Merge from df35ff6 with conflicts

Author: gitbot

library/Cargo.lock

@@ -16,8 +16,12 @@ bench = false
 
 [dependencies]
 core = { path = "../core", public = true }
+<<<<<<< HEAD
 compiler_builtins = { version = "=0.1.155", features = ['rustc-dep-of-std'] }
 safety = { path = "../contracts/safety" }
+=======
+compiler_builtins = { version = "=0.1.156", features = ['rustc-dep-of-std'] }
+>>>>>>> subtree/library
 
 [features]
 compiler-builtins-mem = ['compiler_builtins/mem']

library/alloc/Cargo.toml

@@ -151,6 +151,9 @@ impl f128 {
     pub const RADIX: u32 = 2;
 
     /// Number of significant digits in base 2.
+    ///
+    /// Note that the size of the mantissa in the bitwise representation is one
+    /// smaller than this since the leading 1 is not stored explicitly.
     #[unstable(feature = "f128", issue = "116909")]
     pub const MANTISSA_DIGITS: u32 = 113;
 

library/core/src/num/f128.rs

@@ -146,6 +146,9 @@ impl f16 {
     pub const RADIX: u32 = 2;
 
     /// Number of significant digits in base 2.
+    ///
+    /// Note that the size of the mantissa in the bitwise representation is one
+    /// smaller than this since the leading 1 is not stored explicitly.
     #[unstable(feature = "f16", issue = "116909")]
     pub const MANTISSA_DIGITS: u32 = 11;
 

library/core/src/num/f16.rs

@@ -396,6 +396,9 @@ impl f32 {
     pub const RADIX: u32 = 2;
 
     /// Number of significant digits in base 2.
+    ///
+    /// Note that the size of the mantissa in the bitwise representation is one
+    /// smaller than this since the leading 1 is not stored explicitly.
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
     pub const MANTISSA_DIGITS: u32 = 24;
 

library/core/src/num/f32.rs

@@ -396,6 +396,9 @@ impl f64 {
     pub const RADIX: u32 = 2;
 
     /// Number of significant digits in base 2.
+    ///
+    /// Note that the size of the mantissa in the bitwise representation is one
+    /// smaller than this since the leading 1 is not stored explicitly.
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
     pub const MANTISSA_DIGITS: u32 = 53;
     /// Approximate number of significant digits in base 10.

library/core/src/num/f64.rs

@@ -18,7 +18,7 @@ cfg-if = { version = "1.0", features = ['rustc-dep-of-std'] }
 panic_unwind = { path = "../panic_unwind", optional = true }
 panic_abort = { path = "../panic_abort" }
 core = { path = "../core", public = true }
-compiler_builtins = { version = "=0.1.155" }
+compiler_builtins = { version = "=0.1.156" }
 unwind = { path = "../unwind" }
 hashbrown = { version = "0.15", default-features = false, features = [
     'rustc-dep-of-std',

library/std/Cargo.toml

@@ -353,6 +353,15 @@ fn split_file_at_dot(file: &OsStr) -> (&OsStr, Option<&OsStr>) {
     }
 }
 
+/// Checks whether the string is valid as a file extension, or panics otherwise.
+fn validate_extension(extension: &OsStr) {
+    for &b in extension.as_encoded_bytes() {
+        if is_sep_byte(b) {
+            panic!("extension cannot contain path separators: {extension:?}");
+        }
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // The core iterators
 ////////////////////////////////////////////////////////////////////////////////
@@ -1507,13 +1516,7 @@ impl PathBuf {
     }
 
     fn _set_extension(&mut self, extension: &OsStr) -> bool {
-        for &b in extension.as_encoded_bytes() {
-            if b < 128 {
-                if is_separator(b as char) {
-                    panic!("extension cannot contain path separators: {:?}", extension);
-                }
-            }
-        }
+        validate_extension(extension);
 
