Auto merge of rust-lang#48146 - Mark-Simulacrum:beta-next, r=alexcric…

…hton

[beta] Release notes, dist with time crate, and rust-lang#48092

Backports of
 - rust-lang#48092
 - rust-lang#48013
 - rust-lang#47286
 - rust-lang#48144

RELEASES.md

@@ -1,3 +1,117 @@
+Version 1.24.0 (2018-02-15)
+==========================
+
+Language
+--------
+- [External `sysv64` ffi is now available.][46528]
+  eg. `extern "sysv64" fn foo () {}`
+
+Compiler
+--------
+- [rustc now uses 16 codegen units by default for release builds.][46910]
+  For the fastest builds, utilize `codegen-units=1`.
+- [Added `armv4t-unknown-linux-gnueabi` target.][47018]
+- [Add `aarch64-unknown-openbsd` support][46760]
+
+Libraries
+---------
+- [`str::find::<char>` now uses memchr.][46735] This should lead to a 10x
+  improvement in performance in the majority of cases.
+- [`OsStr`'s `Debug` implementation is now lossless and consistent
+  with Windows.][46798]
+- [`time::{SystemTime, Instant}` now implement `Hash`.][46828]
+- [impl `From<bool>` for `AtomicBool`][46293]
+- [impl `From<{CString, &CStr}>` for `{Arc<CStr>, Rc<CStr>}`][45990]
+- [impl `From<{OsString, &OsStr}>` for `{Arc<OsStr>, Rc<OsStr>}`][45990]
+- [impl `From<{PathBuf, &Path}>` for `{Arc<Path>, Rc<Path>}`][45990]
+- [float::from_bits now just uses transmute.][46012] This provides
+  some optimisations from LLVM.
+- [Copied `AsciiExt` methods onto `char`][46077]
+- [Remove `T: Sized` requirement on `ptr::is_null()`][46094]
+- [impl `From<RecvError>` for `{TryRecvError, RecvTimeoutError}`][45506]
+- [Optimised `f32::{min, max}` to generate more efficent x86 assembly][47080]
+- [`[u8]::contains` now uses memchr which provides a 3x speed improvement][46713]
+
+Stabilized APIs
+---------------
+- [`RefCell::replace`]
+- [`RefCell::swap`]
+- [`atomic::spin_loop_hint`]
+
+The following functions can now be used in a constant expression.
+eg. `let buffer: [u8; size_of::<usize>()];`, `static COUNTER: AtomicUsize = AtomicUsize::new(1);`
+
+- [`AtomicBool::new`][46287]
+- [`AtomicUsize::new`][46287]
+- [`AtomicIsize::new`][46287]
+- [`AtomicPtr::new`][46287]
+- [`Cell::new`][46287]
+- [`{integer}::min_value`][46287]
+- [`{integer}::max_value`][46287]
+- [`mem::size_of`][46287]
+- [`mem::align_of`][46287]
+- [`ptr::null`][46287]
+- [`ptr::null_mut`][46287]
+- [`RefCell::new`][46287]
+- [`UnsafeCell::new`][46287]
+
+Cargo
+-----
+- [Added a `workspace.default-members` config that
+  overrides implied `--all` in virtual workspaces.][cargo/4743]
+- [Enable incremental by default on development builds.][cargo/4817] Also added
+  configuration keys to `Cargo.toml` and `.cargo/config` to disable on a
+  per-project or global basis respectively.
+
+Misc
+----
+
+Compatibility Notes
+-------------------
+- [Floating point types `Debug` impl now always prints a decimal point.][46831]
+- [`Ipv6Addr` now rejects superfluous `::`'s in IPv6 addresses][46671] This is
+  in accordance with IETF RFC 4291 §2.2.
+- [Unwinding will no longer go past FFI boundaries, and will instead abort.][46833]
+- [`Formatter::flags` method is now deprecated.][46284] The `sign_plus`,
+  `sign_minus`, `alternate`, and `sign_aware_zero_pad` should be used instead.
+- [Leading zeros in tuple struct members is now an error][47084]
+- [`column!()` macro is one-based instead of zero-based][46977]
+- [`fmt::Arguments` can no longer be shared across threads][45198]
+- [Access to `#[repr(packed)]` struct fields is now unsafe][44884]
+
+[44884]: https://github.com/rust-lang/rust/pull/44884
+[45198]: https://github.com/rust-lang/rust/pull/45198
+[45506]: https://github.com/rust-lang/rust/pull/45506
+[45904]: https://github.com/rust-lang/rust/pull/45904
+[45990]: https://github.com/rust-lang/rust/pull/45990
+[46012]: https://github.com/rust-lang/rust/pull/46012
+[46077]: https://github.com/rust-lang/rust/pull/46077
+[46094]: https://github.com/rust-lang/rust/pull/46094
+[46284]: https://github.com/rust-lang/rust/pull/46284
+[46287]: https://github.com/rust-lang/rust/pull/46287
+[46293]: https://github.com/rust-lang/rust/pull/46293
+[46528]: https://github.com/rust-lang/rust/pull/46528
+[46671]: https://github.com/rust-lang/rust/pull/46671
+[46713]: https://github.com/rust-lang/rust/pull/46713
+[46735]: https://github.com/rust-lang/rust/pull/46735
+[46749]: https://github.com/rust-lang/rust/pull/46749
+[46760]: https://github.com/rust-lang/rust/pull/46760
+[46798]: https://github.com/rust-lang/rust/pull/46798
+[46828]: https://github.com/rust-lang/rust/pull/46828
+[46831]: https://github.com/rust-lang/rust/pull/46831
+[46833]: https://github.com/rust-lang/rust/pull/46833
+[46910]: https://github.com/rust-lang/rust/pull/46910
+[46977]: https://github.com/rust-lang/rust/pull/46977
+[47018]: https://github.com/rust-lang/rust/pull/47018
+[47080]: https://github.com/rust-lang/rust/pull/47080
+[47084]: https://github.com/rust-lang/rust/pull/47084
+[cargo/4743]: https://github.com/rust-lang/cargo/pull/4743
+[cargo/4817]: https://github.com/rust-lang/cargo/pull/4817
+[`RefCell::replace`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.replace
+[`RefCell::swap`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.swap
+[`atomic::spin_loop_hint`]: https://doc.rust-lang.org/std/sync/atomic/fn.spin_loop_hint.html
+
+
 Version 1.23.0 (2018-01-04)
 ==========================
 

