Auto merge of #37382 - jonathandturner:rollup, r=jonathandturner

Rollup of 7 pull requests

- Successful merges: #37228, #37304, #37324, #37328, #37336, #37349, #37372
- Failed merges:

Author: bors

Diff for: src/doc/book/deref-coercions.md

@@ -69,7 +69,7 @@ foo(&counted);
 All we’ve done is wrap our `String` in an `Rc<T>`. But we can now pass the
 `Rc<String>` around anywhere we’d have a `String`. The signature of `foo`
 didn’t change, but works just as well with either type. This example has two
-conversions: `Rc<String>` to `String` and then `String` to `&str`. Rust will do
+conversions: `&Rc<String>` to `&String` and then `&String` to `&str`. Rust will do
 this as many times as possible until the types match.
 
 Another very common implementation provided by the standard library is:

Diff for: src/librustc/traits/error_reporting.rs

@@ -445,8 +445,10 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                                 let mut err = struct_span_err!(self.tcx.sess, span, E0277,
                                     "the trait bound `{}` is not satisfied",
                                     trait_ref.to_predicate());
-                                err.span_label(span, &format!("trait `{}` not satisfied",
-                                                              trait_ref.to_predicate()));
+                                err.span_label(span, &format!("the trait `{}` is not implemented \
+                                                               for `{}`",
+                                                              trait_ref,
+                                                              trait_ref.self_ty()));
 
                                 // Try to report a help message
 

Diff for: src/librustc/ty/util.rs

@@ -392,27 +392,30 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     }
 }
 
-// When hashing a type this ends up affecting properties like symbol names. We
-// want these symbol names to be calculated independent of other factors like
-// what architecture you're compiling *from*.
-//
-// The hashing just uses the standard `Hash` trait, but the implementations of
-// `Hash` for the `usize` and `isize` types are *not* architecture independent
-// (e.g. they has 4 or 8 bytes). As a result we want to avoid `usize` and
-// `isize` completely when hashing. To ensure that these don't leak in we use a
-// custom hasher implementation here which inflates the size of these to a `u64`
-// and `i64`.
-struct WidenUsizeHasher<H> {
+/// When hashing a type this ends up affecting properties like symbol names. We
+/// want these symbol names to be calculated independent of other factors like
+/// what architecture you're compiling *from*.
+///
+/// The hashing just uses the standard `Hash` trait, but the implementations of
+/// `Hash` for the `usize` and `isize` types are *not* architecture independent
+/// (e.g. they has 4 or 8 bytes). As a result we want to avoid `usize` and
+/// `isize` completely when hashing. To ensure that these don't leak in we use a
+/// custom hasher implementation here which inflates the size of these to a `u64`
+/// and `i64`.
+///
+/// The same goes for endianess: We always convert multi-byte integers to little
+/// endian before hashing.
+pub struct ArchIndependentHasher<H> {
     inner: H,
 }
 
-impl<H> WidenUsizeHasher<H> {
-    fn new(inner: H) -> WidenUsizeHasher<H> {
-        WidenUsizeHasher { inner: inner }
+impl<H> ArchIndependentHasher<H> {
+    pub fn new(inner: H) -> ArchIndependentHasher<H> {
+        ArchIndependentHasher { inner: inner }
     }
 }
 
-impl<H: Hasher> Hasher for WidenUsizeHasher<H> {
+impl<H: Hasher> Hasher for ArchIndependentHasher<H> {
     fn write(&mut self, bytes: &[u8]) {
         self.inner.write(bytes)
     }
@@ -425,44 +428,44 @@ impl<H: Hasher> Hasher for WidenUsizeHasher<H> {
         self.inner.write_u8(i)
     }
     fn write_u16(&mut self, i: u16) {
-        self.inner.write_u16(i)
+        self.inner.write_u16(i.to_le())
     }
     fn write_u32(&mut self, i: u32) {
-        self.inner.write_u32(i)
+        self.inner.write_u32(i.to_le())
     }
     fn write_u64(&mut self, i: u64) {
-        self.inner.write_u64(i)
+        self.inner.write_u64(i.to_le())
     }
     fn write_usize(&mut self, i: usize) {
-        self.inner.write_u64(i as u64)
+        self.inner.write_u64((i as u64).to_le())
     }
     fn write_i8(&mut self, i: i8) {
         self.inner.write_i8(i)
     }
     fn write_i16(&mut self, i: i16) {
-        self.inner.write_i16(i)
+        self.inner.write_i16(i.to_le())
     }
     fn write_i32(&mut self, i: i32) {
-        self.inner.write_i32(i)
+        self.inner.write_i32(i.to_le())
     }
     fn write_i64(&mut self, i: i64) {
-        self.inner.write_i64(i)
+        self.inner.write_i64(i.to_le())
     }
     fn write_isize(&mut self, i: isize) {
-        self.inner.write_i64(i as i64)
+        self.inner.write_i64((i as i64).to_le())
     }
 }
 
