Rollup of 14 pull requests

.gitmodules

@@ -34,7 +34,7 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
 	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/13.0-2021-08-08
+	branch = rustc/13.0-2021-09-30
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book
 	url = https://github.com/rust-embedded/book.git

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -683,31 +683,53 @@ impl<'a> AstValidator<'a> {
         }
     }
 
+    fn emit_e0568(&self, span: Span, ident_span: Span) {
+        struct_span_err!(
+            self.session,
+            span,
+            E0568,
+            "auto traits cannot have super traits or lifetime bounds"
+        )
+        .span_label(ident_span, "auto trait cannot have super traits or lifetime bounds")
+        .span_suggestion(
+            span,
+            "remove the super traits or lifetime bounds",
+            String::new(),
+            Applicability::MachineApplicable,
+        )
+        .emit();
+    }
+
     fn deny_super_traits(&self, bounds: &GenericBounds, ident_span: Span) {
-        if let [first @ last] | [first, .., last] = &bounds[..] {
-            let span = first.span().to(last.span());
-            struct_span_err!(self.session, span, E0568, "auto traits cannot have super traits")
-                .span_label(ident_span, "auto trait cannot have super traits")
-                .span_suggestion(
-                    span,
-                    "remove the super traits",
-                    String::new(),
-                    Applicability::MachineApplicable,
-                )
-                .emit();
+        if let [.., last] = &bounds[..] {
+            let span = ident_span.shrink_to_hi().to(last.span());
+            self.emit_e0568(span, ident_span);
+        }
+    }
+
+    fn deny_where_clause(&self, where_clause: &WhereClause, ident_span: Span) {
+        if !where_clause.predicates.is_empty() {
+            self.emit_e0568(where_clause.span, ident_span);
         }
     }
 
     fn deny_items(&self, trait_items: &[P<AssocItem>], ident_span: Span) {
         if !trait_items.is_empty() {
             let spans: Vec<_> = trait_items.iter().map(|i| i.ident.span).collect();
+            let total_span = trait_items.first().unwrap().span.to(trait_items.last().unwrap().span);
             struct_span_err!(
                 self.session,
                 spans,
                 E0380,
-                "auto traits cannot have methods or associated items"
+                "auto traits cannot have associated items"
+            )
+            .span_suggestion(
+                total_span,
+                "remove these associated items",
+                String::new(),
+                Applicability::MachineApplicable,
             )
-            .span_label(ident_span, "auto trait cannot have items")
+            .span_label(ident_span, "auto trait cannot have associated items")
             .emit();
         }
     }
@@ -1184,6 +1206,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                     // Auto traits cannot have generics, super traits nor contain items.
                     self.deny_generic_params(generics, item.ident.span);
                     self.deny_super_traits(bounds, item.ident.span);
+                    self.deny_where_clause(&generics.where_clause, item.ident.span);
                     self.deny_items(trait_items, item.ident.span);
                 }
                 self.no_questions_in_bounds(bounds, "supertraits", true);

compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs

@@ -171,9 +171,7 @@ impl OutlivesSuggestionBuilder {
         let outlived_fr_name = self.region_vid_to_name(mbcx, errci.outlived_fr);
 
         if let (Some(fr_name), Some(outlived_fr_name)) = (fr_name, outlived_fr_name) {
-            if let RegionNameSource::Static = outlived_fr_name.source {
-                diag.help(&format!("consider replacing `{}` with `'static`", fr_name));
-            } else {
+            if !matches!(outlived_fr_name.source, RegionNameSource::Static) {
                 diag.help(&format!(
                     "consider adding the following bound: `{}: {}`",
                     fr_name, outlived_fr_name

