Auto merge of #47998 - kennytm:rollup, r=kennytm

Rollup of 10 pull requests

- Successful merges: #47862, #47877, #47896, #47912, #47947, #47958, #47978, #47996, #47999, #47892
- Failed merges:

39 files changed, 417 insertions, 204 deletions

diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 5fdc6e00920..e4c1cdb79fd 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -610,7 +610,6 @@ static HOST_COMPILETESTS: &[Test] = &[
         mode: "incremental",
         suite: "incremental-fulldeps",
     },
-    Test { path: "src/test/run-make", mode: "run-make", suite: "run-make" },
     Test { path: "src/test/rustdoc", mode: "rustdoc", suite: "rustdoc" },
 
     Test { path: "src/test/pretty", mode: "pretty", suite: "pretty" },
@@ -619,6 +618,7 @@ static HOST_COMPILETESTS: &[Test] = &[
     Test { path: "src/test/run-pass-valgrind/pretty", mode: "pretty", suite: "run-pass-valgrind" },
     Test { path: "src/test/run-pass-fulldeps/pretty", mode: "pretty", suite: "run-pass-fulldeps" },
     Test { path: "src/test/run-fail-fulldeps/pretty", mode: "pretty", suite: "run-fail-fulldeps" },
+    Test { path: "src/test/run-make", mode: "run-make", suite: "run-make" },
 ];
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
diff --git a/src/doc/unstable-book/src/language-features/match-beginning-vert.md b/src/doc/unstable-book/src/language-features/match-beginning-vert.md
deleted file mode 100644
index f0a51af7fd1..00000000000
--- a/src/doc/unstable-book/src/language-features/match-beginning-vert.md
+++ /dev/null
@@ -1,23 +0,0 @@
-# `match_beginning_vert`
-
-The tracking issue for this feature is [#44101].
-
-With this feature enabled, you are allowed to add a '|' to the beginning of a
-match arm:
-
-```rust
-#![feature(match_beginning_vert)]
-
-enum Foo { A, B, C }
-
-fn main() {
-    let x = Foo::A;
-    match x {
-        | Foo::A 
-        | Foo::B => println!("AB"),
-        | Foo::C => println!("C"),
-    }
-}
-```
-
-[#44101]: https://github.com/rust-lang/rust/issues/44101
\ No newline at end of file
diff --git a/src/libcore/any.rs b/src/libcore/any.rs
index 338e5c7fd95..566bfe2a3fb 100644
--- a/src/libcore/any.rs
+++ b/src/libcore/any.rs
@@ -367,9 +367,36 @@ impl TypeId {
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg(stage0)]
     pub fn of<T: ?Sized + 'static>() -> TypeId {
         TypeId {
             t: unsafe { intrinsics::type_id::<T>() },
         }
     }
+
+    /// Returns the `TypeId` of the type this generic function has been
+    /// instantiated with.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::any::{Any, TypeId};
+    ///
+    /// fn is_string<T: ?Sized + Any>(_s: &T) -> bool {
+    ///     TypeId::of::<String>() == TypeId::of::<T>()
+    /// }
+    ///
+    /// fn main() {
+    ///     assert_eq!(is_string(&0), false);
+    ///     assert_eq!(is_string(&"cookie monster".to_string()), true);
+    /// }
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature="const_type_id")]
+    #[cfg(not(stage0))]
+    pub const fn of<T: ?Sized + 'static>() -> TypeId {
+        TypeId {
+            t: unsafe { intrinsics::type_id::<T>() },
+        }
+    }
 }
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 2e1f925c49a..59a296c2a76 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -91,6 +91,7 @@
 #![feature(untagged_unions)]
 #![feature(unwind_attributes)]
 #![feature(doc_spotlight)]
+#![feature(rustc_const_unstable)]
 
 #[prelude_import]
 #[allow(unused)]
diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs
index 3b644aa13f3..c0feb8ad020 100644
--- a/src/librustc/mir/mod.rs
+++ b/src/librustc/mir/mod.rs
@@ -1825,7 +1825,7 @@ pub struct Location {
     /// the location is within this block
     pub block: BasicBlock,
 
