diff --git a/config.toml.example b/config.toml.example
index 35f69cd05b607..087dc418e2dce 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -82,6 +82,10 @@
 # passed to prefer linking to shared libraries.
 #link-shared = false
 
+# When building llvm, this configures what is being appended to the version.
+# If absent, we let the version as-is.
+#version-suffix = "-rust"
+
 # On MSVC you can compile LLVM with clang-cl, but the test suite doesn't pass
 # with clang-cl, so this is special in that it only compiles LLVM with clang-cl
 #clang-cl = '/path/to/clang-cl.exe'
diff --git a/src/Cargo.lock b/src/Cargo.lock
index fc2dfcfd8604c..77618a32e2c5f 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -138,7 +138,7 @@ dependencies = [
  "lazy_static 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "petgraph 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "petgraph 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.5.1 (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)",
@@ -1471,7 +1471,7 @@ dependencies = [
 
 [[package]]
 name = "petgraph"
-version = "0.4.12"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "fixedbitset 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2433,6 +2433,7 @@ name = "rustdoc"
 version = "0.0.0"
 dependencies = [
  "minifier 0.0.19 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "pulldown-cmark 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -3243,7 +3244,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum percent-encoding 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "31010dd2e1ac33d5b46a5b413495239882813e0369f8ed8a5e266f173602f831"
 "checksum pest 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0fce5d8b5cc33983fc74f78ad552b5522ab41442c4ca91606e4236eb4b5ceefc"
 "checksum pest_derive 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "ab94faafeb93f4c5e3ce81ca0e5a779529a602ad5d09ae6d21996bfb8b6a52bf"
-"checksum petgraph 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "8b30dc85588cd02b9b76f5e386535db546d21dc68506cff2abebee0b6445e8e4"
+"checksum petgraph 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)" = "9c3659d1ee90221741f65dd128d9998311b0e40c5d3c23a62445938214abce4f"
 "checksum phf 0.7.22 (registry+https://github.com/rust-lang/crates.io-index)" = "7d37a244c75a9748e049225155f56dbcb98fe71b192fd25fd23cb914b5ad62f2"
 "checksum phf_codegen 0.7.22 (registry+https://github.com/rust-lang/crates.io-index)" = "4e4048fe7dd7a06b8127ecd6d3803149126e9b33c7558879846da3a63f734f2b"
 "checksum phf_generator 0.7.22 (registry+https://github.com/rust-lang/crates.io-index)" = "05a079dd052e7b674d21cb31cbb6c05efd56a2cd2827db7692e2f1a507ebd998"
diff --git a/src/bootstrap/Cargo.toml b/src/bootstrap/Cargo.toml
index 57a526038041e..3e91c2b3e86c8 100644
--- a/src/bootstrap/Cargo.toml
+++ b/src/bootstrap/Cargo.toml
@@ -47,7 +47,7 @@ serde_json = "1.0.2"
 toml = "0.4"
 lazy_static = "0.2"
 time = "0.1"
-petgraph = "0.4.12"
+petgraph = "0.4.13"
 
 [dev-dependencies]
 pretty_assertions = "0.5"
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index bf4d39c4947e5..70b21a1567b0f 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -86,6 +86,7 @@ pub struct Config {
     pub llvm_targets: Option<String>,
     pub llvm_experimental_targets: String,
     pub llvm_link_jobs: Option<u32>,
+    pub llvm_version_suffix: Option<String>,
 
     pub lld_enabled: bool,
     pub lldb_enabled: bool,
@@ -256,6 +257,7 @@ struct Llvm {
     experimental_targets: Option<String>,
     link_jobs: Option<u32>,
     link_shared: Option<bool>,
+    version_suffix: Option<String>,
     clang_cl: Option<String>
 }
 
@@ -516,6 +518,7 @@ impl Config {
             config.llvm_experimental_targets = llvm.experimental_targets.clone()
                 .unwrap_or("WebAssembly;RISCV".to_string());
             config.llvm_link_jobs = llvm.link_jobs;
+            config.llvm_version_suffix = llvm.version_suffix.clone();
             config.llvm_clang_cl = llvm.clang_cl.clone();
         }
 
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index 167e4a78edaf8..2d94704fda7d6 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -2056,7 +2056,8 @@ impl Step for Lldb {
         drop(fs::remove_dir_all(&image));
 
         // Prepare the image directory
-        let dst = image.join("bin");
+        let root = image.join("lib/rustlib").join(&*target);
+        let dst = root.join("bin");
         t!(fs::create_dir_all(&dst));
         for program in &["lldb", "lldb-argdumper", "lldb-mi", "lldb-server"] {
             let exe = bindir.join(exe(program, &target));
@@ -2065,7 +2066,7 @@ impl Step for Lldb {
 
         // The libraries.
         let libdir = builder.llvm_out(target).join("lib");
-        let dst = image.join("lib");
+        let dst = root.join("lib");
         t!(fs::create_dir_all(&dst));
         for entry in t!(fs::read_dir(&libdir)) {
             let entry = entry.unwrap();
@@ -2093,7 +2094,7 @@ impl Step for Lldb {
             let entry = t!(entry);
             if let Ok(name) = entry.file_name().into_string() {
                 if name.starts_with("python") {
-                    let dst = image.join(libdir_name)
+                    let dst = root.join(libdir_name)
                         .join(entry.file_name());
                     t!(fs::create_dir_all(&dst));
                     builder.cp_r(&entry.path(), &dst);
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index caf38d766f54e..828a7d14c0437 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -239,6 +239,10 @@ impl Step for Llvm {
             cfg.define("LLVM_NATIVE_BUILD", builder.llvm_out(builder.config.build).join("build"));
         }
 
+        if let Some(ref suffix) = builder.config.llvm_version_suffix {
+            cfg.define("LLVM_VERSION_SUFFIX", suffix);
+        }
+
         if let Some(ref python) = builder.config.python {
             cfg.define("PYTHON_EXECUTABLE", python);
         }
diff --git a/src/doc/book b/src/doc/book
index 16c9dee7666c2..cff0930664b68 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit 16c9dee7666c2b2766fd98d89003e028679d1207
+Subproject commit cff0930664b688f1dd22aefb3d16944eb4cdbfd5
diff --git a/src/doc/nomicon b/src/doc/nomicon
index ae42ad7aa4d79..7fd493465b7dd 160000
--- a/src/doc/nomicon
+++ b/src/doc/nomicon
@@ -1 +1 @@
-Subproject commit ae42ad7aa4d7907cca941371c9eee8de8c2ee40d
+Subproject commit 7fd493465b7dd6cf3476f0b834884059bbdd1d93
diff --git a/src/doc/reference b/src/doc/reference
index 219e261ddb833..821355a6fd642 160000
--- a/src/doc/reference
+++ b/src/doc/reference
@@ -1 +1 @@
-Subproject commit 219e261ddb833a5683627b0a9be87a0f4486abb9
+Subproject commit 821355a6fd642b71988a2f88a3162fb358732012
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
index e3719fc78ff4a..e459fb3f07f2b 160000
--- a/src/doc/rust-by-example
+++ b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit e3719fc78ff4a21dfd13cfcc9e2ca42cb5de29f4
+Subproject commit e459fb3f07f2b930ccd25d348671b8eae233fd64
diff --git a/src/etc/rust-lldb b/src/etc/rust-lldb
index 6a2849b55485e..6ed8210349e17 100755
--- a/src/etc/rust-lldb
+++ b/src/etc/rust-lldb
@@ -12,27 +12,35 @@
 # Exit if anything fails
 set -e
 
-LLDB_VERSION=`lldb --version 2>/dev/null | head -1 | cut -d. -f1`
+# Find out where to look for the pretty printer Python module
+RUSTC_SYSROOT=`rustc --print sysroot`
+
+# Find the host triple so we can find lldb in rustlib.
+host=`rustc -vV | sed -n -e 's/^host: //p'`
+
+lldb=lldb
+if [ -f "$RUSTC_SYSROOT/lib/rustlib/$host/bin/lldb" ]; then
+    lldb="$RUSTC_SYSROOT/lib/rustlib/$host/bin/lldb"
+else
+    LLDB_VERSION=`"$lldb" --version 2>/dev/null | head -1 | cut -d. -f1`
 
-if [ "$LLDB_VERSION" = "lldb-350" ]
-then
-    echo "***"
+    if [ "$LLDB_VERSION" = "lldb-350" ]
+    then
+        echo "***"
 	echo \
 "WARNING: This version of LLDB has known issues with Rust and cannot \
 display the contents of local variables!"
-    echo "***"
+        echo "***"
+    fi
 fi
 
-# Find out where to look for the pretty printer Python module
-RUSTC_SYSROOT=`rustc --print sysroot`
-
 # Prepare commands that will be loaded before any file on the command line has been loaded
 script_import="command script import \"$RUSTC_SYSROOT/lib/rustlib/etc/lldb_rust_formatters.py\""
 category_definition="type summary add --no-value --python-function lldb_rust_formatters.print_val -x \".*\" --category Rust"
 category_enable="type category enable Rust"
 
 # Call LLDB with the commands added to the argument list
-exec lldb --one-line-before-file="$script_import" \
+exec "$lldb" --one-line-before-file="$script_import" \
     --one-line-before-file="$category_definition" \
     --one-line-before-file="$category_enable" \
     "$@"
diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index dfe0a395ca140..d15568af6aebe 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -574,6 +574,7 @@ define_dep_nodes!( <'tcx>
     [] IsPanicRuntime(CrateNum),
     [] IsCompilerBuiltins(CrateNum),
     [] HasGlobalAllocator(CrateNum),
+    [] HasPanicHandler(CrateNum),
     [input] ExternCrate(DefId),
     [eval_always] LintLevels,
     [] Specializes { impl1: DefId, impl2: DefId },
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 778c388c7dec7..272967282e03b 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -159,6 +159,9 @@ pub struct Session {
     /// Metadata about the allocators for the current crate being compiled
     pub has_global_allocator: Once<bool>,
 
+    /// Metadata about the panic handlers for the current crate being compiled
+    pub has_panic_handler: Once<bool>,
+
     /// Cap lint level specified by a driver specifically.
     pub driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
 }
@@ -1160,6 +1163,7 @@ pub fn build_session_(
             (*GLOBAL_JOBSERVER).clone()
         },
         has_global_allocator: Once::new(),
+        has_panic_handler: Once::new(),
         driver_lint_caps: FxHashMap(),
     };
 
diff --git a/src/librustc/ty/query/config.rs b/src/librustc/ty/query/config.rs
index 837354bfcaf36..2bbf5aacc1aca 100644
--- a/src/librustc/ty/query/config.rs
+++ b/src/librustc/ty/query/config.rs
@@ -464,6 +464,12 @@ impl<'tcx> QueryDescription<'tcx> for queries::has_global_allocator<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription<'tcx> for queries::has_panic_handler<'tcx> {
+    fn describe(_: TyCtxt, _: CrateNum) -> String {
+        "checking if the crate has_panic_handler".to_string()
+    }
+}
+
 impl<'tcx> QueryDescription<'tcx> for queries::extern_crate<'tcx> {
     fn describe(_: TyCtxt, _: DefId) -> String {
         "getting crate's ExternCrateData".to_string()
diff --git a/src/librustc/ty/query/mod.rs b/src/librustc/ty/query/mod.rs
index 993ba2fd13d0d..f0ca168e9e467 100644
--- a/src/librustc/ty/query/mod.rs
+++ b/src/librustc/ty/query/mod.rs
@@ -381,6 +381,7 @@ define_queries! { <'tcx>
         [fatal_cycle] fn is_panic_runtime: IsPanicRuntime(CrateNum) -> bool,
         [fatal_cycle] fn is_compiler_builtins: IsCompilerBuiltins(CrateNum) -> bool,
         [fatal_cycle] fn has_global_allocator: HasGlobalAllocator(CrateNum) -> bool,
+        [fatal_cycle] fn has_panic_handler: HasPanicHandler(CrateNum) -> bool,
         [fatal_cycle] fn is_sanitizer_runtime: IsSanitizerRuntime(CrateNum) -> bool,
         [fatal_cycle] fn is_profiler_runtime: IsProfilerRuntime(CrateNum) -> bool,
         [fatal_cycle] fn panic_strategy: GetPanicStrategy(CrateNum) -> PanicStrategy,
diff --git a/src/librustc/ty/query/plumbing.rs b/src/librustc/ty/query/plumbing.rs
index 215fba54499b7..3c26732fbac67 100644
--- a/src/librustc/ty/query/plumbing.rs
+++ b/src/librustc/ty/query/plumbing.rs
@@ -1168,6 +1168,7 @@ pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>,
         DepKind::IsPanicRuntime => { force!(is_panic_runtime, krate!()); }
         DepKind::IsCompilerBuiltins => { force!(is_compiler_builtins, krate!()); }
         DepKind::HasGlobalAllocator => { force!(has_global_allocator, krate!()); }
+        DepKind::HasPanicHandler => { force!(has_panic_handler, krate!()); }
         DepKind::ExternCrate => { force!(extern_crate, def_id!()); }
         DepKind::LintLevels => { force!(lint_levels, LOCAL_CRATE); }
         DepKind::InScopeTraits => { force!(in_scope_traits_map, def_id!().index); }
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index 5aa05270a2a0b..87a32b5a53e7a 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -173,6 +173,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     is_panic_runtime => { cdata.root.panic_runtime }
     is_compiler_builtins => { cdata.root.compiler_builtins }
     has_global_allocator => { cdata.root.has_global_allocator }
+    has_panic_handler => { cdata.root.has_panic_handler }
     is_sanitizer_runtime => { cdata.root.sanitizer_runtime }
     is_profiler_runtime => { cdata.root.profiler_runtime }
     panic_strategy => { cdata.root.panic_strategy }
diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs
index 0fd43c592c853..aae45c17c6771 100644
--- a/src/librustc_metadata/encoder.rs
+++ b/src/librustc_metadata/encoder.rs
@@ -484,6 +484,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let is_proc_macro = tcx.sess.crate_types.borrow().contains(&CrateType::ProcMacro);
         let has_default_lib_allocator = attr::contains_name(&attrs, "default_lib_allocator");
         let has_global_allocator = *tcx.sess.has_global_allocator.get();
+        let has_panic_handler = *tcx.sess.has_panic_handler.try_get().unwrap_or(&false);
 
