Rollup of 13 pull requests

.gitignore

@@ -69,8 +69,8 @@ __pycache__/
 *$py.class
 
 ## Node
-**node_modules
-**package-lock.json
+node_modules
+package-lock.json
 
 ## Rustdoc GUI tests
 src/test/rustdoc-gui/src/**.lock

compiler/rustc_index/src/bit_set.rs

@@ -841,7 +841,7 @@ impl<T: Idx> GrowableBitSet<T> {
     #[inline]
     pub fn contains(&self, elem: T) -> bool {
         let (word_index, mask) = word_index_and_mask(elem);
-        if let Some(word) = self.bit_set.words.get(word_index) { (word & mask) != 0 } else { false }
+        self.bit_set.words.get(word_index).map_or(false, |word| (word & mask) != 0)
     }
 }
 

compiler/rustc_resolve/src/diagnostics.rs

@@ -1277,6 +1277,34 @@ impl<'a> Resolver<'a> {
 
         err.emit();
     }
+
+    crate fn find_similarly_named_module_or_crate(
+        &mut self,
+        ident: Symbol,
+        current_module: &Module<'a>,
+    ) -> Option<Symbol> {
+        let mut candidates = self
+            .extern_prelude
+            .iter()
+            .map(|(ident, _)| ident.name)
+            .chain(
+                self.module_map
+                    .iter()
+                    .filter(|(_, module)| {
+                        current_module.is_ancestor_of(module) && !ptr::eq(current_module, *module)
+                    })
+                    .map(|(_, module)| module.kind.name())
+                    .flatten(),
+            )
+            .filter(|c| !c.to_string().is_empty())
+            .collect::<Vec<_>>();
+        candidates.sort();
+        candidates.dedup();
+        match find_best_match_for_name(&candidates, ident, None) {
+            Some(sugg) if sugg == ident => None,
+            sugg => sugg,
+        }
+    }
 }
 
 impl<'a, 'b> ImportResolver<'a, 'b> {

compiler/rustc_resolve/src/lib.rs

@@ -2555,7 +2555,22 @@ impl<'a> Resolver<'a> {
 
                             (format!("use of undeclared type `{}`", ident), suggestion)
                         } else {
-                            (format!("use of undeclared crate or module `{}`", ident), None)
+                            (
+                                format!("use of undeclared crate or module `{}`", ident),
+                                self.find_similarly_named_module_or_crate(
+                                    ident.name,
+                                    &parent_scope.module,
+                                )
+                                .map(|sugg| {
+                                    (
+                                        vec![(ident.span, sugg.to_string())],
+                                        String::from(
+                                            "there is a crate or module with a similar name",
+                                        ),
+                                        Applicability::MaybeIncorrect,
+                                    )
+                                }),
+                            )
                         }
                     } else {
                         let parent = path[i - 1].ident.name;

config.toml.example

@@ -423,6 +423,18 @@ changelog-seen = 2
 # set this value to `true`.
 #debug-logging = rust.debug-assertions (boolean)
 
+# Whether or not overflow checks are enabled for the compiler and standard
+# library.
+#
+# Defaults to rust.debug value
+#overflow-checks = rust.debug (boolean)
+
+# Whether or not overflow checks are enabled for the standard library.
+# Overrides the `overflow-checks` option, if defined.
+#
+# Defaults to rust.overflow-checks value
+#overflow-checks-std = rust.overflow-checks (boolean)
+
 # Debuginfo level for most of Rust code, corresponds to the `-C debuginfo=N` option of `rustc`.
 # `0` - no debug info
 # `1` - line tables only - sufficient to generate backtraces that include line

library/alloc/src/str.rs

@@ -538,7 +538,7 @@ impl str {
     /// [`make_ascii_uppercase`]: str::make_ascii_uppercase
     /// [`to_uppercase`]: #method.to_uppercase
     #[cfg(not(no_global_oom_handling))]
-    #[must_use = "to uppercase the value in-place, use `make_ascii_lowercase()`"]
+    #[must_use = "to uppercase the value in-place, use `make_ascii_uppercase()`"]
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
     #[inline]
     pub fn to_ascii_uppercase(&self) -> String {

library/alloc/src/vec/mod.rs

@@ -1973,8 +1973,9 @@ impl<T, A: Allocator> Vec<T, A> {
     /// `'a`. If the type has only static references, or none at all, then this
     /// may be chosen to be `'static`.
     ///
-    /// This function is similar to the [`leak`][Box::leak] function on [`Box`]
-    /// except that there is no way to recover the leaked memory.
+    /// As of Rust 1.57, this method does not reallocate or shrink the `Vec`,
+    /// so the leaked allocation may include unused capacity that is not part
+    /// of the returned slice.
     ///
     /// This function is mainly useful for data that lives for the remainder of
     /// the program's life. Dropping the returned reference will cause a memory
@@ -1997,7 +1998,8 @@ impl<T, A: Allocator> Vec<T, A> {
     where
         A: 'a,
     {
-        Box::leak(self.into_boxed_slice())
+        let mut me = ManuallyDrop::new(self);
+        unsafe { slice::from_raw_parts_mut(me.as_mut_ptr(), me.len) }
     }
 