-    /// the location is the start of the this statement; or, if `statement_index`
+    /// the location is the start of the statement; or, if `statement_index`
     /// == num-statements, then the start of the terminator.
     pub statement_index: usize,
 }
diff --git a/src/librustc_const_eval/eval.rs b/src/librustc_const_eval/eval.rs
index 1d2813e4f67..8e4ec93c14b 100644
--- a/src/librustc_const_eval/eval.rs
+++ b/src/librustc_const_eval/eval.rs
@@ -327,6 +327,10 @@ fn eval_const_expr_partial<'a, 'tcx>(cx: &ConstContext<'a, 'tcx>,
                     return Ok(mk_const(Integral(Usize(ConstUsize::new(align,
                         tcx.sess.target.usize_ty).unwrap()))));
                 }
+                "type_id" => {
+                    let type_id = tcx.type_id_hash(substs.type_at(0));
+                    return Ok(mk_const(Integral(U64(type_id))));
+                }
                 _ => signal!(e, TypeckError)
             }
           }
diff --git a/src/librustc_lint/unused.rs b/src/librustc_lint/unused.rs
index ef6475f9ee4..56f863ab3aa 100644
--- a/src/librustc_lint/unused.rs
+++ b/src/librustc_lint/unused.rs
@@ -302,19 +302,38 @@ impl EarlyLintPass for UnusedParens {
             Assign(_, ref value) => (value, "assigned value", false),
             AssignOp(.., ref value) => (value, "assigned value", false),
             InPlace(_, ref value) => (value, "emplacement value", false),
-            Call(_, ref args) => {
-                for arg in args {
-                    self.check_unused_parens_core(cx, arg, "function argument", false)
+            // either function/method call, or something this lint doesn't care about
+            ref call_or_other => {
+                let args_to_check;
+                let call_kind;
+                match *call_or_other {
+                    Call(_, ref args) => {
+                        call_kind = "function";
+                        args_to_check = &args[..];
+                    },
+                    MethodCall(_, ref args) => {
+                        call_kind = "method";
+                        // first "argument" is self (which sometimes needs parens)
+                        args_to_check = &args[1..];
+                    }
+                    // actual catch-all arm
+                    _ => { return; }
                 }
-                return;
-            },
-            MethodCall(_, ref args) => {
-                for arg in &args[1..] { // first "argument" is self (which sometimes needs parens)
-                    self.check_unused_parens_core(cx, arg, "method argument", false)
+                // Don't lint if this is a nested macro expansion: otherwise, the lint could
+                // trigger in situations that macro authors shouldn't have to care about, e.g.,
+                // when a parenthesized token tree matched in one macro expansion is matched as
+                // an expression in another and used as a fn/method argument (Issue #47775)
+                if e.span.ctxt().outer().expn_info()
+                    .map_or(false, |info| info.call_site.ctxt().outer()
+                            .expn_info().is_some()) {
+                        return;
+                }
+                let msg = format!("{} argument", call_kind);
+                for arg in args_to_check {
+                    self.check_unused_parens_core(cx, arg, &msg, false);
                 }
                 return;
             }
-            _ => return,
         };
         self.check_unused_parens_core(cx, &value, msg, struct_lit_needs_parens);
     }
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index fb2ab43fbbb..c0c680a4ddc 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -374,13 +374,20 @@ impl<'a, 'b, 'gcx, 'tcx> TypeVerifier<'a, 'b, 'gcx, 'tcx> {
             }
         };
         if let PlaceContext::Copy = context {
-            let ty = place_ty.to_ty(self.tcx());
-            if self.cx
-                .infcx
-                .type_moves_by_default(self.cx.param_env, ty, DUMMY_SP)
-            {
-                span_mirbug!(self, place, "attempted copy of non-Copy type ({:?})", ty);
-            }
+            let tcx = self.tcx();
+            let trait_ref = ty::TraitRef {
+                def_id: tcx.lang_items().copy_trait().unwrap(),
+                substs: tcx.mk_substs_trait(place_ty.to_ty(tcx), &[]),
+            };
+
+            // In order to have a Copy operand, the type T of the value must be Copy. Note that we
+            // prove that T: Copy, rather than using the type_moves_by_default test. This is
+            // important because type_moves_by_default ignores the resulting region obligations and
+            // assumes they pass. This can result in bounds from Copy impls being unsoundly ignored
+            // (e.g., #29149). Note that we decide to use Copy before knowing whether the bounds
+            // fully apply: in effect, the rule is that if a value of some type could implement
+            // Copy, then it must.
+            self.cx.prove_trait_ref(trait_ref, location);
         }
         place_ty
     }
diff --git a/src/librustc_mir/interpret/const_eval.rs b/src/librustc_mir/interpret/const_eval.rs
index 2913f72460e..d3b084fde6a 100644
--- a/src/librustc_mir/interpret/const_eval.rs
+++ b/src/librustc_mir/interpret/const_eval.rs
@@ -243,6 +243,12 @@ impl<'tcx> super::Machine<'tcx> for CompileTimeEvaluator {
                 ecx.write_primval(dest, PrimVal::from_u128(size), dest_layout.ty)?;
             }
 
+            "type_id" => {
+                let ty = substs.type_at(0);
+                let type_id = ecx.tcx.type_id_hash(ty) as u128;
+                ecx.write_primval(dest, PrimVal::from_u128(type_id), dest_layout.ty)?;
+            }
+
             name => return Err(ConstEvalError::NeedsRfc(format!("calling intrinsic `{}`", name)).into()),
         }
 
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index b896e6ca853..da76adfd48f 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -737,7 +737,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Qualifier<'a, 'tcx, 'tcx> {
                     Abi::PlatformIntrinsic => {
                         assert!(!self.tcx.is_const_fn(def_id));
                         match &self.tcx.item_name(def_id)[..] {
-                            "size_of" | "min_align_of" => is_const_fn = Some(def_id),
+                            "size_of" | "min_align_of" | "type_id" => is_const_fn = Some(def_id),
 