         let root = self.lazy(&CrateRoot {
             name: tcx.crate_name(LOCAL_CRATE),
@@ -494,6 +495,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             panic_strategy: tcx.sess.panic_strategy(),
             edition: hygiene::default_edition(),
             has_global_allocator: has_global_allocator,
+            has_panic_handler: has_panic_handler,
             has_default_lib_allocator: has_default_lib_allocator,
             plugin_registrar_fn: tcx.sess
                 .plugin_registrar_fn
diff --git a/src/librustc_metadata/schema.rs b/src/librustc_metadata/schema.rs
index 8e454ddc0adc4..ab22a8e4db919 100644
--- a/src/librustc_metadata/schema.rs
+++ b/src/librustc_metadata/schema.rs
@@ -193,6 +193,7 @@ pub struct CrateRoot {
     pub panic_strategy: PanicStrategy,
     pub edition: Edition,
     pub has_global_allocator: bool,
+    pub has_panic_handler: bool,
     pub has_default_lib_allocator: bool,
     pub plugin_registrar_fn: Option<DefIndex>,
     pub macro_derive_registrar: Option<DefIndex>,
diff --git a/src/librustc_mir/borrow_check/mod.rs b/src/librustc_mir/borrow_check/mod.rs
index 272f5024f9f1a..5050b5ab2b414 100644
--- a/src/librustc_mir/borrow_check/mod.rs
+++ b/src/librustc_mir/borrow_check/mod.rs
@@ -1605,10 +1605,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         place_span: (&Place<'tcx>, Span),
         flow_state: &Flows<'cx, 'gcx, 'tcx>,
     ) {
-        // FIXME: analogous code in check_loans first maps `place` to
-        // its base_path ... but is that what we want here?
-        let place = self.base_path(place_span.0);
-
         let maybe_uninits = &flow_state.uninits;
 
         // Bad scenarios:
@@ -1646,8 +1642,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         //
         // This code covers scenarios 1, 2, and 3.
 
-        debug!("check_if_full_path_is_moved place: {:?}", place);
-        match self.move_path_closest_to(place) {
+        debug!("check_if_full_path_is_moved place: {:?}", place_span.0);
+        match self.move_path_closest_to(place_span.0) {
             Ok(mpi) => {
                 if maybe_uninits.contains(&mpi) {
                     self.report_use_of_moved_or_uninitialized(
@@ -1677,10 +1673,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         place_span: (&Place<'tcx>, Span),
         flow_state: &Flows<'cx, 'gcx, 'tcx>,
     ) {
-        // FIXME: analogous code in check_loans first maps `place` to
-        // its base_path ... but is that what we want here?
-        let place = self.base_path(place_span.0);
-
         let maybe_uninits = &flow_state.uninits;
 
         // Bad scenarios:
@@ -1709,8 +1701,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         //
         // This code covers scenario 1.
 
-        debug!("check_if_path_or_subpath_is_moved place: {:?}", place);
-        if let Some(mpi) = self.move_path_for_place(place) {
+        debug!("check_if_path_or_subpath_is_moved place: {:?}", place_span.0);
+        if let Some(mpi) = self.move_path_for_place(place_span.0) {
             if let Some(child_mpi) = maybe_uninits.has_any_child_of(mpi) {
                 self.report_use_of_moved_or_uninitialized(
                     context,
@@ -1813,11 +1805,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                             let tcx = self.tcx;
                             match base.ty(self.mir, tcx).to_ty(tcx).sty {
                                 ty::Adt(def, _) if def.has_dtor(tcx) => {
-
-                                    // FIXME: analogous code in
-                                    // check_loans.rs first maps
-                                    // `base` to its base_path.
-
                                     self.check_if_path_or_subpath_is_moved(
                                         context, InitializationRequiringAction::Assignment,
                                         (base, span), flow_state);
@@ -2190,35 +2177,6 @@ enum Overlap {
     Disjoint,
 }
 
-impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
-    // FIXME (#16118): function intended to allow the borrow checker
-    // to be less precise in its handling of Box while still allowing
-    // moves out of a Box. They should be removed when/if we stop
-    // treating Box specially (e.g. when/if DerefMove is added...)
-
-    fn base_path<'d>(&self, place: &'d Place<'tcx>) -> &'d Place<'tcx> {
-        //! Returns the base of the leftmost (deepest) dereference of an
-        //! Box in `place`. If there is no dereference of an Box
-        //! in `place`, then it just returns `place` itself.
-
-        let mut cursor = place;
-        let mut deepest = place;
-        loop {
-            let proj = match *cursor {
-                Place::Promoted(_) |
-                Place::Local(..) | Place::Static(..) => return deepest,
-                Place::Projection(ref proj) => proj,
-            };
-            if proj.elem == ProjectionElem::Deref
-                && place.ty(self.mir, self.tcx).to_ty(self.tcx).is_box()
-            {
-                deepest = &proj.base;
-            }
-            cursor = &proj.base;
-        }
-    }
-}
-
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 struct Context {
     kind: ContextKind,
diff --git a/src/librustc_mir/dataflow/impls/borrows.rs b/src/librustc_mir/dataflow/impls/borrows.rs
index cb551df910627..995e70fb382fc 100644
--- a/src/librustc_mir/dataflow/impls/borrows.rs
+++ b/src/librustc_mir/dataflow/impls/borrows.rs
@@ -21,7 +21,7 @@ use rustc::ty::{RegionKind, RegionVid};
 use rustc::ty::RegionKind::ReScope;
 
 use rustc_data_structures::bitslice::{BitwiseOperator, Word};
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::indexed_set::IdxSet;
 use rustc_data_structures::indexed_vec::IndexVec;
 use rustc_data_structures::sync::Lrc;
@@ -53,6 +53,13 @@ pub struct Borrows<'a, 'gcx: 'tcx, 'tcx: 'a> {
     _nonlexical_regioncx: Rc<RegionInferenceContext<'tcx>>,
 }
 
+struct StackEntry {
+    bb: mir::BasicBlock,
+    lo: usize,
+    hi: usize,
+    first_part_only: bool
+}
+
 fn precompute_borrows_out_of_scope<'tcx>(
     mir: &Mir<'tcx>,
     regioncx: &Rc<RegionInferenceContext<'tcx>>,
@@ -61,48 +68,79 @@ fn precompute_borrows_out_of_scope<'tcx>(
     borrow_region: RegionVid,
     location: Location,
 ) {
-    // Keep track of places we've locations to check and locations that we have checked.
-    let mut stack = vec![ location ];
-    let mut visited = FxHashSet();
-    visited.insert(location);
-
-    debug!(
-        "borrow {:?} has region {:?} with value {:?}",
-        borrow_index,
-        borrow_region,
-        regioncx.region_value_str(borrow_region),
-    );
-    debug!("borrow {:?} starts at {:?}", borrow_index, location);
-    while let Some(location) = stack.pop() {
-        // If region does not contain a point at the location, then add to list and skip
-        // successor locations.
-        if !regioncx.region_contains(borrow_region, location) {
-            debug!("borrow {:?} gets killed at {:?}", borrow_index, location);
-            borrows_out_of_scope_at_location
-                .entry(location)
-                .or_default()
-                .push(borrow_index);
-            continue;
+    // We visit one BB at a time. The complication is that we may start in the
+    // middle of the first BB visited (the one containing `location`), in which
+    // case we may have to later on process the first part of that BB if there
+    // is a path back to its start.
+
+    // For visited BBs, we record the index of the first statement processed.
+    // (In fully processed BBs this index is 0.) Note also that we add BBs to
+    // `visited` once they are added to `stack`, before they are actually
+    // processed, because this avoids the need to look them up again on
+    // completion.
+    let mut visited = FxHashMap();
+    visited.insert(location.block, location.statement_index);
+
+    let mut stack = vec![];
+    stack.push(StackEntry {
+        bb: location.block,
+        lo: location.statement_index,
+        hi: mir[location.block].statements.len(),
+        first_part_only: false,
+    });
+
+    while let Some(StackEntry { bb, lo, hi, first_part_only }) = stack.pop() {
+        let mut finished_early = first_part_only;
+        for i in lo ..= hi {
+            let location = Location { block: bb, statement_index: i };
+            // If region does not contain a point at the location, then add to list and skip
+            // successor locations.
+            if !regioncx.region_contains(borrow_region, location) {
+                debug!("borrow {:?} gets killed at {:?}", borrow_index, location);
+                borrows_out_of_scope_at_location
+                    .entry(location)
+                    .or_default()
+                    .push(borrow_index);
+                finished_early = true;
+                break;
+            }
         }
 
-        let bb_data = &mir[location.block];
-        // If this is the last statement in the block, then add the
-        // terminator successors next.
-        if location.statement_index == bb_data.statements.len() {
-            // Add successors to locations to visit, if not visited before.
-            if let Some(ref terminator) = bb_data.terminator {
-                for block in terminator.successors() {
-                    let loc = block.start_location();
-                    if visited.insert(loc) {
-                        stack.push(loc);
-                    }
-                }
-            }
-        } else {
-            // Visit next statement in block.
-            let loc = location.successor_within_block();
-            if visited.insert(loc) {
-                stack.push(loc);
+        if !finished_early {
+            // Add successor BBs to the work list, if necessary.
+            let bb_data = &mir[bb];
+            assert!(hi == bb_data.statements.len());
+            for &succ_bb in bb_data.terminator.as_ref().unwrap().successors() {
+                visited.entry(succ_bb)
+                    .and_modify(|lo| {
+                        // `succ_bb` has been seen before. If it wasn't
+                        // fully processed, add its first part to `stack`
+                        // for processing.
+                        if *lo > 0 {
+                            stack.push(StackEntry {
+                                bb: succ_bb,
+                                lo: 0,
+                                hi: *lo - 1,
+                                first_part_only: true,
+                            });
+                        }
+                        // And update this entry with 0, to represent the
+                        // whole BB being processed.
+                        *lo = 0;
+                    })
+                    .or_insert_with(|| {
+                        // succ_bb hasn't been seen before. Add it to
+                        // `stack` for processing.
+                        stack.push(StackEntry {
+                            bb: succ_bb,
+                            lo: 0,
+                            hi: mir[succ_bb].statements.len(),
+                            first_part_only: false,
+                        });
+                        // Insert 0 for this BB, to represent the whole BB
+                        // being processed.
+                        0
+                    });
             }
         }
     }
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 73c9af0d11c47..a72ee7ae3794c 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -1147,7 +1147,15 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                 None => continue,
             };
 
