Auto merge of #55502 - kennytm:rollup, r=kennytm

Rollup of 12 pull requests

Successful merges:

 - #54885 (Don't lint 'unused_parens` on `if (break _) { .. }`)
 - #55205 (Improve a few cases of collecting to an FxHash(Map/Set))
 - #55450 (msp430: remove the whole Atomic* API)
 - #55459 (Add UI test for #49296)
 - #55472 (Use opt.take() instead of mem::replace(opt, None))
 - #55473 (Take advantage of impl Iterator in (transitive/elaborate)_bounds)
 - #55474 (Fix validation false positive)
 - #55476 (Change a flat_map with 0/1-element vecs to a filter_map)
 - #55487 (Adjust Ids of path segments in visibility modifiers)
 - #55493 (Doc fixes)
 - #55494 (borrowck=migrate must look at parents of closures)
 - #55496 (Update clippy)

Failed merges:

r? @ghost

src/Cargo.lock

@@ -326,7 +326,7 @@ dependencies = [
  "clippy-mini-macro-test 0.2.0",
  "clippy_dev 0.0.1",
  "clippy_lints 0.0.212",
- "compiletest_rs 0.3.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "compiletest_rs 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive-new 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -443,7 +443,7 @@ dependencies = [
 
 [[package]]
 name = "compiletest_rs"
-version = "0.3.13"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -452,6 +452,7 @@ dependencies = [
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "miow 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.75 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.75 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1289,7 +1290,7 @@ dependencies = [
  "byteorder 1.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "cargo_metadata 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "colored 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "compiletest_rs 0.3.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "compiletest_rs 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.5.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "vergen 3.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3202,7 +3203,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum colored 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b0aa3473e85a3161b59845d6096b289bb577874cafeaf75ea1b1beaa6572c7fc"
 "checksum commoncrypto 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d056a8586ba25a1e4d61cb090900e495952c7886786fc55f909ab2f819b69007"
 "checksum commoncrypto-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1fed34f46747aa73dfaa578069fd8279d2818ade2b55f38f22a9401c7f4083e2"
-"checksum compiletest_rs 0.3.13 (registry+https://github.com/rust-lang/crates.io-index)" = "d3064bc712922596dd5ab449fca9261d411893356581fe5297b96aa8f53bb1b8"
+"checksum compiletest_rs 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)" = "75e809f56d6aa9575b67924b0af686c4f4c1380314f47947e235e9ff7fa94bed"
 "checksum core-foundation 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cc3532ec724375c7cb7ff0a097b714fde180bb1f6ed2ab27cfcd99ffca873cd2"
 "checksum core-foundation-sys 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a3fb15cdbdd9cf8b82d97d0296bb5cd3631bba58d6e31650a002a8e7fb5721f9"
 "checksum crossbeam 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "24ce9782d4d5c53674646a6a4c1863a21a8fc0cb649b3c94dfc16e45071dea19"

src/liballoc/collections/vec_deque.rs

@@ -36,6 +36,8 @@ use vec::Vec;
 
 const INITIAL_CAPACITY: usize = 7; // 2^3 - 1
 const MINIMUM_CAPACITY: usize = 1; // 2 - 1
+#[cfg(target_pointer_width = "16")]
+const MAXIMUM_ZST_CAPACITY: usize = 1 << (16 - 1); // Largest possible power of two
 #[cfg(target_pointer_width = "32")]
 const MAXIMUM_ZST_CAPACITY: usize = 1 << (32 - 1); // Largest possible power of two
 #[cfg(target_pointer_width = "64")]

src/librustc/hir/lowering.rs

@@ -3022,8 +3022,14 @@ impl<'a> LoweringContext<'a> {
                             hir::VisibilityKind::Inherited => hir::VisibilityKind::Inherited,
                             hir::VisibilityKind::Restricted { ref path, id: _, hir_id: _ } => {
                                 let id = this.next_id();
+                                let mut path = path.clone();
+                                for seg in path.segments.iter_mut() {
+                                    if seg.id.is_some() {
+                                        seg.id = Some(this.next_id().node_id);
+                                    }
+                                }
                                 hir::VisibilityKind::Restricted {
-                                    path: path.clone(),
+                                    path,
                                     id: id.node_id,
                                     hir_id: id.hir_id,
                                 }

