rephrase the note

ada4a · ada4a · commit 706d5195dba8 · 2025-11-08T12:10:49.000+01:00
diff --git a/clippy_lints_internal/src/repeated_is_diagnostic_item.rs b/clippy_lints_internal/src/repeated_is_diagnostic_item.rs
@@ -35,6 +35,8 @@ declare_tool_lint! {
 }
 declare_lint_pass!(RepeatedIsDiagnosticItem => [REPEATED_IS_DIAGNOSTIC_ITEM]);
 
+const NOTE: &str = "each call performs the same compiler query -- it's faster to query once, and reuse the results";
+
 impl LateLintPass<'_> for RepeatedIsDiagnosticItem {
     #[expect(clippy::too_many_lines)]
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
@@ -57,7 +59,7 @@ impl LateLintPass<'_> for RepeatedIsDiagnosticItem {
                         expr.span,
                         format!("repeated calls to `{recv_ty}::is_diag_item`"),
                         |diag| {
-                            diag.note("this calls `TyCtxt::is_diagnostic_item` internally, which is expensive");
+                            diag.note(NOTE);
 
                             let mut app = Applicability::MachineApplicable;
                             let cx_str = snippet_with_applicability(cx, cx1.span, "_", &mut app);
@@ -87,7 +89,7 @@ impl LateLintPass<'_> for RepeatedIsDiagnosticItem {
                         expr.span,
                         "repeated calls to `TyCtxt::is_diagnostic_item`",
                         |diag| {
-                            diag.note("this calls an expensive compiler query");
+                            diag.note(NOTE);
 
                             let mut app = Applicability::MachineApplicable;
                             let tcx = snippet_with_applicability(cx, tcx1.span, "_", &mut app);
@@ -127,7 +129,7 @@ impl LateLintPass<'_> for RepeatedIsDiagnosticItem {
                         expr.span,
                         format!("repeated calls to `{recv_ty}::is_diag_item`"),
                         |diag| {
-                            diag.note("this calls `TyCtxt::is_diagnostic_item` internally, which is expensive");
+                            diag.note(NOTE);
 
                             let mut app = Applicability::MachineApplicable;
                             let cx_str = snippet_with_applicability(cx, cx1.span, "_", &mut app);
@@ -157,7 +159,7 @@ impl LateLintPass<'_> for RepeatedIsDiagnosticItem {
                         expr.span,
                         "repeated calls to `TyCtxt::is_diagnostic_item`",
                         |diag| {
-                            diag.note("this calls an expensive compiler query");
+                            diag.note(NOTE);
 
                             let mut app = Applicability::MachineApplicable;
                             let tcx = snippet_with_applicability(cx, tcx1.span, "_", &mut app);
diff --git a/tests/ui-internal/repeated_is_diagnostic_item.stderr b/tests/ui-internal/repeated_is_diagnostic_item.stderr
@@ -4,7 +4,7 @@ error: repeated calls to `Ty::is_diag_item`
 LL |     let _ = ty.is_diag_item(cx, sym::Option) || ty.is_diag_item(cx, sym::Result);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
+   = note: each call performs the same compiler query -- it's faster to query once, and reuse the results
    = note: `-D clippy::repeated-is-diagnostic-item` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::repeated_is_diagnostic_item)]`
 help: call `Ty::opt_diag_name`, and reuse the results
@@ -19,7 +19,7 @@ error: repeated calls to `Ty::is_diag_item`
 LL |     let _ = !ty.is_diag_item(cx, sym::Option) && !ty.is_diag_item(cx, sym::Result);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
+   = note: each call performs the same compiler query -- it's faster to query once, and reuse the results
 help: call `Ty::opt_diag_name`, and reuse the results
    |
 LL -     let _ = !ty.is_diag_item(cx, sym::Option) && !ty.is_diag_item(cx, sym::Result);
@@ -32,7 +32,7 @@ error: repeated calls to `AdtDef::is_diag_item`
 LL |     let _ = adt_def.is_diag_item(cx, sym::Option) || adt_def.is_diag_item(cx, sym::Result);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
+   = note: each call performs the same compiler query -- it's faster to query once, and reuse the results
 help: call `AdtDef::opt_diag_name`, and reuse the results
    |
 LL -     let _ = adt_def.is_diag_item(cx, sym::Option) || adt_def.is_diag_item(cx, sym::Result);
@@ -45,7 +45,7 @@ error: repeated calls to `AdtDef::is_diag_item`
 LL |     let _ = !adt_def.is_diag_item(cx, sym::Option) && !adt_def.is_diag_item(cx, sym::Result);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
+   = note: each call performs the same compiler query -- it's faster to query once, and reuse the results
 help: call `AdtDef::opt_diag_name`, and reuse the results
    |
 LL -     let _ = !adt_def.is_diag_item(cx, sym::Option) && !adt_def.is_diag_item(cx, sym::Result);
@@ -58,7 +58,7 @@ error: repeated calls to `TyCtxt::is_diagnostic_item`
 LL |     let _ = cx.tcx.is_diagnostic_item(sym::Option, did) || cx.tcx.is_diagnostic_item(sym::Result, did);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this calls an expensive compiler query
+   = note: each call performs the same compiler query -- it's faster to query once, and reuse the results
 help: call `TyCtxt::get_diagnostic_name`, and reuse the results
    |
 LL -     let _ = cx.tcx.is_diagnostic_item(sym::Option, did) || cx.tcx.is_diagnostic_item(sym::Result, did);
@@ -71,7 +71,7 @@ error: repeated calls to `TyCtxt::is_diagnostic_item`
 LL |     let _ = !cx.tcx.is_diagnostic_item(sym::Option, did) && !cx.tcx.is_diagnostic_item(sym::Result, did);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: this calls an expensive compiler query
+   = note: each call performs the same compiler query -- it's faster to query once, and reuse the results
 help: call `TyCtxt::get_diagnostic_name`, and reuse the results
    |
 LL -     let _ = !cx.tcx.is_diagnostic_item(sym::Option, did) && !cx.tcx.is_diagnostic_item(sym::Result, did);

