Auto merge of #67803 - Centril:librustc_hir, r=Zoxc

Extract `rustc_hir` out of `rustc`

The new crate contains:
```rust
pub mod def;
pub mod def_id;
mod hir;
pub mod hir_id;
pub mod itemlikevisit;
pub mod pat_util;
pub mod print;
mod stable_hash_impls;

pub use hir::*;
pub use hir_id::*;
pub use stable_hash_impls::HashStableContext;
```

Remains to be done in follow-up PRs:

- Move `rustc::hir::map` into `rustc_hir_map` -- this has to be a separate crate due to the `dep_graph` (blocked on #67761).

- Move references to `rustc::hir` to `rustc_hir` where possible.

cc #65031

r? @Zoxc

Cargo.lock

@@ -3091,6 +3091,7 @@ dependencies = [
  "rustc_errors",
  "rustc_feature",
  "rustc_fs_util",
+ "rustc_hir",
  "rustc_index",
  "rustc_macros",
  "rustc_session",
@@ -3368,6 +3369,7 @@ dependencies = [
  "rustc_error_codes",
  "rustc_errors",
  "rustc_index",
+ "rustc_session",
  "rustc_span",
  "rustc_target",
  "smallvec 1.0.0",
@@ -3562,6 +3564,22 @@ dependencies = [
 name = "rustc_fs_util"
 version = "0.0.0"
 
+[[package]]
+name = "rustc_hir"
+version = "0.0.0"
+dependencies = [
+ "rustc_data_structures",
+ "rustc_errors",
+ "rustc_index",
+ "rustc_macros",
+ "rustc_session",
+ "rustc_span",
+ "rustc_target",
+ "serialize",
+ "smallvec 1.0.0",
+ "syntax",
+]
+
 [[package]]
 name = "rustc_incremental"
 version = "0.0.0"
@@ -3602,6 +3620,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_expand",
+ "rustc_hir",
  "rustc_incremental",
  "rustc_lint",
  "rustc_metadata",
@@ -3808,6 +3827,7 @@ dependencies = [
  "rustc_expand",
  "rustc_feature",
  "rustc_metadata",
+ "rustc_session",
  "rustc_span",
  "smallvec 1.0.0",
  "syntax",

src/librustc/Cargo.toml

@@ -23,6 +23,7 @@ rustc-rayon-core = "0.3.0"
 polonius-engine = "0.11.0"
 rustc_apfloat = { path = "../librustc_apfloat" }
 rustc_feature = { path = "../librustc_feature" }
+rustc_hir = { path = "../librustc_hir" }
 rustc_target = { path = "../librustc_target" }
 rustc_macros = { path = "../librustc_macros" }
 rustc_data_structures = { path = "../librustc_data_structures" }

