Auto merge of #96745 - ehuss:even-more-attribute-validation, r=cjgillot

Visit attributes in more places.

This adds 3 loosely related changes (I can split PRs if desired):

- Attribute checking on pattern struct fields.
- Attribute checking on struct expression fields.
- Lint level visiting on pattern struct fields, struct expression fields, and generic parameters.

There are still some lints which ignore lint levels in various positions. This is a consequence of how the lints themselves are implemented. For example, lint levels on associated consts don't work with `unused_braces`.

compiler/rustc_ast_lowering/src/expr.rs

@@ -1406,8 +1406,10 @@ 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);
         hir::ExprField {
-            hir_id: self.next_id(),
+            hir_id,
             ident: self.lower_ident(f.ident),
             expr: self.lower_expr(&f.expr),
             span: self.lower_span(f.span),

compiler/rustc_ast_lowering/src/index.rs

@@ -199,6 +199,13 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
+    fn visit_pat_field(&mut self, field: &'hir PatField<'hir>) {
+        self.insert(field.span, field.hir_id, Node::PatField(field));
+        self.with_parent(field.hir_id, |this| {
+            intravisit::walk_pat_field(this, field);
+        });
+    }
+
     fn visit_arm(&mut self, arm: &'hir Arm<'hir>) {
         let node = Node::Arm(arm);
 
@@ -225,6 +232,13 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
+    fn visit_expr_field(&mut self, field: &'hir ExprField<'hir>) {
+        self.insert(field.span, field.hir_id, Node::ExprField(field));
+        self.with_parent(field.hir_id, |this| {
+            intravisit::walk_expr_field(this, field);
+        });
+    }
+
     fn visit_stmt(&mut self, stmt: &'hir Stmt<'hir>) {
         self.insert(stmt.span, stmt.hir_id, Node::Stmt(stmt));
 

compiler/rustc_ast_lowering/src/pat.rs

@@ -64,12 +64,17 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                             ImplTraitContext::Disallowed(ImplTraitPosition::Path),
                         );
 
-                        let fs = self.arena.alloc_from_iter(fields.iter().map(|f| hir::PatField {
-                            hir_id: self.next_id(),
-                            ident: self.lower_ident(f.ident),
-                            pat: self.lower_pat(&f.pat),
-                            is_shorthand: f.is_shorthand,
-                            span: self.lower_span(f.span),
+                        let fs = self.arena.alloc_from_iter(fields.iter().map(|f| {
+                            let hir_id = self.lower_node_id(f.id);
+                            self.lower_attrs(hir_id, &f.attrs);
+
+                            hir::PatField {
+                                hir_id,
+                                ident: self.lower_ident(f.ident),
+                                pat: self.lower_pat(&f.pat),
+                                is_shorthand: f.is_shorthand,
+                                span: self.lower_span(f.span),
+                            }
                         }));
                         break hir::PatKind::Struct(qpath, fs, etc);
                     }

compiler/rustc_hir/src/hir.rs

@@ -3332,12 +3332,14 @@ pub enum Node<'hir> {
     Field(&'hir FieldDef<'hir>),
     AnonConst(&'hir AnonConst),
     Expr(&'hir Expr<'hir>),
+    ExprField(&'hir ExprField<'hir>),
     Stmt(&'hir Stmt<'hir>),
     PathSegment(&'hir PathSegment<'hir>),
     Ty(&'hir Ty<'hir>),
     TypeBinding(&'hir TypeBinding<'hir>),
     TraitRef(&'hir TraitRef<'hir>),
     Pat(&'hir Pat<'hir>),
+    PatField(&'hir PatField<'hir>),
     Arm(&'hir Arm<'hir>),
     Block(&'hir Block<'hir>),
     Local(&'hir Local<'hir>),
@@ -3388,6 +3390,8 @@ impl<'hir> Node<'hir> {
             | Node::Block(..)
             | Node::Ctor(..)
             | Node::Pat(..)
+            | Node::PatField(..)
+            | Node::ExprField(..)
             | Node::Arm(..)
             | Node::Local(..)
             | Node::Crate(..)

compiler/rustc_hir/src/intravisit.rs

@@ -325,6 +325,9 @@ pub trait Visitor<'v>: Sized {
     fn visit_pat(&mut self, p: &'v Pat<'v>) {
         walk_pat(self, p)
     }
+    fn visit_pat_field(&mut self, f: &'v PatField<'v>) {
+        walk_pat_field(self, f)
+    }
     fn visit_array_length(&mut self, len: &'v ArrayLen) {
         walk_array_len(self, len)
     }
@@ -337,6 +340,9 @@ pub trait Visitor<'v>: Sized {
     fn visit_let_expr(&mut self, lex: &'v Let<'v>) {
         walk_let_expr(self, lex)
     }
+    fn visit_expr_field(&mut self, field: &'v ExprField<'v>) {
+        walk_expr_field(self, field)
+    }
     fn visit_ty(&mut self, t: &'v Ty<'v>) {
         walk_ty(self, t)
     }
@@ -761,11 +767,7 @@ pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
         }
         PatKind::Struct(ref qpath, fields, _) => {
             visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
-            for field in fields {
-                visitor.visit_id(field.hir_id);
-                visitor.visit_ident(field.ident);
-                visitor.visit_pat(&field.pat)
-            }
+            walk_list!(visitor, visit_pat_field, fields);
         }
         PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
         PatKind::Tuple(tuple_elements, _) => {
@@ -792,6 +794,12 @@ pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
     }
 }
 
