Auto merge of #51448 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 13 pull requests

Successful merges:

 - #50143 (Add deprecation lint for duplicated `macro_export`s)
 - #51099 (Fix Issue 38777)
 - #51276 (Dedup auto traits in trait objects.)
 - #51298 (Stabilize unit tests with non-`()` return type)
 - #51360 (Suggest parentheses when a struct literal needs them)
 - #51391 (Use spans pointing at the inside of a rustdoc attribute)
 - #51394 (Use scope tree depths to speed up `nearest_common_ancestor`.)
 - #51396 (Make the size of Option<NonZero*> a documented guarantee.)
 - #51401 (Warn on `repr` without hints)
 - #51412 (Avoid useless Vec clones in pending_obligations().)
 - #51427 (compiletest: autoremove duplicate .nll.* files (#51204))
 - #51436 (Do not require stage 2 compiler for rustdoc)
 - #51437 (rustbuild: generate full list of dependencies for metadata)

Failed merges:

src/bootstrap/builder.rs

@@ -800,10 +800,7 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTC_ERROR_FORMAT", error_format);
         }
         if cmd != "build" && cmd != "check" && want_rustdoc {
-            cargo.env(
+            cargo.env("RUSTDOC_LIBDIR", self.sysroot_libdir(compiler, self.config.build));
-                "RUSTDOC_LIBDIR",
-                self.rustc_libdir(self.compiler(2, self.config.build)),
-            );
         }
 
         if mode.is_tool() {

src/bootstrap/lib.rs

@@ -280,7 +280,8 @@ pub struct Build {
 struct Crate {
     name: Interned<String>,
     version: String,
-    deps: Vec<Interned<String>>,
+    deps: HashSet<Interned<String>>,
+    id: String,
     path: PathBuf,
     doc_step: String,
     build_step: String,

src/bootstrap/metadata.rs

@@ -11,6 +11,7 @@
 use std::collections::HashMap;
 use std::process::Command;
 use std::path::PathBuf;
+use std::collections::HashSet;
 
 use build_helper::output;
 use serde_json;
@@ -45,45 +46,17 @@ struct ResolveNode {
 }
 
 pub fn build(build: &mut Build) {
-    build_krate(build, "src/libstd");
+    let mut resolves = Vec::new();
-    build_krate(build, "src/libtest");
+    build_krate(&build.std_features(), build, &mut resolves, "src/libstd");
-    build_krate(build, "src/rustc");
+    build_krate("", build, &mut resolves, "src/libtest");
-}
+    build_krate(&build.rustc_features(), build, &mut resolves, "src/rustc");
 
-fn build_krate(build: &mut Build, krate: &str) {
-    // Run `cargo metadata` to figure out what crates we're testing.
-    //
-    // Down below we're going to call `cargo test`, but to test the right set
-    // of packages we're going to have to know what `-p` arguments to pass it
-    // to know what crates to test. Here we run `cargo metadata` to learn about
-    // the dependency graph and what `-p` arguments there are.
-    let mut cargo = Command::new(&build.initial_cargo);
-    cargo.arg("metadata")
-         .arg("--format-version").arg("1")
-         .arg("--manifest-path").arg(build.src.join(krate).join("Cargo.toml"));
-    let output = output(&mut cargo);
-    let output: Output = serde_json::from_str(&output).unwrap();
     let mut id2name = HashMap::new();
-    for package in output.packages {
+    for (name, krate) in build.crates.iter() {
-        if package.source.is_none() {
+        id2name.insert(krate.id.clone(), name.clone());
-            let name = INTERNER.intern_string(package.name);
-            id2name.insert(package.id, name);
-            let mut path = PathBuf::from(package.manifest_path);
-            path.pop();
-            build.crates.insert(name, Crate {
-                build_step: format!("build-crate-{}", name),
-                doc_step: format!("doc-crate-{}", name),
-                test_step: format!("test-crate-{}", name),
-                bench_step: format!("bench-crate-{}", name),
-                name,
-                version: package.version,
-                deps: Vec::new(),
-                path,
-            });
-        }
     }
 
-    for node in output.resolve.nodes {
+    for node in resolves {
         let name = match id2name.get(&node.id) {
             Some(name) => name,
             None => continue,
@@ -95,7 +68,42 @@ fn build_krate(build: &mut Build, krate: &str) {
                 Some(dep) => dep,
                 None => continue,
             };
-            krate.deps.push(*dep);
+            krate.deps.insert(*dep);
         }
     }
 }
+
+fn build_krate(features: &str, build: &mut Build, resolves: &mut Vec<ResolveNode>, krate: &str) {
+    // Run `cargo metadata` to figure out what crates we're testing.
+    //
+    // Down below we're going to call `cargo test`, but to test the right set
+    // of packages we're going to have to know what `-p` arguments to pass it
+    // to know what crates to test. Here we run `cargo metadata` to learn about
+    // the dependency graph and what `-p` arguments there are.
+    let mut cargo = Command::new(&build.initial_cargo);
+    cargo.arg("metadata")
+         .arg("--format-version").arg("1")
+         .arg("--features").arg(features)
+         .arg("--manifest-path").arg(build.src.join(krate).join("Cargo.toml"));
+    let output = output(&mut cargo);
+    let output: Output = serde_json::from_str(&output).unwrap();
+    for package in output.packages {
+        if package.source.is_none() {
+            let name = INTERNER.intern_string(package.name);
+            let mut path = PathBuf::from(package.manifest_path);
+            path.pop();
+            build.crates.insert(name, Crate {
+                build_step: format!("build-crate-{}", name),
+                doc_step: format!("doc-crate-{}", name),
+                test_step: format!("test-crate-{}", name),
+                bench_step: format!("bench-crate-{}", name),
+                name,
+                version: package.version,
+                id: package.id,
+                deps: HashSet::new(),
+                path,
+            });
+        }
+    }
+    resolves.extend(output.resolve.nodes);
+}

src/libcore/num/mod.rs

@@ -39,10 +39,10 @@ macro_rules! nonzero_integers {
         $(
             /// An integer that is known not to equal zero.
             ///
-            /// This may enable some memory layout optimization such as:
+            /// This enables some memory layout optimization.
+            /// For example, `Option<NonZeroU32>` is the same size as `u32`:
             ///
             /// ```rust
-            /// # #![feature(nonzero)]
             /// use std::mem::size_of;
             /// assert_eq!(size_of::<Option<std::num::NonZeroU32>>(), size_of::<u32>());
             /// ```

src/librustc/lint/builtin.rs

@@ -17,6 +17,7 @@
 use errors::{Applicability, DiagnosticBuilder};
 use lint::{LintPass, LateLintPass, LintArray};
 use session::Session;
+use syntax::ast;
 use syntax::codemap::Span;
 
 declare_lint! {
@@ -206,6 +207,12 @@ declare_lint! {
     "potentially-conflicting impls were erroneously allowed"
 }
 
+declare_lint! {
+    pub BAD_REPR,
+    Warn,
+    "detects incorrect use of `repr` attribute"
+}
+
 declare_lint! {
     pub DEPRECATED,
     Warn,
@@ -285,6 +292,12 @@ declare_lint! {
     "warns about duplicate associated type bindings in generics"
 }
 
+declare_lint! {
+    pub DUPLICATE_MACRO_EXPORTS,
+    Deny,
+    "detects duplicate macro exports"
+}
+
 /// Does nothing as a lint pass, but registers some `Lint`s
 /// which are used by other parts of the compiler.
 #[derive(Copy, Clone)]
@@ -337,6 +350,7 @@ impl LintPass for HardwiredLints {
             ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
             UNSTABLE_NAME_COLLISIONS,
             DUPLICATE_ASSOCIATED_TYPE_BINDINGS,
+            DUPLICATE_MACRO_EXPORTS,
         )
     }
 }
@@ -348,6 +362,7 @@ pub enum BuiltinLintDiagnostics {
     Normal,
     BareTraitObject(Span, /* is_global */ bool),
     AbsPathWithModule(Span),
+    DuplicatedMacroExports(ast::Ident, Span, Span),
 }
 
 impl BuiltinLintDiagnostics {
@@ -380,6 +395,10 @@ impl BuiltinLintDiagnostics {
                 };
                 db.span_suggestion_with_applicability(span, "use `crate`", sugg, app);
             }
+            BuiltinLintDiagnostics::DuplicatedMacroExports(ident, earlier_span, later_span) => {
+                db.span_label(later_span, format!("`{}` already exported", ident));
+                db.span_note(earlier_span, "previous macro export is now shadowed");
+            }
         }
     }
 }

src/librustc/middle/region.rs

@@ -22,7 +22,6 @@ use ty;
 
 use std::fmt;
 use std::mem;
-use rustc_data_structures::small_vec::SmallVec;
 use rustc_data_structures::sync::Lrc;
 use syntax::codemap;
 use syntax::ast;
@@ -280,6 +279,8 @@ impl Scope {
     }
 }
 
