Auto merge of #66794 - tmandry:rollup-99qrpr0, r=tmandry

Rollup of 14 pull requests

Successful merges:

 - #66128 (alloc: Add new_zeroed() versions like new_uninit().)
 - #66661 (Add riscv64gc-unknown-linux-gnu target)
 - #66663 (Miri: print leak report even without tracing)
 - #66711 (Add hardware floating point features to aarch64-pc-windows-msvc)
 - #66713 (introduce a target to build the kernel of the unikernel HermitCore)
 - #66717 (tidy: Accommodate rustfmt's preferred layout of stability attributes)
 - #66719 (Store pointer width as u32 on Config)
 - #66720 (Move ErrorReported to rustc_errors)
 - #66737 (Error codes cleanup)
 - #66754 (Various tweaks to diagnostic output)
 - #66763 (Minor edit for documentation-tests.md that increases clarity)
 - #66779 (follow the same function order in the trait)
 - #66786 (Add wildcard test for const_if_match)
 - #66788 (Allow `Unreachable` terminators through `min_const_fn` checks)

Failed merges:

r? @ghost

Author: bors

src/doc/rustdoc/src/documentation-tests.md

@@ -1,7 +1,7 @@
 # Documentation tests
 
 `rustdoc` supports executing your documentation examples as tests. This makes sure
-that your tests are up to date and working.
+that examples within your documentation are up to date and working.
 
 The basic idea is this:
 

src/liballoc/boxed.rs

@@ -152,6 +152,33 @@ impl<T> Box<T> {
         Box(ptr.cast().into())
     }
 
+    /// Constructs a new `Box` with uninitialized contents, with the memory
+    /// being filled with `0` bytes.
+    ///
+    /// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
+    /// of this method.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// let zero = Box::<u32>::new_zeroed();
+    /// let zero = unsafe { zero.assume_init() };
+    ///
+    /// assert_eq!(*zero, 0)
+    /// ```
+    ///
+    /// [zeroed]: ../../std/mem/union.MaybeUninit.html#method.zeroed
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    pub fn new_zeroed() -> Box<mem::MaybeUninit<T>> {
+        unsafe {
+            let mut uninit = Self::new_uninit();
+            ptr::write_bytes::<T>(uninit.as_mut_ptr(), 0, 1);
+            uninit
+        }
+    }
+
     /// Constructs a new `Pin<Box<T>>`. If `T` does not implement `Unpin`, then
     /// `x` will be pinned in memory and unable to be moved.
     #[stable(feature = "pin", since = "1.33.0")]

src/liballoc/rc.rs

@@ -361,6 +361,35 @@ impl<T> Rc<T> {
         }
     }
 
+    /// Constructs a new `Rc` with uninitialized contents, with the memory
+    /// being filled with `0` bytes.
+    ///
+    /// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and
+    /// incorrect usage of this method.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// use std::rc::Rc;
+    ///
+    /// let zero = Rc::<u32>::new_zeroed();
+    /// let zero = unsafe { zero.assume_init() };
+    ///
+    /// assert_eq!(*zero, 0)
+    /// ```
+    ///
+    /// [zeroed]: ../../std/mem/union.MaybeUninit.html#method.zeroed
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    pub fn new_zeroed() -> Rc<mem::MaybeUninit<T>> {
+        unsafe {
+            let mut uninit = Self::new_uninit();
+            ptr::write_bytes::<T>(Rc::get_mut_unchecked(&mut uninit).as_mut_ptr(), 0, 1);
+            uninit
+        }
+    }
+
     /// Constructs a new `Pin<Rc<T>>`. If `T` does not implement `Unpin`, then
     /// `value` will be pinned in memory and unable to be moved.
     #[stable(feature = "pin", since = "1.33.0")]

src/liballoc/sync.rs

@@ -341,6 +341,35 @@ impl<T> Arc<T> {
         }
     }
 
+    /// Constructs a new `Arc` with uninitialized contents, with the memory
+    /// being filled with `0` bytes.
+    ///
+    /// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
+    /// of this method.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(new_uninit)]
+    ///
+    /// use std::sync::Arc;
+    ///
+    /// let zero = Arc::<u32>::new_zeroed();
+    /// let zero = unsafe { zero.assume_init() };
+    ///
+    /// assert_eq!(*zero, 0)
+    /// ```
+    ///
+    /// [zeroed]: ../../std/mem/union.MaybeUninit.html#method.zeroed
+    #[unstable(feature = "new_uninit", issue = "63291")]
+    pub fn new_zeroed() -> Arc<mem::MaybeUninit<T>> {
+        unsafe {
+            let mut uninit = Self::new_uninit();
+            ptr::write_bytes::<T>(Arc::get_mut_unchecked(&mut uninit).as_mut_ptr(), 0, 1);
+            uninit
+        }
+    }
+
     /// Constructs a new `Pin<Arc<T>>`. If `T` does not implement `Unpin`, then
     /// `data` will be pinned in memory and unable to be moved.
     #[stable(feature = "pin", since = "1.33.0")]

src/libcore/cmp.rs

@@ -464,9 +464,9 @@ impl<T: PartialOrd> PartialOrd for Reverse<T> {
     #[inline]
     fn le(&self, other: &Self) -> bool { other.0 <= self.0 }
     #[inline]
-    fn ge(&self, other: &Self) -> bool { other.0 >= self.0 }
-    #[inline]
     fn gt(&self, other: &Self) -> bool { other.0 > self.0 }
+    #[inline]
+    fn ge(&self, other: &Self) -> bool { other.0 >= self.0 }
 }
 