+pub fn walk_pat_field<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v PatField<'v>) {
+    visitor.visit_id(field.hir_id);
+    visitor.visit_ident(field.ident);
+    visitor.visit_pat(&field.pat)
+}
+
 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
     visitor.visit_id(foreign_item.hir_id());
     visitor.visit_ident(foreign_item.ident);
@@ -1059,6 +1067,12 @@ pub fn walk_let_expr<'v, V: Visitor<'v>>(visitor: &mut V, let_expr: &'v Let<'v>)
     walk_list!(visitor, visit_ty, let_expr.ty);
 }
 
+pub fn walk_expr_field<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v ExprField<'v>) {
+    visitor.visit_id(field.hir_id);
+    visitor.visit_ident(field.ident);
+    visitor.visit_expr(&field.expr)
+}
+
 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
     visitor.visit_id(expression.hir_id);
     match expression.kind {
@@ -1073,11 +1087,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
         }
         ExprKind::Struct(ref qpath, fields, ref optional_base) => {
             visitor.visit_qpath(qpath, expression.hir_id, expression.span);
-            for field in fields {
-                visitor.visit_id(field.hir_id);
-                visitor.visit_ident(field.ident);
-                visitor.visit_expr(&field.expr)
-            }
+            walk_list!(visitor, visit_expr_field, fields);
             walk_list!(visitor, visit_expr, optional_base);
         }
         ExprKind::Tup(subexpressions) => {

compiler/rustc_hir/src/target.rs

@@ -56,6 +56,8 @@ pub enum Target {
     GenericParam(GenericParamKind),
     MacroDef,
     Param,
+    PatField,
+    ExprField,
 }
 
 impl Display for Target {
@@ -183,6 +185,8 @@ impl Target {
             },
             Target::MacroDef => "macro def",
             Target::Param => "function param",
+            Target::PatField => "pattern field",
+            Target::ExprField => "struct field",
         }
     }
 }

compiler/rustc_hir_pretty/src/lib.rs

@@ -83,12 +83,14 @@ impl<'a> State<'a> {
             Node::Variant(a) => self.print_variant(a),
             Node::AnonConst(a) => self.print_anon_const(a),
             Node::Expr(a) => self.print_expr(a),
+            Node::ExprField(a) => self.print_expr_field(&a),
             Node::Stmt(a) => self.print_stmt(a),
             Node::PathSegment(a) => self.print_path_segment(a),
             Node::Ty(a) => self.print_type(a),
             Node::TypeBinding(a) => self.print_type_binding(a),
             Node::TraitRef(a) => self.print_trait_ref(a),
             Node::Pat(a) => self.print_pat(a),
+            Node::PatField(a) => self.print_patfield(&a),
             Node::Arm(a) => self.print_arm(a),
             Node::Infer(_) => self.word("_"),
             Node::Block(a) => {
@@ -1127,20 +1129,7 @@ impl<'a> State<'a> {
     ) {
         self.print_qpath(qpath, true);
         self.word("{");
-        self.commasep_cmnt(
-            Consistent,
-            fields,
-            |s, field| {
-                s.ibox(INDENT_UNIT);
-                if !field.is_shorthand {
-                    s.print_ident(field.ident);
-                    s.word_space(":");
-                }
-                s.print_expr(field.expr);
-                s.end()
-            },
-            |f| f.span,
-        );
+        self.commasep_cmnt(Consistent, fields, |s, field| s.print_expr_field(field), |f| f.span);
         if let Some(expr) = wth {
             self.ibox(INDENT_UNIT);
             if !fields.is_empty() {
@@ -1157,6 +1146,20 @@ impl<'a> State<'a> {
         self.word("}");
     }
 
