Auto merge of #37289 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 7 pull requests

- Successful merges: #37165, #37187, #37241, #37283, #37285, #37287, #37288
- Failed merges:

Author: bors

src/doc/book/testing.md

@@ -380,9 +380,9 @@ the `tests` directory.
 
 # The `tests` directory
 
-Each file in `tests/*.rs` directory is treated as individual crate.
-So, to write an integration test, let's make a `tests` directory, and
-put a `tests/integration_test.rs` file inside, with this as its contents:
+Each file in `tests/*.rs` directory is treated as an individual crate.
+To write an integration test, let's make a `tests` directory and
+put a `tests/integration_test.rs` file inside with this as its contents:
 
 ```rust,ignore
 extern crate adder;

src/libcollections/borrow.rs

@@ -86,16 +86,29 @@ impl<T> ToOwned for T where T: Clone {
 /// ```
 /// use std::borrow::Cow;
 ///
-/// # #[allow(dead_code)]
 /// fn abs_all(input: &mut Cow<[i32]>) {
 ///     for i in 0..input.len() {
 ///         let v = input[i];
 ///         if v < 0 {
-///             // clones into a vector the first time (if not already owned)
+///             // Clones into a vector if not already owned.
 ///             input.to_mut()[i] = -v;
 ///         }
 ///     }
 /// }
+///
+/// // No clone occurs because `input` doesn't need to be mutated.
+/// let slice = [0, 1, 2];
+/// let mut input = Cow::from(&slice[..]);
+/// abs_all(&mut input);
+///
+/// // Clone occurs because `input` needs to be mutated.
+/// let slice = [-1, 0, 1];
+/// let mut input = Cow::from(&slice[..]);
+/// abs_all(&mut input);
+///
+/// // No clone occurs because `input` is already owned.
+/// let mut input = Cow::from(vec![-1, 0, 1]);
+/// abs_all(&mut input);
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Cow<'a, B: ?Sized + 'a>

src/librustc/infer/freshen.rs

@@ -61,9 +61,8 @@ impl<'a, 'gcx, 'tcx> TypeFreshener<'a, 'gcx, 'tcx> {
                   -> Ty<'tcx> where
         F: FnOnce(u32) -> ty::InferTy,
     {
-        match opt_ty {
-            Some(ty) => { return ty.fold_with(self); }
-            None => { }
+        if let Some(ty) = opt_ty {
+            return ty.fold_with(self);
         }
 
         match self.freshen_map.entry(key) {

src/librustc/middle/region.rs

@@ -478,12 +478,9 @@ impl RegionMaps {
         //! Returns the scope when temp created by expr_id will be cleaned up
 
         // check for a designated rvalue scope
-        match self.rvalue_scopes.borrow().get(&expr_id) {
-            Some(&s) => {
-                debug!("temporary_scope({:?}) = {:?} [custom]", expr_id, s);
-                return Some(s);
-            }
-            None => { }
+        if let Some(&s) = self.rvalue_scopes.borrow().get(&expr_id) {
+            debug!("temporary_scope({:?}) = {:?} [custom]", expr_id, s);
+            return Some(s);
         }
 
         let scope_map : &[CodeExtent] = &self.scope_map.borrow();
@@ -928,19 +925,15 @@ fn resolve_local(visitor: &mut RegionResolutionVisitor, local: &hir::Local) {
     //
     // FIXME(#6308) -- Note that `[]` patterns work more smoothly post-DST.
