Rollup merge of #58273 - taiki-e:rename-dependency, r=matthewjasper

Rename rustc_errors dependency in rust 2018 crates

I think this is a better solution than `use rustc_errors as errors` in `lib.rs` and `use crate::errors` in modules.

Related: rust-lang/cargo#5653

cc #58099

r? @Centril

65 files changed, 114 insertions, 121 deletions

diff --git a/src/librustc/Cargo.toml b/src/librustc/Cargo.toml
index c9a04f4c683..cb9eb32f8d2 100644
--- a/src/librustc/Cargo.toml
+++ b/src/librustc/Cargo.toml
@@ -25,7 +25,7 @@ rustc-rayon-core = "0.1.1"
 rustc_apfloat = { path = "../librustc_apfloat" }
 rustc_target = { path = "../librustc_target" }
 rustc_data_structures = { path = "../librustc_data_structures" }
-rustc_errors = { path = "../librustc_errors" }
+errors = { path = "../librustc_errors", package = "rustc_errors" }
 serialize = { path = "../libserialize" }
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }
diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs
index 59ec459de96..de57edc1251 100644
--- a/src/librustc/dep_graph/graph.rs
+++ b/src/librustc/dep_graph/graph.rs
@@ -1,4 +1,4 @@
-use crate::errors::{Diagnostic, DiagnosticBuilder};
+use errors::{Diagnostic, DiagnosticBuilder};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs
index 6ff4db75004..cc5b105bad0 100644
--- a/src/librustc/hir/lowering.rs
+++ b/src/librustc/hir/lowering.rs
@@ -31,7 +31,6 @@
 //! in the HIR, especially for multiple identifiers.
 
 use crate::dep_graph::DepGraph;
-use crate::errors::Applicability;
 use crate::hir::{self, ParamName};
 use crate::hir::HirVec;
 use crate::hir::map::{DefKey, DefPathData, Definitions};
@@ -41,14 +40,15 @@ use crate::hir::GenericArg;
 use crate::lint::builtin::{self, PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
                     ELIDED_LIFETIMES_IN_PATHS};
 use crate::middle::cstore::CrateStore;
-use rustc_data_structures::fx::FxHashSet;
-use rustc_data_structures::indexed_vec::IndexVec;
-use rustc_data_structures::thin_vec::ThinVec;
-use rustc_data_structures::sync::Lrc;
 use crate::session::Session;
 use crate::session::config::nightly_options;
 use crate::util::common::FN_OUTPUT_NAME;
 use crate::util::nodemap::{DefIdMap, NodeMap};
+use errors::Applicability;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::indexed_vec::IndexVec;
+use rustc_data_structures::thin_vec::ThinVec;
+use rustc_data_structures::sync::Lrc;
 
 use std::collections::{BTreeSet, BTreeMap};
 use std::fmt::Debug;
diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs
index d9759da9dfc..bf16ec0be83 100644
--- a/src/librustc/hir/mod.rs
+++ b/src/librustc/hir/mod.rs
@@ -10,12 +10,12 @@ pub use self::PrimTy::*;
 pub use self::UnOp::*;
 pub use self::UnsafeSource::*;
 
-use crate::errors::FatalError;
 use crate::hir::def::Def;
 use crate::hir::def_id::{DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX};
 use crate::util::nodemap::{NodeMap, FxHashSet};
 use crate::mir::mono::Linkage;
 
+use errors::FatalError;
 use syntax_pos::{Span, DUMMY_SP, symbol::InternedString};
 use syntax::source_map::Spanned;
 use rustc_target::spec::abi::Abi;
diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs
index 89237b34c7f..ff4e520d8e0 100644
--- a/src/librustc/infer/error_reporting/mod.rs
+++ b/src/librustc/infer/error_reporting/mod.rs
@@ -50,16 +50,16 @@ use super::region_constraints::GenericKind;
 use super::{InferCtxt, RegionVariableOrigin, SubregionOrigin, TypeTrace, ValuePairs};
 use crate::infer::{self, SuppressRegionErrors};
 
-use crate::errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
 use crate::hir;
 use crate::hir::def_id::DefId;
 use crate::hir::Node;
 use crate::middle::region;
-use std::{cmp, fmt};
-use syntax_pos::{Pos, Span};
 use crate::traits::{ObligationCause, ObligationCauseCode};
 use crate::ty::error::TypeError;
 use crate::ty::{self, subst::Subst, Region, Ty, TyCtxt, TyKind, TypeFoldable};
+use errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
+use std::{cmp, fmt};
+use syntax_pos::{Pos, Span};
 
 mod note;
 
diff --git a/src/librustc/infer/error_reporting/need_type_info.rs b/src/librustc/infer/error_reporting/need_type_info.rs
index e63fa230b3e..0fbdbe15a3c 100644
--- a/src/librustc/infer/error_reporting/need_type_info.rs
+++ b/src/librustc/infer/error_reporting/need_type_info.rs
@@ -5,7 +5,7 @@ use crate::infer::type_variable::TypeVariableOrigin;
 use crate::ty::{self, Ty, Infer, TyVar};
 use syntax::source_map::CompilerDesugaringKind;
 use syntax_pos::Span;
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 struct FindLocalByTypeVisitor<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
     infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
diff --git a/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs b/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs
index d66bb274b34..b10af400f2b 100644
--- a/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs
+++ b/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs
@@ -3,7 +3,7 @@
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::ty;
 use crate::util::common::ErrorReported;
-use crate::errors::Applicability;
+use errors::Applicability;
 
 impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> {
     /// When given a `ConcreteFailure` for a function with arguments containing a named region and
diff --git a/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs b/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
index 6893a1fb168..843fa8b0182 100644
--- a/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
+++ b/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
@@ -1,4 +1,4 @@
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 use crate::hir::def_id::DefId;
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError;
diff --git a/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs b/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs
index 3f029795227..23acaeb31f8 100644
--- a/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -4,7 +4,7 @@ use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError;
 use crate::ty::{BoundRegion, FreeRegion, RegionKind};
 use crate::util::common::ErrorReported;
-use crate::errors::Applicability;
+use errors::Applicability;
 
 impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> {
     /// Print the error message for lifetime errors when the return type is a static impl Trait.
diff --git a/src/librustc/infer/error_reporting/note.rs b/src/librustc/infer/error_reporting/note.rs
index 6c481e8c0c1..c05c6567bbe 100644
--- a/src/librustc/infer/error_reporting/note.rs
+++ b/src/librustc/infer/error_reporting/note.rs
@@ -2,7 +2,7 @@ use crate::infer::{self, InferCtxt, SubregionOrigin};
 use crate::middle::region;
 use crate::ty::{self, Region};
 use crate::ty::error::TypeError;
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     pub(super) fn note_region_origin(&self,
diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs
index c183c1adb12..88423086058 100644
--- a/src/librustc/infer/mod.rs
+++ b/src/librustc/infer/mod.rs
@@ -7,21 +7,12 @@ pub use self::SubregionOrigin::*;
 pub use self::ValuePairs::*;
 pub use crate::ty::IntVarValue;
 