+    fn print_expr_field(&mut self, field: &hir::ExprField<'_>) {
+        if self.attrs(field.hir_id).is_empty() {
+            self.space();
+        }
+        self.cbox(INDENT_UNIT);
+        self.print_outer_attributes(&self.attrs(field.hir_id));
+        if !field.is_shorthand {
+            self.print_ident(field.ident);
+            self.word_space(":");
+        }
+        self.print_expr(&field.expr);
+        self.end()
+    }
+
     fn print_expr_tup(&mut self, exprs: &[hir::Expr<'_>]) {
         self.popen();
         self.commasep_exprs(Inconsistent, exprs);
@@ -1803,20 +1806,7 @@ impl<'a> State<'a> {
                 if !empty {
                     self.space();
                 }
-                self.commasep_cmnt(
-                    Consistent,
-                    fields,
-                    |s, f| {
-                        s.cbox(INDENT_UNIT);
-                        if !f.is_shorthand {
-                            s.print_ident(f.ident);
-                            s.word_nbsp(":");
-                        }
-                        s.print_pat(f.pat);
-                        s.end()
-                    },
-                    |f| f.pat.span,
-                );
+                self.commasep_cmnt(Consistent, &fields, |s, f| s.print_patfield(f), |f| f.pat.span);
                 if etc {
                     if !fields.is_empty() {
                         self.word_space(",");
@@ -1911,6 +1901,20 @@ impl<'a> State<'a> {
         self.ann.post(self, AnnNode::Pat(pat))
     }
 
+    pub fn print_patfield(&mut self, field: &hir::PatField<'_>) {
+        if self.attrs(field.hir_id).is_empty() {
+            self.space();
+        }
+        self.cbox(INDENT_UNIT);
+        self.print_outer_attributes(&self.attrs(field.hir_id));
+        if !field.is_shorthand {
+            self.print_ident(field.ident);
+            self.word_nbsp(":");
+        }
+        self.print_pat(field.pat);
+        self.end();
+    }
+
     pub fn print_param(&mut self, arg: &hir::Param<'_>) {
         self.print_outer_attributes(self.attrs(arg.hir_id));
         self.print_pat(arg.pat);

compiler/rustc_lint/src/early.rs

@@ -101,6 +101,12 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
         run_early_pass!(self, check_pat_post, p);
     }
 
+    fn visit_pat_field(&mut self, field: &'a ast::PatField) {
+        self.with_lint_attrs(field.id, &field.attrs, |cx| {
+            ast_visit::walk_pat_field(cx, field);
+        });
+    }
+
     fn visit_anon_const(&mut self, c: &'a ast::AnonConst) {
         self.check_id(c.id);
         ast_visit::walk_anon_const(self, c);
@@ -219,9 +225,10 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
     }
 
     fn visit_generic_param(&mut self, param: &'a ast::GenericParam) {
-        run_early_pass!(self, check_generic_param, param);
-        self.check_id(param.id);
-        ast_visit::walk_generic_param(self, param);
+        self.with_lint_attrs(param.id, &param.attrs, |cx| {
+            run_early_pass!(cx, check_generic_param, param);
+            ast_visit::walk_generic_param(cx, param);
+        });
     }
 
     fn visit_generics(&mut self, g: &'a ast::Generics) {

compiler/rustc_lint/src/levels.rs

@@ -766,6 +766,12 @@ impl<'tcx> intravisit::Visitor<'tcx> for LintLevelMapBuilder<'tcx> {
         })
     }
 
+    fn visit_expr_field(&mut self, field: &'tcx hir::ExprField<'tcx>) {
+        self.with_lint_attrs(field.hir_id, |builder| {
+            intravisit::walk_expr_field(builder, field);
+        })
+    }
+
     fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
         self.with_lint_attrs(s.hir_id, |builder| {
             intravisit::walk_field_def(builder, s);
@@ -801,6 +807,18 @@ impl<'tcx> intravisit::Visitor<'tcx> for LintLevelMapBuilder<'tcx> {
             intravisit::walk_impl_item(builder, impl_item);
         });
     }
+
+    fn visit_pat_field(&mut self, field: &'tcx hir::PatField<'tcx>) {
+        self.with_lint_attrs(field.hir_id, |builder| {
+            intravisit::walk_pat_field(builder, field);
+        })
+    }
+
+    fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam<'tcx>) {
+        self.with_lint_attrs(p.hir_id, |builder| {
+            intravisit::walk_generic_param(builder, p);
+        });
+    }
 }
 
 pub fn provide(providers: &mut Providers) {

compiler/rustc_lint/src/nonstandard_style.rs

@@ -437,19 +437,14 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
 
     fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
         if let PatKind::Binding(_, hid, ident, _) = p.kind {
-            if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
+            if let hir::Node::PatField(field) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
             {
-                if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
-                    if field_pats
-                        .iter()
-                        .any(|field| !field.is_shorthand && field.pat.hir_id == p.hir_id)
-                    {
-                        // Only check if a new name has been introduced, to avoid warning
-                        // on both the struct definition and this pattern.
-                        self.check_snake_case(cx, "variable", &ident);
-                    }
-                    return;
+                if !field.is_shorthand {
+                    // Only check if a new name has been introduced, to avoid warning
+                    // on both the struct definition and this pattern.
+                    self.check_snake_case(cx, "variable", &ident);
                 }
+                return;
             }
             self.check_snake_case(cx, "variable", &ident);
         }