src/librustc/arena.rs

@@ -41,10 +41,10 @@ macro_rules! arena_types {
                 rustc::hir::def_id::DefId,
                 rustc::ty::subst::SubstsRef<$tcx>
             )>,
-            [few, decode] mir_keys: rustc::util::nodemap::DefIdSet,
+            [few, decode] mir_keys: rustc::hir::def_id::DefIdSet,
             [decode] specialization_graph: rustc::traits::specialization_graph::Graph,
             [] region_scope_tree: rustc::middle::region::ScopeTree,
-            [] item_local_set: rustc::util::nodemap::ItemLocalSet,
+            [] item_local_set: rustc::hir::ItemLocalSet,
             [decode] mir_const_qualif: rustc_index::bit_set::BitSet<rustc::mir::Local>,
             [] trait_impls_of: rustc::ty::trait_def::TraitImpls,
             [] dropck_outlives:
@@ -87,7 +87,7 @@ macro_rules! arena_types {
                 >,
             [few] crate_inherent_impls: rustc::ty::CrateInherentImpls,
             [few] upstream_monomorphizations:
-                rustc::util::nodemap::DefIdMap<
+                rustc::hir::def_id::DefIdMap<
                     rustc_data_structures::fx::FxHashMap<
                         rustc::ty::subst::SubstsRef<'tcx>,
                         rustc::hir::def_id::CrateNum
@@ -113,10 +113,10 @@ macro_rules! arena_types {
             >,
             [few] get_lib_features: rustc::middle::lib_features::LibFeatures,
             [few] defined_lib_features: rustc::middle::lang_items::LanguageItems,
-            [few] visible_parent_map: rustc::util::nodemap::DefIdMap<rustc::hir::def_id::DefId>,
+            [few] visible_parent_map: rustc::hir::def_id::DefIdMap<rustc::hir::def_id::DefId>,
             [few] foreign_module: rustc::middle::cstore::ForeignModule,
             [few] foreign_modules: Vec<rustc::middle::cstore::ForeignModule>,
-            [few] reachable_non_generics: rustc::util::nodemap::DefIdMap<
+            [few] reachable_non_generics: rustc::hir::def_id::DefIdMap<
                 rustc::middle::exported_symbols::SymbolExportLevel
             >,
             [few] crate_variances: rustc::ty::CrateVariancesMap<'tcx>,

src/librustc/dep_graph/dep_node.rs

@@ -396,12 +396,6 @@ impl DefPathHash {
     }
 }
 
-impl DefId {
-    pub fn to_dep_node(self, tcx: TyCtxt<'_>, kind: DepKind) -> DepNode {
-        DepNode::from_def_path_hash(kind, tcx.def_path_hash(self))
-    }
-}
-
 rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
     // We use this for most things when incr. comp. is turned off.
     [] Null,

src/librustc/hir.rs

@@ -0,0 +1,30 @@
+//! HIR datatypes. See the [rustc guide] for more info.
+//!
+//! [rustc guide]: https://rust-lang.github.io/rustc-guide/hir.html
+
+pub mod check_attr;
+pub use rustc_hir::def;
+pub mod exports;
+pub use rustc_hir::def_id;
+pub use rustc_hir::hir_id::*;
+pub mod intravisit;
+pub use rustc_hir::itemlikevisit;
+pub mod map;
+pub use rustc_hir::pat_util;
+pub use rustc_hir::print;
+pub mod upvars;
+
+pub use rustc_hir::BlockCheckMode::*;
+pub use rustc_hir::FunctionRetTy::*;
+pub use rustc_hir::PrimTy::*;
+pub use rustc_hir::UnOp::*;
+pub use rustc_hir::UnsafeSource::*;
+pub use rustc_hir::*;
+
+use crate::ty::query::Providers;
+
+pub fn provide(providers: &mut Providers<'_>) {
+    check_attr::provide(providers);
+    map::provide(providers);
+    upvars::provide(providers);
+}

src/librustc/hir/check_attr.rs

@@ -7,14 +7,15 @@
 use crate::hir::def_id::DefId;
 use crate::hir::intravisit::{self, NestedVisitorMap, Visitor};
 use crate::hir::DUMMY_HIR_ID;
-use crate::hir::{self, Attribute, HirId, Item, ItemKind, TraitItem, TraitItemKind};
+use crate::hir::{self, HirId, Item, ItemKind, TraitItem, TraitItemKind};
 use crate::lint::builtin::UNUSED_ATTRIBUTES;
 use crate::ty::query::Providers;
 use crate::ty::TyCtxt;
 
 use rustc_error_codes::*;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
+use syntax::ast::Attribute;
 use syntax::attr;
 
 use std::fmt::{self, Display};