-use arena::SyncDroplessArena;
-use crate::errors::DiagnosticBuilder;
 use crate::hir::def_id::DefId;
 use crate::infer::canonical::{Canonical, CanonicalVarValues};
 use crate::middle::free_region::RegionRelations;
 use crate::middle::lang_items;
 use crate::middle::region;
-use rustc_data_structures::unify as ut;
 use crate::session::config::BorrowckMode;
-use std::cell::{Cell, Ref, RefCell, RefMut};
-use std::collections::BTreeMap;
-use std::fmt;
-use syntax::ast;
-use syntax_pos::symbol::InternedString;
-use syntax_pos::{self, Span};
 use crate::traits::{self, ObligationCause, PredicateObligations, TraitEngine};
 use crate::ty::error::{ExpectedFound, TypeError, UnconstrainedNumeric};
 use crate::ty::fold::TypeFoldable;
@@ -31,6 +22,16 @@ use crate::ty::{self, GenericParamDefKind, Ty, TyCtxt, CtxtInterners};
 use crate::ty::{FloatVid, IntVid, TyVid};
 use crate::util::nodemap::FxHashMap;
 
+use arena::SyncDroplessArena;
+use errors::DiagnosticBuilder;
+use rustc_data_structures::unify as ut;
+use std::cell::{Cell, Ref, RefCell, RefMut};
+use std::collections::BTreeMap;
+use std::fmt;
+use syntax::ast;
+use syntax_pos::symbol::InternedString;
+use syntax_pos::Span;
+
 use self::combine::CombineFields;
 use self::lexical_region_resolve::LexicalRegionResolutions;
 use self::outlives::env::OutlivesEnvironment;
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index be147556477..bfe59eda06e 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -153,8 +153,6 @@ mod rustc {
     pub use crate::lint;
 }
 
-use rustc_errors as errors;
-
 // FIXME(#27438): right now the unit tests of librustc don't refer to any actual
 //                functions generated in librustc_data_structures (all
 //                references are through generic functions), but statics are
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index cb31441ca47..6f10b0e2c0e 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -4,9 +4,9 @@
 //! compiler code, rather than using their own custom pass. Those
 //! lints are all available in `rustc_lint::builtin`.
 
-use crate::errors::{Applicability, DiagnosticBuilder};
 use crate::lint::{LintPass, LateLintPass, LintArray};
 use crate::session::Session;
+use errors::{Applicability, DiagnosticBuilder};
 use syntax::ast;
 use syntax::source_map::Span;
 
diff --git a/src/librustc/lint/context.rs b/src/librustc/lint/context.rs
index b90ef4ea221..9032fcf8b61 100644
--- a/src/librustc/lint/context.rs
+++ b/src/librustc/lint/context.rs
@@ -34,7 +34,7 @@ use std::default::Default as StdDefault;
 use syntax::ast;
 use syntax::edition;
 use syntax_pos::{MultiSpan, Span, symbol::{LocalInternedString, Symbol}};
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 use crate::hir;
 use crate::hir::def_id::LOCAL_CRATE;
 use crate::hir::intravisit as hir_visit;
diff --git a/src/librustc/lint/levels.rs b/src/librustc/lint/levels.rs
index 62bd54de7c9..924aa3fde0a 100644
--- a/src/librustc/lint/levels.rs
+++ b/src/librustc/lint/levels.rs
@@ -1,20 +1,20 @@
 use std::cmp;
 
-use crate::errors::{Applicability, DiagnosticBuilder};
 use crate::hir::HirId;
 use crate::ich::StableHashingContext;
 use crate::lint::builtin;
 use crate::lint::context::CheckLintNameResult;
 use crate::lint::{self, Lint, LintId, Level, LintSource};
+use crate::session::Session;
+use crate::util::nodemap::FxHashMap;
+use errors::{Applicability, DiagnosticBuilder};
 use rustc_data_structures::stable_hasher::{HashStable, ToStableHashKey,
                                            StableHasher, StableHasherResult};
-use crate::session::Session;
 use syntax::ast;
 use syntax::attr;
 use syntax::feature_gate;
 use syntax::source_map::MultiSpan;
 use syntax::symbol::Symbol;
-use crate::util::nodemap::FxHashMap;
 
 pub struct LintLevelSets {
     list: Vec<LintSet>,
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index 9fcc3be66aa..859ceb4bd07 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -23,13 +23,16 @@ pub use self::LintSource::*;
 
 use rustc_data_structures::sync::{self, Lrc};
 
-use crate::errors::{DiagnosticBuilder, DiagnosticId};
 use crate::hir::def_id::{CrateNum, LOCAL_CRATE};
 use crate::hir::intravisit;
 use crate::hir;
 use crate::lint::builtin::{BuiltinLintDiagnostics, DUPLICATE_MATCHER_BINDING_NAME};
 use crate::lint::builtin::parser::{QUESTION_MARK_MACRO_SEP, ILL_FORMED_ATTRIBUTE_INPUT};
 use crate::session::{Session, DiagnosticMessageId};
+use crate::ty::TyCtxt;
+use crate::ty::query::Providers;
+use crate::util::nodemap::NodeMap;
+use errors::{DiagnosticBuilder, DiagnosticId};
 use std::{hash, ptr};
 use syntax::ast;
 use syntax::source_map::{MultiSpan, ExpnFormat};
@@ -37,9 +40,6 @@ use syntax::early_buffered_lints::BufferedEarlyLintId;
 use syntax::edition::Edition;
 use syntax::symbol::Symbol;
 use syntax_pos::Span;
-use crate::ty::TyCtxt;
-use crate::ty::query::Providers;
-use crate::util::nodemap::NodeMap;
 
 pub use crate::lint::context::{LateContext, EarlyContext, LintContext, LintStore,
                         check_crate, check_ast_crate, CheckLintNameResult,
diff --git a/src/librustc/middle/lib_features.rs b/src/librustc/middle/lib_features.rs
index 45095d9bc98..331343e052d 100644
--- a/src/librustc/middle/lib_features.rs
+++ b/src/librustc/middle/lib_features.rs
@@ -5,12 +5,12 @@
 // (unlike lang features), which means we need to collect them instead.
 
