Merging upstream version 1.66.0+dfsg1.

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

9 files changed, 564 insertions, 504 deletions

diff --git a/compiler/rustc_metadata/Cargo.toml b/compiler/rustc_metadata/Cargo.toml
index 2c5db9d8b..6d85103c9 100644
--- a/compiler/rustc_metadata/Cargo.toml
+++ b/compiler/rustc_metadata/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 libloading = "0.7.1"
diff --git a/compiler/rustc_metadata/src/errors.rs b/compiler/rustc_metadata/src/errors.rs
index 7d63fad32..7c387b9a9 100644
--- a/compiler/rustc_metadata/src/errors.rs
+++ b/compiler/rustc_metadata/src/errors.rs
@@ -3,137 +3,137 @@ use std::{
     path::{Path, PathBuf},
 };
 
-use rustc_errors::{error_code, ErrorGuaranteed};
-use rustc_macros::SessionDiagnostic;
-use rustc_session::{config, SessionDiagnostic};
+use rustc_errors::{error_code, ErrorGuaranteed, IntoDiagnostic};
+use rustc_macros::Diagnostic;
+use rustc_session::config;
 use rustc_span::{sym, Span, Symbol};
 use rustc_target::spec::{PanicStrategy, TargetTriple};
 
 use crate::locator::CrateFlavor;
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::rlib_required)]
+#[derive(Diagnostic)]
+#[diag(metadata_rlib_required)]
 pub struct RlibRequired {
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::lib_required)]
+#[derive(Diagnostic)]
+#[diag(metadata_lib_required)]
 pub struct LibRequired<'a> {
     pub crate_name: Symbol,
     pub kind: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::crate_dep_multiple)]
+#[derive(Diagnostic)]
+#[diag(metadata_crate_dep_multiple)]
 #[help]
 pub struct CrateDepMultiple {
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::two_panic_runtimes)]
+#[derive(Diagnostic)]
+#[diag(metadata_two_panic_runtimes)]
 pub struct TwoPanicRuntimes {
     pub prev_name: Symbol,
     pub cur_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::bad_panic_strategy)]
+#[derive(Diagnostic)]
+#[diag(metadata_bad_panic_strategy)]
 pub struct BadPanicStrategy {
     pub runtime: Symbol,
     pub strategy: PanicStrategy,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::required_panic_strategy)]
+#[derive(Diagnostic)]
+#[diag(metadata_required_panic_strategy)]
 pub struct RequiredPanicStrategy {
     pub crate_name: Symbol,
     pub found_strategy: PanicStrategy,
     pub desired_strategy: PanicStrategy,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::incompatible_panic_in_drop_strategy)]
+#[derive(Diagnostic)]
+#[diag(metadata_incompatible_panic_in_drop_strategy)]
 pub struct IncompatiblePanicInDropStrategy {
     pub crate_name: Symbol,
     pub found_strategy: PanicStrategy,
     pub desired_strategy: PanicStrategy,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_names_in_link)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_names_in_link)]
 pub struct MultipleNamesInLink {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_kinds_in_link)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_kinds_in_link)]
 pub struct MultipleKindsInLink {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_name_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_link_name_form)]
 pub struct LinkNameForm {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_kind_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_link_kind_form)]
 pub struct LinkKindForm {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_modifiers_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_link_modifiers_form)]
 pub struct LinkModifiersForm {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_cfg_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_link_cfg_form)]
 pub struct LinkCfgForm {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::wasm_import_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_wasm_import_form)]
 pub struct WasmImportForm {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::empty_link_name, code = "E0454")]
+#[derive(Diagnostic)]
+#[diag(metadata_empty_link_name, code = "E0454")]
 pub struct EmptyLinkName {
     #[primary_span]
     #[label]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_framework_apple, code = "E0455")]
+#[derive(Diagnostic)]
+#[diag(metadata_link_framework_apple, code = "E0455")]
 pub struct LinkFrameworkApple {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::framework_only_windows, code = "E0455")]
+#[derive(Diagnostic)]
+#[diag(metadata_framework_only_windows, code = "E0455")]
 pub struct FrameworkOnlyWindows {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::unknown_link_kind, code = "E0458")]
+#[derive(Diagnostic)]
+#[diag(metadata_unknown_link_kind, code = "E0458")]
 pub struct UnknownLinkKind<'a> {
     #[primary_span]
     #[label]
@@ -141,269 +141,303 @@ pub struct UnknownLinkKind<'a> {
     pub kind: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_link_modifiers)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_link_modifiers)]
 pub struct MultipleLinkModifiers {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_cfgs)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_cfgs)]
 pub struct MultipleCfgs {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_cfg_single_predicate)]
+#[derive(Diagnostic)]
+#[diag(metadata_link_cfg_single_predicate)]
 pub struct LinkCfgSinglePredicate {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_wasm_import)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_wasm_import)]
 pub struct MultipleWasmImport {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::unexpected_link_arg)]
+#[derive(Diagnostic)]
+#[diag(metadata_unexpected_link_arg)]
 pub struct UnexpectedLinkArg {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::invalid_link_modifier)]
+#[derive(Diagnostic)]
+#[diag(metadata_invalid_link_modifier)]
 pub struct InvalidLinkModifier {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_modifiers)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_modifiers)]
 pub struct MultipleModifiers<'a> {
     #[primary_span]
     pub span: Span,
     pub modifier: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::bundle_needs_static)]
+#[derive(Diagnostic)]
+#[diag(metadata_bundle_needs_static)]
 pub struct BundleNeedsStatic {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::whole_archive_needs_static)]
+#[derive(Diagnostic)]
+#[diag(metadata_whole_archive_needs_static)]
 pub struct WholeArchiveNeedsStatic {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::as_needed_compatibility)]
+#[derive(Diagnostic)]
+#[diag(metadata_as_needed_compatibility)]
 pub struct AsNeededCompatibility {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::unknown_link_modifier)]
+#[derive(Diagnostic)]
+#[diag(metadata_unknown_link_modifier)]
 pub struct UnknownLinkModifier<'a> {
     #[primary_span]
     pub span: Span,
     pub modifier: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::incompatible_wasm_link)]
+#[derive(Diagnostic)]
+#[diag(metadata_incompatible_wasm_link)]
 pub struct IncompatibleWasmLink {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_requires_name, code = "E0459")]
+#[derive(Diagnostic)]
+#[diag(metadata_link_requires_name, code = "E0459")]
 pub struct LinkRequiresName {
     #[primary_span]
     #[label]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::raw_dylib_no_nul)]
+#[derive(Diagnostic)]
+#[diag(metadata_raw_dylib_no_nul)]
 pub struct RawDylibNoNul {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::link_ordinal_raw_dylib)]
+#[derive(Diagnostic)]
+#[diag(metadata_link_ordinal_raw_dylib)]
 pub struct LinkOrdinalRawDylib {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::lib_framework_apple)]
+#[derive(Diagnostic)]
+#[diag(metadata_lib_framework_apple)]
 pub struct LibFrameworkApple;
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::empty_renaming_target)]
+#[derive(Diagnostic)]
+#[diag(metadata_empty_renaming_target)]
 pub struct EmptyRenamingTarget<'a> {
     pub lib_name: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::renaming_no_link)]
+#[derive(Diagnostic)]
+#[diag(metadata_renaming_no_link)]
 pub struct RenamingNoLink<'a> {
     pub lib_name: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_renamings)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_renamings)]
 pub struct MultipleRenamings<'a> {
     pub lib_name: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::no_link_mod_override)]
+#[derive(Diagnostic)]
+#[diag(metadata_no_link_mod_override)]
 pub struct NoLinkModOverride {
     #[primary_span]
     pub span: Option<Span>,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::unsupported_abi_i686)]
+#[derive(Diagnostic)]
+#[diag(metadata_unsupported_abi_i686)]
 pub struct UnsupportedAbiI686 {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::unsupported_abi)]
+#[derive(Diagnostic)]
+#[diag(metadata_unsupported_abi)]
 pub struct UnsupportedAbi {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::fail_create_file_encoder)]
+#[derive(Diagnostic)]
+#[diag(metadata_fail_create_file_encoder)]
 pub struct FailCreateFileEncoder {
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::fail_seek_file)]
+#[derive(Diagnostic)]
+#[diag(metadata_fail_seek_file)]
 pub struct FailSeekFile {
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::fail_write_file)]
+#[derive(Diagnostic)]
+#[diag(metadata_fail_write_file)]
 pub struct FailWriteFile {
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::crate_not_panic_runtime)]
+#[derive(Diagnostic)]
+#[diag(metadata_crate_not_panic_runtime)]
 pub struct CrateNotPanicRuntime {
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::no_panic_strategy)]
+#[derive(Diagnostic)]
+#[diag(metadata_no_panic_strategy)]
 pub struct NoPanicStrategy {
     pub crate_name: Symbol,
     pub strategy: PanicStrategy,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::profiler_builtins_needs_core)]
+#[derive(Diagnostic)]
+#[diag(metadata_profiler_builtins_needs_core)]
 pub struct ProfilerBuiltinsNeedsCore;
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::not_profiler_runtime)]
+#[derive(Diagnostic)]
+#[diag(metadata_not_profiler_runtime)]
 pub struct NotProfilerRuntime {
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::no_multiple_global_alloc)]
+#[derive(Diagnostic)]
+#[diag(metadata_no_multiple_global_alloc)]
 pub struct NoMultipleGlobalAlloc {
     #[primary_span]
     #[label]
     pub span2: Span,
-    #[label(metadata::prev_global_alloc)]
+    #[label(metadata_prev_global_alloc)]
     pub span1: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::conflicting_global_alloc)]
+#[derive(Diagnostic)]
+#[diag(metadata_conflicting_global_alloc)]
 pub struct ConflictingGlobalAlloc {
     pub crate_name: Symbol,
     pub other_crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::global_alloc_required)]
+#[derive(Diagnostic)]
+#[diag(metadata_global_alloc_required)]
 pub struct GlobalAllocRequired;
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::no_transitive_needs_dep)]
+#[derive(Diagnostic)]
+#[diag(metadata_no_transitive_needs_dep)]
 pub struct NoTransitiveNeedsDep<'a> {
     pub crate_name: Symbol,
     pub needs_crate_name: &'a str,
     pub deps_crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::failed_write_error)]
+#[derive(Diagnostic)]
+#[diag(metadata_failed_write_error)]
 pub struct FailedWriteError {
     pub filename: PathBuf,
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::missing_native_library)]
+#[derive(Diagnostic)]
+#[diag(metadata_missing_native_library)]
 pub struct MissingNativeLibrary<'a> {
-    pub libname: &'a str,
+    libname: &'a str,
+    #[subdiagnostic]
+    suggest_name: Option<SuggestLibraryName<'a>>,
+}
+
+impl<'a> MissingNativeLibrary<'a> {
+    pub fn new(libname: &'a str, verbatim: bool) -> Self {
+        // if it looks like the user has provided a complete filename rather just the bare lib name,
+        // then provide a note that they might want to try trimming the name
+        let suggested_name = if !verbatim {
+            if let Some(libname) = libname.strip_prefix("lib") && let Some(libname) = libname.strip_suffix(".a") {
+                // this is a unix style filename so trim prefix & suffix
+                Some(libname)
+            } else if let Some(libname) = libname.strip_suffix(".lib") {
+                // this is a Windows style filename so just trim the suffix
+                Some(libname)
+            } else {
+                None
+            }
+        } else {
+            None
+        };
+
+        Self {
+            libname,
+            suggest_name: suggested_name
+                .map(|suggested_name| SuggestLibraryName { suggested_name }),
+        }
+    }
+}
+
+#[derive(Subdiagnostic)]
+#[help(metadata_only_provide_library_name)]
+pub struct SuggestLibraryName<'a> {
+    suggested_name: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::failed_create_tempdir)]
+#[derive(Diagnostic)]
+#[diag(metadata_failed_create_tempdir)]
 pub struct FailedCreateTempdir {
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::failed_create_file)]
+#[derive(Diagnostic)]
+#[diag(metadata_failed_create_file)]
 pub struct FailedCreateFile<'a> {
     pub filename: &'a Path,
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::failed_create_encoded_metadata)]
+#[derive(Diagnostic)]
+#[diag(metadata_failed_create_encoded_metadata)]
 pub struct FailedCreateEncodedMetadata {
     pub err: Error,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::non_ascii_name)]
+#[derive(Diagnostic)]
+#[diag(metadata_non_ascii_name)]
 pub struct NonAsciiName {
     #[primary_span]
     pub span: Span,
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::extern_location_not_exist)]
+#[derive(Diagnostic)]
+#[diag(metadata_extern_location_not_exist)]
 pub struct ExternLocationNotExist<'a> {
     #[primary_span]
     pub span: Span,
@@ -411,8 +445,8 @@ pub struct ExternLocationNotExist<'a> {
     pub location: &'a Path,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::extern_location_not_file)]
+#[derive(Diagnostic)]
+#[diag(metadata_extern_location_not_file)]
 pub struct ExternLocationNotFile<'a> {
     #[primary_span]
     pub span: Span,
@@ -427,12 +461,12 @@ pub(crate) struct MultipleCandidates {
     pub candidates: Vec<PathBuf>,
 }
 
