Auto merge of #73669 - Manishearth:rollup-0n4u7vq, r=Manishearth

Rollup of 11 pull requests

Successful merges:

 - #72780 (Enforce doc alias check)
 - #72876 (Mention that BTreeMap::new() doesn't allocate)
 - #73244 (Check for assignments between non-conflicting generator saved locals)
 - #73488 (code coverage foundation for hash and num_counters)
 - #73523 (Fix -Z unpretty=everybody_loops)
 - #73587 (Move remaining `NodeId` APIs from `Definitions` to `Resolver`)
 - #73601 (Point at the call span when overflow occurs during monomorphization)
 - #73613 (The const propagator cannot trace references.)
 - #73614 (fix `intrinsics::needs_drop` docs)
 - #73630 (Provide context on E0308 involving fn items)
 - #73665 (rustc: Modernize wasm checks for atomics)

Failed merges:

r? @ghost

Cargo.lock

@@ -4200,6 +4200,7 @@ dependencies = [
  "rustc_expand",
  "rustc_feature",
  "rustc_hir",
+ "rustc_index",
  "rustc_metadata",
  "rustc_middle",
  "rustc_session",

src/liballoc/collections/btree/map.rs

@@ -490,6 +490,8 @@ struct MergeIter<K, V, I: Iterator<Item = (K, V)>> {
 impl<K: Ord, V> BTreeMap<K, V> {
     /// Makes a new empty BTreeMap with a reasonable choice for B.
     ///
+    /// Does not allocate anything on its own.
+    ///
     /// # Examples
     ///
     /// Basic usage:

src/libcore/intrinsics.rs

@@ -1291,7 +1291,7 @@ extern "rust-intrinsic" {
     /// implements `Copy`.
     ///
     /// If the actual type neither requires drop glue nor implements
-    /// `Copy`, then may return `true` or `false`.
+    /// `Copy`, then the return value of this function is unspecified.
     ///
     /// The stabilized version of this intrinsic is
     /// [`std::mem::needs_drop`](../../std/mem/fn.needs_drop.html).

src/librustc_ast_lowering/item.rs

@@ -253,7 +253,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 hir::ItemKind::Const(ty, body_id)
             }
             ItemKind::Fn(_, FnSig { ref decl, header }, ref generics, ref body) => {
-                let fn_def_id = self.resolver.definitions().local_def_id(id);
+                let fn_def_id = self.resolver.local_def_id(id);
                 self.with_new_scopes(|this| {
                     this.current_item = Some(ident.span);
 
@@ -342,7 +342,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 self_ty: ref ty,
                 items: ref impl_items,
             } => {
-                let def_id = self.resolver.definitions().local_def_id(id);
+                let def_id = self.resolver.local_def_id(id);
 
                 // Lower the "impl header" first. This ordering is important
                 // for in-band lifetimes! Consider `'a` here:
@@ -646,7 +646,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_foreign_item(&mut self, i: &ForeignItem) -> hir::ForeignItem<'hir> {
-        let def_id = self.resolver.definitions().local_def_id(i.id);
+        let def_id = self.resolver.local_def_id(i.id);
         hir::ForeignItem {
             hir_id: self.lower_node_id(i.id),
             ident: i.ident,
@@ -747,7 +747,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_trait_item(&mut self, i: &AssocItem) -> hir::TraitItem<'hir> {
-        let trait_item_def_id = self.resolver.definitions().local_def_id(i.id);
+        let trait_item_def_id = self.resolver.local_def_id(i.id);
 
         let (generics, kind) = match i.kind {
             AssocItemKind::Const(_, ref ty, ref default) => {
@@ -812,7 +812,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_impl_item(&mut self, i: &AssocItem) -> hir::ImplItem<'hir> {
-        let impl_item_def_id = self.resolver.definitions().local_def_id(i.id);
+        let impl_item_def_id = self.resolver.local_def_id(i.id);
 