 use crate::ty::TyCtxt;
+use crate::hir::intravisit::{self, NestedVisitorMap, Visitor};
 use syntax::symbol::Symbol;
 use syntax::ast::{Attribute, MetaItem, MetaItemKind};
 use syntax_pos::Span;
-use crate::hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_data_structures::fx::{FxHashSet, FxHashMap};
-use crate::errors::DiagnosticId;
+use errors::DiagnosticId;
 
 pub struct LibFeatures {
     // A map from feature to stabilisation version.
diff --git a/src/librustc/middle/liveness.rs b/src/librustc/middle/liveness.rs
index a18574f030c..d3925f40e09 100644
--- a/src/librustc/middle/liveness.rs
+++ b/src/librustc/middle/liveness.rs
@@ -102,9 +102,9 @@ use crate::hir::Node;
 use crate::ty::{self, TyCtxt};
 use crate::ty::query::Providers;
 use crate::lint;
-use crate::errors::Applicability;
 use crate::util::nodemap::{NodeMap, HirIdMap, HirIdSet};
 
+use errors::Applicability;
 use std::collections::{BTreeMap, VecDeque};
 use std::{fmt, u32};
 use std::io::prelude::*;
diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs
index 4e42816b3c6..5f7b9cc3366 100644
--- a/src/librustc/middle/resolve_lifetime.rs
+++ b/src/librustc/middle/resolve_lifetime.rs
@@ -11,10 +11,11 @@ use crate::hir::map::Map;
 use crate::hir::{GenericArg, GenericParam, ItemLocalId, LifetimeName, Node, ParamName};
 use crate::ty::{self, DefIdTree, GenericParamDefKind, TyCtxt};
 
-use crate::errors::{Applicability, DiagnosticBuilder};
 use crate::rustc::lint;
-use rustc_data_structures::sync::Lrc;
 use crate::session::Session;
+use crate::util::nodemap::{DefIdMap, FxHashMap, FxHashSet, NodeMap, NodeSet};
+use errors::{Applicability, DiagnosticBuilder};
+use rustc_data_structures::sync::Lrc;
 use std::borrow::Cow;
 use std::cell::Cell;
 use std::mem::replace;
@@ -23,7 +24,6 @@ use syntax::attr;
 use syntax::ptr::P;
 use syntax::symbol::keywords;
 use syntax_pos::Span;
-use crate::util::nodemap::{DefIdMap, FxHashMap, FxHashSet, NodeMap, NodeSet};
 
 use crate::hir::intravisit::{self, NestedVisitorMap, Visitor};
 use crate::hir::{self, GenericParamKind, LifetimeParamKind};
diff --git a/src/librustc/mir/interpret/error.rs b/src/librustc/mir/interpret/error.rs
index d456f29439d..29beabdb2ab 100644
--- a/src/librustc/mir/interpret/error.rs
+++ b/src/librustc/mir/interpret/error.rs
@@ -11,7 +11,7 @@ use super::{RawConst, Pointer, InboundsCheck, ScalarMaybeUndef};
 use backtrace::Backtrace;
 
 use crate::ty::query::TyCtxtAt;
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 use syntax_pos::{Pos, Span};
 use syntax::ast;
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index 5f807bf99e7..22b1c3f18ac 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -19,7 +19,7 @@ use syntax::parse;
 use syntax::symbol::Symbol;
 use syntax::feature_gate::UnstableFeatures;
 
-use crate::errors::{ColorConfig, FatalError, Handler};
+use errors::{ColorConfig, FatalError, Handler};
 
 use getopts;
 use std::collections::{BTreeMap, BTreeSet};
@@ -2569,7 +2569,6 @@ mod dep_tracking {
 
 #[cfg(test)]
 mod tests {
-    use crate::errors;
     use getopts;
     use crate::lint;
     use crate::middle::cstore;
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index bfd447e8dd8..58bd4782b21 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -21,8 +21,8 @@ use rustc_data_structures::sync::{
     Ordering::SeqCst,
 };
 
-use crate::errors::{self, DiagnosticBuilder, DiagnosticId, Applicability};
-use crate::errors::emitter::{Emitter, EmitterWriter};
+use errors::{DiagnosticBuilder, DiagnosticId, Applicability};
+use errors::emitter::{Emitter, EmitterWriter};
 use syntax::ast::{self, NodeId};
 use syntax::edition::Edition;
 use syntax::feature_gate::{self, AttributeType};
diff --git a/src/librustc/traits/coherence.rs b/src/librustc/traits/coherence.rs
index a57007e51d3..35d8e2beef5 100644
--- a/src/librustc/traits/coherence.rs
+++ b/src/librustc/traits/coherence.rs
@@ -39,7 +39,7 @@ pub struct OverlapResult<'tcx> {
     pub involves_placeholder: bool,
 }
 
-pub fn add_placeholder_note(err: &mut crate::errors::DiagnosticBuilder<'_>) {
+pub fn add_placeholder_note(err: &mut errors::DiagnosticBuilder<'_>) {
     err.note(&format!(
         "this behavior recently changed as a result of a bug fix; \
          see rust-lang/rust#56105 for details"
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index 3a47b554b2a..eb284645d36 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -17,14 +17,11 @@ use super::{
     Overflow,
 };
 
-use crate::errors::{Applicability, DiagnosticBuilder};
 use crate::hir;
 use crate::hir::Node;
 use crate::hir::def_id::DefId;
 use crate::infer::{self, InferCtxt};
 use crate::infer::type_variable::TypeVariableOrigin;
-use std::fmt;
-use syntax::ast;
 use crate::session::DiagnosticMessageId;
 use crate::ty::{self, AdtKind, ToPredicate, ToPolyTraitRef, Ty, TyCtxt, TypeFoldable};
 use crate::ty::GenericParamDefKind;
@@ -35,6 +32,9 @@ use crate::ty::subst::Subst;
 use crate::ty::SubtypePredicate;
 use crate::util::nodemap::{FxHashMap, FxHashSet};
 
