Auto merge of #129665 - matthiaskrgr:rollup-hy23k7d, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #129507 (make it possible to enable const_precise_live_drops per-function)
 - #129581 (exit: explain our expectations for the exit handlers registered in a Rust program)
 - #129634 (Fix tidy to allow `edition = "2024"` in `Cargo.toml`)
 - #129635 (Use unsafe extern blocks throughout the compiler)
 - #129645 (Fix typos in floating-point primitive type docs)
 - #129648 (More `unreachable_pub`)
 - #129649 (ABI compat check: detect unadjusted ABI mismatches)
 - #129652 (fix Pointer to reference conversion docs)

r? `@ghost`
`@rustbot` modify labels: rollup

121 files changed, 802 insertions, 734 deletions

diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index ea634d7485e..df29b3d54f0 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -1700,7 +1700,9 @@ impl<FieldIdx: Idx, VariantIdx: Idx> LayoutS<FieldIdx, VariantIdx> {
 
     /// Checks if these two `Layout` are equal enough to be considered "the same for all function
     /// call ABIs". Note however that real ABIs depend on more details that are not reflected in the
-    /// `Layout`; the `PassMode` need to be compared as well.
+    /// `Layout`; the `PassMode` need to be compared as well. Also note that we assume
+    /// aggregates are passed via `PassMode::Indirect` or `PassMode::Cast`; more strict
+    /// checks would otherwise be required.
     pub fn eq_abi(&self, other: &Self) -> bool {
         // The one thing that we are not capturing here is that for unsized types, the metadata must
         // also have the same ABI, and moreover that the same metadata leads to the same size. The
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 7f26bbd7f87..6a303e1e602 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -6,6 +6,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(unsafe_extern_blocks))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 7a495174ff1..5e0d7418993 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -564,12 +564,12 @@ pub enum ArchiveKind {
 }
 
 // LLVMRustThinLTOData
-extern "C" {
+unsafe extern "C" {
     pub type ThinLTOData;
 }
 
 // LLVMRustThinLTOBuffer
-extern "C" {
+unsafe extern "C" {
     pub type ThinLTOBuffer;
 }
 
@@ -621,7 +621,7 @@ pub enum MemoryEffects {
     InaccessibleMemOnly,
 }
 
-extern "C" {
+unsafe extern "C" {
     type Opaque;
 }
 #[repr(C)]
@@ -631,54 +631,54 @@ struct InvariantOpaque<'a> {
 }
 
 // Opaque pointer types
-extern "C" {
+unsafe extern "C" {
     pub type Module;
 }
-extern "C" {
+unsafe extern "C" {
     pub type Context;
 }
-extern "C" {
+unsafe extern "C" {
     pub type Type;
 }
-extern "C" {
+unsafe extern "C" {
     pub type Value;
 }
-extern "C" {
+unsafe extern "C" {
     pub type ConstantInt;
 }
-extern "C" {
+unsafe extern "C" {
     pub type Attribute;
 }
-extern "C" {
+unsafe extern "C" {
     pub type Metadata;
 }
-extern "C" {
+unsafe extern "C" {
     pub type BasicBlock;
 }
 #[repr(C)]
 pub struct Builder<'a>(InvariantOpaque<'a>);
 #[repr(C)]
 pub struct PassManager<'a>(InvariantOpaque<'a>);
-extern "C" {
+unsafe extern "C" {
     pub type Pass;
 }
-extern "C" {
+unsafe extern "C" {
     pub type TargetMachine;
 }
-extern "C" {
+unsafe extern "C" {
     pub type Archive;
 }
 #[repr(C)]
 pub struct ArchiveIterator<'a>(InvariantOpaque<'a>);
 #[repr(C)]
 pub struct ArchiveChild<'a>(InvariantOpaque<'a>);
-extern "C" {
+unsafe extern "C" {
     pub type Twine;
 }
-extern "C" {
+unsafe extern "C" {
     pub type DiagnosticInfo;
 }
-extern "C" {
+unsafe extern "C" {
     pub type SMDiagnostic;
 }
 #[repr(C)]
@@ -688,7 +688,7 @@ pub struct OperandBundleDef<'a>(InvariantOpaque<'a>);
 #[repr(C)]
 pub struct Linker<'a>(InvariantOpaque<'a>);
 
-extern "C" {
+unsafe extern "C" {
     pub type DiagnosticHandler;
 }
 
@@ -823,7 +823,7 @@ bitflags! {
     }
 }
 
-extern "C" {
+unsafe extern "C" {
     pub type ModuleBuffer;
 }
 
@@ -834,7 +834,7 @@ pub type SelfProfileAfterPassCallback = unsafe extern "C" fn(*mut c_void);
 pub type GetSymbolsCallback = unsafe extern "C" fn(*mut c_void, *const c_char) -> *mut c_void;
 pub type GetSymbolsErrorCallback = unsafe extern "C" fn(*const c_char) -> *mut c_void;
 
-extern "C" {
+unsafe extern "C" {
     // Create and destroy contexts.
     pub fn LLVMContextDispose(C: &'static mut Context);
     pub fn LLVMGetMDKindIDInContext(C: &Context, Name: *const c_char, SLen: c_uint) -> c_uint;
@@ -1518,7 +1518,7 @@ extern "C" {
 }
 
 #[link(name = "llvm-wrapper", kind = "static")]
-extern "C" {
+unsafe extern "C" {
     pub fn LLVMRustInstallErrorHandlers();
     pub fn LLVMRustDisableSystemDialogsOnCrash();
 
diff --git a/compiler/rustc_const_eval/src/check_consts/post_drop_elaboration.rs b/compiler/rustc_const_eval/src/check_consts/post_drop_elaboration.rs
index c4f06e5af0b..f0998300dc8 100644
--- a/compiler/rustc_const_eval/src/check_consts/post_drop_elaboration.rs
+++ b/compiler/rustc_const_eval/src/check_consts/post_drop_elaboration.rs
@@ -9,13 +9,19 @@ use super::check::Qualifs;
 use super::ops::{self, NonConstOp};
 use super::qualifs::{NeedsNonConstDrop, Qualif};
 use super::ConstCx;
+use crate::check_consts::rustc_allow_const_fn_unstable;
 
 /// Returns `true` if we should use the more precise live drop checker that runs after drop
 /// elaboration.
 pub fn checking_enabled(ccx: &ConstCx<'_, '_>) -> bool {
-    // Const-stable functions must always use the stable live drop checker.
+    // Const-stable functions must always use the stable live drop checker...
     if ccx.is_const_stable_const_fn() {
-        return false;
+        // ...except if they have the feature flag set via `rustc_allow_const_fn_unstable`.
+        return rustc_allow_const_fn_unstable(
+            ccx.tcx,
+            ccx.body.source.def_id().expect_local(),
+            sym::const_precise_live_drops,
+        );
     }
 
     ccx.tcx.features().const_precise_live_drops
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 2b7dc040f64..820ba96b100 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -7,6 +7,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
+#![cfg_attr(bootstrap, feature(unsafe_extern_blocks))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(decl_macro)]
@@ -15,6 +16,7 @@
 #![feature(panic_update_hook)]
 #![feature(result_flattening)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::cmp::max;
diff --git a/compiler/rustc_driver_impl/src/signal_handler.rs b/compiler/rustc_driver_impl/src/signal_handler.rs
index 51f2a508cf9..e1f868c2522 100644
--- a/compiler/rustc_driver_impl/src/signal_handler.rs
+++ b/compiler/rustc_driver_impl/src/signal_handler.rs
@@ -6,7 +6,7 @@ use std::{fmt, mem, ptr};
 
 use rustc_interface::util::{DEFAULT_STACK_SIZE, STACK_SIZE};
 
-extern "C" {
+unsafe extern "C" {
     fn backtrace_symbols_fd(buffer: *const *mut libc::c_void, size: libc::c_int, fd: libc::c_int);
 }
 
diff --git a/compiler/rustc_error_codes/src/lib.rs b/compiler/rustc_error_codes/src/lib.rs
index 2a7bc2501c0..150f99a3ee7 100644
--- a/compiler/rustc_error_codes/src/lib.rs
+++ b/compiler/rustc_error_codes/src/lib.rs
@@ -6,6 +6,7 @@
 #![deny(rustdoc::invalid_codeblock_attributes)]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 // This higher-order macro defines the error codes that are in use. It is used
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index 87dee2898da..e84d7be45d7 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -4,6 +4,7 @@
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 #![feature(type_alias_impl_trait)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::borrow::Cow;
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index fae8b5647fc..3303e4ee752 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -204,7 +204,7 @@ pub trait LintDiagnostic<'a, G: EmissionGuarantee> {
 }
 
 #[derive(Clone, Debug, Encodable, Decodable)]
-pub struct DiagLocation {
+pub(crate) struct DiagLocation {
     file: Cow<'static, str>,
     line: u32,
     col: u32,
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 9ce5d77ef6c..2bc29dabd18 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -2387,7 +2387,7 @@ enum DisplaySuggestion {
 impl FileWithAnnotatedLines {
     /// Preprocess all the annotations so that they are grouped by file and by line number
     /// This helps us quickly iterate over the whole message (including secondary file spans)
-    pub fn collect_annotations(
+    pub(crate) fn collect_annotations(
         emitter: &dyn Emitter,
         args: &FluentArgs<'_>,
         msp: &MultiSpan,
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index fd203c38318..99ee8fb17d7 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -25,6 +25,7 @@
 #![feature(trait_alias)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 extern crate self as rustc_errors;
@@ -1701,7 +1702,7 @@ impl DiagCtxtInner {
     }
 
     /// Translate `message` eagerly with `args` to `SubdiagMessage::Eager`.
-    pub fn eagerly_translate<'a>(
+    fn eagerly_translate<'a>(
         &self,
         message: DiagMessage,
         args: impl Iterator<Item = DiagArg<'a>>,
@@ -1710,7 +1711,7 @@ impl DiagCtxtInner {
     }
 
     /// Translate `message` eagerly with `args` to `String`.
-    pub fn eagerly_translate_to_string<'a>(
+    fn eagerly_translate_to_string<'a>(
         &self,
         message: DiagMessage,
         args: impl Iterator<Item = DiagArg<'a>>,
diff --git a/compiler/rustc_errors/src/lock.rs b/compiler/rustc_errors/src/lock.rs
index 915542c9092..7557969f374 100644
--- a/compiler/rustc_errors/src/lock.rs
+++ b/compiler/rustc_errors/src/lock.rs
@@ -12,7 +12,7 @@
 use std::any::Any;
 
 #[cfg(windows)]
-pub fn acquire_global_lock(name: &str) -> Box<dyn Any> {
+pub(crate) fn acquire_global_lock(name: &str) -> Box<dyn Any> {
     use std::ffi::CString;
     use std::io;
 
@@ -80,6 +80,6 @@ pub fn acquire_global_lock(name: &str) -> Box<dyn Any> {
 }
 
 #[cfg(not(windows))]
-pub fn acquire_global_lock(_name: &str) -> Box<dyn Any> {
+pub(crate) fn acquire_global_lock(_name: &str) -> Box<dyn Any> {
     Box::new(())
 }
diff --git a/compiler/rustc_errors/src/markdown/parse.rs b/compiler/rustc_errors/src/markdown/parse.rs
index 46f8959b6f2..b1db44dd215 100644
--- a/compiler/rustc_errors/src/markdown/parse.rs
+++ b/compiler/rustc_errors/src/markdown/parse.rs
@@ -74,7 +74,7 @@ enum ParseOpt {
 }
 
 /// Parse a buffer
-pub fn entrypoint(txt: &str) -> MdStream<'_> {
+pub(crate) fn entrypoint(txt: &str) -> MdStream<'_> {
     let ctx = Context { top_block: true, prev: Prev::Newline };
     normalize(parse_recursive(txt.trim().as_bytes(), ctx), &mut Vec::new())
 }
diff --git a/compiler/rustc_errors/src/markdown/term.rs b/compiler/rustc_errors/src/markdown/term.rs
index 06c1333d93d..579e00b8b85 100644
--- a/compiler/rustc_errors/src/markdown/term.rs
+++ b/compiler/rustc_errors/src/markdown/term.rs
@@ -15,7 +15,7 @@ thread_local! {
 }
 
 /// Print to terminal output to a buffer
-pub fn entrypoint(stream: &MdStream<'_>, buf: &mut Buffer) -> io::Result<()> {
+pub(crate) fn entrypoint(stream: &MdStream<'_>, buf: &mut Buffer) -> io::Result<()> {
     #[cfg(not(test))]
     if let Some((w, _)) = termize::dimensions() {
         WIDTH.with(|c| c.set(std::cmp::min(w, DEFAULT_COLUMN_WIDTH)));
@@ -47,7 +47,7 @@ fn write_stream(
     Ok(())
 }
 
-pub fn write_tt(tt: &MdTree<'_>, buf: &mut Buffer, indent: usize) -> io::Result<()> {
+fn write_tt(tt: &MdTree<'_>, buf: &mut Buffer, indent: usize) -> io::Result<()> {
     match tt {
         MdTree::CodeBlock { txt, lang: _ } => {
             buf.set_color(ColorSpec::new().set_dimmed(true))?;
diff --git a/compiler/rustc_errors/src/snippet.rs b/compiler/rustc_errors/src/snippet.rs
index 50abf8a49c2..8485d7087cf 100644
--- a/compiler/rustc_errors/src/snippet.rs
+++ b/compiler/rustc_errors/src/snippet.rs
@@ -5,13 +5,13 @@ use rustc_macros::{Decodable, Encodable};
 use crate::{Level, Loc};
 
 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
-pub struct Line {
+pub(crate) struct Line {
     pub line_index: usize,
     pub annotations: Vec<Annotation>,
 }
 
 #[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Default)]
-pub struct AnnotationColumn {
+pub(crate) struct AnnotationColumn {
     /// the (0-indexed) column for *display* purposes, counted in characters, not utf-8 bytes
     pub display: usize,
     /// the (0-indexed) column in the file, counted in characters, not utf-8 bytes.
@@ -31,13 +31,13 @@ pub struct AnnotationColumn {
 }
 
 impl AnnotationColumn {
-    pub fn from_loc(loc: &Loc) -> AnnotationColumn {
+    pub(crate) fn from_loc(loc: &Loc) -> AnnotationColumn {
         AnnotationColumn { display: loc.col_display, file: loc.col.0 }
     }
 }
 
 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
-pub struct MultilineAnnotation {
+pub(crate) struct MultilineAnnotation {
     pub depth: usize,
     pub line_start: usize,
     pub line_end: usize,
@@ -49,19 +49,19 @@ pub struct MultilineAnnotation {
 }
 
 impl MultilineAnnotation {
-    pub fn increase_depth(&mut self) {
+    pub(crate) fn increase_depth(&mut self) {
         self.depth += 1;
     }
 
     /// Compare two `MultilineAnnotation`s considering only the `Span` they cover.
-    pub fn same_span(&self, other: &MultilineAnnotation) -> bool {
+    pub(crate) fn same_span(&self, other: &MultilineAnnotation) -> bool {
         self.line_start == other.line_start
             && self.line_end == other.line_end
             && self.start_col == other.start_col
             && self.end_col == other.end_col
     }
 
-    pub fn as_start(&self) -> Annotation {
+    pub(crate) fn as_start(&self) -> Annotation {
         Annotation {
             start_col: self.start_col,
             end_col: AnnotationColumn {
@@ -76,7 +76,7 @@ impl MultilineAnnotation {
         }
     }
 
-    pub fn as_end(&self) -> Annotation {
+    pub(crate) fn as_end(&self) -> Annotation {
         Annotation {
             start_col: AnnotationColumn {
                 // these might not correspond to the same place anymore,
@@ -91,7 +91,7 @@ impl MultilineAnnotation {
         }
     }
 
-    pub fn as_line(&self) -> Annotation {
+    pub(crate) fn as_line(&self) -> Annotation {
         Annotation {
             start_col: Default::default(),
             end_col: Default::default(),
@@ -103,7 +103,7 @@ impl MultilineAnnotation {
 }
 
 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
-pub enum AnnotationType {
+pub(crate) enum AnnotationType {
     /// Annotation under a single line of code
     Singleline,
 
@@ -129,7 +129,7 @@ pub enum AnnotationType {
 }
 
 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
-pub struct Annotation {
+pub(crate) struct Annotation {
     /// Start column.
     /// Note that it is important that this field goes
     /// first, so that when we sort, we sort orderings by start
@@ -152,12 +152,12 @@ pub struct Annotation {
 
 impl Annotation {
     /// Whether this annotation is a vertical line placeholder.
-    pub fn is_line(&self) -> bool {
+    pub(crate) fn is_line(&self) -> bool {
         matches!(self.annotation_type, AnnotationType::MultilineLine(_))
     }
 
     /// Length of this annotation as displayed in the stderr output
-    pub fn len(&self) -> usize {
+    pub(crate) fn len(&self) -> usize {
         // Account for usize underflows
         if self.end_col.display > self.start_col.display {
             self.end_col.display - self.start_col.display
@@ -166,7 +166,7 @@ impl Annotation {
         }
     }
 
-    pub fn has_label(&self) -> bool {
+    pub(crate) fn has_label(&self) -> bool {
         if let Some(ref label) = self.label {
             // Consider labels with no text as effectively not being there
             // to avoid weird output with unnecessary vertical lines, like:
@@ -184,7 +184,7 @@ impl Annotation {
         }
     }
 
-    pub fn takes_space(&self) -> bool {
+    pub(crate) fn takes_space(&self) -> bool {
         // Multiline annotations always have to keep vertical space.
         matches!(
             self.annotation_type,
@@ -194,7 +194,7 @@ impl Annotation {
 }
 
 #[derive(Debug)]
-pub struct StyledString {
+pub(crate) struct StyledString {
     pub text: String,
     pub style: Style,
 }
diff --git a/compiler/rustc_errors/src/styled_buffer.rs b/compiler/rustc_errors/src/styled_buffer.rs
index 9aa14e1f214..5ca9e9b18f3 100644
--- a/compiler/rustc_errors/src/styled_buffer.rs
+++ b/compiler/rustc_errors/src/styled_buffer.rs
@@ -3,7 +3,7 @@
 use crate::snippet::{Style, StyledString};
 
 #[derive(Debug)]
-pub struct StyledBuffer {
+pub(crate) struct StyledBuffer {
     lines: Vec<Vec<StyledChar>>,
 }
 
@@ -22,12 +22,12 @@ impl StyledChar {
 }
 
 impl StyledBuffer {
-    pub fn new() -> StyledBuffer {
+    pub(crate) fn new() -> StyledBuffer {
         StyledBuffer { lines: vec![] }
     }
 
     /// Returns content of `StyledBuffer` split by lines and line styles
-    pub fn render(&self) -> Vec<Vec<StyledString>> {
+    pub(crate) fn render(&self) -> Vec<Vec<StyledString>> {
         // Tabs are assumed to have been replaced by spaces in calling code.
         debug_assert!(self.lines.iter().all(|r| !r.iter().any(|sc| sc.chr == '\t')));
 
@@ -70,7 +70,7 @@ impl StyledBuffer {
     /// Sets `chr` with `style` for given `line`, `col`.
     /// If `line` does not exist in our buffer, adds empty lines up to the given
     /// and fills the last line with unstyled whitespace.
-    pub fn putc(&mut self, line: usize, col: usize, chr: char, style: Style) {
+    pub(crate) fn putc(&mut self, line: usize, col: usize, chr: char, style: Style) {
         self.ensure_lines(line);
         if col >= self.lines[line].len() {
             self.lines[line].resize(col + 1, StyledChar::SPACE);
@@ -81,7 +81,7 @@ impl StyledBuffer {
     /// Sets `string` with `style` for given `line`, starting from `col`.
     /// If `line` does not exist in our buffer, adds empty lines up to the given
     /// and fills the last line with unstyled whitespace.
-    pub fn puts(&mut self, line: usize, col: usize, string: &str, style: Style) {
+    pub(crate) fn puts(&mut self, line: usize, col: usize, string: &str, style: Style) {
         let mut n = col;
         for c in string.chars() {
             self.putc(line, n, c, style);
@@ -91,7 +91,7 @@ impl StyledBuffer {
 
     /// For given `line` inserts `string` with `style` before old content of that line,
     /// adding lines if needed
-    pub fn prepend(&mut self, line: usize, string: &str, style: Style) {
+    pub(crate) fn prepend(&mut self, line: usize, string: &str, style: Style) {
         self.ensure_lines(line);
         let string_len = string.chars().count();
 
@@ -107,7 +107,7 @@ impl StyledBuffer {
 
     /// For given `line` inserts `string` with `style` after old content of that line,
     /// adding lines if needed
-    pub fn append(&mut self, line: usize, string: &str, style: Style) {
+    pub(crate) fn append(&mut self, line: usize, string: &str, style: Style) {
         if line >= self.lines.len() {
             self.puts(line, 0, string, style);
         } else {
@@ -116,14 +116,14 @@ impl StyledBuffer {
         }
     }
 
-    pub fn num_lines(&self) -> usize {
+    pub(crate) fn num_lines(&self) -> usize {
         self.lines.len()
     }
 
     /// Set `style` for `line`, `col_start..col_end` range if:
     /// 1. That line and column range exist in `StyledBuffer`
     /// 2. `overwrite` is `true` or existing style is `Style::NoStyle` or `Style::Quotation`
-    pub fn set_style_range(
+    pub(crate) fn set_style_range(
         &mut self,
         line: usize,
         col_start: usize,
@@ -139,7 +139,7 @@ impl StyledBuffer {
     /// Set `style` for `line`, `col` if:
     /// 1. That line and column exist in `StyledBuffer`
     /// 2. `overwrite` is `true` or existing style is `Style::NoStyle` or `Style::Quotation`
-    pub fn set_style(&mut self, line: usize, col: usize, style: Style, overwrite: bool) {
+    fn set_style(&mut self, line: usize, col: usize, style: Style, overwrite: bool) {
         if let Some(ref mut line) = self.lines.get_mut(line) {
             if let Some(StyledChar { style: s, .. }) = line.get_mut(col) {
                 if overwrite || matches!(s, Style::NoStyle | Style::Quotation) {
diff --git a/compiler/rustc_expand/src/errors.rs b/compiler/rustc_expand/src/errors.rs
index f6b5cd394b6..0fdccb08918 100644
--- a/compiler/rustc_expand/src/errors.rs
+++ b/compiler/rustc_expand/src/errors.rs
@@ -350,7 +350,7 @@ pub(crate) struct ModuleMultipleCandidates {
 
 #[derive(Diagnostic)]
 #[diag(expand_trace_macro)]
-pub struct TraceMacro {
+pub(crate) struct TraceMacro {
     #[primary_span]
     pub span: Span,
 }
@@ -402,14 +402,14 @@ pub(crate) struct CustomAttributePanickedHelp {
 
 #[derive(Diagnostic)]
 #[diag(expand_proc_macro_derive_tokens)]
-pub struct ProcMacroDeriveTokens {
+pub(crate) struct ProcMacroDeriveTokens {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(expand_duplicate_matcher_binding)]
-pub struct DuplicateMatcherBinding {
+pub(crate) struct DuplicateMatcherBinding {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -421,7 +421,7 @@ pub struct DuplicateMatcherBinding {
 #[diag(expand_missing_fragment_specifier)]
 #[note]
 #[help(expand_valid)]
-pub struct MissingFragmentSpecifier {
+pub(crate) struct MissingFragmentSpecifier {
     #[primary_span]
     pub span: Span,
     #[suggestion(
@@ -437,7 +437,7 @@ pub struct MissingFragmentSpecifier {
 #[derive(Diagnostic)]
 #[diag(expand_invalid_fragment_specifier)]
 #[help]
-pub struct InvalidFragmentSpecifier {
+pub(crate) struct InvalidFragmentSpecifier {
     #[primary_span]
     pub span: Span,
     pub fragment: Ident,
@@ -446,7 +446,7 @@ pub struct InvalidFragmentSpecifier {
 
 #[derive(Diagnostic)]
 #[diag(expand_expected_paren_or_brace)]
-pub struct ExpectedParenOrBrace<'a> {
+pub(crate) struct ExpectedParenOrBrace<'a> {
     #[primary_span]
     pub span: Span,
     pub token: Cow<'a, str>,
@@ -479,7 +479,7 @@ pub(crate) struct GlobDelegationTraitlessQpath {
 #[derive(Diagnostic)]
 #[diag(expand_proc_macro_back_compat)]
 #[note]
-pub struct ProcMacroBackCompat {
+pub(crate) struct ProcMacroBackCompat {
     pub crate_name: String,
     pub fixed_version: String,
 }
diff --git a/compiler/rustc_expand/src/lib.rs b/compiler/rustc_expand/src/lib.rs
index 4222c9fe906..777044e3f33 100644
--- a/compiler/rustc_expand/src/lib.rs
+++ b/compiler/rustc_expand/src/lib.rs
@@ -13,6 +13,7 @@
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 extern crate proc_macro as pm;
diff --git a/compiler/rustc_expand/src/mbe/diagnostics.rs b/compiler/rustc_expand/src/mbe/diagnostics.rs
index 628c6bfeb79..5778f661622 100644
--- a/compiler/rustc_expand/src/mbe/diagnostics.rs
+++ b/compiler/rustc_expand/src/mbe/diagnostics.rs
@@ -196,13 +196,14 @@ impl<'dcx> CollectTrackerAndEmitter<'dcx, '_> {
     }
 }
 
-/// Currently used by macro_rules! compilation to extract a little information from the `Failure` case.
-pub struct FailureForwarder<'matcher> {
+/// Currently used by macro_rules! compilation to extract a little information from the `Failure`
+/// case.
+pub(crate) struct FailureForwarder<'matcher> {
     expected_token: Option<&'matcher Token>,
 }
 
 impl<'matcher> FailureForwarder<'matcher> {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         Self { expected_token: None }
     }
 }
diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs
index e5b9c627429..9011d02da33 100644
--- a/compiler/rustc_expand/src/mbe/macro_parser.rs
+++ b/compiler/rustc_expand/src/mbe/macro_parser.rs
@@ -407,7 +407,7 @@ fn token_name_eq(t1: &Token, t2: &Token) -> bool {
 
 // Note: the vectors could be created and dropped within `parse_tt`, but to avoid excess
 // allocations we have a single vector for each kind that is cleared and reused repeatedly.
-pub struct TtParser {
+pub(crate) struct TtParser {
     macro_name: Ident,
 
     /// The set of current mps to be processed. This should be empty by the end of a successful
diff --git a/compiler/rustc_expand/src/mbe/quoted.rs b/compiler/rustc_expand/src/mbe/quoted.rs
index b2f7c8f5183..5df0aebfe57 100644
--- a/compiler/rustc_expand/src/mbe/quoted.rs
+++ b/compiler/rustc_expand/src/mbe/quoted.rs
@@ -14,12 +14,11 @@ use crate::mbe::macro_parser::count_metavar_decls;
 use crate::mbe::{Delimited, KleeneOp, KleeneToken, MetaVarExpr, SequenceRepetition, TokenTree};
 
 const VALID_FRAGMENT_NAMES_MSG: &str = "valid fragment specifiers are \
-                                        `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, \
-                                        `literal`, `path`, `meta`, `tt`, `item` and `vis`";
-pub const VALID_FRAGMENT_NAMES_MSG_2021: &str = "valid fragment specifiers are \
-                                             `ident`, `block`, `stmt`, `expr`, `expr_2021`, `pat`, \
-                                             `ty`, `lifetime`, `literal`, `path`, `meta`, `tt`, \
-                                             `item` and `vis`";
+    `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, `path`, `meta`, `tt`, \
+    `item` and `vis`";
+pub(crate) const VALID_FRAGMENT_NAMES_MSG_2021: &str = "valid fragment specifiers are \
+    `ident`, `block`, `stmt`, `expr`, `expr_2021`, `pat`, `ty`, `lifetime`, `literal`, `path`, \
+    `meta`, `tt`, `item` and `vis`";
 
 /// Takes a `tokenstream::TokenStream` and returns a `Vec<self::TokenTree>`. Specifically, this
 /// takes a generic `TokenStream`, such as is used in the rest of the compiler, and returns a
diff --git a/compiler/rustc_expand/src/placeholders.rs b/compiler/rustc_expand/src/placeholders.rs
index 1e455d465e4..469bed3cd59 100644
--- a/compiler/rustc_expand/src/placeholders.rs
+++ b/compiler/rustc_expand/src/placeholders.rs
@@ -191,12 +191,12 @@ pub(crate) fn placeholder(
 }
 
 #[derive(Default)]
-pub struct PlaceholderExpander {
+pub(crate) struct PlaceholderExpander {
     expanded_fragments: FxHashMap<ast::NodeId, AstFragment>,
 }
 
 impl PlaceholderExpander {
-    pub fn add(&mut self, id: ast::NodeId, mut fragment: AstFragment) {
+    pub(crate) fn add(&mut self, id: ast::NodeId, mut fragment: AstFragment) {
         fragment.mut_visit_with(self);
         self.expanded_fragments.insert(id, fragment);
     }
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 1438d1ad11f..4ff5da1a4bd 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -414,7 +414,7 @@ impl ToInternal<rustc_errors::Level> for Level {
     }
 }
 
-pub struct FreeFunctions;
+pub(crate) struct FreeFunctions;
 
 pub(crate) struct Rustc<'a, 'b> {
     ecx: &'a mut ExtCtxt<'b>,
@@ -426,7 +426,7 @@ pub(crate) struct Rustc<'a, 'b> {
 }
 
 impl<'a, 'b> Rustc<'a, 'b> {
-    pub fn new(ecx: &'a mut ExtCtxt<'b>) -> Self {
+    pub(crate) fn new(ecx: &'a mut ExtCtxt<'b>) -> Self {
         let expn_data = ecx.current_expansion.id.expn_data();
         Rustc {
             def_site: ecx.with_def_site_ctxt(expn_data.def_site),
diff --git a/compiler/rustc_feature/src/lib.rs b/compiler/rustc_feature/src/lib.rs
index dcc1c3202ea..adaaba3cd23 100644
--- a/compiler/rustc_feature/src/lib.rs
+++ b/compiler/rustc_feature/src/lib.rs
@@ -15,6 +15,7 @@
 #![allow(internal_features)]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod accepted;
diff --git a/compiler/rustc_fluent_macro/src/lib.rs b/compiler/rustc_fluent_macro/src/lib.rs
index 0a04e6743a8..6e5add24bcc 100644
--- a/compiler/rustc_fluent_macro/src/lib.rs
+++ b/compiler/rustc_fluent_macro/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use proc_macro::TokenStream;
diff --git a/compiler/rustc_graphviz/src/lib.rs b/compiler/rustc_graphviz/src/lib.rs
index c8f8fd5be02..b5774f64b66 100644
--- a/compiler/rustc_graphviz/src/lib.rs
+++ b/compiler/rustc_graphviz/src/lib.rs
@@ -277,6 +277,7 @@
 )]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::borrow::Cow;
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
index e517c3fd07a..c1a4a4497c7 100644
--- a/compiler/rustc_hir/src/lib.rs
+++ b/compiler/rustc_hir/src/lib.rs
@@ -10,6 +10,7 @@
 #![feature(never_type)]
 #![feature(rustc_attrs)]
 #![feature(variant_count)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 extern crate self as rustc_hir;
diff --git a/compiler/rustc_hir_analysis/src/bounds.rs b/compiler/rustc_hir_analysis/src/bounds.rs
index c30a6f1eeb9..d0b0c08aa79 100644
--- a/compiler/rustc_hir_analysis/src/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/bounds.rs
@@ -26,13 +26,13 @@ use rustc_span::Span;
 /// Our representation is a bit mixed here -- in some cases, we
 /// include the self type (e.g., `trait_bounds`) but in others we do not
 #[derive(Default, PartialEq, Eq, Clone, Debug)]
-pub struct Bounds<'tcx> {
+pub(crate) struct Bounds<'tcx> {
     clauses: Vec<(ty::Clause<'tcx>, Span)>,
     effects_min_tys: FxIndexMap<Ty<'tcx>, Span>,
 }
 
 impl<'tcx> Bounds<'tcx> {
-    pub fn push_region_bound(
+    pub(crate) fn push_region_bound(
         &mut self,
         tcx: TyCtxt<'tcx>,
         region: ty::PolyTypeOutlivesPredicate<'tcx>,
@@ -42,7 +42,7 @@ impl<'tcx> Bounds<'tcx> {
             .push((region.map_bound(|p| ty::ClauseKind::TypeOutlives(p)).upcast(tcx), span));
     }
 
