Rollup merge of #90826 - petrochenkov:binattr, r=cjgillot

rustc_feature: Convert `BuiltinAttribute` from tuple to a struct

The tuple starts having too many fields.
Noticed while reviewing https://github.com/rust-lang/rust/pull/88681.

6 files changed, 62 insertions, 44 deletions

diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
index f45a79f026f..b011a2e8117 100644
--- a/compiler/rustc_ast_passes/src/feature_gate.rs
+++ b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -3,7 +3,7 @@ use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor};
 use rustc_ast::{AssocTyConstraint, AssocTyConstraintKind, NodeId};
 use rustc_ast::{PatKind, RangeEnd, VariantData};
 use rustc_errors::struct_span_err;
-use rustc_feature::{AttributeGate, BUILTIN_ATTRIBUTE_MAP};
+use rustc_feature::{AttributeGate, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
 use rustc_feature::{Features, GateIssue};
 use rustc_session::parse::{feature_err, feature_err_issue};
 use rustc_session::Session;
@@ -301,11 +301,14 @@ impl<'a> PostExpansionVisitor<'a> {
 
 impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
     fn visit_attribute(&mut self, attr: &ast::Attribute) {
-        let attr_info =
-            attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)).map(|a| **a);
+        let attr_info = attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name));
         // Check feature gates for built-in attributes.
-        if let Some((.., AttributeGate::Gated(_, name, descr, has_feature))) = attr_info {
-            gate_feature_fn!(self, has_feature, attr.span, name, descr);
+        if let Some(BuiltinAttribute {
+            gate: AttributeGate::Gated(_, name, descr, has_feature),
+            ..
+        }) = attr_info
+        {
+            gate_feature_fn!(self, has_feature, attr.span, *name, descr);
         }
         // Check unstable flavors of the `#[doc]` attribute.
         if attr.has_name(sym::doc) {
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 33188d375f5..7212bbf38c7 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -115,16 +115,26 @@ macro_rules! template {
 
 macro_rules! ungated {
     ($attr:ident, $typ:expr, $tpl:expr $(,)?) => {
-        (sym::$attr, $typ, $tpl, Ungated)
+        BuiltinAttribute { name: sym::$attr, type_: $typ, template: $tpl, gate: Ungated }
     };
 }
 
 macro_rules! gated {
     ($attr:ident, $typ:expr, $tpl:expr, $gate:ident, $msg:expr $(,)?) => {
-        (sym::$attr, $typ, $tpl, Gated(Stability::Unstable, sym::$gate, $msg, cfg_fn!($gate)))
+        BuiltinAttribute {
+            name: sym::$attr,
+            type_: $typ,
+            template: $tpl,
+            gate: Gated(Stability::Unstable, sym::$gate, $msg, cfg_fn!($gate)),
+        }
     };
     ($attr:ident, $typ:expr, $tpl:expr, $msg:expr $(,)?) => {
-        (sym::$attr, $typ, $tpl, Gated(Stability::Unstable, sym::$attr, $msg, cfg_fn!($attr)))
+        BuiltinAttribute {
+            name: sym::$attr,
+            type_: $typ,
+            template: $tpl,
+            gate: Gated(Stability::Unstable, sym::$attr, $msg, cfg_fn!($attr)),
+        }
     };
 }
 
@@ -143,12 +153,12 @@ macro_rules! rustc_attr {
         )
     };
     ($attr:ident, $typ:expr, $tpl:expr, $msg:expr $(,)?) => {
-        (
-            sym::$attr,
-            $typ,
-            $tpl,
-            Gated(Stability::Unstable, sym::rustc_attrs, $msg, cfg_fn!(rustc_attrs)),
-        )
+        BuiltinAttribute {
+            name: sym::$attr,
+            type_: $typ,
+            template: $tpl,
+            gate: Gated(Stability::Unstable, sym::rustc_attrs, $msg, cfg_fn!(rustc_attrs)),
+        }
     };
 }
 