+use errors::{Applicability, DiagnosticBuilder};
+use std::fmt;
+use syntax::ast;
 use syntax_pos::{DUMMY_SP, Span, ExpnInfo, ExpnFormat};
 
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
diff --git a/src/librustc/traits/select.rs b/src/librustc/traits/select.rs
index 557784b3e3c..c2c05ce7af5 100644
--- a/src/librustc/traits/select.rs
+++ b/src/librustc/traits/select.rs
@@ -103,7 +103,7 @@ impl IntercrateAmbiguityCause {
     /// See #23980 for details.
     pub fn add_intercrate_ambiguity_hint<'a, 'tcx>(
         &self,
-        err: &mut crate::errors::DiagnosticBuilder<'_>,
+        err: &mut errors::DiagnosticBuilder<'_>,
     ) {
         err.note(&self.intercrate_ambiguity_hint());
     }
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 5a19b959684..18b0afe1fd9 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -2,7 +2,6 @@
 
 use crate::dep_graph::DepGraph;
 use crate::dep_graph::{self, DepNode, DepConstructor};
-use crate::errors::DiagnosticBuilder;
 use crate::session::Session;
 use crate::session::config::{BorrowckMode, OutputFilenames};
 use crate::session::config::CrateType;
@@ -43,6 +42,7 @@ use crate::ty::{BoundVar, BindingMode};
 use crate::ty::CanonicalPolyFnSig;
 use crate::util::nodemap::{DefIdMap, DefIdSet, ItemLocalMap};
 use crate::util::nodemap::{FxHashMap, FxHashSet};
+use errors::DiagnosticBuilder;
 use rustc_data_structures::interner::HashInterner;
 use smallvec::SmallVec;
 use rustc_data_structures::stable_hasher::{HashStable, hash_stable_hashmap,
@@ -1816,7 +1816,7 @@ pub mod tls {
     use std::ptr;
     use syntax_pos;
     use crate::ty::query;
-    use crate::errors::{Diagnostic, TRACK_DIAGNOSTICS};
+    use errors::{Diagnostic, TRACK_DIAGNOSTICS};
     use rustc_data_structures::OnDrop;
     use rustc_data_structures::sync::{self, Lrc, Lock};
     use rustc_data_structures::thin_vec::ThinVec;
diff --git a/src/librustc/ty/error.rs b/src/librustc/ty/error.rs
index d0c9677ea6e..e3e0ce14774 100644
--- a/src/librustc/ty/error.rs
+++ b/src/librustc/ty/error.rs
@@ -4,7 +4,7 @@ use std::borrow::Cow;
 use std::fmt;
 use rustc_target::spec::abi;
 use syntax::ast;
-use crate::errors::{Applicability, DiagnosticBuilder};
+use errors::{Applicability, DiagnosticBuilder};
 use syntax_pos::Span;
 
 use crate::hir;
diff --git a/src/librustc/ty/query/mod.rs b/src/librustc/ty/query/mod.rs
index 67a5c7d6c9a..3b191d4201f 100644
--- a/src/librustc/ty/query/mod.rs
+++ b/src/librustc/ty/query/mod.rs
@@ -1,9 +1,7 @@
 use crate::dep_graph::{self, DepConstructor, DepNode};
-use crate::errors::DiagnosticBuilder;
 use crate::hir::def_id::{CrateNum, DefId, DefIndex};
 use crate::hir::def::{Def, Export};
 use crate::hir::{self, TraitCandidate, ItemLocalId, CodegenFnAttrs};
-use rustc_data_structures::svh::Svh;
 use crate::infer::canonical::{self, Canonical};
 use crate::lint;
 use crate::middle::borrowck::BorrowCheckResult;
@@ -44,6 +42,8 @@ use crate::util::common::{ErrorReported};
 use crate::util::profiling::ProfileCategory::*;
 use crate::session::Session;
 
+use errors::DiagnosticBuilder;
+use rustc_data_structures::svh::Svh;
 use rustc_data_structures::bit_set::BitSet;
 use rustc_data_structures::indexed_vec::IndexVec;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
diff --git a/src/librustc/ty/query/on_disk_cache.rs b/src/librustc/ty/query/on_disk_cache.rs
index f948abc7f6f..c16f861dedb 100644
--- a/src/librustc/ty/query/on_disk_cache.rs
+++ b/src/librustc/ty/query/on_disk_cache.rs
@@ -1,28 +1,29 @@
 use crate::dep_graph::{DepNodeIndex, SerializedDepNodeIndex};
-use crate::errors::Diagnostic;
 use crate::hir;
 use crate::hir::def_id::{CrateNum, DefIndex, DefId, LocalDefId, LOCAL_CRATE};
 use crate::hir::map::definitions::DefPathHash;
 use crate::ich::{CachingSourceMapView, Fingerprint};
 use crate::mir::{self, interpret};
 use crate::mir::interpret::{AllocDecodingSession, AllocDecodingState};
-use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::thin_vec::ThinVec;
-use rustc_data_structures::sync::{Lrc, Lock, HashMapExt, Once};
-use rustc_data_structures::indexed_vec::{IndexVec, Idx};
 use crate::rustc_serialize::{Decodable, Decoder, Encodable, Encoder, opaque,
                       SpecializedDecoder, SpecializedEncoder,
                       UseSpecializedDecodable, UseSpecializedEncodable};
 use crate::session::{CrateDisambiguator, Session};
+use crate::ty;
+use crate::ty::codec::{self as ty_codec, TyDecoder, TyEncoder};
+use crate::ty::context::TyCtxt;
+use crate::util::common::time;
+
+use errors::Diagnostic;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::thin_vec::ThinVec;
+use rustc_data_structures::sync::{Lrc, Lock, HashMapExt, Once};
+use rustc_data_structures::indexed_vec::{IndexVec, Idx};
 use std::mem;
 use syntax::ast::NodeId;
 use syntax::source_map::{SourceMap, StableSourceFileId};
 use syntax_pos::{BytePos, Span, DUMMY_SP, SourceFile};
 use syntax_pos::hygiene::{Mark, SyntaxContext, ExpnInfo};
-use crate::ty;
-use crate::ty::codec::{self as ty_codec, TyDecoder, TyEncoder};
-use crate::ty::context::TyCtxt;
-use crate::util::common::time;
 
 const TAG_FILE_FOOTER: u128 = 0xC0FFEE_C0FFEE_C0FFEE_C0FFEE_C0FFEE;
 
diff --git a/src/librustc/ty/query/plumbing.rs b/src/librustc/ty/query/plumbing.rs
index 9b2a70a6a6d..267ee89a2ff 100644
--- a/src/librustc/ty/query/plumbing.rs
+++ b/src/librustc/ty/query/plumbing.rs
@@ -3,10 +3,6 @@
 //! manage the caches, and so forth.
 