src/librustc/hir/map/collector.rs

@@ -217,7 +217,7 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
                 };
 
                 bug!("inconsistent DepNode for `{}`: \
-                      current_dep_node_owner={} ({:?}), hir_id.owner={} ({:?}) {}",
+                      current_dep_node_owner={} ({:?}), hir_id.owner={} ({:?}){}",
                     node_str,
                     self.definitions
                         .def_path(self.current_dep_node_owner)

src/librustc/infer/lexical_region_resolve/graphviz.rs

@@ -230,10 +230,7 @@ impl<'a, 'gcx, 'tcx> dot::GraphWalk<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
     type Node = Node;
     type Edge = Edge<'tcx>;
     fn nodes(&self) -> dot::Nodes<'_, Node> {
-        let mut set = FxHashSet::default();
-        for node in self.node_ids.keys() {
-            set.insert(*node);
-        }
+        let set = self.node_ids.keys().cloned().collect::<FxHashSet<_>>();
         debug!("constraint graph has {} nodes", set.len());
         set.into_iter().collect()
     }

src/librustc/middle/dependency_format.rs

@@ -94,12 +94,11 @@ pub enum Linkage {
 
 pub fn calculate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
     let sess = &tcx.sess;
-    let mut fmts = FxHashMap::default();
-    for &ty in sess.crate_types.borrow().iter() {
+    let fmts = sess.crate_types.borrow().iter().map(|&ty| {
         let linkage = calculate_type(tcx, ty);
         verify_ok(tcx, &linkage);
-        fmts.insert(ty, linkage);
-    }
+        (ty, linkage)
+    }).collect::<FxHashMap<_, _>>();
     sess.abort_if_errors();
     sess.dependency_formats.set(fmts);
 }

src/librustc/traits/util.rs

@@ -103,11 +103,10 @@ pub fn elaborate_trait_ref<'cx, 'gcx, 'tcx>(
 
 pub fn elaborate_trait_refs<'cx, 'gcx, 'tcx>(
     tcx: TyCtxt<'cx, 'gcx, 'tcx>,
-    trait_refs: &[ty::PolyTraitRef<'tcx>])
+    trait_refs: impl Iterator<Item = ty::PolyTraitRef<'tcx>>)
     -> Elaborator<'cx, 'gcx, 'tcx>
 {
-    let predicates = trait_refs.iter()
-                               .map(|trait_ref| trait_ref.to_predicate())
+    let predicates = trait_refs.map(|trait_ref| trait_ref.to_predicate())
                                .collect();
     elaborate_predicates(tcx, predicates)
 }
@@ -271,7 +270,7 @@ pub fn supertraits<'cx, 'gcx, 'tcx>(tcx: TyCtxt<'cx, 'gcx, 'tcx>,
 }
 
 pub fn transitive_bounds<'cx, 'gcx, 'tcx>(tcx: TyCtxt<'cx, 'gcx, 'tcx>,
-                                          bounds: &[ty::PolyTraitRef<'tcx>])
+                                          bounds: impl Iterator<Item = ty::PolyTraitRef<'tcx>>)
                                           -> Supertraits<'cx, 'gcx, 'tcx>
 {
     elaborate_trait_refs(tcx, bounds).filter_to_traits()

src/librustc/ty/query/on_disk_cache.rs

@@ -174,10 +174,13 @@ impl<'sess> OnDiskCache<'sess> {
         tcx.dep_graph.with_ignore(|| {
             // Allocate SourceFileIndices
             let (file_to_file_index, file_index_to_stable_id) = {
-                let mut file_to_file_index = FxHashMap::default();
-                let mut file_index_to_stable_id = FxHashMap::default();
+                let files = tcx.sess.source_map().files();
+                let mut file_to_file_index = FxHashMap::with_capacity_and_hasher(
+                    files.len(), Default::default());
+                let mut file_index_to_stable_id = FxHashMap::with_capacity_and_hasher(
+                    files.len(), Default::default());
 
-                for (index, file) in tcx.sess.source_map().files().iter().enumerate() {
+                for (index, file) in files.iter().enumerate() {
                     let index = SourceFileIndex(index as u32);
                     let file_ptr: *const SourceFile = &**file as *const _;
                     file_to_file_index.insert(file_ptr, index);

src/librustc/ty/steal.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 use rustc_data_structures::sync::{RwLock, ReadGuard, MappedReadGuard};
-use std::mem;
 
