Auto merge of #117041 - matthiaskrgr:rollup-b18h0ln, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #116985 (Use gdb.ValuePrinter tag class)
 - #116989 (Skip test if Unix sockets are unsupported)
 - #117034 (Don't crash on empty match in the `nonexhaustive_omitted_patterns` lint)
 - #117037 (rustdoc book doc example error)

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

compiler/rustc_mir_build/src/thir/pattern/usefulness.rs

@@ -884,6 +884,9 @@ fn collect_nonexhaustive_missing_variants<'p, 'tcx>(
     cx: &MatchCheckCtxt<'p, 'tcx>,
     column: &[&DeconstructedPat<'p, 'tcx>],
 ) -> Vec<WitnessPat<'tcx>> {
+    if column.is_empty() {
+        return Vec::new();
+    }
     let ty = column[0].ty();
     let pcx = &PatCtxt { cx, ty, span: DUMMY_SP, is_top_level: false };
 

library/std/src/fs/tests.rs

@@ -1717,7 +1717,7 @@ fn windows_unix_socket_exists() {
     let tmp = tmpdir();
     let socket_path = tmp.join("socket");
 
-    // std doesn't current support Unix sockets on Windows so manually create one here.
+    // std doesn't currently support Unix sockets on Windows so manually create one here.
     net::init();
     unsafe {
         let socket = c::WSASocketW(
@@ -1728,7 +1728,16 @@ fn windows_unix_socket_exists() {
             0,
             c::WSA_FLAG_OVERLAPPED | c::WSA_FLAG_NO_HANDLE_INHERIT,
         );
-        assert_ne!(socket, c::INVALID_SOCKET);
+        // AF_UNIX is not supported on earlier versions of Windows,
+        // so skip this test if it's unsupported and we're not in CI.
+        if socket == c::INVALID_SOCKET {
+            let error = c::WSAGetLastError();
+            if env::var_os("CI").is_none() && error == c::WSAEAFNOSUPPORT {
+                return;
+            } else {
+                panic!("Creating AF_UNIX socket failed (OS error {error})");
+            }
+        }
         let mut addr = c::SOCKADDR_UN { sun_family: c::AF_UNIX, sun_path: mem::zeroed() };
         let bytes = socket_path.as_os_str().as_encoded_bytes();
         addr.sun_path[..bytes.len()].copy_from_slice(bytes);

src/doc/rustdoc/src/write-documentation/what-to-include.md

@@ -73,7 +73,7 @@ and your test suite, this example needs some additional code:
 ``````text
 /// Example
 /// ```rust
-/// # main() -> Result<(), std::num::ParseIntError> {
+/// # fn main() -> Result<(), std::num::ParseIntError> {
 /// let fortytwo = "42".parse::<u32>()?;
 /// println!("{} + 10 = {}", fortytwo, fortytwo+10);
 /// #     Ok(())