Rollup merge of #70777 - faern:use-assoc-int-consts2, r=dtolnay

Don't import integer and float modules, use assoc consts

Stop importing the standard library integer and float modules to reach the `MIN`, `MAX` and other constants. They are available directly on the primitive types now.

This PR is a follow up of #69860 which made sure we use the new constants in documentation.

This type of change touches a lot of files, and previously all my assoc int consts PRs had collisions and were accepted only after a long delay. So I'd prefer to do it in smaller steps now. Just removing these imports seem like a good next step.

r? @dtolnay

42 files changed, 27 insertions, 75 deletions

diff --git a/src/etc/test-float-parse/u64-pow2.rs b/src/etc/test-float-parse/u64-pow2.rs
index 1c9bda948ff..7e67e2b1246 100644
--- a/src/etc/test-float-parse/u64-pow2.rs
+++ b/src/etc/test-float-parse/u64-pow2.rs
@@ -1,7 +1,6 @@
 mod _common;
 
 use _common::validate;
-use std::u64;
 
 fn main() {
     for exp in 19..64 {
diff --git a/src/liballoc/alloc.rs b/src/liballoc/alloc.rs
index 66575e3ef55..d31c73cc1bd 100644
--- a/src/liballoc/alloc.rs
+++ b/src/liballoc/alloc.rs
@@ -4,7 +4,6 @@
 
 use core::intrinsics::{self, min_align_of_val, size_of_val};
 use core::ptr::{NonNull, Unique};
-use core::usize;
 
 #[stable(feature = "alloc_module", since = "1.28.0")]
 #[doc(inline)]
diff --git a/src/liballoc/collections/binary_heap.rs b/src/liballoc/collections/binary_heap.rs
index 9908a304976..a01e9b25dd6 100644
--- a/src/liballoc/collections/binary_heap.rs
+++ b/src/liballoc/collections/binary_heap.rs
@@ -20,7 +20,6 @@
 //! ```
 //! use std::cmp::Ordering;
 //! use std::collections::BinaryHeap;
-//! use std::usize;
 //!
 //! #[derive(Copy, Clone, Eq, PartialEq)]
 //! struct State {
diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 6a78a7398a6..9db997e8641 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -250,7 +250,6 @@ use core::ops::{CoerceUnsized, Deref, DispatchFromDyn, Receiver};
 use core::pin::Pin;
 use core::ptr::{self, NonNull};
 use core::slice::{self, from_raw_parts_mut};
-use core::usize;
 
 use crate::alloc::{box_free, handle_alloc_error, AllocInit, AllocRef, Global, Layout};
 use crate::string::String;
diff --git a/src/liballoc/slice.rs b/src/liballoc/slice.rs
index 2ce5bc8ed2f..a3d9c78b7f5 100644
--- a/src/liballoc/slice.rs
+++ b/src/liballoc/slice.rs
@@ -90,7 +90,6 @@ use core::borrow::{Borrow, BorrowMut};
 use core::cmp::Ordering::{self, Less};
 use core::mem::{self, size_of};
 use core::ptr;
-use core::{u16, u32, u8};
 
 use crate::borrow::ToOwned;
 use crate::boxed::Box;
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index 111a7651b5e..1cfb26eb35a 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -23,7 +23,6 @@ use core::ptr::{self, NonNull};
 use core::slice::{self, from_raw_parts_mut};
 use core::sync::atomic;
 use core::sync::atomic::Ordering::{Acquire, Relaxed, Release, SeqCst};
-use core::{isize, usize};
 
 use crate::alloc::{box_free, handle_alloc_error, AllocInit, AllocRef, Global, Layout};
 use crate::boxed::Box;
diff --git a/src/liballoc/tests.rs b/src/liballoc/tests.rs
index 1b6e0bb291c..bddaab0c761 100644
--- a/src/liballoc/tests.rs
+++ b/src/liballoc/tests.rs
@@ -3,8 +3,6 @@
 use core::any::Any;
 use core::clone::Clone;
 use core::convert::TryInto;
-use core::f64;
-use core::i64;
 use core::ops::Deref;
 use core::result::Result::{Err, Ok};
 
diff --git a/src/liballoc/tests/string.rs b/src/liballoc/tests/string.rs
index d2f09eb4a75..6e2a5abe90d 100644
--- a/src/liballoc/tests/string.rs
+++ b/src/liballoc/tests/string.rs
@@ -1,7 +1,6 @@
 use std::borrow::Cow;
 use std::collections::TryReserveError::*;
 use std::mem::size_of;
-use std::{isize, usize};
 