-impl SessionDiagnostic<'_> for MultipleCandidates {
+impl IntoDiagnostic<'_> for MultipleCandidates {
     fn into_diagnostic(
         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(rustc_errors::fluent::metadata_multiple_candidates);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("flavor", self.flavor);
         diag.code(error_code!(E0465));
@@ -444,8 +478,8 @@ impl SessionDiagnostic<'_> for MultipleCandidates {
     }
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_matching_crates, code = "E0464")]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_matching_crates, code = "E0464")]
 #[note]
 pub struct MultipleMatchingCrates {
     #[primary_span]
@@ -454,24 +488,24 @@ pub struct MultipleMatchingCrates {
     pub candidates: String,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::symbol_conflicts_current, code = "E0519")]
+#[derive(Diagnostic)]
+#[diag(metadata_symbol_conflicts_current, code = "E0519")]
 pub struct SymbolConflictsCurrent {
     #[primary_span]
     pub span: Span,
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::symbol_conflicts_others, code = "E0523")]
+#[derive(Diagnostic)]
+#[diag(metadata_symbol_conflicts_others, code = "E0523")]
 pub struct SymbolConflictsOthers {
     #[primary_span]
     pub span: Span,
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::stable_crate_id_collision)]
+#[derive(Diagnostic)]
+#[diag(metadata_stable_crate_id_collision)]
 pub struct StableCrateIdCollision {
     #[primary_span]
     pub span: Span,
@@ -479,18 +513,18 @@ pub struct StableCrateIdCollision {
     pub crate_name1: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::dl_error)]
+#[derive(Diagnostic)]
+#[diag(metadata_dl_error)]
 pub struct DlError {
     #[primary_span]
     pub span: Span,
     pub err: String,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::newer_crate_version, code = "E0460")]
+#[derive(Diagnostic)]
+#[diag(metadata_newer_crate_version, code = "E0460")]
 #[note]
-#[note(metadata::found_crate_versions)]
+#[note(metadata_found_crate_versions)]
 pub struct NewerCrateVersion {
     #[primary_span]
     pub span: Span,
@@ -499,9 +533,9 @@ pub struct NewerCrateVersion {
     pub found_crates: String,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::no_crate_with_triple, code = "E0461")]
-#[note(metadata::found_crate_versions)]
+#[derive(Diagnostic)]
+#[diag(metadata_no_crate_with_triple, code = "E0461")]
+#[note(metadata_found_crate_versions)]
 pub struct NoCrateWithTriple<'a> {
     #[primary_span]
     pub span: Span,
@@ -511,9 +545,9 @@ pub struct NoCrateWithTriple<'a> {
     pub found_crates: String,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::found_staticlib, code = "E0462")]
-#[note(metadata::found_crate_versions)]
+#[derive(Diagnostic)]
+#[diag(metadata_found_staticlib, code = "E0462")]
+#[note(metadata_found_crate_versions)]
 #[help]
 pub struct FoundStaticlib {
     #[primary_span]
@@ -523,9 +557,9 @@ pub struct FoundStaticlib {
     pub found_crates: String,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::incompatible_rustc, code = "E0514")]
-#[note(metadata::found_crate_versions)]
+#[derive(Diagnostic)]
+#[diag(metadata_incompatible_rustc, code = "E0514")]
+#[note(metadata_found_crate_versions)]
 #[help]
 pub struct IncompatibleRustc {
     #[primary_span]
@@ -543,12 +577,12 @@ pub struct InvalidMetadataFiles {
     pub crate_rejections: Vec<String>,
 }
 
