Auto merge of #13180 - Jarcho:deprecated_shrink, r=flip1995

Simplify lint deprecation

A couple of small changes:
* A few deprecations were changed to renames. They all had a message similar to "this lint has been replaced by ..." which is just describing a rename.
* The website and warning message are now the same. The website description was usually just a wordier version that contained no extra information. This can be worked around if needed, but I don't think that will happen.
* The legacy deprecations have been removed. rustc should handle this since it already suggests adding the `clippy::` for all lints (deprecated or not) when they're used without it. It wouldn't be a problem to add them back in.
* The website no longer has a "view source" link for deprecated lints since they're no longer read from the HIR tree. I could store the line number, but the link seems totally useless for these lints.

This came up as part of separating the internal lints into their own crate. Both the metadata collector and the lint registration code needs access to the deprecated and renamed lists. This form lets all the deprecations be a separate crate.

r? `@flip1995`

changelog: none

2 files changed, 46 insertions, 107 deletions

diff --git a/clippy_lints/src/utils/internal_lints/lint_without_lint_pass.rs b/clippy_lints/src/utils/internal_lints/lint_without_lint_pass.rs
index 84f84781e71..df342e48d63 100644
--- a/clippy_lints/src/utils/internal_lints/lint_without_lint_pass.rs
+++ b/clippy_lints/src/utils/internal_lints/lint_without_lint_pass.rs
@@ -1,4 +1,3 @@
-use crate::utils::internal_lints::metadata_collector::is_deprecated_lint;
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
 use clippy_utils::macros::root_macro_call_first_node;
 use clippy_utils::{is_lint_allowed, match_def_path, paths};
@@ -87,82 +86,32 @@ declare_clippy_lint! {
     "found clippy lint without `clippy::version` attribute"
 }
 
-declare_clippy_lint! {
-    /// ### What it does
-    /// Checks for cases of an auto-generated deprecated lint without an updated reason,
-    /// i.e. `"default deprecation note"`.
-    ///
-    /// ### Why is this bad?
-    /// Indicates that the documentation is incomplete.
-    ///
-    /// ### Example
-    /// ```rust,ignore
-    /// declare_deprecated_lint! {
-    ///     /// ### What it does
-    ///     /// Nothing. This lint has been deprecated.
-    ///     ///
-    ///     /// ### Deprecation reason
-    ///     /// TODO
-    ///     #[clippy::version = "1.63.0"]
-    ///     pub COOL_LINT,
-    ///     "default deprecation note"
-    /// }
-    /// ```
-    ///
-    /// Use instead:
-    /// ```rust,ignore
-    /// declare_deprecated_lint! {
-    ///     /// ### What it does
-    ///     /// Nothing. This lint has been deprecated.
-    ///     ///
-    ///     /// ### Deprecation reason
-    ///     /// This lint has been replaced by `cooler_lint`
-    ///     #[clippy::version = "1.63.0"]
-    ///     pub COOL_LINT,
-    ///     "this lint has been replaced by `cooler_lint`"
-    /// }
-    /// ```
-    pub DEFAULT_DEPRECATION_REASON,
-    internal,
-    "found 'default deprecation note' in a deprecated lint declaration"
-}
-
 #[derive(Clone, Debug, Default)]
 pub struct LintWithoutLintPass {
     declared_lints: FxHashMap<Symbol, Span>,
     registered_lints: FxHashSet<Symbol>,
 }
 
-impl_lint_pass!(LintWithoutLintPass => [DEFAULT_LINT, LINT_WITHOUT_LINT_PASS, INVALID_CLIPPY_VERSION_ATTRIBUTE, MISSING_CLIPPY_VERSION_ATTRIBUTE, DEFAULT_DEPRECATION_REASON]);
+impl_lint_pass!(LintWithoutLintPass => [DEFAULT_LINT, LINT_WITHOUT_LINT_PASS, INVALID_CLIPPY_VERSION_ATTRIBUTE, MISSING_CLIPPY_VERSION_ATTRIBUTE]);
 
 impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if is_lint_allowed(cx, DEFAULT_LINT, item.hir_id())
-            || is_lint_allowed(cx, DEFAULT_DEPRECATION_REASON, item.hir_id())
-        {
+        if is_lint_allowed(cx, DEFAULT_LINT, item.hir_id()) {
             return;
         }
 
         if let hir::ItemKind::Static(ty, Mutability::Not, body_id) = item.kind {
-            let is_lint_ref_ty = is_lint_ref_type(cx, ty);
-            if is_deprecated_lint(cx, ty) || is_lint_ref_ty {
+            if is_lint_ref_type(cx, ty) {
                 check_invalid_clippy_version_attribute(cx, item);
 
                 let expr = &cx.tcx.hir().body(body_id).value;
-                let fields;
-                if is_lint_ref_ty {
-                    if let ExprKind::AddrOf(_, _, inner_exp) = expr.kind
-                        && let ExprKind::Struct(_, struct_fields, _) = inner_exp.kind
-                    {
-                        fields = struct_fields;
-                    } else {
-                        return;
-                    }
-                } else if let ExprKind::Struct(_, struct_fields, _) = expr.kind {
-                    fields = struct_fields;
+                let fields = if let ExprKind::AddrOf(_, _, inner_exp) = expr.kind
+                    && let ExprKind::Struct(_, struct_fields, _) = inner_exp.kind
+                {
+                    struct_fields
                 } else {
                     return;
-                }
+                };
 
                 let field = fields
                     .iter()
@@ -175,25 +124,15 @@ impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass {
                 }) = field.expr.kind
                 {
                     let sym_str = sym.as_str();
-                    if is_lint_ref_ty {
-                        if sym_str == "default lint description" {
-                            span_lint(
-                                cx,
-                                DEFAULT_LINT,
-                                item.span,
-                                format!("the lint `{}` has the default lint description", item.ident.name),
-                            );
-                        }
-
-                        self.declared_lints.insert(item.ident.name, item.span);
-                    } else if sym_str == "default deprecation note" {
+                    if sym_str == "default lint description" {
                         span_lint(
                             cx,
-                            DEFAULT_DEPRECATION_REASON,
+                            DEFAULT_LINT,
                             item.span,
-                            format!("the lint `{}` has the default deprecation reason", item.ident.name),
+                            format!("the lint `{}` has the default lint description", item.ident.name),
                         );
                     }
+                    self.declared_lints.insert(item.ident.name, item.span);
                 }
             }
         } else if let Some(macro_call) = root_macro_call_first_node(cx, item) {
diff --git a/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
index 7f9173df005..57f45aa3e48 100644
--- a/clippy_lints/src/utils/internal_lints/metadata_collector.rs
+++ b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
@@ -7,13 +7,12 @@
 //! during any comparison or mapping. (Please take care of this, it's not fun to spend time on such
 //! a simple mistake)
 
-use crate::renamed_lints::RENAMED_LINTS;
 use crate::utils::internal_lints::lint_without_lint_pass::{extract_clippy_version_value, is_lint_ref_type};
 use clippy_config::{get_configuration_metadata, ClippyConfiguration};
 
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::ty::{match_type, walk_ptrs_ty_depth};
-use clippy_utils::{last_path_segment, match_def_path, match_function_call, match_path, paths};
+use clippy_utils::{last_path_segment, match_function_call, match_path, paths};
 use itertools::Itertools;
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashMap;
@@ -85,7 +84,6 @@ const SUGGESTION_DIAG_METHODS: [(&str, bool); 9] = [
     ("tool_only_multipart_suggestion", true),
     ("span_suggestions", true),
 ];
-const DEPRECATED_LINT_TYPE: [&str; 3] = ["clippy_lints", "deprecated_lints", "ClippyDeprecatedLint"];
 
 /// The index of the applicability name of `paths::APPLICABILITY_VALUES`
 const APPLICABILITY_NAME_INDEX: usize = 2;
@@ -212,6 +210,13 @@ impl Drop for MetadataCollector {
 
         let mut applicability_info = std::mem::take(&mut self.applicability_info);
 
