Auto merge of #66072 - Mark-Simulacrum:next-node-id, r=nikomatsakis

Move next node ID to Resolver

This moves the `next_node_id` method(s) and related tracking information to the resolver. By doing so, we also remove the OneThread and Cell on next_node_id in Session in this move, which means that the new code is simpler and less "interesting" as it doesn't tie itself to a single thread.

This required moving some of the pretty-printing logic around, but this was just copying the code without any semantic changes, so it's just a second commit instead of a separate PR; I can polish it up a bit more if desired.

Author: bors

Cargo.lock

@@ -3506,6 +3506,7 @@ dependencies = [
  "rustc_mir",
  "rustc_plugin",
  "rustc_plugin_impl",
+ "rustc_resolve",
  "rustc_save_analysis",
  "rustc_target",
  "serialize",

src/librustc/hir/lowering.rs

@@ -183,6 +183,8 @@ pub trait Resolver {
     ) -> (ast::Path, Res<NodeId>);
 
     fn lint_buffer(&mut self) -> &mut lint::LintBuffer;
+
+    fn next_node_id(&mut self) -> NodeId;
 }
 
 type NtToTokenstream = fn(&Nonterminal, &ParseSess, Span) -> TokenStream;
@@ -672,7 +674,8 @@ impl<'a> LoweringContext<'a> {
     }
 
     fn next_id(&mut self) -> hir::HirId {
-        self.lower_node_id(self.sess.next_node_id())
+        let node_id = self.resolver.next_node_id();
+        self.lower_node_id(node_id)
     }
 
     fn lower_res(&mut self, res: Res<NodeId>) -> Res {
@@ -781,7 +784,7 @@ impl<'a> LoweringContext<'a> {
         hir_name: ParamName,
         parent_index: DefIndex,
     ) -> hir::GenericParam {
-        let node_id = self.sess.next_node_id();
+        let node_id = self.resolver.next_node_id();
 
         // Get the name we'll use to make the def-path. Note
         // that collisions are ok here and this shouldn't
@@ -1106,7 +1109,7 @@ impl<'a> LoweringContext<'a> {
                     // Desugar `AssocTy: Bounds` into `AssocTy = impl Bounds`. We do this by
                     // constructing the HIR for `impl bounds...` and then lowering that.
 
-                    let impl_trait_node_id = self.sess.next_node_id();
+                    let impl_trait_node_id = self.resolver.next_node_id();
                     let parent_def_index = self.current_hir_id_owner.last().unwrap().0;
                     self.resolver.definitions().create_def_with_parent(
                         parent_def_index,
@@ -1117,9 +1120,10 @@ impl<'a> LoweringContext<'a> {
                     );
 
                     self.with_dyn_type_scope(false, |this| {
+                        let node_id = this.resolver.next_node_id();
                         let ty = this.lower_ty(
                             &Ty {
-                                id: this.sess.next_node_id(),
+                                id: node_id,
                                 kind: TyKind::ImplTrait(impl_trait_node_id, bounds.clone()),
                                 span: constraint.span,
                             },
@@ -1586,7 +1590,7 @@ impl<'a> LoweringContext<'a> {
                         name,
                     }));
 
-                    let def_node_id = self.context.sess.next_node_id();
+                    let def_node_id = self.context.resolver.next_node_id();
                     let hir_id =
                         self.context.lower_node_id_with_owner(def_node_id, self.opaque_ty_id);
                     self.context.resolver.definitions().create_def_with_parent(
@@ -3234,7 +3238,7 @@ impl<'a> LoweringContext<'a> {
             Some(id) => (id, "`'_` cannot be used here", "`'_` is a reserved lifetime name"),
 
             None => (
-                self.sess.next_node_id(),
+                self.resolver.next_node_id(),
                 "`&` without an explicit lifetime name cannot be used here",
                 "explicit lifetime name needed here",
             ),
@@ -3271,7 +3275,7 @@ impl<'a> LoweringContext<'a> {
                     span,
                     "expected 'implicit elided lifetime not allowed' error",
                 );
-                let id = self.sess.next_node_id();
+                let id = self.resolver.next_node_id();
                 self.new_named_lifetime(id, span, hir::LifetimeName::Error)
             }
             // `PassThrough` is the normal case.

src/librustc/hir/lowering/expr.rs

@@ -595,7 +595,7 @@ impl LoweringContext<'_> {
         };
 
         // `::std::task::Poll::Ready(result) => break result`
-        let loop_node_id = self.sess.next_node_id();
+        let loop_node_id = self.resolver.next_node_id();
         let loop_hir_id = self.lower_node_id(loop_node_id);
         let ready_arm = {
             let x_ident = Ident::with_dummy_span(sym::result);

src/librustc/hir/lowering/item.rs

@@ -522,7 +522,7 @@ impl LoweringContext<'_> {
                     let ident = *ident;
                     let mut path = path.clone();
                     for seg in &mut path.segments {
-                        seg.id = self.sess.next_node_id();
+                        seg.id = self.resolver.next_node_id();
                     }
                     let span = path.span;
 
@@ -599,7 +599,7 @@ impl LoweringContext<'_> {
 
                     // Give the segments new node-ids since they are being cloned.
                     for seg in &mut prefix.segments {
-                        seg.id = self.sess.next_node_id();
+                        seg.id = self.resolver.next_node_id();
                     }
 
                     // Each `use` import is an item and thus are owners of the

src/librustc/session/config.rs

@@ -1,10 +1,13 @@
 //! Contains infrastructure for configuring the compiler, including parsing
 //! command-line options.
 
