Rollup merge of #129732 - nnethercote:unreachable_pub-3, r=Urgau

Add `unreachable_pub`, round 3

A follow-up to #129648.

r? `@Urgau`

compiler/rustc_macros/src/diagnostics/mod.rs

@@ -55,7 +55,7 @@ use synstructure::Structure;
 ///
 /// See rustc dev guide for more examples on using the `#[derive(Diagnostic)]`:
 /// <https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html>
-pub fn diagnostic_derive(mut s: Structure<'_>) -> TokenStream {
+pub(super) fn diagnostic_derive(mut s: Structure<'_>) -> TokenStream {
     s.underscore_const(true);
     DiagnosticDerive::new(s).into_tokens()
 }
@@ -102,7 +102,7 @@ pub fn diagnostic_derive(mut s: Structure<'_>) -> TokenStream {
 ///
 /// See rustc dev guide for more examples on using the `#[derive(LintDiagnostic)]`:
 /// <https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html#reference>
-pub fn lint_diagnostic_derive(mut s: Structure<'_>) -> TokenStream {
+pub(super) fn lint_diagnostic_derive(mut s: Structure<'_>) -> TokenStream {
     s.underscore_const(true);
     LintDiagnosticDerive::new(s).into_tokens()
 }
@@ -153,7 +153,7 @@ pub fn lint_diagnostic_derive(mut s: Structure<'_>) -> TokenStream {
 ///
 /// diag.subdiagnostic(RawIdentifierSuggestion { span, applicability, ident });
 /// ```
-pub fn subdiagnostic_derive(mut s: Structure<'_>) -> TokenStream {
+pub(super) fn subdiagnostic_derive(mut s: Structure<'_>) -> TokenStream {
     s.underscore_const(true);
     SubdiagnosticDerive::new().into_tokens(s)
 }

compiler/rustc_macros/src/lib.rs

@@ -6,6 +6,7 @@
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]
 #![feature(proc_macro_tracked_env)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use proc_macro::TokenStream;

compiler/rustc_macros/src/lift.rs

@@ -1,7 +1,7 @@
 use quote::quote;
 use syn::parse_quote;
 
-pub fn lift_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn lift_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     s.add_bounds(synstructure::AddBounds::Generics);
     s.bind_with(|_| synstructure::BindStyle::Move);
     s.underscore_const(true);

compiler/rustc_macros/src/query.rs

@@ -307,7 +307,7 @@ fn add_query_desc_cached_impl(
     });
 }
 
-pub fn rustc_queries(input: TokenStream) -> TokenStream {
+pub(super) fn rustc_queries(input: TokenStream) -> TokenStream {
     let queries = parse_macro_input!(input as List<Query>);
 
     let mut query_stream = quote! {};

compiler/rustc_macros/src/serialize.rs

@@ -3,7 +3,9 @@ use quote::{quote, quote_spanned};
 use syn::parse_quote;
 use syn::spanned::Spanned;
 
-pub fn type_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn type_decodable_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     let decoder_ty = quote! { __D };
     let bound = if s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
         quote! { <I = ::rustc_middle::ty::TyCtxt<'tcx>> }
@@ -20,7 +22,9 @@ pub fn type_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
     decodable_body(s, decoder_ty)
 }
 
-pub fn meta_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn meta_decodable_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
         s.add_impl_generic(parse_quote! { 'tcx });
     }
@@ -32,7 +36,7 @@ pub fn meta_decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
     decodable_body(s, decoder_ty)
 }
 
-pub fn decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     let decoder_ty = quote! { __D };
     s.add_impl_generic(parse_quote! { #decoder_ty: ::rustc_span::SpanDecoder });
     s.add_bounds(synstructure::AddBounds::Generics);
@@ -41,7 +45,9 @@ pub fn decodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::Toke
     decodable_body(s, decoder_ty)
 }
 
-pub fn decodable_generic_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn decodable_generic_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     let decoder_ty = quote! { __D };
     s.add_impl_generic(parse_quote! { #decoder_ty: ::rustc_serialize::Decoder });
     s.add_bounds(synstructure::AddBounds::Generics);
@@ -123,7 +129,9 @@ fn decode_field(field: &syn::Field) -> proc_macro2::TokenStream {
     quote_spanned! { field_span=> #decode_inner_method(#__decoder) }
 }
 
-pub fn type_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn type_encodable_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     let bound = if s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
         quote! { <I = ::rustc_middle::ty::TyCtxt<'tcx>> }
     } else if s.ast().generics.type_params().any(|ty| ty.ident == "I") {
@@ -140,7 +148,9 @@ pub fn type_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
     encodable_body(s, encoder_ty, false)
 }
 
-pub fn meta_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn meta_encodable_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
         s.add_impl_generic(parse_quote! { 'tcx });
     }
@@ -152,7 +162,7 @@ pub fn meta_encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
     encodable_body(s, encoder_ty, true)
 }
 
-pub fn encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     let encoder_ty = quote! { __E };
     s.add_impl_generic(parse_quote! { #encoder_ty: ::rustc_span::SpanEncoder });
     s.add_bounds(synstructure::AddBounds::Generics);
@@ -161,7 +171,9 @@ pub fn encodable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::Toke
     encodable_body(s, encoder_ty, false)
 }
 
-pub fn encodable_generic_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn encodable_generic_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     let encoder_ty = quote! { __E };
     s.add_impl_generic(parse_quote! { #encoder_ty: ::rustc_serialize::Encoder });
     s.add_bounds(synstructure::AddBounds::Generics);

compiler/rustc_macros/src/symbols.rs

@@ -131,7 +131,7 @@ impl Errors {
     }
 }
 
-pub fn symbols(input: TokenStream) -> TokenStream {
+pub(super) fn symbols(input: TokenStream) -> TokenStream {
     let (mut output, errors) = symbols_with_errors(input);
 
     // If we generated any errors, then report them as compiler_error!() macro calls.

compiler/rustc_macros/src/type_foldable.rs

@@ -1,7 +1,7 @@
 use quote::{quote, ToTokens};
 use syn::parse_quote;
 
-pub fn type_foldable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn type_foldable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     if let syn::Data::Union(_) = s.ast().data {
         panic!("cannot derive on union")
     }

compiler/rustc_macros/src/type_visitable.rs

@@ -1,7 +1,9 @@
 use quote::quote;
 use syn::parse_quote;
 
-pub fn type_visitable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
+pub(super) fn type_visitable_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
     if let syn::Data::Union(_) = s.ast().data {
         panic!("cannot derive on union")
     }

compiler/rustc_metadata/src/lib.rs

@@ -16,6 +16,7 @@
 #![feature(proc_macro_internals)]
 #![feature(rustdoc_internals)]
 #![feature(trusted_len)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 extern crate proc_macro;

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -56,13 +56,13 @@ impl std::ops::Deref for MetadataBlob {
 
 impl MetadataBlob {
     /// Runs the [`MemDecoder`] validation and if it passes, constructs a new [`MetadataBlob`].
-    pub fn new(slice: OwnedSlice) -> Result<Self, ()> {
+    pub(crate) fn new(slice: OwnedSlice) -> Result<Self, ()> {
         if MemDecoder::new(&slice, 0).is_ok() { Ok(Self(slice)) } else { Err(()) }
     }
 
     /// Since this has passed the validation of [`MetadataBlob::new`], this returns bytes which are
     /// known to pass the [`MemDecoder`] validation.
-    pub fn bytes(&self) -> &OwnedSlice {
+    pub(crate) fn bytes(&self) -> &OwnedSlice {
         &self.0
     }
 }
@@ -332,12 +332,12 @@ impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
     }
 