-    pub fn push_trait_bound(
+    pub(crate) fn push_trait_bound(
         &mut self,
         tcx: TyCtxt<'tcx>,
         defining_def_id: DefId,
@@ -154,7 +154,7 @@ impl<'tcx> Bounds<'tcx> {
         self.clauses.push((bound_trait_ref.rebind(new_trait_ref).upcast(tcx), span));
     }
 
-    pub fn push_projection_bound(
+    pub(crate) fn push_projection_bound(
         &mut self,
         tcx: TyCtxt<'tcx>,
         projection: ty::PolyProjectionPredicate<'tcx>,
@@ -166,14 +166,14 @@ impl<'tcx> Bounds<'tcx> {
         ));
     }
 
-    pub fn push_sized(&mut self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, span: Span) {
+    pub(crate) fn push_sized(&mut self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, span: Span) {
         let sized_def_id = tcx.require_lang_item(LangItem::Sized, Some(span));
         let trait_ref = ty::TraitRef::new(tcx, sized_def_id, [ty]);
         // Preferable to put this obligation first, since we report better errors for sized ambiguity.
         self.clauses.insert(0, (trait_ref.upcast(tcx), span));
     }
 
-    pub fn clauses(
+    pub(crate) fn clauses(
         &self,
         // FIXME(effects): remove tcx
         _tcx: TyCtxt<'tcx>,
@@ -181,7 +181,7 @@ impl<'tcx> Bounds<'tcx> {
         self.clauses.iter().cloned()
     }
 
-    pub fn effects_min_tys(&self) -> impl Iterator<Item = Ty<'tcx>> + '_ {
+    pub(crate) fn effects_min_tys(&self) -> impl Iterator<Item = Ty<'tcx>> + '_ {
         self.effects_min_tys.keys().copied()
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index 728c3790098..d414bcdb95b 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -1053,7 +1053,7 @@ fn check_impl_items_against_trait<'tcx>(
     }
 }
 
-pub fn check_simd(tcx: TyCtxt<'_>, sp: Span, def_id: LocalDefId) {
+fn check_simd(tcx: TyCtxt<'_>, sp: Span, def_id: LocalDefId) {
     let t = tcx.type_of(def_id).instantiate_identity();
     if let ty::Adt(def, args) = t.kind()
         && def.is_struct()
diff --git a/compiler/rustc_hir_analysis/src/check/errs.rs b/compiler/rustc_hir_analysis/src/check/errs.rs
index 19a0476e630..22d7d1fea9c 100644
--- a/compiler/rustc_hir_analysis/src/check/errs.rs
+++ b/compiler/rustc_hir_analysis/src/check/errs.rs
@@ -6,7 +6,7 @@ use rustc_span::Span;
 use crate::errors;
 
 /// Check for shared or mutable references of `static mut` inside expression
-pub fn maybe_expr_static_mut(tcx: TyCtxt<'_>, expr: hir::Expr<'_>) {
+pub(crate) fn maybe_expr_static_mut(tcx: TyCtxt<'_>, expr: hir::Expr<'_>) {
     let span = expr.span;
     let hir_id = expr.hir_id;
     if let hir::ExprKind::AddrOf(borrow_kind, m, expr) = expr.kind
@@ -26,7 +26,7 @@ pub fn maybe_expr_static_mut(tcx: TyCtxt<'_>, expr: hir::Expr<'_>) {
 }
 
 /// Check for shared or mutable references of `static mut` inside statement
-pub fn maybe_stmt_static_mut(tcx: TyCtxt<'_>, stmt: hir::Stmt<'_>) {
+pub(crate) fn maybe_stmt_static_mut(tcx: TyCtxt<'_>, stmt: hir::Stmt<'_>) {
     if let hir::StmtKind::Let(loc) = stmt.kind
         && let hir::PatKind::Binding(ba, _, _, _) = loc.pat.kind
         && let hir::ByRef::Yes(rmutbl) = ba.0
diff --git a/compiler/rustc_hir_analysis/src/check/region.rs b/compiler/rustc_hir_analysis/src/check/region.rs
index bc6641c688c..48335173979 100644
--- a/compiler/rustc_hir_analysis/src/check/region.rs
+++ b/compiler/rustc_hir_analysis/src/check/region.rs
@@ -22,7 +22,7 @@ use rustc_span::source_map;
 use super::errs::{maybe_expr_static_mut, maybe_stmt_static_mut};
 
 #[derive(Debug, Copy, Clone)]
-pub struct Context {
+struct Context {
     /// The scope that contains any new variables declared, plus its depth in
     /// the scope tree.
     var_parent: Option<(Scope, ScopeDepth)>,
@@ -893,7 +893,7 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
 /// re-use in incremental scenarios. We may sometimes need to rerun the
 /// type checker even when the HIR hasn't changed, and in those cases
 /// we can avoid reconstructing the region scope tree.
-pub fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
+pub(crate) fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
     let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
     if typeck_root_def_id != def_id {
         return tcx.region_scope_tree(typeck_root_def_id);
diff --git a/compiler/rustc_hir_analysis/src/check_unused.rs b/compiler/rustc_hir_analysis/src/check_unused.rs
index ed23dc2a827..ca9e2e8a3cc 100644
--- a/compiler/rustc_hir_analysis/src/check_unused.rs
+++ b/compiler/rustc_hir_analysis/src/check_unused.rs
@@ -5,7 +5,7 @@ use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint;
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { check_unused_traits, ..*providers };
 }
 
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index fecd78bc38f..23f1adfe302 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -332,7 +332,7 @@ fn visit_implementation_of_dispatch_from_dyn(checker: &Checker<'_>) -> Result<()
     }
 }
 
-pub fn coerce_unsized_info<'tcx>(
+pub(crate) fn coerce_unsized_info<'tcx>(
     tcx: TyCtxt<'tcx>,
     impl_did: LocalDefId,
 ) -> Result<CoerceUnsizedInfo, ErrorGuaranteed> {
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
index 89acb778d6c..bd8b43e28e5 100644
--- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
@@ -19,7 +19,7 @@ use rustc_span::ErrorGuaranteed;
 use crate::errors;
 
 /// On-demand query: yields a map containing all types mapped to their inherent impls.
-pub fn crate_inherent_impls(
+pub(crate) fn crate_inherent_impls(
     tcx: TyCtxt<'_>,
     (): (),
 ) -> Result<&'_ CrateInherentImpls, ErrorGuaranteed> {
@@ -32,7 +32,7 @@ pub fn crate_inherent_impls(
     Ok(tcx.arena.alloc(collect.impls_map))
 }
 
-pub fn crate_incoherent_impls(
+pub(crate) fn crate_incoherent_impls(
     tcx: TyCtxt<'_>,
     simp: SimplifiedType,
 ) -> Result<&[DefId], ErrorGuaranteed> {
@@ -43,7 +43,10 @@ pub fn crate_incoherent_impls(
 }
 
 /// On-demand query: yields a vector of the inherent impls for a specific type.
-pub fn inherent_impls(tcx: TyCtxt<'_>, ty_def_id: LocalDefId) -> Result<&[DefId], ErrorGuaranteed> {
+pub(crate) fn inherent_impls(
+    tcx: TyCtxt<'_>,
+    ty_def_id: LocalDefId,
+) -> Result<&[DefId], ErrorGuaranteed> {
     let crate_map = tcx.crate_inherent_impls(())?;
     Ok(match crate_map.inherent_impls.get(&ty_def_id) {
         Some(v) => &v[..],
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
index cd5cc33d65a..00bbbf7130f 100644
--- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
@@ -11,7 +11,10 @@ use rustc_span::{ErrorGuaranteed, Symbol};
 use rustc_trait_selection::traits::{self, SkipLeakCheck};
 use smallvec::SmallVec;
 
-pub fn crate_inherent_impls_overlap_check(tcx: TyCtxt<'_>, (): ()) -> Result<(), ErrorGuaranteed> {
+pub(crate) fn crate_inherent_impls_overlap_check(
+    tcx: TyCtxt<'_>,
+    (): (),
+) -> Result<(), ErrorGuaranteed> {
     let mut inherent_overlap_checker = InherentOverlapChecker { tcx };
     let mut res = Ok(());
     for id in tcx.hir().items() {
diff --git a/compiler/rustc_hir_analysis/src/coherence/mod.rs b/compiler/rustc_hir_analysis/src/coherence/mod.rs
index 8e4da90ca26..3d800bb165c 100644
--- a/compiler/rustc_hir_analysis/src/coherence/mod.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/mod.rs
@@ -123,7 +123,7 @@ fn enforce_empty_impls_for_marker_traits(
     .emit())
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     use self::builtin::coerce_unsized_info;
     use self::inherent_impls::{crate_incoherent_impls, crate_inherent_impls, inherent_impls};
     use self::inherent_impls_overlap::crate_inherent_impls_overlap_check;
diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
index 0cf9e128bce..e38492d9e64 100644
--- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
+++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
@@ -2071,7 +2071,7 @@ fn is_late_bound_map(
     }
 }
 
-pub fn deny_non_region_late_bound(
+fn deny_non_region_late_bound(
     tcx: TyCtxt<'_>,
     bound_vars: &mut FxIndexMap<LocalDefId, ResolvedArg>,
     where_: &str,
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs
index 8cb4ba6c669..96256b91b9f 100644
--- a/compiler/rustc_hir_analysis/src/collect/type_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/type_of.rs
@@ -725,7 +725,7 @@ fn check_feature_inherent_assoc_ty(tcx: TyCtxt<'_>, span: Span) {
     }
 }
 
-pub fn type_alias_is_lazy<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> bool {
+pub(crate) fn type_alias_is_lazy<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> bool {
     use hir::intravisit::Visitor;
     if tcx.features().lazy_type_alias {
         return true;
diff --git a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
index 620170164f5..edf65245664 100644
--- a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
+++ b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
@@ -6,7 +6,7 @@ use rustc_span::Span;
 use rustc_type_ir::fold::TypeFoldable;
 
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
-pub struct Parameter(pub u32);
+pub(crate) struct Parameter(pub u32);
 
 impl From<ty::ParamTy> for Parameter {
     fn from(param: ty::ParamTy) -> Self {
@@ -27,7 +27,7 @@ impl From<ty::ParamConst> for Parameter {
 }
 
 /// Returns the set of parameters constrained by the impl header.
-pub fn parameters_for_impl<'tcx>(
+pub(crate) fn parameters_for_impl<'tcx>(
     tcx: TyCtxt<'tcx>,
     impl_self_ty: Ty<'tcx>,
     impl_trait_ref: Option<ty::TraitRef<'tcx>>,
@@ -44,7 +44,7 @@ pub fn parameters_for_impl<'tcx>(
 /// uniquely determined by `value` (see RFC 447). If it is true, return the list
 /// of parameters whose values are needed in order to constrain `value` - these
 /// differ, with the latter being a superset, in the presence of projections.
-pub fn parameters_for<'tcx>(
+pub(crate) fn parameters_for<'tcx>(
     tcx: TyCtxt<'tcx>,
     value: impl TypeFoldable<TyCtxt<'tcx>>,
     include_nonconstraining: bool,
@@ -102,7 +102,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ParameterCollector {
     }
 }
 
-pub fn identify_constrained_generic_params<'tcx>(
+pub(crate) fn identify_constrained_generic_params<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: ty::GenericPredicates<'tcx>,
     impl_trait_ref: Option<ty::TraitRef<'tcx>>,
@@ -156,7 +156,7 @@ pub fn identify_constrained_generic_params<'tcx>(
 /// which is determined by 1, which requires `U`, that is determined
 /// by 0. I should probably pick a less tangled example, but I can't
 /// think of any.
-pub fn setup_constraining_predicates<'tcx>(
+pub(crate) fn setup_constraining_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: &mut [(ty::Clause<'tcx>, Span)],
     impl_trait_ref: Option<ty::TraitRef<'tcx>>,
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index 821f79505f0..39df18ff658 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -11,15 +11,15 @@ use rustc_span::{Span, Symbol};
 
 use crate::fluent_generated as fluent;
 mod pattern_types;
-pub use pattern_types::*;
-pub mod wrong_number_of_generic_args;
+pub(crate) use pattern_types::*;
+pub(crate) mod wrong_number_of_generic_args;
 
 mod precise_captures;
 pub(crate) use precise_captures::*;
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_ambiguous_assoc_item)]
-pub struct AmbiguousAssocItem<'a> {
+pub(crate) struct AmbiguousAssocItem<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -30,7 +30,7 @@ pub struct AmbiguousAssocItem<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_assoc_kind_mismatch)]
-pub struct AssocKindMismatch {
+pub(crate) struct AssocKindMismatch {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -52,7 +52,7 @@ pub struct AssocKindMismatch {
     hir_analysis_assoc_kind_mismatch_wrap_in_braces_sugg,
     applicability = "maybe-incorrect"
 )]
-pub struct AssocKindMismatchWrapInBracesSugg {
+pub(crate) struct AssocKindMismatchWrapInBracesSugg {
     #[suggestion_part(code = "{{ ")]
     pub lo: Span,
     #[suggestion_part(code = " }}")]
@@ -61,7 +61,7 @@ pub struct AssocKindMismatchWrapInBracesSugg {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_assoc_item_is_private, code = E0624)]
-pub struct AssocItemIsPrivate {
+pub(crate) struct AssocItemIsPrivate {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -73,7 +73,7 @@ pub struct AssocItemIsPrivate {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_assoc_item_not_found, code = E0220)]
-pub struct AssocItemNotFound<'a> {
+pub(crate) struct AssocItemNotFound<'a> {
     #[primary_span]
     pub span: Span,
     pub assoc_name: Ident,
@@ -86,7 +86,7 @@ pub struct AssocItemNotFound<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum AssocItemNotFoundLabel<'a> {
+pub(crate) enum AssocItemNotFoundLabel<'a> {
     #[label(hir_analysis_assoc_item_not_found_label)]
     NotFound {
         #[primary_span]
@@ -105,7 +105,7 @@ pub enum AssocItemNotFoundLabel<'a> {
 
 #[derive(Subdiagnostic)]
 
-pub enum AssocItemNotFoundSugg<'a> {
+pub(crate) enum AssocItemNotFoundSugg<'a> {
     #[suggestion(
         hir_analysis_assoc_item_not_found_similar_sugg,
         code = "{suggested_name}",
@@ -162,7 +162,7 @@ pub enum AssocItemNotFoundSugg<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_unrecognized_atomic_operation, code = E0092)]
-pub struct UnrecognizedAtomicOperation<'a> {
+pub(crate) struct UnrecognizedAtomicOperation<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -171,7 +171,7 @@ pub struct UnrecognizedAtomicOperation<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_wrong_number_of_generic_arguments_to_intrinsic, code = E0094)]
-pub struct WrongNumberOfGenericArgumentsToIntrinsic<'a> {
+pub(crate) struct WrongNumberOfGenericArgumentsToIntrinsic<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -183,7 +183,7 @@ pub struct WrongNumberOfGenericArgumentsToIntrinsic<'a> {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_unrecognized_intrinsic_function, code = E0093)]
 #[help]
-pub struct UnrecognizedIntrinsicFunction {
+pub(crate) struct UnrecognizedIntrinsicFunction {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -192,7 +192,7 @@ pub struct UnrecognizedIntrinsicFunction {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_lifetimes_or_bounds_mismatch_on_trait, code = E0195)]
-pub struct LifetimesOrBoundsMismatchOnTrait {
+pub(crate) struct LifetimesOrBoundsMismatchOnTrait {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -208,14 +208,14 @@ pub struct LifetimesOrBoundsMismatchOnTrait {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_drop_impl_on_wrong_item, code = E0120)]
-pub struct DropImplOnWrongItem {
+pub(crate) struct DropImplOnWrongItem {
     #[primary_span]
     #[label]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
-pub enum FieldAlreadyDeclared {
+pub(crate) enum FieldAlreadyDeclared {
     #[diag(hir_analysis_field_already_declared, code = E0124)]
     NotNested {
         field_name: Symbol,
@@ -272,14 +272,14 @@ pub enum FieldAlreadyDeclared {
 
 #[derive(Subdiagnostic)]
 #[help(hir_analysis_field_already_declared_nested_help)]
-pub struct FieldAlreadyDeclaredNestedHelp {
+pub(crate) struct FieldAlreadyDeclaredNestedHelp {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_copy_impl_on_type_with_dtor, code = E0184)]
-pub struct CopyImplOnTypeWithDtor {
+pub(crate) struct CopyImplOnTypeWithDtor {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -287,14 +287,14 @@ pub struct CopyImplOnTypeWithDtor {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_multiple_relaxed_default_bounds, code = E0203)]
-pub struct MultipleRelaxedDefaultBounds {
+pub(crate) struct MultipleRelaxedDefaultBounds {
     #[primary_span]
     pub spans: Vec<Span>,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_copy_impl_on_non_adt, code = E0206)]
-pub struct CopyImplOnNonAdt {
+pub(crate) struct CopyImplOnNonAdt {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -302,7 +302,7 @@ pub struct CopyImplOnNonAdt {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_const_param_ty_impl_on_unsized)]
-pub struct ConstParamTyImplOnUnsized {
+pub(crate) struct ConstParamTyImplOnUnsized {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -310,7 +310,7 @@ pub struct ConstParamTyImplOnUnsized {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_const_param_ty_impl_on_non_adt)]
-pub struct ConstParamTyImplOnNonAdt {
+pub(crate) struct ConstParamTyImplOnNonAdt {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -318,7 +318,7 @@ pub struct ConstParamTyImplOnNonAdt {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_trait_object_declared_with_no_traits, code = E0224)]
-pub struct TraitObjectDeclaredWithNoTraits {
+pub(crate) struct TraitObjectDeclaredWithNoTraits {
     #[primary_span]
     pub span: Span,
     #[label(hir_analysis_alias_span)]
@@ -327,14 +327,14 @@ pub struct TraitObjectDeclaredWithNoTraits {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_ambiguous_lifetime_bound, code = E0227)]
-pub struct AmbiguousLifetimeBound {
+pub(crate) struct AmbiguousLifetimeBound {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_assoc_item_constraints_not_allowed_here, code = E0229)]
-pub struct AssocItemConstraintsNotAllowedHere {
+pub(crate) struct AssocItemConstraintsNotAllowedHere {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -383,7 +383,7 @@ pub(crate) struct EscapingBoundVarInTyOfAssocConstBinding<'tcx> {
 
 #[derive(Subdiagnostic)]
 #[help(hir_analysis_parenthesized_fn_trait_expansion)]
-pub struct ParenthesizedFnTraitExpansion {
+pub(crate) struct ParenthesizedFnTraitExpansion {
     #[primary_span]
     pub span: Span,
 
@@ -392,7 +392,7 @@ pub struct ParenthesizedFnTraitExpansion {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_typeof_reserved_keyword_used, code = E0516)]
-pub struct TypeofReservedKeywordUsed<'tcx> {
+pub(crate) struct TypeofReservedKeywordUsed<'tcx> {
     pub ty: Ty<'tcx>,
     #[primary_span]
     #[label]
@@ -403,7 +403,7 @@ pub struct TypeofReservedKeywordUsed<'tcx> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_value_of_associated_struct_already_specified, code = E0719)]
-pub struct ValueOfAssociatedStructAlreadySpecified {
+pub(crate) struct ValueOfAssociatedStructAlreadySpecified {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -416,7 +416,7 @@ pub struct ValueOfAssociatedStructAlreadySpecified {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_unconstrained_opaque_type)]
 #[note]
-pub struct UnconstrainedOpaqueType {
+pub(crate) struct UnconstrainedOpaqueType {
     #[primary_span]
     pub span: Span,
     pub name: Symbol,
@@ -426,7 +426,7 @@ pub struct UnconstrainedOpaqueType {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_tait_forward_compat)]
 #[note]
-pub struct TaitForwardCompat {
+pub(crate) struct TaitForwardCompat {
     #[primary_span]
     pub span: Span,
     #[note]
@@ -436,7 +436,7 @@ pub struct TaitForwardCompat {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_tait_forward_compat2)]
 #[note]
-pub struct TaitForwardCompat2 {
+pub(crate) struct TaitForwardCompat2 {
     #[primary_span]
     pub span: Span,
     #[note(hir_analysis_opaque)]
@@ -444,7 +444,7 @@ pub struct TaitForwardCompat2 {
     pub opaque_type: String,
 }
 
-pub struct MissingTypeParams {
+pub(crate) struct MissingTypeParams {
     pub span: Span,
     pub def_span: Span,
     pub span_snippet: Option<String>,
@@ -512,7 +512,7 @@ impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for MissingTypeParams {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_manual_implementation, code = E0183)]
 #[help]
-pub struct ManualImplementation {
+pub(crate) struct ManualImplementation {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -521,14 +521,14 @@ pub struct ManualImplementation {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_generic_args_on_overridden_impl)]
-pub struct GenericArgsOnOverriddenImpl {
+pub(crate) struct GenericArgsOnOverriddenImpl {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_const_impl_for_non_const_trait)]
-pub struct ConstImplForNonConstTrait {
+pub(crate) struct ConstImplForNonConstTrait {
     #[primary_span]
     pub trait_ref_span: Span,
     pub trait_name: String,
@@ -542,7 +542,7 @@ pub struct ConstImplForNonConstTrait {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_const_bound_for_non_const_trait)]
-pub struct ConstBoundForNonConstTrait {
+pub(crate) struct ConstBoundForNonConstTrait {
     #[primary_span]
     pub span: Span,
     pub modifier: &'static str,
@@ -550,7 +550,7 @@ pub struct ConstBoundForNonConstTrait {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_self_in_impl_self)]
-pub struct SelfInImplSelf {
+pub(crate) struct SelfInImplSelf {
     #[primary_span]
     pub span: MultiSpan,
     #[note]
@@ -567,7 +567,7 @@ pub(crate) struct LinkageType {
 #[derive(Diagnostic)]
 #[help]
 #[diag(hir_analysis_auto_deref_reached_recursion_limit, code = E0055)]
-pub struct AutoDerefReachedRecursionLimit<'a> {
+pub(crate) struct AutoDerefReachedRecursionLimit<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -736,7 +736,7 @@ pub(crate) struct InvalidUnionField {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_invalid_unnamed_field_ty)]
-pub struct InvalidUnnamedFieldTy {
+pub(crate) struct InvalidUnnamedFieldTy {
     #[primary_span]
     pub span: Span,
 }
@@ -894,7 +894,7 @@ pub(crate) struct SIMDFFIHighlyExperimental {
 }
 
 #[derive(Diagnostic)]
-pub enum ImplNotMarkedDefault {
+pub(crate) enum ImplNotMarkedDefault {
     #[diag(hir_analysis_impl_not_marked_default, code = E0520)]
     #[note]
     Ok {
@@ -1137,7 +1137,7 @@ pub(crate) enum LateBoundInApit {
 #[derive(LintDiagnostic)]
 #[diag(hir_analysis_unused_associated_type_bounds)]
 #[note]
-pub struct UnusedAssociatedTypeBounds {
+pub(crate) struct UnusedAssociatedTypeBounds {
     #[suggestion(code = "")]
     pub span: Span,
 }
@@ -1162,7 +1162,7 @@ pub(crate) struct ReturnPositionImplTraitInTraitRefined<'tcx> {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_ty_outside, code = E0390)]
 #[help]
-pub struct InherentTyOutside {
+pub(crate) struct InherentTyOutside {
     #[primary_span]
     #[help(hir_analysis_span_help)]
     pub span: Span,
@@ -1170,7 +1170,7 @@ pub struct InherentTyOutside {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0378)]
-pub struct DispatchFromDynCoercion<'a> {
+pub(crate) struct DispatchFromDynCoercion<'a> {
     #[primary_span]
     pub span: Span,
     pub trait_name: &'a str,
@@ -1182,7 +1182,7 @@ pub struct DispatchFromDynCoercion<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_dispatch_from_dyn_repr, code = E0378)]
-pub struct DispatchFromDynRepr {
+pub(crate) struct DispatchFromDynRepr {
     #[primary_span]
     pub span: Span,
 }
@@ -1190,7 +1190,7 @@ pub struct DispatchFromDynRepr {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_ty_outside_relevant, code = E0390)]
 #[help]
-pub struct InherentTyOutsideRelevant {
+pub(crate) struct InherentTyOutsideRelevant {
     #[primary_span]
     pub span: Span,
     #[help(hir_analysis_span_help)]
@@ -1200,7 +1200,7 @@ pub struct InherentTyOutsideRelevant {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_ty_outside_new, code = E0116)]
 #[note]
-pub struct InherentTyOutsideNew {
+pub(crate) struct InherentTyOutsideNew {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1209,7 +1209,7 @@ pub struct InherentTyOutsideNew {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_ty_outside_primitive, code = E0390)]
 #[help]
-pub struct InherentTyOutsidePrimitive {
+pub(crate) struct InherentTyOutsidePrimitive {
     #[primary_span]
     pub span: Span,
     #[help(hir_analysis_span_help)]
@@ -1219,7 +1219,7 @@ pub struct InherentTyOutsidePrimitive {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_primitive_ty, code = E0390)]
 #[help]
-pub struct InherentPrimitiveTy<'a> {
+pub(crate) struct InherentPrimitiveTy<'a> {
     #[primary_span]
     pub span: Span,
     #[subdiagnostic]
@@ -1228,14 +1228,14 @@ pub struct InherentPrimitiveTy<'a> {
 
 #[derive(Subdiagnostic)]
 #[note(hir_analysis_inherent_primitive_ty_note)]
-pub struct InherentPrimitiveTyNote<'a> {
+pub(crate) struct InherentPrimitiveTyNote<'a> {
     pub subty: Ty<'a>,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_dyn, code = E0785)]
 #[note]
-pub struct InherentDyn {
+pub(crate) struct InherentDyn {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1244,7 +1244,7 @@ pub struct InherentDyn {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_inherent_nominal, code = E0118)]
 #[note]
-pub struct InherentNominal {
+pub(crate) struct InherentNominal {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1253,7 +1253,7 @@ pub struct InherentNominal {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_dispatch_from_dyn_zst, code = E0378)]
 #[note]
-pub struct DispatchFromDynZST<'a> {
+pub(crate) struct DispatchFromDynZST<'a> {
     #[primary_span]
     pub span: Span,
     pub name: Symbol,
@@ -1262,7 +1262,7 @@ pub struct DispatchFromDynZST<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0378)]
-pub struct DispatchFromDynSingle<'a> {
+pub(crate) struct DispatchFromDynSingle<'a> {
     #[primary_span]
     pub span: Span,
     pub trait_name: &'a str,
@@ -1273,7 +1273,7 @@ pub struct DispatchFromDynSingle<'a> {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_dispatch_from_dyn_multi, code = E0378)]
 #[note]
-pub struct DispatchFromDynMulti {
+pub(crate) struct DispatchFromDynMulti {
     #[primary_span]
     pub span: Span,
     #[note(hir_analysis_coercions_note)]
@@ -1284,7 +1284,7 @@ pub struct DispatchFromDynMulti {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0376)]
-pub struct DispatchFromDynStruct<'a> {
+pub(crate) struct DispatchFromDynStruct<'a> {
     #[primary_span]
     pub span: Span,
     pub trait_name: &'a str,
@@ -1292,7 +1292,7 @@ pub struct DispatchFromDynStruct<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0377)]
-pub struct DispatchFromDynSame<'a> {
+pub(crate) struct DispatchFromDynSame<'a> {
     #[primary_span]
     pub span: Span,
     pub trait_name: &'a str,
@@ -1304,7 +1304,7 @@ pub struct DispatchFromDynSame<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0374)]
-pub struct CoerceUnsizedOneField<'a> {
+pub(crate) struct CoerceUnsizedOneField<'a> {
     #[primary_span]
     pub span: Span,
     pub trait_name: &'a str,
@@ -1315,7 +1315,7 @@ pub struct CoerceUnsizedOneField<'a> {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_multi, code = E0375)]
 #[note]
-pub struct CoerceUnsizedMulti {
+pub(crate) struct CoerceUnsizedMulti {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1327,7 +1327,7 @@ pub struct CoerceUnsizedMulti {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0378)]
-pub struct CoerceUnsizedMay<'a> {
+pub(crate) struct CoerceUnsizedMay<'a> {
     #[primary_span]
     pub span: Span,
     pub trait_name: &'a str,
@@ -1335,7 +1335,7 @@ pub struct CoerceUnsizedMay<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_trait_cannot_impl_for_ty, code = E0204)]
-pub struct TraitCannotImplForTy {
+pub(crate) struct TraitCannotImplForTy {
     #[primary_span]
     pub span: Span,
     pub trait_name: String,
@@ -1347,7 +1347,7 @@ pub struct TraitCannotImplForTy {
 
 #[derive(Subdiagnostic)]
 #[note(hir_analysis_requires_note)]
-pub struct ImplForTyRequires {
+pub(crate) struct ImplForTyRequires {
     #[primary_span]
     pub span: MultiSpan,
     pub error_predicate: String,
@@ -1358,7 +1358,7 @@ pub struct ImplForTyRequires {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_traits_with_defualt_impl, code = E0321)]
 #[note]
-pub struct TraitsWithDefaultImpl<'a> {
+pub(crate) struct TraitsWithDefaultImpl<'a> {
     #[primary_span]
     pub span: Span,
     pub traits: String,
@@ -1368,7 +1368,7 @@ pub struct TraitsWithDefaultImpl<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_cross_crate_traits, code = E0321)]
-pub struct CrossCrateTraits<'a> {
+pub(crate) struct CrossCrateTraits<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1378,7 +1378,7 @@ pub struct CrossCrateTraits<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_cross_crate_traits_defined, code = E0321)]
-pub struct CrossCrateTraitsDefined {
+pub(crate) struct CrossCrateTraitsDefined {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1390,7 +1390,7 @@ pub struct CrossCrateTraitsDefined {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_ty_param_first_local, code = E0210)]
 #[note]
-pub struct TyParamFirstLocal<'tcx> {
+pub(crate) struct TyParamFirstLocal<'tcx> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1403,7 +1403,7 @@ pub struct TyParamFirstLocal<'tcx> {
 #[derive(LintDiagnostic)]
 #[diag(hir_analysis_ty_param_first_local, code = E0210)]
 #[note]
-pub struct TyParamFirstLocalLint<'tcx> {
+pub(crate) struct TyParamFirstLocalLint<'tcx> {
     #[label]
     pub span: Span,
     #[note(hir_analysis_case_note)]
@@ -1415,7 +1415,7 @@ pub struct TyParamFirstLocalLint<'tcx> {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_ty_param_some, code = E0210)]
 #[note]
-pub struct TyParamSome {
+pub(crate) struct TyParamSome {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1427,7 +1427,7 @@ pub struct TyParamSome {
 #[derive(LintDiagnostic)]
 #[diag(hir_analysis_ty_param_some, code = E0210)]
 #[note]
-pub struct TyParamSomeLint {
+pub(crate) struct TyParamSomeLint {
     #[label]
     pub span: Span,
     #[note(hir_analysis_only_note)]
@@ -1436,7 +1436,7 @@ pub struct TyParamSomeLint {
 }
 
 #[derive(Diagnostic)]
-pub enum OnlyCurrentTraits {
+pub(crate) enum OnlyCurrentTraits {
     #[diag(hir_analysis_only_current_traits_outside, code = E0117)]
     Outside {
         #[primary_span]
@@ -1465,20 +1465,20 @@ pub enum OnlyCurrentTraits {
 
 #[derive(Subdiagnostic)]
 #[label(hir_analysis_only_current_traits_opaque)]
-pub struct OnlyCurrentTraitsOpaque {
+pub(crate) struct OnlyCurrentTraitsOpaque {
     #[primary_span]
     pub span: Span,
 }
 #[derive(Subdiagnostic)]
 #[label(hir_analysis_only_current_traits_foreign)]
-pub struct OnlyCurrentTraitsForeign {
+pub(crate) struct OnlyCurrentTraitsForeign {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Subdiagnostic)]
 #[label(hir_analysis_only_current_traits_name)]
-pub struct OnlyCurrentTraitsName<'a> {
+pub(crate) struct OnlyCurrentTraitsName<'a> {
     #[primary_span]
     pub span: Span,
     pub name: &'a str,
@@ -1486,7 +1486,7 @@ pub struct OnlyCurrentTraitsName<'a> {
 
