Remove hir::map::blocks and use FnKind instead

compiler/rustc_const_eval/src/const_eval/fn_queries.rs

@@ -1,6 +1,5 @@
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
-use rustc_middle::hir::map::blocks::FnLikeNode;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::Symbol;
@@ -44,8 +43,8 @@ fn is_const_fn_raw(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
         } else {
             false
         }
-    } else if let Some(fn_like) = FnLikeNode::from_node(node) {
-        if fn_like.constness() == hir::Constness::Const {
+    } else if let Some(fn_kind) = node.fn_kind() {
+        if fn_kind.constness() == hir::Constness::Const {
             return true;
         }
 

compiler/rustc_hir/src/hir.rs

@@ -1,6 +1,7 @@
 use crate::def::{CtorKind, DefKind, Res};
 use crate::def_id::DefId;
 crate use crate::hir_id::{HirId, ItemLocalId};
+use crate::intravisit::FnKind;
 use crate::LangItem;
 
 use rustc_ast::util::parser::ExprPrecedence;
@@ -3258,6 +3259,32 @@ impl<'hir> Node<'hir> {
             _ => None,
         }
     }
+
+    pub fn fn_kind(self) -> Option<FnKind<'hir>> {
+        match self {
+            Node::Item(i) => match i.kind {
+                ItemKind::Fn(ref sig, ref generics, _) => {
+                    Some(FnKind::ItemFn(i.ident, generics, sig.header, &i.vis))
+                }
+                _ => None,
+            },
+            Node::TraitItem(ti) => match ti.kind {
+                TraitItemKind::Fn(ref sig, TraitFn::Provided(_)) => {
+                    Some(FnKind::Method(ti.ident, sig, None))
+                }
+                _ => None,
+            },
+            Node::ImplItem(ii) => match ii.kind {
+                ImplItemKind::Fn(ref sig, _) => Some(FnKind::Method(ii.ident, sig, Some(&ii.vis))),
+                _ => None,
+            },
+            Node::Expr(e) => match e.kind {
+                ExprKind::Closure(..) => Some(FnKind::Closure),
+                _ => None,
+            },
+            _ => None,
+        }
+    }
 }
 
 // Some nodes are used a lot. Make sure they don't unintentionally get bigger.

compiler/rustc_hir/src/intravisit.rs

@@ -117,6 +117,14 @@ impl<'a> FnKind<'a> {
             FnKind::Closure => None,
         }
     }
+
+    pub fn constness(self) -> Constness {
+        self.header().map_or(Constness::NotConst, |header| header.constness)
+    }
+
+    pub fn asyncness(self) -> IsAsync {
+        self.header().map_or(IsAsync::NotAsync, |header| header.asyncness)
+    }
 }
 
 /// An abstract representation of the HIR `rustc_middle::hir::map::Map`.

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs

@@ -143,9 +143,8 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         // similar to the asyncness fn in rustc_ty_utils::ty
         let hir_id = self.tcx().hir().local_def_id_to_hir_id(local_def_id);
         let node = self.tcx().hir().get(hir_id);
-        let fn_like = rustc_middle::hir::map::blocks::FnLikeNode::from_node(node)?;
-
-        Some(fn_like.asyncness())
+        let fn_kind = node.fn_kind()?;
+        Some(fn_kind.asyncness())
     }
 
     // Here, we check for the case where the anonymous region

compiler/rustc_middle/src/hir/map/mod.rs

@@ -20,8 +20,6 @@ use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 use std::collections::VecDeque;
 
-pub mod blocks;
-
 fn fn_decl<'hir>(node: Node<'hir>) -> Option<&'hir FnDecl<'hir>> {
     match node {
         Node::Item(Item { kind: ItemKind::Fn(sig, _, _), .. })

compiler/rustc_mir_build/src/lints.rs

@@ -2,7 +2,6 @@ use rustc_data_structures::graph::iterate::{
     NodeStatus, TriColorDepthFirstSearch, TriColorVisitor,
 };
 use rustc_hir::intravisit::FnKind;
-use rustc_middle::hir::map::blocks::FnLikeNode;
 use rustc_middle::mir::{BasicBlock, Body, Operand, TerminatorKind};
 use rustc_middle::ty::subst::{GenericArg, InternalSubsts};
 use rustc_middle::ty::{self, AssocItem, AssocItemContainer, Instance, TyCtxt};
@@ -14,8 +13,8 @@ crate fn check<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) {
     let def_id = body.source.def_id().expect_local();
     let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
 
-    if let Some(fn_like_node) = FnLikeNode::from_node(tcx.hir().get(hir_id)) {
-        if let FnKind::Closure = fn_like_node.kind() {
+    if let Some(fn_kind) = tcx.hir().get(hir_id).fn_kind() {
+        if let FnKind::Closure = fn_kind {
             // closures can't recur, so they don't matter.
             return;
         }

compiler/rustc_mir_transform/src/const_prop.rs

@@ -68,11 +68,10 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
             return;
         }
 
-        use rustc_middle::hir::map::blocks::FnLikeNode;
         let def_id = body.source.def_id().expect_local();
         let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
 
-        let is_fn_like = FnLikeNode::from_node(tcx.hir().get(hir_id)).is_some();
+        let is_fn_like = tcx.hir().get(hir_id).fn_kind().is_some();
         let is_assoc_const = tcx.def_kind(def_id.to_def_id()) == DefKind::AssocConst;
 
         // Only run const prop on functions, methods, closures and associated constants

compiler/rustc_mir_transform/src/coverage/mod.rs

@@ -19,7 +19,6 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_index::vec::IndexVec;
 use rustc_middle::hir;
-use rustc_middle::hir::map::blocks::FnLikeNode;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir::coverage::*;
 use rustc_middle::mir::dump_enabled;
@@ -64,7 +63,7 @@ impl<'tcx> MirPass<'tcx> for InstrumentCoverage {
         }
 
         let hir_id = tcx.hir().local_def_id_to_hir_id(mir_source.def_id().expect_local());
-        let is_fn_like = FnLikeNode::from_node(tcx.hir().get(hir_id)).is_some();
+        let is_fn_like = tcx.hir().get(hir_id).fn_kind().is_some();
 
         // Only instrument functions, methods, and closures (not constants since they are evaluated
         // at compile time by Miri).
@@ -74,7 +73,7 @@ impl<'tcx> MirPass<'tcx> for InstrumentCoverage {
         // be tricky if const expressions have no corresponding statements in the enclosing MIR.
         // Closures are carved out by their initial `Assign` statement.)
         if !is_fn_like {
-            trace!("InstrumentCoverage skipped for {:?} (not an FnLikeNode)", mir_source.def_id());
+            trace!("InstrumentCoverage skipped for {:?} (not an fn-like)", mir_source.def_id());
             return;
         }