Auto merge of #62119 - Centril:rollup-el20wu0, r=Centril

Rollup of 7 pull requests

Successful merges:

 - #61814 (Fix an ICE with uninhabited consts)
 - #61987 (rustc: produce AST instead of HIR from `hir::lowering::Resolver` methods.)
 - #62055 (Fix error counting)
 - #62078 (Remove built-in derive macros `Send` and `Sync`)
 - #62085 (Add test for issue-38591)
 - #62091 (HirIdification: almost there)
 - #62096 (Implement From<Local> for Place and PlaceBase)

Failed merges:

r? @ghost

src/librustc/hir/lowering.rs

@@ -148,11 +148,11 @@ pub struct LoweringContext<'a> {
 
 pub trait Resolver {
     /// Resolve a path generated by the lowerer when expanding `for`, `if let`, etc.
-    fn resolve_hir_path(
+    fn resolve_ast_path(
         &mut self,
         path: &ast::Path,
         is_value: bool,
-    ) -> hir::Path;
+    ) -> Res<NodeId>;
 
     /// Obtain resolution for a `NodeId` with a single resolution.
     fn get_partial_res(&mut self, id: NodeId) -> Option<PartialRes>;
@@ -167,15 +167,15 @@ pub trait Resolver {
     /// This should only return `None` during testing.
     fn definitions(&mut self) -> &mut Definitions;
 
-    /// Given suffix `["b", "c", "d"]`, creates a HIR path for `[::crate_root]::b::c::d` and
+    /// Given suffix `["b", "c", "d"]`, creates an AST path for `[::crate_root]::b::c::d` and
     /// resolves it based on `is_value`.
     fn resolve_str_path(
         &mut self,
         span: Span,
         crate_root: Option<Symbol>,
         components: &[Symbol],
         is_value: bool,
-    ) -> hir::Path;
+    ) -> (ast::Path, Res<NodeId>);
 }
 
 /// Context of `impl Trait` in code, which determines whether it is allowed in an HIR subtree,
@@ -5546,16 +5546,26 @@ impl<'a> LoweringContext<'a> {
         params: Option<P<hir::GenericArgs>>,
         is_value: bool,
     ) -> hir::Path {
-        let mut path = self.resolver
+        let (path, res) = self.resolver
             .resolve_str_path(span, self.crate_root, components, is_value);
-        path.segments.last_mut().unwrap().args = params;
 
-        for seg in path.segments.iter_mut() {
-            if seg.hir_id.is_some() {
-                seg.hir_id = Some(self.next_id());
+        let mut segments: Vec<_> = path.segments.iter().map(|segment| {
+            let res = self.expect_full_res(segment.id);
+            hir::PathSegment {
+                ident: segment.ident,
+                hir_id: Some(self.lower_node_id(segment.id)),
+                res: Some(self.lower_res(res)),
+                infer_args: true,
+                args: None,
             }
+        }).collect();
+        segments.last_mut().unwrap().args = params;
+
+        hir::Path {
+            span,
+            res: res.map_id(|_| panic!("unexpected node_id")),
+            segments: segments.into(),
         }
-        path
     }
 
     fn ty_path(&mut self, mut hir_id: hir::HirId, span: Span, qpath: hir::QPath) -> hir::Ty {

src/librustc/hir/map/blocks.rs

@@ -87,7 +87,7 @@ impl<'a> Code<'a> {
         match map.get(id) {
             map::Node::Block(_) => {
                 //  Use the parent, hopefully an expression node.
-                Code::from_node(map, map.get_parent_node_by_hir_id(id))
+                Code::from_node(map, map.get_parent_node(id))
             }
             map::Node::Expr(expr) => Some(Code::Expr(expr)),
             node => FnLikeNode::from_node(node).map(Code::FnLike)