 #[stable(feature = "reverse_cmp_key", since = "1.19.0")]
@@ -1176,9 +1176,9 @@ mod impls {
         #[inline]
         fn le(&self, other: & &B) -> bool { PartialOrd::le(*self, *other) }
         #[inline]
-        fn ge(&self, other: & &B) -> bool { PartialOrd::ge(*self, *other) }
-        #[inline]
         fn gt(&self, other: & &B) -> bool { PartialOrd::gt(*self, *other) }
+        #[inline]
+        fn ge(&self, other: & &B) -> bool { PartialOrd::ge(*self, *other) }
     }
     #[stable(feature = "rust1", since = "1.0.0")]
     impl<A: ?Sized> Ord for &A where A: Ord {
@@ -1208,9 +1208,9 @@ mod impls {
         #[inline]
         fn le(&self, other: &&mut B) -> bool { PartialOrd::le(*self, *other) }
         #[inline]
-        fn ge(&self, other: &&mut B) -> bool { PartialOrd::ge(*self, *other) }
-        #[inline]
         fn gt(&self, other: &&mut B) -> bool { PartialOrd::gt(*self, *other) }
+        #[inline]
+        fn ge(&self, other: &&mut B) -> bool { PartialOrd::ge(*self, *other) }
     }
     #[stable(feature = "rust1", since = "1.0.0")]
     impl<A: ?Sized> Ord for &mut A where A: Ord {

src/librustc/infer/error_reporting/mod.rs

@@ -463,7 +463,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         &self,
         err: &mut DiagnosticBuilder<'_>,
         terr: &TypeError<'tcx>,
-        sp: Span,
     ) {
         use hir::def_id::CrateNum;
         use hir::map::DisambiguatedDefPathData;
@@ -577,14 +576,10 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 };
                 if same_path().unwrap_or(false) {
                     let crate_name = self.tcx.crate_name(did1.krate);
-                    err.span_note(
-                        sp,
-                        &format!(
-                            "Perhaps two different versions \
-                             of crate `{}` are being used?",
-                            crate_name
-                        ),
-                    );
+                    err.note(&format!(
+                        "perhaps two different versions of crate `{}` are being used?",
+                        crate_name
+                    ));
                 }
             }
         };
@@ -1434,7 +1429,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             .unwrap_or_else(|| {
                 self.tcx.hir().body_owner_def_id(hir::BodyId { hir_id: cause.body_id })
             });
-        self.check_and_note_conflicting_crates(diag, terr, span);
+        self.check_and_note_conflicting_crates(diag, terr);
         self.tcx.note_and_explain_type_err(diag, terr, span, body_owner_def_id);
 
         // It reads better to have the error origin as the final

src/librustc/session/config.rs

@@ -12,7 +12,7 @@ use rustc_target::spec::{LinkerFlavor, MergeFunctions, PanicStrategy, RelroLevel
 use rustc_target::spec::{Target, TargetTriple};
 
 use syntax;
-use syntax::ast::{self, IntTy, UintTy};
+use syntax::ast;
 use syntax::source_map::{FileName, FilePathMapping};
 use syntax::edition::{Edition, EDITION_NAME_LIST, DEFAULT_EDITION};
 use syntax::symbol::{sym, Symbol};
@@ -36,8 +36,7 @@ use std::path::{Path, PathBuf};
 
 pub struct Config {
     pub target: Target,
-    pub isize_ty: IntTy,
-    pub usize_ty: UintTy,
+    pub ptr_width: u32,
 }
 
 #[derive(Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
@@ -1621,10 +1620,10 @@ pub fn build_target_config(opts: &Options, sp: &Handler) -> Config {
         FatalError.raise();
     });
 
-    let (isize_ty, usize_ty) = match &target.target_pointer_width[..] {
-        "16" => (ast::IntTy::I16, ast::UintTy::U16),
-        "32" => (ast::IntTy::I32, ast::UintTy::U32),
-        "64" => (ast::IntTy::I64, ast::UintTy::U64),
+    let ptr_width = match &target.target_pointer_width[..] {
+        "16" => 16,
+        "32" => 32,
+        "64" => 64,
         w => sp.fatal(&format!(
             "target specification was invalid: \
              unrecognized target-pointer-width {}",
@@ -1634,8 +1633,7 @@ pub fn build_target_config(opts: &Options, sp: &Handler) -> Config {
 
     Config {
         target,
-        isize_ty,
-        usize_ty,
+        ptr_width,
     }
 }
 

src/librustc/util/common.rs

@@ -7,7 +7,6 @@ use std::fmt::Debug;
 use std::time::{Duration, Instant};
 
 use syntax::symbol::{Symbol, sym};
-use rustc_macros::HashStable;
 use crate::session::Session;
 