 pub struct TypeIdHasher<'a, 'gcx: 'a+'tcx, 'tcx: 'a, H> {
     tcx: TyCtxt<'a, 'gcx, 'tcx>,
-    state: WidenUsizeHasher<H>,
+    state: ArchIndependentHasher<H>,
 }
 
 impl<'a, 'gcx, 'tcx, H: Hasher> TypeIdHasher<'a, 'gcx, 'tcx, H> {
     pub fn new(tcx: TyCtxt<'a, 'gcx, 'tcx>, state: H) -> Self {
         TypeIdHasher {
             tcx: tcx,
-            state: WidenUsizeHasher::new(state),
+            state: ArchIndependentHasher::new(state),
         }
     }
 
@@ -493,6 +496,10 @@ impl<'a, 'gcx, 'tcx, H: Hasher> TypeIdHasher<'a, 'gcx, 'tcx, H> {
     pub fn def_path(&mut self, def_path: &ast_map::DefPath) {
         def_path.deterministic_hash_to(self.tcx, &mut self.state);
     }
+
+    pub fn into_inner(self) -> H {
+        self.state.inner
+    }
 }
 
 impl<'a, 'gcx, 'tcx, H: Hasher> TypeVisitor<'tcx> for TypeIdHasher<'a, 'gcx, 'tcx, H> {

Diff for: src/librustc_metadata/astencode.rs

@@ -30,7 +30,7 @@ use rustc_serialize::Encodable;
 pub struct Ast<'tcx> {
     id_range: IdRange,
     item: Lazy<InlinedItem>,
-    side_tables: LazySeq<(ast::NodeId, TableEntry<'tcx>)>
+    side_tables: LazySeq<(ast::NodeId, TableEntry<'tcx>)>,
 }
 
 #[derive(RustcEncodable, RustcDecodable)]
@@ -39,7 +39,7 @@ enum TableEntry<'tcx> {
     NodeType(Ty<'tcx>),
     ItemSubsts(ty::ItemSubsts<'tcx>),
     Adjustment(ty::adjustment::AutoAdjustment<'tcx>),
-    ConstQualif(ConstQualif)
+    ConstQualif(ConstQualif),
 }
 
 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
@@ -48,7 +48,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         match ii {
             InlinedItemRef::Item(_, i) => id_visitor.visit_item(i),
             InlinedItemRef::TraitItem(_, ti) => id_visitor.visit_trait_item(ti),
-            InlinedItemRef::ImplItem(_, ii) => id_visitor.visit_impl_item(ii)
+            InlinedItemRef::ImplItem(_, ii) => id_visitor.visit_impl_item(ii),
         }
 
         let ii_pos = self.position();
@@ -58,27 +58,27 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let tables_count = {
             let mut visitor = SideTableEncodingIdVisitor {
                 ecx: self,
-                count: 0
+                count: 0,
             };
             match ii {
                 InlinedItemRef::Item(_, i) => visitor.visit_item(i),
                 InlinedItemRef::TraitItem(_, ti) => visitor.visit_trait_item(ti),
-                InlinedItemRef::ImplItem(_, ii) => visitor.visit_impl_item(ii)
+                InlinedItemRef::ImplItem(_, ii) => visitor.visit_impl_item(ii),
             }
             visitor.count
         };
 
         self.lazy(&Ast {
             id_range: id_visitor.result(),
             item: Lazy::with_position(ii_pos),
-            side_tables: LazySeq::with_position_and_length(tables_pos, tables_count)
+            side_tables: LazySeq::with_position_and_length(tables_pos, tables_count),
         })
     }
 }
 
-struct SideTableEncodingIdVisitor<'a, 'b:'a, 'tcx:'b> {
+struct SideTableEncodingIdVisitor<'a, 'b: 'a, 'tcx: 'b> {
     ecx: &'a mut EncodeContext<'b, 'tcx>,
-    count: usize
+    count: usize,
 }
 
