8 files changed, 105 insertions, 34 deletions
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 2c9d212a6a6..4b6917fdfdd 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -2215,7 +2215,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,compile_fail
+    /// ```rust
     /// #![feature(rustc_attrs)]
     /// ```
     ///
@@ -2226,7 +2226,7 @@ declare_lint! {
     /// These features are an implementation detail of the compiler and standard
     /// library and are not supposed to be used in user code.
     pub INTERNAL_FEATURES,
-    Deny,
+    Warn,
     "internal features are not supposed to be used"
 }
 
@@ -2237,7 +2237,7 @@ declare_lint_pass!(
 
 impl EarlyLintPass for IncompleteInternalFeatures {
     fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &ast::Crate) {
-        let features = cx.sess().features_untracked();
+        let features = cx.builder.features();
         features
             .declared_lang_features
             .iter()
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index f7e56b30553..f73797415bc 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -27,6 +27,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync;
 use rustc_errors::{add_elided_lifetime_in_path_suggestion, DiagnosticBuilder, DiagnosticMessage};
 use rustc_errors::{Applicability, DecorateLint, MultiSpan, SuggestionStyle};
+use rustc_feature::Features;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::{CrateNum, DefId};
@@ -1071,6 +1072,7 @@ pub trait LintContext: Sized {
 impl<'a> EarlyContext<'a> {
     pub(crate) fn new(
         sess: &'a Session,
+        features: &'a Features,
         warn_about_weird_lints: bool,
         lint_store: &'a LintStore,
         registered_tools: &'a RegisteredTools,
@@ -1079,6 +1081,7 @@ impl<'a> EarlyContext<'a> {
         EarlyContext {
             builder: LintLevelsBuilder::new(
                 sess,
+                features,
                 warn_about_weird_lints,
                 lint_store,
                 registered_tools,
diff --git a/compiler/rustc_lint/src/early.rs b/compiler/rustc_lint/src/early.rs
index 9f1f5a26ee5..211ea8f4347 100644
--- a/compiler/rustc_lint/src/early.rs
+++ b/compiler/rustc_lint/src/early.rs
@@ -20,6 +20,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::visit::{self as ast_visit, Visitor};
 use rustc_ast::{self as ast, walk_list, HasAttrs};
 use rustc_data_structures::stack::ensure_sufficient_stack;
+use rustc_feature::Features;
 use rustc_middle::ty::RegisteredTools;
 use rustc_session::lint::{BufferedEarlyLint, LintBuffer, LintPass};
 use rustc_session::Session;
@@ -381,6 +382,7 @@ impl<'a> EarlyCheckNode<'a> for (ast::NodeId, &'a [ast::Attribute], &'a [P<ast::
 
 pub fn check_ast_node<'a>(
     sess: &Session,
+    features: &Features,
     pre_expansion: bool,
     lint_store: &LintStore,
     registered_tools: &RegisteredTools,
@@ -390,6 +392,7 @@ pub fn check_ast_node<'a>(
 ) {
     let context = EarlyContext::new(
         sess,
+        features,
         !pre_expansion,
         lint_store,
         registered_tools,
diff --git a/compiler/rustc_lint/src/late.rs b/compiler/rustc_lint/src/late.rs
index 3331dbad4a9..73af51d9e90 100644
--- a/compiler/rustc_lint/src/late.rs
+++ b/compiler/rustc_lint/src/late.rs
@@ -19,7 +19,7 @@ use rustc_ast as ast;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::sync::join;
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_hir::intravisit as hir_visit;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
@@ -338,7 +338,7 @@ crate::late_lint_methods!(impl_late_lint_pass, []);
 
 pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
     tcx: TyCtxt<'tcx>,
-    module_def_id: LocalDefId,
+    module_def_id: LocalModDefId,
     builtin_lints: T,
 ) {
     let context = LateContext {
@@ -369,7 +369,7 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
 
 fn late_lint_mod_inner<'tcx, T: LateLintPass<'tcx>>(
     tcx: TyCtxt<'tcx>,
-    module_def_id: LocalDefId,
+    module_def_id: LocalModDefId,
     context: LateContext<'tcx>,
     pass: T,
 ) {
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 18b178d8882..1f4e5fa4d3b 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -12,6 +12,7 @@ use rustc_ast as ast;
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{DecorateLint, DiagnosticBuilder, DiagnosticMessage, MultiSpan};
+use rustc_feature::Features;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::HirId;
@@ -119,6 +120,7 @@ fn lint_expectations(tcx: TyCtxt<'_>, (): ()) -> Vec<(LintExpectationId, LintExp
 