 pub trait IntoCow<'a, B: ?Sized>
 where
diff --git a/src/liballoc/tests/vec.rs b/src/liballoc/tests/vec.rs
index 6321e7154e7..b63d81796f9 100644
--- a/src/liballoc/tests/vec.rs
+++ b/src/liballoc/tests/vec.rs
@@ -3,7 +3,6 @@ use std::collections::TryReserveError::*;
 use std::mem::size_of;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::vec::{Drain, IntoIter};
-use std::{isize, usize};
 
 struct DropCounter<'a> {
     count: &'a mut u32,
diff --git a/src/liballoc/tests/vec_deque.rs b/src/liballoc/tests/vec_deque.rs
index 101dd67d97a..c287d56fa53 100644
--- a/src/liballoc/tests/vec_deque.rs
+++ b/src/liballoc/tests/vec_deque.rs
@@ -3,7 +3,6 @@ use std::collections::{vec_deque::Drain, VecDeque};
 use std::fmt::Debug;
 use std::mem::size_of;
 use std::panic::{catch_unwind, AssertUnwindSafe};
-use std::{isize, usize};
 
 use crate::hash;
 
diff --git a/src/libcore/benches/num/flt2dec/strategy/dragon.rs b/src/libcore/benches/num/flt2dec/strategy/dragon.rs
index 4052fec3381..4e1fd8bf753 100644
--- a/src/libcore/benches/num/flt2dec/strategy/dragon.rs
+++ b/src/libcore/benches/num/flt2dec/strategy/dragon.rs
@@ -1,6 +1,5 @@
 use super::super::*;
 use core::num::flt2dec::strategy::dragon::*;
-use std::{f64, i16};
 use test::Bencher;
 
 #[bench]
diff --git a/src/libcore/benches/num/flt2dec/strategy/grisu.rs b/src/libcore/benches/num/flt2dec/strategy/grisu.rs
index 495074747c2..77ca901a90a 100644
--- a/src/libcore/benches/num/flt2dec/strategy/grisu.rs
+++ b/src/libcore/benches/num/flt2dec/strategy/grisu.rs
@@ -1,6 +1,5 @@
 use super::super::*;
 use core::num::flt2dec::strategy::grisu::*;
-use std::{f64, i16};
 use test::Bencher;
 
 pub fn decode_finite<T: DecodableFloat>(v: T) -> Decoded {
diff --git a/src/libcore/tests/fmt/num.rs b/src/libcore/tests/fmt/num.rs
index a50c2b46a91..275a1d062ca 100644
--- a/src/libcore/tests/fmt/num.rs
+++ b/src/libcore/tests/fmt/num.rs
@@ -104,7 +104,6 @@ fn test_format_int() {
 
 #[test]
 fn test_format_int_exp_limits() {
-    use core::{i128, i16, i32, i64, i8, u128, u16, u32, u64, u8};
     assert_eq!(format!("{:e}", i8::MIN), "-1.28e2");
     assert_eq!(format!("{:e}", i8::MAX), "1.27e2");
     assert_eq!(format!("{:e}", i16::MIN), "-3.2768e4");
@@ -125,8 +124,6 @@ fn test_format_int_exp_limits() {
 
 #[test]
 fn test_format_int_exp_precision() {
-    use core::{i128, i16, i32, i64, i8};
-
     //test that float and integer match
     let big_int: u32 = 314_159_265;
     assert_eq!(format!("{:.1e}", big_int), format!("{:.1e}", f64::from(big_int)));
@@ -214,7 +211,6 @@ fn test_format_int_sign_padding() {
 
 #[test]
 fn test_format_int_twos_complement() {
-    use core::{i16, i32, i64, i8};
     assert_eq!(format!("{}", i8::MIN), "-128");
     assert_eq!(format!("{}", i16::MIN), "-32768");
     assert_eq!(format!("{}", i32::MIN), "-2147483648");
diff --git a/src/libcore/tests/iter.rs b/src/libcore/tests/iter.rs
index 98e3eeb982b..e0954a661c8 100644
--- a/src/libcore/tests/iter.rs
+++ b/src/libcore/tests/iter.rs
@@ -3,8 +3,6 @@
 use core::cell::Cell;
 use core::convert::TryFrom;
 use core::iter::*;
-use core::usize;
-use core::{i16, i8, isize};
 