 use crate::dep_graph::{DepNodeIndex, DepNode, DepKind, SerializedDepNodeIndex};
-use crate::errors::DiagnosticBuilder;
-use crate::errors::Level;
-use crate::errors::Diagnostic;
-use crate::errors::FatalError;
 use crate::ty::tls;
 use crate::ty::{TyCtxt};
 use crate::ty::query::Query;
@@ -16,6 +12,10 @@ use crate::ty::item_path;
 
 use crate::util::common::{profq_msg, ProfileQueriesMsg, QueryMsg};
 
+use errors::DiagnosticBuilder;
+use errors::Level;
+use errors::Diagnostic;
+use errors::FatalError;
 use rustc_data_structures::fx::{FxHashMap};
 use rustc_data_structures::sync::{Lrc, Lock};
 use rustc_data_structures::thin_vec::ThinVec;
diff --git a/src/librustc_resolve/Cargo.toml b/src/librustc_resolve/Cargo.toml
index 0ce82f2ce52..836b4ad38ca 100644
--- a/src/librustc_resolve/Cargo.toml
+++ b/src/librustc_resolve/Cargo.toml
@@ -16,7 +16,7 @@ log = "0.4"
 syntax = { path = "../libsyntax" }
 rustc = { path = "../librustc" }
 arena = { path = "../libarena" }
-rustc_errors = { path = "../librustc_errors" }
+errors = { path = "../librustc_errors", package = "rustc_errors" }
 syntax_pos = { path = "../libsyntax_pos" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_metadata = { path = "../librustc_metadata" }
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index 45cb2b6d5a8..a82f8df1547 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -22,7 +22,7 @@ use std::cell::Cell;
 use std::ptr;
 use rustc_data_structures::sync::Lrc;
 
-use crate::errors::Applicability;
+use errors::Applicability;
 
 use syntax::ast::{Name, Ident};
 use syntax::attr;
diff --git a/src/librustc_resolve/error_reporting.rs b/src/librustc_resolve/error_reporting.rs
index 8300e691bbe..0cabee71df9 100644
--- a/src/librustc_resolve/error_reporting.rs
+++ b/src/librustc_resolve/error_reporting.rs
@@ -1,5 +1,6 @@
 use std::cmp::Reverse;
 
+use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
 use log::debug;
 use rustc::hir::def::*;
 use rustc::hir::def::Namespace::*;
@@ -9,7 +10,6 @@ use syntax::ast::{ExprKind};
 use syntax::symbol::keywords;
 use syntax_pos::Span;
 
-use crate::errors::{Applicability, DiagnosticBuilder, DiagnosticId};
 use crate::macros::ParentScope;
 use crate::resolve_imports::ImportResolver;
 use crate::{import_candidate_to_enum_paths, is_self_type, is_self_value, path_names_to_string};
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index ab2ae4a8435..6e5c0acc570 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -10,8 +10,6 @@
 
 #![deny(rust_2018_idioms)]
 
-use rustc_errors as errors;
-
 pub use rustc::hir::def::{Namespace, PerNS};
 
 use GenericParameters::*;
diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs
index 55b5cf90eb0..63f752ac9c9 100644
--- a/src/librustc_resolve/macros.rs
+++ b/src/librustc_resolve/macros.rs
@@ -27,7 +27,7 @@ use syntax::symbol::{Symbol, keywords};
 use syntax::visit::Visitor;
 use syntax::util::lev_distance::find_best_match_for_name;
 use syntax_pos::{Span, DUMMY_SP};
-use crate::errors::Applicability;
+use errors::Applicability;
 
 use std::cell::Cell;
 use std::{mem, ptr};
diff --git a/src/libsyntax/Cargo.toml b/src/libsyntax/Cargo.toml
index f1e60ba78b7..4a0bb0302ff 100644
--- a/src/libsyntax/Cargo.toml
+++ b/src/libsyntax/Cargo.toml
@@ -15,7 +15,7 @@ serialize = { path = "../libserialize" }
 log = "0.4"
 scoped-tls = "0.1"
 syntax_pos = { path = "../libsyntax_pos" }
-rustc_errors = { path = "../librustc_errors" }
+errors = { path = "../librustc_errors", package = "rustc_errors" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_target = { path = "../librustc_target" }
 smallvec = { version = "0.6.7", features = ["union", "may_dangle"] }
diff --git a/src/libsyntax/attr/builtin.rs b/src/libsyntax/attr/builtin.rs
index 0b1e5d037c8..e84adc01cf0 100644
--- a/src/libsyntax/attr/builtin.rs
+++ b/src/libsyntax/attr/builtin.rs
@@ -1,10 +1,10 @@
 //! Parsing and validation of builtin attributes
 
 use crate::ast::{self, Attribute, MetaItem, Name, NestedMetaItemKind};
-use crate::errors::{Applicability, Handler};
 use crate::feature_gate::{Features, GatedCfg};
 use crate::parse::ParseSess;
 
+use errors::{Applicability, Handler};
 use syntax_pos::{symbol::Symbol, Span};
 
 use super::{list_contains_name, mark_used, MetaItemKind};
diff --git a/src/libsyntax/config.rs b/src/libsyntax/config.rs
index 5bab9e4e2c9..4e4432a3f33 100644
--- a/src/libsyntax/config.rs
+++ b/src/libsyntax/config.rs
@@ -9,12 +9,12 @@ use crate::feature_gate::{
 use crate::attr;
 use crate::ast;
 use crate::edition::Edition;
-use crate::errors::Applicability;
 use crate::mut_visit::*;
 use crate::parse::{token, ParseSess};
 use crate::ptr::P;
 use crate::util::map_in_place::MapInPlace;
 
+use errors::Applicability;
 use smallvec::SmallVec;
 
 /// A folder that strips out items that do not belong in the current configuration.
diff --git a/src/libsyntax/diagnostics/plugin.rs b/src/libsyntax/diagnostics/plugin.rs
index e79378d93bd..21024eb41ef 100644
--- a/src/libsyntax/diagnostics/plugin.rs
+++ b/src/libsyntax/diagnostics/plugin.rs
@@ -15,7 +15,7 @@ use syntax_pos::Span;
 
 use crate::diagnostics::metadata::output_metadata;
 
