diff --git a/CHANGELOG.md b/CHANGELOG.md index 47a503510..1323f973c 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -4987,6 +4987,7 @@ Released 2018-09-13 [`unnecessary_safety_doc`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_safety_doc [`unnecessary_self_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_self_imports [`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by +[`unnecessary_struct_initialization`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_struct_initialization [`unnecessary_to_owned`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_to_owned [`unnecessary_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap [`unnecessary_wraps`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_wraps diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index 2331e857b..8ca913014 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -618,6 +618,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::unnamed_address::VTABLE_ADDRESS_COMPARISONS_INFO, crate::unnecessary_owned_empty_strings::UNNECESSARY_OWNED_EMPTY_STRINGS_INFO, crate::unnecessary_self_imports::UNNECESSARY_SELF_IMPORTS_INFO, + crate::unnecessary_struct_initialization::UNNECESSARY_STRUCT_INITIALIZATION_INFO, crate::unnecessary_wraps::UNNECESSARY_WRAPS_INFO, crate::unnested_or_patterns::UNNESTED_OR_PATTERNS_INFO, crate::unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME_INFO, diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 100cba456..c9210bf73 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -302,6 +302,7 @@ mod unit_types; mod unnamed_address; mod unnecessary_owned_empty_strings; mod unnecessary_self_imports; +mod unnecessary_struct_initialization; mod unnecessary_wraps; mod unnested_or_patterns; mod unsafe_removed_from_name; @@ -938,6 +939,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|_| Box::new(let_with_type_underscore::UnderscoreTyped)); store.register_late_pass(|_| Box::new(allow_attributes::AllowAttribute)); store.register_late_pass(move |_| Box::new(manual_main_separator_str::ManualMainSeparatorStr::new(msrv()))); + store.register_late_pass(|_| Box::new(unnecessary_struct_initialization::UnnecessaryStruct)); // add lints here, do not remove this comment, it's used in `new_lint` } diff --git a/clippy_lints/src/unnecessary_struct_initialization.rs b/clippy_lints/src/unnecessary_struct_initialization.rs new file mode 100644 index 000000000..af0b4b159 --- /dev/null +++ b/clippy_lints/src/unnecessary_struct_initialization.rs @@ -0,0 +1,84 @@ +use clippy_utils::{diagnostics::span_lint_and_sugg, get_parent_expr, path_to_local, source::snippet, ty::is_copy}; +use rustc_hir::{BindingAnnotation, Expr, ExprKind, Node, PatKind, UnOp}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; + +declare_clippy_lint! { + /// ### What it does + /// Checks for initialization of a `struct` by copying a base without setting + /// any field. + /// + /// ### Why is this bad? + /// Readibility suffers from unnecessary struct building. + /// + /// ### Example + /// ```rust + /// struct S { s: String } + /// + /// let a = S { s: String::from("Hello, world!") }; + /// let b = S { ..a }; + /// ``` + /// Use instead: + /// ```rust + /// struct S { s: String } + /// + /// let a = S { s: String::from("Hello, world!") }; + /// let b = a; + /// ``` + #[clippy::version = "1.70.0"] + pub UNNECESSARY_STRUCT_INITIALIZATION, + complexity, + "struct built from a base that can be written mode concisely" +} +declare_lint_pass!(UnnecessaryStruct => [UNNECESSARY_STRUCT_INITIALIZATION]); + +impl LateLintPass<'_> for UnnecessaryStruct { + fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { + if let ExprKind::Struct(_, &[], Some(base)) = expr.kind { + if let Some(parent) = get_parent_expr(cx, expr) && + let parent_ty = cx.typeck_results().expr_ty_adjusted(parent) && + parent_ty.is_any_ptr() + { + if is_copy(cx, cx.typeck_results().expr_ty(expr)) && path_to_local(base).is_some() { + // When the type implements `Copy`, a reference to the new struct works on the + // copy. Using the original would borrow it. + return; + } + + if parent_ty.is_mutable_ptr() && !is_mutable(cx, base) { + // The original can be used in a mutable reference context only if it is mutable. + return; + } + } + + // TODO: do not propose to replace *XX if XX is not Copy + if let ExprKind::Unary(UnOp::Deref, target) = base.kind && + matches!