 #[test]
 fn test_lt() {
@@ -2251,62 +2249,58 @@ fn test_range_inclusive_folds() {
 
 #[test]
 fn test_range_size_hint() {
-    use core::usize::MAX as UMAX;
     assert_eq!((0..0usize).size_hint(), (0, Some(0)));
     assert_eq!((0..100usize).size_hint(), (100, Some(100)));
-    assert_eq!((0..UMAX).size_hint(), (UMAX, Some(UMAX)));
+    assert_eq!((0..usize::MAX).size_hint(), (usize::MAX, Some(usize::MAX)));
 
-    let umax = u128::try_from(UMAX).unwrap();
+    let umax = u128::try_from(usize::MAX).unwrap();
     assert_eq!((0..0u128).size_hint(), (0, Some(0)));
     assert_eq!((0..100u128).size_hint(), (100, Some(100)));
-    assert_eq!((0..umax).size_hint(), (UMAX, Some(UMAX)));
-    assert_eq!((0..umax + 1).size_hint(), (UMAX, None));
+    assert_eq!((0..umax).size_hint(), (usize::MAX, Some(usize::MAX)));
+    assert_eq!((0..umax + 1).size_hint(), (usize::MAX, None));
 
-    use core::isize::{MAX as IMAX, MIN as IMIN};
     assert_eq!((0..0isize).size_hint(), (0, Some(0)));
     assert_eq!((-100..100isize).size_hint(), (200, Some(200)));
-    assert_eq!((IMIN..IMAX).size_hint(), (UMAX, Some(UMAX)));
+    assert_eq!((isize::MIN..isize::MAX).size_hint(), (usize::MAX, Some(usize::MAX)));
 
-    let imin = i128::try_from(IMIN).unwrap();
-    let imax = i128::try_from(IMAX).unwrap();
+    let imin = i128::try_from(isize::MIN).unwrap();
+    let imax = i128::try_from(isize::MAX).unwrap();
     assert_eq!((0..0i128).size_hint(), (0, Some(0)));
     assert_eq!((-100..100i128).size_hint(), (200, Some(200)));
-    assert_eq!((imin..imax).size_hint(), (UMAX, Some(UMAX)));
-    assert_eq!((imin..imax + 1).size_hint(), (UMAX, None));
+    assert_eq!((imin..imax).size_hint(), (usize::MAX, Some(usize::MAX)));
+    assert_eq!((imin..imax + 1).size_hint(), (usize::MAX, None));
 }
 
 #[test]
 fn test_range_inclusive_size_hint() {
-    use core::usize::MAX as UMAX;
     assert_eq!((1..=0usize).size_hint(), (0, Some(0)));
     assert_eq!((0..=0usize).size_hint(), (1, Some(1)));
     assert_eq!((0..=100usize).size_hint(), (101, Some(101)));
-    assert_eq!((0..=UMAX - 1).size_hint(), (UMAX, Some(UMAX)));
-    assert_eq!((0..=UMAX).size_hint(), (UMAX, None));
+    assert_eq!((0..=usize::MAX - 1).size_hint(), (usize::MAX, Some(usize::MAX)));
+    assert_eq!((0..=usize::MAX).size_hint(), (usize::MAX, None));
 
-    let umax = u128::try_from(UMAX).unwrap();
+    let umax = u128::try_from(usize::MAX).unwrap();
     assert_eq!((1..=0u128).size_hint(), (0, Some(0)));
     assert_eq!((0..=0u128).size_hint(), (1, Some(1)));
     assert_eq!((0..=100u128).size_hint(), (101, Some(101)));
-    assert_eq!((0..=umax - 1).size_hint(), (UMAX, Some(UMAX)));
-    assert_eq!((0..=umax).size_hint(), (UMAX, None));
-    assert_eq!((0..=umax + 1).size_hint(), (UMAX, None));
+    assert_eq!((0..=umax - 1).size_hint(), (usize::MAX, Some(usize::MAX)));
+    assert_eq!((0..=umax).size_hint(), (usize::MAX, None));
+    assert_eq!((0..=umax + 1).size_hint(), (usize::MAX, None));
 