-            if binding.is_import() || binding.is_macro_def() {
+            // Don't reexport `uniform_path` canaries.
+            let non_canary_import = match binding.kind {
+                NameBindingKind::Import { directive, .. } => {
+                    !directive.is_uniform_paths_canary
+                }
+                _ => false,
+            };
+
+            if non_canary_import || binding.is_macro_def() {
                 let def = binding.def();
                 if def != Def::Err {
                     if !def.def_id().is_local() {
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index a45e5c8ec2a45..a1e4c85f82141 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1138,6 +1138,11 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>,
     if let Some(panic_impl_did) = fcx.tcx.lang_items().panic_impl() {
         if panic_impl_did == fcx.tcx.hir.local_def_id(fn_id) {
             if let Some(panic_info_did) = fcx.tcx.lang_items().panic_info() {
+                // at this point we don't care if there are duplicate handlers or if the handler has
+                // the wrong signature as this value we'll be used when writing metadata and that
+                // only happens if compilation succeeded
+                fcx.tcx.sess.has_panic_handler.try_set_same(true);
+
                 if declared_ret_ty.sty != ty::Never {
                     fcx.tcx.sess.span_err(
                         decl.output.span(),
diff --git a/src/librustc_typeck/check_unused.rs b/src/librustc_typeck/check_unused.rs
index fa152b386a825..5967bd1ba3eea 100644
--- a/src/librustc_typeck/check_unused.rs
+++ b/src/librustc_typeck/check_unused.rs
@@ -117,6 +117,7 @@ fn unused_crates_lint<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>) {
             !tcx.is_compiler_builtins(cnum)
                 && !tcx.is_panic_runtime(cnum)
                 && !tcx.has_global_allocator(cnum)
+                && !tcx.has_panic_handler(cnum)
         })
         .cloned()
         .collect();
diff --git a/src/librustdoc/Cargo.toml b/src/librustdoc/Cargo.toml
index e163fc68cbda7..845bfad7807d3 100644
--- a/src/librustdoc/Cargo.toml
+++ b/src/librustdoc/Cargo.toml
@@ -11,3 +11,4 @@ path = "lib.rs"
 pulldown-cmark = { version = "0.1.2", default-features = false }
 minifier = "0.0.19"
 tempfile = "3"
+parking_lot = "0.6.4"
diff --git a/src/librustdoc/clean/blanket_impl.rs b/src/librustdoc/clean/blanket_impl.rs
index e7e371cd56785..34c4c70159f3a 100644
--- a/src/librustdoc/clean/blanket_impl.rs
+++ b/src/librustdoc/clean/blanket_impl.rs
@@ -69,7 +69,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> BlanketImplFinder <'a, 'tcx, 'rcx, 'cstore> {
         let real_name = name.clone().map(|name| Ident::from_str(&name));
         let param_env = self.cx.tcx.param_env(def_id);
         for &trait_def_id in self.cx.all_traits.iter() {
-            if !self.cx.access_levels.borrow().is_doc_reachable(trait_def_id) ||
+            if !self.cx.renderinfo.borrow().access_levels.is_doc_reachable(trait_def_id) ||
                self.cx.generated_synthetics
                       .borrow_mut()
                       .get(&(def_id, trait_def_id))
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 75d7488d26a75..6e1c1d17d6e15 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -29,8 +29,6 @@ use clean::{
     self,
     GetDefId,
     ToSource,
-    get_auto_traits_with_def_id,
-    get_blanket_impls_with_def_id,
 };
 
 use super::Clean;
@@ -56,7 +54,7 @@ pub fn try_inline(cx: &DocContext, def: Def, name: ast::Name, visited: &mut FxHa
     let inner = match def {
         Def::Trait(did) => {
             record_extern_fqn(cx, did, clean::TypeKind::Trait);
-            ret.extend(build_impls(cx, did, false));
+            ret.extend(build_impls(cx, did));
             clean::TraitItem(build_external_trait(cx, did))
         }
         Def::Fn(did) => {
@@ -65,27 +63,27 @@ pub fn try_inline(cx: &DocContext, def: Def, name: ast::Name, visited: &mut FxHa
         }
         Def::Struct(did) => {
             record_extern_fqn(cx, did, clean::TypeKind::Struct);
-            ret.extend(build_impls(cx, did, true));
+            ret.extend(build_impls(cx, did));
             clean::StructItem(build_struct(cx, did))
         }
         Def::Union(did) => {
             record_extern_fqn(cx, did, clean::TypeKind::Union);
-            ret.extend(build_impls(cx, did, true));
+            ret.extend(build_impls(cx, did));
             clean::UnionItem(build_union(cx, did))
         }
         Def::TyAlias(did) => {
             record_extern_fqn(cx, did, clean::TypeKind::Typedef);
-            ret.extend(build_impls(cx, did, false));
+            ret.extend(build_impls(cx, did));
             clean::TypedefItem(build_type_alias(cx, did), false)
         }
         Def::Enum(did) => {
             record_extern_fqn(cx, did, clean::TypeKind::Enum);
-            ret.extend(build_impls(cx, did, true));
+            ret.extend(build_impls(cx, did));
             clean::EnumItem(build_enum(cx, did))
         }
         Def::ForeignTy(did) => {
             record_extern_fqn(cx, did, clean::TypeKind::Foreign);
-            ret.extend(build_impls(cx, did, false));
+            ret.extend(build_impls(cx, did));
             clean::ForeignTypeItem
         }
         // Never inline enum variants but leave them shown as re-exports.
@@ -158,12 +156,11 @@ pub fn load_attrs(cx: &DocContext, did: DefId) -> clean::Attributes {
 /// These names are used later on by HTML rendering to generate things like
 /// source links back to the original item.
 pub fn record_extern_fqn(cx: &DocContext, did: DefId, kind: clean::TypeKind) {
+    let mut crate_name = cx.tcx.crate_name(did.krate).to_string();
     if did.is_local() {
-        debug!("record_extern_fqn(did={:?}, kind+{:?}): def_id is local, aborting", did, kind);
-        return;
+        crate_name = cx.crate_name.clone().unwrap_or(crate_name);
     }
 
-    let crate_name = cx.tcx.crate_name(did.krate).to_string();
     let relative = cx.tcx.def_path(did).data.into_iter().filter_map(|elem| {
         // extern blocks have an empty name
         let s = elem.data.to_string();
@@ -178,7 +175,12 @@ pub fn record_extern_fqn(cx: &DocContext, did: DefId, kind: clean::TypeKind) {
     } else {
         once(crate_name).chain(relative).collect()
     };
-    cx.renderinfo.borrow_mut().external_paths.insert(did, (fqn, kind));
+
+    if did.is_local() {
+        cx.renderinfo.borrow_mut().exact_paths.insert(did, fqn);
+    } else {
+        cx.renderinfo.borrow_mut().external_paths.insert(did, (fqn, kind));
+    }
 }
 
 pub fn build_external_trait(cx: &DocContext, did: DefId) -> clean::Trait {
@@ -270,7 +272,7 @@ fn build_type_alias(cx: &DocContext, did: DefId) -> clean::Typedef {
     }
 }
 
-pub fn build_impls(cx: &DocContext, did: DefId, auto_traits: bool) -> Vec<clean::Item> {
+pub fn build_impls(cx: &DocContext, did: DefId) -> Vec<clean::Item> {
     let tcx = cx.tcx;
     let mut impls = Vec::new();
 
@@ -278,85 +280,6 @@ pub fn build_impls(cx: &DocContext, did: DefId, auto_traits: bool) -> Vec<clean:
         build_impl(cx, did, &mut impls);
     }
 
-    if auto_traits {
-        let auto_impls = get_auto_traits_with_def_id(cx, did);
-        {
-            let mut renderinfo = cx.renderinfo.borrow_mut();
-            let new_impls: Vec<clean::Item> = auto_impls.into_iter()
-                .filter(|i| renderinfo.inlined.insert(i.def_id)).collect();
-
-            impls.extend(new_impls);
-        }
-        impls.extend(get_blanket_impls_with_def_id(cx, did));
-    }
-
-    // If this is the first time we've inlined something from another crate, then
-    // we inline *all* impls from all the crates into this crate. Note that there's
-    // currently no way for us to filter this based on type, and we likely need
-    // many impls for a variety of reasons.
-    //
-    // Primarily, the impls will be used to populate the documentation for this
-    // type being inlined, but impls can also be used when generating
-    // documentation for primitives (no way to find those specifically).
-    if cx.populated_all_crate_impls.get() {
-        return impls;
-    }
-
-    cx.populated_all_crate_impls.set(true);
-
-    for &cnum in tcx.crates().iter() {
-        for did in tcx.all_trait_implementations(cnum).iter() {
-            build_impl(cx, *did, &mut impls);
-        }
-    }
-
-    // Also try to inline primitive impls from other crates.
-    let lang_items = tcx.lang_items();
-    let primitive_impls = [
-        lang_items.isize_impl(),
-        lang_items.i8_impl(),
-        lang_items.i16_impl(),
-        lang_items.i32_impl(),
-        lang_items.i64_impl(),
-        lang_items.i128_impl(),
-        lang_items.usize_impl(),
-        lang_items.u8_impl(),
-        lang_items.u16_impl(),
-        lang_items.u32_impl(),
-        lang_items.u64_impl(),
-        lang_items.u128_impl(),
-        lang_items.f32_impl(),
-        lang_items.f64_impl(),
-        lang_items.f32_runtime_impl(),
-        lang_items.f64_runtime_impl(),
-        lang_items.char_impl(),
-        lang_items.str_impl(),
-        lang_items.slice_impl(),
-        lang_items.slice_u8_impl(),
-        lang_items.str_alloc_impl(),
-        lang_items.slice_alloc_impl(),
-        lang_items.slice_u8_alloc_impl(),
-        lang_items.const_ptr_impl(),
-        lang_items.mut_ptr_impl(),
-    ];
-
-    for def_id in primitive_impls.iter().filter_map(|&def_id| def_id) {
-        if !def_id.is_local() {
-            build_impl(cx, def_id, &mut impls);
-
-            let auto_impls = get_auto_traits_with_def_id(cx, def_id);
-            let blanket_impls = get_blanket_impls_with_def_id(cx, def_id);
-            let mut renderinfo = cx.renderinfo.borrow_mut();
-
-            let new_impls: Vec<clean::Item> = auto_impls.into_iter()
-                .chain(blanket_impls.into_iter())
-                .filter(|i| renderinfo.inlined.insert(i.def_id))
-                .collect();
-
-            impls.extend(new_impls);
-        }
-    }
-
     impls
 }
 
@@ -371,30 +294,60 @@ pub fn build_impl(cx: &DocContext, did: DefId, ret: &mut Vec<clean::Item>) {
 
     // Only inline impl if the implemented trait is
     // reachable in rustdoc generated documentation
-    if let Some(traitref) = associated_trait {
-        if !cx.access_levels.borrow().is_doc_reachable(traitref.def_id) {
-            return
+    if !did.is_local() {
+        if let Some(traitref) = associated_trait {
+            if !cx.renderinfo.borrow().access_levels.is_doc_reachable(traitref.def_id) {
+                return
+            }
         }
     }
 
-    let for_ = tcx.type_of(did).clean(cx);
+    let for_ = if let Some(nodeid) = tcx.hir.as_local_node_id(did) {
+        match tcx.hir.expect_item(nodeid).node {
+            hir::ItemKind::Impl(.., ref t, _) => {
+                t.clean(cx)
+            }
+            _ => panic!("did given to build_impl was not an impl"),
+        }
+    } else {
+        tcx.type_of(did).clean(cx)
+    };
 
     // Only inline impl if the implementing type is
     // reachable in rustdoc generated documentation
-    if let Some(did) = for_.def_id() {
-        if !cx.access_levels.borrow().is_doc_reachable(did) {
-            return
+    if !did.is_local() {
+        if let Some(did) = for_.def_id() {
+            if !cx.renderinfo.borrow().access_levels.is_doc_reachable(did) {
+                return
+            }
         }
     }
 
     let predicates = tcx.predicates_of(did);
-    let trait_items = tcx.associated_items(did).filter_map(|item| {
-        if associated_trait.is_some() || item.vis == ty::Visibility::Public {
-            Some(item.clean(cx))
-        } else {
-            None
+    let (trait_items, generics) = if let Some(nodeid) = tcx.hir.as_local_node_id(did) {
+        match tcx.hir.expect_item(nodeid).node {
+            hir::ItemKind::Impl(.., ref gen, _, _, ref item_ids) => {
+                (
+                    item_ids.iter()
+                            .map(|ii| tcx.hir.impl_item(ii.id).clean(cx))
+                            .collect::<Vec<_>>(),
+                    gen.clean(cx),
+                )
+            }
+            _ => panic!("did given to build_impl was not an impl"),
         }
-    }).collect::<Vec<_>>();
+    } else {
+        (
+            tcx.associated_items(did).filter_map(|item| {
+                if associated_trait.is_some() || item.vis == ty::Visibility::Public {
+                    Some(item.clean(cx))
+                } else {
+                    None
+                }
+            }).collect::<Vec<_>>(),
+            (tcx.generics_of(did), &predicates).clean(cx),
+        )
+    };
     let polarity = tcx.impl_polarity(did);
     let trait_ = associated_trait.clean(cx).map(|bound| {
         match bound {
@@ -416,10 +369,12 @@ pub fn build_impl(cx: &DocContext, did: DefId, ret: &mut Vec<clean::Item>) {
            .collect()
     }).unwrap_or(FxHashSet());
 
