feat(rustc_lint): make CheckLintName respect lint level

compiler/rustc_lint/messages.ftl

@@ -156,15 +156,6 @@ lint_builtin_unused_doc_comment = unused doc comment
 lint_builtin_while_true = denote infinite loops with `loop {"{"} ... {"}"}`
     .suggestion = use `loop`
 
-lint_check_name_deprecated = lint name `{$lint_name}` is deprecated and does not have an effect anymore. Use: {$new_name}
-
-lint_check_name_removed = lint `{$lint_name}` has been removed: {$reason}
-
-lint_check_name_renamed = lint `{$lint_name}` has been renamed to `{$replace}`
-
-lint_check_name_unknown = unknown lint: `{$lint_name}`
-    .help = did you mean: `{$suggestion}`
-
 lint_check_name_unknown_tool = unknown lint tool: `{$tool_name}`
 
 lint_command_line_source = `forbid` lint level was set on command line
@@ -187,6 +178,7 @@ lint_default_source = `forbid` lint level is the default for {$id}
 lint_deprecated_lint_name =
     lint name `{$name}` is deprecated and may not have an effect in the future.
     .suggestion = change it to
+    .help = change it to {$replace}
 
 lint_diag_out_of_impl =
     diagnostics should only be created in `IntoDiagnostic`/`AddToDiagnostic` impls
@@ -528,6 +520,7 @@ lint_unknown_gated_lint =
 lint_unknown_lint =
     unknown lint: `{$name}`
     .suggestion = did you mean
+    .help = did you mean: `{$replace}`
 
 lint_unknown_tool_in_scoped_lint = unknown tool name `{$tool_name}` found in scoped lint: `{$tool_name}::{$lint_name}`
     .help = add `#![register_tool({$tool_name})]` to the crate root

compiler/rustc_lint/src/errors.rs

@@ -1,7 +1,5 @@
 use crate::fluent_generated as fluent;
-use rustc_errors::{
-    AddToDiagnostic, Diagnostic, ErrorGuaranteed, Handler, IntoDiagnostic, SubdiagnosticMessage,
-};
+use rustc_errors::{AddToDiagnostic, Diagnostic, SubdiagnosticMessage};
 use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_session::lint::Level;
 use rustc_span::{Span, Symbol};
@@ -102,60 +100,10 @@ pub struct UnsupportedGroup {
     pub lint_group: String,
 }
 
-pub struct CheckNameUnknown<'a> {
-    pub lint_name: &'a str,
-    pub suggestion: Option<Symbol>,
-    pub sub: RequestedLevel<'a>,
-}
-
-impl IntoDiagnostic<'_> for CheckNameUnknown<'_> {
-    fn into_diagnostic(
-        self,
-        handler: &Handler,
-    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = handler.struct_err(fluent::lint_check_name_unknown);
-        diag.code(rustc_errors::error_code!(E0602));
-        if let Some(suggestion) = self.suggestion {
-            diag.help(fluent::lint_help);
-            diag.set_arg("suggestion", suggestion);
-        }
-        diag.set_arg("lint_name", self.lint_name);
-        diag.subdiagnostic(self.sub);
-        diag
-    }
-}
-
 #[derive(Diagnostic)]
 #[diag(lint_check_name_unknown_tool, code = "E0602")]
 pub struct CheckNameUnknownTool<'a> {
     pub tool_name: Symbol,
     #[subdiagnostic]
     pub sub: RequestedLevel<'a>,
 }
-
-#[derive(Diagnostic)]
-#[diag(lint_check_name_renamed)]
-pub struct CheckNameRenamed<'a> {
-    pub lint_name: &'a str,
-    pub replace: &'a str,
-    #[subdiagnostic]
-    pub sub: RequestedLevel<'a>,
-}
-
-#[derive(Diagnostic)]
-#[diag(lint_check_name_removed)]
-pub struct CheckNameRemoved<'a> {
-    pub lint_name: &'a str,
-    pub reason: &'a str,
-    #[subdiagnostic]
-    pub sub: RequestedLevel<'a>,
-}
-
-#[derive(Diagnostic)]
-#[diag(lint_check_name_deprecated)]
-pub struct CheckNameDeprecated<'a> {
-    pub lint_name: &'a str,
-    pub new_name: &'a str,
-    #[subdiagnostic]
-    pub sub: RequestedLevel<'a>,
-}