+pub type ScopeDepth = u32;
+
 /// The region scope tree encodes information about region relationships.
 #[derive(Default, Debug)]
 pub struct ScopeTree {
@@ -297,7 +298,7 @@ pub struct ScopeTree {
     /// conditional expression or repeating block. (Note that the
     /// enclosing scope id for the block associated with a closure is
     /// the closure itself.)
-    parent_map: FxHashMap<Scope, Scope>,
+    parent_map: FxHashMap<Scope, (Scope, ScopeDepth)>,
 
     /// `var_map` maps from a variable or binding id to the block in
     /// which that variable is declared.
@@ -415,11 +416,12 @@ pub struct Context {
     /// details.
     root_id: Option<hir::ItemLocalId>,
 
-    /// the scope that contains any new variables declared
+    /// The scope that contains any new variables declared, plus its depth in
-    var_parent: Option<Scope>,
+    /// the scope tree.
+    var_parent: Option<(Scope, ScopeDepth)>,
 
-    /// region parent of expressions etc
+    /// Region parent of expressions, etc., plus its depth in the scope tree.
-    parent: Option<Scope>,
+    parent: Option<(Scope, ScopeDepth)>,
 }
 
 struct RegionResolutionVisitor<'a, 'tcx: 'a> {
@@ -499,7 +501,7 @@ impl<'tcx> Visitor<'tcx> for ExprLocatorVisitor {
 }
 
 impl<'tcx> ScopeTree {
-    pub fn record_scope_parent(&mut self, child: Scope, parent: Option<Scope>) {
+    pub fn record_scope_parent(&mut self, child: Scope, parent: Option<(Scope, ScopeDepth)>) {
         debug!("{:?}.parent = {:?}", child, parent);
 
         if let Some(p) = parent {
@@ -515,7 +517,7 @@ impl<'tcx> ScopeTree {
 
     pub fn each_encl_scope<E>(&self, mut e:E) where E: FnMut(Scope, Scope) {
         for (&child, &parent) in &self.parent_map {
-            e(child, parent)
+            e(child, parent.0)
         }
     }
 
@@ -558,7 +560,7 @@ impl<'tcx> ScopeTree {
 
     pub fn opt_encl_scope(&self, id: Scope) -> Option<Scope> {
         //! Returns the narrowest scope that encloses `id`, if any.
-        self.parent_map.get(&id).cloned()
+        self.parent_map.get(&id).cloned().map(|(p, _)| p)
     }
 
     #[allow(dead_code)] // used in cfg
@@ -590,7 +592,7 @@ impl<'tcx> ScopeTree {
         // returned.
         let mut id = Scope::Node(expr_id);
 
-        while let Some(&p) = self.parent_map.get(&id) {
+        while let Some(&(p, _)) = self.parent_map.get(&id) {
             match p.data() {
                 ScopeData::Destruction(..) => {
                     debug!("temporary_scope({:?}) = {:?} [enclosing]",
@@ -658,57 +660,61 @@ impl<'tcx> ScopeTree {
         }
     }
 
-    /// Finds the nearest common ancestor (if any) of two scopes.  That is, finds the smallest
+    /// Finds the nearest common ancestor of two scopes.  That is, finds the
-    /// scope which is greater than or equal to both `scope_a` and `scope_b`.
+    /// smallest scope which is greater than or equal to both `scope_a` and
-    pub fn nearest_common_ancestor(&self,
+    /// `scope_b`.
-                                   scope_a: Scope,
+    pub fn nearest_common_ancestor(&self, scope_a: Scope, scope_b: Scope) -> Scope {
-                                   scope_b: Scope)
-                                   -> Scope {
         if scope_a == scope_b { return scope_a; }
 
-        // Process the lists in tandem from the innermost scope, recording the
+        let mut a = scope_a;
-        // scopes seen so far. The first scope that comes up for a second time
+        let mut b = scope_b;
-        // is the nearest common ancestor.
-        //
-        // Note: another way to compute the nearest common ancestor is to get
-        // the full scope chain for both scopes and then compare the chains to
-        // find the first scope in a common tail. But getting a parent scope
-        // requires a hash table lookup, and we often have very long scope
-        // chains (10s or 100s of scopes) that only differ by a few elements at
-        // the start. So this algorithm is faster.
 
-        let mut ma = Some(&scope_a);
+        // Get the depth of each scope's parent. If either scope has no parent,
-        let mut mb = Some(&scope_b);
+        // it must be the root, which means we can stop immediately because the
+        // root must be the nearest common ancestor. (In practice, this is
+        // moderately common.)
+        let (parent_a, parent_a_depth) = match self.parent_map.get(&a) {
+            Some(pd) => *pd,
+            None => return a,
+        };
+        let (parent_b, parent_b_depth) = match self.parent_map.get(&b) {
+            Some(pd) => *pd,
+            None => return b,
+        };
 
-        // A HashSet<Scope> is a more obvious choice for these, but SmallVec is
+        if parent_a_depth > parent_b_depth {
-        // faster because the set size is normally small so linear search is
+            // `a` is lower than `b`. Move `a` up until it's at the same depth
-        // as good or better than a hash table lookup, plus the size is usually
+            // as `b`. The first move up is trivial because we already found
-        // small enough to avoid a heap allocation.
+            // `parent_a` above; the loop does the remaining N-1 moves.
-        let mut seen_a: SmallVec<[&Scope; 32]> = SmallVec::new();
+            a = parent_a;
-        let mut seen_b: SmallVec<[&Scope; 32]> = SmallVec::new();
+            for _ in 0..(parent_a_depth - parent_b_depth - 1) {
-
+                a = self.parent_map.get(&a).unwrap().0;
-        loop {
-            if let Some(a) = ma {
-                if seen_b.iter().any(|s| *s == a) {
-                    return *a;
             }
-                seen_a.push(a);
+        } else if parent_b_depth > parent_a_depth {
-                ma = self.parent_map.get(&a);
+            // `b` is lower than `a`.
+            b = parent_b;
+            for _ in 0..(parent_b_depth - parent_a_depth - 1) {
+                b = self.parent_map.get(&b).unwrap().0;
+            }
+        } else {
+            // Both scopes are at the same depth, and we know they're not equal
+            // because that case was tested for at the top of this function. So
+            // we can trivially move them both up one level now.
+            assert!(parent_a_depth != 0);
+            a = parent_a;
+            b = parent_b;
         }
 
-            if let Some(b) = mb {
+        // Now both scopes are at the same level. We move upwards in lockstep
-                if seen_a.iter().any(|s| *s == b) {
+        // until they match. In practice, this loop is almost always executed
-                    return *b;
+        // zero times because `a` is almost always a direct ancestor of `b` or
-                }
+        // vice versa.
-                seen_b.push(b);
+        while a != b {
-                mb = self.parent_map.get(&b);
+            a = self.parent_map.get(&a).unwrap().0;
-            }
+            b = self.parent_map.get(&b).unwrap().0;
+        };
 
-            if ma.is_none() && mb.is_none() {
+        a
-                // No nearest common ancestor found.
-                bug!();
-            }
-        }
     }
 
     /// Assuming that the provided region was defined within this `ScopeTree`,
@@ -807,7 +813,7 @@ fn record_var_lifetime(visitor: &mut RegionResolutionVisitor,
             //
             // extern fn isalnum(c: c_int) -> c_int
         }
-        Some(parent_scope) =>
+        Some((parent_scope, _)) =>
             visitor.scope_tree.record_var_scope(var_id, parent_scope),
     }
 }
@@ -1019,7 +1025,7 @@ fn resolve_expr<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, expr:
             // Keep traversing up while we can.
             match visitor.scope_tree.parent_map.get(&scope) {
                 // Don't cross from closure bodies to their parent.
-                Some(&superscope) => match superscope.data() {
+                Some(&(superscope, _)) => match superscope.data() {
                     ScopeData::CallSite(_) => break,
                     _ => scope = superscope
                 },
@@ -1036,7 +1042,7 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
                            init: Option<&'tcx hir::Expr>) {
     debug!("resolve_local(pat={:?}, init={:?})", pat, init);
 