+        // Add deprecated lints
+        self.lints.extend(
+            crate::deprecated_lints::DEPRECATED
+                .iter()
+                .zip(crate::deprecated_lints::DEPRECATED_VERSION)
+                .filter_map(|((lint, reason), version)| LintMetadata::new_deprecated(lint, reason, version)),
+        );
         // Mapping the final data
         let mut lints = std::mem::take(&mut self.lints).into_sorted_vec();
         for x in &mut lints {
@@ -257,7 +262,7 @@ Please use that command to update the file and do not edit it by hand.
 #[derive(Debug, Clone, Serialize, PartialEq, Eq, PartialOrd, Ord)]
 struct LintMetadata {
     id: String,
-    id_span: SerializableSpan,
+    id_span: Option<SerializableSpan>,
     group: String,
     level: String,
     docs: String,
@@ -281,7 +286,7 @@ impl LintMetadata {
     ) -> Self {
         Self {
             id,
-            id_span,
+            id_span: Some(id_span),
             group,
             level: level.to_string(),
             version,
@@ -290,6 +295,29 @@ impl LintMetadata {
             former_ids: BTreeSet::new(),
         }
     }
+
+    fn new_deprecated(name: &str, reason: &str, version: &str) -> Option<Self> {
+        // The reason starts with a lowercase letter and end without a period.
+        // This needs to be fixed for the website.
+        let mut reason = reason.to_owned();
+        if let Some(reason) = reason.get_mut(0..1) {
+            reason.make_ascii_uppercase();
+        }
+        name.strip_prefix("clippy::").map(|name| Self {
+            id: name.into(),
+            id_span: None,
+            group: DEPRECATED_LINT_GROUP_STR.into(),
+            level: DEPRECATED_LINT_LEVEL.into(),
+            version: version.into(),
+            docs: format!(
+                "### What it does\n\n\
+                Nothing. This lint has been deprecated\n\n\
+                ### Deprecation reason\n\n{reason}.\n",
+            ),
+            applicability: None,
+            former_ids: BTreeSet::new(),
+        })
+    }
 }
 
 fn replace_produces(lint_name: &str, docs: &mut String, clippy_project_root: &Path) {
@@ -560,24 +588,6 @@ impl<'hir> LateLintPass<'hir> for MetadataCollector {
                     raw_docs,
                 ));
             }
-
-            if is_deprecated_lint(cx, ty)
-                // disallow check
-                && let lint_name = sym_to_string(item.ident.name).to_ascii_lowercase()
-                // Metadata the little we can get from a deprecated lint
-                && let Some(raw_docs) = extract_attr_docs_or_lint(cx, item)
-            {
-                let version = get_lint_version(cx, item);
-
-                self.lints.push(LintMetadata::new(
-                    lint_name,
-                    SerializableSpan::from_item(cx, item),
-                    DEPRECATED_LINT_GROUP_STR.to_string(),
-                    DEPRECATED_LINT_LEVEL,
-                    version,
-                    raw_docs,
-                ));
-            }
         }
     }
 
@@ -767,16 +777,6 @@ fn get_lint_level_from_group(lint_group: &str) -> Option<&'static str> {
         .find_map(|(group_name, group_level)| (*group_name == lint_group).then_some(*group_level))
 }
 
-pub(super) fn is_deprecated_lint(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool {
-    if let hir::TyKind::Path(ref path) = ty.kind {
-        if let hir::def::Res::Def(DefKind::Struct, def_id) = cx.qpath_res(path, ty.hir_id) {
-            return match_def_path(cx, def_id, &DEPRECATED_LINT_TYPE);
-        }
-    }
-
-    false
-}
-
 fn collect_renames(lints: &mut Vec<LintMetadata>) {
     for lint in lints {
         let mut collected = String::new();
@@ -784,7 +784,7 @@ fn collect_renames(lints: &mut Vec<LintMetadata>) {
 
         loop {
             if let Some(lint_name) = names.pop() {
-                for (k, v) in RENAMED_LINTS {
+                for (k, v) in crate::deprecated_lints::RENAMED {
                     if let Some(name) = v.strip_prefix(CLIPPY_LINT_GROUP_PREFIX)
                         && name == lint_name
                         && let Some(past_name) = k.strip_prefix(CLIPPY_LINT_GROUP_PREFIX)