Auto merge of #80524 - jyn514:unknown-tool-lints, r=flip1995,matthewjasper

Don't make tools responsible for checking unknown and renamed lints

Previously, clippy (and any other tool emitting lints) had to have their
own separate UNKNOWN_LINTS pass, because the compiler assumed any tool
lint could be valid. Now, as long as any lint starting with the tool
prefix exists, the compiler will warn when an unknown lint is present.

This may interact with the unstable `tool_lint` feature, which I don't entirely understand, but it will take the burden off those external tools to add their own lint pass, which seems like a step in the right direction to me.

- Don't mark `ineffective_unstable_trait_impl` as an internal lint
- Use clippy's more advanced lint suggestions
- Deprecate the `UNKNOWN_CLIPPY_LINTS` pass (and make it a no-op)
- Say 'unknown lint `clippy::x`' instead of 'unknown lint x'

This is tested by existing clippy tests. When https://github.com/rust-lang/rust/pull/80527 merges, it will also be tested in rustdoc tests. AFAIK there is no way to test this with rustc directly.

6 files changed, 50 insertions, 91 deletions

diff --git a/src/tools/clippy/clippy_lints/src/attrs.rs b/src/tools/clippy/clippy_lints/src/attrs.rs
index 3edbe723922..7607394b2fe 100644
--- a/src/tools/clippy/clippy_lints/src/attrs.rs
+++ b/src/tools/clippy/clippy_lints/src/attrs.rs
@@ -10,11 +10,10 @@ use rustc_errors::Applicability;
 use rustc_hir::{
     Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind,
 };
-use rustc_lint::{CheckLintNameResult, EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::source_map::Span;
 use rustc_span::sym;
 use rustc_span::symbol::{Symbol, SymbolStr};
@@ -157,33 +156,6 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for `allow`/`warn`/`deny`/`forbid` attributes with scoped clippy
-    /// lints and if those lints exist in clippy. If there is an uppercase letter in the lint name
-    /// (not the tool name) and a lowercase version of this lint exists, it will suggest to lowercase
-    /// the lint name.
-    ///
-    /// **Why is this bad?** A lint attribute with a mistyped lint name won't have an effect.
-    ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
-    /// Bad:
-    /// ```rust
-    /// #![warn(if_not_els)]
-    /// #![deny(clippy::All)]
-    /// ```
-    ///
-    /// Good:
-    /// ```rust
-    /// #![warn(if_not_else)]
-    /// #![deny(clippy::all)]
-    /// ```
-    pub UNKNOWN_CLIPPY_LINTS,
-    style,
-    "unknown_lints for scoped Clippy lints"
-}
-
-declare_clippy_lint! {
     /// **What it does:** Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category.
     ///
     /// **Why is this bad?** Restriction lints sometimes are in contrast with other lints or even go against idiomatic rust.
@@ -272,7 +244,6 @@ declare_lint_pass!(Attributes => [
     INLINE_ALWAYS,
     DEPRECATED_SEMVER,
     USELESS_ATTRIBUTE,
-    UNKNOWN_CLIPPY_LINTS,
     BLANKET_CLIPPY_RESTRICTION_LINTS,
 ]);
 
@@ -409,48 +380,9 @@ fn extract_clippy_lint(lint: &NestedMetaItem) -> Option<SymbolStr> {
 }
 
 fn check_clippy_lint_names(cx: &LateContext<'_>, ident: &str, items: &[NestedMetaItem]) {
-    let lint_store = cx.lints();
     for lint in items {
         if let Some(lint_name) = extract_clippy_lint(lint) {
-            if let CheckLintNameResult::Tool(Err((None, _))) = lint_store.check_lint_name(&lint_name, Some(sym::clippy))
-            {
-                span_lint_and_then(
-                    cx,
-                    UNKNOWN_CLIPPY_LINTS,
-                    lint.span(),
-                    &format!("unknown clippy lint: clippy::{}", lint_name),
-                    |diag| {
-                        let name_lower = lint_name.to_lowercase();
-                        let symbols = lint_store
-                            .get_lints()
-                            .iter()
-                            .map(|l| Symbol::intern(&l.name_lower()))
-                            .collect::<Vec<_>>();
-                        let sugg = find_best_match_for_name(
-                            &symbols,
-                            Symbol::intern(&format!("clippy::{}", name_lower)),
-                            None,
-                        );
-                        if lint_name.chars().any(char::is_uppercase)
-                            && lint_store.find_lints(&format!("clippy::{}", name_lower)).is_ok()
-                        {
-                            diag.span_suggestion(
-                                lint.span(),
-                                "lowercase the lint name",
-                                format!("clippy::{}", name_lower),
-                                Applicability::MachineApplicable,
-                            );
-                        } else if let Some(sugg) = sugg {
-                            diag.span_suggestion(
-                                lint.span(),
-                                "did you mean",
-                                sugg.to_string(),
-                                Applicability::MachineApplicable,
-                            );
-                        }
-                    },
-                );
-            } else if lint_name == "restriction" && ident != "allow" {
+            if lint_name == "restriction" && ident != "allow" {
                 span_lint_and_help(
                     cx,
                     BLANKET_CLIPPY_RESTRICTION_LINTS,
diff --git a/src/tools/clippy/clippy_lints/src/deprecated_lints.rs b/src/tools/clippy/clippy_lints/src/deprecated_lints.rs
index bec0c9f93a0..47b3cc3ad30 100644
--- a/src/tools/clippy/clippy_lints/src/deprecated_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/deprecated_lints.rs
@@ -163,6 +163,19 @@ declare_deprecated_lint! {
 }
 