-    let blk_scope = visitor.cx.var_parent;
+    let blk_scope = visitor.cx.var_parent.map(|(p, _)| p);
 
     // As an exception to the normal rules governing temporary
     // lifetimes, initializers in a let have a temporary lifetime
@@ -1261,16 +1267,20 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
 
 impl<'a, 'tcx> RegionResolutionVisitor<'a, 'tcx> {
     /// Records the current parent (if any) as the parent of `child_scope`.
-    fn record_child_scope(&mut self, child_scope: Scope) {
+    /// Returns the depth of `child_scope`.
+    fn record_child_scope(&mut self, child_scope: Scope) -> ScopeDepth {
         let parent = self.cx.parent;
         self.scope_tree.record_scope_parent(child_scope, parent);
+        // If `child_scope` has no parent, it must be the root node, and so has
+        // a depth of 1. Otherwise, its depth is one more than its parent's.
+        parent.map_or(1, |(_p, d)| d + 1)
     }
 
     /// Records the current parent (if any) as the parent of `child_scope`,
     /// and sets `child_scope` as the new current parent.
     fn enter_scope(&mut self, child_scope: Scope) {
-        self.record_child_scope(child_scope);
+        let child_depth = self.record_child_scope(child_scope);
-        self.cx.parent = Some(child_scope);
+        self.cx.parent = Some((child_scope, child_depth));
     }
 
     fn enter_node_scope_with_dtor(&mut self, id: hir::ItemLocalId) {

src/librustc/traits/engine.rs

@@ -13,7 +13,7 @@ use ty::{self, Ty, TyCtxt};
 use hir::def_id::DefId;
 
 use super::{FulfillmentContext, FulfillmentError};
-use super::{ObligationCause, PendingPredicateObligation, PredicateObligation};
+use super::{ObligationCause, PredicateObligation};
 
 pub trait TraitEngine<'tcx>: 'tcx {
     fn normalize_projection_type<'a, 'gcx>(
@@ -49,7 +49,7 @@ pub trait TraitEngine<'tcx>: 'tcx {
         infcx: &InferCtxt<'a, 'gcx, 'tcx>,
     ) -> Result<(), Vec<FulfillmentError<'tcx>>>;
 
-    fn pending_obligations(&self) -> Vec<PendingPredicateObligation<'tcx>>;
+    fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>>;
 }
 
 impl<'a, 'gcx, 'tcx> dyn TraitEngine<'tcx> {

src/librustc/traits/fulfill.rs

@@ -241,8 +241,8 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> {
         self.select(&mut selcx)
     }
 
-    fn pending_obligations(&self) -> Vec<PendingPredicateObligation<'tcx>> {
+    fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>> {
-        self.predicates.pending_obligations()
+        self.predicates.map_pending_obligations(|o| o.obligation.clone())
     }
 }
 

src/librustc_data_structures/obligation_forest/mod.rs

@@ -229,13 +229,13 @@ impl<O: ForestObligation> ObligationForest<O> {
     }
 
     /// Returns the set of obligations that are in a pending state.
-    pub fn pending_obligations(&self) -> Vec<O>
+    pub fn map_pending_obligations<P, F>(&self, f: F) -> Vec<P>
-        where O: Clone
+        where F: Fn(&O) -> P
     {
         self.nodes
             .iter()
             .filter(|n| n.state.get() == NodeState::Pending)
-            .map(|n| n.obligation.clone())
+            .map(|n| f(&n.obligation))
             .collect()
     }
 

src/librustc_driver/test.rs

@@ -191,11 +191,12 @@ impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
         self.infcx.tcx
     }
 
-    pub fn create_region_hierarchy(&mut self, rh: &RH, parent: region::Scope) {
+    pub fn create_region_hierarchy(&mut self, rh: &RH,
+                                   parent: (region::Scope, region::ScopeDepth)) {
         let me = region::Scope::Node(rh.id);
         self.region_scope_tree.record_scope_parent(me, Some(parent));
         for child_rh in rh.sub {
-            self.create_region_hierarchy(child_rh, me);
+            self.create_region_hierarchy(child_rh, (me, parent.1 + 1));
         }
     }
 
@@ -215,7 +216,7 @@ impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
                 id: hir::ItemLocalId(11),
                 sub: &[],
             }],
-        }, dscope);
+        }, (dscope, 1));
     }
 
     #[allow(dead_code)] // this seems like it could be useful, even if we don't use it now

src/librustc_lint/builtin.rs

@@ -673,6 +673,79 @@ impl EarlyLintPass for AnonymousParameters {
     }
 }
 
+/// Checks for incorrect use use of `repr` attributes.
+#[derive(Clone)]
+pub struct BadRepr;
+
+impl LintPass for BadRepr {
+    fn get_lints(&self) -> LintArray {
+        lint_array!()
+    }
+}
+
+impl EarlyLintPass for BadRepr {
+    fn check_attribute(&mut self, cx: &EarlyContext, attr: &ast::Attribute) {
+        if attr.name() == "repr" {
+            let list = attr.meta_item_list();
+
+            let repr_str = |lit: &str| { format!("#[repr({})]", lit) };
+
+            // Emit warnings with `repr` either has a literal assignment (`#[repr = "C"]`) or
+            // no hints (``#[repr]`)
+            let has_hints = list.as_ref().map(|ref list| !list.is_empty()).unwrap_or(false);
+            if !has_hints {
+                let mut suggested = false;
+                let mut warn = if let Some(ref lit) = attr.value_str() {
+                    // avoid warning about empty `repr` on `#[repr = "foo"]`
+                    let mut warn = cx.struct_span_lint(
+                        BAD_REPR,
+                        attr.span,
+                        "`repr` attribute isn't configurable with a literal",
+                    );
+                    match format!("{}", lit).as_ref() {
+                        | "C" | "packed" | "rust" | "transparent"
+                        | "u8" | "u16" | "u32" | "u64" | "u128" | "usize"
+                        | "i8" | "i16" | "i32" | "i64" | "i128" | "isize" => {
+                            // if the literal could have been a valid `repr` arg,
+                            // suggest the correct syntax
+                            warn.span_suggestion(
+                                attr.span,
+                                "give `repr` a hint",
+                                repr_str(&lit.as_str()),
+                            );
+                            suggested = true;
+                        }
+                        _ => {  // the literal wasn't a valid `repr` arg
+                            warn.span_label(attr.span, "needs a hint");
+                        }
+                    };
+                    warn
+                } else {
+                    let mut warn = cx.struct_span_lint(
+                        BAD_REPR,
+                        attr.span,
+                        "`repr` attribute must have a hint",
+                    );
+                    warn.span_label(attr.span, "needs a hint");
+                    warn
+                };
+                if !suggested {
+                    warn.help(&format!(
+                        "valid hints include `{}`, `{}`, `{}` and `{}`",
+                        repr_str("C"),
+                        repr_str("packed"),
+                        repr_str("rust"),
+                        repr_str("transparent"),
+                    ));
+                    warn.note("for more information, visit \
+                               <https://doc.rust-lang.org/reference/type-layout.html>");
+                }
+                warn.emit();
+            }
+        }
+    }
+}
+
 /// Checks for use of attributes which have been deprecated.
 #[derive(Clone)]
 pub struct DeprecatedAttr {

src/librustc_lint/lib.rs

@@ -107,6 +107,7 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
                        UnusedImportBraces,
                        AnonymousParameters,
                        UnusedDocComment,
+                       BadRepr,
                        );
 
     add_early_builtin_with_new!(sess,
@@ -211,6 +212,11 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
             edition: None,
         },
+        FutureIncompatibleInfo {
+            id: LintId::of(DUPLICATE_MACRO_EXPORTS),
+            reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
+            edition: Some(Edition::Edition2018),
+        },
         FutureIncompatibleInfo {
             id: LintId::of(SAFE_EXTERN_STATICS),
             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",

