Auto merge of #45956 - kennytm:rollup, r=kennytm

Rollup of 9 pull requests

- Successful merges: #45828, #45892, #45893, #45914, #45917, #45927, #45933, #45952, #45954
- Failed merges:

Author: bors

src/libcore/option.rs

@@ -634,16 +634,12 @@ impl<T> Option<T> {
     #[inline]
     #[unstable(feature = "option_filter", issue = "45860")]
     pub fn filter<P: FnOnce(&T) -> bool>(self, predicate: P) -> Self {
-        match self {
-            Some(x) => {
-                if predicate(&x) {
-                    Some(x)
-                } else {
-                    None
-                }
+        if let Some(x) = self {
+            if predicate(&x) {
+                return Some(x)
             }
-            None => None,
         }
+        None
     }
 
     /// Returns the option if it contains a value, otherwise returns `optb`.

src/librustc/hir/mod.rs

@@ -1949,7 +1949,7 @@ impl ForeignItem_ {
 }
 
 /// A free variable referred to in a function.
-#[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
+#[derive(Debug, Copy, Clone, RustcEncodable, RustcDecodable)]
 pub struct Freevar {
     /// The variable being accessed free.
     pub def: Def,

src/librustc/mir/mod.rs

@@ -267,10 +267,10 @@ impl<'tcx> Mir<'tcx> {
         let block = &self[location.block];
         let stmts = &block.statements;
         let idx = location.statement_index;
-        if location.statement_index < stmts.len() {
+        if idx < stmts.len() {
             &stmts[idx].source_info
         } else {
-            assert!(location.statement_index == stmts.len());
+            assert!(idx == stmts.len());
             &block.terminator().source_info
         }
     }

src/librustc/session/mod.rs

@@ -164,11 +164,13 @@ enum DiagnosticBuilderMethod {
     // add more variants as needed to support one-time diagnostics
 }
 
-/// Diagnostic message id - used in order to avoid emitting the same message more than once
+/// Diagnostic message ID—used by `Session.one_time_diagnostics` to avoid
+/// emitting the same message more than once
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum DiagnosticMessageId {
+    ErrorId(u16), // EXXXX error code as integer
     LintId(lint::LintId),
-    StabilityId(u32)
+    StabilityId(u32) // issue number
 }
 
 impl Session {

src/librustc/traits/error_reporting.rs

@@ -36,6 +36,7 @@ use middle::const_val;
 use rustc::lint::builtin::EXTRA_REQUIREMENT_IN_IMPL;
 use std::fmt;
 use syntax::ast;
+use session::DiagnosticMessageId;
 use ty::{self, AdtKind, ToPredicate, ToPolyTraitRef, Ty, TyCtxt, TypeFoldable};
 use ty::error::ExpectedFound;
 use ty::fast_reject;
@@ -219,13 +220,19 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 }
             }
 
-            let mut diag = struct_span_err!(
-                self.tcx.sess, obligation.cause.span, E0271,
-                "type mismatch resolving `{}`", predicate
-            );
-            self.note_type_err(&mut diag, &obligation.cause, None, values, err);
-            self.note_obligation_cause(&mut diag, obligation);
-            diag.emit();
+            let msg = format!("type mismatch resolving `{}`", predicate);
+            let error_id = (DiagnosticMessageId::ErrorId(271),
+                            Some(obligation.cause.span), msg.clone());
+            let fresh = self.tcx.sess.one_time_diagnostics.borrow_mut().insert(error_id);
+            if fresh {
+                let mut diag = struct_span_err!(
+                    self.tcx.sess, obligation.cause.span, E0271,
+                    "type mismatch resolving `{}`", predicate
+                );
+                self.note_type_err(&mut diag, &obligation.cause, None, values, err);
+                self.note_obligation_cause(&mut diag, obligation);
+                diag.emit();
+            }
         });
     }
 

src/librustc_mir/borrow_check.rs

@@ -1169,8 +1169,72 @@ impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx>
         err.emit();
     }
 
