Rollup of 5 pull requests

src/libcore/iter/mod.rs

@@ -643,7 +643,9 @@ impl<A, B> FusedIterator for Chain<A, B>
 pub struct Zip<A, B> {
     a: A,
     b: B,
-    spec: <(A, B) as ZipImplData>::Data,
+    // index and len are only used by the specialized version of zip
+    index: usize,
+    len: usize,
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -685,17 +687,6 @@ trait ZipImpl<A, B> {
               B: DoubleEndedIterator + ExactSizeIterator;
 }
 
-// Zip specialization data members
-#[doc(hidden)]
-trait ZipImplData {
-    type Data: 'static + Clone + Default + fmt::Debug;
-}
-
-#[doc(hidden)]
-impl<T> ZipImplData for T {
-    default type Data = ();
-}
-
 // General Zip impl
 #[doc(hidden)]
 impl<A, B> ZipImpl<A, B> for Zip<A, B>
@@ -706,7 +697,8 @@ impl<A, B> ZipImpl<A, B> for Zip<A, B>
         Zip {
             a: a,
             b: b,
-            spec: Default::default(), // unused
+            index: 0, // unused
+            len: 0, // unused
         }
     }
 
@@ -759,20 +751,6 @@ impl<A, B> ZipImpl<A, B> for Zip<A, B>
     }
 }
 
-#[doc(hidden)]
-#[derive(Default, Debug, Clone)]
-struct ZipImplFields {
-    index: usize,
-    len: usize,
-}
-
-#[doc(hidden)]
-impl<A, B> ZipImplData for (A, B)
-    where A: TrustedRandomAccess, B: TrustedRandomAccess
-{
-    type Data = ZipImplFields;
-}
-
 #[doc(hidden)]
 impl<A, B> ZipImpl<A, B> for Zip<A, B>
     where A: TrustedRandomAccess, B: TrustedRandomAccess
@@ -782,18 +760,16 @@ impl<A, B> ZipImpl<A, B> for Zip<A, B>
         Zip {
             a: a,
             b: b,
-            spec: ZipImplFields {
-                index: 0,
-                len: len,
-            }
+            index: 0,
+            len: len,
         }
     }
 
     #[inline]
     fn next(&mut self) -> Option<(A::Item, B::Item)> {
-        if self.spec.index < self.spec.len {
-            let i = self.spec.index;
-            self.spec.index += 1;
+        if self.index < self.len {
+            let i = self.index;
+            self.index += 1;
             unsafe {
                 Some((self.a.get_unchecked(i), self.b.get_unchecked(i)))
             }
@@ -804,7 +780,7 @@ impl<A, B> ZipImpl<A, B> for Zip<A, B>
 
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.spec.len - self.spec.index;
+        let len = self.len - self.index;
         (len, Some(len))
     }
 
@@ -813,9 +789,9 @@ impl<A, B> ZipImpl<A, B> for Zip<A, B>
         where A: DoubleEndedIterator + ExactSizeIterator,
               B: DoubleEndedIterator + ExactSizeIterator
     {
-        if self.spec.index < self.spec.len {
-            self.spec.len -= 1;
-            let i = self.spec.len;
+        if self.index < self.len {
+            self.len -= 1;
+            let i = self.len;
             unsafe {
                 Some((self.a.get_unchecked(i), self.b.get_unchecked(i)))
             }

src/librustc/middle/resolve_lifetime.rs

@@ -337,7 +337,6 @@ impl<'a, 'tcx, 'v> Visitor<'v> for LifetimeContext<'a, 'tcx> {
 
         if !self.trait_ref_hack || !trait_ref.bound_lifetimes.is_empty() {
             if self.trait_ref_hack {
-                println!("{:?}", trait_ref.span);
                 span_err!(self.sess, trait_ref.span, E0316,
                           "nested quantification of lifetimes");
             }

src/librustc_driver/driver.rs

@@ -1017,13 +1017,16 @@ pub fn phase_4_translate_to_llvm<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         passes.push_pass(box mir::transform::no_landing_pads::NoLandingPads);
         passes.push_pass(box mir::transform::simplify_cfg::SimplifyCfg::new("no-landing-pads"));
 
+        // From here on out, regions are gone.
         passes.push_pass(box mir::transform::erase_regions::EraseRegions);
 
         passes.push_pass(box mir::transform::add_call_guards::AddCallGuards);
         passes.push_pass(box borrowck::ElaborateDrops);
         passes.push_pass(box mir::transform::no_landing_pads::NoLandingPads);
         passes.push_pass(box mir::transform::simplify_cfg::SimplifyCfg::new("elaborate-drops"));
 
