Enum TrapCode

pub enum TrapCode {
    UnreachableCodeReached,
    MemoryOutOfBounds,
    TableOutOfBounds,
    IndirectCallToNull,
    IntegerDivisionByZero,
    IntegerOverflow,
    BadConversionToInteger,
    StackOverflow,
    BadSignature,
    OutOfFuel,
    GrowthOperationLimited,
}

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

See Trap for details.

Variants

UnreachableCodeReached

Wasm code executed unreachable opcode.

This indicates that unreachable Wasm code was actually reached. This opcode have a similar purpose as ud2 in x86.

MemoryOutOfBounds

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).

TableOutOfBounds

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 unsigned integers, out of bounds access can’t happen with negative indexes (i.e. they will always wrap).

IndirectCallToNull

Indicates that a call_indirect instruction called a function at an uninitialized (i.e. null) table index.

IntegerDivisionByZero

Attempt to divide by zero.

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

IntegerOverflow

An integer arithmetic operation caused an overflow.

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.

BadConversionToInteger

Attempted to make an invalid conversion to an integer type.

This can for example happen when trying to truncate NaNs, infinity, or value for which the result is out of range into an integer.

StackOverflow

Stack overflow.

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

BadSignature

Attempt to invoke a function with mismatching signature.

This can happen with indirect calls as they always specify the expected signature of function. If an indirect call is executed with an index that points to a function with signature different of what is expected by this indirect call, this trap is raised.

OutOfFuel

This trap is raised when a WebAssembly execution ran out of fuel.

The Wasmi execution engine can be configured to instrument its internal bytecode so that fuel is consumed for each executed instruction. This is useful to deterministically halt or yield a WebAssembly execution.

GrowthOperationLimited

This trap is raised when a growth operation was attempted and an installed wasmi::ResourceLimiter returned Err(...) from the associated table_growing or memory_growing method, indicating a desire on the part of the embedder to trap the interpreter rather than merely fail the growth operation.

Implementations

impl TrapCode

pub fn trap_message(&self) -> &'static str

Returns the trap message as specified by the WebAssembly specification.

Note

This API is primarily useful for the Wasm spec testsuite but might have other uses since it avoid heap memory allocation in certain cases.

Trait Implementations

impl Clone for TrapCode

fn clone(&self) -> TrapCode

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TrapCode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for TrapCode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<TrapCode> for Trap

fn from(error: TrapCode) -> Self

Converts to this type from the input type.

impl PartialEq for TrapCode

fn eq(&self, other: &TrapCode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for TrapCode

impl Eq for TrapCode

impl StructuralPartialEq for TrapCode