     let mut builder = LintLevelsBuilder {
         sess: tcx.sess,
+        features: tcx.features(),
         provider: QueryMapExpectationsWrapper {
             tcx,
             cur: hir::CRATE_HIR_ID,
@@ -148,6 +150,7 @@ fn shallow_lint_levels_on(tcx: TyCtxt<'_>, owner: hir::OwnerId) -> ShallowLintLe
 
     let mut levels = LintLevelsBuilder {
         sess: tcx.sess,
+        features: tcx.features(),
         provider: LintLevelQueryMap {
             tcx,
             cur: owner.into(),
@@ -435,6 +438,7 @@ impl<'tcx> Visitor<'tcx> for LintLevelsBuilder<'_, QueryMapExpectationsWrapper<'
 
 pub struct LintLevelsBuilder<'s, P> {
     sess: &'s Session,
+    features: &'s Features,
     provider: P,
     warn_about_weird_lints: bool,
     store: &'s LintStore,
@@ -448,12 +452,14 @@ pub(crate) struct BuilderPush {
 impl<'s> LintLevelsBuilder<'s, TopDown> {
     pub(crate) fn new(
         sess: &'s Session,
+        features: &'s Features,
         warn_about_weird_lints: bool,
         store: &'s LintStore,
         registered_tools: &'s RegisteredTools,
     ) -> Self {
         let mut builder = LintLevelsBuilder {
             sess,
+            features,
             provider: TopDown { sets: LintLevelSets::new(), cur: COMMAND_LINE },
             warn_about_weird_lints,
             store,
@@ -526,6 +532,10 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         self.sess
     }
 
+    pub(crate) fn features(&self) -> &Features {
+        self.features
+    }
+
     pub(crate) fn lint_store(&self) -> &LintStore {
         self.store
     }
@@ -716,7 +726,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                     ast::MetaItemKind::NameValue(ref name_value) => {
                         if item.path == sym::reason {
                             if let ast::LitKind::Str(rationale, _) = name_value.kind {
-                                if !self.sess.features_untracked().lint_reasons {
+                                if !self.features.lint_reasons {
                                     feature_err(
                                         &self.sess.parse_sess,
                                         sym::lint_reasons,
@@ -992,7 +1002,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     #[track_caller]
     fn check_gated_lint(&self, lint_id: LintId, span: Span) -> bool {
         if let Some(feature) = lint_id.lint.feature_gate {
-            if !self.sess.features_untracked().enabled(feature) {
+            if !self.features.enabled(feature) {
                 let lint = builtin::UNKNOWN_LINTS;
                 let (level, src) = self.lint_level(builtin::UNKNOWN_LINTS);
                 struct_lint_level(
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index 42378951af3..585b10e79e4 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -90,7 +90,7 @@ use rustc_ast as ast;
 use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
 use rustc_fluent_macro::fluent_messages;
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{LocalDefId, LocalModDefId};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::{
@@ -145,7 +145,7 @@ pub fn provide(providers: &mut Providers) {
     *providers = Providers { lint_mod, ..*providers };
 }
 
-fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
     late_lint_mod(tcx, module_def_id, BuiltinCombinedModuleLateLintPass::new());
 }
 
diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs
index ed3d4721049..2577cabb3f0 100644
--- a/compiler/rustc_lint/src/reference_casting.rs
+++ b/compiler/rustc_lint/src/reference_casting.rs
@@ -98,32 +98,69 @@ impl<'tcx> LateLintPass<'tcx> for InvalidReferenceCasting {
 fn is_cast_from_const_to_mut<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> bool {
     let e = e.peel_blocks();
 