     #[inline]
-    pub fn blob(&self) -> &'a MetadataBlob {
+    pub(crate) fn blob(&self) -> &'a MetadataBlob {
         self.blob
     }
 
     #[inline]
-    pub fn cdata(&self) -> CrateMetadataRef<'a> {
+    fn cdata(&self) -> CrateMetadataRef<'a> {
         debug_assert!(self.cdata.is_some(), "missing CrateMetadata in DecodeContext");
         self.cdata.unwrap()
     }
@@ -377,7 +377,7 @@ impl<'a, 'tcx> DecodeContext<'a, 'tcx> {
     }
 
     #[inline]
-    pub fn read_raw_bytes(&mut self, len: usize) -> &[u8] {
+    fn read_raw_bytes(&mut self, len: usize) -> &[u8] {
         self.opaque.read_raw_bytes(len)
     }
 }

compiler/rustc_metadata/src/rmeta/def_path_hash_map.rs

@@ -17,7 +17,7 @@ parameterized_over_tcx! {
 
 impl DefPathHashMapRef<'_> {
     #[inline]
-    pub fn def_path_hash_to_def_index(&self, def_path_hash: &DefPathHash) -> DefIndex {
+    pub(crate) fn def_path_hash_to_def_index(&self, def_path_hash: &DefPathHash) -> DefIndex {
         match *self {
             DefPathHashMapRef::OwnedFromMetadata(ref map) => {
                 map.get(&def_path_hash.local_hash()).unwrap()

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -2309,7 +2309,7 @@ fn encode_root_position(mut file: &File, pos: usize) -> Result<(), std::io::Erro
     Ok(())
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers {
         doc_link_resolutions: |tcx, def_id| {
             tcx.resolutions(())

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -61,8 +61,9 @@ use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalModDefId, ModDefId, LO
 use rustc_hir::definitions::DefPathHash;
 use rustc_hir::{HirId, ItemLocalId, OwnerId};
 pub use rustc_query_system::dep_graph::dep_node::DepKind;
+pub use rustc_query_system::dep_graph::DepNode;
 use rustc_query_system::dep_graph::FingerprintStyle;
-pub use rustc_query_system::dep_graph::{DepContext, DepNode, DepNodeParams};
+pub(crate) use rustc_query_system::dep_graph::{DepContext, DepNodeParams};
 use rustc_span::symbol::Symbol;
 
 use crate::mir::mono::MonoItem;
@@ -101,7 +102,7 @@ macro_rules! define_dep_nodes {
 
         // This checks that the discriminants of the variants have been assigned consecutively
         // from 0 so that they can be used as a dense index.
-        pub const DEP_KIND_VARIANTS: u16 = {
+        pub(crate) const DEP_KIND_VARIANTS: u16 = {
             let deps = &[$(dep_kinds::$variant,)*];
             let mut i = 0;
             while i < deps.len() {

compiler/rustc_middle/src/lib.rs

@@ -62,6 +62,7 @@
 #![feature(try_blocks)]
 #![feature(type_alias_impl_trait)]
 #![feature(yeet_expr)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 #[cfg(test)]

compiler/rustc_middle/src/mir/basic_blocks.rs

@@ -18,9 +18,9 @@ pub struct BasicBlocks<'tcx> {
 }
 
 // Typically 95%+ of basic blocks have 4 or fewer predecessors.
-pub type Predecessors = IndexVec<BasicBlock, SmallVec<[BasicBlock; 4]>>;
+type Predecessors = IndexVec<BasicBlock, SmallVec<[BasicBlock; 4]>>;
 
-pub type SwitchSources = FxHashMap<(BasicBlock, BasicBlock), SmallVec<[Option<u128>; 1]>>;
+type SwitchSources = FxHashMap<(BasicBlock, BasicBlock), SmallVec<[Option<u128>; 1]>>;
 
 #[derive(Clone, Default, Debug)]
 struct Cache {

compiler/rustc_middle/src/mir/generic_graph.rs

@@ -2,7 +2,7 @@ use gsgdt::{Edge, Graph, Node, NodeStyle};
 use rustc_middle::mir::*;
 
 /// Convert an MIR function into a gsgdt Graph
-pub fn mir_fn_to_generic_graph<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Graph {
+pub(crate) fn mir_fn_to_generic_graph<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Graph {
     let def_id = body.source.def_id();
     let def_name = graphviz_safe_def_name(def_id);
     let graph_name = format!("Mir_{def_name}");

compiler/rustc_middle/src/mir/interpret/allocation/init_mask.rs

@@ -243,7 +243,7 @@ impl hash::Hash for InitMaskMaterialized {
 }
 
 impl InitMaskMaterialized {
-    pub const BLOCK_SIZE: u64 = 64;
+    const BLOCK_SIZE: u64 = 64;
 
     fn new(size: Size, state: bool) -> Self {
         let mut m = InitMaskMaterialized { blocks: vec![] };

compiler/rustc_middle/src/mir/mono.rs

@@ -396,7 +396,7 @@ impl<'tcx> CodegenUnit<'tcx> {
         // The codegen tests rely on items being process in the same order as
         // they appear in the file, so for local items, we sort by node_id first
         #[derive(PartialEq, Eq, PartialOrd, Ord)]
-        pub struct ItemSortKey<'tcx>(Option<usize>, SymbolName<'tcx>);
+        struct ItemSortKey<'tcx>(Option<usize>, SymbolName<'tcx>);
 
         fn item_sort_key<'tcx>(tcx: TyCtxt<'tcx>, item: MonoItem<'tcx>) -> ItemSortKey<'tcx> {
             ItemSortKey(

compiler/rustc_middle/src/ty/context.rs

@@ -2190,7 +2190,7 @@ macro_rules! sty_debug_print {
                 all_infer: usize,
             }
 
-            pub fn go(fmt: &mut std::fmt::Formatter<'_>, tcx: TyCtxt<'_>) -> std::fmt::Result {
+            pub(crate) fn go(fmt: &mut std::fmt::Formatter<'_>, tcx: TyCtxt<'_>) -> std::fmt::Result {
                 let mut total = DebugStat {
                     total: 0,
                     lt_infer: 0,

compiler/rustc_mir_build/src/check_unsafety.rs

@@ -1027,7 +1027,7 @@ impl UnsafeOpKind {
     }
 }
 
-pub fn check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) {
+pub(crate) fn check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) {
     // Closures and inline consts are handled by their owner, if it has a body
     // Also, don't safety check custom MIR
     if tcx.is_typeck_child(def.to_def_id()) || tcx.has_attr(def, sym::custom_mir) {

compiler/rustc_mir_build/src/lib.rs

@@ -8,6 +8,7 @@
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod build;

compiler/rustc_mir_dataflow/src/framework/engine.rs

@@ -24,7 +24,7 @@ use crate::errors::{
 };
 use crate::framework::BitSetExt;
 
-pub type EntrySets<'tcx, A> = IndexVec<BasicBlock, <A as AnalysisDomain<'tcx>>::Domain>;
+type EntrySets<'tcx, A> = IndexVec<BasicBlock, <A as AnalysisDomain<'tcx>>::Domain>;
 
 /// A dataflow analysis that has converged to fixpoint.
 #[derive(Clone)]

compiler/rustc_mir_dataflow/src/framework/mod.rs

@@ -510,7 +510,7 @@ impl<T: Idx> GenKill<T> for lattice::Dual<BitSet<T>> {
 
 // NOTE: DO NOT CHANGE VARIANT ORDER. The derived `Ord` impls rely on the current order.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub enum Effect {
+enum Effect {
     /// The "before" effect (e.g., `apply_before_statement_effect`) for a statement (or
     /// terminator).
     Before,
@@ -520,7 +520,7 @@ pub enum Effect {
 }
 
 impl Effect {
-    pub const fn at_index(self, statement_index: usize) -> EffectIndex {
+    const fn at_index(self, statement_index: usize) -> EffectIndex {
         EffectIndex { effect: self, statement_index }
     }
 }

compiler/rustc_mir_dataflow/src/lib.rs

@@ -5,6 +5,7 @@
 #![feature(exact_size_is_empty)]
 #![feature(let_chains)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use rustc_middle::ty;

compiler/rustc_mir_dataflow/src/move_paths/abs_domain.rs

@@ -15,12 +15,12 @@ use rustc_middle::mir::{Local, Operand, PlaceElem, ProjectionElem};
 use rustc_middle::ty::Ty;
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-pub struct AbstractOperand;
+pub(crate) struct AbstractOperand;
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-pub struct AbstractType;
-pub type AbstractElem = ProjectionElem<AbstractOperand, AbstractType>;
+pub(crate) struct AbstractType;
+pub(crate) type AbstractElem = ProjectionElem<AbstractOperand, AbstractType>;
 
-pub trait Lift {
+pub(crate) trait Lift {
     type Abstract;
     fn lift(&self) -> Self::Abstract;
 }

compiler/rustc_monomorphize/src/collector.rs

@@ -242,12 +242,12 @@ use tracing::{debug, instrument, trace};
 use crate::errors::{self, EncounteredErrorWhileInstantiating, NoOptimizedMir, RecursionLimit};
 
 #[derive(PartialEq)]
-pub enum MonoItemCollectionStrategy {
+pub(crate) enum MonoItemCollectionStrategy {
     Eager,
     Lazy,
 }
 
-pub struct UsageMap<'tcx> {
+pub(crate) struct UsageMap<'tcx> {
     // Maps every mono item to the mono items used by it.
     used_map: UnordMap<MonoItem<'tcx>, Vec<MonoItem<'tcx>>>,
 
@@ -306,13 +306,17 @@ impl<'tcx> UsageMap<'tcx> {
         assert!(self.used_map.insert(user_item, used_items).is_none());
     }
 
-    pub fn get_user_items(&self, item: MonoItem<'tcx>) -> &[MonoItem<'tcx>] {
+    pub(crate) fn get_user_items(&self, item: MonoItem<'tcx>) -> &[MonoItem<'tcx>] {
         self.user_map.get(&item).map(|items| items.as_slice()).unwrap_or(&[])
     }
 
     /// Internally iterate over all inlined items used by `item`.
-    pub fn for_each_inlined_used_item<F>(&self, tcx: TyCtxt<'tcx>, item: MonoItem<'tcx>, mut f: F)
-    where
+    pub(crate) fn for_each_inlined_used_item<F>(
+        &self,
+        tcx: TyCtxt<'tcx>,
+        item: MonoItem<'tcx>,
+        mut f: F,
+    ) where
         F: FnMut(MonoItem<'tcx>),
     {
         let used_items = self.used_map.get(&item).unwrap();
@@ -1615,6 +1619,6 @@ pub(crate) fn collect_crate_mono_items<'tcx>(
     (mono_items, state.usage_map.into_inner())
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.hooks.should_codegen_locally = should_codegen_locally;
 }

compiler/rustc_monomorphize/src/errors.rs

@@ -8,7 +8,7 @@ use crate::fluent_generated as fluent;
 
 #[derive(Diagnostic)]
 #[diag(monomorphize_recursion_limit)]
-pub struct RecursionLimit {
+pub(crate) struct RecursionLimit {
     #[primary_span]
     pub span: Span,
     pub shrunk: String,
@@ -22,13 +22,13 @@ pub struct RecursionLimit {
 
 #[derive(Diagnostic)]
 #[diag(monomorphize_no_optimized_mir)]
-pub struct NoOptimizedMir {
+pub(crate) struct NoOptimizedMir {
     #[note]
     pub span: Span,
     pub crate_name: Symbol,
 }
 
-pub struct UnusedGenericParamsHint {
+pub(crate) struct UnusedGenericParamsHint {
     pub span: Span,
     pub param_spans: Vec<Span>,
     pub param_names: Vec<String>,
@@ -53,7 +53,7 @@ impl<G: EmissionGuarantee> Diagnostic<'_, G> for UnusedGenericParamsHint {
 #[derive(LintDiagnostic)]
 #[diag(monomorphize_large_assignments)]
 #[note]
-pub struct LargeAssignmentsLint {
+pub(crate) struct LargeAssignmentsLint {
     #[label]
     pub span: Span,
     pub size: u64,
@@ -62,7 +62,7 @@ pub struct LargeAssignmentsLint {
 
 #[derive(Diagnostic)]
 #[diag(monomorphize_symbol_already_defined)]
-pub struct SymbolAlreadyDefined {
+pub(crate) struct SymbolAlreadyDefined {
     #[primary_span]
     pub span: Option<Span>,
     pub symbol: String,
@@ -70,13 +70,13 @@ pub struct SymbolAlreadyDefined {
 
 #[derive(Diagnostic)]
 #[diag(monomorphize_couldnt_dump_mono_stats)]
-pub struct CouldntDumpMonoStats {
+pub(crate) struct CouldntDumpMonoStats {
     pub error: String,
 }
 
 #[derive(Diagnostic)]
 #[diag(monomorphize_encountered_error_while_instantiating)]
-pub struct EncounteredErrorWhileInstantiating {
+pub(crate) struct EncounteredErrorWhileInstantiating {
     #[primary_span]
     pub span: Span,
     pub formatted_item: String,
@@ -85,10 +85,10 @@ pub struct EncounteredErrorWhileInstantiating {
 #[derive(Diagnostic)]
 #[diag(monomorphize_start_not_found)]
 #[help]
-pub struct StartNotFound;
+pub(crate) struct StartNotFound;
 
 #[derive(Diagnostic)]
 #[diag(monomorphize_unknown_cgu_collection_mode)]
-pub struct UnknownCguCollectionMode<'a> {
+pub(crate) struct UnknownCguCollectionMode<'a> {
     pub mode: &'a str,
 }

compiler/rustc_monomorphize/src/lib.rs

@@ -1,5 +1,6 @@
 // tidy-alphabetical-start
 #![feature(array_windows)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use rustc_hir::lang_items::LangItem;

compiler/rustc_monomorphize/src/partitioning.rs

@@ -1300,7 +1300,7 @@ fn dump_mono_items_stats<'tcx>(
     Ok(())
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.collect_and_partition_mono_items = collect_and_partition_mono_items;
 
     providers.is_codegened_item = |tcx, def_id| {

compiler/rustc_monomorphize/src/polymorphize.rs

@@ -19,7 +19,7 @@ use tracing::{debug, instrument};
 use crate::errors::UnusedGenericParamsHint;
 
 /// Provide implementations of queries relating to polymorphization analysis.
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.unused_generic_params = unused_generic_params;
 }
 

compiler/rustc_next_trait_solver/src/lib.rs

@@ -4,6 +4,10 @@
 //! but were uplifted in the process of making the new trait solver generic.
 //! So if you got to this crate from the old solver, it's totally normal.
 
+// tidy-alphabetical-start
+#![warn(unreachable_pub)]
+// tidy-alphabetical-end
+
 pub mod canonicalizer;
 pub mod coherence;
 pub mod delegate;

compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs

@@ -92,7 +92,7 @@ where
 #[derive(TypeVisitable_Generic, TypeFoldable_Generic, Lift_Generic)]
 #[cfg_attr(feature = "nightly", derive(TyDecodable, TyEncodable, HashStable_NoContext))]
 // FIXME: This can be made crate-private once `EvalCtxt` also lives in this crate.
-pub struct NestedGoals<I: Interner> {
+struct NestedGoals<I: Interner> {
     /// These normalizes-to goals are treated specially during the evaluation
     /// loop. In each iteration we take the RHS of the projection, replace it with
     /// a fresh inference variable, and only after evaluating that goal do we
@@ -109,11 +109,11 @@ pub struct NestedGoals<I: Interner> {
 }
 
 impl<I: Interner> NestedGoals<I> {
-    pub fn new() -> Self {
+    fn new() -> Self {
         Self { normalizes_to_goals: Vec::new(), goals: Vec::new() }
     }
 
-    pub fn is_empty(&self) -> bool {
+    fn is_empty(&self) -> bool {
         self.normalizes_to_goals.is_empty() && self.goals.is_empty()
     }
 }

compiler/rustc_next_trait_solver/src/solve/inspect/build.rs

@@ -222,13 +222,13 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         self.state.as_deref_mut()
     }
 
-    pub fn take_and_enter_probe(&mut self) -> ProofTreeBuilder<D> {
+    pub(crate) fn take_and_enter_probe(&mut self) -> ProofTreeBuilder<D> {
         let mut nested = ProofTreeBuilder { state: self.state.take(), _infcx: PhantomData };
         nested.enter_probe();
         nested
     }
 
-    pub fn finalize(self) -> Option<inspect::GoalEvaluation<I>> {
+    pub(crate) fn finalize(self) -> Option<inspect::GoalEvaluation<I>> {
         match *self.state? {
             DebugSolver::GoalEvaluation(wip_goal_evaluation) => {
                 Some(wip_goal_evaluation.finalize())
@@ -237,22 +237,22 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn new_maybe_root(generate_proof_tree: GenerateProofTree) -> ProofTreeBuilder<D> {
+    pub(crate) fn new_maybe_root(generate_proof_tree: GenerateProofTree) -> ProofTreeBuilder<D> {
         match generate_proof_tree {
             GenerateProofTree::No => ProofTreeBuilder::new_noop(),
             GenerateProofTree::Yes => ProofTreeBuilder::new_root(),
         }
     }
 
-    pub fn new_root() -> ProofTreeBuilder<D> {
+    fn new_root() -> ProofTreeBuilder<D> {
         ProofTreeBuilder::new(DebugSolver::Root)
     }
 
-    pub fn new_noop() -> ProofTreeBuilder<D> {
+    fn new_noop() -> ProofTreeBuilder<D> {
         ProofTreeBuilder { state: None, _infcx: PhantomData }
     }
 
-    pub fn is_noop(&self) -> bool {
+    pub(crate) fn is_noop(&self) -> bool {
         self.state.is_none()
     }
 
@@ -272,7 +272,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         })
     }
 
-    pub fn new_canonical_goal_evaluation(
+    pub(crate) fn new_canonical_goal_evaluation(
         &mut self,
         goal: CanonicalInput<I>,
     ) -> ProofTreeBuilder<D> {
@@ -284,7 +284,10 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         })
     }
 
-    pub fn canonical_goal_evaluation(&mut self, canonical_goal_evaluation: ProofTreeBuilder<D>) {
+    pub(crate) fn canonical_goal_evaluation(
+        &mut self,
+        canonical_goal_evaluation: ProofTreeBuilder<D>,
+    ) {
         if let Some(this) = self.as_mut() {
             match (this, *canonical_goal_evaluation.state.unwrap()) {
                 (
@@ -299,7 +302,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn canonical_goal_evaluation_overflow(&mut self) {
+    pub(crate) fn canonical_goal_evaluation_overflow(&mut self) {
         if let Some(this) = self.as_mut() {
             match this {
                 DebugSolver::CanonicalGoalEvaluation(canonical_goal_evaluation) => {
@@ -310,7 +313,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn goal_evaluation(&mut self, goal_evaluation: ProofTreeBuilder<D>) {
+    pub(crate) fn goal_evaluation(&mut self, goal_evaluation: ProofTreeBuilder<D>) {
         if let Some(this) = self.as_mut() {
             match this {
                 DebugSolver::Root => *this = *goal_evaluation.state.unwrap(),
@@ -322,7 +325,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn new_goal_evaluation_step(
+    pub(crate) fn new_goal_evaluation_step(
         &mut self,
         var_values: ty::CanonicalVarValues<I>,
         instantiated_goal: QueryInput<I, I::Predicate>,
@@ -340,7 +343,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         })
     }
 
-    pub fn goal_evaluation_step(&mut self, goal_evaluation_step: ProofTreeBuilder<D>) {
+    pub(crate) fn goal_evaluation_step(&mut self, goal_evaluation_step: ProofTreeBuilder<D>) {
         if let Some(this) = self.as_mut() {
             match (this, *goal_evaluation_step.state.unwrap()) {
                 (
@@ -354,7 +357,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn add_var_value<T: Into<I::GenericArg>>(&mut self, arg: T) {
+    pub(crate) fn add_var_value<T: Into<I::GenericArg>>(&mut self, arg: T) {
         match self.as_mut() {
             None => {}
             Some(DebugSolver::CanonicalGoalEvaluationStep(state)) => {
@@ -364,7 +367,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn enter_probe(&mut self) {
+    fn enter_probe(&mut self) {
         match self.as_mut() {
             None => {}
             Some(DebugSolver::CanonicalGoalEvaluationStep(state)) => {
@@ -381,7 +384,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn probe_kind(&mut self, probe_kind: inspect::ProbeKind<I>) {
+    pub(crate) fn probe_kind(&mut self, probe_kind: inspect::ProbeKind<I>) {
         match self.as_mut() {
             None => {}
             Some(DebugSolver::CanonicalGoalEvaluationStep(state)) => {
@@ -392,7 +395,11 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn probe_final_state(&mut self, delegate: &D, max_input_universe: ty::UniverseIndex) {
+    pub(crate) fn probe_final_state(
+        &mut self,
+        delegate: &D,
+        max_input_universe: ty::UniverseIndex,
+    ) {
         match self.as_mut() {
             None => {}
             Some(DebugSolver::CanonicalGoalEvaluationStep(state)) => {
@@ -409,7 +416,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn add_normalizes_to_goal(
+    pub(crate) fn add_normalizes_to_goal(
         &mut self,
         delegate: &D,
         max_input_universe: ty::UniverseIndex,
@@ -423,7 +430,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         );
     }
 
-    pub fn add_goal(
+    pub(crate) fn add_goal(
         &mut self,
         delegate: &D,
         max_input_universe: ty::UniverseIndex,
@@ -469,7 +476,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn make_canonical_response(&mut self, shallow_certainty: Certainty) {
+    pub(crate) fn make_canonical_response(&mut self, shallow_certainty: Certainty) {
         match self.as_mut() {
             Some(DebugSolver::CanonicalGoalEvaluationStep(state)) => {
                 state
@@ -482,7 +489,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         }
     }
 
-    pub fn finish_probe(mut self) -> ProofTreeBuilder<D> {
+    pub(crate) fn finish_probe(mut self) -> ProofTreeBuilder<D> {
         match self.as_mut() {
             None => {}
             Some(DebugSolver::CanonicalGoalEvaluationStep(state)) => {
@@ -497,7 +504,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> ProofTreeBuilder<D> {
         self
     }
 
-    pub fn query_result(&mut self, result: QueryResult<I>) {
+    pub(crate) fn query_result(&mut self, result: QueryResult<I>) {
         if let Some(this) = self.as_mut() {
             match this {
                 DebugSolver::CanonicalGoalEvaluation(canonical_goal_evaluation) => {

compiler/rustc_next_trait_solver/src/solve/normalizes_to/opaque_types.rs

@@ -97,7 +97,7 @@ where
 /// Checks whether each generic argument is simply a unique generic placeholder.
 ///
 /// FIXME: Interner argument is needed to constrain the `I` parameter.
-pub fn uses_unique_placeholders_ignoring_regions<I: Interner>(
+fn uses_unique_placeholders_ignoring_regions<I: Interner>(
     _cx: I,
     args: I::GenericArgs,
 ) -> Result<(), NotUniqueParam<I>> {
@@ -130,7 +130,7 @@ pub fn uses_unique_placeholders_ignoring_regions<I: Interner>(
 }
 
 // FIXME: This should check for dupes and non-params first, then infer vars.
-pub enum NotUniqueParam<I: Interner> {
+enum NotUniqueParam<I: Interner> {
     DuplicateParam(I::GenericArg),
     NotParam(I::GenericArg),
 }

compiler/rustc_parse/src/errors.rs

@@ -260,7 +260,7 @@ pub(crate) struct NotAsNegationOperator {
 }
 
 #[derive(Subdiagnostic)]
-pub enum NotAsNegationOperatorSub {
+pub(crate) enum NotAsNegationOperatorSub {
     #[suggestion(
         parse_unexpected_token_after_not_default,
         style = "verbose",
@@ -424,7 +424,7 @@ pub(crate) enum IfExpressionMissingThenBlockSub {
 #[derive(Diagnostic)]
 #[diag(parse_ternary_operator)]
 #[help]
-pub struct TernaryOperator {
+pub(crate) struct TernaryOperator {
     #[primary_span]
     pub span: Span,
 }
@@ -1088,7 +1088,7 @@ pub(crate) enum ExpectedIdentifierFound {
 }
 
 impl ExpectedIdentifierFound {
-    pub fn new(token_descr: Option<TokenDescription>, span: Span) -> Self {
+    pub(crate) fn new(token_descr: Option<TokenDescription>, span: Span) -> Self {
         (match token_descr {
             Some(TokenDescription::ReservedIdentifier) => {
                 ExpectedIdentifierFound::ReservedIdentifier
@@ -1659,7 +1659,7 @@ pub(crate) struct SelfArgumentPointer {
 
 #[derive(Diagnostic)]
 #[diag(parse_unexpected_token_after_dot)]
-pub struct UnexpectedTokenAfterDot<'a> {
+pub(crate) struct UnexpectedTokenAfterDot<'a> {
     #[primary_span]
     pub span: Span,
     pub actual: Cow<'a, str>,
@@ -1928,7 +1928,7 @@ pub(crate) enum UnexpectedTokenAfterStructName {
 }
 
 impl UnexpectedTokenAfterStructName {
-    pub fn new(span: Span, token: Token) -> Self {
+    pub(crate) fn new(span: Span, token: Token) -> Self {
         match TokenDescription::from_token(&token) {
             Some(TokenDescription::ReservedIdentifier) => Self::ReservedIdentifier { span, token },
             Some(TokenDescription::Keyword) => Self::Keyword { span, token },
@@ -2006,7 +2006,7 @@ pub(crate) enum TopLevelOrPatternNotAllowed {
 
 #[derive(Diagnostic)]
 #[diag(parse_cannot_be_raw_ident)]
-pub struct CannotBeRawIdent {
+pub(crate) struct CannotBeRawIdent {
     #[primary_span]
     pub span: Span,
     pub ident: Symbol,
@@ -2014,14 +2014,14 @@ pub struct CannotBeRawIdent {
 
 #[derive(Diagnostic)]
 #[diag(parse_keyword_lifetime)]
-pub struct KeywordLifetime {
+pub(crate) struct KeywordLifetime {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(parse_invalid_label)]
-pub struct InvalidLabel {
+pub(crate) struct InvalidLabel {
     #[primary_span]
     pub span: Span,
     pub name: Symbol,
@@ -2029,7 +2029,7 @@ pub struct InvalidLabel {
 
 #[derive(Diagnostic)]
 #[diag(parse_cr_doc_comment)]
-pub struct CrDocComment {
+pub(crate) struct CrDocComment {
     #[primary_span]
     pub span: Span,
     pub block: bool,
@@ -2037,14 +2037,14 @@ pub struct CrDocComment {
 
 #[derive(Diagnostic)]
 #[diag(parse_no_digits_literal, code = E0768)]
-pub struct NoDigitsLiteral {
+pub(crate) struct NoDigitsLiteral {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(parse_invalid_digit_literal)]
-pub struct InvalidDigitLiteral {
+pub(crate) struct InvalidDigitLiteral {
     #[primary_span]
     pub span: Span,
     pub base: u32,
@@ -2052,14 +2052,14 @@ pub struct InvalidDigitLiteral {
 
 #[derive(Diagnostic)]
 #[diag(parse_empty_exponent_float)]
-pub struct EmptyExponentFloat {
+pub(crate) struct EmptyExponentFloat {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(parse_float_literal_unsupported_base)]
-pub struct FloatLiteralUnsupportedBase {
+pub(crate) struct FloatLiteralUnsupportedBase {
     #[primary_span]
     pub span: Span,
     pub base: &'static str,
@@ -2068,7 +2068,7 @@ pub struct FloatLiteralUnsupportedBase {
 #[derive(Diagnostic)]
 #[diag(parse_unknown_prefix)]
 #[note]
-pub struct UnknownPrefix<'a> {
+pub(crate) struct UnknownPrefix<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -2079,12 +2079,12 @@ pub struct UnknownPrefix<'a> {
 
 #[derive(Subdiagnostic)]
 #[note(parse_macro_expands_to_adt_field)]
-pub struct MacroExpandsToAdtField<'a> {
+pub(crate) struct MacroExpandsToAdtField<'a> {
     pub adt_ty: &'a str,
 }
 
 #[derive(Subdiagnostic)]
-pub enum UnknownPrefixSugg {
+pub(crate) enum UnknownPrefixSugg {
     #[suggestion(
         parse_suggestion_br,
         code = "br",
@@ -2114,7 +2114,7 @@ pub enum UnknownPrefixSugg {
 
 #[derive(Diagnostic)]
 #[diag(parse_too_many_hashes)]
-pub struct TooManyHashes {
+pub(crate) struct TooManyHashes {
     #[primary_span]
     pub span: Span,
     pub num: u32,
@@ -2122,7 +2122,7 @@ pub struct TooManyHashes {
 
 #[derive(Diagnostic)]
 #[diag(parse_unknown_start_of_token)]
-pub struct UnknownTokenStart {
+pub(crate) struct UnknownTokenStart {
     #[primary_span]
     pub span: Span,
     pub escaped: String,
@@ -2135,7 +2135,7 @@ pub struct UnknownTokenStart {
 }
 
 #[derive(Subdiagnostic)]
-pub enum TokenSubstitution {
+pub(crate) enum TokenSubstitution {
     #[suggestion(
         parse_sugg_quotes,
         code = "{suggestion}",
@@ -2168,16 +2168,16 @@ pub enum TokenSubstitution {
 
 #[derive(Subdiagnostic)]
 #[note(parse_note_repeats)]
-pub struct UnknownTokenRepeat {
+pub(crate) struct UnknownTokenRepeat {
     pub repeats: usize,
 }
 
 #[derive(Subdiagnostic)]
 #[help(parse_help_null)]
-pub struct UnknownTokenNull;
+pub(crate) struct UnknownTokenNull;
 
 #[derive(Diagnostic)]
-pub enum UnescapeError {
+pub(crate) enum UnescapeError {
     #[diag(parse_invalid_unicode_escape)]
     #[help]
     InvalidUnicodeEscape {
@@ -2322,7 +2322,7 @@ pub enum UnescapeError {
 }
 
 #[derive(Subdiagnostic)]
-pub enum MoreThanOneCharSugg {
+pub(crate) enum MoreThanOneCharSugg {
     #[suggestion(
         parse_consider_normalized,
         code = "{normalized}",
@@ -2370,7 +2370,7 @@ pub enum MoreThanOneCharSugg {
 }
 
 #[derive(Subdiagnostic)]
-pub enum MoreThanOneCharNote {
+pub(crate) enum MoreThanOneCharNote {
     #[note(parse_followed_by)]
     AllCombining {
         #[primary_span]
@@ -2388,7 +2388,7 @@ pub enum MoreThanOneCharNote {
 }
 
 #[derive(Subdiagnostic)]
-pub enum NoBraceUnicodeSub {
+pub(crate) enum NoBraceUnicodeSub {
     #[suggestion(
         parse_use_braces,
         code = "{suggestion}",
@@ -2703,7 +2703,7 @@ pub(crate) struct InvalidDynKeyword {
 }
 
 #[derive(Subdiagnostic)]
-pub enum HelpUseLatestEdition {
+pub(crate) enum HelpUseLatestEdition {
     #[help(parse_help_set_edition_cargo)]
     #[note(parse_note_edition_guide)]
     Cargo { edition: Edition },
@@ -2713,7 +2713,7 @@ 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 }
@@ -2725,7 +2725,7 @@ impl HelpUseLatestEdition {
 
 #[derive(Diagnostic)]
 #[diag(parse_box_syntax_removed)]
-pub struct BoxSyntaxRemoved {
+pub(crate) struct BoxSyntaxRemoved {
     #[primary_span]
     pub span: Span,
     #[subdiagnostic]
@@ -2738,7 +2738,7 @@ pub struct BoxSyntaxRemoved {
     applicability = "machine-applicable",
     style = "verbose"
 )]
-pub struct AddBoxNew {
+pub(crate) struct AddBoxNew {
     #[suggestion_part(code = "Box::new(")]
     pub box_kw_and_lo: Span,
     #[suggestion_part(code = ")")]
@@ -3190,7 +3190,7 @@ pub(crate) struct DotDotRangeAttribute {
 #[derive(Diagnostic)]
 #[diag(parse_invalid_attr_unsafe)]
 #[note]
-pub struct InvalidAttrUnsafe {
+pub(crate) struct InvalidAttrUnsafe {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -3199,7 +3199,7 @@ pub struct InvalidAttrUnsafe {
 
 #[derive(Diagnostic)]
 #[diag(parse_unsafe_attr_outside_unsafe)]
-pub struct UnsafeAttrOutsideUnsafe {
+pub(crate) struct UnsafeAttrOutsideUnsafe {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -3212,7 +3212,7 @@ pub struct UnsafeAttrOutsideUnsafe {
     parse_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 = ")")]
@@ -3221,7 +3221,7 @@ pub struct UnsafeAttrOutsideUnsafeSuggestion {
 
 #[derive(Diagnostic)]
 #[diag(parse_binder_before_modifiers)]
-pub struct BinderBeforeModifiers {
+pub(crate) struct BinderBeforeModifiers {
     #[primary_span]
     pub binder_span: Span,
     #[label]
@@ -3230,7 +3230,7 @@ pub struct BinderBeforeModifiers {
 
 #[derive(Diagnostic)]
 #[diag(parse_binder_and_polarity)]
-pub struct BinderAndPolarity {
+pub(crate) struct BinderAndPolarity {
     #[primary_span]
     pub polarity_span: Span,
     #[label]
@@ -3240,7 +3240,7 @@ pub struct BinderAndPolarity {
 
 #[derive(Diagnostic)]
 #[diag(parse_modifiers_and_polarity)]
-pub struct PolarityAndModifiers {
+pub(crate) struct PolarityAndModifiers {
     #[primary_span]
     pub polarity_span: Span,
     #[label]

compiler/rustc_parse/src/lib.rs

@@ -11,6 +11,7 @@
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::path::Path;

compiler/rustc_parse_format/src/lib.rs

@@ -13,6 +13,7 @@
     html_playground_url = "https://play.rust-lang.org/",
     test(attr(deny(warnings)))
 )]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::{iter, str, string};

compiler/rustc_passes/src/debugger_visualizer.rs

@@ -95,6 +95,6 @@ fn debugger_visualizers(tcx: TyCtxt<'_>, _: LocalCrate) -> Vec<DebuggerVisualize
     visitor.visualizers
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.debugger_visualizers = debugger_visualizers;
 }

compiler/rustc_passes/src/diagnostic_items.rs

@@ -90,7 +90,7 @@ fn all_diagnostic_items(tcx: TyCtxt<'_>, (): ()) -> DiagnosticItems {
     items
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.diagnostic_items = diagnostic_items;
     providers.all_diagnostic_items = all_diagnostic_items;
 }

compiler/rustc_passes/src/lang_items.rs

@@ -359,6 +359,6 @@ impl<'ast, 'tcx> visit::Visitor<'ast> for LanguageItemCollector<'ast, 'tcx> {
     }
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.get_lang_items = get_lang_items;
 }

compiler/rustc_passes/src/lib.rs

@@ -12,6 +12,7 @@
 #![feature(map_try_insert)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use rustc_middle::query::Providers;

compiler/rustc_passes/src/lib_features.rs

@@ -16,7 +16,7 @@ use rustc_span::{sym, Span};
 
 use crate::errors::{FeaturePreviouslyDeclared, FeatureStableTwice};
 
-pub struct LibFeatureCollector<'tcx> {
+struct LibFeatureCollector<'tcx> {
     tcx: TyCtxt<'tcx>,
     lib_features: LibFeatures,
 }
@@ -153,6 +153,6 @@ fn lib_features(tcx: TyCtxt<'_>, LocalCrate: LocalCrate) -> LibFeatures {
     collector.lib_features
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.lib_features = lib_features;
 }

compiler/rustc_passes/src/liveness.rs

@@ -178,7 +178,7 @@ fn check_liveness(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     lsets.warn_about_unused_args(&body, entry_ln);
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { check_liveness, ..*providers };
 }
 

compiler/rustc_passes/src/reachable.rs

@@ -500,6 +500,6 @@ fn reachable_set(tcx: TyCtxt<'_>, (): ()) -> LocalDefIdSet {
     reachable_context.reachable_symbols
 }
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { reachable_set, ..*providers };
 }

compiler/rustc_passes/src/upvars.rs

@@ -9,7 +9,7 @@ use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::Span;
 
-pub fn provide(providers: &mut Providers) {
+pub(crate) fn provide(providers: &mut Providers) {
     providers.upvars_mentioned = |tcx, def_id| {
         if !tcx.is_closure_like(def_id) {
             return None;

compiler/rustc_passes/src/weak_lang_items.rs

@@ -15,7 +15,11 @@ use crate::errors::{
 
 /// Checks the crate for usage of weak lang items, returning a vector of all the
 /// lang items required by this crate, but not defined yet.
-pub fn check_crate(tcx: TyCtxt<'_>, items: &mut lang_items::LanguageItems, krate: &ast::Crate) {
+pub(crate) fn check_crate(
+    tcx: TyCtxt<'_>,
+    items: &mut lang_items::LanguageItems,
+    krate: &ast::Crate,
+) {
     // These are never called by user code, they're generated by the compiler.
     // They will never implicitly be added to the `missing` array unless we do
     // so here.

compiler/rustc_pattern_analysis/src/lib.rs

@@ -6,6 +6,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![cfg_attr(feature = "rustc", feature(let_chains))]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 pub mod constructor;

compiler/rustc_privacy/src/errors.rs

@@ -5,7 +5,7 @@ use rustc_span::{Span, Symbol};
 
 #[derive(Diagnostic)]
 #[diag(privacy_field_is_private, code = E0451)]
-pub struct FieldIsPrivate {
+pub(crate) struct FieldIsPrivate {
     #[primary_span]
     pub span: Span,
     pub field_name: Symbol,
@@ -16,7 +16,7 @@ pub struct FieldIsPrivate {
 }
 
 #[derive(Subdiagnostic)]
-pub enum FieldIsPrivateLabel {
+pub(crate) enum FieldIsPrivateLabel {
     #[label(privacy_field_is_private_is_update_syntax_label)]
     IsUpdateSyntax {
         #[primary_span]
@@ -32,7 +32,7 @@ pub enum FieldIsPrivateLabel {
 
 #[derive(Diagnostic)]
 #[diag(privacy_item_is_private)]
-pub struct ItemIsPrivate<'a> {
+pub(crate) struct ItemIsPrivate<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -42,7 +42,7 @@ pub struct ItemIsPrivate<'a> {
 
 #[derive(Diagnostic)]
 #[diag(privacy_unnamed_item_is_private)]
-pub struct UnnamedItemIsPrivate {
+pub(crate) struct UnnamedItemIsPrivate {
     #[primary_span]
     pub span: Span,
     pub kind: &'static str,
@@ -50,7 +50,7 @@ pub struct UnnamedItemIsPrivate {
 
 #[derive(Diagnostic)]
 #[diag(privacy_in_public_interface, code = E0446)]
-pub struct InPublicInterface<'a> {
+pub(crate) struct InPublicInterface<'a> {
     #[primary_span]
     #[label]
     pub span: Span,
@@ -63,7 +63,7 @@ pub struct InPublicInterface<'a> {
 
 #[derive(Diagnostic)]
 #[diag(privacy_report_effective_visibility)]
-pub struct ReportEffectiveVisibility {
+pub(crate) struct ReportEffectiveVisibility {
     #[primary_span]
     pub span: Span,
     pub descr: String,
@@ -71,7 +71,7 @@ pub struct ReportEffectiveVisibility {
 
 #[derive(LintDiagnostic)]
 #[diag(privacy_from_private_dep_in_public_interface)]
-pub struct FromPrivateDependencyInPublicInterface<'a> {
+pub(crate) struct FromPrivateDependencyInPublicInterface<'a> {
     pub kind: &'a str,
     pub descr: DiagArgFromDisplay<'a>,
     pub krate: Symbol,
@@ -79,7 +79,7 @@ pub struct FromPrivateDependencyInPublicInterface<'a> {
 
 #[derive(LintDiagnostic)]
 #[diag(privacy_unnameable_types_lint)]
-pub struct UnnameableTypesLint<'a> {
+pub(crate) struct UnnameableTypesLint<'a> {
     #[label]
     pub span: Span,
     pub kind: &'a str,
@@ -93,7 +93,7 @@ pub struct UnnameableTypesLint<'a> {
 // See https://rust-lang.github.io/rfcs/2145-type-privacy.html for more details.
 #[derive(LintDiagnostic)]
 #[diag(privacy_private_interface_or_bounds_lint)]
-pub struct PrivateInterfacesOrBoundsLint<'a> {
+pub(crate) struct PrivateInterfacesOrBoundsLint<'a> {
     #[label(privacy_item_label)]
     pub item_span: Span,
     pub item_kind: &'a str,

compiler/rustc_privacy/src/lib.rs

@@ -6,6 +6,7 @@
 #![feature(let_chains)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 mod errors;
@@ -1497,7 +1498,7 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'tcx, '_> {
         self.effective_visibilities.effective_vis(def_id).copied()
     }
 
-    pub fn check_item(&mut self, id: ItemId) {
+    fn check_item(&mut self, id: ItemId) {
         let tcx = self.tcx;
         let def_id = id.owner_id.def_id;
         let item_visibility = tcx.local_visibility(def_id);

compiler/rustc_query_impl/src/lib.rs

@@ -8,6 +8,7 @@
 #![feature(min_specialization)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use field_offset::offset_of;

compiler/rustc_query_impl/src/plumbing.rs

@@ -541,7 +541,7 @@ macro_rules! expand_if_cached {
 /// Don't show the backtrace for query system by default
 /// use `RUST_BACKTRACE=full` to show all the backtraces
 #[inline(never)]
-pub fn __rust_begin_short_backtrace<F, T>(f: F) -> T
+pub(crate) fn __rust_begin_short_backtrace<F, T>(f: F) -> T
 where
     F: FnOnce() -> T,
 {
@@ -557,17 +557,17 @@ macro_rules! define_queries {
      $($(#[$attr:meta])*
         [$($modifiers:tt)*] fn $name:ident($($K:tt)*) -> $V:ty,)*) => {
 
-        pub(crate) mod query_impl { $(pub mod $name {
+        pub(crate) mod query_impl { $(pub(crate) mod $name {
             use super::super::*;
             use std::marker::PhantomData;
 
-            pub mod get_query_incr {
+            pub(crate) mod get_query_incr {
                 use super::*;
 
                 // Adding `__rust_end_short_backtrace` marker to backtraces so that we emit the frames
                 // when `RUST_BACKTRACE=1`, add a new mod with `$name` here is to allow duplicate naming
                 #[inline(never)]
-                pub fn __rust_end_short_backtrace<'tcx>(
+                pub(crate) fn __rust_end_short_backtrace<'tcx>(
                     tcx: TyCtxt<'tcx>,
                     span: Span,
                     key: queries::$name::Key<'tcx>,
@@ -585,11 +585,11 @@ macro_rules! define_queries {
                 }
             }
 
-            pub mod get_query_non_incr {
+            pub(crate) mod get_query_non_incr {
                 use super::*;
 
                 #[inline(never)]
-                pub fn __rust_end_short_backtrace<'tcx>(
+                pub(crate) fn __rust_end_short_backtrace<'tcx>(
                     tcx: TyCtxt<'tcx>,
                     span: Span,
                     key: queries::$name::Key<'tcx>,
@@ -604,7 +604,9 @@ macro_rules! define_queries {
                 }
             }
 
-            pub fn dynamic_query<'tcx>() -> DynamicQuery<'tcx, queries::$name::Storage<'tcx>> {
+            pub(crate) fn dynamic_query<'tcx>()
+                -> DynamicQuery<'tcx, queries::$name::Storage<'tcx>>
+            {
                 DynamicQuery {
                     name: stringify!($name),
                     eval_always: is_eval_always!([$($modifiers)*]),
@@ -667,7 +669,7 @@ macro_rules! define_queries {
             }
 
             #[derive(Copy, Clone, Default)]
-            pub struct QueryType<'tcx> {
+            pub(crate) struct QueryType<'tcx> {
                 data: PhantomData<&'tcx ()>
             }
 
@@ -696,7 +698,7 @@ macro_rules! define_queries {
                 }
             }
 
-            pub fn try_collect_active_jobs<'tcx>(tcx: TyCtxt<'tcx>, qmap: &mut QueryMap) {
+            pub(crate) fn try_collect_active_jobs<'tcx>(tcx: TyCtxt<'tcx>, qmap: &mut QueryMap) {
                 let make_query = |tcx, key| {
                     let kind = rustc_middle::dep_graph::dep_kinds::$name;
                     let name = stringify!($name);
@@ -711,11 +713,17 @@ macro_rules! define_queries {
                 // don't `unwrap()` here, just manually check for `None` and do best-effort error
                 // reporting.
                 if res.is_none() {
-                    tracing::warn!("Failed to collect active jobs for query with name `{}`!", stringify!($name));
+                    tracing::warn!(
+                        "Failed to collect active jobs for query with name `{}`!",
+                        stringify!($name)
+                    );
                 }
             }
 
-            pub fn alloc_self_profile_query_strings<'tcx>(tcx: TyCtxt<'tcx>, string_cache: &mut QueryKeyStringCache) {
+            pub(crate) fn alloc_self_profile_query_strings<'tcx>(
+                tcx: TyCtxt<'tcx>,
+                string_cache: &mut QueryKeyStringCache
+            ) {
                 $crate::profiling_support::alloc_self_profile_query_strings_for_query_cache(
                     tcx,
                     stringify!($name),
@@ -725,7 +733,7 @@ macro_rules! define_queries {
             }
 
             item_if_cached! { [$($modifiers)*] {
-                pub fn encode_query_results<'tcx>(
+                pub(crate) fn encode_query_results<'tcx>(
                     tcx: TyCtxt<'tcx>,
                     encoder: &mut CacheEncoder<'_, 'tcx>,
                     query_result_index: &mut EncodedDepNodeIndex
@@ -739,7 +747,7 @@ macro_rules! define_queries {
                 }
             }}
 
-            pub fn query_key_hash_verify<'tcx>(tcx: TyCtxt<'tcx>) {
+            pub(crate) fn query_key_hash_verify<'tcx>(tcx: TyCtxt<'tcx>) {
                 $crate::plumbing::query_key_hash_verify(
                     query_impl::$name::QueryType::config(tcx),
                     QueryCtxt::new(tcx),
@@ -795,7 +803,7 @@ macro_rules! define_queries {
             use rustc_query_system::dep_graph::FingerprintStyle;
 
             // We use this for most things when incr. comp. is turned off.
-            pub fn Null<'tcx>() -> DepKindStruct<'tcx> {
+            pub(crate) fn Null<'tcx>() -> DepKindStruct<'tcx> {
                 DepKindStruct {
                     is_anon: false,
                     is_eval_always: false,
@@ -807,7 +815,7 @@ macro_rules! define_queries {
             }
 
             // We use this for the forever-red node.
-            pub fn Red<'tcx>() -> DepKindStruct<'tcx> {
+            pub(crate) fn Red<'tcx>() -> DepKindStruct<'tcx> {
                 DepKindStruct {
                     is_anon: false,
                     is_eval_always: false,
@@ -818,7 +826,7 @@ macro_rules! define_queries {
                 }
             }
 
-            pub fn TraitSelect<'tcx>() -> DepKindStruct<'tcx> {
+            pub(crate) fn TraitSelect<'tcx>() -> DepKindStruct<'tcx> {
                 DepKindStruct {
                     is_anon: true,
                     is_eval_always: false,
@@ -829,7 +837,7 @@ macro_rules! define_queries {
                 }
             }
 
-            pub fn CompileCodegenUnit<'tcx>() -> DepKindStruct<'tcx> {
+            pub(crate) fn CompileCodegenUnit<'tcx>() -> DepKindStruct<'tcx> {
                 DepKindStruct {
                     is_anon: false,
                     is_eval_always: false,
@@ -840,7 +848,7 @@ macro_rules! define_queries {
                 }
             }
 
-            pub fn CompileMonoItem<'tcx>() -> DepKindStruct<'tcx> {
+            pub(crate) fn CompileMonoItem<'tcx>() -> DepKindStruct<'tcx> {
                 DepKindStruct {
                     is_anon: false,
                     is_eval_always: false,

compiler/rustc_query_system/src/dep_graph/serialized.rs

@@ -617,14 +617,14 @@ impl<D: Deps> EncoderState<D> {
     }
 }
 
-pub struct GraphEncoder<D: Deps> {
+pub(crate) struct GraphEncoder<D: Deps> {
     profiler: SelfProfilerRef,
     status: Lock<Option<EncoderState<D>>>,
     record_graph: Option<Lock<DepGraphQuery>>,
 }
 
 impl<D: Deps> GraphEncoder<D> {
-    pub fn new(
+    pub(crate) fn new(
         encoder: FileEncoder,
         prev_node_count: usize,
         record_graph: bool,
@@ -723,7 +723,7 @@ impl<D: Deps> GraphEncoder<D> {
         )
     }
 
-    pub fn finish(&self) -> FileEncodeResult {
+    pub(crate) fn finish(&self) -> FileEncodeResult {
         let _prof_timer = self.profiler.generic_activity("incr_comp_encode_dep_graph_finish");
 
         self.status.lock().take().unwrap().finish(&self.profiler)

compiler/rustc_query_system/src/error.rs

@@ -5,7 +5,7 @@ use rustc_span::{Span, Symbol};
 
 #[derive(Subdiagnostic)]
 #[note(query_system_cycle_stack_middle)]
-pub struct CycleStack {
+pub(crate) struct CycleStack {
     #[primary_span]
     pub span: Span,
     pub desc: String,
@@ -20,7 +20,7 @@ pub enum HandleCycleError {
 }
 
 #[derive(Subdiagnostic)]
-pub enum StackCount {
+pub(crate) enum StackCount {
     #[note(query_system_cycle_stack_single)]
     Single,
     #[note(query_system_cycle_stack_multiple)]
@@ -28,7 +28,7 @@ pub enum StackCount {
 }
 
 #[derive(Subdiagnostic)]
-pub enum Alias {
+pub(crate) enum Alias {
     #[note(query_system_cycle_recursive_ty_alias)]
     #[help(query_system_cycle_recursive_ty_alias_help1)]
     #[help(query_system_cycle_recursive_ty_alias_help2)]
@@ -39,7 +39,7 @@ pub enum Alias {
 
 #[derive(Subdiagnostic)]
 #[note(query_system_cycle_usage)]
-pub struct CycleUsage {
+pub(crate) struct CycleUsage {
     #[primary_span]
     pub span: Span,
     pub usage: String,
@@ -47,7 +47,7 @@ pub struct CycleUsage {
 
 #[derive(Diagnostic)]
 #[diag(query_system_cycle, code = E0391)]
-pub struct Cycle {
+pub(crate) struct Cycle {
     #[primary_span]
     pub span: Span,
     pub stack_bottom: String,
@@ -65,14 +65,14 @@ pub struct Cycle {
 
 #[derive(Diagnostic)]
 #[diag(query_system_reentrant)]
-pub struct Reentrant;
+pub(crate) struct Reentrant;
 
 #[derive(Diagnostic)]
 #[diag(query_system_increment_compilation)]
 #[help]
 #[note(query_system_increment_compilation_note1)]
 #[note(query_system_increment_compilation_note2)]
-pub struct IncrementCompilation {
+pub(crate) struct IncrementCompilation {
     pub run_cmd: String,
     pub dep_node: String,
 }

compiler/rustc_query_system/src/lib.rs

@@ -5,6 +5,7 @@
 #![feature(hash_raw_entry)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 pub mod cache;

compiler/rustc_resolve/src/lib.rs

@@ -21,6 +21,7 @@
 #![feature(let_chains)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::cell::{Cell, RefCell};