 
-    match local.init {
-        Some(ref expr) => {
-            record_rvalue_scope_if_borrow_expr(visitor, &expr, blk_scope);
+    if let Some(ref expr) = local.init {
+        record_rvalue_scope_if_borrow_expr(visitor, &expr, blk_scope);
 
-            let is_borrow =
-                if let Some(ref ty) = local.ty { is_borrowed_ty(&ty) } else { false };
+        let is_borrow =
+            if let Some(ref ty) = local.ty { is_borrowed_ty(&ty) } else { false };
 
-            if is_binding_pat(&local.pat) || is_borrow {
-                record_rvalue_scope(visitor, &expr, blk_scope);
-            }
+        if is_binding_pat(&local.pat) || is_borrow {
+            record_rvalue_scope(visitor, &expr, blk_scope);
         }
-
-        None => { }
     }
 
     intravisit::walk_local(visitor, local);
@@ -1023,16 +1016,12 @@ fn resolve_local(visitor: &mut RegionResolutionVisitor, local: &hir::Local) {
                 record_rvalue_scope_if_borrow_expr(visitor, &subexpr, blk_id)
             }
             hir::ExprBlock(ref block) => {
-                match block.expr {
-                    Some(ref subexpr) => {
-                        record_rvalue_scope_if_borrow_expr(
-                            visitor, &subexpr, blk_id);
-                    }
-                    None => { }
+                if let Some(ref subexpr) = block.expr {
+                    record_rvalue_scope_if_borrow_expr(
+                        visitor, &subexpr, blk_id);
                 }
             }
-            _ => {
-            }
+            _ => {}
         }
     }
 

src/librustc/traits/project.rs

@@ -1405,9 +1405,8 @@ impl<'tcx> ProjectionCache<'tcx> {
     /// cache hit, so it's actually a good thing).
     fn try_start(&mut self, key: ty::ProjectionTy<'tcx>)
                  -> Result<(), ProjectionCacheEntry<'tcx>> {
-        match self.map.get(&key) {
-            Some(entry) => return Err(entry.clone()),
-            None => { }
+        if let Some(entry) = self.map.get(&key) {
+            return Err(entry.clone());
         }
 
         self.map.insert(key, ProjectionCacheEntry::InProgress);

src/librustc/traits/select.rs

@@ -788,14 +788,11 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
                stack);
         assert!(!stack.obligation.predicate.has_escaping_regions());
 
-        match self.check_candidate_cache(&cache_fresh_trait_pred) {
-            Some(c) => {
-                debug!("CACHE HIT: SELECT({:?})={:?}",
-                       cache_fresh_trait_pred,
-                       c);
-                return c;
-            }
-            None => { }
+        if let Some(c) = self.check_candidate_cache(&cache_fresh_trait_pred) {
+            debug!("CACHE HIT: SELECT({:?})={:?}",
+                   cache_fresh_trait_pred,
+                   c);
+            return c;
         }
 
         // If no match, compute result and insert into cache.

src/librustc_borrowck/borrowck/check_loans.rs

@@ -135,15 +135,12 @@ impl<'a, 'tcx> euv::Delegate<'tcx> for CheckLoanCtxt<'a, 'tcx> {
                borrow_id, cmt, loan_region,
                bk, loan_cause);
 
-        match opt_loan_path(&cmt) {
-            Some(lp) => {
-                let moved_value_use_kind = match loan_cause {
-                    euv::ClosureCapture(_) => MovedInCapture,
-                    _ => MovedInUse,
-                };
-                self.check_if_path_is_moved(borrow_id, borrow_span, moved_value_use_kind, &lp);
-            }
-            None => { }
+        if let Some(lp) = opt_loan_path(&cmt) {
+            let moved_value_use_kind = match loan_cause {
+                euv::ClosureCapture(_) => MovedInCapture,
+                _ => MovedInUse,
+            };
+            self.check_if_path_is_moved(borrow_id, borrow_span, moved_value_use_kind, &lp);
         }
 
         self.check_for_conflicting_loans(borrow_id);
@@ -158,33 +155,29 @@ impl<'a, 'tcx> euv::Delegate<'tcx> for CheckLoanCtxt<'a, 'tcx> {
         debug!("mutate(assignment_id={}, assignee_cmt={:?})",
                assignment_id, assignee_cmt);
 
-        match opt_loan_path(&assignee_cmt) {
-            Some(lp) => {
-                match mode {
-                    MutateMode::Init | MutateMode::JustWrite => {
-                        // In a case like `path = 1`, then path does not
-                        // have to be *FULLY* initialized, but we still
-                        // must be careful lest it contains derefs of
-                        // pointers.