compiler/rustc_lint/src/levels.rs

@@ -1,6 +1,7 @@
-use crate::errors::{
-    CheckNameDeprecated, CheckNameRemoved, CheckNameRenamed, CheckNameUnknown,
-    CheckNameUnknownTool, RequestedLevel, UnsupportedGroup,
+use crate::errors::{CheckNameUnknownTool, RequestedLevel, UnsupportedGroup};
+use crate::lints::{
+    DeprecatedLintNameFromCommandLine, RemovedLintFromCommandLine, RenamedLintFromCommandLine,
+    UnknownLintFromCommandLine,
 };
 use crate::{
     builtin::MISSING_DOCS,
@@ -564,33 +565,32 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                 self.sess.emit_err(UnsupportedGroup { lint_group: crate::WARNINGS.name_lower() });
             }
             match self.store.check_lint_name(lint_name_only, tool_name, self.registered_tools) {
-                CheckLintNameResult::Renamed(replace) => {
-                    self.sess.emit_warning(CheckNameRenamed {
-                        lint_name,
-                        replace: &replace,
-                        sub: RequestedLevel { level, lint_name },
-                    });
+                CheckLintNameResult::Renamed(ref replace) => {
+                    let name = lint_name.as_str();
+                    let suggestion = RenamedLintSuggestion::WithoutSpan { replace };
+                    let requested_level = RequestedLevel { level, lint_name };
+                    let lint = RenamedLintFromCommandLine { name, suggestion, requested_level };
+                    self.emit_lint(RENAMED_AND_REMOVED_LINTS, lint);
                 }
-                CheckLintNameResult::Removed(reason) => {
-                    self.sess.emit_warning(CheckNameRemoved {
-                        lint_name,
-                        reason: &reason,
-                        sub: RequestedLevel { level, lint_name },
-                    });
+                CheckLintNameResult::Removed(ref reason) => {
+                    let name = lint_name.as_str();
+                    let requested_level = RequestedLevel { level, lint_name };
+                    let lint = RemovedLintFromCommandLine { name, reason, requested_level };
+                    self.emit_lint(RENAMED_AND_REMOVED_LINTS, lint);
                 }
                 CheckLintNameResult::NoLint(suggestion) => {
-                    self.sess.emit_err(CheckNameUnknown {
-                        lint_name,
-                        suggestion,
-                        sub: RequestedLevel { level, lint_name },
-                    });
+                    let name = lint_name.clone();
+                    let suggestion =
+                        suggestion.map(|replace| UnknownLintSuggestion::WithoutSpan { replace });
+                    let requested_level = RequestedLevel { level, lint_name };
+                    let lint = UnknownLintFromCommandLine { name, suggestion, requested_level };
+                    self.emit_lint(UNKNOWN_LINTS, lint);
                 }
-                CheckLintNameResult::Tool(Err((Some(_), new_name))) => {
-                    self.sess.emit_warning(CheckNameDeprecated {
-                        lint_name,
-                        new_name: &new_name,
-                        sub: RequestedLevel { level, lint_name },
-                    });
+                CheckLintNameResult::Tool(Err((Some(_), ref replace))) => {
+                    let name = lint_name.clone();
+                    let requested_level = RequestedLevel { level, lint_name };
+                    let lint = DeprecatedLintNameFromCommandLine { name, replace, requested_level };
+                    self.emit_lint(RENAMED_AND_REMOVED_LINTS, lint);
                 }
                 CheckLintNameResult::NoTool => {
                     self.sess.emit_err(CheckNameUnknownTool {
@@ -963,24 +963,18 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
 
                     _ if !self.warn_about_weird_lints => {}
 
-                    CheckLintNameResult::Renamed(new_name) => {
+                    CheckLintNameResult::Renamed(ref replace) => {
                         let suggestion =
-                            RenamedLintSuggestion { suggestion: sp, replace: new_name.as_str() };
+                            RenamedLintSuggestion::WithSpan { suggestion: sp, replace };
                         let name = tool_ident.map(|tool| format!("{tool}::{name}")).unwrap_or(name);
-                        self.emit_spanned_lint(
-                            RENAMED_AND_REMOVED_LINTS,
-                            sp.into(),
-                            RenamedLint { name: name.as_str(), suggestion },
-                        );
+                        let lint = RenamedLint { name: name.as_str(), suggestion };
+                        self.emit_spanned_lint(RENAMED_AND_REMOVED_LINTS, sp.into(), lint);
                     }
 