+    debug!("build_impl: impl {:?} for {:?}", trait_.def_id(), for_.def_id());
+
     ret.push(clean::Item {
         inner: clean::ImplItem(clean::Impl {
             unsafety: hir::Unsafety::Normal,
-            generics: (tcx.generics_of(did), &predicates).clean(cx),
+            generics,
             provided_trait_methods: provided,
             trait_,
             for_,
@@ -464,7 +419,11 @@ fn build_module(cx: &DocContext, did: DefId, visited: &mut FxHashSet<DefId>) ->
 }
 
 pub fn print_inlined_const(cx: &DocContext, did: DefId) -> String {
-    cx.tcx.rendered_const(did)
+    if let Some(node_id) = cx.tcx.hir.as_local_node_id(did) {
+        cx.tcx.hir.node_to_pretty_string(node_id)
+    } else {
+        cx.tcx.rendered_const(did)
+    }
 }
 
 fn build_const(cx: &DocContext, did: DefId) -> clean::Constant {
@@ -575,16 +534,27 @@ fn separate_supertrait_bounds(mut g: clean::Generics)
 }
 
 pub fn record_extern_trait(cx: &DocContext, did: DefId) {
-    if cx.external_traits.borrow().contains_key(&did) ||
-        cx.active_extern_traits.borrow().contains(&did)
-    {
+    if did.is_local() {
         return;
     }
 
+    {
+        let external_traits = cx.external_traits.lock();
+        if external_traits.borrow().contains_key(&did) ||
+            cx.active_extern_traits.borrow().contains(&did)
+        {
+            return;
+        }
+    }
+
     cx.active_extern_traits.borrow_mut().push(did);
 
+    debug!("record_extern_trait: {:?}", did);
     let trait_ = build_external_trait(cx, did);
 
-    cx.external_traits.borrow_mut().insert(did, trait_);
+    {
+        let external_traits = cx.external_traits.lock();
+        external_traits.borrow_mut().insert(did, trait_);
+    }
     cx.active_extern_traits.borrow_mut().remove_item(&did);
 }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index da18e3e6b91b3..943bd2526c9c2 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -28,7 +28,6 @@ use syntax::symbol::InternedString;
 use syntax_pos::{self, DUMMY_SP, Pos, FileName};
 
 use rustc::mir::interpret::ConstValue;
-use rustc::middle::privacy::AccessLevels;
 use rustc::middle::resolve_lifetime as rl;
 use rustc::ty::fold::TypeFolder;
 use rustc::middle::lang_items;
@@ -56,6 +55,8 @@ use std::cell::RefCell;
 use std::sync::Arc;
 use std::u32;
 
+use parking_lot::ReentrantMutex;
+
 use core::{self, DocContext};
 use doctree;
 use visit_ast;
@@ -135,10 +136,9 @@ pub struct Crate {
     pub module: Option<Item>,
     pub externs: Vec<(CrateNum, ExternalCrate)>,
     pub primitives: Vec<(DefId, PrimitiveType, Attributes)>,
-    pub access_levels: Arc<AccessLevels<DefId>>,
     // These are later on moved into `CACHEKEY`, leaving the map empty.
     // Only here so that they can be filtered through the rustdoc passes.
-    pub external_traits: FxHashMap<DefId, Trait>,
+    pub external_traits: Arc<ReentrantMutex<RefCell<FxHashMap<DefId, Trait>>>>,
     pub masked_crates: FxHashSet<CrateNum>,
 }
 
@@ -209,9 +209,6 @@ impl<'a, 'tcx, 'rcx, 'cstore> Clean<Crate> for visit_ast::RustdocVisitor<'a, 'tc
             }));
         }
 
-        let mut access_levels = cx.access_levels.borrow_mut();
-        let mut external_traits = cx.external_traits.borrow_mut();
-
         Crate {
             name,
             version: None,
@@ -219,8 +216,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> Clean<Crate> for visit_ast::RustdocVisitor<'a, 'tc
             module: Some(module),
             externs,
             primitives,
-            access_levels: Arc::new(mem::replace(&mut access_levels, Default::default())),
-            external_traits: mem::replace(&mut external_traits, Default::default()),
+            external_traits: cx.external_traits.clone(),
             masked_crates,
         }
     }
@@ -579,9 +575,9 @@ impl Clean<Item> for doctree::Module {
         let mut items: Vec<Item> = vec![];
         items.extend(self.extern_crates.iter().map(|x| x.clean(cx)));
         items.extend(self.imports.iter().flat_map(|x| x.clean(cx)));
-        items.extend(self.structs.iter().flat_map(|x| x.clean(cx)));
-        items.extend(self.unions.iter().flat_map(|x| x.clean(cx)));
-        items.extend(self.enums.iter().flat_map(|x| x.clean(cx)));
+        items.extend(self.structs.iter().map(|x| x.clean(cx)));
+        items.extend(self.unions.iter().map(|x| x.clean(cx)));
+        items.extend(self.enums.iter().map(|x| x.clean(cx)));
         items.extend(self.fns.iter().map(|x| x.clean(cx)));
         items.extend(self.foreigns.iter().flat_map(|x| x.clean(cx)));
         items.extend(self.mods.iter().map(|x| x.clean(cx)));
@@ -2436,7 +2432,7 @@ impl Clean<Type> for hir::Ty {
                 if let Def::TyAlias(def_id) = path.def {
                     // Substitute private type aliases
                     if let Some(node_id) = cx.tcx.hir.as_local_node_id(def_id) {
-                        if !cx.access_levels.borrow().is_exported(def_id) {
+                        if !cx.renderinfo.borrow().access_levels.is_exported(def_id) {
                             alias = Some(&cx.tcx.hir.expect_item(node_id).node);
                         }
                     }
@@ -2816,14 +2812,10 @@ pub struct Union {
     pub fields_stripped: bool,
 }
 
-impl Clean<Vec<Item>> for doctree::Struct {
-    fn clean(&self, cx: &DocContext) -> Vec<Item> {
-        let name = self.name.clean(cx);
-        let mut ret = get_auto_traits_with_node_id(cx, self.id, name.clone());
-        ret.extend(get_blanket_impls_with_node_id(cx, self.id, name.clone()));
-
-        ret.push(Item {
-            name: Some(name),
+impl Clean<Item> for doctree::Struct {
+    fn clean(&self, cx: &DocContext) -> Item {
+        Item {
+            name: Some(self.name.clean(cx)),
             attrs: self.attrs.clean(cx),
             source: self.whence.clean(cx),
             def_id: cx.tcx.hir.local_def_id(self.id),
@@ -2836,20 +2828,14 @@ impl Clean<Vec<Item>> for doctree::Struct {
                 fields: self.fields.clean(cx),
                 fields_stripped: false,
             }),
-        });
-
-        ret
+        }
     }
 }
 
-impl Clean<Vec<Item>> for doctree::Union {
-    fn clean(&self, cx: &DocContext) -> Vec<Item> {
-        let name = self.name.clean(cx);
-        let mut ret = get_auto_traits_with_node_id(cx, self.id, name.clone());
-        ret.extend(get_blanket_impls_with_node_id(cx, self.id, name.clone()));
-
-        ret.push(Item {
-            name: Some(name),
+impl Clean<Item> for doctree::Union {
+    fn clean(&self, cx: &DocContext) -> Item {
+        Item {
+            name: Some(self.name.clean(cx)),
             attrs: self.attrs.clean(cx),
             source: self.whence.clean(cx),
             def_id: cx.tcx.hir.local_def_id(self.id),
@@ -2862,9 +2848,7 @@ impl Clean<Vec<Item>> for doctree::Union {
                 fields: self.fields.clean(cx),
                 fields_stripped: false,
             }),
-        });
-
-        ret
+        }
     }
 }
 
@@ -2895,14 +2879,10 @@ pub struct Enum {
     pub variants_stripped: bool,
 }
 
-impl Clean<Vec<Item>> for doctree::Enum {
-    fn clean(&self, cx: &DocContext) -> Vec<Item> {
-        let name = self.name.clean(cx);
-        let mut ret = get_auto_traits_with_node_id(cx, self.id, name.clone());
-        ret.extend(get_blanket_impls_with_node_id(cx, self.id, name.clone()));
-
-        ret.push(Item {
-            name: Some(name),
+impl Clean<Item> for doctree::Enum {
+    fn clean(&self, cx: &DocContext) -> Item {
+        Item {
+            name: Some(self.name.clean(cx)),
             attrs: self.attrs.clean(cx),
             source: self.whence.clean(cx),
             def_id: cx.tcx.hir.local_def_id(self.id),
@@ -2914,9 +2894,7 @@ impl Clean<Vec<Item>> for doctree::Enum {
                 generics: self.generics.clean(cx),
                 variants_stripped: false,
             }),
-        });
-
-        ret
+        }
     }
 }
 
@@ -3445,11 +3423,7 @@ fn build_deref_target_impls(cx: &DocContext,
         let primitive = match *target {
             ResolvedPath { did, .. } if did.is_local() => continue,
             ResolvedPath { did, .. } => {
-                // We set the last parameter to false to avoid looking for auto-impls for traits
-                // and therefore avoid an ICE.
-                // The reason behind this is that auto-traits don't propagate through Deref so
-                // we're not supposed to synthesise impls for them.
-                ret.extend(inline::build_impls(cx, did, false));
+                ret.extend(inline::build_impls(cx, did));
                 continue
             }
             _ => match target.primitive_type() {
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index a312913a69c17..253d8b93c667b 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -36,11 +36,13 @@ use syntax::symbol::keywords;
 use syntax_pos::DUMMY_SP;
 use errors;
 use errors::emitter::{Emitter, EmitterWriter};
+use parking_lot::ReentrantMutex;
 
-use std::cell::{RefCell, Cell};
+use std::cell::RefCell;
 use std::mem;
 use rustc_data_structures::sync::{self, Lrc};
 use std::rc::Rc;
+use std::sync::Arc;
 use std::path::PathBuf;
 
 use visit_ast::RustdocVisitor;
@@ -60,16 +62,13 @@ pub struct DocContext<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx> {
     /// The stack of module NodeIds up till this point
     pub crate_name: Option<String>,
     pub cstore: Rc<CStore>,
-    pub populated_all_crate_impls: Cell<bool>,
     // Note that external items for which `doc(hidden)` applies to are shown as
     // non-reachable while local items aren't. This is because we're reusing
     // the access levels from crateanalysis.
-    /// Later on moved into `clean::Crate`
-    pub access_levels: RefCell<AccessLevels<DefId>>,
     /// Later on moved into `html::render::CACHE_KEY`
     pub renderinfo: RefCell<RenderInfo>,
     /// Later on moved through `clean::Crate` into `html::render::CACHE_KEY`
-    pub external_traits: RefCell<FxHashMap<DefId, clean::Trait>>,
+    pub external_traits: Arc<ReentrantMutex<RefCell<FxHashMap<DefId, clean::Trait>>>>,
     /// Used while populating `external_traits` to ensure we don't process the same trait twice at
     /// the same time.
     pub active_extern_traits: RefCell<Vec<DefId>>,
@@ -506,16 +505,17 @@ pub fn run_core(search_paths: SearchPaths,
                 clean::path_to_def(&tcx, &["core", "marker", "Send"])
             };
 
