Enum rustc_const_eval::interpret::UndefinedBehaviorInfo

pub enum UndefinedBehaviorInfo {
    Ub(String),
    Unreachable,
    BoundsCheckFailed {
        len: u64,
        index: u64,
    },
    DivisionByZero,
    RemainderByZero,
    DivisionOverflow,
    RemainderOverflow,
    PointerArithOverflow,
    InvalidMeta(&'static str),
    UnterminatedCString(Pointer<AllocId>),
    PointerUseAfterFree(AllocId),
    PointerOutOfBounds {
        alloc_id: AllocId,
        alloc_size: Size,
        ptr_offset: i64,
        ptr_size: Size,
        msg: CheckInAllocMsg,
    },
    DanglingIntPointer(u64, CheckInAllocMsg),
    AlignmentCheckFailed {
        required: Align,
        has: Align,
    },
    WriteToReadOnly(AllocId),
    DerefFunctionPointer(AllocId),
    DerefVTablePointer(AllocId),
    ValidationFailure {
        path: Option<String>,
        msg: String,
    },
    InvalidBool(u8),
    InvalidChar(u32),
    InvalidTag(Scalar<AllocId>),
    InvalidFunctionPointer(Pointer<AllocId>),
    InvalidVTablePointer(Pointer<AllocId>),
    InvalidStr(Utf8Error),
    InvalidUninitBytes(Option<(AllocId, UninitBytesAccess)>),
    DeadLocal,
    ScalarSizeMismatch(ScalarSizeMismatch),
    UninhabitedEnumVariantWritten,
}

Error information for when the program caused Undefined Behavior.

Variants

Ub(String)

Free-form case. Only for errors that are never caught!

Unreachable

Unreachable code was executed.

BoundsCheckFailed

Fields

len: u64

index: u64

A slice/array index projection went out-of-bounds.

DivisionByZero

Something was divided by 0 (x / 0).

RemainderByZero

Something was “remainded” by 0 (x % 0).

DivisionOverflow

Signed division overflowed (INT_MIN / -1).

RemainderOverflow

Signed remainder overflowed (INT_MIN % -1).

PointerArithOverflow

Overflowing inbounds pointer arithmetic.

InvalidMeta(&'static str)

Invalid metadata in a wide pointer (using str to avoid allocations).

UnterminatedCString(Pointer<AllocId>)

Reading a C string that does not end within its allocation.

PointerUseAfterFree(AllocId)

Dereferencing a dangling pointer after it got freed.

PointerOutOfBounds

Fields

alloc_id: AllocId

alloc_size: Size

ptr_offset: i64

ptr_size: Size

msg: CheckInAllocMsg

Used a pointer outside the bounds it is valid for. (If ptr_size > 0, determines the size of the memory range that was expected to be in-bounds.)

DanglingIntPointer(u64, CheckInAllocMsg)

Using an integer as a pointer in the wrong way.

AlignmentCheckFailed

Fields

required: Align

has: Align

Used a pointer with bad alignment.

WriteToReadOnly(AllocId)

Writing to read-only memory.

DerefFunctionPointer(AllocId)

DerefVTablePointer(AllocId)

ValidationFailure

Fields

path: Option<String>

The “path” to the value in question, e.g. .0[5].field for a struct field in the 6th element of an array that is the first element of a tuple.

msg: String

The value validity check found a problem. Should only be thrown by validity.rs and always point out which part of the value is the problem.

InvalidBool(u8)

Using a non-boolean u8 as bool.

InvalidChar(u32)

Using a non-character u32 as character.

InvalidTag(Scalar<AllocId>)

The tag of an enum does not encode an actual discriminant.

InvalidFunctionPointer(Pointer<AllocId>)

Using a pointer-not-to-a-function as function pointer.

InvalidVTablePointer(Pointer<AllocId>)

Using a pointer-not-to-a-vtable as vtable pointer.

InvalidStr(Utf8Error)

Using a string that is not valid UTF-8,

InvalidUninitBytes(Option<(AllocId, UninitBytesAccess)>)

Using uninitialized data where it is not allowed.

DeadLocal

Working with a local that is not currently live.

ScalarSizeMismatch(ScalarSizeMismatch)

Data size is not equal to target size.

UninhabitedEnumVariantWritten

A discriminant of an uninhabited enum variant is written.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 56 bytes

Size for each variant:

• Ub: 31 bytes
• Unreachable: 0 bytes
• BoundsCheckFailed: 23 bytes
• DivisionByZero: 0 bytes
• RemainderByZero: 0 bytes
• DivisionOverflow: 0 bytes
• RemainderOverflow: 0 bytes
• PointerArithOverflow: 0 bytes
• InvalidMeta: 23 bytes
• UnterminatedCString: 23 bytes
• PointerUseAfterFree: 15 bytes
• PointerOutOfBounds: 39 bytes
• DanglingIntPointer: 15 bytes
• AlignmentCheckFailed: 2 bytes
• WriteToReadOnly: 15 bytes
• DerefFunctionPointer: 15 bytes
• DerefVTablePointer: 15 bytes
• ValidationFailure: 55 bytes
• InvalidBool: 1 byte
• InvalidChar: 7 bytes
• InvalidTag: 31 bytes
• InvalidFunctionPointer: 23 bytes
• InvalidVTablePointer: 23 bytes
• InvalidStr: 23 bytes
• InvalidUninitBytes: 47 bytes
• DeadLocal: 0 bytes
• ScalarSizeMismatch: 23 bytes
• UninhabitedEnumVariantWritten: 0 bytes