-pub use crate::errors::*;
+pub use errors::*;
 
 // Maximum width of any line in an extended error description (inclusive).
 const MAX_DESCRIPTION_WIDTH: usize = 80;
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 8491b3d0cad..5980261593d 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -4,7 +4,6 @@ use crate::ast::{self, Attribute, Name, PatKind, MetaItem};
 use crate::attr::HasAttrs;
 use crate::source_map::{SourceMap, Spanned, respan};
 use crate::edition::Edition;
-use crate::errors::{DiagnosticBuilder, DiagnosticId};
 use crate::ext::expand::{self, AstFragment, Invocation};
 use crate::ext::hygiene::{self, Mark, SyntaxContext, Transparency};
 use crate::mut_visit::{self, MutVisitor};
@@ -15,6 +14,7 @@ use crate::symbol::{keywords, Ident, Symbol};
 use crate::ThinVec;
 use crate::tokenstream::{self, TokenStream};
 
+use errors::{DiagnosticBuilder, DiagnosticId};
 use smallvec::{smallvec, SmallVec};
 use syntax_pos::{Span, MultiSpan, DUMMY_SP};
 
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 6c90662d658..d398437d7af 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -3,7 +3,6 @@ use crate::ast::{MacStmtStyle, StmtKind, ItemKind};
 use crate::attr::{self, HasAttrs};
 use crate::source_map::{ExpnInfo, MacroBang, MacroAttribute, dummy_spanned, respan};
 use crate::config::StripUnconfigured;
-use crate::errors::{Applicability, FatalError};
 use crate::ext::base::*;
 use crate::ext::derive::{add_derived_markers, collect_derives};
 use crate::ext::hygiene::{self, Mark, SyntaxContext};
@@ -20,6 +19,7 @@ use crate::tokenstream::{TokenStream, TokenTree};
 use crate::visit::{self, Visitor};
 use crate::util::map_in_place::MapInPlace;
 
+use errors::{Applicability, FatalError};
 use smallvec::{smallvec, SmallVec};
 use syntax_pos::{Span, DUMMY_SP, FileName};
 use syntax_pos::hygiene::ExpnFormat;
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index d4ea3b81a60..5de1ccec860 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -75,7 +75,6 @@ pub use ParseResult::*;
 use TokenTreeOrTokenTreeSlice::*;
 
 use crate::ast::Ident;
-use crate::errors::FatalError;
 use crate::ext::tt::quoted::{self, TokenTree};
 use crate::parse::{Directory, ParseSess};
 use crate::parse::parser::{Parser, PathStyle};
@@ -84,8 +83,9 @@ use crate::print::pprust;
 use crate::symbol::keywords;
 use crate::tokenstream::{DelimSpan, TokenStream};
 
+use errors::FatalError;
 use smallvec::{smallvec, SmallVec};
-use syntax_pos::{self, Span};
+use syntax_pos::Span;
 
 use rustc_data_structures::fx::FxHashMap;
 use std::collections::hash_map::Entry::{Occupied, Vacant};
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index f4e0041c862..bd64bb01021 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -1,6 +1,5 @@
 use crate::{ast, attr};
 use crate::edition::Edition;
-use crate::errors::FatalError;
 use crate::ext::base::{DummyResult, ExtCtxt, MacResult, SyntaxExtension};
 use crate::ext::base::{NormalTT, TTMacroExpander};
 use crate::ext::expand::{AstFragment, AstFragmentKind};
@@ -17,6 +16,7 @@ use crate::parse::token::Token::*;
 use crate::symbol::Symbol;
 use crate::tokenstream::{DelimSpan, TokenStream, TokenTree};
 
+use errors::FatalError;
 use syntax_pos::{Span, DUMMY_SP, symbol::Ident};
 use log::debug;
 
@@ -25,7 +25,7 @@ use std::borrow::Cow;
 use std::collections::hash_map::Entry;
 
 use rustc_data_structures::sync::Lrc;
-use crate::errors::Applicability;
+use errors::Applicability;
 
 const VALID_FRAGMENT_NAMES_MSG: &str = "valid fragment specifiers are \
     `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, \
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index ce0fae5fb45..d574b410ccc 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -20,11 +20,11 @@ use crate::attr;
 use crate::early_buffered_lints::BufferedEarlyLintId;
 use crate::source_map::Spanned;
 use crate::edition::{ALL_EDITIONS, Edition};
-use crate::errors::{DiagnosticBuilder, Handler};
 use crate::visit::{self, FnKind, Visitor};
 use crate::parse::ParseSess;
 use crate::symbol::Symbol;
 
+use errors::{DiagnosticBuilder, Handler};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_target::spec::abi::Abi;
 use syntax_pos::{Span, DUMMY_SP};
diff --git a/src/libsyntax/json.rs b/src/libsyntax/json.rs
index af785050532..9acd0d099a0 100644
--- a/src/libsyntax/json.rs
+++ b/src/libsyntax/json.rs
@@ -10,12 +10,13 @@
 // FIXME: spec the JSON output properly.
 
 use crate::source_map::{SourceMap, FilePathMapping};
-use crate::errors::registry::Registry;
-use crate::errors::{DiagnosticBuilder, SubDiagnostic, CodeSuggestion, SourceMapper};
-use crate::errors::{DiagnosticId, Applicability};
-use crate::errors::emitter::{Emitter, EmitterWriter};
 
-use syntax_pos::{self, MacroBacktrace, Span, SpanLabel, MultiSpan};
+use errors::registry::Registry;
+use errors::{DiagnosticBuilder, SubDiagnostic, CodeSuggestion, SourceMapper};
+use errors::{DiagnosticId, Applicability};
+use errors::emitter::{Emitter, EmitterWriter};
+
+use syntax_pos::{MacroBacktrace, Span, SpanLabel, MultiSpan};
 use rustc_data_structures::sync::{self, Lrc};
 use std::io::{self, Write};
 use std::vec;
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index a56cdf623bf..36488b3a69f 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -24,7 +24,7 @@
 #[allow(unused_extern_crates)]
 extern crate serialize as rustc_serialize; // used by deriving
 
