remove redundant imports

detects redundant imports that can be eliminated.

for #117772 :

In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.

src/borrow_tracker/stacked_borrows/diagnostics.rs

@@ -2,12 +2,11 @@ use smallvec::SmallVec;
 use std::fmt;
 
 use rustc_data_structures::fx::FxHashSet;
-use rustc_middle::mir::interpret::{alloc_range, AllocId, AllocRange, InterpError};
 use rustc_span::{Span, SpanData};
 use rustc_target::abi::Size;
 
 use crate::borrow_tracker::{
-    stacked_borrows::Permission, AccessKind, GlobalStateInner, ProtectorKind,
+    AccessKind, GlobalStateInner, ProtectorKind,
 };
 use crate::*;
 

src/borrow_tracker/stacked_borrows/mod.rs

@@ -18,8 +18,7 @@ use rustc_target::abi::{Abi, Size};
 
 use crate::borrow_tracker::{
     stacked_borrows::diagnostics::{AllocHistory, DiagnosticCx, DiagnosticCxBuilder},
-    AccessKind, GlobalStateInner, ProtectorKind, RetagFields,
-};
+    AccessKind, GlobalStateInner, ProtectorKind,};
 use crate::*;
 
 use diagnostics::{RetagCause, RetagInfo};

src/borrow_tracker/tree_borrows/mod.rs

@@ -3,7 +3,7 @@ use log::trace;
 use rustc_target::abi::{Abi, Size};
 
 use crate::borrow_tracker::{
-    AccessKind, GlobalState, GlobalStateInner, ProtectorKind, RetagFields,
+    AccessKind, GlobalState, GlobalStateInner, ProtectorKind,
 };
 use rustc_middle::{
     mir::{Mutability, RetagKind},

src/borrow_tracker/tree_borrows/tree.rs

@@ -14,7 +14,6 @@ use std::fmt;
 
 use smallvec::SmallVec;
 
-use rustc_const_eval::interpret::InterpResult;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_span::Span;
 use rustc_target::abi::Size;

src/concurrency/weak_memory.rs

@@ -82,7 +82,6 @@ use std::{
     collections::VecDeque,
 };
 
-use rustc_const_eval::interpret::{alloc_range, AllocRange, InterpResult, MPlaceTy, Scalar};
 use rustc_data_structures::fx::FxHashMap;
 
 use crate::*;

src/eval.rs

@@ -10,7 +10,6 @@ use std::thread;
 use log::info;
 use rustc_middle::ty::Ty;
 
-use crate::borrow_tracker::RetagFields;
 use crate::concurrency::thread::TlsAllocAction;
 use crate::diagnostics::report_leaks;
 use rustc_data_structures::fx::FxHashSet;

src/shims/env.rs

@@ -3,7 +3,6 @@ use std::ffi::{OsStr, OsString};
 use std::io::ErrorKind;
 use std::mem;
 
-use rustc_const_eval::interpret::Pointer;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::Ty;

src/shims/unix/fs.rs

@@ -1,7 +1,6 @@
 use std::any::Any;
 use std::borrow::Cow;
 use std::collections::BTreeMap;
-use std::convert::TryInto;
 use std::fs::{
     read_dir, remove_dir, remove_file, rename, DirBuilder, File, FileType, OpenOptions, ReadDir,
 };

src/shims/unix/linux/sync.rs

@@ -1,6 +1,6 @@
 use std::time::SystemTime;
 
-use crate::concurrency::thread::{MachineCallback, Time};
+use crate::concurrency::thread::MachineCallback;
 use crate::*;
 
 /// Implementation of the SYS_futex syscall.

src/shims/unix/sync.rs

@@ -1,7 +1,7 @@
 use std::time::SystemTime;
 
 use crate::concurrency::sync::CondvarLock;
-use crate::concurrency::thread::{MachineCallback, Time};
+use crate::concurrency::thread::MachineCallback;
 use crate::*;
 
 // pthread_mutexattr_t is either 4 or 8 bytes, depending on the platform.

tests/pass-dep/shims/libc-fs.rs

@@ -4,7 +4,6 @@
 #![feature(io_error_more)]
 #![feature(io_error_uncategorized)]
 
-use std::convert::TryInto;
 use std::ffi::CString;
 use std::fs::{canonicalize, remove_dir_all, remove_file, File};
 use std::io::{Error, ErrorKind, Write};

tests/pass/arrays.rs

@@ -1,5 +1,3 @@
-use std::convert::TryFrom;
-
 fn empty_array() -> [u16; 0] {
     []
 }

tests/pass/binary-heap.rs

@@ -1,5 +1,4 @@
 use std::collections::BinaryHeap;
-use std::iter::Iterator;
 
 fn zero_sized_push() {
     const N: usize = 8;

tests/pass/enum-nullable-const-null-with-fields.rs

@@ -1,5 +1,3 @@
-use std::result::Result;
-use std::result::Result::Ok;
 
 static C: Result<(), Box<isize>> = Ok(());