-impl SessionDiagnostic<'_> for InvalidMetadataFiles {
+impl IntoDiagnostic<'_> for InvalidMetadataFiles {
     fn into_diagnostic(
         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(rustc_errors::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));
@@ -571,12 +605,12 @@ pub struct CannotFindCrate {
     pub locator_triple: TargetTriple,
 }
 
-impl SessionDiagnostic<'_> for CannotFindCrate {
+impl IntoDiagnostic<'_> for CannotFindCrate {
     fn into_diagnostic(
         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(rustc_errors::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);
@@ -587,54 +621,54 @@ impl SessionDiagnostic<'_> 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(rustc_errors::fluent::metadata_target_not_installed);
             } else {
-                diag.note(rustc_errors::fluent::metadata::target_no_std_support);
+                diag.note(rustc_errors::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(rustc_errors::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(rustc_errors::fluent::metadata_std_required);
             }
             if self.is_nightly_build {
-                diag.help(rustc_errors::fluent::metadata::consider_building_std);
+                diag.help(rustc_errors::fluent::metadata_consider_building_std);
             }
         } else if self.crate_name == self.profiler_runtime {
-            diag.note(rustc_errors::fluent::metadata::compiler_missing_profiler);
+            diag.note(rustc_errors::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(rustc_errors::fluent::metadata_install_missing_components);
         }
-        diag.span_label(self.span, rustc_errors::fluent::metadata::cant_find_crate);
+        diag.span_label(self.span, rustc_errors::fluent::metadata_cant_find_crate);
         diag
     }
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::no_dylib_plugin, code = "E0457")]
+#[derive(Diagnostic)]
+#[diag(metadata_no_dylib_plugin, code = "E0457")]
 pub struct NoDylibPlugin {
     #[primary_span]
     pub span: Span,
     pub crate_name: Symbol,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::crate_location_unknown_type)]
+#[derive(Diagnostic)]
+#[diag(metadata_crate_location_unknown_type)]
 pub struct CrateLocationUnknownType<'a> {
     #[primary_span]
     pub span: Span,
     pub path: &'a Path,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::lib_filename_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_lib_filename_form)]
 pub struct LibFilenameForm<'a> {
     #[primary_span]
     pub span: Span,
@@ -642,37 +676,37 @@ pub struct LibFilenameForm<'a> {
     pub dll_suffix: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::multiple_import_name_type)]
+#[derive(Diagnostic)]
+#[diag(metadata_multiple_import_name_type)]
 pub struct MultipleImportNameType {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::import_name_type_form)]
+#[derive(Diagnostic)]
+#[diag(metadata_import_name_type_form)]
 pub struct ImportNameTypeForm {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::import_name_type_x86)]
+#[derive(Diagnostic)]
+#[diag(metadata_import_name_type_x86)]
 pub struct ImportNameTypeX86 {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::unknown_import_name_type)]
+#[derive(Diagnostic)]
+#[diag(metadata_unknown_import_name_type)]
 pub struct UnknownImportNameType<'a> {
     #[primary_span]
     pub span: Span,
     pub import_name_type: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
-#[diag(metadata::import_name_type_raw)]
+#[derive(Diagnostic)]
+#[diag(metadata_import_name_type_raw)]
 pub struct ImportNameTypeRaw {
     #[primary_span]
     pub span: Span,
diff --git a/compiler/rustc_metadata/src/foreign_modules.rs b/compiler/rustc_metadata/src/foreign_modules.rs
index 2ca4cd17f..d1c2f3104 100644
--- a/compiler/rustc_metadata/src/foreign_modules.rs
+++ b/compiler/rustc_metadata/src/foreign_modules.rs
@@ -6,13 +6,13 @@ use rustc_session::cstore::ForeignModule;
 pub(crate) fn collect(tcx: TyCtxt<'_>) -> Vec<ForeignModule> {
     let mut modules = Vec::new();
     for id in tcx.hir().items() {
-        if !matches!(tcx.def_kind(id.def_id), DefKind::ForeignMod) {
+        if !matches!(tcx.def_kind(id.owner_id), DefKind::ForeignMod) {
             continue;
         }
         let item = tcx.hir().item(id);
         if let hir::ItemKind::ForeignMod { items, .. } = item.kind {
-            let foreign_items = items.iter().map(|it| it.id.def_id.to_def_id()).collect();
-            modules.push(ForeignModule { foreign_items, def_id: id.def_id.to_def_id() });
+            let foreign_items = items.iter().map(|it| it.id.owner_id.to_def_id()).collect();
+            modules.push(ForeignModule { foreign_items, def_id: id.owner_id.to_def_id() });
         }
     }
     modules
diff --git a/compiler/rustc_metadata/src/lib.rs b/compiler/rustc_metadata/src/lib.rs
index 6f5604b7e..98cf6fef5 100644
--- a/compiler/rustc_metadata/src/lib.rs
+++ b/compiler/rustc_metadata/src/lib.rs
@@ -2,10 +2,8 @@
 #![feature(decl_macro)]
 #![feature(drain_filter)]
 #![feature(generators)]
-#![cfg_attr(bootstrap, feature(generic_associated_types))]
 #![feature(iter_from_generator)]
 #![feature(let_chains)]
-#![cfg_attr(bootstrap, feature(let_else))]
 #![feature(once_cell)]
 #![feature(proc_macro_internals)]
 #![feature(macro_metavar_expr)]
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index 257741c13..20a2e7829 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -33,29 +33,26 @@ pub fn find_native_static_library(
     search_paths: &[PathBuf],
     sess: &Session,
 ) -> PathBuf {
-    let verbatim = verbatim.unwrap_or(false);
-    // On Windows, static libraries sometimes show up as libfoo.a and other
-    // times show up as foo.lib
-    let oslibname = if verbatim {
-        name.to_string()
+    let formats = if verbatim.unwrap_or(false) {
+        vec![("".into(), "".into())]
     } else {
-        format!("{}{}{}", sess.target.staticlib_prefix, name, sess.target.staticlib_suffix)
+        let os = (sess.target.staticlib_prefix.clone(), sess.target.staticlib_suffix.clone());
+        // On Windows, static libraries sometimes show up as libfoo.a and other
+        // times show up as foo.lib
+        let unix = ("lib".into(), ".a".into());
+        if os == unix { vec![os] } else { vec![os, unix] }
     };
-    let unixlibname = format!("lib{}.a", name);
 
     for path in search_paths {
-        let test = path.join(&oslibname);
-        if test.exists() {
-            return test;
-        }
-        if oslibname != unixlibname {
-            let test = path.join(&unixlibname);
+        for (prefix, suffix) in &formats {
+            let test = path.join(format!("{}{}{}", prefix, name, suffix));
             if test.exists() {
                 return test;
             }
         }
     }
-    sess.emit_fatal(MissingNativeLibrary { libname: name });
+
+    sess.emit_fatal(MissingNativeLibrary::new(name, verbatim.unwrap_or(false)));
 }
 
 fn find_bundled_library(
@@ -101,7 +98,7 @@ struct Collector<'tcx> {
 
 impl<'tcx> Collector<'tcx> {
     fn process_item(&mut self, id: rustc_hir::ItemId) {
-        if !matches!(self.tcx.def_kind(id.def_id), DefKind::ForeignMod) {
+        if !matches!(self.tcx.def_kind(id.owner_id), DefKind::ForeignMod) {
             return;
         }
 