src/librustc_resolve/lib.rs

@@ -2934,8 +2934,38 @@ impl<'a> Resolver<'a> {
                                                               here due to private fields"));
                             }
                         } else {
-                            err.span_label(span, format!("did you mean `{} {{ /* fields */ }}`?",
+                            // HACK(estebank): find a better way to figure out that this was a
-                                                         path_str));
+                            // parser issue where a struct literal is being used on an expression
+                            // where a brace being opened means a block is being started. Look
+                            // ahead for the next text to see if `span` is followed by a `{`.
+                            let cm = this.session.codemap();
+                            let mut sp = span;
+                            loop {
+                                sp = cm.next_point(sp);
+                                match cm.span_to_snippet(sp) {
+                                    Ok(ref snippet) => {
+                                        if snippet.chars().any(|c| { !c.is_whitespace() }) {
+                                            break;
+                                        }
+                                    }
+                                    _ => break,
+                                }
+                            }
+                            let followed_by_brace = match cm.span_to_snippet(sp) {
+                                Ok(ref snippet) if snippet == "{" => true,
+                                _ => false,
+                            };
+                            if let (PathSource::Expr(None), true) = (source, followed_by_brace) {
+                                err.span_label(
+                                    span,
+                                    format!("did you mean `({} {{ /* fields */ }})`?", path_str),
+                                );
+                            } else {
+                                err.span_label(
+                                    span,
+                                    format!("did you mean `{} {{ /* fields */ }}`?", path_str),
+                                );
+                            }
                         }
                         return (err, candidates);
                     }

src/librustc_resolve/resolve_imports.rs

@@ -18,13 +18,14 @@ use {names_to_string, module_to_string};
 use {resolve_error, ResolutionError};
 
 use rustc::ty;
-use rustc::lint::builtin::PUB_USE_OF_PRIVATE_EXTERN_CRATE;
+use rustc::lint::builtin::BuiltinLintDiagnostics;
+use rustc::lint::builtin::{DUPLICATE_MACRO_EXPORTS, PUB_USE_OF_PRIVATE_EXTERN_CRATE};
 use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
 use rustc::hir::def::*;
 use rustc::session::DiagnosticMessageId;
 use rustc::util::nodemap::{FxHashMap, FxHashSet};
 
-use syntax::ast::{Ident, Name, NodeId};
+use syntax::ast::{Ident, Name, NodeId, CRATE_NODE_ID};
 use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
 use syntax::ext::hygiene::Mark;
 use syntax::symbol::keywords;
@@ -974,7 +975,16 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
         if module as *const _ == self.graph_root as *const _ {
             let macro_exports = mem::replace(&mut self.macro_exports, Vec::new());
             for export in macro_exports.into_iter().rev() {
-                if exported_macro_names.insert(export.ident.modern(), export.span).is_none() {
+                if let Some(later_span) = exported_macro_names.insert(export.ident.modern(),
+                                                                      export.span) {
+                    self.session.buffer_lint_with_diagnostic(
+                        DUPLICATE_MACRO_EXPORTS,
+                        CRATE_NODE_ID,
+                        later_span,
+                        &format!("a macro named `{}` has already been exported", export.ident),
+                        BuiltinLintDiagnostics::DuplicatedMacroExports(
+                            export.ident, export.span, later_span));
+                } else {
                     reexports.push(export);
                 }
             }

src/librustc_typeck/astconv.rs

@@ -30,6 +30,7 @@ use util::common::ErrorReported;
 use util::nodemap::{FxHashSet, FxHashMap};
 use errors::FatalError;
 
+// use std::cmp::Ordering;
 use std::iter;
 use syntax::ast;
 use syntax::feature_gate::{GateIssue, emit_feature_err};
@@ -646,7 +647,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                                             &mut vec![]);
         }
 
-        let (auto_traits, trait_bounds) = split_auto_traits(tcx, &trait_bounds[1..]);
+        let (mut auto_traits, trait_bounds) = split_auto_traits(tcx, &trait_bounds[1..]);
 
         if !trait_bounds.is_empty() {
             let b = &trait_bounds[0];
@@ -707,6 +708,10 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                         .emit();
         }
 
+        // Dedup auto traits so that `dyn Trait + Send + Send` is the same as `dyn Trait + Send`.
+        auto_traits.sort();
+        auto_traits.dedup();
+
         // skip_binder is okay, because the predicates are re-bound.
         let mut v =
             iter::once(ty::ExistentialPredicate::Trait(*existential_principal.skip_binder()))
@@ -1319,7 +1324,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
     }
 }
 
-/// Divides a list of general trait bounds into two groups: builtin bounds (Sync/Send) and the
+/// Divides a list of general trait bounds into two groups: auto traits (e.g. Sync and Send) and the
 /// remaining general trait bounds.
 fn split_auto_traits<'a, 'b, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                                          trait_bounds: &'b [hir::PolyTraitRef])

src/librustc_typeck/check/closure.rs

@@ -225,7 +225,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let expected_sig = fulfillment_cx
             .pending_obligations()
             .iter()
-            .map(|obligation| &obligation.obligation)
             .filter_map(|obligation| {
                 debug!(
                     "deduce_expectations_from_obligations: obligation.predicate={:?}",
@@ -257,7 +256,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         let expected_kind = fulfillment_cx
             .pending_obligations()
             .iter()
-            .map(|obligation| &obligation.obligation)
             .filter_map(|obligation| {
                 let opt_trait_ref = match obligation.predicate {
                     ty::Predicate::Projection(ref data) => Some(data.to_poly_trait_ref(self.tcx)),

src/librustdoc/clean/mod.rs

@@ -1251,30 +1251,60 @@ fn resolution_failure(
     link_range: Option<Range<usize>>,
 ) {
     let sp = span_of_attrs(attrs);
-    let mut diag = cx.sess()
+    let msg = format!("`[{}]` cannot be resolved, ignoring it...", path_str);
-        .struct_span_warn(sp, &format!("[{}] cannot be resolved, ignoring it...", path_str));
 
-    if let Some(link_range) = link_range {
+    let code_dox = sp.to_src(cx);
+
+    let doc_comment_padding = 3;
+    let mut diag = if let Some(link_range) = link_range {
         // blah blah blah\nblah\nblah [blah] blah blah\nblah blah
         //                       ^    ~~~~~~
         //                       |    link_range
         //                       last_new_line_offset
 
+        let mut diag;
+        if dox.lines().count() == code_dox.lines().count() {
+            let line_offset = dox[..link_range.start].lines().count();
+            // The span starts in the `///`, so we don't have to account for the leading whitespace
+            let code_dox_len = if line_offset <= 1 {
+                doc_comment_padding
+            } else {
+                // The first `///`
+                doc_comment_padding +
+                    // Each subsequent leading whitespace and `///`
+                    code_dox.lines().skip(1).take(line_offset - 1).fold(0, |sum, line| {
+                        sum + doc_comment_padding + line.len() - line.trim().len()
+                    })
+            };
+
+            // Extract the specific span
+            let sp = sp.from_inner_byte_pos(
+                link_range.start + code_dox_len,
+                link_range.end + code_dox_len,
+            );
+
+            diag = cx.sess().struct_span_warn(sp, &msg);
+            diag.span_label(sp, "cannot be resolved, ignoring");
+        } else {
+            diag = cx.sess().struct_span_warn(sp, &msg);
+
             let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
             let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
 
             // Print the line containing the `link_range` and manually mark it with '^'s
             diag.note(&format!(
-            "the link appears in this line:\n\n{line}\n{indicator: <before$}{indicator:^<found$}",
+                "the link appears in this line:\n\n{line}\n\
+                 {indicator: <before$}{indicator:^<found$}",
                 line=line,
                 indicator="",
                 before=link_range.start - last_new_line_offset,
                 found=link_range.len(),
             ));
-    } else {
-
         }
-
+        diag
+    } else {
+        cx.sess().struct_span_warn(sp, &msg)
+    };
     diag.emit();
 }
 

src/libsyntax/feature_gate.rs

@@ -398,9 +398,6 @@ declare_features! (
     // `foo.rs` as an alternative to `foo/mod.rs`
     (active, non_modrs_mods, "1.24.0", Some(44660), Some(Edition::Edition2018)),
 