src/bootstrap/Cargo.toml

@@ -41,3 +41,4 @@ serde_derive = "1.0.8"
 serde_json = "1.0.2"
 toml = "0.4"
 lazy_static = "0.2"
+time = "0.1"

src/bootstrap/dist.rs

@@ -33,6 +33,7 @@ use builder::{Builder, RunConfig, ShouldRun, Step};
 use compile;
 use tool::{self, Tool};
 use cache::{INTERNER, Interned};
+use time;
 
 pub fn pkgname(build: &Build, component: &str) -> String {
     if component == "cargo" {
@@ -436,8 +437,7 @@ impl Step for Rustc {
             t!(fs::create_dir_all(image.join("share/man/man1")));
             let man_src = build.src.join("src/doc/man");
             let man_dst = image.join("share/man/man1");
-            let date_output = output(Command::new("date").arg("+%B %Y"));
-            let month_year = date_output.trim();
+            let month_year = t!(time::strftime("%B %Y", &time::now()));
             // don't use our `bootstrap::util::{copy, cp_r}`, because those try
             // to hardlink, and we don't want to edit the source templates
             for entry_result in t!(fs::read_dir(man_src)) {
@@ -447,7 +447,7 @@ impl Step for Rustc {
                 t!(fs::copy(&page_src, &page_dst));
                 // template in month/year and version number
                 replace_in_file(&page_dst,
-                                &[("<INSERT DATE HERE>", month_year),
+                                &[("<INSERT DATE HERE>", &month_year),
                                   ("<INSERT VERSION HERE>", channel::CFG_RELEASE_NUM)]);
             }
 

src/bootstrap/lib.rs

@@ -130,6 +130,7 @@ extern crate cc;
 extern crate getopts;
 extern crate num_cpus;
 extern crate toml;
+extern crate time;
 
 #[cfg(unix)]
 extern crate libc;

src/librustc/mir/tcx.rs

@@ -182,9 +182,8 @@ impl<'tcx> Rvalue<'tcx> {
                 if let ty::TyAdt(adt_def, _) = ty.sty {
                     adt_def.repr.discr_type().to_ty(tcx)
                 } else {
-                    // Undefined behaviour, bug for now; may want to return something for
-                    // the `discriminant` intrinsic later.
-                    bug!("Rvalue::Discriminant on Place of type {:?}", ty);
+                    // This can only be `0`, for now, so `u8` will suffice.
+                    tcx.types.u8
                 }
             }
             Rvalue::NullaryOp(NullOp::Box, t) => tcx.mk_box(t),

src/librustc_mir/build/matches/mod.rs

@@ -38,6 +38,22 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                       -> BlockAnd<()> {
         let discriminant_place = unpack!(block = self.as_place(block, discriminant));
 
+        // Matching on a `discriminant_place` with an uninhabited type doesn't
+        // generate any memory reads by itself, and so if the place "expression"
+        // contains unsafe operations like raw pointer dereferences or union
+        // field projections, we wouldn't know to require an `unsafe` block
+        // around a `match` equivalent to `std::intrinsics::unreachable()`.
+        // See issue #47412 for this hole being discovered in the wild.
+        //
+        // HACK(eddyb) Work around the above issue by adding a dummy inspection
+        // of `discriminant_place`, specifically by applying `Rvalue::Discriminant`
+        // (which will work regardless of type) and storing the result in a temp.
+        let dummy_source_info = self.source_info(span);
+        let dummy_access = Rvalue::Discriminant(discriminant_place.clone());
+        let dummy_ty = dummy_access.ty(&self.local_decls, self.hir.tcx());
+        let dummy_temp = self.temp(dummy_ty, dummy_source_info.span);
+        self.cfg.push_assign(block, dummy_source_info, &dummy_temp, dummy_access);
+
         let mut arm_blocks = ArmBlocks {
             blocks: arms.iter()
                         .map(|_| self.cfg.start_new_block())