 #[derive(Subdiagnostic)]
 #[label(hir_analysis_only_current_traits_pointer)]
-pub struct OnlyCurrentTraitsPointer<'a> {
+pub(crate) struct OnlyCurrentTraitsPointer<'a> {
     #[primary_span]
     pub span: Span,
     pub pointer: Ty<'a>,
@@ -1494,7 +1494,7 @@ pub struct OnlyCurrentTraitsPointer<'a> {
 
 #[derive(Subdiagnostic)]
 #[label(hir_analysis_only_current_traits_ty)]
-pub struct OnlyCurrentTraitsTy<'a> {
+pub(crate) struct OnlyCurrentTraitsTy<'a> {
     #[primary_span]
     pub span: Span,
     pub ty: Ty<'a>,
@@ -1502,7 +1502,7 @@ pub struct OnlyCurrentTraitsTy<'a> {
 
 #[derive(Subdiagnostic)]
 #[label(hir_analysis_only_current_traits_adt)]
-pub struct OnlyCurrentTraitsAdt {
+pub(crate) struct OnlyCurrentTraitsAdt {
     #[primary_span]
     pub span: Span,
     pub name: String,
@@ -1513,11 +1513,11 @@ pub struct OnlyCurrentTraitsAdt {
     hir_analysis_only_current_traits_pointer_sugg,
     applicability = "maybe-incorrect"
 )]
-pub struct OnlyCurrentTraitsPointerSugg<'a> {
+pub(crate) struct OnlyCurrentTraitsPointerSugg<'a> {
     #[suggestion_part(code = "WrapperType")]
     pub wrapper_span: Span,
     #[suggestion_part(code = "struct WrapperType(*{mut_key}{ptr_ty});\n\n")]
-    pub struct_span: Span,
+    pub(crate) struct_span: Span,
     pub mut_key: &'a str,
     pub ptr_ty: Ty<'a>,
 }
@@ -1525,7 +1525,7 @@ pub struct OnlyCurrentTraitsPointerSugg<'a> {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_static_mut_ref, code = E0796)]
 #[note]
-pub struct StaticMutRef<'a> {
+pub(crate) struct StaticMutRef<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1535,7 +1535,7 @@ pub struct StaticMutRef<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum MutRefSugg {
+pub(crate) enum MutRefSugg {
     #[multipart_suggestion(
         hir_analysis_suggestion,
         style = "verbose",
@@ -1565,7 +1565,7 @@ pub enum MutRefSugg {
 #[diag(hir_analysis_static_mut_refs_lint)]
 #[note]
 #[note(hir_analysis_why_note)]
-pub struct RefOfMutStatic<'a> {
+pub(crate) struct RefOfMutStatic<'a> {
     #[label]
     pub span: Span,
     #[subdiagnostic]
@@ -1575,7 +1575,7 @@ pub struct RefOfMutStatic<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_not_supported_delegation)]
-pub struct UnsupportedDelegation<'a> {
+pub(crate) struct UnsupportedDelegation<'a> {
     #[primary_span]
     pub span: Span,
     pub descr: &'a str,
@@ -1585,7 +1585,7 @@ pub struct UnsupportedDelegation<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_method_should_return_future)]
-pub struct MethodShouldReturnFuture {
+pub(crate) struct MethodShouldReturnFuture {
     #[primary_span]
     pub span: Span,
     pub method_name: Symbol,
@@ -1649,7 +1649,7 @@ pub(crate) struct UnconstrainedGenericParameter {
 }
 
 #[derive(Diagnostic)]
-pub enum UnnamedFieldsRepr<'a> {
+pub(crate) enum UnnamedFieldsRepr<'a> {
     #[diag(hir_analysis_unnamed_fields_repr_missing_repr_c)]
     MissingReprC {
         #[primary_span]
@@ -1678,14 +1678,14 @@ pub enum UnnamedFieldsRepr<'a> {
 
 #[derive(Subdiagnostic)]
 #[note(hir_analysis_unnamed_fields_repr_field_defined)]
-pub struct UnnamedFieldsReprFieldDefined {
+pub(crate) struct UnnamedFieldsReprFieldDefined {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_opaque_captures_higher_ranked_lifetime, code = E0657)]
-pub struct OpaqueCapturesHigherRankedLifetime {
+pub(crate) struct OpaqueCapturesHigherRankedLifetime {
     #[primary_span]
     pub span: Span,
     #[label]
@@ -1697,7 +1697,7 @@ pub struct OpaqueCapturesHigherRankedLifetime {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_pattern_type_non_const_range)]
-pub struct NonConstRange {
+pub(crate) struct NonConstRange {
     #[primary_span]
     pub span: Span,
 }
@@ -1706,7 +1706,7 @@ pub struct NonConstRange {
 #[diag(hir_analysis_invalid_receiver_ty, code = E0307)]
 #[note]
 #[help(hir_analysis_invalid_receiver_ty_help)]
-pub struct InvalidReceiverTy<'tcx> {
+pub(crate) struct InvalidReceiverTy<'tcx> {
     #[primary_span]
     pub span: Span,
     pub receiver_ty: Ty<'tcx>,
@@ -1716,12 +1716,12 @@ pub struct InvalidReceiverTy<'tcx> {
 #[diag(hir_analysis_effects_without_next_solver)]
 #[note]
 #[help]
-pub struct EffectsWithoutNextSolver;
+pub(crate) struct EffectsWithoutNextSolver;
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_cmse_call_inputs_stack_spill, code = E0798)]
 #[note]
-pub struct CmseCallInputsStackSpill {
+pub(crate) struct CmseCallInputsStackSpill {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1732,7 +1732,7 @@ pub struct CmseCallInputsStackSpill {
 #[diag(hir_analysis_cmse_call_output_stack_spill, code = E0798)]
 #[note(hir_analysis_note1)]
 #[note(hir_analysis_note2)]
-pub struct CmseCallOutputStackSpill {
+pub(crate) struct CmseCallOutputStackSpill {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -1740,7 +1740,7 @@ pub struct CmseCallOutputStackSpill {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_cmse_call_generic, code = E0798)]
-pub struct CmseCallGeneric {
+pub(crate) struct CmseCallGeneric {
     #[primary_span]
     pub span: Span,
 }
diff --git a/compiler/rustc_hir_analysis/src/errors/pattern_types.rs b/compiler/rustc_hir_analysis/src/errors/pattern_types.rs
index 008d2698989..bb771d6ea17 100644
--- a/compiler/rustc_hir_analysis/src/errors/pattern_types.rs
+++ b/compiler/rustc_hir_analysis/src/errors/pattern_types.rs
@@ -3,7 +3,7 @@ use rustc_span::Span;
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_pattern_type_wild_pat)]
-pub struct WildPatTy {
+pub(crate) struct WildPatTy {
     #[primary_span]
     pub span: Span,
 }
diff --git a/compiler/rustc_hir_analysis/src/errors/precise_captures.rs b/compiler/rustc_hir_analysis/src/errors/precise_captures.rs
index 8a9b5fe6369..af2bb053c0a 100644
--- a/compiler/rustc_hir_analysis/src/errors/precise_captures.rs
+++ b/compiler/rustc_hir_analysis/src/errors/precise_captures.rs
@@ -4,7 +4,7 @@ use rustc_span::{Span, Symbol};
 #[derive(Diagnostic)]
 #[diag(hir_analysis_param_not_captured)]
 #[note]
-pub struct ParamNotCaptured {
+pub(crate) struct ParamNotCaptured {
     #[primary_span]
     pub opaque_span: Span,
     #[label]
@@ -15,7 +15,7 @@ pub struct ParamNotCaptured {
 #[derive(Diagnostic)]
 #[diag(hir_analysis_self_ty_not_captured)]
 #[note]
-pub struct SelfTyNotCaptured {
+pub(crate) struct SelfTyNotCaptured {
     #[primary_span]
     pub opaque_span: Span,
     #[label]
@@ -24,7 +24,7 @@ pub struct SelfTyNotCaptured {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_lifetime_not_captured)]
-pub struct LifetimeNotCaptured {
+pub(crate) struct LifetimeNotCaptured {
     #[primary_span]
     pub use_span: Span,
     #[label(hir_analysis_param_label)]
@@ -35,7 +35,7 @@ pub struct LifetimeNotCaptured {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_bad_precise_capture)]
-pub struct BadPreciseCapture {
+pub(crate) struct BadPreciseCapture {
     #[primary_span]
     pub span: Span,
     pub kind: &'static str,
@@ -44,7 +44,7 @@ pub struct BadPreciseCapture {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_precise_capture_self_alias)]
-pub struct PreciseCaptureSelfAlias {
+pub(crate) struct PreciseCaptureSelfAlias {
     #[primary_span]
     pub span: Span,
     #[label]
@@ -54,7 +54,7 @@ pub struct PreciseCaptureSelfAlias {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_duplicate_precise_capture)]
-pub struct DuplicatePreciseCapture {
+pub(crate) struct DuplicatePreciseCapture {
     #[primary_span]
     pub first_span: Span,
     pub name: Symbol,
@@ -64,7 +64,7 @@ pub struct DuplicatePreciseCapture {
 
 #[derive(Diagnostic)]
 #[diag(hir_analysis_lifetime_must_be_first)]
-pub struct LifetimesMustBeFirst {
+pub(crate) struct LifetimesMustBeFirst {
     #[primary_span]
     pub lifetime_span: Span,
     pub name: Symbol,
diff --git a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
index 8ecf53bfacb..f8b2469dfea 100644
--- a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
+++ b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
@@ -8,7 +8,7 @@ use rustc_span::def_id::DefId;
 use GenericArgsInfo::*;
 
 /// Handles the `wrong number of type / lifetime / ... arguments` family of error messages.
-pub struct WrongNumberOfGenericArgs<'a, 'tcx> {
+pub(crate) struct WrongNumberOfGenericArgs<'a, 'tcx> {
     pub(crate) tcx: TyCtxt<'tcx>,
 
     pub(crate) angle_brackets: AngleBrackets,
@@ -49,7 +49,7 @@ pub(crate) enum AngleBrackets {
 
 // Information about the kind of arguments that are either missing or are unexpected
 #[derive(Debug)]
-pub enum GenericArgsInfo {
+pub(crate) enum GenericArgsInfo {
     MissingLifetimes {
         num_missing_args: usize,
     },
@@ -87,7 +87,7 @@ pub enum GenericArgsInfo {
 }
 
 impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
-    pub fn new(
+    pub(crate) fn new(
         tcx: TyCtxt<'tcx>,
         gen_args_info: GenericArgsInfo,
         path_segment: &'a hir::PathSegment<'_>,
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs
index e99717ce00f..1b73cecd666 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs
@@ -11,7 +11,7 @@ use crate::errors;
 /// Check conditions on inputs and outputs that the cmse ABIs impose: arguments and results MUST be
 /// returned via registers (i.e. MUST NOT spill to the stack). LLVM will also validate these
 /// conditions, but by checking them here rustc can emit nicer error messages.
-pub fn validate_cmse_abi<'tcx>(
+pub(crate) fn validate_cmse_abi<'tcx>(
     tcx: TyCtxt<'tcx>,
     dcx: DiagCtxtHandle<'_>,
     hir_id: HirId,
diff --git a/compiler/rustc_hir_analysis/src/hir_wf_check.rs b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
index 7d2cabd3f2c..3ecf61501f6 100644
--- a/compiler/rustc_hir_analysis/src/hir_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
@@ -11,7 +11,7 @@ use rustc_trait_selection::traits::{self, ObligationCtxt};
 
 use crate::collect::ItemCtxt;
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { diagnostic_hir_wf_check, ..*providers };
 }
 
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index 02520c472b9..7f183324f04 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -53,7 +53,10 @@ mod min_specialization;
 /// impl<'a> Trait<Foo> for Bar { type X = &'a i32; }
 /// //   ^ 'a is unused and appears in assoc type, error
 /// ```
-pub fn check_impl_wf(tcx: TyCtxt<'_>, impl_def_id: LocalDefId) -> Result<(), ErrorGuaranteed> {
+pub(crate) fn check_impl_wf(
+    tcx: TyCtxt<'_>,
+    impl_def_id: LocalDefId,
+) -> Result<(), ErrorGuaranteed> {
     let min_specialization = tcx.features().min_specialization;
     let mut res = Ok(());
     debug_assert_matches!(tcx.def_kind(impl_def_id), DefKind::Impl { .. });
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 291d57f2a17..f6d96003ce9 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -72,6 +72,7 @@ This API is completely unstable and subject to change.
 #![feature(slice_partition_dedup)]
 #![feature(try_blocks)]
 #![feature(unwrap_infallible)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 #[macro_use]
diff --git a/compiler/rustc_hir_analysis/src/outlives/explicit.rs b/compiler/rustc_hir_analysis/src/outlives/explicit.rs
index bbfadbb5c30..f576499ecac 100644
--- a/compiler/rustc_hir_analysis/src/outlives/explicit.rs
+++ b/compiler/rustc_hir_analysis/src/outlives/explicit.rs
@@ -5,12 +5,12 @@ use rustc_middle::ty::{self, OutlivesPredicate, TyCtxt};
 use super::utils::*;
 
 #[derive(Debug)]
-pub struct ExplicitPredicatesMap<'tcx> {
+pub(crate) struct ExplicitPredicatesMap<'tcx> {
     map: FxIndexMap<DefId, ty::EarlyBinder<'tcx, RequiredPredicates<'tcx>>>,
 }
 
 impl<'tcx> ExplicitPredicatesMap<'tcx> {
-    pub fn new() -> ExplicitPredicatesMap<'tcx> {
+    pub(crate) fn new() -> ExplicitPredicatesMap<'tcx> {
         ExplicitPredicatesMap { map: FxIndexMap::default() }
     }
 
diff --git a/compiler/rustc_hir_analysis/src/outlives/mod.rs b/compiler/rustc_hir_analysis/src/outlives/mod.rs
index cb61ef7c64d..e3cdb1bf5f7 100644
--- a/compiler/rustc_hir_analysis/src/outlives/mod.rs
+++ b/compiler/rustc_hir_analysis/src/outlives/mod.rs
@@ -9,7 +9,7 @@ mod explicit;
 mod implicit_infer;
 mod utils;
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { inferred_outlives_of, inferred_outlives_crate, ..*providers };
 }
 
diff --git a/compiler/rustc_hir_analysis/src/variance/constraints.rs b/compiler/rustc_hir_analysis/src/variance/constraints.rs
index ce9e73bf245..4fb7a02f8c9 100644
--- a/compiler/rustc_hir_analysis/src/variance/constraints.rs
+++ b/compiler/rustc_hir_analysis/src/variance/constraints.rs
@@ -12,7 +12,7 @@ use rustc_middle::{bug, span_bug};
 use super::terms::VarianceTerm::*;
 use super::terms::*;
 
-pub struct ConstraintContext<'a, 'tcx> {
+pub(crate) struct ConstraintContext<'a, 'tcx> {
     pub terms_cx: TermsContext<'a, 'tcx>,
 
     // These are pointers to common `ConstantTerm` instances
@@ -27,7 +27,7 @@ pub struct ConstraintContext<'a, 'tcx> {
 /// Declares that the variable `decl_id` appears in a location with
 /// variance `variance`.
 #[derive(Copy, Clone)]
-pub struct Constraint<'a> {
+pub(crate) struct Constraint<'a> {
     pub inferred: InferredIndex,
     pub variance: &'a VarianceTerm<'a>,
 }
@@ -41,11 +41,11 @@ pub struct Constraint<'a> {
 /// ```
 /// then while we are visiting `Bar<T>`, the `CurrentItem` would have
 /// the `DefId` and the start of `Foo`'s inferreds.
-pub struct CurrentItem {
+struct CurrentItem {
     inferred_start: InferredIndex,
 }
 
-pub fn add_constraints_from_crate<'a, 'tcx>(
+pub(crate) fn add_constraints_from_crate<'a, 'tcx>(
     terms_cx: TermsContext<'a, 'tcx>,
 ) -> ConstraintContext<'a, 'tcx> {
     let tcx = terms_cx.tcx;
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index 8a4114c3e4b..e8e2caf7e62 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -28,7 +28,7 @@ pub(crate) mod dump;
 /// Code for transforming variances.
 mod xform;
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { variances_of, crate_variances, ..*providers };
 }
 
diff --git a/compiler/rustc_hir_analysis/src/variance/solve.rs b/compiler/rustc_hir_analysis/src/variance/solve.rs
index e64c6721fe0..4f1bac17e71 100644
--- a/compiler/rustc_hir_analysis/src/variance/solve.rs
+++ b/compiler/rustc_hir_analysis/src/variance/solve.rs
@@ -21,7 +21,7 @@ struct SolveContext<'a, 'tcx> {
     solutions: Vec<ty::Variance>,
 }
 
-pub fn solve_constraints<'tcx>(
+pub(crate) fn solve_constraints<'tcx>(
     constraints_cx: ConstraintContext<'_, 'tcx>,
 ) -> ty::CrateVariancesMap<'tcx> {
     let ConstraintContext { terms_cx, constraints, .. } = constraints_cx;
diff --git a/compiler/rustc_hir_analysis/src/variance/terms.rs b/compiler/rustc_hir_analysis/src/variance/terms.rs
index 36bff60e019..597699b37b1 100644
--- a/compiler/rustc_hir_analysis/src/variance/terms.rs
+++ b/compiler/rustc_hir_analysis/src/variance/terms.rs
@@ -18,13 +18,13 @@ use rustc_middle::ty::{self, TyCtxt};
 
 use self::VarianceTerm::*;
 
-pub type VarianceTermPtr<'a> = &'a VarianceTerm<'a>;
+pub(crate) type VarianceTermPtr<'a> = &'a VarianceTerm<'a>;
 
 #[derive(Copy, Clone, Debug)]
-pub struct InferredIndex(pub usize);
+pub(crate) struct InferredIndex(pub usize);
 
 #[derive(Copy, Clone)]
-pub enum VarianceTerm<'a> {
+pub(crate) enum VarianceTerm<'a> {
     ConstantTerm(ty::Variance),
     TransformTerm(VarianceTermPtr<'a>, VarianceTermPtr<'a>),
     InferredTerm(InferredIndex),
@@ -45,7 +45,7 @@ impl<'a> fmt::Debug for VarianceTerm<'a> {
 
 /// The first pass over the crate simply builds up the set of inferreds.
 
-pub struct TermsContext<'a, 'tcx> {
+pub(crate) struct TermsContext<'a, 'tcx> {
     pub tcx: TyCtxt<'tcx>,
     pub arena: &'a DroplessArena,
 
@@ -62,7 +62,7 @@ pub struct TermsContext<'a, 'tcx> {
     pub inferred_terms: Vec<VarianceTermPtr<'a>>,
 }
 
-pub fn determine_parameters_to_be_inferred<'a, 'tcx>(
+pub(crate) fn determine_parameters_to_be_inferred<'a, 'tcx>(
     tcx: TyCtxt<'tcx>,
     arena: &'a DroplessArena,
 ) -> TermsContext<'a, 'tcx> {
diff --git a/compiler/rustc_hir_analysis/src/variance/xform.rs b/compiler/rustc_hir_analysis/src/variance/xform.rs
index 027f0859fcd..2e9964788e6 100644
--- a/compiler/rustc_hir_analysis/src/variance/xform.rs
+++ b/compiler/rustc_hir_analysis/src/variance/xform.rs
@@ -1,6 +1,6 @@
 use rustc_middle::ty;
 
-pub fn glb(v1: ty::Variance, v2: ty::Variance) -> ty::Variance {
+pub(crate) fn glb(v1: ty::Variance, v2: ty::Variance) -> ty::Variance {
     // Greatest lower bound of the variance lattice as
     // defined in The Paper:
     //
diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs
index cff21173f79..ac6707f9316 100644
--- a/compiler/rustc_hir_pretty/src/lib.rs
+++ b/compiler/rustc_hir_pretty/src/lib.rs
@@ -3,6 +3,7 @@
 
 // tidy-alphabetical-start
 #![recursion_limit = "256"]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::cell::Cell;
diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index bc0ed4a7fa9..7427fb14716 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -374,7 +374,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn maybe_get_coercion_reason(
+    pub(crate) fn maybe_get_coercion_reason(
         &self,
         hir_id: hir::HirId,
         sp: Span,
@@ -584,7 +584,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     // (e.g. we're in the tail of a function body)
     //
     // Returns the `LocalDefId` of the RPIT, which is always identity-substituted.
-    pub fn return_position_impl_trait_from_match_expectation(
+    pub(crate) fn return_position_impl_trait_from_match_expectation(
         &self,
         expectation: Expectation<'tcx>,
     ) -> Option<LocalDefId> {
diff --git a/compiler/rustc_hir_typeck/src/autoderef.rs b/compiler/rustc_hir_typeck/src/autoderef.rs
index 69c4889d7a4..d2d6da8f32b 100644
--- a/compiler/rustc_hir_typeck/src/autoderef.rs
+++ b/compiler/rustc_hir_typeck/src/autoderef.rs
@@ -13,11 +13,11 @@ use super::method::MethodCallee;
 use super::{FnCtxt, PlaceOp};
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn autoderef(&'a self, span: Span, base_ty: Ty<'tcx>) -> Autoderef<'a, 'tcx> {
+    pub(crate) fn autoderef(&'a self, span: Span, base_ty: Ty<'tcx>) -> Autoderef<'a, 'tcx> {
         Autoderef::new(self, self.param_env, self.body_id, span, base_ty)
     }
 
-    pub fn try_overloaded_deref(
+    pub(crate) fn try_overloaded_deref(
         &self,
         span: Span,
         base_ty: Ty<'tcx>,
@@ -26,11 +26,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Returns the adjustment steps.
-    pub fn adjust_steps(&self, autoderef: &Autoderef<'a, 'tcx>) -> Vec<Adjustment<'tcx>> {
+    pub(crate) fn adjust_steps(&self, autoderef: &Autoderef<'a, 'tcx>) -> Vec<Adjustment<'tcx>> {
         self.register_infer_ok_obligations(self.adjust_steps_as_infer_ok(autoderef))
     }
 
-    pub fn adjust_steps_as_infer_ok(
+    pub(crate) fn adjust_steps_as_infer_ok(
         &self,
         autoderef: &Autoderef<'a, 'tcx>,
     ) -> InferOk<'tcx, Vec<Adjustment<'tcx>>> {
diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index 44cb08e44eb..fc08b872efc 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -29,7 +29,7 @@ use crate::errors;
 /// Checks that it is legal to call methods of the trait corresponding
 /// to `trait_id` (this only cares about the trait, not the specific
 /// method that is called).
-pub fn check_legal_trait_for_method_call(
+pub(crate) fn check_legal_trait_for_method_call(
     tcx: TyCtxt<'_>,
     span: Span,
     receiver: Option<Span>,
@@ -62,7 +62,7 @@ enum CallStep<'tcx> {
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn check_call(
+    pub(crate) fn check_call(
         &self,
         call_expr: &'tcx hir::Expr<'tcx>,
         callee_expr: &'tcx hir::Expr<'tcx>,
@@ -940,7 +940,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 }
 
 #[derive(Debug)]
-pub struct DeferredCallResolution<'tcx> {
+pub(crate) struct DeferredCallResolution<'tcx> {
     call_expr: &'tcx hir::Expr<'tcx>,
     callee_expr: &'tcx hir::Expr<'tcx>,
     closure_ty: Ty<'tcx>,
@@ -949,7 +949,7 @@ pub struct DeferredCallResolution<'tcx> {
 }
 
 impl<'a, 'tcx> DeferredCallResolution<'tcx> {
-    pub fn resolve(self, fcx: &FnCtxt<'a, 'tcx>) {
+    pub(crate) fn resolve(self, fcx: &FnCtxt<'a, 'tcx>) {
         debug!("DeferredCallResolution::resolve() {:?}", self);
 
         // we should not be invoked until the closure kind has been
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index b47d8a97bce..dabc5a89397 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -976,7 +976,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// adjusted type of the expression, if successful.
     /// Adjustments are only recorded if the coercion succeeded.
     /// The expressions *must not* have any preexisting adjustments.
-    pub fn coerce(
+    pub(crate) fn coerce(
         &self,
         expr: &hir::Expr<'_>,
         expr_ty: Ty<'tcx>,
@@ -1011,7 +1011,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ///
     /// Returns false if the coercion creates any obligations that result in
     /// errors.
-    pub fn can_coerce(&self, expr_ty: Ty<'tcx>, target: Ty<'tcx>) -> bool {
+    pub(crate) fn can_coerce(&self, expr_ty: Ty<'tcx>, target: Ty<'tcx>) -> bool {
         // FIXME(-Znext-solver): We need to structurally resolve both types here.
         let source = self.resolve_vars_with_obligations(expr_ty);
         debug!("coercion::can_with_predicates({:?} -> {:?})", source, target);
@@ -1032,7 +1032,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Given a type and a target type, this function will calculate and return
     /// how many dereference steps needed to achieve `expr_ty <: target`. If
     /// it's not possible, return `None`.
-    pub fn deref_steps(&self, expr_ty: Ty<'tcx>, target: Ty<'tcx>) -> Option<usize> {
+    pub(crate) fn deref_steps(&self, expr_ty: Ty<'tcx>, target: Ty<'tcx>) -> Option<usize> {
         let cause = self.cause(DUMMY_SP, ObligationCauseCode::ExprAssignable);
         // We don't ever need two-phase here since we throw out the result of the coercion
         let coerce = Coerce::new(self, cause, AllowTwoPhase::No);
@@ -1047,7 +1047,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// This function is for diagnostics only, since it does not register
     /// trait or region sub-obligations. (presumably we could, but it's not
     /// particularly important for diagnostics...)
-    pub fn deref_once_mutably_for_diagnostic(&self, expr_ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
+    pub(crate) fn deref_once_mutably_for_diagnostic(&self, expr_ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
         self.autoderef(DUMMY_SP, expr_ty).nth(1).and_then(|(deref_ty, _)| {
             self.infcx
                 .type_implements_trait(
@@ -1341,7 +1341,7 @@ pub fn can_coerce<'tcx>(
 /// }
 /// let final_ty = coerce.complete(fcx);
 /// ```
-pub struct CoerceMany<'tcx, 'exprs, E: AsCoercionSite> {
+pub(crate) struct CoerceMany<'tcx, 'exprs, E: AsCoercionSite> {
     expected_ty: Ty<'tcx>,
     final_ty: Option<Ty<'tcx>>,
     expressions: Expressions<'tcx, 'exprs, E>,
@@ -1350,7 +1350,7 @@ pub struct CoerceMany<'tcx, 'exprs, E: AsCoercionSite> {
 
 /// The type of a `CoerceMany` that is storing up the expressions into
 /// a buffer. We use this in `check/mod.rs` for things like `break`.
-pub type DynamicCoerceMany<'tcx> = CoerceMany<'tcx, 'tcx, &'tcx hir::Expr<'tcx>>;
+pub(crate) type DynamicCoerceMany<'tcx> = CoerceMany<'tcx, 'tcx, &'tcx hir::Expr<'tcx>>;
 
 enum Expressions<'tcx, 'exprs, E: AsCoercionSite> {
     Dynamic(Vec<&'tcx hir::Expr<'tcx>>),
@@ -1361,7 +1361,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     /// The usual case; collect the set of expressions dynamically.
     /// If the full set of coercion sites is known before hand,
     /// consider `with_coercion_sites()` instead to avoid allocation.
-    pub fn new(expected_ty: Ty<'tcx>) -> Self {
+    pub(crate) fn new(expected_ty: Ty<'tcx>) -> Self {
         Self::make(expected_ty, Expressions::Dynamic(vec![]))
     }
 
@@ -1370,7 +1370,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     /// expected to pass each element in the slice to `coerce(...)` in
     /// order. This is used with arrays in particular to avoid
     /// needlessly cloning the slice.
-    pub fn with_coercion_sites(expected_ty: Ty<'tcx>, coercion_sites: &'exprs [E]) -> Self {
+    pub(crate) fn with_coercion_sites(expected_ty: Ty<'tcx>, coercion_sites: &'exprs [E]) -> Self {
         Self::make(expected_ty, Expressions::UpFront(coercion_sites))
     }
 
@@ -1386,7 +1386,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     /// Typically, this is used as the expected type when
     /// type-checking each of the alternative expressions whose types
     /// we are trying to merge.
-    pub fn expected_ty(&self) -> Ty<'tcx> {
+    pub(crate) fn expected_ty(&self) -> Ty<'tcx> {
         self.expected_ty
     }
 
@@ -1394,7 +1394,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     /// at the LUB of the expressions we've seen so far (if any). This
     /// isn't *final* until you call `self.complete()`, which will return
     /// the merged type.
-    pub fn merged_ty(&self) -> Ty<'tcx> {
+    pub(crate) fn merged_ty(&self) -> Ty<'tcx> {
         self.final_ty.unwrap_or(self.expected_ty)
     }
 
@@ -1403,7 +1403,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     /// could coerce from. This will record `expression`, and later
     /// calls to `coerce` may come back and add adjustments and things
     /// if necessary.
-    pub fn coerce<'a>(
+    pub(crate) fn coerce<'a>(
         &mut self,
         fcx: &FnCtxt<'a, 'tcx>,
         cause: &ObligationCause<'tcx>,
@@ -1425,7 +1425,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     /// The `augment_error` gives you a chance to extend the error
     /// message, in case any results (e.g., we use this to suggest
     /// removing a `;`).
-    pub fn coerce_forced_unit<'a>(
+    pub(crate) fn coerce_forced_unit<'a>(
         &mut self,
         fcx: &FnCtxt<'a, 'tcx>,
         cause: &ObligationCause<'tcx>,
@@ -1920,7 +1920,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
         }
     }
 
-    pub fn complete<'a>(self, fcx: &FnCtxt<'a, 'tcx>) -> Ty<'tcx> {
+    pub(crate) fn complete<'a>(self, fcx: &FnCtxt<'a, 'tcx>) -> Ty<'tcx> {
         if let Some(final_ty) = self.final_ty {
             final_ty
         } else {
@@ -1934,7 +1934,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
 
 /// Something that can be converted into an expression to which we can
 /// apply a coercion.
-pub trait AsCoercionSite {
+pub(crate) trait AsCoercionSite {
     fn as_coercion_site(&self) -> &hir::Expr<'_>;
 }
 
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs
index 0a9fa5c64a5..89f27e80774 100644
--- a/compiler/rustc_hir_typeck/src/demand.rs
+++ b/compiler/rustc_hir_typeck/src/demand.rs
@@ -18,7 +18,7 @@ use super::method::probe;
 use crate::FnCtxt;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn emit_type_mismatch_suggestions(
+    pub(crate) fn emit_type_mismatch_suggestions(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'tcx>,
@@ -70,7 +70,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn emit_coerce_suggestions(
+    pub(crate) fn emit_coerce_suggestions(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'tcx>,
@@ -165,13 +165,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     /// Requires that the two types unify, and prints an error message if
     /// they don't.
-    pub fn demand_suptype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) {
+    pub(crate) fn demand_suptype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) {
         if let Err(e) = self.demand_suptype_diag(sp, expected, actual) {
             e.emit();
         }
     }
 
-    pub fn demand_suptype_diag(
+    pub(crate) fn demand_suptype_diag(
         &'a self,
         sp: Span,
         expected: Ty<'tcx>,
@@ -193,13 +193,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .map_err(|e| self.err_ctxt().report_mismatched_types(cause, expected, actual, e))
     }
 
-    pub fn demand_eqtype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) {
+    pub(crate) fn demand_eqtype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) {
         if let Err(err) = self.demand_eqtype_diag(sp, expected, actual) {
             err.emit();
         }
     }
 
-    pub fn demand_eqtype_diag(
+    pub(crate) fn demand_eqtype_diag(
         &'a self,
         sp: Span,
         expected: Ty<'tcx>,
@@ -208,7 +208,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.demand_eqtype_with_origin(&self.misc(sp), expected, actual)
     }
 
-    pub fn demand_eqtype_with_origin(
+    pub(crate) fn demand_eqtype_with_origin(
         &'a self,
         cause: &ObligationCause<'tcx>,
         expected: Ty<'tcx>,
@@ -220,7 +220,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .map_err(|e| self.err_ctxt().report_mismatched_types(cause, expected, actual, e))
     }
 