+        // No lifetime analysis based on borrowing can be done from here on out.
+        passes.push_pass(box mir::transform::instcombine::InstCombine::new());
         passes.push_pass(box mir::transform::deaggregator::Deaggregator);
 
         passes.push_pass(box mir::transform::add_call_guards::AddCallGuards);

src/librustc_mir/transform/instcombine.rs

@@ -0,0 +1,110 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Performs various peephole optimizations.
+
+use rustc::mir::repr::{Location, Lvalue, Mir, Operand, ProjectionElem, Rvalue};
+use rustc::mir::transform::{MirPass, MirSource, Pass};
+use rustc::mir::visit::{MutVisitor, Visitor};
+use rustc::ty::TyCtxt;
+use rustc::util::nodemap::FnvHashSet;
+use std::mem;
+
+pub struct InstCombine {
+    optimizations: OptimizationList,
+}
+
+impl InstCombine {
+    pub fn new() -> InstCombine {
+        InstCombine {
+            optimizations: OptimizationList::default(),
+        }
+    }
+}
+
+impl Pass for InstCombine {}
+
+impl<'tcx> MirPass<'tcx> for InstCombine {
+    fn run_pass<'a>(&mut self,
+                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                    _: MirSource,
+                    mir: &mut Mir<'tcx>) {
+        // We only run when optimizing MIR (at any level).
+        if tcx.sess.opts.debugging_opts.mir_opt_level == Some(0) {
+            return
+        }
+
+        // First, find optimization opportunities. This is done in a pre-pass to keep the MIR
+        // read-only so that we can do global analyses on the MIR in the process (e.g.
+        // `Lvalue::ty()`).
+        {
+            let mut optimization_finder = OptimizationFinder::new(mir, tcx);
+            optimization_finder.visit_mir(mir);
+            self.optimizations = optimization_finder.optimizations
+        }
+
+        // Then carry out those optimizations.
+        MutVisitor::visit_mir(&mut *self, mir);
+    }
+}
+
+impl<'tcx> MutVisitor<'tcx> for InstCombine {
+    fn visit_rvalue(&mut self, rvalue: &mut Rvalue<'tcx>, location: Location) {
+        if self.optimizations.and_stars.remove(&location) {
+            debug!("Replacing `&*`: {:?}", rvalue);
+            let new_lvalue = match *rvalue {
+                Rvalue::Ref(_, _, Lvalue::Projection(ref mut projection)) => {
+                    mem::replace(&mut projection.base, Lvalue::ReturnPointer)
+                }
+                _ => bug!("Detected `&*` but didn't find `&*`!"),
+            };
+            *rvalue = Rvalue::Use(Operand::Consume(new_lvalue))
+        }
+
+        self.super_rvalue(rvalue, location)
+    }
+}
+
+/// Finds optimization opportunities on the MIR.
+struct OptimizationFinder<'b, 'a, 'tcx:'a+'b> {
+    mir: &'b Mir<'tcx>,
+    tcx: TyCtxt<'a, 'tcx, 'tcx>,
+    optimizations: OptimizationList,
+}
+
+impl<'b, 'a, 'tcx:'b> OptimizationFinder<'b, 'a, 'tcx> {
+    fn new(mir: &'b Mir<'tcx>, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> OptimizationFinder<'b, 'a, 'tcx> {
+        OptimizationFinder {
+            mir: mir,
+            tcx: tcx,
+            optimizations: OptimizationList::default(),
+        }
+    }
+}
+
+impl<'b, 'a, 'tcx> Visitor<'tcx> for OptimizationFinder<'b, 'a, 'tcx> {
+    fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) {
+        if let Rvalue::Ref(_, _, Lvalue::Projection(ref projection)) = *rvalue {
+            if let ProjectionElem::Deref = projection.elem {
+                if projection.base.ty(self.mir, self.tcx).to_ty(self.tcx).is_region_ptr() {
+                    self.optimizations.and_stars.insert(location);
+                }
+            }
+        }
+
+        self.super_rvalue(rvalue, location)
+    }
+}
+
+#[derive(Default)]
+struct OptimizationList {
+    and_stars: FnvHashSet<Location>,
+}
+