src/librustc/hir/map/mod.rs

@@ -292,7 +292,7 @@ impl<'hir> Map<'hir> {
     }
 
     fn def_kind(&self, hir_id: HirId) -> Option<DefKind> {
-        let node = if let Some(node) = self.find_by_hir_id(hir_id) {
+        let node = if let Some(node) = self.find(hir_id) {
             node
         } else {
             return None
@@ -347,7 +347,7 @@ impl<'hir> Map<'hir> {
                 if variant_data.ctor_hir_id().is_none() {
                     return None;
                 }
-                let ctor_of = match self.find_by_hir_id(self.get_parent_node_by_hir_id(hir_id)) {
+                let ctor_of = match self.find(self.get_parent_node(hir_id)) {
                     Some(Node::Item(..)) => def::CtorOf::Struct,
                     Some(Node::Variant(..)) => def::CtorOf::Variant,
                     _ => unreachable!(),
@@ -424,7 +424,7 @@ impl<'hir> Map<'hir> {
     /// which this is the body of, i.e., a `fn`, `const` or `static`
     /// item (possibly associated), a closure, or a `hir::AnonConst`.
     pub fn body_owner(&self, BodyId { hir_id }: BodyId) -> HirId {
-        let parent = self.get_parent_node_by_hir_id(hir_id);
+        let parent = self.get_parent_node(hir_id);
         assert!(self.lookup(parent).map_or(false, |e| e.is_body_owner(hir_id)));
         parent
     }
@@ -485,7 +485,7 @@ impl<'hir> Map<'hir> {
         match self.get(id) {
             Node::Item(&Item { node: ItemKind::Trait(..), .. }) |
             Node::Item(&Item { node: ItemKind::TraitAlias(..), .. }) => id,
-            Node::GenericParam(_) => self.get_parent_node_by_hir_id(id),
+            Node::GenericParam(_) => self.get_parent_node(id),
             _ => bug!("ty_param_owner: {} not a type parameter", self.node_to_string(id))
         }
     }
@@ -563,7 +563,7 @@ impl<'hir> Map<'hir> {
     /// Retrieves the `Node` corresponding to `id`, panicking if it cannot be found.
     pub fn get(&self, id: HirId) -> Node<'hir> {
         // read recorded by `find`
-        self.find_by_hir_id(id).unwrap_or_else(||
+        self.find(id).unwrap_or_else(||
             bug!("couldn't find hir id {} in the HIR map", id))
     }
 
@@ -595,13 +595,7 @@ impl<'hir> Map<'hir> {
     }
 
     /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
-    pub fn find(&self, id: NodeId) -> Option<Node<'hir>> {
-        let hir_id = self.node_to_hir_id(id);
-        self.find_by_hir_id(hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn find_by_hir_id(&self, hir_id: HirId) -> Option<Node<'hir>> {
+    pub fn find(&self, hir_id: HirId) -> Option<Node<'hir>> {
         let result = self.find_entry(hir_id).and_then(|entry| {
             if let Node::Crate = entry.node {
                 None
@@ -615,24 +609,17 @@ impl<'hir> Map<'hir> {
         result
     }
 
-    /// Similar to `get_parent`; returns the parent node-ID, or just `hir_id` if there
-    /// is no parent. Note that the parent may be `CRATE_NODE_ID`, which is not itself
+    /// Similar to `get_parent`; returns the parent HIR Id, or just `hir_id` if there
+    /// is no parent. Note that the parent may be `CRATE_HIR_ID`, which is not itself
     /// present in the map, so passing the return value of `get_parent_node` to
     /// `get` may in fact panic.
-    /// This function returns the immediate parent in the AST, whereas `get_parent`
+    /// This function returns the immediate parent in the HIR, whereas `get_parent`
     /// returns the enclosing item. Note that this might not be the actual parent
-    /// node in the AST -- some kinds of nodes are not in the map and these will
+    /// node in the HIR -- some kinds of nodes are not in the map and these will
     /// never appear as the parent node. Thus, you can always walk the parent nodes
-    /// from a node to the root of the AST (unless you get back the same ID here,
+    /// from a node to the root of the HIR (unless you get back the same ID here,
     /// which can happen if the ID is not in the map itself or is just weird).
-    pub fn get_parent_node(&self, id: NodeId) -> NodeId {
-        let hir_id = self.node_to_hir_id(id);
-        let parent_hir_id = self.get_parent_node_by_hir_id(hir_id);
-        self.hir_to_node_id(parent_hir_id)
-    }
-
-    // FIXME(@ljedrz): replace the `NodeId` variant.
-    pub fn get_parent_node_by_hir_id(&self, hir_id: HirId) -> HirId {
+    pub fn get_parent_node(&self, hir_id: HirId) -> HirId {
         if self.dep_graph.is_fully_enabled() {
             let hir_id_owner = hir_id.owner;
             let def_path_hash = self.definitions.def_path_hash(hir_id_owner);
@@ -646,7 +633,7 @@ impl<'hir> Map<'hir> {
 