                             name if name.starts_with("simd_shuffle") => {
                                 is_shuffle = true;
diff --git a/src/librustc_trans/mir/constant.rs b/src/librustc_trans/mir/constant.rs
index a3e55205dd8..cd1975488a2 100644
--- a/src/librustc_trans/mir/constant.rs
+++ b/src/librustc_trans/mir/constant.rs
@@ -411,6 +411,11 @@ impl<'a, 'tcx> MirConstContext<'a, 'tcx> {
                                         self.cx.align_of(substs.type_at(0)).abi());
                                     Ok(Const::new(llval, tcx.types.usize))
                                 }
+                                "type_id" => {
+                                    let llval = C_u64(self.cx,
+                                        self.cx.tcx.type_id_hash(substs.type_at(0)));
+                                    Ok(Const::new(llval, tcx.types.u64))
+                                }
                                 _ => span_bug!(span, "{:?} in constant", terminator.kind)
                             }
                         } else if let Some((op, is_checked)) = self.is_binop_lang_item(def_id) {
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 0929b833c19..7c9a49c82a9 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2447,7 +2447,12 @@ impl Clean<Type> for hir::Ty {
                 let def_id = cx.tcx.hir.body_owner_def_id(n);
                 let param_env = cx.tcx.param_env(def_id);
                 let substs = Substs::identity_for_item(cx.tcx, def_id);
-                let n = cx.tcx.const_eval(param_env.and((def_id, substs))).unwrap();
+                let n = cx.tcx.const_eval(param_env.and((def_id, substs))).unwrap_or_else(|_| {
+                    cx.tcx.mk_const(ty::Const {
+                        val: ConstVal::Unevaluated(def_id, substs),
+                        ty: cx.tcx.types.usize
+                    })
+                });
                 let n = if let ConstVal::Integral(ConstInt::Usize(n)) = n.val {
                     n.to_string()
                 } else if let ConstVal::Unevaluated(def_id, _) = n.val {
@@ -2577,7 +2582,9 @@ impl<'tcx> Clean<Type> for Ty<'tcx> {
                 let mut n = cx.tcx.lift(&n).unwrap();
                 if let ConstVal::Unevaluated(def_id, substs) = n.val {
                     let param_env = cx.tcx.param_env(def_id);
-                    n = cx.tcx.const_eval(param_env.and((def_id, substs))).unwrap()
+                    if let Ok(new_n) = cx.tcx.const_eval(param_env.and((def_id, substs))) {
+                        n = new_n;
+                    }
                 };
                 let n = if let ConstVal::Integral(ConstInt::Usize(n)) = n.val {
                     n.to_string()
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index d1f3ccbd2c6..5cea389531f 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -482,20 +482,42 @@ impl File {
         self.inner.file_attr().map(Metadata)
     }
 
-    /// Creates a new independently owned handle to the underlying file.
-    ///
-    /// The returned `File` is a reference to the same state that this object
-    /// references. Both handles will read and write with the same cursor
-    /// position.
+    /// Create a new `File` instance that shares the same underlying file handle
+    /// as the existing `File` instance. Reads, writes, and seeks will affect
+    /// both `File` instances simultaneously.
     ///
     /// # Examples
     ///
+    /// Create two handles for a file named `foo.txt`:
+    ///
     /// ```no_run
     /// use std::fs::File;
     ///
     /// # fn foo() -> std::io::Result<()> {
-    /// let mut f = File::open("foo.txt")?;
-    /// let file_copy = f.try_clone()?;
+    /// let mut file = File::open("foo.txt")?;
+    /// let file_copy = file.try_clone()?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// Assuming there’s a file named `foo.txt` with contents `abcdef\n`, create
+    /// two handles, seek one of them, and read the remaining bytes from the
+    /// other handle:
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::io::SeekFrom;
+    /// use std::io::prelude::*;
+    ///
+    /// # fn foo() -> std::io::Result<()> {
+    /// let mut file = File::open("foo.txt")?;
+    /// let mut file_copy = file.try_clone()?;
+    ///
+    /// file.seek(SeekFrom::Start(3))?;
+    ///
+    /// let mut contents = vec![];
+    /// file_copy.read_to_end(&mut contents)?;
+    /// assert_eq!(contents, b"def\n");
     /// # Ok(())
     /// # }
     /// ```
@@ -1001,7 +1023,7 @@ impl Metadata {
         self.0.accessed().map(FromInner::from_inner)
     }
 
-    /// Returns the creation time listed in the this metadata.
+    /// Returns the creation time listed in this metadata.
     ///
     /// The returned value corresponds to the `birthtime` field of `stat` on
     /// Unix platforms and the `ftCreationTime` field on Windows platforms.
diff --git a/src/libstd/sys/cloudabi/thread.rs b/src/libstd/sys/cloudabi/thread.rs
index c980ae75261..78a3b82546e 100644
--- a/src/libstd/sys/cloudabi/thread.rs
+++ b/src/libstd/sys/cloudabi/thread.rs
@@ -111,10 +111,11 @@ impl Drop for Thread {
 
 #[cfg_attr(test, allow(dead_code))]
 pub mod guard {
-    pub unsafe fn current() -> Option<usize> {
+    pub type Guard = !;
+    pub unsafe fn current() -> Option<Guard> {
         None
     }
-    pub unsafe fn init() -> Option<usize> {
+    pub unsafe fn init() -> Option<Guard> {
         None
     }
 }
diff --git a/src/libstd/sys/redox/thread.rs b/src/libstd/sys/redox/thread.rs
index c4aad8d86f8..c4719a94c7e 100644
--- a/src/libstd/sys/redox/thread.rs
+++ b/src/libstd/sys/redox/thread.rs
@@ -88,6 +88,7 @@ impl Thread {
 }
 
 pub mod guard {
-    pub unsafe fn current() -> Option<usize> { None }
-    pub unsafe fn init() -> Option<usize> { None }
+    pub type Guard = !;
+    pub unsafe fn current() -> Option<Guard> { None }
+    pub unsafe fn init() -> Option<Guard> { None }
 }
diff --git a/src/libstd/sys/unix/stack_overflow.rs b/src/libstd/sys/unix/stack_overflow.rs
index 51adbc24ae0..40453f9b8a1 100644
--- a/src/libstd/sys/unix/stack_overflow.rs
+++ b/src/libstd/sys/unix/stack_overflow.rs
@@ -57,9 +57,6 @@ mod imp {
     use sys_common::thread_info;
 
