diff --git a/compiler/rustc_arena/src/lib.rs b/compiler/rustc_arena/src/lib.rs
index b4bf31b1abae5..166f7f53c41ac 100644
--- a/compiler/rustc_arena/src/lib.rs
+++ b/compiler/rustc_arena/src/lib.rs
@@ -15,7 +15,6 @@
 #![feature(new_uninit)]
 #![feature(maybe_uninit_slice)]
 #![cfg_attr(test, feature(test))]
-#![allow(deprecated)]
 
 use rustc_data_structures::cold_path;
 use smallvec::SmallVec;
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 23a3be1a2f2e8..67191ac0e4640 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -931,7 +931,6 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         unsafe { llvm::LLVMBuildSelect(self.llbuilder, cond, then_val, else_val, UNNAMED) }
     }
 
-    #[allow(dead_code)]
     fn va_arg(&mut self, list: &'ll Value, ty: &'ll Type) -> &'ll Value {
         unsafe { llvm::LLVMBuildVAArg(self.llbuilder, list, ty, UNNAMED) }
     }
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index 0b1cf03fa7e42..0992410a728bd 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -1,5 +1,3 @@
-#![allow(non_camel_case_types, non_snake_case)]
-
 //! Code that is useful in various codegen modules.
 
 use crate::consts::{self, const_alloc_to_llvm};
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 868eb74cf09cd..987149cb4c25c 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1845,7 +1845,6 @@ impl<'tcx> VariantInfo<'_, 'tcx> {
         None
     }
 
-    #[allow(dead_code)]
     fn is_artificial(&self) -> bool {
         match self {
             VariantInfo::Generator { .. } => true,
diff --git a/compiler/rustc_codegen_llvm/src/va_arg.rs b/compiler/rustc_codegen_llvm/src/va_arg.rs
index 54efa05aee81e..22ed4dd7576b5 100644
--- a/compiler/rustc_codegen_llvm/src/va_arg.rs
+++ b/compiler/rustc_codegen_llvm/src/va_arg.rs
@@ -11,7 +11,6 @@ use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::Ty;
 use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Size};
 
-#[allow(dead_code)]
 fn round_pointer_up_to_alignment(
     bx: &mut Builder<'a, 'll, 'tcx>,
     addr: &'ll Value,
diff --git a/compiler/rustc_codegen_ssa/src/common.rs b/compiler/rustc_codegen_ssa/src/common.rs
index e04ed531bbff2..780b1d2cd9433 100644
--- a/compiler/rustc_codegen_ssa/src/common.rs
+++ b/compiler/rustc_codegen_ssa/src/common.rs
@@ -1,4 +1,4 @@
-#![allow(non_camel_case_types, non_snake_case)]
+#![allow(non_camel_case_types)]
 
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -25,7 +25,6 @@ pub enum IntPredicate {
     IntSLE,
 }
 
-#[allow(dead_code)]
 pub enum RealPredicate {
     RealPredicateFalse,
     RealOEQ,
@@ -60,7 +59,6 @@ pub enum AtomicRmwBinOp {
 }
 
 pub enum AtomicOrdering {
-    #[allow(dead_code)]
     NotAtomic,
     Unordered,
     Monotonic,
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index 9ded10e9c26ac..90b0f25475181 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -7,7 +7,6 @@
 //! This API is completely unstable and subject to change.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
-#![allow(incomplete_features)]
 #![feature(array_windows)]
 #![feature(control_flow_enum)]
 #![feature(in_band_lifetimes)]
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index 76cf6bd47769f..820d664c07d92 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -256,7 +256,6 @@ pub trait Visitor<'v>: Sized {
     /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
     /// reason to override this method is if you want a nested pattern
     /// but cannot supply a `Map`; see `nested_visit_map` for advice.
-    #[allow(unused_variables)]
     fn visit_nested_item(&mut self, id: ItemId) {
         let opt_item = self.nested_visit_map().inter().map(|map| map.item(id.id));
         walk_list!(self, visit_item, opt_item);
@@ -265,7 +264,6 @@ pub trait Visitor<'v>: Sized {
     /// Like `visit_nested_item()`, but for trait items. See
     /// `visit_nested_item()` for advice on when to override this
     /// method.
-    #[allow(unused_variables)]
     fn visit_nested_trait_item(&mut self, id: TraitItemId) {
         let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
         walk_list!(self, visit_trait_item, opt_item);
@@ -274,7 +272,6 @@ pub trait Visitor<'v>: Sized {
     /// Like `visit_nested_item()`, but for impl items. See
     /// `visit_nested_item()` for advice on when to override this
     /// method.
-    #[allow(unused_variables)]
     fn visit_nested_impl_item(&mut self, id: ImplItemId) {
         let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
         walk_list!(self, visit_impl_item, opt_item);
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index 2cbdc954e2007..95137410c6245 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -1275,7 +1275,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     }
 
     /// Gives temporary access to the region constraint data.
-    #[allow(non_camel_case_types)] // bug with impl trait
     pub fn with_region_constraints<R>(
         &self,
         op: impl FnOnce(&RegionConstraintData<'tcx>) -> R,
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index 6aa28d04ae197..9925444b869f9 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -1,5 +1,3 @@
-#![allow(non_snake_case)]
-
 use crate::{LateContext, LateLintPass, LintContext};
 use rustc_ast as ast;
 use rustc_attr as attr;
diff --git a/compiler/rustc_llvm/src/lib.rs b/compiler/rustc_llvm/src/lib.rs
index a7a10b91b4eca..a381290d46f97 100644
--- a/compiler/rustc_llvm/src/lib.rs
+++ b/compiler/rustc_llvm/src/lib.rs
@@ -21,7 +21,6 @@ impl RustString {
 