     /// Check if the node is an argument. An argument is a local variable whose
     /// immediate parent is an item or a closure.
-    pub fn is_argument(&self, id: NodeId) -> bool {
+    pub fn is_argument(&self, id: HirId) -> bool {
         match self.find(id) {
             Some(Node::Binding(_)) => (),
             _ => return false,
@@ -687,7 +674,7 @@ impl<'hir> Map<'hir> {
     {
         let mut id = start_id;
         loop {
-            let parent_id = self.get_parent_node_by_hir_id(id);
+            let parent_id = self.get_parent_node(id);
             if parent_id == CRATE_HIR_ID {
                 return Ok(CRATE_HIR_ID);
             }
@@ -872,28 +859,28 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn expect_item(&self, id: HirId) -> &'hir Item {
-        match self.find_by_hir_id(id) { // read recorded by `find`
+        match self.find(id) { // read recorded by `find`
             Some(Node::Item(item)) => item,
             _ => bug!("expected item, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_impl_item(&self, id: HirId) -> &'hir ImplItem {
-        match self.find_by_hir_id(id) {
+        match self.find(id) {
             Some(Node::ImplItem(item)) => item,
             _ => bug!("expected impl item, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_trait_item(&self, id: HirId) -> &'hir TraitItem {
-        match self.find_by_hir_id(id) {
+        match self.find(id) {
             Some(Node::TraitItem(item)) => item,
             _ => bug!("expected trait item, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_variant_data(&self, id: HirId) -> &'hir VariantData {
-        match self.find_by_hir_id(id) {
+        match self.find(id) {
             Some(Node::Item(i)) => {
                 match i.node {
                     ItemKind::Struct(ref struct_def, _) |
@@ -908,21 +895,21 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn expect_variant(&self, id: HirId) -> &'hir Variant {
-        match self.find_by_hir_id(id) {
+        match self.find(id) {
             Some(Node::Variant(variant)) => variant,
             _ => bug!("expected variant, found {}", self.node_to_string(id)),
         }
     }
 
     pub fn expect_foreign_item(&self, id: HirId) -> &'hir ForeignItem {
-        match self.find_by_hir_id(id) {
+        match self.find(id) {
             Some(Node::ForeignItem(item)) => item,
             _ => bug!("expected foreign item, found {}", self.node_to_string(id))
         }
     }
 
     pub fn expect_expr(&self, id: HirId) -> &'hir Expr {
-        match self.find_by_hir_id(id) { // read recorded by find
+        match self.find(id) { // read recorded by find
             Some(Node::Expr(expr)) => expr,
             _ => bug!("expected expr, found {}", self.node_to_string(id))
         }
@@ -1028,8 +1015,8 @@ impl<'hir> Map<'hir> {
             Some(Node::Pat(pat)) => pat.span,
             Some(Node::Arm(arm)) => arm.span,
             Some(Node::Block(block)) => block.span,
-            Some(Node::Ctor(..)) => match self.find_by_hir_id(
-                self.get_parent_node_by_hir_id(hir_id))
+            Some(Node::Ctor(..)) => match self.find(
+                self.get_parent_node(hir_id))
             {
                 Some(Node::Item(item)) => item.span,
                 Some(Node::Variant(variant)) => variant.span,
@@ -1100,7 +1087,7 @@ impl<'a> NodesMatchingSuffix<'a> {
         // chain, then returns `None`.
         fn find_first_mod_parent<'a>(map: &'a Map<'_>, mut id: HirId) -> Option<(HirId, Name)> {
             loop {
-                if let Node::Item(item) = map.find_by_hir_id(id)? {
+                if let Node::Item(item) = map.find(id)? {
                     if item_is_mod(&item) {
                         return Some((id, item.ident.name))
                     }
@@ -1273,7 +1260,7 @@ fn hir_id_to_string(map: &Map<'_>, id: HirId, include_id: bool) -> String {
         })
     };
 
-    match map.find_by_hir_id(id) {
+    match map.find(id) {
         Some(Node::Item(item)) => {
             let item_str = match item.node {
                 ItemKind::ExternCrate(..) => "extern crate",

src/librustc/infer/error_reporting/mod.rs

@@ -86,7 +86,7 @@ impl<'tcx> TyCtxt<'tcx> {
                     )
                 };
                 let span = scope.span(self, region_scope_tree);
-                let tag = match self.hir().find_by_hir_id(scope.hir_id(region_scope_tree)) {
+                let tag = match self.hir().find(scope.hir_id(region_scope_tree)) {
                     Some(Node::Block(_)) => "block",
                     Some(Node::Expr(expr)) => match expr.node {
                         hir::ExprKind::Call(..) => "call",
@@ -182,7 +182,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
         let scope = region.free_region_binding_scope(self);
         let node = self.hir().as_local_hir_id(scope).unwrap_or(hir::DUMMY_HIR_ID);
-        let tag = match self.hir().find_by_hir_id(node) {
+        let tag = match self.hir().find(node) {
             Some(Node::Block(_)) | Some(Node::Expr(_)) => "body",
             Some(Node::Item(it)) => Self::item_scope_tag(&it),
             Some(Node::TraitItem(it)) => Self::trait_item_scope_tag(&it),

src/librustc/infer/mod.rs

@@ -171,6 +171,7 @@ pub struct InferCtxt<'a, 'tcx> {
     /// Track how many errors were reported when this infcx is created.
     /// If the number of errors increases, that's also a sign (line
     /// `tained_by_errors`) to avoid reporting certain kinds of errors.
+    // FIXME(matthewjasper) Merge into `tainted_by_errors_flag`
     err_count_on_creation: usize,
 
