Auto merge of #3506 - rust-lang:rustup-2024-04-24, r=RalfJung

Automatic Rustup

8 files changed, 104 insertions, 23 deletions

diff --git a/library/core/src/alloc/layout.rs b/library/core/src/alloc/layout.rs
index 2a02870e30b..0b92767c932 100644
--- a/library/core/src/alloc/layout.rs
+++ b/library/core/src/alloc/layout.rs
@@ -25,7 +25,9 @@ const fn size_align<T>() -> (usize, usize) {
 /// An instance of `Layout` describes a particular layout of memory.
 /// You build a `Layout` up as an input to give to an allocator.
 ///
-/// All layouts have an associated size and a power-of-two alignment.
+/// All layouts have an associated size and a power-of-two alignment. The size, when rounded up to
+/// the nearest multiple of `align`, does not overflow isize (i.e., the rounded value will always be
+/// less than or equal to `isize::MAX`).
 ///
 /// (Note that layouts are *not* required to have non-zero size,
 /// even though `GlobalAlloc` requires that all memory requests
diff --git a/library/core/src/fmt/rt.rs b/library/core/src/fmt/rt.rs
index 5e4dac8f49b..92626feabf3 100644
--- a/library/core/src/fmt/rt.rs
+++ b/library/core/src/fmt/rt.rs
@@ -153,7 +153,7 @@ impl<'a> Argument<'a> {
     ///
     /// # Safety
     ///
-    /// This argument must actually be a placeholer argument.
+    /// This argument must actually be a placeholder argument.
     ///
     // FIXME: Transmuting formatter in new and indirectly branching to/calling
     // it here is an explicit CFI violation.
diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index 92f1bd27408..7ace874fa90 100644
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -1987,6 +1987,13 @@ extern "rust-intrinsic" {
     /// The stabilized versions of this intrinsic are available on the integer
     /// primitives via the `count_ones` method. For example,
     /// [`u32::count_ones`]
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "const_ctpop", since = "1.40.0")]
+    #[rustc_safe_intrinsic]
+    #[rustc_nounwind]
+    pub fn ctpop<T: Copy>(x: T) -> u32;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "const_ctpop", since = "1.40.0")]
     #[rustc_safe_intrinsic]
     #[rustc_nounwind]
@@ -2028,6 +2035,13 @@ extern "rust-intrinsic" {
     /// let num_leading = ctlz(x);
     /// assert_eq!(num_leading, 16);
     /// ```
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "const_ctlz", since = "1.40.0")]
+    #[rustc_safe_intrinsic]
+    #[rustc_nounwind]
+    pub fn ctlz<T: Copy>(x: T) -> u32;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "const_ctlz", since = "1.40.0")]
     #[rustc_safe_intrinsic]
     #[rustc_nounwind]
@@ -2050,6 +2064,12 @@ extern "rust-intrinsic" {
     /// let num_leading = unsafe { ctlz_nonzero(x) };
     /// assert_eq!(num_leading, 3);
     /// ```
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "constctlz", since = "1.50.0")]
+    #[rustc_nounwind]
+    pub fn ctlz_nonzero<T: Copy>(x: T) -> u32;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "constctlz", since = "1.50.0")]
     #[rustc_nounwind]
     pub fn ctlz_nonzero<T: Copy>(x: T) -> T;
@@ -2090,6 +2110,13 @@ extern "rust-intrinsic" {
     /// let num_trailing = cttz(x);
     /// assert_eq!(num_trailing, 16);
     /// ```
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "const_cttz", since = "1.40.0")]
+    #[rustc_safe_intrinsic]
+    #[rustc_nounwind]
+    pub fn cttz<T: Copy>(x: T) -> u32;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "const_cttz", since = "1.40.0")]
     #[rustc_safe_intrinsic]
     #[rustc_nounwind]
@@ -2112,6 +2139,12 @@ extern "rust-intrinsic" {
     /// let num_trailing = unsafe { cttz_nonzero(x) };
     /// assert_eq!(num_trailing, 3);
     /// ```
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "const_cttz_nonzero", since = "1.53.0")]
+    #[rustc_nounwind]
+    pub fn cttz_nonzero<T: Copy>(x: T) -> u32;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "const_cttz_nonzero", since = "1.53.0")]
     #[rustc_nounwind]
     pub fn cttz_nonzero<T: Copy>(x: T) -> T;
@@ -2288,6 +2321,13 @@ extern "rust-intrinsic" {
     /// The stabilized versions of this intrinsic are available on the integer
     /// primitives via the `rotate_left` method. For example,
     /// [`u32::rotate_left`]
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "const_int_rotate", since = "1.40.0")]
+    #[rustc_safe_intrinsic]
+    #[rustc_nounwind]
+    pub fn rotate_left<T: Copy>(x: T, shift: u32) -> T;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "const_int_rotate", since = "1.40.0")]
     #[rustc_safe_intrinsic]
     #[rustc_nounwind]
@@ -2303,6 +2343,13 @@ extern "rust-intrinsic" {
     /// The stabilized versions of this intrinsic are available on the integer
     /// primitives via the `rotate_right` method. For example,
     /// [`u32::rotate_right`]
+    #[cfg(not(bootstrap))]
+    #[rustc_const_stable(feature = "const_int_rotate", since = "1.40.0")]
+    #[rustc_safe_intrinsic]
+    #[rustc_nounwind]
+    pub fn rotate_right<T: Copy>(x: T, shift: u32) -> T;
+
+    #[cfg(bootstrap)]
     #[rustc_const_stable(feature = "const_int_rotate", since = "1.40.0")]
     #[rustc_safe_intrinsic]
     #[rustc_nounwind]
diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs
index b9d771ba359..5a0958fdc89 100644
--- a/library/core/src/num/nonzero.rs
+++ b/library/core/src/num/nonzero.rs
@@ -527,7 +527,12 @@ macro_rules! nonzero_integer {
             #[inline]
             pub const fn leading_zeros(self) -> u32 {
                 // SAFETY: since `self` cannot be zero, it is safe to call `ctlz_nonzero`.
-                unsafe { intrinsics::ctlz_nonzero(self.get() as $UnsignedPrimitive) as u32 }
+                unsafe {
+                    #[cfg(not(bootstrap))]
+                    return intrinsics::ctlz_nonzero(self.get() as $UnsignedPrimitive);
+                    #[cfg(bootstrap)]
+                    return intrinsics::ctlz_nonzero(self.get() as $UnsignedPrimitive) as u32;
+                }
             }
 
             /// Returns the number of trailing zeros in the binary representation
@@ -551,7 +556,12 @@ macro_rules! nonzero_integer {
             #[inline]
             pub const fn trailing_zeros(self) -> u32 {
                 // SAFETY: since `self` cannot be zero, it is safe to call `cttz_nonzero`.
-                unsafe { intrinsics::cttz_nonzero(self.get() as $UnsignedPrimitive) as u32 }
+                unsafe {
+                    #[cfg(not(bootstrap))]
+                    return intrinsics::cttz_nonzero(self.get() as $UnsignedPrimitive);
+                    #[cfg(bootstrap)]
+                    return intrinsics::cttz_nonzero(self.get() as $UnsignedPrimitive) as u32;
+                }
             }
 
             /// Returns the number of ones in the binary representation of `self`.
diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
index c13763243f0..ea14d769cc1 100644
--- a/library/core/src/num/uint_macros.rs
+++ b/library/core/src/num/uint_macros.rs
@@ -77,7 +77,10 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[inline(always)]
         pub const fn count_ones(self) -> u32 {
-            intrinsics::ctpop(self as $ActualT) as u32
+            #[cfg(not(bootstrap))]
+            return intrinsics::ctpop(self as $ActualT);
+            #[cfg(bootstrap)]
+            return intrinsics::ctpop(self as $ActualT) as u32;
         }
 
         /// Returns the number of zeros in the binary representation of `self`.
@@ -119,7 +122,10 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[inline(always)]
         pub const fn leading_zeros(self) -> u32 {
-            intrinsics::ctlz(self as $ActualT) as u32
+            #[cfg(not(bootstrap))]
+            return intrinsics::ctlz(self as $ActualT);
+            #[cfg(bootstrap)]
+            return intrinsics::ctlz(self as $ActualT) as u32;
         }
 
         /// Returns the number of trailing zeros in the binary representation
@@ -140,7 +146,10 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[inline(always)]
         pub const fn trailing_zeros(self) -> u32 {
-            intrinsics::cttz(self) as u32
+            #[cfg(not(bootstrap))]
+            return intrinsics::cttz(self);
+            #[cfg(bootstrap)]
+            return intrinsics::cttz(self) as u32;
         }
 
         /// Returns the number of leading ones in the binary representation of `self`.
@@ -205,7 +214,10 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[inline(always)]
         pub const fn rotate_left(self, n: u32) -> Self {
-            intrinsics::rotate_left(self, n as $SelfT)
+            #[cfg(not(bootstrap))]
+            return intrinsics::rotate_left(self, n);
+            #[cfg(bootstrap)]
+            return intrinsics::rotate_left(self, n as $SelfT);
         }
 
         /// Shifts the bits to the right by a specified amount, `n`,
@@ -230,7 +242,10 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[inline(always)]
         pub const fn rotate_right(self, n: u32) -> Self {
-            intrinsics::rotate_right(self, n as $SelfT)
+            #[cfg(not(bootstrap))]
+            return intrinsics::rotate_right(self, n);
+            #[cfg(bootstrap)]
+            return intrinsics::rotate_right(self, n as $SelfT);
         }
 
