Auto merge of #59433 - Centril:rollup, r=Centril

Rollup of 10 pull requests

Successful merges:

 - #59150 (Expand suggestions for type ascription parse errors)
 - #59232 (Merge `Promoted` and `Static` in `mir::Place`)
 - #59267 (Provide suggestion when using field access instead of path)
 - #59315 (Add no_hash to query macro and move some queries over)
 - #59334 (Update build instructions in README.md)
 - #59362 (Demo `FromIterator` short-circuiting)
 - #59374 (Simplify checked_duration_since)
 - #59389 (replace redundant note in deprecation warning)
 - #59410 (Clarify `{Ord,f32,f64}::clamp` docs a little)
 - #59419 (Utilize `?` instead of `return None`.)

Failed merges:

r? @ghost

Author: bors

Diff for: Cargo.lock

@@ -2811,6 +2811,7 @@ dependencies = [
 name = "rustc_macros"
 version = "0.1.0"
 dependencies = [
+ "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",

Diff for: README.md

@@ -45,6 +45,22 @@ of the rustc-guide instead._
     $ ./x.py build && sudo ./x.py install
     ```
 
+    If after running `sudo ./x.py install` you see an error message like
+
+    ```
+    error: failed to load source for a dependency on 'cc'
+    ```
+
+    then run these two commands and then try `sudo ./x.py install` again:
+
+    ```
+    $ cargo install cargo-vendor
+    ```
+
+    ```
+    $ cargo vendor
+    ```
+
     > ***Note:*** Install locations can be adjusted by copying the config file
     > from `./config.toml.example` to `./config.toml`, and
     > adjusting the `prefix` option under `[install]`. Various other options, such

Diff for: src/libcore/cmp.rs

@@ -568,8 +568,14 @@ pub trait Ord: Eq + PartialOrd<Self> {
         if self <= other { self } else { other }
     }
 
-    /// Returns max if self is greater than max, and min if self is less than min.
-    /// Otherwise this will return self.  Panics if min > max.
+    /// Restrict a value to a certain interval.
+    ///
+    /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
+    /// less than `min`. Otherwise this returns `self`.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `min > max`.
     ///
     /// # Examples
     ///
@@ -586,8 +592,7 @@ pub trait Ord: Eq + PartialOrd<Self> {
         assert!(min <= max);
         if self < min {
             min
-        }
-        else if self > max {
+        } else if self > max {
             max
         } else {
             self

Diff for: src/libcore/num/flt2dec/mod.rs

@@ -239,10 +239,8 @@ impl<'a> Formatted<'a> {
 
         let mut written = self.sign.len();
         for part in self.parts {
-            match part.write(&mut out[written..]) {
-                Some(len) => { written += len; }
-                None => { return None; }
-            }
+            let len = part.write(&mut out[written..])?;
+            written += len;
         }
         Some(written)
     }

Diff for: src/libcore/option.rs

@@ -1315,6 +1315,26 @@ impl<A, V: FromIterator<A>> FromIterator<Option<A>> for Option<V> {
     /// Since the last element is zero, it would underflow. Thus, the resulting
     /// value is `None`.
     ///
+    /// Here is a variation on the previous example, showing that no
+    /// further elements are taken from `iter` after the first `None`.
+    ///
+    /// ```
+    /// let items = vec![3_u16, 2, 1, 10];
+    ///
+    /// let mut shared = 0;
+    ///
+    /// let res: Option<Vec<u16>> = items
+    ///     .iter()
+    ///     .map(|x| { shared += x; x.checked_sub(2) })
+    ///     .collect();
+    ///
+    /// assert_eq!(res, None);
+    /// assert_eq!(shared, 6);
+    /// ```
+    ///
+    /// Since the third element caused an underflow, no further elements were taken,
+    /// so the final value of `shared` is 6 (= `3 + 2 + 1`), not 16.
+    ///
     /// [`Iterator`]: ../iter/trait.Iterator.html
     #[inline]
     fn from_iter<I: IntoIterator<Item=Option<A>>>(iter: I) -> Option<V> {