-    // Termination trait in tests (RFC 1937)
-    (active, termination_trait_test, "1.24.0", Some(48854), Some(Edition::Edition2018)),
-
     // `extern` in paths
     (active, extern_in_paths, "1.23.0", Some(44660), None),
 
@@ -616,6 +613,8 @@ declare_features! (
     (accepted, fn_must_use, "1.27.0", Some(43302), None),
     // Allows use of the :lifetime macro fragment specifier
     (accepted, macro_lifetime_matcher, "1.27.0", Some(34303), None),
+    // Termination trait in tests (RFC 1937)
+    (accepted, termination_trait_test, "1.27.0", Some(48854), None),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must

src/libsyntax/parse/parser.rs

@@ -652,7 +652,7 @@ impl<'a> Parser<'a> {
                 Err(err)
             }
         } else {
-            self.expect_one_of(unsafe { slice::from_raw_parts(t, 1) }, &[])
+            self.expect_one_of(slice::from_ref(t), &[])
         }
     }
 
@@ -1108,7 +1108,12 @@ impl<'a> Parser<'a> {
     {
         let mut first: bool = true;
         let mut v = vec![];
-        while !kets.contains(&&self.token) {
+        while !kets.iter().any(|k| {
+                match expect {
+                    TokenExpectType::Expect => self.check(k),
+                    TokenExpectType::NoExpect => self.token == **k,
+                }
+            }) {
             match self.token {
                 token::CloseDelim(..) | token::Eof => break,
                 _ => {}

src/libsyntax/test.rs

@@ -335,7 +335,7 @@ enum BadTestSignature {
 fn is_test_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
     let has_test_attr = attr::contains_name(&i.attrs, "test");
 
-    fn has_test_signature(cx: &TestCtxt, i: &ast::Item) -> HasTestSignature {
+    fn has_test_signature(_cx: &TestCtxt, i: &ast::Item) -> HasTestSignature {
         let has_should_panic_attr = attr::contains_name(&i.attrs, "should_panic");
         match i.node {
             ast::ItemKind::Fn(ref decl, _, _, _, ref generics, _) => {
@@ -351,15 +351,14 @@ fn is_test_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
                     return No(BadTestSignature::NoArgumentsAllowed);
                 }
 
-                match (has_output, cx.features.termination_trait_test, has_should_panic_attr) {
+                match (has_output, has_should_panic_attr) {
-                    (true, true, true) => No(BadTestSignature::ShouldPanicOnlyWithNoArgs),
+                    (true, true) => No(BadTestSignature::ShouldPanicOnlyWithNoArgs),
-                    (true, true, false) => if generics.is_parameterized() {
+                    (true, false) => if generics.is_parameterized() {
                         No(BadTestSignature::WrongTypeSignature)
                     } else {
                         Yes
                     },
-                    (true, false, _) => No(BadTestSignature::WrongTypeSignature),
+                    (false, _) => Yes
-                    (false, _, _) => Yes
                 }
             }
             _ => No(BadTestSignature::NotEvenAFunction),
@@ -395,31 +394,12 @@ fn is_test_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
 fn is_bench_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
     let has_bench_attr = attr::contains_name(&i.attrs, "bench");
 
-    fn has_bench_signature(cx: &TestCtxt, i: &ast::Item) -> bool {
+    fn has_bench_signature(_cx: &TestCtxt, i: &ast::Item) -> bool {
         match i.node {
-            ast::ItemKind::Fn(ref decl, _, _, _, ref generics, _) => {
+            ast::ItemKind::Fn(ref decl, _, _, _, _, _) => {
-                let input_cnt = decl.inputs.len();
-
-                // If the termination trait is active, the compiler will check that the output
-                // type implements the `Termination` trait as `libtest` enforces that.
-                let output_matches = if cx.features.termination_trait_test {
-                    true
-                } else {
-                    let no_output = match decl.output {
-                        ast::FunctionRetTy::Default(..) => true,
-                        ast::FunctionRetTy::Ty(ref t) if t.node == ast::TyKind::Tup(vec![]) => true,
-                        _ => false
-                    };
-                    let tparm_cnt = generics.params.iter()
-                        .filter(|param| param.is_type_param())
-                        .count();
-
-                    no_output && tparm_cnt == 0
-                };
-
                 // NB: inadequate check, but we're running
                 // well before resolve, can't get too deep.
-                input_cnt == 1 && output_matches
+                decl.inputs.len() == 1
             }
             _ => false
         }
@@ -430,13 +410,8 @@ fn is_bench_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
     if has_bench_attr && !has_bench_signature {
         let diag = cx.span_diagnostic;
 
-        if cx.features.termination_trait_test {
         diag.span_err(i.span, "functions used as benches must have signature \
                                    `fn(&mut Bencher) -> impl Termination`");
-        } else {
-            diag.span_err(i.span, "functions used as benches must have signature \
-                                   `fn(&mut Bencher) -> ()`");
-        }
     }
 
     has_bench_attr && has_bench_signature

src/test/compile-fail/issue-39616.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 fn foo(a: [0; 1]) {} //~ ERROR expected type, found `0`
-//~| ERROR expected one of `->`, `where`, or `{`, found `]`
+//~| ERROR expected one of `)`, `,`, `->`, `where`, or `{`, found `]`
 // FIXME(jseyfried): avoid emitting the second error (preexisting)
 
 fn main() {}

src/test/compile-fail/issue-43988.rs

@@ -34,6 +34,7 @@ fn main() {
     #[repr]
     let _y = "123";
     //~^^ ERROR attribute should not be applied to a statement
+    //~| WARN `repr` attribute must have a hint
 
 
     fn foo() {}
@@ -44,5 +45,5 @@ fn main() {
 
     let _z = #[repr] 1;
     //~^ ERROR attribute should not be applied to an expression
-
+    //~| WARN `repr` attribute must have a hint
 }

src/test/run-pass/auxiliary/issue_38715.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(duplicate_macro_exports)]
+
 #[macro_export]
 macro_rules! foo { ($i:ident) => {} }
 

src/test/run-pass/auxiliary/two_macros_2.rs

@@ -1,4 +1,4 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,15 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// compile-flags: --test
+macro_rules! macro_one { ($($t:tt)*) => ($($t)*) }
 
-fn main() {}
+macro_rules! macro_two { ($($t:tt)*) => ($($t)*) }
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn it_works() -> Result<(), ()> {
-    //~^ ERROR functions used as tests must have signature fn() -> ()
-        Ok(())
-    }
-}

src/test/run-pass/mod_dir_path.rs

@@ -20,12 +20,12 @@ pub fn main() {
 
     #[path = "auxiliary"]
     mod foo {
-        mod two_macros;
+        mod two_macros_2;
     }
 
     #[path = "auxiliary"]
     mod bar {
-        macro_rules! m { () => { mod two_macros; } }
+        macro_rules! m { () => { mod two_macros_2; } }
         m!();
     }
 }

src/test/run-pass/trait-object-auto-dedup.rs

@@ -0,0 +1,53 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that duplicate auto trait bounds in trait objects don't create new types.
+#[allow(unused_assignments)]
+
+use std::marker::Send as SendAlias;
+
+// A dummy trait for the non-auto trait.
+trait Trait {}
+
+// A dummy struct to implement Trait, Send, and .
+struct Struct;
+
+impl Trait for Struct {}
+
+// These three functions should be equivalent.
+fn takes_dyn_trait_send(_: Box<dyn Trait + Send>) {}
+fn takes_dyn_trait_send_send(_: Box<dyn Trait + Send + Send>) {}
+fn takes_dyn_trait_send_sendalias(_: Box<dyn Trait + Send + SendAlias>) {}
+
+impl dyn Trait + Send + Send {
+    fn do_nothing(&self) {}
+}
+
+fn main() {
+    // 1. Moving into a variable with more Sends and back.
+    let mut dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
+    let dyn_trait_send_send: Box<dyn Trait + Send + Send> = dyn_trait_send;
+    dyn_trait_send = dyn_trait_send_send;
+
+    // 2. Calling methods with different number of Sends.
+    let dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
+    takes_dyn_trait_send_send(dyn_trait_send);
+
+    let dyn_trait_send_send = Box::new(Struct) as Box<dyn Trait + Send + Send>;
+    takes_dyn_trait_send(dyn_trait_send_send);
+
+    // 3. Aliases to the trait are transparent.
+    let dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
+    takes_dyn_trait_send_sendalias(dyn_trait_send);
+
+    // 4. Calling an impl that duplicates an auto trait.
+    let dyn_trait_send = Box::new(Struct) as Box<dyn Trait + Send>;
+    dyn_trait_send.do_nothing();
+}

src/test/rustdoc-ui/intra-links-warning.rs

@@ -10,10 +10,48 @@
 
 // compile-pass
 
-//! Test with [Foo::baz], [Bar::foo], ...
+       //! Test with [Foo::baz], [Bar::foo], ...
-//!
+     //! , [Uniooon::X] and [Qux::Z].
-//! and [Uniooon::X].
+       //!
+      //! , [Uniooon::X] and [Qux::Z].
 