     /// Returns the remaining spare capacity of the vector as a slice of

library/core/src/char/methods.rs

@@ -328,9 +328,11 @@ impl char {
     ///
     /// ```should_panic
     /// // this panics
-    /// '1'.to_digit(37);
+    /// let _ = '1'.to_digit(37);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub fn to_digit(self, radix: u32) -> Option<u32> {
         assert!(radix <= 36, "to_digit: radix is too high (maximum 36)");

library/core/src/convert/mod.rs

@@ -664,7 +664,7 @@ impl AsMut<str> for str {
 ///
 /// However there is one case where `!` syntax can be used
 /// before `!` is stabilized as a full-fledged type: in the position of a function’s return type.
-/// Specifically, it is possible implementations for two different function pointer types:
+/// Specifically, it is possible to have implementations for two different function pointer types:
 ///
 /// ```
 /// trait MyTrait {}

library/core/src/num/int_log10.rs

@@ -1,5 +1,6 @@
 mod unchecked {
     // 0 < val <= u8::MAX
+    #[inline]
     pub const fn u8(val: u8) -> u32 {
         let val = val as u32;
 
@@ -20,6 +21,7 @@ mod unchecked {
     }
 
     // 0 < val < 100_000
+    #[inline]
     const fn less_than_5(val: u32) -> u32 {
         // Similar to u8, when adding one of these constants to val,
         // we get two possible bit patterns above the low 17 bits,
@@ -40,11 +42,13 @@ mod unchecked {
     }
 
     // 0 < val <= u16::MAX
+    #[inline]
     pub const fn u16(val: u16) -> u32 {
         less_than_5(val as u32)
     }
 
     // 0 < val <= u32::MAX
+    #[inline]
     pub const fn u32(mut val: u32) -> u32 {
         let mut log = 0;
         if val >= 100_000 {
@@ -55,6 +59,7 @@ mod unchecked {
     }
 
     // 0 < val <= u64::MAX
+    #[inline]
     pub const fn u64(mut val: u64) -> u32 {
         let mut log = 0;
         if val >= 10_000_000_000 {
@@ -69,6 +74,7 @@ mod unchecked {
     }
 
     // 0 < val <= u128::MAX
+    #[inline]
     pub const fn u128(mut val: u128) -> u32 {
         let mut log = 0;
         if val >= 100_000_000_000_000_000_000_000_000_000_000 {
@@ -84,33 +90,39 @@ mod unchecked {
     }
 
     // 0 < val <= i8::MAX
+    #[inline]
     pub const fn i8(val: i8) -> u32 {
         u8(val as u8)
     }
 
     // 0 < val <= i16::MAX
+    #[inline]
     pub const fn i16(val: i16) -> u32 {
         u16(val as u16)
     }
 
     // 0 < val <= i32::MAX
+    #[inline]
     pub const fn i32(val: i32) -> u32 {
         u32(val as u32)
     }
 
     // 0 < val <= i64::MAX
+    #[inline]
     pub const fn i64(val: i64) -> u32 {
         u64(val as u64)
     }
 
     // 0 < val <= i128::MAX
+    #[inline]
     pub const fn i128(val: i128) -> u32 {
         u128(val as u128)
     }
 }
 
 macro_rules! impl_checked {
     ($T:ident) => {
+        #[inline]
         pub const fn $T(val: $T) -> Option<u32> {
             if val > 0 { Some(unchecked::$T(val)) } else { None }
         }

library/core/src/ptr/non_null.rs

@@ -242,6 +242,8 @@ impl<T: ?Sized> NonNull<T> {
     /// The pointer can be later reconstructed with [`NonNull::from_raw_parts`].
     #[unstable(feature = "ptr_metadata", issue = "81513")]
     #[rustc_const_unstable(feature = "ptr_metadata", issue = "81513")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub const fn to_raw_parts(self) -> (NonNull<()>, <T as super::Pointee>::Metadata) {
         (self.cast(), super::metadata(self.as_ptr()))
@@ -386,6 +388,8 @@ impl<T: ?Sized> NonNull<T> {
     /// ```
     #[stable(feature = "nonnull_cast", since = "1.27.0")]
     #[rustc_const_stable(feature = "const_nonnull_cast", since = "1.36.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub const fn cast<U>(self) -> NonNull<U> {
         // SAFETY: `self` is a `NonNull` pointer which is necessarily non-null