@@ -375,17 +372,17 @@ impl<'tcx> Collector<'tcx> {
                 }
                 _ => {
                     for child_item in foreign_mod_items {
-                        if self.tcx.def_kind(child_item.id.def_id).has_codegen_attrs()
+                        if self.tcx.def_kind(child_item.id.owner_id).has_codegen_attrs()
                             && self
                                 .tcx
-                                .codegen_fn_attrs(child_item.id.def_id)
+                                .codegen_fn_attrs(child_item.id.owner_id)
                                 .link_ordinal
                                 .is_some()
                         {
                             let link_ordinal_attr = self
                                 .tcx
                                 .hir()
-                                .attrs(self.tcx.hir().local_def_id_to_hir_id(child_item.id.def_id))
+                                .attrs(child_item.id.owner_id.into())
                                 .iter()
                                 .find(|a| a.has_name(sym::link_ordinal))
                                 .unwrap();
@@ -405,7 +402,7 @@ impl<'tcx> Collector<'tcx> {
                 filename,
                 kind,
                 cfg,
-                foreign_module: Some(it.def_id.to_def_id()),
+                foreign_module: Some(it.owner_id.to_def_id()),
                 wasm_import_module: wasm_import_module.map(|(name, _)| name),
                 verbatim,
                 dll_imports,
@@ -508,7 +505,7 @@ impl<'tcx> Collector<'tcx> {
     fn i686_arg_list_size(&self, item: &hir::ForeignItemRef) -> usize {
         let argument_types: &List<Ty<'_>> = self.tcx.erase_late_bound_regions(
             self.tcx
-                .type_of(item.id.def_id)
+                .type_of(item.id.owner_id)
                 .fn_sig(self.tcx)
                 .inputs()
                 .map_bound(|slice| self.tcx.mk_type_list(slice.iter())),
@@ -560,7 +557,7 @@ impl<'tcx> Collector<'tcx> {
             }
         };
 
-        let codegen_fn_attrs = self.tcx.codegen_fn_attrs(item.id.def_id);
+        let codegen_fn_attrs = self.tcx.codegen_fn_attrs(item.id.owner_id);
         let import_name_type = codegen_fn_attrs
             .link_ordinal
             .map_or(import_name_type, |ord| Some(PeImportNameType::Ordinal(ord)));
@@ -570,7 +567,7 @@ impl<'tcx> Collector<'tcx> {
             import_name_type,
             calling_convention,
             span: item.span,
-            is_fn: self.tcx.def_kind(item.id.def_id).is_fn_like(),
+            is_fn: self.tcx.def_kind(item.id.owner_id).is_fn_like(),
         }
     }
 }
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 830417eea..691e3d0f8 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -773,7 +773,15 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     }
 
     fn opt_item_name(self, item_index: DefIndex) -> Option<Symbol> {
-        self.def_key(item_index).disambiguated_data.data.get_opt_name()
+        let def_key = self.def_key(item_index);
+        def_key.disambiguated_data.data.get_opt_name().or_else(|| {
+            if def_key.disambiguated_data.data == DefPathData::Ctor {
+                let parent_index = def_key.parent.expect("no parent for a constructor");
+                self.def_key(parent_index).disambiguated_data.data.get_opt_name()
+            } else {
+                None
+            }
+        })
     }
 
     fn item_name(self, item_index: DefIndex) -> Symbol {
@@ -905,7 +913,13 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 .get(self, item_id)
                 .unwrap_or_else(LazyArray::empty)
                 .decode(self)
-                .map(|index| self.get_variant(&self.def_kind(index), index, did))
+                .filter_map(|index| {
+                    let kind = self.def_kind(index);
+                    match kind {
+                        DefKind::Ctor(..) => None,
+                        _ => Some(self.get_variant(&kind, index, did)),
+                    }
+                })
                 .collect()
         } else {
             std::iter::once(self.get_variant(&kind, item_id, did)).collect()
@@ -1029,50 +1043,27 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
 
                 callback(ModChild { ident, res, vis, span, macro_rules });
 
-                // For non-re-export structs and variants add their constructors to children.
-                // Re-export lists automatically contain constructors when necessary.
-                match kind {
-                    DefKind::Struct => {
-                        if let Some((ctor_def_id, ctor_kind)) =
-                            self.get_ctor_def_id_and_kind(child_index)
-                        {
-                            let ctor_res =
-                                Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
-                            let vis = self.get_visibility(ctor_def_id.index);
-                            callback(ModChild {
-                                ident,
-                                res: ctor_res,
-                                vis,
-                                span,
-                                macro_rules: false,
-                            });
-                        }
-                    }
-                    DefKind::Variant => {
-                        // Braced variants, unlike structs, generate unusable names in
-                        // value namespace, they are reserved for possible future use.
-                        // It's ok to use the variant's id as a ctor id since an
-                        // error will be reported on any use of such resolution anyway.
-                        let (ctor_def_id, ctor_kind) = self
-                            .get_ctor_def_id_and_kind(child_index)
-                            .unwrap_or((def_id, CtorKind::Fictive));
-                        let ctor_res =
-                            Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
-                        let mut vis = self.get_visibility(ctor_def_id.index);
-                        if ctor_def_id == def_id && vis.is_public() {
-                            // For non-exhaustive variants lower the constructor visibility to
-                            // within the crate. We only need this for fictive constructors,
-                            // for other constructors correct visibilities
-                            // were already encoded in metadata.
-                            let mut attrs = self.get_item_attrs(def_id.index, sess);
-                            if attrs.any(|item| item.has_name(sym::non_exhaustive)) {
-                                let crate_def_id = self.local_def_id(CRATE_DEF_INDEX);
-                                vis = ty::Visibility::Restricted(crate_def_id);
-                            }
+                // For non-reexport variants add their fictive constructors to children.
+                // Braced variants, unlike structs, generate unusable names in value namespace,
+                // they are reserved for possible future use. It's ok to use the variant's id as
+                // a ctor id since an error will be reported on any use of such resolution anyway.
+                // Reexport lists automatically contain such constructors when necessary.
+                if kind == DefKind::Variant && self.get_ctor_def_id_and_kind(child_index).is_none()
+                {
+                    let ctor_res =
+                        Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fictive), def_id);
+                    let mut vis = vis;
+                    if vis.is_public() {
+                        // For non-exhaustive variants lower the constructor visibility to
+                        // within the crate. We only need this for fictive constructors,
+                        // for other constructors correct visibilities
+                        // were already encoded in metadata.
+                        let mut attrs = self.get_item_attrs(def_id.index, sess);
+                        if attrs.any(|item| item.has_name(sym::non_exhaustive)) {
+                            vis = ty::Visibility::Restricted(self.local_def_id(CRATE_DEF_INDEX));
                         }
-                        callback(ModChild { ident, res: ctor_res, vis, span, macro_rules: false });
                     }
-                    _ => {}
+                    callback(ModChild { ident, res: ctor_res, vis, span, macro_rules: false });
                 }
             }
         }
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index dede1b212..a0a085525 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -15,7 +15,6 @@ use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::query::{ExternProviders, Providers};
 use rustc_middle::ty::{self, TyCtxt, Visibility};
 use rustc_session::cstore::{CrateSource, CrateStore};
-use rustc_session::utils::NativeLibKind;
 use rustc_session::{Session, StableCrateId};
 use rustc_span::hygiene::{ExpnHash, ExpnId};
 use rustc_span::source_map::{Span, Spanned};
@@ -210,6 +209,7 @@ provide! { tcx, def_id, other, cdata,
     lookup_const_stability => { table }
     lookup_default_body_stability => { table }
     lookup_deprecation_entry => { table }
+    params_in_repr => { table }
     unused_generic_params => { table }
     opt_def_kind => { table_direct }
     impl_parent => { table }
@@ -223,6 +223,16 @@ provide! { tcx, def_id, other, cdata,
     fn_arg_names => { table }
     generator_kind => { table }
     trait_def => { table }
+    deduced_param_attrs => { table }
+    collect_trait_impl_trait_tys => {
+        Ok(cdata
+            .root
+            .tables
+            .trait_impl_trait_tys
+            .get(cdata, def_id.index)
+            .map(|lazy| lazy.decode((cdata, tcx)))
+            .process_decoded(tcx, || panic!("{:?} does not have trait_impl_trait_tys", def_id)))
+     }
 