+       /// [Qux:Y]
 pub struct Foo {
     pub bar: usize,
 }
+
+/// Foo
+/// bar [BarA] bar
+/// baz
+pub fn a() {}
+
+/**
+ * Foo
+ * bar [BarB] bar
+ * baz
+ */
+pub fn b() {}
+
+/** Foo
+
+bar [BarC] bar
+baz
+
+    let bar_c_1 = 0;
+    let bar_c_2 = 0;
+    let g = [bar_c_1];
+    let h = g[bar_c_2];
+
+*/
+pub fn c() {}
+
+#[doc = "Foo\nbar [BarD] bar\nbaz"]
+pub fn d() {}
+
+macro_rules! f {
+    ($f:expr) => {
+        #[doc = $f]
+        pub fn f() {}
+    }
+}
+f!("Foo\nbar [BarF] bar\nbaz");

src/test/rustdoc-ui/intra-links-warning.stderr

@@ -1,39 +1,105 @@
-warning: [Foo::baz] cannot be resolved, ignoring it...
+warning: `[Foo::baz]` cannot be resolved, ignoring it...
-  --> $DIR/intra-links-warning.rs:13:1
+  --> $DIR/intra-links-warning.rs:13:23
    |
-13 | / //! Test with [Foo::baz], [Bar::foo], ...
+13 |        //! Test with [Foo::baz], [Bar::foo], ...
-14 | | //!
+   |                       ^^^^^^^^ cannot be resolved, ignoring
-15 | | //! and [Uniooon::X].
+
-   | |_____________________^
+warning: `[Bar::foo]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:13:35
+   |
+13 |        //! Test with [Foo::baz], [Bar::foo], ...
+   |                                   ^^^^^^^^ cannot be resolved, ignoring
+
+warning: `[Uniooon::X]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:14:13
+   |
+14 |      //! , [Uniooon::X] and [Qux::Z].
+   |             ^^^^^^^^^^ cannot be resolved, ignoring
+
+warning: `[Qux::Z]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:14:30
+   |
+14 |      //! , [Uniooon::X] and [Qux::Z].
+   |                              ^^^^^^ cannot be resolved, ignoring
+
+warning: `[Uniooon::X]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:16:14
+   |
+16 |       //! , [Uniooon::X] and [Qux::Z].
+   |              ^^^^^^^^^^ cannot be resolved, ignoring
+
+warning: `[Qux::Z]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:16:31
+   |
+16 |       //! , [Uniooon::X] and [Qux::Z].
+   |                               ^^^^^^ cannot be resolved, ignoring
+
+warning: `[Qux:Y]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:18:13
+   |
+18 |        /// [Qux:Y]
+   |             ^^^^^ cannot be resolved, ignoring
+
+warning: `[BarA]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:24:10
+   |
+24 | /// bar [BarA] bar
+   |          ^^^^ cannot be resolved, ignoring
+
+warning: `[BarB]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:28:1
+   |
+28 | / /**
+29 | |  * Foo
+30 | |  * bar [BarB] bar
+31 | |  * baz
+32 | |  */
+   | |___^
    |
    = note: the link appears in this line:
            
-            Test with [Foo::baz], [Bar::foo], ...
+            bar [BarB] bar
-                       ^^^^^^^^
+                 ^^^^
 
-warning: [Bar::foo] cannot be resolved, ignoring it...
+warning: `[BarC]` cannot be resolved, ignoring it...
-  --> $DIR/intra-links-warning.rs:13:1
+  --> $DIR/intra-links-warning.rs:35:1
    |
-13 | / //! Test with [Foo::baz], [Bar::foo], ...
+35 | / /** Foo
-14 | | //!
+36 | |
-15 | | //! and [Uniooon::X].
+37 | | bar [BarC] bar
-   | |_____________________^
+38 | | baz
+...  |
+44 | |
+45 | | */
+   | |__^
    |
    = note: the link appears in this line:
            
-            Test with [Foo::baz], [Bar::foo], ...
+           bar [BarC] bar
-                                   ^^^^^^^^
+                ^^^^
 
-warning: [Uniooon::X] cannot be resolved, ignoring it...
+warning: `[BarD]` cannot be resolved, ignoring it...
-  --> $DIR/intra-links-warning.rs:13:1
+  --> $DIR/intra-links-warning.rs:48:1
    |
-13 | / //! Test with [Foo::baz], [Bar::foo], ...
+48 | #[doc = "Foo/nbar [BarD] bar/nbaz"]
-14 | | //!
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-15 | | //! and [Uniooon::X].
-   | |_____________________^
    |
    = note: the link appears in this line:
            
-            and [Uniooon::X].
+           bar [BarD] bar
-                 ^^^^^^^^^^
+                ^^^^
+
+warning: `[BarF]` cannot be resolved, ignoring it...
+  --> $DIR/intra-links-warning.rs:53:9
+   |
+53 |         #[doc = $f]
+   |         ^^^^^^^^^^^
+...
+57 | f!("Foo/nbar [BarF] bar/nbaz");
+   | ------------------------------- in this macro invocation
+   |
+   = note: the link appears in this line:
+           
+           bar [BarF] bar
+                ^^^^
 

src/test/ui/error-codes/E0423.rs

@@ -13,3 +13,22 @@ fn main () {
 
     let f = Foo(); //~ ERROR E0423
 }
+
+fn bar() {
+    struct S { x: i32, y: i32 }
+    #[derive(PartialEq)]
+    struct T {}
+
+    if let S { x: _x, y: 2 } = S { x: 1, y: 2 } { println!("Ok"); }
+    //~^ ERROR E0423
+    //~|  expected type, found `1`
+    if T {} == T {} { println!("Ok"); }
+    //~^ ERROR E0423
+    //~| ERROR expected expression, found `==`
+}
+
+fn foo() {
+    for _ in std::ops::Range { start: 0, end: 10 } {}
+    //~^ ERROR E0423
+    //~| ERROR expected type, found `0`
+}

src/test/ui/error-codes/E0423.stderr

@@ -1,9 +1,48 @@
+error: expected type, found `1`
+  --> $DIR/E0423.rs:22:39
+   |
+LL |     if let S { x: _x, y: 2 } = S { x: 1, y: 2 } { println!("Ok"); }
+   |                                       ^ expecting a type here because of type ascription
+
+error: expected expression, found `==`
+  --> $DIR/E0423.rs:25:13
+   |
+LL |     if T {} == T {} { println!("Ok"); }
+   |             ^^ expected expression
+
+error: expected type, found `0`
+  --> $DIR/E0423.rs:31:39
+   |
+LL |     for _ in std::ops::Range { start: 0, end: 10 } {}
+   |                                       ^ expecting a type here because of type ascription
+
 error[E0423]: expected function, found struct `Foo`
   --> $DIR/E0423.rs:14:13
    |
 LL |     let f = Foo(); //~ ERROR E0423
-   |             ^^^ did you mean `Foo { /* fields */ }`?
+   |             ^^^
+   |             |
+   |             did you mean `foo`?
+   |             did you mean `Foo { /* fields */ }`?
 