(target.kind, ExprKind::Path(..)) && + !is_copy(cx, cx.typeck_results().expr_ty(expr)) + { + // `*base` cannot be used instead of the struct in the general case if it is not Copy. + return; + } + + span_lint_and_sugg( + cx, + UNNECESSARY_STRUCT_INITIALIZATION, + expr.span, + "unnecessary struct building", + "replace with", + snippet(cx, base.span, "..").into_owned(), + rustc_errors::Applicability::MachineApplicable, + ); + } + } +} + +fn is_mutable(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { + if let Some(hir_id) = path_to_local(expr) && + let Node::Pat(pat) = cx.tcx.hir().get(hir_id) + { + matches!(pat.kind, PatKind::Binding(BindingAnnotation::MUT, ..)) + } else { + true + } +} diff --git a/tests/ui/needless_update.rs b/tests/ui/needless_update.rs index b93ff048a..4e8517cad 100644 --- a/tests/ui/needless_update.rs +++ b/tests/ui/needless_update.rs @@ -1,5 +1,5 @@ #![warn(clippy::needless_update)] -#![allow(clippy::no_effect)] +#![allow(clippy::no_effect, clippy::unnecessary_struct_initialization)] struct S { pub a: i32, diff --git a/tests/ui/no_effect.rs b/tests/ui/no_effect.rs index f08eb092e..ac8b1e756 100644 --- a/tests/ui/no_effect.rs +++ b/tests/ui/no_effect.rs @@ -1,7 +1,12 @@ #![feature(box_syntax, fn_traits, unboxed_closures)] #![warn(clippy::no_effect_underscore_binding)] #![allow(dead_code, path_statements)] -#![allow(clippy::deref_addrof, clippy::redundant_field_names, clippy::uninlined_format_args)] +#![allow( + clippy::deref_addrof, + clippy::redundant_field_names, + clippy::uninlined_format_args, + clippy::unnecessary_struct_initialization +)] struct Unit; struct Tuple(i32); diff --git a/tests/ui/no_effect.stderr b/tests/ui/no_effect.stderr index 6a1e636f9..2efefd2b2 100644 --- a/tests/ui/no_effect.stderr +++ b/tests/ui/no_effect.stderr @@ -1,5 +1,5 @@ error: statement with no effect - --> $DIR/no_effect.rs:92:5 + --> $DIR/no_effect.rs:97:5 | LL | 0; | ^^ @@ -7,157 +7,157 @@ LL | 0; = note: `-D clippy::no-effect` implied by `-D warnings` error: statement with no effect - --> $DIR/no_effect.rs:93:5 + --> $DIR/no_effect.rs:98:5 | LL | s2; | ^^^ error: statement with no effect - --> $DIR/no_effect.rs:94:5 + --> $DIR/no_effect.rs:99:5 | LL | Unit; | ^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:95:5 + --> $DIR/no_effect.rs:100:5 | LL | Tuple(0); | ^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:96:5 + --> $DIR/no_effect.rs:101:5 | LL | Struct { field: 0 }; | ^^^^^^^^^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:97:5 + --> $DIR/no_effect.rs:102:5 | LL | Struct { ..s }; | ^^^^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:98:5 + --> $DIR/no_effect.rs:103:5 | LL | Union { a: 0 }; | ^^^^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:99:5 + --> $DIR/no_effect.rs:104:5 | LL | Enum::Tuple(0); | ^^^^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:100:5 + --> $DIR/no_effect.rs:105:5 | LL | Enum::Struct { field: 0 }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:101:5 + --> $DIR/no_effect.rs:106:5 | LL | 5 + 6; | ^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:102:5 + --> $DIR/no_effect.rs:107:5 | LL | *&42; | ^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:103:5 + --> $DIR/no_effect.rs:108:5 | LL | &6; | ^^^ error: statement with no effect - --> $DIR/no_effect.rs:104:5 + --> $DIR/no_effect.rs:109:5 | LL | (5, 6, 7); | ^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:105:5 + --> $DIR/no_effect.rs:110:5 | LL | box 42; | ^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:106:5 + --> $DIR/no_effect.rs:111:5 | LL | ..; | ^^^ error: statement with no effect - --> $DIR/no_effect.rs:107:5 + --> $DIR/no_effect.rs:112:5 | LL | 5..; | ^^^^ error: statement with no effect - --> $DIR/no_effect.rs:108:5 + --> $DIR/no_effect.rs:113:5 | LL | ..5; | ^^^^ error: statement with no effect - --> $DIR/no_effect.rs:109:5 + --> $DIR/no_effect.rs:114:5 | LL | 5..6; | ^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:110:5 + --> $DIR/no_effect.rs:115:5 | LL | 5..