     visibility => { cdata.get_visibility(def_id.index) }
     adt_def => { cdata.get_adt_def(def_id.index, tcx) }
@@ -329,20 +339,10 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
     // resolve! Does this work? Unsure! That's what the issue is about
     *providers = Providers {
         allocator_kind: |tcx, ()| CStore::from_tcx(tcx).allocator_kind(),
-        is_dllimport_foreign_item: |tcx, id| match tcx.native_library_kind(id) {
-            Some(
-                NativeLibKind::Dylib { .. } | NativeLibKind::RawDylib | NativeLibKind::Unspecified,
-            ) => true,
-            _ => false,
-        },
-        is_statically_included_foreign_item: |tcx, id| {
-            matches!(tcx.native_library_kind(id), Some(NativeLibKind::Static { .. }))
-        },
         is_private_dep: |_tcx, cnum| {
             assert_eq!(cnum, LOCAL_CRATE);
             false
         },
-        native_library_kind: |tcx, id| tcx.native_library(id).map(|l| l.kind),
         native_library: |tcx, id| {
             tcx.native_libraries(id.krate)
                 .iter()
@@ -587,11 +587,6 @@ impl CStore {
         self.get_crate_data(cnum).get_proc_macro_quoted_span(id, sess)
     }
 
-    /// Decodes all traits in the crate (for rustdoc).
-    pub fn traits_in_crate_untracked(&self, cnum: CrateNum) -> impl Iterator<Item = DefId> + '_ {
-        self.get_crate_data(cnum).get_traits()
-    }
-
     /// Decodes all trait impls in the crate (for rustdoc).
     pub fn trait_impls_in_crate_untracked(
         &self,
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 5a60ea794..049514ec7 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -3,6 +3,7 @@ use crate::rmeta::def_path_hash_map::DefPathHashMapRef;
 use crate::rmeta::table::TableBuilder;
 use crate::rmeta::*;
 
+use rustc_ast::Attribute;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_data_structures::memmap::{Mmap, MmapMut};
@@ -28,8 +29,9 @@ use rustc_middle::ty::codec::TyEncoder;
 use rustc_middle::ty::fast_reject::{self, SimplifiedType, TreatParams};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
+use rustc_middle::util::common::to_readable_str;
 use rustc_serialize::{opaque, Decodable, Decoder, Encodable, Encoder};
-use rustc_session::config::CrateType;
+use rustc_session::config::{CrateType, OptLevel};
 use rustc_session::cstore::{ForeignModule, LinkagePreference, NativeLib};
 use rustc_span::hygiene::{ExpnIndex, HygieneEncodeContext, MacroKind};
 use rustc_span::symbol::{sym, Symbol};
@@ -261,10 +263,10 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
         // This allows us to avoid loading the dependencies of proc-macro crates: all of
         // the information we need to decode `Span`s is stored in the proc-macro crate.
         let (tag, metadata_index) = if source_file.is_imported() && !s.is_proc_macro {
-            // To simplify deserialization, we 'rebase' this span onto the crate it originally came from
-            // (the crate that 'owns' the file it references. These rebased 'lo' and 'hi' values
-            // are relative to the source map information for the 'foreign' crate whose CrateNum
-            // we write into the metadata. This allows `imported_source_files` to binary
+            // To simplify deserialization, we 'rebase' this span onto the crate it originally came
+            // from (the crate that 'owns' the file it references. These rebased 'lo' and 'hi'
+            // values are relative to the source map information for the 'foreign' crate whose
+            // CrateNum we write into the metadata. This allows `imported_source_files` to binary
             // search through the 'foreign' crate's source map information, using the
             // deserialized 'lo' and 'hi' values directly.
             //
@@ -554,78 +556,56 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
 
     fn encode_crate_root(&mut self) -> LazyValue<CrateRoot> {
         let tcx = self.tcx;
-        let mut i = 0;
-        let preamble_bytes = self.position() - i;
-
-        // Encode the crate deps
-        i = self.position();
-        let crate_deps = self.encode_crate_deps();
-        let dylib_dependency_formats = self.encode_dylib_dependency_formats();
-        let dep_bytes = self.position() - i;
-
-        // Encode the lib features.
-        i = self.position();
-        let lib_features = self.encode_lib_features();
-        let lib_feature_bytes = self.position() - i;
-
-        // Encode the stability implications.
-        i = self.position();
-        let stability_implications = self.encode_stability_implications();
-        let stability_implications_bytes = self.position() - i;
-
-        // Encode the language items.
-        i = self.position();
-        let lang_items = self.encode_lang_items();
-        let lang_items_missing = self.encode_lang_items_missing();
-        let lang_item_bytes = self.position() - i;
-
-        // Encode the diagnostic items.
-        i = self.position();
-        let diagnostic_items = self.encode_diagnostic_items();
-        let diagnostic_item_bytes = self.position() - i;
-
-        // Encode the native libraries used
-        i = self.position();
-        let native_libraries = self.encode_native_libraries();
-        let native_lib_bytes = self.position() - i;
-
-        i = self.position();
-        let foreign_modules = self.encode_foreign_modules();
-        let foreign_modules_bytes = self.position() - i;
-
-        // Encode DefPathTable
-        i = self.position();
-        self.encode_def_path_table();
-        let def_path_table_bytes = self.position() - i;
+        let mut stats: Vec<(&'static str, usize)> = Vec::with_capacity(32);
+
+        macro_rules! stat {
+            ($label:literal, $f:expr) => {{
+                let orig_pos = self.position();
+                let res = $f();
+                stats.push(($label, self.position() - orig_pos));
+                res
+            }};
+        }
+
+        // We have already encoded some things. Get their combined size from the current position.
+        stats.push(("preamble", self.position()));
+
+        let (crate_deps, dylib_dependency_formats) =
+            stat!("dep", || (self.encode_crate_deps(), self.encode_dylib_dependency_formats()));
+
+        let lib_features = stat!("lib-features", || self.encode_lib_features());
+
+        let stability_implications =
+            stat!("stability-implications", || self.encode_stability_implications());
+
+        let (lang_items, lang_items_missing) = stat!("lang-items", || {
+            (self.encode_lang_items(), self.encode_lang_items_missing())
+        });
+
+        let diagnostic_items = stat!("diagnostic-items", || self.encode_diagnostic_items());
+
+        let native_libraries = stat!("native-libs", || self.encode_native_libraries());
+
+        let foreign_modules = stat!("foreign-modules", || self.encode_foreign_modules());
+
+        _ = stat!("def-path-table", || self.encode_def_path_table());
 
         // Encode the def IDs of traits, for rustdoc and diagnostics.
-        i = self.position();
-        let traits = self.encode_traits();
-        let traits_bytes = self.position() - i;
+        let traits = stat!("traits", || self.encode_traits());
 