+            let mut renderinfo = RenderInfo::default();
+            renderinfo.access_levels = access_levels;
+
             let ctxt = DocContext {
                 tcx,
                 resolver: &resolver,
                 crate_name,
                 cstore: cstore.clone(),
-                populated_all_crate_impls: Cell::new(false),
-                access_levels: RefCell::new(access_levels),
                 external_traits: Default::default(),
                 active_extern_traits: Default::default(),
-                renderinfo: Default::default(),
+                renderinfo: RefCell::new(renderinfo),
                 ty_substs: Default::default(),
                 lt_substs: Default::default(),
                 impl_trait_bounds: Default::default(),
diff --git a/src/librustdoc/fold.rs b/src/librustdoc/fold.rs
index 6d96bc8e36038..b8e27c5317083 100644
--- a/src/librustdoc/fold.rs
+++ b/src/librustdoc/fold.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::mem;
-
 use clean::*;
 
 pub struct StripItem(pub Item);
@@ -116,11 +114,14 @@ pub trait DocFolder : Sized {
     fn fold_crate(&mut self, mut c: Crate) -> Crate {
         c.module = c.module.take().and_then(|module| self.fold_item(module));
 
-        let traits = mem::replace(&mut c.external_traits, Default::default());
-        c.external_traits.extend(traits.into_iter().map(|(k, mut v)| {
-            v.items = v.items.into_iter().filter_map(|i| self.fold_item(i)).collect();
-            (k, v)
-        }));
+        {
+            let guard = c.external_traits.lock();
+            let traits = guard.replace(Default::default());
+            guard.borrow_mut().extend(traits.into_iter().map(|(k, mut v)| {
+                v.items = v.items.into_iter().filter_map(|i| self.fold_item(i)).collect();
+                (k, v)
+            }));
+        }
         c
     }
 }
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 972c2f0e15c5e..e6ef9e97da8eb 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -313,7 +313,7 @@ pub struct Cache {
     // Note that external items for which `doc(hidden)` applies to are shown as
     // non-reachable while local items aren't. This is because we're reusing
     // the access levels from crateanalysis.
-    pub access_levels: Arc<AccessLevels<DefId>>,
+    pub access_levels: AccessLevels<DefId>,
 
     /// The version of the crate being documented, if given from the `--crate-version` flag.
     pub crate_version: Option<String>,
@@ -337,6 +337,15 @@ pub struct Cache {
     // and their parent id here and indexes them at the end of crate parsing.
     orphan_impl_items: Vec<(DefId, clean::Item)>,
 
+    // Similarly to `orphan_impl_items`, sometimes trait impls are picked up
+    // even though the trait itself is not exported. This can happen if a trait
+    // was defined in function/expression scope, since the impl will be picked
+    // up by `collect-trait-impls` but the trait won't be scraped out in the HIR
+    // crawl. In order to prevent crashes when looking for spotlight traits or
+    // when gathering trait documentation on a type, hold impls here while
+    // folding and add them to the cache later on if we find the trait.
+    orphan_trait_impls: Vec<(DefId, FxHashSet<DefId>, Impl)>,
+
     /// Aliases added through `#[doc(alias = "...")]`. Since a few items can have the same alias,
     /// we need the alias element to have an array of items.
     aliases: FxHashMap<String, Vec<IndexItem>>,
@@ -350,6 +359,7 @@ pub struct RenderInfo {
     pub external_paths: ::core::ExternalPaths,
     pub external_typarams: FxHashMap<DefId, String>,
     pub exact_paths: FxHashMap<DefId, Vec<String>>,
+    pub access_levels: AccessLevels<DefId>,
     pub deref_trait_did: Option<DefId>,
     pub deref_mut_trait_did: Option<DefId>,
     pub owned_box_did: Option<DefId>,
@@ -569,6 +579,7 @@ pub fn run(mut krate: clean::Crate,
         external_paths,
         external_typarams,
         exact_paths,
+        access_levels,
         deref_trait_did,
         deref_mut_trait_did,
         owned_box_did,
@@ -591,10 +602,11 @@ pub fn run(mut krate: clean::Crate,
         extern_locations: FxHashMap(),
         primitive_locations: FxHashMap(),
         stripped_mod: false,
-        access_levels: krate.access_levels.clone(),
+        access_levels,
         crate_version: krate.version.take(),
         orphan_impl_items: Vec::new(),
-        traits: mem::replace(&mut krate.external_traits, FxHashMap()),
+        orphan_trait_impls: Vec::new(),
+        traits: krate.external_traits.lock().replace(FxHashMap()),
         deref_trait_did,
         deref_mut_trait_did,
         owned_box_did,
@@ -636,6 +648,14 @@ pub fn run(mut krate: clean::Crate,
     cache.stack.push(krate.name.clone());
     krate = cache.fold_crate(krate);
 
+    for (trait_did, dids, impl_) in cache.orphan_trait_impls.drain(..) {
+        if cache.traits.contains_key(&trait_did) {
+            for did in dids {
+                cache.impls.entry(did).or_insert(vec![]).push(impl_.clone());
+            }
+        }
+    }
+
     // Build our search index
     let index = build_index(&krate, &mut cache);
 
@@ -1223,6 +1243,10 @@ impl<'a> SourceCollector<'a> {
 
 impl DocFolder for Cache {
     fn fold_item(&mut self, item: clean::Item) -> Option<clean::Item> {
+        if item.def_id.is_local() {
+            debug!("folding {} \"{:?}\", id {:?}", item.type_(), item.name, item.def_id);
+        }
+
         // If this is a stripped module,
         // we don't want it or its children in the search index.
         let orig_stripped_mod = match item.inner {
@@ -1451,10 +1475,16 @@ impl DocFolder for Cache {
                 } else {
                     unreachable!()
                 };
-                for did in dids {
-                    self.impls.entry(did).or_default().push(Impl {
-                        impl_item: item.clone(),
-                    });
+                let impl_item = Impl {
+                    impl_item: item,
+                };
+                if impl_item.trait_did().map_or(true, |d| self.traits.contains_key(&d)) {
+                    for did in dids {
+                        self.impls.entry(did).or_insert(vec![]).push(impl_item.clone());
+                    }
+                } else {
+                    let trait_did = impl_item.trait_did().unwrap();
+                    self.orphan_trait_impls.push((trait_did, dids, impl_item));
                 }
                 None
             } else {
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 1acae86f0068f..d0b00fd52ee77 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -25,6 +25,7 @@
 #![feature(ptr_offset_from)]
 #![feature(crate_visibility_modifier)]
 #![feature(const_fn)]
+#![feature(drain_filter)]
 
 #![recursion_limit="256"]
 
@@ -49,6 +50,7 @@ extern crate rustc_errors as errors;
 extern crate pulldown_cmark;
 extern crate tempfile;
 extern crate minifier;
+extern crate parking_lot;
 
 extern crate serialize as rustc_serialize; // used by deriving
 
diff --git a/src/librustdoc/passes/collect_trait_impls.rs b/src/librustdoc/passes/collect_trait_impls.rs
new file mode 100644
index 0000000000000..56940483d7be2
--- /dev/null
+++ b/src/librustdoc/passes/collect_trait_impls.rs
@@ -0,0 +1,130 @@
+// 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.
+
+use clean::*;
+
+use super::Pass;
+use core::DocContext;
+use fold::DocFolder;
+
+pub const COLLECT_TRAIT_IMPLS: Pass =
+    Pass::early("collect-trait-impls", collect_trait_impls,
+                "retrieves trait impls for items in the crate");
+
+pub fn collect_trait_impls(krate: Crate, cx: &DocContext) -> Crate {
+    let mut synth = SyntheticImplCollector::new(cx);
+    let mut krate = synth.fold_crate(krate);
+
+    if let Some(ref mut it) = krate.module {
+        if let ModuleItem(Module { ref mut items, .. }) = it.inner {
+            items.extend(synth.impls);
+
+            for &cnum in cx.tcx.crates().iter() {
+                for &did in cx.tcx.all_trait_implementations(cnum).iter() {
+                    inline::build_impl(cx, did, items);
+                }
+            }
+
+            // `tcx.crates()` doesn't include the local crate, and `tcx.all_trait_implementations`
+            // doesn't work with it anyway, so pull them from the HIR map instead
+            for &trait_did in cx.all_traits.iter() {
+                for &impl_node in cx.tcx.hir.trait_impls(trait_did) {
+                    let impl_did = cx.tcx.hir.local_def_id(impl_node);
+                    inline::build_impl(cx, impl_did, items);
+                }
+            }
+
+            // Also try to inline primitive impls from other crates.
+            let lang_items = cx.tcx.lang_items();
+            let primitive_impls = [
+                lang_items.isize_impl(),
+                lang_items.i8_impl(),
+                lang_items.i16_impl(),
+                lang_items.i32_impl(),
+                lang_items.i64_impl(),
+                lang_items.i128_impl(),
+                lang_items.usize_impl(),
+                lang_items.u8_impl(),
+                lang_items.u16_impl(),
+                lang_items.u32_impl(),
+                lang_items.u64_impl(),
+                lang_items.u128_impl(),
+                lang_items.f32_impl(),
+                lang_items.f64_impl(),
+                lang_items.f32_runtime_impl(),
+                lang_items.f64_runtime_impl(),
+                lang_items.char_impl(),
+                lang_items.str_impl(),
+                lang_items.slice_impl(),
+                lang_items.slice_u8_impl(),
+                lang_items.str_alloc_impl(),
+                lang_items.slice_alloc_impl(),
+                lang_items.slice_u8_alloc_impl(),
+                lang_items.const_ptr_impl(),
+                lang_items.mut_ptr_impl(),
+            ];
+
+            for def_id in primitive_impls.iter().filter_map(|&def_id| def_id) {
+                if !def_id.is_local() {
+                    inline::build_impl(cx, def_id, items);
+
+                    let auto_impls = get_auto_traits_with_def_id(cx, def_id);
+                    let blanket_impls = get_blanket_impls_with_def_id(cx, def_id);
+                    let mut renderinfo = cx.renderinfo.borrow_mut();
+
+                    let new_impls: Vec<Item> = auto_impls.into_iter()
+                        .chain(blanket_impls.into_iter())
+                        .filter(|i| renderinfo.inlined.insert(i.def_id))
+                        .collect();
+
+                    items.extend(new_impls);
+                }
+            }
+        } else {
+            panic!("collect-trait-impls can't run");
+        }
+    } else {
+        panic!("collect-trait-impls can't run");
+    }
+
+    krate
+}
+
+struct SyntheticImplCollector<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx> {
+    cx: &'a DocContext<'a, 'tcx, 'rcx, 'cstore>,
+    impls: Vec<Item>,
+}
+
+impl<'a, 'tcx, 'rcx, 'cstore> SyntheticImplCollector<'a, 'tcx, 'rcx, 'cstore> {
+    fn new(cx: &'a DocContext<'a, 'tcx, 'rcx, 'cstore>) -> Self {
+        SyntheticImplCollector {
+            cx,
+            impls: Vec::new(),
+        }
+    }
+}
+
+impl<'a, 'tcx, 'rcx, 'cstore> DocFolder for SyntheticImplCollector<'a, 'tcx, 'rcx, 'cstore> {
+    fn fold_item(&mut self, i: Item) -> Option<Item> {
+        if i.is_struct() || i.is_enum() || i.is_union() {
+            if let (Some(node_id), Some(name)) =
+                (self.cx.tcx.hir.as_local_node_id(i.def_id), i.name.clone())
+            {
+                self.impls.extend(get_auto_traits_with_node_id(self.cx, node_id, name.clone()));
+                self.impls.extend(get_blanket_impls_with_node_id(self.cx, node_id, name));
+            } else {
+                self.impls.extend(get_auto_traits_with_def_id(self.cx, i.def_id));
+                self.impls.extend(get_blanket_impls_with_def_id(self.cx, i.def_id));
+            }
+        }
+
+        self.fold_item_recur(i)
+    }
+}
diff --git a/src/librustdoc/passes/mod.rs b/src/librustdoc/passes/mod.rs
index 16251877bb106..24fec62dd573a 100644
--- a/src/librustdoc/passes/mod.rs
+++ b/src/librustdoc/passes/mod.rs
@@ -43,6 +43,9 @@ pub use self::propagate_doc_cfg::PROPAGATE_DOC_CFG;
 mod collect_intra_doc_links;
 pub use self::collect_intra_doc_links::COLLECT_INTRA_DOC_LINKS;
 
+mod collect_trait_impls;
+pub use self::collect_trait_impls::COLLECT_TRAIT_IMPLS;
+
 /// Represents a single pass.
 #[derive(Copy, Clone)]
 pub enum Pass {
@@ -132,10 +135,12 @@ pub const PASSES: &'static [Pass] = &[
     STRIP_PRIV_IMPORTS,
     PROPAGATE_DOC_CFG,
     COLLECT_INTRA_DOC_LINKS,
+    COLLECT_TRAIT_IMPLS,
 ];
 