-    pub fn demand_coerce(
+    pub(crate) fn demand_coerce(
         &self,
         expr: &'tcx hir::Expr<'tcx>,
         checked_ty: Ty<'tcx>,
@@ -279,7 +279,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     /// Notes the point at which a variable is constrained to some type incompatible
     /// with some expectation given by `source`.
-    pub fn note_source_of_type_mismatch_constraint(
+    pub(crate) fn note_source_of_type_mismatch_constraint(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'_>,
@@ -558,7 +558,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     // When encountering a type error on the value of a `break`, try to point at the reason for the
     // expected type.
-    pub fn annotate_loop_expected_due_to_inference(
+    pub(crate) fn annotate_loop_expected_due_to_inference(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'_>,
@@ -964,7 +964,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
     }
 
-    pub fn get_conversion_methods_for_diagnostic(
+    pub(crate) fn get_conversion_methods_for_diagnostic(
         &self,
         span: Span,
         expected: Ty<'tcx>,
@@ -1186,7 +1186,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 }
 
-pub enum TypeMismatchSource<'tcx> {
+pub(crate) enum TypeMismatchSource<'tcx> {
     /// Expected the binding to have the given type, but it was found to have
     /// a different type. Find out when that type first became incompatible.
     Ty(Ty<'tcx>),
diff --git a/compiler/rustc_hir_typeck/src/diverges.rs b/compiler/rustc_hir_typeck/src/diverges.rs
index aa30fb0f0af..3066561a31d 100644
--- a/compiler/rustc_hir_typeck/src/diverges.rs
+++ b/compiler/rustc_hir_typeck/src/diverges.rs
@@ -8,7 +8,7 @@ use rustc_span::{Span, DUMMY_SP};
 /// as diverging), with some manual adjustments for control-flow
 /// primitives (approximating a CFG).
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub enum Diverges {
+pub(crate) enum Diverges {
     /// Potentially unknown, some cases converge,
     /// others require a CFG to determine them.
     Maybe,
diff --git a/compiler/rustc_hir_typeck/src/errors.rs b/compiler/rustc_hir_typeck/src/errors.rs
index c35f7a84c4f..4d2770d2e50 100644
--- a/compiler/rustc_hir_typeck/src/errors.rs
+++ b/compiler/rustc_hir_typeck/src/errors.rs
@@ -17,7 +17,7 @@ use crate::fluent_generated as fluent;
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_field_multiply_specified_in_initializer, code = E0062)]
-pub struct FieldMultiplySpecifiedInInitializer {
+pub(crate) struct FieldMultiplySpecifiedInInitializer {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -28,7 +28,7 @@ pub struct FieldMultiplySpecifiedInInitializer {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_return_stmt_outside_of_fn_body, code = E0572)]
-pub struct ReturnStmtOutsideOfFnBody {
+pub(crate) struct ReturnStmtOutsideOfFnBody {
     #[primary_span]
     pub span: Span,
     #[label(hir_typeck_encl_body_label)]
@@ -38,7 +38,7 @@ pub struct ReturnStmtOutsideOfFnBody {
     pub statement_kind: ReturnLikeStatementKind,
 }
 
-pub enum ReturnLikeStatementKind {
+pub(crate) enum ReturnLikeStatementKind {
     Return,
     Become,
 }
@@ -57,21 +57,21 @@ impl IntoDiagArg for ReturnLikeStatementKind {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_rustcall_incorrect_args)]
-pub struct RustCallIncorrectArgs {
+pub(crate) struct RustCallIncorrectArgs {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_yield_expr_outside_of_coroutine, code = E0627)]
-pub struct YieldExprOutsideOfCoroutine {
+pub(crate) struct YieldExprOutsideOfCoroutine {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_struct_expr_non_exhaustive, code = E0639)]
-pub struct StructExprNonExhaustive {
+pub(crate) struct StructExprNonExhaustive {
     #[primary_span]
     pub span: Span,
     pub what: &'static str,
@@ -79,21 +79,21 @@ pub struct StructExprNonExhaustive {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_functional_record_update_on_non_struct, code = E0436)]
-pub struct FunctionalRecordUpdateOnNonStruct {
+pub(crate) struct FunctionalRecordUpdateOnNonStruct {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_address_of_temporary_taken, code = E0745)]
-pub struct AddressOfTemporaryTaken {
+pub(crate) struct AddressOfTemporaryTaken {
     #[primary_span]
     #[label]
     pub span: Span,
 }
 
 #[derive(Subdiagnostic)]
-pub enum AddReturnTypeSuggestion {
+pub(crate) enum AddReturnTypeSuggestion {
     #[suggestion(
         hir_typeck_add_return_type_add,
         code = " -> {found}",
@@ -116,7 +116,7 @@ pub enum AddReturnTypeSuggestion {
 }
 
 #[derive(Subdiagnostic)]
-pub enum ExpectedReturnTypeLabel<'tcx> {
+pub(crate) enum ExpectedReturnTypeLabel<'tcx> {
     #[label(hir_typeck_expected_default_return_type)]
     Unit {
         #[primary_span]
@@ -132,7 +132,7 @@ pub enum ExpectedReturnTypeLabel<'tcx> {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_explicit_destructor, code = E0040)]
-pub struct ExplicitDestructorCall {
+pub(crate) struct ExplicitDestructorCall {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -141,7 +141,7 @@ pub struct ExplicitDestructorCall {
 }
 
 #[derive(Subdiagnostic)]
-pub enum ExplicitDestructorCallSugg {
+pub(crate) enum ExplicitDestructorCallSugg {
     #[suggestion(hir_typeck_suggestion, code = "drop", applicability = "maybe-incorrect")]
     Empty(#[primary_span] Span),
     #[multipart_suggestion(hir_typeck_suggestion, style = "short")]
@@ -155,7 +155,7 @@ pub enum ExplicitDestructorCallSugg {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_missing_parentheses_in_range, code = E0689)]
-pub struct MissingParenthesesInRange {
+pub(crate) struct MissingParenthesesInRange {
     #[primary_span]
     #[label(hir_typeck_missing_parentheses_in_range)]
     pub span: Span,
@@ -166,7 +166,7 @@ pub struct MissingParenthesesInRange {
 }
 
 #[derive(LintDiagnostic)]
-pub enum NeverTypeFallbackFlowingIntoUnsafe {
+pub(crate) enum NeverTypeFallbackFlowingIntoUnsafe {
     #[help]
     #[diag(hir_typeck_never_type_fallback_flowing_into_unsafe_call)]
     Call,
@@ -187,7 +187,7 @@ pub enum NeverTypeFallbackFlowingIntoUnsafe {
 #[derive(LintDiagnostic)]
 #[help]
 #[diag(hir_typeck_dependency_on_unit_never_type_fallback)]
-pub struct DependencyOnUnitNeverTypeFallback<'tcx> {
+pub(crate) struct DependencyOnUnitNeverTypeFallback<'tcx> {
     #[note]
     pub obligation_span: Span,
     pub obligation: ty::Predicate<'tcx>,
@@ -199,7 +199,7 @@ pub struct DependencyOnUnitNeverTypeFallback<'tcx> {
     style = "verbose",
     applicability = "maybe-incorrect"
 )]
-pub struct AddMissingParenthesesInRange {
+pub(crate) struct AddMissingParenthesesInRange {
     pub func_name: String,
     #[suggestion_part(code = "(")]
     pub left: Span,
@@ -207,7 +207,7 @@ pub struct AddMissingParenthesesInRange {
     pub right: Span,
 }
 
-pub struct TypeMismatchFruTypo {
+pub(crate) struct TypeMismatchFruTypo {
     /// Span of the LHS of the range
     pub expr_span: Span,
     /// Span of the `..RHS` part of the range
@@ -246,7 +246,7 @@ impl Subdiagnostic for TypeMismatchFruTypo {
 #[derive(LintDiagnostic)]
 #[diag(hir_typeck_lossy_provenance_int2ptr)]
 #[help]
-pub struct LossyProvenanceInt2Ptr<'tcx> {
+pub(crate) struct LossyProvenanceInt2Ptr<'tcx> {
     pub expr_ty: Ty<'tcx>,
     pub cast_ty: Ty<'tcx>,
     #[subdiagnostic]
@@ -255,14 +255,14 @@ pub struct LossyProvenanceInt2Ptr<'tcx> {
 
 #[derive(LintDiagnostic)]
 #[diag(hir_typeck_ptr_cast_add_auto_to_object)]
-pub struct PtrCastAddAutoToObject {
+pub(crate) struct PtrCastAddAutoToObject {
     pub traits_len: usize,
     pub traits: DiagSymbolList<String>,
 }
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(hir_typeck_suggestion, applicability = "has-placeholders")]
-pub struct LossyProvenanceInt2PtrSuggestion {
+pub(crate) struct LossyProvenanceInt2PtrSuggestion {
     #[suggestion_part(code = "(...).with_addr(")]
     pub lo: Span,
     #[suggestion_part(code = ")")]
@@ -272,7 +272,7 @@ pub struct LossyProvenanceInt2PtrSuggestion {
 #[derive(LintDiagnostic)]
 #[diag(hir_typeck_lossy_provenance_ptr2int)]
 #[help]
-pub struct LossyProvenancePtr2Int<'tcx> {
+pub(crate) struct LossyProvenancePtr2Int<'tcx> {
     pub expr_ty: Ty<'tcx>,
     pub cast_ty: Ty<'tcx>,
     #[subdiagnostic]
@@ -280,7 +280,7 @@ pub struct LossyProvenancePtr2Int<'tcx> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum LossyProvenancePtr2IntSuggestion<'tcx> {
+pub(crate) enum LossyProvenancePtr2IntSuggestion<'tcx> {
     #[multipart_suggestion(hir_typeck_suggestion, applicability = "maybe-incorrect")]
     NeedsParensCast {
         #[suggestion_part(code = "(")]
@@ -314,7 +314,7 @@ pub enum LossyProvenancePtr2IntSuggestion<'tcx> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum HelpUseLatestEdition {
+pub(crate) enum HelpUseLatestEdition {
     #[help(hir_typeck_help_set_edition_cargo)]
     #[note(hir_typeck_note_edition_guide)]
     Cargo { edition: Edition },
@@ -324,7 +324,7 @@ pub enum HelpUseLatestEdition {
 }
 
 impl HelpUseLatestEdition {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         let edition = LATEST_STABLE_EDITION;
         if rustc_session::utils::was_invoked_from_cargo() {
             Self::Cargo { edition }
@@ -336,7 +336,7 @@ impl HelpUseLatestEdition {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_invalid_callee, code = E0618)]
-pub struct InvalidCallee {
+pub(crate) struct InvalidCallee {
     #[primary_span]
     pub span: Span,
     pub ty: String,
@@ -344,7 +344,7 @@ pub struct InvalidCallee {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_int_to_fat, code = E0606)]
-pub struct IntToWide<'tcx> {
+pub(crate) struct IntToWide<'tcx> {
     #[primary_span]
     #[label(hir_typeck_int_to_fat_label)]
     pub span: Span,
@@ -357,7 +357,7 @@ pub struct IntToWide<'tcx> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum OptionResultRefMismatch {
+pub(crate) enum OptionResultRefMismatch {
     #[suggestion(
         hir_typeck_option_result_copied,
         code = ".copied()",
@@ -396,7 +396,7 @@ pub enum OptionResultRefMismatch {
     // },
 }
 
-pub struct RemoveSemiForCoerce {
+pub(crate) struct RemoveSemiForCoerce {
     pub expr: Span,
     pub ret: Span,
     pub semi: Span,
@@ -426,7 +426,7 @@ impl Subdiagnostic for RemoveSemiForCoerce {
 #[derive(Diagnostic)]
 #[diag(hir_typeck_const_select_must_be_const)]
 #[help]
-pub struct ConstSelectMustBeConst {
+pub(crate) struct ConstSelectMustBeConst {
     #[primary_span]
     pub span: Span,
 }
@@ -435,7 +435,7 @@ pub struct ConstSelectMustBeConst {
 #[diag(hir_typeck_const_select_must_be_fn)]
 #[note]
 #[help]
-pub struct ConstSelectMustBeFn<'a> {
+pub(crate) struct ConstSelectMustBeFn<'a> {
     #[primary_span]
     pub span: Span,
     pub ty: Ty<'a>,
@@ -443,14 +443,14 @@ pub struct ConstSelectMustBeFn<'a> {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_union_pat_multiple_fields)]
-pub struct UnionPatMultipleFields {
+pub(crate) struct UnionPatMultipleFields {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_union_pat_dotdot)]
-pub struct UnionPatDotDot {
+pub(crate) struct UnionPatDotDot {
     #[primary_span]
     pub span: Span,
 }
@@ -461,7 +461,7 @@ pub struct UnionPatDotDot {
     applicability = "maybe-incorrect",
     style = "verbose"
 )]
-pub struct UseIsEmpty {
+pub(crate) struct UseIsEmpty {
     #[suggestion_part(code = "!")]
     pub lo: Span,
     #[suggestion_part(code = ".is_empty()")]
@@ -471,13 +471,13 @@ pub struct UseIsEmpty {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_arg_mismatch_indeterminate)]
-pub struct ArgMismatchIndeterminate {
+pub(crate) struct ArgMismatchIndeterminate {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Subdiagnostic)]
-pub enum SuggestBoxing {
+pub(crate) enum SuggestBoxing {
     #[note(hir_typeck_suggest_boxing_note)]
     #[multipart_suggestion(
         hir_typeck_suggest_boxing_when_appropriate,
@@ -511,7 +511,7 @@ pub enum SuggestBoxing {
     style = "verbose",
     code = "core::ptr::null_mut()"
 )]
-pub struct SuggestPtrNullMut {
+pub(crate) struct SuggestPtrNullMut {
     #[primary_span]
     pub span: Span,
 }
@@ -519,7 +519,7 @@ pub struct SuggestPtrNullMut {
 #[derive(LintDiagnostic)]
 #[diag(hir_typeck_trivial_cast)]
 #[help]
-pub struct TrivialCast<'tcx> {
+pub(crate) struct TrivialCast<'tcx> {
     pub numeric: bool,
     pub expr_ty: Ty<'tcx>,
     pub cast_ty: Ty<'tcx>,
@@ -527,7 +527,7 @@ pub struct TrivialCast<'tcx> {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_no_associated_item, code = E0599)]
-pub struct NoAssociatedItem {
+pub(crate) struct NoAssociatedItem {
     #[primary_span]
     pub span: Span,
     pub item_kind: &'static str,
@@ -539,7 +539,7 @@ pub struct NoAssociatedItem {
 
 #[derive(Subdiagnostic)]
 #[note(hir_typeck_candidate_trait_note)]
-pub struct CandidateTraitNote {
+pub(crate) struct CandidateTraitNote {
     #[primary_span]
     pub span: Span,
     pub trait_name: String,
@@ -549,7 +549,7 @@ pub struct CandidateTraitNote {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_cannot_cast_to_bool, code = E0054)]
-pub struct CannotCastToBool<'tcx> {
+pub(crate) struct CannotCastToBool<'tcx> {
     #[primary_span]
     pub span: Span,
     pub expr_ty: Ty<'tcx>,
@@ -559,14 +559,14 @@ pub struct CannotCastToBool<'tcx> {
 
 #[derive(LintDiagnostic)]
 #[diag(hir_typeck_cast_enum_drop)]
-pub struct CastEnumDrop<'tcx> {
+pub(crate) struct CastEnumDrop<'tcx> {
     pub expr_ty: Ty<'tcx>,
     pub cast_ty: Ty<'tcx>,
 }
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_cast_unknown_pointer, code = E0641)]
-pub struct CastUnknownPointer {
+pub(crate) struct CastUnknownPointer {
     #[primary_span]
     pub span: Span,
     pub to: bool,
@@ -574,7 +574,7 @@ pub struct CastUnknownPointer {
     pub sub: CastUnknownPointerSub,
 }
 
-pub enum CastUnknownPointerSub {
+pub(crate) enum CastUnknownPointerSub {
     To(Span),
     From(Span),
 }
@@ -601,7 +601,7 @@ impl rustc_errors::Subdiagnostic for CastUnknownPointerSub {
 }
 
 #[derive(Subdiagnostic)]
-pub enum CannotCastToBoolHelp {
+pub(crate) enum CannotCastToBoolHelp {
     #[suggestion(
         hir_typeck_suggestion,
         applicability = "machine-applicable",
@@ -615,7 +615,7 @@ pub enum CannotCastToBoolHelp {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_ctor_is_private, code = E0603)]
-pub struct CtorIsPrivate {
+pub(crate) struct CtorIsPrivate {
     #[primary_span]
     pub span: Span,
     pub def: String,
@@ -623,7 +623,7 @@ pub struct CtorIsPrivate {
 
 #[derive(Subdiagnostic)]
 #[note(hir_typeck_deref_is_empty)]
-pub struct DerefImplsIsEmpty {
+pub(crate) struct DerefImplsIsEmpty {
     #[primary_span]
     pub span: Span,
     pub deref_ty: String,
@@ -635,7 +635,7 @@ pub struct DerefImplsIsEmpty {
     applicability = "machine-applicable",
     style = "verbose"
 )]
-pub struct SuggestConvertViaMethod<'tcx> {
+pub(crate) struct SuggestConvertViaMethod<'tcx> {
     #[suggestion_part(code = "{sugg}")]
     pub span: Span,
     #[suggestion_part(code = "")]
@@ -647,13 +647,13 @@ pub struct SuggestConvertViaMethod<'tcx> {
 
 #[derive(Subdiagnostic)]
 #[note(hir_typeck_note_caller_chooses_ty_for_ty_param)]
-pub struct NoteCallerChoosesTyForTyParam<'tcx> {
+pub(crate) struct NoteCallerChoosesTyForTyParam<'tcx> {
     pub ty_param_name: Symbol,
     pub found_ty: Ty<'tcx>,
 }
 
 #[derive(Subdiagnostic)]
-pub enum SuggestBoxingForReturnImplTrait {
+pub(crate) enum SuggestBoxingForReturnImplTrait {
     #[multipart_suggestion(hir_typeck_rpit_change_return_type, applicability = "maybe-incorrect")]
     ChangeReturnType {
         #[suggestion_part(code = "Box<dyn")]
@@ -672,7 +672,7 @@ pub enum SuggestBoxingForReturnImplTrait {
 
 #[derive(Diagnostic)]
 #[diag(hir_typeck_self_ctor_from_outer_item, code = E0401)]
-pub struct SelfCtorFromOuterItem {
+pub(crate) struct SelfCtorFromOuterItem {
     #[primary_span]
     pub span: Span,
     #[label]
@@ -683,7 +683,7 @@ pub struct SelfCtorFromOuterItem {
 
 #[derive(LintDiagnostic)]
 #[diag(hir_typeck_self_ctor_from_outer_item)]
-pub struct SelfCtorFromOuterItemLint {
+pub(crate) struct SelfCtorFromOuterItemLint {
     #[label]
     pub impl_span: Span,
     #[subdiagnostic]
@@ -692,7 +692,7 @@ pub struct SelfCtorFromOuterItemLint {
 
 #[derive(Subdiagnostic)]
 #[suggestion(hir_typeck_suggestion, code = "{name}", applicability = "machine-applicable")]
-pub struct ReplaceWithName {
+pub(crate) struct ReplaceWithName {
     #[primary_span]
     pub span: Span,
     pub name: String,
diff --git a/compiler/rustc_hir_typeck/src/expectation.rs b/compiler/rustc_hir_typeck/src/expectation.rs
index 76ae41db5c5..67f4dbee3cb 100644
--- a/compiler/rustc_hir_typeck/src/expectation.rs
+++ b/compiler/rustc_hir_typeck/src/expectation.rs
@@ -7,7 +7,7 @@ use super::FnCtxt;
 /// When type-checking an expression, we propagate downward
 /// whatever type hint we are able in the form of an `Expectation`.
 #[derive(Copy, Clone, Debug)]
-pub enum Expectation<'tcx> {
+pub(crate) enum Expectation<'tcx> {
     /// We know nothing about what type this expression should have.
     NoExpectation,
 
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 91778a36668..dd33b947b0d 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -51,7 +51,7 @@ use crate::{
 };
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn check_expr_has_type_or_error(
+    pub(crate) fn check_expr_has_type_or_error(
         &self,
         expr: &'tcx hir::Expr<'tcx>,
         expected_ty: Ty<'tcx>,
@@ -977,7 +977,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Check if the expression that could not be assigned to was a typoed expression that
-    pub fn check_for_missing_semi(&self, expr: &'tcx hir::Expr<'tcx>, err: &mut Diag<'_>) -> bool {
+    pub(crate) fn check_for_missing_semi(
+        &self,
+        expr: &'tcx hir::Expr<'tcx>,
+        err: &mut Diag<'_>,
+    ) -> bool {
         if let hir::ExprKind::Binary(binop, lhs, rhs) = expr.kind
             && let hir::BinOpKind::Mul = binop.node
             && self.tcx.sess.source_map().is_multiline(lhs.span.between(rhs.span))
diff --git a/compiler/rustc_hir_typeck/src/fallback.rs b/compiler/rustc_hir_typeck/src/fallback.rs
index 6e1b7504626..b1dc19b3777 100644
--- a/compiler/rustc_hir_typeck/src/fallback.rs
+++ b/compiler/rustc_hir_typeck/src/fallback.rs
@@ -18,7 +18,7 @@ use rustc_trait_selection::traits::{ObligationCause, ObligationCtxt};
 use crate::{errors, FnCtxt, TypeckRootCtxt};
 
 #[derive(Copy, Clone)]
-pub enum DivergingFallbackBehavior {
+pub(crate) enum DivergingFallbackBehavior {
     /// Always fallback to `()` (aka "always spontaneous decay")
     ToUnit,
     /// Sometimes fallback to `!`, but mainly fallback to `()` so that most of the crates are not broken.
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 21e6ac9332c..2d205d1ede9 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -132,18 +132,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         deferred_call_resolutions.remove(&closure_def_id).unwrap_or_default()
     }
 
-    pub fn tag(&self) -> String {
+    fn tag(&self) -> String {
         format!("{self:p}")
     }
 
-    pub fn local_ty(&self, span: Span, nid: HirId) -> Ty<'tcx> {
+    pub(crate) fn local_ty(&self, span: Span, nid: HirId) -> Ty<'tcx> {
         self.locals.borrow().get(&nid).cloned().unwrap_or_else(|| {
             span_bug!(span, "no type for local variable {}", self.tcx.hir().node_to_string(nid))
         })
     }
 
     #[inline]
-    pub fn write_ty(&self, id: HirId, ty: Ty<'tcx>) {
+    pub(crate) fn write_ty(&self, id: HirId, ty: Ty<'tcx>) {
         debug!("write_ty({:?}, {:?}) in fcx {}", id, self.resolve_vars_if_possible(ty), self.tag());
         let mut typeck = self.typeck_results.borrow_mut();
         let mut node_ty = typeck.node_types_mut();
@@ -165,7 +165,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn write_field_index(
+    pub(crate) fn write_field_index(
         &self,
         hir_id: HirId,
         index: FieldIdx,
@@ -198,7 +198,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.write_args(hir_id, method.args);
     }
 
-    pub fn write_args(&self, node_id: HirId, args: GenericArgsRef<'tcx>) {
+    fn write_args(&self, node_id: HirId, args: GenericArgsRef<'tcx>) {
         if !args.is_empty() {
             debug!("write_args({:?}, {:?}) in fcx {}", node_id, args, self.tag());
 
@@ -364,7 +364,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         )
     }
 
-    pub fn require_type_meets(
+    pub(crate) fn require_type_meets(
         &self,
         ty: Ty<'tcx>,
         span: Span,
@@ -374,7 +374,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.register_bound(ty, def_id, traits::ObligationCause::new(span, self.body_id, code));
     }
 
-    pub fn require_type_is_sized(
+    pub(crate) fn require_type_is_sized(
         &self,
         ty: Ty<'tcx>,
         span: Span,
@@ -386,7 +386,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn require_type_is_sized_deferred(
+    pub(crate) fn require_type_is_sized_deferred(
         &self,
         ty: Ty<'tcx>,
         span: Span,
@@ -397,7 +397,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn require_type_has_static_alignment(
+    pub(crate) fn require_type_has_static_alignment(
         &self,
         ty: Ty<'tcx>,
         span: Span,
@@ -426,7 +426,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn register_bound(
+    pub(crate) fn register_bound(
         &self,
         ty: Ty<'tcx>,
         def_id: DefId,
@@ -443,7 +443,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn lower_ty(&self, hir_ty: &hir::Ty<'tcx>) -> LoweredTy<'tcx> {
+    pub(crate) fn lower_ty(&self, hir_ty: &hir::Ty<'tcx>) -> LoweredTy<'tcx> {
         let ty = self.lowerer().lower_ty(hir_ty);
         self.register_wf_obligation(ty.into(), hir_ty.span, ObligationCauseCode::WellFormed(None));
         LoweredTy::from_raw(self, hir_ty.span, ty)
@@ -474,7 +474,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn lower_array_length(&self, length: &hir::ArrayLen<'tcx>) -> ty::Const<'tcx> {
+    pub(crate) fn lower_array_length(&self, length: &hir::ArrayLen<'tcx>) -> ty::Const<'tcx> {
         match length {
             hir::ArrayLen::Infer(inf) => self.ct_infer(None, inf.span),
             hir::ArrayLen::Body(const_arg) => {
@@ -486,7 +486,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn lower_const_arg(
+    pub(crate) fn lower_const_arg(
         &self,
         const_arg: &'tcx hir::ConstArg<'tcx>,
         param_def_id: DefId,
@@ -515,7 +515,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         t.has_free_regions() || t.has_aliases() || t.has_infer_types()
     }
 
-    pub fn node_ty(&self, id: HirId) -> Ty<'tcx> {
+    pub(crate) fn node_ty(&self, id: HirId) -> Ty<'tcx> {
         match self.typeck_results.borrow().node_types().get(id) {
             Some(&t) => t,
             None if let Some(e) = self.tainted_by_errors() => Ty::new_error(self.tcx, e),
@@ -529,7 +529,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn node_ty_opt(&self, id: HirId) -> Option<Ty<'tcx>> {
+    pub(crate) fn node_ty_opt(&self, id: HirId) -> Option<Ty<'tcx>> {
         match self.typeck_results.borrow().node_types().get(id) {
             Some(&t) => Some(t),
             None if let Some(e) = self.tainted_by_errors() => Some(Ty::new_error(self.tcx, e)),
@@ -538,7 +538,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Registers an obligation for checking later, during regionck, that `arg` is well-formed.
-    pub fn register_wf_obligation(
+    pub(crate) fn register_wf_obligation(
         &self,
         arg: ty::GenericArg<'tcx>,
         span: Span,
@@ -555,7 +555,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Registers obligations that all `args` are well-formed.
-    pub fn add_wf_bounds(&self, args: GenericArgsRef<'tcx>, expr: &hir::Expr<'_>) {
+    pub(crate) fn add_wf_bounds(&self, args: GenericArgsRef<'tcx>, expr: &hir::Expr<'_>) {
         for arg in args.iter().filter(|arg| {
             matches!(arg.unpack(), GenericArgKind::Type(..) | GenericArgKind::Const(..))
         }) {
@@ -566,7 +566,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     // FIXME(arielb1): use this instead of field.ty everywhere
     // Only for fields! Returns <none> for methods>
     // Indifferent to privacy flags
-    pub fn field_ty(
+    pub(crate) fn field_ty(
         &self,
         span: Span,
         field: &'tcx ty::FieldDef,
@@ -897,7 +897,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     /// Given a `HirId`, return the `HirId` of the enclosing function, its `FnDecl`, and whether a
     /// suggestion can be made, `None` otherwise.
-    pub fn get_fn_decl(
+    pub(crate) fn get_fn_decl(
         &self,
         blk_id: HirId,
     ) -> Option<(LocalDefId, &'tcx hir::FnDecl<'tcx>, bool)> {
@@ -1534,7 +1534,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ///
     /// If no resolution is possible, then an error is reported.
     /// Numeric inference variables may be left unresolved.
-    pub fn structurally_resolve_type(&self, sp: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
+    pub(crate) fn structurally_resolve_type(&self, sp: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
         let ty = self.try_structurally_resolve_type(sp, ty);
 
         if !ty.is_ty_var() {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
index 130fd130ec8..a8ba9f139cc 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
@@ -12,7 +12,7 @@ use rustc_trait_selection::traits;
 use crate::FnCtxt;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn adjust_fulfillment_error_for_expr_obligation(
+    pub(crate) fn adjust_fulfillment_error_for_expr_obligation(
         &self,
         error: &mut traits::FulfillmentError<'tcx>,
     ) -> bool {
@@ -483,7 +483,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
      *
      * This function only updates the error span.
      */
-    pub fn blame_specific_expr_if_possible(
+    pub(crate) fn blame_specific_expr_if_possible(
         &self,
         error: &mut traits::FulfillmentError<'tcx>,
         expr: &'tcx hir::Expr<'tcx>,
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs
index 78895689433..cb77d3f85d9 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs
@@ -17,7 +17,7 @@ rustc_index::newtype_index! {
 }
 
 impl ExpectedIdx {
-    pub fn to_provided_idx(self) -> ProvidedIdx {
+    pub(crate) fn to_provided_idx(self) -> ProvidedIdx {
         ProvidedIdx::from_usize(self.as_usize())
     }
 }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index aca29d47587..5333982c420 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -45,7 +45,7 @@ use crate::{
 };
 
 #[derive(Clone, Copy, Default)]
-pub enum DivergingBlockBehavior {
+pub(crate) enum DivergingBlockBehavior {
     /// This is the current stable behavior:
     ///
     /// ```rust
@@ -1556,7 +1556,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn check_struct_path(
+    pub(crate) fn check_struct_path(
         &self,
         qpath: &QPath<'tcx>,
         hir_id: HirId,
@@ -1622,7 +1622,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn check_decl_initializer(
+    fn check_decl_initializer(
         &self,
         hir_id: HirId,
         pat: &'tcx hir::Pat<'tcx>,
@@ -1700,7 +1700,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Type check a `let` statement.
-    pub fn check_decl_local(&self, local: &'tcx hir::LetStmt<'tcx>) {
+    fn check_decl_local(&self, local: &'tcx hir::LetStmt<'tcx>) {
         self.check_decl(local.into());
         if local.pat.is_never_pattern() {
             self.diverges.set(Diverges::Always {
@@ -1710,7 +1710,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn check_stmt(&self, stmt: &'tcx hir::Stmt<'tcx>) {
+    fn check_stmt(&self, stmt: &'tcx hir::Stmt<'tcx>) {
         // Don't do all the complex logic below for `DeclItem`.
         match stmt.kind {
             hir::StmtKind::Item(..) => return,
@@ -1745,7 +1745,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.diverges.set(self.diverges.get() | old_diverges);
     }
 
-    pub fn check_block_no_value(&self, blk: &'tcx hir::Block<'tcx>) {
+    pub(crate) fn check_block_no_value(&self, blk: &'tcx hir::Block<'tcx>) {
         let unit = self.tcx.types.unit;
         let ty = self.check_block_with_expected(blk, ExpectHasType(unit));
 
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
index 33f80dd3773..8e69a075030 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
@@ -117,7 +117,7 @@ pub(crate) struct FnCtxt<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn new(
+    pub(crate) fn new(
         root_ctxt: &'a TypeckRootCtxt<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
         body_id: LocalDefId,
@@ -148,15 +148,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.root_ctxt.infcx.dcx()
     }
 
-    pub fn cause(&self, span: Span, code: ObligationCauseCode<'tcx>) -> ObligationCause<'tcx> {
+    pub(crate) fn cause(
+        &self,
+        span: Span,
+        code: ObligationCauseCode<'tcx>,
+    ) -> ObligationCause<'tcx> {
         ObligationCause::new(span, self.body_id, code)
     }
 
-    pub fn misc(&self, span: Span) -> ObligationCause<'tcx> {
+    pub(crate) fn misc(&self, span: Span) -> ObligationCause<'tcx> {
         self.cause(span, ObligationCauseCode::Misc)
     }
 
-    pub fn sess(&self) -> &Session {
+    pub(crate) fn sess(&self) -> &Session {
         self.tcx.sess
     }
 