-    use core::isize::{MAX as IMAX, MIN as IMIN};
     assert_eq!((0..=-1isize).size_hint(), (0, Some(0)));
     assert_eq!((0..=0isize).size_hint(), (1, Some(1)));
     assert_eq!((-100..=100isize).size_hint(), (201, Some(201)));
-    assert_eq!((IMIN..=IMAX - 1).size_hint(), (UMAX, Some(UMAX)));
-    assert_eq!((IMIN..=IMAX).size_hint(), (UMAX, None));
+    assert_eq!((isize::MIN..=isize::MAX - 1).size_hint(), (usize::MAX, Some(usize::MAX)));
+    assert_eq!((isize::MIN..=isize::MAX).size_hint(), (usize::MAX, None));
 
-    let imin = i128::try_from(IMIN).unwrap();
-    let imax = i128::try_from(IMAX).unwrap();
+    let imin = i128::try_from(isize::MIN).unwrap();
+    let imax = i128::try_from(isize::MAX).unwrap();
     assert_eq!((0..=-1i128).size_hint(), (0, Some(0)));
     assert_eq!((0..=0i128).size_hint(), (1, Some(1)));
     assert_eq!((-100..=100i128).size_hint(), (201, Some(201)));
-    assert_eq!((imin..=imax - 1).size_hint(), (UMAX, Some(UMAX)));
-    assert_eq!((imin..=imax).size_hint(), (UMAX, None));
-    assert_eq!((imin..=imax + 1).size_hint(), (UMAX, None));
+    assert_eq!((imin..=imax - 1).size_hint(), (usize::MAX, Some(usize::MAX)));
+    assert_eq!((imin..=imax).size_hint(), (usize::MAX, None));
+    assert_eq!((imin..=imax + 1).size_hint(), (usize::MAX, None));
 }
 
 #[test]
diff --git a/src/libcore/tests/num/dec2flt/mod.rs b/src/libcore/tests/num/dec2flt/mod.rs
index a1fa5556ae5..1c172f49c27 100644
--- a/src/libcore/tests/num/dec2flt/mod.rs
+++ b/src/libcore/tests/num/dec2flt/mod.rs
@@ -1,7 +1,5 @@
 #![allow(overflowing_literals)]
 
-use std::{f32, f64, i64};
-
 mod parse;
 mod rawfp;
 
diff --git a/src/libcore/tests/num/flt2dec/mod.rs b/src/libcore/tests/num/flt2dec/mod.rs
index e945d9c4a54..ae892e3b0bf 100644
--- a/src/libcore/tests/num/flt2dec/mod.rs
+++ b/src/libcore/tests/num/flt2dec/mod.rs
@@ -1,4 +1,4 @@
-use std::{f32, f64, fmt, i16, str};
+use std::{fmt, str};
 
 use core::num::flt2dec::{decode, DecodableFloat, Decoded, FullDecoded};
 use core::num::flt2dec::{round_up, Formatted, Part, Sign, MAX_SIG_DIGITS};
diff --git a/src/libcore/tests/num/flt2dec/random.rs b/src/libcore/tests/num/flt2dec/random.rs
index ecdfc4b30a5..5b050a2c356 100644
--- a/src/libcore/tests/num/flt2dec/random.rs
+++ b/src/libcore/tests/num/flt2dec/random.rs
@@ -1,6 +1,5 @@
 #![cfg(not(target_arch = "wasm32"))]
 
-use std::i16;
 use std::str;
 
 use core::num::flt2dec::strategy::grisu::format_exact_opt;
diff --git a/src/libcore/tests/num/int_macros.rs b/src/libcore/tests/num/int_macros.rs
index 48a49073b2c..8396a0dd62d 100644
--- a/src/libcore/tests/num/int_macros.rs
+++ b/src/libcore/tests/num/int_macros.rs
@@ -2,7 +2,6 @@ macro_rules! int_module {
     ($T:ident, $T_i:ident) => {
         #[cfg(test)]
         mod tests {
-            use core::isize;
             use core::mem;
             use core::ops::{BitAnd, BitOr, BitXor, Not, Shl, Shr};
             use core::$T_i::*;
diff --git a/src/librustc_ast/util/comments.rs b/src/librustc_ast/util/comments.rs
index 0e42ae11fa2..5f5d4810cb5 100644
--- a/src/librustc_ast/util/comments.rs
+++ b/src/librustc_ast/util/comments.rs
@@ -5,7 +5,6 @@ use rustc_span::source_map::SourceMap;
 use rustc_span::{BytePos, CharPos, FileName, Pos};
 
 use log::debug;
-use std::usize;
 