+// ignore-tidy-filelength
+
 use crate::lint;
 use crate::middle::cstore;
 use crate::session::{early_error, early_warn, Session};
 use crate::session::search_paths::SearchPath;
+use crate::hir::map as hir_map;
 
 use rustc_data_structures::fx::FxHashSet;
 
@@ -440,6 +443,8 @@ top_level_options!(
         // `true` if we're emitting JSON blobs about each artifact produced
         // by the compiler.
         json_artifact_notifications: bool [TRACKED],
+
+        pretty: Option<(PpMode, Option<UserIdentifiedItem>)> [UNTRACKED],
     }
 );
 
@@ -621,6 +626,7 @@ impl Default for Options {
             remap_path_prefix: Vec::new(),
             edition: DEFAULT_EDITION,
             json_artifact_notifications: false,
+            pretty: None,
         }
     }
 }
@@ -2516,6 +2522,8 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
 
     let remap_path_prefix = parse_remap_path_prefix(matches, error_format);
 
+    let pretty = parse_pretty(matches, &debugging_opts, error_format);
+
     Options {
         crate_types,
         optimize: opt_level,
@@ -2546,6 +2554,73 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         remap_path_prefix,
         edition,
         json_artifact_notifications,
+        pretty,
+    }
+}
+
+fn parse_pretty(
+    matches: &getopts::Matches,
+    debugging_opts: &DebuggingOptions,
+    efmt: ErrorOutputType,
+) -> Option<(PpMode, Option<UserIdentifiedItem>)> {
+    let pretty = if debugging_opts.unstable_options {
+        matches.opt_default("pretty", "normal").map(|a| {
+            // stable pretty-print variants only
+            parse_pretty_inner(efmt, &a, false)
+        })
+    } else {
+        None
+    };
+
+    return if pretty.is_none() {
+        debugging_opts.unpretty.as_ref().map(|a| {
+            // extended with unstable pretty-print variants
+            parse_pretty_inner(efmt, &a, true)
+        })
+    } else {
+        pretty
+    };
+
+    fn parse_pretty_inner(
+        efmt: ErrorOutputType,
+        name: &str,
+        extended: bool,
+    ) -> (PpMode, Option<UserIdentifiedItem>) {
+        use PpMode::*;
+        use PpSourceMode::*;
+        let mut split = name.splitn(2, '=');
+        let first = split.next().unwrap();
+        let opt_second = split.next();
+        let first = match (first, extended) {
+            ("normal", _) => PpmSource(PpmNormal),
+            ("identified", _) => PpmSource(PpmIdentified),
+            ("everybody_loops", true) => PpmSource(PpmEveryBodyLoops),
+            ("expanded", _) => PpmSource(PpmExpanded),
+            ("expanded,identified", _) => PpmSource(PpmExpandedIdentified),
+            ("expanded,hygiene", _) => PpmSource(PpmExpandedHygiene),
+            ("hir", true) => PpmHir(PpmNormal),
+            ("hir,identified", true) => PpmHir(PpmIdentified),
+            ("hir,typed", true) => PpmHir(PpmTyped),
+            ("hir-tree", true) => PpmHirTree(PpmNormal),
+            ("mir", true) => PpmMir,
+            ("mir-cfg", true) => PpmMirCFG,
+            _ => {
+                if extended {
+                    early_error(efmt, &format!("argument to `unpretty` must be one of `normal`, \
+                                        `expanded`, `identified`, `expanded,identified`, \
+                                        `expanded,hygiene`, `everybody_loops`, \
+                                        `hir`, `hir,identified`, `hir,typed`, `hir-tree`, \
+                                        `mir` or `mir-cfg`; got {}",
+                                        name));
+                } else {
+                    early_error(efmt, &format!("argument to `pretty` must be one of `normal`, \
+                                        `expanded`, `identified`, or `expanded,identified`; got {}",
+                                        name));
+                }
+            }
+        };
+        let opt_second = opt_second.and_then(|s| s.parse::<UserIdentifiedItem>().ok());
+        (first, opt_second)
     }
 }
 