-pub use rustc_errors as errors;
+pub use errors;
 use rustc_data_structures::sync::Lock;
 use rustc_data_structures::bit_set::GrowableBitSet;
 pub use rustc_data_structures::thin_vec::ThinVec;
@@ -37,7 +37,7 @@ use ast::AttrId;
 macro_rules! panictry {
     ($e:expr) => ({
         use std::result::Result::{Ok, Err};
-        use crate::errors::FatalError;
+        use errors::FatalError;
         match $e {
             Ok(e) => e,
             Err(mut e) => {
@@ -52,7 +52,7 @@ macro_rules! panictry {
 macro_rules! panictry_buffer {
     ($handler:expr, $e:expr) => ({
         use std::result::Result::{Ok, Err};
-        use crate::errors::{FatalError, DiagnosticBuilder};
+        use errors::{FatalError, DiagnosticBuilder};
         match $e {
             Ok(e) => e,
             Err(errs) => {
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 9168d4b61c1..babe0eef20f 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -1,10 +1,10 @@
 use crate::ast::{self, Ident};
 use crate::source_map::{SourceMap, FilePathMapping};
-use crate::errors::{Applicability, FatalError, Diagnostic, DiagnosticBuilder};
 use crate::parse::{token, ParseSess};
 use crate::symbol::{Symbol, keywords};
 
-use syntax_pos::{self, BytePos, CharPos, Pos, Span, NO_EXPANSION};
+use errors::{Applicability, FatalError, Diagnostic, DiagnosticBuilder};
+use syntax_pos::{BytePos, CharPos, Pos, Span, NO_EXPANSION};
 use core::unicode::property::Pattern_White_Space;
 
 use std::borrow::Cow;
@@ -1882,7 +1882,6 @@ mod tests {
     use crate::ast::{Ident, CrateConfig};
     use crate::symbol::Symbol;
     use crate::source_map::SourceMap;
-    use crate::errors;
     use crate::feature_gate::UnstableFeatures;
     use crate::parse::token;
     use crate::diagnostics::plugin::ErrorMap;
diff --git a/src/libsyntax/parse/lexer/unicode_chars.rs b/src/libsyntax/parse/lexer/unicode_chars.rs
index 75862178169..7da4284c0e4 100644
--- a/src/libsyntax/parse/lexer/unicode_chars.rs
+++ b/src/libsyntax/parse/lexer/unicode_chars.rs
@@ -2,7 +2,7 @@
 // http://www.unicode.org/Public/security/10.0.0/confusables.txt
 
 use syntax_pos::{Span, NO_EXPANSION};
-use crate::errors::{Applicability, DiagnosticBuilder};
+use errors::{Applicability, DiagnosticBuilder};
 use super::StringReader;
 
 const UNICODE_ARRAY: &[(char, &str, char)] = &[
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 69940ae621c..b2d4d97d57d 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -3,7 +3,6 @@
 use crate::ast::{self, CrateConfig, NodeId};
 use crate::early_buffered_lints::{BufferedEarlyLint, BufferedEarlyLintId};
 use crate::source_map::{SourceMap, FilePathMapping};
-use crate::errors::{FatalError, Level, Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
 use crate::feature_gate::UnstableFeatures;
 use crate::parse::parser::Parser;
 use crate::symbol::Symbol;
@@ -11,6 +10,7 @@ use crate::tokenstream::{TokenStream, TokenTree};
 use crate::diagnostics::plugin::ErrorMap;
 use crate::print::pprust::token_to_string;
 
+use errors::{FatalError, Level, Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
 use rustc_data_structures::sync::{Lrc, Lock};
 use syntax_pos::{Span, SourceFile, FileName, MultiSpan};
 use log::debug;
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 67154305735..50cedc0f8d4 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -33,7 +33,6 @@ use crate::ast::{RangeEnd, RangeSyntax};
 use crate::{ast, attr};
 use crate::ext::base::DummyResult;
 use crate::source_map::{self, SourceMap, Spanned, respan};
-use crate::errors::{self, Applicability, DiagnosticBuilder, DiagnosticId};
 use crate::parse::{self, SeqSep, classify, token};
 use crate::parse::lexer::{TokenAndSpan, UnmatchedBrace};
 use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
@@ -47,8 +46,9 @@ use crate::ThinVec;
 use crate::tokenstream::{self, DelimSpan, TokenTree, TokenStream, TreeAndJoint};
 use crate::symbol::{Symbol, keywords};
 
+use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
 use rustc_target::spec::abi::{self, Abi};
-use syntax_pos::{self, Span, MultiSpan, BytePos, FileName};
+use syntax_pos::{Span, MultiSpan, BytePos, FileName};
 use log::{debug, trace};
 
 use std::borrow::Cow;
diff --git a/src/libsyntax/show_span.rs b/src/libsyntax/show_span.rs
index 2c32771266e..5e0cf9eea78 100644
--- a/src/libsyntax/show_span.rs
+++ b/src/libsyntax/show_span.rs
@@ -6,7 +6,6 @@
 use std::str::FromStr;
 
 use crate::ast;
-use crate::errors;
 use crate::visit;
 use crate::visit::Visitor;
 
diff --git a/src/libsyntax/source_map.rs b/src/libsyntax/source_map.rs
index 1784bad0362..62a6972122a 100644
--- a/src/libsyntax/source_map.rs
+++ b/src/libsyntax/source_map.rs
@@ -24,7 +24,7 @@ use std::fs;
 use std::io;
 use log::debug;
 
-use crate::errors::SourceMapper;
+use errors::SourceMapper;
 
 /// Returns the span itself if it doesn't come from a macro expansion,
 /// otherwise return the call site span up to the `enclosing_sp` by
diff --git a/src/libsyntax/test.rs b/src/libsyntax/test.rs
index f45bf034ba2..56290fa771b 100644
--- a/src/libsyntax/test.rs
+++ b/src/libsyntax/test.rs
@@ -12,11 +12,10 @@ use std::vec;
 
 use log::debug;
 use smallvec::{smallvec, SmallVec};
-use syntax_pos::{self, DUMMY_SP, NO_EXPANSION, Span, SourceFile, BytePos};
+use syntax_pos::{DUMMY_SP, NO_EXPANSION, Span, SourceFile, BytePos};
 
 use crate::attr::{self, HasAttrs};
 use crate::source_map::{self, SourceMap, ExpnInfo, MacroAttribute, dummy_spanned, respan};
-use crate::errors;
 use crate::config;
 use crate::entry::{self, EntryPointType};
 use crate::ext::base::{ExtCtxt, Resolver};
diff --git a/src/libsyntax/test_snippet.rs b/src/libsyntax/test_snippet.rs
index add4d2bead1..cf39090e188 100644
--- a/src/libsyntax/test_snippet.rs
+++ b/src/libsyntax/test_snippet.rs
@@ -1,8 +1,9 @@
 use crate::source_map::{SourceMap, FilePathMapping};
-use crate::errors::Handler;
-use crate::errors::emitter::EmitterWriter;
 use crate::with_globals;
 