-                        self.check_if_assigned_path_is_moved(assignee_cmt.id,
-                                                             assignment_span,
-                                                             MovedInUse,
-                                                             &lp);
-                    }
-                    MutateMode::WriteAndRead => {
-                        // In a case like `path += 1`, then path must be
-                        // fully initialized, since we will read it before
-                        // we write it.
-                        self.check_if_path_is_moved(assignee_cmt.id,
-                                                    assignment_span,
-                                                    MovedInUse,
-                                                    &lp);
-                    }
+        if let Some(lp) = opt_loan_path(&assignee_cmt) {
+            match mode {
+                MutateMode::Init | MutateMode::JustWrite => {
+                    // In a case like `path = 1`, then path does not
+                    // have to be *FULLY* initialized, but we still
+                    // must be careful lest it contains derefs of
+                    // pointers.
+                    self.check_if_assigned_path_is_moved(assignee_cmt.id,
+                                                         assignment_span,
+                                                         MovedInUse,
+                                                         &lp);
+                }
+                MutateMode::WriteAndRead => {
+                    // In a case like `path += 1`, then path must be
+                    // fully initialized, since we will read it before
+                    // we write it.
+                    self.check_if_path_is_moved(assignee_cmt.id,
+                                                assignment_span,
+                                                MovedInUse,
+                                                &lp);
                 }
             }
-            None => { }
         }
-
         self.check_assignment(assignment_id, assignment_span, assignee_cmt);
     }
 
@@ -601,39 +594,36 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
                       span: Span,
                       cmt: mc::cmt<'tcx>,
                       mode: euv::ConsumeMode) {
-        match opt_loan_path(&cmt) {
-            Some(lp) => {
-                let moved_value_use_kind = match mode {
-                    euv::Copy => {
-                        self.check_for_copy_of_frozen_path(id, span, &lp);
-                        MovedInUse
-                    }
-                    euv::Move(_) => {
-                        match self.move_data.kind_of_move_of_path(id, &lp) {
-                            None => {
-                                // Sometimes moves don't have a move kind;
-                                // this either means that the original move
-                                // was from something illegal to move,
-                                // or was moved from referent of an unsafe
-                                // pointer or something like that.
+        if let Some(lp) = opt_loan_path(&cmt) {
+            let moved_value_use_kind = match mode {
+                euv::Copy => {
+                    self.check_for_copy_of_frozen_path(id, span, &lp);
+                    MovedInUse
+                }
+                euv::Move(_) => {
+                    match self.move_data.kind_of_move_of_path(id, &lp) {
+                        None => {
+                            // Sometimes moves don't have a move kind;
+                            // this either means that the original move
+                            // was from something illegal to move,
+                            // or was moved from referent of an unsafe
+                            // pointer or something like that.
