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-rw-r--r--compiler/rustc_lint/src/builtin.rs82
1 files changed, 44 insertions, 38 deletions
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index ef8100da9e2..dbb8c667532 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -4,21 +4,14 @@
 //! AST visitor. Also see `rustc_session::lint::builtin`, which contains the
 //! definitions of lints that are emitted directly inside the main compiler.
 //!
-//! To add a new lint to rustc, declare it here using `declare_lint!()`.
+//! To add a new lint to rustc, declare it here using [`declare_lint!`].
 //! Then add code to emit the new lint in the appropriate circumstances.
-//! You can do that in an existing `LintPass` if it makes sense, or in a
-//! new `LintPass`, or using `Session::add_lint` elsewhere in the
-//! compiler. Only do the latter if the check can't be written cleanly as a
-//! `LintPass` (also, note that such lints will need to be defined in
-//! `rustc_session::lint::builtin`, not here).
 //!
-//! If you define a new `EarlyLintPass`, you will also need to add it to the
-//! `add_early_builtin!` or `add_early_builtin_with_new!` invocation in
-//! `lib.rs`. Use the former for unit-like structs and the latter for structs
-//! with a `pub fn new()`.
+//! If you define a new [`EarlyLintPass`], you will also need to add it to the
+//! [`crate::early_lint_methods!`] invocation in `lib.rs`.
 //!
-//! If you define a new `LateLintPass`, you will also need to add it to the
-//! `late_lint_methods!` invocation in `lib.rs`.
+//! If you define a new [`LateLintPass`], you will also need to add it to the
+//! [`crate::late_lint_methods!`] invocation in `lib.rs`.
 
 use std::fmt::Write;
 
@@ -73,7 +66,6 @@ use crate::{
     EarlyContext, EarlyLintPass, LateContext, LateLintPass, Level, LintContext,
     fluent_generated as fluent,
 };
-
 declare_lint! {
     /// The `while_true` lint detects `while true { }`.
     ///
@@ -241,7 +233,8 @@ declare_lint! {
     /// behavior.
     UNSAFE_CODE,
     Allow,
-    "usage of `unsafe` code and other potentially unsound constructs"
+    "usage of `unsafe` code and other potentially unsound constructs",
+    @eval_always = true
 }
 
 declare_lint_pass!(UnsafeCode => [UNSAFE_CODE]);
@@ -389,6 +382,7 @@ declare_lint! {
     report_in_external_macro
 }
 
+#[derive(Default)]
 pub struct MissingDoc;
 
 impl_lint_pass!(MissingDoc => [MISSING_DOCS]);
@@ -819,8 +813,8 @@ pub struct DeprecatedAttr {
 
 impl_lint_pass!(DeprecatedAttr => []);
 
-impl DeprecatedAttr {
-    pub fn new() -> DeprecatedAttr {
+impl Default for DeprecatedAttr {
+    fn default() -> Self {
         DeprecatedAttr { depr_attrs: deprecated_attributes() }
     }
 }
@@ -1235,7 +1229,7 @@ impl<'tcx> LateLintPass<'tcx> for UngatedAsyncFnTrackCaller {
         def_id: LocalDefId,
     ) {
         if fn_kind.asyncness().is_async()
-            && !cx.tcx.features().async_fn_track_caller
+            && !cx.tcx.features().async_fn_track_caller()
             // Now, check if the function has the `#[track_caller]` attribute
             && let Some(attr) = cx.tcx.get_attr(def_id, sym::track_caller)
         {
@@ -1424,7 +1418,7 @@ impl<'tcx> LateLintPass<'tcx> for TypeAliasBounds {
         // See also `tests/ui/const-generics/generic_const_exprs/type-alias-bounds.rs`.
         let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
         if ty.has_type_flags(ty::TypeFlags::HAS_CT_PROJECTION)
-            && cx.tcx.features().generic_const_exprs
+            && cx.tcx.features().generic_const_exprs()
         {
             return;
         }
@@ -1538,7 +1532,7 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
         use rustc_middle::ty::ClauseKind;
 