 /// The list of passes run by default.
 pub const DEFAULT_PASSES: &'static [&'static str] = &[
+    "collect-trait-impls",
     "strip-hidden",
     "strip-private",
     "collect-intra-doc-links",
@@ -146,6 +151,7 @@ pub const DEFAULT_PASSES: &'static [&'static str] = &[
 
 /// The list of default passes run with `--document-private-items` is passed to rustdoc.
 pub const DEFAULT_PRIVATE_PASSES: &'static [&'static str] = &[
+    "collect-trait-impls",
     "strip-priv-imports",
     "collect-intra-doc-links",
     "collapse-docs",
@@ -189,6 +195,7 @@ impl<'a> fold::DocFolder for Stripper<'a> {
                 // We need to recurse into stripped modules to strip things
                 // like impl methods but when doing so we must not add any
                 // items to the `retained` set.
+                debug!("Stripper: recursing into stripped {} {:?}", i.type_(), i.name);
                 let old = mem::replace(&mut self.update_retained, false);
                 let ret = self.fold_item_recur(i);
                 self.update_retained = old;
@@ -212,6 +219,7 @@ impl<'a> fold::DocFolder for Stripper<'a> {
             | clean::ForeignTypeItem => {
                 if i.def_id.is_local() {
                     if !self.access_levels.is_exported(i.def_id) {
+                        debug!("Stripper: stripping {} {:?}", i.type_(), i.name);
                         return None;
                     }
                 }
@@ -225,6 +233,7 @@ impl<'a> fold::DocFolder for Stripper<'a> {
 
             clean::ModuleItem(..) => {
                 if i.def_id.is_local() && i.visibility != Some(clean::Public) {
+                    debug!("Stripper: stripping module {:?}", i.name);
                     let old = mem::replace(&mut self.update_retained, false);
                     let ret = StripItem(self.fold_item_recur(i).unwrap()).strip();
                     self.update_retained = old;
@@ -296,11 +305,13 @@ impl<'a> fold::DocFolder for ImplStripper<'a> {
             }
             if let Some(did) = imp.for_.def_id() {
                 if did.is_local() && !imp.for_.is_generic() && !self.retained.contains(&did) {
+                    debug!("ImplStripper: impl item for stripped type; removing");
                     return None;
                 }
             }
             if let Some(did) = imp.trait_.def_id() {
                 if did.is_local() && !self.retained.contains(&did) {
+                    debug!("ImplStripper: impl item for stripped trait; removing");
                     return None;
                 }
             }
@@ -308,6 +319,8 @@ impl<'a> fold::DocFolder for ImplStripper<'a> {
                 for typaram in generics {
                     if let Some(did) = typaram.def_id() {
                         if did.is_local() && !self.retained.contains(&did) {
+                            debug!("ImplStripper: stripped item in trait's generics; \
+                                    removing impl");
                             return None;
                         }
                     }
diff --git a/src/librustdoc/passes/strip_hidden.rs b/src/librustdoc/passes/strip_hidden.rs
index cc0b6fb6d6705..24dd4cc13bfe8 100644
--- a/src/librustdoc/passes/strip_hidden.rs
+++ b/src/librustdoc/passes/strip_hidden.rs
@@ -35,7 +35,9 @@ pub fn strip_hidden(krate: clean::Crate, _: &DocContext) -> clean::Crate {
 
     // strip all impls referencing stripped items
     let mut stripper = ImplStripper { retained: &retained };
-    stripper.fold_crate(krate)
+    let krate = stripper.fold_crate(krate);
+
+    krate
 }
 
 struct Stripper<'a> {
@@ -46,7 +48,7 @@ struct Stripper<'a> {
 impl<'a> fold::DocFolder for Stripper<'a> {
     fn fold_item(&mut self, i: Item) -> Option<Item> {
         if i.attrs.lists("doc").has_word("hidden") {
-            debug!("found one in strip_hidden; removing");
+            debug!("strip_hidden: stripping {} {:?}", i.type_(), i.name);
             // use a dedicated hidden item for given item type if any
             match i.inner {
                 clean::StructFieldItem(..) | clean::ModuleItem(..) => {
diff --git a/src/librustdoc/passes/strip_private.rs b/src/librustdoc/passes/strip_private.rs
index 3b17a768ffdee..46d0034497e28 100644
--- a/src/librustdoc/passes/strip_private.rs
+++ b/src/librustdoc/passes/strip_private.rs
@@ -22,10 +22,10 @@ pub const STRIP_PRIVATE: Pass =
 
 /// Strip private items from the point of view of a crate or externally from a
 /// crate, specified by the `xcrate` flag.
-pub fn strip_private(mut krate: clean::Crate, _: &DocContext) -> clean::Crate {
+pub fn strip_private(mut krate: clean::Crate, cx: &DocContext) -> clean::Crate {
     // This stripper collects all *retained* nodes.
     let mut retained = DefIdSet();
-    let access_levels = krate.access_levels.clone();
+    let access_levels = cx.renderinfo.borrow().access_levels.clone();
 
     // strip all private items
     {
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 451e24d6c0dc9..3f8b13d145856 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -269,7 +269,10 @@ impl<'a, 'tcx, 'rcx, 'cstore> RustdocVisitor<'a, 'tcx, 'rcx, 'cstore> {
                 Def::Enum(did) |
                 Def::ForeignTy(did) |
                 Def::TyAlias(did) if !self_is_hidden => {
-                    self.cx.access_levels.borrow_mut().map.insert(did, AccessLevel::Public);
+                    self.cx.renderinfo
+                        .borrow_mut()
+                        .access_levels.map
+                        .insert(did, AccessLevel::Public);
                 },
                 Def::Mod(did) => if !self_is_hidden {
                     ::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did);
@@ -284,7 +287,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> RustdocVisitor<'a, 'tcx, 'rcx, 'cstore> {
             Some(n) => n, None => return false
         };
 
-        let is_private = !self.cx.access_levels.borrow().is_public(def_did);
+        let is_private = !self.cx.renderinfo.borrow().access_levels.is_public(def_did);
         let is_hidden = inherits_doc_hidden(self.cx, def_node_id);
 
         // Only inline if requested or if the item would otherwise be stripped
@@ -510,9 +513,9 @@ impl<'a, 'tcx, 'rcx, 'cstore> RustdocVisitor<'a, 'tcx, 'rcx, 'cstore> {
                           ref tr,
                           ref ty,
                           ref item_ids) => {
-                // Don't duplicate impls when inlining, we'll pick them up
-                // regardless of where they're located.
-                if !self.inlining {
+                // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
+                // them up regardless of where they're located.
+                if !self.inlining && tr.is_none() {
                     let items = item_ids.iter()
                                         .map(|ii| self.cx.tcx.hir.impl_item(ii.id).clone())
                                         .collect();
diff --git a/src/librustdoc/visit_lib.rs b/src/librustdoc/visit_lib.rs
index 10a4e69dcc6cd..fd81f937f30c7 100644
--- a/src/librustdoc/visit_lib.rs
+++ b/src/librustdoc/visit_lib.rs
@@ -38,7 +38,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> LibEmbargoVisitor<'a, 'tcx, 'rcx, 'cstore> {
     ) -> LibEmbargoVisitor<'a, 'tcx, 'rcx, 'cstore> {
         LibEmbargoVisitor {
             cx,
-            access_levels: cx.access_levels.borrow_mut(),
+            access_levels: RefMut::map(cx.renderinfo.borrow_mut(), |ri| &mut ri.access_levels),
             prev_level: Some(AccessLevel::Public),
             visited_mods: FxHashSet()
         }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index e7195b3e21ee3..4278926b042f3 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -312,7 +312,6 @@
 #![feature(doc_keyword)]
 #![feature(panic_info_message)]
 #![cfg_attr(stage0, feature(panic_implementation))]
-#![cfg_attr(not(stage0), feature(panic_handler))]
 #![feature(non_exhaustive)]
 
 #![default_lib_allocator]
diff --git a/src/libstd/sys/unix/fd.rs b/src/libstd/sys/unix/fd.rs
index 12e14734ff515..db2ea6b660a7a 100644
--- a/src/libstd/sys/unix/fd.rs
+++ b/src/libstd/sys/unix/fd.rs
@@ -11,7 +11,7 @@
 #![unstable(reason = "not public", issue = "0", feature = "fd")]
 
 use cmp;
-use io::{self, Read};
+use io::{self, Read, Initializer};
 use libc::{self, c_int, c_void, ssize_t};
 use mem;
 use sync::atomic::{AtomicBool, Ordering};
@@ -270,6 +270,11 @@ impl<'a> Read for &'a FileDesc {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         (**self).read(buf)
     }
+
+    #[inline]
+    unsafe fn initializer(&self) -> Initializer {
+        Initializer::nop()
+    }
 }
 
 impl AsInner<c_int> for FileDesc {
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index e3ea3563d853b..0270e36db1177 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -487,7 +487,6 @@ declare_features! (
 
     // RFC 2070: #[panic_implementation] / #[panic_handler]
     (active, panic_implementation, "1.28.0", Some(44489), None),
-    (active, panic_handler, "1.30.0", Some(44489), None),
 
     // #[doc(keyword = "...")]
     (active, doc_keyword, "1.28.0", Some(51315), None),
@@ -674,6 +673,7 @@ declare_features! (
     (accepted, proc_macro_path_invoc, "1.30.0", Some(38356), None),
     // Allows all literals in attribute lists and values of key-value pairs.
     (accepted, attr_literals, "1.30.0", Some(34981), None),
+    (accepted, panic_handler, "1.30.0", Some(44489), None),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must
@@ -1143,10 +1143,7 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
            cfg_fn!(panic_implementation))),
 
     // RFC 2070
-    ("panic_handler", Normal, Gated(Stability::Unstable,
-                                    "panic_handler",
-                                    "#[panic_handler] is an unstable feature",
-                                    cfg_fn!(panic_handler))),
+    ("panic_handler", Normal, Ungated),
 
     ("alloc_error_handler", Normal, Gated(Stability::Unstable,
                            "alloc_error_handler",
diff --git a/src/test/compile-fail/auxiliary/some-panic-impl.rs b/src/test/compile-fail/auxiliary/some-panic-impl.rs
index e3b4fba176e3c..090123198d175 100644
--- a/src/test/compile-fail/auxiliary/some-panic-impl.rs
+++ b/src/test/compile-fail/auxiliary/some-panic-impl.rs
@@ -11,7 +11,6 @@
 // no-prefer-dynamic
 
 #![crate_type = "rlib"]
-#![feature(panic_handler)]
 #![no_std]
 
 use core::panic::PanicInfo;
diff --git a/src/test/compile-fail/panic-handler-twice.rs b/src/test/compile-fail/panic-handler-twice.rs
index 6c9515ca90994..10e0453cf5ed4 100644
--- a/src/test/compile-fail/panic-handler-twice.rs
+++ b/src/test/compile-fail/panic-handler-twice.rs
@@ -10,7 +10,6 @@
 
 // aux-build:some-panic-impl.rs
 
-#![feature(panic_handler)]
 #![feature(lang_items)]
 #![no_std]
 #![no_main]
diff --git a/src/test/run-make-fulldeps/issue-51671/app.rs b/src/test/run-make-fulldeps/issue-51671/app.rs
index e980b12039e96..4066214f4b47e 100644
--- a/src/test/run-make-fulldeps/issue-51671/app.rs
+++ b/src/test/run-make-fulldeps/issue-51671/app.rs
@@ -10,7 +10,6 @@
 
