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use crate::{core::TrapCode, for_each_op, index::*, primitive::Offset64Hi, *};
use ::core::num::{NonZeroI32, NonZeroI64, NonZeroU32, NonZeroU64};
macro_rules! define_enum {
(
$(
$( #[doc = $doc:literal] )*
#[snake_name($snake_name:ident)]
$name:ident
$(
{
$(
@ $result_name:ident: $result_ty:ty,
)?
$(
$( #[$field_docs:meta] )*
$field_name:ident: $field_ty:ty
),*
$(,)?
}
)?
),* $(,)?
) => {
/// A Wasmi instruction.
///
/// Wasmi instructions are composed of so-called instruction words.
/// This type represents all such words and for simplicity we call the type [`Instruction`], still.
///
/// Most instructions are composed of a single instruction word. An example of
/// this is [`Instruction::I32Add`]. However, some instructions, like
/// [`Instruction::Select`], are composed of two or more instruction words.
///
/// The Wasmi bytecode translation makes sure that instructions always appear in valid sequences.
/// The Wasmi executor relies on the guarantees that the Wasmi translator provides.
///
/// The documentation of each [`Instruction`] describes its encoding in the
/// `#Encoding` section of its documentation if it requires more than a single
/// instruction for its encoding.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[repr(u16)]
pub enum Instruction {
$(
$( #[doc = $doc] )*
$name
$(
{
$(
/// The register(s) storing the result of the instruction.
$result_name: $result_ty,
)?
$(
$( #[$field_docs] )*
$field_name: $field_ty
),*
}
)?
),*
}
impl Instruction {
$(
#[doc = concat!("Creates a new [`Instruction::", stringify!($name), "`].")]
pub fn $snake_name(
$(
$( $result_name: impl Into<$result_ty>, )?
$( $field_name: impl Into<$field_ty> ),*
)?
) -> Self {
Self::$name {
$(
$( $result_name: $result_name.into(), )?
$( $field_name: $field_name.into() ),*
)?
}
}
)*
}
};
}
for_each_op::for_each_op!(define_enum);
/// Helper trait for [`Instruction::result`] method implementation.
trait IntoReg: Sized {
/// Converts `self` into a [`Reg`] if possible.
fn into_reg(self) -> Option<Reg> {
None
}
}
impl IntoReg for Reg {
fn into_reg(self) -> Option<Reg> {
Some(self)
}
}
impl IntoReg for RegSpan {}
impl<const N: u16> IntoReg for FixedRegSpan<N> {}
impl IntoReg for () {}
macro_rules! define_result {
(
$(
$( #[doc = $doc:literal] )*
#[snake_name($snake_name:ident)]
$name:ident
$(
{
$(
@ $result_name:ident: $result_ty:ty,
)?
$(
$( #[$field_docs:meta] )*
$field_name:ident: $field_ty:ty
),*
$(,)?
}
)?
),* $(,)?
) => {
impl Instruction {
/// Returns the result [`Reg`] for `self`.
///
/// Returns `None` if `self` does not statically return a single [`Reg`].
pub fn result(&self) -> Option<$crate::Reg> {
match *self {
$(
Self::$name { $( $( $result_name, )? )* .. } => {
IntoReg::into_reg((
$( $( $result_name )? )*
))
}
)*
}
}
}
};
}
for_each_op::for_each_op!(define_result);
impl Instruction {
/// Creates a new [`Instruction::ReturnReg2`] for the given [`Reg`] indices.
pub fn return_reg2_ext(reg0: impl Into<Reg>, reg1: impl Into<Reg>) -> Self {
Self::return_reg2([reg0.into(), reg1.into()])
}
/// Creates a new [`Instruction::ReturnReg3`] for the given [`Reg`] indices.
pub fn return_reg3_ext(
reg0: impl Into<Reg>,
reg1: impl Into<Reg>,
reg2: impl Into<Reg>,
) -> Self {
Self::return_reg3([reg0.into(), reg1.into(), reg2.into()])
}
/// Creates a new [`Instruction::ReturnMany`] for the given [`Reg`] indices.
pub fn return_many_ext(
reg0: impl Into<Reg>,
reg1: impl Into<Reg>,
reg2: impl Into<Reg>,
) -> Self {
Self::return_many([reg0.into(), reg1.into(), reg2.into()])
}
/// Creates a new [`Instruction::ReturnNezReg2`] for the given `condition` and `value`.