 #[cfg(test)]
 mod tests;
diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs
index 5734eae7d59..63730c56f0e 100644
--- a/src/librustc_codegen_llvm/intrinsic.rs
+++ b/src/librustc_codegen_llvm/intrinsic.rs
@@ -25,7 +25,7 @@ use rustc_span::Span;
 use rustc_target::abi::{self, HasDataLayout, LayoutOf, Primitive};
 
 use std::cmp::Ordering;
-use std::{i128, iter, u128};
+use std::iter;
 
 fn get_simple_intrinsic(cx: &CodegenCx<'ll, '_>, name: &str) -> Option<&'ll Value> {
     let llvm_name = match name {
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 33f449ed270..57fe7b0da6f 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -17,8 +17,6 @@ use rustc_span::source_map::{Span, DUMMY_SP};
 use rustc_span::symbol::sym;
 use rustc_target::abi::{Abi, Int, LayoutOf, Variants};
 
-use std::{i128, u128};
-
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     pub fn codegen_rvalue(
         &mut self,
diff --git a/src/librustc_data_structures/graph/implementation/mod.rs b/src/librustc_data_structures/graph/implementation/mod.rs
index f705c2f0b75..1aa7ac024d9 100644
--- a/src/librustc_data_structures/graph/implementation/mod.rs
+++ b/src/librustc_data_structures/graph/implementation/mod.rs
@@ -23,7 +23,6 @@
 use crate::snapshot_vec::{SnapshotVec, SnapshotVecDelegate};
 use rustc_index::bit_set::BitSet;
 use std::fmt::Debug;
-use std::usize;
 
 #[cfg(test)]
 mod tests;
diff --git a/src/librustc_data_structures/profiling.rs b/src/librustc_data_structures/profiling.rs
index a7cdc48d603..23f3558cbdf 100644
--- a/src/librustc_data_structures/profiling.rs
+++ b/src/librustc_data_structures/profiling.rs
@@ -93,7 +93,6 @@ use std::path::Path;
 use std::process;
 use std::sync::Arc;
 use std::time::{Duration, Instant};
-use std::u32;
 
 use measureme::{EventId, EventIdBuilder, SerializableString, StringId};
 use parking_lot::RwLock;
diff --git a/src/librustc_index/vec.rs b/src/librustc_index/vec.rs
index d8c67f6210c..a84f89c7cd9 100644
--- a/src/librustc_index/vec.rs
+++ b/src/librustc_index/vec.rs
@@ -7,7 +7,6 @@ use std::iter::{self, FromIterator};
 use std::marker::PhantomData;
 use std::ops::{Index, IndexMut, Range, RangeBounds};
 use std::slice;
-use std::u32;
 use std::vec;
 
 /// Represents some newtyped `usize` wrapper.
diff --git a/src/librustc_infer/infer/type_variable.rs b/src/librustc_infer/infer/type_variable.rs
index 8e4199f0c26..1de820cdb62 100644
--- a/src/librustc_infer/infer/type_variable.rs
+++ b/src/librustc_infer/infer/type_variable.rs
@@ -8,7 +8,6 @@ use rustc_data_structures::unify as ut;
 use std::cmp;
 use std::marker::PhantomData;
 use std::ops::Range;
-use std::u32;
 
 pub struct TypeVariableTable<'tcx> {
     values: sv::SnapshotVec<Delegate>,
diff --git a/src/librustc_lint/types.rs b/src/librustc_lint/types.rs
index a6e1ed84c87..aa805a2f2db 100644
--- a/src/librustc_lint/types.rs
+++ b/src/librustc_lint/types.rs
@@ -21,7 +21,6 @@ use rustc_target::spec::abi::Abi;
 
 use log::debug;
 use std::cmp;
-use std::{f32, f64, i16, i32, i64, i8, u16, u32, u64, u8};
 
 declare_lint! {
     UNUSED_COMPARISONS,
diff --git a/src/librustc_metadata/rmeta/decoder.rs b/src/librustc_metadata/rmeta/decoder.rs
index c59b155d5db..29a4254d9ee 100644
--- a/src/librustc_metadata/rmeta/decoder.rs
+++ b/src/librustc_metadata/rmeta/decoder.rs
@@ -42,7 +42,6 @@ use std::io;
 use std::mem;
 use std::num::NonZeroUsize;
 use std::path::Path;
-use std::u32;
 