 
-    // This is initialized in init() and only read from after
-    static mut PAGE_SIZE: usize = 0;
-
     #[cfg(any(target_os = "linux", target_os = "android"))]
     unsafe fn siginfo_si_addr(info: *mut libc::siginfo_t) -> usize {
         #[repr(C)]
@@ -102,12 +99,12 @@ mod imp {
                                     _data: *mut libc::c_void) {
         use sys_common::util::report_overflow;
 
-        let guard = thread_info::stack_guard().unwrap_or(0);
+        let guard = thread_info::stack_guard().unwrap_or(0..0);
         let addr = siginfo_si_addr(info);
 
         // If the faulting address is within the guard page, then we print a
         // message saying so and abort.
-        if guard != 0 && guard - PAGE_SIZE <= addr && addr < guard {
+        if guard.start <= addr && addr < guard.end {
             report_overflow();
             rtabort!("stack overflow");
         } else {
@@ -123,8 +120,6 @@ mod imp {
     static mut MAIN_ALTSTACK: *mut libc::c_void = ptr::null_mut();
 
     pub unsafe fn init() {
-        PAGE_SIZE = ::sys::os::page_size();
-
         let mut action: sigaction = mem::zeroed();
         action.sa_flags = SA_SIGINFO | SA_ONSTACK;
         action.sa_sigaction = signal_handler as sighandler_t;
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index 525882c1e1e..72cdb9440b8 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -205,8 +205,10 @@ impl Drop for Thread {
           not(target_os = "solaris")))]
 #[cfg_attr(test, allow(dead_code))]
 pub mod guard {
-    pub unsafe fn current() -> Option<usize> { None }
-    pub unsafe fn init() -> Option<usize> { None }
+    use ops::Range;
+    pub type Guard = Range<usize>;
+    pub unsafe fn current() -> Option<Guard> { None }
+    pub unsafe fn init() -> Option<Guard> { None }
 }
 
 
@@ -222,14 +224,43 @@ pub mod guard {
     use libc;
     use libc::mmap;
     use libc::{PROT_NONE, MAP_PRIVATE, MAP_ANON, MAP_FAILED, MAP_FIXED};
+    use ops::Range;
     use sys::os;
 
-    #[cfg(any(target_os = "macos",
-              target_os = "bitrig",
-              target_os = "openbsd",
-              target_os = "solaris"))]
+    // This is initialized in init() and only read from after
+    static mut PAGE_SIZE: usize = 0;
+
+    pub type Guard = Range<usize>;
+
+    #[cfg(target_os = "solaris")]
+    unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
+        let mut current_stack: libc::stack_t = ::mem::zeroed();
+        assert_eq!(libc::stack_getbounds(&mut current_stack), 0);
+        Some(current_stack.ss_sp)
+    }
+
+    #[cfg(target_os = "macos")]
     unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
-        current().map(|s| s as *mut libc::c_void)
+        let stackaddr = libc::pthread_get_stackaddr_np(libc::pthread_self()) as usize -
+             libc::pthread_get_stacksize_np(libc::pthread_self());
+        Some(stackaddr as *mut libc::c_void)
+    }
+
+    #[cfg(any(target_os = "openbsd", target_os = "bitrig"))]
+    unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
+        let mut current_stack: libc::stack_t = ::mem::zeroed();
+        assert_eq!(libc::pthread_stackseg_np(libc::pthread_self(),
+                                             &mut current_stack), 0);
+
+        let extra = if cfg!(target_os = "bitrig") {3} else {1} * PAGE_SIZE;
+        let stackaddr = if libc::pthread_main_np() == 1 {
+            // main thread
+            current_stack.ss_sp as usize - current_stack.ss_size + extra
+        } else {
+            // new thread
+            current_stack.ss_sp as usize - current_stack.ss_size
+        };
+        Some(stackaddr as *mut libc::c_void)
     }
 
     #[cfg(any(target_os = "android", target_os = "freebsd",
@@ -253,8 +284,9 @@ pub mod guard {
         ret
     }
 
-    pub unsafe fn init() -> Option<usize> {
-        let psize = os::page_size();
+    pub unsafe fn init() -> Option<Guard> {
+        PAGE_SIZE = os::page_size();
+
         let mut stackaddr = get_stack_start()?;
 
         // Ensure stackaddr is page aligned! A parent process might
@@ -263,9 +295,9 @@ pub mod guard {
         // stackaddr < stackaddr + stacksize, so if stackaddr is not
         // page-aligned, calculate the fix such that stackaddr <
         // new_page_aligned_stackaddr < stackaddr + stacksize
-        let remainder = (stackaddr as usize) % psize;
+        let remainder = (stackaddr as usize) % PAGE_SIZE;
         if remainder != 0 {
-            stackaddr = ((stackaddr as usize) + psize - remainder)
+            stackaddr = ((stackaddr as usize) + PAGE_SIZE - remainder)
                 as *mut libc::c_void;
         }
 
@@ -280,60 +312,42 @@ pub mod guard {
             // Instead, we'll just note where we expect rlimit to start
             // faulting, so our handler can report "stack overflow", and
             // trust that the kernel's own stack guard will work.
-            Some(stackaddr as usize)
+            let stackaddr = stackaddr as usize;
+            Some(stackaddr - PAGE_SIZE..stackaddr)
         } else {
             // Reallocate the last page of the stack.
             // This ensures SIGBUS will be raised on
             // stack overflow.
-            let result = mmap(stackaddr, psize, PROT_NONE,
+            let result = mmap(stackaddr, PAGE_SIZE, PROT_NONE,
                               MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
 
             if result != stackaddr || result == MAP_FAILED {
                 panic!("failed to allocate a guard page");
             }
 