-        if cx.tcx.features().trivial_bounds {
+        if cx.tcx.features().trivial_bounds() {
             let predicates = cx.tcx.predicates_of(item.owner_id);
             for &(predicate, span) in predicates.predicates {
                 let predicate_kind_name = match predicate.kind().skip_binder() {
@@ -1554,7 +1548,9 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
                     // Ignore bounds that a user can't type
                     | ClauseKind::WellFormed(..)
                     // FIXME(generic_const_exprs): `ConstEvaluatable` can be written
-                    | ClauseKind::ConstEvaluatable(..)  => continue,
+                    | ClauseKind::ConstEvaluatable(..)
+                    // Users don't write this directly, only via another trait ref.
+                    | ty::ClauseKind::HostEffect(..) => continue,
                 };
                 if predicate.is_global() {
                     cx.emit_span_lint(TRIVIAL_BOUNDS, span, BuiltinTrivialBounds {
@@ -1892,11 +1888,11 @@ impl EarlyLintPass for KeywordIdents {
     fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::MacCall) {
         self.check_tokens(cx, &mac.args.tokens);
     }
-    fn check_ident(&mut self, cx: &EarlyContext<'_>, ident: Ident) {
+    fn check_ident(&mut self, cx: &EarlyContext<'_>, ident: &Ident) {
         if ident.name.as_str().starts_with('\'') {
             self.check_ident_token(cx, UnderMacro(false), ident.without_first_quote(), "'");
         } else {
-            self.check_ident_token(cx, UnderMacro(false), ident, "");
+            self.check_ident_token(cx, UnderMacro(false), *ident, "");
         }
     }
 }
@@ -2287,13 +2283,15 @@ declare_lint_pass!(
 impl EarlyLintPass for IncompleteInternalFeatures {
     fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &ast::Crate) {
         let features = cx.builder.features();
-        features
-            .declared_lang_features
-            .iter()
-            .map(|(name, span, _)| (name, span))
-            .chain(features.declared_lib_features.iter().map(|(name, span)| (name, span)))
-            .filter(|(&name, _)| features.incomplete(name) || features.internal(name))
-            .for_each(|(&name, &span)| {
+        let lang_features =
+            features.enabled_lang_features().iter().map(|feat| (feat.gate_name, feat.attr_sp));
+        let lib_features =
+            features.enabled_lib_features().iter().map(|feat| (feat.gate_name, feat.attr_sp));
+
+        lang_features
+            .chain(lib_features)
+            .filter(|(name, _)| features.incomplete(*name) || features.internal(*name))
+            .for_each(|(name, span)| {
                 if features.incomplete(name) {
                     let note = rustc_feature::find_feature_issue(name, GateIssue::Language)
                         .map(|n| BuiltinFeatureIssueNote { n });
@@ -2657,8 +2655,8 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// Dereferencing a null pointer causes [undefined behavior] even as a place expression,
-    /// like `&*(0 as *const i32)` or `addr_of!(*(0 as *const i32))`.
+    /// Dereferencing a null pointer causes [undefined behavior] if it is accessed
+    /// (loaded from or stored to).
     ///
     /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
     pub DEREF_NULLPTR,
@@ -2673,14 +2671,14 @@ impl<'tcx> LateLintPass<'tcx> for DerefNullPtr {
         /// test if expression is a null ptr
         fn is_null_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
             match &expr.kind {
-                rustc_hir::ExprKind::Cast(expr, ty) => {
-                    if let rustc_hir::TyKind::Ptr(_) = ty.kind {
+                hir::ExprKind::Cast(expr, ty) => {
+                    if let hir::TyKind::Ptr(_) = ty.kind {
                         return is_zero(expr) || is_null_ptr(cx, expr);
                     }
                 }
                 // check for call to `core::ptr::null` or `core::ptr::null_mut`
-                rustc_hir::ExprKind::Call(path, _) => {
-                    if let rustc_hir::ExprKind::Path(ref qpath) = path.kind {
+                hir::ExprKind::Call(path, _) => {
+                    if let hir::ExprKind::Path(ref qpath) = path.kind {
                         if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id() {
                             return matches!(
                                 cx.tcx.get_diagnostic_name(def_id),
@@ -2697,7 +2695,7 @@ impl<'tcx> LateLintPass<'tcx> for DerefNullPtr {
         /// test if expression is the literal `0`
         fn is_zero(expr: &hir::Expr<'_>) -> bool {
             match &expr.kind {
-                rustc_hir::ExprKind::Lit(lit) => {
+                hir::ExprKind::Lit(lit) => {
                     if let LitKind::Int(a, _) = lit.node {
                         return a == 0;
                     }
@@ -2707,8 +2705,16 @@ impl<'tcx> LateLintPass<'tcx> for DerefNullPtr {
             false
         }
 
-        if let rustc_hir::ExprKind::Unary(rustc_hir::UnOp::Deref, expr_deref) = expr.kind {
-            if is_null_ptr(cx, expr_deref) {
+        if let hir::ExprKind::Unary(hir::UnOp::Deref, expr_deref) = expr.kind
+            && is_null_ptr(cx, expr_deref)
+        {
+            if let hir::Node::Expr(hir::Expr {
+                kind: hir::ExprKind::AddrOf(hir::BorrowKind::Raw, ..),
+                ..
+            }) = cx.tcx.parent_hir_node(expr.hir_id)
+            {
+                // `&raw *NULL` is ok.
+            } else {
                 cx.emit_span_lint(DEREF_NULLPTR, expr.span, BuiltinDerefNullptr {
                     label: expr.span,
                 });