intermediate step

clippy_lints/src/trailing_zero_sized_array_without_repr_c.rs

@@ -1,8 +1,6 @@
 use clippy_utils::consts::{miri_to_const, Constant};
-use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::source::snippet;
+use clippy_utils::diagnostics::span_lint_and_help;
 use rustc_ast::Attribute;
-use rustc_errors::Applicability;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::{Item, ItemKind, VariantData};
 use rustc_lint::{LateContext, LateLintPass};
@@ -47,15 +45,15 @@ impl<'tcx> LateLintPass<'tcx> for TrailingZeroSizedArrayWithoutReprC {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
         dbg!(item.ident);
         if is_struct_with_trailing_zero_sized_array(cx, item) && !has_repr_attr(cx, item.def_id) {
-            span_lint_and_sugg(
-                cx,
-                TRAILING_ZERO_SIZED_ARRAY_WITHOUT_REPR_C,
-                item.span,
-                "trailing zero-sized array in a struct which is not marked `#[repr(C)]`",
-                "try annotating the struct definition with `#[repr(C)]` (or another `repr` attribute):",
-                format!("#[repr(C)]\n{}", snippet(cx, item.span, "..")),
-                Applicability::MaybeIncorrect,
-            );
+            // span_lint_and_help(
+            //     cx,
+            //     TRAILING_ZERO_SIZED_ARRAY_WITHOUT_REPR_C,
+            //     item.span,
+            //     "trailing zero-sized array in a struct which is not marked `#[repr(C)]`",
+            //     None,
+            //     "consider annotating the struct definition with `#[repr(C)]` (or another `repr` attribute)",
+            // );
+            eprintln!("— consider yourself linted — 🦀")
         }
     }
 }
@@ -87,15 +85,16 @@ fn is_struct_with_trailing_zero_sized_array(cx: &LateContext<'tcx>, item: &'tcx
 fn has_repr_attr(cx: &LateContext<'tcx>, def_id: LocalDefId) -> bool {
     let attrs_get_attrs = get_attrs_get_attrs(cx, def_id);
     let attrs_hir_map = get_attrs_hir_map(cx, def_id);
-    let b11 = dbg!(includes_repr_attr_using_sym(attrs_get_attrs));
-    let b12 = dbg!(includes_repr_attr_using_sym(attrs_hir_map));
-    let b21 = dbg!(includes_repr_attr_using_helper(cx, attrs_get_attrs));
-    let b22 = dbg!(includes_repr_attr_using_helper(cx, attrs_hir_map));
-    let b3 = dbg!(has_repr_attr_using_adt(cx, def_id));
-    let all_same = b11 && b12 && b21 && b22 && b3;
+
+    let b11 = includes_repr_attr_using_sym(attrs_get_attrs);
+    let b12 = includes_repr_attr_using_sym(attrs_hir_map);
+    let b21 = includes_repr_attr_using_helper(cx, attrs_get_attrs);
+    let b22 = includes_repr_attr_using_helper(cx, attrs_hir_map);
+    let b3 =  has_repr_attr_using_adt(cx, def_id);
+    let all_same = (b11 && b12 && b21 && b22 && b3) || (!b11 && !b12 && !b21 && !b22 && !b3);
     dbg!(all_same);
 
-    b11
+    b21
 }
 
 fn get_attrs_get_attrs(cx: &LateContext<'tcx>, def_id: LocalDefId) -> &'tcx [Attribute] {
@@ -108,7 +107,9 @@ fn get_attrs_hir_map(cx: &LateContext<'tcx>, def_id: LocalDefId) -> &'tcx [Attri
     hir_map.attrs(hir_id)
 }
 
-// Don't like this because it's so dependent on the current list of `repr` flags and it would have to be manually updated if that ever expanded. idk if there's any mechanism in `bitflag!` or elsewhere for requiring that sort of exhaustiveness
+// Don't like this because it's so dependent on the current list of `repr` flags and it would have
+// to be manually updated if that ever expanded. idk if there's any mechanism in `bitflag!` or
+// elsewhere for requiring that sort of exhaustiveness
 fn has_repr_attr_using_adt(cx: &LateContext<'tcx>, def_id: LocalDefId) -> bool {
     let ty = cx.tcx.type_of(def_id.to_def_id());
     if let ty_mod::Adt(adt, _) = ty.kind() {
@@ -129,5 +130,7 @@ fn includes_repr_attr_using_sym(attrs: &'tcx [Attribute]) -> bool {
 }
 
 fn includes_repr_attr_using_helper(cx: &LateContext<'tcx>, attrs: &'tcx [Attribute]) -> bool {
-    attrs.iter().any(|attr| !rustc_attr::find_repr_attrs(cx.tcx.sess(), attr).is_empty())
+    attrs
+        .iter()
+        .any(|attr| !rustc_attr::find_repr_attrs(cx.tcx.sess(), attr).is_empty())
 }

tests/ui/trailing_zero_sized_array_without_repr_c.rs

@@ -1,5 +1,5 @@
 #![warn(clippy::trailing_zero_sized_array_without_repr_c)]
-// #![feature(const_generics_defaults)] // see below
+#![feature(const_generics_defaults)] // see below
 
 // Do lint:
 
@@ -20,13 +20,13 @@ struct GenericArrayType<T> {
 #[derive(Debug)]
 struct PlayNiceWithOtherAttributesDerive {
     field: i32,
-    last: [usize; 0]
+    last: [usize; 0],
 }
 
 #[must_use]
 struct PlayNiceWithOtherAttributesMustUse {
     field: i32,
-    last: [usize; 0]
+    last: [usize; 0],
 }
 
 const ZERO: usize = 0;
@@ -72,7 +72,7 @@ struct GoodReason {
     last: [usize; 0],
 }
 
-struct SizedArray {
+struct NonZeroSizedArray {
     field: i32,
     last: [usize; 1],
 }
@@ -114,8 +114,8 @@ enum DontLintAnonymousStructsFromDesuraging {
     C { x: u32, y: [u64; 0] },
 }
 
-// NOTE: including these (along with the required feature) triggers an ICE. Should make sure the
-// const generics people are aware of that if they weren't already.
+// NOTE: including these (along with the required feature) triggers an ICE. Not sure why. Should
+// make sure the const generics people are aware of that if they weren't already.
 
 // #[repr(C)]
 // struct ConstParamOk<const N: usize = 0> {
@@ -129,5 +129,5 @@ enum DontLintAnonymousStructsFromDesuraging {
 // }
 
 fn main() {
-    let _ = PlayNiceWithOtherAttributesMustUse {field: 0, last: []};
+    let _ = PlayNiceWithOtherAttributesMustUse { field: 0, last: [] };
 }