Enum wasmi::TrapKind

source ·

pub enum TrapKind {
    Unreachable,
    MemoryAccessOutOfBounds,
    TableAccessOutOfBounds,
    ElemUninitialized,
    DivisionByZero,
    InvalidConversionToInt,
    StackOverflow,
    UnexpectedSignature,
    Host(Box<dyn HostError>),
}

Expand description

Error type which can be thrown by wasm code or by host environment.

See Trap for details.

Variants§

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Unreachable

Wasm code executed unreachable opcode.

unreachable is a special opcode which always traps upon execution. This opcode have a similar purpose as ud2 in x86.

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MemoryAccessOutOfBounds

Attempt to load or store at the address which lies outside of bounds of the memory.

Since addresses are interpreted as unsigned integers, out of bounds access can’t happen with negative addresses (i.e. they will always wrap).

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TableAccessOutOfBounds

Attempt to access table element at index which lies outside of bounds.

This typically can happen when call_indirect is executed with index that lies out of bounds.

Since indexes are interpreted as unsinged integers, out of bounds access can’t happen with negative indexes (i.e. they will always wrap).

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ElemUninitialized

Attempt to access table element which is uninitialized (i.e. None).

This typically can happen when call_indirect is executed.

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DivisionByZero

Attempt to divide by zero.

This trap typically can happen if div or rem is executed with zero as divider.

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InvalidConversionToInt

Attempt to make a conversion to an int failed.

This can happen when:

trying to do signed division (or get the remainder) -2^N-1 over -1. This is because the result +2^N-1 isn’t representable as a N-bit signed integer.
trying to truncate NaNs, infinity, or value for which the result is out of range into an integer.

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StackOverflow

Stack overflow.

This is likely caused by some infinite or very deep recursion. Extensive inlining might also be the cause of stack overflow.

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UnexpectedSignature

Attempt to invoke a function with mismatching signature.

This can happen if FuncInstance was invoked with mismatching signature.

This can always happen with indirect calls. call_indirect instruction always specifies the expected signature of function. If call_indirect is executed with index that points on function with signature different that is expected by this call_indirect, this trap is raised.

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