         let (generics, kind) = match &i.kind {
             AssocItemKind::Const(_, ty, expr) => {
@@ -1320,12 +1320,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                                     if let Some(def_id) = def_id.as_local() {
                                         for param in &generics.params {
                                             if let GenericParamKind::Type { .. } = param.kind {
-                                                if def_id
-                                                    == self
-                                                        .resolver
-                                                        .definitions()
-                                                        .local_def_id(param.id)
-                                                {
+                                                if def_id == self.resolver.local_def_id(param.id) {
                                                     add_bounds
                                                         .entry(param.id)
                                                         .or_default()

src/librustc_ast_lowering/lib.rs

@@ -54,7 +54,7 @@ use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX};
 use rustc_hir::definitions::{DefKey, DefPathData, Definitions};
 use rustc_hir::intravisit;
 use rustc_hir::{ConstArg, GenericArg, ParamName};
-use rustc_index::vec::IndexVec;
+use rustc_index::vec::{Idx, IndexVec};
 use rustc_session::config::nightly_options;
 use rustc_session::lint::{builtin::BARE_TRAIT_OBJECTS, BuiltinLintDiagnostics, LintBuffer};
 use rustc_session::parse::ParseSess;
@@ -205,6 +205,19 @@ pub trait Resolver {
     fn next_node_id(&mut self) -> NodeId;
 
     fn trait_map(&self) -> &NodeMap<Vec<hir::TraitCandidate>>;
+
+    fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId>;
+
+    fn local_def_id(&self, node: NodeId) -> LocalDefId;
+
+    fn create_def(
+        &mut self,
+        parent: LocalDefId,
+        node_id: ast::NodeId,
+        data: DefPathData,
+        expn_id: ExpnId,
+        span: Span,
+    ) -> LocalDefId;
 }
 
 type NtToTokenstream = fn(&Nonterminal, &ParseSess, Span) -> TokenStream;
@@ -436,7 +449,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 match tree.kind {
                     UseTreeKind::Simple(_, id1, id2) => {
                         for &id in &[id1, id2] {
-                            self.lctx.resolver.definitions().create_def_with_parent(
+                            self.lctx.resolver.create_def(
                                 owner,
                                 id,
                                 DefPathData::Misc,
@@ -488,7 +501,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     | ItemKind::Enum(_, ref generics)
                     | ItemKind::TyAlias(_, ref generics, ..)
                     | ItemKind::Trait(_, _, ref generics, ..) => {
-                        let def_id = self.lctx.resolver.definitions().local_def_id(item.id);
+                        let def_id = self.lctx.resolver.local_def_id(item.id);
                         let count = generics
                             .params
                             .iter()
@@ -564,7 +577,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             .map(|(&k, v)| (self.node_id_to_hir_id[k].unwrap(), v.clone()))
             .collect();
 
-        self.resolver.definitions().init_node_id_to_hir_id_mapping(self.node_id_to_hir_id);
+        let mut def_id_to_hir_id = IndexVec::default();
+
+        for (node_id, hir_id) in self.node_id_to_hir_id.into_iter_enumerated() {
+            if let Some(def_id) = self.resolver.opt_local_def_id(node_id) {
+                if def_id_to_hir_id.len() <= def_id.index() {
+                    def_id_to_hir_id.resize(def_id.index() + 1, None);
+                }
+                def_id_to_hir_id[def_id] = hir_id;
+            }
+        }
+
+        self.resolver.definitions().init_def_id_to_hir_id_mapping(def_id_to_hir_id);
 
         hir::Crate {
             item: hir::CrateItem { module, attrs, span: c.span },
@@ -628,7 +652,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             .item_local_id_counters
             .insert(owner, HIR_ID_COUNTER_LOCKED)
             .unwrap_or_else(|| panic!("no `item_local_id_counters` entry for {:?}", owner));
-        let def_id = self.resolver.definitions().local_def_id(owner);
+        let def_id = self.resolver.local_def_id(owner);
         self.current_hir_id_owner.push((def_id, counter));
         let ret = f(self);
         let (new_def_id, new_counter) = self.current_hir_id_owner.pop().unwrap();
@@ -671,8 +695,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             debug_assert!(local_id != HIR_ID_COUNTER_LOCKED);
 
