Make inconsistent_struct_constructor "all fields are shorthand" requirement configurable (rust-lang#13737)

Fixes rust-lang#11846.

This PR has three commits:
- The first commit adds an `initializer-suggestions` configuration to
control suggestion applicability when initializers are present. The
following are the options:
  - "none": do not suggest
- "maybe-incorrect": suggest, but do not apply suggestions with `--fix`
  - "machine-applicable": suggest and apply suggestions with `--fix`
- The second commit fixes suggestions to handle field attributes
(problem [noticed by
@samueltardieu](rust-lang/rust-clippy#13737 (comment))).
- The third commit adds `initializer-suggestions = "machine-applicable"`
to Clippy's `clippy.toml` and applies the suggestions. (Nothing seems to
break.)

---

changelog: make `inconsistent_struct_constructor` "all fields are
shorthand" requirement configurable

Author: y21

CHANGELOG.md

@@ -6252,6 +6252,7 @@ Released 2018-09-13
 [`future-size-threshold`]: https://doc.rust-lang.org/clippy/lint_configuration.html#future-size-threshold
 [`ignore-interior-mutability`]: https://doc.rust-lang.org/clippy/lint_configuration.html#ignore-interior-mutability
 [`large-error-threshold`]: https://doc.rust-lang.org/clippy/lint_configuration.html#large-error-threshold
+[`lint-inconsistent-struct-field-initializers`]: https://doc.rust-lang.org/clippy/lint_configuration.html#lint-inconsistent-struct-field-initializers
 [`literal-representation-threshold`]: https://doc.rust-lang.org/clippy/lint_configuration.html#literal-representation-threshold
 [`matches-for-let-else`]: https://doc.rust-lang.org/clippy/lint_configuration.html#matches-for-let-else
 [`max-fn-params-bools`]: https://doc.rust-lang.org/clippy/lint_configuration.html#max-fn-params-bools

book/src/lint_configuration.md

@@ -582,6 +582,33 @@ The maximum size of the `Err`-variant in a `Result` returned from a function
 * [`result_large_err`](https://rust-lang.github.io/rust-clippy/master/index.html#result_large_err)
 
 
+## `lint-inconsistent-struct-field-initializers`
+Whether to suggest reordering constructor fields when initializers are present.
+
+Warnings produced by this configuration aren't necessarily fixed by just reordering the fields. Even if the
+suggested code would compile, it can change semantics if the initializer expressions have side effects. The
+following example [from rust-clippy#11846] shows how the suggestion can run into borrow check errors:
+
+```rust
+struct MyStruct {
+    vector: Vec<u32>,
+    length: usize
+}
+fn main() {
+    let vector = vec![1,2,3];
+    MyStruct { length: vector.len(), vector};
+}
+```
+
+[from rust-clippy#11846]: https://github.com/rust-lang/rust-clippy/issues/11846#issuecomment-1820747924
+
+**Default Value:** `false`
+
+---
+**Affected lints:**
+* [`inconsistent_struct_constructor`](https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_struct_constructor)
+
+
 ## `literal-representation-threshold`
 The lower bound for linting decimal literals
 

clippy.toml

@@ -1,5 +1,7 @@
 avoid-breaking-exported-api = false
 
+lint-inconsistent-struct-field-initializers = true
+
 [[disallowed-methods]]
 path = "rustc_lint::context::LintContext::lint"
 reason = "this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint*` functions instead"

clippy_config/src/conf.rs

@@ -532,6 +532,26 @@ define_Conf! {
     /// The maximum size of the `Err`-variant in a `Result` returned from a function
     #[lints(result_large_err)]
     large_error_threshold: u64 = 128,
+    /// Whether to suggest reordering constructor fields when initializers are present.
+    ///
+    /// Warnings produced by this configuration aren't necessarily fixed by just reordering the fields. Even if the
+    /// suggested code would compile, it can change semantics if the initializer expressions have side effects. The
+    /// following example [from rust-clippy#11846] shows how the suggestion can run into borrow check errors:
+    ///
+    /// ```rust
+    /// struct MyStruct {
+    ///     vector: Vec<u32>,
+    ///     length: usize
+    /// }
+    /// fn main() {
+    ///     let vector = vec![1,2,3];
+    ///     MyStruct { length: vector.len(), vector};
+    /// }
+    /// ```
+    ///
+    /// [from rust-clippy#11846]: https://github.com/rust-lang/rust-clippy/issues/11846#issuecomment-1820747924
+    #[lints(inconsistent_struct_constructor)]
+    lint_inconsistent_struct_field_initializers: bool = false,
     /// The lower bound for linting decimal literals
     #[lints(decimal_literal_representation)]
     literal_representation_threshold: u64 = 16384,