Diff for: src/libcore/result.rs

@@ -1202,6 +1202,34 @@ impl<A, E, V: FromIterator<A>> FromIterator<Result<A, E>> for Result<V, E> {
     /// ).collect();
     /// assert_eq!(res, Ok(vec![2, 3]));
     /// ```
+    ///
+    /// Here is another example that tries to subtract one from another list
+    /// of integers, this time checking for underflow:
+    ///
+    /// ```
+    /// let v = vec![1, 2, 0];
+    /// let res: Result<Vec<u32>, &'static str> = v.iter().map(|x: &u32|
+    ///     x.checked_sub(1).ok_or("Underflow!")
+    /// ).collect();
+    /// assert_eq!(res, Err("Underflow!"));
+    /// ```
+    ///
+    /// Here is a variation on the previous example, showing that no
+    /// further elements are taken from `iter` after the first `Err`.
+    ///
+    /// ```
+    /// let v = vec![3, 2, 1, 10];
+    /// let mut shared = 0;
+    /// let res: Result<Vec<u32>, &'static str> = v.iter().map(|x: &u32| {
+    ///     shared += x;
+    ///     x.checked_sub(2).ok_or("Underflow!")
+    /// }).collect();
+    /// assert_eq!(res, Err("Underflow!"));
+    /// assert_eq!(shared, 6);
+    /// ```
+    ///
+    /// Since the third element caused an underflow, no further elements were taken,
+    /// so the final value of `shared` is 6 (= `3 + 2 + 1`), not 16.
     #[inline]
     fn from_iter<I: IntoIterator<Item=Result<A, E>>>(iter: I) -> Result<V, E> {
         // FIXME(#11084): This could be replaced with Iterator::scan when this

Diff for: src/librustc/dep_graph/dep_node.rs

@@ -461,11 +461,6 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
 
     // Represents the MIR for a fn; also used as the task node for
     // things read/modify that MIR.
-    [] MirConstQualif(DefId),
-    [] MirBuilt(DefId),
-    [] MirConst(DefId),
-    [] MirValidated(DefId),
-    [] MirOptimized(DefId),
     [] MirShim { instance_def: InstanceDef<'tcx> },
 
     [] BorrowCheckKrate,
@@ -485,7 +480,6 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
     [] CollectModItemTypes(DefId),
 
     [] Reachability,
-    [] MirKeys,
     [eval_always] CrateVariances,
 
     // Nodes representing bits of computed IR in the tcx. Each shared
@@ -544,7 +538,6 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
     [anon] TraitSelect,
 
     [] ParamEnv(DefId),
-    [] Environment(DefId),
     [] DescribeDef(DefId),
 
     // FIXME(mw): DefSpans are not really inputs since they are derived from
@@ -571,7 +564,6 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
     [] HasGlobalAllocator(CrateNum),
     [] HasPanicHandler(CrateNum),
     [input] ExternCrate(DefId),
-    [eval_always] LintLevels,
     [] Specializes { impl1: DefId, impl2: DefId },
     [input] InScopeTraits(DefIndex),
     [input] ModuleExports(DefId),
@@ -621,14 +613,6 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
     [input] UsedCrateSource(CrateNum),
     [input] PostorderCnums,
 
-    // These queries are not expected to have inputs -- as a result, they
-    // are not good candidates for "replay" because they are essentially
-    // pure functions of their input (and hence the expectation is that
-    // no caller would be green **apart** from just these
-    // queries). Making them anonymous avoids hashing the result, which
-    // may save a bit of time.
-    [anon] EraseRegionsTy { ty: Ty<'tcx> },
-
     [input] Freevars(DefId),
     [input] MaybeUnusedTraitImport(DefId),
     [input] MaybeUnusedExternCrates,
@@ -667,9 +651,6 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
 
     [input] Features,
 
-    [] ProgramClausesFor(DefId),
-    [] ProgramClausesForEnv(traits::Environment<'tcx>),
-    [] WasmImportModuleMap(CrateNum),
     [] ForeignModules(CrateNum),
 
     [] UpstreamMonomorphizations(CrateNum),

Diff for: src/librustc/middle/stability.rs

@@ -582,7 +582,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 if let hir::Node::Expr(_) = self.hir().get_by_hir_id(id) {
                     diag.span_suggestion(
                         span,
-                        &msg,
+                        "replace the use of the deprecated item",
                         suggestion.to_string(),
                         Applicability::MachineApplicable,
                     );

Diff for: src/librustc/mir/mod.rs

@@ -1913,22 +1913,24 @@ pub enum PlaceBase<'tcx> {
 
     /// static or static mut variable
     Static(Box<Static<'tcx>>),
-
-    /// Constant code promoted to an injected static
-    Promoted(Box<(Promoted, Ty<'tcx>)>),
 }
 
