Auto merge of #40806 - frewsxcv:rollup, r=frewsxcv

Rollup of 8 pull requests

- Successful merges: #40567, #40602, #40636, #40739, #40756, #40790, #40794, #40803
- Failed merges:

Author: bors

CONTRIBUTING.md

@@ -311,9 +311,13 @@ To save @bors some work, and to get small changes through more quickly, when
 the other rollup-eligible patches too, and they'll get tested and merged at
 the same time.
 
-To find documentation-related issues, sort by the [A-docs label][adocs].
+To find documentation-related issues, sort by the [T-doc label][tdoc].
 
-[adocs]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AA-docs
+[tdoc]: https://github.com/rust-lang/rust/issues?q=is%3Aopen%20is%3Aissue%20label%3AT-doc
+
+You can find documentation style guidelines in [RFC 1574][rfc1574].
+
+[rfc1574]: https://github.com/rust-lang/rfcs/blob/master/text/1574-more-api-documentation-conventions.md#appendix-a-full-conventions-text
 
 In many cases, you don't need a full `./x.py doc`. You can use `rustdoc` directly
 to check small fixes. For example, `rustdoc src/doc/reference.md` will render

src/libcollections/btree/map.rs

@@ -141,8 +141,7 @@ pub struct BTreeMap<K, V> {
 unsafe impl<#[may_dangle] K, #[may_dangle] V> Drop for BTreeMap<K, V> {
     fn drop(&mut self) {
         unsafe {
-            for _ in ptr::read(self).into_iter() {
-            }
+            drop(ptr::read(self).into_iter());
         }
     }
 }

src/libcollections/slice.rs

@@ -1162,7 +1162,7 @@ impl<T> [T] {
     ///
     /// # Current implementation
     ///
-    /// The current algorithm is based on Orson Peters' [pdqsort][pattern-defeating quicksort],
+    /// The current algorithm is based on Orson Peters' [pattern-defeating quicksort][pdqsort],
     /// which is a quicksort variant designed to be very fast on certain kinds of patterns,
     /// sometimes achieving linear time. It is randomized but deterministic, and falls back to
     /// heapsort on degenerate inputs.
@@ -1199,7 +1199,7 @@ impl<T> [T] {
     ///
     /// # Current implementation
     ///
-    /// The current algorithm is based on Orson Peters' [pdqsort][pattern-defeating quicksort],
+    /// The current algorithm is based on Orson Peters' [pattern-defeating quicksort][pdqsort],
     /// which is a quicksort variant designed to be very fast on certain kinds of patterns,
     /// sometimes achieving linear time. It is randomized but deterministic, and falls back to
     /// heapsort on degenerate inputs.
@@ -1239,7 +1239,7 @@ impl<T> [T] {
     ///
     /// # Current implementation
     ///
-    /// The current algorithm is based on Orson Peters' [pdqsort][pattern-defeating quicksort],
+    /// The current algorithm is based on Orson Peters' [pattern-defeating quicksort][pdqsort],
     /// which is a quicksort variant designed to be very fast on certain kinds of patterns,
     /// sometimes achieving linear time. It is randomized but deterministic, and falls back to
     /// heapsort on degenerate inputs.

src/librustc/mir/mod.rs

@@ -983,16 +983,16 @@ impl<'tcx> Debug for Operand<'tcx> {
 }
 
 impl<'tcx> Operand<'tcx> {
-    pub fn item<'a>(tcx: ty::TyCtxt<'a, 'tcx, 'tcx>,
-                    def_id: DefId,
-                    substs: &'tcx Substs<'tcx>,
-                    span: Span)
-                    -> Self
-    {
+    pub fn function_handle<'a>(
+        tcx: ty::TyCtxt<'a, 'tcx, 'tcx>,
+        def_id: DefId,
+        substs: &'tcx Substs<'tcx>,
+        span: Span,
+    ) -> Self {
         Operand::Constant(Constant {
             span: span,
             ty: tcx.item_type(def_id).subst(tcx, substs),
-            literal: Literal::Item { def_id, substs }
+            literal: Literal::Value { value: ConstVal::Function(def_id, substs) },
         })
     }
 

src/librustc_mir/build/scope.rs

@@ -89,6 +89,7 @@ should go to.
 use build::{BlockAnd, BlockAndExtension, Builder, CFG};
 use rustc::middle::region::{CodeExtent, CodeExtentData};
 use rustc::middle::lang_items;
+use rustc::middle::const_val::ConstVal;
 use rustc::ty::subst::{Kind, Subst};
 use rustc::ty::{Ty, TyCtxt};
 use rustc::mir::*;
@@ -784,9 +785,8 @@ fn build_free<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
         func: Operand::Constant(Constant {
             span: data.span,
             ty: tcx.item_type(free_func).subst(tcx, substs),
-            literal: Literal::Item {
-                def_id: free_func,
-                substs: substs
+            literal: Literal::Value {
+                value: ConstVal::Function(free_func, substs),
             }
         }),
         args: vec![Operand::Consume(data.value.clone())],

