Rollup of 6 pull requests

src/etc/lldb_rust_formatters.py

@@ -290,6 +290,8 @@ def render_element(i):
 
 
 def read_utf8_string(ptr_val, byte_count):
+    if byte_count == 0:
+        return '""'
     error = lldb.SBError()
     process = ptr_val.get_wrapped_value().GetProcess()
     data = process.ReadMemory(ptr_val.as_integer(), byte_count, error)

src/libcore/benches/iter.rs

@@ -185,13 +185,13 @@ bench_sums! {
 bench_sums! {
     bench_filter_sum,
     bench_filter_ref_sum,
-    (0i64..1000000).filter(|x| x % 2 == 0)
+    (0i64..1000000).filter(|x| x % 3 == 0)
 }
 
 bench_sums! {
     bench_filter_chain_sum,
     bench_filter_chain_ref_sum,
-    (0i64..1000000).chain(0..1000000).filter(|x| x % 2 == 0)
+    (0i64..1000000).chain(0..1000000).filter(|x| x % 3 == 0)
 }
 
 bench_sums! {
@@ -306,3 +306,31 @@ fn bench_skip_then_zip(b: &mut Bencher) {
         assert_eq!(s, 2009900);
     });
 }
+
+#[bench]
+fn bench_filter_count(b: &mut Bencher) {
+    b.iter(|| {
+        (0i64..1000000).map(black_box).filter(|x| x % 3 == 0).count()
+    })
+}
+
+#[bench]
+fn bench_filter_ref_count(b: &mut Bencher) {
+    b.iter(|| {
+        (0i64..1000000).map(black_box).by_ref().filter(|x| x % 3 == 0).count()
+    })
+}
+
+#[bench]
+fn bench_filter_chain_count(b: &mut Bencher) {
+    b.iter(|| {
+        (0i64..1000000).chain(0..1000000).map(black_box).filter(|x| x % 3 == 0).count()
+    })
+}
+
+#[bench]
+fn bench_filter_chain_ref_count(b: &mut Bencher) {
+    b.iter(|| {
+        (0i64..1000000).chain(0..1000000).map(black_box).by_ref().filter(|x| x % 3 == 0).count()
+    })
+}

src/libcore/iter/adapters/mod.rs

@@ -681,12 +681,7 @@ impl<I: Iterator, P> Iterator for Filter<I, P> where P: FnMut(&I::Item) -> bool
 
     #[inline]
     fn next(&mut self) -> Option<I::Item> {
-        for x in &mut self.iter {
-            if (self.predicate)(&x) {
-                return Some(x);
-            }
-        }
-        None
+        self.try_for_each(Err).err()
     }
 
     #[inline]
@@ -707,12 +702,9 @@ impl<I: Iterator, P> Iterator for Filter<I, P> where P: FnMut(&I::Item) -> bool
     // Using the branchless version will also simplify the LLVM byte code, thus
     // leaving more budget for LLVM optimizations.
     #[inline]
-    fn count(mut self) -> usize {
-        let mut count = 0;
-        for x in &mut self.iter {
-            count += (self.predicate)(&x) as usize;
-        }
-        count
+    fn count(self) -> usize {
+        let mut predicate = self.predicate;
+        self.iter.map(|x| predicate(&x) as usize).sum()
     }
 
     #[inline]
@@ -746,12 +738,7 @@ impl<I: DoubleEndedIterator, P> DoubleEndedIterator for Filter<I, P>
 {
     #[inline]
     fn next_back(&mut self) -> Option<I::Item> {
-        for x in self.iter.by_ref().rev() {
-            if (self.predicate)(&x) {
-                return Some(x);
-            }
-        }
-        None
+        self.try_rfold((), |_, x| Err(x)).err()
     }
 
     #[inline]
@@ -820,12 +807,7 @@ impl<B, I: Iterator, F> Iterator for FilterMap<I, F>
 
     #[inline]
     fn next(&mut self) -> Option<B> {
-        for x in self.iter.by_ref() {
-            if let Some(y) = (self.f)(x) {
-                return Some(y);
-            }
-        }
-        None
+        self.try_for_each(Err).err()
     }
 
