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Fixed issue #15192 (#15241)

Browse Source 
Fixes rust-lang/rust-clippy#15192 by adding checks for no_std while
giving out Box recommendation

```
changelog: [`large_enum_variant`]: Dont suggest `Box` in `no_std` mode
```
This commit is contained in:
Timo
2025-07-20 10:37:58 +00:00
committed by GitHub
parent 56de455c7f b738d96325
commit c8e333c8c0
6 changed files with 72 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
clippy_lints/src/large_enum_variant.rs
View File

@@ -1,5 +1,6 @@
use clippy_config::Conf;
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::is_no_std_crate;
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::ty::{AdtVariantInfo, approx_ty_size, is_copy};
use rustc_errors::Applicability;
@@ -83,7 +84,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
let mut difference = variants_size[0].size - variants_size[1].size;
if difference > self.maximum_size_difference_allowed {
let help_text = "consider boxing the large fields to reduce the total size of the enum";
let help_text = "consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum";
span_lint_and_then(
cx,
LARGE_ENUM_VARIANT,
@@ -117,7 +118,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
ident.span,
"boxing a variant would require the type no longer be `Copy`",
);
} else {
} else if !is_no_std_crate(cx) {
let sugg: Vec<(Span, String)> = variants_size[0]
.fields_size
.iter()

2
tests/ui-toml/enum_variant_size/enum_variant_size.stderr
View File

@@ -12,7 +12,7 @@ LL | | }
|
= note: `-D clippy::large-enum-variant` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::large_enum_variant)]`
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B([u8; 501]),
LL + B(Box<[u8; 501]>),

36
tests/ui/large_enum_variant.32bit.stderr
View File

@@ -12,7 +12,7 @@ LL | | }
|
= note: `-D clippy::large-enum-variant` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::large_enum_variant)]`
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B([i32; 8000]),
LL + B(Box<[i32; 8000]>),
@@ -30,7 +30,7 @@ LL | | ContainingLargeEnum(LargeEnum),
LL | | }
| |_^ the entire enum is at least 32004 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - ContainingLargeEnum(LargeEnum),
LL + ContainingLargeEnum(Box<LargeEnum>),
@@ -49,7 +49,7 @@ LL | | StructLikeLittle { x: i32, y: i32 },
LL | | }
| |_^ the entire enum is at least 70008 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - ContainingMoreThanOneField(i32, [i32; 8000], [i32; 9500]),
LL + ContainingMoreThanOneField(i32, Box<[i32; 8000]>, Box<[i32; 9500]>),
@@ -67,7 +67,7 @@ LL | | StructLikeLarge { x: [i32; 8000], y: i32 },
LL | | }
| |_^ the entire enum is at least 32008 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - StructLikeLarge { x: [i32; 8000], y: i32 },
LL + StructLikeLarge { x: Box<[i32; 8000]>, y: i32 },
@@ -85,7 +85,7 @@ LL | | StructLikeLarge2 { x: [i32; 8000] },
LL | | }
| |_^ the entire enum is at least 32004 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - StructLikeLarge2 { x: [i32; 8000] },
LL + StructLikeLarge2 { x: Box<[i32; 8000]> },
@@ -104,7 +104,7 @@ LL | | C([u8; 200]),
LL | | }
| |_^ the entire enum is at least 1256 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B([u8; 1255]),
LL + B(Box<[u8; 1255]>),
@@ -122,7 +122,7 @@ LL | | ContainingMoreThanOneField([i32; 8000], [i32; 2], [i32; 9500], [i32;
LL | | }
| |_^ the entire enum is at least 70132 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - ContainingMoreThanOneField([i32; 8000], [i32; 2], [i32; 9500], [i32; 30]),
LL + ContainingMoreThanOneField(Box<[i32; 8000]>, [i32; 2], Box<[i32; 9500]>, [i32; 30]),
@@ -140,7 +140,7 @@ LL | | B(Struct2),
LL | | }
| |_^ the entire enum is at least 32004 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B(Struct2),
LL + B(Box<Struct2>),
@@ -158,7 +158,7 @@ LL | | B(Struct2),
LL | | }
| |_^ the entire enum is at least 32000 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B(Struct2),
LL + B(Box<Struct2>),
@@ -176,7 +176,7 @@ LL | | B(Struct2),
LL | | }
| |_^ the entire enum is at least 32000 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B(Struct2),
LL + B(Box<Struct2>),
@@ -199,7 +199,7 @@ note: boxing a variant would require the type no longer be `Copy`
|
LL | enum CopyableLargeEnum {
| ^^^^^^^^^^^^^^^^^
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant.rs:118:5
|
LL | B([u64; 8000]),
@@ -222,7 +222,7 @@ note: boxing a variant would require the type no longer be `Copy`
|
LL | enum ManuallyCopyLargeEnum {
| ^^^^^^^^^^^^^^^^^^^^^
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant.rs:124:5
|
LL | B([u64; 8000]),
@@ -245,7 +245,7 @@ note: boxing a variant would require the type no longer be `Copy`
|
LL | enum SomeGenericPossiblyCopyEnum<T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant.rs:138:5
|
LL | B([u64; 4000]),
@@ -263,7 +263,7 @@ LL | | Large((T, [u8; 512])),
LL | | }
| |_^ the entire enum is at least 512 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Large((T, [u8; 512])),
LL + Large(Box<(T, [u8; 512])>),
@@ -281,7 +281,7 @@ LL | | Small(u8),
LL | | }
| |_^ the entire enum is at least 516 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Large([Foo<u64>; 64]),
LL + Large(Box<[Foo<u64>; 64]>),
@@ -299,7 +299,7 @@ LL | | Error(PossiblyLargeEnumWithConst<256>),
LL | | }
| |_^ the entire enum is at least 514 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Error(PossiblyLargeEnumWithConst<256>),
LL + Error(Box<PossiblyLargeEnumWithConst<256>>),
@@ -317,7 +317,7 @@ LL | | Recursive(Box<WithRecursion>),
LL | | }
| |_^ the entire enum is at least 516 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Large([u64; 64]),
LL + Large(Box<[u64; 64]>),
@@ -335,7 +335,7 @@ LL | | Error(WithRecursionAndGenerics<u64>),
LL | | }
| |_^ the entire enum is at least 516 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Error(WithRecursionAndGenerics<u64>),
LL + Error(Box<WithRecursionAndGenerics<u64>>),

