Auto merge of rust-lang#122511 - matthiaskrgr:rollup-swzilin, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - rust-lang#117118 ([AIX] Remove AixLinker's debuginfo() implementation)
 - rust-lang#121650 (change std::process to drop supplementary groups based on CAP_SETGID)
 - rust-lang#121764 (Make incremental sessions identity no longer depend on the crate names provided by source code)
 - rust-lang#122212 (Copy byval argument to alloca if alignment is insufficient)
 - rust-lang#122322 (coverage: Initial support for branch coverage instrumentation)
 - rust-lang#122373 (Fix the conflict problem between the diagnostics fixes of lint `unnecessary_qualification`  and  `unused_imports`)
 - rust-lang#122479 (Implement `Duration::as_millis_{f64,f32}`)
 - rust-lang#122487 (Rename `StmtKind::Local` variant into `StmtKind::Let`)
 - rust-lang#122498 (Update version of cc crate)
 - rust-lang#122503 (Make `SubdiagMessageOp` well-formed)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

core/src/time.rs

@@ -856,6 +856,48 @@ impl Duration {
         (self.secs as f32) + (self.nanos.0 as f32) / (NANOS_PER_SEC as f32)
     }
 
+    /// Returns the number of milliseconds contained by this `Duration` as `f64`.
+    ///
+    /// The returned value does include the fractional (nanosecond) part of the duration.
+    ///
+    /// # Examples
+    /// ```
+    /// #![feature(duration_millis_float)]
+    /// use std::time::Duration;
+    ///
+    /// let dur = Duration::new(2, 345_678_000);
+    /// assert_eq!(dur.as_millis_f64(), 2345.678);
+    /// ```
+    #[unstable(feature = "duration_millis_float", issue = "122451")]
+    #[must_use]
+    #[inline]
+    #[rustc_const_unstable(feature = "duration_consts_float", issue = "72440")]
+    pub const fn as_millis_f64(&self) -> f64 {
+        (self.secs as f64) * (MILLIS_PER_SEC as f64)
+            + (self.nanos.0 as f64) / (NANOS_PER_MILLI as f64)
+    }
+
+    /// Returns the number of milliseconds contained by this `Duration` as `f32`.
+    ///
+    /// The returned value does include the fractional (nanosecond) part of the duration.
+    ///
+    /// # Examples
+    /// ```
+    /// #![feature(duration_millis_float)]
+    /// use std::time::Duration;
+    ///
+    /// let dur = Duration::new(2, 345_678_000);
+    /// assert_eq!(dur.as_millis_f32(), 2345.678);
+    /// ```
+    #[unstable(feature = "duration_millis_float", issue = "122451")]
+    #[must_use]
+    #[inline]
+    #[rustc_const_unstable(feature = "duration_consts_float", issue = "72440")]
+    pub const fn as_millis_f32(&self) -> f32 {
+        (self.secs as f32) * (MILLIS_PER_SEC as f32)
+            + (self.nanos.0 as f32) / (NANOS_PER_MILLI as f32)
+    }
+
     /// Creates a new `Duration` from the specified number of seconds represented
     /// as `f64`.
     ///

profiler_builtins/Cargo.toml

@@ -13,4 +13,4 @@ core = { path = "../core" }
 compiler_builtins = { version = "0.1.0", features = ['rustc-dep-of-std'] }
 
 [build-dependencies]
-cc = "1.0.69"
+cc = "1.0.90"

std/src/os/unix/process.rs

@@ -39,6 +39,13 @@ pub trait CommandExt: Sealed {
     /// Sets the child process's user ID. This translates to a
     /// `setuid` call in the child process. Failure in the `setuid`
     /// call will cause the spawn to fail.
+    ///
+    /// # Notes
+    ///
+    /// This will also trigger a call to `setgroups(0, NULL)` in the child
+    /// process if no groups have been specified.
+    /// This removes supplementary groups that might have given the child
+    /// unwanted permissions.
     #[stable(feature = "rust1", since = "1.0.0")]
     fn uid(&mut self, id: UserId) -> &mut process::Command;
 

std/src/sys/pal/unix/process/process_unix.rs

@@ -330,14 +330,22 @@ impl Command {
             if let Some(u) = self.get_uid() {
                 // When dropping privileges from root, the `setgroups` call
                 // will remove any extraneous groups. We only drop groups
-                // if the current uid is 0 and we weren't given an explicit
+                // if we have CAP_SETGID and we weren't given an explicit
                 // set of groups. If we don't call this, then even though our
                 // uid has dropped, we may still have groups that enable us to
                 // do super-user things.
                 //FIXME: Redox kernel does not support setgroups yet
                 #[cfg(not(target_os = "redox"))]
-                if libc::getuid() == 0 && self.get_groups().is_none() {
-                    cvt(libc::setgroups(0, crate::ptr::null()))?;
+                if self.get_groups().is_none() {
+                    let res = cvt(libc::setgroups(0, crate::ptr::null()));
+                    if let Err(e) = res {
+                        // Here we ignore the case of not having CAP_SETGID.
+                        // An alternative would be to require CAP_SETGID (in
+                        // addition to CAP_SETUID) for setting the UID.
+                        if e.raw_os_error() != Some(libc::EPERM) {
+                            return Err(e.into());
+                        }
+                    }
                 }
                 cvt(libc::setuid(u as uid_t))?;
             }