src/librustc/hir/exports.rs

@@ -0,0 +1,32 @@
+use crate::hir::def::Res;
+use crate::hir::def_id::DefIdMap;
+use crate::ty;
+
+use rustc_macros::HashStable;
+use rustc_span::Span;
+use syntax::ast;
+
+use std::fmt::Debug;
+
+/// This is the replacement export map. It maps a module to all of the exports
+/// within.
+pub type ExportMap<Id> = DefIdMap<Vec<Export<Id>>>;
+
+#[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, HashStable)]
+pub struct Export<Id> {
+    /// The name of the target.
+    pub ident: ast::Ident,
+    /// The resolution of the target.
+    pub res: Res<Id>,
+    /// The span of the target.
+    pub span: Span,
+    /// The visibility of the export.
+    /// We include non-`pub` exports for hygienic macros that get used from extern crates.
+    pub vis: ty::Visibility,
+}
+
+impl<Id> Export<Id> {
+    pub fn map_id<R>(self, map: impl FnMut(Id) -> R) -> Export<R> {
+        Export { ident: self.ident, res: self.res.map_id(map), span: self.span, vis: self.vis }
+    }
+}

src/librustc/hir/intravisit.rs

@@ -31,13 +31,66 @@
 //! This order consistency is required in a few places in rustc, for
 //! example generator inference, and possibly also HIR borrowck.
 
-use super::itemlikevisit::DeepVisitor;
-
+use crate::hir::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor};
 use crate::hir::map::Map;
 use crate::hir::*;
 
 use rustc_span::Span;
-use syntax::ast::{Attribute, Ident, Name};
+use syntax::ast::{Attribute, Ident, Label, Name};
+
+pub struct DeepVisitor<'v, V> {
+    visitor: &'v mut V,
+}
+
+impl<'v, 'hir, V> DeepVisitor<'v, V>
+where
+    V: Visitor<'hir> + 'v,
+{
+    pub fn new(base: &'v mut V) -> Self {
+        DeepVisitor { visitor: base }
+    }
+}
+
+impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
+where
+    V: Visitor<'hir>,
+{
+    fn visit_item(&mut self, item: &'hir Item<'hir>) {
+        self.visitor.visit_item(item);
+    }
+
+    fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>) {
+        self.visitor.visit_trait_item(trait_item);
+    }
+
+    fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>) {
+        self.visitor.visit_impl_item(impl_item);
+    }
+}
+
+pub trait IntoVisitor<'hir> {
+    type Visitor: Visitor<'hir>;
+    fn into_visitor(&self) -> Self::Visitor;
+}
+
+pub struct ParDeepVisitor<V>(pub V);
+
+impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
+where
+    V: IntoVisitor<'hir>,
+{
+    fn visit_item(&self, item: &'hir Item<'hir>) {
+        self.0.into_visitor().visit_item(item);
+    }
+
+    fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
+        self.0.into_visitor().visit_trait_item(trait_item);
+    }
+
+    fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
+        self.0.into_visitor().visit_impl_item(impl_item);
+    }
+}
 
 #[derive(Copy, Clone)]
 pub enum FnKind<'a> {

src/librustc/hir/map/collector.rs

@@ -1,16 +1,15 @@
 use super::*;
 use crate::dep_graph::{DepGraph, DepKind, DepNodeIndex};
 use crate::hir;
-use crate::hir::def_id::{CrateNum, LOCAL_CRATE};
+use crate::hir::def_id::{CrateNum, DefIndex, LOCAL_CRATE};
 use crate::hir::intravisit::{NestedVisitorMap, Visitor};
 use crate::hir::map::HirEntryMap;
 use crate::ich::Fingerprint;
 use crate::middle::cstore::CrateStore;
-use crate::session::CrateDisambiguator;
-use crate::session::Session;
-use crate::util::nodemap::FxHashMap;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::svh::Svh;
 use rustc_index::vec::IndexVec;
+use rustc_session::{CrateDisambiguator, Session};
 use rustc_span::source_map::SourceMap;
 use rustc_span::Span;
 use std::iter::repeat;