40
tests/ui/large_enum_variant.64bit.stderr
View File

@@ -12,7 +12,7 @@ LL | | }
|
= note: `-D clippy::large-enum-variant` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::large_enum_variant)]`
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B([i32; 8000]),
LL + B(Box<[i32; 8000]>),
@@ -30,7 +30,7 @@ LL | | ContainingLargeEnum(LargeEnum),
LL | | }
| |_^ the entire enum is at least 32004 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - ContainingLargeEnum(LargeEnum),
LL + ContainingLargeEnum(Box<LargeEnum>),
@@ -49,7 +49,7 @@ LL | | StructLikeLittle { x: i32, y: i32 },
LL | | }
| |_^ the entire enum is at least 70008 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - ContainingMoreThanOneField(i32, [i32; 8000], [i32; 9500]),
LL + ContainingMoreThanOneField(i32, Box<[i32; 8000]>, Box<[i32; 9500]>),
@@ -67,7 +67,7 @@ LL | | StructLikeLarge { x: [i32; 8000], y: i32 },
LL | | }
| |_^ the entire enum is at least 32008 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - StructLikeLarge { x: [i32; 8000], y: i32 },
LL + StructLikeLarge { x: Box<[i32; 8000]>, y: i32 },
@@ -85,7 +85,7 @@ LL | | StructLikeLarge2 { x: [i32; 8000] },
LL | | }
| |_^ the entire enum is at least 32004 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - StructLikeLarge2 { x: [i32; 8000] },
LL + StructLikeLarge2 { x: Box<[i32; 8000]> },
@@ -104,7 +104,7 @@ LL | | C([u8; 200]),
LL | | }
| |_^ the entire enum is at least 1256 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B([u8; 1255]),
LL + B(Box<[u8; 1255]>),
@@ -122,7 +122,7 @@ LL | | ContainingMoreThanOneField([i32; 8000], [i32; 2], [i32; 9500], [i32;
LL | | }
| |_^ the entire enum is at least 70132 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - ContainingMoreThanOneField([i32; 8000], [i32; 2], [i32; 9500], [i32; 30]),
LL + ContainingMoreThanOneField(Box<[i32; 8000]>, [i32; 2], Box<[i32; 9500]>, [i32; 30]),
@@ -140,7 +140,7 @@ LL | | B(Struct2),
LL | | }
| |_^ the entire enum is at least 32004 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B(Struct2),
LL + B(Box<Struct2>),
@@ -158,7 +158,7 @@ LL | | B(Struct2),
LL | | }
| |_^ the entire enum is at least 32000 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B(Struct2),
LL + B(Box<Struct2>),
@@ -176,7 +176,7 @@ LL | | B(Struct2),
LL | | }
| |_^ the entire enum is at least 32000 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - B(Struct2),
LL + B(Box<Struct2>),
@@ -199,7 +199,7 @@ note: boxing a variant would require the type no longer be `Copy`
|
LL | enum CopyableLargeEnum {
| ^^^^^^^^^^^^^^^^^
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant.rs:118:5
|
LL | B([u64; 8000]),
@@ -222,7 +222,7 @@ note: boxing a variant would require the type no longer be `Copy`
|
LL | enum ManuallyCopyLargeEnum {
| ^^^^^^^^^^^^^^^^^^^^^
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant.rs:124:5
|
LL | B([u64; 8000]),