=6; | ^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:111:5 + --> $DIR/no_effect.rs:116:5 | LL | [42, 55]; | ^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:112:5 + --> $DIR/no_effect.rs:117:5 | LL | [42, 55][1]; | ^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:113:5 + --> $DIR/no_effect.rs:118:5 | LL | (42, 55).1; | ^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:114:5 + --> $DIR/no_effect.rs:119:5 | LL | [42; 55]; | ^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:115:5 + --> $DIR/no_effect.rs:120:5 | LL | [42; 55][13]; | ^^^^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:117:5 + --> $DIR/no_effect.rs:122:5 | LL | || x += 5; | ^^^^^^^^^^ error: statement with no effect - --> $DIR/no_effect.rs:119:5 + --> $DIR/no_effect.rs:124:5 | LL | FooString { s: s }; | ^^^^^^^^^^^^^^^^^^^ error: binding to `_` prefixed variable with no side-effect - --> $DIR/no_effect.rs:120:5 + --> $DIR/no_effect.rs:125:5 | LL | let _unused = 1; | ^^^^^^^^^^^^^^^^ @@ -165,19 +165,19 @@ LL | let _unused = 1; = note: `-D clippy::no-effect-underscore-binding` implied by `-D warnings` error: binding to `_` prefixed variable with no side-effect - --> $DIR/no_effect.rs:121:5 + --> $DIR/no_effect.rs:126:5 | LL | let _penguin = || println!("Some helpful closure"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: binding to `_` prefixed variable with no side-effect - --> $DIR/no_effect.rs:122:5 + --> $DIR/no_effect.rs:127:5 | LL | let _duck = Struct { field: 0 }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: binding to `_` prefixed variable with no side-effect - --> $DIR/no_effect.rs:123:5 + --> $DIR/no_effect.rs:128:5 | LL | let _cat = [2, 4, 6, 8][2]; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/tests/ui/unnecessary_operation.fixed b/tests/ui/unnecessary_operation.fixed index d37163570..ec931c726 100644 --- a/tests/ui/unnecessary_operation.fixed +++ b/tests/ui/unnecessary_operation.fixed @@ -1,7 +1,13 @@ // run-rustfix #![feature(box_syntax)] -#![allow(clippy::deref_addrof, dead_code, unused, clippy::no_effect)] +#![allow( + clippy::deref_addrof, + dead_code, + unused, + clippy::no_effect, + clippy::unnecessary_struct_initialization +)] #![warn(clippy::unnecessary_operation)] struct Tuple(i32); diff --git a/tests/ui/unnecessary_operation.rs b/tests/ui/unnecessary_operation.rs index a14fd4bca..d896df32e 100644 --- a/tests/ui/unnecessary_operation.rs +++ b/tests/ui/unnecessary_operation.rs @@ -1,7 +1,13 @@ // run-rustfix #![feature(box_syntax)] -#![allow(clippy::deref_addrof, dead_code, unused, clippy::no_effect)] +#![allow( + clippy::deref_addrof, + dead_code, + unused, + clippy::no_effect, + clippy::unnecessary_struct_initialization +)] #![warn(clippy::unnecessary_operation)] struct Tuple(i32); diff --git a/tests/ui/unnecessary_operation.stderr b/tests/ui/unnecessary_operation.stderr index f66d08ecb..c183082ec 100644 --- a/tests/ui/unnecessary_operation.stderr +++ b/tests/ui/unnecessary_operation.stderr @@ -1,5 +1,5 @@ error: unnecessary operation - --> $DIR/unnecessary_operation.rs:51:5 + --> $DIR/unnecessary_operation.rs:57:5 | LL | Tuple(get_number()); | ^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` @@ -7,109 +7,109 @@ LL | Tuple(get_number()); = note: `-D clippy::unnecessary-operation` implied by `-D warnings` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:52:5 + --> $DIR/unnecessary_operation.rs:58:5 | LL | Struct { field: get_number() }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:53:5 + --> $DIR/unnecessary_operation.rs:59:5 | LL | Struct { ..get_struct() }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_struct();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:54:5 + --> $DIR/unnecessary_operation.rs:60:5 | LL | Enum::Tuple(get_number()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:55:5 + --> $DIR/unnecessary_operation.rs:61:5 | LL | Enum::Struct { field: get_number() }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:56:5 + --> $DIR/unnecessary_operation.rs:62:5 | LL | 5 + get_number(); | ^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:57:5 + --> $DIR/unnecessary_operation.rs:63:5 | LL | *&get_number(); | ^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:58:5 + --> $DIR/unnecessary_operation.rs:64:5 | LL | &get_number(); | ^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:59:5 + --> $DIR/unnecessary_operation.rs:65:5 | LL | (5, 6, get_number()); | ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;6;get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:60:5 + --> $DIR/unnecessary_operation.rs:66:5 | LL | box get_number(); | ^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:61:5 + --> $DIR/unnecessary_operation.rs:67:5 | LL | get_number()..; | ^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:62:5 + --> $DIR/unnecessary_operation.rs:68:5 | LL | ..get_number(); | ^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:63:5 + --> $DIR/unnecessary_operation.rs:69:5 | LL | 5..get_number(); | ^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:64:5 + --> $DIR/unnecessary_operation.rs:70:5 | LL | [42, get_number()]; | ^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42;get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:65:5 + --> $DIR/unnecessary_operation.rs:71:5 | LL | [42, 55][get_usize()]; | ^^^^^^^^^^^^^^^^^^^^^^ help: statement can be written as: `assert!([42, 55].len() > get_usize());` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:66:5 + --> $DIR/unnecessary_operation.rs:72:5 | LL | (42, get_number()).1; | ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42;get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:67:5 + --> $DIR/unnecessary_operation.rs:73:5 | LL | [get_number(); 55]; | ^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:68:5 + --> $DIR/unnecessary_operation.rs:74:5 | LL | [42; 55][get_usize()]; | ^^^^^^^^^^^^^^^^^^^^^^ help: statement can be written as: `assert!([42; 55].len() > get_usize());` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:69:5 + --> $DIR/unnecessary_operation.rs:75:5 | LL | / { LL | | get_number() @@ -117,7 +117,7 @@ LL | | }; | |______^ help: statement can be reduced to: `get_number();` error: unnecessary operation - --> $DIR/unnecessary_operation.rs:72:5 + --> $DIR/unnecessary_operation.rs:78:5 | LL | / FooString { LL | | s: String::from("blah"), diff --git a/tests/ui/unnecessary_struct_initialization.fixed b/tests/ui/unnecessary_struct_initialization.fixed new file mode 100644 index 000000000..b47129e4a --- /dev/null +++ b/tests/ui/unnecessary_struct_initialization.fixed @@ -0,0 +1,73 @@ +// run-rustfix + +#![allow(unused)] +#![warn(clippy::unnecessary_struct_initialization)] + +struct S { + f: String, +} + +#[derive(Clone, Copy)] +struct T { + f: u32, +} + +struct U { + f: u32, +} + +impl Clone for U { + fn clone(&self) -> Self { + // Do not lint: `Self` does not implement `Copy` + Self { ..*self } + } +} + +#[derive(Copy)] +struct V { + f: u32, +} + +impl Clone for V { + fn clone(&self) -> Self { + // Lint: `Self` implements `Copy` + *self + } +} + +fn main() { + // Should lint: `a` would be consumed anyway + let a = S { f: String::from("foo") }; + let mut b = a; + + // Should lint: `b` would be consumed, and is mutable + let c = &mut b; + + // Should not lint as `d` is not mutable + let d = S { f: String::from("foo") }; + let e = &mut S { ..d }; + + // Should lint as `f` would be consumed anyway + let f = S { f: String::from("foo") }; + let g = &f; + + // Should lint: the result of an expression is mutable + let h = &mut *Box::new(S { f: String::from("foo") }); + + // Should not lint: `m` would be both alive and borrowed + let m = T { f: 17 }; + let n = &T { ..m }; + + // Should not lint: `m` should not be modified + let o = &mut T { ..m }; + o.f = 32; + assert_eq!