src/librustc/hir/map/definitions.rs

@@ -7,12 +7,12 @@
 use crate::hir;
 use crate::hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
 use crate::ich::Fingerprint;
-use crate::session::CrateDisambiguator;
-use crate::util::nodemap::NodeMap;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_index::vec::IndexVec;
+use rustc_session::node_id::NodeMap;
+use rustc_session::CrateDisambiguator;
 use rustc_span::hygiene::ExpnId;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;

src/librustc/hir/map/mod.rs

@@ -4,20 +4,21 @@ pub use self::definitions::{
 };
 
 use crate::dep_graph::{DepGraph, DepKind, DepNode, DepNodeIndex};
-use crate::hir::def_id::{DefId, LocalDefId, CRATE_DEF_INDEX};
+use crate::hir::def::{DefKind, Res};
+use crate::hir::def_id::{DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX};
 use crate::hir::itemlikevisit::ItemLikeVisitor;
 use crate::hir::print::Nested;
-use crate::hir::DefKind;
 use crate::hir::*;
 use crate::middle::cstore::CrateStoreDyn;
 use crate::ty::query::Providers;
 use crate::util::common::time;
-use crate::util::nodemap::FxHashMap;
 
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::svh::Svh;
 use rustc_index::vec::IndexVec;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::Spanned;
+use rustc_span::symbol::kw;
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
 use syntax::ast::{self, Name, NodeId};
@@ -1203,7 +1204,7 @@ impl Named for ImplItem<'_> {
 }
 
 pub fn map_crate<'hir>(
-    sess: &crate::session::Session,
+    sess: &rustc_session::Session,
     cstore: &CrateStoreDyn,
     forest: &'hir Forest<'hir>,
     definitions: Definitions,
@@ -1265,45 +1266,6 @@ impl<'hir> print::PpAnn for Map<'hir> {
     }
 }
 
-impl<'a> print::State<'a> {
-    pub fn print_node(&mut self, node: Node<'_>) {
-        match node {
-            Node::Param(a) => self.print_param(&a),
-            Node::Item(a) => self.print_item(&a),
-            Node::ForeignItem(a) => self.print_foreign_item(&a),
-            Node::TraitItem(a) => self.print_trait_item(a),
-            Node::ImplItem(a) => self.print_impl_item(a),
-            Node::Variant(a) => self.print_variant(&a),
-            Node::AnonConst(a) => self.print_anon_const(&a),
-            Node::Expr(a) => self.print_expr(&a),
-            Node::Stmt(a) => self.print_stmt(&a),
-            Node::PathSegment(a) => self.print_path_segment(&a),
-            Node::Ty(a) => self.print_type(&a),
-            Node::TraitRef(a) => self.print_trait_ref(&a),
-            Node::Binding(a) | Node::Pat(a) => self.print_pat(&a),
-            Node::Arm(a) => self.print_arm(&a),
-            Node::Block(a) => {
-                // Containing cbox, will be closed by print-block at `}`.
-                self.cbox(print::INDENT_UNIT);
-                // Head-ibox, will be closed by print-block after `{`.
-                self.ibox(0);
-                self.print_block(&a)
-            }
-            Node::Lifetime(a) => self.print_lifetime(&a),
-            Node::Visibility(a) => self.print_visibility(&a),
-            Node::GenericParam(_) => bug!("cannot print Node::GenericParam"),
-            Node::Field(_) => bug!("cannot print StructField"),
-            // These cases do not carry enough information in the
-            // `hir_map` to reconstruct their full structure for pretty
-            // printing.
-            Node::Ctor(..) => bug!("cannot print isolated Ctor"),
-            Node::Local(a) => self.print_local_decl(&a),
-            Node::MacroDef(_) => bug!("cannot print MacroDef"),
-            Node::Crate => bug!("cannot print Crate"),
-        }
-    }
-}
-
 fn hir_id_to_string(map: &Map<'_>, id: HirId, include_id: bool) -> String {
     let id_str = format!(" (hir_id={})", id);
     let id_str = if include_id { &id_str[..] } else { "" };