diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index aac5d296f17b5..fe1d190b4ec1a 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -1,4 +1,3 @@
-// ignore-tidy-filelength
 use crate::def::{CtorKind, DefKind, Res};
 use crate::def_id::{DefId, CRATE_DEF_ID};
 crate use crate::hir_id::{HirId, ItemLocalId};
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index c590cd00bd545..f341ca686593c 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -1,5 +1,3 @@
-// ignore-tidy-filelength
-
 //! Lints in the Rust compiler.
 //!
 //! This contains lints which can feasibly be implemented as their own
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 9b1ee53df23bd..8376734166bb8 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -1,5 +1,3 @@
-// ignore-tidy-filelength
-
 //! Some lints that are built in to the compiler.
 //!
 //! These are the built-in lints that are emitted direct in the main
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 2e4395cfca8c1..423f3faf21fff 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -1,4 +1,3 @@
-// ignore-tidy-filelength
 use crate::ich::StableHashingContext;
 use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use crate::mir::{GeneratorLayout, GeneratorSavedLocal};
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index 06cb33b9ebf4b..eb94fde21099b 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -1,4 +1,3 @@
-// ignore-tidy-filelength
 //! "Collection" is the process of determining the type and other external
 //! details of each item in Rust. Collection is specifically concerned
 //! with *inter-procedural* things -- for example, for a function
@@ -15,8 +14,6 @@
 //! At present, however, we do run collection across all items in the
 //! crate as a kind of pass. This should eventually be factored away.
 
-// ignore-tidy-filelength
-
 use crate::astconv::{AstConv, SizedByDefault};
 use crate::bounds::Bounds;
 use crate::check::intrinsic::intrinsic_operation_unsafety;
diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs
index 537e42f66de1b..c199b068cbb59 100644
--- a/library/core/src/iter/traits/iterator.rs
+++ b/library/core/src/iter/traits/iterator.rs
@@ -1,7 +1,3 @@
-// ignore-tidy-filelength
-// This file almost exclusively consists of the definition of `Iterator`. We
-// can't split that into multiple files.
-
 use crate::cmp::{self, Ordering};
 use crate::ops::{ControlFlow, Try};
 
diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs
index 419bf0e292ae1..d67af9cf6680c 100644
--- a/library/core/src/slice/iter.rs
+++ b/library/core/src/slice/iter.rs
@@ -1,4 +1,3 @@
-// ignore-tidy-filelength
 //! Definitions of a bunch of iterators for `[T]`.
 
 #[macro_use] // import iterator! and forward_iterator!
diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index 67eecab99d89a..51227d5411549 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -1,5 +1,3 @@
-// ignore-tidy-filelength
-
 //! Slice management and manipulation.
 //!
 //! For more details see [`std::slice`].
diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
index 933d686521e53..1628e1bceda72 100644
--- a/library/std/src/collections/hash/map.rs
+++ b/library/std/src/collections/hash/map.rs
@@ -1,5 +1,3 @@
-// ignore-tidy-filelength
-
 #[cfg(test)]
 mod tests;
 
diff --git a/src/tools/tidy/src/style.rs b/src/tools/tidy/src/style.rs
index 15ed2f7a0a975..d8d3dc3ddb1e5 100644
--- a/src/tools/tidy/src/style.rs
+++ b/src/tools/tidy/src/style.rs
@@ -344,7 +344,10 @@ pub fn check(path: &Path, bad: &mut bool) {
             } else {
                 trailing_new_lines = 0;
             }
-            lines = i;
+
+            if !line.trim().starts_with("//") {
+                lines += 1;
+            }
         }
         if leading_new_lines {
             tidy_error!(bad, "{}: leading newline", file.display());