+    /// Finds the span of arguments of a closure (within `maybe_closure_span`) and its usage of
+    /// the local assigned at `location`.
+    /// This is done by searching in statements succeeding `location`
+    /// and originating from `maybe_closure_span`.
+    fn find_closure_span(
+        &self,
+        maybe_closure_span: Span,
+        location: Location,
+    ) -> Option<(Span, Span)> {
+        use rustc::hir::ExprClosure;
+        use rustc::mir::AggregateKind;
+
+        let local = if let StatementKind::Assign(Lvalue::Local(local), _) =
+            self.mir[location.block].statements[location.statement_index].kind
+        {
+            local
+        } else {
+            return None;
+        };
+
+        for stmt in &self.mir[location.block].statements[location.statement_index + 1..] {
+            if maybe_closure_span != stmt.source_info.span {
+                break;
+            }
+
+            if let StatementKind::Assign(_, Rvalue::Aggregate(ref kind, ref lvs)) = stmt.kind {
+                if let AggregateKind::Closure(def_id, _) = **kind {
+                    debug!("find_closure_span: found closure {:?}", lvs);
+
+                    return if let Some(node_id) = self.tcx.hir.as_local_node_id(def_id) {
+                        let args_span = if let ExprClosure(_, _, _, span, _) =
+                            self.tcx.hir.expect_expr(node_id).node
+                        {
+                            span
+                        } else {
+                            return None;
+                        };
+
+                        self.tcx
+                            .with_freevars(node_id, |freevars| {
+                                for (v, lv) in freevars.iter().zip(lvs) {
+                                    if let Operand::Consume(Lvalue::Local(l)) = *lv {
+                                        if local == l {
+                                            debug!(
+                                                "find_closure_span: found captured local {:?}",
+                                                l
+                                            );
+                                            return Some(v.span);
+                                        }
+                                    }
+                                }
+                                None
+                            })
+                            .map(|var_span| (args_span, var_span))
+                    } else {
+                        None
+                    };
+                }
+            }
+        }
+
+        None
+    }
+
     fn report_conflicting_borrow(&mut self,
-                                 _context: Context,
+                                 context: Context,
                                  common_prefix: &Lvalue,
                                  (lvalue, span): (&Lvalue, Span),
                                  gen_borrow_kind: BorrowKind,
@@ -1183,38 +1247,60 @@ impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx>
 
         let issued_span = self.retrieve_borrow_span(issued_borrow);
 
+        let new_closure_span = self.find_closure_span(span, context.loc);
+        let span = new_closure_span.map(|(args, _)| args).unwrap_or(span);
+        let old_closure_span = self.find_closure_span(issued_span, issued_borrow.location);
+        let issued_span = old_closure_span.map(|(args, _)| args).unwrap_or(issued_span);
+
+        let desc_lvalue = self.describe_lvalue(lvalue);
+
         // FIXME: supply non-"" `opt_via` when appropriate
         let mut err = match (gen_borrow_kind, "immutable", "mutable",
                              issued_borrow.kind, "immutable", "mutable") {
             (BorrowKind::Shared, lft, _, BorrowKind::Mut, _, rgt) |
             (BorrowKind::Mut, _, lft, BorrowKind::Shared, rgt, _) =>
                 self.tcx.cannot_reborrow_already_borrowed(
-                    span, &self.describe_lvalue(lvalue), "", lft, issued_span,
+                    span, &desc_lvalue, "", lft, issued_span,
                     "it", rgt, "", end_issued_loan_span, Origin::Mir),
 
             (BorrowKind::Mut, _, _, BorrowKind::Mut, _, _) =>
                 self.tcx.cannot_mutably_borrow_multiply(
-                    span, &self.describe_lvalue(lvalue), "", issued_span,
+                    span, &desc_lvalue, "", issued_span,
                     "", end_issued_loan_span, Origin::Mir),
 
             (BorrowKind::Unique, _, _, BorrowKind::Unique, _, _) =>
                 self.tcx.cannot_uniquely_borrow_by_two_closures(
-                    span, &self.describe_lvalue(lvalue), issued_span,
+                    span, &desc_lvalue, issued_span,
                     end_issued_loan_span, Origin::Mir),
 
             (BorrowKind::Unique, _, _, _, _, _) =>
                 self.tcx.cannot_uniquely_borrow_by_one_closure(
-                    span, &self.describe_lvalue(lvalue), "",
+                    span, &desc_lvalue, "",
                     issued_span, "it", "", end_issued_loan_span, Origin::Mir),
 
             (_, _, _, BorrowKind::Unique, _, _) =>
                 self.tcx.cannot_reborrow_already_uniquely_borrowed(
-                    span, &self.describe_lvalue(lvalue), "it", "",
+                    span, &desc_lvalue, "it", "",
                     issued_span, "", end_issued_loan_span, Origin::Mir),
 
             (BorrowKind::Shared, _, _, BorrowKind::Shared, _, _) =>
                 unreachable!(),
         };
+
+        if let Some((_, var_span)) = old_closure_span {
+            err.span_label(
+                var_span,
+                format!("previous borrow occurs due to use of `{}` in closure", desc_lvalue),
+            );
+        }
+
+        if let Some((_, var_span)) = new_closure_span {
+            err.span_label(
+                var_span,
+                format!("borrow occurs due to use of `{}` in closure", desc_lvalue),
+            );
+        }
+
         err.emit();
     }
 

src/librustc_trans/back/link.rs

@@ -503,31 +503,10 @@ fn link_staticlib(sess: &Session,
     if !all_native_libs.is_empty() {
         if sess.opts.prints.contains(&PrintRequest::NativeStaticLibs) {
             print_native_static_libs(sess, &all_native_libs);
-        } else {
-            // Fallback for backwards compatibility only
-            print_native_static_libs_legacy(sess, &all_native_libs);
         }
     }
 }
 
