Auto merge of rust-lang#3778 - RalfJung:fd, r=oli-obk

FD: refactor API names a little

I feel like these two functions are different enough that their names should not indicate complete symmetry. I am not sure what the best names would be, though... `@oli-obk` any opinions?

Author: bors

src/tools/miri/src/shims/unix/fd.rs

@@ -240,25 +240,25 @@ impl FdTable {
     }
     pub(crate) fn init(mute_stdout_stderr: bool) -> FdTable {
         let mut fds = FdTable::new();
-        fds.insert_fd(io::stdin());
+        fds.insert_new(io::stdin());
         if mute_stdout_stderr {
-            assert_eq!(fds.insert_fd(NullOutput), 1);
-            assert_eq!(fds.insert_fd(NullOutput), 2);
+            assert_eq!(fds.insert_new(NullOutput), 1);
+            assert_eq!(fds.insert_new(NullOutput), 2);
         } else {
-            assert_eq!(fds.insert_fd(io::stdout()), 1);
-            assert_eq!(fds.insert_fd(io::stderr()), 2);
+            assert_eq!(fds.insert_new(io::stdout()), 1);
+            assert_eq!(fds.insert_new(io::stderr()), 2);
         }
         fds
     }
 
     /// Insert a new file description to the FdTable.
-    pub fn insert_fd(&mut self, fd: impl FileDescription) -> i32 {
+    pub fn insert_new(&mut self, fd: impl FileDescription) -> i32 {
         let file_handle = FileDescriptionRef::new(fd);
-        self.insert_fd_with_min_fd(file_handle, 0)
+        self.insert_ref_with_min_fd(file_handle, 0)
     }
 
-    /// Insert a new FD that is at least `min_fd`.
-    fn insert_fd_with_min_fd(&mut self, file_handle: FileDescriptionRef, min_fd: i32) -> i32 {
+    /// Insert a file description, giving it a file descriptor that is at least `min_fd`.
+    fn insert_ref_with_min_fd(&mut self, file_handle: FileDescriptionRef, min_fd: i32) -> i32 {
         // Find the lowest unused FD, starting from min_fd. If the first such unused FD is in
         // between used FDs, the find_map combinator will return it. If the first such unused FD
         // is after all other used FDs, the find_map combinator will return None, and we will use
@@ -294,7 +294,7 @@ impl FdTable {
         Some(fd.borrow_mut())
     }
 
-    pub fn dup(&self, fd: i32) -> Option<FileDescriptionRef> {
+    pub fn get_ref(&self, fd: i32) -> Option<FileDescriptionRef> {
         let fd = self.fds.get(&fd)?;
         Some(fd.clone())
     }
@@ -313,16 +313,16 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
     fn dup(&mut self, old_fd: i32) -> InterpResult<'tcx, Scalar> {
         let this = self.eval_context_mut();
 
-        let Some(dup_fd) = this.machine.fds.dup(old_fd) else {
+        let Some(dup_fd) = this.machine.fds.get_ref(old_fd) else {
             return Ok(Scalar::from_i32(this.fd_not_found()?));
         };
-        Ok(Scalar::from_i32(this.machine.fds.insert_fd_with_min_fd(dup_fd, 0)))
+        Ok(Scalar::from_i32(this.machine.fds.insert_ref_with_min_fd(dup_fd, 0)))
     }
 
     fn dup2(&mut self, old_fd: i32, new_fd: i32) -> InterpResult<'tcx, Scalar> {
         let this = self.eval_context_mut();
 
-        let Some(dup_fd) = this.machine.fds.dup(old_fd) else {
+        let Some(dup_fd) = this.machine.fds.get_ref(old_fd) else {
             return Ok(Scalar::from_i32(this.fd_not_found()?));
         };
         if new_fd != old_fd {
@@ -408,9 +408,9 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             }
             let start = this.read_scalar(&args[2])?.to_i32()?;
 
-            match this.machine.fds.dup(fd) {
+            match this.machine.fds.get_ref(fd) {
                 Some(dup_fd) =>
-                    Ok(Scalar::from_i32(this.machine.fds.insert_fd_with_min_fd(dup_fd, start))),
+                    Ok(Scalar::from_i32(this.machine.fds.insert_ref_with_min_fd(dup_fd, start))),
                 None => Ok(Scalar::from_i32(this.fd_not_found()?)),
             }
         } else if this.tcx.sess.target.os == "macos" && cmd == this.eval_libc_i32("F_FULLFSYNC") {
@@ -481,7 +481,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let communicate = this.machine.communicate();
 
         // We temporarily dup the FD to be able to retain mutable access to `this`.
-        let Some(fd) = this.machine.fds.dup(fd) else {
+        let Some(fd) = this.machine.fds.get_ref(fd) else {
             trace!("read: FD not found");
             return Ok(Scalar::from_target_isize(this.fd_not_found()?, this));
         };
@@ -546,7 +546,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 
         let bytes = this.read_bytes_ptr_strip_provenance(buf, Size::from_bytes(count))?.to_owned();
         // We temporarily dup the FD to be able to retain mutable access to `this`.
-        let Some(fd) = this.machine.fds.dup(fd) else {
+        let Some(fd) = this.machine.fds.get_ref(fd) else {
             return Ok(Scalar::from_target_isize(this.fd_not_found()?, this));
         };
 

src/tools/miri/src/shims/unix/fs.rs

@@ -545,7 +545,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 
         let fd = options
             .open(path)
-            .map(|file| this.machine.fds.insert_fd(FileHandle { file, writable }));
+            .map(|file| this.machine.fds.insert_new(FileHandle { file, writable }));
 
         Ok(Scalar::from_i32(this.try_unwrap_io_result(fd)?))
     }
@@ -1634,7 +1634,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 
             match file {
                 Ok(f) => {
-                    let fd = this.machine.fds.insert_fd(FileHandle { file: f, writable: true });
+                    let fd = this.machine.fds.insert_new(FileHandle { file: f, writable: true });
                     return Ok(Scalar::from_i32(fd));
                 }
                 Err(e) =>

src/tools/miri/src/shims/unix/linux/epoll.rs

@@ -64,7 +64,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             );
         }
 
-        let fd = this.machine.fds.insert_fd(Epoll::default());
+        let fd = this.machine.fds.insert_new(Epoll::default());
         Ok(Scalar::from_i32(fd))
     }
 

src/tools/miri/src/shims/unix/linux/eventfd.rs

@@ -178,7 +178,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             throw_unsup_format!("eventfd: encountered unknown unsupported flags {:#x}", flags);
         }
 
-        let fd = this.machine.fds.insert_fd(Event {
+        let fd = this.machine.fds.insert_new(Event {
             counter: val.into(),
             is_nonblock,
             clock: VClock::default(),

src/tools/miri/src/shims/unix/socket.rs

@@ -219,8 +219,8 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         };
 
         let fds = &mut this.machine.fds;
-        let sv0 = fds.insert_fd(socketpair_0);
-        let sv1 = fds.insert_fd(socketpair_1);
+        let sv0 = fds.insert_new(socketpair_0);
+        let sv1 = fds.insert_new(socketpair_1);
         let sv0 = Scalar::from_int(sv0, sv.layout.size);
         let sv1 = Scalar::from_int(sv1, sv.layout.size);