         // Encode the def IDs of impls, for coherence checking.
-        i = self.position();
-        let impls = self.encode_impls();
-        let impls_bytes = self.position() - i;
-
-        i = self.position();
-        let incoherent_impls = self.encode_incoherent_impls();
-        let incoherent_impls_bytes = self.position() - i;
-
-        // Encode MIR.
-        i = self.position();
-        self.encode_mir();
-        let mir_bytes = self.position() - i;
-
-        // Encode the items.
-        i = self.position();
-        self.encode_def_ids();
-        self.encode_info_for_items();
-        let item_bytes = self.position() - i;
-
-        // Encode the allocation index
-        i = self.position();
-        let interpret_alloc_index = {
+        let impls = stat!("impls", || self.encode_impls());
+
+        let incoherent_impls = stat!("incoherent-impls", || self.encode_incoherent_impls());
+
+        _ = stat!("mir", || self.encode_mir());
+
+        _ = stat!("items", || {
+            self.encode_def_ids();
+            self.encode_info_for_items();
+        });
+
+        let interpret_alloc_index = stat!("interpret-alloc-index", || {
             let mut interpret_alloc_index = Vec::new();
             let mut n = 0;
             trace!("beginning to encode alloc ids");
@@ -646,126 +626,90 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 n = new_n;
             }
             self.lazy_array(interpret_alloc_index)
-        };
-        let interpret_alloc_index_bytes = self.position() - i;
+        });
 
-        // Encode the proc macro data. This affects 'tables',
-        // so we need to do this before we encode the tables.
-        // This overwrites def_keys, so it must happen after encode_def_path_table.
-        i = self.position();
-        let proc_macro_data = self.encode_proc_macros();
-        let proc_macro_data_bytes = self.position() - i;
+        // Encode the proc macro data. This affects `tables`, so we need to do this before we
+        // encode the tables. This overwrites def_keys, so it must happen after
+        // encode_def_path_table.
+        let proc_macro_data = stat!("proc-macro-data", || self.encode_proc_macros());
 
-        i = self.position();
-        let tables = self.tables.encode(&mut self.opaque);
-        let tables_bytes = self.position() - i;
+        let tables = stat!("tables", || self.tables.encode(&mut self.opaque));
 
-        i = self.position();
-        let debugger_visualizers = self.encode_debugger_visualizers();
-        let debugger_visualizers_bytes = self.position() - i;
+        let debugger_visualizers =
+            stat!("debugger-visualizers", || self.encode_debugger_visualizers());
 
         // Encode exported symbols info. This is prefetched in `encode_metadata` so we encode
         // this as late as possible to give the prefetching as much time as possible to complete.
-        i = self.position();
-        let exported_symbols = tcx.exported_symbols(LOCAL_CRATE);
-        let exported_symbols = self.encode_exported_symbols(&exported_symbols);
-        let exported_symbols_bytes = self.position() - i;
-
-        // Encode the hygiene data,
-        // IMPORTANT: this *must* be the last thing that we encode (other than `SourceMap`). The process
-        // of encoding other items (e.g. `optimized_mir`) may cause us to load
-        // data from the incremental cache. If this causes us to deserialize a `Span`,
-        // then we may load additional `SyntaxContext`s into the global `HygieneData`.
-        // Therefore, we need to encode the hygiene data last to ensure that we encode
-        // any `SyntaxContext`s that might be used.
-        i = self.position();
-        let (syntax_contexts, expn_data, expn_hashes) = self.encode_hygiene();
-        let hygiene_bytes = self.position() - i;
-
-        i = self.position();
-        let def_path_hash_map = self.encode_def_path_hash_map();
-        let def_path_hash_map_bytes = self.position() - i;
-
-        // Encode source_map. This needs to be done last,
-        // since encoding `Span`s tells us which `SourceFiles` we actually
-        // need to encode.
-        i = self.position();
-        let source_map = self.encode_source_map();
-        let source_map_bytes = self.position() - i;
-
-        i = self.position();
-        let attrs = tcx.hir().krate_attrs();
-        let has_default_lib_allocator = tcx.sess.contains_name(&attrs, sym::default_lib_allocator);
-        let root = self.lazy(CrateRoot {
-            name: tcx.crate_name(LOCAL_CRATE),
-            extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
-            triple: tcx.sess.opts.target_triple.clone(),
-            hash: tcx.crate_hash(LOCAL_CRATE),
-            stable_crate_id: tcx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(),
-            required_panic_strategy: tcx.required_panic_strategy(LOCAL_CRATE),
-            panic_in_drop_strategy: tcx.sess.opts.unstable_opts.panic_in_drop,
-            edition: tcx.sess.edition(),
-            has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
-            has_panic_handler: tcx.has_panic_handler(LOCAL_CRATE),
-            has_default_lib_allocator,
-            proc_macro_data,
-            debugger_visualizers,
-            compiler_builtins: tcx.sess.contains_name(&attrs, sym::compiler_builtins),
-            needs_allocator: tcx.sess.contains_name(&attrs, sym::needs_allocator),
-            needs_panic_runtime: tcx.sess.contains_name(&attrs, sym::needs_panic_runtime),
-            no_builtins: tcx.sess.contains_name(&attrs, sym::no_builtins),
-            panic_runtime: tcx.sess.contains_name(&attrs, sym::panic_runtime),
-            profiler_runtime: tcx.sess.contains_name(&attrs, sym::profiler_runtime),
-            symbol_mangling_version: tcx.sess.opts.get_symbol_mangling_version(),
-
-            crate_deps,
-            dylib_dependency_formats,
-            lib_features,
-            stability_implications,
-            lang_items,
-            diagnostic_items,
-            lang_items_missing,
-            native_libraries,
-            foreign_modules,
-            source_map,
-            traits,
-            impls,
-            incoherent_impls,
-            exported_symbols,
-            interpret_alloc_index,
-            tables,
-            syntax_contexts,
-            expn_data,
-            expn_hashes,
-            def_path_hash_map,
+        let exported_symbols = stat!("exported-symbols", || {
+            self.encode_exported_symbols(&tcx.exported_symbols(LOCAL_CRATE))
+        });
+
+        // Encode the hygiene data.
+        // IMPORTANT: this *must* be the last thing that we encode (other than `SourceMap`). The
+        // process of encoding other items (e.g. `optimized_mir`) may cause us to load data from
+        // the incremental cache. If this causes us to deserialize a `Span`, then we may load
+        // additional `SyntaxContext`s into the global `HygieneData`. Therefore, we need to encode
+        // the hygiene data last to ensure that we encode any `SyntaxContext`s that might be used.
+        let (syntax_contexts, expn_data, expn_hashes) = stat!("hygiene", || self.encode_hygiene());
+
+        let def_path_hash_map = stat!("def-path-hash-map", || self.encode_def_path_hash_map());
+
+        // Encode source_map. This needs to be done last, because encoding `Span`s tells us which
+        // `SourceFiles` we actually need to encode.
+        let source_map = stat!("source-map", || self.encode_source_map());
+
+        let root = stat!("final", || {
+            let attrs = tcx.hir().krate_attrs();
+            self.lazy(CrateRoot {
+                name: tcx.crate_name(LOCAL_CRATE),
+                extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
+                triple: tcx.sess.opts.target_triple.clone(),
+                hash: tcx.crate_hash(LOCAL_CRATE),
+                stable_crate_id: tcx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(),
+                required_panic_strategy: tcx.required_panic_strategy(LOCAL_CRATE),
+                panic_in_drop_strategy: tcx.sess.opts.unstable_opts.panic_in_drop,
+                edition: tcx.sess.edition(),
+                has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
+                has_panic_handler: tcx.has_panic_handler(LOCAL_CRATE),
+                has_default_lib_allocator: tcx
+                    .sess
+                    .contains_name(&attrs, sym::default_lib_allocator),
+                proc_macro_data,
+                debugger_visualizers,
+                compiler_builtins: tcx.sess.contains_name(&attrs, sym::compiler_builtins),
+                needs_allocator: tcx.sess.contains_name(&attrs, sym::needs_allocator),
+                needs_panic_runtime: tcx.sess.contains_name(&attrs, sym::needs_panic_runtime),
+                no_builtins: tcx.sess.contains_name(&attrs, sym::no_builtins),
+                panic_runtime: tcx.sess.contains_name(&attrs, sym::panic_runtime),
+                profiler_runtime: tcx.sess.contains_name(&attrs, sym::profiler_runtime),
+                symbol_mangling_version: tcx.sess.opts.get_symbol_mangling_version(),
+
+                crate_deps,
+                dylib_dependency_formats,
+                lib_features,
+                stability_implications,
+                lang_items,
+                diagnostic_items,
+                lang_items_missing,
+                native_libraries,
+                foreign_modules,
+                source_map,
+                traits,
+                impls,
+                incoherent_impls,
+                exported_symbols,
+                interpret_alloc_index,
+                tables,
+                syntax_contexts,
+                expn_data,
+                expn_hashes,
+                def_path_hash_map,
+            })
         });
-        let final_bytes = self.position() - i;
 