@@ -165,7 +169,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Use [`InferCtxtErrorExt::err_ctxt`] to start one without a `TypeckResults`.
     ///
     /// [`InferCtxtErrorExt::err_ctxt`]: rustc_trait_selection::error_reporting::InferCtxtErrorExt::err_ctxt
-    pub fn err_ctxt(&'a self) -> TypeErrCtxt<'a, 'tcx> {
+    pub(crate) fn err_ctxt(&'a self) -> TypeErrCtxt<'a, 'tcx> {
         let mut sub_relations = SubRelations::default();
         sub_relations.add_constraints(
             self,
@@ -365,7 +369,7 @@ impl<'tcx> HirTyLowerer<'tcx> for FnCtxt<'_, 'tcx> {
 /// This is a bridge between the interface of HIR ty lowering, which outputs a raw
 /// `Ty`, and the API in this module, which expect `Ty` to be fully normalized.
 #[derive(Clone, Copy, Debug)]
-pub struct LoweredTy<'tcx> {
+pub(crate) struct LoweredTy<'tcx> {
     /// The unnormalized type provided by the user.
     pub raw: Ty<'tcx>,
 
@@ -374,7 +378,7 @@ pub struct LoweredTy<'tcx> {
 }
 
 impl<'tcx> LoweredTy<'tcx> {
-    pub fn from_raw(fcx: &FnCtxt<'_, 'tcx>, span: Span, raw: Ty<'tcx>) -> LoweredTy<'tcx> {
+    fn from_raw(fcx: &FnCtxt<'_, 'tcx>, span: Span, raw: Ty<'tcx>) -> LoweredTy<'tcx> {
         // FIXME(-Znext-solver): We're still figuring out how to best handle
         // normalization and this doesn't feel too great. We should look at this
         // code again before stabilizing it.
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 11c6e65a211..031aa6159d2 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -64,7 +64,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// - Points out the method's return type as the reason for the expected type.
     /// - Possible missing semicolon.
     /// - Possible missing return type if the return type is the default, and not `fn main()`.
-    pub fn suggest_mismatched_types_on_tail(
+    pub(crate) fn suggest_mismatched_types_on_tail(
         &self,
         err: &mut Diag<'_>,
         expr: &'tcx hir::Expr<'tcx>,
@@ -177,7 +177,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.err_ctxt().extract_callable_info(self.body_id, self.param_env, ty)
     }
 
-    pub fn suggest_two_fn_call(
+    pub(crate) fn suggest_two_fn_call(
         &self,
         err: &mut Diag<'_>,
         lhs_expr: &'tcx hir::Expr<'tcx>,
@@ -251,7 +251,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn suggest_remove_last_method_call(
+    pub(crate) fn suggest_remove_last_method_call(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'tcx>,
@@ -280,7 +280,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         false
     }
 
-    pub fn suggest_deref_ref_or_into(
+    pub(crate) fn suggest_deref_ref_or_into(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'tcx>,
@@ -747,7 +747,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ///
     /// If the expression is the expression of a closure without block (`|| expr`), a
     /// block is needed to be added too (`|| { expr; }`). This is denoted by `needs_block`.
-    pub fn suggest_missing_semicolon(
+    pub(crate) fn suggest_missing_semicolon(
         &self,
         err: &mut Diag<'_>,
         expression: &'tcx hir::Expr<'tcx>,
@@ -2077,7 +2077,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     // If the expr is a while or for loop and is the tail expr of its
     // enclosing body suggest returning a value right after it
-    pub fn suggest_returning_value_after_loop(
+    pub(crate) fn suggest_returning_value_after_loop(
         &self,
         err: &mut Diag<'_>,
         expr: &hir::Expr<'tcx>,
diff --git a/compiler/rustc_hir_typeck/src/intrinsicck.rs b/compiler/rustc_hir_typeck/src/intrinsicck.rs
index a9c929e76d5..62aa29e673d 100644
--- a/compiler/rustc_hir_typeck/src/intrinsicck.rs
+++ b/compiler/rustc_hir_typeck/src/intrinsicck.rs
@@ -38,7 +38,7 @@ fn unpack_option_like<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn check_transmute(&self, from: Ty<'tcx>, to: Ty<'tcx>, hir_id: HirId) {
+    pub(crate) fn check_transmute(&self, from: Ty<'tcx>, to: Ty<'tcx>, hir_id: HirId) {
         let tcx = self.tcx;
         let dl = &tcx.data_layout;
         let span = tcx.hir().span(hir_id);
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 8ff4c11f24a..8e6484f1e29 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -8,6 +8,7 @@
 #![feature(let_chains)]
 #![feature(never_type)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 #[macro_use]
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index e0c0adac076..2c3cfcf3cbd 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -42,13 +42,13 @@ impl<'a, 'tcx> Deref for ConfirmContext<'a, 'tcx> {
 }
 
 #[derive(Debug)]
-pub struct ConfirmResult<'tcx> {
+pub(crate) struct ConfirmResult<'tcx> {
     pub callee: MethodCallee<'tcx>,
     pub illegal_sized_bound: Option<Span>,
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn confirm_method(
+    pub(crate) fn confirm_method(
         &self,
         span: Span,
         self_expr: &'tcx hir::Expr<'tcx>,
@@ -66,7 +66,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         confirm_cx.confirm(unadjusted_self_ty, pick, segment)
     }
 
-    pub fn confirm_method_for_diagnostic(
+    pub(crate) fn confirm_method_for_diagnostic(
         &self,
         span: Span,
         self_expr: &'tcx hir::Expr<'tcx>,
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs
index d6110ab94c1..39307a29dad 100644
--- a/compiler/rustc_hir_typeck/src/method/mod.rs
+++ b/compiler/rustc_hir_typeck/src/method/mod.rs
@@ -4,7 +4,7 @@
 
 mod confirm;
 mod prelude_edition_lints;
-pub mod probe;
+pub(crate) mod probe;
 mod suggest;
 
 use rustc_errors::{Applicability, Diag, SubdiagMessage};
@@ -24,15 +24,15 @@ use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
 use rustc_trait_selection::traits::{self, NormalizeExt};
 
 use self::probe::{IsSuggestion, ProbeScope};
-pub use self::MethodError::*;
+pub(crate) use self::MethodError::*;
 use crate::FnCtxt;
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     probe::provide(providers);
 }
 
 #[derive(Clone, Copy, Debug)]
-pub struct MethodCallee<'tcx> {
+pub(crate) struct MethodCallee<'tcx> {
     /// Impl method ID, for inherent methods, or trait method ID, otherwise.
     pub def_id: DefId,
     pub args: GenericArgsRef<'tcx>,
@@ -44,7 +44,7 @@ pub struct MethodCallee<'tcx> {
 }
 
 #[derive(Debug)]
-pub enum MethodError<'tcx> {
+pub(crate) enum MethodError<'tcx> {
     // Did not find an applicable method, but we did find various near-misses that may work.
     NoMatch(NoMatchData<'tcx>),
 
@@ -70,7 +70,7 @@ pub enum MethodError<'tcx> {
 // Contains a list of static methods that may apply, a list of unsatisfied trait predicates which
 // could lead to matches if satisfied, and a list of not-in-scope traits which may work.
 #[derive(Debug)]
-pub struct NoMatchData<'tcx> {
+pub(crate) struct NoMatchData<'tcx> {
     pub static_candidates: Vec<CandidateSource>,
     pub unsatisfied_predicates:
         Vec<(ty::Predicate<'tcx>, Option<ty::Predicate<'tcx>>, Option<ObligationCause<'tcx>>)>,
@@ -82,7 +82,7 @@ pub struct NoMatchData<'tcx> {
 // A pared down enum describing just the places from which a method
 // candidate can arise. Used for error reporting only.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum CandidateSource {
+pub(crate) enum CandidateSource {
     Impl(DefId),
     Trait(DefId /* trait id */),
 }
@@ -254,7 +254,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         Ok(result.callee)
     }
 
-    pub fn lookup_method_for_diagnostic(
+    pub(crate) fn lookup_method_for_diagnostic(
         &self,
         self_ty: Ty<'tcx>,
         segment: &hir::PathSegment<'tcx>,
@@ -296,7 +296,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         Ok(pick)
     }
 
-    pub fn lookup_probe_for_diagnostic(
+    pub(crate) fn lookup_probe_for_diagnostic(
         &self,
         method_name: Ident,
         self_ty: Ty<'tcx>,
@@ -569,7 +569,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     /// Finds item with name `item_name` defined in impl/trait `def_id`
     /// and return it, or `None`, if no such item was defined there.
-    pub fn associated_value(&self, def_id: DefId, item_name: Ident) -> Option<ty::AssocItem> {
+    fn associated_value(&self, def_id: DefId, item_name: Ident) -> Option<ty::AssocItem> {
         self.tcx
             .associated_items(def_id)
             .find_by_name_and_namespace(self.tcx, item_name, Namespace::ValueNS, def_id)
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 28f537c87c4..48e33c81b85 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -38,14 +38,14 @@ use rustc_trait_selection::traits::{self, ObligationCause, ObligationCtxt};
 use smallvec::{smallvec, SmallVec};
 
 use self::CandidateKind::*;
-pub use self::PickKind::*;
+pub(crate) use self::PickKind::*;
 use super::{suggest, CandidateSource, MethodError, NoMatchData};
 use crate::FnCtxt;
 
 /// Boolean flag used to indicate if this search is for a suggestion
 /// or not. If true, we can allow ambiguity and so forth.
 #[derive(Clone, Copy, Debug)]
-pub struct IsSuggestion(pub bool);
+pub(crate) struct IsSuggestion(pub bool);
 
 pub(crate) struct ProbeContext<'a, 'tcx> {
     fcx: &'a FnCtxt<'a, 'tcx>,
@@ -134,7 +134,7 @@ enum ProbeResult {
 /// (at most) one of these. Either the receiver has type `T` and we convert it to `&T` (or with
 /// `mut`), or it has type `*mut T` and we convert it to `*const T`.
 #[derive(Debug, PartialEq, Copy, Clone)]
-pub enum AutorefOrPtrAdjustment {
+pub(crate) enum AutorefOrPtrAdjustment {
     /// Receiver has type `T`, add `&` or `&mut` (it `T` is `mut`), and maybe also "unsize" it.
     /// Unsizing is used to convert a `[T; N]` to `[T]`, which only makes sense when autorefing.
     Autoref {
@@ -158,7 +158,7 @@ impl AutorefOrPtrAdjustment {
 }
 
 #[derive(Debug, Clone)]
-pub struct Pick<'tcx> {
+pub(crate) struct Pick<'tcx> {
     pub item: ty::AssocItem,
     pub kind: PickKind<'tcx>,
     pub import_ids: SmallVec<[LocalDefId; 1]>,
@@ -179,7 +179,7 @@ pub struct Pick<'tcx> {
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub enum PickKind<'tcx> {
+pub(crate) enum PickKind<'tcx> {
     InherentImplPick,
     ObjectPick,
     TraitPick,
@@ -189,10 +189,10 @@ pub enum PickKind<'tcx> {
     ),
 }
 
-pub type PickResult<'tcx> = Result<Pick<'tcx>, MethodError<'tcx>>;
+pub(crate) type PickResult<'tcx> = Result<Pick<'tcx>, MethodError<'tcx>>;
 
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
-pub enum Mode {
+pub(crate) enum Mode {
     // An expression of the form `receiver.method_name(...)`.
     // Autoderefs are performed on `receiver`, lookup is done based on the
     // `self` argument of the method, and static methods aren't considered.
@@ -204,7 +204,7 @@ pub enum Mode {
 }
 
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
-pub enum ProbeScope {
+pub(crate) enum ProbeScope {
     // Single candidate coming from pre-resolved delegation method.
     Single(DefId),
 
@@ -507,7 +507,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.method_autoderef_steps = method_autoderef_steps;
 }
 
@@ -1288,7 +1288,7 @@ impl<'tcx> Pick<'tcx> {
     /// Checks whether two picks do not refer to the same trait item for the same `Self` type.
     /// Only useful for comparisons of picks in order to improve diagnostics.
     /// Do not use for type checking.
-    pub fn differs_from(&self, other: &Self) -> bool {
+    pub(crate) fn differs_from(&self, other: &Self) -> bool {
         let Self {
             item:
                 AssocItem {
@@ -1312,7 +1312,7 @@ impl<'tcx> Pick<'tcx> {
     }
 
     /// In case there were unstable name collisions, emit them as a lint.
-    pub fn maybe_emit_unstable_name_collision_hint(
+    pub(crate) fn maybe_emit_unstable_name_collision_hint(
         &self,
         tcx: TyCtxt<'tcx>,
         span: Span,
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 8b8bb29dacd..b78bb8cb98d 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -415,7 +415,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err
     }
 
-    pub fn suggest_use_shadowed_binding_with_method(
+    fn suggest_use_shadowed_binding_with_method(
         &self,
         self_source: SelfSource<'tcx>,
         method_name: Ident,
@@ -4223,19 +4223,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 }
 
 #[derive(Copy, Clone, Debug)]
-pub enum SelfSource<'a> {
+enum SelfSource<'a> {
     QPath(&'a hir::Ty<'a>),
     MethodCall(&'a hir::Expr<'a> /* rcvr */),
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
-pub struct TraitInfo {
+pub(crate) struct TraitInfo {
     pub def_id: DefId,
 }
 
 /// Retrieves all traits in this crate and any dependent crates,
 /// and wraps them into `TraitInfo` for custom sorting.
-pub fn all_traits(tcx: TyCtxt<'_>) -> Vec<TraitInfo> {
+pub(crate) fn all_traits(tcx: TyCtxt<'_>) -> Vec<TraitInfo> {
     tcx.all_traits().map(|def_id| TraitInfo { def_id }).collect()
 }
 
diff --git a/compiler/rustc_hir_typeck/src/op.rs b/compiler/rustc_hir_typeck/src/op.rs
index c54f6cfd099..fb0d30d5b0e 100644
--- a/compiler/rustc_hir_typeck/src/op.rs
+++ b/compiler/rustc_hir_typeck/src/op.rs
@@ -25,7 +25,7 @@ use crate::Expectation;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Checks a `a <op>= b`
-    pub fn check_binop_assign(
+    pub(crate) fn check_binop_assign(
         &self,
         expr: &'tcx hir::Expr<'tcx>,
         op: hir::BinOp,
@@ -84,7 +84,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Checks a potentially overloaded binary operator.
-    pub fn check_binop(
+    pub(crate) fn check_binop(
         &self,
         expr: &'tcx hir::Expr<'tcx>,
         op: hir::BinOp,
@@ -770,7 +770,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn check_user_unop(
+    pub(crate) fn check_user_unop(
         &self,
         ex: &'tcx hir::Expr<'tcx>,
         operand_ty: Ty<'tcx>,
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs
index a8e5e09c8bb..206de455cd5 100644
--- a/compiler/rustc_hir_typeck/src/pat.rs
+++ b/compiler/rustc_hir_typeck/src/pat.rs
@@ -944,7 +944,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn check_dereferenceable(
+    fn check_dereferenceable(
         &self,
         span: Span,
         expected: Ty<'tcx>,
diff --git a/compiler/rustc_hir_typeck/src/place_op.rs b/compiler/rustc_hir_typeck/src/place_op.rs
index ad04b6b8b1d..bb227272584 100644
--- a/compiler/rustc_hir_typeck/src/place_op.rs
+++ b/compiler/rustc_hir_typeck/src/place_op.rs
@@ -246,7 +246,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// always know whether a place needs to be mutable or not in the first pass.
     /// This happens whether there is an implicit mutable reborrow, e.g. when the type
     /// is used as the receiver of a method call.
-    pub fn convert_place_derefs_to_mutable(&self, expr: &hir::Expr<'_>) {
+    pub(crate) fn convert_place_derefs_to_mutable(&self, expr: &hir::Expr<'_>) {
         // Gather up expressions we want to munge.
         let mut exprs = vec![expr];
 
diff --git a/compiler/rustc_hir_typeck/src/rvalue_scopes.rs b/compiler/rustc_hir_typeck/src/rvalue_scopes.rs
index f22a13d292e..fb0fe23be65 100644
--- a/compiler/rustc_hir_typeck/src/rvalue_scopes.rs
+++ b/compiler/rustc_hir_typeck/src/rvalue_scopes.rs
@@ -65,7 +65,7 @@ fn record_rvalue_scope(
     }
 }
 
-pub fn resolve_rvalue_scopes<'a, 'tcx>(
+pub(crate) fn resolve_rvalue_scopes<'a, 'tcx>(
     fcx: &'a FnCtxt<'a, 'tcx>,
     scope_tree: &'a ScopeTree,
     def_id: DefId,
diff --git a/compiler/rustc_hir_typeck/src/typeck_root_ctxt.rs b/compiler/rustc_hir_typeck/src/typeck_root_ctxt.rs
index a43164589b5..e6b8da3e5d6 100644
--- a/compiler/rustc_hir_typeck/src/typeck_root_ctxt.rs
+++ b/compiler/rustc_hir_typeck/src/typeck_root_ctxt.rs
@@ -77,7 +77,7 @@ impl<'tcx> Deref for TypeckRootCtxt<'tcx> {
 }
 
 impl<'tcx> TypeckRootCtxt<'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
+    pub(crate) fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
         let hir_owner = tcx.local_def_id_to_hir_id(def_id).owner;
 
         let infcx = tcx.infer_ctxt().ignoring_regions().with_opaque_type_inference(def_id).build();
@@ -124,7 +124,7 @@ impl<'tcx> TypeckRootCtxt<'tcx> {
         infer_ok.value
     }
 
-    pub fn update_infer_var_info(&self, obligation: &PredicateObligation<'tcx>) {
+    fn update_infer_var_info(&self, obligation: &PredicateObligation<'tcx>) {
         let infer_var_info = &mut self.infer_var_info.borrow_mut();
 
         // (*) binder skipped
diff --git a/compiler/rustc_hir_typeck/src/upvar.rs b/compiler/rustc_hir_typeck/src/upvar.rs
index 55f002291f0..5350affb3bc 100644
--- a/compiler/rustc_hir_typeck/src/upvar.rs
+++ b/compiler/rustc_hir_typeck/src/upvar.rs
@@ -74,7 +74,7 @@ enum PlaceAncestryRelation {
 type InferredCaptureInformation<'tcx> = Vec<(Place<'tcx>, ty::CaptureInfo)>;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn closure_analyze(&self, body: &'tcx hir::Body<'tcx>) {
+    pub(crate) fn closure_analyze(&self, body: &'tcx hir::Body<'tcx>) {
         InferBorrowKindVisitor { fcx: self }.visit_body(body);
 
         // it's our job to process these.
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 0327a3097ec..0853ed9b05b 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -35,7 +35,7 @@ use crate::FnCtxt;
 // resolve_type_vars_in_body, which creates a new TypeTables which
 // doesn't contain any inference types.
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn resolve_type_vars_in_body(
+    pub(crate) fn resolve_type_vars_in_body(
         &self,
         body: &'tcx hir::Body<'tcx>,
     ) -> &'tcx ty::TypeckResults<'tcx> {
diff --git a/compiler/rustc_incremental/src/assert_dep_graph.rs b/compiler/rustc_incremental/src/assert_dep_graph.rs
index b29ba59c9f3..46f30526d2a 100644
--- a/compiler/rustc_incremental/src/assert_dep_graph.rs
+++ b/compiler/rustc_incremental/src/assert_dep_graph.rs
@@ -55,7 +55,7 @@ use {rustc_ast as ast, rustc_graphviz as dot, rustc_hir as hir};
 use crate::errors;
 
 #[allow(missing_docs)]
-pub fn assert_dep_graph(tcx: TyCtxt<'_>) {
+pub(crate) fn assert_dep_graph(tcx: TyCtxt<'_>) {
     tcx.dep_graph.with_ignore(|| {
         if tcx.sess.opts.unstable_opts.dump_dep_graph {
             tcx.dep_graph.with_query(dump_graph);
@@ -261,7 +261,7 @@ fn dump_graph(query: &DepGraphQuery) {
 }
 
 #[allow(missing_docs)]
-pub struct GraphvizDepGraph(FxIndexSet<DepKind>, Vec<(DepKind, DepKind)>);
+struct GraphvizDepGraph(FxIndexSet<DepKind>, Vec<(DepKind, DepKind)>);
 
 impl<'a> dot::GraphWalk<'a> for GraphvizDepGraph {
     type Node = DepKind;
diff --git a/compiler/rustc_incremental/src/errors.rs b/compiler/rustc_incremental/src/errors.rs
index c6f8b99bcd6..cb21f975878 100644
--- a/compiler/rustc_incremental/src/errors.rs
+++ b/compiler/rustc_incremental/src/errors.rs
@@ -6,7 +6,7 @@ use rustc_span::{Span, Symbol};
 
 #[derive(Diagnostic)]
 #[diag(incremental_unrecognized_depnode)]
-pub struct UnrecognizedDepNode {
+pub(crate) struct UnrecognizedDepNode {
     #[primary_span]
     pub span: Span,
     pub name: Symbol,
@@ -14,28 +14,28 @@ pub struct UnrecognizedDepNode {
 
 #[derive(Diagnostic)]
 #[diag(incremental_missing_depnode)]
-pub struct MissingDepNode {
+pub(crate) struct MissingDepNode {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_missing_if_this_changed)]
-pub struct MissingIfThisChanged {
+pub(crate) struct MissingIfThisChanged {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_ok)]
-pub struct Ok {
+pub(crate) struct Ok {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_no_path)]
-pub struct NoPath {
+pub(crate) struct NoPath {
     #[primary_span]
     pub span: Span,
     pub target: Symbol,
@@ -44,7 +44,7 @@ pub struct NoPath {
 
 #[derive(Diagnostic)]
 #[diag(incremental_assertion_auto)]
-pub struct AssertionAuto<'a> {
+pub(crate) struct AssertionAuto<'a> {
     #[primary_span]
     pub span: Span,
     pub name: &'a str,
@@ -53,7 +53,7 @@ pub struct AssertionAuto<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_undefined_clean_dirty_assertions_item)]
-pub struct UndefinedCleanDirtyItem {
+pub(crate) struct UndefinedCleanDirtyItem {
     #[primary_span]
     pub span: Span,
     pub kind: String,
@@ -61,7 +61,7 @@ pub struct UndefinedCleanDirtyItem {
 
 #[derive(Diagnostic)]
 #[diag(incremental_undefined_clean_dirty_assertions)]
-pub struct UndefinedCleanDirty {
+pub(crate) struct UndefinedCleanDirty {
     #[primary_span]
     pub span: Span,
     pub kind: String,
@@ -69,7 +69,7 @@ pub struct UndefinedCleanDirty {
 
 #[derive(Diagnostic)]
 #[diag(incremental_repeated_depnode_label)]
-pub struct RepeatedDepNodeLabel<'a> {
+pub(crate) struct RepeatedDepNodeLabel<'a> {
     #[primary_span]
     pub span: Span,
     pub label: &'a str,
@@ -77,7 +77,7 @@ pub struct RepeatedDepNodeLabel<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_unrecognized_depnode_label)]
-pub struct UnrecognizedDepNodeLabel<'a> {
+pub(crate) struct UnrecognizedDepNodeLabel<'a> {
     #[primary_span]
     pub span: Span,
     pub label: &'a str,
@@ -85,7 +85,7 @@ pub struct UnrecognizedDepNodeLabel<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_not_dirty)]
-pub struct NotDirty<'a> {
+pub(crate) struct NotDirty<'a> {
     #[primary_span]
     pub span: Span,
     pub dep_node_str: &'a str,
@@ -93,7 +93,7 @@ pub struct NotDirty<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_not_clean)]
-pub struct NotClean<'a> {
+pub(crate) struct NotClean<'a> {
     #[primary_span]
     pub span: Span,
     pub dep_node_str: &'a str,
@@ -101,7 +101,7 @@ pub struct NotClean<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_not_loaded)]
-pub struct NotLoaded<'a> {
+pub(crate) struct NotLoaded<'a> {
     #[primary_span]
     pub span: Span,
     pub dep_node_str: &'a str,
@@ -109,7 +109,7 @@ pub struct NotLoaded<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_unknown_item)]
-pub struct UnknownItem {
+pub(crate) struct UnknownItem {
     #[primary_span]
     pub span: Span,
     pub name: Symbol,
@@ -117,14 +117,14 @@ pub struct UnknownItem {
 
 #[derive(Diagnostic)]
 #[diag(incremental_no_cfg)]
-pub struct NoCfg {
+pub(crate) struct NoCfg {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_associated_value_expected_for)]
-pub struct AssociatedValueExpectedFor {
+pub(crate) struct AssociatedValueExpectedFor {
     #[primary_span]
     pub span: Span,
     pub ident: Ident,
@@ -132,21 +132,21 @@ pub struct AssociatedValueExpectedFor {
 
 #[derive(Diagnostic)]
 #[diag(incremental_associated_value_expected)]
-pub struct AssociatedValueExpected {
+pub(crate) struct AssociatedValueExpected {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_unchecked_clean)]
-pub struct UncheckedClean {
+pub(crate) struct UncheckedClean {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_delete_old)]
-pub struct DeleteOld<'a> {
+pub(crate) struct DeleteOld<'a> {
     pub name: &'a str,
     pub path: PathBuf,
     pub err: std::io::Error,
@@ -154,7 +154,7 @@ pub struct DeleteOld<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_create_new)]
-pub struct CreateNew<'a> {
+pub(crate) struct CreateNew<'a> {
     pub name: &'a str,
     pub path: PathBuf,
     pub err: std::io::Error,
@@ -162,7 +162,7 @@ pub struct CreateNew<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_write_new)]
-pub struct WriteNew<'a> {
+pub(crate) struct WriteNew<'a> {
     pub name: &'a str,
     pub path: PathBuf,
     pub err: std::io::Error,
@@ -170,14 +170,14 @@ pub struct WriteNew<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_canonicalize_path)]
-pub struct CanonicalizePath {
+pub(crate) struct CanonicalizePath {
     pub path: PathBuf,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_create_incr_comp_dir)]
-pub struct CreateIncrCompDir<'a> {
+pub(crate) struct CreateIncrCompDir<'a> {
     pub tag: &'a str,
     pub path: &'a Path,
     pub err: std::io::Error,
@@ -185,7 +185,7 @@ pub struct CreateIncrCompDir<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_create_lock)]
-pub struct CreateLock<'a> {
+pub(crate) struct CreateLock<'a> {
     pub lock_err: std::io::Error,
     pub session_dir: &'a Path,
     #[note(incremental_lock_unsupported)]
@@ -197,84 +197,84 @@ pub struct CreateLock<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_delete_lock)]
-pub struct DeleteLock<'a> {
+pub(crate) struct DeleteLock<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_hard_link_failed)]
-pub struct HardLinkFailed<'a> {
+pub(crate) struct HardLinkFailed<'a> {
     pub path: &'a Path,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_delete_partial)]
-pub struct DeletePartial<'a> {
+pub(crate) struct DeletePartial<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_delete_full)]
-pub struct DeleteFull<'a> {
+pub(crate) struct DeleteFull<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_finalize)]
-pub struct Finalize<'a> {
+pub(crate) struct Finalize<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_invalid_gc_failed)]
-pub struct InvalidGcFailed<'a> {
+pub(crate) struct InvalidGcFailed<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_finalized_gc_failed)]
-pub struct FinalizedGcFailed<'a> {
+pub(crate) struct FinalizedGcFailed<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_session_gc_failed)]
-pub struct SessionGcFailed<'a> {
+pub(crate) struct SessionGcFailed<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_assert_not_loaded)]
-pub struct AssertNotLoaded;
+pub(crate) struct AssertNotLoaded;
 
 #[derive(Diagnostic)]
 #[diag(incremental_assert_loaded)]
-pub struct AssertLoaded;
+pub(crate) struct AssertLoaded;
 
 #[derive(Diagnostic)]
 #[diag(incremental_delete_incompatible)]
-pub struct DeleteIncompatible {
+pub(crate) struct DeleteIncompatible {
     pub path: PathBuf,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_load_dep_graph)]
-pub struct LoadDepGraph {
+pub(crate) struct LoadDepGraph {
     pub path: PathBuf,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_move_dep_graph)]
-pub struct MoveDepGraph<'a> {
+pub(crate) struct MoveDepGraph<'a> {
     pub from: &'a Path,
     pub to: &'a Path,
     pub err: std::io::Error,
@@ -282,14 +282,14 @@ pub struct MoveDepGraph<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_create_dep_graph)]
-pub struct CreateDepGraph<'a> {
+pub(crate) struct CreateDepGraph<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_copy_workproduct_to_cache)]
-pub struct CopyWorkProductToCache<'a> {
+pub(crate) struct CopyWorkProductToCache<'a> {
     pub from: &'a Path,
     pub to: &'a Path,
     pub err: std::io::Error,
@@ -297,13 +297,13 @@ pub struct CopyWorkProductToCache<'a> {
 
 #[derive(Diagnostic)]
 #[diag(incremental_delete_workproduct)]
-pub struct DeleteWorkProduct<'a> {
+pub(crate) struct DeleteWorkProduct<'a> {
     pub path: &'a Path,
     pub err: std::io::Error,
 }
 
 #[derive(Diagnostic)]
 #[diag(incremental_corrupt_file)]
-pub struct CorruptFile<'a> {
+pub(crate) struct CorruptFile<'a> {
     pub path: &'a Path,
 }
diff --git a/compiler/rustc_incremental/src/lib.rs b/compiler/rustc_incremental/src/lib.rs
index fcdcb08eed6..c79d108183c 100644
--- a/compiler/rustc_incremental/src/lib.rs
+++ b/compiler/rustc_incremental/src/lib.rs
@@ -6,6 +6,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod assert_dep_graph;
diff --git a/compiler/rustc_incremental/src/persist/data.rs b/compiler/rustc_incremental/src/persist/data.rs
index 81e5410978d..d962dc866f4 100644
--- a/compiler/rustc_incremental/src/persist/data.rs
+++ b/compiler/rustc_incremental/src/persist/data.rs
@@ -4,7 +4,7 @@ use rustc_macros::{Decodable, Encodable};
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 
 #[derive(Debug, Encodable, Decodable)]
-pub struct SerializedWorkProduct {
+pub(crate) struct SerializedWorkProduct {
     /// node that produced the work-product
     pub id: WorkProductId,
 
diff --git a/compiler/rustc_incremental/src/persist/dirty_clean.rs b/compiler/rustc_incremental/src/persist/dirty_clean.rs
index 1e02324f404..88cb82f0f37 100644
--- a/compiler/rustc_incremental/src/persist/dirty_clean.rs
+++ b/compiler/rustc_incremental/src/persist/dirty_clean.rs
@@ -133,7 +133,7 @@ struct Assertion {
     loaded_from_disk: Labels,
 }
 
-pub fn check_dirty_clean_annotations(tcx: TyCtxt<'_>) {
+pub(crate) fn check_dirty_clean_annotations(tcx: TyCtxt<'_>) {
     if !tcx.sess.opts.unstable_opts.query_dep_graph {
         return;
     }
@@ -174,7 +174,7 @@ pub fn check_dirty_clean_annotations(tcx: TyCtxt<'_>) {
     })
 }
 
-pub struct DirtyCleanVisitor<'tcx> {
+struct DirtyCleanVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
     checked_attrs: FxHashSet<ast::AttrId>,
 }
@@ -429,7 +429,7 @@ fn expect_associated_value(tcx: TyCtxt<'_>, item: &NestedMetaItem) -> Symbol {
 /// A visitor that collects all `#[rustc_clean]` attributes from
 /// the HIR. It is used to verify that we really ran checks for all annotated
 /// nodes.
-pub struct FindAllAttrs<'tcx> {
+struct FindAllAttrs<'tcx> {
     tcx: TyCtxt<'tcx>,
     found_attrs: Vec<&'tcx Attribute>,
 }
diff --git a/compiler/rustc_incremental/src/persist/file_format.rs b/compiler/rustc_incremental/src/persist/file_format.rs
index 174414d0c85..f834c48cbf8 100644
--- a/compiler/rustc_incremental/src/persist/file_format.rs
+++ b/compiler/rustc_incremental/src/persist/file_format.rs
@@ -89,7 +89,7 @@ where
 ///   incompatible version of the compiler.
 /// - Returns `Err(..)` if some kind of IO error occurred while reading the
 ///   file.
-pub fn read_file(
+pub(crate) fn read_file(
     path: &Path,
     report_incremental_info: bool,
     is_nightly_build: bool,
diff --git a/compiler/rustc_incremental/src/persist/fs.rs b/compiler/rustc_incremental/src/persist/fs.rs
index 0e87bc1e692..feb25a9a89d 100644
--- a/compiler/rustc_incremental/src/persist/fs.rs
+++ b/compiler/rustc_incremental/src/persist/fs.rs
@@ -157,7 +157,7 @@ pub(crate) fn work_products_path(sess: &Session) -> PathBuf {
 }
 