     #[inline]
@@ -863,12 +845,7 @@ impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for FilterMap<I, F>
 {
     #[inline]
     fn next_back(&mut self) -> Option<B> {
-        for x in self.iter.by_ref().rev() {
-            if let Some(y) = (self.f)(x) {
-                return Some(y);
-            }
-        }
-        None
+        self.try_rfold((), |_, x| Err(x)).err()
     }
 
     #[inline]

src/libcore/str/mod.rs

@@ -3965,7 +3965,7 @@ impl str {
         me.make_ascii_lowercase()
     }
 
-    /// Return an iterator that escapes each char in `s` with [`char::escape_debug`].
+    /// Return an iterator that escapes each char in `self` with [`char::escape_debug`].
     ///
     /// Note: only extended grapheme codepoints that begin the string will be
     /// escaped.
@@ -4013,7 +4013,7 @@ impl str {
         }
     }
 
-    /// Return an iterator that escapes each char in `s` with [`char::escape_default`].
+    /// Return an iterator that escapes each char in `self` with [`char::escape_default`].
     ///
     /// [`char::escape_default`]: ../std/primitive.char.html#method.escape_default
     ///
@@ -4051,7 +4051,7 @@ impl str {
         EscapeDefault { inner: self.chars().flat_map(CharEscapeDefault) }
     }
 
-    /// Return an iterator that escapes each char in `s` with [`char::escape_unicode`].
+    /// Return an iterator that escapes each char in `self` with [`char::escape_unicode`].
     ///
     /// [`char::escape_unicode`]: ../std/primitive.char.html#method.escape_unicode
     ///

src/librustc/ich/impls_mir.rs

@@ -209,13 +209,13 @@ impl<'a, 'gcx> HashStable<StableHashingContext<'a>> for mir::Place<'gcx> {
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
-            mir::Place::Local(ref local) => {
+            mir::Place::Base(mir::PlaceBase::Local(ref local)) => {
                 local.hash_stable(hcx, hasher);
             }
-            mir::Place::Static(ref statik) => {
+            mir::Place::Base(mir::PlaceBase::Static(ref statik)) => {
                 statik.hash_stable(hcx, hasher);
             }
-            mir::Place::Promoted(ref promoted) => {
+            mir::Place::Base(mir::PlaceBase::Promoted(ref promoted)) => {
                 promoted.hash_stable(hcx, hasher);
             }
             mir::Place::Projection(ref place_projection) => {

src/librustc/lint/mod.rs

@@ -132,14 +132,22 @@ macro_rules! declare_lint {
 
 #[macro_export]
 macro_rules! declare_tool_lint {
-    ($vis: vis $tool: ident ::$NAME: ident, $Level: ident, $desc: expr) => (
-        declare_tool_lint!{$vis $tool::$NAME, $Level, $desc, false}
+    (
+        $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level: ident, $desc: expr
+    ) => (
+        declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false}
     );
-    ($vis: vis $tool: ident ::$NAME: ident, $Level: ident, $desc: expr,
-     report_in_external_macro: $rep: expr) => (
-         declare_tool_lint!{$vis $tool::$NAME, $Level, $desc, $rep}
+    (
+        $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
+        report_in_external_macro: $rep:expr
+    ) => (
+         declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep}
     );
-    ($vis: vis $tool: ident ::$NAME: ident, $Level: ident, $desc: expr, $external: expr) => (
+    (
+        $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
+        $external:expr
+    ) => (
+        $(#[$attr])*
         $vis static $NAME: &$crate::lint::Lint = &$crate::lint::Lint {
             name: &concat!(stringify!($tool), "::", stringify!($NAME)),
             default_level: $crate::lint::$Level,

src/librustc/mir/mod.rs

@@ -1896,6 +1896,14 @@ impl<'tcx> Debug for Statement<'tcx> {
 /// changing or disturbing program state.
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
 pub enum Place<'tcx> {
+    Base(PlaceBase<'tcx>),
+
+    /// projection out of a place (access a field, deref a pointer, etc)
+    Projection(Box<PlaceProjection<'tcx>>),
+}
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
+pub enum PlaceBase<'tcx> {
     /// local variable
     Local(Local),
 