+                            MovedInUse
+                        }
+                        Some(move_kind) => {
+                            self.check_for_move_of_borrowed_path(id, span,
+                                                                 &lp, move_kind);
+                            if move_kind == move_data::Captured {
+                                MovedInCapture
+                            } else {
                                 MovedInUse
                             }
-                            Some(move_kind) => {
-                                self.check_for_move_of_borrowed_path(id, span,
-                                                                     &lp, move_kind);
-                                if move_kind == move_data::Captured {
-                                    MovedInCapture
-                                } else {
-                                    MovedInUse
-                                }
-                            }
                         }
                     }
-                };
+                }
+            };
 
-                self.check_if_path_is_moved(id, span, moved_value_use_kind, &lp);
-            }
-            None => { }
+            self.check_if_path_is_moved(id, span, moved_value_use_kind, &lp);
         }
     }
 

src/librustc_data_structures/control_flow_graph/dominators/mod.rs

@@ -57,9 +57,9 @@ pub fn dominators_given_rpo<G: ControlFlowGraph>(graph: &G,
                     // (*)
                     // (*) dominators for `pred` have been calculated
                     new_idom = intersect_opt(&post_order_rank,
-                                                  &immediate_dominators,
-                                                  new_idom,
-                                                  Some(pred));
+                                             &immediate_dominators,
+                                             new_idom,
+                                             Some(pred));
                 }
             }
 
@@ -77,10 +77,10 @@ pub fn dominators_given_rpo<G: ControlFlowGraph>(graph: &G,
 }
 
 fn intersect_opt<Node: Idx>(post_order_rank: &IndexVec<Node, usize>,
-                                      immediate_dominators: &IndexVec<Node, Option<Node>>,
-                                      node1: Option<Node>,
-                                      node2: Option<Node>)
-                                      -> Option<Node> {
+                            immediate_dominators: &IndexVec<Node, Option<Node>>,
+                            node1: Option<Node>,
+                            node2: Option<Node>)
+                            -> Option<Node> {
     match (node1, node2) {
         (None, None) => None,
         (Some(n), None) | (None, Some(n)) => Some(n),
@@ -89,10 +89,10 @@ fn intersect_opt<Node: Idx>(post_order_rank: &IndexVec<Node, usize>,
 }
 
 fn intersect<Node: Idx>(post_order_rank: &IndexVec<Node, usize>,
-                                  immediate_dominators: &IndexVec<Node, Option<Node>>,
-                                  mut node1: Node,
-                                  mut node2: Node)
-                                  -> Node {
+                        immediate_dominators: &IndexVec<Node, Option<Node>>,
+                        mut node1: Node,
+                        mut node2: Node)
+                        -> Node {
     while node1 != node2 {
         while post_order_rank[node1] < post_order_rank[node2] {
             node1 = immediate_dominators[node1].unwrap();
@@ -142,9 +142,9 @@ impl<Node: Idx> Dominators<Node> {
                 "node {:?} is not reachable",
                 node2);
         intersect::<Node>(&self.post_order_rank,
-                  &self.immediate_dominators,
-                  node1,
-                  node2)
+                          &self.immediate_dominators,
+                          node1,
+                          node2)
     }
 
     pub fn mutual_dominator<I>(&self, iter: I) -> Option<Node>

src/librustc_data_structures/control_flow_graph/dominators/test.rs

@@ -14,12 +14,7 @@ use super::*;
 
 #[test]
 fn diamond() {
-    let graph = TestGraph::new(0, &[
-        (0, 1),
-        (0, 2),
-        (1, 3),
-        (2, 3),
-    ]);
+    let graph = TestGraph::new(0, &[(0, 1), (0, 2), (1, 3), (2, 3)]);
 
     let dominators = dominators(&graph);
     let immediate_dominators = dominators.all_immediate_dominators();
@@ -32,17 +27,9 @@ fn diamond() {
 #[test]
 fn paper() {
     // example from the paper:
-    let graph = TestGraph::new(6, &[
-        (6, 5),
-        (6, 4),
-        (5, 1),
-        (4, 2),
-        (4, 3),
-        (1, 2),
-        (2, 3),
-        (3, 2),
-        (2, 1),
-    ]);
+    let graph = TestGraph::new(6,
+                               &[(6, 5), (6, 4), (5, 1), (4, 2), (4, 3), (1, 2), (2, 3), (3, 2),
+                                 (2, 1)]);
 
     let dominators = dominators(&graph);
     let immediate_dominators = dominators.all_immediate_dominators();
@@ -54,4 +41,3 @@ fn paper() {
     assert_eq!(immediate_dominators[5], Some(6));
     assert_eq!(immediate_dominators[6], Some(6));
 }
-