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -102,7 +102,7 @@ impl NonConstOp for FnCallUnstable {
         );
 
         if ccx.is_const_stable_const_fn() {
-            err.help("Const-stable functions can only call other const-stable functions");
+            err.help("const-stable functions can only call other const-stable functions");
         } else if ccx.tcx.sess.is_nightly_build() {
             if let Some(feature) = feature {
                 err.help(&format!(

compiler/rustc_lint/src/nonstandard_style.rs

@@ -437,12 +437,13 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
             if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
             {
                 if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
-                    for field in field_pats.iter() {
-                        if field.ident != ident {
-                            // Only check if a new name has been introduced, to avoid warning
-                            // on both the struct definition and this pattern.
-                            self.check_snake_case(cx, "variable", &ident);
-                        }
+                    if field_pats
+                        .iter()
+                        .any(|field| !field.is_shorthand && field.pat.hir_id == p.hir_id)
+                    {
+                        // Only check if a new name has been introduced, to avoid warning
+                        // on both the struct definition and this pattern.
+                        self.check_snake_case(cx, "variable", &ident);
                     }
                     return;
                 }

compiler/rustc_typeck/src/check/check.rs

@@ -58,7 +58,7 @@ pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Ab
             tcx.sess,
             span,
             E0781,
-            "the `\"C-cmse-nonsecure-call\"` ABI is only allowed on function pointers."
+            "the `\"C-cmse-nonsecure-call\"` ABI is only allowed on function pointers"
         )
         .emit()
     }

library/alloc/src/collections/vec_deque/pair_slices.rs

@@ -20,10 +20,10 @@ use super::VecDeque;
 ///
 /// and the uneven remainder of either A or B is skipped.
 pub struct PairSlices<'a, 'b, T> {
-    pub(crate) a0: &'a mut [T],
-    pub(crate) a1: &'a mut [T],
-    pub(crate) b0: &'b [T],
-    pub(crate) b1: &'b [T],
+    a0: &'a mut [T],
+    a1: &'a mut [T],
+    b0: &'b [T],
+    b1: &'b [T],
 }
 
 impl<'a, 'b, T> PairSlices<'a, 'b, T> {

library/core/src/num/int_macros.rs

@@ -2235,6 +2235,46 @@ macro_rules! int_impl {
             }
         }
 
+        /// Computes the absolute difference between `self` and `other`.
+        ///
+        /// This function always returns the correct answer without overflow or
+        /// panics by returning an unsigned integer.
+        ///
+        /// # Examples
+        ///
+        /// Basic usage:
+        ///
+        /// ```
+        /// #![feature(int_abs_diff)]
+        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")]
+        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")]
+        #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")]
+        #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")]
+        /// ```
+        #[unstable(feature = "int_abs_diff", issue = "89492")]
+        #[inline]
+        pub const fn abs_diff(self, other: Self) -> $UnsignedT {
+            if self < other {
+                // Converting a non-negative x from signed to unsigned by using
+                // `x as U` is left unchanged, but a negative x is converted
+                // to value x + 2^N. Thus if `s` and `o` are binary variables
+                // respectively indicating whether `self` and `other` are
+                // negative, we are computing the mathematical value:
+                //
+                //    (other + o*2^N) - (self + s*2^N)    mod  2^N
+                //    other - self + (o-s)*2^N            mod  2^N
+                //    other - self                        mod  2^N
+                //
+                // Finally, taking the mod 2^N of the mathematical value of
+                // `other - self` does not change it as it already is
+                // in the range [0, 2^N).
+                (other as $UnsignedT).wrapping_sub(self as $UnsignedT)
+            } else {
+                (self as $UnsignedT).wrapping_sub(other as $UnsignedT)
+            }
+        }
+
         /// Returns a number representing sign of `self`.
         ///
         ///  - `0` if the number is zero

library/core/src/num/uint_macros.rs

@@ -1490,6 +1490,33 @@ macro_rules! uint_impl {
             (c, b | d)
         }
 
+        /// Computes the absolute difference between `self` and `other`.
+        ///
+        /// # Examples
+        ///
+        /// Basic usage:
+        ///
+        /// ```
+        /// #![feature(int_abs_diff)]
+        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($SelfT), ");")]
+        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($SelfT), ");")]
+        /// ```
+        #[unstable(feature = "int_abs_diff", issue = "89492")]
+        #[inline]
+        pub const fn abs_diff(self, other: Self) -> Self {
+            if mem::size_of::<Self>() == 1 {
+                // Trick LLVM into generating the psadbw instruction when SSE2
+                // is available and this function is autovectorized for u8's.
+                (self as i32).wrapping_sub(other as i32).abs() as Self
+            } else {
+                if self < other {
+                    other - self
+                } else {
+                    self - other
+                }
+            }
+        }
+
         /// Calculates the multiplication of `self` and `rhs`.
         ///
         /// Returns a tuple of the multiplication along with a boolean