@@ -1904,9 +1912,6 @@ pub enum Place<'tcx> {
 
     /// Constant code promoted to an injected static
     Promoted(Box<(Promoted, Ty<'tcx>)>),
-
-    /// projection out of a place (access a field, deref a pointer, etc)
-    Projection(Box<PlaceProjection<'tcx>>),
 }
 
 /// The `DefId` of a static, along with its normalized type (which is
@@ -1994,6 +1999,8 @@ newtype_index! {
 }
 
 impl<'tcx> Place<'tcx> {
+    pub const RETURN_PLACE: Place<'tcx> = Place::Base(PlaceBase::Local(RETURN_PLACE));
+
     pub fn field(self, f: Field, ty: Ty<'tcx>) -> Place<'tcx> {
         self.elem(ProjectionElem::Field(f, ty))
     }
@@ -2020,9 +2027,9 @@ impl<'tcx> Place<'tcx> {
     // FIXME: can we safely swap the semantics of `fn base_local` below in here instead?
     pub fn local(&self) -> Option<Local> {
         match self {
-            Place::Local(local) |
+            Place::Base(PlaceBase::Local(local)) |
             Place::Projection(box Projection {
-                base: Place::Local(local),
+                base: Place::Base(PlaceBase::Local(local)),
                 elem: ProjectionElem::Deref,
             }) => Some(*local),
             _ => None,
@@ -2032,9 +2039,9 @@ impl<'tcx> Place<'tcx> {
     /// Finds the innermost `Local` from this `Place`.
     pub fn base_local(&self) -> Option<Local> {
         match self {
-            Place::Local(local) => Some(*local),
+            Place::Base(PlaceBase::Local(local)) => Some(*local),
             Place::Projection(box Projection { base, elem: _ }) => base.base_local(),
-            Place::Promoted(..) | Place::Static(..) => None,
+            Place::Base(PlaceBase::Promoted(..)) | Place::Base(PlaceBase::Static(..)) => None,
         }
     }
 }
@@ -2044,14 +2051,19 @@ impl<'tcx> Debug for Place<'tcx> {
         use self::Place::*;
 
         match *self {
-            Local(id) => write!(fmt, "{:?}", id),
-            Static(box self::Static { def_id, ty }) => write!(
+            Base(PlaceBase::Local(id)) => write!(fmt, "{:?}", id),
+            Base(PlaceBase::Static(box self::Static { def_id, ty })) => write!(
                 fmt,
                 "({}: {:?})",
                 ty::tls::with(|tcx| tcx.item_path_str(def_id)),
                 ty
             ),
-            Promoted(ref promoted) => write!(fmt, "({:?}: {:?})", promoted.0, promoted.1),
+            Base(PlaceBase::Promoted(ref promoted)) => write!(
+                fmt,
+                "({:?}: {:?})",
+                promoted.0,
+                promoted.1
+            ),
             Projection(ref data) => match data.elem {
                 ProjectionElem::Downcast(ref adt_def, index) => {
                     write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].ident)

src/librustc/mir/tcx.rs

@@ -158,10 +158,10 @@ impl<'tcx> Place<'tcx> {
         where D: HasLocalDecls<'tcx>
     {
         match *self {
-            Place::Local(index) =>
+            Place::Base(PlaceBase::Local(index)) =>
                 PlaceTy::Ty { ty: local_decls.local_decls()[index].ty },
-            Place::Promoted(ref data) => PlaceTy::Ty { ty: data.1 },
-            Place::Static(ref data) =>
+            Place::Base(PlaceBase::Promoted(ref data)) => PlaceTy::Ty { ty: data.1 },
+            Place::Base(PlaceBase::Static(ref data)) =>
                 PlaceTy::Ty { ty: data.ty },
             Place::Projection(ref proj) =>
                 proj.base.ty(local_decls, tcx).projection_ty(tcx, &proj.elem),