             *local_id_counter += 1;
-            let owner = this.resolver.definitions().opt_local_def_id(owner).expect(
-                "you forgot to call `create_def_with_parent` or are lowering node-IDs \
+            let owner = this.resolver.opt_local_def_id(owner).expect(
+                "you forgot to call `create_def` or are lowering node-IDs \
                  that do not belong to the current owner",
             );
 
@@ -800,7 +824,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         };
 
         // Add a definition for the in-band lifetime def.
-        self.resolver.definitions().create_def_with_parent(
+        self.resolver.create_def(
             parent_def_id,
             node_id,
             DefPathData::LifetimeNs(str_name),
@@ -1088,7 +1112,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
                     let impl_trait_node_id = self.resolver.next_node_id();
                     let parent_def_id = self.current_hir_id_owner.last().unwrap().0;
-                    self.resolver.definitions().create_def_with_parent(
+                    self.resolver.create_def(
                         parent_def_id,
                         impl_trait_node_id,
                         DefPathData::ImplTrait,
@@ -1154,7 +1178,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                             let node_id = self.resolver.next_node_id();
 
                             // Add a definition for the in-band const def.
-                            self.resolver.definitions().create_def_with_parent(
+                            self.resolver.create_def(
                                 parent_def_id,
                                 node_id,
                                 DefPathData::AnonConst,
@@ -1339,7 +1363,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     }
                     ImplTraitContext::Universal(in_band_ty_params) => {
                         // Add a definition for the in-band `Param`.
-                        let def_id = self.resolver.definitions().local_def_id(def_node_id);
+                        let def_id = self.resolver.local_def_id(def_node_id);
 
                         let hir_bounds = self.lower_param_bounds(
                             bounds,
@@ -1428,7 +1452,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         // frequently opened issues show.
         let opaque_ty_span = self.mark_span_with_reason(DesugaringKind::OpaqueTy, span, None);
 
-        let opaque_ty_def_id = self.resolver.definitions().local_def_id(opaque_ty_node_id);
+        let opaque_ty_def_id = self.resolver.local_def_id(opaque_ty_node_id);
 
         self.allocate_hir_id_counter(opaque_ty_node_id);
 
@@ -1620,7 +1644,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     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(
+                    self.context.resolver.create_def(
                         self.parent,
                         def_node_id,
                         DefPathData::LifetimeNs(name.ident().name),
@@ -1870,7 +1894,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         let opaque_ty_span = self.mark_span_with_reason(DesugaringKind::Async, span, None);
 
-        let opaque_ty_def_id = self.resolver.definitions().local_def_id(opaque_ty_node_id);
+        let opaque_ty_def_id = self.resolver.local_def_id(opaque_ty_node_id);
 
         self.allocate_hir_id_counter(opaque_ty_node_id);
 

src/librustc_codegen_llvm/back/write.rs

@@ -23,6 +23,7 @@ use rustc_middle::bug;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{self, Lto, OutputType, Passes, SanitizerSet, SwitchWithOptPath};
 use rustc_session::Session;
+use rustc_span::symbol::sym;
 use rustc_span::InnerSpan;
 use rustc_target::spec::{CodeModel, RelocModel};
 
