;
 use rustc::util::common::ErrorReported;
 
+use rustc_attr::{SignedInt, UnsignedInt};
 use rustc_span::{Span, DUMMY_SP};
-use syntax::attr::{SignedInt, UnsignedInt};
 
 use arena::TypedArena;
 

src/librustc_mir_build/hair/pattern/mod.rs

@@ -1036,7 +1036,7 @@ crate fn compare_const_vals<'tcx>(
             }
             ty::Int(ity) => {
                 use rustc::ty::layout::{Integer, IntegerExt};
-                use syntax::attr::SignedInt;
+                use rustc_attr::SignedInt;
                 let size = Integer::from_attr(&tcx, SignedInt(ity)).size();
                 let a = sign_extend(a, size);
                 let b = sign_extend(b, size);

src/librustc_parse/Cargo.toml

@@ -12,6 +12,7 @@ doctest = false
 [dependencies]
 bitflags = "1.0"
 log = "0.4"
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_feature = { path = "../librustc_feature" }
 rustc_lexer = { path = "../librustc_lexer" }

src/librustc_parse/config.rs

@@ -9,6 +9,7 @@
 //! [#64197]: https://github.com/rust-lang/rust/issues/64197
 
 use crate::{parse_in, validate_attr};
+use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{error_code, struct_span_err, Applicability, Handler};
 use rustc_feature::{Feature, Features, State as FeatureState};
@@ -19,7 +20,6 @@ use rustc_span::edition::{Edition, ALL_EDITIONS};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use syntax::ast::{self, AttrItem, Attribute, MetaItem};
-use syntax::attr;
 use syntax::attr::HasAttrs;
 use syntax::mut_visit::*;
 use syntax::ptr::P;

src/librustc_passes/Cargo.toml

@@ -11,6 +11,7 @@ path = "lib.rs"
 [dependencies]
 log = "0.4"
 rustc = { path = "../librustc" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_feature = { path = "../librustc_feature" }

src/librustc_passes/stability.rs

@@ -10,6 +10,7 @@ use rustc::session::Session;
 use rustc::traits::misc::can_type_implement_copy;
 use rustc::ty::query::Providers;
 use rustc::ty::TyCtxt;
+use rustc_attr::{self as attr, Stability};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -20,7 +21,6 @@ use rustc_hir::{Generics, HirId, Item, StructField, Variant};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;
 use syntax::ast::Attribute;
-use syntax::attr::{self, Stability};
 
 use std::cmp::Ordering;
 use std::mem::replace;

src/librustc_privacy/Cargo.toml

@@ -10,6 +10,7 @@ path = "lib.rs"
 
 [dependencies]
 rustc = { path = "../librustc" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_hir = { path = "../librustc_hir" }
 rustc_typeck = { path = "../librustc_typeck" }

src/librustc_privacy/lib.rs

@@ -11,6 +11,7 @@ use rustc::ty::fold::TypeVisitor;
 use rustc::ty::query::Providers;
 use rustc::ty::subst::InternalSubsts;
 use rustc::ty::{self, GenericParamDefKind, TraitRef, Ty, TyCtxt, TypeFoldable};
+use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -22,7 +23,6 @@ use rustc_span::hygiene::Transparency;
 use rustc_span::symbol::{kw, sym};
 use rustc_span::Span;
 use syntax::ast::Ident;
-use syntax::attr;
 
 use std::marker::PhantomData;
 use std::{cmp, fmt, mem};

src/librustc_resolve/Cargo.toml

@@ -17,6 +17,7 @@ syntax = { path = "../libsyntax" }
 arena = { path = "../libarena" }
 rustc = { path = "../librustc" }
 rustc_ast_lowering = { path = "../librustc_ast_lowering" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_expand = { path = "../librustc_expand" }

src/librustc_resolve/build_reduced_graph.rs

@@ -20,6 +20,7 @@ use rustc::bug;
 use rustc::hir::exports::Export;
 use rustc::middle::cstore::CrateStore;
 use rustc::ty;
+use rustc_attr as attr;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{struct_span_err, Applicability};
 use rustc_expand::base::SyntaxExtension;
@@ -34,7 +35,6 @@ use rustc_span::{Span, DUMMY_SP};
 use syntax::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
 use syntax::ast::{AssocItem, AssocItemKind, MetaItemKind, StmtKind};
 use syntax::ast::{Ident, Name};
-use syntax::attr;
 use syntax::token::{self, Token};
 use syntax::visit::{self, Visitor};
 