-fn print_native_static_libs_legacy(sess: &Session, all_native_libs: &[NativeLibrary]) {
-    sess.note_without_error("link against the following native artifacts when linking against \
-                             this static library");
-    sess.note_without_error("This list will not be printed by default. \
-        Please add --print=native-static-libs if you need this information");
-
-    for lib in all_native_libs.iter().filter(|l| relevant_lib(sess, l)) {
-        let name = match lib.kind {
-            NativeLibraryKind::NativeStaticNobundle |
-            NativeLibraryKind::NativeUnknown => "library",
-            NativeLibraryKind::NativeFramework => "framework",
-            // These are included, no need to print them
-            NativeLibraryKind::NativeStatic => continue,
-        };
-        sess.note_without_error(&format!("{}: {}", name, lib.name));
-    }
-}
-
 fn print_native_static_libs(sess: &Session, all_native_libs: &[NativeLibrary]) {
     let lib_args: Vec<_> = all_native_libs.iter()
         .filter(|l| relevant_lib(sess, l))

src/libstd/path.rs

@@ -1690,11 +1690,11 @@ impl Path {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[allow(deprecated)]
     pub fn is_absolute(&self) -> bool {
-        if !cfg!(target_os = "redox") {
-            self.has_root() && (cfg!(unix) || self.prefix().is_some())
-        } else {
+        if cfg!(target_os = "redox") {
             // FIXME: Allow Redox prefixes
-            has_redox_scheme(self.as_u8_slice())
+            self.has_root() || has_redox_scheme(self.as_u8_slice())
+        } else {
+            self.has_root() && (cfg!(unix) || self.prefix().is_some())
         }
     }
 

src/libstd/sys/redox/condvar.rs

@@ -9,12 +9,12 @@
 // except according to those terms.
 
 use cell::UnsafeCell;
-use intrinsics::{atomic_cxchg, atomic_xadd, atomic_xchg};
+use intrinsics::{atomic_cxchg, atomic_load, atomic_xadd, atomic_xchg};
 use ptr;
 use time::Duration;
 
 use sys::mutex::{mutex_unlock, Mutex};
-use sys::syscall::{futex, FUTEX_WAIT, FUTEX_WAKE, FUTEX_REQUEUE};
+use sys::syscall::{futex, TimeSpec, FUTEX_WAIT, FUTEX_WAKE, FUTEX_REQUEUE};
 
 pub struct Condvar {
     lock: UnsafeCell<*mut i32>,
@@ -63,33 +63,50 @@ impl Condvar {
     }
 
     #[inline]
-    pub fn wait(&self, mutex: &Mutex) {
-        unsafe {
-            let lock = self.lock.get();
-            let seq = self.seq.get();
-
-            if *lock != mutex.lock.get() {
-                if *lock != ptr::null_mut() {
-                    panic!("Condvar used with more than one Mutex");
-                }
+    unsafe fn wait_inner(&self, mutex: &Mutex, timeout_ptr: *const TimeSpec) -> bool {
+        let lock = self.lock.get();
+        let seq = self.seq.get();
 
-                atomic_cxchg(lock as *mut usize, 0, mutex.lock.get() as usize);
+        if *lock != mutex.lock.get() {
+            if *lock != ptr::null_mut() {
+                panic!("Condvar used with more than one Mutex");
             }
 
-            mutex_unlock(*lock);
+            atomic_cxchg(lock as *mut usize, 0, mutex.lock.get() as usize);
+        }
 
-            let _ = futex(seq, FUTEX_WAIT, *seq, 0, ptr::null_mut());
+        mutex_unlock(*lock);
 
-            while atomic_xchg(*lock, 2) != 0 {
-                let _ = futex(*lock, FUTEX_WAIT, 2, 0, ptr::null_mut());
-            }
+        let seq_before = atomic_load(seq);
+
+        let _ = futex(seq, FUTEX_WAIT, seq_before, timeout_ptr as usize, ptr::null_mut());
+
+        let seq_after = atomic_load(seq);
+
+        while atomic_xchg(*lock, 2) != 0 {
+            let _ = futex(*lock, FUTEX_WAIT, 2, 0, ptr::null_mut());
+        }
+
+        seq_before != seq_after
+    }
+
+    #[inline]
+    pub fn wait(&self, mutex: &Mutex) {
+        unsafe {
+            assert!(self.wait_inner(mutex, ptr::null()));
         }
     }
 
     #[inline]
-    pub fn wait_timeout(&self, _mutex: &Mutex, _dur: Duration) -> bool {
-        ::sys_common::util::dumb_print(format_args!("condvar wait_timeout\n"));
-        unimplemented!();
+    pub fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool {
+        unsafe {
+            let timeout = TimeSpec {
+                tv_sec: dur.as_secs() as i64,
+                tv_nsec: dur.subsec_nanos() as i32
+            };
+
+            self.wait_inner(mutex, &timeout as *const TimeSpec)
+        }
     }
 
     #[inline]

src/libstd/sys/redox/fs.rs

@@ -437,8 +437,7 @@ pub fn symlink(src: &Path, dst: &Path) -> io::Result<()> {
 }
 
 pub fn link(_src: &Path, _dst: &Path) -> io::Result<()> {
-    ::sys_common::util::dumb_print(format_args!("Link\n"));
-    unimplemented!();
+    Err(Error::from_raw_os_error(syscall::ENOSYS))
 }
 
 pub fn stat(p: &Path) -> io::Result<FileAttr> {