 /// Returns the path to a session's query cache.
-pub fn query_cache_path(sess: &Session) -> PathBuf {
+pub(crate) fn query_cache_path(sess: &Session) -> PathBuf {
     in_incr_comp_dir_sess(sess, QUERY_CACHE_FILENAME)
 }
 
diff --git a/compiler/rustc_index/src/lib.rs b/compiler/rustc_index/src/lib.rs
index b9d2a43206b..eb47ac3c68e 100644
--- a/compiler/rustc_index/src/lib.rs
+++ b/compiler/rustc_index/src/lib.rs
@@ -3,6 +3,7 @@
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", feature(extend_one, new_uninit, step_trait, test))]
 #![cfg_attr(feature = "nightly", feature(new_zeroed_alloc))]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 pub mod bit_set;
diff --git a/compiler/rustc_infer/src/errors/mod.rs b/compiler/rustc_infer/src/errors/mod.rs
index 1a5c0137219..76ea9c3433d 100644
--- a/compiler/rustc_infer/src/errors/mod.rs
+++ b/compiler/rustc_infer/src/errors/mod.rs
@@ -3,7 +3,7 @@ use rustc_span::Span;
 
 #[derive(Diagnostic)]
 #[diag(infer_opaque_hidden_type)]
-pub struct OpaqueHiddenTypeDiag {
+pub(crate) struct OpaqueHiddenTypeDiag {
     #[primary_span]
     #[label]
     pub span: Span,
diff --git a/compiler/rustc_infer/src/infer/free_regions.rs b/compiler/rustc_infer/src/infer/free_regions.rs
index 0dde3082d48..9a5674369da 100644
--- a/compiler/rustc_infer/src/infer/free_regions.rs
+++ b/compiler/rustc_infer/src/infer/free_regions.rs
@@ -18,11 +18,11 @@ pub(crate) struct RegionRelations<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> RegionRelations<'a, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, free_regions: &'a FreeRegionMap<'tcx>) -> Self {
+    pub(crate) fn new(tcx: TyCtxt<'tcx>, free_regions: &'a FreeRegionMap<'tcx>) -> Self {
         Self { tcx, free_regions }
     }
 
-    pub fn lub_param_regions(&self, r_a: Region<'tcx>, r_b: Region<'tcx>) -> Region<'tcx> {
+    pub(crate) fn lub_param_regions(&self, r_a: Region<'tcx>, r_b: Region<'tcx>) -> Region<'tcx> {
         self.free_regions.lub_param_regions(self.tcx, r_a, r_b)
     }
 }
@@ -80,7 +80,7 @@ impl<'tcx> FreeRegionMap<'tcx> {
     /// cases, this is more conservative than necessary, in order to
     /// avoid making arbitrary choices. See
     /// `TransitiveRelation::postdom_upper_bound` for more details.
-    pub fn lub_param_regions(
+    pub(crate) fn lub_param_regions(
         &self,
         tcx: TyCtxt<'tcx>,
         r_a: Region<'tcx>,
diff --git a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
index c2c0c7a41fe..e5533213400 100644
--- a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
+++ b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
@@ -43,7 +43,7 @@ pub(crate) fn resolve<'tcx>(
 /// Contains the result of lexical region resolution. Offers methods
 /// to lookup up the final value of a region variable.
 #[derive(Clone)]
-pub struct LexicalRegionResolutions<'tcx> {
+pub(crate) struct LexicalRegionResolutions<'tcx> {
     pub(crate) values: IndexVec<RegionVid, VarValue<'tcx>>,
 }
 
diff --git a/compiler/rustc_infer/src/infer/relate/generalize.rs b/compiler/rustc_infer/src/infer/relate/generalize.rs
index 542104fa10b..6fa10a95313 100644
--- a/compiler/rustc_infer/src/infer/relate/generalize.rs
+++ b/compiler/rustc_infer/src/infer/relate/generalize.rs
@@ -705,7 +705,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for Generalizer<'_, 'tcx> {
 /// not only the generalized type, but also a bool flag
 /// indicating whether further WF checks are needed.
 #[derive(Debug)]
-pub struct Generalization<T> {
+struct Generalization<T> {
     /// When generalizing `<?0 as Trait>::Assoc` or
     /// `<T as Bar<<?0 as Foo>::Assoc>>::Assoc`
     /// for `?0` generalization returns an inference
diff --git a/compiler/rustc_infer/src/infer/relate/lattice.rs b/compiler/rustc_infer/src/infer/relate/lattice.rs
index f555fedbb5b..1eafbb9acb3 100644
--- a/compiler/rustc_infer/src/infer/relate/lattice.rs
+++ b/compiler/rustc_infer/src/infer/relate/lattice.rs
@@ -29,7 +29,7 @@ use crate::traits::ObligationCause;
 ///
 /// GLB moves "down" the lattice (to smaller values); LUB moves
 /// "up" the lattice (to bigger values).
-pub trait LatticeDir<'f, 'tcx>: PredicateEmittingRelation<InferCtxt<'tcx>> {
+pub(crate) trait LatticeDir<'f, 'tcx>: PredicateEmittingRelation<InferCtxt<'tcx>> {
     fn infcx(&self) -> &'f InferCtxt<'tcx>;
 
     fn cause(&self) -> &ObligationCause<'tcx>;
diff --git a/compiler/rustc_infer/src/infer/snapshot/fudge.rs b/compiler/rustc_infer/src/infer/snapshot/fudge.rs
index bc954054ea2..fdf55447f79 100644
--- a/compiler/rustc_infer/src/infer/snapshot/fudge.rs
+++ b/compiler/rustc_infer/src/infer/snapshot/fudge.rs
@@ -170,7 +170,7 @@ impl<'tcx> InferCtxt<'tcx> {
     }
 }
 
-pub struct InferenceFudger<'a, 'tcx> {
+struct InferenceFudger<'a, 'tcx> {
     infcx: &'a InferCtxt<'tcx>,
     type_vars: (Range<TyVid>, Vec<TypeVariableOrigin>),
     int_vars: Range<IntVid>,
diff --git a/compiler/rustc_infer/src/infer/snapshot/undo_log.rs b/compiler/rustc_infer/src/infer/snapshot/undo_log.rs
index 50a0d3bf214..366af913ddc 100644
--- a/compiler/rustc_infer/src/infer/snapshot/undo_log.rs
+++ b/compiler/rustc_infer/src/infer/snapshot/undo_log.rs
@@ -158,7 +158,7 @@ impl<'tcx> InferCtxtInner<'tcx> {
 }
 
 impl<'tcx> InferCtxtUndoLogs<'tcx> {
-    pub fn start_snapshot(&mut self) -> Snapshot<'tcx> {
+    pub(crate) fn start_snapshot(&mut self) -> Snapshot<'tcx> {
         self.num_open_snapshots += 1;
         Snapshot { undo_len: self.logs.len(), _marker: PhantomData }
     }
diff --git a/compiler/rustc_infer/src/lib.rs b/compiler/rustc_infer/src/lib.rs
index 30dc666128c..94aa2ddd92f 100644
--- a/compiler/rustc_infer/src/lib.rs
+++ b/compiler/rustc_infer/src/lib.rs
@@ -28,6 +28,7 @@
 #![feature(let_chains)]
 #![feature(rustdoc_internals)]
 #![recursion_limit = "512"] // For rustdoc
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 #[macro_use]
diff --git a/compiler/rustc_infer/src/traits/mod.rs b/compiler/rustc_infer/src/traits/mod.rs
index 4f34c139545..3a05b576a97 100644
--- a/compiler/rustc_infer/src/traits/mod.rs
+++ b/compiler/rustc_infer/src/traits/mod.rs
@@ -22,7 +22,7 @@ pub use self::engine::{FromSolverError, ScrubbedTraitError, TraitEngine};
 pub(crate) use self::project::UndoLog;
 pub use self::project::{
     MismatchedProjectionTypes, Normalized, NormalizedTerm, ProjectionCache, ProjectionCacheEntry,
-    ProjectionCacheKey, ProjectionCacheStorage, Reveal,
+    ProjectionCacheKey, ProjectionCacheStorage,
 };
 pub use self::ImplSource::*;
 pub use self::SelectionError::*;
diff --git a/compiler/rustc_infer/src/traits/project.rs b/compiler/rustc_infer/src/traits/project.rs
index 9ed557ec40b..3d4ec9e51db 100644
--- a/compiler/rustc_infer/src/traits/project.rs
+++ b/compiler/rustc_infer/src/traits/project.rs
@@ -2,7 +2,7 @@
 
 use rustc_data_structures::snapshot_map::{self, SnapshotMapRef, SnapshotMapStorage};
 use rustc_data_structures::undo_log::Rollback;
-pub use rustc_middle::traits::{EvaluationResult, Reveal};
+use rustc_middle::traits::EvaluationResult;
 use rustc_middle::ty;
 
 use super::PredicateObligation;
diff --git a/compiler/rustc_interface/src/lib.rs b/compiler/rustc_interface/src/lib.rs
index 3492df69b8d..3b6c2acaf30 100644
--- a/compiler/rustc_interface/src/lib.rs
+++ b/compiler/rustc_interface/src/lib.rs
@@ -2,6 +2,7 @@
 #![feature(decl_macro)]
 #![feature(let_chains)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod callbacks;
diff --git a/compiler/rustc_lexer/src/lib.rs b/compiler/rustc_lexer/src/lib.rs
index 2116ba6c079..31fdd2d7cec 100644
--- a/compiler/rustc_lexer/src/lib.rs
+++ b/compiler/rustc_lexer/src/lib.rs
@@ -23,6 +23,7 @@
 // We want to be able to build this crate with a stable compiler,
 // so no `#![feature]` attributes should be added.
 #![deny(unstable_features)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod cursor;
diff --git a/compiler/rustc_lint/src/early.rs b/compiler/rustc_lint/src/early.rs
index 6fb0a624644..0ee9dda1fef 100644
--- a/compiler/rustc_lint/src/early.rs
+++ b/compiler/rustc_lint/src/early.rs
@@ -413,7 +413,7 @@ pub fn check_ast_node<'a>(
     }
 }
 
-pub fn check_ast_node_inner<'a, T: EarlyLintPass>(
+fn check_ast_node_inner<'a, T: EarlyLintPass>(
     sess: &Session,
     check_node: impl EarlyCheckNode<'a>,
     context: EarlyContext<'_>,
diff --git a/compiler/rustc_lint/src/errors.rs b/compiler/rustc_lint/src/errors.rs
index 85ee18aba8f..d109a5c9030 100644
--- a/compiler/rustc_lint/src/errors.rs
+++ b/compiler/rustc_lint/src/errors.rs
@@ -8,7 +8,7 @@ use crate::fluent_generated as fluent;
 
 #[derive(Diagnostic)]
 #[diag(lint_overruled_attribute, code = E0453)]
-pub struct OverruledAttribute<'a> {
+pub(crate) struct OverruledAttribute<'a> {
     #[primary_span]
     pub span: Span,
     #[label]
@@ -19,7 +19,7 @@ pub struct OverruledAttribute<'a> {
     pub sub: OverruledAttributeSub,
 }
 
-pub enum OverruledAttributeSub {
+pub(crate) enum OverruledAttributeSub {
     DefaultSource { id: String },
     NodeSource { span: Span, reason: Option<Symbol> },
     CommandLineSource,
@@ -52,7 +52,7 @@ impl Subdiagnostic for OverruledAttributeSub {
 
 #[derive(Diagnostic)]
 #[diag(lint_malformed_attribute, code = E0452)]
-pub struct MalformedAttribute {
+pub(crate) struct MalformedAttribute {
     #[primary_span]
     pub span: Span,
     #[subdiagnostic]
@@ -60,7 +60,7 @@ pub struct MalformedAttribute {
 }
 
 #[derive(Subdiagnostic)]
-pub enum MalformedAttributeSub {
+pub(crate) enum MalformedAttributeSub {
     #[label(lint_bad_attribute_argument)]
     BadAttributeArgument(#[primary_span] Span),
     #[label(lint_reason_must_be_string_literal)]
@@ -71,7 +71,7 @@ pub enum MalformedAttributeSub {
 
 #[derive(Diagnostic)]
 #[diag(lint_unknown_tool_in_scoped_lint, code = E0710)]
-pub struct UnknownToolInScopedLint {
+pub(crate) struct UnknownToolInScopedLint {
     #[primary_span]
     pub span: Option<Span>,
     pub tool_name: Symbol,
@@ -82,7 +82,7 @@ pub struct UnknownToolInScopedLint {
 
 #[derive(Diagnostic)]
 #[diag(lint_builtin_ellipsis_inclusive_range_patterns, code = E0783)]
-pub struct BuiltinEllipsisInclusiveRangePatterns {
+pub(crate) struct BuiltinEllipsisInclusiveRangePatterns {
     #[primary_span]
     pub span: Span,
     #[suggestion(style = "short", code = "{replace}", applicability = "machine-applicable")]
@@ -92,20 +92,20 @@ pub struct BuiltinEllipsisInclusiveRangePatterns {
 
 #[derive(Subdiagnostic)]
 #[note(lint_requested_level)]
-pub struct RequestedLevel<'a> {
+pub(crate) struct RequestedLevel<'a> {
     pub level: Level,
     pub lint_name: &'a str,
 }
 
 #[derive(Diagnostic)]
 #[diag(lint_unsupported_group, code = E0602)]
-pub struct UnsupportedGroup {
+pub(crate) struct UnsupportedGroup {
     pub lint_group: String,
 }
 
 #[derive(Diagnostic)]
 #[diag(lint_check_name_unknown_tool, code = E0602)]
-pub struct CheckNameUnknownTool<'a> {
+pub(crate) struct CheckNameUnknownTool<'a> {
     pub tool_name: Symbol,
     #[subdiagnostic]
     pub sub: RequestedLevel<'a>,
diff --git a/compiler/rustc_lint/src/late.rs b/compiler/rustc_lint/src/late.rs
index 638b623510e..cb369d99a84 100644
--- a/compiler/rustc_lint/src/late.rs
+++ b/compiler/rustc_lint/src/late.rs
@@ -47,7 +47,7 @@ macro_rules! lint_callback { ($cx:expr, $f:ident, $($args:expr),*) => ({
 
 /// Implements the AST traversal for late lint passes. `T` provides the
 /// `check_*` methods.
-pub struct LateContextAndPass<'tcx, T: LateLintPass<'tcx>> {
+struct LateContextAndPass<'tcx, T: LateLintPass<'tcx>> {
     context: LateContext<'tcx>,
     pass: T,
 }
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 91d4f95df80..07ac63ec96c 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -1103,7 +1103,7 @@ pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { shallow_lint_levels_on, lint_expectations, ..*providers };
 }
 
-pub fn parse_lint_and_tool_name(lint_name: &str) -> (Option<Symbol>, &str) {
+pub(crate) fn parse_lint_and_tool_name(lint_name: &str) -> (Option<Symbol>, &str) {
     match lint_name.split_once("::") {
         Some((tool_name, lint_name)) => {
             let tool_name = Symbol::intern(tool_name);
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index a6e7d288f08..c5a5c5b30af 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -39,6 +39,7 @@
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 #![feature(trait_upcasting)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod async_closures;
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index c12c5427997..c6bcb1f3e83 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -26,7 +26,7 @@ use crate::{fluent_generated as fluent, LateContext};
 // array_into_iter.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_shadowed_into_iter)]
-pub struct ShadowedIntoIterDiag {
+pub(crate) struct ShadowedIntoIterDiag {
     pub target: &'static str,
     pub edition: &'static str,
     #[suggestion(lint_use_iter_suggestion, code = "iter", applicability = "machine-applicable")]
@@ -36,7 +36,7 @@ pub struct ShadowedIntoIterDiag {
 }
 
 #[derive(Subdiagnostic)]
-pub enum ShadowedIntoIterDiagSub {
+pub(crate) enum ShadowedIntoIterDiagSub {
     #[suggestion(lint_remove_into_iter_suggestion, code = "", applicability = "maybe-incorrect")]
     RemoveIntoIter {
         #[primary_span]
@@ -57,7 +57,7 @@ pub enum ShadowedIntoIterDiagSub {
 // builtin.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_while_true)]
-pub struct BuiltinWhileTrue {
+pub(crate) struct BuiltinWhileTrue {
     #[suggestion(style = "short", code = "{replace}", applicability = "machine-applicable")]
     pub suggestion: Span,
     pub replace: String,
@@ -65,7 +65,7 @@ pub struct BuiltinWhileTrue {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_non_shorthand_field_patterns)]
-pub struct BuiltinNonShorthandFieldPatterns {
+pub(crate) struct BuiltinNonShorthandFieldPatterns {
     pub ident: Ident,
     #[suggestion(code = "{prefix}{ident}", applicability = "machine-applicable")]
     pub suggestion: Span,
@@ -73,7 +73,7 @@ pub struct BuiltinNonShorthandFieldPatterns {
 }
 
 #[derive(LintDiagnostic)]
-pub enum BuiltinUnsafe {
+pub(crate) enum BuiltinUnsafe {
     #[diag(lint_builtin_allow_internal_unsafe)]
     AllowInternalUnsafe,
     #[diag(lint_builtin_unsafe_block)]
@@ -121,16 +121,16 @@ pub enum BuiltinUnsafe {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_missing_doc)]
-pub struct BuiltinMissingDoc<'a> {
+pub(crate) struct BuiltinMissingDoc<'a> {
     pub article: &'a str,
     pub desc: &'a str,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_missing_copy_impl)]
-pub struct BuiltinMissingCopyImpl;
+pub(crate) struct BuiltinMissingCopyImpl;
 
-pub struct BuiltinMissingDebugImpl<'a> {
+pub(crate) struct BuiltinMissingDebugImpl<'a> {
     pub tcx: TyCtxt<'a>,
     pub def_id: DefId,
 }
@@ -145,7 +145,7 @@ impl<'a> LintDiagnostic<'a, ()> for BuiltinMissingDebugImpl<'_> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_anonymous_params)]
-pub struct BuiltinAnonymousParams<'a> {
+pub(crate) struct BuiltinAnonymousParams<'a> {
     #[suggestion(code = "_: {ty_snip}")]
     pub suggestion: (Span, Applicability),
     pub ty_snip: &'a str,
@@ -154,7 +154,7 @@ pub struct BuiltinAnonymousParams<'a> {
 // FIXME(davidtwco) translatable deprecated attr
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_deprecated_attr_link)]
-pub struct BuiltinDeprecatedAttrLink<'a> {
+pub(crate) struct BuiltinDeprecatedAttrLink<'a> {
     pub name: Symbol,
     pub reason: &'a str,
     pub link: &'a str,
@@ -163,7 +163,7 @@ pub struct BuiltinDeprecatedAttrLink<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum BuiltinDeprecatedAttrLinkSuggestion<'a> {
+pub(crate) enum BuiltinDeprecatedAttrLinkSuggestion<'a> {
     #[suggestion(lint_msg_suggestion, code = "", applicability = "machine-applicable")]
     Msg {
         #[primary_span]
@@ -179,7 +179,7 @@ pub enum BuiltinDeprecatedAttrLinkSuggestion<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_deprecated_attr_used)]
-pub struct BuiltinDeprecatedAttrUsed {
+pub(crate) struct BuiltinDeprecatedAttrUsed {
     pub name: String,
     #[suggestion(
         lint_builtin_deprecated_attr_default_suggestion,
@@ -192,7 +192,7 @@ pub struct BuiltinDeprecatedAttrUsed {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_unused_doc_comment)]
-pub struct BuiltinUnusedDocComment<'a> {
+pub(crate) struct BuiltinUnusedDocComment<'a> {
     pub kind: &'a str,
     #[label]
     pub label: Span,
@@ -201,7 +201,7 @@ pub struct BuiltinUnusedDocComment<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum BuiltinUnusedDocCommentSub {
+pub(crate) enum BuiltinUnusedDocCommentSub {
     #[help(lint_plain_help)]
     PlainHelp,
     #[help(lint_block_help)]
@@ -210,7 +210,7 @@ pub enum BuiltinUnusedDocCommentSub {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_no_mangle_generic)]
-pub struct BuiltinNoMangleGeneric {
+pub(crate) struct BuiltinNoMangleGeneric {
     // Use of `#[no_mangle]` suggests FFI intent; correct
     // fix may be to monomorphize source by hand
     #[suggestion(style = "short", code = "", applicability = "maybe-incorrect")]
@@ -219,21 +219,21 @@ pub struct BuiltinNoMangleGeneric {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_const_no_mangle)]
-pub struct BuiltinConstNoMangle {
+pub(crate) struct BuiltinConstNoMangle {
     #[suggestion(code = "pub static", applicability = "machine-applicable")]
     pub suggestion: Span,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_mutable_transmutes)]
-pub struct BuiltinMutablesTransmutes;
+pub(crate) struct BuiltinMutablesTransmutes;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_unstable_features)]
-pub struct BuiltinUnstableFeatures;
+pub(crate) struct BuiltinUnstableFeatures;
 
 // lint_ungated_async_fn_track_caller
-pub struct BuiltinUngatedAsyncFnTrackCaller<'a> {
+pub(crate) struct BuiltinUngatedAsyncFnTrackCaller<'a> {
     pub label: Span,
     pub session: &'a Session,
 }
@@ -252,7 +252,7 @@ impl<'a> LintDiagnostic<'a, ()> for BuiltinUngatedAsyncFnTrackCaller<'_> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_unreachable_pub)]
-pub struct BuiltinUnreachablePub<'a> {
+pub(crate) struct BuiltinUnreachablePub<'a> {
     pub what: &'a str,
     #[suggestion(code = "pub(crate)")]
     pub suggestion: (Span, Applicability),
@@ -262,12 +262,12 @@ pub struct BuiltinUnreachablePub<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_macro_expr_fragment_specifier_2024_migration)]
-pub struct MacroExprFragment2024 {
+pub(crate) struct MacroExprFragment2024 {
     #[suggestion(code = "expr_2021", applicability = "machine-applicable")]
     pub suggestion: Span,
 }
 
-pub struct BuiltinTypeAliasBounds<'a, 'hir> {
+pub(crate) struct BuiltinTypeAliasBounds<'a, 'hir> {
     pub in_where_clause: bool,
     pub label: Span,
     pub enable_feat_help: bool,
@@ -338,13 +338,13 @@ impl<'a> LintDiagnostic<'a, ()> for BuiltinTypeAliasBounds<'_, '_> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_trivial_bounds)]
-pub struct BuiltinTrivialBounds<'a> {
+pub(crate) struct BuiltinTrivialBounds<'a> {
     pub predicate_kind_name: &'a str,
     pub predicate: Clause<'a>,
 }
 
 #[derive(LintDiagnostic)]
-pub enum BuiltinEllipsisInclusiveRangePatternsLint {
+pub(crate) enum BuiltinEllipsisInclusiveRangePatternsLint {
     #[diag(lint_builtin_ellipsis_inclusive_range_patterns)]
     Parenthesise {
         #[suggestion(code = "{replace}", applicability = "machine-applicable")]
@@ -360,7 +360,7 @@ pub enum BuiltinEllipsisInclusiveRangePatternsLint {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_keyword_idents)]
-pub struct BuiltinKeywordIdents {
+pub(crate) struct BuiltinKeywordIdents {
     pub kw: Ident,
     pub next: Edition,
     #[suggestion(code = "r#{kw}", applicability = "machine-applicable")]
@@ -369,7 +369,7 @@ pub struct BuiltinKeywordIdents {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_explicit_outlives)]
-pub struct BuiltinExplicitOutlives {
+pub(crate) struct BuiltinExplicitOutlives {
     pub count: usize,
     #[subdiagnostic]
     pub suggestion: BuiltinExplicitOutlivesSuggestion,
@@ -377,7 +377,7 @@ pub struct BuiltinExplicitOutlives {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion)]
-pub struct BuiltinExplicitOutlivesSuggestion {
+pub(crate) struct BuiltinExplicitOutlivesSuggestion {
     #[suggestion_part(code = "")]
     pub spans: Vec<Span>,
     #[applicability]
@@ -386,7 +386,7 @@ pub struct BuiltinExplicitOutlivesSuggestion {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_incomplete_features)]
-pub struct BuiltinIncompleteFeatures {
+pub(crate) struct BuiltinIncompleteFeatures {
     pub name: Symbol,
     #[subdiagnostic]
     pub note: Option<BuiltinFeatureIssueNote>,
@@ -397,21 +397,21 @@ pub struct BuiltinIncompleteFeatures {
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_internal_features)]
 #[note]
-pub struct BuiltinInternalFeatures {
+pub(crate) struct BuiltinInternalFeatures {
     pub name: Symbol,
 }
 
 #[derive(Subdiagnostic)]
 #[help(lint_help)]
-pub struct BuiltinIncompleteFeaturesHelp;
+pub(crate) struct BuiltinIncompleteFeaturesHelp;
 
 #[derive(Subdiagnostic)]
 #[note(lint_note)]
-pub struct BuiltinFeatureIssueNote {
+pub(crate) struct BuiltinFeatureIssueNote {
     pub n: NonZero<u32>,
 }
 
-pub struct BuiltinUnpermittedTypeInit<'a> {
+pub(crate) struct BuiltinUnpermittedTypeInit<'a> {
     pub msg: DiagMessage,
     pub ty: Ty<'a>,
     pub label: Span,
@@ -436,7 +436,7 @@ impl<'a> LintDiagnostic<'a, ()> for BuiltinUnpermittedTypeInit<'_> {
 }
 
 // FIXME(davidtwco): make translatable
-pub struct BuiltinUnpermittedTypeInitSub {
+pub(crate) struct BuiltinUnpermittedTypeInitSub {
     pub err: InitError,
 }
 
@@ -463,7 +463,7 @@ impl Subdiagnostic for BuiltinUnpermittedTypeInitSub {
 }
 
 #[derive(LintDiagnostic)]
-pub enum BuiltinClashingExtern<'a> {
+pub(crate) enum BuiltinClashingExtern<'a> {
     #[diag(lint_builtin_clashing_extern_same_name)]
     SameName {
         this: Symbol,
@@ -489,7 +489,7 @@ pub enum BuiltinClashingExtern<'a> {
 }
 
 // FIXME(davidtwco): translatable expected/found
-pub struct BuiltinClashingExternSub<'a> {
+pub(crate) struct BuiltinClashingExternSub<'a> {
     pub tcx: TyCtxt<'a>,
     pub expected: Ty<'a>,
     pub found: Ty<'a>,
@@ -511,7 +511,7 @@ impl Subdiagnostic for BuiltinClashingExternSub<'_> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_builtin_deref_nullptr)]
-pub struct BuiltinDerefNullptr {
+pub(crate) struct BuiltinDerefNullptr {
     #[label]
     pub label: Span,
 }
@@ -519,7 +519,7 @@ pub struct BuiltinDerefNullptr {
 // FIXME: migrate fluent::lint::builtin_asm_labels
 
 #[derive(LintDiagnostic)]
-pub enum BuiltinSpecialModuleNameUsed {
+pub(crate) enum BuiltinSpecialModuleNameUsed {
     #[diag(lint_builtin_special_module_name_used_lib)]
     #[note]
     #[help]
@@ -532,7 +532,7 @@ pub enum BuiltinSpecialModuleNameUsed {
 // deref_into_dyn_supertrait.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_supertrait_as_deref_target)]
-pub struct SupertraitAsDerefTarget<'a> {
+pub(crate) struct SupertraitAsDerefTarget<'a> {
     pub self_ty: Ty<'a>,
     pub supertrait_principal: PolyExistentialTraitRef<'a>,
     pub target_principal: PolyExistentialTraitRef<'a>,
@@ -544,7 +544,7 @@ pub struct SupertraitAsDerefTarget<'a> {
 
 #[derive(Subdiagnostic)]
 #[label(lint_label2)]
-pub struct SupertraitAsDerefTargetLabel {
+pub(crate) struct SupertraitAsDerefTargetLabel {
     #[primary_span]
     pub label: Span,
 }
@@ -552,7 +552,7 @@ pub struct SupertraitAsDerefTargetLabel {
 // enum_intrinsics_non_enums.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_enum_intrinsics_mem_discriminant)]
-pub struct EnumIntrinsicsMemDiscriminate<'a> {
+pub(crate) struct EnumIntrinsicsMemDiscriminate<'a> {
     pub ty_param: Ty<'a>,
     #[note]
     pub note: Span,
@@ -561,14 +561,14 @@ pub struct EnumIntrinsicsMemDiscriminate<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_enum_intrinsics_mem_variant)]
 #[note]
-pub struct EnumIntrinsicsMemVariant<'a> {
+pub(crate) struct EnumIntrinsicsMemVariant<'a> {
     pub ty_param: Ty<'a>,
 }
 
 // expect.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_expectation)]
-pub struct Expectation {
+pub(crate) struct Expectation {
     #[subdiagnostic]
     pub rationale: Option<ExpectationNote>,
     #[note]
@@ -577,13 +577,13 @@ pub struct Expectation {
 
 #[derive(Subdiagnostic)]
 #[note(lint_rationale)]
-pub struct ExpectationNote {
+pub(crate) struct ExpectationNote {
     pub rationale: Symbol,
 }
 
 // ptr_nulls.rs
 #[derive(LintDiagnostic)]
-pub enum PtrNullChecksDiag<'a> {
+pub(crate) enum PtrNullChecksDiag<'a> {
     #[diag(lint_ptr_null_checks_fn_ptr)]
     #[help(lint_help)]
     FnPtr {
@@ -604,7 +604,7 @@ pub enum PtrNullChecksDiag<'a> {
 // for_loops_over_fallibles.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_for_loops_over_fallibles)]
-pub struct ForLoopsOverFalliblesDiag<'a> {
+pub(crate) struct ForLoopsOverFalliblesDiag<'a> {
     pub article: &'static str,
     pub ref_prefix: &'static str,
     pub ty: &'static str,
@@ -617,7 +617,7 @@ pub struct ForLoopsOverFalliblesDiag<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum ForLoopsOverFalliblesLoopSub<'a> {
+pub(crate) enum ForLoopsOverFalliblesLoopSub<'a> {
     #[suggestion(lint_remove_next, code = ".by_ref()", applicability = "maybe-incorrect")]
     RemoveNext {
         #[primary_span]
@@ -636,14 +636,14 @@ pub enum ForLoopsOverFalliblesLoopSub<'a> {
 
 #[derive(Subdiagnostic)]
 #[suggestion(lint_use_question_mark, code = "?", applicability = "maybe-incorrect")]
-pub struct ForLoopsOverFalliblesQuestionMark {
+pub(crate) struct ForLoopsOverFalliblesQuestionMark {
     #[primary_span]
     pub suggestion: Span,
 }
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion, applicability = "maybe-incorrect")]
-pub struct ForLoopsOverFalliblesSuggestion<'a> {
+pub(crate) struct ForLoopsOverFalliblesSuggestion<'a> {
     pub var: &'a str,
     #[suggestion_part(code = "if let {var}(")]
     pub start_span: Span,
@@ -652,7 +652,7 @@ pub struct ForLoopsOverFalliblesSuggestion<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum UseLetUnderscoreIgnoreSuggestion {
+pub(crate) enum UseLetUnderscoreIgnoreSuggestion {
     #[note(lint_use_let_underscore_ignore_suggestion)]
     Note,
     #[multipart_suggestion(
@@ -671,7 +671,7 @@ pub enum UseLetUnderscoreIgnoreSuggestion {
 // drop_forget_useless.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_dropping_references)]
-pub struct DropRefDiag<'a> {
+pub(crate) struct DropRefDiag<'a> {
     pub arg_ty: Ty<'a>,
     #[label]
     pub label: Span,
@@ -681,7 +681,7 @@ pub struct DropRefDiag<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_dropping_copy_types)]
-pub struct DropCopyDiag<'a> {
+pub(crate) struct DropCopyDiag<'a> {
     pub arg_ty: Ty<'a>,
     #[label]
     pub label: Span,
@@ -691,7 +691,7 @@ pub struct DropCopyDiag<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_forgetting_references)]
-pub struct ForgetRefDiag<'a> {
+pub(crate) struct ForgetRefDiag<'a> {
     pub arg_ty: Ty<'a>,
     #[label]
     pub label: Span,
@@ -701,7 +701,7 @@ pub struct ForgetRefDiag<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_forgetting_copy_types)]
-pub struct ForgetCopyDiag<'a> {
+pub(crate) struct ForgetCopyDiag<'a> {
     pub arg_ty: Ty<'a>,
     #[label]
     pub label: Span,
@@ -711,7 +711,7 @@ pub struct ForgetCopyDiag<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_undropped_manually_drops)]
-pub struct UndroppedManuallyDropsDiag<'a> {
+pub(crate) struct UndroppedManuallyDropsDiag<'a> {
     pub arg_ty: Ty<'a>,
     #[label]
     pub label: Span,
@@ -721,7 +721,7 @@ pub struct UndroppedManuallyDropsDiag<'a> {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion, applicability = "machine-applicable")]
-pub struct UndroppedManuallyDropsSuggestion {
+pub(crate) struct UndroppedManuallyDropsSuggestion {
     #[suggestion_part(code = "std::mem::ManuallyDrop::into_inner(")]
     pub start_span: Span,
     #[suggestion_part(code = ")")]
@@ -730,7 +730,7 @@ pub struct UndroppedManuallyDropsSuggestion {
 