 #![crate_type = "bin"]
 #![feature(lang_items)]
-#![feature(panic_handler)]
 #![no_main]
 #![no_std]
 
diff --git a/src/test/run-make-fulldeps/issue-53964/Makefile b/src/test/run-make-fulldeps/issue-53964/Makefile
new file mode 100644
index 0000000000000..c56beb52fdd61
--- /dev/null
+++ b/src/test/run-make-fulldeps/issue-53964/Makefile
@@ -0,0 +1,5 @@
+-include ../tools.mk
+
+all:
+	$(RUSTC) panic.rs
+	$(RUSTC) -C panic=abort --emit=obj app.rs -L $(TMPDIR)
diff --git a/src/test/run-make-fulldeps/issue-53964/app.rs b/src/test/run-make-fulldeps/issue-53964/app.rs
new file mode 100644
index 0000000000000..8127b9578bfee
--- /dev/null
+++ b/src/test/run-make-fulldeps/issue-53964/app.rs
@@ -0,0 +1,8 @@
+#![crate_type = "bin"]
+#![no_main]
+#![no_std]
+
+#![deny(unused_extern_crates)]
+
+// `panic` provides a `panic_handler` so it shouldn't trip the `unused_extern_crates` lint
+extern crate panic;
diff --git a/src/test/ui/feature-gates/feature-gate-panic-handler.rs b/src/test/run-make-fulldeps/issue-53964/panic.rs
similarity index 75%
rename from src/test/ui/feature-gates/feature-gate-panic-handler.rs
rename to src/test/run-make-fulldeps/issue-53964/panic.rs
index fd16268ef8b4e..87c7b218822a0 100644
--- a/src/test/ui/feature-gates/feature-gate-panic-handler.rs
+++ b/src/test/run-make-fulldeps/issue-53964/panic.rs
@@ -8,14 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// compile-flags:-C panic=abort
-
+#![crate_type = "lib"]
+#![feature(panic_handler)]
 #![no_std]
-#![no_main]
 
 use core::panic::PanicInfo;
 
-#[panic_handler] //~ ERROR #[panic_handler] is an unstable feature (see issue #44489)
-fn panic(info: &PanicInfo) -> ! {
+#[panic_handler]
+fn panic(_: &PanicInfo) -> ! {
     loop {}
 }
diff --git a/src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-provider.rs b/src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-provider.rs
index 065b2b6bf18fa..77aae7ee2c06b 100644
--- a/src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-provider.rs
+++ b/src/test/run-make-fulldeps/panic-impl-transitive/panic-impl-provider.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 #![crate_type = "rlib"]
-#![feature(panic_handler)]
 #![no_std]
 
 use core::panic::PanicInfo;
diff --git a/src/test/run-pass/uniform-paths/auxiliary/issue-53691.rs b/src/test/run-pass/uniform-paths/auxiliary/issue-53691.rs
new file mode 100644
index 0000000000000..5845afd72fbe7
--- /dev/null
+++ b/src/test/run-pass/uniform-paths/auxiliary/issue-53691.rs
@@ -0,0 +1,19 @@
+// 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.
+
+// edition:2018
+
+#![feature(uniform_paths)]
+
+mod m { pub fn f() {} }
+mod n { pub fn g() {} }
+
+pub use m::f;
+pub use n::g;
diff --git a/src/test/run-pass/uniform-paths/issue-53691.rs b/src/test/run-pass/uniform-paths/issue-53691.rs
new file mode 100644
index 0000000000000..62be31d6b85fe
--- /dev/null
+++ b/src/test/run-pass/uniform-paths/issue-53691.rs
@@ -0,0 +1,18 @@
+// 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.
+
+// aux-build:issue-53691.rs
+
+extern crate issue_53691;
+
+fn main() {
+    issue_53691::f();
+    issue_53691::g();
+}
diff --git a/src/test/rustdoc/doc-proc-macro.rs b/src/test/rustdoc/doc-proc-macro.rs
index b3b403a7b86aa..01a4a410b03fb 100644
--- a/src/test/rustdoc/doc-proc-macro.rs
+++ b/src/test/rustdoc/doc-proc-macro.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-stage1
+
 // Issue #52129: ICE when trying to document the `quote` proc-macro from proc_macro
 
 // As of this writing, we don't currently attempt to document proc-macros. However, we shouldn't
diff --git a/src/test/rustdoc/inline_cross/auxiliary/trait-vis.rs b/src/test/rustdoc/inline_cross/auxiliary/trait-vis.rs
new file mode 100644
index 0000000000000..7457a5d4899fe
--- /dev/null
+++ b/src/test/rustdoc/inline_cross/auxiliary/trait-vis.rs
@@ -0,0 +1,23 @@
+// 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.
+
+#![crate_name = "inner"]
+
+pub struct SomeStruct;
+
+fn asdf() {
+    const _FOO: () = {
+        impl Clone for SomeStruct {
+            fn clone(&self) -> Self {
+                SomeStruct
+            }
+        }
+    };
+}
diff --git a/src/test/rustdoc/inline_cross/trait-vis.rs b/src/test/rustdoc/inline_cross/trait-vis.rs
new file mode 100644
index 0000000000000..5b5410b1da44d
--- /dev/null
+++ b/src/test/rustdoc/inline_cross/trait-vis.rs
@@ -0,0 +1,17 @@
+// 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.
+
+// aux-build:trait-vis.rs
+
+extern crate inner;
+
+// @has trait_vis/struct.SomeStruct.html
+// @has - '//code' 'impl Clone for SomeStruct'
+pub use inner::SomeStruct;
diff --git a/src/test/rustdoc/inline_local/trait-vis.rs b/src/test/rustdoc/inline_local/trait-vis.rs
new file mode 100644
index 0000000000000..73b1cc2ce8f2d
--- /dev/null
+++ b/src/test/rustdoc/inline_local/trait-vis.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.
+
+pub trait ThisTrait {}
+
+mod asdf {
+    use ThisTrait;
+
+    pub struct SomeStruct;
+
+    impl ThisTrait for SomeStruct {}
+
+    trait PrivateTrait {}
+
+    impl PrivateTrait for SomeStruct {}
+}
+
+// @has trait_vis/struct.SomeStruct.html
+// @has - '//code' 'impl ThisTrait for SomeStruct'
+// !@has - '//code' 'impl PrivateTrait for SomeStruct'
+pub use asdf::SomeStruct;
diff --git a/src/test/rustdoc/primitive-generic-impl.rs b/src/test/rustdoc/primitive-generic-impl.rs
index b4351b8268c8b..a771b1b15ce4d 100644
--- a/src/test/rustdoc/primitive-generic-impl.rs
+++ b/src/test/rustdoc/primitive-generic-impl.rs
@@ -10,9 +10,6 @@
 
 #![crate_name = "foo"]
 
-// we need to reexport something from libstd so that `all_trait_implementations` is called.
-pub use std::string::String;
-
 include!("primitive/primitive-generic-impl.rs");
 
 // @has foo/primitive.i32.html '//h3[@id="impl-ToString"]//code' 'impl<T> ToString for T'
diff --git a/src/test/rustdoc/traits-in-bodies-private.rs b/src/test/rustdoc/traits-in-bodies-private.rs
new file mode 100644
index 0000000000000..ac3be7e61e9a0
--- /dev/null
+++ b/src/test/rustdoc/traits-in-bodies-private.rs
@@ -0,0 +1,23 @@
+// 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.
+
+// when implementing the fix for traits-in-bodies, there was an ICE when documenting private items
+// and a trait was defined in non-module scope
+
+// compile-flags:--document-private-items
+
+// @has traits_in_bodies_private/struct.SomeStruct.html
+// @!has - '//code' 'impl HiddenTrait for SomeStruct'
+pub struct SomeStruct;
+
+fn __implementation_details() {
+    trait HiddenTrait {}
+    impl HiddenTrait for SomeStruct {}
+}
diff --git a/src/test/rustdoc/traits-in-bodies.rs b/src/test/rustdoc/traits-in-bodies.rs
index 3acf4af5fd247..a1d4019bba2bf 100644
--- a/src/test/rustdoc/traits-in-bodies.rs
+++ b/src/test/rustdoc/traits-in-bodies.rs
@@ -11,11 +11,10 @@
 //prior to fixing `everybody_loops` to preserve items, rustdoc would crash on this file, as it
 //didn't see that `SomeStruct` implemented `Clone`
 
-//FIXME(misdreavus): whenever rustdoc shows traits impl'd inside bodies, make sure this test
-//reflects that
-
 pub struct Bounded<T: Clone>(T);
 
+// @has traits_in_bodies/struct.SomeStruct.html
+// @has - '//code' 'impl Clone for SomeStruct'
 pub struct SomeStruct;
 
 fn asdf() -> Bounded<SomeStruct> {
@@ -27,3 +26,37 @@ fn asdf() -> Bounded<SomeStruct> {
 
     Bounded(SomeStruct)
 }
+
+// @has traits_in_bodies/struct.Point.html
+// @has - '//code' 'impl Copy for Point'
+#[derive(Clone)]
+pub struct Point {
+    x: i32,
+    y: i32,
+}
+
+const _FOO: () = {
+    impl Copy for Point {}
+    ()
+};
+
+// @has traits_in_bodies/struct.Inception.html
+// @has - '//code' 'impl Clone for Inception'
+pub struct Inception;
+
+static _BAR: usize = {
+    trait HiddenTrait {
+        fn hidden_fn(&self) {
+            for _ in 0..5 {
+                impl Clone for Inception {
+                    fn clone(&self) -> Self {
+                        // we need to go deeper
+                        Inception
+                    }
+                }
+            }
+        }
+    }
+
+    5
+};
diff --git a/src/test/ui/borrowck/borrowck-box-insensitivity.nll.stderr b/src/test/ui/borrowck/borrowck-box-insensitivity.nll.stderr
index 601f05b499c75..0e380e90e7591 100644
--- a/src/test/ui/borrowck/borrowck-box-insensitivity.nll.stderr
+++ b/src/test/ui/borrowck/borrowck-box-insensitivity.nll.stderr
@@ -1,25 +1,14 @@
-error[E0382]: use of moved value: `a.y`
-  --> $DIR/borrowck-box-insensitivity.rs:46:14
-   |
-LL |     let _x = a.x;
-   |              --- value moved here
-LL |     //~^ value moved here
-LL |     let _y = a.y; //~ ERROR use of moved
-   |              ^^^ value used here after move
-   |
-   = note: move occurs because `a.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
-
-error[E0382]: use of moved value: `a.y`
-  --> $DIR/borrowck-box-insensitivity.rs:108:14
-   |
-LL |     let _x = a.x.x;
-   |              ----- value moved here
-LL |     //~^ value moved here
-LL |     let _y = a.y; //~ ERROR use of collaterally moved
-   |              ^^^ value used here after move
-   |
-   = note: move occurs because `a.x.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
+error: compilation successful
+  --> $DIR/borrowck-box-insensitivity.rs:160:1
+   |
+LL | / fn main() {
+LL | |     copy_after_move();
+LL | |     move_after_move();
+LL | |     borrow_after_move();
+...  |
+LL | |     mut_borrow_after_borrow_nested();
+LL | | }
+   | |_^
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0382`.
diff --git a/src/test/ui/borrowck/borrowck-box-insensitivity.rs b/src/test/ui/borrowck/borrowck-box-insensitivity.rs
index 75bf6bce04b39..eabb8d7bca3fa 100644
--- a/src/test/ui/borrowck/borrowck-box-insensitivity.rs
+++ b/src/test/ui/borrowck/borrowck-box-insensitivity.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(box_syntax)]
+#![feature(box_syntax, rustc_attrs)]
 
 struct A {
     x: Box<isize>,
@@ -156,6 +156,7 @@ fn mut_borrow_after_borrow_nested() {
     //~^ mutable borrow occurs here
 }
 
+#[rustc_error]
 fn main() {
     copy_after_move();
     move_after_move();
diff --git a/src/test/ui/consts/const-eval/const_panic_libcore_main.rs b/src/test/ui/consts/const-eval/const_panic_libcore_main.rs
index f5e5f9778faed..0364123994dff 100644
--- a/src/test/ui/consts/const-eval/const_panic_libcore_main.rs
+++ b/src/test/ui/consts/const-eval/const_panic_libcore_main.rs
@@ -10,7 +10,6 @@
 