+            let guardaddr = stackaddr as usize;
             let offset = if cfg!(target_os = "freebsd") {
                 2
             } else {
                 1
             };
 
-            Some(stackaddr as usize + offset * psize)
+            Some(guardaddr..guardaddr + offset * PAGE_SIZE)
         }
     }
 
-    #[cfg(target_os = "solaris")]
-    pub unsafe fn current() -> Option<usize> {
-        let mut current_stack: libc::stack_t = ::mem::zeroed();
-        assert_eq!(libc::stack_getbounds(&mut current_stack), 0);
-        Some(current_stack.ss_sp as usize)
-    }
-
-    #[cfg(target_os = "macos")]
-    pub unsafe fn current() -> Option<usize> {
-        Some(libc::pthread_get_stackaddr_np(libc::pthread_self()) as usize -
-             libc::pthread_get_stacksize_np(libc::pthread_self()))
-    }
-
-    #[cfg(any(target_os = "openbsd", target_os = "bitrig"))]
-    pub unsafe fn current() -> Option<usize> {
-        let mut current_stack: libc::stack_t = ::mem::zeroed();
-        assert_eq!(libc::pthread_stackseg_np(libc::pthread_self(),
-                                             &mut current_stack), 0);
-
-        let extra = if cfg!(target_os = "bitrig") {3} else {1} * os::page_size();
-        Some(if libc::pthread_main_np() == 1 {
-            // main thread
-            current_stack.ss_sp as usize - current_stack.ss_size + extra
-        } else {
-            // new thread
-            current_stack.ss_sp as usize - current_stack.ss_size
-        })
+    #[cfg(any(target_os = "macos",
+              target_os = "bitrig",
+              target_os = "openbsd",
+              target_os = "solaris"))]
+    pub unsafe fn current() -> Option<Guard> {
+        let stackaddr = get_stack_start()? as usize;
+        Some(stackaddr - PAGE_SIZE..stackaddr)
     }
 
     #[cfg(any(target_os = "android", target_os = "freebsd",
               target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
-    pub unsafe fn current() -> Option<usize> {
+    pub unsafe fn current() -> Option<Guard> {
         let mut ret = None;
         let mut attr: libc::pthread_attr_t = ::mem::zeroed();
         assert_eq!(libc::pthread_attr_init(&mut attr), 0);
@@ -352,12 +366,23 @@ pub mod guard {
             assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr,
                                                    &mut size), 0);
 
+            let stackaddr = stackaddr as usize;
             ret = if cfg!(target_os = "freebsd") {
-                Some(stackaddr as usize - guardsize)
+                // FIXME does freebsd really fault *below* the guard addr?
+                let guardaddr = stackaddr - guardsize;
+                Some(guardaddr - PAGE_SIZE..guardaddr)
             } else if cfg!(target_os = "netbsd") {
-                Some(stackaddr as usize)
+                Some(stackaddr - guardsize..stackaddr)
+            } else if cfg!(all(target_os = "linux", target_env = "gnu")) {
+                // glibc used to include the guard area within the stack, as noted in the BUGS
+                // section of `man pthread_attr_getguardsize`.  This has been corrected starting
+                // with glibc 2.27, and in some distro backports, so the guard is now placed at the
+                // end (below) the stack.  There's no easy way for us to know which we have at
+                // runtime, so we'll just match any fault in the range right above or below the
+                // stack base to call that fault a stack overflow.
+                Some(stackaddr - guardsize..stackaddr + guardsize)
             } else {
-                Some(stackaddr as usize + guardsize)
+                Some(stackaddr..stackaddr + guardsize)
             };
         }
         assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
diff --git a/src/libstd/sys/wasm/thread.rs b/src/libstd/sys/wasm/thread.rs
index 13980e0cc19..6a066509b49 100644
--- a/src/libstd/sys/wasm/thread.rs
+++ b/src/libstd/sys/wasm/thread.rs
@@ -43,6 +43,7 @@ impl Thread {
 }
 
 pub mod guard {
-    pub unsafe fn current() -> Option<usize> { None }
-    pub unsafe fn init() -> Option<usize> { None }
+    pub type Guard = !;
+    pub unsafe fn current() -> Option<Guard> { None }
+    pub unsafe fn init() -> Option<Guard> { None }
 }
diff --git a/src/libstd/sys/windows/thread.rs b/src/libstd/sys/windows/thread.rs
index 74786d09285..43abfbb1f64 100644
--- a/src/libstd/sys/windows/thread.rs
+++ b/src/libstd/sys/windows/thread.rs
@@ -93,6 +93,7 @@ impl Thread {
 
 #[cfg_attr(test, allow(dead_code))]
 pub mod guard {
-    pub unsafe fn current() -> Option<usize> { None }
-    pub unsafe fn init() -> Option<usize> { None }
+    pub type Guard = !;
+    pub unsafe fn current() -> Option<Guard> { None }
+    pub unsafe fn init() -> Option<Guard> { None }
 }
diff --git a/src/libstd/sys_common/thread_info.rs b/src/libstd/sys_common/thread_info.rs
index 7970042b1d6..6a2b6742367 100644
--- a/src/libstd/sys_common/thread_info.rs
+++ b/src/libstd/sys_common/thread_info.rs
@@ -11,10 +11,11 @@
 #![allow(dead_code)] // stack_guard isn't used right now on all platforms
 
 use cell::RefCell;
+use sys::thread::guard::Guard;
 use thread::Thread;
 
 struct ThreadInfo {
-    stack_guard: Option<usize>,
+    stack_guard: Option<Guard>,
     thread: Thread,
 }
 