@@ -140,7 +141,7 @@ pub fn target_machine_factory(
     // lower atomic operations to single-threaded operations.
     if singlethread
         && sess.target.target.llvm_target.contains("wasm32")
-        && features.iter().any(|s| *s == "+atomics")
+        && sess.target_features.contains(&sym::atomics)
     {
         singlethread = false;
     }

src/librustc_codegen_llvm/intrinsic.rs

@@ -23,7 +23,6 @@ use rustc_middle::ty::layout::{FnAbiExt, HasTyCtxt};
 use rustc_middle::ty::{self, Ty};
 use rustc_middle::{bug, span_bug};
 use rustc_span::Span;
-use rustc_span::Symbol;
 use rustc_target::abi::{self, HasDataLayout, LayoutOf, Primitive};
 use rustc_target::spec::PanicStrategy;
 
@@ -141,26 +140,20 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
                 self.call(llfn, &[], None)
             }
             "count_code_region" => {
-                if let ty::InstanceDef::Item(fn_def_id) = caller_instance.def {
-                    let caller_fn_path = tcx.def_path_str(fn_def_id);
-                    debug!(
-                        "count_code_region to llvm.instrprof.increment(fn_name={})",
-                        caller_fn_path
-                    );
-
-                    // FIXME(richkadel): (1) Replace raw function name with mangled function name;
-                    // (2) Replace hardcoded `1234` in `hash` with a computed hash (as discussed in)
-                    // the MCP (compiler-team/issues/278); and replace the hardcoded `1` for
-                    // `num_counters` with the actual number of counters per function (when the
-                    // changes are made to inject more than one counter per function).
-                    let (fn_name, _len_val) = self.const_str(Symbol::intern(&caller_fn_path));
-                    let index = args[0].immediate();
-                    let hash = self.const_u64(1234);
-                    let num_counters = self.const_u32(1);
-                    self.instrprof_increment(fn_name, hash, num_counters, index)
-                } else {
-                    bug!("intrinsic count_code_region: no src.instance");
-                }
+                // FIXME(richkadel): The current implementation assumes the MIR for the given
+                // caller_instance represents a single function. Validate and/or correct if inlining
+                // and/or monomorphization invalidates these assumptions.
+                let coverage_data = tcx.coverage_data(caller_instance.def_id());
+                let mangled_fn = tcx.symbol_name(caller_instance);
+                let (mangled_fn_name, _len_val) = self.const_str(mangled_fn.name);
+                let hash = self.const_u64(coverage_data.hash);
+                let num_counters = self.const_u32(coverage_data.num_counters);
+                let index = args[0].immediate();
+                debug!(
+                    "count_code_region to LLVM intrinsic instrprof.increment(fn_name={}, hash={:?}, num_counters={:?}, index={:?})",
+                    mangled_fn.name, hash, num_counters, index
+                );
+                self.instrprof_increment(mangled_fn_name, hash, num_counters, index)
             }
             "va_start" => self.va_start(args[0].immediate()),
             "va_end" => self.va_end(args[0].immediate()),

src/librustc_codegen_ssa/back/linker.rs

@@ -1,6 +1,7 @@
 use super::archive;
 use super::command::Command;
 use super::symbol_export;
+use rustc_span::symbol::sym;
 
 use std::ffi::{OsStr, OsString};
 use std::fs::{self, File};
@@ -1036,9 +1037,7 @@ impl<'a> WasmLd<'a> {
         //
         // * `--export=*tls*` - when `#[thread_local]` symbols are used these
         //   symbols are how the TLS segments are initialized and configured.
-        let atomics = sess.opts.cg.target_feature.contains("+atomics")
-            || sess.target.target.options.features.contains("+atomics");
-        if atomics {
+        if sess.target_features.contains(&sym::atomics) {
             cmd.arg("--shared-memory");
             cmd.arg("--max-memory=1073741824");
             cmd.arg("--import-memory");

src/librustc_driver/lib.rs

@@ -307,6 +307,7 @@ pub fn run_compiler(
                         compiler.output_file().as_ref().map(|p| &**p),
                     );
                 }
+                trace!("finished pretty-printing");
                 return early_exit();
             }