@@ -161,7 +171,12 @@ macro_rules! experimental {
 const IMPL_DETAIL: &str = "internal implementation detail";
 const INTERNAL_UNSTABLE: &str = "this is an internal attribute that will never be stable";
 
-pub type BuiltinAttribute = (Symbol, AttributeType, AttributeTemplate, AttributeGate);
+pub struct BuiltinAttribute {
+    pub name: Symbol,
+    pub type_: AttributeType,
+    pub template: AttributeTemplate,
+    pub gate: AttributeGate,
+}
 
 /// Attributes that have a special meaning to rustc or rustdoc.
 #[rustfmt::skip]
@@ -290,9 +305,11 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     ),
 
     // Plugins:
-    (
-        sym::plugin, CrateLevel, template!(List: "name"),
-        Gated(
+    BuiltinAttribute {
+        name: sym::plugin,
+        type_: CrateLevel,
+        template: template!(List: "name"),
+        gate: Gated(
             Stability::Deprecated(
                 "https://github.com/rust-lang/rust/pull/64675",
                 Some("may be removed in a future compiler version"),
@@ -300,8 +317,8 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
             sym::plugin,
             "compiler plugins are deprecated",
             cfg_fn!(plugin)
-        )
-    ),
+        ),
+    },
 
     // Testing:
     gated!(allow_fail, Normal, template!(Word), experimental!(allow_fail)),
@@ -497,17 +514,17 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         lang, Normal, template!(NameValueStr: "name"), lang_items,
         "language items are subject to change",
     ),
-    (
-        sym::rustc_diagnostic_item,
-        Normal,
-        template!(NameValueStr: "name"),
-        Gated(
+    BuiltinAttribute {
+        name: sym::rustc_diagnostic_item,
+        type_: Normal,
+        template: template!(NameValueStr: "name"),
+        gate: Gated(
             Stability::Unstable,
             sym::rustc_attrs,
             "diagnostic items compiler internal support for linting",
             cfg_fn!(rustc_attrs),
         ),
-    ),
+    },
     gated!(
         // Used in resolve:
         prelude_import, Normal, template!(Word),
@@ -601,7 +618,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
 ];
 
 pub fn deprecated_attributes() -> Vec<&'static BuiltinAttribute> {
-    BUILTIN_ATTRIBUTES.iter().filter(|(.., gate)| gate.is_deprecated()).collect()
+    BUILTIN_ATTRIBUTES.iter().filter(|attr| attr.gate.is_deprecated()).collect()
 }
 
 pub fn is_builtin_attr_name(name: Symbol) -> bool {
@@ -612,8 +629,8 @@ pub static BUILTIN_ATTRIBUTE_MAP: SyncLazy<FxHashMap<Symbol, &BuiltinAttribute>>
     SyncLazy::new(|| {
         let mut map = FxHashMap::default();
         for attr in BUILTIN_ATTRIBUTES.iter() {
-            if map.insert(attr.0, attr).is_some() {
-                panic!("duplicate builtin attribute `{}`", attr.0);
+            if map.insert(attr.name, attr).is_some() {
+                panic!("duplicate builtin attribute `{}`", attr.name);
             }
         }
         map
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 6548cdc0fdc..f2e4e70a197 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -32,8 +32,7 @@ use rustc_ast_pretty::pprust::{self, expr_to_string};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
-use rustc_feature::{deprecated_attributes, AttributeGate, AttributeTemplate, AttributeType};
-use rustc_feature::{GateIssue, Stability};
+use rustc_feature::{deprecated_attributes, AttributeGate, BuiltinAttribute, GateIssue, Stability};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
@@ -959,7 +958,7 @@ impl EarlyLintPass for AnonymousParameters {
 pub struct DeprecatedAttr {
     // This is not free to compute, so we want to keep it around, rather than
     // compute it for every attribute.
-    depr_attrs: Vec<&'static (Symbol, AttributeType, AttributeTemplate, AttributeGate)>,
+    depr_attrs: Vec<&'static BuiltinAttribute>,
 }
 
 impl_lint_pass!(DeprecatedAttr => []);
@@ -990,14 +989,14 @@ fn lint_deprecated_attr(
 