 #[cfg(test)]
@@ -16,10 +15,7 @@ mod tests;
 // The name of the associated type for `Fn` return types.
 pub const FN_OUTPUT_NAME: Symbol = sym::Output;
 
-// Useful type to use with `Result<>` indicate that an error has already
-// been reported to the user, so no need to continue checking.
-#[derive(Clone, Copy, Debug, RustcEncodable, RustcDecodable, HashStable)]
-pub struct ErrorReported;
+pub use errors::ErrorReported;
 
 thread_local!(static TIME_DEPTH: Cell<usize> = Cell::new(0));
 

src/librustc_codegen_llvm/builder.rs

@@ -325,8 +325,8 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         use rustc::ty::{Int, Uint};
 
         let new_kind = match ty.kind {
-            Int(Isize) => Int(self.tcx.sess.target.isize_ty),
-            Uint(Usize) => Uint(self.tcx.sess.target.usize_ty),
+            Int(t @ Isize) => Int(t.normalize(self.tcx.sess.target.ptr_width)),
+            Uint(t @ Usize) => Uint(t.normalize(self.tcx.sess.target.ptr_width)),
             ref t @ Uint(_) | ref t @ Int(_) => t.clone(),
             _ => panic!("tried to get overflow intrinsic for op applied to non-int type")
         };

src/librustc_codegen_llvm/intrinsic.rs

@@ -1926,15 +1926,15 @@ unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#,
 fn int_type_width_signed(ty: Ty<'_>, cx: &CodegenCx<'_, '_>) -> Option<(u64, bool)> {
     match ty.kind {
         ty::Int(t) => Some((match t {
-            ast::IntTy::Isize => cx.tcx.sess.target.isize_ty.bit_width().unwrap() as u64,
+            ast::IntTy::Isize => cx.tcx.sess.target.ptr_width as u64,
             ast::IntTy::I8 => 8,
             ast::IntTy::I16 => 16,
             ast::IntTy::I32 => 32,
             ast::IntTy::I64 => 64,
             ast::IntTy::I128 => 128,
         }, true)),
         ty::Uint(t) => Some((match t {
-            ast::UintTy::Usize => cx.tcx.sess.target.usize_ty.bit_width().unwrap() as u64,
+            ast::UintTy::Usize => cx.tcx.sess.target.ptr_width as u64,
             ast::UintTy::U8 => 8,
             ast::UintTy::U16 => 16,
             ast::UintTy::U32 => 32,

src/librustc_error_codes/error_codes/E0062.md

@@ -1,6 +1,6 @@
-This error indicates that during an attempt to build a struct or struct-like
-enum variant, one of the fields was specified more than once. Erroneous code
-example:
+A struct's or struct-like enum variant's field was specified more than once.
+
+Erroneous code example:
 
 ```compile_fail,E0062
 struct Foo {
@@ -15,7 +15,9 @@ fn main() {
 }
 ```
 
-Each field should be specified exactly one time. Example:
+This error indicates that during an attempt to build a struct or struct-like
+enum variant, one of the fields was specified more than once. Each field should
+be specified exactly one time. Example:
 
 ```
 struct Foo {

src/librustc_error_codes/error_codes/E0063.md

@@ -1,5 +1,6 @@
-This error indicates that during an attempt to build a struct or struct-like
-enum variant, one of the fields was not provided. Erroneous code example:
+A struct's or struct-like enum variant's field was not provided.
+
+Erroneous code example:
 
 ```compile_fail,E0063
 struct Foo {

src/librustc_error_codes/error_codes/E0067.md

@@ -1,33 +1,15 @@
-The left-hand side of a compound assignment expression must be a place
-expression. A place expression represents a memory location and includes
-item paths (ie, namespaced variables), dereferences, indexing expressions,
-and field references.
+An invalid left-hand side expression was used on an assignment operation.
 
-Let's start with some erroneous code examples:
+Erroneous code example:
 
 ```compile_fail,E0067
-use std::collections::LinkedList;
-
-// Bad: assignment to non-place expression
-LinkedList::new() += 1;
-
-// ...
-
-fn some_func(i: &mut i32) {
-    i += 12; // Error : '+=' operation cannot be applied on a reference !
-}
+12 += 1; // error!
 ```
 
-And now some working examples:
+You need to have a place expression to be able to assign it something. For
+example:
 
 ```
-let mut i : i32 = 0;
-
-i += 12; // Good !
-
-// ...
-
-fn some_func(i: &mut i32) {
-    *i += 12; // Good !
-}
+let mut x: i8 = 12;
+x += 1; // ok!
 ```

src/librustc_error_codes/error_codes/E0069.md

@@ -1,5 +1,7 @@
 The compiler found a function whose body contains a `return;` statement but
-whose return type is not `()`. An example of this is:
+whose return type is not `()`.
+
+Erroneous code example:
 
 ```compile_fail,E0069
 // error