 pub use cstore_impl::{provide, provide_extern};
 
diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs
index f2e9f4d7e0b..d75298fae00 100644
--- a/src/librustc_metadata/rmeta/encoder.rs
+++ b/src/librustc_metadata/rmeta/encoder.rs
@@ -39,7 +39,6 @@ use rustc_target::abi::VariantIdx;
 use std::hash::Hash;
 use std::num::NonZeroUsize;
 use std::path::Path;
-use std::u32;
 
 struct EncodeContext<'tcx> {
     opaque: opaque::Encoder,
diff --git a/src/librustc_middle/mir/mod.rs b/src/librustc_middle/mir/mod.rs
index 36e10f8759d..b82008f429f 100644
--- a/src/librustc_middle/mir/mod.rs
+++ b/src/librustc_middle/mir/mod.rs
@@ -33,7 +33,7 @@ use std::borrow::Cow;
 use std::fmt::{self, Debug, Display, Formatter, Write};
 use std::ops::Index;
 use std::slice;
-use std::{iter, mem, option, u32};
+use std::{iter, mem, option};
 
 pub use self::cache::{BodyAndCache, ReadOnlyBodyAndCache};
 pub use self::query::*;
diff --git a/src/librustc_mir/transform/promote_consts.rs b/src/librustc_mir/transform/promote_consts.rs
index 34fa12e1b56..ec0b89ebb4d 100644
--- a/src/librustc_mir/transform/promote_consts.rs
+++ b/src/librustc_mir/transform/promote_consts.rs
@@ -27,7 +27,7 @@ use rustc_index::vec::{Idx, IndexVec};
 use rustc_target::spec::abi::Abi;
 
 use std::cell::Cell;
-use std::{cmp, iter, mem, usize};
+use std::{cmp, iter, mem};
 
 use crate::const_eval::{is_const_fn, is_unstable_const_fn};
 use crate::transform::check_consts::{is_lang_panic_fn, qualifs, ConstKind, Item};
diff --git a/src/librustc_mir_build/build/matches/util.rs b/src/librustc_mir_build/build/matches/util.rs
index 967a44b9b96..393af108a6e 100644
--- a/src/librustc_mir_build/build/matches/util.rs
+++ b/src/librustc_mir_build/build/matches/util.rs
@@ -5,7 +5,6 @@ use rustc_middle::mir::*;
 use rustc_middle::ty;
 use smallvec::SmallVec;
 use std::convert::TryInto;
-use std::u32;
 
 impl<'a, 'tcx> Builder<'a, 'tcx> {
     crate fn field_match_pairs<'pat>(
diff --git a/src/librustc_mir_build/build/mod.rs b/src/librustc_mir_build/build/mod.rs
index 24395702020..04cb509d44e 100644
--- a/src/librustc_mir_build/build/mod.rs
+++ b/src/librustc_mir_build/build/mod.rs
@@ -17,7 +17,6 @@ use rustc_span::symbol::kw;
 use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 use rustc_target::spec::PanicStrategy;
-use std::u32;
 
 use super::lints;
 
diff --git a/src/librustc_mir_build/hair/pattern/_match.rs b/src/librustc_mir_build/hair/pattern/_match.rs
index 8c0843124f4..51ba84416d6 100644
--- a/src/librustc_mir_build/hair/pattern/_match.rs
+++ b/src/librustc_mir_build/hair/pattern/_match.rs
@@ -256,7 +256,6 @@ use std::convert::TryInto;
 use std::fmt;
 use std::iter::{FromIterator, IntoIterator};
 use std::ops::RangeInclusive;
-use std::u128;
 
 crate fn expand_pattern<'a, 'tcx>(cx: &MatchCheckCtxt<'a, 'tcx>, pat: Pat<'tcx>) -> Pat<'tcx> {
     LiteralExpander { tcx: cx.tcx, param_env: cx.param_env }.fold_pattern(&pat)
diff --git a/src/librustc_passes/liveness.rs b/src/librustc_passes/liveness.rs
index c9060334a9a..ee71d09cb21 100644
--- a/src/librustc_passes/liveness.rs
+++ b/src/librustc_passes/liveness.rs
@@ -112,10 +112,10 @@ use rustc_span::symbol::sym;
 use rustc_span::Span;
 
 use std::collections::VecDeque;
+use std::fmt;
 use std::io;
 use std::io::prelude::*;
 use std::rc::Rc;
-use std::{fmt, u32};
 