src/test/compile-fail/borrowck/borrowck-describe-lvalue.rs

@@ -72,7 +72,7 @@ fn main() {
     {
         let mut e = Baz::X(2);
         let _e0 = e.x();
-        match e {
+        match e { //[mir]~ ERROR cannot use `e` because it was mutably borrowed
             Baz::X(value) => value
             //[ast]~^ ERROR cannot use `e.0` because it was mutably borrowed
             //[mir]~^^ ERROR cannot use `e.0` because it was mutably borrowed
@@ -110,7 +110,7 @@ fn main() {
     {
         let mut e = Box::new(Baz::X(3));
         let _e0 = e.x();
-        match *e {
+        match *e { //[mir]~ ERROR cannot use `*e` because it was mutably borrowed
             Baz::X(value) => value
             //[ast]~^ ERROR cannot use `e.0` because it was mutably borrowed
             //[mir]~^^ ERROR cannot use `e.0` because it was mutably borrowed
@@ -127,25 +127,25 @@ fn main() {
     {
         let mut v = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
         let _v = &mut v;
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[x, _, .., _, _] => println!("{}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
                             _ => panic!("other case"),
         }
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[_, x, .., _, _] => println!("{}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
                             _ => panic!("other case"),
         }
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[_, _, .., x, _] => println!("{}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
                             _ => panic!("other case"),
         }
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[_, _, .., _, x] => println!("{}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
@@ -156,25 +156,25 @@ fn main() {
     {
         let mut v = &[1, 2, 3, 4, 5];
         let _v = &mut v;
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[x..] => println!("{:?}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
             _ => panic!("other case"),
         }
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[_, x..] => println!("{:?}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
             _ => panic!("other case"),
         }
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[x.., _] => println!("{:?}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
             _ => panic!("other case"),
         }
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[_, x.., _] => println!("{:?}", x),
                 //[ast]~^ ERROR cannot use `v[..]` because it was mutably borrowed
                 //[mir]~^^ ERROR cannot use `v[..]` because it was mutably borrowed
@@ -187,7 +187,7 @@ fn main() {
 
         let mut e = E::A(3);
         let _e = &mut e;
-        match e {
+        match e { //[mir]~ ERROR cannot use `e` because it was mutably borrowed
             E::A(ref ax) =>
                 //[ast]~^ ERROR cannot borrow `e.0` as immutable because `e` is also borrowed as mutable
                 //[mir]~^^ ERROR cannot borrow `e.0` as immutable because it is also borrowed as mutable
@@ -205,14 +205,14 @@ fn main() {
         struct S { x: F, y: (u32, u32), };
         let mut s = S { x: F { x: 1, y: 2}, y: (999, 998) };
         let _s = &mut s;
-        match s {
+        match s { //[mir]~ ERROR cannot use `s` because it was mutably borrowed
             S  { y: (ref y0, _), .. } =>
                 //[ast]~^ ERROR cannot borrow `s.y.0` as immutable because `s` is also borrowed as mutable
                 //[mir]~^^ ERROR cannot borrow `s.y.0` as immutable because it is also borrowed as mutable
                 println!("y0: {:?}", y0),
             _ => panic!("other case"),
         }
-        match s {
+        match s { //[mir]~ ERROR cannot use `s` because it was mutably borrowed
             S  { x: F { y: ref x0, .. }, .. } =>
                 //[ast]~^ ERROR cannot borrow `s.x.y` as immutable because `s` is also borrowed as mutable
                 //[mir]~^^ ERROR cannot borrow `s.x.y` as immutable because it is also borrowed as mutable
@@ -263,7 +263,7 @@ fn main() {
         struct F {x: u32, y: u32};
         let mut v = &[F{x: 1, y: 2}, F{x: 3, y: 4}];
         let _v = &mut v;
-        match v {
+        match v { //[mir]~ ERROR cannot use `v` because it was mutably borrowed
             &[_, F {x: ref xf, ..}] => println!("{}", xf),
             //[mir]~^ ERROR cannot borrow `v[..].x` as immutable because it is also borrowed as mutable
             // No errors in AST

src/test/compile-fail/borrowck/borrowck-match-already-borrowed.rs

@@ -19,7 +19,7 @@ enum Foo {
 fn match_enum() {
     let mut foo = Foo::B;
     let p = &mut foo;
-    let _ = match foo {
+    let _ = match foo { //[mir]~ ERROR [E0503]
         Foo::B => 1, //[mir]~ ERROR [E0503]
         _ => 2,
         Foo::A(x) => x //[ast]~ ERROR [E0503]
@@ -31,7 +31,7 @@ fn match_enum() {
 fn main() {
     let mut x = 1;
     let _x = &mut x;
-    let _ = match x {
+    let _ = match x { //[mir]~ ERROR [E0503]
         x => x + 1, //[ast]~ ERROR [E0503]
                     //[mir]~^ ERROR [E0503]
         y => y + 2, //[ast]~ ERROR [E0503]