src/librustc_resolve/macros.rs

@@ -10,6 +10,7 @@ use rustc::middle::stability;
 use rustc::session::parse::feature_err;
 use rustc::session::Session;
 use rustc::{lint, span_bug, ty};
+use rustc_attr::{self as attr, StabilityLevel};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_expand::base::SyntaxExtension;
 use rustc_expand::base::{self, Indeterminate, InvocationRes};
@@ -23,7 +24,6 @@ use rustc_span::hygiene::{self, ExpnData, ExpnId, ExpnKind};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use syntax::ast::{self, Ident, NodeId};
-use syntax::attr::{self, StabilityLevel};
 use syntax::print::pprust;
 
 use rustc_data_structures::sync::Lrc;

src/librustc_typeck/Cargo.toml

@@ -14,6 +14,7 @@ doctest = false
 arena = { path = "../libarena" }
 log = "0.4"
 rustc = { path = "../librustc" }
+rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_hir = { path = "../librustc_hir" }

src/librustc_typeck/check/mod.rs

@@ -115,6 +115,7 @@ use rustc::ty::{
     self, AdtKind, CanonicalUserType, Const, GenericParamDefKind, RegionKind, ToPolyTraitRef,
     ToPredicate, Ty, TyCtxt, UserType, WithConstness,
 };
+use rustc_attr as attr;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder, DiagnosticId};
@@ -131,7 +132,6 @@ use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{self, BytePos, MultiSpan, Span};
 use rustc_target::spec::abi::Abi;
 use syntax::ast;
-use syntax::attr;
 use syntax::util::parser::ExprPrecedence;
 
 use std::cell::{Cell, Ref, RefCell, RefMut};

src/librustc_typeck/collect.rs

@@ -33,6 +33,7 @@ use rustc::ty::util::Discr;
 use rustc::ty::util::IntTypeExt;
 use rustc::ty::{self, AdtKind, Const, DefIdTree, ToPolyTraitRef, Ty, TyCtxt, WithConstness};
 use rustc::ty::{ReprOptions, ToPredicate};
+use rustc_attr::{list_contains_name, mark_used, InlineAttr, OptimizeAttr};
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{struct_span_err, Applicability, StashKey};
@@ -46,7 +47,6 @@ use rustc_span::{Span, DUMMY_SP};
 use rustc_target::spec::abi;
 use syntax::ast;
 use syntax::ast::{Ident, MetaItemKind};
-use syntax::attr::{list_contains_name, mark_used, InlineAttr, OptimizeAttr};
 
 struct OnlySelfBounds(bool);
 

src/librustdoc/clean/mod.rs

@@ -16,6 +16,7 @@ use rustc::middle::stability;
 use rustc::ty::fold::TypeFolder;
 use rustc::ty::subst::InternalSubsts;
 use rustc::ty::{self, AdtKind, Lift, Ty, TyCtxt};
+use rustc_attr as attr;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
@@ -27,7 +28,6 @@ use rustc_span::symbol::{kw, sym};
 use rustc_span::{self, Pos};
 use rustc_typeck::hir_ty_to_ty;
 use syntax::ast::{self, Ident};
-use syntax::attr;
 
 use std::collections::hash_map::Entry;
 use std::default::Default;

src/librustdoc/core.rs

@@ -15,13 +15,13 @@ use rustc_lint;
 use rustc_resolve as resolve;
 use rustc_session::lint;
 
+use rustc_attr as attr;
 use rustc_errors::emitter::{Emitter, EmitterWriter};
 use rustc_errors::json::JsonEmitter;
 use rustc_span::source_map;
 use rustc_span::symbol::sym;
 use rustc_span::DUMMY_SP;
 use syntax::ast::CRATE_NODE_ID;
-use syntax::attr;
 
 use rustc_data_structures::sync::{self, Lrc};
 use std::cell::RefCell;

src/librustdoc/lib.rs

@@ -21,6 +21,7 @@
 extern crate env_logger;
 extern crate getopts;
 extern crate rustc;
+extern crate rustc_attr;
 extern crate rustc_data_structures;
 extern crate rustc_driver;
 extern crate rustc_errors;

src/libsyntax/attr/mod.rs

@@ -1,12 +1,5 @@
 //! Functions dealing with attributes and meta items.
 
-mod builtin;
-
-pub use builtin::*;
-pub use IntType::*;
-pub use ReprAttr::*;
-pub use StabilityLevel::*;
-
 use crate::ast;
 use crate::ast::{AttrId, AttrItem, AttrKind, AttrStyle, AttrVec, Attribute};
 use crate::ast::{Expr, GenericParam, Item, Lit, LitKind, Local, Stmt, StmtKind};