Use &[u8] instead of Vec<u8>

Author: tiif

src/shims/unix/fd.rs

@@ -143,7 +143,7 @@ impl FileDescription for io::Stdin {
             helpers::isolation_abort_error("`read` from stdin")?;
         }
         let result = Read::read(&mut { self }, &mut bytes);
-        ecx.return_read_bytes_and_count(ptr, bytes, result, dest)
+        ecx.return_read_bytes_and_count(ptr, &bytes, result, dest)
     }
 
     fn is_tty(&self, communicate_allowed: bool) -> bool {
@@ -646,7 +646,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
     fn return_read_bytes_and_count(
         &mut self,
         buf: Pointer,
-        bytes: Vec<u8>,
+        bytes: &[u8],
         result: io::Result<usize>,
         dest: &MPlaceTy<'tcx>,
     ) -> InterpResult<'tcx> {

src/shims/unix/fs.rs

@@ -42,7 +42,7 @@ impl FileDescription for FileHandle {
         assert!(communicate_allowed, "isolation should have prevented even opening a file");
         let mut bytes = vec![0; usize::try_from(len).unwrap()];
         let result = (&mut &self.file).read(&mut bytes);
-        ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest)
+        ecx.return_read_bytes_and_count(ptr, &bytes, result, dest)
     }
 
     fn write<'tcx>(
@@ -83,7 +83,7 @@ impl FileDescription for FileHandle {
             res
         };
         let result = f();
-        ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest)
+        ecx.return_read_bytes_and_count(ptr, &bytes, result, dest)
     }
 
     fn pwrite<'tcx>(

src/shims/unix/unnamed_socket.rs

@@ -137,7 +137,7 @@ impl FileDescription for AnonSocket {
         // Always succeed on read size 0.
         if request_byte_size == 0 {
             let result = Ok(0);
-            return ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest);
+            return ecx.return_read_bytes_and_count(ptr, &bytes, result, dest);
         }
 
         let Some(readbuf) = &self.readbuf else {
@@ -151,7 +151,7 @@ impl FileDescription for AnonSocket {
                 // Socketpair with no peer and empty buffer.
                 // 0 bytes successfully read indicates end-of-file.
                 let result = Ok(0);
-                return ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest);
+                return ecx.return_read_bytes_and_count(ptr, &bytes, result, dest);
             } else {
                 if self.is_nonblock {
                     // Non-blocking socketpair with writer and empty buffer.
@@ -160,7 +160,7 @@ impl FileDescription for AnonSocket {
                     // POSIX.1-2001 allows either error to be returned for this case.
                     // Since there is no ErrorKind for EAGAIN, WouldBlock is used.
                     let result = Err(Error::from(ErrorKind::WouldBlock));
-                    return ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest);
+                    return ecx.return_read_bytes_and_count(ptr, &bytes, result, dest);
                 } else {
                     // Blocking socketpair with writer and empty buffer.
                     // FIXME: blocking is currently not supported
@@ -193,7 +193,7 @@ impl FileDescription for AnonSocket {
         }
 
         let result = Ok(actual_read_size);
-        ecx.return_read_bytes_and_count(ptr, bytes.to_vec(), result, dest)
+        ecx.return_read_bytes_and_count(ptr, &bytes, result, dest)
     }
 
     fn write<'tcx>(