Auto merge of #78623 - m-ou-se:rollup-m6y5j0m, r=m-ou-se

Rollup of 6 pull requests

Successful merges:

 - #78073 (Add #[inline] to some functions in core::str.)
 - #78596 (Fix doc links to std::fmt)
 - #78599 (Add note to process::arg[s] that args shouldn't be escaped or quoted)
 - #78602 (fix various aliasing issues in the standard library)
 - #78603 (expand: Tweak a comment in implementation of `macro_rules`)
 - #78621 (Inline Default::default() for atomics)

Failed merges:

r? `@ghost`

compiler/rustc_expand/src/mbe/transcribe.rs

@@ -232,17 +232,19 @@ pub(super) fn transcribe<'a>(
                 // the meta-var.
                 let ident = MacroRulesNormalizedIdent::new(orignal_ident);
                 if let Some(cur_matched) = lookup_cur_matched(ident, interp, &repeats) {
-                    if let MatchedNonterminal(ref nt) = cur_matched {
-                        // FIXME #2887: why do we apply a mark when matching a token tree meta-var
-                        // (e.g. `$x:tt`), but not when we are matching any other type of token
-                        // tree?
-                        if let NtTT(ref tt) = **nt {
-                            result.push(tt.clone().into());
+                    if let MatchedNonterminal(nt) = cur_matched {
+                        let token = if let NtTT(tt) = &**nt {
+                            // `tt`s are emitted into the output stream directly as "raw tokens",
+                            // without wrapping them into groups.
+                            tt.clone()
                         } else {
+                            // Other variables are emitted into the output stream as groups with
+                            // `Delimiter::None` to maintain parsing priorities.
+                            // `Interpolated` is currenty used for such groups in rustc parser.
                             marker.visit_span(&mut sp);
-                            let token = TokenTree::token(token::Interpolated(nt.clone()), sp);
-                            result.push(token.into());
-                        }
+                            TokenTree::token(token::Interpolated(nt.clone()), sp)
+                        };
+                        result.push(token.into());
                     } else {
                         // We were unable to descend far enough. This is an error.
                         return Err(cx.struct_span_err(

library/alloc/src/collections/binary_heap.rs

@@ -1036,8 +1036,9 @@ impl<'a, T> Hole<'a, T> {
         debug_assert!(index != self.pos);
         debug_assert!(index < self.data.len());
         unsafe {
-            let index_ptr: *const _ = self.data.get_unchecked(index);
-            let hole_ptr = self.data.get_unchecked_mut(self.pos);
+            let ptr = self.data.as_mut_ptr();
+            let index_ptr: *const _ = ptr.add(index);
+            let hole_ptr = ptr.add(self.pos);
             ptr::copy_nonoverlapping(index_ptr, hole_ptr, 1);
         }
         self.pos = index;

library/alloc/src/macros.rs

@@ -71,7 +71,7 @@ macro_rules! vec {
 ///
 /// Additional parameters passed to `format!` replace the `{}`s within the
 /// formatting string in the order given unless named or positional parameters
-/// are used; see [`std::fmt`][fmt] for more information.
+/// are used; see [`std::fmt`] for more information.
 ///
 /// A common use for `format!` is concatenation and interpolation of strings.
 /// The same convention is used with [`print!`] and [`write!`] macros,
@@ -80,7 +80,7 @@ macro_rules! vec {
 /// To convert a single value to a string, use the [`to_string`] method. This
 /// will use the [`Display`] formatting trait.
 ///
-/// [fmt]: core::fmt
+/// [`std::fmt`]: ../std/fmt/index.html
 /// [`print!`]: ../std/macro.print.html
 /// [`write!`]: core::write
 /// [`to_string`]: crate::string::ToString

library/core/src/fmt/num.rs

@@ -595,7 +595,6 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R
     // 2^128 is about 3*10^38, so 39 gives an extra byte of space
     let mut buf = [MaybeUninit::<u8>::uninit(); 39];
     let mut curr = buf.len() as isize;
-    let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
 
     let (n, rem) = udiv_1e19(n);
     parse_u64_into(rem, &mut buf, &mut curr);
@@ -606,7 +605,11 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R
         // SAFETY: Guaranteed that we wrote at most 19 bytes, and there must be space
         // remaining since it has length 39
         unsafe {
-            ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
+            ptr::write_bytes(
+                MaybeUninit::slice_as_mut_ptr(&mut buf).offset(target),
+                b'0',
+                (curr - target) as usize,
+            );
         }
         curr = target;
 