 declare_deprecated_lint! {
+    /// **What it does:** Nothing. This lint has been deprecated.
+    ///
+    /// **Deprecation reason:** This lint has been uplifted to rustc and is now called
+    /// `panic_fmt`.
     pub PANIC_PARAMS,
     "this lint has been uplifted to rustc and is now called `panic_fmt`"
 }
+
+declare_deprecated_lint! {
+    /// **What it does:** Nothing. This lint has been deprecated.
+    ///
+    /// **Deprecation reason:** This lint has been integrated into the `unknown_lints`
+    /// rustc lint.
+    pub UNKNOWN_CLIPPY_LINTS,
+    "this lint has been integrated into the `unknown_lints` rustc lint"
+}
diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs
index 35b057d7b6a..aaa17561f06 100644
--- a/src/tools/clippy/clippy_lints/src/lib.rs
+++ b/src/tools/clippy/clippy_lints/src/lib.rs
@@ -500,6 +500,10 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         "clippy::panic_params",
         "this lint has been uplifted to rustc and is now called `panic_fmt`",
     );
+    store.register_removed(
+        "clippy::unknown_clippy_lints",
+        "this lint has been integrated into the `unknown_lints` rustc lint",
+    );
     // end deprecated lints, do not remove this comment, it’s used in `update_lints`
 
     // begin register lints, do not remove this comment, it’s used in `update_lints`
@@ -541,7 +545,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &attrs::EMPTY_LINE_AFTER_OUTER_ATTR,
         &attrs::INLINE_ALWAYS,
         &attrs::MISMATCHED_TARGET_OS,
-        &attrs::UNKNOWN_CLIPPY_LINTS,
         &attrs::USELESS_ATTRIBUTE,
         &await_holding_invalid::AWAIT_HOLDING_LOCK,
         &await_holding_invalid::AWAIT_HOLDING_REFCELL_REF,
@@ -1375,7 +1378,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&attrs::DEPRECATED_CFG_ATTR),
         LintId::of(&attrs::DEPRECATED_SEMVER),
         LintId::of(&attrs::MISMATCHED_TARGET_OS),
-        LintId::of(&attrs::UNKNOWN_CLIPPY_LINTS),
         LintId::of(&attrs::USELESS_ATTRIBUTE),
         LintId::of(&bit_mask::BAD_BIT_MASK),
         LintId::of(&bit_mask::INEFFECTIVE_BIT_MASK),
@@ -1650,7 +1652,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
         LintId::of(&assign_ops::ASSIGN_OP_PATTERN),
         LintId::of(&attrs::BLANKET_CLIPPY_RESTRICTION_LINTS),
-        LintId::of(&attrs::UNKNOWN_CLIPPY_LINTS),
         LintId::of(&blacklisted_name::BLACKLISTED_NAME),
         LintId::of(&blocks_in_if_conditions::BLOCKS_IN_IF_CONDITIONS),
         LintId::of(&collapsible_if::COLLAPSIBLE_IF),
diff --git a/src/tools/clippy/tests/ui/deprecated.rs b/src/tools/clippy/tests/ui/deprecated.rs
index e1ee8dbca2c..4a538021b98 100644
--- a/src/tools/clippy/tests/ui/deprecated.rs
+++ b/src/tools/clippy/tests/ui/deprecated.rs
@@ -9,5 +9,6 @@
 #[warn(clippy::drop_bounds)]
 #[warn(clippy::temporary_cstring_as_ptr)]
 #[warn(clippy::panic_params)]
+#[warn(clippy::unknown_clippy_lints)]
 
 fn main() {}
diff --git a/src/tools/clippy/tests/ui/deprecated.stderr b/src/tools/clippy/tests/ui/deprecated.stderr
index edbb891afe0..3429317498e 100644
--- a/src/tools/clippy/tests/ui/deprecated.stderr
+++ b/src/tools/clippy/tests/ui/deprecated.stderr
@@ -66,11 +66,17 @@ error: lint `clippy::panic_params` has been removed: `this lint has been uplifte
 LL | #[warn(clippy::panic_params)]
    |        ^^^^^^^^^^^^^^^^^^^^
 