 // invalid_from_utf8.rs
 #[derive(LintDiagnostic)]
-pub enum InvalidFromUtf8Diag {
+pub(crate) enum InvalidFromUtf8Diag {
     #[diag(lint_invalid_from_utf8_unchecked)]
     Unchecked {
         method: String,
@@ -749,7 +749,7 @@ pub enum InvalidFromUtf8Diag {
 
 // reference_casting.rs
 #[derive(LintDiagnostic)]
-pub enum InvalidReferenceCastingDiag<'tcx> {
+pub(crate) enum InvalidReferenceCastingDiag<'tcx> {
     #[diag(lint_invalid_reference_casting_borrow_as_mut)]
     #[note(lint_invalid_reference_casting_note_book)]
     BorrowAsMut {
@@ -784,7 +784,7 @@ pub enum InvalidReferenceCastingDiag<'tcx> {
 #[derive(LintDiagnostic)]
 #[diag(lint_hidden_unicode_codepoints)]
 #[note]
-pub struct HiddenUnicodeCodepointsDiag<'a> {
+pub(crate) struct HiddenUnicodeCodepointsDiag<'a> {
     pub label: &'a str,
     pub count: usize,
     #[label]
@@ -795,7 +795,7 @@ pub struct HiddenUnicodeCodepointsDiag<'a> {
     pub sub: HiddenUnicodeCodepointsDiagSub,
 }
 
-pub struct HiddenUnicodeCodepointsDiagLabels {
+pub(crate) struct HiddenUnicodeCodepointsDiagLabels {
     pub spans: Vec<(char, Span)>,
 }
 
@@ -811,7 +811,7 @@ impl Subdiagnostic for HiddenUnicodeCodepointsDiagLabels {
     }
 }
 
-pub enum HiddenUnicodeCodepointsDiagSub {
+pub(crate) enum HiddenUnicodeCodepointsDiagSub {
     Escape { spans: Vec<(char, Span)> },
     NoEscape { spans: Vec<(char, Span)> },
 }
@@ -866,7 +866,7 @@ impl Subdiagnostic for HiddenUnicodeCodepointsDiagSub {
 #[derive(LintDiagnostic)]
 #[diag(lint_map_unit_fn)]
 #[note]
-pub struct MappingToUnit {
+pub(crate) struct MappingToUnit {
     #[label(lint_function_label)]
     pub function_label: Span,
     #[label(lint_argument_label)]
@@ -882,7 +882,7 @@ pub struct MappingToUnit {
 #[derive(LintDiagnostic)]
 #[diag(lint_default_hash_types)]
 #[note]
-pub struct DefaultHashTypesDiag<'a> {
+pub(crate) struct DefaultHashTypesDiag<'a> {
     pub preferred: &'a str,
     pub used: Symbol,
 }
@@ -890,17 +890,17 @@ pub struct DefaultHashTypesDiag<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_query_instability)]
 #[note]
-pub struct QueryInstability {
+pub(crate) struct QueryInstability {
     pub query: Symbol,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_span_use_eq_ctxt)]
-pub struct SpanUseEqCtxtDiag;
+pub(crate) struct SpanUseEqCtxtDiag;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_tykind_kind)]
-pub struct TykindKind {
+pub(crate) struct TykindKind {
     #[suggestion(code = "ty", applicability = "maybe-incorrect")]
     pub suggestion: Span,
 }
@@ -908,11 +908,11 @@ pub struct TykindKind {
 #[derive(LintDiagnostic)]
 #[diag(lint_tykind)]
 #[help]
-pub struct TykindDiag;
+pub(crate) struct TykindDiag;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_ty_qualified)]
-pub struct TyQualified {
+pub(crate) struct TyQualified {
     pub ty: String,
     #[suggestion(code = "{ty}", applicability = "maybe-incorrect")]
     pub suggestion: Span,
@@ -920,7 +920,7 @@ pub struct TyQualified {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_non_glob_import_type_ir_inherent)]
-pub struct NonGlobImportTypeIrInherent {
+pub(crate) struct NonGlobImportTypeIrInherent {
     #[suggestion(code = "{snippet}", applicability = "maybe-incorrect")]
     pub suggestion: Option<Span>,
     pub snippet: &'static str,
@@ -929,32 +929,32 @@ pub struct NonGlobImportTypeIrInherent {
 #[derive(LintDiagnostic)]
 #[diag(lint_lintpass_by_hand)]
 #[help]
-pub struct LintPassByHand;
+pub(crate) struct LintPassByHand;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_non_existent_doc_keyword)]
 #[help]
-pub struct NonExistentDocKeyword {
+pub(crate) struct NonExistentDocKeyword {
     pub keyword: Symbol,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_diag_out_of_impl)]
-pub struct DiagOutOfImpl;
+pub(crate) struct DiagOutOfImpl;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_untranslatable_diag)]
-pub struct UntranslatableDiag;
+pub(crate) struct UntranslatableDiag;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_bad_opt_access)]
-pub struct BadOptAccessDiag<'a> {
+pub(crate) struct BadOptAccessDiag<'a> {
     pub msg: &'a str,
 }
 
 // let_underscore.rs
 #[derive(LintDiagnostic)]
-pub enum NonBindingLet {
+pub(crate) enum NonBindingLet {
     #[diag(lint_non_binding_let_on_sync_lock)]
     SyncLock {
         #[label]
@@ -969,7 +969,7 @@ pub enum NonBindingLet {
     },
 }
 
-pub struct NonBindingLetSub {
+pub(crate) struct NonBindingLetSub {
     pub suggestion: Span,
     pub drop_fn_start_end: Option<(Span, Span)>,
     pub is_assign_desugar: bool,
@@ -1012,7 +1012,7 @@ impl Subdiagnostic for NonBindingLetSub {
 // levels.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_overruled_attribute)]
-pub struct OverruledAttributeLint<'a> {
+pub(crate) struct OverruledAttributeLint<'a> {
     #[label]
     pub overruled: Span,
     pub lint_level: &'a str,
@@ -1023,7 +1023,7 @@ pub struct OverruledAttributeLint<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_deprecated_lint_name)]
-pub struct DeprecatedLintName<'a> {
+pub(crate) struct DeprecatedLintName<'a> {
     pub name: String,
     #[suggestion(code = "{replace}", applicability = "machine-applicable")]
     pub suggestion: Span,
@@ -1033,7 +1033,7 @@ pub struct DeprecatedLintName<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_deprecated_lint_name)]
 #[help]
-pub struct DeprecatedLintNameFromCommandLine<'a> {
+pub(crate) struct DeprecatedLintNameFromCommandLine<'a> {
     pub name: String,
     pub replace: &'a str,
     #[subdiagnostic]
@@ -1042,14 +1042,14 @@ pub struct DeprecatedLintNameFromCommandLine<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_renamed_lint)]
-pub struct RenamedLint<'a> {
+pub(crate) struct RenamedLint<'a> {
     pub name: &'a str,
     #[subdiagnostic]
     pub suggestion: RenamedLintSuggestion<'a>,
 }
 
 #[derive(Subdiagnostic)]
-pub enum RenamedLintSuggestion<'a> {
+pub(crate) enum RenamedLintSuggestion<'a> {
     #[suggestion(lint_suggestion, code = "{replace}", applicability = "machine-applicable")]
     WithSpan {
         #[primary_span]
@@ -1062,7 +1062,7 @@ pub enum RenamedLintSuggestion<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_renamed_lint)]
-pub struct RenamedLintFromCommandLine<'a> {
+pub(crate) struct RenamedLintFromCommandLine<'a> {
     pub name: &'a str,
     #[subdiagnostic]
     pub suggestion: RenamedLintSuggestion<'a>,
@@ -1072,14 +1072,14 @@ pub struct RenamedLintFromCommandLine<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_removed_lint)]
-pub struct RemovedLint<'a> {
+pub(crate) struct RemovedLint<'a> {
     pub name: &'a str,
     pub reason: &'a str,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_removed_lint)]
-pub struct RemovedLintFromCommandLine<'a> {
+pub(crate) struct RemovedLintFromCommandLine<'a> {
     pub name: &'a str,
     pub reason: &'a str,
     #[subdiagnostic]
@@ -1088,14 +1088,14 @@ pub struct RemovedLintFromCommandLine<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unknown_lint)]
-pub struct UnknownLint {
+pub(crate) struct UnknownLint {
     pub name: String,
     #[subdiagnostic]
     pub suggestion: Option<UnknownLintSuggestion>,
 }
 
 #[derive(Subdiagnostic)]
-pub enum UnknownLintSuggestion {
+pub(crate) enum UnknownLintSuggestion {
     #[suggestion(lint_suggestion, code = "{replace}", applicability = "maybe-incorrect")]
     WithSpan {
         #[primary_span]
@@ -1109,7 +1109,7 @@ pub enum UnknownLintSuggestion {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unknown_lint, code = E0602)]
-pub struct UnknownLintFromCommandLine<'a> {
+pub(crate) struct UnknownLintFromCommandLine<'a> {
     pub name: String,
     #[subdiagnostic]
     pub suggestion: Option<UnknownLintSuggestion>,
@@ -1119,7 +1119,7 @@ pub struct UnknownLintFromCommandLine<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_ignored_unless_crate_specified)]
-pub struct IgnoredUnlessCrateSpecified<'a> {
+pub(crate) struct IgnoredUnlessCrateSpecified<'a> {
     pub level: &'a str,
     pub name: Symbol,
 }
@@ -1129,7 +1129,7 @@ pub struct IgnoredUnlessCrateSpecified<'a> {
 #[diag(lint_cstring_ptr)]
 #[note]
 #[help]
-pub struct CStringPtr {
+pub(crate) struct CStringPtr {
     #[label(lint_as_ptr_label)]
     pub as_ptr: Span,
     #[label(lint_unwrap_label)]
@@ -1139,19 +1139,19 @@ pub struct CStringPtr {
 // multiple_supertrait_upcastable.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_multiple_supertrait_upcastable)]
-pub struct MultipleSupertraitUpcastable {
+pub(crate) struct MultipleSupertraitUpcastable {
     pub ident: Ident,
 }
 
 // non_ascii_idents.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_identifier_non_ascii_char)]
-pub struct IdentifierNonAsciiChar;
+pub(crate) struct IdentifierNonAsciiChar;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_identifier_uncommon_codepoints)]
 #[note]
-pub struct IdentifierUncommonCodepoints {
+pub(crate) struct IdentifierUncommonCodepoints {
     pub codepoints: Vec<char>,
     pub codepoints_len: usize,
     pub identifier_type: &'static str,
@@ -1159,7 +1159,7 @@ pub struct IdentifierUncommonCodepoints {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_confusable_identifier_pair)]
-pub struct ConfusableIdentifierPair {
+pub(crate) struct ConfusableIdentifierPair {
     pub existing_sym: Symbol,
     pub sym: Symbol,
     #[label(lint_other_use)]
@@ -1172,13 +1172,13 @@ pub struct ConfusableIdentifierPair {
 #[diag(lint_mixed_script_confusables)]
 #[note(lint_includes_note)]
 #[note]
-pub struct MixedScriptConfusables {
+pub(crate) struct MixedScriptConfusables {
     pub set: String,
     pub includes: String,
 }
 
 // non_fmt_panic.rs
-pub struct NonFmtPanicUnused {
+pub(crate) struct NonFmtPanicUnused {
     pub count: usize,
     pub suggestion: Option<Span>,
 }
@@ -1209,7 +1209,7 @@ impl<'a> LintDiagnostic<'a, ()> for NonFmtPanicUnused {
 #[derive(LintDiagnostic)]
 #[diag(lint_non_fmt_panic_braces)]
 #[note]
-pub struct NonFmtPanicBraces {
+pub(crate) struct NonFmtPanicBraces {
     pub count: usize,
     #[suggestion(code = "\"{{}}\", ", applicability = "machine-applicable")]
     pub suggestion: Option<Span>,
@@ -1218,7 +1218,7 @@ pub struct NonFmtPanicBraces {
 // nonstandard_style.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_non_camel_case_type)]
-pub struct NonCamelCaseType<'a> {
+pub(crate) struct NonCamelCaseType<'a> {
     pub sort: &'a str,
     pub name: &'a str,
     #[subdiagnostic]
@@ -1226,7 +1226,7 @@ pub struct NonCamelCaseType<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum NonCamelCaseTypeSub {
+pub(crate) enum NonCamelCaseTypeSub {
     #[label(lint_label)]
     Label {
         #[primary_span]
@@ -1242,7 +1242,7 @@ pub enum NonCamelCaseTypeSub {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_non_snake_case)]
-pub struct NonSnakeCaseDiag<'a> {
+pub(crate) struct NonSnakeCaseDiag<'a> {
     pub sort: &'a str,
     pub name: &'a str,
     pub sc: String,
@@ -1250,7 +1250,7 @@ pub struct NonSnakeCaseDiag<'a> {
     pub sub: NonSnakeCaseDiagSub,
 }
 
-pub enum NonSnakeCaseDiagSub {
+pub(crate) enum NonSnakeCaseDiagSub {
     Label { span: Span },
     Help,
     RenameOrConvertSuggestion { span: Span, suggestion: Ident },
@@ -1302,7 +1302,7 @@ impl Subdiagnostic for NonSnakeCaseDiagSub {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_non_upper_case_global)]
-pub struct NonUpperCaseGlobal<'a> {
+pub(crate) struct NonUpperCaseGlobal<'a> {
     pub sort: &'a str,
     pub name: &'a str,
     #[subdiagnostic]
@@ -1310,7 +1310,7 @@ pub struct NonUpperCaseGlobal<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum NonUpperCaseGlobalSub {
+pub(crate) enum NonUpperCaseGlobalSub {
     #[label(lint_label)]
     Label {
         #[primary_span]
@@ -1328,7 +1328,7 @@ pub enum NonUpperCaseGlobalSub {
 #[derive(LintDiagnostic)]
 #[diag(lint_noop_method_call)]
 #[note]
-pub struct NoopMethodCallDiag<'a> {
+pub(crate) struct NoopMethodCallDiag<'a> {
     pub method: Symbol,
     pub orig_ty: Ty<'a>,
     pub trait_: Symbol,
@@ -1344,18 +1344,18 @@ pub struct NoopMethodCallDiag<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_suspicious_double_ref_deref)]
-pub struct SuspiciousDoubleRefDerefDiag<'a> {
+pub(crate) struct SuspiciousDoubleRefDerefDiag<'a> {
     pub ty: Ty<'a>,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_suspicious_double_ref_clone)]
-pub struct SuspiciousDoubleRefCloneDiag<'a> {
+pub(crate) struct SuspiciousDoubleRefCloneDiag<'a> {
     pub ty: Ty<'a>,
 }
 
 // non_local_defs.rs
-pub enum NonLocalDefinitionsDiag {
+pub(crate) enum NonLocalDefinitionsDiag {
     Impl {
         depth: u32,
         body_kind_descr: &'static str,
@@ -1487,7 +1487,7 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
 
 #[derive(Subdiagnostic)]
 #[note(lint_non_local_definitions_cargo_update)]
-pub struct NonLocalDefinitionsCargoUpdateNote {
+pub(crate) struct NonLocalDefinitionsCargoUpdateNote {
     pub macro_kind: &'static str,
     pub macro_name: Symbol,
     pub crate_name: Symbol,
@@ -1497,7 +1497,7 @@ pub struct NonLocalDefinitionsCargoUpdateNote {
 #[derive(LintDiagnostic)]
 #[diag(lint_ambiguous_negative_literals)]
 #[note(lint_example)]
-pub struct AmbiguousNegativeLiteralsDiag {
+pub(crate) struct AmbiguousNegativeLiteralsDiag {
     #[subdiagnostic]
     pub negative_literal: AmbiguousNegativeLiteralsNegativeLiteralSuggestion,
     #[subdiagnostic]
@@ -1506,7 +1506,7 @@ pub struct AmbiguousNegativeLiteralsDiag {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_negative_literal, applicability = "maybe-incorrect")]
-pub struct AmbiguousNegativeLiteralsNegativeLiteralSuggestion {
+pub(crate) struct AmbiguousNegativeLiteralsNegativeLiteralSuggestion {
     #[suggestion_part(code = "(")]
     pub start_span: Span,
     #[suggestion_part(code = ")")]
@@ -1515,7 +1515,7 @@ pub struct AmbiguousNegativeLiteralsNegativeLiteralSuggestion {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_current_behavior, applicability = "maybe-incorrect")]
-pub struct AmbiguousNegativeLiteralsCurrentBehaviorSuggestion {
+pub(crate) struct AmbiguousNegativeLiteralsCurrentBehaviorSuggestion {
     #[suggestion_part(code = "(")]
     pub start_span: Span,
     #[suggestion_part(code = ")")]
@@ -1525,7 +1525,7 @@ pub struct AmbiguousNegativeLiteralsCurrentBehaviorSuggestion {
 // pass_by_value.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_pass_by_value)]
-pub struct PassByValueDiag {
+pub(crate) struct PassByValueDiag {
     pub ty: String,
     #[suggestion(code = "{ty}", applicability = "maybe-incorrect")]
     pub suggestion: Span,
@@ -1534,14 +1534,14 @@ pub struct PassByValueDiag {
 // redundant_semicolon.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_redundant_semicolons)]
-pub struct RedundantSemicolonsDiag {
+pub(crate) struct RedundantSemicolonsDiag {
     pub multiple: bool,
     #[suggestion(code = "", applicability = "maybe-incorrect")]
     pub suggestion: Span,
 }
 
 // traits.rs
-pub struct DropTraitConstraintsDiag<'a> {
+pub(crate) struct DropTraitConstraintsDiag<'a> {
     pub predicate: Clause<'a>,
     pub tcx: TyCtxt<'a>,
     pub def_id: DefId,
@@ -1556,7 +1556,7 @@ impl<'a> LintDiagnostic<'a, ()> for DropTraitConstraintsDiag<'_> {
     }
 }
 
-pub struct DropGlue<'a> {
+pub(crate) struct DropGlue<'a> {
     pub tcx: TyCtxt<'a>,
     pub def_id: DefId,
 }
@@ -1572,14 +1572,14 @@ impl<'a> LintDiagnostic<'a, ()> for DropGlue<'_> {
 // types.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_range_endpoint_out_of_range)]
-pub struct RangeEndpointOutOfRange<'a> {
+pub(crate) struct RangeEndpointOutOfRange<'a> {
     pub ty: &'a str,
     #[subdiagnostic]
     pub sub: UseInclusiveRange<'a>,
 }
 
 #[derive(Subdiagnostic)]
-pub enum UseInclusiveRange<'a> {
+pub(crate) enum UseInclusiveRange<'a> {
     #[suggestion(
         lint_range_use_inclusive_range,
         code = "{start}..={literal}{suffix}",
@@ -1605,7 +1605,7 @@ pub enum UseInclusiveRange<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_overflowing_bin_hex)]
-pub struct OverflowingBinHex<'a> {
+pub(crate) struct OverflowingBinHex<'a> {
     pub ty: &'a str,
     pub lit: String,
     pub dec: u128,
@@ -1618,7 +1618,7 @@ pub struct OverflowingBinHex<'a> {
     pub sign_bit_sub: Option<OverflowingBinHexSignBitSub<'a>>,
 }
 
-pub enum OverflowingBinHexSign {
+pub(crate) enum OverflowingBinHexSign {
     Positive,
     Negative,
 }
@@ -1642,7 +1642,7 @@ impl Subdiagnostic for OverflowingBinHexSign {
 }
 
 #[derive(Subdiagnostic)]
-pub enum OverflowingBinHexSub<'a> {
+pub(crate) enum OverflowingBinHexSub<'a> {
     #[suggestion(
         lint_suggestion,
         code = "{sans_suffix}{suggestion_ty}",
@@ -1664,7 +1664,7 @@ pub enum OverflowingBinHexSub<'a> {
     code = "{lit_no_suffix}{uint_ty} as {int_ty}",
     applicability = "maybe-incorrect"
 )]
-pub struct OverflowingBinHexSignBitSub<'a> {
+pub(crate) struct OverflowingBinHexSignBitSub<'a> {
     #[primary_span]
     pub span: Span,
     pub lit_no_suffix: &'a str,
@@ -1676,7 +1676,7 @@ pub struct OverflowingBinHexSignBitSub<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_overflowing_int)]
 #[note]
-pub struct OverflowingInt<'a> {
+pub(crate) struct OverflowingInt<'a> {
     pub ty: &'a str,
     pub lit: String,
     pub min: i128,
@@ -1687,13 +1687,13 @@ pub struct OverflowingInt<'a> {
 
 #[derive(Subdiagnostic)]
 #[help(lint_help)]
-pub struct OverflowingIntHelp<'a> {
+pub(crate) struct OverflowingIntHelp<'a> {
     pub suggestion_ty: &'a str,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_only_cast_u8_to_char)]
-pub struct OnlyCastu8ToChar {
+pub(crate) struct OnlyCastu8ToChar {
     #[suggestion(code = "'\\u{{{literal:X}}}'", applicability = "machine-applicable")]
     pub span: Span,
     pub literal: u128,
@@ -1702,7 +1702,7 @@ pub struct OnlyCastu8ToChar {
 #[derive(LintDiagnostic)]
 #[diag(lint_overflowing_uint)]
 #[note]
-pub struct OverflowingUInt<'a> {
+pub(crate) struct OverflowingUInt<'a> {
     pub ty: &'a str,
     pub lit: String,
     pub min: u128,
@@ -1712,17 +1712,17 @@ pub struct OverflowingUInt<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_overflowing_literal)]
 #[note]
-pub struct OverflowingLiteral<'a> {
+pub(crate) struct OverflowingLiteral<'a> {
     pub ty: &'a str,
     pub lit: String,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_comparisons)]
-pub struct UnusedComparisons;
+pub(crate) struct UnusedComparisons;
 
 #[derive(LintDiagnostic)]
-pub enum InvalidNanComparisons {
+pub(crate) enum InvalidNanComparisons {
     #[diag(lint_invalid_nan_comparisons_eq_ne)]
     EqNe {
         #[subdiagnostic]
@@ -1733,7 +1733,7 @@ pub enum InvalidNanComparisons {
 }
 
 #[derive(Subdiagnostic)]
-pub enum InvalidNanComparisonsSuggestion {
+pub(crate) enum InvalidNanComparisonsSuggestion {
     #[multipart_suggestion(
         lint_suggestion,
         style = "verbose",
@@ -1752,7 +1752,7 @@ pub enum InvalidNanComparisonsSuggestion {
 }
 
 #[derive(LintDiagnostic)]
-pub enum AmbiguousWidePointerComparisons<'a> {
+pub(crate) enum AmbiguousWidePointerComparisons<'a> {
     #[diag(lint_ambiguous_wide_pointer_comparisons)]
     Spanful {
         #[subdiagnostic]
@@ -1773,7 +1773,7 @@ pub enum AmbiguousWidePointerComparisons<'a> {
     // FIXME(#53934): make machine-applicable again
     applicability = "maybe-incorrect"
 )]
-pub struct AmbiguousWidePointerComparisonsAddrMetadataSuggestion<'a> {
+pub(crate) struct AmbiguousWidePointerComparisonsAddrMetadataSuggestion<'a> {
     pub ne: &'a str,
     pub deref_left: &'a str,
     pub deref_right: &'a str,
@@ -1788,7 +1788,7 @@ pub struct AmbiguousWidePointerComparisonsAddrMetadataSuggestion<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum AmbiguousWidePointerComparisonsAddrSuggestion<'a> {
+pub(crate) enum AmbiguousWidePointerComparisonsAddrSuggestion<'a> {
     #[multipart_suggestion(
         lint_addr_suggestion,
         style = "verbose",
@@ -1832,7 +1832,7 @@ pub enum AmbiguousWidePointerComparisonsAddrSuggestion<'a> {
     },
 }
 
-pub struct ImproperCTypes<'a> {
+pub(crate) struct ImproperCTypes<'a> {
     pub ty: Ty<'a>,
     pub desc: &'a str,
     pub label: Span,
@@ -1860,29 +1860,29 @@ impl<'a> LintDiagnostic<'a, ()> for ImproperCTypes<'_> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_variant_size_differences)]
-pub struct VariantSizeDifferencesDiag {
+pub(crate) struct VariantSizeDifferencesDiag {
     pub largest: u64,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_atomic_ordering_load)]
 #[help]
-pub struct AtomicOrderingLoad;
+pub(crate) struct AtomicOrderingLoad;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_atomic_ordering_store)]
 #[help]
-pub struct AtomicOrderingStore;
+pub(crate) struct AtomicOrderingStore;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_atomic_ordering_fence)]
 #[help]
-pub struct AtomicOrderingFence;
+pub(crate) struct AtomicOrderingFence;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_atomic_ordering_invalid)]
 #[help]
-pub struct InvalidAtomicOrderingDiag {
+pub(crate) struct InvalidAtomicOrderingDiag {
     pub method: Symbol,
     #[label]
     pub fail_order_arg_span: Span,
@@ -1891,7 +1891,7 @@ pub struct InvalidAtomicOrderingDiag {
 // unused.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_op)]
-pub struct UnusedOp<'a> {
+pub(crate) struct UnusedOp<'a> {
     pub op: &'a str,
     #[label]
     pub label: Span,
@@ -1900,7 +1900,7 @@ pub struct UnusedOp<'a> {
 }
 
 #[derive(Subdiagnostic)]
-pub enum UnusedOpSuggestion {
+pub(crate) enum UnusedOpSuggestion {
     #[suggestion(
         lint_suggestion,
         style = "verbose",
@@ -1922,7 +1922,7 @@ pub enum UnusedOpSuggestion {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_result)]
-pub struct UnusedResult<'a> {
+pub(crate) struct UnusedResult<'a> {
     pub ty: Ty<'a>,
 }
 
@@ -1931,7 +1931,7 @@ pub struct UnusedResult<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_closure)]
 #[note]
-pub struct UnusedClosure<'a> {
+pub(crate) struct UnusedClosure<'a> {
     pub count: usize,
     pub pre: &'a str,
     pub post: &'a str,
@@ -1942,7 +1942,7 @@ pub struct UnusedClosure<'a> {
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_coroutine)]
 #[note]
-pub struct UnusedCoroutine<'a> {
+pub(crate) struct UnusedCoroutine<'a> {
     pub count: usize,
     pub pre: &'a str,
     pub post: &'a str,
@@ -1950,7 +1950,7 @@ pub struct UnusedCoroutine<'a> {
 
 // FIXME(davidtwco): this isn't properly translatable because of the pre/post
 // strings
-pub struct UnusedDef<'a, 'b> {
+pub(crate) struct UnusedDef<'a, 'b> {
     pub pre: &'a str,
     pub post: &'a str,
     pub cx: &'a LateContext<'b>,
@@ -1961,7 +1961,7 @@ pub struct UnusedDef<'a, 'b> {
 
 #[derive(Subdiagnostic)]
 
-pub enum UnusedDefSuggestion {
+pub(crate) enum UnusedDefSuggestion {
     #[suggestion(
         lint_suggestion,
         style = "verbose",
@@ -2000,13 +2000,13 @@ impl<'a> LintDiagnostic<'a, ()> for UnusedDef<'_, '_> {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_path_statement_drop)]
-pub struct PathStatementDrop {
+pub(crate) struct PathStatementDrop {
     #[subdiagnostic]
     pub sub: PathStatementDropSub,
 }
 
 #[derive(Subdiagnostic)]
-pub enum PathStatementDropSub {
+pub(crate) enum PathStatementDropSub {
     #[suggestion(lint_suggestion, code = "drop({snippet});", applicability = "machine-applicable")]
     Suggestion {
         #[primary_span]
@@ -2022,11 +2022,11 @@ pub enum PathStatementDropSub {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_path_statement_no_effect)]
-pub struct PathStatementNoEffect;
+pub(crate) struct PathStatementNoEffect;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_delim)]
-pub struct UnusedDelim<'a> {
+pub(crate) struct UnusedDelim<'a> {
     pub delim: &'static str,
     pub item: &'a str,
     #[subdiagnostic]
@@ -2035,7 +2035,7 @@ pub struct UnusedDelim<'a> {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion, applicability = "machine-applicable")]
-pub struct UnusedDelimSuggestion {
+pub(crate) struct UnusedDelimSuggestion {
     #[suggestion_part(code = "{start_replace}")]
     pub start_span: Span,
     pub start_replace: &'static str,
@@ -2046,19 +2046,19 @@ pub struct UnusedDelimSuggestion {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_import_braces)]
-pub struct UnusedImportBracesDiag {
+pub(crate) struct UnusedImportBracesDiag {
     pub node: Symbol,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_allocation)]
-pub struct UnusedAllocationDiag;
+pub(crate) struct UnusedAllocationDiag;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_allocation_mut)]
-pub struct UnusedAllocationMutDiag;
+pub(crate) struct UnusedAllocationMutDiag;
 
-pub struct AsyncFnInTraitDiag {
+pub(crate) struct AsyncFnInTraitDiag {
     pub sugg: Option<Vec<(Span, String)>>,
 }
 
@@ -2074,13 +2074,13 @@ impl<'a> LintDiagnostic<'a, ()> for AsyncFnInTraitDiag {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unit_bindings)]
-pub struct UnitBindingsDiag {
+pub(crate) struct UnitBindingsDiag {
     #[label]
     pub label: Span,
 }
 
 #[derive(LintDiagnostic)]
-pub enum InvalidAsmLabel {
+pub(crate) enum InvalidAsmLabel {
     #[diag(lint_invalid_asm_label_named)]
     #[help]
     #[note]
@@ -2110,7 +2110,7 @@ pub enum InvalidAsmLabel {
 }
 
 #[derive(Subdiagnostic)]
-pub enum UnexpectedCfgCargoHelp {
+pub(crate) enum UnexpectedCfgCargoHelp {
     #[help(lint_unexpected_cfg_add_cargo_feature)]
     #[help(lint_unexpected_cfg_add_cargo_toml_lint_cfg)]
     LintCfg { cargo_toml_lint_cfg: String },
@@ -2127,13 +2127,13 @@ impl UnexpectedCfgCargoHelp {
         )
     }
 
-    pub fn lint_cfg(unescaped: &str) -> Self {
+    pub(crate) fn lint_cfg(unescaped: &str) -> Self {
         UnexpectedCfgCargoHelp::LintCfg {
             cargo_toml_lint_cfg: Self::cargo_toml_lint_cfg(unescaped),
         }
     }
 
-    pub fn lint_cfg_and_build_rs(unescaped: &str, escaped: &str) -> Self {
+    pub(crate) fn lint_cfg_and_build_rs(unescaped: &str, escaped: &str) -> Self {
         UnexpectedCfgCargoHelp::LintCfgAndBuildRs {
             cargo_toml_lint_cfg: Self::cargo_toml_lint_cfg(unescaped),
             build_rs_println: format!("println!(\"cargo::rustc-check-cfg={escaped}\");"),
@@ -2143,19 +2143,19 @@ impl UnexpectedCfgCargoHelp {
 