@@ -2656,6 +2731,151 @@ impl fmt::Display for CrateType {
     }
 }
 
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum PpSourceMode {
+    PpmNormal,
+    PpmEveryBodyLoops,
+    PpmExpanded,
+    PpmIdentified,
+    PpmExpandedIdentified,
+    PpmExpandedHygiene,
+    PpmTyped,
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum PpMode {
+    PpmSource(PpSourceMode),
+    PpmHir(PpSourceMode),
+    PpmHirTree(PpSourceMode),
+    PpmMir,
+    PpmMirCFG,
+}
+
+impl PpMode {
+    pub fn needs_ast_map(&self, opt_uii: &Option<UserIdentifiedItem>) -> bool {
+        use PpMode::*;
+        use PpSourceMode::*;
+        match *self {
+            PpmSource(PpmNormal) |
+            PpmSource(PpmEveryBodyLoops) |
+            PpmSource(PpmIdentified) => opt_uii.is_some(),
+
+            PpmSource(PpmExpanded) |
+            PpmSource(PpmExpandedIdentified) |
+            PpmSource(PpmExpandedHygiene) |
+            PpmHir(_) |
+            PpmHirTree(_) |
+            PpmMir |
+            PpmMirCFG => true,
+            PpmSource(PpmTyped) => panic!("invalid state"),
+        }
+    }
+
+    pub fn needs_analysis(&self) -> bool {
+        use PpMode::*;
+        match *self {
+            PpmMir | PpmMirCFG => true,
+            _ => false,
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+pub enum UserIdentifiedItem {
+    ItemViaNode(ast::NodeId),
+    ItemViaPath(Vec<String>),
+}
+
+impl FromStr for UserIdentifiedItem {
+    type Err = ();
+    fn from_str(s: &str) -> Result<UserIdentifiedItem, ()> {
+        use UserIdentifiedItem::*;
+        Ok(s.parse()
+            .map(ast::NodeId::from_u32)
+            .map(ItemViaNode)
+            .unwrap_or_else(|_| ItemViaPath(s.split("::").map(|s| s.to_string()).collect())))
+    }
+}
+
+pub enum NodesMatchingUII<'a> {
+    NodesMatchingDirect(std::option::IntoIter<ast::NodeId>),
+    NodesMatchingSuffix(Box<dyn Iterator<Item = ast::NodeId> + 'a>),
+}
+
+impl<'a> Iterator for NodesMatchingUII<'a> {
+    type Item = ast::NodeId;
+
+    fn next(&mut self) -> Option<ast::NodeId> {
+        use NodesMatchingUII::*;
+        match self {
+            &mut NodesMatchingDirect(ref mut iter) => iter.next(),
+            &mut NodesMatchingSuffix(ref mut iter) => iter.next(),
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        use NodesMatchingUII::*;
+        match self {
+            &NodesMatchingDirect(ref iter) => iter.size_hint(),
+            &NodesMatchingSuffix(ref iter) => iter.size_hint(),
+        }
+    }
+}
+
+impl UserIdentifiedItem {
+    pub fn reconstructed_input(&self) -> String {
+        use UserIdentifiedItem::*;
+        match *self {
+            ItemViaNode(node_id) => node_id.to_string(),
+            ItemViaPath(ref parts) => parts.join("::"),
+        }
+    }
+
+    pub fn all_matching_node_ids<'a, 'hir>(&'a self,
+                                       map: &'a hir_map::Map<'hir>)
+                                       -> NodesMatchingUII<'a> {
+        use UserIdentifiedItem::*;
+        use NodesMatchingUII::*;
+        match *self {
+            ItemViaNode(node_id) => NodesMatchingDirect(Some(node_id).into_iter()),
+            ItemViaPath(ref parts) => {
+                NodesMatchingSuffix(Box::new(map.nodes_matching_suffix(&parts)))
+            }
+        }
+    }
+
+    pub fn to_one_node_id(self,
+                      user_option: &str,
+                      sess: &Session,
+                      map: &hir_map::Map<'_>)
+                      -> ast::NodeId {
+        let fail_because = |is_wrong_because| -> ast::NodeId {
+            let message = format!("{} needs NodeId (int) or unique path suffix (b::c::d); got \
+                                   {}, which {}",
+                                  user_option,
+                                  self.reconstructed_input(),
+                                  is_wrong_because);
+            sess.fatal(&message)
+        };
+
+        let mut saw_node = ast::DUMMY_NODE_ID;
+        let mut seen = 0;
+        for node in self.all_matching_node_ids(map) {
+            saw_node = node;
+            seen += 1;
+            if seen > 1 {
+                fail_because("does not resolve uniquely");
+            }
+        }
+        if seen == 0 {
+            fail_because("does not resolve to any item");
+        }
+
+        assert!(seen == 1);
+        return saw_node;
+    }
+}
+
 /// Command-line arguments passed to the compiler have to be incorporated with
 /// the dependency tracking system for incremental compilation. This module
 /// provides some utilities to make this more convenient.