clippy: eliminate warnings & errors

Signed-off-by: Erdem Meydanli <[email protected]>

src/common/mod.rs

@@ -56,8 +56,9 @@ const SOCKETS_DIR_PATH: &str = "/run/nitro_enclaves";
 const BACKTRACE_VAR: &str = "BACKTRACE";
 
 /// All possible errors which may occur.
-#[derive(Debug, Clone, Copy, Hash, PartialEq)]
+#[derive(Debug, Default, Clone, Copy, Hash, PartialEq)]
 pub enum NitroCliErrorEnum {
+    #[default]
     /// Unspecified error (should avoid using it thoughout the code).
     UnspecifiedError = 0,
     /// Error for handling missing arguments.
@@ -180,12 +181,6 @@ pub enum NitroCliErrorEnum {
     EIFSignatureCheckerError,
 }
 
-impl Default for NitroCliErrorEnum {
-    fn default() -> NitroCliErrorEnum {
-        NitroCliErrorEnum::UnspecifiedError
-    }
-}
-
 impl Eq for NitroCliErrorEnum {}
 
 /// The type of commands that can be sent to an enclave process.

src/enclave_proc/connection.rs

@@ -12,7 +12,6 @@ use std::collections::HashMap;
 use std::io::Write;
 use std::os::unix::io::AsRawFd;
 use std::os::unix::net::UnixStream;
-use std::string::ToString;
 use std::sync::{Arc, Mutex};
 
 use crate::common::{receive_from_stream, write_u64_le};

src/enclave_proc/resource_manager.rs

@@ -11,7 +11,6 @@ use eif_loader::{enclave_ready, TIMEOUT_MINUTE_MS};
 use libc::c_int;
 use log::{debug, info};
 use std::collections::BTreeMap;
-use std::convert::{From, Into};
 use std::fs::{File, OpenOptions};
 use std::io::prelude::*;
 use std::io::Error;
@@ -109,8 +108,9 @@ pub struct MemoryRegion {
 }
 
 /// The state an enclave may be in.
-#[derive(Clone)]
+#[derive(Clone, Default)]
 pub enum EnclaveState {
+    #[default]
     /// The enclave is not running (it's either not started or has been terminated).
     Empty,
     /// The enclave is running.
@@ -180,12 +180,6 @@ impl ToString for EnclaveState {
     }
 }
 
-impl Default for EnclaveState {
-    fn default() -> Self {
-        EnclaveState::Empty
-    }
-}
-
 impl Default for EnclaveBuildInfo {
     fn default() -> Self {
         EnclaveBuildInfo::new(BTreeMap::new())