src/librustc_mir/hair/cx/expr.rs

@@ -714,9 +714,8 @@ fn method_callee<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
         ty: callee.ty,
         span: expr.span,
         kind: ExprKind::Literal {
-            literal: Literal::Item {
-                def_id: callee.def_id,
-                substs: callee.substs,
+            literal: Literal::Value {
+                value: ConstVal::Function(callee.def_id, callee.substs),
             },
         },
     }
@@ -743,22 +742,32 @@ fn convert_path_expr<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                      -> ExprKind<'tcx> {
     let substs = cx.tables().node_id_item_substs(expr.id)
         .unwrap_or_else(|| cx.tcx.intern_substs(&[]));
-    let def_id = match def {
+    match def {
         // A regular function, constructor function or a constant.
         Def::Fn(def_id) |
         Def::Method(def_id) |
         Def::StructCtor(def_id, CtorKind::Fn) |
-        Def::VariantCtor(def_id, CtorKind::Fn) |
+        Def::VariantCtor(def_id, CtorKind::Fn) => ExprKind::Literal {
+            literal: Literal::Value {
+                value: ConstVal::Function(def_id, substs),
+            },
+        },
+
         Def::Const(def_id) |
-        Def::AssociatedConst(def_id) => def_id,
+        Def::AssociatedConst(def_id) => ExprKind::Literal {
+            literal: Literal::Item {
+                def_id: def_id,
+                substs: substs,
+            },
+        },
 
         Def::StructCtor(def_id, CtorKind::Const) |
         Def::VariantCtor(def_id, CtorKind::Const) => {
             match cx.tables().node_id_to_type(expr.id).sty {
                 // A unit struct/variant which is used as a value.
                 // We return a completely different ExprKind here to account for this special case.
                 ty::TyAdt(adt_def, substs) => {
-                    return ExprKind::Adt {
+                    ExprKind::Adt {
                         adt_def: adt_def,
                         variant_index: adt_def.variant_index_with_id(def_id),
                         substs: substs,
@@ -770,17 +779,11 @@ fn convert_path_expr<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
             }
         }
 
-        Def::Static(node_id, _) => return ExprKind::StaticRef { id: node_id },
+        Def::Static(node_id, _) => ExprKind::StaticRef { id: node_id },
 
-        Def::Local(..) | Def::Upvar(..) => return convert_var(cx, expr, def),
+        Def::Local(..) | Def::Upvar(..) => convert_var(cx, expr, def),
 
         _ => span_bug!(expr.span, "def `{:?}` not yet implemented", def),
-    };
-    ExprKind::Literal {
-        literal: Literal::Item {
-            def_id: def_id,
-            substs: substs,
-        },
     }
 }
 

src/librustc_mir/hair/cx/mod.rs

@@ -132,9 +132,8 @@ impl<'a, 'gcx, 'tcx> Cx<'a, 'gcx, 'tcx> {
                 let method_ty = self.tcx.item_type(item.def_id);
                 let method_ty = method_ty.subst(self.tcx, substs);
                 return (method_ty,
-                        Literal::Item {
-                            def_id: item.def_id,
-                            substs: substs,
+                        Literal::Value {
+                            value: ConstVal::Function(item.def_id, substs),
                         });
             }
         }

src/librustc_mir/shim.rs

@@ -12,6 +12,7 @@ use rustc::hir;
 use rustc::hir::def_id::DefId;
 use rustc::infer;
 use rustc::middle::region::ROOT_CODE_EXTENT;
+use rustc::middle::const_val::ConstVal;
 use rustc::mir::*;
 use rustc::mir::transform::MirSource;
 use rustc::ty::{self, Ty};
@@ -335,7 +336,9 @@ fn build_call_shim<'a, 'tcx>(tcx: ty::TyCtxt<'a, 'tcx, 'tcx>,
             Operand::Constant(Constant {
                 span: span,
                 ty: tcx.item_type(def_id).subst(tcx, param_env.free_substs),
-                literal: Literal::Item { def_id, substs: param_env.free_substs },
+                literal: Literal::Value {
+                    value: ConstVal::Function(def_id, param_env.free_substs),
+                },
             }),
             vec![rcvr]
         )

src/librustc_mir/transform/qualify_consts.rs

@@ -568,11 +568,6 @@ impl<'a, 'tcx> Visitor<'tcx> for Qualifier<'a, 'tcx, 'tcx> {
                 });
             }
             Operand::Constant(ref constant) => {
-                // Only functions and methods can have these types.
-                if let ty::TyFnDef(..) = constant.ty.sty {
-                    return;
-                }
-
                 if let Literal::Item { def_id, substs } = constant.literal {
                     // Don't peek inside generic (associated) constants.
                     if substs.types().next().is_some() {

src/librustc_mir/transform/type_check.rs

@@ -15,6 +15,7 @@ use rustc::infer::{self, InferCtxt, InferOk};
 use rustc::traits::{self, Reveal};
 use rustc::ty::fold::TypeFoldable;
 use rustc::ty::{self, Ty, TyCtxt, TypeVariants};
+use rustc::middle::const_val::ConstVal;
 use rustc::mir::*;
 use rustc::mir::tcx::LvalueTy;
 use rustc::mir::transform::{MirPass, MirSource, Pass};
@@ -526,7 +527,9 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
     fn is_box_free(&self, operand: &Operand<'tcx>) -> bool {
         match operand {
             &Operand::Constant(Constant {
-                literal: Literal::Item { def_id, .. }, ..
+                literal: Literal::Value {
+                    value: ConstVal::Function(def_id, _), ..
+                }, ..
             }) => {
                 Some(def_id) == self.tcx().lang_items.box_free_fn()
             }