+use errors::Handler;
+use errors::emitter::EmitterWriter;
+
 use std::io;
 use std::io::prelude::*;
 use rustc_data_structures::sync::Lrc;
diff --git a/src/libsyntax_ext/Cargo.toml b/src/libsyntax_ext/Cargo.toml
index c22b55b8c13..773f0948a8a 100644
--- a/src/libsyntax_ext/Cargo.toml
+++ b/src/libsyntax_ext/Cargo.toml
@@ -11,7 +11,7 @@ crate-type = ["dylib"]
 
 [dependencies]
 fmt_macros = { path = "../libfmt_macros" }
-rustc_errors = { path = "../librustc_errors" }
+errors = { path = "../librustc_errors", package = "rustc_errors" }
 syntax = { path = "../libsyntax" }
 syntax_pos = { path = "../libsyntax_pos" }
 rustc_data_structures = { path = "../librustc_data_structures" }
diff --git a/src/libsyntax_ext/asm.rs b/src/libsyntax_ext/asm.rs
index ebcdceea7c5..8edd0e1ae38 100644
--- a/src/libsyntax_ext/asm.rs
+++ b/src/libsyntax_ext/asm.rs
@@ -4,7 +4,7 @@ use State::*;
 
 use rustc_data_structures::thin_vec::ThinVec;
 
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 use syntax::ast;
 use syntax::ext::base::{self, *};
diff --git a/src/libsyntax_ext/assert.rs b/src/libsyntax_ext/assert.rs
index 984ef26f5ab..d2c397e0ecc 100644
--- a/src/libsyntax_ext/assert.rs
+++ b/src/libsyntax_ext/assert.rs
@@ -1,4 +1,4 @@
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 use syntax::ast::{self, *};
 use syntax::source_map::Spanned;
diff --git a/src/libsyntax_ext/cfg.rs b/src/libsyntax_ext/cfg.rs
index e2104550878..090d730289d 100644
--- a/src/libsyntax_ext/cfg.rs
+++ b/src/libsyntax_ext/cfg.rs
@@ -2,7 +2,7 @@
 /// a literal `true` or `false` based on whether the given cfg matches the
 /// current compilation environment.
 
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 use syntax::ast;
 use syntax::ext::base::{self, *};
diff --git a/src/libsyntax_ext/deriving/custom.rs b/src/libsyntax_ext/deriving/custom.rs
index 7d9b8402cac..6aba4d83cd2 100644
--- a/src/libsyntax_ext/deriving/custom.rs
+++ b/src/libsyntax_ext/deriving/custom.rs
@@ -1,7 +1,7 @@
-use crate::errors::FatalError;
 use crate::proc_macro_impl::EXEC_STRATEGY;
 use crate::proc_macro_server;
 
+use errors::FatalError;
 use syntax::ast::{self, ItemKind, Attribute, Mac};
 use syntax::attr::{mark_used, mark_known};
 use syntax::source_map::Span;
diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index 428e9524340..5efa6b36f67 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -3,8 +3,8 @@ use Position::*;
 
 use fmt_macros as parse;
 
-use crate::errors::DiagnosticBuilder;
-use crate::errors::Applicability;
+use errors::DiagnosticBuilder;
+use errors::Applicability;
 
 use syntax::ast;
 use syntax::ext::base::{self, *};
diff --git a/src/libsyntax_ext/global_asm.rs b/src/libsyntax_ext/global_asm.rs
index 14dbd930023..2baf530aeda 100644
--- a/src/libsyntax_ext/global_asm.rs
+++ b/src/libsyntax_ext/global_asm.rs
@@ -8,7 +8,7 @@
 /// LLVM's `module asm "some assembly here"`. All of LLVM's caveats
 /// therefore apply.
 
-use crate::errors::DiagnosticBuilder;
+use errors::DiagnosticBuilder;
 
 use syntax::ast;
 use syntax::source_map::respan;
diff --git a/src/libsyntax_ext/lib.rs b/src/libsyntax_ext/lib.rs
index 77e60c13637..aa472eee3ca 100644
--- a/src/libsyntax_ext/lib.rs
+++ b/src/libsyntax_ext/lib.rs
@@ -16,8 +16,6 @@
 
 extern crate proc_macro;
 
-use rustc_errors as errors;
-
 mod diagnostics;
 
 mod asm;
diff --git a/src/libsyntax_ext/proc_macro_decls.rs b/src/libsyntax_ext/proc_macro_decls.rs
index 5730081ce01..d8f8decef39 100644
--- a/src/libsyntax_ext/proc_macro_decls.rs
+++ b/src/libsyntax_ext/proc_macro_decls.rs
@@ -1,7 +1,6 @@
 use std::mem;
 
 use crate::deriving;
-use crate::errors;
 
 use syntax::ast::{self, Ident};
 use syntax::attr;
diff --git a/src/libsyntax_ext/proc_macro_impl.rs b/src/libsyntax_ext/proc_macro_impl.rs
index 88e20e3dc7c..f0fc6392cd7 100644
--- a/src/libsyntax_ext/proc_macro_impl.rs
+++ b/src/libsyntax_ext/proc_macro_impl.rs
@@ -1,6 +1,6 @@
-use crate::errors::FatalError;
 use crate::proc_macro_server;
 
+use errors::FatalError;
 use syntax::source_map::Span;
 use syntax::ext::base::{self, *};
 use syntax::tokenstream::TokenStream;
diff --git a/src/libsyntax_ext/proc_macro_server.rs b/src/libsyntax_ext/proc_macro_server.rs
index 2158cfc089b..fd82dac5ab6 100644
--- a/src/libsyntax_ext/proc_macro_server.rs
+++ b/src/libsyntax_ext/proc_macro_server.rs
@@ -1,4 +1,4 @@
-use crate::errors::{self, Diagnostic, DiagnosticBuilder};
+use errors::{Diagnostic, DiagnosticBuilder};
 
 use std::panic;