@@ -615,6 +618,9 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R
         // Should this following branch be annotated with unlikely?
         if n != 0 {
             let target = (buf.len() - 38) as isize;
+            // The raw `buf_ptr` pointer is only valid until `buf` is used the next time,
+            // buf `buf` is not used in this scope so we are good.
+            let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
             // SAFETY: At this point we wrote at most 38 bytes, pad up to that point,
             // There can only be at most 1 digit remaining.
             unsafe {
@@ -629,7 +635,7 @@ fn fmt_u128(n: u128, is_nonnegative: bool, f: &mut fmt::Formatter<'_>) -> fmt::R
     // UTF-8 since `DEC_DIGITS_LUT` is
     let buf_slice = unsafe {
         str::from_utf8_unchecked(slice::from_raw_parts(
-            buf_ptr.offset(curr),
+            MaybeUninit::slice_as_mut_ptr(&mut buf).offset(curr),
             buf.len() - curr as usize,
         ))
     };

library/core/src/hash/sip.rs

@@ -111,7 +111,7 @@ macro_rules! load_int_le {
         debug_assert!($i + mem::size_of::<$int_ty>() <= $buf.len());
         let mut data = 0 as $int_ty;
         ptr::copy_nonoverlapping(
-            $buf.get_unchecked($i),
+            $buf.as_ptr().add($i),
             &mut data as *mut _ as *mut u8,
             mem::size_of::<$int_ty>(),
         );

library/core/src/macros/mod.rs

@@ -327,7 +327,7 @@ macro_rules! r#try {
 ///
 /// See [`std::fmt`] for more information on the format string syntax.
 ///
-/// [`std::fmt`]: crate::fmt
+/// [`std::fmt`]: ../std/fmt/index.html
 /// [`fmt::Write`]: crate::fmt::Write
 /// [`io::Write`]: ../std/io/trait.Write.html
 /// [`fmt::Result`]: crate::fmt::Result

library/core/src/mem/maybe_uninit.rs

@@ -842,13 +842,13 @@ impl<T> MaybeUninit<T> {
     #[unstable(feature = "maybe_uninit_slice", issue = "63569")]
     #[inline(always)]
     pub fn slice_as_ptr(this: &[MaybeUninit<T>]) -> *const T {
-        this as *const [MaybeUninit<T>] as *const T
+        this.as_ptr() as *const T
     }
 
     /// Gets a mutable pointer to the first element of the array.
     #[unstable(feature = "maybe_uninit_slice", issue = "63569")]
     #[inline(always)]
     pub fn slice_as_mut_ptr(this: &mut [MaybeUninit<T>]) -> *mut T {
-        this as *mut [MaybeUninit<T>] as *mut T
+        this.as_mut_ptr() as *mut T
     }
 }

library/core/src/str/error.rs

@@ -72,6 +72,7 @@ impl Utf8Error {
     /// assert_eq!(1, error.valid_up_to());
     /// ```
     #[stable(feature = "utf8_error", since = "1.5.0")]
+    #[inline]
     pub fn valid_up_to(&self) -> usize {
         self.valid_up_to
     }
@@ -92,6 +93,7 @@ impl Utf8Error {
     ///
     /// [U+FFFD]: ../../std/char/constant.REPLACEMENT_CHARACTER.html
     #[stable(feature = "utf8_error_error_len", since = "1.20.0")]
+    #[inline]
     pub fn error_len(&self) -> Option<usize> {
         self.error_len.map(|len| len as usize)
     }

library/core/src/str/iter.rs

@@ -326,6 +326,7 @@ unsafe impl TrustedLen for Bytes<'_> {}
 #[doc(hidden)]
 #[unstable(feature = "trusted_random_access", issue = "none")]
 unsafe impl TrustedRandomAccess for Bytes<'_> {
+    #[inline]
     fn may_have_side_effect() -> bool {
         false
     }