(m.f, 17); + + // Should not lint: `m` should not be modified + let o = &mut T { ..m } as *mut T; + unsafe { &mut *o }.f = 32; + assert_eq!(m.f, 17); + + // Should lint: the result of an expression is mutable and temporary + let p = &mut *Box::new(T { f: 5 }); +} diff --git a/tests/ui/unnecessary_struct_initialization.rs b/tests/ui/unnecessary_struct_initialization.rs new file mode 100644 index 000000000..63b11c626 --- /dev/null +++ b/tests/ui/unnecessary_struct_initialization.rs @@ -0,0 +1,77 @@ +// run-rustfix + +#![allow(unused)] +#![warn(clippy::unnecessary_struct_initialization)] + +struct S { + f: String, +} + +#[derive(Clone, Copy)] +struct T { + f: u32, +} + +struct U { + f: u32, +} + +impl Clone for U { + fn clone(&self) -> Self { + // Do not lint: `Self` does not implement `Copy` + Self { ..*self } + } +} + +#[derive(Copy)] +struct V { + f: u32, +} + +impl Clone for V { + fn clone(&self) -> Self { + // Lint: `Self` implements `Copy` + Self { ..*self } + } +} + +fn main() { + // Should lint: `a` would be consumed anyway + let a = S { f: String::from("foo") }; + let mut b = S { ..a }; + + // Should lint: `b` would be consumed, and is mutable + let c = &mut S { ..b }; + + // Should not lint as `d` is not mutable + let d = S { f: String::from("foo") }; + let e = &mut S { ..d }; + + // Should lint as `f` would be consumed anyway + let f = S { f: String::from("foo") }; + let g = &S { ..f }; + + // Should lint: the result of an expression is mutable + let h = &mut S { + ..*Box::new(S { f: String::from("foo") }) + }; + + // Should not lint: `m` would be both alive and borrowed + let m = T { f: 17 }; + let n = &T { ..m }; + + // Should not lint: `m` should not be modified + let o = &mut T { ..m }; + o.f = 32; + assert_eq!(m.f, 17); + + // Should not lint: `m` should not be modified + let o = &mut T { ..m } as *mut T; + unsafe { &mut *o }.f = 32; + assert_eq!(m.f, 17); + + // Should lint: the result of an expression is mutable and temporary + let p = &mut T { + ..*Box::new(T { f: 5 }) + }; +} diff --git a/tests/ui/unnecessary_struct_initialization.stderr b/tests/ui/unnecessary_struct_initialization.stderr new file mode 100644 index 000000000..ca4970577 --- /dev/null +++ b/tests/ui/unnecessary_struct_initialization.stderr @@ -0,0 +1,46 @@ +error: unnecessary struct building + --> $DIR/unnecessary_struct_initialization.rs:34:9 + | +LL | Self { ..*self } + | ^^^^^^^^^^^^^^^^ help: replace with: `*self` + | + = note: `-D clippy::unnecessary-struct-initialization` implied by `-D warnings` + +error: unnecessary struct building + --> $DIR/unnecessary_struct_initialization.rs:41:17 + | +LL | let mut b = S { ..a }; + | ^^^^^^^^^ help: replace with: `a` + +error: unnecessary struct building + --> $DIR/unnecessary_struct_initialization.rs:44:18 + | +LL | let c = &mut S { ..b }; + | ^^^^^^^^^ help: replace with: `b` + +error: unnecessary struct building + --> $DIR/unnecessary_struct_initialization.rs:52:14 + | +LL | let g = &S { ..f }; + | ^^^^^^^^^ help: replace with: `f` + +error: unnecessary struct building + --> $DIR/unnecessary_struct_initialization.rs:55:18 + | +LL | let h = &mut S { + | __________________^ +LL | | ..*Box::new(S { f: String::from("foo") }) +LL | | }; + | |_____^ help: replace with: `*Box::new(S { f: String::from("foo") })` + +error: unnecessary struct building + --> $DIR/unnecessary_struct_initialization.rs:74:18 + | +LL | let p = &mut T { + | __________________^ +LL | | ..*Box::new(T { f: 5 }) +LL | | }; + | |_____^ help: replace with: `*Box::new(T { f: 5 })` + +error: aborting due to 6 previous errors +