clippy_dev/src/fmt.rs

@@ -179,8 +179,8 @@ fn fmt_conf(check: bool) -> Result<(), Error> {
                 #[expect(clippy::drain_collect)]
                 fields.push(ClippyConf {
                     name,
-                    lints: lints.drain(..).collect(),
                     attrs: &conf[attrs_start..attrs_end],
+                    lints: lints.drain(..).collect(),
                     field: conf[field_start..i].trim_end(),
                 });
                 attrs_start = i;
@@ -191,8 +191,8 @@ fn fmt_conf(check: bool) -> Result<(), Error> {
                 #[expect(clippy::drain_collect)]
                 fields.push(ClippyConf {
                     name,
-                    lints: lints.drain(..).collect(),
                     attrs: &conf[attrs_start..attrs_end],
+                    lints: lints.drain(..).collect(),
                     field: conf[field_start..i].trim_end(),
                 });
                 attrs_start = i;
@@ -220,8 +220,8 @@ fn fmt_conf(check: bool) -> Result<(), Error> {
     }
     fields.push(ClippyConf {
         name,
-        lints,
         attrs: &conf[attrs_start..attrs_end],
+        lints,
         field: conf[field_start..].trim_end(),
     });
 

clippy_lints/src/arbitrary_source_item_ordering.rs

@@ -428,8 +428,8 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
 
             // Makes a note of the current item for comparison with the next.
             cur_t = Some(CurItem {
-                order: module_level_order,
                 item,
+                order: module_level_order,
                 name: get_item_name(item),
             });
         }

clippy_lints/src/doc/mod.rs

@@ -797,8 +797,8 @@ fn check_attrs(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &[
         parser.into_offset_iter(),
         &doc,
         Fragments {
-            fragments: &fragments,
             doc: &doc,
+            fragments: &fragments,
         },
     ))
 }

clippy_lints/src/entry.rs

@@ -678,12 +678,12 @@ fn find_insert_calls<'tcx>(
         map: contains_expr.map,
         key: contains_expr.key,
         ctxt: expr.span.ctxt(),
-        edits: Vec::new(),
-        is_map_used: false,
         allow_insert_closure: true,
         can_use_entry: true,
         in_tail_pos: true,
         is_single_insert: true,
+        is_map_used: false,
+        edits: Vec::new(),
         loops: Vec::new(),
         locals: HirIdSet::default(),
     };

clippy_lints/src/implied_bounds_in_impls.rs

@@ -243,11 +243,11 @@ fn collect_supertrait_bounds<'tcx>(cx: &LateContext<'tcx>, bounds: GenericBounds
                 && !predicates.is_empty()
             {
                 Some(ImplTraitBound {
+                    span: bound.span(),
                     predicates,
+                    trait_def_id,
                     args: path.args.map_or([].as_slice(), |p| p.args),
                     constraints: path.args.map_or([].as_slice(), |p| p.constraints),
-                    trait_def_id,
-                    span: bound.span(),
                 })
             } else {
                 None

clippy_lints/src/inconsistent_struct_constructor.rs

@@ -1,19 +1,21 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_config::Conf;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::fulfill_or_allowed;
 use clippy_utils::source::snippet;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::Applicability;
-use rustc_hir::{self as hir, ExprKind, StructTailExpr};
+use rustc_hir::{self as hir, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::declare_lint_pass;
+use rustc_middle::ty::TyCtxt;
+use rustc_session::impl_lint_pass;
+use rustc_span::Span;
 use rustc_span::symbol::Symbol;
-use std::fmt::{self, Write as _};
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for struct constructors where all fields are shorthand and
-    /// the order of the field init shorthand in the constructor is inconsistent
-    /// with the order in the struct definition.
+    /// Checks for struct constructors where the order of the field
+    /// init in the constructor is inconsistent with the order in the
+    /// struct definition.
     ///
     /// ### Why is this bad?
     /// Since the order of fields in a constructor doesn't affect the
@@ -59,16 +61,37 @@ declare_clippy_lint! {
     #[clippy::version = "1.52.0"]
     pub INCONSISTENT_STRUCT_CONSTRUCTOR,
     pedantic,
-    "the order of the field init shorthand is inconsistent with the order in the struct definition"
+    "the order of the field init is inconsistent with the order in the struct definition"
 }
 