         let file_stem = match self.file_stem() {
             None => return false,
@@ -1541,6 +1544,11 @@ impl PathBuf {
     /// Returns `false` and does nothing if [`self.file_name`] is [`None`],
     /// returns `true` and updates the extension otherwise.
     ///
+    /// # Panics
+    ///
+    /// Panics if the passed extension contains a path separator (see
+    /// [`is_separator`]).
+    ///
     /// # Caveats
     ///
     /// The appended `extension` may contain dots and will be used in its entirety,
@@ -1582,6 +1590,8 @@ impl PathBuf {
     }
 
     fn _add_extension(&mut self, extension: &OsStr) -> bool {
+        validate_extension(extension);
+
         let file_name = match self.file_name() {
             None => return false,
             Some(f) => f.as_encoded_bytes(),

library/std/src/path.rs

@@ -415,6 +415,7 @@ impl Command {
         all(target_os = "linux", target_env = "musl"),
         target_os = "nto",
         target_vendor = "apple",
+        target_os = "cygwin",
     )))]
     fn posix_spawn(
         &mut self,
@@ -433,6 +434,7 @@ impl Command {
         all(target_os = "linux", target_env = "musl"),
         target_os = "nto",
         target_vendor = "apple",
+        target_os = "cygwin",
     ))]
     fn posix_spawn(
         &mut self,
@@ -584,7 +586,7 @@ impl Command {
         /// Some platforms can set a new working directory for a spawned process in the
         /// `posix_spawn` path. This function looks up the function pointer for adding
         /// such an action to a `posix_spawn_file_actions_t` struct.
-        #[cfg(not(all(target_os = "linux", target_env = "musl")))]
+        #[cfg(not(any(all(target_os = "linux", target_env = "musl"), target_os = "cygwin")))]
         fn get_posix_spawn_addchdir() -> Option<PosixSpawnAddChdirFn> {
             use crate::sys::weak::weak;
 
@@ -618,7 +620,9 @@ impl Command {
         /// Weak symbol lookup doesn't work with statically linked libcs, so in cases
         /// where static linking is possible we need to either check for the presence
         /// of the symbol at compile time or know about it upfront.
-        #[cfg(all(target_os = "linux", target_env = "musl"))]
+        ///
+        /// Cygwin doesn't support weak symbol, so just link it.
+        #[cfg(any(all(target_os = "linux", target_env = "musl"), target_os = "cygwin"))]
         fn get_posix_spawn_addchdir() -> Option<PosixSpawnAddChdirFn> {
             // Our minimum required musl supports this function, so we can just use it.
             Some(libc::posix_spawn_file_actions_addchdir_np)

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

@@ -112,6 +112,8 @@ fn test_nan() {
     assert!(!nan.is_sign_negative());
     assert!(!nan.is_normal());
     assert_eq!(Fp::Nan, nan.classify());
+    // Ensure the quiet bit is set.
+    assert!(nan.to_bits() & (1 << (f128::MANTISSA_DIGITS - 2)) != 0);
 }
 
 #[test]

library/std/tests/floats/f128.rs

@@ -95,6 +95,8 @@ fn test_nan() {
     assert!(!nan.is_sign_negative());
     assert!(!nan.is_normal());
     assert_eq!(Fp::Nan, nan.classify());
+    // Ensure the quiet bit is set.
+    assert!(nan.to_bits() & (1 << (f16::MANTISSA_DIGITS - 2)) != 0);
 }
 
 #[test]

library/std/tests/floats/f16.rs

@@ -72,6 +72,8 @@ fn test_nan() {
     assert!(nan.is_sign_positive());
     assert!(!nan.is_sign_negative());
     assert_eq!(Fp::Nan, nan.classify());
+    // Ensure the quiet bit is set.
+    assert!(nan.to_bits() & (1 << (f32::MANTISSA_DIGITS - 2)) != 0);
 }
 
 #[test]

library/std/tests/floats/f32.rs

@@ -60,6 +60,8 @@ fn test_nan() {
     assert!(nan.is_sign_positive());
     assert!(!nan.is_sign_negative());
     assert_eq!(Fp::Nan, nan.classify());
+    // Ensure the quiet bit is set.
+    assert!(nan.to_bits() & (1 << (f64::MANTISSA_DIGITS - 2)) != 0);
 }
 
 #[test]