library/std/src/sys/unix/os.rs

@@ -380,20 +380,24 @@ pub fn current_exe() -> io::Result<PathBuf> {
 
 #[cfg(any(target_os = "solaris", target_os = "illumos"))]
 pub fn current_exe() -> io::Result<PathBuf> {
-    extern "C" {
-        fn getexecname() -> *const c_char;
-    }
-    unsafe {
-        let path = getexecname();
-        if path.is_null() {
-            Err(io::Error::last_os_error())
-        } else {
-            let filename = CStr::from_ptr(path).to_bytes();
-            let path = PathBuf::from(<OsStr as OsStrExt>::from_bytes(filename));
+    if let Ok(path) = crate::fs::read_link("/proc/self/path/a.out") {
+        Ok(path)
+    } else {
+        extern "C" {
+            fn getexecname() -> *const c_char;
+        }
+        unsafe {
+            let path = getexecname();
+            if path.is_null() {
+                Err(io::Error::last_os_error())
+            } else {
+                let filename = CStr::from_ptr(path).to_bytes();
+                let path = PathBuf::from(<OsStr as OsStrExt>::from_bytes(filename));
 
-            // Prepend a current working directory to the path if
-            // it doesn't contain an absolute pathname.
-            if filename[0] == b'/' { Ok(path) } else { getcwd().map(|cwd| cwd.join(path)) }
+                // Prepend a current working directory to the path if
+                // it doesn't contain an absolute pathname.
+                if filename[0] == b'/' { Ok(path) } else { getcwd().map(|cwd| cwd.join(path)) }
+            }
         }
     }
 }

library/std/src/sys/unix/thread.rs

@@ -339,14 +339,18 @@ pub fn available_concurrency() -> io::Result<NonZeroUsize> {
 
             Ok(unsafe { NonZeroUsize::new_unchecked(cpus as usize) })
         } else if #[cfg(target_os = "haiku")] {
-            let mut sinfo: libc::system_info = crate::mem::zeroed();
-            let res = libc::get_system_info(&mut sinfo);
+            // system_info cpu_count field gets the static data set at boot time with `smp_set_num_cpus`
+            // `get_system_info` calls then `smp_get_num_cpus`
+            unsafe {
+                let mut sinfo: libc::system_info = crate::mem::zeroed();
+                let res = libc::get_system_info(&mut sinfo);
 
-            if res != libc::B_OK {
-                return Err(io::Error::last_os_error());
-            }
+                if res != libc::B_OK {
+                    return Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform"));
+                }
 
-            Ok(unsafe { NonZeroUsize::new_unchecked(sinfo.cpu_count as usize) })
+                Ok(NonZeroUsize::new_unchecked(sinfo.cpu_count as usize))
+            }
         } else {
             // FIXME: implement on vxWorks, Redox, l4re
             Err(io::Error::new_const(io::ErrorKind::Unsupported, &"Getting the number of hardware threads is not supported on the target platform"))

library/std/src/time/monotonic.rs

@@ -5,7 +5,7 @@ pub(super) fn monotonize(raw: time::Instant) -> time::Instant {
     inner::monotonize(raw)
 }
 
-#[cfg(all(target_has_atomic = "64", not(target_has_atomic = "128")))]
+#[cfg(any(all(target_has_atomic = "64", not(target_has_atomic = "128")), target_arch = "aarch64"))]
 pub mod inner {
     use crate::sync::atomic::AtomicU64;
     use crate::sync::atomic::Ordering::*;
@@ -71,7 +71,7 @@ pub mod inner {
     }
 }
 
-#[cfg(target_has_atomic = "128")]
+#[cfg(all(target_has_atomic = "128", not(target_arch = "aarch64")))]
 pub mod inner {
     use crate::sync::atomic::AtomicU128;
     use crate::sync::atomic::Ordering::*;

src/etc/check_missing_items.py

@@ -9,7 +9,7 @@
 import sys
 import json
 
-crate = json.load(open(sys.argv[1]))
+crate = json.load(open(sys.argv[1], encoding="utf-8"))
 
 
 def get_local_item(item_id):