src/librustc/mir/visit.rs

@@ -733,13 +733,13 @@ macro_rules! make_mir_visitor {
                             context: PlaceContext<'tcx>,
                             location: Location) {
                 match place {
-                    Place::Local(local) => {
+                    Place::Base(PlaceBase::Local(local)) => {
                         self.visit_local(local, context, location);
                     }
-                    Place::Static(static_) => {
+                    Place::Base(PlaceBase::Static(static_)) => {
                         self.visit_static(static_, context, location);
                     }
-                    Place::Promoted(promoted) => {
+                    Place::Base(PlaceBase::Promoted(promoted)) => {
                         self.visit_ty(& $($mutability)? promoted.1, TyContext::Location(location));
                     },
                     Place::Projection(proj) => {

src/librustc_codegen_llvm/back/write.rs

@@ -13,10 +13,8 @@ use crate::common;
 use crate::LlvmCodegenBackend;
 use rustc_codegen_ssa::back::write::{CodegenContext, ModuleConfig, run_assembler};
 use rustc_codegen_ssa::traits::*;
-use rustc::hir::def_id::LOCAL_CRATE;
 use rustc::session::config::{self, OutputType, Passes, Lto};
 use rustc::session::Session;
-use rustc::ty::TyCtxt;
 use rustc_codegen_ssa::{ModuleCodegen, CompiledModule};
 use rustc::util::common::time_ext;
 use rustc_fs_util::{path_to_c_string, link_or_copy};
@@ -82,14 +80,6 @@ pub fn write_output_file(
     }
 }
 
-pub fn create_target_machine(
-    tcx: TyCtxt<'_, '_, '_>,
-    find_features: bool,
-) -> &'static mut llvm::TargetMachine {
-    target_machine_factory(tcx.sess, tcx.backend_optimization_level(LOCAL_CRATE), find_features)()
-        .unwrap_or_else(|err| llvm_err(tcx.sess.diagnostic(), &err).raise() )
-}
-
 pub fn create_informational_target_machine(
     sess: &Session,
     find_features: bool,

src/librustc_codegen_llvm/context.rs

@@ -154,7 +154,7 @@ pub unsafe fn create_module(
 
     // Ensure the data-layout values hardcoded remain the defaults.
     if sess.target.target.options.is_builtin {
-        let tm = crate::back::write::create_target_machine(tcx, false);
+        let tm = crate::back::write::create_informational_target_machine(&tcx.sess, false);
         llvm::LLVMRustSetDataLayoutFromTargetMachine(llmod, tm);
         llvm::LLVMRustDisposeTargetMachine(tm);
 

src/librustc_codegen_llvm/lib.rs

@@ -24,7 +24,7 @@
 #![deny(rust_2018_idioms)]
 #![allow(explicit_outlives_requirements)]
 
-use back::write::create_target_machine;
+use back::write::create_informational_target_machine;
 use syntax_pos::symbol::Symbol;
 
 extern crate flate2;
@@ -114,8 +114,9 @@ pub struct LlvmCodegenBackend(());
 
 impl ExtraBackendMethods for LlvmCodegenBackend {
     fn new_metadata(&self, tcx: TyCtxt<'_, '_, '_>, mod_name: &str) -> ModuleLlvm {
-        ModuleLlvm::new(tcx, mod_name)
+        ModuleLlvm::new_metadata(tcx, mod_name)
     }
+
     fn write_metadata<'b, 'gcx>(
         &self,
         tcx: TyCtxt<'b, 'gcx, 'gcx>,
@@ -366,15 +367,14 @@ unsafe impl Send for ModuleLlvm { }
 unsafe impl Sync for ModuleLlvm { }
 
 impl ModuleLlvm {
-    fn new(tcx: TyCtxt<'_, '_, '_>, mod_name: &str) -> Self {
+    fn new_metadata(tcx: TyCtxt<'_, '_, '_>, mod_name: &str) -> Self {
         unsafe {
             let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
             let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
-
             ModuleLlvm {
                 llmod_raw,
                 llcx,
-                tm: create_target_machine(tcx, false),
+                tm: create_informational_target_machine(&tcx.sess, false),
             }
         }
     }