         /// Reverses the byte order of the integer.
diff --git a/library/core/src/option.rs b/library/core/src/option.rs
index 631e1654ce0..1e3ed0f7c49 100644
--- a/library/core/src/option.rs
+++ b/library/core/src/option.rs
@@ -554,7 +554,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use crate::iter::{self, FusedIterator, TrustedLen};
-use crate::panicking::{panic, panic_str};
+use crate::panicking::{panic, panic_display};
 use crate::pin::Pin;
 use crate::{
     cmp, convert, hint, mem,
@@ -1991,7 +1991,7 @@ const fn unwrap_failed() -> ! {
 #[track_caller]
 #[rustc_const_unstable(feature = "const_option", issue = "67441")]
 const fn expect_failed(msg: &str) -> ! {
-    panic_str(msg)
+    panic_display(&msg)
 }
 
 /////////////////////////////////////////////////////////////////////////////
diff --git a/library/core/src/panic.rs b/library/core/src/panic.rs
index b520efe93f9..8771f40f9b4 100644
--- a/library/core/src/panic.rs
+++ b/library/core/src/panic.rs
@@ -27,9 +27,9 @@ pub macro panic_2015 {
     ($msg:literal $(,)?) => (
         $crate::panicking::panic($msg)
     ),
-    // Use `panic_str` instead of `panic_display::<&str>` for non_fmt_panic lint.
+    // Use `panic_str_2015` instead of `panic_display::<&str>` for non_fmt_panic lint.
     ($msg:expr $(,)?) => ({
-        $crate::panicking::panic_str($msg);
+        $crate::panicking::panic_str_2015($msg);
     }),
     // Special-case the single-argument case for const_panic.
     ("{}", $arg:expr $(,)?) => ({
diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs
index cbb0a7d61db..3ee56e6c579 100644
--- a/library/core/src/panicking.rs
+++ b/library/core/src/panicking.rs
@@ -124,8 +124,8 @@ pub const fn panic_nounwind_fmt(fmt: fmt::Arguments<'_>, force_no_backtrace: boo
 // above.
 
 /// The underlying implementation of core's `panic!` macro when no formatting is used.
-// never inline unless panic_immediate_abort to avoid code
-// bloat at the call sites as much as possible
+// Never inline unless panic_immediate_abort to avoid code
+// bloat at the call sites as much as possible.
 #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)]
 #[cfg_attr(feature = "panic_immediate_abort", inline)]
 #[track_caller]
@@ -138,6 +138,11 @@ pub const fn panic(expr: &'static str) -> ! {
     // truncation and padding (even though none is used here). Using
     // Arguments::new_const may allow the compiler to omit Formatter::pad from the
     // output binary, saving up to a few kilobytes.
+    // However, this optimization only works for `'static` strings: `new_const` also makes this
+    // message return `Some` from `Arguments::as_str`, which means it can become part of the panic
+    // payload without any allocation or copying. Shorter-lived strings would become invalid as
+    // stack frames get popped during unwinding, and couldn't be directly referenced from the
+    // payload.
     panic_fmt(fmt::Arguments::new_const(&[expr]));
 }
 
@@ -223,14 +228,6 @@ pub fn panic_nounwind_nobacktrace(expr: &'static str) -> ! {
     panic_nounwind_fmt(fmt::Arguments::new_const(&[expr]), /* force_no_backtrace */ true);
 }
 
-#[inline]
-#[track_caller]
-#[rustc_diagnostic_item = "panic_str"]
-#[rustc_const_unstable(feature = "panic_internals", issue = "none")]
-pub const fn panic_str(expr: &str) -> ! {
-    panic_display(&expr);
-}
-
 #[track_caller]
 #[cfg_attr(not(feature = "panic_immediate_abort"), inline(never), cold)]
 #[cfg_attr(feature = "panic_immediate_abort", inline)]
@@ -246,6 +243,16 @@ pub fn unreachable_display<T: fmt::Display>(x: &T) -> ! {
     panic_fmt(format_args!("internal error: entered unreachable code: {}", *x));
 }
 
+/// This exists solely for the 2015 edition `panic!` macro to trigger
+/// a lint on `panic!(my_str_variable);`.
+#[inline]
+#[track_caller]
+#[rustc_diagnostic_item = "panic_str_2015"]
+#[rustc_const_unstable(feature = "panic_internals", issue = "none")]
+pub const fn panic_str_2015(expr: &str) -> ! {
+    panic_display(&expr);
+}
+
 #[inline]
 #[track_caller]
 #[rustc_do_not_const_check] // hooked by const-eval