src/librustc_mir/transform/mod.rs

@@ -18,3 +18,5 @@ pub mod promote_consts;
 pub mod qualify_consts;
 pub mod dump_mir;
 pub mod deaggregator;
+pub mod instcombine;
+

src/librustc_trans/adt.rs

@@ -54,6 +54,7 @@ use syntax::ast;
 use syntax::attr;
 use syntax::attr::IntType;
 use abi::FAT_PTR_ADDR;
+use base;
 use build::*;
 use common::*;
 use debuginfo::DebugLoc;
@@ -963,16 +964,32 @@ pub fn trans_set_discr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, r: &Repr<'tcx>,
                 Store(bcx, C_null(llptrty), val);
             }
         }
-        StructWrappedNullablePointer { nndiscr, ref discrfield, .. } => {
+        StructWrappedNullablePointer { nndiscr, ref discrfield, ref nonnull, .. } => {
             if discr != nndiscr {
-                let llptrptr = GEPi(bcx, val, &discrfield[..]);
-                let llptrty = val_ty(llptrptr).element_type();
-                Store(bcx, C_null(llptrty), llptrptr);
+                if target_sets_discr_via_memset(bcx) {
+                    // Issue #34427: As workaround for LLVM bug on
+                    // ARM, use memset of 0 on whole struct rather
+                    // than storing null to single target field.
+                    let b = B(bcx);
+                    let llptr = b.pointercast(val, Type::i8(b.ccx).ptr_to());
+                    let fill_byte = C_u8(b.ccx, 0);
+                    let size = C_u64(b.ccx, nonnull.size);
+                    let align = C_u32(b.ccx, nonnull.align);
+                    base::call_memset(&b, llptr, fill_byte, size, align, false);
+                } else {
+                    let llptrptr = GEPi(bcx, val, &discrfield[..]);
+                    let llptrty = val_ty(llptrptr).element_type();
+                    Store(bcx, C_null(llptrty), llptrptr);
+                }
             }
         }
     }
 }
 
+fn target_sets_discr_via_memset<'blk, 'tcx>(bcx: Block<'blk, 'tcx>) -> bool {
+    bcx.sess().target.target.arch == "arm" || bcx.sess().target.target.arch == "aarch64"
+}
+
 fn assert_discr_in_range(ity: IntType, min: Disr, max: Disr, discr: Disr) {
     match ity {
         attr::UnsignedInt(_) => {

src/libsyntax/parse/attr.rs

@@ -125,8 +125,8 @@ impl<'a> Parser<'a> {
 
                 self.expect(&token::OpenDelim(token::Bracket))?;
                 let meta_item = self.parse_meta_item()?;
-                let hi = self.last_span.hi;
                 self.expect(&token::CloseDelim(token::Bracket))?;
+                let hi = self.last_span.hi;
 
                 (mk_sp(lo, hi), meta_item, style)
             }

src/test/run-pass/issue-34427.rs

@@ -0,0 +1,26 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Issue #34427: On ARM, the code in `foo` at one time was generating
+// a machine code instruction of the form: `str r0, [r0, rN]!` (for
+// some N), which is not legal because the source register and base
+// register cannot be identical in the preindexed form signalled by
+// the `!`.
+//
+// See LLVM bug: https://llvm.org/bugs/show_bug.cgi?id=28809
+
+#[inline(never)]
+fn foo(n: usize) -> Vec<Option<(*mut (), &'static ())>> {
+    (0..n).map(|_| None).collect()
+}
+
+fn main() {
+    let _ = (foo(10), foo(32));
+}

src/test/run-pass/variance-iterators-in-libcore.rs

@@ -0,0 +1,17 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![allow(warnings)]
+
+use std::iter::Zip;
+
+fn zip_covariant<'a, A, B>(iter: Zip<&'static A, &'static B>) -> Zip<&'a A, &'a B> { iter }
+
+fn main() { }

src/test/ui/span/issue-36530.rs

@@ -0,0 +1,14 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#[foo]
+mod foo {
+    #![foo]
+}

src/test/ui/span/issue-36530.stderr

@@ -0,0 +1,18 @@
+error: The attribute `foo` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
+  --> $DIR/issue-36530.rs:11:1
+   |
+11 | #[foo]
+   | ^^^^^^
+   |
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error: The attribute `foo` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
+  --> $DIR/issue-36530.rs:13:5
+   |
+13 |     #![foo]
+   |     ^^^^^^^
+   |
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error: aborting due to 2 previous errors
+