+error: lint `clippy::unknown_clippy_lints` has been removed: `this lint has been integrated into the `unknown_lints` rustc lint`
+  --> $DIR/deprecated.rs:12:8
+   |
+LL | #[warn(clippy::unknown_clippy_lints)]
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 error: lint `clippy::unstable_as_slice` has been removed: ``Vec::as_slice` has been stabilized in 1.7`
   --> $DIR/deprecated.rs:1:8
    |
 LL | #[warn(clippy::unstable_as_slice)]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 12 previous errors
+error: aborting due to 13 previous errors
 
diff --git a/src/tools/clippy/tests/ui/unknown_clippy_lints.stderr b/src/tools/clippy/tests/ui/unknown_clippy_lints.stderr
index 1b859043bb5..94a667e5898 100644
--- a/src/tools/clippy/tests/ui/unknown_clippy_lints.stderr
+++ b/src/tools/clippy/tests/ui/unknown_clippy_lints.stderr
@@ -1,52 +1,58 @@
-error: unknown clippy lint: clippy::if_not_els
+error: unknown lint: `clippy::All`
+  --> $DIR/unknown_clippy_lints.rs:5:10
+   |
+LL | #![allow(clippy::All)]
+   |          ^^^^^^^^^^^ help: did you mean: `clippy::all`
+   |
+   = note: `-D unknown-lints` implied by `-D warnings`
+
+error: unknown lint: `clippy::CMP_NAN`
+  --> $DIR/unknown_clippy_lints.rs:6:9
+   |
+LL | #![warn(clippy::CMP_NAN)]
+   |         ^^^^^^^^^^^^^^^ help: did you mean: `clippy::cmp_nan`
+
+error: unknown lint: `clippy::if_not_els`
   --> $DIR/unknown_clippy_lints.rs:9:8
    |
 LL | #[warn(clippy::if_not_els)]
    |        ^^^^^^^^^^^^^^^^^^ help: did you mean: `clippy::if_not_else`
-   |
-   = note: `-D clippy::unknown-clippy-lints` implied by `-D warnings`
 
-error: unknown clippy lint: clippy::UNNecsaRy_cAst
+error: unknown lint: `clippy::UNNecsaRy_cAst`
   --> $DIR/unknown_clippy_lints.rs:10:8
    |
 LL | #[warn(clippy::UNNecsaRy_cAst)]
    |        ^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `clippy::unnecessary_cast`
 
-error: unknown clippy lint: clippy::useles_transute
+error: unknown lint: `clippy::useles_transute`
   --> $DIR/unknown_clippy_lints.rs:11:8
    |
 LL | #[warn(clippy::useles_transute)]
    |        ^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `clippy::useless_transmute`
 
-error: unknown clippy lint: clippy::dead_cod
+error: unknown lint: `clippy::dead_cod`
   --> $DIR/unknown_clippy_lints.rs:13:8
    |
 LL | #[warn(clippy::dead_cod)]
    |        ^^^^^^^^^^^^^^^^ help: did you mean: `clippy::drop_copy`
 
-error: unknown clippy lint: clippy::unused_colle
+error: unknown lint: `clippy::unused_colle`
   --> $DIR/unknown_clippy_lints.rs:15:8
    |
 LL | #[warn(clippy::unused_colle)]
    |        ^^^^^^^^^^^^^^^^^^^^ help: did you mean: `clippy::unused_self`
 
-error: unknown clippy lint: clippy::const_static_lifetim
+error: unknown lint: `clippy::const_static_lifetim`
   --> $DIR/unknown_clippy_lints.rs:17:8
    |
 LL | #[warn(clippy::const_static_lifetim)]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `clippy::redundant_static_lifetimes`
 
-error: unknown clippy lint: clippy::All
+error: unknown lint: `clippy::All`
   --> $DIR/unknown_clippy_lints.rs:5:10
    |
 LL | #![allow(clippy::All)]
-   |          ^^^^^^^^^^^ help: lowercase the lint name: `clippy::all`
-
-error: unknown clippy lint: clippy::CMP_NAN
-  --> $DIR/unknown_clippy_lints.rs:6:9
-   |
-LL | #![warn(clippy::CMP_NAN)]
-   |         ^^^^^^^^^^^^^^^ help: lowercase the lint name: `clippy::cmp_nan`
+   |          ^^^^^^^^^^^ help: did you mean: `clippy::all`
 
-error: aborting due to 8 previous errors
+error: aborting due to 9 previous errors