     /// This flag is true while there is an active snapshot.

src/librustc/infer/opaque_types/mod.rs

@@ -777,7 +777,7 @@ impl<'a, 'tcx> Instantiator<'a, 'tcx> {
                                                 .local_def_id_from_hir_id(opaque_parent_hir_id)
                         };
                         let (in_definition_scope, origin) =
-                            match tcx.hir().find_by_hir_id(opaque_hir_id)
+                            match tcx.hir().find(opaque_hir_id)
                         {
                             Some(Node::Item(item)) => match item.node {
                                 // Anonymous `impl Trait`

src/librustc/middle/dead.rs

@@ -27,7 +27,7 @@ use syntax_pos;
 // function, then we should explore its block to check for codes that
 // may need to be marked as live.
 fn should_explore<'tcx>(tcx: TyCtxt<'tcx>, hir_id: hir::HirId) -> bool {
-    match tcx.hir().find_by_hir_id(hir_id) {
+    match tcx.hir().find(hir_id) {
         Some(Node::Item(..)) |
         Some(Node::ImplItem(..)) |
         Some(Node::ForeignItem(..)) |
@@ -145,7 +145,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
             // tuple struct constructor function
             let id = self.struct_constructors.get(&id).cloned().unwrap_or(id);
 
-            if let Some(node) = self.tcx.hir().find_by_hir_id(id) {
+            if let Some(node) = self.tcx.hir().find(id) {
                 self.live_symbols.insert(id);
                 self.visit_node(node);
             }

src/librustc/middle/liveness.rs

@@ -110,7 +110,7 @@ use std::{fmt, u32};
 use std::io::prelude::*;
 use std::io;
 use std::rc::Rc;
-use syntax::ast::{self, NodeId};
+use syntax::ast;
 use syntax::ptr::P;
 use syntax::symbol::{kw, sym};
 use syntax_pos::Span;
@@ -369,7 +369,7 @@ fn visit_fn<'tcx>(
     // Don't run unused pass for #[derive()]
     if let FnKind::Method(..) = fk {
         let parent = ir.tcx.hir().get_parent_item(id);
-        if let Some(Node::Item(i)) = ir.tcx.hir().find_by_hir_id(parent) {
+        if let Some(Node::Item(i)) = ir.tcx.hir().find(parent) {
             if i.attrs.iter().any(|a| a.check_name(sym::automatically_derived)) {
                 return;
             }
@@ -1327,12 +1327,11 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
         }
     }
 
-    fn access_var(&mut self, hir_id: HirId, nid: NodeId, succ: LiveNode, acc: u32, span: Span)
+    fn access_var(&mut self, hir_id: HirId, var_hid: HirId, succ: LiveNode, acc: u32, span: Span)
                   -> LiveNode {
         let ln = self.live_node(hir_id, span);
         if acc != 0 {
             self.init_from_succ(ln, succ);
-            let var_hid = self.ir.tcx.hir().node_to_hir_id(nid);
             let var = self.variable(var_hid, span);
             self.acc(ln, var, acc);
         }
@@ -1345,8 +1344,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             Res::Local(hid) => {
                 let upvars = self.ir.tcx.upvars(self.ir.body_owner);
                 if !upvars.map_or(false, |upvars| upvars.contains_key(&hid)) {
-                    let nid = self.ir.tcx.hir().hir_to_node_id(hid);
-                    self.access_var(hir_id, nid, succ, acc, path.span)
+                    self.access_var(hir_id, hid, succ, acc, path.span)
                 } else {
                     succ
                 }

src/librustc/middle/mem_categorization.rs

@@ -1526,7 +1526,7 @@ impl<'tcx> cmt_<'tcx> {
                 "non-place".into()
             }
             Categorization::Local(vid) => {
-                if tcx.hir().is_argument(tcx.hir().hir_to_node_id(vid)) {
+                if tcx.hir().is_argument(vid) {
                     "argument"
                 } else {
                     "local variable"