@@ -38,11 +39,11 @@ pub fn current_thread() -> Option<Thread> {
     ThreadInfo::with(|info| info.thread.clone())
 }
 
-pub fn stack_guard() -> Option<usize> {
-    ThreadInfo::with(|info| info.stack_guard).and_then(|o| o)
+pub fn stack_guard() -> Option<Guard> {
+    ThreadInfo::with(|info| info.stack_guard.clone()).and_then(|o| o)
 }
 
-pub fn set(stack_guard: Option<usize>, thread: Thread) {
+pub fn set(stack_guard: Option<Guard>, thread: Thread) {
     THREAD_INFO.with(|c| assert!(c.borrow().is_none()));
     THREAD_INFO.with(move |c| *c.borrow_mut() = Some(ThreadInfo{
         stack_guard,
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 73810b3fe81..c7ab6158256 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -883,7 +883,6 @@ pub struct Arm {
     pub pats: Vec<P<Pat>>,
     pub guard: Option<P<Expr>>,
     pub body: P<Expr>,
-    pub beginning_vert: Option<Span>, // For RFC 1925 feature gate
 }
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index cf63592c2ec..2e6de96d65a 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -883,7 +883,6 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             pats,
             guard: None,
             body: expr,
-            beginning_vert: None,
         }
     }
 
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 3e523fca92a..3e858c3b923 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -386,9 +386,6 @@ declare_features! (
     // allow `#[must_use]` on functions and comparison operators (RFC 1940)
     (active, fn_must_use, "1.21.0", Some(43302)),
 
-    // allow '|' at beginning of match arms (RFC 1925)
-    (active, match_beginning_vert, "1.21.0", Some(44101)),
-
     // Future-proofing enums/structs with #[non_exhaustive] attribute (RFC 2008)
     (active, non_exhaustive, "1.22.0", Some(44109)),
 
@@ -545,6 +542,8 @@ declare_features! (
     (accepted, abi_sysv64, "1.24.0", Some(36167)),
     // Allows `repr(align(16))` struct attribute (RFC 1358)
     (accepted, repr_align, "1.24.0", Some(33626)),
+    // allow '|' at beginning of match arms (RFC 1925)
+    (accepted, match_beginning_vert, "1.25.0", Some(44101)),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must
@@ -1683,11 +1682,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
     }
 
     fn visit_arm(&mut self, arm: &'a ast::Arm) {
-        if let Some(span) = arm.beginning_vert {
-            gate_feature_post!(&self, match_beginning_vert,
-                               span,
-                               "Use of a '|' at the beginning of a match arm is experimental")
-        }
         visit::walk_arm(self, arm)
     }
 
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 0f8fe57e380..921ed3565a4 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -340,14 +340,13 @@ pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> Thi
     fold_attrs(attrs.into(), fld).into()
 }
 
-pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body, beginning_vert}: Arm,
+pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm,
     fld: &mut T) -> Arm {
     Arm {
         attrs: fold_attrs(attrs, fld),
         pats: pats.move_map(|x| fld.fold_pat(x)),
         guard: guard.map(|x| fld.fold_expr(x)),
         body: fld.fold_expr(body),
-        beginning_vert,
     }
 }
 
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index b3c485a85c0..764b3d0a848 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -3398,11 +3398,7 @@ impl<'a> Parser<'a> {
 
         let attrs = self.parse_outer_attributes()?;
         // Allow a '|' before the pats (RFC 1925)
-        let beginning_vert = if self.eat(&token::BinOp(token::Or)) {
-            Some(self.prev_span)
-        } else {
-            None
-        };
+        self.eat(&token::BinOp(token::Or));
         let pats = self.parse_pats()?;
         let guard = if self.eat_keyword(keywords::If) {
             Some(self.parse_expr()?)
@@ -3426,7 +3422,6 @@ impl<'a> Parser<'a> {
             pats,
             guard,
             body: expr,
-            beginning_vert,
         })
     }
 