-    // <expr> as *mut ...
-    let e = if let ExprKind::Cast(e, t) = e.kind
-        && let ty::RawPtr(TypeAndMut { mutbl: Mutability::Mut, .. }) = cx.typeck_results().node_type(t.hir_id).kind() {
-        e
-    // <expr>.cast_mut()
-    } else if let ExprKind::MethodCall(_, expr, [], _) = e.kind
-        && let Some(def_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
-        && cx.tcx.is_diagnostic_item(sym::ptr_cast_mut, def_id) {
-        expr
-    } else {
-        return false;
-    };
+    fn from_casts<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
+        // <expr> as *mut ...
+        let mut e = if let ExprKind::Cast(e, t) = e.kind
+            && let ty::RawPtr(TypeAndMut { mutbl: Mutability::Mut, .. }) = cx.typeck_results().node_type(t.hir_id).kind() {
+            e
+        // <expr>.cast_mut()
+        } else if let ExprKind::MethodCall(_, expr, [], _) = e.kind
+            && let Some(def_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
+            && cx.tcx.is_diagnostic_item(sym::ptr_cast_mut, def_id) {
+            expr
+        } else {
+            return None;
+        };
 
-    let e = e.peel_blocks();
+        let mut had_at_least_one_cast = false;
+        loop {
+            e = e.peel_blocks();
+            // <expr> as *mut/const ... or <expr> as <uint>
+            e = if let ExprKind::Cast(expr, t) = e.kind
+                && matches!(cx.typeck_results().node_type(t.hir_id).kind(), ty::RawPtr(_) | ty::Uint(_))  {
+                had_at_least_one_cast = true;
+                expr
+            // <expr>.cast(), <expr>.cast_mut() or <expr>.cast_const()
+            } else if let ExprKind::MethodCall(_, expr, [], _) = e.kind
+                && let Some(def_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
+                && matches!(
+                    cx.tcx.get_diagnostic_name(def_id),
+                    Some(sym::ptr_cast | sym::const_ptr_cast | sym::ptr_cast_mut | sym::ptr_cast_const)
+                )
+            {
+                had_at_least_one_cast = true;
+                expr
+            // ptr::from_ref(<expr>)
+            } else if let ExprKind::Call(path, [arg]) = e.kind
+                && let ExprKind::Path(ref qpath) = path.kind
+                && let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
+                && cx.tcx.is_diagnostic_item(sym::ptr_from_ref, def_id) {
+                return Some(arg);
+            } else if had_at_least_one_cast {
+                return Some(e);
+            } else {
+                return None;
+            };
+        }
+    }
+
+    fn from_transmute<'tcx>(
+        cx: &LateContext<'tcx>,
+        e: &'tcx Expr<'tcx>,
+    ) -> Option<&'tcx Expr<'tcx>> {
+        // mem::transmute::<_, *mut _>(<expr>)
+        if let ExprKind::Call(path, [arg]) = e.kind
+            && let ExprKind::Path(ref qpath) = path.kind
+            && let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
+            && cx.tcx.is_diagnostic_item(sym::transmute, def_id)
+            && let ty::RawPtr(TypeAndMut { mutbl: Mutability::Mut, .. }) = cx.typeck_results().node_type(e.hir_id).kind() {
+            Some(arg)
+        } else {
+            None
+        }
+    }
 
-    // <expr> as *const ...
-    let e = if let ExprKind::Cast(e, t) = e.kind
-        && let ty::RawPtr(TypeAndMut { mutbl: Mutability::Not, .. }) = cx.typeck_results().node_type(t.hir_id).kind() {
-        e
-    // ptr::from_ref(<expr>)
-    } else if let ExprKind::Call(path, [arg]) = e.kind
-        && let ExprKind::Path(ref qpath) = path.kind
-        && let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
-        && cx.tcx.is_diagnostic_item(sym::ptr_from_ref, def_id) {
-        arg
-    } else {
+    let Some(e) = from_casts(cx, e).or_else(|| from_transmute(cx, e)) else {
         return false;
     };
 
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index 3db6b302790..6041f80753b 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -666,6 +666,24 @@ trait UnusedDelimLint {
         if !followed_by_block {
             return false;
         }
+
+        // Check if we need parens for `match &( Struct { feild:  }) {}`.
+        {
+            let mut innermost = inner;
+            loop {
+                innermost = match &innermost.kind {
+                    ExprKind::AddrOf(_, _, expr) => expr,
+                    _ => {
+                        if parser::contains_exterior_struct_lit(&innermost) {
+                            return true;
+                        } else {
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+
         let mut innermost = inner;
         loop {
             innermost = match &innermost.kind {