-/// The `DefId` of a static, along with its normalized type (which is
-/// stored to avoid requiring normalization when reading MIR).
+/// We store the normalized type to avoid requiring normalization when reading MIR
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
 pub struct Static<'tcx> {
-    pub def_id: DefId,
     pub ty: Ty<'tcx>,
+    pub kind: StaticKind,
+}
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable, RustcEncodable, RustcDecodable)]
+pub enum StaticKind {
+    Promoted(Promoted),
+    Static(DefId),
 }
 
 impl_stable_hash_for!(struct Static<'tcx> {
-    def_id,
-    ty
+    ty,
+    kind
 });
 
 /// The `Projection` data structure defines things of the form `B.x`
@@ -2048,7 +2050,7 @@ impl<'tcx> Place<'tcx> {
         match self {
             Place::Base(PlaceBase::Local(local)) => Some(*local),
             Place::Projection(box Projection { base, elem: _ }) => base.base_local(),
-            Place::Base(PlaceBase::Promoted(..)) | Place::Base(PlaceBase::Static(..)) => None,
+            Place::Base(PlaceBase::Static(..)) => None,
         }
     }
 }
@@ -2059,18 +2061,24 @@ impl<'tcx> Debug for Place<'tcx> {
 
         match *self {
             Base(PlaceBase::Local(id)) => write!(fmt, "{:?}", id),
-            Base(PlaceBase::Static(box self::Static { def_id, ty })) => write!(
-                fmt,
-                "({}: {:?})",
-                ty::tls::with(|tcx| tcx.def_path_str(def_id)),
-                ty
-            ),
-            Base(PlaceBase::Promoted(ref promoted)) => write!(
-                fmt,
-                "({:?}: {:?})",
-                promoted.0,
-                promoted.1
-            ),
+            Base(PlaceBase::Static(box self::Static { ty, kind: StaticKind::Static(def_id) })) => {
+                write!(
+                    fmt,
+                    "({}: {:?})",
+                    ty::tls::with(|tcx| tcx.def_path_str(def_id)),
+                    ty
+                )
+            },
+            Base(PlaceBase::Static(
+                box self::Static { ty, kind: StaticKind::Promoted(promoted) })
+            ) => {
+                write!(
+                    fmt,
+                    "({:?}: {:?})",
+                    promoted,
+                    ty
+                )
+            },
             Projection(ref data) => match data.elem {
                 ProjectionElem::Downcast(ref adt_def, index) => {
                     write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].ident)

Diff for: src/librustc/mir/tcx.rs

@@ -160,7 +160,6 @@ impl<'tcx> Place<'tcx> {
         match *self {
             Place::Base(PlaceBase::Local(index)) =>
                 PlaceTy::Ty { ty: local_decls.local_decls()[index].ty },
-            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) =>

Diff for: src/librustc/mir/visit.rs

@@ -156,13 +156,6 @@ macro_rules! make_mir_visitor {
                 self.super_place(place, context, location);
             }
 
-            fn visit_static(&mut self,
-                            static_: & $($mutability)? Static<'tcx>,
-                            context: PlaceContext<'tcx>,
-                            location: Location) {
-                self.super_static(static_, context, location);
-            }
-
             fn visit_projection(&mut self,
                                 place: & $($mutability)? PlaceProjection<'tcx>,
                                 context: PlaceContext<'tcx>,
@@ -736,27 +729,18 @@ macro_rules! make_mir_visitor {
                     Place::Base(PlaceBase::Local(local)) => {
                         self.visit_local(local, context, location);
                     }
-                    Place::Base(PlaceBase::Static(static_)) => {
-                        self.visit_static(static_, context, location);
+                    Place::Base(PlaceBase::Static(box Static { kind, ty })) => {
+                        if let StaticKind::Static(def_id) = kind {
+                            self.visit_def_id(& $($mutability)? *def_id, location)
+                        }
+                        self.visit_ty(& $($mutability)? *ty, TyContext::Location(location));
                     }
-                    Place::Base(PlaceBase::Promoted(promoted)) => {
-                        self.visit_ty(& $($mutability)? promoted.1, TyContext::Location(location));
-                    },
                     Place::Projection(proj) => {
                         self.visit_projection(proj, context, location);
                     }
                 }
             }
 
-            fn super_static(&mut self,
-                            static_: & $($mutability)? Static<'tcx>,
-                            _context: PlaceContext<'tcx>,
-                            location: Location) {
-                let Static { def_id, ty } = static_;
-                self.visit_def_id(def_id, location);
-                self.visit_ty(ty, TyContext::Location(location));
-            }
-
             fn super_projection(&mut self,
                                 proj: & $($mutability)? PlaceProjection<'tcx>,
                                 context: PlaceContext<'tcx>,