         let total_bytes = self.position();
 
-        let computed_total_bytes = preamble_bytes
-            + dep_bytes
-            + lib_feature_bytes
-            + stability_implications_bytes
-            + lang_item_bytes
-            + diagnostic_item_bytes
-            + native_lib_bytes
-            + foreign_modules_bytes
-            + def_path_table_bytes
-            + traits_bytes
-            + impls_bytes
-            + incoherent_impls_bytes
-            + mir_bytes
-            + item_bytes
-            + interpret_alloc_index_bytes
-            + proc_macro_data_bytes
-            + tables_bytes
-            + debugger_visualizers_bytes
-            + exported_symbols_bytes
-            + hygiene_bytes
-            + def_path_hash_map_bytes
-            + source_map_bytes
-            + final_bytes;
+        let computed_total_bytes: usize = stats.iter().map(|(_, size)| size).sum();
         assert_eq!(total_bytes, computed_total_bytes);
 
         if tcx.sess.meta_stats() {
@@ -783,48 +727,77 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             assert_eq!(self.opaque.file().stream_position().unwrap(), pos_before_rewind);
 
+            stats.sort_by_key(|&(_, usize)| usize);
+
+            let prefix = "meta-stats";
             let perc = |bytes| (bytes * 100) as f64 / total_bytes as f64;
-            let p = |label, bytes| {
-                eprintln!("{:>21}: {:>8} bytes ({:4.1}%)", label, bytes, perc(bytes));
-            };
 
-            eprintln!("");
+            eprintln!("{} METADATA STATS", prefix);
+            eprintln!("{} {:<23}{:>10}", prefix, "Section", "Size");
+            eprintln!(
+                "{} ----------------------------------------------------------------",
+                prefix
+            );
+            for (label, size) in stats {
+                eprintln!(
+                    "{} {:<23}{:>10} ({:4.1}%)",
+                    prefix,
+                    label,
+                    to_readable_str(size),
+                    perc(size)
+                );
+            }
+            eprintln!(
+                "{} ----------------------------------------------------------------",
+                prefix
+            );
             eprintln!(
-                "{} metadata bytes, of which {} bytes ({:.1}%) are zero",
-                total_bytes,
-                zero_bytes,
+                "{} {:<23}{:>10} (of which {:.1}% are zero bytes)",
+                prefix,
+                "Total",
+                to_readable_str(total_bytes),
                 perc(zero_bytes)
             );
-            p("preamble", preamble_bytes);
-            p("dep", dep_bytes);
-            p("lib feature", lib_feature_bytes);
-            p("stability_implications", stability_implications_bytes);
-            p("lang item", lang_item_bytes);
-            p("diagnostic item", diagnostic_item_bytes);
-            p("native lib", native_lib_bytes);
-            p("foreign modules", foreign_modules_bytes);
-            p("def-path table", def_path_table_bytes);
-            p("traits", traits_bytes);
-            p("impls", impls_bytes);
-            p("incoherent_impls", incoherent_impls_bytes);
-            p("mir", mir_bytes);
-            p("item", item_bytes);
-            p("interpret_alloc_index", interpret_alloc_index_bytes);
-            p("proc-macro-data", proc_macro_data_bytes);
-            p("tables", tables_bytes);
-            p("debugger visualizers", debugger_visualizers_bytes);
-            p("exported symbols", exported_symbols_bytes);
-            p("hygiene", hygiene_bytes);
-            p("def-path hashes", def_path_hash_map_bytes);
-            p("source_map", source_map_bytes);
-            p("final", final_bytes);
-            eprintln!("");
+            eprintln!("{}", prefix);
         }
 
         root
     }
 }
 
+/// 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
+/// 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 {
+    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(()).effective_vis(def_id).is_some())
+    } 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)
+    } else {
+        true
+    }
+}
+
 fn should_encode_visibility(def_kind: DefKind) -> bool {
     match def_kind {
         DefKind::Mod
@@ -1120,14 +1093,44 @@ fn should_encode_const(def_kind: DefKind) -> bool {
     }
 }
 
+fn should_encode_trait_impl_trait_tys<'tcx>(tcx: TyCtxt<'tcx>, 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;
+    }
+
+    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::Projection(data) = ty.kind()
+            && tcx.def_kind(data.item_def_id) == DefKind::ImplTraitPlaceholder
+        {
+            true
+        } else {
+            false
+        }
+    })
+}
+
 impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     fn encode_attrs(&mut self, def_id: LocalDefId) {
-        let mut attrs = self
-            .tcx
+        let tcx = self.tcx;
+        let mut is_public: Option<bool> = None;
+
+        let mut attrs = tcx
             .hir()
-            .attrs(self.tcx.hir().local_def_id_to_hir_id(def_id))
+            .attrs(tcx.hir().local_def_id_to_hir_id(def_id))
             .iter()
-            .filter(|attr| !rustc_feature::is_builtin_only_local(attr.name_or_empty()));
+            .filter(move |attr| should_encode_attr(tcx, attr, def_id, &mut is_public));
 
         record_array!(self.tables.attributes[def_id.to_def_id()] <- attrs.clone());
         if attrs.any(|attr| attr.may_have_doc_links()) {
@@ -1189,6 +1192,15 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             if let DefKind::Trait | DefKind::TraitAlias = def_kind {
                 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);
+            }
+            if should_encode_trait_impl_trait_tys(tcx, def_id)
+                && let Ok(table) = self.tcx.collect_trait_impl_trait_tys(def_id)
+            {
+                record!(self.tables.trait_impl_trait_tys[def_id] <- table);
+            }
         }
         let inherent_impls = tcx.crate_inherent_impls(());
         for (def_id, implementations) in inherent_impls.inherent_impls.iter() {
@@ -1278,14 +1290,21 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                         // from name resolution point of view.
                         hir::ItemKind::ForeignMod { items, .. } => {
                             for foreign_item in items {
-                                yield foreign_item.id.def_id.local_def_index;
+                                yield foreign_item.id.owner_id.def_id.local_def_index;
                             }
                         }
                         // Only encode named non-reexport children, reexports are encoded
                         // separately and unnamed items are not used by name resolution.
                         hir::ItemKind::ExternCrate(..) => continue,
-                        _ if tcx.def_key(item_id.def_id.to_def_id()).get_opt_name().is_some() => {
-                            yield item_id.def_id.local_def_index;
+                        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 tcx.def_key(item_id.owner_id.to_def_id()).get_opt_name().is_some() => {
+                            yield item_id.owner_id.def_id.local_def_index;
                         }
                         _ => continue,
                     }
@@ -1436,6 +1455,21 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.unused_generic_params[def_id.to_def_id()] <- unused);
             }
         }
+
+        // Encode all the deduced parameter attributes for everything that has MIR, even for items
+        // that can't be inlined. But don't if we aren't optimizing in non-incremental mode, to
+        // save the query traffic.
+        if tcx.sess.opts.output_types.should_codegen()
+            && tcx.sess.opts.optimize != OptLevel::No
+            && tcx.sess.opts.incremental.is_none()
+        {
+            for &local_def_id in tcx.mir_keys(()) {
+                if let DefKind::AssocFn | DefKind::Fn = tcx.def_kind(local_def_id) {
+                    record_array!(self.tables.deduced_param_attrs[local_def_id.to_def_id()] <-
+                        self.tcx.deduced_param_attrs(local_def_id.to_def_id()));
+                }
+            }
+        }
     }
 