 #![crate_type = "bin"]
 #![feature(lang_items)]
-#![feature(panic_handler)]
 #![feature(const_panic)]
 #![no_main]
 #![no_std]
diff --git a/src/test/ui/consts/const-eval/const_panic_libcore_main.stderr b/src/test/ui/consts/const-eval/const_panic_libcore_main.stderr
index 7cb9f51c427a7..44b30c08cdea2 100644
--- a/src/test/ui/consts/const-eval/const_panic_libcore_main.stderr
+++ b/src/test/ui/consts/const-eval/const_panic_libcore_main.stderr
@@ -1,31 +1,31 @@
 error: this constant cannot be used
-  --> $DIR/const_panic_libcore_main.rs:20:1
+  --> $DIR/const_panic_libcore_main.rs:19:1
    |
 LL | const Z: () = panic!("cheese");
    | ^^^^^^^^^^^^^^----------------^
    |               |
-   |               the evaluated program panicked at 'cheese', $DIR/const_panic_libcore_main.rs:20:15
+   |               the evaluated program panicked at 'cheese', $DIR/const_panic_libcore_main.rs:19:15
    |
    = note: #[deny(const_err)] on by default
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 error: this constant cannot be used
-  --> $DIR/const_panic_libcore_main.rs:23:1
+  --> $DIR/const_panic_libcore_main.rs:22:1
    |
 LL | const Y: () = unreachable!();
    | ^^^^^^^^^^^^^^--------------^
    |               |
-   |               the evaluated program panicked at 'internal error: entered unreachable code', $DIR/const_panic_libcore_main.rs:23:15
+   |               the evaluated program panicked at 'internal error: entered unreachable code', $DIR/const_panic_libcore_main.rs:22:15
    |
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 error: this constant cannot be used
-  --> $DIR/const_panic_libcore_main.rs:26:1
+  --> $DIR/const_panic_libcore_main.rs:25:1
    |
 LL | const X: () = unimplemented!();
    | ^^^^^^^^^^^^^^----------------^
    |               |
-   |               the evaluated program panicked at 'not yet implemented', $DIR/const_panic_libcore_main.rs:26:15
+   |               the evaluated program panicked at 'not yet implemented', $DIR/const_panic_libcore_main.rs:25:15
    |
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
diff --git a/src/test/ui/feature-gates/feature-gate-panic-handler.stderr b/src/test/ui/feature-gates/feature-gate-panic-handler.stderr
deleted file mode 100644
index 9680a240a9925..0000000000000
--- a/src/test/ui/feature-gates/feature-gate-panic-handler.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error[E0658]: #[panic_handler] is an unstable feature (see issue #44489)
-  --> $DIR/feature-gate-panic-handler.rs:18:1
-   |
-LL | #[panic_handler] //~ ERROR #[panic_handler] is an unstable feature (see issue #44489)
-   | ^^^^^^^^^^^^^^^^
-   |
-   = help: add #![feature(panic_handler)] to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/panic-handler/auxiliary/some-panic-impl.rs b/src/test/ui/panic-handler/auxiliary/some-panic-impl.rs
index e3b4fba176e3c..090123198d175 100644
--- a/src/test/ui/panic-handler/auxiliary/some-panic-impl.rs
+++ b/src/test/ui/panic-handler/auxiliary/some-panic-impl.rs
@@ -11,7 +11,6 @@
 // no-prefer-dynamic
 
 #![crate_type = "rlib"]
-#![feature(panic_handler)]
 #![no_std]
 
 use core::panic::PanicInfo;
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-1.rs b/src/test/ui/panic-handler/panic-handler-bad-signature-1.rs
index cc7e337fc9e65..8d53c66adbd93 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-1.rs
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-1.rs
@@ -10,7 +10,6 @@
 
 // compile-flags:-C panic=abort
 
-#![feature(panic_handler)]
 #![no_std]
 #![no_main]
 
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-1.stderr b/src/test/ui/panic-handler/panic-handler-bad-signature-1.stderr
index 5771f4277b46d..72b85da028f1f 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-1.stderr
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-1.stderr
@@ -1,11 +1,11 @@
 error: return type should be `!`
-  --> $DIR/panic-handler-bad-signature-1.rs:22:6
+  --> $DIR/panic-handler-bad-signature-1.rs:21:6
    |
 LL | ) -> () //~ ERROR return type should be `!`
    |      ^^
 
 error: argument should be `&PanicInfo`
-  --> $DIR/panic-handler-bad-signature-1.rs:21:11
+  --> $DIR/panic-handler-bad-signature-1.rs:20:11
    |
 LL |     info: PanicInfo, //~ ERROR argument should be `&PanicInfo`
    |           ^^^^^^^^^
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-2.rs b/src/test/ui/panic-handler/panic-handler-bad-signature-2.rs
index ec698903c846e..0e8b3d5e855cb 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-2.rs
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-2.rs
@@ -10,7 +10,6 @@
 
 // compile-flags:-C panic=abort
 
-#![feature(panic_handler)]
 #![no_std]
 #![no_main]
 
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-2.stderr b/src/test/ui/panic-handler/panic-handler-bad-signature-2.stderr
index 4823f8a2781b0..f2bcb6b680952 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-2.stderr
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-2.stderr
@@ -1,5 +1,5 @@
 error: argument should be `&PanicInfo`
-  --> $DIR/panic-handler-bad-signature-2.rs:21:11
+  --> $DIR/panic-handler-bad-signature-2.rs:20:11
    |
 LL |     info: &'static PanicInfo, //~ ERROR argument should be `&PanicInfo`
    |           ^^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-3.rs b/src/test/ui/panic-handler/panic-handler-bad-signature-3.rs
index 585716c7c7569..ac1b19105b62e 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-3.rs
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-3.rs
@@ -10,7 +10,6 @@
 
 // compile-flags:-C panic=abort
 
-#![feature(panic_handler)]
 #![no_std]
 #![no_main]
 
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-3.stderr b/src/test/ui/panic-handler/panic-handler-bad-signature-3.stderr
index 5d0395e17f54d..77227e0d5a61c 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-3.stderr
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-3.stderr
@@ -1,5 +1,5 @@
 error: function should have one argument
-  --> $DIR/panic-handler-bad-signature-3.rs:20:1
+  --> $DIR/panic-handler-bad-signature-3.rs:19:1
    |
 LL | fn panic() -> ! { //~ ERROR function should have one argument
    | ^^^^^^^^^^^^^^^
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-4.rs b/src/test/ui/panic-handler/panic-handler-bad-signature-4.rs
index 9cda37f27b332..f4728408a1afa 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-4.rs
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-4.rs
@@ -10,7 +10,6 @@
 
 // compile-flags:-C panic=abort
 
-#![feature(panic_handler)]
 #![no_std]
 #![no_main]
 
diff --git a/src/test/ui/panic-handler/panic-handler-bad-signature-4.stderr b/src/test/ui/panic-handler/panic-handler-bad-signature-4.stderr
index a61b9b3743c7d..0dd47cafd7553 100644
--- a/src/test/ui/panic-handler/panic-handler-bad-signature-4.stderr
+++ b/src/test/ui/panic-handler/panic-handler-bad-signature-4.stderr
@@ -1,5 +1,5 @@
 error: should have no type parameters
-  --> $DIR/panic-handler-bad-signature-4.rs:20:1
+  --> $DIR/panic-handler-bad-signature-4.rs:19:1
    |
 LL | / fn panic<T>(pi: &PanicInfo) -> ! {
 LL | |     //~^ ERROR should have no type parameters
diff --git a/src/test/ui/panic-handler/panic-handler-duplicate.rs b/src/test/ui/panic-handler/panic-handler-duplicate.rs
index 7d7fe251869f1..c4fb4903e0031 100644
--- a/src/test/ui/panic-handler/panic-handler-duplicate.rs
+++ b/src/test/ui/panic-handler/panic-handler-duplicate.rs
@@ -11,7 +11,6 @@
 // compile-flags:-C panic=abort
 
 #![feature(lang_items)]
-#![feature(panic_handler)]
 #![no_std]
 #![no_main]
 
diff --git a/src/test/ui/panic-handler/panic-handler-duplicate.stderr b/src/test/ui/panic-handler/panic-handler-duplicate.stderr
index d8afaa27e2662..e243d9079d851 100644
--- a/src/test/ui/panic-handler/panic-handler-duplicate.stderr
+++ b/src/test/ui/panic-handler/panic-handler-duplicate.stderr
@@ -1,5 +1,5 @@
 error[E0152]: duplicate lang item found: `panic_impl`.
-  --> $DIR/panic-handler-duplicate.rs:26:1
+  --> $DIR/panic-handler-duplicate.rs:25:1
    |
 LL | / fn panic2(info: &PanicInfo) -> ! { //~ ERROR duplicate lang item found: `panic_impl`.
 LL | |     loop {}
@@ -7,7 +7,7 @@ LL | | }
    | |_^
    |
 note: first defined here.
-  --> $DIR/panic-handler-duplicate.rs:21:1
+  --> $DIR/panic-handler-duplicate.rs:20:1
    |
 LL | / fn panic(info: &PanicInfo) -> ! {
 LL | |     loop {}
diff --git a/src/test/ui/panic-handler/panic-handler-requires-panic-info.rs b/src/test/ui/panic-handler/panic-handler-requires-panic-info.rs
index ec68a414f54d5..133d6c0557ab6 100644
--- a/src/test/ui/panic-handler/panic-handler-requires-panic-info.rs
+++ b/src/test/ui/panic-handler/panic-handler-requires-panic-info.rs
@@ -13,7 +13,6 @@
 
 #![feature(lang_items)]
 #![feature(no_core)]
-#![feature(panic_handler)]
 #![no_core]
 #![no_main]
 
diff --git a/src/test/ui/panic-handler/panic-handler-std.rs b/src/test/ui/panic-handler/panic-handler-std.rs
index 7cbe0a35baed8..ff5995237cf21 100644
--- a/src/test/ui/panic-handler/panic-handler-std.rs
+++ b/src/test/ui/panic-handler/panic-handler-std.rs
@@ -10,7 +10,6 @@
 
 // error-pattern: duplicate lang item found: `panic_impl`.
 
-#![feature(panic_handler)]
 
 use std::panic::PanicInfo;
 
diff --git a/src/test/ui/panic-handler/panic-handler-std.stderr b/src/test/ui/panic-handler/panic-handler-std.stderr
index b141a2171646c..4ec1c6df35522 100644
--- a/src/test/ui/panic-handler/panic-handler-std.stderr
+++ b/src/test/ui/panic-handler/panic-handler-std.stderr
@@ -1,5 +1,5 @@
 error[E0152]: duplicate lang item found: `panic_impl`.
-  --> $DIR/panic-handler-std.rs:18:1
+  --> $DIR/panic-handler-std.rs:17:1
    |
 LL | / fn panic(info: PanicInfo) -> ! {
 LL | |     loop {}
@@ -9,7 +9,7 @@ LL | | }
    = note: first defined in crate `std`.
 
 error: argument should be `&PanicInfo`
-  --> $DIR/panic-handler-std.rs:18:16
+  --> $DIR/panic-handler-std.rs:17:16
    |
 LL | fn panic(info: PanicInfo) -> ! {
    |                ^^^^^^^^^
diff --git a/src/test/ui/panic_implementation-closures.rs b/src/test/ui/panic_implementation-closures.rs
index 6642db6ee76bf..5902a1ae1b023 100644
--- a/src/test/ui/panic_implementation-closures.rs
+++ b/src/test/ui/panic_implementation-closures.rs
@@ -12,7 +12,6 @@
 
 #![crate_type = "rlib"]
 #![no_std]
-#![feature(panic_handler)]
 
 #[panic_handler]
 pub fn panic_fmt(_: &::core::panic::PanicInfo) -> ! {
diff --git a/src/test/ui/removing-extern-crate.rs b/src/test/ui/removing-extern-crate.rs
index 3905d285becb5..9762db38a1ca6 100644
--- a/src/test/ui/removing-extern-crate.rs
+++ b/src/test/ui/removing-extern-crate.rs
@@ -16,12 +16,12 @@
 #![warn(rust_2018_idioms)]
 #![allow(unused_imports)]
 
-extern crate std as foo;
+extern crate removing_extern_crate as foo;
 extern crate core;
 
 mod another {
-    extern crate std as foo;
-    extern crate std;
+    extern crate removing_extern_crate as foo;
+    extern crate core;
 }
 
 fn main() {}
diff --git a/src/test/ui/removing-extern-crate.stderr b/src/test/ui/removing-extern-crate.stderr
index f2eed27a26693..758ec67d17823 100644
--- a/src/test/ui/removing-extern-crate.stderr
+++ b/src/test/ui/removing-extern-crate.stderr
@@ -1,8 +1,8 @@
 warning: unused extern crate
   --> $DIR/removing-extern-crate.rs:19:1
    |
-LL | extern crate std as foo;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
+LL | extern crate removing_extern_crate as foo;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
    |
 note: lint level defined here
   --> $DIR/removing-extern-crate.rs:16:9
@@ -20,12 +20,12 @@ LL | extern crate core;
 warning: unused extern crate
   --> $DIR/removing-extern-crate.rs:23:5
    |
-LL |     extern crate std as foo;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
+LL |     extern crate removing_extern_crate as foo;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
 
 warning: unused extern crate
   --> $DIR/removing-extern-crate.rs:24:5
    |
-LL |     extern crate std;
-   |     ^^^^^^^^^^^^^^^^^ help: remove it
+LL |     extern crate core;
+   |     ^^^^^^^^^^^^^^^^^^ help: remove it