 /// Appending to a Rust string -- used by RawRustStringOstream.
 #[no_mangle]
-#[allow(improper_ctypes_definitions)]
 pub unsafe extern "C" fn LLVMRustStringWriteImpl(
     sr: &RustString,
     ptr: *const c_char,
diff --git a/compiler/rustc_macros/src/query.rs b/compiler/rustc_macros/src/query.rs
index 204e8e800cd48..e7c054653accb 100644
--- a/compiler/rustc_macros/src/query.rs
+++ b/compiler/rustc_macros/src/query.rs
@@ -9,7 +9,6 @@ use syn::{
     ReturnType, Token, Type,
 };
 
-#[allow(non_camel_case_types)]
 mod kw {
     syn::custom_keyword!(query);
 }
diff --git a/compiler/rustc_macros/src/symbols.rs b/compiler/rustc_macros/src/symbols.rs
index 352665f0ab199..94d4ad78e8d90 100644
--- a/compiler/rustc_macros/src/symbols.rs
+++ b/compiler/rustc_macros/src/symbols.rs
@@ -4,7 +4,6 @@ use std::collections::HashSet;
 use syn::parse::{Parse, ParseStream, Result};
 use syn::{braced, parse_macro_input, Ident, LitStr, Token};
 
-#[allow(non_camel_case_types)]
 mod kw {
     syn::custom_keyword!(Keywords);
     syn::custom_keyword!(Symbols);
diff --git a/compiler/rustc_middle/src/util/common.rs b/compiler/rustc_middle/src/util/common.rs
index 1e09702bf27ca..da857b0a403b4 100644
--- a/compiler/rustc_middle/src/util/common.rs
+++ b/compiler/rustc_middle/src/util/common.rs
@@ -1,5 +1,3 @@
-#![allow(non_camel_case_types)]
-
 use rustc_data_structures::sync::Lock;
 
 use std::fmt::Debug;
diff --git a/compiler/rustc_mir/src/borrow_check/prefixes.rs b/compiler/rustc_mir/src/borrow_check/prefixes.rs
index 5bfe02ff3b04e..6c5d42296f72b 100644
--- a/compiler/rustc_mir/src/borrow_check/prefixes.rs
+++ b/compiler/rustc_mir/src/borrow_check/prefixes.rs
@@ -33,7 +33,6 @@ pub(super) struct Prefixes<'cx, 'tcx> {
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
-#[allow(dead_code)]
 pub(super) enum PrefixSet {
     /// Doesn't stop until it returns the base case (a Local or
     /// Static prefix).
diff --git a/compiler/rustc_mir/src/dataflow/move_paths/mod.rs b/compiler/rustc_mir/src/dataflow/move_paths/mod.rs
index d66d2625d78ea..7c63025918603 100644
--- a/compiler/rustc_mir/src/dataflow/move_paths/mod.rs
+++ b/compiler/rustc_mir/src/dataflow/move_paths/mod.rs
@@ -144,7 +144,6 @@ impl<'tcx> fmt::Display for MovePath<'tcx> {
     }
 }
 
-#[allow(unused)]
 struct MovePathLinearIter<'a, 'tcx, F> {
     next: Option<(MovePathIndex, &'a MovePath<'tcx>)>,
     fetch_next: F,
diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs
index 284fca652ece7..12a268d5b1dda 100644
--- a/compiler/rustc_session/src/filesearch.rs
+++ b/compiler/rustc_session/src/filesearch.rs
@@ -1,5 +1,3 @@
-#![allow(non_camel_case_types)]
-
 pub use self::FileMatch::*;
 
 use std::borrow::Cow;
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 35bfeff10b4aa..e40067202e112 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -32,6 +32,7 @@ pub enum AutoTraitResult<A> {
     NegativeImpl,
 }
 
+#[allow(dead_code)]
 impl<A> AutoTraitResult<A> {
     fn is_auto(&self) -> bool {
         match *self {
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 79495ba7f9b30..c93087a18cf04 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -2,7 +2,6 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/resolution.html
 
-#[allow(dead_code)]
 pub mod auto_trait;
 mod chalk_fulfill;
 pub mod codegen;
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 5e2f7d81d000a..57f1fedacbe5a 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2148,7 +2148,6 @@ trait TraitObligationExt<'tcx> {
 }
 
 impl<'tcx> TraitObligationExt<'tcx> for TraitObligation<'tcx> {
-    #[allow(unused_comparisons)]
     fn derived_cause(
         &self,
         variant: fn(DerivedObligationCause<'tcx>) -> ObligationCauseCode<'tcx>,
diff --git a/compiler/rustc_typeck/src/lib.rs b/compiler/rustc_typeck/src/lib.rs
index 84efb92582ed2..e8fa2b13a9f24 100644
--- a/compiler/rustc_typeck/src/lib.rs
+++ b/compiler/rustc_typeck/src/lib.rs
@@ -56,7 +56,6 @@ This API is completely unstable and subject to change.
 */
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
-#![allow(non_camel_case_types)]
 #![feature(bool_to_option)]
 #![feature(box_syntax)]
 #![feature(crate_visibility_modifier)]