 #[derive(Copy, Clone, PartialEq)]
 struct Variable(u32);
diff --git a/src/librustc_span/def_id.rs b/src/librustc_span/def_id.rs
index 3551220c5c5..73b46d753d7 100644
--- a/src/librustc_span/def_id.rs
+++ b/src/librustc_span/def_id.rs
@@ -7,7 +7,6 @@ use rustc_macros::HashStable_Generic;
 use rustc_serialize::{Decoder, Encoder};
 use std::borrow::Borrow;
 use std::fmt;
-use std::{u32, u64};
 
 rustc_index::newtype_index! {
     pub struct CrateId {
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index e027db8b56c..f4111483902 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -32,7 +32,6 @@ use std::collections::hash_map::Entry;
 use std::default::Default;
 use std::hash::Hash;
 use std::rc::Rc;
-use std::u32;
 use std::{mem, vec};
 
 use crate::core::{self, DocContext, ImplTraitParam};
diff --git a/src/librustdoc/passes/unindent_comments.rs b/src/librustdoc/passes/unindent_comments.rs
index d4e09ce47a3..5604a9c2dc1 100644
--- a/src/librustdoc/passes/unindent_comments.rs
+++ b/src/librustdoc/passes/unindent_comments.rs
@@ -1,6 +1,5 @@
 use std::cmp;
 use std::string::String;
-use std::usize;
 
 use crate::clean::{self, DocFragment, Item};
 use crate::core::DocContext;
diff --git a/src/libserialize/tests/json.rs b/src/libserialize/tests/json.rs
index c16426b5919..688bddc2baf 100644
--- a/src/libserialize/tests/json.rs
+++ b/src/libserialize/tests/json.rs
@@ -17,7 +17,6 @@ use rustc_serialize::{Decodable, Encodable};
 use std::collections::BTreeMap;
 use std::io::prelude::*;
 use std::string;
-use std::{f32, f64, i64, u64};
 use Animal::*;
 
 #[derive(RustcDecodable, Eq, PartialEq, Debug)]
diff --git a/src/libstd/sync/mpsc/shared.rs b/src/libstd/sync/mpsc/shared.rs
index 2b0393573fd..c4e929624d7 100644
--- a/src/libstd/sync/mpsc/shared.rs
+++ b/src/libstd/sync/mpsc/shared.rs
@@ -12,7 +12,6 @@ use self::StartResult::*;
 
 use core::cmp;
 use core::intrinsics::abort;
-use core::isize;
 
 use crate::cell::UnsafeCell;
 use crate::ptr;
diff --git a/src/libstd/sync/mpsc/stream.rs b/src/libstd/sync/mpsc/stream.rs
index 2e3270e81fc..f33493ee0c9 100644
--- a/src/libstd/sync/mpsc/stream.rs
+++ b/src/libstd/sync/mpsc/stream.rs
@@ -11,7 +11,6 @@ use self::Message::*;
 pub use self::UpgradeResult::*;
 
 use core::cmp;
-use core::isize;
 
 use crate::cell::UnsafeCell;
 use crate::ptr;
diff --git a/src/libstd/sync/mpsc/sync.rs b/src/libstd/sync/mpsc/sync.rs
index 79e86817154..3e2050799cc 100644
--- a/src/libstd/sync/mpsc/sync.rs
+++ b/src/libstd/sync/mpsc/sync.rs
@@ -26,7 +26,6 @@ use self::Blocker::*;
 pub use self::Failure::*;
 
 use core::intrinsics::abort;
-use core::isize;
 use core::mem;
 use core::ptr;
 
diff --git a/src/libstd/sys/hermit/thread.rs b/src/libstd/sys/hermit/thread.rs
index c7bea168f34..34f88eea0d7 100644
--- a/src/libstd/sys/hermit/thread.rs
+++ b/src/libstd/sys/hermit/thread.rs
@@ -6,7 +6,6 @@ use crate::io;
 use crate::mem;
 use crate::sys::hermit::abi;
 use crate::time::Duration;
-use core::u32;
 
 pub type Tid = abi::Tid;