Rollup of 11 pull requests

compiler/rustc_data_structures/src/captures.rs

@@ -3,8 +3,6 @@
 /// Basically a workaround; see [this comment] for details.
 ///
 /// [this comment]: https://github.com/rust-lang/rust/issues/34511#issuecomment-373423999
-// FIXME(eddyb) false positive, the lifetime parameter is "phantom" but needed.
-#[allow(unused_lifetimes)]
 pub trait Captures<'a> {}
 
 impl<'a, T: ?Sized> Captures<'a> for T {}

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -11,7 +11,7 @@ use crate::check::{
 use rustc_ast as ast;
 use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticId};
 use rustc_hir as hir;
-use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{ExprKind, Node, QPath};
 use rustc_middle::ty::adjustment::AllowTwoPhase;
@@ -120,8 +120,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                  error_code: &str,
                                  c_variadic: bool,
                                  sugg_unit: bool| {
-            let (span, start_span, args) = match &expr.kind {
-                hir::ExprKind::Call(hir::Expr { span, .. }, args) => (*span, *span, &args[..]),
+            let (span, start_span, args, ctor_of) = match &expr.kind {
+                hir::ExprKind::Call(
+                    hir::Expr {
+                        span,
+                        kind:
+                            hir::ExprKind::Path(hir::QPath::Resolved(
+                                _,
+                                hir::Path { res: Res::Def(DefKind::Ctor(of, _), _), .. },
+                            )),
+                        ..
+                    },
+                    args,
+                ) => (*span, *span, &args[..], Some(of)),
+                hir::ExprKind::Call(hir::Expr { span, .. }, args) => {
+                    (*span, *span, &args[..], None)
+                }
                 hir::ExprKind::MethodCall(path_segment, span, args, _) => (
                     *span,
                     // `sp` doesn't point at the whole `foo.bar()`, only at `bar`.
@@ -137,6 +151,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         })
                         .unwrap_or(*span),
                     &args[1..], // Skip the receiver.
+                    None,       // methods are never ctors
                 ),
                 k => span_bug!(sp, "checking argument types on a non-call: `{:?}`", k),
             };
@@ -157,7 +172,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let mut err = tcx.sess.struct_span_err_with_code(
                 span,
                 &format!(
-                    "this function takes {}{} but {} {} supplied",
+                    "this {} takes {}{} but {} {} supplied",
+                    match ctor_of {
+                        Some(CtorOf::Struct) => "struct",
+                        Some(CtorOf::Variant) => "enum variant",
+                        None => "function",
+                    },
                     if c_variadic { "at least " } else { "" },
                     potentially_plural_count(expected_count, "argument"),
                     potentially_plural_count(arg_count, "argument"),

library/core/src/num/int_macros.rs

@@ -1772,9 +1772,9 @@ macro_rules! int_impl {
         #[inline]
         #[rustc_inherit_overflow_checks]
         pub const fn abs(self) -> Self {
-            // Note that the #[inline] above means that the overflow
-            // semantics of the subtraction depend on the crate we're being
-            // inlined into.
+            // Note that the #[rustc_inherit_overflow_checks] and #[inline]
+            // above mean that the overflow semantics of the subtraction
+            // depend on the crate we're being called from.
             if self.is_negative() {
                 -self
             } else {

library/std/src/backtrace.rs

@@ -399,12 +399,11 @@ impl fmt::Display for Backtrace {
         let mut f = backtrace_rs::BacktraceFmt::new(fmt, style, &mut print_path);
         f.add_context()?;
         for frame in frames {
-            let mut f = f.frame();
             if frame.symbols.is_empty() {
-                f.print_raw(frame.frame.ip(), None, None, None)?;
+                f.frame().print_raw(frame.frame.ip(), None, None, None)?;
             } else {
                 for symbol in frame.symbols.iter() {
-                    f.print_raw_with_column(
+                    f.frame().print_raw_with_column(
                         frame.frame.ip(),
                         symbol.name.as_ref().map(|b| backtrace_rs::SymbolName::new(b)),
                         symbol.filename.as_ref().map(|b| match b {