-error: aborting due to previous error
+error[E0423]: expected value, found struct `S`
+  --> $DIR/E0423.rs:22:32
+   |
+LL |     if let S { x: _x, y: 2 } = S { x: 1, y: 2 } { println!("Ok"); }
+   |                                ^ did you mean `(S { /* fields */ })`?
+
+error[E0423]: expected value, found struct `T`
+  --> $DIR/E0423.rs:25:8
+   |
+LL |     if T {} == T {} { println!("Ok"); }
+   |        ^ did you mean `(T { /* fields */ })`?
+
+error[E0423]: expected value, found struct `std::ops::Range`
+  --> $DIR/E0423.rs:31:14
+   |
+LL |     for _ in std::ops::Range { start: 0, end: 10 } {}
+   |              ^^^^^^^^^^^^^^^ did you mean `(std::ops::Range { /* fields */ })`?
+
+error: aborting due to 7 previous errors
 
 For more information about this error, try `rustc --explain E0423`.

src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs

@@ -59,7 +59,9 @@
 #![start                     = "x4300"] //~ WARN unused attribute
 // see issue-43106-gating-of-test.rs for crate-level; but non crate-level is below at "4200"
 // see issue-43106-gating-of-bench.rs for crate-level; but non crate-level is below at "4100"
-#![repr                       = "3900"] //~ WARN unused attribute
+#![repr                       = "3900"]
+//~^ WARN unused attribute
+//~| WARN `repr` attribute isn't configurable with a literal
 #![path                       = "3800"] //~ WARN unused attribute
 #![abi                        = "3700"] //~ WARN unused attribute
 #![automatically_derived      = "3600"] //~ WARN unused attribute
@@ -309,20 +311,25 @@ mod bench {
 
 #[repr = "3900"]
 //~^ WARN unused attribute
+//~| WARN `repr` attribute isn't configurable with a literal
 mod repr {
     mod inner { #![repr="3900"] }
     //~^ WARN unused attribute
+    //~| WARN `repr` attribute isn't configurable with a literal
 
     #[repr = "3900"] fn f() { }
     //~^ WARN unused attribute
+    //~| WARN `repr` attribute isn't configurable with a literal
 
     struct S;
 
     #[repr = "3900"] type T = S;
     //~^ WARN unused attribute
+    //~| WARN `repr` attribute isn't configurable with a literal
 
     #[repr = "3900"] impl S { }
     //~^ WARN unused attribute
+    //~| WARN `repr` attribute isn't configurable with a literal
 }
 
 #[path = "3800"]

src/test/ui/issue-38715.rs

@@ -0,0 +1,16 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[macro_export]
+macro_rules! foo { ($i:ident) => {} }
+
+#[macro_export]
+macro_rules! foo { () => {} } //~ ERROR a macro named `foo` has already been exported
+                              //~| WARN this was previously accepted

src/test/ui/issue-38715.stderr

@@ -0,0 +1,22 @@
+error: a macro named `foo` has already been exported
+  --> $DIR/issue-38715.rs:15:1
+   |
+LL | macro_rules! foo { () => {} } //~ ERROR a macro named `foo` has already been exported
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `foo` already exported
+   |
+   = note: #[deny(duplicate_macro_exports)] on by default
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2018 edition!
+   = note: for more information, see issue #35896 <https://github.com/rust-lang/rust/issues/35896>
+note: previous macro export is now shadowed
+  --> $DIR/issue-38715.rs:12:1
+   |
+LL | macro_rules! foo { ($i:ident) => {} }
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0601]: `main` function not found in crate `issue_38715`
+   |
+   = note: consider adding a `main` function to `$DIR/issue-38715.rs`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0601`.

src/test/ui/resolve/token-error-correct-3.stderr

@@ -10,11 +10,11 @@ note: unclosed delimiter
 LL |             callback(path.as_ref(); //~ ERROR expected one of
    |                     ^
 
-error: expected one of `,`, `.`, `?`, or an operator, found `;`
+error: expected one of `)`, `,`, `.`, `?`, or an operator, found `;`
   --> $DIR/token-error-correct-3.rs:24:35
    |
 LL |             callback(path.as_ref(); //~ ERROR expected one of
-   |                                   ^ expected one of `,`, `.`, `?`, or an operator here
+   |                                   ^ expected one of `)`, `,`, `.`, `?`, or an operator here
 
 error: expected one of `.`, `;`, `?`, `}`, or an operator, found `)`
   --> $DIR/token-error-correct-3.rs:30:9

src/test/ui/rfc-1937-termination-trait/termination-trait-in-test-should-panic.rs

@@ -10,7 +10,6 @@
 
 // compile-flags: --test
 
-#![feature(termination_trait_test)]
 #![feature(test)]
 
 extern crate test;

src/test/ui/rfc-1937-termination-trait/termination-trait-in-test-should-panic.stderr

@@ -1,5 +1,5 @@
 error: functions using `#[should_panic]` must return `()`
-  --> $DIR/termination-trait-in-test-should-panic.rs:22:1
+  --> $DIR/termination-trait-in-test-should-panic.rs:21:1
    |
 LL | / fn not_a_num() -> Result<(), ParseIntError> {
 LL | |     //~^ ERROR functions using `#[should_panic]` must return `()`

src/test/ui/rfc-1937-termination-trait/termination-trait-in-test.rs

@@ -11,7 +11,6 @@
 // compile-flags: --test
 // run-pass
 
-#![feature(termination_trait_test)]
 #![feature(test)]
 
 extern crate test;

src/test/ui/rfc-1937-termination-trait/termination-trait-test-wrong-type.rs

@@ -10,8 +10,6 @@
 
 // compile-flags: --test
 
-#![feature(termination_trait_test)]
-
 use std::num::ParseIntError;
 
 #[test]

src/test/ui/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr

@@ -1,5 +1,5 @@
 error[E0277]: `main` has invalid return type `std::result::Result<f32, std::num::ParseIntError>`
-  --> $DIR/termination-trait-test-wrong-type.rs:18:1
+  --> $DIR/termination-trait-test-wrong-type.rs:16:1
    |
 LL | / fn can_parse_zero_as_f32() -> Result<f32, ParseIntError> { //~ ERROR
 LL | |     "0".parse()

src/test/ui/similar-tokens.rs

@@ -14,6 +14,6 @@ mod x {
 }
 
 // `.` is similar to `,` so list parsing should continue to closing `}`
-use x::{A. B}; //~ ERROR expected one of `,`, `::`, or `as`, found `.`
+use x::{A. B}; //~ ERROR expected one of `,`, `::`, `as`, or `}`, found `.`
 
 fn main() {}

src/test/ui/similar-tokens.stderr

@@ -1,8 +1,8 @@
-error: expected one of `,`, `::`, or `as`, found `.`
+error: expected one of `,`, `::`, `as`, or `}`, found `.`
   --> $DIR/similar-tokens.rs:17:10
    |
-LL | use x::{A. B}; //~ ERROR expected one of `,`, `::`, or `as`, found `.`
+LL | use x::{A. B}; //~ ERROR expected one of `,`, `::`, `as`, or `}`, found `.`
-   |          ^ expected one of `,`, `::`, or `as` here
+   |          ^ expected one of `,`, `::`, `as`, or `}` here
 
 error: aborting due to previous error
 

src/test/ui/suggestions/repr.rs

@@ -0,0 +1,28 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+
+#[repr]
+//^ WARN `repr` attribute must have a hint
+struct _A {}
+
+#[repr = "B"]
+//^ WARN `repr` attribute isn't configurable with a literal
+struct _B {}
+
+#[repr = "C"]
+//^ WARN `repr` attribute isn't configurable with a literal
+struct _C {}
+
+#[repr(C)]
+struct _D {}
+
+fn main() {}

src/test/ui/suggestions/repr.stderr

@@ -0,0 +1,25 @@
+warning: `repr` attribute must have a hint
+  --> $DIR/repr.rs:13:1
+   |
+LL | #[repr]
+   | ^^^^^^^ needs a hint
+   |
+   = note: #[warn(bad_repr)] on by default
+   = help: valid hints include `#[repr(C)]`, `#[repr(packed)]`, `#[repr(rust)]` and `#[repr(transparent)]`
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
+
+warning: `repr` attribute isn't configurable with a literal
+  --> $DIR/repr.rs:17:1
+   |
+LL | #[repr = "B"]
+   | ^^^^^^^^^^^^^ needs a hint
+   |
+   = help: valid hints include `#[repr(C)]`, `#[repr(packed)]`, `#[repr(rust)]` and `#[repr(transparent)]`
+   = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
+
+warning: `repr` attribute isn't configurable with a literal
+  --> $DIR/repr.rs:21:1
+   |
+LL | #[repr = "C"]
+   | ^^^^^^^^^^^^^ help: give `repr` a hint: `#[repr(C)]`
+

src/test/ui/token/issue-10636-2.stderr

@@ -10,11 +10,11 @@ note: unclosed delimiter
 LL |     option.map(|some| 42;
    |               ^
 