 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for SideTableEncodingIdVisitor<'a, 'b, 'tcx> {
@@ -114,10 +114,11 @@ pub fn decode_inlined_item<'a, 'tcx>(cdata: &CrateMetadata,
 
     let cnt = ast.id_range.max.as_usize() - ast.id_range.min.as_usize();
     let start = tcx.sess.reserve_node_ids(cnt);
-    let id_ranges = [ast.id_range, IdRange {
-        min: start,
-        max: ast::NodeId::new(start.as_usize() + cnt)
-    }];
+    let id_ranges = [ast.id_range,
+                     IdRange {
+                         min: start,
+                         max: ast::NodeId::new(start.as_usize() + cnt),
+                     }];
 
     let ii = ast.item.decode((cdata, tcx, id_ranges));
     let ii = ast_map::map_decoded_item(&tcx.map,
@@ -129,7 +130,7 @@ pub fn decode_inlined_item<'a, 'tcx>(cdata: &CrateMetadata,
     let item_node_id = match ii {
         &InlinedItem::Item(_, ref i) => i.id,
         &InlinedItem::TraitItem(_, ref ti) => ti.id,
-        &InlinedItem::ImplItem(_, ref ii) => ii.id
+        &InlinedItem::ImplItem(_, ref ii) => ii.id,
     };
     let inlined_did = tcx.map.local_def_id(item_node_id);
     tcx.register_item_type(inlined_did, tcx.lookup_item_type(orig_did));

Diff for: src/librustc_metadata/cstore.rs

@@ -54,7 +54,7 @@ pub struct ImportedFileMap {
     /// The end of this FileMap within the codemap of its original crate
     pub original_end_pos: syntax_pos::BytePos,
     /// The imported FileMap's representation within the local codemap
-    pub translated_filemap: Rc<syntax_pos::FileMap>
+    pub translated_filemap: Rc<syntax_pos::FileMap>,
 }
 
 pub struct CrateMetadata {
@@ -141,21 +141,23 @@ impl CStore {
         self.metas.borrow_mut().insert(cnum, data);
     }
 
-    pub fn iter_crate_data<I>(&self, mut i: I) where
-        I: FnMut(CrateNum, &Rc<CrateMetadata>),
+    pub fn iter_crate_data<I>(&self, mut i: I)
+        where I: FnMut(CrateNum, &Rc<CrateMetadata>)
     {
         for (&k, v) in self.metas.borrow().iter() {
             i(k, v);
         }
     }
 
     /// Like `iter_crate_data`, but passes source paths (if available) as well.
-    pub fn iter_crate_data_origins<I>(&self, mut i: I) where
-        I: FnMut(CrateNum, &CrateMetadata, Option<CrateSource>),
+    pub fn iter_crate_data_origins<I>(&self, mut i: I)
+        where I: FnMut(CrateNum, &CrateMetadata, Option<CrateSource>)
     {
         for (&k, v) in self.metas.borrow().iter() {
             let origin = self.opt_used_crate_source(k);
-            origin.as_ref().map(|cs| { assert!(k == cs.cnum); });
+            origin.as_ref().map(|cs| {
+                assert!(k == cs.cnum);
+            });
             i(k, &v, origin);
         }
     }
@@ -167,10 +169,12 @@ impl CStore {
         }
     }
 
-    pub fn opt_used_crate_source(&self, cnum: CrateNum)
-                                 -> Option<CrateSource> {
-        self.used_crate_sources.borrow_mut()
-            .iter().find(|source| source.cnum == cnum).cloned()
+    pub fn opt_used_crate_source(&self, cnum: CrateNum) -> Option<CrateSource> {
+        self.used_crate_sources
+            .borrow_mut()
+            .iter()
+            .find(|source| source.cnum == cnum)
+            .cloned()
     }
 
     pub fn reset(&self) {
@@ -182,19 +186,17 @@ impl CStore {
         self.statically_included_foreign_items.borrow_mut().clear();
     }
 
-    pub fn crate_dependencies_in_rpo(&self, krate: CrateNum) -> Vec<CrateNum>
-    {
+    pub fn crate_dependencies_in_rpo(&self, krate: CrateNum) -> Vec<CrateNum> {
         let mut ordering = Vec::new();
         self.push_dependencies_in_postorder(&mut ordering, krate);
         ordering.reverse();
         ordering
     }
 