 /// The `Steal` struct is intended to used as the value for a query.
 /// Specifically, we sometimes have queries (*cough* MIR *cough*)
@@ -51,7 +50,7 @@ impl<T> Steal<T> {
 
     pub fn steal(&self) -> T {
         let value_ref = &mut *self.value.try_write().expect("stealing value which is locked");
-        let value = mem::replace(value_ref, None);
+        let value = value_ref.take();
         value.expect("attempt to read from stolen value")
     }
 }

src/librustc_data_structures/tiny_list.rs

@@ -22,8 +22,6 @@
 //! If you expect to store more than 1 element in the common case, steer clear
 //! and use a `Vec<T>`, `Box<[T]>`, or a `SmallVec<T>`.
 
-use std::mem;
-
 #[derive(Clone, Hash, Debug, PartialEq)]
 pub struct TinyList<T: PartialEq> {
     head: Option<Element<T>>
@@ -52,15 +50,15 @@ impl<T: PartialEq> TinyList<T> {
     pub fn insert(&mut self, data: T) {
         self.head = Some(Element {
             data,
-            next: mem::replace(&mut self.head, None).map(Box::new),
+            next: self.head.take().map(Box::new)
         });
     }
 
     #[inline]
     pub fn remove(&mut self, data: &T) -> bool {
         self.head = match self.head {
             Some(ref mut head) if head.data == *data => {
-                mem::replace(&mut head.next, None).map(|x| *x)
+                head.next.take().map(|x| *x)
             }
             Some(ref mut head) => return head.remove_next(data),
             None => return false,
@@ -100,7 +98,7 @@ impl<T: PartialEq> Element<T> {
             if next.data != *data {
                 return next.remove_next(data)
             } else {
-                mem::replace(&mut next.next, None)
+                next.next.take()
             }
         } else {
             return false

src/librustc_lint/unused.rs

@@ -278,10 +278,9 @@ impl UnusedParens {
                                 msg: &str,
                                 followed_by_block: bool) {
         if let ast::ExprKind::Paren(ref inner) = value.node {
-            let necessary = followed_by_block && if let ast::ExprKind::Ret(_) = inner.node {
-                true
-            } else {
-                parser::contains_exterior_struct_lit(&inner)
+            let necessary = followed_by_block && match inner.node {
+                ast::ExprKind::Ret(_) | ast::ExprKind::Break(..) => true,
+                _ => parser::contains_exterior_struct_lit(&inner),
             };
             if !necessary {
                 let expr_text = if let Ok(snippet) = cx.sess().source_map()

src/librustc_mir/borrow_check/mod.rs

@@ -346,7 +346,33 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>(
         mbcx.errors_buffer.sort_by_key(|diag| diag.span.primary_span());
 
         if tcx.migrate_borrowck() {
-            match tcx.borrowck(def_id).signalled_any_error {
+            // When borrowck=migrate, check if AST-borrowck would
+            // error on the given code.
+
+            // rust-lang/rust#55492: loop over parents to ensure that
+            // errors that AST-borrowck only detects in some parent of
+            // a closure still allows NLL to signal an error.
+            let mut curr_def_id = def_id;
+            let signalled_any_error = loop {
+                match tcx.borrowck(curr_def_id).signalled_any_error {
+                    SignalledError::NoErrorsSeen => {
+                        // keep traversing (and borrow-checking) parents
+                    }
+                    SignalledError::SawSomeError => {
+                        // stop search here
+                        break SignalledError::SawSomeError;
+                    }
+                }
+
+                if tcx.is_closure(curr_def_id) {
+                    curr_def_id = tcx.parent_def_id(curr_def_id)
+                        .expect("a closure must have a parent_def_id");
+                } else {
+                    break SignalledError::NoErrorsSeen;
+                }
+            };
+
+            match signalled_any_error {
                 SignalledError::NoErrorsSeen => {
                     // if AST-borrowck signalled no errors, then
                     // downgrade all the buffered MIR-borrowck errors

