Auto merge of #13145 - xFrednet:07797-restriction-and-then-why, r=Jarcho

Make restriction lint's use `span_lint_and_then` (q -> w)

This migrates a few restriction lints to use `span_lint_and_then`. This change is motivated by #7797.

I've also cleaned up some lint message. Mostly minor stuff. For example: suggestions with a longer message than `"try"` now use `SuggestionStyle::ShowAlways`

---

cc: #7797

sister PR of: #13136

changelog: none

Author: bors

clippy_lints/src/matches/match_wild_enum.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::ty::is_type_diagnostic_item;
 use clippy_utils::{is_refutable, peel_hir_pat_refs, recurse_or_patterns};
 use rustc_errors::Applicability;
@@ -148,23 +148,27 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>]) {
             Applicability::MaybeIncorrect,
         ),
         variants => {
-            let mut suggestions: Vec<_> = variants.iter().copied().map(format_suggestion).collect();
-            let message = if adt_def.is_variant_list_non_exhaustive() || has_external_hidden {
-                suggestions.push("_".into());
-                "wildcard matches known variants and will also match future added variants"
+            let (message, add_wildcard) = if adt_def.is_variant_list_non_exhaustive() || has_external_hidden {
+                (
+                    "wildcard matches known variants and will also match future added variants",
+                    true,
+                )
             } else {
-                "wildcard match will also match any future added variants"
+                ("wildcard match will also match any future added variants", false)
             };
 
-            span_lint_and_sugg(
-                cx,
-                WILDCARD_ENUM_MATCH_ARM,
-                wildcard_span,
-                message,
-                "try",
-                suggestions.join(" | "),
-                Applicability::MaybeIncorrect,
-            );
+            span_lint_and_then(cx, WILDCARD_ENUM_MATCH_ARM, wildcard_span, message, |diag| {
+                let mut suggestions: Vec<_> = variants.iter().copied().map(format_suggestion).collect();
+                if add_wildcard {
+                    suggestions.push("_".into());
+                }
+                diag.span_suggestion(
+                    wildcard_span,
+                    "try",
+                    suggestions.join(" | "),
+                    Applicability::MaybeIncorrect,
+                );
+            });
         },
     };
 }

clippy_lints/src/matches/rest_pat_in_fully_bound_struct.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 use rustc_hir::{Pat, PatKind, QPath};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
@@ -15,13 +15,15 @@ pub(crate) fn check(cx: &LateContext<'_>, pat: &Pat<'_>) {
         && fields.len() == def.non_enum_variant().fields.len()
         && !def.non_enum_variant().is_field_list_non_exhaustive()
     {
-        span_lint_and_help(
+        #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+        span_lint_and_then(
             cx,
             REST_PAT_IN_FULLY_BOUND_STRUCTS,
             pat.span,
             "unnecessary use of `..` pattern in struct binding. All fields were already bound",
-            None,
-            "consider removing `..` from this binding",
+            |diag| {
+                diag.help("consider removing `..` from this binding");
+            },
         );
     }
 }

clippy_lints/src/matches/try_err.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::ty::is_type_diagnostic_item;
 use clippy_utils::{get_parent_expr, is_res_lang_ctor, path_res};
@@ -48,29 +48,28 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, scrutine
             return;
         };
 
-        let expr_err_ty = cx.typeck_results().expr_ty(err_arg);
-        let span = hygiene::walk_chain(err_arg.span, try_arg.span.ctxt());
-        let mut applicability = Applicability::MachineApplicable;
-        let origin_snippet = snippet_with_applicability(cx, span, "_", &mut applicability);
-        let ret_prefix = if get_parent_expr(cx, expr).map_or(false, |e| matches!(e.kind, ExprKind::Ret(_))) {
-            "" // already returns
-        } else {
-            "return "
-        };
-        let suggestion = if err_ty == expr_err_ty {
-            format!("{ret_prefix}{prefix}{origin_snippet}{suffix}")
-        } else {
-            format!("{ret_prefix}{prefix}{origin_snippet}.into(){suffix}")
-        };
-
-        span_lint_and_sugg(
+        span_lint_and_then(
             cx,
             TRY_ERR,
             expr.span,
             "returning an `Err(_)` with the `?` operator",
-            "try",
-            suggestion,
-            applicability,
+            |diag| {
+                let expr_err_ty = cx.typeck_results().expr_ty(err_arg);
+                let span = hygiene::walk_chain(err_arg.span, try_arg.span.ctxt());
+                let mut applicability = Applicability::MachineApplicable;
+                let origin_snippet = snippet_with_applicability(cx, span, "_", &mut applicability);
+                let ret_prefix = if get_parent_expr(cx, expr).map_or(false, |e| matches!(e.kind, ExprKind::Ret(_))) {
+                    "" // already returns
+                } else {
+                    "return "
+                };
+                let suggestion = if err_ty == expr_err_ty {
+                    format!("{ret_prefix}{prefix}{origin_snippet}{suffix}")
+                } else {
+                    format!("{ret_prefix}{prefix}{origin_snippet}.into(){suffix}")
+                };
+                diag.span_suggestion(expr.span, "try", suggestion, applicability);
+            },
         );
     }
 }