@@ -245,7 +245,7 @@ note: boxing a variant would require the type no longer be `Copy`
|
LL | enum SomeGenericPossiblyCopyEnum<T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant.rs:138:5
|
LL | B([u64; 4000]),
@@ -263,7 +263,7 @@ LL | | Large((T, [u8; 512])),
LL | | }
| |_^ the entire enum is at least 512 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Large((T, [u8; 512])),
LL + Large(Box<(T, [u8; 512])>),
@@ -281,7 +281,7 @@ LL | | Small(u8),
LL | | }
| |_^ the entire enum is at least 520 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Large([Foo<u64>; 64]),
LL + Large(Box<[Foo<u64>; 64]>),
@@ -299,7 +299,7 @@ LL | | Error(PossiblyLargeEnumWithConst<256>),
LL | | }
| |_^ the entire enum is at least 514 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Error(PossiblyLargeEnumWithConst<256>),
LL + Error(Box<PossiblyLargeEnumWithConst<256>>),
@@ -317,7 +317,7 @@ LL | | Recursive(Box<WithRecursion>),
LL | | }
| |_^ the entire enum is at least 520 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Large([u64; 64]),
LL + Large(Box<[u64; 64]>),
@@ -335,7 +335,7 @@ LL | | Error(WithRecursionAndGenerics<u64>),
LL | | }
| |_^ the entire enum is at least 520 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - Error(WithRecursionAndGenerics<u64>),
LL + Error(Box<WithRecursionAndGenerics<u64>>),
@@ -353,7 +353,7 @@ LL | | _SmallBoi(u8),
LL | | }
| |_____^ the entire enum is at least 296 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - BigBoi(PublishWithBytes),
LL + BigBoi(Box<PublishWithBytes>),
@@ -371,7 +371,7 @@ LL | | _SmallBoi(u8),
LL | | }
| |_____^ the entire enum is at least 224 bytes
|
help: consider boxing the large fields to reduce the total size of the enum
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
|
LL - BigBoi(PublishWithVec),
LL + BigBoi(Box<PublishWithVec>),

8
tests/ui/large_enum_variant_no_std.rs Normal file
View File

@@ -0,0 +1,8 @@
#![no_std]
#![warn(clippy::large_enum_variant)]
enum Myenum {
//~^ ERROR: large size difference between variants
Small(u8),
Large([u8; 1024]),
}

22
tests/ui/large_enum_variant_no_std.stderr Normal file
View File

@@ -0,0 +1,22 @@
error: large size difference between variants
--> tests/ui/large_enum_variant_no_std.rs:4:1
|
LL | / enum Myenum {
LL | |
LL | | Small(u8),
| | --------- the second-largest variant contains at least 1 bytes
LL | | Large([u8; 1024]),
| | ----------------- the largest variant contains at least 1024 bytes
LL | | }
| |_^ the entire enum is at least 1025 bytes
|
help: consider boxing the large fields or introducing indirection in some other way to reduce the total size of the enum
--> tests/ui/large_enum_variant_no_std.rs:7:5
|
LL | Large([u8; 1024]),
| ^^^^^^^^^^^^^^^^^
= note: `-D clippy::large-enum-variant` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::large_enum_variant)]`
error: aborting due to 1 previous error