-    pub fn push_dependencies_in_postorder(&self,
-                                          ordering: &mut Vec<CrateNum>,
-                                          krate: CrateNum)
-    {
-        if ordering.contains(&krate) { return }
+    pub fn push_dependencies_in_postorder(&self, ordering: &mut Vec<CrateNum>, krate: CrateNum) {
+        if ordering.contains(&krate) {
+            return;
+        }
 
         let data = self.get_crate_data(krate);
         for &dep in data.cnum_map.borrow().iter() {
@@ -215,20 +217,25 @@ impl CStore {
     // In order to get this left-to-right dependency ordering, we perform a
     // topological sort of all crates putting the leaves at the right-most
     // positions.
-    pub fn do_get_used_crates(&self, prefer: LinkagePreference)
+    pub fn do_get_used_crates(&self,
+                              prefer: LinkagePreference)
                               -> Vec<(CrateNum, Option<PathBuf>)> {
         let mut ordering = Vec::new();
         for (&num, _) in self.metas.borrow().iter() {
             self.push_dependencies_in_postorder(&mut ordering, num);
         }
         info!("topological ordering: {:?}", ordering);
         ordering.reverse();
-        let mut libs = self.used_crate_sources.borrow()
+        let mut libs = self.used_crate_sources
+            .borrow()
             .iter()
-            .map(|src| (src.cnum, match prefer {
-                LinkagePreference::RequireDynamic => src.dylib.clone().map(|p| p.0),
-                LinkagePreference::RequireStatic => src.rlib.clone().map(|p| p.0),
-            }))
+            .map(|src| {
+                (src.cnum,
+                 match prefer {
+                     LinkagePreference::RequireDynamic => src.dylib.clone().map(|p| p.0),
+                     LinkagePreference::RequireStatic => src.rlib.clone().map(|p| p.0),
+                 })
+            })
             .collect::<Vec<_>>();
         libs.sort_by(|&(a, _), &(b, _)| {
             let a = ordering.iter().position(|x| *x == a);
@@ -243,9 +250,7 @@ impl CStore {
         self.used_libraries.borrow_mut().push((lib, kind));
     }
 
-    pub fn get_used_libraries<'a>(&'a self)
-                              -> &'a RefCell<Vec<(String,
-                                                  NativeLibraryKind)>> {
+    pub fn get_used_libraries<'a>(&'a self) -> &'a RefCell<Vec<(String, NativeLibraryKind)>> {
         &self.used_libraries
     }
 
@@ -255,13 +260,11 @@ impl CStore {
         }
     }
 
-    pub fn get_used_link_args<'a>(&'a self) -> &'a RefCell<Vec<String> > {
+    pub fn get_used_link_args<'a>(&'a self) -> &'a RefCell<Vec<String>> {
         &self.used_link_args
     }
 
-    pub fn add_extern_mod_stmt_cnum(&self,
-                                    emod_id: ast::NodeId,
-                                    cnum: CrateNum) {
+    pub fn add_extern_mod_stmt_cnum(&self, emod_id: ast::NodeId, cnum: CrateNum) {
         self.extern_mod_crate_map.borrow_mut().insert(emod_id, cnum);
     }
 
@@ -273,8 +276,7 @@ impl CStore {
         self.statically_included_foreign_items.borrow().contains(&id)
     }
 
-    pub fn do_extern_mod_stmt_cnum(&self, emod_id: ast::NodeId) -> Option<CrateNum>
-    {
+    pub fn do_extern_mod_stmt_cnum(&self, emod_id: ast::NodeId) -> Option<CrateNum> {
         self.extern_mod_crate_map.borrow().get(&emod_id).cloned()
     }
 
@@ -288,14 +290,20 @@ impl CStore {
 }
 
 impl CrateMetadata {
-    pub fn name(&self) -> &str { &self.root.name }
-    pub fn hash(&self) -> Svh { self.root.hash }
-    pub fn disambiguator(&self) -> &str { &self.root.disambiguator }
+    pub fn name(&self) -> &str {
+        &self.root.name
+    }
+    pub fn hash(&self) -> Svh {
+        self.root.hash
+    }
+    pub fn disambiguator(&self) -> &str {
+        &self.root.disambiguator
+    }
 
     pub fn is_staged_api(&self) -> bool {
-        self.get_item_attrs(CRATE_DEF_INDEX).iter().any(|attr| {
-            attr.name() == "stable" || attr.name() == "unstable"
-        })
+        self.get_item_attrs(CRATE_DEF_INDEX)
+            .iter()
+            .any(|attr| attr.name() == "stable" || attr.name() == "unstable")
     }
 
     pub fn is_allocator(&self) -> bool {