 #[derive(Subdiagnostic)]
 #[help(lint_unexpected_cfg_add_cmdline_arg)]
-pub struct UnexpectedCfgRustcHelp {
+pub(crate) struct UnexpectedCfgRustcHelp {
     pub cmdline_arg: String,
 }
 
 impl UnexpectedCfgRustcHelp {
-    pub fn new(unescaped: &str) -> Self {
+    pub(crate) fn new(unescaped: &str) -> Self {
         Self { cmdline_arg: format!("--check-cfg={unescaped}") }
     }
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unexpected_cfg_name)]
-pub struct UnexpectedCfgName {
+pub(crate) struct UnexpectedCfgName {
     #[subdiagnostic]
     pub code_sugg: unexpected_cfg_name::CodeSuggestion,
     #[subdiagnostic]
@@ -2164,13 +2164,13 @@ pub struct UnexpectedCfgName {
     pub name: Symbol,
 }
 
-pub mod unexpected_cfg_name {
+pub(crate) mod unexpected_cfg_name {
     use rustc_errors::DiagSymbolList;
     use rustc_macros::Subdiagnostic;
     use rustc_span::{Span, Symbol};
 
     #[derive(Subdiagnostic)]
-    pub enum CodeSuggestion {
+    pub(crate) enum CodeSuggestion {
         #[help(lint_unexpected_cfg_define_features)]
         DefineFeatures,
         #[suggestion(
@@ -2227,7 +2227,7 @@ pub mod unexpected_cfg_name {
 
     #[derive(Subdiagnostic)]
     #[help(lint_unexpected_cfg_name_expected_values)]
-    pub struct ExpectedValues {
+    pub(crate) struct ExpectedValues {
         pub best_match: Symbol,
         pub possibilities: DiagSymbolList,
     }
@@ -2238,7 +2238,7 @@ pub mod unexpected_cfg_name {
         applicability = "maybe-incorrect",
         code = "{code}"
     )]
-    pub struct FoundWithSimilarValue {
+    pub(crate) struct FoundWithSimilarValue {
         #[primary_span]
         pub span: Span,
         pub code: String,
@@ -2246,13 +2246,13 @@ pub mod unexpected_cfg_name {
 
     #[derive(Subdiagnostic)]
     #[help_once(lint_unexpected_cfg_name_expected_names)]
-    pub struct ExpectedNames {
+    pub(crate) struct ExpectedNames {
         pub possibilities: DiagSymbolList,
         pub and_more: usize,
     }
 
     #[derive(Subdiagnostic)]
-    pub enum InvocationHelp {
+    pub(crate) enum InvocationHelp {
         #[note(lint_unexpected_cfg_doc_cargo)]
         Cargo {
             #[subdiagnostic]
@@ -2265,7 +2265,7 @@ pub mod unexpected_cfg_name {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unexpected_cfg_value)]
-pub struct UnexpectedCfgValue {
+pub(crate) struct UnexpectedCfgValue {
     #[subdiagnostic]
     pub code_sugg: unexpected_cfg_value::CodeSuggestion,
     #[subdiagnostic]
@@ -2275,13 +2275,13 @@ pub struct UnexpectedCfgValue {
     pub value: String,
 }
 
-pub mod unexpected_cfg_value {
+pub(crate) mod unexpected_cfg_value {
     use rustc_errors::DiagSymbolList;
     use rustc_macros::Subdiagnostic;
     use rustc_span::{Span, Symbol};
 
     #[derive(Subdiagnostic)]
-    pub enum CodeSuggestion {
+    pub(crate) enum CodeSuggestion {
         ChangeValue {
             #[subdiagnostic]
             expected_values: ExpectedValues,
@@ -2305,7 +2305,7 @@ pub mod unexpected_cfg_value {
     }
 
     #[derive(Subdiagnostic)]
-    pub enum ChangeValueSuggestion {
+    pub(crate) enum ChangeValueSuggestion {
         #[suggestion(
             lint_unexpected_cfg_value_similar_name,
             code = r#""{best_match}""#,
@@ -2334,7 +2334,7 @@ pub mod unexpected_cfg_value {
         code = "",
         applicability = "maybe-incorrect"
     )]
-    pub struct RemoveValueSuggestion {
+    pub(crate) struct RemoveValueSuggestion {
         #[primary_span]
         pub span: Span,
     }
@@ -2345,14 +2345,14 @@ pub mod unexpected_cfg_value {
         code = "",
         applicability = "maybe-incorrect"
     )]
-    pub struct RemoveConditionSuggestion {
+    pub(crate) struct RemoveConditionSuggestion {
         #[primary_span]
         pub span: Span,
     }
 
     #[derive(Subdiagnostic)]
     #[note(lint_unexpected_cfg_value_expected_values)]
-    pub struct ExpectedValues {
+    pub(crate) struct ExpectedValues {
         pub name: Symbol,
         pub have_none_possibility: bool,
         pub possibilities: DiagSymbolList,
@@ -2360,7 +2360,7 @@ pub mod unexpected_cfg_value {
     }
 
     #[derive(Subdiagnostic)]
-    pub enum InvocationHelp {
+    pub(crate) enum InvocationHelp {
         #[note(lint_unexpected_cfg_doc_cargo)]
         Cargo(#[subdiagnostic] Option<CargoHelp>),
         #[note(lint_unexpected_cfg_doc_rustc)]
@@ -2368,7 +2368,7 @@ pub mod unexpected_cfg_value {
     }
 
     #[derive(Subdiagnostic)]
-    pub enum CargoHelp {
+    pub(crate) enum CargoHelp {
         #[help(lint_unexpected_cfg_value_add_feature)]
         AddFeature {
             value: Symbol,
@@ -2383,7 +2383,7 @@ pub mod unexpected_cfg_value {
 #[diag(lint_unexpected_builtin_cfg)]
 #[note(lint_controlled_by)]
 #[note(lint_incoherent)]
-pub struct UnexpectedBuiltinCfg {
+pub(crate) struct UnexpectedBuiltinCfg {
     pub(crate) cfg: String,
     pub(crate) cfg_name: Symbol,
     pub(crate) controlled_by: &'static str,
@@ -2392,15 +2392,15 @@ pub struct UnexpectedBuiltinCfg {
 #[derive(LintDiagnostic)]
 #[diag(lint_macro_use_deprecated)]
 #[help]
-pub struct MacroUseDeprecated;
+pub(crate) struct MacroUseDeprecated;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_macro_use)]
-pub struct UnusedMacroUse;
+pub(crate) struct UnusedMacroUse;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_private_extern_crate_reexport, code = E0365)]
-pub struct PrivateExternCrateReexport {
+pub(crate) struct PrivateExternCrateReexport {
     pub ident: Ident,
     #[suggestion(code = "pub ", style = "verbose", applicability = "maybe-incorrect")]
     pub sugg: Span,
@@ -2408,28 +2408,28 @@ pub struct PrivateExternCrateReexport {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_label)]
-pub struct UnusedLabel;
+pub(crate) struct UnusedLabel;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_macro_is_private)]
-pub struct MacroIsPrivate {
+pub(crate) struct MacroIsPrivate {
     pub ident: Ident,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_macro_definition)]
-pub struct UnusedMacroDefinition {
+pub(crate) struct UnusedMacroDefinition {
     pub name: Symbol,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_macro_rule_never_used)]
-pub struct MacroRuleNeverUsed {
+pub(crate) struct MacroRuleNeverUsed {
     pub n: usize,
     pub name: Symbol,
 }
 
-pub struct UnstableFeature {
+pub(crate) struct UnstableFeature {
     pub msg: DiagMessage,
 }
 
@@ -2441,81 +2441,81 @@ impl<'a> LintDiagnostic<'a, ()> for UnstableFeature {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_avoid_intel_syntax)]
-pub struct AvoidIntelSyntax;
+pub(crate) struct AvoidIntelSyntax;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_avoid_att_syntax)]
-pub struct AvoidAttSyntax;
+pub(crate) struct AvoidAttSyntax;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_incomplete_include)]
-pub struct IncompleteInclude;
+pub(crate) struct IncompleteInclude;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unnameable_test_items)]
-pub struct UnnameableTestItems;
+pub(crate) struct UnnameableTestItems;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_duplicate_macro_attribute)]
-pub struct DuplicateMacroAttribute;
+pub(crate) struct DuplicateMacroAttribute;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_cfg_attr_no_attributes)]
-pub struct CfgAttrNoAttributes;
+pub(crate) struct CfgAttrNoAttributes;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_crate_type_in_cfg_attr_deprecated)]
-pub struct CrateTypeInCfgAttr;
+pub(crate) struct CrateTypeInCfgAttr;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_crate_name_in_cfg_attr_deprecated)]
-pub struct CrateNameInCfgAttr;
+pub(crate) struct CrateNameInCfgAttr;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_missing_fragment_specifier)]
-pub struct MissingFragmentSpecifier;
+pub(crate) struct MissingFragmentSpecifier;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_metavariable_still_repeating)]
-pub struct MetaVariableStillRepeating {
+pub(crate) struct MetaVariableStillRepeating {
     pub name: MacroRulesNormalizedIdent,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_metavariable_wrong_operator)]
-pub struct MetaVariableWrongOperator;
+pub(crate) struct MetaVariableWrongOperator;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_duplicate_matcher_binding)]
-pub struct DuplicateMatcherBinding;
+pub(crate) struct DuplicateMatcherBinding;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unknown_macro_variable)]
-pub struct UnknownMacroVariable {
+pub(crate) struct UnknownMacroVariable {
     pub name: MacroRulesNormalizedIdent,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_crate_dependency)]
 #[help]
-pub struct UnusedCrateDependency {
+pub(crate) struct UnusedCrateDependency {
     pub extern_crate: Symbol,
     pub local_crate: Symbol,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_wasm_c_abi)]
-pub struct WasmCAbi;
+pub(crate) struct WasmCAbi;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_ill_formed_attribute_input)]
-pub struct IllFormedAttributeInput {
+pub(crate) struct IllFormedAttributeInput {
     pub num_suggestions: usize,
     pub suggestions: DiagArgValue,
 }
 
 #[derive(LintDiagnostic)]
-pub enum InnerAttributeUnstable {
+pub(crate) enum InnerAttributeUnstable {
     #[diag(lint_inner_macro_attribute_unstable)]
     InnerMacroAttribute,
     #[diag(lint_custom_inner_attribute_unstable)]
@@ -2524,7 +2524,7 @@ pub enum InnerAttributeUnstable {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unknown_diagnostic_attribute)]
-pub struct UnknownDiagnosticAttribute {
+pub(crate) struct UnknownDiagnosticAttribute {
     #[subdiagnostic]
     pub typo: Option<UnknownDiagnosticAttributeTypoSugg>,
 }
@@ -2536,7 +2536,7 @@ pub struct UnknownDiagnosticAttribute {
     code = "{typo_name}",
     applicability = "machine-applicable"
 )]
-pub struct UnknownDiagnosticAttributeTypoSugg {
+pub(crate) struct UnknownDiagnosticAttributeTypoSugg {
     #[primary_span]
     pub span: Span,
     pub typo_name: Symbol,
@@ -2545,7 +2545,7 @@ pub struct UnknownDiagnosticAttributeTypoSugg {
 #[derive(LintDiagnostic)]
 #[diag(lint_unicode_text_flow)]
 #[note]
-pub struct UnicodeTextFlow {
+pub(crate) struct UnicodeTextFlow {
     #[label]
     pub comment_span: Span,
     #[subdiagnostic]
@@ -2558,7 +2558,7 @@ pub struct UnicodeTextFlow {
 
 #[derive(Subdiagnostic)]
 #[label(lint_label_comment_char)]
-pub struct UnicodeCharNoteSub {
+pub(crate) struct UnicodeCharNoteSub {
     #[primary_span]
     pub span: Span,
     pub c_debug: String,
@@ -2566,21 +2566,21 @@ pub struct UnicodeCharNoteSub {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion, applicability = "machine-applicable", style = "hidden")]
-pub struct UnicodeTextFlowSuggestion {
+pub(crate) struct UnicodeTextFlowSuggestion {
     #[suggestion_part(code = "")]
     pub spans: Vec<Span>,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_abs_path_with_module)]
-pub struct AbsPathWithModule {
+pub(crate) struct AbsPathWithModule {
     #[subdiagnostic]
     pub sugg: AbsPathWithModuleSugg,
 }
 
 #[derive(Subdiagnostic)]
 #[suggestion(lint_suggestion, code = "{replacement}")]
-pub struct AbsPathWithModuleSugg {
+pub(crate) struct AbsPathWithModuleSugg {
     #[primary_span]
     pub span: Span,
     #[applicability]
@@ -2590,7 +2590,7 @@ pub struct AbsPathWithModuleSugg {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_proc_macro_derive_resolution_fallback)]
-pub struct ProcMacroDeriveResolutionFallback {
+pub(crate) struct ProcMacroDeriveResolutionFallback {
     #[label]
     pub span: Span,
     pub ns: Namespace,
@@ -2599,28 +2599,28 @@ pub struct ProcMacroDeriveResolutionFallback {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_macro_expanded_macro_exports_accessed_by_absolute_paths)]
-pub struct MacroExpandedMacroExportsAccessedByAbsolutePaths {
+pub(crate) struct MacroExpandedMacroExportsAccessedByAbsolutePaths {
     #[note]
     pub definition: Span,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_hidden_lifetime_parameters)]
-pub struct ElidedLifetimesInPaths {
+pub(crate) struct ElidedLifetimesInPaths {
     #[subdiagnostic]
     pub subdiag: ElidedLifetimeInPathSubdiag,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_invalid_crate_type_value)]
-pub struct UnknownCrateTypes {
+pub(crate) struct UnknownCrateTypes {
     #[subdiagnostic]
     pub sugg: Option<UnknownCrateTypesSub>,
 }
 
 #[derive(Subdiagnostic)]
 #[suggestion(lint_suggestion, code = r#""{candidate}""#, applicability = "maybe-incorrect")]
-pub struct UnknownCrateTypesSub {
+pub(crate) struct UnknownCrateTypesSub {
     #[primary_span]
     pub span: Span,
     pub candidate: Symbol,
@@ -2628,7 +2628,7 @@ pub struct UnknownCrateTypesSub {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_imports)]
-pub struct UnusedImports {
+pub(crate) struct UnusedImports {
     #[subdiagnostic]
     pub sugg: UnusedImportsSugg,
     #[help]
@@ -2639,7 +2639,7 @@ pub struct UnusedImports {
 }
 
 #[derive(Subdiagnostic)]
-pub enum UnusedImportsSugg {
+pub(crate) enum UnusedImportsSugg {
     #[suggestion(
         lint_suggestion_remove_whole_use,
         applicability = "machine-applicable",
@@ -2664,7 +2664,7 @@ pub enum UnusedImportsSugg {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_redundant_import)]
-pub struct RedundantImport {
+pub(crate) struct RedundantImport {
     #[subdiagnostic]
     pub subs: Vec<RedundantImportSub>,
 
@@ -2672,7 +2672,7 @@ pub struct RedundantImport {
 }
 
 #[derive(Subdiagnostic)]
-pub enum RedundantImportSub {
+pub(crate) enum RedundantImportSub {
     #[label(lint_label_imported_here)]
     ImportedHere(#[primary_span] Span),
     #[label(lint_label_defined_here)]
@@ -2686,13 +2686,13 @@ pub enum RedundantImportSub {
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_doc_comment)]
 #[help]
-pub struct UnusedDocComment {
+pub(crate) struct UnusedDocComment {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-pub enum PatternsInFnsWithoutBody {
+pub(crate) enum PatternsInFnsWithoutBody {
     #[diag(lint_pattern_in_foreign)]
     Foreign {
         #[subdiagnostic]
@@ -2707,7 +2707,7 @@ pub enum PatternsInFnsWithoutBody {
 
 #[derive(Subdiagnostic)]
 #[suggestion(lint_remove_mut_from_pattern, code = "{ident}", applicability = "machine-applicable")]
-pub struct PatternsInFnsWithoutBodySub {
+pub(crate) struct PatternsInFnsWithoutBodySub {
     #[primary_span]
     pub span: Span,
 
@@ -2717,7 +2717,7 @@ pub struct PatternsInFnsWithoutBodySub {
 #[derive(LintDiagnostic)]
 #[diag(lint_extern_without_abi)]
 #[help]
-pub struct MissingAbi {
+pub(crate) struct MissingAbi {
     #[label]
     pub span: Span,
 
@@ -2726,14 +2726,14 @@ pub struct MissingAbi {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_legacy_derive_helpers)]
-pub struct LegacyDeriveHelpers {
+pub(crate) struct LegacyDeriveHelpers {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_or_patterns_back_compat)]
-pub struct OrPatternsBackCompat {
+pub(crate) struct OrPatternsBackCompat {
     #[suggestion(code = "{suggestion}", applicability = "machine-applicable")]
     pub span: Span,
     pub suggestion: String,
@@ -2741,7 +2741,7 @@ pub struct OrPatternsBackCompat {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_reserved_prefix)]
-pub struct ReservedPrefix {
+pub(crate) struct ReservedPrefix {
     #[label]
     pub label: Span,
     #[suggestion(code = " ", applicability = "machine-applicable")]
@@ -2752,7 +2752,7 @@ pub struct ReservedPrefix {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_builtin_attribute)]
-pub struct UnusedBuiltinAttribute {
+pub(crate) struct UnusedBuiltinAttribute {
     #[note]
     pub invoc_span: Span,
 
@@ -2762,7 +2762,7 @@ pub struct UnusedBuiltinAttribute {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_trailing_semi_macro)]
-pub struct TrailingMacro {
+pub(crate) struct TrailingMacro {
     #[note(lint_note1)]
     #[note(lint_note2)]
     pub is_trailing: bool,
@@ -2772,14 +2772,14 @@ pub struct TrailingMacro {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_break_with_label_and_loop)]
-pub struct BreakWithLabelAndLoop {
+pub(crate) struct BreakWithLabelAndLoop {
     #[subdiagnostic]
     pub sub: BreakWithLabelAndLoopSub,
 }
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion, applicability = "machine-applicable")]
-pub struct BreakWithLabelAndLoopSub {
+pub(crate) struct BreakWithLabelAndLoopSub {
     #[suggestion_part(code = "(")]
     pub left: Span,
     #[suggestion_part(code = ")")]
@@ -2789,13 +2789,13 @@ pub struct BreakWithLabelAndLoopSub {
 #[derive(LintDiagnostic)]
 #[diag(lint_deprecated_where_clause_location)]
 #[note]
-pub struct DeprecatedWhereClauseLocation {
+pub(crate) struct DeprecatedWhereClauseLocation {
     #[subdiagnostic]
     pub suggestion: DeprecatedWhereClauseLocationSugg,
 }
 
 #[derive(Subdiagnostic)]
-pub enum DeprecatedWhereClauseLocationSugg {
+pub(crate) enum DeprecatedWhereClauseLocationSugg {
     #[multipart_suggestion(lint_suggestion_move_to_end, applicability = "machine-applicable")]
     MoveToEnd {
         #[suggestion_part(code = "")]
@@ -2814,14 +2814,14 @@ pub enum DeprecatedWhereClauseLocationSugg {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_missing_unsafe_on_extern)]
-pub struct MissingUnsafeOnExtern {
+pub(crate) struct MissingUnsafeOnExtern {
     #[suggestion(code = "unsafe ", applicability = "machine-applicable")]
     pub suggestion: Span,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_single_use_lifetime)]
-pub struct SingleUseLifetime {
+pub(crate) struct SingleUseLifetime {
     #[label(lint_label_param)]
     pub param_span: Span,
     #[label(lint_label_use)]
@@ -2834,7 +2834,7 @@ pub struct SingleUseLifetime {
 
 #[derive(Subdiagnostic)]
 #[multipart_suggestion(lint_suggestion, applicability = "machine-applicable")]
-pub struct SingleUseLifetimeSugg {
+pub(crate) struct SingleUseLifetimeSugg {
     #[suggestion_part(code = "")]
     pub deletion_span: Option<Span>,
     #[suggestion_part(code = "{replace_lt}")]
@@ -2845,7 +2845,7 @@ pub struct SingleUseLifetimeSugg {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_lifetime)]
-pub struct UnusedLifetime {
+pub(crate) struct UnusedLifetime {
     #[suggestion(code = "", applicability = "machine-applicable")]
     pub deletion_span: Option<Span>,
 
@@ -2854,7 +2854,7 @@ pub struct UnusedLifetime {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_named_argument_used_positionally)]
-pub struct NamedArgumentUsedPositionally {
+pub(crate) struct NamedArgumentUsedPositionally {
     #[label(lint_label_named_arg)]
     pub named_arg_sp: Span,
     #[label(lint_label_position_arg)]
@@ -2869,21 +2869,21 @@ pub struct NamedArgumentUsedPositionally {
 #[derive(LintDiagnostic)]
 #[diag(lint_byte_slice_in_packed_struct_with_derive)]
 #[help]
-pub struct ByteSliceInPackedStructWithDerive {
+pub(crate) struct ByteSliceInPackedStructWithDerive {
     // FIXME: make this translatable
     pub ty: String,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unused_extern_crate)]
-pub struct UnusedExternCrate {
+pub(crate) struct UnusedExternCrate {
     #[suggestion(code = "", applicability = "machine-applicable")]
     pub removal_span: Span,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_extern_crate_not_idiomatic)]
-pub struct ExternCrateNotIdiomatic {
+pub(crate) struct ExternCrateNotIdiomatic {
     #[suggestion(style = "verbose", code = "{code}", applicability = "machine-applicable")]
     pub span: Span,
 
@@ -2891,7 +2891,7 @@ pub struct ExternCrateNotIdiomatic {
 }
 
 // FIXME: make this translatable
-pub struct AmbiguousGlobImports {
+pub(crate) struct AmbiguousGlobImports {
     pub ambiguity: AmbiguityErrorDiag,
 }
 
@@ -2904,7 +2904,7 @@ impl<'a, G: EmissionGuarantee> LintDiagnostic<'a, G> for AmbiguousGlobImports {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_ambiguous_glob_reexport)]
-pub struct AmbiguousGlobReexports {
+pub(crate) struct AmbiguousGlobReexports {
     #[label(lint_label_first_reexport)]
     pub first_reexport: Span,
     #[label(lint_label_duplicate_reexport)]
@@ -2917,7 +2917,7 @@ pub struct AmbiguousGlobReexports {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_hidden_glob_reexport)]
-pub struct HiddenGlobReexports {
+pub(crate) struct HiddenGlobReexports {
     #[note(lint_note_glob_reexport)]
     pub glob_reexport: Span,
     #[note(lint_note_private_item)]
@@ -2930,14 +2930,14 @@ pub struct HiddenGlobReexports {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unnecessary_qualification)]
-pub struct UnusedQualifications {
+pub(crate) struct UnusedQualifications {
     #[suggestion(style = "verbose", code = "", applicability = "machine-applicable")]
     pub removal_span: Span,
 }
 
 #[derive(LintDiagnostic)]
 #[diag(lint_associated_const_elided_lifetime)]
-pub struct AssociatedConstElidedLifetime {
+pub(crate) struct AssociatedConstElidedLifetime {
     #[suggestion(style = "verbose", code = "{code}", applicability = "machine-applicable")]
     pub span: Span,
 
@@ -2949,7 +2949,7 @@ pub struct AssociatedConstElidedLifetime {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_redundant_import_visibility)]
-pub struct RedundantImportVisibility {
+pub(crate) struct RedundantImportVisibility {
     #[note]
     pub span: Span,
     #[help]
@@ -2961,7 +2961,7 @@ pub struct RedundantImportVisibility {
 
 #[derive(LintDiagnostic)]
 #[diag(lint_unsafe_attr_outside_unsafe)]
-pub struct UnsafeAttrOutsideUnsafe {
+pub(crate) struct UnsafeAttrOutsideUnsafe {
     #[label]
     pub span: Span,
     #[subdiagnostic]
@@ -2973,7 +2973,7 @@ pub struct UnsafeAttrOutsideUnsafe {
     lint_unsafe_attr_outside_unsafe_suggestion,
     applicability = "machine-applicable"
 )]
-pub struct UnsafeAttrOutsideUnsafeSuggestion {
+pub(crate) struct UnsafeAttrOutsideUnsafeSuggestion {
     #[suggestion_part(code = "unsafe(")]
     pub left: Span,
     #[suggestion_part(code = ")")]
@@ -2983,6 +2983,6 @@ pub struct UnsafeAttrOutsideUnsafeSuggestion {
 #[derive(LintDiagnostic)]
 #[diag(lint_out_of_scope_macro_calls)]
 #[help]
-pub struct OutOfScopeMacroCalls {
+pub(crate) struct OutOfScopeMacroCalls {
     pub path: String,
 }
diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
index 5ad677995da..13a3c741fe3 100644
--- a/compiler/rustc_lint/src/non_local_def.rs
+++ b/compiler/rustc_lint/src/non_local_def.rs
@@ -55,7 +55,7 @@ declare_lint! {
 }
 
 #[derive(Default)]
-pub struct NonLocalDefinitions {
+pub(crate) struct NonLocalDefinitions {
     body_depth: u32,
 }
 
diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs
index d7fd41c0ad7..d81052b5e24 100644
--- a/compiler/rustc_lint/src/nonstandard_style.rs
+++ b/compiler/rustc_lint/src/nonstandard_style.rs
@@ -17,13 +17,13 @@ use crate::lints::{
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 
 #[derive(PartialEq)]
-pub enum MethodLateContext {
+pub(crate) enum MethodLateContext {
     TraitAutoImpl,
     TraitImpl,
     PlainImpl,
 }
 
-pub fn method_context(cx: &LateContext<'_>, id: LocalDefId) -> MethodLateContext {
+pub(crate) fn method_context(cx: &LateContext<'_>, id: LocalDefId) -> MethodLateContext {
     let item = cx.tcx.associated_item(id);
     match item.container {
         ty::TraitContainer => MethodLateContext::TraitAutoImpl,
diff --git a/compiler/rustc_lint/src/shadowed_into_iter.rs b/compiler/rustc_lint/src/shadowed_into_iter.rs
index 4fe35a6a0a3..bb9c7d85c2e 100644
--- a/compiler/rustc_lint/src/shadowed_into_iter.rs
+++ b/compiler/rustc_lint/src/shadowed_into_iter.rs
@@ -65,7 +65,7 @@ declare_lint! {
 }
 
 #[derive(Copy, Clone)]
-pub struct ShadowedIntoIter;
+pub(crate) struct ShadowedIntoIter;
 
 impl_lint_pass!(ShadowedIntoIter => [ARRAY_INTO_ITER, BOXED_SLICE_INTO_ITER]);
 
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index f1da14bb1f3..f2f7c0eaa4d 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -165,7 +165,7 @@ declare_lint! {
 }
 
 #[derive(Copy, Clone)]
-pub struct TypeLimits {
+pub(crate) struct TypeLimits {
     /// Id of the last visited negated expression
     negated_expr_id: Option<hir::HirId>,
     /// Span of the last visited negated expression
@@ -180,7 +180,7 @@ impl_lint_pass!(TypeLimits => [
 ]);
 
 impl TypeLimits {
-    pub fn new() -> TypeLimits {
+    pub(crate) fn new() -> TypeLimits {
         TypeLimits { negated_expr_id: None, negated_expr_span: None }
     }
 }
@@ -1008,7 +1008,7 @@ pub(crate) fn nonnull_optimization_guaranteed<'tcx>(
 
 /// `repr(transparent)` structs can have a single non-1-ZST field, this function returns that
 /// field.
-pub fn transparent_newtype_field<'a, 'tcx>(
+pub(crate) fn transparent_newtype_field<'a, 'tcx>(
     tcx: TyCtxt<'tcx>,
     variant: &'a ty::VariantDef,
 ) -> Option<&'a ty::FieldDef> {
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index 553d9db12c5..c3b80e01c36 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -1019,7 +1019,7 @@ declare_lint! {
     "`if`, `match`, `while` and `return` do not need parentheses"
 }
 
-pub struct UnusedParens {
+pub(crate) struct UnusedParens {
     with_self_ty_parens: bool,
     /// `1 as (i32) < 2` parses to ExprKind::Lt
     /// `1 as i32 < 2` parses to i32::<2[missing angle bracket]
@@ -1027,7 +1027,7 @@ pub struct UnusedParens {
 }
 
 impl UnusedParens {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         Self { with_self_ty_parens: false, parens_in_cast_in_lt: Vec::new() }
     }
 }
diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs
index 0f07de43e80..c17b85db3b0 100644
--- a/compiler/rustc_lint_defs/src/lib.rs
+++ b/compiler/rustc_lint_defs/src/lib.rs
@@ -1,3 +1,7 @@
+// tidy-alphabetical-start
+#![warn(unreachable_pub)]
+// tidy-alphabetical-end
+
 use rustc_ast::node_id::NodeId;
 use rustc_ast::{AttrId, Attribute};
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
diff --git a/compiler/rustc_llvm/src/lib.rs b/compiler/rustc_llvm/src/lib.rs
index 939e5e4dbd4..3532d50c64e 100644
--- a/compiler/rustc_llvm/src/lib.rs
+++ b/compiler/rustc_llvm/src/lib.rs
@@ -1,8 +1,10 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(unsafe_attributes, unsafe_extern_blocks))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 // NOTE: This crate only exists to allow linking on mingw targets.
@@ -28,7 +30,7 @@ impl RustString {
 }
 
 /// Appending to a Rust string -- used by RawRustStringOstream.
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn LLVMRustStringWriteImpl(
     sr: &RustString,
     ptr: *const c_char,
@@ -46,7 +48,7 @@ pub fn initialize_available_targets() {
         ($cfg:meta, $($method:ident),*) => { {
             #[cfg($cfg)]
             fn init() {
-                extern "C" {
+                unsafe extern "C" {
                     $(fn $method();)*
                 }
                 unsafe {
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index 6886562d9b7..ce330b4744b 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -28,7 +28,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::potential_query_instability)]
 #![allow(rustc::untranslatable_diagnostic)]
-#![cfg_attr(bootstrap, feature(min_exhaustive_patterns))]
+#![cfg_attr(bootstrap, feature(min_exhaustive_patterns, unsafe_extern_blocks))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(allocator_api)]
diff --git a/compiler/rustc_middle/src/ty/list.rs b/compiler/rustc_middle/src/ty/list.rs
index 1a1acf36d77..af76d5b7d92 100644
--- a/compiler/rustc_middle/src/ty/list.rs
+++ b/compiler/rustc_middle/src/ty/list.rs
@@ -58,7 +58,7 @@ impl<T> Default for &List<T> {
     }
 }
 
-extern "C" {
+unsafe extern "C" {
     /// A dummy type used to force `List` to be unsized while not requiring
     /// references to it be wide pointers.
     type OpaqueListContents;
diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index c1ddfcb2f90..082c169b210 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/compiler/rustc_target/src/abi/call/mod.rs
@@ -745,10 +745,25 @@ impl<'a, Ty> ArgAbi<'a, Ty> {
 
     /// Checks if these two `ArgAbi` are equal enough to be considered "the same for all
     /// function call ABIs".
-    pub fn eq_abi(&self, other: &Self) -> bool {
+    pub fn eq_abi(&self, other: &Self) -> bool
+    where
+        Ty: PartialEq,
+    {
         // Ideally we'd just compare the `mode`, but that is not enough -- for some modes LLVM will look
         // at the type.
-        self.layout.eq_abi(&other.layout) && self.mode.eq_abi(&other.mode)
+        self.layout.eq_abi(&other.layout) && self.mode.eq_abi(&other.mode) && {
+            // `fn_arg_sanity_check` accepts `PassMode::Direct` for some aggregates.
+            // That elevates any type difference to an ABI difference since we just use the
+            // full Rust type as the LLVM argument/return type.
+            if matches!(self.mode, PassMode::Direct(..))
+                && matches!(self.layout.abi, Abi::Aggregate { .. })
+            {
+                // For aggregates in `Direct` mode to be compatible, the types need to be equal.
+                self.layout.ty == other.layout.ty
+            } else {
+                true
+            }
+        }
     }
 }
 
diff --git a/compiler/rustc_target/src/spec/abi/mod.rs b/compiler/rustc_target/src/spec/abi/mod.rs
index 0d61345a70e..cc383f88fbc 100644
--- a/compiler/rustc_target/src/spec/abi/mod.rs
+++ b/compiler/rustc_target/src/spec/abi/mod.rs
@@ -53,6 +53,8 @@ pub enum Abi {
     },
     RustIntrinsic,
     RustCall,
+    /// *Not* a stable ABI, just directly use the Rust types to describe the ABI for LLVM. Even
+    /// normally ABI-compatible Rust types can become ABI-incompatible with this ABI!
     Unadjusted,
     /// For things unlikely to be called, where reducing register pressure in
     /// `extern "Rust"` callers is worth paying extra cost in the callee.