library/std/src/ffi/c_str.rs

@@ -1342,6 +1342,8 @@ impl CStr {
     /// assert_eq!(cstr.to_bytes(), b"foo");
     /// ```
     #[inline]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_bytes(&self) -> &[u8] {
         let bytes = self.to_bytes_with_nul();
@@ -1367,6 +1369,8 @@ impl CStr {
     /// assert_eq!(cstr.to_bytes_with_nul(), b"foo\0");
     /// ```
     #[inline]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_bytes_with_nul(&self) -> &[u8] {
         unsafe { &*(&self.inner as *const [c_char] as *const [u8]) }
@@ -1437,6 +1441,8 @@ impl CStr {
     ///     Cow::Owned(String::from("Hello �World")) as Cow<'_, str>
     /// );
     /// ```
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[stable(feature = "cstr_to_str", since = "1.4.0")]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         String::from_utf8_lossy(self.to_bytes())

library/std/src/ffi/os_str.rs

@@ -576,6 +576,8 @@ impl OsStr {
     /// assert_eq!(os_str.to_str(), Some("foo"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub fn to_str(&self) -> Option<&str> {
         self.inner.to_str()
@@ -627,6 +629,8 @@ impl OsStr {
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         self.inner.to_string_lossy()
@@ -644,6 +648,8 @@ impl OsStr {
     /// assert_eq!(os_string, OsString::from("foo"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub fn to_os_string(&self) -> OsString {
         OsString { inner: self.inner.to_owned() }

library/std/src/net/ip.rs

@@ -426,6 +426,8 @@ impl IpAddr {
     /// assert_eq!(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1)).to_canonical().is_loopback(), true);
     /// ```
     #[inline]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[rustc_const_unstable(feature = "const_ip", issue = "76205")]
     #[unstable(feature = "ip", issue = "27709")]
     pub const fn to_canonical(&self) -> IpAddr {
@@ -901,6 +903,8 @@ impl Ipv4Addr {
     /// ```
     #[rustc_const_stable(feature = "const_ipv4", since = "1.50.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub const fn to_ipv6_compatible(&self) -> Ipv6Addr {
         let [a, b, c, d] = self.octets();
@@ -926,6 +930,8 @@ impl Ipv4Addr {
     /// ```
     #[rustc_const_stable(feature = "const_ipv4", since = "1.50.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub const fn to_ipv6_mapped(&self) -> Ipv6Addr {
         let [a, b, c, d] = self.octets();
@@ -1648,6 +1654,8 @@ impl Ipv6Addr {
     /// ```
     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
     #[unstable(feature = "ip", issue = "27709")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub const fn to_ipv4_mapped(&self) -> Option<Ipv4Addr> {
         match self.octets() {
@@ -1685,6 +1693,8 @@ impl Ipv6Addr {
     /// ```
     #[rustc_const_stable(feature = "const_ipv6", since = "1.50.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub const fn to_ipv4(&self) -> Option<Ipv4Addr> {
         if let [0, 0, 0, 0, 0, 0 | 0xffff, ab, cd] = self.segments() {
@@ -1708,9 +1718,11 @@ impl Ipv6Addr {
     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1).is_loopback(), false);
     /// assert_eq!(Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0x7f00, 0x1).to_canonical().is_loopback(), true);
     /// ```
-    #[inline]
     #[rustc_const_unstable(feature = "const_ipv6", issue = "76205")]
     #[unstable(feature = "ip", issue = "27709")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
+    #[inline]
     pub const fn to_canonical(&self) -> IpAddr {
         if let Some(mapped) = self.to_ipv4_mapped() {
             return IpAddr::V4(mapped);

library/std/src/path.rs

@@ -1952,6 +1952,8 @@ impl Path {
     /// assert_eq!(path.to_str(), Some("foo.txt"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub fn to_str(&self) -> Option<&str> {
         self.inner.to_str()
@@ -1978,6 +1980,8 @@ impl Path {
     /// Had `path` contained invalid unicode, the `to_string_lossy` call might
     /// have returned `"fo�.txt"`.
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         self.inner.to_string_lossy()
@@ -1994,6 +1998,8 @@ impl Path {
     /// assert_eq!(path_buf, std::path::PathBuf::from("foo.txt"));
     /// ```
     #[rustc_conversion_suggestion]
+    #[must_use = "this returns the result of the operation, \
+                  without modifying the original"]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn to_path_buf(&self) -> PathBuf {
         PathBuf::from(self.inner.to_os_string())