clippy_lints/src/methods/verbose_file_reads.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::is_trait_method;
 use clippy_utils::ty::is_type_diagnostic_item;
 use rustc_hir::{Expr, ExprKind, QPath};
@@ -23,6 +23,9 @@ pub(super) fn check<'tcx>(
         && matches!(recv.kind, ExprKind::Path(QPath::Resolved(None, _)))
         && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty_adjusted(recv).peel_refs(), sym::File)
     {
-        span_lint_and_help(cx, VERBOSE_FILE_READS, expr.span, msg, None, help);
+        #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+        span_lint_and_then(cx, VERBOSE_FILE_READS, expr.span, msg, |diag| {
+            diag.help(help);
+        });
     }
 }

clippy_lints/src/misc_early/literal_suffix.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::diagnostics::span_lint_and_then;
 use rustc_errors::Applicability;
 use rustc_lint::EarlyContext;
 use rustc_span::Span;
@@ -12,24 +12,36 @@ pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, lit_snip: &str, suffi
     // Do not lint when literal is unsuffixed.
     if !suffix.is_empty() {
         if lit_snip.as_bytes()[maybe_last_sep_idx] == b'_' {
-            span_lint_and_sugg(
+            #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+            span_lint_and_then(
                 cx,
                 SEPARATED_LITERAL_SUFFIX,
                 lit_span,
                 format!("{sugg_type} type suffix should not be separated by an underscore"),
-                "remove the underscore",
-                format!("{}{suffix}", &lit_snip[..maybe_last_sep_idx]),
-                Applicability::MachineApplicable,
+                |diag| {
+                    diag.span_suggestion(
+                        lit_span,
+                        "remove the underscore",
+                        format!("{}{suffix}", &lit_snip[..maybe_last_sep_idx]),
+                        Applicability::MachineApplicable,
+                    );
+                },
             );
         } else {
-            span_lint_and_sugg(
+            #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+            span_lint_and_then(
                 cx,
                 UNSEPARATED_LITERAL_SUFFIX,
                 lit_span,
                 format!("{sugg_type} type suffix should be separated by an underscore"),
-                "add an underscore",
-                format!("{}_{suffix}", &lit_snip[..=maybe_last_sep_idx]),
-                Applicability::MachineApplicable,
+                |diag| {
+                    diag.span_suggestion(
+                        lit_span,
+                        "add an underscore",
+                        format!("{}_{suffix}", &lit_snip[..=maybe_last_sep_idx]),
+                        Applicability::MachineApplicable,
+                    );
+                },
             );
         }
     }

clippy_lints/src/misc_early/unneeded_field_pattern.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
 use clippy_utils::source::snippet_opt;
 use rustc_ast::ast::{Pat, PatKind};
 use rustc_lint::EarlyContext;
@@ -21,13 +21,15 @@ pub(super) fn check(cx: &EarlyContext<'_>, pat: &Pat) {
             }
         }
         if !pfields.is_empty() && wilds == pfields.len() {
-            span_lint_and_help(
+            #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+            span_lint_and_then(
                 cx,
                 UNNEEDED_FIELD_PATTERN,
                 pat.span,
                 "all the struct fields are matched to a wildcard pattern, consider using `..`",
-                None,
-                format!("try with `{type_name} {{ .. }}` instead"),
+                |diag| {
+                    diag.help(format!("try with `{type_name} {{ .. }}` instead"));
+                },
             );
             return;
         }
@@ -56,14 +58,15 @@ pub(super) fn check(cx: &EarlyContext<'_>, pat: &Pat) {
                             }
                         }
 
-                        span_lint_and_help(
+                        #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+                        span_lint_and_then(
                             cx,
                             UNNEEDED_FIELD_PATTERN,
                             field.span,
-                            "you matched a field with a wildcard pattern, consider using `..` \
-                             instead",
-                            None,
-                            format!("try with `{type_name} {{ {}, .. }}`", normal[..].join(", ")),
+                            "you matched a field with a wildcard pattern, consider using `..` instead",
+                            |diag| {
+                                diag.help(format!("try with `{type_name} {{ {}, .. }}`", normal[..].join(", ")));
+                            },
                         );
                     }
                 }

clippy_lints/src/question_mark_used.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 
 use clippy_utils::macros::span_is_local;
 use rustc_hir::{Expr, ExprKind, MatchSource};
@@ -39,13 +39,15 @@ impl<'tcx> LateLintPass<'tcx> for QuestionMarkUsed {
                 return;
             }
 