-declare_lint_pass!(InconsistentStructConstructor => [INCONSISTENT_STRUCT_CONSTRUCTOR]);
+pub struct InconsistentStructConstructor {
+    lint_inconsistent_struct_field_initializers: bool,
+}
+
+impl InconsistentStructConstructor {
+    pub fn new(conf: &'static Conf) -> Self {
+        Self {
+            lint_inconsistent_struct_field_initializers: conf.lint_inconsistent_struct_field_initializers,
+        }
+    }
+}
+
+impl_lint_pass!(InconsistentStructConstructor => [INCONSISTENT_STRUCT_CONSTRUCTOR]);
 
 impl<'tcx> LateLintPass<'tcx> for InconsistentStructConstructor {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
-        if let ExprKind::Struct(qpath, fields, base) = expr.kind
-            && fields.iter().all(|f| f.is_shorthand)
-            && !expr.span.from_expansion()
+        let ExprKind::Struct(_, fields, _) = expr.kind else {
+            return;
+        };
+        let all_fields_are_shorthand = fields.iter().all(|f| f.is_shorthand);
+        let applicability = if all_fields_are_shorthand {
+            Applicability::MachineApplicable
+        } else if self.lint_inconsistent_struct_field_initializers {
+            Applicability::MaybeIncorrect
+        } else {
+            return;
+        };
+        if !expr.span.from_expansion()
             && let ty = cx.typeck_results().expr_ty(expr)
             && let Some(adt_def) = ty.ty_adt_def()
             && adt_def.is_struct()
@@ -85,36 +108,24 @@ impl<'tcx> LateLintPass<'tcx> for InconsistentStructConstructor {
                 return;
             }
 
-            let mut ordered_fields: Vec<_> = fields.iter().map(|f| f.ident.name).collect();
-            ordered_fields.sort_unstable_by_key(|id| def_order_map[id]);
-
-            let mut fields_snippet = String::new();
-            let (last_ident, idents) = ordered_fields.split_last().unwrap();
-            for ident in idents {
-                let _: fmt::Result = write!(fields_snippet, "{ident}, ");
-            }
-            fields_snippet.push_str(&last_ident.to_string());
-
-            let base_snippet = if let StructTailExpr::Base(base) = base {
-                format!(", ..{}", snippet(cx, base.span, ".."))
-            } else {
-                String::new()
-            };
-
-            let sugg = format!(
-                "{} {{ {fields_snippet}{base_snippet} }}",
-                snippet(cx, qpath.span(), ".."),
-            );
+            let span = field_with_attrs_span(cx.tcx, fields.first().unwrap())
+                .with_hi(field_with_attrs_span(cx.tcx, fields.last().unwrap()).hi());
 
             if !fulfill_or_allowed(cx, INCONSISTENT_STRUCT_CONSTRUCTOR, Some(ty_hir_id)) {
-                span_lint_and_sugg(
+                span_lint_and_then(
                     cx,
                     INCONSISTENT_STRUCT_CONSTRUCTOR,
-                    expr.span,
+                    span,
                     "struct constructor field order is inconsistent with struct definition field order",
-                    "try",
-                    sugg,
-                    Applicability::MachineApplicable,
+                    |diag| {
+                        let msg = if all_fields_are_shorthand {
+                            "try"
+                        } else {
+                            "if the field evaluation order doesn't matter, try"
+                        };
+                        let sugg = suggestion(cx, fields, &def_order_map);
+                        diag.span_suggestion(span, msg, sugg, applicability);
+                    },
                 );
             }
         }
@@ -135,3 +146,45 @@ fn is_consistent_order<'tcx>(fields: &'tcx [hir::ExprField<'tcx>], def_order_map
 