 impl EarlyLintPass for DeprecatedAttr {
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &ast::Attribute) {
-        for &&(n, _, _, ref g) in &self.depr_attrs {
-            if attr.ident().map(|ident| ident.name) == Some(n) {
+        for BuiltinAttribute { name, gate, .. } in &self.depr_attrs {
+            if attr.ident().map(|ident| ident.name) == Some(*name) {
                 if let &AttributeGate::Gated(
                     Stability::Deprecated(link, suggestion),
                     name,
                     reason,
                     _,
-                ) = g
+                ) = gate
                 {
                     let msg =
                         format!("use of deprecated attribute `{}`: {}. See {}", name, reason, link);
diff --git a/compiler/rustc_parse/src/validate_attr.rs b/compiler/rustc_parse/src/validate_attr.rs
index 2aa20d02c88..4781813ee8e 100644
--- a/compiler/rustc_parse/src/validate_attr.rs
+++ b/compiler/rustc_parse/src/validate_attr.rs
@@ -5,7 +5,7 @@ use crate::parse_in;
 use rustc_ast::tokenstream::{DelimSpan, TokenTree};
 use rustc_ast::{self as ast, Attribute, MacArgs, MacDelimiter, MetaItem, MetaItemKind};
 use rustc_errors::{Applicability, FatalError, PResult};
-use rustc_feature::{AttributeTemplate, BUILTIN_ATTRIBUTE_MAP};
+use rustc_feature::{AttributeTemplate, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
 use rustc_session::lint::builtin::ILL_FORMED_ATTRIBUTE_INPUT;
 use rustc_session::parse::ParseSess;
 use rustc_span::{sym, Symbol};
@@ -15,14 +15,13 @@ pub fn check_meta(sess: &ParseSess, attr: &Attribute) {
         return;
     }
 
-    let attr_info =
-        attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)).map(|a| **a);
+    let attr_info = attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name));
 
     // Check input tokens for built-in and key-value attributes.
     match attr_info {
         // `rustc_dummy` doesn't have any restrictions specific to built-in attributes.
-        Some((name, _, template, _)) if name != sym::rustc_dummy => {
-            check_builtin_attribute(sess, attr, name, template)
+        Some(BuiltinAttribute { name, template, .. }) if *name != sym::rustc_dummy => {
+            check_builtin_attribute(sess, attr, *name, *template)
         }
         _ if let MacArgs::Eq(..) = attr.get_normal_item().args => {
             // All key-value attributes are restricted to meta-item syntax.
@@ -168,7 +167,7 @@ pub fn emit_fatal_malformed_builtin_attribute(
     attr: &Attribute,
     name: Symbol,
 ) -> ! {
-    let template = BUILTIN_ATTRIBUTE_MAP.get(&name).expect("builtin attr defined").2;
+    let template = BUILTIN_ATTRIBUTE_MAP.get(&name).expect("builtin attr defined").template;
     emit_malformed_attribute(sess, attr, name, template);
     // This is fatal, otherwise it will likely cause a cascade of other errors
     // (and an error here is expected to be very rare).
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 596d13d2d9a..129a9fdab82 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -11,7 +11,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, NestedMetaItem};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{pluralize, struct_span_err, Applicability};
-use rustc_feature::{AttributeType, BUILTIN_ATTRIBUTE_MAP};
+use rustc_feature::{AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
@@ -148,7 +148,7 @@ impl CheckAttrVisitor<'tcx> {
             }
 
             if hir_id != CRATE_HIR_ID {
-                if let Some((_, AttributeType::CrateLevel, ..)) =
+                if let Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) =
                     attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name))
                 {
                     self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| {
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 094a5ed7bfb..c46a18e5103 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -731,7 +731,7 @@ impl<'a> Resolver<'a> {
                         suggestions.extend(
                             BUILTIN_ATTRIBUTES
                                 .iter()
-                                .map(|(name, ..)| TypoSuggestion::typo_from_res(*name, res)),
+                                .map(|attr| TypoSuggestion::typo_from_res(attr.name, res)),
                         );
                     }
                 }