-            span_lint_and_help(
+            #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+            span_lint_and_then(
                 cx,
                 QUESTION_MARK_USED,
                 expr.span,
                 "question mark operator was used",
-                None,
-                "consider using a custom macro or match expression",
+                |diag| {
+                    diag.help("consider using a custom macro or match expression");
+                },
             );
         }
     }

clippy_lints/src/ref_patterns.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 use rustc_ast::ast::{BindingMode, Pat, PatKind};
 use rustc_lint::{EarlyContext, EarlyLintPass};
 use rustc_session::declare_lint_pass;
@@ -33,14 +33,10 @@ impl EarlyLintPass for RefPatterns {
         if let PatKind::Ident(BindingMode::REF, _, _) = pat.kind
             && !pat.span.from_expansion()
         {
-            span_lint_and_help(
-                cx,
-                REF_PATTERNS,
-                pat.span,
-                "usage of ref pattern",
-                None,
-                "consider using `&` for clarity instead",
-            );
+            #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+            span_lint_and_then(cx, REF_PATTERNS, pat.span, "usage of ref pattern", |diag| {
+                diag.help("consider using `&` for clarity instead");
+            });
         }
     }
 }

clippy_lints/src/shadow.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_note;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
 use clippy_utils::visitors::is_local_used;
 use rustc_data_structures::fx::FxHashMap;
@@ -194,14 +194,9 @@ fn lint_shadow(cx: &LateContext<'_>, pat: &Pat<'_>, shadowed: HirId, span: Span)
             (SHADOW_UNRELATED, msg)
         },
     };
-    span_lint_and_note(
-        cx,
-        lint,
-        span,
-        msg,
-        Some(cx.tcx.hir().span(shadowed)),
-        "previous binding is here",
-    );
+    span_lint_and_then(cx, lint, span, msg, |diag| {
+        diag.span_note(cx.tcx.hir().span(shadowed), "previous binding is here");
+    });
 }
 
 /// Returns true if the expression is a simple transformation of a local binding such as `&x`

clippy_lints/src/single_char_lifetime_names.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 use rustc_ast::ast::{GenericParam, GenericParamKind};
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
@@ -48,13 +48,15 @@ impl EarlyLintPass for SingleCharLifetimeNames {
 
         if let GenericParamKind::Lifetime = param.kind {
             if !param.is_placeholder && param.ident.as_str().len() <= 2 {
-                span_lint_and_help(
+                #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+                span_lint_and_then(
                     ctx,
                     SINGLE_CHAR_LIFETIME_NAMES,
                     param.ident.span,
                     "single-character lifetime names are likely uninformative",
-                    None,
-                    "use a more informative name",
+                    |diag| {
+                        diag.help("use a more informative name");
+                    },
                 );
             }
         }

clippy_lints/src/strings.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::source::{snippet, snippet_with_applicability};
 use clippy_utils::ty::is_type_lang_item;
 use clippy_utils::{
@@ -399,17 +399,16 @@ impl<'tcx> LateLintPass<'tcx> for StrToString {
             && let ty::Ref(_, ty, ..) = ty.kind()
             && ty.is_str()
         {
-            let mut applicability = Applicability::MachineApplicable;
-            let snippet = snippet_with_applicability(cx, self_arg.span, "..", &mut applicability);
-
-            span_lint_and_sugg(
+            span_lint_and_then(
                 cx,
                 STR_TO_STRING,
                 expr.span,
                 "`to_string()` called on a `&str`",
-                "try",
-                format!("{snippet}.to_owned()"),
-                applicability,
+                |diag| {
+                    let mut applicability = Applicability::MachineApplicable;
+                    let snippet = snippet_with_applicability(cx, self_arg.span, "..", &mut applicability);
+                    diag.span_suggestion(expr.span, "try", format!("{snippet}.to_owned()"), applicability);
+                },
             );
         }
     }
@@ -455,13 +454,15 @@ impl<'tcx> LateLintPass<'tcx> for StringToString {
             && let ty = cx.typeck_results().expr_ty(self_arg)
             && is_type_lang_item(cx, ty, LangItem::String)
         {
-            span_lint_and_help(
+            #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
+            span_lint_and_then(
                 cx,
                 STRING_TO_STRING,
                 expr.span,
                 "`to_string()` called on a `String`",
-                None,
-                "consider using `.clone()`",
+                |diag| {
+                    diag.help("consider using `.clone()`");
+                },
             );
         }
     }