library/std/src/io/cursor.rs

@@ -205,6 +205,88 @@ impl<T> Cursor<T> {
     }
 }
 
+impl<T> Cursor<T>
+where
+    T: AsRef<[u8]>,
+{
+    /// Returns the remaining length.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(cursor_remaining)]
+    /// use std::io::Cursor;
+    ///
+    /// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);
+    ///
+    /// assert_eq!(buff.remaining(), 5);
+    ///
+    /// buff.set_position(2);
+    /// assert_eq!(buff.remaining(), 3);
+    ///
+    /// buff.set_position(4);
+    /// assert_eq!(buff.remaining(), 1);
+    ///
+    /// buff.set_position(6);
+    /// assert_eq!(buff.remaining(), 0);
+    /// ```
+    #[unstable(feature = "cursor_remaining", issue = "86369")]
+    pub fn remaining(&self) -> u64 {
+        (self.inner.as_ref().len() as u64).checked_sub(self.pos).unwrap_or(0)
+    }
+
+    /// Returns the remaining slice.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(cursor_remaining)]
+    /// use std::io::Cursor;
+    ///
+    /// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);
+    ///
+    /// assert_eq!(buff.remaining_slice(), &[1, 2, 3, 4, 5]);
+    ///
+    /// buff.set_position(2);
+    /// assert_eq!(buff.remaining_slice(), &[3, 4, 5]);
+    ///
+    /// buff.set_position(4);
+    /// assert_eq!(buff.remaining_slice(), &[5]);
+    ///
+    /// buff.set_position(6);
+    /// assert_eq!(buff.remaining_slice(), &[]);
+    /// ```
+    #[unstable(feature = "cursor_remaining", issue = "86369")]
+    pub fn remaining_slice(&self) -> &[u8] {
+        let len = self.pos.min(self.inner.as_ref().len() as u64);
+        &self.inner.as_ref()[(len as usize)..]
+    }
+
+    /// Returns `true` if the remaining slice is empty.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(cursor_remaining)]
+    /// use std::io::Cursor;
+    ///
+    /// let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);
+    ///
+    /// buff.set_position(2);
+    /// assert!(!buff.is_empty());
+    ///
+    /// buff.set_position(5);
+    /// assert!(buff.is_empty());
+    ///
+    /// buff.set_position(10);
+    /// assert!(buff.is_empty());
+    /// ```
+    #[unstable(feature = "cursor_remaining", issue = "86369")]
+    pub fn is_empty(&self) -> bool {
+        self.pos >= self.inner.as_ref().len() as u64
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> Clone for Cursor<T>
 where
@@ -268,7 +350,7 @@ where
     T: AsRef<[u8]>,
 {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        let n = Read::read(&mut self.fill_buf()?, buf)?;
+        let n = Read::read(&mut self.remaining_slice(), buf)?;
         self.pos += n as u64;
         Ok(n)
     }
@@ -291,7 +373,7 @@ where
 
     fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
         let n = buf.len();
-        Read::read_exact(&mut self.fill_buf()?, buf)?;
+        Read::read_exact(&mut self.remaining_slice(), buf)?;
         self.pos += n as u64;
         Ok(())
     }
@@ -308,8 +390,7 @@ where
     T: AsRef<[u8]>,
 {
     fn fill_buf(&mut self) -> io::Result<&[u8]> {
-        let amt = cmp::min(self.pos, self.inner.as_ref().len() as u64);
-        Ok(&self.inner.as_ref()[(amt as usize)..])
+        Ok(self.remaining_slice())
     }
     fn consume(&mut self, amt: usize) {
         self.pos += amt as u64;

library/std/src/os/fortanix_sgx/arch.rs

@@ -33,13 +33,13 @@ pub fn egetkey(request: &Align512<[u8; 512]>) -> Result<Align16<[u8; 16]>, u32>
 
         asm!(
             // rbx is reserved by LLVM
-            "xchg {0}, rbx",
+            "xchg %rbx, {0}",
             "enclu",
-            "mov rbx, {0}",
+            "mov {0}, %rbx",
             inout(reg) request => _,
             inlateout("eax") ENCLU_EGETKEY => error,
             in("rcx") out.as_mut_ptr(),
-            options(nostack),
+            options(att_syntax, nostack),
         );
 
         match error {
@@ -64,14 +64,14 @@ pub fn ereport(
 
         asm!(
             // rbx is reserved by LLVM
-            "xchg {0}, rbx",
+            "xchg %rbx, {0}",
             "enclu",
-            "mov rbx, {0}",
+            "mov {0}, %rbx",
             inout(reg) targetinfo => _,
             in("eax") ENCLU_EREPORT,
             in("rcx") reportdata,
             in("rdx") report.as_mut_ptr(),
-            options(preserves_flags, nostack),
+            options(att_syntax, preserves_flags, nostack),
         );
 
         report.assume_init()

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

@@ -1,8 +1,10 @@
 #![allow(dead_code)]
 