pub fn return_nez_reg2_ext(
condition: impl Into<Reg>,
value0: impl Into<Reg>,
value1: impl Into<Reg>,
) -> Self {
Self::return_nez_reg2(condition, [value0.into(), value1.into()])
}
/// Creates a new [`Instruction::ReturnNezMany`] for the given `condition` and `value`.
pub fn return_nez_many_ext(
condition: impl Into<Reg>,
head0: impl Into<Reg>,
head1: impl Into<Reg>,
) -> Self {
Self::return_nez_many(condition, [head0.into(), head1.into()])
}
/// Creates a new [`Instruction::Copy2`].
pub fn copy2_ext(results: RegSpan, value0: impl Into<Reg>, value1: impl Into<Reg>) -> Self {
let span = FixedRegSpan::new(results).unwrap_or_else(|_| {
panic!("encountered invalid `results` `RegSpan` for `Copy2`: {results:?}")
});
Self::copy2(span, [value0.into(), value1.into()])
}
/// Creates a new [`Instruction::CopyMany`].
pub fn copy_many_ext(results: RegSpan, head0: impl Into<Reg>, head1: impl Into<Reg>) -> Self {
Self::copy_many(results, [head0.into(), head1.into()])
}
/// Creates a new [`Instruction::CopyManyNonOverlapping`].
pub fn copy_many_non_overlapping_ext(
results: RegSpan,
head0: impl Into<Reg>,
head1: impl Into<Reg>,
) -> Self {
Self::copy_many_non_overlapping(results, [head0.into(), head1.into()])
}
/// Creates a new [`Instruction::Register2`] instruction parameter.
pub fn register2_ext(reg0: impl Into<Reg>, reg1: impl Into<Reg>) -> Self {
Self::register2([reg0.into(), reg1.into()])
}
/// Creates a new [`Instruction::Register3`] instruction parameter.
pub fn register3_ext(reg0: impl Into<Reg>, reg1: impl Into<Reg>, reg2: impl Into<Reg>) -> Self {
Self::register3([reg0.into(), reg1.into(), reg2.into()])
}
/// Creates a new [`Instruction::RegisterList`] instruction parameter.
pub fn register_list_ext(
reg0: impl Into<Reg>,
reg1: impl Into<Reg>,
reg2: impl Into<Reg>,
) -> Self {
Self::register_list([reg0.into(), reg1.into(), reg2.into()])
}
/// Creates a new [`Instruction::RegisterAndImm32`] from the given `reg` and `offset_hi`.
pub fn register_and_offset_hi(reg: impl Into<Reg>, offset_hi: Offset64Hi) -> Self {
Self::register_and_imm32(reg, offset_hi.0)
}
/// Returns `Some` [`Reg`] and [`Offset64Hi`] if encoded properly.
///
/// # Errors
///
/// Returns back `self` if it was an incorrect [`Instruction`].
/// This allows for a better error message to inform the user.
pub fn filter_register_and_offset_hi(self) -> Result<(Reg, Offset64Hi), Self> {
if let Instruction::RegisterAndImm32 { reg, imm } = self {
return Ok((reg, Offset64Hi(u32::from(imm))));
}
Err(self)
}
/// Creates a new [`Instruction::Imm16AndImm32`] from the given `value` and `offset_hi`.
pub fn imm16_and_offset_hi(value: impl Into<AnyConst16>, offset_hi: Offset64Hi) -> Self {
Self::imm16_and_imm32(value, offset_hi.0)
}
/// Returns `Some` [`Reg`] and [`Offset64Hi`] if encoded properly.
///
/// # Errors
///
/// Returns back `self` if it was an incorrect [`Instruction`].
/// This allows for a better error message to inform the user.
pub fn filter_imm16_and_offset_hi<T>(self) -> Result<(T, Offset64Hi), Self>
where
T: From<AnyConst16>,
{
if let Instruction::Imm16AndImm32 { imm16, imm32 } = self {
return Ok((T::from(imm16), Offset64Hi(u32::from(imm32))));
}
Err(self)
}
}
#[test]
fn size_of() {
// Note: In case this test starts failing:
//
// There currently is a bug in the Rust compiler that causes
// Rust `enum` definitions with `#[repr(uN)]` to be incorrectly
// sized: https://github.com/rust-lang/rust/issues/53657
//
// Until that bug is fixed we need to order the `enum` variant
// fields in a precise order to end up with the correct `enum` size.
assert_eq!(::core::mem::size_of::<Instruction>(), 8);
assert_eq!(::core::mem::align_of::<Instruction>(), 4);
}