Auto merge of #110214 - compiler-errors:rollup-mkig4t6, r=compiler-errors

Rollup of 10 pull requests

Successful merges:

 - #96971 (Initial support for loongarch64-unknown-linux-gnu)
 - #109894 (Remove Errors section from var_os docs)
 - #110000 (Rename tests/ui/unique to tests/ui/box/unit)
 - #110018 (Pass host linker to compiletest.)
 - #110104 ( Reword the docstring in todo! macro definition, fixing a typo)
 - #110113 (Fix `x test ui --target foo` when download-rustc is enabled)
 - #110126 (Support safe transmute in new solver)
 - #110155 (Fix typos in librustdoc, tools and config files)
 - #110162 (rustdoc: remove redundant expandSection code from main.js)
 - #110173 (kmc-solid: Implement `Socket::read_buf`)

Failed merges:

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

5 files changed, 28 insertions, 18 deletions

diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 183f9ab3b08..d372fa64065 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -236,21 +236,14 @@ fn _var(key: &OsStr) -> Result<String, VarError> {
 }
 
 /// Fetches the environment variable `key` from the current process, returning
-/// [`None`] if the variable isn't set or there's another error.
+/// [`None`] if the variable isn't set or if there is another error.
 ///
-/// Note that the method will not check if the environment variable
-/// is valid Unicode. If you want to have an error on invalid UTF-8,
-/// use the [`var`] function instead.
-///
-/// # Errors
-///
-/// This function returns an error if the environment variable isn't set.
-///
-/// This function may return an error if the environment variable's name contains
+/// It may return `None` if the environment variable's name contains
 /// the equal sign character (`=`) or the NUL character.
 ///
-/// This function may return an error if the environment variable's value contains
-/// the NUL character.
+/// Note that this function will not check if the environment variable
+/// is valid Unicode. If you want to have an error on invalid UTF-8,
+/// use the [`var`] function instead.
 ///
 /// # Examples
 ///
@@ -895,6 +888,7 @@ pub mod consts {
     /// - x86_64
     /// - arm
     /// - aarch64
+    /// - loongarch64
     /// - m68k
     /// - mips
     /// - mips64
diff --git a/library/std/src/os/linux/raw.rs b/library/std/src/os/linux/raw.rs
index f46028c3a96..c55ca8ba26e 100644
--- a/library/std/src/os/linux/raw.rs
+++ b/library/std/src/os/linux/raw.rs
@@ -231,6 +231,7 @@ mod arch {
 }
 
 #[cfg(any(
+    target_arch = "loongarch64",
     target_arch = "mips64",
     target_arch = "s390x",
     target_arch = "sparc64",
diff --git a/library/std/src/personality/gcc.rs b/library/std/src/personality/gcc.rs
index 41c0fe725a5..0421b47be02 100644
--- a/library/std/src/personality/gcc.rs
+++ b/library/std/src/personality/gcc.rs
@@ -77,6 +77,9 @@ const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1
 #[cfg(any(target_arch = "riscv64", target_arch = "riscv32"))]
 const UNWIND_DATA_REG: (i32, i32) = (10, 11); // x10, x11
 
+#[cfg(target_arch = "loongarch64")]
+const UNWIND_DATA_REG: (i32, i32) = (4, 5); // a0, a1
+
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:
 // https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc
 // https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c
diff --git a/library/std/src/sys/common/alloc.rs b/library/std/src/sys/common/alloc.rs
index 403a5e627f1..a5fcbdf39c6 100644
--- a/library/std/src/sys/common/alloc.rs
+++ b/library/std/src/sys/common/alloc.rs
@@ -22,6 +22,7 @@ pub const MIN_ALIGN: usize = 8;
 #[cfg(any(
     target_arch = "x86_64",
     target_arch = "aarch64",
+    target_arch = "loongarch64",
     target_arch = "mips64",
     target_arch = "s390x",
     target_arch = "sparc64",
diff --git a/library/std/src/sys/solid/net.rs b/library/std/src/sys/solid/net.rs
index 1b98ef993b0..7d7bfae1432 100644
--- a/library/std/src/sys/solid/net.rs
+++ b/library/std/src/sys/solid/net.rs
@@ -2,7 +2,7 @@ use super::abi;
 use crate::{
     cmp,
     ffi::CStr,
-    io::{self, ErrorKind, IoSlice, IoSliceMut},
+    io::{self, BorrowedBuf, BorrowedCursor, ErrorKind, IoSlice, IoSliceMut},
     mem,
     net::{Shutdown, SocketAddr},
     ptr, str,
@@ -294,19 +294,30 @@ impl Socket {
         self.0.duplicate().map(Socket)
     }
 
-    fn recv_with_flags(&self, buf: &mut [u8], flags: c_int) -> io::Result<usize> {
+    fn recv_with_flags(&self, mut buf: BorrowedCursor<'_>, flags: c_int) -> io::Result<()> {
         let ret = cvt(unsafe {
-            netc::recv(self.0.raw(), buf.as_mut_ptr() as *mut c_void, buf.len(), flags)
+            netc::recv(self.0.raw(), buf.as_mut().as_mut_ptr().cast(), buf.capacity(), flags)
         })?;
-        Ok(ret as usize)
+        unsafe {
+            buf.advance(ret as usize);
+        }
+        Ok(())
     }
 
     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
-        self.recv_with_flags(buf, 0)
+        let mut buf = BorrowedBuf::from(buf);
+        self.recv_with_flags(buf.unfilled(), 0)?;
+        Ok(buf.len())
     }
 
     pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
-        self.recv_with_flags(buf, MSG_PEEK)
+        let mut buf = BorrowedBuf::from(buf);
+        self.recv_with_flags(buf.unfilled(), MSG_PEEK)?;
+        Ok(buf.len())
+    }
+
+    pub fn read_buf(&self, buf: BorrowedCursor<'_>) -> io::Result<()> {
+        self.recv_with_flags(buf, 0)
     }
 
     pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {