Merging upstream version 1.69.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

13 files changed, 1017 insertions, 638 deletions

diff --git a/compiler/rustc_metadata/Cargo.toml b/compiler/rustc_metadata/Cargo.toml
index 6d85103c9..bee5c8541 100644
--- a/compiler/rustc_metadata/Cargo.toml
+++ b/compiler/rustc_metadata/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 [lib]
 
 [dependencies]
+bitflags = "1.2.1"
 libloading = "0.7.1"
 odht = { version = "0.3.1", features = ["nightly"] }
 snap = "1"
diff --git a/compiler/rustc_metadata/locales/en-US.ftl b/compiler/rustc_metadata/locales/en-US.ftl
new file mode 100644
index 000000000..79b8b4172
--- /dev/null
+++ b/compiler/rustc_metadata/locales/en-US.ftl
@@ -0,0 +1,288 @@
+metadata_rlib_required =
+    crate `{$crate_name}` required to be available in rlib format, but was not found in this form
+
+metadata_lib_required =
+    crate `{$crate_name}` required to be available in {$kind} format, but was not found in this form
+
+metadata_rustc_lib_required =
+    crate `{$crate_name}` required to be available in {$kind} format, but was not found in this form
+    .note = only .rmeta files are distributed for `rustc_private` crates other than `rustc_driver`
+    .help = try adding `extern crate rustc_driver;` at the top level of this crate
+
+metadata_crate_dep_multiple =
+    cannot satisfy dependencies so `{$crate_name}` only shows up once
+    .help = having upstream crates all available in one format will likely make this go away
+
+metadata_two_panic_runtimes =
+    cannot link together two panic runtimes: {$prev_name} and {$cur_name}
+
+metadata_bad_panic_strategy =
+    the linked panic runtime `{$runtime}` is not compiled with this crate's panic strategy `{$strategy}`
+
+metadata_required_panic_strategy =
+    the crate `{$crate_name}` requires panic strategy `{$found_strategy}` which is incompatible with this crate's strategy of `{$desired_strategy}`
+
+metadata_incompatible_panic_in_drop_strategy =
+    the crate `{$crate_name}` is compiled with the panic-in-drop strategy `{$found_strategy}` which is incompatible with this crate's strategy of `{$desired_strategy}`
+
+metadata_multiple_names_in_link =
+    multiple `name` arguments in a single `#[link]` attribute
+
+metadata_multiple_kinds_in_link =
+    multiple `kind` arguments in a single `#[link]` attribute
+
+metadata_link_name_form =
+    link name must be of the form `name = "string"`
+
+metadata_link_kind_form =
+    link kind must be of the form `kind = "string"`
+
+metadata_link_modifiers_form =
+    link modifiers must be of the form `modifiers = "string"`
+
+metadata_link_cfg_form =
+    link cfg must be of the form `cfg(/* predicate */)`
+
+metadata_wasm_import_form =
+    wasm import module must be of the form `wasm_import_module = "string"`
+
+metadata_empty_link_name =
+    link name must not be empty
+    .label = empty link name
+
+metadata_link_framework_apple =
+    link kind `framework` is only supported on Apple targets
+
+metadata_framework_only_windows =
+    link kind `raw-dylib` is only supported on Windows targets
+
+metadata_unknown_link_kind =
+    unknown link kind `{$kind}`, expected one of: static, dylib, framework, raw-dylib
+    .label = unknown link kind
+
+metadata_multiple_link_modifiers =
+    multiple `modifiers` arguments in a single `#[link]` attribute
+
+metadata_multiple_cfgs =
+    multiple `cfg` arguments in a single `#[link]` attribute
+
+metadata_link_cfg_single_predicate =
+    link cfg must have a single predicate argument
+
+metadata_multiple_wasm_import =
+    multiple `wasm_import_module` arguments in a single `#[link]` attribute
+
+metadata_unexpected_link_arg =
+    unexpected `#[link]` argument, expected one of: name, kind, modifiers, cfg, wasm_import_module, import_name_type
+
+metadata_invalid_link_modifier =
+    invalid linking modifier syntax, expected '+' or '-' prefix before one of: bundle, verbatim, whole-archive, as-needed
+
+metadata_multiple_modifiers =
+    multiple `{$modifier}` modifiers in a single `modifiers` argument
+
+metadata_bundle_needs_static =
+    linking modifier `bundle` is only compatible with `static` linking kind
+
+metadata_whole_archive_needs_static =
+    linking modifier `whole-archive` is only compatible with `static` linking kind
+
+metadata_as_needed_compatibility =
+    linking modifier `as-needed` is only compatible with `dylib` and `framework` linking kinds
+
+metadata_unknown_link_modifier =
+    unknown linking modifier `{$modifier}`, expected one of: bundle, verbatim, whole-archive, as-needed
+
+metadata_incompatible_wasm_link =
+    `wasm_import_module` is incompatible with other arguments in `#[link]` attributes
+
+metadata_link_requires_name =
+    `#[link]` attribute requires a `name = "string"` argument
+    .label = missing `name` argument
+
+metadata_raw_dylib_no_nul =
+    link name must not contain NUL characters if link kind is `raw-dylib`
+
+metadata_link_ordinal_raw_dylib =
+    `#[link_ordinal]` is only supported if link kind is `raw-dylib`
+
+metadata_lib_framework_apple =
+    library kind `framework` is only supported on Apple targets
+
+metadata_empty_renaming_target =
+    an empty renaming target was specified for library `{$lib_name}`
+
+metadata_renaming_no_link =
+    renaming of the library `{$lib_name}` was specified, however this crate contains no `#[link(...)]` attributes referencing this library
+
+metadata_multiple_renamings =
+    multiple renamings were specified for library `{$lib_name}`
+
+metadata_no_link_mod_override =
+    overriding linking modifiers from command line is not supported
+
+metadata_unsupported_abi_i686 =
+    ABI not supported by `#[link(kind = "raw-dylib")]` on i686
+
+metadata_unsupported_abi =
+    ABI not supported by `#[link(kind = "raw-dylib")]` on this architecture
+
+metadata_fail_create_file_encoder =
+    failed to create file encoder: {$err}
+
+metadata_fail_seek_file =
+    failed to seek the file: {$err}
+
+metadata_fail_write_file =
+    failed to write to the file: {$err}
+
+metadata_crate_not_panic_runtime =
+    the crate `{$crate_name}` is not a panic runtime
+
+metadata_no_panic_strategy =
+    the crate `{$crate_name}` does not have the panic strategy `{$strategy}`
+
+metadata_profiler_builtins_needs_core =
+    `profiler_builtins` crate (required by compiler options) is not compatible with crate attribute `#![no_core]`
+
+metadata_not_profiler_runtime =
+    the crate `{$crate_name}` is not a profiler runtime
+
+metadata_no_multiple_global_alloc =
+    cannot define multiple global allocators
+    .label = cannot define a new global allocator
+
+metadata_prev_global_alloc =
+    previous global allocator defined here
+
+metadata_no_multiple_alloc_error_handler =
+    cannot define multiple allocation error handlers
+    .label = cannot define a new allocation error handler
+
+metadata_prev_alloc_error_handler =
+    previous allocation error handler defined here
+
+metadata_conflicting_global_alloc =
+    the `#[global_allocator]` in {$other_crate_name} conflicts with global allocator in: {$crate_name}
+
+metadata_conflicting_alloc_error_handler =
+    the `#[alloc_error_handler]` in {$other_crate_name} conflicts with allocation error handler in: {$crate_name}
+
+metadata_global_alloc_required =
+    no global memory allocator found but one is required; link to std or add `#[global_allocator]` to a static item that implements the GlobalAlloc trait
+
+metadata_no_transitive_needs_dep =
+    the crate `{$crate_name}` cannot depend on a crate that needs {$needs_crate_name}, but it depends on `{$deps_crate_name}`
+
+metadata_failed_write_error =
+    failed to write {$filename}: {$err}
+
+metadata_missing_native_library =
+    could not find native static library `{$libname}`, perhaps an -L flag is missing?
+
+metadata_only_provide_library_name = only provide the library name `{$suggested_name}`, not the full filename
+
+metadata_failed_create_tempdir =
+    couldn't create a temp dir: {$err}
+
+metadata_failed_create_file =
+    failed to create the file {$filename}: {$err}
+
+metadata_failed_create_encoded_metadata =
+    failed to create encoded metadata from file: {$err}
+
+metadata_non_ascii_name =
+    cannot load a crate with a non-ascii name `{$crate_name}`
+
+metadata_extern_location_not_exist =
+    extern location for {$crate_name} does not exist: {$location}
+
+metadata_extern_location_not_file =
+    extern location for {$crate_name} is not a file: {$location}
+
+metadata_multiple_candidates =
+    multiple candidates for `{$flavor}` dependency `{$crate_name}` found
+
+metadata_symbol_conflicts_current =
+    the current crate is indistinguishable from one of its dependencies: it has the same crate-name `{$crate_name}` and was compiled with the same `-C metadata` arguments. This will result in symbol conflicts between the two.
+
+metadata_symbol_conflicts_others =
+    found two different crates with name `{$crate_name}` that are not distinguished by differing `-C metadata`. This will result in symbol conflicts between the two.
+
+metadata_stable_crate_id_collision =
+    found crates (`{$crate_name0}` and `{$crate_name1}`) with colliding StableCrateId values.
+
+metadata_dl_error =
+    {$err}
+
+metadata_newer_crate_version =
+    found possibly newer version of crate `{$crate_name}`{$add_info}
+    .note = perhaps that crate needs to be recompiled?
+
+metadata_found_crate_versions =
+    the following crate versions were found:{$found_crates}
+
+metadata_no_crate_with_triple =
+    couldn't find crate `{$crate_name}` with expected target triple {$locator_triple}{$add_info}
+
+metadata_found_staticlib =
+    found staticlib `{$crate_name}` instead of rlib or dylib{$add_info}
+    .help = please recompile that crate using --crate-type lib
+
+metadata_incompatible_rustc =
+    found crate `{$crate_name}` compiled by an incompatible version of rustc{$add_info}
+    .help = please recompile that crate using this compiler ({$rustc_version}) (consider running `cargo clean` first)
+
+metadata_invalid_meta_files =
+    found invalid metadata files for crate `{$crate_name}`{$add_info}
+
+metadata_cannot_find_crate =
+    can't find crate for `{$crate_name}`{$add_info}
+
+metadata_no_dylib_plugin =
+    plugin `{$crate_name}` only found in rlib format, but must be available in dylib format
+
+metadata_target_not_installed =
+    the `{$locator_triple}` target may not be installed
+
+metadata_target_no_std_support =
+    the `{$locator_triple}` target may not support the standard library
+
+metadata_consider_downloading_target =
+    consider downloading the target with `rustup target add {$locator_triple}`
+
+metadata_std_required =
+    `std` is required by `{$current_crate}` because it does not declare `#![no_std]`
+
+metadata_consider_building_std =
+    consider building the standard library from source with `cargo build -Zbuild-std`
+
+metadata_compiler_missing_profiler =
+    the compiler may have been built without the profiler runtime
+
+metadata_install_missing_components =
+    maybe you need to install the missing components with: `rustup component add rust-src rustc-dev llvm-tools-preview`
+
+metadata_cant_find_crate =
+    can't find crate
+
+metadata_crate_location_unknown_type =
+    extern location for {$crate_name} is of an unknown type: {$path}
+
+metadata_lib_filename_form =
+    file name should be lib*.rlib or {$dll_prefix}*{$dll_suffix}
+
+metadata_multiple_import_name_type =
+    multiple `import_name_type` arguments in a single `#[link]` attribute
+
+metadata_import_name_type_form =
+    import name type must be of the form `import_name_type = "string"`
+
+metadata_import_name_type_x86 =
+    import name type is only supported on x86
+
+metadata_unknown_import_name_type =
+    unknown import name type `{$import_name_type}`, expected one of: decorated, noprefix, undecorated
+
+metadata_import_name_type_raw =
+    import name type can only be used with link kind `raw-dylib`
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 653f2b39d..b05626311 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -1,10 +1,6 @@
 //! Validates all used crates and extern libraries and loads their metadata
 
-use crate::errors::{
-    ConflictingAllocErrorHandler, ConflictingGlobalAlloc, CrateNotPanicRuntime,
-    GlobalAllocRequired, NoMultipleAllocErrorHandler, NoMultipleGlobalAlloc, NoPanicStrategy,
-    NoTransitiveNeedsDep, NotProfilerRuntime, ProfilerBuiltinsNeedsCore,
-};
+use crate::errors;
 use crate::locator::{CrateError, CrateLocator, CratePaths};
 use crate::rmeta::{CrateDep, CrateMetadata, CrateNumMap, CrateRoot, MetadataBlob};
 
@@ -12,15 +8,15 @@ use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_ast::{self as ast, *};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::svh::Svh;
-use rustc_data_structures::sync::{Lrc, ReadGuard};
+use rustc_data_structures::sync::MappedReadGuard;
 use rustc_expand::base::SyntaxExtension;
 use rustc_hir::def_id::{CrateNum, LocalDefId, StableCrateId, LOCAL_CRATE};
 use rustc_hir::definitions::Definitions;
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{self, CrateType, ExternLocation};
+use rustc_session::cstore::ExternCrateSource;
 use rustc_session::cstore::{CrateDepKind, CrateSource, ExternCrate};
-use rustc_session::cstore::{ExternCrateSource, MetadataLoaderDyn};
 use rustc_session::lint;
 use rustc_session::output::validate_crate_name;
 use rustc_session::search_paths::PathKind;
@@ -33,11 +29,11 @@ use rustc_target::spec::{PanicStrategy, TargetTriple};
 use proc_macro::bridge::client::ProcMacro;
 use std::ops::Fn;
 use std::path::Path;
-use std::{cmp, env};
+use std::time::Duration;
+use std::{cmp, env, iter};
 
-#[derive(Clone)]
 pub struct CStore {
-    metas: IndexVec<CrateNum, Option<Lrc<CrateMetadata>>>,
+    metas: IndexVec<CrateNum, Option<Box<CrateMetadata>>>,
     injected_panic_runtime: Option<CrateNum>,
     /// This crate needs an allocator and either provides it itself, or finds it in a dependency.
     /// If the above is true, then this field denotes the kind of the found allocator.
@@ -64,17 +60,22 @@ impl std::fmt::Debug for CStore {
     }
 }
 
-pub struct CrateLoader<'a> {
+pub struct CrateLoader<'a, 'tcx: 'a> {
     // Immutable configuration.
-    sess: &'a Session,
-    metadata_loader: &'a MetadataLoaderDyn,
-    definitions: ReadGuard<'a, Definitions>,
-    local_crate_name: Symbol,
+    tcx: TyCtxt<'tcx>,
     // Mutable output.
     cstore: &'a mut CStore,
     used_extern_options: &'a mut FxHashSet<Symbol>,
 }
 
+impl<'a, 'tcx> std::ops::Deref for CrateLoader<'a, 'tcx> {
+    type Target = TyCtxt<'tcx>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.tcx
+    }
+}
+
 pub enum LoadedMacro {
     MacroDef(ast::Item, Edition),
     ProcMacro(SyntaxExtension),
@@ -131,11 +132,10 @@ impl<'a> std::fmt::Debug for CrateDump<'a> {
 }
 
 impl CStore {
-    pub fn from_tcx(tcx: TyCtxt<'_>) -> &CStore {
-        tcx.cstore_untracked()
-            .as_any()
-            .downcast_ref::<CStore>()
-            .expect("`tcx.cstore` is not a `CStore`")
+    pub fn from_tcx(tcx: TyCtxt<'_>) -> MappedReadGuard<'_, CStore> {
+        MappedReadGuard::map(tcx.cstore_untracked(), |c| {
+            c.as_any().downcast_ref::<CStore>().expect("`tcx.cstore` is not a `CStore`")
+        })
     }
 
     fn alloc_new_crate_num(&mut self) -> CrateNum {
@@ -156,7 +156,7 @@ impl CStore {
 
     fn set_crate_data(&mut self, cnum: CrateNum, data: CrateMetadata) {
         assert!(self.metas[cnum].is_none(), "Overwriting crate metadata entry");
-        self.metas[cnum] = Some(Lrc::new(data));
+        self.metas[cnum] = Some(Box::new(data));
     }
 
     pub(crate) fn iter_crate_data(&self) -> impl Iterator<Item = (CrateNum, &CrateMetadata)> {
@@ -248,7 +248,7 @@ impl CStore {
             // order to make array indices in `metas` match with the
             // corresponding `CrateNum`. This first entry will always remain
             // `None`.
-            metas: IndexVec::from_elem_n(None, 1),
+            metas: IndexVec::from_iter(iter::once(None)),
             injected_panic_runtime: None,
             allocator_kind: None,
             alloc_error_handler_kind: None,
@@ -260,23 +260,13 @@ impl CStore {
     }
 }
 
-impl<'a> CrateLoader<'a> {
+impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
     pub fn new(
-        sess: &'a Session,
-        metadata_loader: &'a MetadataLoaderDyn,
-        local_crate_name: Symbol,
+        tcx: TyCtxt<'tcx>,
         cstore: &'a mut CStore,
-        definitions: ReadGuard<'a, Definitions>,
         used_extern_options: &'a mut FxHashSet<Symbol>,
     ) -> Self {
-        CrateLoader {
-            sess,
-            metadata_loader,
-            local_crate_name,
-            cstore,
-            used_extern_options,
-            definitions,
-        }
+        CrateLoader { tcx, cstore, used_extern_options }
     }
     pub fn cstore(&self) -> &CStore {
         &self.cstore
@@ -359,7 +349,12 @@ impl<'a> CrateLoader<'a> {
         for (_, other) in self.cstore.iter_crate_data() {
             // Same stable crate id but different SVH
             if other.stable_crate_id() == root.stable_crate_id() && other.hash() != root.hash() {
-                return Err(CrateError::SymbolConflictsOthers(root.name()));
+                bug!(
+                    "Previously returned E0523 here. \
+                     See https://github.com/rust-lang/rust/pull/100599 for additional discussion.\
+                     root.name() = {}.",
+                    root.name()
+                );
             }
         }
 
@@ -562,9 +557,10 @@ impl<'a> CrateLoader<'a> {
             (LoadResult::Previous(cnum), None)
         } else {
             info!("falling back to a load");
+            let metadata_loader = self.tcx.metadata_loader(()).borrow();
             let mut locator = CrateLocator::new(
                 self.sess,
-                &*self.metadata_loader,
+                &**metadata_loader,
                 name,
                 hash,
                 extra_filename,
@@ -689,8 +685,7 @@ impl<'a> CrateLoader<'a> {
     ) -> Result<&'static [ProcMacro], CrateError> {
         // Make sure the path contains a / or the linker will search for it.
         let path = env::current_dir().unwrap().join(path);
-        let lib = unsafe { libloading::Library::new(path) }
-            .map_err(|err| CrateError::DlOpen(err.to_string()))?;
+        let lib = load_dylib(&path, 5).map_err(|err| CrateError::DlOpen(err))?;
 
         let sym_name = self.sess.generate_proc_macro_decls_symbol(stable_crate_id);
         let sym = unsafe { lib.get::<*const &[ProcMacro]>(sym_name.as_bytes()) }
@@ -768,10 +763,11 @@ impl<'a> CrateLoader<'a> {
         // Sanity check the loaded crate to ensure it is indeed a panic runtime
         // and the panic strategy is indeed what we thought it was.
         if !data.is_panic_runtime() {
-            self.sess.emit_err(CrateNotPanicRuntime { crate_name: name });
+            self.sess.emit_err(errors::CrateNotPanicRuntime { crate_name: name });
         }
         if data.required_panic_strategy() != Some(desired_strategy) {
-            self.sess.emit_err(NoPanicStrategy { crate_name: name, strategy: desired_strategy });
+            self.sess
+                .emit_err(errors::NoPanicStrategy { crate_name: name, strategy: desired_strategy });
         }
 
         self.cstore.injected_panic_runtime = Some(cnum);
@@ -791,7 +787,7 @@ impl<'a> CrateLoader<'a> {
 
         let name = Symbol::intern(&self.sess.opts.unstable_opts.profiler_runtime);
         if name == sym::profiler_builtins && self.sess.contains_name(&krate.attrs, sym::no_core) {
-            self.sess.emit_err(ProfilerBuiltinsNeedsCore);
+            self.sess.emit_err(errors::ProfilerBuiltinsNeedsCore);
         }
 
         let Some(cnum) = self.resolve_crate(name, DUMMY_SP, CrateDepKind::Implicit) else { return; };
@@ -799,21 +795,22 @@ impl<'a> CrateLoader<'a> {
 
         // Sanity check the loaded crate to ensure it is indeed a profiler runtime
         if !data.is_profiler_runtime() {
-            self.sess.emit_err(NotProfilerRuntime { crate_name: name });
+            self.sess.emit_err(errors::NotProfilerRuntime { crate_name: name });
         }
     }
 
     fn inject_allocator_crate(&mut self, krate: &ast::Crate) {
         self.cstore.has_global_allocator = match &*global_allocator_spans(&self.sess, krate) {
             [span1, span2, ..] => {
-                self.sess.emit_err(NoMultipleGlobalAlloc { span2: *span2, span1: *span1 });
+                self.sess.emit_err(errors::NoMultipleGlobalAlloc { span2: *span2, span1: *span1 });
                 true
             }
             spans => !spans.is_empty(),
         };
         self.cstore.has_alloc_error_handler = match &*alloc_error_handler_spans(&self.sess, krate) {
             [span1, span2, ..] => {
-                self.sess.emit_err(NoMultipleAllocErrorHandler { span2: *span2, span1: *span1 });
+                self.sess
+                    .emit_err(errors::NoMultipleAllocErrorHandler { span2: *span2, span1: *span1 });
                 true
             }
             spans => !spans.is_empty(),
@@ -849,7 +846,7 @@ impl<'a> CrateLoader<'a> {
             if data.has_global_allocator() {
                 match global_allocator {
                     Some(other_crate) => {
-                        self.sess.emit_err(ConflictingGlobalAlloc {
+                        self.sess.emit_err(errors::ConflictingGlobalAlloc {
                             crate_name: data.name(),
                             other_crate_name: other_crate,
                         });
@@ -864,7 +861,7 @@ impl<'a> CrateLoader<'a> {
             if data.has_alloc_error_handler() {
                 match alloc_error_handler {
                     Some(other_crate) => {
-                        self.sess.emit_err(ConflictingAllocErrorHandler {
+                        self.sess.emit_err(errors::ConflictingAllocErrorHandler {
                             crate_name: data.name(),
                             other_crate_name: other_crate,
                         });
@@ -884,7 +881,7 @@ impl<'a> CrateLoader<'a> {
             if !self.sess.contains_name(&krate.attrs, sym::default_lib_allocator)
                 && !self.cstore.iter_crate_data().any(|(_, data)| data.has_default_lib_allocator())
             {
-                self.sess.emit_err(GlobalAllocRequired);
+                self.sess.emit_err(errors::GlobalAllocRequired);
             }
             self.cstore.allocator_kind = Some(AllocatorKind::Default);
         }
@@ -917,7 +914,7 @@ impl<'a> CrateLoader<'a> {
         for dep in self.cstore.crate_dependencies_in_reverse_postorder(krate) {
             let data = self.cstore.get_crate_data(dep);
             if needs_dep(&data) {
-                self.sess.emit_err(NoTransitiveNeedsDep {
+                self.sess.emit_err(errors::NoTransitiveNeedsDep {
                     crate_name: self.cstore.get_crate_data(krate).name(),
                     needs_crate_name: what,
                     deps_crate_name: data.name(),
@@ -968,7 +965,7 @@ impl<'a> CrateLoader<'a> {
                     &format!(
                         "external crate `{}` unused in `{}`: remove the dependency or add `use {} as _;`",
                         name,
-                        self.local_crate_name,
+                        self.tcx.crate_name(LOCAL_CRATE),
                         name),
                 );
         }
@@ -988,6 +985,7 @@ impl<'a> CrateLoader<'a> {
         &mut self,
         item: &ast::Item,
         def_id: LocalDefId,
+        definitions: &Definitions,
     ) -> Option<CrateNum> {
         match item.kind {
             ast::ItemKind::ExternCrate(orig_name) => {
@@ -1010,7 +1008,7 @@ impl<'a> CrateLoader<'a> {
 
                 let cnum = self.resolve_crate(name, item.span, dep_kind)?;
 
-                let path_len = self.definitions.def_path(def_id).data.len();
+                let path_len = definitions.def_path(def_id).data.len();
                 self.update_extern_crate(
                     cnum,
                     ExternCrate {
@@ -1093,3 +1091,41 @@ fn alloc_error_handler_spans(sess: &Session, krate: &ast::Crate) -> Vec<Span> {
     visit::walk_crate(&mut f, krate);
     f.spans
 }
+
+// On Windows the compiler would sometimes intermittently fail to open the
+// proc-macro DLL with `Error::LoadLibraryExW`. It is suspected that something in the
+// system still holds a lock on the file, so we retry a few times before calling it
+// an error.
+fn load_dylib(path: &Path, max_attempts: usize) -> Result<libloading::Library, String> {
+    assert!(max_attempts > 0);
+
+    let mut last_error = None;
+
+    for attempt in 0..max_attempts {
+        match unsafe { libloading::Library::new(&path) } {
+            Ok(lib) => {
+                if attempt > 0 {
+                    debug!(
+                        "Loaded proc-macro `{}` after {} attempts.",
+                        path.display(),
+                        attempt + 1
+                    );
+                }
+                return Ok(lib);
+            }
+            Err(err) => {
+                // Only try to recover from this specific error.
+                if !matches!(err, libloading::Error::LoadLibraryExW { .. }) {
+                    return Err(err.to_string());
+                }
+
+                last_error = Some(err);
+                std::thread::sleep(Duration::from_millis(100));
+                debug!("Failed to load proc-macro `{}`. Retrying.", path.display());
+            }
+        }
+    }
+
+    debug!("Failed to load proc-macro `{}` even after {} attempts.", path.display(), max_attempts);
+    Err(format!("{} (retried {} times)", last_error.unwrap(), max_attempts))
+}
diff --git a/compiler/rustc_metadata/src/dependency_format.rs b/compiler/rustc_metadata/src/dependency_format.rs
index cee4ba56a..39ef4276f 100644
--- a/compiler/rustc_metadata/src/dependency_format.rs
+++ b/compiler/rustc_metadata/src/dependency_format.rs
@@ -113,37 +113,37 @@ fn calculate_type(tcx: TyCtxt<'_>, ty: CrateType) -> DependencyList {
         CrateType::Staticlib => Linkage::Static,
     };
 
-    if preferred_linkage == Linkage::NotLinked {
+    match preferred_linkage {
         // If the crate is not linked, there are no link-time dependencies.
-        return Vec::new();
-    }
-
-    if preferred_linkage == Linkage::Static {
-        // Attempt static linkage first. For dylibs and executables, we may be
-        // able to retry below with dynamic linkage.
-        if let Some(v) = attempt_static(tcx) {
-            return v;
-        }
+        Linkage::NotLinked => return Vec::new(),
+        Linkage::Static => {
+            // Attempt static linkage first. For dylibs and executables, we may be
+            // able to retry below with dynamic linkage.
+            if let Some(v) = attempt_static(tcx) {
+                return v;
+            }
 
-        // Staticlibs and static executables must have all static dependencies.
-        // If any are not found, generate some nice pretty errors.
-        if ty == CrateType::Staticlib
-            || (ty == CrateType::Executable
-                && sess.crt_static(Some(ty))
-                && !sess.target.crt_static_allows_dylibs)
-        {
-            for &cnum in tcx.crates(()).iter() {
-                if tcx.dep_kind(cnum).macros_only() {
-                    continue;
+            // Staticlibs and static executables must have all static dependencies.
+            // If any are not found, generate some nice pretty errors.
+            if ty == CrateType::Staticlib
+                || (ty == CrateType::Executable
+                    && sess.crt_static(Some(ty))
+                    && !sess.target.crt_static_allows_dylibs)
+            {
+                for &cnum in tcx.crates(()).iter() {
+                    if tcx.dep_kind(cnum).macros_only() {
+                        continue;
+                    }
+                    let src = tcx.used_crate_source(cnum);
+                    if src.rlib.is_some() {
+                        continue;
+                    }
+                    sess.emit_err(RlibRequired { crate_name: tcx.crate_name(cnum) });
                 }
-                let src = tcx.used_crate_source(cnum);
-                if src.rlib.is_some() {
-                    continue;
-                }
-                sess.emit_err(RlibRequired { crate_name: tcx.crate_name(cnum) });
+                return Vec::new();
             }
-            return Vec::new();
         }
+        Linkage::Dynamic | Linkage::IncludedFromDylib => {}
     }
 
     let mut formats = FxHashMap::default();
@@ -283,12 +283,9 @@ fn attempt_static(tcx: TyCtxt<'_>) -> Option<DependencyList> {
     let mut ret = tcx
         .crates(())
         .iter()
-        .map(|&cnum| {
-            if tcx.dep_kind(cnum) == CrateDepKind::Explicit {
-                Linkage::Static
-            } else {
-                Linkage::NotLinked
-            }
+        .map(|&cnum| match tcx.dep_kind(cnum) {
+            CrateDepKind::Explicit => Linkage::Static,
+            CrateDepKind::MacrosOnly | CrateDepKind::Implicit => Linkage::NotLinked,
         })
         .collect::<Vec<_>>();
 
diff --git a/compiler/rustc_metadata/src/errors.rs b/compiler/rustc_metadata/src/errors.rs
index 02c03114e..51b41b5f6 100644
--- a/compiler/rustc_metadata/src/errors.rs
+++ b/compiler/rustc_metadata/src/errors.rs
@@ -9,6 +9,7 @@ use rustc_session::config;
 use rustc_span::{sym, Span, Symbol};
 use rustc_target::spec::{PanicStrategy, TargetTriple};
 
+use crate::fluent_generated as fluent;
 use crate::locator::CrateFlavor;
 
 #[derive(Diagnostic)]
@@ -491,7 +492,7 @@ impl IntoDiagnostic<'_> for MultipleCandidates {
         self,
         handler: &'_ rustc_errors::Handler,
     ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = handler.struct_err(rustc_errors::fluent::metadata_multiple_candidates);
+        let mut diag = handler.struct_err(fluent::metadata_multiple_candidates);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("flavor", self.flavor);
         diag.code(error_code!(E0464));
@@ -512,14 +513,6 @@ pub struct SymbolConflictsCurrent {
 }
 
 #[derive(Diagnostic)]
-#[diag(metadata_symbol_conflicts_others, code = "E0523")]
-pub struct SymbolConflictsOthers {
-    #[primary_span]
-    pub span: Span,
-    pub crate_name: Symbol,
-}
-
-#[derive(Diagnostic)]
 #[diag(metadata_stable_crate_id_collision)]
 pub struct StableCrateIdCollision {
     #[primary_span]
@@ -598,7 +591,7 @@ impl IntoDiagnostic<'_> for InvalidMetadataFiles {
         self,
         handler: &'_ rustc_errors::Handler,
     ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = handler.struct_err(rustc_errors::fluent::metadata_invalid_meta_files);
+        let mut diag = handler.struct_err(fluent::metadata_invalid_meta_files);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("add_info", self.add_info);
         diag.code(error_code!(E0786));
@@ -627,7 +620,7 @@ impl IntoDiagnostic<'_> for CannotFindCrate {
         self,
         handler: &'_ rustc_errors::Handler,
     ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = handler.struct_err(rustc_errors::fluent::metadata_cannot_find_crate);
+        let mut diag = handler.struct_err(fluent::metadata_cannot_find_crate);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("current_crate", self.current_crate);
         diag.set_arg("add_info", self.add_info);
@@ -638,32 +631,32 @@ impl IntoDiagnostic<'_> for CannotFindCrate {
             && self.locator_triple != TargetTriple::from_triple(config::host_triple())
         {
             if self.missing_core {
-                diag.note(rustc_errors::fluent::metadata_target_not_installed);
+                diag.note(fluent::metadata_target_not_installed);
             } else {
-                diag.note(rustc_errors::fluent::metadata_target_no_std_support);
+                diag.note(fluent::metadata_target_no_std_support);
             }
             // NOTE: this suggests using rustup, even though the user may not have it installed.
             // That's because they could choose to install it; or this may give them a hint which
             // target they need to install from their distro.
             if self.missing_core {
-                diag.help(rustc_errors::fluent::metadata_consider_downloading_target);
+                diag.help(fluent::metadata_consider_downloading_target);
             }
             // Suggest using #![no_std]. #[no_core] is unstable and not really supported anyway.
             // NOTE: this is a dummy span if `extern crate std` was injected by the compiler.
             // If it's not a dummy, that means someone added `extern crate std` explicitly and
             // `#![no_std]` won't help.
             if !self.missing_core && self.span.is_dummy() {
-                diag.note(rustc_errors::fluent::metadata_std_required);
+                diag.note(fluent::metadata_std_required);
             }
             if self.is_nightly_build {
-                diag.help(rustc_errors::fluent::metadata_consider_building_std);
+                diag.help(fluent::metadata_consider_building_std);
             }
         } else if self.crate_name == self.profiler_runtime {
-            diag.note(rustc_errors::fluent::metadata_compiler_missing_profiler);
+            diag.note(fluent::metadata_compiler_missing_profiler);
         } else if self.crate_name.as_str().starts_with("rustc_") {
-            diag.help(rustc_errors::fluent::metadata_install_missing_components);
+            diag.help(fluent::metadata_install_missing_components);
         }
-        diag.span_label(self.span, rustc_errors::fluent::metadata_cant_find_crate);
+        diag.span_label(self.span, fluent::metadata_cant_find_crate);
         diag
     }
 }
diff --git a/compiler/rustc_metadata/src/lib.rs b/compiler/rustc_metadata/src/lib.rs
index 1987f88e6..6f6d3731c 100644
--- a/compiler/rustc_metadata/src/lib.rs
+++ b/compiler/rustc_metadata/src/lib.rs
@@ -30,6 +30,8 @@ extern crate rustc_data_structures;
 extern crate tracing;
 
 pub use rmeta::{provide, provide_extern};
+use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
+use rustc_macros::fluent_messages;
 
 mod dependency_format;
 mod foreign_modules;
@@ -44,3 +46,5 @@ pub mod locator;
 pub use fs::{emit_wrapper_file, METADATA_FILENAME};
 pub use native_libs::find_native_static_library;
 pub use rmeta::{encode_metadata, EncodedMetadata, METADATA_HEADER};
+
+fluent_messages! { "../locales/en-US.ftl" }
diff --git a/compiler/rustc_metadata/src/locator.rs b/compiler/rustc_metadata/src/locator.rs
index 0f5f74007..755a24253 100644
--- a/compiler/rustc_metadata/src/locator.rs
+++ b/compiler/rustc_metadata/src/locator.rs
@@ -213,12 +213,7 @@
 //! metadata::locator or metadata::creader for all the juicy details!
 
 use crate::creader::Library;
-use crate::errors::{
-    CannotFindCrate, CrateLocationUnknownType, DlError, ExternLocationNotExist,
-    ExternLocationNotFile, FoundStaticlib, IncompatibleRustc, InvalidMetadataFiles,
-    LibFilenameForm, MultipleCandidates, NewerCrateVersion, NoCrateWithTriple, NoDylibPlugin,
-    NonAsciiName, StableCrateIdCollision, SymbolConflictsCurrent, SymbolConflictsOthers,
-};
+use crate::errors;
 use crate::rmeta::{rustc_version, MetadataBlob, METADATA_HEADER};
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
@@ -950,7 +945,6 @@ pub(crate) enum CrateError {
     ExternLocationNotFile(Symbol, PathBuf),
     MultipleCandidates(Symbol, CrateFlavor, Vec<PathBuf>),
     SymbolConflictsCurrent(Symbol),
-    SymbolConflictsOthers(Symbol),
     StableCrateIdCollision(Symbol, Symbol),
     DlOpen(String),
     DlSym(String),
@@ -980,28 +974,25 @@ impl CrateError {
     pub(crate) fn report(self, sess: &Session, span: Span, missing_core: bool) {
         match self {
             CrateError::NonAsciiName(crate_name) => {
-                sess.emit_err(NonAsciiName { span, crate_name });
+                sess.emit_err(errors::NonAsciiName { span, crate_name });
             }
             CrateError::ExternLocationNotExist(crate_name, loc) => {
-                sess.emit_err(ExternLocationNotExist { span, crate_name, location: &loc });
+                sess.emit_err(errors::ExternLocationNotExist { span, crate_name, location: &loc });
             }
             CrateError::ExternLocationNotFile(crate_name, loc) => {
-                sess.emit_err(ExternLocationNotFile { span, crate_name, location: &loc });
+                sess.emit_err(errors::ExternLocationNotFile { span, crate_name, location: &loc });
             }
             CrateError::MultipleCandidates(crate_name, flavor, candidates) => {
-                sess.emit_err(MultipleCandidates { span, crate_name, flavor, candidates });
+                sess.emit_err(errors::MultipleCandidates { span, crate_name, flavor, candidates });
             }
             CrateError::SymbolConflictsCurrent(root_name) => {
-                sess.emit_err(SymbolConflictsCurrent { span, crate_name: root_name });
-            }
-            CrateError::SymbolConflictsOthers(root_name) => {
-                sess.emit_err(SymbolConflictsOthers { span, crate_name: root_name });
+                sess.emit_err(errors::SymbolConflictsCurrent { span, crate_name: root_name });
             }
             CrateError::StableCrateIdCollision(crate_name0, crate_name1) => {
-                sess.emit_err(StableCrateIdCollision { span, crate_name0, crate_name1 });
+                sess.emit_err(errors::StableCrateIdCollision { span, crate_name0, crate_name1 });
             }
             CrateError::DlOpen(s) | CrateError::DlSym(s) => {
-                sess.emit_err(DlError { span, err: s });
+                sess.emit_err(errors::DlError { span, err: s });
             }
             CrateError::LocatorCombined(locator) => {
                 let crate_name = locator.crate_name;
@@ -1012,8 +1003,12 @@ impl CrateError {
                 if !locator.crate_rejections.via_filename.is_empty() {
                     let mismatches = locator.crate_rejections.via_filename.iter();
                     for CrateMismatch { path, .. } in mismatches {
-                        sess.emit_err(CrateLocationUnknownType { span, path: &path, crate_name });
-                        sess.emit_err(LibFilenameForm {
+                        sess.emit_err(errors::CrateLocationUnknownType {
+                            span,
+                            path: &path,
+                            crate_name,
+                        });
+                        sess.emit_err(errors::LibFilenameForm {
                             span,
                             dll_prefix: &locator.dll_prefix,
                             dll_suffix: &locator.dll_suffix,
@@ -1039,7 +1034,7 @@ impl CrateError {
                             ));
                         }
                     }
-                    sess.emit_err(NewerCrateVersion {
+                    sess.emit_err(errors::NewerCrateVersion {
                         span,
                         crate_name: crate_name,
                         add_info,
@@ -1055,7 +1050,7 @@ impl CrateError {
                             path.display(),
                         ));
                     }
-                    sess.emit_err(NoCrateWithTriple {
+                    sess.emit_err(errors::NoCrateWithTriple {
                         span,
                         crate_name,
                         locator_triple: locator.triple.triple(),
@@ -1071,7 +1066,12 @@ impl CrateError {
                             path.display()
                         ));
                     }
-                    sess.emit_err(FoundStaticlib { span, crate_name, add_info, found_crates });
+                    sess.emit_err(errors::FoundStaticlib {
+                        span,
+                        crate_name,
+                        add_info,
+                        found_crates,
+                    });
                 } else if !locator.crate_rejections.via_version.is_empty() {
                     let mismatches = locator.crate_rejections.via_version.iter();
                     for CrateMismatch { path, got } in mismatches {
@@ -1082,7 +1082,7 @@ impl CrateError {
                             path.display(),
                         ));
                     }
-                    sess.emit_err(IncompatibleRustc {
+                    sess.emit_err(errors::IncompatibleRustc {
                         span,
                         crate_name,
                         add_info,
@@ -1094,14 +1094,14 @@ impl CrateError {
                     for CrateMismatch { path: _, got } in locator.crate_rejections.via_invalid {
                         crate_rejections.push(got);
                     }
-                    sess.emit_err(InvalidMetadataFiles {
+                    sess.emit_err(errors::InvalidMetadataFiles {
                         span,
                         crate_name,
                         add_info,
                         crate_rejections,
                     });
                 } else {
-                    sess.emit_err(CannotFindCrate {
+                    sess.emit_err(errors::CannotFindCrate {
                         span,
                         crate_name,
                         add_info,
@@ -1118,7 +1118,7 @@ impl CrateError {
                 }
             }
             CrateError::NonDylibPlugin(crate_name) => {
-                sess.emit_err(NoDylibPlugin { span, crate_name });
+                sess.emit_err(errors::NoDylibPlugin { span, crate_name });
             }
         }
     }
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index 6f05c76e8..d6f68b2e1 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -13,17 +13,7 @@ use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_target::spec::abi::Abi;
 
-use crate::errors::{
-    AsNeededCompatibility, BundleNeedsStatic, EmptyLinkName, EmptyRenamingTarget,
-    FrameworkOnlyWindows, ImportNameTypeForm, ImportNameTypeRaw, ImportNameTypeX86,
-    IncompatibleWasmLink, InvalidLinkModifier, LibFrameworkApple, LinkCfgForm,
-    LinkCfgSinglePredicate, LinkFrameworkApple, LinkKindForm, LinkModifiersForm, LinkNameForm,
-    LinkOrdinalRawDylib, LinkRequiresName, MissingNativeLibrary, MultipleCfgs,
-    MultipleImportNameType, MultipleKindsInLink, MultipleLinkModifiers, MultipleModifiers,
-    MultipleNamesInLink, MultipleRenamings, MultipleWasmImport, NoLinkModOverride, RawDylibNoNul,
-    RenamingNoLink, UnexpectedLinkArg, UnknownImportNameType, UnknownLinkKind, UnknownLinkModifier,
-    UnsupportedAbi, UnsupportedAbiI686, WasmImportForm, WholeArchiveNeedsStatic,
-};
+use crate::errors;
 
 use std::path::PathBuf;
 
@@ -52,27 +42,28 @@ pub fn find_native_static_library(
         }
     }
 
-    sess.emit_fatal(MissingNativeLibrary::new(name, verbatim));
+    sess.emit_fatal(errors::MissingNativeLibrary::new(name, verbatim));
 }
 
 fn find_bundled_library(
     name: Option<Symbol>,
     verbatim: Option<bool>,
     kind: NativeLibKind,
+    has_cfg: bool,
     sess: &Session,
 ) -> Option<Symbol> {
-    if sess.opts.unstable_opts.packed_bundled_libs &&
-            sess.crate_types().iter().any(|ct| ct == &CrateType::Rlib || ct == &CrateType::Staticlib) &&
-            let NativeLibKind::Static { bundle: Some(true) | None, .. } = kind {
-        find_native_static_library(
-            name.unwrap().as_str(),
-            verbatim.unwrap_or(false),
-            &sess.target_filesearch(PathKind::Native).search_path_dirs(),
-            sess,
-        ).file_name().and_then(|s| s.to_str()).map(Symbol::intern)
-    } else {
-        None
+    if let NativeLibKind::Static { bundle: Some(true) | None, whole_archive } = kind
+        && sess.crate_types().iter().any(|t| matches!(t, &CrateType::Rlib | CrateType::Staticlib))
+        && (sess.opts.unstable_opts.packed_bundled_libs || has_cfg || whole_archive == Some(true))
+    {
+        let verbatim = verbatim.unwrap_or(false);
+        let search_paths = &sess.target_filesearch(PathKind::Native).search_path_dirs();
+        return find_native_static_library(name.unwrap().as_str(), verbatim, search_paths, sess)
+            .file_name()
+            .and_then(|s| s.to_str())
+            .map(Symbol::intern);
     }
+    None
 }
 
 pub(crate) fn collect(tcx: TyCtxt<'_>) -> Vec<NativeLib> {
@@ -107,13 +98,18 @@ impl<'tcx> Collector<'tcx> {
             return;
         };
 
-        if abi == Abi::Rust || abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic {
+        if matches!(abi, Abi::Rust | Abi::RustIntrinsic | Abi::PlatformIntrinsic) {
             return;
         }
 
         // Process all of the #[link(..)]-style arguments
-        let sess = &self.tcx.sess;
+        let sess = self.tcx.sess;
         let features = self.tcx.features();
+
+        if !sess.opts.unstable_opts.link_directives {
+            return;
+        }
+
         for m in self.tcx.hir().attrs(it.hir_id()).iter().filter(|a| a.has_name(sym::link)) {
             let Some(items) = m.meta_item_list() else {
                 continue;
@@ -129,26 +125,26 @@ impl<'tcx> Collector<'tcx> {
                 match item.name_or_empty() {
                     sym::name => {
                         if name.is_some() {
-                            sess.emit_err(MultipleNamesInLink { span: item.span() });
+                            sess.emit_err(errors::MultipleNamesInLink { span: item.span() });
                             continue;
                         }
                         let Some(link_name) = item.value_str() else {
-                            sess.emit_err(LinkNameForm { span: item.span() });
+                            sess.emit_err(errors::LinkNameForm { span: item.span() });
                             continue;
                         };
                         let span = item.name_value_literal_span().unwrap();
                         if link_name.is_empty() {
-                            sess.emit_err(EmptyLinkName { span });
+                            sess.emit_err(errors::EmptyLinkName { span });
                         }
                         name = Some((link_name, span));
                     }
                     sym::kind => {
                         if kind.is_some() {
-                            sess.emit_err(MultipleKindsInLink { span: item.span() });
+                            sess.emit_err(errors::MultipleKindsInLink { span: item.span() });
                             continue;
                         }
                         let Some(link_kind) = item.value_str() else {
-                            sess.emit_err(LinkKindForm { span: item.span() });
+                            sess.emit_err(errors::LinkKindForm { span: item.span() });
                             continue;
                         };
 
@@ -158,13 +154,13 @@ impl<'tcx> Collector<'tcx> {
                             "dylib" => NativeLibKind::Dylib { as_needed: None },
                             "framework" => {
                                 if !sess.target.is_like_osx {
-                                    sess.emit_err(LinkFrameworkApple { span });
+                                    sess.emit_err(errors::LinkFrameworkApple { span });
                                 }
                                 NativeLibKind::Framework { as_needed: None }
                             }
                             "raw-dylib" => {
                                 if !sess.target.is_like_windows {
-                                    sess.emit_err(FrameworkOnlyWindows { span });
+                                    sess.emit_err(errors::FrameworkOnlyWindows { span });
                                 } else if !features.raw_dylib && sess.target.arch == "x86" {
                                     feature_err(
                                         &sess.parse_sess,
@@ -177,7 +173,7 @@ impl<'tcx> Collector<'tcx> {
                                 NativeLibKind::RawDylib
                             }
                             kind => {
-                                sess.emit_err(UnknownLinkKind { span, kind });
+                                sess.emit_err(errors::UnknownLinkKind { span, kind });
                                 continue;
                             }
                         };
@@ -185,26 +181,26 @@ impl<'tcx> Collector<'tcx> {
                     }
                     sym::modifiers => {
                         if modifiers.is_some() {
-                            sess.emit_err(MultipleLinkModifiers { span: item.span() });
+                            sess.emit_err(errors::MultipleLinkModifiers { span: item.span() });
                             continue;
                         }
                         let Some(link_modifiers) = item.value_str() else {
-                            sess.emit_err(LinkModifiersForm { span: item.span() });
+                            sess.emit_err(errors::LinkModifiersForm { span: item.span() });
                             continue;
                         };
                         modifiers = Some((link_modifiers, item.name_value_literal_span().unwrap()));
                     }
                     sym::cfg => {
                         if cfg.is_some() {
-                            sess.emit_err(MultipleCfgs { span: item.span() });
+                            sess.emit_err(errors::MultipleCfgs { span: item.span() });
                             continue;
                         }
                         let Some(link_cfg) = item.meta_item_list() else {
-                            sess.emit_err(LinkCfgForm { span: item.span() });
+                            sess.emit_err(errors::LinkCfgForm { span: item.span() });
                             continue;
                         };
                         let [NestedMetaItem::MetaItem(link_cfg)] = link_cfg else {
-                            sess.emit_err(LinkCfgSinglePredicate { span: item.span() });
+                            sess.emit_err(errors::LinkCfgSinglePredicate { span: item.span() });
                             continue;
                         };
                         if !features.link_cfg {
@@ -220,26 +216,26 @@ impl<'tcx> Collector<'tcx> {
                     }
                     sym::wasm_import_module => {
                         if wasm_import_module.is_some() {
-                            sess.emit_err(MultipleWasmImport { span: item.span() });
+                            sess.emit_err(errors::MultipleWasmImport { span: item.span() });
                             continue;
                         }
                         let Some(link_wasm_import_module) = item.value_str() else {
-                            sess.emit_err(WasmImportForm { span: item.span() });
+                            sess.emit_err(errors::WasmImportForm { span: item.span() });
                             continue;
                         };
                         wasm_import_module = Some((link_wasm_import_module, item.span()));
                     }
                     sym::import_name_type => {
                         if import_name_type.is_some() {
-                            sess.emit_err(MultipleImportNameType { span: item.span() });
+                            sess.emit_err(errors::MultipleImportNameType { span: item.span() });
                             continue;
                         }
                         let Some(link_import_name_type) = item.value_str() else {
-                            sess.emit_err(ImportNameTypeForm { span: item.span() });
+                            sess.emit_err(errors::ImportNameTypeForm { span: item.span() });
                             continue;
                         };
                         if self.tcx.sess.target.arch != "x86" {
-                            sess.emit_err(ImportNameTypeX86 { span: item.span() });
+                            sess.emit_err(errors::ImportNameTypeX86 { span: item.span() });
                             continue;
                         }
 
@@ -248,7 +244,7 @@ impl<'tcx> Collector<'tcx> {
                             "noprefix" => PeImportNameType::NoPrefix,
                             "undecorated" => PeImportNameType::Undecorated,
                             import_name_type => {
-                                sess.emit_err(UnknownImportNameType {
+                                sess.emit_err(errors::UnknownImportNameType {
                                     span: item.span(),
                                     import_name_type,
                                 });
@@ -268,7 +264,7 @@ impl<'tcx> Collector<'tcx> {
                         import_name_type = Some((link_import_name_type, item.span()));
                     }
                     _ => {
-                        sess.emit_err(UnexpectedLinkArg { span: item.span() });
+                        sess.emit_err(errors::UnexpectedLinkArg { span: item.span() });
                     }
                 }
             }
@@ -280,7 +276,7 @@ impl<'tcx> Collector<'tcx> {
                     let (modifier, value) = match modifier.strip_prefix(&['+', '-']) {
                         Some(m) => (m, modifier.starts_with('+')),
                         None => {
-                            sess.emit_err(InvalidLinkModifier { span });
+                            sess.emit_err(errors::InvalidLinkModifier { span });
                             continue;
                         }
                     };
@@ -298,7 +294,7 @@ impl<'tcx> Collector<'tcx> {
                     }
                     let assign_modifier = |dst: &mut Option<bool>| {
                         if dst.is_some() {
-                            sess.emit_err(MultipleModifiers { span, modifier });
+                            sess.emit_err(errors::MultipleModifiers { span, modifier });
                         } else {
                             *dst = Some(value);
                         }
@@ -308,7 +304,7 @@ impl<'tcx> Collector<'tcx> {
                             assign_modifier(bundle)
                         }
                         ("bundle", _) => {
-                            sess.emit_err(BundleNeedsStatic { span });
+                            sess.emit_err(errors::BundleNeedsStatic { span });
                         }
 
                         ("verbatim", _) => assign_modifier(&mut verbatim),
@@ -317,7 +313,7 @@ impl<'tcx> Collector<'tcx> {
                             assign_modifier(whole_archive)
                         }
                         ("whole-archive", _) => {
-                            sess.emit_err(WholeArchiveNeedsStatic { span });
+                            sess.emit_err(errors::WholeArchiveNeedsStatic { span });
                         }
 
                         ("as-needed", Some(NativeLibKind::Dylib { as_needed }))
@@ -326,11 +322,11 @@ impl<'tcx> Collector<'tcx> {
                             assign_modifier(as_needed)
                         }
                         ("as-needed", _) => {
-                            sess.emit_err(AsNeededCompatibility { span });
+                            sess.emit_err(errors::AsNeededCompatibility { span });
                         }
 
                         _ => {
-                            sess.emit_err(UnknownLinkModifier { span, modifier });
+                            sess.emit_err(errors::UnknownLinkModifier { span, modifier });
                         }
                     }
                 }
@@ -338,23 +334,23 @@ impl<'tcx> Collector<'tcx> {
 
             if let Some((_, span)) = wasm_import_module {
                 if name.is_some() || kind.is_some() || modifiers.is_some() || cfg.is_some() {
-                    sess.emit_err(IncompatibleWasmLink { span });
+                    sess.emit_err(errors::IncompatibleWasmLink { span });
                 }
             } else if name.is_none() {
-                sess.emit_err(LinkRequiresName { span: m.span });
+                sess.emit_err(errors::LinkRequiresName { span: m.span });
             }
 
             // Do this outside of the loop so that `import_name_type` can be specified before `kind`.
             if let Some((_, span)) = import_name_type {
                 if kind != Some(NativeLibKind::RawDylib) {
-                    sess.emit_err(ImportNameTypeRaw { span });
+                    sess.emit_err(errors::ImportNameTypeRaw { span });
                 }
             }
 
             let dll_imports = match kind {
                 Some(NativeLibKind::RawDylib) => {
                     if let Some((name, span)) = name && name.as_str().contains('\0') {
-                        sess.emit_err(RawDylibNoNul { span });
+                        sess.emit_err(errors::RawDylibNoNul { span });
                     }
                     foreign_mod_items
                         .iter()
@@ -383,7 +379,9 @@ impl<'tcx> Collector<'tcx> {
                                 .iter()
                                 .find(|a| a.has_name(sym::link_ordinal))
                                 .unwrap();
-                            sess.emit_err(LinkOrdinalRawDylib { span: link_ordinal_attr.span });
+                            sess.emit_err(errors::LinkOrdinalRawDylib {
+                                span: link_ordinal_attr.span,
+                            });
                         }
                     }
 
@@ -393,7 +391,7 @@ impl<'tcx> Collector<'tcx> {
 
             let name = name.map(|(name, _)| name);
             let kind = kind.unwrap_or(NativeLibKind::Unspecified);
-            let filename = find_bundled_library(name, verbatim, kind, sess);
+            let filename = find_bundled_library(name, verbatim, kind, cfg.is_some(), sess);
             self.libs.push(NativeLib {
                 name,
                 filename,
@@ -414,7 +412,7 @@ impl<'tcx> Collector<'tcx> {
         for lib in &self.tcx.sess.opts.libs {
             if let NativeLibKind::Framework { .. } = lib.kind && !self.tcx.sess.target.is_like_osx {
                 // Cannot check this when parsing options because the target is not yet available.
-                self.tcx.sess.emit_err(LibFrameworkApple);
+                self.tcx.sess.emit_err(errors::LibFrameworkApple);
             }
             if let Some(ref new_name) = lib.new_name {
                 let any_duplicate = self
@@ -423,11 +421,11 @@ impl<'tcx> Collector<'tcx> {
                     .filter_map(|lib| lib.name.as_ref())
                     .any(|n| n.as_str() == lib.name);
                 if new_name.is_empty() {
-                    self.tcx.sess.emit_err(EmptyRenamingTarget { lib_name: &lib.name });
+                    self.tcx.sess.emit_err(errors::EmptyRenamingTarget { lib_name: &lib.name });
                 } else if !any_duplicate {
-                    self.tcx.sess.emit_err(RenamingNoLink { lib_name: &lib.name });
+                    self.tcx.sess.emit_err(errors::RenamingNoLink { lib_name: &lib.name });
                 } else if !renames.insert(&lib.name) {
-                    self.tcx.sess.emit_err(MultipleRenamings { lib_name: &lib.name });
+                    self.tcx.sess.emit_err(errors::MultipleRenamings { lib_name: &lib.name });
                 }
             }
         }
@@ -453,12 +451,15 @@ impl<'tcx> Collector<'tcx> {
                             // explicit `:rename` in particular.
                             if lib.has_modifiers() || passed_lib.has_modifiers() {
                                 match lib.foreign_module {
-                                    Some(def_id) => self.tcx.sess.emit_err(NoLinkModOverride {
-                                        span: Some(self.tcx.def_span(def_id)),
-                                    }),
-                                    None => {
-                                        self.tcx.sess.emit_err(NoLinkModOverride { span: None })
+                                    Some(def_id) => {
+                                        self.tcx.sess.emit_err(errors::NoLinkModOverride {
+                                            span: Some(self.tcx.def_span(def_id)),
+                                        })
                                     }
+                                    None => self
+                                        .tcx
+                                        .sess
+                                        .emit_err(errors::NoLinkModOverride { span: None }),
                                 };
                             }
                             if passed_lib.kind != NativeLibKind::Unspecified {
@@ -480,7 +481,7 @@ impl<'tcx> Collector<'tcx> {
                 let name = Some(Symbol::intern(new_name.unwrap_or(&passed_lib.name)));
                 let sess = self.tcx.sess;
                 let filename =
-                    find_bundled_library(name, passed_lib.verbatim, passed_lib.kind, sess);
+                    find_bundled_library(name, passed_lib.verbatim, passed_lib.kind, false, sess);
                 self.libs.push(NativeLib {
                     name,
                     filename,
@@ -503,9 +504,10 @@ impl<'tcx> Collector<'tcx> {
         let argument_types: &List<Ty<'_>> = self.tcx.erase_late_bound_regions(
             self.tcx
                 .type_of(item.id.owner_id)
+                .subst_identity()
                 .fn_sig(self.tcx)
                 .inputs()
-                .map_bound(|slice| self.tcx.mk_type_list(slice.iter())),
+                .map_bound(|slice| self.tcx.mk_type_list(slice)),
         );
 
         argument_types
@@ -542,14 +544,14 @@ impl<'tcx> Collector<'tcx> {
                     DllCallingConvention::Vectorcall(self.i686_arg_list_size(item))
                 }
                 _ => {
-                    self.tcx.sess.emit_fatal(UnsupportedAbiI686 { span: item.span });
+                    self.tcx.sess.emit_fatal(errors::UnsupportedAbiI686 { span: item.span });
                 }
             }
         } else {
             match abi {
                 Abi::C { .. } | Abi::Win64 { .. } | Abi::System { .. } => DllCallingConvention::C,
                 _ => {
-                    self.tcx.sess.emit_fatal(UnsupportedAbi { span: item.span });
+                    self.tcx.sess.emit_fatal(errors::UnsupportedAbi { span: item.span });
                 }
             }
         };
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 143d8f2f1..b1e59b0a4 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -11,7 +11,7 @@ use rustc_data_structures::sync::{Lock, LockGuard, Lrc, OnceCell};
 use rustc_data_structures::unhash::UnhashMap;
 use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
 use rustc_expand::proc_macro::{AttrProcMacro, BangProcMacro, DeriveProcMacro};
-use rustc_hir::def::{CtorKind, DefKind, Res};
+use rustc_hir::def::{CtorKind, DefKind, DocLinkResMap, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
 use rustc_hir::diagnostic_items::DiagnosticItems;
@@ -654,7 +654,7 @@ impl<'a, 'tcx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyValue<T> {
 impl<'a, 'tcx, T> Decodable<DecodeContext<'a, 'tcx>> for LazyArray<T> {
     fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Self {
         let len = decoder.read_usize();
-        if len == 0 { LazyArray::empty() } else { decoder.read_lazy_array(len) }
+        if len == 0 { LazyArray::default() } else { decoder.read_lazy_array(len) }
     }
 }
 
@@ -864,7 +864,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 .tables
                 .children
                 .get(self, index)
-                .unwrap_or_else(LazyArray::empty)
+                .expect("fields are not encoded for a variant")
                 .decode(self)
                 .map(|index| ty::FieldDef {
                     did: self.local_def_id(index),
@@ -896,7 +896,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 .tables
                 .children
                 .get(self, item_id)
-                .unwrap_or_else(LazyArray::empty)
+                .expect("variants are not encoded for an enum")
                 .decode(self)
                 .filter_map(|index| {
                     let kind = self.def_kind(index);
@@ -910,7 +910,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             std::iter::once(self.get_variant(&kind, item_id, did)).collect()
         };
 
-        tcx.alloc_adt_def(did, adt_kind, variants, repr)
+        tcx.mk_adt_def(did, adt_kind, variants, repr)
     }
 
     fn get_generics(self, item_id: DefIndex, sess: &Session) -> ty::Generics {
@@ -985,7 +985,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         let vis = self.get_visibility(id);
         let span = self.get_span(id, sess);
         let macro_rules = match kind {
-            DefKind::Macro(..) => self.root.tables.macro_rules.get(self, id).is_some(),
+            DefKind::Macro(..) => self.root.tables.is_macro_rules.get(self, id),
             _ => false,
         };
 
@@ -1045,7 +1045,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             .tables
             .fn_arg_names
             .get(self, id)
-            .unwrap_or_else(LazyArray::empty)
+            .expect("argument names not encoded for a function")
             .decode((self, sess))
             .nth(0)
             .map_or(false, |ident| ident.name == kw::SelfLower)
@@ -1060,7 +1060,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             .tables
             .children
             .get(self, id)
-            .unwrap_or_else(LazyArray::empty)
+            .expect("associated items not encoded for an item")
             .decode((self, sess))
             .map(move |child_index| self.local_def_id(child_index))
     }
@@ -1068,13 +1068,12 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     fn get_associated_item(self, id: DefIndex, sess: &'a Session) -> ty::AssocItem {
         let name = self.item_name(id);
 
-        let kind = match self.def_kind(id) {
-            DefKind::AssocConst => ty::AssocKind::Const,
-            DefKind::AssocFn => ty::AssocKind::Fn,
-            DefKind::AssocTy => ty::AssocKind::Type,
+        let (kind, has_self) = match self.def_kind(id) {
+            DefKind::AssocConst => (ty::AssocKind::Const, false),
+            DefKind::AssocFn => (ty::AssocKind::Fn, self.get_fn_has_self_parameter(id, sess)),
+            DefKind::AssocTy => (ty::AssocKind::Type, false),
             _ => bug!("cannot get associated-item of `{:?}`", self.def_key(id)),
         };
-        let has_self = self.get_fn_has_self_parameter(id, sess);
         let container = self.root.tables.assoc_container.get(self, id).unwrap();
 
         ty::AssocItem {
@@ -1131,7 +1130,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             .tables
             .children
             .get(self, id)
-            .unwrap_or_else(LazyArray::empty)
+            .expect("fields not encoded for a struct")
             .decode(self)
             .map(move |index| respan(self.get_span(index, sess), self.item_name(index)))
     }
@@ -1144,7 +1143,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             .tables
             .children
             .get(self, id)
-            .unwrap_or_else(LazyArray::empty)
+            .expect("fields not encoded for a struct")
             .decode(self)
             .map(move |field_index| self.get_visibility(field_index))
     }
@@ -1159,52 +1158,23 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 .tables
                 .inherent_impls
                 .get(self, id)
-                .unwrap_or_else(LazyArray::empty)
                 .decode(self)
                 .map(|index| self.local_def_id(index)),
         )
     }
 
-    /// Decodes all inherent impls in the crate (for rustdoc).
-    fn get_inherent_impls(self) -> impl Iterator<Item = (DefId, DefId)> + 'a {
-        (0..self.root.tables.inherent_impls.size()).flat_map(move |i| {
-            let ty_index = DefIndex::from_usize(i);
-            let ty_def_id = self.local_def_id(ty_index);
-            self.root
-                .tables
-                .inherent_impls
-                .get(self, ty_index)
-                .unwrap_or_else(LazyArray::empty)
-                .decode(self)
-                .map(move |impl_index| (ty_def_id, self.local_def_id(impl_index)))
-        })
-    }
-
     /// Decodes all traits in the crate (for rustdoc and rustc diagnostics).
     fn get_traits(self) -> impl Iterator<Item = DefId> + 'a {
         self.root.traits.decode(self).map(move |index| self.local_def_id(index))
     }
 
     /// Decodes all trait impls in the crate (for rustdoc).
-    fn get_trait_impls(self) -> impl Iterator<Item = (DefId, DefId, Option<SimplifiedType>)> + 'a {
-        self.cdata.trait_impls.iter().flat_map(move |(&(trait_cnum_raw, trait_index), impls)| {
-            let trait_def_id = DefId {
-                krate: self.cnum_map[CrateNum::from_u32(trait_cnum_raw)],
-                index: trait_index,
-            };
-            impls.decode(self).map(move |(impl_index, simplified_self_ty)| {
-                (trait_def_id, self.local_def_id(impl_index), simplified_self_ty)
-            })
+    fn get_trait_impls(self) -> impl Iterator<Item = DefId> + 'a {
+        self.cdata.trait_impls.values().flat_map(move |impls| {
+            impls.decode(self).map(move |(impl_index, _)| self.local_def_id(impl_index))
         })
     }
 
-    fn get_all_incoherent_impls(self) -> impl Iterator<Item = DefId> + 'a {
-        self.cdata
-            .incoherent_impls
-            .values()
-            .flat_map(move |impls| impls.decode(self).map(move |idx| self.local_def_id(idx)))
-    }
-
     fn get_incoherent_impls(self, tcx: TyCtxt<'tcx>, simp: SimplifiedType) -> &'tcx [DefId] {
         if let Some(impls) = self.cdata.incoherent_impls.get(&simp) {
             tcx.arena.alloc_from_iter(impls.decode(self).map(|idx| self.local_def_id(idx)))
@@ -1283,7 +1253,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     fn get_macro(self, id: DefIndex, sess: &Session) -> ast::MacroDef {
         match self.def_kind(id) {
             DefKind::Macro(_) => {
-                let macro_rules = self.root.tables.macro_rules.get(self, id).is_some();
+                let macro_rules = self.root.tables.is_macro_rules.get(self, id);
                 let body =
                     self.root.tables.macro_definition.get(self, id).unwrap().decode((self, sess));
                 ast::MacroDef { macro_rules, body: ast::ptr::P(body) }
@@ -1322,7 +1292,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     ) -> DefPathHash {
         *def_path_hashes
             .entry(index)
-            .or_insert_with(|| self.root.tables.def_path_hashes.get(self, index).unwrap())
+            .or_insert_with(|| self.root.tables.def_path_hashes.get(self, index))
     }
 
     #[inline]
@@ -1594,12 +1564,30 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             })
     }
 
-    fn get_may_have_doc_links(self, index: DefIndex) -> bool {
-        self.root.tables.may_have_doc_links.get(self, index).is_some()
+    fn get_attr_flags(self, index: DefIndex) -> AttrFlags {
+        self.root.tables.attr_flags.get(self, index)
     }
 
     fn get_is_intrinsic(self, index: DefIndex) -> bool {
-        self.root.tables.is_intrinsic.get(self, index).is_some()
+        self.root.tables.is_intrinsic.get(self, index)
+    }
+
+    fn get_doc_link_resolutions(self, index: DefIndex) -> DocLinkResMap {
+        self.root
+            .tables
+            .doc_link_resolutions
+            .get(self, index)
+            .expect("no resolutions for a doc link")
+            .decode(self)
+    }
+
+    fn get_doc_link_traits_in_scope(self, index: DefIndex) -> impl Iterator<Item = DefId> + 'a {
+        self.root
+            .tables
+            .doc_link_traits_in_scope
+            .get(self, index)
+            .expect("no traits in scope for a doc link")
+            .decode(self)
     }
 }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 6fd5bd52a..83a0e833e 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -1,6 +1,8 @@
 use crate::creader::{CStore, LoadedMacro};
 use crate::foreign_modules;
 use crate::native_libs;
+use crate::rmeta::table::IsDefault;
+use crate::rmeta::AttrFlags;
 
 use rustc_ast as ast;
 use rustc_attr::Deprecation;
@@ -87,6 +89,14 @@ macro_rules! provide_one {
             }
         }
     };
+    ($tcx:ident, $def_id:ident, $other:ident, $cdata:ident, $name:ident => { table_defaulted_array }) => {
+        provide_one! {
+            $tcx, $def_id, $other, $cdata, $name => {
+                let lazy = $cdata.root.tables.$name.get($cdata, $def_id.index);
+                if lazy.is_default() { &[] } else { $tcx.arena.alloc_from_iter(lazy.decode(($cdata, $tcx))) }
+            }
+        }
+    };
     ($tcx:ident, $def_id:ident, $other:ident, $cdata:ident, $name:ident => { table_direct }) => {
         provide_one! {
             $tcx, $def_id, $other, $cdata, $name => {
@@ -104,7 +114,7 @@ macro_rules! provide_one {
         fn $name<'tcx>(
             $tcx: TyCtxt<'tcx>,
             def_id_arg: ty::query::query_keys::$name<'tcx>,
-        ) -> ty::query::query_values::$name<'tcx> {
+        ) -> ty::query::query_provided::$name<'tcx> {
             let _prof_timer =
                 $tcx.prof.generic_activity(concat!("metadata_decode_entry_", stringify!($name)));
 
@@ -120,7 +130,13 @@ macro_rules! provide_one {
                 $tcx.ensure().crate_hash($def_id.krate);
             }
 
-            let $cdata = CStore::from_tcx($tcx).get_crate_data($def_id.krate);
+            let cdata = rustc_data_structures::sync::MappedReadGuard::map(CStore::from_tcx($tcx), |c| {
+                c.get_crate_data($def_id.krate).cdata
+            });
+            let $cdata = crate::creader::CrateMetadataRef {
+                cdata: &cdata,
+                cstore: &CStore::from_tcx($tcx),
+            };
 
             $compute
         }
@@ -186,10 +202,10 @@ impl IntoArgs for (CrateNum, SimplifiedType) {
 }
 
 provide! { tcx, def_id, other, cdata,
-    explicit_item_bounds => { table }
+    explicit_item_bounds => { table_defaulted_array }
     explicit_predicates_of => { table }
     generics_of => { table }
-    inferred_outlives_of => { table }
+    inferred_outlives_of => { table_defaulted_array }
     super_predicates_of => { table }
     type_of => { table }
     variances_of => { table }
@@ -201,6 +217,7 @@ provide! { tcx, def_id, other, cdata,
     thir_abstract_const => { table }
     optimized_mir => { table }
     mir_for_ctfe => { table }
+    mir_generator_witnesses => { table }
     promoted_mir => { table }
     def_span => { table }
     def_ident_span => { table }
@@ -225,12 +242,7 @@ provide! { tcx, def_id, other, cdata,
     deduced_param_attrs => { table }
     is_type_alias_impl_trait => {
         debug_assert_eq!(tcx.def_kind(def_id), DefKind::OpaqueTy);
-        cdata
-            .root
-            .tables
-            .is_type_alias_impl_trait
-            .get(cdata, def_id.index)
-            .is_some()
+        cdata.root.tables.is_type_alias_impl_trait.get(cdata, def_id.index)
     }
     collect_return_position_impl_trait_in_trait_tys => {
         Ok(cdata
@@ -242,6 +254,8 @@ provide! { tcx, def_id, other, cdata,
             .process_decoded(tcx, || panic!("{def_id:?} does not have trait_impl_trait_tys")))
      }
 
+    associated_items_for_impl_trait_in_trait => { table_defaulted_array }
+
     visibility => { cdata.get_visibility(def_id.index) }
     adt_def => { cdata.get_adt_def(def_id.index, tcx) }
     adt_destructor => {
@@ -298,6 +312,7 @@ provide! { tcx, def_id, other, cdata,
     extra_filename => { cdata.root.extra_filename.clone() }
 
     traits_in_crate => { tcx.arena.alloc_from_iter(cdata.get_traits()) }
+    trait_impls_in_crate => { tcx.arena.alloc_from_iter(cdata.get_trait_impls()) }
     implementations_of_trait => { cdata.get_implementations_of_trait(tcx, other) }
     crate_incoherent_impls => { cdata.get_incoherent_impls(tcx, other) }
 
@@ -338,6 +353,11 @@ provide! { tcx, def_id, other, cdata,
     crate_extern_paths => { cdata.source().paths().cloned().collect() }
     expn_that_defined => { cdata.get_expn_that_defined(def_id.index, tcx.sess) }
     generator_diagnostic_data => { cdata.get_generator_diagnostic_data(tcx, def_id.index) }
+    is_doc_hidden => { cdata.get_attr_flags(def_id.index).contains(AttrFlags::IS_DOC_HIDDEN) }
+    doc_link_resolutions => { tcx.arena.alloc(cdata.get_doc_link_resolutions(def_id.index)) }
+    doc_link_traits_in_scope => {
+        tcx.arena.alloc_from_iter(cdata.get_doc_link_traits_in_scope(def_id.index))
+    }
 }
 
 pub(in crate::rmeta) fn provide(providers: &mut Providers) {
@@ -425,7 +445,7 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
                         return;
                     }
 
-                    if ty::util::is_doc_hidden(tcx, parent) {
+                    if tcx.is_doc_hidden(parent) {
                         fallback_map.push((def_id, parent));
                         return;
                     }
@@ -597,42 +617,6 @@ impl CStore {
     ) -> Span {
         self.get_crate_data(cnum).get_proc_macro_quoted_span(id, sess)
     }
-
-    /// Decodes all trait impls in the crate (for rustdoc).
-    pub fn trait_impls_in_crate_untracked(
-        &self,
-        cnum: CrateNum,
-    ) -> impl Iterator<Item = (DefId, DefId, Option<SimplifiedType>)> + '_ {
-        self.get_crate_data(cnum).get_trait_impls()
-    }
-
-    /// Decodes all inherent impls in the crate (for rustdoc).
-    pub fn inherent_impls_in_crate_untracked(
-        &self,
-        cnum: CrateNum,
-    ) -> impl Iterator<Item = (DefId, DefId)> + '_ {
-        self.get_crate_data(cnum).get_inherent_impls()
-    }
-
-    /// Decodes all incoherent inherent impls in the crate (for rustdoc).
-    pub fn incoherent_impls_in_crate_untracked(
-        &self,
-        cnum: CrateNum,
-    ) -> impl Iterator<Item = DefId> + '_ {
-        self.get_crate_data(cnum).get_all_incoherent_impls()
-    }
-
-    pub fn associated_item_def_ids_untracked<'a>(
-        &'a self,
-        def_id: DefId,
-        sess: &'a Session,
-    ) -> impl Iterator<Item = DefId> + 'a {
-        self.get_crate_data(def_id.krate).get_associated_item_def_ids(def_id.index, sess)
-    }
-
-    pub fn may_have_doc_links_untracked(&self, def_id: DefId) -> bool {
-        self.get_crate_data(def_id.krate).get_may_have_doc_links(def_id.index)
-    }
 }
 
 impl CrateStore for CStore {
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 8f7a61b72..3ab01f780 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -38,7 +38,6 @@ use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{
     self, DebuggerVisualizerFile, ExternalSource, FileName, SourceFile, Span, SyntaxContext,
 };
-use rustc_target::abi::VariantIdx;
 use std::borrow::Borrow;
 use std::collections::hash_map::Entry;
 use std::hash::Hash;
@@ -76,13 +75,13 @@ pub(super) struct EncodeContext<'a, 'tcx> {
     symbol_table: FxHashMap<Symbol, usize>,
 }
 
-/// If the current crate is a proc-macro, returns early with `LazyArray::empty()`.
+/// If the current crate is a proc-macro, returns early with `LazyArray::default()`.
 /// This is useful for skipping the encoding of things that aren't needed
 /// for proc-macro crates.
 macro_rules! empty_proc_macro {
     ($self:ident) => {
         if $self.is_proc_macro {
-            return LazyArray::empty();
+            return LazyArray::default();
         }
     };
 }
@@ -365,25 +364,35 @@ impl<'a, 'tcx> TyEncoder for EncodeContext<'a, 'tcx> {
     }
 }
 
-// Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy_value($value))`, which would
+// Shorthand for `$self.$tables.$table.set_some($def_id.index, $self.lazy_value($value))`, which would
 // normally need extra variables to avoid errors about multiple mutable borrows.
 macro_rules! record {
     ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
         {
             let value = $value;
             let lazy = $self.lazy(value);
-            $self.$tables.$table.set($def_id.index, lazy);
+            $self.$tables.$table.set_some($def_id.index, lazy);
         }
     }};
 }
 
-// Shorthand for `$self.$tables.$table.set($def_id.index, $self.lazy_value($value))`, which would
+// Shorthand for `$self.$tables.$table.set_some($def_id.index, $self.lazy_value($value))`, which would
 // normally need extra variables to avoid errors about multiple mutable borrows.
 macro_rules! record_array {
     ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
         {
             let value = $value;
             let lazy = $self.lazy_array(value);
+            $self.$tables.$table.set_some($def_id.index, lazy);
+        }
+    }};
+}
+
+macro_rules! record_defaulted_array {
+    ($self:ident.$tables:ident.$table:ident[$def_id:expr] <- $value:expr) => {{
+        {
+            let value = $value;
+            let lazy = $self.lazy_array(value);
             $self.$tables.$table.set($def_id.index, lazy);
         }
     }};
@@ -467,13 +476,13 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             {
                 let def_key = self.lazy(table.def_key(def_index));
                 let def_path_hash = table.def_path_hash(def_index);
-                self.tables.def_keys.set(def_index, def_key);
+                self.tables.def_keys.set_some(def_index, def_key);
                 self.tables.def_path_hashes.set(def_index, def_path_hash);
             }
         } else {
             for (def_index, def_key, def_path_hash) in table.enumerated_keys_and_path_hashes() {
                 let def_key = self.lazy(def_key);
-                self.tables.def_keys.set(def_index, def_key);
+                self.tables.def_keys.set_some(def_index, def_key);
                 self.tables.def_path_hashes.set(def_index, *def_path_hash);
             }
         }
@@ -483,7 +492,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         self.lazy(DefPathHashMapRef::BorrowedFromTcx(self.tcx.def_path_hash_to_def_index_map()))
     }
 
-    fn encode_source_map(&mut self) -> LazyTable<u32, LazyValue<rustc_span::SourceFile>> {
+    fn encode_source_map(&mut self) -> LazyTable<u32, Option<LazyValue<rustc_span::SourceFile>>> {
         let source_map = self.tcx.sess.source_map();
         let all_source_files = source_map.files();
 
@@ -548,7 +557,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
 
             let on_disk_index: u32 =
                 on_disk_index.try_into().expect("cannot export more than U32_MAX files");
-            adapted.set(on_disk_index, self.lazy(source_file));
+            adapted.set_some(on_disk_index, self.lazy(source_file));
         }
 
         adapted.encode(&mut self.opaque)
@@ -760,36 +769,50 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     }
 }
 
+struct AnalyzeAttrState {
+    is_exported: bool,
+    is_doc_hidden: bool,
+}
+
 /// Returns whether an attribute needs to be recorded in metadata, that is, if it's usable and
 /// useful in downstream crates. Local-only attributes are an obvious example, but some
 /// rustdoc-specific attributes can equally be of use while documenting the current crate only.
 ///
 /// Removing these superfluous attributes speeds up compilation by making the metadata smaller.
 ///
-/// Note: the `is_def_id_public` parameter is used to cache whether the given `DefId` has a public
+/// Note: the `is_exported` parameter is used to cache whether the given `DefId` has a public
 /// visibility: this is a piece of data that can be computed once per defid, and not once per
 /// attribute. Some attributes would only be usable downstream if they are public.
 #[inline]
-fn should_encode_attr(
-    tcx: TyCtxt<'_>,
-    attr: &Attribute,
-    def_id: LocalDefId,
-    is_def_id_public: &mut Option<bool>,
-) -> bool {
+fn analyze_attr(attr: &Attribute, state: &mut AnalyzeAttrState) -> bool {
+    let mut should_encode = false;
     if rustc_feature::is_builtin_only_local(attr.name_or_empty()) {
         // Attributes marked local-only don't need to be encoded for downstream crates.
-        false
     } else if attr.doc_str().is_some() {
-        // We keep all public doc comments because they might be "imported" into downstream crates
-        // if they use `#[doc(inline)]` to copy an item's documentation into their own.
-        *is_def_id_public.get_or_insert_with(|| tcx.effective_visibilities(()).is_exported(def_id))
+        // We keep all doc comments reachable to rustdoc because they might be "imported" into
+        // downstream crates if they use `#[doc(inline)]` to copy an item's documentation into
+        // their own.
+        if state.is_exported {
+            should_encode = true;
+        }
     } else if attr.has_name(sym::doc) {
-        // If this is a `doc` attribute, and it's marked `inline` (as in `#[doc(inline)]`), we can
-        // remove it. It won't be inlinable in downstream crates.
-        attr.meta_item_list().map(|l| l.iter().any(|l| !l.has_name(sym::inline))).unwrap_or(false)
+        // If this is a `doc` attribute that doesn't have anything except maybe `inline` (as in
+        // `#[doc(inline)]`), then we can remove it. It won't be inlinable in downstream crates.
+        if let Some(item_list) = attr.meta_item_list() {
+            for item in item_list {
+                if !item.has_name(sym::inline) {
+                    should_encode = true;
+                    if item.has_name(sym::hidden) {
+                        state.is_doc_hidden = true;
+                        break;
+                    }
+                }
+            }
+        }
     } else {
-        true
+        should_encode = true;
     }
+    should_encode
 }
 
 fn should_encode_visibility(def_kind: DefKind) -> bool {
@@ -815,7 +838,7 @@ fn should_encode_visibility(def_kind: DefKind) -> bool {
         | DefKind::ForeignMod
         | DefKind::OpaqueTy
         | DefKind::ImplTraitPlaceholder
-        | DefKind::Impl
+        | DefKind::Impl { .. }
         | DefKind::Field => true,
         DefKind::TyParam
         | DefKind::ConstParam
@@ -850,7 +873,7 @@ fn should_encode_stability(def_kind: DefKind) -> bool {
         | DefKind::ImplTraitPlaceholder
         | DefKind::Enum
         | DefKind::Union
-        | DefKind::Impl
+        | DefKind::Impl { .. }
         | DefKind::Trait
         | DefKind::TraitAlias
         | DefKind::Macro(..)
@@ -928,7 +951,7 @@ fn should_encode_variances(def_kind: DefKind) -> bool {
         | DefKind::Const
         | DefKind::ForeignMod
         | DefKind::TyAlias
-        | DefKind::Impl
+        | DefKind::Impl { .. }
         | DefKind::Trait
         | DefKind::TraitAlias
         | DefKind::Macro(..)
@@ -965,7 +988,7 @@ fn should_encode_generics(def_kind: DefKind) -> bool {
         | DefKind::InlineConst
         | DefKind::OpaqueTy
         | DefKind::ImplTraitPlaceholder
-        | DefKind::Impl
+        | DefKind::Impl { .. }
         | DefKind::Field
         | DefKind::TyParam
         | DefKind::Closure
@@ -995,7 +1018,7 @@ fn should_encode_type(tcx: TyCtxt<'_>, def_id: LocalDefId, def_kind: DefKind) ->
         | DefKind::TyAlias
         | DefKind::OpaqueTy
         | DefKind::ForeignTy
-        | DefKind::Impl
+        | DefKind::Impl { .. }
         | DefKind::AssocFn
         | DefKind::AssocConst
         | DefKind::Closure
@@ -1058,7 +1081,7 @@ fn should_encode_const(def_kind: DefKind) -> bool {
         | DefKind::OpaqueTy
         | DefKind::ImplTraitPlaceholder
         | DefKind::ForeignTy
-        | DefKind::Impl
+        | DefKind::Impl { .. }
         | DefKind::AssocFn
         | DefKind::Closure
         | DefKind::Generator
@@ -1078,49 +1101,40 @@ fn should_encode_const(def_kind: DefKind) -> bool {
     }
 }
 
-fn should_encode_trait_impl_trait_tys(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
-    if tcx.def_kind(def_id) != DefKind::AssocFn {
-        return false;
-    }
-
-    let Some(item) = tcx.opt_associated_item(def_id) else { return false; };
-    if item.container != ty::AssocItemContainer::ImplContainer {
-        return false;
+// We only encode impl trait in trait when using `lower-impl-trait-in-trait-to-assoc-ty` unstable
+// option.
+fn should_encode_fn_impl_trait_in_trait<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
+    if tcx.sess.opts.unstable_opts.lower_impl_trait_in_trait_to_assoc_ty
+        && let Some(assoc_item) = tcx.opt_associated_item(def_id)
+        && assoc_item.container == ty::AssocItemContainer::TraitContainer
+        && assoc_item.kind == ty::AssocKind::Fn
+    {
+        true
+    } else {
+        false
     }
-
-    let Some(trait_item_def_id) = item.trait_item_def_id else { return false; };
-
-    // FIXME(RPITIT): This does a somewhat manual walk through the signature
-    // of the trait fn to look for any RPITITs, but that's kinda doing a lot
-    // of work. We can probably remove this when we refactor RPITITs to be
-    // associated types.
-    tcx.fn_sig(trait_item_def_id).skip_binder().output().walk().any(|arg| {
-        if let ty::GenericArgKind::Type(ty) = arg.unpack()
-            && let ty::Alias(ty::Projection, data) = ty.kind()
-            && tcx.def_kind(data.def_id) == DefKind::ImplTraitPlaceholder
-        {
-            true
-        } else {
-            false
-        }
-    })
 }
 
 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     fn encode_attrs(&mut self, def_id: LocalDefId) {
         let tcx = self.tcx;
-        let mut is_public: Option<bool> = None;
-
-        let mut attrs = tcx
-            .hir()
-            .attrs(tcx.hir().local_def_id_to_hir_id(def_id))
+        let mut state = AnalyzeAttrState {
+            is_exported: tcx.effective_visibilities(()).is_exported(def_id),
+            is_doc_hidden: false,
+        };
+        let attr_iter = tcx
+            .opt_local_def_id_to_hir_id(def_id)
+            .map_or(Default::default(), |hir_id| tcx.hir().attrs(hir_id))
             .iter()
-            .filter(move |attr| should_encode_attr(tcx, attr, def_id, &mut is_public));
+            .filter(|attr| analyze_attr(attr, &mut state));
+
+        record_array!(self.tables.attributes[def_id.to_def_id()] <- attr_iter);
 
-        record_array!(self.tables.attributes[def_id.to_def_id()] <- attrs.clone());
-        if attrs.any(|attr| attr.may_have_doc_links()) {
-            self.tables.may_have_doc_links.set(def_id.local_def_index, ());
+        let mut attr_flags = AttrFlags::empty();
+        if state.is_doc_hidden {
+            attr_flags |= AttrFlags::IS_DOC_HIDDEN;
         }
+        self.tables.attr_flags.set(def_id.local_def_index, attr_flags);
     }
 
     fn encode_def_ids(&mut self) {
@@ -1132,7 +1146,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             let def_id = local_id.to_def_id();
             let def_kind = tcx.opt_def_kind(local_id);
             let Some(def_kind) = def_kind else { continue };
-            self.tables.opt_def_kind.set(def_id.index, def_kind);
+            self.tables.opt_def_kind.set_some(def_id.index, def_kind);
             let def_span = tcx.def_span(local_id);
             record!(self.tables.def_span[def_id] <- def_span);
             self.encode_attrs(local_id);
@@ -1163,9 +1177,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.generics_of[def_id] <- g);
                 record!(self.tables.explicit_predicates_of[def_id] <- self.tcx.explicit_predicates_of(def_id));
                 let inferred_outlives = self.tcx.inferred_outlives_of(def_id);
-                if !inferred_outlives.is_empty() {
-                    record_array!(self.tables.inferred_outlives_of[def_id] <- inferred_outlives);
-                }
+                record_defaulted_array!(self.tables.inferred_outlives_of[def_id] <- inferred_outlives);
             }
             if should_encode_type(tcx, local_id, def_kind) {
                 record!(self.tables.type_of[def_id] <- self.tcx.type_of(def_id));
@@ -1178,70 +1190,85 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.super_predicates_of[def_id] <- self.tcx.super_predicates_of(def_id));
             }
             if let DefKind::Enum | DefKind::Struct | DefKind::Union = def_kind {
-                let params_in_repr = self.tcx.params_in_repr(def_id);
-                record!(self.tables.params_in_repr[def_id] <- params_in_repr);
+                self.encode_info_for_adt(def_id);
             }
-            if should_encode_trait_impl_trait_tys(tcx, def_id)
+            if tcx.impl_method_has_trait_impl_trait_tys(def_id)
                 && let Ok(table) = self.tcx.collect_return_position_impl_trait_in_trait_tys(def_id)
             {
                 record!(self.tables.trait_impl_trait_tys[def_id] <- table);
             }
+            if should_encode_fn_impl_trait_in_trait(tcx, def_id) {
+                let table = tcx.associated_items_for_impl_trait_in_trait(def_id);
+                record_defaulted_array!(self.tables.associated_items_for_impl_trait_in_trait[def_id] <- table);
+            }
         }
+
         let inherent_impls = tcx.with_stable_hashing_context(|hcx| {
             tcx.crate_inherent_impls(()).inherent_impls.to_sorted(&hcx, true)
         });
-
-        for (def_id, implementations) in inherent_impls {
-            if implementations.is_empty() {
-                continue;
-            }
-            record_array!(self.tables.inherent_impls[def_id.to_def_id()] <- implementations.iter().map(|&def_id| {
+        for (def_id, impls) in inherent_impls {
+            record_defaulted_array!(self.tables.inherent_impls[def_id.to_def_id()] <- impls.iter().map(|def_id| {
                 assert!(def_id.is_local());
                 def_id.index
             }));
         }
+
+        for (def_id, res_map) in &tcx.resolutions(()).doc_link_resolutions {
+            record!(self.tables.doc_link_resolutions[def_id.to_def_id()] <- res_map);
+        }
+
+        for (def_id, traits) in &tcx.resolutions(()).doc_link_traits_in_scope {
+            record_array!(self.tables.doc_link_traits_in_scope[def_id.to_def_id()] <- traits);
+        }
     }
 
-    fn encode_enum_variant_info(&mut self, def: ty::AdtDef<'tcx>, index: VariantIdx) {
+    #[instrument(level = "trace", skip(self))]
+    fn encode_info_for_adt(&mut self, def_id: DefId) {
         let tcx = self.tcx;
-        let variant = &def.variant(index);
-        let def_id = variant.def_id;
-        debug!("EncodeContext::encode_enum_variant_info({:?})", def_id);
-
-        let data = VariantData {
-            discr: variant.discr,
-            ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
-            is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-        };
+        let adt_def = tcx.adt_def(def_id);
+        record!(self.tables.repr_options[def_id] <- adt_def.repr());
+
+        let params_in_repr = self.tcx.params_in_repr(def_id);
+        record!(self.tables.params_in_repr[def_id] <- params_in_repr);
 
-        record!(self.tables.variant_data[def_id] <- data);
-        self.tables.constness.set(def_id.index, hir::Constness::Const);
-        record_array!(self.tables.children[def_id] <- variant.fields.iter().map(|f| {
-            assert!(f.did.is_local());
-            f.did.index
-        }));
-        if let Some((CtorKind::Fn, ctor_def_id)) = variant.ctor {
-            // FIXME(eddyb) encode signature only in `encode_enum_variant_ctor`.
-            record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(ctor_def_id));
+        if adt_def.is_enum() {
+            record_array!(self.tables.children[def_id] <- iter::from_generator(||
+                for variant in tcx.adt_def(def_id).variants() {
+                    yield variant.def_id.index;
+                    // Encode constructors which take a separate slot in value namespace.
+                    if let Some(ctor_def_id) = variant.ctor_def_id() {
+                        yield ctor_def_id.index;
+                    }
+                }
+            ));
+        } else {
+            // For non-enum, there is only one variant, and its def_id is the adt's.
+            debug_assert_eq!(adt_def.variants().len(), 1);
+            debug_assert_eq!(adt_def.non_enum_variant().def_id, def_id);
+            // Therefore, the loop over variants will encode its fields as the adt's children.
         }
-    }
 
-    fn encode_enum_variant_ctor(&mut self, def: ty::AdtDef<'tcx>, index: VariantIdx) {
-        let variant = &def.variant(index);
-        let Some((ctor_kind, def_id)) = variant.ctor else { return };
-        debug!("EncodeContext::encode_enum_variant_ctor({:?})", def_id);
+        for variant in adt_def.variants().iter() {
+            let data = VariantData {
+                discr: variant.discr,
+                ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
+                is_non_exhaustive: variant.is_field_list_non_exhaustive(),
+            };
+            record!(self.tables.variant_data[variant.def_id] <- data);
 
-        // FIXME(eddyb) encode only the `CtorKind` for constructors.
-        let data = VariantData {
-            discr: variant.discr,
-            ctor: Some((ctor_kind, def_id.index)),
-            is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-        };
+            self.tables.constness.set_some(variant.def_id.index, hir::Constness::Const);
+            record_array!(self.tables.children[variant.def_id] <- variant.fields.iter().map(|f| {
+                assert!(f.did.is_local());
+                f.did.index
+            }));
 
-        record!(self.tables.variant_data[def_id] <- data);
-        self.tables.constness.set(def_id.index, hir::Constness::Const);
-        if ctor_kind == CtorKind::Fn {
-            record!(self.tables.fn_sig[def_id] <- self.tcx.fn_sig(def_id));
+            if let Some((CtorKind::Fn, ctor_def_id)) = variant.ctor {
+                self.tables.constness.set_some(ctor_def_id.index, hir::Constness::Const);
+                let fn_sig = tcx.fn_sig(ctor_def_id);
+                record!(self.tables.fn_sig[ctor_def_id] <- fn_sig);
+                // FIXME only encode signature for ctor_def_id
+                record!(self.tables.fn_sig[variant.def_id] <- fn_sig);
+            }
         }
     }
 
@@ -1275,8 +1302,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                         hir::ItemKind::Struct(ref vdata, _) => {
                             yield item_id.owner_id.def_id.local_def_index;
                             // Encode constructors which take a separate slot in value namespace.
-                            if let Some(ctor_hir_id) = vdata.ctor_hir_id() {
-                                yield tcx.hir().local_def_id(ctor_hir_id).local_def_index;
+                            if let Some(ctor_def_id) = vdata.ctor_def_id() {
+                                yield ctor_def_id.local_def_index;
                             }
                         }
                         _ if tcx.def_key(item_id.owner_id.to_def_id()).get_opt_name().is_some() => {
@@ -1294,31 +1321,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         }
     }
 
-    fn encode_struct_ctor(&mut self, adt_def: ty::AdtDef<'tcx>) {
-        let variant = adt_def.non_enum_variant();
-        let Some((ctor_kind, def_id)) = variant.ctor else { return };
-        debug!("EncodeContext::encode_struct_ctor({:?})", def_id);
-
-        let data = VariantData {
-            discr: variant.discr,
-            ctor: Some((ctor_kind, def_id.index)),
-            is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-        };
-
-        record!(self.tables.repr_options[def_id] <- adt_def.repr());
-        record!(self.tables.variant_data[def_id] <- data);
-        self.tables.constness.set(def_id.index, hir::Constness::Const);
-        if ctor_kind == CtorKind::Fn {
-            record!(self.tables.fn_sig[def_id] <- self.tcx.fn_sig(def_id));
-        }
-    }
-
     fn encode_explicit_item_bounds(&mut self, def_id: DefId) {
         debug!("EncodeContext::encode_explicit_item_bounds({:?})", def_id);
         let bounds = self.tcx.explicit_item_bounds(def_id);
-        if !bounds.is_empty() {
-            record_array!(self.tables.explicit_item_bounds[def_id] <- bounds);
-        }
+        record_defaulted_array!(self.tables.explicit_item_bounds[def_id] <- bounds);
     }
 
     fn encode_info_for_trait_item(&mut self, def_id: DefId) {
@@ -1326,16 +1332,16 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let tcx = self.tcx;
 
         let impl_defaultness = tcx.impl_defaultness(def_id.expect_local());
-        self.tables.impl_defaultness.set(def_id.index, impl_defaultness);
+        self.tables.impl_defaultness.set_some(def_id.index, impl_defaultness);
         let trait_item = tcx.associated_item(def_id);
-        self.tables.assoc_container.set(def_id.index, trait_item.container);
+        self.tables.assoc_container.set_some(def_id.index, trait_item.container);
 
         match trait_item.kind {
             ty::AssocKind::Const => {}
             ty::AssocKind::Fn => {
                 record_array!(self.tables.fn_arg_names[def_id] <- tcx.fn_arg_names(def_id));
-                self.tables.asyncness.set(def_id.index, tcx.asyncness(def_id));
-                self.tables.constness.set(def_id.index, hir::Constness::NotConst);
+                self.tables.asyncness.set_some(def_id.index, tcx.asyncness(def_id));
+                self.tables.constness.set_some(def_id.index, hir::Constness::NotConst);
             }
             ty::AssocKind::Type => {
                 self.encode_explicit_item_bounds(def_id);
@@ -1351,14 +1357,14 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         let tcx = self.tcx;
 
         let ast_item = self.tcx.hir().expect_impl_item(def_id.expect_local());
-        self.tables.impl_defaultness.set(def_id.index, ast_item.defaultness);
+        self.tables.impl_defaultness.set_some(def_id.index, ast_item.defaultness);
         let impl_item = self.tcx.associated_item(def_id);
-        self.tables.assoc_container.set(def_id.index, impl_item.container);
+        self.tables.assoc_container.set_some(def_id.index, impl_item.container);
 
         match impl_item.kind {
             ty::AssocKind::Fn => {
                 let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind else { bug!() };
-                self.tables.asyncness.set(def_id.index, sig.header.asyncness);
+                self.tables.asyncness.set_some(def_id.index, sig.header.asyncness);
                 record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
                 // Can be inside `impl const Trait`, so using sig.header.constness is not reliable
                 let constness = if self.tcx.is_const_fn_raw(def_id) {
@@ -1366,18 +1372,16 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 } else {
                     hir::Constness::NotConst
                 };
-                self.tables.constness.set(def_id.index, constness);
+                self.tables.constness.set_some(def_id.index, constness);
             }
             ty::AssocKind::Const | ty::AssocKind::Type => {}
         }
         if let Some(trait_item_def_id) = impl_item.trait_item_def_id {
-            self.tables.trait_item_def_id.set(def_id.index, trait_item_def_id.into());
+            self.tables.trait_item_def_id.set_some(def_id.index, trait_item_def_id.into());
         }
         if impl_item.kind == ty::AssocKind::Fn {
             record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
-            if tcx.is_intrinsic(def_id) {
-                self.tables.is_intrinsic.set(def_id.index, ());
-            }
+            self.tables.is_intrinsic.set(def_id.index, tcx.is_intrinsic(def_id));
         }
     }
 
@@ -1398,6 +1402,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             debug!("EntryBuilder::encode_mir({:?})", def_id);
             if encode_opt {
                 record!(self.tables.optimized_mir[def_id.to_def_id()] <- tcx.optimized_mir(def_id));
+
+                if tcx.sess.opts.unstable_opts.drop_tracking_mir && let DefKind::Generator = self.tcx.def_kind(def_id) {
+                    record!(self.tables.mir_generator_witnesses[def_id.to_def_id()] <- tcx.mir_generator_witnesses(def_id));
+                }
             }
             if encode_const {
                 record!(self.tables.mir_for_ctfe[def_id.to_def_id()] <- tcx.mir_for_ctfe(def_id));
@@ -1502,14 +1510,12 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
 
         match item.kind {
             hir::ItemKind::Fn(ref sig, .., body) => {
-                self.tables.asyncness.set(def_id.index, sig.header.asyncness);
+                self.tables.asyncness.set_some(def_id.index, sig.header.asyncness);
                 record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
-                self.tables.constness.set(def_id.index, sig.header.constness);
+                self.tables.constness.set_some(def_id.index, sig.header.constness);
             }
             hir::ItemKind::Macro(ref macro_def, _) => {
-                if macro_def.macro_rules {
-                    self.tables.macro_rules.set(def_id.index, ());
-                }
+                self.tables.is_macro_rules.set(def_id.index, macro_def.macro_rules);
                 record!(self.tables.macro_definition[def_id] <- &*macro_def.body);
             }
             hir::ItemKind::Mod(ref m) => {
@@ -1517,47 +1523,21 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             hir::ItemKind::OpaqueTy(ref opaque) => {
                 self.encode_explicit_item_bounds(def_id);
-                if matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias) {
-                    self.tables.is_type_alias_impl_trait.set(def_id.index, ());
-                }
-            }
-            hir::ItemKind::Enum(..) => {
-                let adt_def = self.tcx.adt_def(def_id);
-                record!(self.tables.repr_options[def_id] <- adt_def.repr());
-            }
-            hir::ItemKind::Struct(..) => {
-                let adt_def = self.tcx.adt_def(def_id);
-                record!(self.tables.repr_options[def_id] <- adt_def.repr());
-                self.tables.constness.set(def_id.index, hir::Constness::Const);
-
-                let variant = adt_def.non_enum_variant();
-                record!(self.tables.variant_data[def_id] <- VariantData {
-                    discr: variant.discr,
-                    ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
-                    is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-                });
-            }
-            hir::ItemKind::Union(..) => {
-                let adt_def = self.tcx.adt_def(def_id);
-                record!(self.tables.repr_options[def_id] <- adt_def.repr());
-
-                let variant = adt_def.non_enum_variant();
-                record!(self.tables.variant_data[def_id] <- VariantData {
-                    discr: variant.discr,
-                    ctor: variant.ctor.map(|(kind, def_id)| (kind, def_id.index)),
-                    is_non_exhaustive: variant.is_field_list_non_exhaustive(),
-                });
+                self.tables
+                    .is_type_alias_impl_trait
+                    .set(def_id.index, matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias));
             }
             hir::ItemKind::Impl(hir::Impl { defaultness, constness, .. }) => {
-                self.tables.impl_defaultness.set(def_id.index, *defaultness);
-                self.tables.constness.set(def_id.index, *constness);
+                self.tables.impl_defaultness.set_some(def_id.index, *defaultness);
+                self.tables.constness.set_some(def_id.index, *constness);
 
-                let trait_ref = self.tcx.impl_trait_ref(def_id).map(ty::EarlyBinder::skip_binder);
+                let trait_ref = self.tcx.impl_trait_ref(def_id);
                 if let Some(trait_ref) = trait_ref {
+                    let trait_ref = trait_ref.skip_binder();
                     let trait_def = self.tcx.trait_def(trait_ref.def_id);
                     if let Ok(mut an) = trait_def.ancestors(self.tcx, def_id) {
                         if let Some(specialization_graph::Node::Impl(parent)) = an.nth(1) {
-                            self.tables.impl_parent.set(def_id.index, parent.into());
+                            self.tables.impl_parent.set_some(def_id.index, parent.into());
                         }
                     }
 
@@ -1571,7 +1551,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 }
 
                 let polarity = self.tcx.impl_polarity(def_id);
-                self.tables.impl_polarity.set(def_id.index, polarity);
+                self.tables.impl_polarity.set_some(def_id.index, polarity);
             }
             hir::ItemKind::Trait(..) => {
                 let trait_def = self.tcx.trait_def(def_id);
@@ -1586,31 +1566,15 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             hir::ItemKind::Static(..)
             | hir::ItemKind::Const(..)
+            | hir::ItemKind::Enum(..)
+            | hir::ItemKind::Struct(..)
+            | hir::ItemKind::Union(..)
             | hir::ItemKind::ForeignMod { .. }
             | hir::ItemKind::GlobalAsm(..)
             | hir::ItemKind::TyAlias(..) => {}
         };
         // FIXME(eddyb) there should be a nicer way to do this.
         match item.kind {
-            hir::ItemKind::Enum(..) => {
-                record_array!(self.tables.children[def_id] <- iter::from_generator(||
-                    for variant in tcx.adt_def(def_id).variants() {
-                        yield variant.def_id.index;
-                        // Encode constructors which take a separate slot in value namespace.
-                        if let Some(ctor_def_id) = variant.ctor_def_id() {
-                            yield ctor_def_id.index;
-                        }
-                    }
-                ))
-            }
-            hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => {
-                record_array!(self.tables.children[def_id] <-
-                    self.tcx.adt_def(def_id).non_enum_variant().fields.iter().map(|f| {
-                        assert!(f.did.is_local());
-                        f.did.index
-                    })
-                )
-            }
             hir::ItemKind::Impl { .. } | hir::ItemKind::Trait(..) => {
                 let associated_item_def_ids = self.tcx.associated_item_def_ids(def_id);
                 record_array!(self.tables.children[def_id] <-
@@ -1624,9 +1588,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         }
         if let hir::ItemKind::Fn(..) = item.kind {
             record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
-            if tcx.is_intrinsic(def_id) {
-                self.tables.is_intrinsic.set(def_id.index, ());
-            }
+            self.tables.is_intrinsic.set(def_id.index, tcx.is_intrinsic(def_id));
         }
         if let hir::ItemKind::Impl { .. } = item.kind {
             if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
@@ -1638,17 +1600,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         // so it's easier to do that here then to wait until we would encounter
         // normally in the visitor walk.
         match item.kind {
-            hir::ItemKind::Enum(..) => {
-                let def = self.tcx.adt_def(item.owner_id.to_def_id());
-                for (i, _) in def.variants().iter_enumerated() {
-                    self.encode_enum_variant_info(def, i);
-                    self.encode_enum_variant_ctor(def, i);
-                }
-            }
-            hir::ItemKind::Struct(..) => {
-                let def = self.tcx.adt_def(item.owner_id.to_def_id());
-                self.encode_struct_ctor(def);
-            }
             hir::ItemKind::Impl { .. } => {
                 for &trait_item_def_id in
                     self.tcx.associated_item_def_ids(item.owner_id.to_def_id()).iter()
@@ -1670,7 +1621,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     #[instrument(level = "debug", skip(self))]
     fn encode_info_for_closure(&mut self, def_id: LocalDefId) {
         // NOTE(eddyb) `tcx.type_of(def_id)` isn't used because it's fully generic,
-        // including on the signature, which is inferred in `typeck.
+        // including on the signature, which is inferred in `typeck`.
         let typeck_result: &'tcx ty::TypeckResults<'tcx> = self.tcx.typeck(def_id);
         let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
         let ty = typeck_result.node_type(hir_id);
@@ -1684,8 +1635,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
 
             ty::Closure(_, substs) => {
                 let constness = self.tcx.constness(def_id.to_def_id());
-                self.tables.constness.set(def_id.to_def_id().index, constness);
-                record!(self.tables.fn_sig[def_id.to_def_id()] <- substs.as_closure().sig());
+                self.tables.constness.set_some(def_id.to_def_id().index, constness);
+                record!(self.tables.fn_sig[def_id.to_def_id()] <- ty::EarlyBinder(substs.as_closure().sig()));
             }
 
             _ => bug!("closure that is neither generator nor closure"),
@@ -1712,12 +1663,12 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         self.hygiene_ctxt.encode(
             &mut (&mut *self, &mut syntax_contexts, &mut expn_data_table, &mut expn_hash_table),
             |(this, syntax_contexts, _, _), index, ctxt_data| {
-                syntax_contexts.set(index, this.lazy(ctxt_data));
+                syntax_contexts.set_some(index, this.lazy(ctxt_data));
             },
             |(this, _, expn_data_table, expn_hash_table), index, expn_data, hash| {
                 if let Some(index) = index.as_local() {
-                    expn_data_table.set(index.as_raw(), this.lazy(expn_data));
-                    expn_hash_table.set(index.as_raw(), this.lazy(hash));
+                    expn_data_table.set_some(index.as_raw(), this.lazy(expn_data));
+                    expn_hash_table.set_some(index.as_raw(), this.lazy(hash));
                 }
             },
         );
@@ -1742,10 +1693,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             let spans = self.tcx.sess.parse_sess.proc_macro_quoted_spans();
             for (i, span) in spans.into_iter().enumerate() {
                 let span = self.lazy(span);
-                self.tables.proc_macro_quoted_spans.set(i, span);
+                self.tables.proc_macro_quoted_spans.set_some(i, span);
             }
 
-            self.tables.opt_def_kind.set(LOCAL_CRATE.as_def_id().index, DefKind::Mod);
+            self.tables.opt_def_kind.set_some(LOCAL_CRATE.as_def_id().index, DefKind::Mod);
             record!(self.tables.def_span[LOCAL_CRATE.as_def_id()] <- tcx.def_span(LOCAL_CRATE.as_def_id()));
             self.encode_attrs(LOCAL_CRATE.as_def_id().expect_local());
             let vis = tcx.local_visibility(CRATE_DEF_ID).map_id(|def_id| def_id.local_def_index);
@@ -1754,6 +1705,12 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.lookup_stability[LOCAL_CRATE.as_def_id()] <- stability);
             }
             self.encode_deprecation(LOCAL_CRATE.as_def_id());
+            if let Some(res_map) = tcx.resolutions(()).doc_link_resolutions.get(&CRATE_DEF_ID) {
+                record!(self.tables.doc_link_resolutions[LOCAL_CRATE.as_def_id()] <- res_map);
+            }
+            if let Some(traits) = tcx.resolutions(()).doc_link_traits_in_scope.get(&CRATE_DEF_ID) {
+                record_array!(self.tables.doc_link_traits_in_scope[LOCAL_CRATE.as_def_id()] <- traits);
+            }
 
             // Normally, this information is encoded when we walk the items
             // defined in this crate. However, we skip doing that for proc-macro crates,
@@ -1787,8 +1744,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 def_key.disambiguated_data.data = DefPathData::MacroNs(name);
 
                 let def_id = id.to_def_id();
-                self.tables.opt_def_kind.set(def_id.index, DefKind::Macro(macro_kind));
-                self.tables.proc_macro.set(def_id.index, macro_kind);
+                self.tables.opt_def_kind.set_some(def_id.index, DefKind::Macro(macro_kind));
+                self.tables.proc_macro.set_some(def_id.index, macro_kind);
                 self.encode_attrs(id);
                 record!(self.tables.def_keys[def_id] <- def_key);
                 record!(self.tables.def_ident_span[def_id] <- span);
@@ -1894,7 +1851,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             FxHashMap::default();
 
         for id in tcx.hir().items() {
-            if matches!(tcx.def_kind(id.owner_id), DefKind::Impl) {
+            if matches!(tcx.def_kind(id.owner_id), DefKind::Impl { .. }) {
                 if let Some(trait_ref) = tcx.impl_trait_ref(id.owner_id) {
                     let trait_ref = trait_ref.subst_identity();
 
@@ -2003,7 +1960,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 Linkage::Static => Some(LinkagePreference::RequireStatic),
             }));
         }
-        LazyArray::empty()
+        LazyArray::default()
     }
 
     fn encode_info_for_foreign_item(&mut self, def_id: DefId, nitem: &hir::ForeignItem<'_>) {
@@ -2013,22 +1970,20 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
 
         match nitem.kind {
             hir::ForeignItemKind::Fn(_, ref names, _) => {
-                self.tables.asyncness.set(def_id.index, hir::IsAsync::NotAsync);
+                self.tables.asyncness.set_some(def_id.index, hir::IsAsync::NotAsync);
                 record_array!(self.tables.fn_arg_names[def_id] <- *names);
                 let constness = if self.tcx.is_const_fn_raw(def_id) {
                     hir::Constness::Const
                 } else {
                     hir::Constness::NotConst
                 };
-                self.tables.constness.set(def_id.index, constness);
+                self.tables.constness.set_some(def_id.index, constness);
                 record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
             }
             hir::ForeignItemKind::Static(..) | hir::ForeignItemKind::Type => {}
         }
         if let hir::ForeignItemKind::Fn(..) = nitem.kind {
-            if tcx.is_intrinsic(def_id) {
-                self.tables.is_intrinsic.set(def_id.index, ());
-            }
+            self.tables.is_intrinsic.set(def_id.index, tcx.is_intrinsic(def_id));
         }
     }
 }
@@ -2266,6 +2221,18 @@ fn encode_metadata_impl(tcx: TyCtxt<'_>, path: &Path) {
 
 pub fn provide(providers: &mut Providers) {
     *providers = Providers {
+        doc_link_resolutions: |tcx, def_id| {
+            tcx.resolutions(())
+                .doc_link_resolutions
+                .get(&def_id.expect_local())
+                .expect("no resolutions for a doc link")
+        },
+        doc_link_traits_in_scope: |tcx, def_id| {
+            tcx.resolutions(())
+                .doc_link_traits_in_scope
+                .get(&def_id.expect_local())
+                .expect("no traits in scope for a doc link")
+        },
         traits_in_crate: |tcx, cnum| {
             assert_eq!(cnum, LOCAL_CRATE);
 
@@ -2280,6 +2247,22 @@ pub fn provide(providers: &mut Providers) {
             traits.sort_by_cached_key(|&def_id| tcx.def_path_hash(def_id));
             tcx.arena.alloc_slice(&traits)
         },
+        trait_impls_in_crate: |tcx, cnum| {
+            assert_eq!(cnum, LOCAL_CRATE);
+
+            let mut trait_impls = Vec::new();
+            for id in tcx.hir().items() {
+                if matches!(tcx.def_kind(id.owner_id), DefKind::Impl { .. })
+                    && tcx.impl_trait_ref(id.owner_id).is_some()
+                {
+                    trait_impls.push(id.owner_id.to_def_id())
+                }
+            }
+
+            // Bring everything into deterministic order.
+            trait_impls.sort_by_cached_key(|&def_id| tcx.def_path_hash(def_id));
+            tcx.arena.alloc_slice(&trait_impls)
+        },
 
         ..*providers
     }
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 5066dbbb9..a7ec2d790 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -9,7 +9,7 @@ use rustc_attr as attr;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::MetadataRef;
 use rustc_hir as hir;
-use rustc_hir::def::{CtorKind, DefKind};
+use rustc_hir::def::{CtorKind, DefKind, DocLinkResMap};
 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, DefPathHash, StableCrateId};
 use rustc_hir::definitions::DefKey;
 use rustc_hir::lang_items::LangItem;
@@ -18,7 +18,7 @@ use rustc_index::vec::IndexVec;
 use rustc_middle::metadata::ModChild;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
-use rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault;
+use rustc_middle::middle::resolve_bound_vars::ObjectLifetimeDefault;
 use rustc_middle::mir;
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::query::Providers;
@@ -115,14 +115,16 @@ impl<T: ParameterizedOverTcx> ParameterizedOverTcx for LazyArray<T> {
     type Value<'tcx> = LazyArray<T::Value<'tcx>>;
 }
 
+impl<T> Default for LazyArray<T> {
+    fn default() -> LazyArray<T> {
+        LazyArray::from_position_and_num_elems(NonZeroUsize::new(1).unwrap(), 0)
+    }
+}
+
 impl<T> LazyArray<T> {
     fn from_position_and_num_elems(position: NonZeroUsize, num_elems: usize) -> LazyArray<T> {
         LazyArray { position, num_elems, _marker: PhantomData }
     }
-
-    fn empty() -> LazyArray<T> {
-        LazyArray::from_position_and_num_elems(NonZeroUsize::new(1).unwrap(), 0)
-    }
 }
 
 /// A list of lazily-decoded values, with the added capability of random access.
@@ -185,9 +187,9 @@ enum LazyState {
     Previous(NonZeroUsize),
 }
 
-type SyntaxContextTable = LazyTable<u32, LazyValue<SyntaxContextData>>;
-type ExpnDataTable = LazyTable<ExpnIndex, LazyValue<ExpnData>>;
-type ExpnHashTable = LazyTable<ExpnIndex, LazyValue<ExpnHash>>;
+type SyntaxContextTable = LazyTable<u32, Option<LazyValue<SyntaxContextData>>>;
+type ExpnDataTable = LazyTable<ExpnIndex, Option<LazyValue<ExpnData>>>;
+type ExpnHashTable = LazyTable<ExpnIndex, Option<LazyValue<ExpnHash>>>;
 
 #[derive(MetadataEncodable, MetadataDecodable)]
 pub(crate) struct ProcMacroData {
@@ -253,7 +255,7 @@ pub(crate) struct CrateRoot {
 
     def_path_hash_map: LazyValue<DefPathHashMapRef<'static>>,
 
-    source_map: LazyTable<u32, LazyValue<rustc_span::SourceFile>>,
+    source_map: LazyTable<u32, Option<LazyValue<rustc_span::SourceFile>>>,
 
     compiler_builtins: bool,
     needs_allocator: bool,
@@ -315,21 +317,27 @@ pub(crate) struct IncoherentImpls {
 
 /// Define `LazyTables` and `TableBuilders` at the same time.
 macro_rules! define_tables {
-    ($($name:ident: Table<$IDX:ty, $T:ty>),+ $(,)?) => {
+    (
+        - defaulted: $($name1:ident: Table<$IDX1:ty, $T1:ty>,)+
+        - optional: $($name2:ident: Table<$IDX2:ty, $T2:ty>,)+
+    ) => {
         #[derive(MetadataEncodable, MetadataDecodable)]
         pub(crate) struct LazyTables {
-            $($name: LazyTable<$IDX, $T>),+
+            $($name1: LazyTable<$IDX1, $T1>,)+
+            $($name2: LazyTable<$IDX2, Option<$T2>>,)+
         }
 
         #[derive(Default)]
         struct TableBuilders {
-            $($name: TableBuilder<$IDX, $T>),+
+            $($name1: TableBuilder<$IDX1, $T1>,)+
+            $($name2: TableBuilder<$IDX2, Option<$T2>>,)+
         }
 
         impl TableBuilders {
             fn encode(&self, buf: &mut FileEncoder) -> LazyTables {
                 LazyTables {
-                    $($name: self.$name.encode(buf)),+
+                    $($name1: self.$name1.encode(buf),)+
+                    $($name2: self.$name2.encode(buf),)+
                 }
             }
         }
@@ -337,9 +345,20 @@ macro_rules! define_tables {
 }
 
 define_tables! {
+- defaulted:
+    is_intrinsic: Table<DefIndex, bool>,
+    is_macro_rules: Table<DefIndex, bool>,
+    is_type_alias_impl_trait: Table<DefIndex, bool>,
+    attr_flags: Table<DefIndex, AttrFlags>,
+    def_path_hashes: Table<DefIndex, DefPathHash>,
+    explicit_item_bounds: Table<DefIndex, LazyArray<(ty::Predicate<'static>, Span)>>,
+    inferred_outlives_of: Table<DefIndex, LazyArray<(ty::Clause<'static>, Span)>>,
+    inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
+    associated_items_for_impl_trait_in_trait: Table<DefIndex, LazyArray<DefId>>,
+
+- optional:
     attributes: Table<DefIndex, LazyArray<ast::Attribute>>,
     children: Table<DefIndex, LazyArray<DefIndex>>,
-
     opt_def_kind: Table<DefIndex, DefKind>,
     visibility: Table<DefIndex, LazyValue<ty::Visibility<DefIndex>>>,
     def_span: Table<DefIndex, LazyValue<Span>>,
@@ -348,29 +367,25 @@ define_tables! {
     lookup_const_stability: Table<DefIndex, LazyValue<attr::ConstStability>>,
     lookup_default_body_stability: Table<DefIndex, LazyValue<attr::DefaultBodyStability>>,
     lookup_deprecation_entry: Table<DefIndex, LazyValue<attr::Deprecation>>,
-    // As an optimization, a missing entry indicates an empty `&[]`.
-    explicit_item_bounds: Table<DefIndex, LazyArray<(ty::Predicate<'static>, Span)>>,
     explicit_predicates_of: Table<DefIndex, LazyValue<ty::GenericPredicates<'static>>>,
     generics_of: Table<DefIndex, LazyValue<ty::Generics>>,
-    // As an optimization, a missing entry indicates an empty `&[]`.
-    inferred_outlives_of: Table<DefIndex, LazyArray<(ty::Clause<'static>, Span)>>,
     super_predicates_of: Table<DefIndex, LazyValue<ty::GenericPredicates<'static>>>,
-    type_of: Table<DefIndex, LazyValue<Ty<'static>>>,
+    type_of: Table<DefIndex, LazyValue<ty::EarlyBinder<Ty<'static>>>>,
     variances_of: Table<DefIndex, LazyArray<ty::Variance>>,
-    fn_sig: Table<DefIndex, LazyValue<ty::PolyFnSig<'static>>>,
+    fn_sig: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::PolyFnSig<'static>>>>,
     codegen_fn_attrs: Table<DefIndex, LazyValue<CodegenFnAttrs>>,
     impl_trait_ref: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::TraitRef<'static>>>>,
     const_param_default: Table<DefIndex, LazyValue<ty::EarlyBinder<rustc_middle::ty::Const<'static>>>>,
     object_lifetime_default: Table<DefIndex, LazyValue<ObjectLifetimeDefault>>,
     optimized_mir: Table<DefIndex, LazyValue<mir::Body<'static>>>,
     mir_for_ctfe: Table<DefIndex, LazyValue<mir::Body<'static>>>,
+    mir_generator_witnesses: Table<DefIndex, LazyValue<mir::GeneratorLayout<'static>>>,
     promoted_mir: Table<DefIndex, LazyValue<IndexVec<mir::Promoted, mir::Body<'static>>>>,
     // FIXME(compiler-errors): Why isn't this a LazyArray?
     thir_abstract_const: Table<DefIndex, LazyValue<ty::Const<'static>>>,
     impl_parent: Table<DefIndex, RawDefId>,
     impl_polarity: Table<DefIndex, ty::ImplPolarity>,
     constness: Table<DefIndex, hir::Constness>,
-    is_intrinsic: Table<DefIndex, ()>,
     impl_defaultness: Table<DefIndex, hir::Defaultness>,
     // FIXME(eddyb) perhaps compute this on the fly if cheap enough?
     coerce_unsized_info: Table<DefIndex, LazyValue<ty::adjustment::CoerceUnsizedInfo>>,
@@ -380,9 +395,7 @@ define_tables! {
     fn_arg_names: Table<DefIndex, LazyArray<Ident>>,
     generator_kind: Table<DefIndex, LazyValue<hir::GeneratorKind>>,
     trait_def: Table<DefIndex, LazyValue<ty::TraitDef>>,
-
     trait_item_def_id: Table<DefIndex, RawDefId>,
-    inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
     expn_that_defined: Table<DefIndex, LazyValue<ExpnId>>,
     unused_generic_params: Table<DefIndex, LazyValue<UnusedGenericParams>>,
     params_in_repr: Table<DefIndex, LazyValue<BitSet<u32>>>,
@@ -392,22 +405,17 @@ define_tables! {
     // `DefPathTable` up front, since we may only ever use a few
     // definitions from any given crate.
     def_keys: Table<DefIndex, LazyValue<DefKey>>,
-    def_path_hashes: Table<DefIndex, DefPathHash>,
     proc_macro_quoted_spans: Table<usize, LazyValue<Span>>,
     generator_diagnostic_data: Table<DefIndex, LazyValue<GeneratorDiagnosticData<'static>>>,
-    may_have_doc_links: Table<DefIndex, ()>,
     variant_data: Table<DefIndex, LazyValue<VariantData>>,
     assoc_container: Table<DefIndex, ty::AssocItemContainer>,
-    // Slot is full when macro is macro_rules.
-    macro_rules: Table<DefIndex, ()>,
     macro_definition: Table<DefIndex, LazyValue<ast::DelimArgs>>,
     proc_macro: Table<DefIndex, MacroKind>,
     module_reexports: Table<DefIndex, LazyArray<ModChild>>,
     deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
-    // Slot is full when opaque is TAIT.
-    is_type_alias_impl_trait: Table<DefIndex, ()>,
-
     trait_impl_trait_tys: Table<DefIndex, LazyValue<FxHashMap<DefId, Ty<'static>>>>,
+    doc_link_resolutions: Table<DefIndex, LazyValue<DocLinkResMap>>,
+    doc_link_traits_in_scope: Table<DefIndex, LazyArray<DefId>>,
 }
 
 #[derive(TyEncodable, TyDecodable)]
@@ -418,6 +426,13 @@ struct VariantData {
     is_non_exhaustive: bool,
 }
 
+bitflags::bitflags! {
+    #[derive(Default)]
+    pub struct AttrFlags: u8 {
+        const IS_DOC_HIDDEN = 1 << 0;
+    }
+}
+
 // Tags used for encoding Spans:
 const TAG_VALID_SPAN_LOCAL: u8 = 0;
 const TAG_VALID_SPAN_FOREIGN: u8 = 1;
@@ -440,4 +455,5 @@ trivially_parameterized_over_tcx! {
     IncoherentImpls,
     CrateRoot,
     CrateDep,
+    AttrFlags,
 }
diff --git a/compiler/rustc_metadata/src/rmeta/table.rs b/compiler/rustc_metadata/src/rmeta/table.rs
index 716655c7f..b89d48ec1 100644
--- a/compiler/rustc_metadata/src/rmeta/table.rs
+++ b/compiler/rustc_metadata/src/rmeta/table.rs
@@ -10,18 +10,61 @@ use rustc_span::hygiene::MacroKind;
 use std::marker::PhantomData;
 use std::num::NonZeroUsize;
 
+pub(super) trait IsDefault: Default {
+    fn is_default(&self) -> bool;
+}
+
+impl<T> IsDefault for Option<T> {
+    fn is_default(&self) -> bool {
+        self.is_none()
+    }
+}
+
+impl IsDefault for AttrFlags {
+    fn is_default(&self) -> bool {
+        self.is_empty()
+    }
+}
+
+impl IsDefault for bool {
+    fn is_default(&self) -> bool {
+        !self
+    }
+}
+
+impl IsDefault for u32 {
+    fn is_default(&self) -> bool {
+        *self == 0
+    }
+}
+
+impl<T> IsDefault for LazyArray<T> {
+    fn is_default(&self) -> bool {
+        self.num_elems == 0
+    }
+}
+
+impl IsDefault for DefPathHash {
+    fn is_default(&self) -> bool {
+        self.0 == Fingerprint::ZERO
+    }
+}
+
 /// Helper trait, for encoding to, and decoding from, a fixed number of bytes.
 /// Used mainly for Lazy positions and lengths.
 /// Unchecked invariant: `Self::default()` should encode as `[0; BYTE_LEN]`,
 /// but this has no impact on safety.
-pub(super) trait FixedSizeEncoding: Default {
+pub(super) trait FixedSizeEncoding: IsDefault {
     /// This should be `[u8; BYTE_LEN]`;
+    /// Cannot use an associated `const BYTE_LEN: usize` instead due to const eval limitations.
     type ByteArray;
 
     fn from_bytes(b: &Self::ByteArray) -> Self;
     fn write_to_bytes(self, b: &mut Self::ByteArray);
 }
 
+/// This implementation is not used generically, but for reading/writing
+/// concrete `u32` fields in `Lazy*` structures, which may be zero.
 impl FixedSizeEncoding for u32 {
     type ByteArray = [u8; 4];
 
@@ -57,7 +100,7 @@ macro_rules! fixed_size_enum {
             fn write_to_bytes(self, b: &mut [u8;1]) {
                 use $ty::*;
                 b[0] = match self {
-                    None => 0,
+                    None => unreachable!(),
                     $(Some($($pat)*) => 1 + ${index()},)*
                 }
             }
@@ -93,7 +136,8 @@ fixed_size_enum! {
         ( Field                                    )
         ( LifetimeParam                            )
         ( GlobalAsm                                )
-        ( Impl                                     )
+        ( Impl { of_trait: false }                 )
+        ( Impl { of_trait: true }                  )
         ( Closure                                  )
         ( Generator                                )
         ( Static(ast::Mutability::Not)             )
@@ -154,20 +198,18 @@ fixed_size_enum! {
 }
 
 // We directly encode `DefPathHash` because a `LazyValue` would incur a 25% cost.
-impl FixedSizeEncoding for Option<DefPathHash> {
+impl FixedSizeEncoding for DefPathHash {
     type ByteArray = [u8; 16];
 
     #[inline]
     fn from_bytes(b: &[u8; 16]) -> Self {
-        Some(DefPathHash(Fingerprint::from_le_bytes(*b)))
+        DefPathHash(Fingerprint::from_le_bytes(*b))
     }
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 16]) {
-        let Some(DefPathHash(fingerprint)) = self else {
-            panic!("Trying to encode absent DefPathHash.")
-        };
-        *b = fingerprint.to_le_bytes();
+        debug_assert!(!self.is_default());
+        *b = self.0.to_le_bytes();
     }
 }
 
@@ -178,17 +220,17 @@ impl FixedSizeEncoding for Option<RawDefId> {
     #[inline]
     fn from_bytes(b: &[u8; 8]) -> Self {
         let krate = u32::from_le_bytes(b[0..4].try_into().unwrap());
-        let index = u32::from_le_bytes(b[4..8].try_into().unwrap());
         if krate == 0 {
             return None;
         }
+        let index = u32::from_le_bytes(b[4..8].try_into().unwrap());
         Some(RawDefId { krate: krate - 1, index })
     }
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 8]) {
         match self {
-            None => *b = [0; 8],
+            None => unreachable!(),
             Some(RawDefId { krate, index }) => {
                 // CrateNum is less than `CrateNum::MAX_AS_U32`.
                 debug_assert!(krate < u32::MAX);
@@ -199,17 +241,33 @@ impl FixedSizeEncoding for Option<RawDefId> {
     }
 }
 
-impl FixedSizeEncoding for Option<()> {
+impl FixedSizeEncoding for AttrFlags {
+    type ByteArray = [u8; 1];
+
+    #[inline]
+    fn from_bytes(b: &[u8; 1]) -> Self {
+        AttrFlags::from_bits_truncate(b[0])
+    }
+
+    #[inline]
+    fn write_to_bytes(self, b: &mut [u8; 1]) {
+        debug_assert!(!self.is_default());
+        b[0] = self.bits();
+    }
+}
+
+impl FixedSizeEncoding for bool {
     type ByteArray = [u8; 1];
 
     #[inline]
     fn from_bytes(b: &[u8; 1]) -> Self {
-        (b[0] != 0).then(|| ())
+        b[0] != 0
     }
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 1]) {
-        b[0] = self.is_some() as u8
+        debug_assert!(!self.is_default());
+        b[0] = self as u8
     }
 }
 
@@ -227,76 +285,115 @@ impl<T> FixedSizeEncoding for Option<LazyValue<T>> {
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 4]) {
-        let position = self.map_or(0, |lazy| lazy.position.get());
+        match self {
+            None => unreachable!(),
+            Some(lazy) => {
+                let position = lazy.position.get();
+                let position: u32 = position.try_into().unwrap();
+                position.write_to_bytes(b)
+            }
+        }
+    }
+}
+
+impl<T> LazyArray<T> {
+    #[inline]
+    fn write_to_bytes_impl(self, b: &mut [u8; 8]) {
+        let ([position_bytes, meta_bytes],[])= b.as_chunks_mut::<4>() else { panic!() };
+
+        let position = self.position.get();
         let position: u32 = position.try_into().unwrap();
-        position.write_to_bytes(b)
+        position.write_to_bytes(position_bytes);
+
+        let len = self.num_elems;
+        let len: u32 = len.try_into().unwrap();
+        len.write_to_bytes(meta_bytes);
+    }
+
+    fn from_bytes_impl(position_bytes: &[u8; 4], meta_bytes: &[u8; 4]) -> Option<LazyArray<T>> {
+        let position = NonZeroUsize::new(u32::from_bytes(position_bytes) as usize)?;
+        let len = u32::from_bytes(meta_bytes) as usize;
+        Some(LazyArray::from_position_and_num_elems(position, len))
     }
 }
 
-impl<T> FixedSizeEncoding for Option<LazyArray<T>> {
+impl<T> FixedSizeEncoding for LazyArray<T> {
     type ByteArray = [u8; 8];
 
     #[inline]
     fn from_bytes(b: &[u8; 8]) -> Self {
-        let ([ref position_bytes, ref meta_bytes],[])= b.as_chunks::<4>() else { panic!() };
-        let position = NonZeroUsize::new(u32::from_bytes(position_bytes) as usize)?;
-        let len = u32::from_bytes(meta_bytes) as usize;
-        Some(LazyArray::from_position_and_num_elems(position, len))
+        let ([position_bytes, meta_bytes],[])= b.as_chunks::<4>() else { panic!() };
+        if *meta_bytes == [0; 4] {
+            return Default::default();
+        }
+        LazyArray::from_bytes_impl(position_bytes, meta_bytes).unwrap()
     }
 
     #[inline]
     fn write_to_bytes(self, b: &mut [u8; 8]) {
-        let ([ref mut position_bytes, ref mut meta_bytes],[])= b.as_chunks_mut::<4>() else { panic!() };
+        assert!(!self.is_default());
+        self.write_to_bytes_impl(b)
+    }
+}
 
-        let position = self.map_or(0, |lazy| lazy.position.get());
-        let position: u32 = position.try_into().unwrap();
-        position.write_to_bytes(position_bytes);
+impl<T> FixedSizeEncoding for Option<LazyArray<T>> {
+    type ByteArray = [u8; 8];
 
-        let len = self.map_or(0, |lazy| lazy.num_elems);
-        let len: u32 = len.try_into().unwrap();
-        len.write_to_bytes(meta_bytes);
+    #[inline]
+    fn from_bytes(b: &[u8; 8]) -> Self {
+        let ([position_bytes, meta_bytes],[])= b.as_chunks::<4>() else { panic!() };
+        LazyArray::from_bytes_impl(position_bytes, meta_bytes)
+    }
+
+    #[inline]
+    fn write_to_bytes(self, b: &mut [u8; 8]) {
+        match self {
+            None => unreachable!(),
+            Some(lazy) => lazy.write_to_bytes_impl(b),
+        }
     }
 }
 
 /// Helper for constructing a table's serialization (also see `Table`).
-pub(super) struct TableBuilder<I: Idx, T>
-where
-    Option<T>: FixedSizeEncoding,
-{
-    blocks: IndexVec<I, <Option<T> as FixedSizeEncoding>::ByteArray>,
+pub(super) struct TableBuilder<I: Idx, T: FixedSizeEncoding> {
+    blocks: IndexVec<I, T::ByteArray>,
     _marker: PhantomData<T>,
 }
 
-impl<I: Idx, T> Default for TableBuilder<I, T>
-where
-    Option<T>: FixedSizeEncoding,
-{
+impl<I: Idx, T: FixedSizeEncoding> Default for TableBuilder<I, T> {
     fn default() -> Self {
         TableBuilder { blocks: Default::default(), _marker: PhantomData }
     }
 }
 
-impl<I: Idx, T> TableBuilder<I, T>
+impl<I: Idx, const N: usize, T> TableBuilder<I, Option<T>>
 where
-    Option<T>: FixedSizeEncoding,
+    Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
 {
-    pub(crate) fn set<const N: usize>(&mut self, i: I, value: T)
-    where
-        Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
-        // FIXME(eddyb) investigate more compact encodings for sparse tables.
-        // On the PR @michaelwoerister mentioned:
-        // > Space requirements could perhaps be optimized by using the HAMT `popcnt`
-        // > trick (i.e. divide things into buckets of 32 or 64 items and then
-        // > store bit-masks of which item in each bucket is actually serialized).
-        self.blocks.ensure_contains_elem(i, || [0; N]);
-        Some(value).write_to_bytes(&mut self.blocks[i]);
-    }
-
-    pub(crate) fn encode<const N: usize>(&self, buf: &mut FileEncoder) -> LazyTable<I, T>
-    where
-        Option<T>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(crate) fn set_some(&mut self, i: I, value: T) {
+        self.set(i, Some(value))
+    }
+}
+
+impl<I: Idx, const N: usize, T: FixedSizeEncoding<ByteArray = [u8; N]>> TableBuilder<I, T> {
+    /// Sets the table value if it is not default.
+    /// ATTENTION: For optimization default values are simply ignored by this function, because
+    /// right now metadata tables never need to reset non-default values to default. If such need
+    /// arises in the future then a new method (e.g. `clear` or `reset`) will need to be introduced
+    /// for doing that explicitly.
+    pub(crate) fn set(&mut self, i: I, value: T) {
+        if !value.is_default() {
+            // FIXME(eddyb) investigate more compact encodings for sparse tables.
+            // On the PR @michaelwoerister mentioned:
+            // > Space requirements could perhaps be optimized by using the HAMT `popcnt`
+            // > trick (i.e. divide things into buckets of 32 or 64 items and then
+            // > store bit-masks of which item in each bucket is actually serialized).
+            self.blocks.ensure_contains_elem(i, || [0; N]);
+            value.write_to_bytes(&mut self.blocks[i]);
+        }
+    }
+
+    pub(crate) fn encode(&self, buf: &mut FileEncoder) -> LazyTable<I, T> {
         let pos = buf.position();
         for block in &self.blocks {
             buf.emit_raw_bytes(block);
@@ -309,34 +406,24 @@ where
     }
 }
 
-impl<I: Idx, T: ParameterizedOverTcx> LazyTable<I, T>
+impl<I: Idx, const N: usize, T: FixedSizeEncoding<ByteArray = [u8; N]> + ParameterizedOverTcx>
+    LazyTable<I, T>
 where
-    Option<T>: FixedSizeEncoding,
+    for<'tcx> T::Value<'tcx>: FixedSizeEncoding<ByteArray = [u8; N]>,
 {
     /// Given the metadata, extract out the value at a particular index (if any).
     #[inline(never)]
-    pub(super) fn get<'a, 'tcx, M: Metadata<'a, 'tcx>, const N: usize>(
-        &self,
-        metadata: M,
-        i: I,
-    ) -> Option<T::Value<'tcx>>
-    where
-        Option<T::Value<'tcx>>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(super) fn get<'a, 'tcx, M: Metadata<'a, 'tcx>>(&self, metadata: M, i: I) -> T::Value<'tcx> {
         debug!("LazyTable::lookup: index={:?} len={:?}", i, self.encoded_size);
 
         let start = self.position.get();
         let bytes = &metadata.blob()[start..start + self.encoded_size];
         let (bytes, []) = bytes.as_chunks::<N>() else { panic!() };
-        let bytes = bytes.get(i.index())?;
-        FixedSizeEncoding::from_bytes(bytes)
+        bytes.get(i.index()).map_or_else(Default::default, FixedSizeEncoding::from_bytes)
     }
 
     /// Size of the table in entries, including possible gaps.
-    pub(super) fn size<const N: usize>(&self) -> usize
-    where
-        for<'tcx> Option<T::Value<'tcx>>: FixedSizeEncoding<ByteArray = [u8; N]>,
-    {
+    pub(super) fn size(&self) -> usize {
         self.encoded_size / N
     }
 }