src/librustc_mir/const_eval.rs

@@ -576,7 +576,11 @@ pub fn const_eval_provider<'a, 'tcx>(
         key.param_env.reveal = Reveal::UserFacing;
         match tcx.const_eval(key) {
             // try again with reveal all as requested
-            Err(ErrorHandled::TooGeneric) => {},
+            Err(ErrorHandled::TooGeneric) => {
+                // Promoteds should never be "too generic" when getting evaluated.
+                // They either don't get evaluated, or we are in a monomorphic context
+                assert!(key.value.promoted.is_none());
+            },
             // dedupliate calls
             other => return other,
         }

src/librustc_mir/interpret/validity.rs

@@ -303,7 +303,8 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
         let (lo, hi) = layout.valid_range.clone().into_inner();
         let max_hi = u128::max_value() >> (128 - size.bits()); // as big as the size fits
         assert!(hi <= max_hi);
-        if lo == 0 && hi == max_hi {
+        // We could also write `(hi + 1) % (max_hi + 1) == lo` but `max_hi + 1` overflows for `u128`
+        if (lo == 0 && hi == max_hi) || (hi + 1 == lo) {
             // Nothing to check
             return Ok(());
         }

src/librustc_target/spec/msp430_none_elf.rs

@@ -35,9 +35,14 @@ pub fn target() -> TargetResult {
             no_integrated_as: true,
 
             // There are no atomic CAS instructions available in the MSP430
-            // instruction set
-            max_atomic_width: Some(16),
+            // instruction set, and the LLVM backend doesn't currently support
+            // compiler fences so the Atomic* API is missing on this target.
+            // When the LLVM backend gains support for compile fences uncomment
+            // the `singlethread: true` line and set `max_atomic_width` to
+            // `Some(16)`.
+            max_atomic_width: Some(0),
             atomic_cas: false,
+            // singlethread: true,
 
             // Because these devices have very little resources having an
             // unwinder is too onerous so we default to "abort" because the

src/librustc_traits/implied_outlives_bounds.rs

@@ -159,14 +159,14 @@ fn implied_bounds_from_components(
 ) -> Vec<OutlivesBound<'tcx>> {
     sup_components
         .into_iter()
-        .flat_map(|component| {
+        .filter_map(|component| {
             match component {
                 Component::Region(r) =>
-                    vec![OutlivesBound::RegionSubRegion(sub_region, r)],
+                    Some(OutlivesBound::RegionSubRegion(sub_region, r)),
                 Component::Param(p) =>
-                    vec![OutlivesBound::RegionSubParam(sub_region, p)],
+                    Some(OutlivesBound::RegionSubParam(sub_region, p)),
                 Component::Projection(p) =>
-                    vec![OutlivesBound::RegionSubProjection(sub_region, p)],
+                    Some(OutlivesBound::RegionSubProjection(sub_region, p)),
                 Component::EscapingProjection(_) =>
                 // If the projection has escaping regions, don't
                 // try to infer any implied bounds even for its
@@ -176,9 +176,9 @@ fn implied_bounds_from_components(
                 // idea is that the WAY that the caller proves
                 // that may change in the future and we want to
                 // give ourselves room to get smarter here.
-                    vec![],
+                    None,
                 Component::UnresolvedInferenceVariable(..) =>
-                    vec![],
+                    None,
             }
         })
         .collect()

src/librustc_typeck/astconv.rs

@@ -1112,12 +1112,12 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx>+'o {
     {
         let tcx = self.tcx();
 
-        let bounds: Vec<_> = self.get_type_parameter_bounds(span, ty_param_def_id)
-            .predicates.into_iter().filter_map(|(p, _)| p.to_opt_poly_trait_ref()).collect();
+        let bounds = self.get_type_parameter_bounds(span, ty_param_def_id)
+            .predicates.into_iter().filter_map(|(p, _)| p.to_opt_poly_trait_ref());
 
         // Check that there is exactly one way to find an associated type with the
         // correct name.
-        let suitable_bounds = traits::transitive_bounds(tcx, &bounds)
+        let suitable_bounds = traits::transitive_bounds(tcx, bounds)
             .filter(|b| self.trait_defines_associated_type_named(b.def_id(), assoc_name));
 
         let param_node_id = tcx.hir.as_local_node_id(ty_param_def_id).unwrap();