     fn encode_stability(&mut self, def_id: DefId) {
@@ -1507,7 +1541,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.macro_definition[def_id] <- &*macro_def.body);
             }
             hir::ItemKind::Mod(ref m) => {
-                return self.encode_info_for_mod(item.def_id, m);
+                return self.encode_info_for_mod(item.owner_id.def_id, m);
             }
             hir::ItemKind::OpaqueTy(..) => {
                 self.encode_explicit_item_bounds(def_id);
@@ -1592,12 +1626,17 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         };
         // FIXME(eddyb) there should be a nicer way to do this.
         match item.kind {
-            hir::ItemKind::Enum(..) => record_array!(self.tables.children[def_id] <-
-                self.tcx.adt_def(def_id).variants().iter().map(|v| {
-                    assert!(v.def_id.is_local());
-                    v.def_id.index
-                })
-            ),
+            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| {
@@ -1634,7 +1673,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         // normally in the visitor walk.
         match item.kind {
             hir::ItemKind::Enum(..) => {
-                let def = self.tcx.adt_def(item.def_id.to_def_id());
+                let def = self.tcx.adt_def(item.owner_id.to_def_id());
                 for (i, variant) in def.variants().iter_enumerated() {
                     self.encode_enum_variant_info(def, i);
 
@@ -1644,7 +1683,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 }
             }
             hir::ItemKind::Struct(ref struct_def, _) => {
-                let def = self.tcx.adt_def(item.def_id.to_def_id());
+                let def = self.tcx.adt_def(item.owner_id.to_def_id());
                 // If the struct has a constructor, encode it.
                 if let Some(ctor_hir_id) = struct_def.ctor_hir_id() {
                     let ctor_def_id = self.tcx.hir().local_def_id(ctor_hir_id);
@@ -1653,13 +1692,14 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             hir::ItemKind::Impl { .. } => {
                 for &trait_item_def_id in
-                    self.tcx.associated_item_def_ids(item.def_id.to_def_id()).iter()
+                    self.tcx.associated_item_def_ids(item.owner_id.to_def_id()).iter()
                 {
                     self.encode_info_for_impl_item(trait_item_def_id);
                 }
             }
             hir::ItemKind::Trait(..) => {
-                for &item_def_id in self.tcx.associated_item_def_ids(item.def_id.to_def_id()).iter()
+                for &item_def_id in
+                    self.tcx.associated_item_def_ids(item.owner_id.to_def_id()).iter()
                 {
                     self.encode_info_for_trait_item(item_def_id);
                 }
@@ -1900,8 +1940,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             FxHashMap::default();
 
         for id in tcx.hir().items() {
-            if matches!(tcx.def_kind(id.def_id), DefKind::Impl) {
-                if let Some(trait_ref) = tcx.impl_trait_ref(id.def_id.to_def_id()) {
+            if matches!(tcx.def_kind(id.owner_id), DefKind::Impl) {
+                if let Some(trait_ref) = tcx.impl_trait_ref(id.owner_id) {
                     let simplified_self_ty = fast_reject::simplify_type(
                         self.tcx,
                         trait_ref.self_ty(),
@@ -1911,7 +1951,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                     fx_hash_map
                         .entry(trait_ref.def_id)
                         .or_default()
-                        .push((id.def_id.local_def_index, simplified_self_ty));
+                        .push((id.owner_id.def_id.local_def_index, simplified_self_ty));
                 }
             }
         }
@@ -2052,12 +2092,12 @@ impl<'a, 'tcx> Visitor<'tcx> for EncodeContext<'a, 'tcx> {
         intravisit::walk_item(self, item);
         match item.kind {
             hir::ItemKind::ExternCrate(_) | hir::ItemKind::Use(..) => {} // ignore these
-            _ => self.encode_info_for_item(item.def_id.to_def_id(), item),
+            _ => self.encode_info_for_item(item.owner_id.to_def_id(), item),
         }
     }
     fn visit_foreign_item(&mut self, ni: &'tcx hir::ForeignItem<'tcx>) {
         intravisit::walk_foreign_item(self, ni);
-        self.encode_info_for_foreign_item(ni.def_id.to_def_id(), ni);
+        self.encode_info_for_foreign_item(ni.owner_id.to_def_id(), ni);
     }
     fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
         intravisit::walk_generics(self, generics);
@@ -2276,8 +2316,8 @@ pub fn provide(providers: &mut Providers) {
 
             let mut traits = Vec::new();
             for id in tcx.hir().items() {
-                if matches!(tcx.def_kind(id.def_id), DefKind::Trait | DefKind::TraitAlias) {
-                    traits.push(id.def_id.to_def_id())
+                if matches!(tcx.def_kind(id.owner_id), DefKind::Trait | DefKind::TraitAlias) {
+                    traits.push(id.owner_id.to_def_id())
                 }
             }
 
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 748b3afec..27dc8ff16 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -1,6 +1,7 @@
 use crate::creader::CrateMetadataRef;
 use decoder::Metadata;
 use def_path_hash_map::DefPathHashMapRef;
+use rustc_data_structures::fx::FxHashMap;
 use table::TableBuilder;
 
 use rustc_ast as ast;
@@ -12,7 +13,8 @@ use rustc_hir::def::{CtorKind, DefKind};
 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, DefPathHash, StableCrateId};
 use rustc_hir::definitions::DefKey;
 use rustc_hir::lang_items;
-use rustc_index::{bit_set::FiniteBitSet, vec::IndexVec};
+use rustc_index::bit_set::{BitSet, FiniteBitSet};
+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};
@@ -21,7 +23,7 @@ use rustc_middle::mir;
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, ReprOptions, Ty};
-use rustc_middle::ty::{GeneratorDiagnosticData, ParameterizedOverTcx, TyCtxt};
+use rustc_middle::ty::{DeducedParamAttrs, GeneratorDiagnosticData, ParameterizedOverTcx, TyCtxt};
 use rustc_serialize::opaque::FileEncoder;
 use rustc_session::config::SymbolManglingVersion;
 use rustc_session::cstore::{CrateDepKind, ForeignModule, LinkagePreference, NativeLib};
@@ -382,6 +384,7 @@ define_tables! {
     inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
     expn_that_defined: Table<DefIndex, LazyValue<ExpnId>>,
     unused_generic_params: Table<DefIndex, LazyValue<FiniteBitSet<u32>>>,
+    params_in_repr: Table<DefIndex, LazyValue<BitSet<u32>>>,
     repr_options: Table<DefIndex, LazyValue<ReprOptions>>,
     // `def_keys` and `def_path_hashes` represent a lazy version of a
     // `DefPathTable`. This allows us to avoid deserializing an entire
@@ -399,6 +402,9 @@ define_tables! {
     macro_definition: Table<DefIndex, LazyValue<ast::MacArgs>>,
     proc_macro: Table<DefIndex, MacroKind>,
     module_reexports: Table<DefIndex, LazyArray<ModChild>>,
+    deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
+
+    trait_impl_trait_tys: Table<DefIndex, LazyValue<FxHashMap<DefId, Ty<'static>>>>,
 }
 
 #[derive(TyEncodable, TyDecodable)]