library/core/src/str/mod.rs

@@ -1712,6 +1712,7 @@ impl str {
     ///
     /// assert_eq!("Hello\tworld", s.trim());
     /// ```
+    #[inline]
     #[must_use = "this returns the trimmed string as a slice, \
                   without modifying the original"]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -1749,6 +1750,7 @@ impl str {
     /// let s = "  עברית  ";
     /// assert!(Some('ע') == s.trim_start().chars().next());
     /// ```
+    #[inline]
     #[must_use = "this returns the trimmed string as a new slice, \
                   without modifying the original"]
     #[stable(feature = "trim_direction", since = "1.30.0")]
@@ -1786,6 +1788,7 @@ impl str {
     /// let s = "  עברית  ";
     /// assert!(Some('ת') == s.trim_end().chars().rev().next());
     /// ```
+    #[inline]
     #[must_use = "this returns the trimmed string as a new slice, \
                   without modifying the original"]
     #[stable(feature = "trim_direction", since = "1.30.0")]
@@ -1824,6 +1827,7 @@ impl str {
     /// let s = "  עברית";
     /// assert!(Some('ע') == s.trim_left().chars().next());
     /// ```
+    #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_deprecated(
         since = "1.33.0",
@@ -1865,6 +1869,7 @@ impl str {
     /// let s = "עברית  ";
     /// assert!(Some('ת') == s.trim_right().chars().rev().next());
     /// ```
+    #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_deprecated(
         since = "1.33.0",
@@ -2260,6 +2265,7 @@ impl str {
     /// assert_eq!("GRüßE, JüRGEN ❤", s);
     /// ```
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[inline]
     pub fn make_ascii_uppercase(&mut self) {
         // SAFETY: safe because we transmute two types with the same layout.
         let me = unsafe { self.as_bytes_mut() };
@@ -2286,6 +2292,7 @@ impl str {
     /// assert_eq!("grÜße, jÜrgen ❤", s);
     /// ```
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[inline]
     pub fn make_ascii_lowercase(&mut self) {
         // SAFETY: safe because we transmute two types with the same layout.
         let me = unsafe { self.as_bytes_mut() };
@@ -2423,6 +2430,7 @@ impl AsRef<[u8]> for str {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Default for &str {
     /// Creates an empty str
+    #[inline]
     fn default() -> Self {
         ""
     }
@@ -2431,6 +2439,7 @@ impl Default for &str {
 #[stable(feature = "default_mut_str", since = "1.28.0")]
 impl Default for &mut str {
     /// Creates an empty mutable str
+    #[inline]
     fn default() -> Self {
         // SAFETY: The empty string is valid UTF-8.
         unsafe { from_utf8_unchecked_mut(&mut []) }

library/core/src/sync/atomic.rs

@@ -155,6 +155,7 @@ pub struct AtomicBool {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Default for AtomicBool {
     /// Creates an `AtomicBool` initialized to `false`.
+    #[inline]
     fn default() -> Self {
         Self::new(false)
     }
@@ -1212,6 +1213,7 @@ macro_rules! atomic_int {
 
         #[$stable]
         impl Default for $atomic_type {
+            #[inline]
             fn default() -> Self {
                 Self::new(Default::default())
             }

library/std/src/process.rs

@@ -557,6 +557,11 @@ impl Command {
     ///
     /// [`args`]: Command::args
     ///
+    /// Note that the argument is not passed through a shell, but given
+    /// literally to the program. This means that shell syntax like quotes,
+    /// escaped characters, word splitting, glob patterns, substitution, etc.
+    /// have no effect.
+    ///
     /// # Examples
     ///
     /// Basic usage:
@@ -582,6 +587,11 @@ impl Command {
     ///
     /// [`arg`]: Command::arg
     ///
+    /// Note that the arguments are not passed through a shell, but given
+    /// literally to the program. This means that shell syntax like quotes,
+    /// escaped characters, word splitting, glob patterns, substitution, etc.
+    /// have no effect.
+    ///
     /// # Examples
     ///
     /// Basic usage:

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

@@ -178,7 +178,8 @@ impl Thread {
                     tv_nsec: nsecs,
                 };
                 secs -= ts.tv_sec as u64;
-                if libc::nanosleep(&ts, &mut ts) == -1 {
+                let ts_ptr = &mut ts as *mut _;
+                if libc::nanosleep(ts_ptr, ts_ptr) == -1 {
                     assert_eq!(os::errno(), libc::EINTR);
                     secs += ts.tv_sec as u64;
                     nsecs = ts.tv_nsec;