-                    CheckLintNameResult::Removed(reason) => {
+                    CheckLintNameResult::Removed(ref reason) => {
                         let name = tool_ident.map(|tool| format!("{tool}::{name}")).unwrap_or(name);
-                        self.emit_spanned_lint(
-                            RENAMED_AND_REMOVED_LINTS,
-                            sp.into(),
-                            RemovedLint { name: name.as_str(), reason: reason.as_str() },
-                        );
+                        let lint = RemovedLint { name: name.as_str(), reason };
+                        self.emit_spanned_lint(RENAMED_AND_REMOVED_LINTS, sp.into(), lint);
                     }
 
                     CheckLintNameResult::NoLint(suggestion) => {
@@ -989,13 +983,11 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                         } else {
                             name.to_string()
                         };
-                        let suggestion = suggestion
-                            .map(|replace| UnknownLintSuggestion { suggestion: sp, replace });
-                        self.emit_spanned_lint(
-                            UNKNOWN_LINTS,
-                            sp.into(),
-                            UnknownLint { name, suggestion },
-                        );
+                        let suggestion = suggestion.map(|replace| {
+                            UnknownLintSuggestion::WithSpan { suggestion: sp, replace }
+                        });
+                        let lint = UnknownLint { name, suggestion };
+                        self.emit_spanned_lint(UNKNOWN_LINTS, sp.into(), lint);
                     }
                 }
                 // If this lint was renamed, apply the new lint instead of ignoring the attribute.

compiler/rustc_lint/src/lints.rs

@@ -2,6 +2,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 use std::num::NonZeroU32;
 
+use crate::errors::RequestedLevel;
 use crate::fluent_generated as fluent;
 use rustc_errors::{
     AddToDiagnostic, Applicability, DecorateLint, DiagnosticMessage, DiagnosticStyledString,
@@ -1012,6 +1013,16 @@ pub struct DeprecatedLintName<'a> {
     pub replace: &'a str,
 }
 
+#[derive(LintDiagnostic)]
+#[diag(lint_deprecated_lint_name)]
+#[help]
+pub struct DeprecatedLintNameFromCommandLine<'a> {
+    pub name: String,
+    pub replace: &'a str,
+    #[subdiagnostic]
+    pub requested_level: RequestedLevel<'a>,
+}
+
 #[derive(LintDiagnostic)]
 #[diag(lint_renamed_lint)]
 pub struct RenamedLint<'a> {
@@ -1021,11 +1032,25 @@ pub struct RenamedLint<'a> {
 }
 
 #[derive(Subdiagnostic)]
-#[suggestion(lint_suggestion, code = "{replace}", applicability = "machine-applicable")]
-pub struct RenamedLintSuggestion<'a> {
-    #[primary_span]
-    pub suggestion: Span,
-    pub replace: &'a str,
+pub enum RenamedLintSuggestion<'a> {
+    #[suggestion(lint_suggestion, code = "{replace}", applicability = "machine-applicable")]
+    WithSpan {
+        #[primary_span]
+        suggestion: Span,
+        replace: &'a str,
+    },
+    #[help(lint_help)]
+    WithoutSpan { replace: &'a str },
+}
+
+#[derive(LintDiagnostic)]
+#[diag(lint_renamed_lint)]
+pub struct RenamedLintFromCommandLine<'a> {
+    pub name: &'a str,
+    #[subdiagnostic]
+    pub suggestion: RenamedLintSuggestion<'a>,
+    #[subdiagnostic]
+    pub requested_level: RequestedLevel<'a>,
 }
 
 #[derive(LintDiagnostic)]
@@ -1035,6 +1060,15 @@ pub struct RemovedLint<'a> {
     pub reason: &'a str,
 }
 