-error: expected one of `,`, `.`, `?`, or an operator, found `;`
+error: expected one of `)`, `,`, `.`, `?`, or an operator, found `;`
   --> $DIR/issue-10636-2.rs:15:25
    |
 LL |     option.map(|some| 42;
-   |                         ^ expected one of `,`, `.`, `?`, or an operator here
+   |                         ^ expected one of `)`, `,`, `.`, `?`, or an operator here
 
 error: expected expression, found `)`
   --> $DIR/issue-10636-2.rs:18:1

src/test/ui/trait-object-auto-dedup-in-impl.rs

@@ -0,0 +1,29 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Checks to make sure that `dyn Trait + Send` and `dyn Trait + Send + Send` are the same type.
+// Issue: #47010
+
+struct Struct;
+impl Trait for Struct {}
+trait Trait {}
+
+type Send1 = Trait + Send;
+type Send2 = Trait + Send + Send;
+
+fn main () {}
+
+impl Trait + Send {
+    fn test(&self) { println!("one"); } //~ ERROR duplicate definitions with name `test`
+}
+
+impl Trait + Send + Send {
+    fn test(&self) { println!("two"); }
+}

src/test/ui/trait-object-auto-dedup-in-impl.stderr

@@ -0,0 +1,12 @@
+error[E0592]: duplicate definitions with name `test`
+  --> $DIR/trait-object-auto-dedup-in-impl.rs:24:5
+   |
+LL |     fn test(&self) { println!("one"); } //~ ERROR duplicate definitions with name `test`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ duplicate definitions for `test`
+...
+LL |     fn test(&self) { println!("two"); }
+   |     ----------------------------------- other definition for `test`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0592`.

src/test/ui/tuple-struct-fields/test.rs

@@ -12,6 +12,6 @@ mod foo {
     type T = ();
     struct S1(pub(in foo) (), pub(T), pub(crate) (), pub(((), T)));
     struct S2(pub((foo)) ());
-    //~^ ERROR expected `,`, found `(`
+    //~^ ERROR expected one of `)` or `,`, found `(`
     //~| ERROR cannot find type `foo` in this scope
 }

src/test/ui/tuple-struct-fields/test.stderr

@@ -0,0 +1,20 @@
+error: expected one of `)` or `,`, found `(`
+  --> $DIR/test.rs:14:26
+   |
+LL |     struct S2(pub((foo)) ());
+   |                          ^ expected one of `)` or `,` here
+
+error[E0412]: cannot find type `foo` in this scope
+  --> $DIR/test.rs:14:20
+   |
+LL |     struct S2(pub((foo)) ());
+   |                    ^^^ not found in this scope
+
+error[E0601]: `main` function not found in crate `test`
+   |
+   = note: consider adding a `main` function to `$DIR/test.rs`
+
+error: aborting due to 3 previous errors
+
+Some errors occurred: E0412, E0601.
+For more information about an error, try `rustc --explain E0412`.

src/test/ui/tuple-struct-fields/test2.rs

@@ -13,7 +13,7 @@ macro_rules! define_struct {
         struct S1(pub $t);
         struct S2(pub (in foo) ());
         struct S3(pub $t ());
-        //~^ ERROR expected `,`, found `(`
+        //~^ ERROR expected one of `)` or `,`, found `(`
     }
 }
 

src/test/ui/tuple-struct-fields/test2.stderr

@@ -0,0 +1,11 @@
+error: expected one of `)` or `,`, found `(`
+  --> $DIR/test2.rs:15:26
+   |
+LL |         struct S3(pub $t ());
+   |                          ^ expected one of `)` or `,` here
+...
+LL |     define_struct! { (foo) }
+   |     ------------------------ in this macro invocation
+
+error: aborting due to previous error
+

src/test/ui/tuple-struct-fields/test3.rs

@@ -13,7 +13,7 @@ macro_rules! define_struct {
         struct S1(pub($t));
         struct S2(pub (in foo) ());
         struct S3(pub($t) ());
-        //~^ ERROR expected `,`, found `(`
+        //~^ ERROR expected one of `)` or `,`, found `(`
     }
 }
 

src/test/ui/tuple-struct-fields/test3.stderr

@@ -0,0 +1,11 @@
+error: expected one of `)` or `,`, found `(`
+  --> $DIR/test3.rs:15:27
+   |
+LL |         struct S3(pub($t) ());
+   |                           ^ expected one of `)` or `,` here
+...
+LL |     define_struct! { foo }
+   |     ---------------------- in this macro invocation
+
+error: aborting due to previous error
+

src/tools/compiletest/src/runtest.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use common::CompareMode;
-use common::{expected_output_path, UI_FIXED, UI_STDERR, UI_STDOUT};
+use common::{expected_output_path, UI_EXTENSIONS, UI_FIXED, UI_STDERR, UI_STDOUT};
 use common::{output_base_dir, output_base_name, output_testname_unique};
 use common::{Codegen, CodegenUnits, DebugInfoGdb, DebugInfoLldb, Rustdoc};
 use common::{CompileFail, ParseFail, Pretty, RunFail, RunPass, RunPassValgrind};
@@ -2609,6 +2609,9 @@ impl<'test> TestCx<'test> {
         errors += self.compare_output("stdout", &normalized_stdout, &expected_stdout);
         errors += self.compare_output("stderr", &normalized_stderr, &expected_stderr);
 
+        let modes_to_prune = vec![CompareMode::Nll];
+        self.prune_duplicate_outputs(&modes_to_prune);
+
         if self.config.compare_mode.is_some() {
             // don't test rustfix with nll right now
         } else if self.props.run_rustfix {
@@ -2971,6 +2974,16 @@ impl<'test> TestCx<'test> {
         }
     }
 
+    fn delete_file(&self, file: &PathBuf) {
+        if let Err(e) = ::std::fs::remove_file(file) {
+            self.fatal(&format!(
+                "failed to delete `{}`: {}",
+                file.display(),
+                e,
+            ));
+        }
+    }
+
     fn compare_output(&self, kind: &str, actual: &str, expected: &str) -> usize {
         if actual == expected {
             return 0;
@@ -3023,13 +3036,7 @@ impl<'test> TestCx<'test> {
 
         for output_file in &files {
             if actual.is_empty() {
-                if let Err(e) = ::std::fs::remove_file(output_file) {
+                self.delete_file(output_file);
-                    self.fatal(&format!(
-                        "failed to delete `{}`: {}",
-                        output_file.display(),
-                        e,
-                    ));
-                }
             } else {
                 match File::create(&output_file).and_then(|mut f| f.write_all(actual.as_bytes())) {
                     Ok(()) => {}
@@ -3054,6 +3061,42 @@ impl<'test> TestCx<'test> {
         }
     }
 
+    fn prune_duplicate_output(&self, mode: CompareMode, kind: &str, canon_content: &str) {
+        let examined_path = expected_output_path(
+            &self.testpaths,
+            self.revision,
+            &Some(mode),
+            kind,
+        );
+
+        let examined_content = self
+            .load_expected_output_from_path(&examined_path)
+            .unwrap_or_else(|_| String::new());
+
+        if examined_path.exists() && canon_content == &examined_content {
+            self.delete_file(&examined_path);
+        }
+    }
+
+    fn prune_duplicate_outputs(&self, modes: &[CompareMode]) {
+        if self.config.bless {
+            for kind in UI_EXTENSIONS {
+                let canon_comparison_path = expected_output_path(
+                    &self.testpaths,
+                    self.revision,
+                    &None,
+                    kind,
+                );
+
+                if let Ok(canon) = self.load_expected_output_from_path(&canon_comparison_path) {
+                    for mode in modes {
+                        self.prune_duplicate_output(mode.clone(), kind, &canon);
+                    }
+                }
+            }
+        }
+    }
+
     fn create_stamp(&self) {
         let mut f = File::create(::stamp(&self.config, self.testpaths, self.revision)).unwrap();
         f.write_all(compute_stamp_hash(&self.config).as_bytes())