Original file line number	Diff line number	Diff line change
@@ -4,7 +4,7 @@ error: repeated calls to `Ty::is_diag_item`
`4`	`4`	`LL \| let _ = ty.is_diag_item(cx, sym::Option) \|\| ty.is_diag_item(cx, sym::Result);`
`5`	`5`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`6`	`6`	`\|`
`7`		- = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
	`7`	`+ = note: each call performs the same compiler query -- it's faster to query once, and reuse the results`
`8`	`8`	= note: `-D clippy::repeated-is-diagnostic-item` implied by `-D warnings`
`9`	`9`	= help: to override `-D warnings` add `#[allow(clippy::repeated_is_diagnostic_item)]`
`10`	`10`	help: call `Ty::opt_diag_name`, and reuse the results
@@ -19,7 +19,7 @@ error: repeated calls to `Ty::is_diag_item`
`19`	`19`	`LL \| let _ = !ty.is_diag_item(cx, sym::Option) && !ty.is_diag_item(cx, sym::Result);`
`20`	`20`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`21`	`21`	`\|`
`22`		- = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
	`22`	`+ = note: each call performs the same compiler query -- it's faster to query once, and reuse the results`
`23`	`23`	help: call `Ty::opt_diag_name`, and reuse the results
`24`	`24`	`\|`
`25`	`25`	`LL - let _ = !ty.is_diag_item(cx, sym::Option) && !ty.is_diag_item(cx, sym::Result);`
@@ -32,7 +32,7 @@ error: repeated calls to `AdtDef::is_diag_item`
`32`	`32`	`LL \| let _ = adt_def.is_diag_item(cx, sym::Option) \|\| adt_def.is_diag_item(cx, sym::Result);`
`33`	`33`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`34`	`34`	`\|`
`35`		- = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
	`35`	`+ = note: each call performs the same compiler query -- it's faster to query once, and reuse the results`
`36`	`36`	help: call `AdtDef::opt_diag_name`, and reuse the results
`37`	`37`	`\|`
`38`	`38`	`LL - let _ = adt_def.is_diag_item(cx, sym::Option) \|\| adt_def.is_diag_item(cx, sym::Result);`
@@ -45,7 +45,7 @@ error: repeated calls to `AdtDef::is_diag_item`
`45`	`45`	`LL \| let _ = !adt_def.is_diag_item(cx, sym::Option) && !adt_def.is_diag_item(cx, sym::Result);`
`46`	`46`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`47`	`47`	`\|`
`48`		- = note: this calls `TyCtxt::is_diagnostic_item` internally, which is expensive
	`48`	`+ = note: each call performs the same compiler query -- it's faster to query once, and reuse the results`
`49`	`49`	help: call `AdtDef::opt_diag_name`, and reuse the results
`50`	`50`	`\|`
`51`	`51`	`LL - let _ = !adt_def.is_diag_item(cx, sym::Option) && !adt_def.is_diag_item(cx, sym::Result);`
@@ -58,7 +58,7 @@ error: repeated calls to `TyCtxt::is_diagnostic_item`
`58`	`58`	`LL \| let _ = cx.tcx.is_diagnostic_item(sym::Option, did) \|\| cx.tcx.is_diagnostic_item(sym::Result, did);`
`59`	`59`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`60`	`60`	`\|`
`61`		`- = note: this calls an expensive compiler query`
	`61`	`+ = note: each call performs the same compiler query -- it's faster to query once, and reuse the results`
`62`	`62`	help: call `TyCtxt::get_diagnostic_name`, and reuse the results
`63`	`63`	`\|`
`64`	`64`	`LL - let _ = cx.tcx.is_diagnostic_item(sym::Option, did) \|\| cx.tcx.is_diagnostic_item(sym::Result, did);`
@@ -71,7 +71,7 @@ error: repeated calls to `TyCtxt::is_diagnostic_item`
`71`	`71`	`LL \| let _ = !cx.tcx.is_diagnostic_item(sym::Option, did) && !cx.tcx.is_diagnostic_item(sym::Result, did);`
`72`	`72`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`73`	`73`	`\|`
`74`		`- = note: this calls an expensive compiler query`
	`74`	`+ = note: each call performs the same compiler query -- it's faster to query once, and reuse the results`
`75`	`75`	help: call `TyCtxt::get_diagnostic_name`, and reuse the results
`76`	`76`	`\|`
`77`	`77`	`LL - let _ = !cx.tcx.is_diagnostic_item(sym::Option, did) && !cx.tcx.is_diagnostic_item(sym::Result, did);`