+#[derive(LintDiagnostic)]
+#[diag(lint_removed_lint)]
+pub struct RemovedLintFromCommandLine<'a> {
+    pub name: &'a str,
+    pub reason: &'a str,
+    #[subdiagnostic]
+    pub requested_level: RequestedLevel<'a>,
+}
+
 #[derive(LintDiagnostic)]
 #[diag(lint_unknown_lint)]
 pub struct UnknownLint {
@@ -1044,11 +1078,25 @@ pub struct UnknownLint {
 }
 
 #[derive(Subdiagnostic)]
-#[suggestion(lint_suggestion, code = "{replace}", applicability = "maybe-incorrect")]
-pub struct UnknownLintSuggestion {
-    #[primary_span]
-    pub suggestion: Span,
-    pub replace: Symbol,
+pub enum UnknownLintSuggestion {
+    #[suggestion(lint_suggestion, code = "{replace}", applicability = "maybe-incorrect")]
+    WithSpan {
+        #[primary_span]
+        suggestion: Span,
+        replace: Symbol,
+    },
+    #[help(lint_help)]
+    WithoutSpan { replace: Symbol },
+}
+
+#[derive(LintDiagnostic)]
+#[diag(lint_unknown_lint, code = "E0602")]
+pub struct UnknownLintFromCommandLine<'a> {
+    pub name: String,
+    #[subdiagnostic]
+    pub suggestion: Option<UnknownLintSuggestion>,
+    #[subdiagnostic]
+    pub requested_level: RequestedLevel<'a>,
 }
 
 #[derive(LintDiagnostic)]

tests/ui-fulldeps/plugin/lint-tool-cmdline-allow.stderr

@@ -1,9 +1,12 @@
-warning: lint name `test_lint` is deprecated and does not have an effect anymore. Use: clippy::test_lint
+warning: lint name `test_lint` is deprecated and may not have an effect in the future.
    |
+   = help: change it to clippy::test_lint
    = note: requested on the command line with `-A test_lint`
+   = note: `#[warn(renamed_and_removed_lints)]` on by default
 
-warning: lint name `test_lint` is deprecated and does not have an effect anymore. Use: clippy::test_lint
+warning: lint name `test_lint` is deprecated and may not have an effect in the future.
    |
+   = help: change it to clippy::test_lint
    = note: requested on the command line with `-A test_lint`
 
 warning: item is named 'lintme'
@@ -22,8 +25,9 @@ LL | #![plugin(lint_tool_test)]
    |
    = note: `#[warn(deprecated)]` on by default
 
-warning: lint name `test_lint` is deprecated and does not have an effect anymore. Use: clippy::test_lint
+warning: lint name `test_lint` is deprecated and may not have an effect in the future.
    |
+   = help: change it to clippy::test_lint
    = note: requested on the command line with `-A test_lint`
 
 warning: 5 warnings emitted

tests/ui/error-codes/E0602.rs

@@ -1,6 +1,8 @@
 // compile-flags:-D bogus
+// check-pass
 
 // error-pattern:E0602
 // error-pattern:requested on the command line with `-D bogus`
+// error-pattern:`#[warn(unknown_lints)]` on by default
 
 fn main() {}

tests/ui/error-codes/E0602.stderr

@@ -1,11 +1,16 @@
-error[E0602]: unknown lint: `bogus`
+warning[E0602]: unknown lint: `bogus`
    |
    = note: requested on the command line with `-D bogus`
+   = note: `#[warn(unknown_lints)]` on by default
 
-error[E0602]: unknown lint: `bogus`
+warning[E0602]: unknown lint: `bogus`
    |
    = note: requested on the command line with `-D bogus`
 
-error: aborting due to 2 previous errors
+warning[E0602]: unknown lint: `bogus`
+   |
+   = note: requested on the command line with `-D bogus`
+
+warning: 3 warnings emitted
 
 For more information about this error, try `rustc --explain E0602`.

tests/ui/lint/cli-unknown-force-warn.rs

@@ -1,7 +1,11 @@
 // Checks that rustc correctly errors when passed an invalid lint with
 // `--force-warn`. This is a regression test for issue #86958.
-//
+
+// check-pass
 // compile-flags: --force-warn foo-qux
+
 // error-pattern: unknown lint: `foo_qux`
+// error-pattern: requested on the command line with `--force-warn foo_qux`
+// error-pattern: `#[warn(unknown_lints)]` on by default
 
 fn main() {}