+use super::unsupported;
 use crate::ffi::CStr;
 use crate::io;
 use crate::mem;
+use crate::num::NonZeroUsize;
 use crate::sys::hermit::abi;
 use crate::sys::hermit::thread_local_dtor::run_dtors;
 use crate::time::Duration;
@@ -95,6 +97,10 @@ impl Thread {
     }
 }
 
+pub fn available_concurrency() -> io::Result<NonZeroUsize> {
+    unsupported()
+}
+
 pub mod guard {
     pub type Guard = !;
     pub unsafe fn current() -> Option<Guard> {

library/std/src/sys/sgx/abi/mem.rs

@@ -36,9 +36,9 @@ pub fn image_base() -> u64 {
     let base: u64;
     unsafe {
         asm!(
-            "lea {}, qword ptr [rip + IMAGE_BASE]",
+            "lea IMAGE_BASE(%rip), {}",
             lateout(reg) base,
-            options(nostack, preserves_flags, nomem, pure),
+            options(att_syntax, nostack, preserves_flags, nomem, pure),
         )
     };
     base

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

@@ -1,6 +1,8 @@
 #![cfg_attr(test, allow(dead_code))] // why is this necessary?
+use super::unsupported;
 use crate::ffi::CStr;
 use crate::io;
+use crate::num::NonZeroUsize;
 use crate::time::Duration;
 
 use super::abi::usercalls;
@@ -135,6 +137,10 @@ impl Thread {
     }
 }
 
+pub fn available_concurrency() -> io::Result<NonZeroUsize> {
+    unsupported()
+}
+
 pub mod guard {
     pub type Guard = !;
     pub unsafe fn current() -> Option<Guard> {

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

@@ -2,6 +2,7 @@ use crate::cmp;
 use crate::ffi::CStr;
 use crate::io;
 use crate::mem;
+use crate::num::NonZeroUsize;
 use crate::ptr;
 use crate::sys::{os, stack_overflow};
 use crate::time::Duration;
@@ -198,6 +199,88 @@ impl Drop for Thread {
     }
 }
 
+pub fn available_concurrency() -> io::Result<NonZeroUsize> {
+    cfg_if::cfg_if! {
+        if #[cfg(any(
+            target_os = "android",
+            target_os = "emscripten",
+            target_os = "fuchsia",
+            target_os = "ios",
+            target_os = "linux",
+            target_os = "macos",
+            target_os = "solaris",
+            target_os = "illumos",
+        ))] {
+            match unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) } {
+                -1 => Err(io::Error::last_os_error()),
+                0 => Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform")),
+                cpus => Ok(unsafe { NonZeroUsize::new_unchecked(cpus as usize) }),
+            }
+        } else if #[cfg(any(target_os = "freebsd", target_os = "dragonfly", target_os = "netbsd"))] {
+            use crate::ptr;
+
+            let mut cpus: libc::c_uint = 0;
+            let mut cpus_size = crate::mem::size_of_val(&cpus);
+
+            unsafe {
+                cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint;
+            }
+
+            // Fallback approach in case of errors or no hardware threads.
+            if cpus < 1 {
+                let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
+                let res = unsafe {
+                    libc::sysctl(
+                        mib.as_mut_ptr(),
+                        2,
+                        &mut cpus as *mut _ as *mut _,
+                        &mut cpus_size as *mut _ as *mut _,
+                        ptr::null_mut(),
+                        0,
+                    )
+                };
+
+                // Handle errors if any.
+                if res == -1 {
+                    return Err(io::Error::last_os_error());
+                } else if cpus == 0 {
+                    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(cpus as usize) })
+        } else if #[cfg(target_os = "openbsd")] {
+            use crate::ptr;
+
+            let mut cpus: libc::c_uint = 0;
+            let mut cpus_size = crate::mem::size_of_val(&cpus);
+            let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
+
+            let res = unsafe {
+                libc::sysctl(
+                    mib.as_mut_ptr(),
+                    2,
+                    &mut cpus as *mut _ as *mut _,
+                    &mut cpus_size as *mut _ as *mut _,
+                    ptr::null_mut(),
+                    0,
+                )
+            };
+
+            // Handle errors if any.
+            if res == -1 {
+                return Err(io::Error::last_os_error());
+            } else if cpus == 0 {
+                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(cpus as usize) })
+        } else {
+            // FIXME: implement on vxWorks, Redox, Haiku, l4re
+            Err(io::Error::new_const(io::ErrorKind::Unsupported, &"Getting the number of hardware threads is not supported on the target platform"))
+        }
+    }
+}
+
 #[cfg(all(
     not(target_os = "linux"),
     not(target_os = "freebsd"),