Use attribute parser for checking #[may_dangle] attribute

compiler/rustc_ast_lowering/src/block.rs

@@ -104,7 +104,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
         };
         let span = self.lower_span(l.span);
         let source = hir::LocalSource::Normal;
-        self.lower_attrs(hir_id, &l.attrs, l.span, Target::Statement);
+        self.lower_attrs(
+            hir_id,
+            &l.attrs,
+            l.span,
+            Target::Statement,
+            rustc_attr_ir::target::AstTarget::Local(l),
+        );
         self.arena.alloc(hir::LetStmt { hir_id, super_, ty, pat, init, els, span, source })
     }
 

compiler/rustc_ast_lowering/src/contract.rs

@@ -352,7 +352,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
         ));
 
         let attrs: rustc_ast::AttrVec = thin_vec![self.unreachable_code_attr(span)];
-        self.lower_attrs(contract_check.hir_id, &attrs, span, Target::Expression);
+        self.lower_attrs(
+            contract_check.hir_id,
+            &attrs,
+            span,
+            Target::Expression,
+            rustc_attr_ir::target::AstTarget::None,
+        );
 
         let ret_block = self.block_all(span, arena_vec![self; ret_stmt], Some(contract_check));
         self.arena.alloc(self.expr_block(self.arena.alloc(ret_block)))

compiler/rustc_ast_lowering/src/expr.rs

@@ -6,7 +6,7 @@ use rustc_ast::node_id::NodeMap;
 use rustc_ast::visit::{Visitor, walk_expr};
 use rustc_ast::*;
 use rustc_attr_ir::lang_items::LangItem;
-use rustc_attr_ir::target::Target;
+use rustc_attr_ir::target::{AstTarget, Target};
 use rustc_errors::msg;
 use rustc_hir as hir;
 use rustc_hir::HirId;
@@ -231,7 +231,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     let old_attrs =
                         self.curr_owner.attrs.get(&ex.hir_id.local_id).copied().unwrap_or(&[]);
                     let new_attrs = self
-                        .lower_attrs_vec(&e.attrs, e.span, ex.hir_id, Target::from_expr(e), None)
+                        .lower_attrs_vec(
+                            &e.attrs,
+                            e.span,
+                            ex.hir_id,
+                            Target::from_expr(e),
+                            AstTarget::None,
+                        )
                         .into_iter()
                         .chain(old_attrs.iter().cloned());
                     let new_attrs = &*self.arena.alloc_from_iter(new_attrs);
@@ -255,7 +261,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
 
         let expr_hir_id = self.lower_node_id(e.id);
-        self.lower_attrs(expr_hir_id, &e.attrs, e.span, Target::from_expr(e));
+        self.lower_attrs(expr_hir_id, &e.attrs, e.span, Target::from_expr(e), AstTarget::Expr(e));
 
         let kind = match &e.kind {
             ExprKind::Array(exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)),
@@ -795,7 +801,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let guard = arm.guard.as_ref().map(|guard| self.lower_expr(&guard.cond));
         let hir_id = self.next_id();
         let span = self.lower_span(arm.span);
-        self.lower_attrs(hir_id, &arm.attrs, arm.span, Target::Arm);
+        self.lower_attrs(hir_id, &arm.attrs, arm.span, Target::Arm, AstTarget::Arm(arm));
         let is_never_pattern = pat.is_never_pattern();
         // We need to lower the body even if it's unneeded for never pattern in match,
         // ensure that we can get HirId for DefId if need (issue #137708).
@@ -1659,7 +1665,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
     fn lower_expr_field(&mut self, f: &ExprField) -> hir::ExprField<'hir> {
         let hir_id = self.lower_node_id(f.id);
-        self.lower_attrs(hir_id, &f.attrs, f.span, Target::ExprField);
+        self.lower_attrs(hir_id, &f.attrs, f.span, Target::ExprField, AstTarget::ExprField(f));
         hir::ExprField {
             hir_id,
             ident: self.lower_ident(f.ident),
@@ -1926,7 +1932,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         //
         // Also, add the attributes to the outer returned expr node.
         let expr = self.expr_drop_temps_mut(for_span, match_expr);
-        self.lower_attrs(expr.hir_id, &e.attrs, e.span, Target::from_expr(e));
+        self.lower_attrs(expr.hir_id, &e.attrs, e.span, Target::from_expr(e), AstTarget::Expr(e));
         expr
     }
 
@@ -1974,7 +1980,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let val_ident = Ident::with_dummy_span(sym::val);
             let (val_pat, val_pat_nid) = self.pat_ident(span, val_ident);
             let val_expr = self.expr_ident(span, val_ident, val_pat_nid);
-            self.lower_attrs(val_expr.hir_id, &attrs, span, Target::Expression);
+            self.lower_attrs(
+                val_expr.hir_id,
+                &attrs,
+                span,
+                Target::Expression,
+                AstTarget::Expr(sub_expr),
+            );
             let continue_pat = self.pat_cf_continue(unstable_span, val_pat);
             self.arm(continue_pat, val_expr, try_span)
         };
@@ -2016,7 +2028,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 let ret_expr = self.checked_return(Some(from_residual_expr));
                 self.arena.alloc(self.expr(try_span, ret_expr))
             };
-            self.lower_attrs(ret_expr.hir_id, &attrs, span, Target::Expression);
+            self.lower_attrs(
+                ret_expr.hir_id,
+                &attrs,
+                span,
+                Target::Expression,
+                AstTarget::Expr(sub_expr),
+            );
 
             let break_pat = self.pat_cf_break(try_span, residual_local);
             self.arm(break_pat, ret_expr, try_span)

compiler/rustc_ast_lowering/src/expr/closure.rs

@@ -20,7 +20,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
         closure: &Closure,
     ) -> hir::Expr<'hir> {
         let expr_hir_id = self.lower_node_id(e.id);
-        let attrs = self.lower_attrs(expr_hir_id, &e.attrs, e.span, Target::from_expr(e));
+        let attrs = self.lower_attrs(
+            expr_hir_id,
+            &e.attrs,
+            e.span,
+            Target::from_expr(e),
+            rustc_attr_ir::target::AstTarget::Closure(closure),
+        );
 
         match closure.coroutine_marker {
             Some(coroutine_marker) => self.lower_expr_coroutine_closure_with_move_exprs(