diff --git a/src/test/codegen/stack-probes.rs b/src/test/codegen/stack-probes.rs
index 5b26dade9af..4a489f1edb3 100644
--- a/src/test/codegen/stack-probes.rs
+++ b/src/test/codegen/stack-probes.rs
@@ -15,7 +15,7 @@
 // ignore-wasm
 // ignore-emscripten
 // ignore-windows
-// no-system-llvm
+// min-system-llvm-version 5.0
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
diff --git a/src/test/compile-fail/const-typeid-of.rs b/src/test/compile-fail/const-typeid-of.rs
new file mode 100644
index 00000000000..401125cef09
--- /dev/null
+++ b/src/test/compile-fail/const-typeid-of.rs
@@ -0,0 +1,18 @@
+// Copyright 2018 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.
+
+use std::any::TypeId;
+
+struct A;
+
+fn main() {
+    const A_ID: TypeId = TypeId::of::<A>();
+    //~^ ERROR `std::any::TypeId::of` is not yet stable as a const fn
+}
diff --git a/src/test/compile-fail/nll/do-not-ignore-lifetime-bounds-in-copy.rs b/src/test/compile-fail/nll/do-not-ignore-lifetime-bounds-in-copy.rs
new file mode 100644
index 00000000000..2a4295fd90a
--- /dev/null
+++ b/src/test/compile-fail/nll/do-not-ignore-lifetime-bounds-in-copy.rs
@@ -0,0 +1,23 @@
+// Copyright 2012 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.
+
+// Test that the 'static bound from the Copy impl is respected. Regression test for #29149.
+
+#![feature(nll)]
+
+#[derive(Clone)] struct Foo<'a>(&'a u32);
+impl Copy for Foo<'static> {}
+
+fn main() {
+    let s = 2;
+    let a = Foo(&s); //~ ERROR `s` does not live long enough [E0597]
+    drop(a);
+    drop(a);
+}
diff --git a/src/test/run-pass/const-typeid-of.rs b/src/test/run-pass/const-typeid-of.rs
new file mode 100644
index 00000000000..ce29e55c6d7
--- /dev/null
+++ b/src/test/run-pass/const-typeid-of.rs
@@ -0,0 +1,43 @@
+// Copyright 2018 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.
+
+#![feature(core_intrinsics)]
+#![feature(const_type_id)]
+
+use std::any::TypeId;
+
+struct A;
+
+static ID_ISIZE: TypeId = TypeId::of::<isize>();
+
+pub fn main() {
+    assert_eq!(ID_ISIZE, TypeId::of::<isize>());
+
+    // sanity test of TypeId
+    const T: (TypeId, TypeId, TypeId) = (TypeId::of::<usize>(),
+                     TypeId::of::<&'static str>(),
+                     TypeId::of::<A>());
+    let (d, e, f) = (TypeId::of::<usize>(), TypeId::of::<&'static str>(),
+                     TypeId::of::<A>());
+
+    assert!(T.0 != T.1);
+    assert!(T.0 != T.2);
+    assert!(T.1 != T.2);
+
+    assert_eq!(T.0, d);
+    assert_eq!(T.1, e);
+    assert_eq!(T.2, f);
+
+    // Check fn pointer against collisions
+    const F: (TypeId, TypeId) = (TypeId::of::<fn(fn(A) -> A) -> A>(),
+            TypeId::of::<fn(fn() -> A, A) -> A>());
+
+    assert!(F.0 != F.1);
+}
diff --git a/src/test/run-pass/match-beginning-vert.rs b/src/test/run-pass/match-beginning-vert.rs
new file mode 100644
index 00000000000..cdacfb2f057
--- /dev/null
+++ b/src/test/run-pass/match-beginning-vert.rs
@@ -0,0 +1,28 @@
+// Copyright 2018 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.
+
+enum Foo {
+    A,
+    B,
+    C,
+    D,
+    E,
+}
+use Foo::*;
+
+fn main() {
+    for foo in &[A, B, C, D, E] {
+        match *foo {
+            | A => println!("A"),
+            | B | C if 1 < 2 => println!("BC!"),
+            | _ => {},
+        }
+    }
+}
diff --git a/src/test/run-pass/stack-probes-lto.rs b/src/test/run-pass/stack-probes-lto.rs
index 22555c8d6a7..4deced1297b 100644
--- a/src/test/run-pass/stack-probes-lto.rs
+++ b/src/test/run-pass/stack-probes-lto.rs
@@ -15,7 +15,7 @@
 // ignore-emscripten no processes
 // ignore-musl FIXME #31506
 // ignore-pretty
-// no-system-llvm
+// min-system-llvm-version 5.0
 // compile-flags: -C lto
 // no-prefer-dynamic
 
diff --git a/src/test/run-pass/stack-probes.rs b/src/test/run-pass/stack-probes.rs
index 248ad701926..4224a65ffd7 100644
--- a/src/test/run-pass/stack-probes.rs
+++ b/src/test/run-pass/stack-probes.rs
@@ -14,7 +14,7 @@
 // ignore-cloudabi no processes
 // ignore-emscripten no processes
 // ignore-musl FIXME #31506
-// no-system-llvm
+// min-system-llvm-version 5.0
 