     true
 }
+
+fn suggestion<'tcx>(
+    cx: &LateContext<'_>,
+    fields: &'tcx [hir::ExprField<'tcx>],
+    def_order_map: &FxHashMap<Symbol, usize>,
+) -> String {
+    let ws = fields
+        .windows(2)
+        .map(|w| {
+            let w0_span = field_with_attrs_span(cx.tcx, &w[0]);
+            let w1_span = field_with_attrs_span(cx.tcx, &w[1]);
+            let span = w0_span.between(w1_span);
+            snippet(cx, span, " ")
+        })
+        .collect::<Vec<_>>();
+
+    let mut fields = fields.to_vec();
+    fields.sort_unstable_by_key(|field| def_order_map[&field.ident.name]);
+    let field_snippets = fields
+        .iter()
+        .map(|field| snippet(cx, field_with_attrs_span(cx.tcx, field), ".."))
+        .collect::<Vec<_>>();
+
+    assert_eq!(field_snippets.len(), ws.len() + 1);
+
+    let mut sugg = String::new();
+    for i in 0..field_snippets.len() {
+        sugg += &field_snippets[i];
+        if i < ws.len() {
+            sugg += &ws[i];
+        }
+    }
+    sugg
+}
+
+fn field_with_attrs_span(tcx: TyCtxt<'_>, field: &hir::ExprField<'_>) -> Span {
+    if let Some(attr) = tcx.hir().attrs(field.hir_id).first() {
+        field.span.with_lo(attr.span.lo())
+    } else {
+        field.span
+    }
+}

clippy_lints/src/lib.rs

@@ -649,7 +649,11 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
     store.register_late_pass(|_| Box::new(implicit_return::ImplicitReturn));
     store.register_late_pass(move |_| Box::new(implicit_saturating_sub::ImplicitSaturatingSub::new(conf)));
     store.register_late_pass(|_| Box::new(default_numeric_fallback::DefaultNumericFallback));
-    store.register_late_pass(|_| Box::new(inconsistent_struct_constructor::InconsistentStructConstructor));
+    store.register_late_pass(move |_| {
+        Box::new(inconsistent_struct_constructor::InconsistentStructConstructor::new(
+            conf,
+        ))
+    });
     store.register_late_pass(|_| Box::new(non_octal_unix_permissions::NonOctalUnixPermissions));
     store.register_early_pass(|| Box::new(unnecessary_self_imports::UnnecessarySelfImports));
     store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(conf)));

clippy_lints/src/loops/infinite_loop.rs

@@ -38,8 +38,8 @@ pub(super) fn check<'tcx>(
         cx,
         label,
         inner_labels: label.into_iter().collect(),
-        is_finite: false,
         loop_depth: 0,
+        is_finite: false,
     };
     loop_visitor.visit_block(loop_block);
 

clippy_lints/src/macro_metavars_in_unsafe.rs

@@ -220,11 +220,11 @@ impl<'tcx> LateLintPass<'tcx> for ExprMetavarsInUnsafe {
         // `check_stmt_post` on `(Late)LintPass`, which we'd need to detect when we're leaving a macro span
 
         let mut vis = BodyVisitor {
+            macro_unsafe_blocks: Vec::new(),
             #[expect(clippy::bool_to_int_with_if)] // obfuscates the meaning
             expn_depth: if body.value.span.from_expansion() { 1 } else { 0 },
-            macro_unsafe_blocks: Vec::new(),
-            lint: self,
-            cx
+            cx,
+            lint: self
         };
         vis.visit_body(body);
     }

clippy_lints/src/methods/needless_collect.rs

@@ -470,14 +470,14 @@ fn detect_iter_and_into_iters<'tcx: 'a, 'a>(
     captured_ids: HirIdSet,
 ) -> Option<Vec<IterFunction>> {
     let mut visitor = IterFunctionVisitor {
-        uses: Vec::new(),
-        target: id,
-        seen_other: false,
-        cx,
-        current_mutably_captured_ids: HirIdSet::default(),
         illegal_mutable_capture_ids: captured_ids,
+        current_mutably_captured_ids: HirIdSet::default(),
+        cx,
+        uses: Vec::new(),
         hir_id_uses_map: FxHashMap::default(),
         current_statement_hir_id: None,
+        seen_other: false,
+        target: id,
     };
     visitor.visit_block(block);
     if visitor.seen_other {

clippy_lints/src/methods/str_splitn.rs

@@ -297,8 +297,8 @@ fn parse_iter_usage<'tcx>(
                     {
                         Some(IterUsage {
                             kind: IterUsageKind::NextTuple,
-                            span: e.span,
                             unwrap_kind: None,
+                            span: e.span,
                         })
                     } else {
                         None