 use std::mem;
 use std::process::Command;
diff --git a/src/test/rustdoc/const-evalutation-ice.rs b/src/test/rustdoc/const-evalutation-ice.rs
new file mode 100644
index 00000000000..9fed67ee583
--- /dev/null
+++ b/src/test/rustdoc/const-evalutation-ice.rs
@@ -0,0 +1,22 @@
+// Copyright 2018 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.
+
+// Just check if we don't get an ICE for the _S type.
+
+#![feature(const_size_of)]
+
+use std::cell::Cell;
+use std::mem;
+
+pub struct S {
+    s: Cell<usize>
+}
+
+pub type _S = [usize; 0 - (mem::size_of::<S>() != 4) as usize];
diff --git a/src/test/ui/feature-gate-match_beginning_vert.rs b/src/test/ui/feature-gate-match_beginning_vert.rs
deleted file mode 100644
index 9085563c99d..00000000000
--- a/src/test/ui/feature-gate-match_beginning_vert.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2017 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(dead_code)]
-enum Foo {
-    A,
-    B,
-    C,
-    D,
-    E,
-}
-use Foo::*;
-
-fn main() {
-    let x = Foo::A;
-    match x {
-        | A => println!("A"),
-        //~^ ERROR: Use of a '|' at the beginning of a match arm is experimental (see issue #44101)
-        | B | C => println!("BC!"),
-        //~^ ERROR: Use of a '|' at the beginning of a match arm is experimental (see issue #44101)
-        | _ => {},
-        //~^ ERROR: Use of a '|' at the beginning of a match arm is experimental (see issue #44101)
-    };
-    match x {
-        A | B | C => println!("ABC!"),
-        _ => {},
-    };
-}
-
diff --git a/src/test/ui/feature-gate-match_beginning_vert.stderr b/src/test/ui/feature-gate-match_beginning_vert.stderr
deleted file mode 100644
index 1d45dedb497..00000000000
--- a/src/test/ui/feature-gate-match_beginning_vert.stderr
+++ /dev/null
@@ -1,26 +0,0 @@
-error[E0658]: Use of a '|' at the beginning of a match arm is experimental (see issue #44101)
-  --> $DIR/feature-gate-match_beginning_vert.rs:24:9
-   |
-24 |         | A => println!("A"),
-   |         ^
-   |
-   = help: add #![feature(match_beginning_vert)] to the crate attributes to enable
-
-error[E0658]: Use of a '|' at the beginning of a match arm is experimental (see issue #44101)
-  --> $DIR/feature-gate-match_beginning_vert.rs:26:9
-   |
-26 |         | B | C => println!("BC!"),
-   |         ^
-   |
-   = help: add #![feature(match_beginning_vert)] to the crate attributes to enable
-
-error[E0658]: Use of a '|' at the beginning of a match arm is experimental (see issue #44101)
-  --> $DIR/feature-gate-match_beginning_vert.rs:28:9
-   |
-28 |         | _ => {},
-   |         ^
-   |
-   = help: add #![feature(match_beginning_vert)] to the crate attributes to enable
-
-error: aborting due to 3 previous errors
-
diff --git a/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.rs b/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.rs
new file mode 100644
index 00000000000..b4e6c5074e3
--- /dev/null
+++ b/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.rs
@@ -0,0 +1,40 @@
+// Copyright 2018 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.
+
+// must-compile-successfully
+
+#![warn(unused_parens)]
+
+macro_rules! the_worship_the_heart_lifts_above {
+    ( @as_expr, $e:expr) => { $e };
+    ( @generate_fn, $name:tt) => {
+        #[allow(dead_code)] fn the_moth_for_the_star<'a>() -> Option<&'a str> {
+            Some(the_worship_the_heart_lifts_above!( @as_expr, $name ))
+        }
+    };
+    ( $name:ident ) => { the_worship_the_heart_lifts_above!( @generate_fn, (stringify!($name))); }
+    // ↑ Notably, this does 𝘯𝘰𝘵 warn: we're declining to lint unused parens in
+    // function/method arguments inside of nested macros because of situations
+    // like those reported in Issue #47775
+}
+
+macro_rules! and_the_heavens_reject_not {
+    () => {
+        // ↓ But let's test that we still lint for unused parens around
+        // function args inside of simple, one-deep macros.
+        #[allow(dead_code)] fn the_night_for_the_morrow() -> Option<isize> { Some((2)) }
+        //~^ WARN unnecessary parentheses around function argument
+    }
+}
+
+the_worship_the_heart_lifts_above!(rah);
+and_the_heavens_reject_not!();
+
+fn main() {}
diff --git a/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.stderr b/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.stderr
new file mode 100644
index 00000000000..097ec1b1c80
--- /dev/null
+++ b/src/test/ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.stderr
@@ -0,0 +1,15 @@
+warning: unnecessary parentheses around function argument
+  --> $DIR/issue-47775-nested-macro-unnecessary-parens-arg.rs:32:83
+   |
+32 |         #[allow(dead_code)] fn the_night_for_the_morrow() -> Option<isize> { Some((2)) }
+   |                                                                                   ^^^ help: remove these parentheses
+...
+38 | and_the_heavens_reject_not!();
+   | ------------------------------ in this macro invocation
+   |
+note: lint level defined here
+  --> $DIR/issue-47775-nested-macro-unnecessary-parens-arg.rs:13:9
+   |
+13 | #![warn(unused_parens)]
+   |         ^^^^^^^^^^^^^
+
diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index ff662736bdd..80750f9a3fe 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -167,7 +167,7 @@ impl EarlyProps {
                         .expect("Malformed llvm version directive");
                     // Ignore if using system LLVM and actual version
                     // is smaller the minimum required version
-                    !(config.system_llvm && &actual_version[..] < min_version)
+                    config.system_llvm && &actual_version[..] < min_version
                 } else {
                     false
                 }
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index abf62a060b8..46df211cbaf 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -79,7 +79,7 @@ pub fn make_diff(expected: &str, actual: &str, context_size: usize) -> Vec<Misma
     let mut results = Vec::new();
     let mut mismatch = Mismatch::new(0);
 
-    for result in diff::lines(actual, expected) {
+    for result in diff::lines(expected, actual) {
         match result {
             diff::Result::Left(str) => {
                 if lines_since_mismatch >= context_size && lines_since_mismatch > 0 {
@@ -91,7 +91,8 @@ pub fn make_diff(expected: &str, actual: &str, context_size: usize) -> Vec<Misma
                     mismatch.lines.push(DiffLine::Context(line.to_owned()));
                 }
 
-                mismatch.lines.push(DiffLine::Resulting(str.to_owned()));
+                mismatch.lines.push(DiffLine::Expected(str.to_owned()));
+                line_number += 1;
                 lines_since_mismatch = 0;
             }
             diff::Result::Right(str) => {
@@ -104,8 +105,7 @@ pub fn make_diff(expected: &str, actual: &str, context_size: usize) -> Vec<Misma
                     mismatch.lines.push(DiffLine::Context(line.to_owned()));
                 }
 
-                mismatch.lines.push(DiffLine::Expected(str.to_owned()));
-                line_number += 1;
+                mismatch.lines.push(DiffLine::Resulting(str.to_owned()));
                 lines_since_mismatch = 0;
             }
             diff::Result::Both(str, _) => {