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use alloc::{
borrow::Cow,
rc::{Rc, Weak},
vec::Vec,
};
use core::fmt;
use host::Externals;
use isa;
use module::ModuleInstance;
use parity_wasm::elements::Local;
use runner::{check_function_args, Interpreter, InterpreterState, StackRecycler};
use types::ValueType;
use value::RuntimeValue;
use {Signature, Trap};
#[derive(Clone, Debug)]
pub struct FuncRef(Rc<FuncInstance>);
impl ::core::ops::Deref for FuncRef {
type Target = FuncInstance;
fn deref(&self) -> &FuncInstance {
&self.0
}
}
pub struct FuncInstance(FuncInstanceInternal);
#[derive(Clone)]
pub(crate) enum FuncInstanceInternal {
Internal {
signature: Rc<Signature>,
module: Weak<ModuleInstance>,
body: Rc<FuncBody>,
},
Host {
signature: Signature,
host_func_index: usize,
},
}
impl fmt::Debug for FuncInstance {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self.as_internal() {
&FuncInstanceInternal::Internal { ref signature, .. } => {
write!(f, "Internal {{ signature={:?} }}", signature,)
}
&FuncInstanceInternal::Host { ref signature, .. } => {
write!(f, "Host {{ signature={:?} }}", signature)
}
}
}
}
impl FuncInstance {
pub fn alloc_host(signature: Signature, host_func_index: usize) -> FuncRef {
let func = FuncInstanceInternal::Host {
signature,
host_func_index,
};
FuncRef(Rc::new(FuncInstance(func)))
}
pub fn signature(&self) -> &Signature {
match *self.as_internal() {
FuncInstanceInternal::Internal { ref signature, .. } => signature,
FuncInstanceInternal::Host { ref signature, .. } => signature,
}
}
pub(crate) fn as_internal(&self) -> &FuncInstanceInternal {
&self.0
}
pub(crate) fn alloc_internal(
module: Weak<ModuleInstance>,
signature: Rc<Signature>,
body: FuncBody,
) -> FuncRef {
let func = FuncInstanceInternal::Internal {
signature,
module: module,
body: Rc::new(body),
};
FuncRef(Rc::new(FuncInstance(func)))
}
pub(crate) fn body(&self) -> Option<Rc<FuncBody>> {
match *self.as_internal() {
FuncInstanceInternal::Internal { ref body, .. } => Some(Rc::clone(body)),
FuncInstanceInternal::Host { .. } => None,
}
}
pub fn invoke<E: Externals>(
func: &FuncRef,
args: &[RuntimeValue],
externals: &mut E,
) -> Result<Option<RuntimeValue>, Trap> {
check_function_args(func.signature(), &args)?;
match *func.as_internal() {
FuncInstanceInternal::Internal { .. } => {
let mut interpreter = Interpreter::new(func, args, None)?;
interpreter.start_execution(externals)
}
FuncInstanceInternal::Host {
ref host_func_index,
..
} => externals.invoke_index(*host_func_index, args.into()),
}
}
pub fn invoke_with_stack<E: Externals>(
func: &FuncRef,
args: &[RuntimeValue],
externals: &mut E,
stack_recycler: &mut StackRecycler,
) -> Result<Option<RuntimeValue>, Trap> {
check_function_args(func.signature(), &args)?;
match *func.as_internal() {
FuncInstanceInternal::Internal { .. } => {
let mut interpreter = Interpreter::new(func, args, Some(stack_recycler))?;
let return_value = interpreter.start_execution(externals);
stack_recycler.recycle(interpreter);
return_value
}
FuncInstanceInternal::Host {
ref host_func_index,
..
} => externals.invoke_index(*host_func_index, args.into()),
}
}
pub fn invoke_resumable<'args>(
func: &FuncRef,
args: impl Into<Cow<'args, [RuntimeValue]>>,
) -> Result<FuncInvocation<'args>, Trap> {
let args = args.into();
check_function_args(func.signature(), &args)?;
match *func.as_internal() {
FuncInstanceInternal::Internal { .. } => {
let interpreter = Interpreter::new(func, &*args, None)?;
Ok(FuncInvocation {
kind: FuncInvocationKind::Internal(interpreter),
})
}
FuncInstanceInternal::Host {
ref host_func_index,
..
} => Ok(FuncInvocation {
kind: FuncInvocationKind::Host {
args,
host_func_index: *host_func_index,
finished: false,
},
}),
}
}
}
#[derive(Debug)]
pub enum ResumableError {
Trap(Trap),
NotResumable,
AlreadyStarted,
}
impl From<Trap> for ResumableError {
fn from(trap: Trap) -> Self {
ResumableError::Trap(trap)
}
}
pub struct FuncInvocation<'args> {
kind: FuncInvocationKind<'args>,
}
enum FuncInvocationKind<'args> {
Internal(Interpreter),
Host {
args: Cow<'args, [RuntimeValue]>,
host_func_index: usize,
finished: bool,
},
}
impl<'args> FuncInvocation<'args> {
pub fn is_resumable(&self) -> bool {
match &self.kind {
&FuncInvocationKind::Internal(ref interpreter) => interpreter.state().is_resumable(),
&FuncInvocationKind::Host { .. } => false,
}
}
pub fn resumable_value_type(&self) -> Option<ValueType> {
match &self.kind {
&FuncInvocationKind::Internal(ref interpreter) => match interpreter.state() {
&InterpreterState::Resumable(ref value_type) => value_type.clone(),
_ => None,
},
&FuncInvocationKind::Host { .. } => None,
}
}
pub fn start_execution<'externals, E: Externals + 'externals>(
&mut self,
externals: &'externals mut E,
) -> Result<Option<RuntimeValue>, ResumableError> {
match self.kind {
FuncInvocationKind::Internal(ref mut interpreter) => {
if interpreter.state() != &InterpreterState::Initialized {
return Err(ResumableError::AlreadyStarted);
}
Ok(interpreter.start_execution(externals)?)
}
FuncInvocationKind::Host {
ref args,
ref mut finished,
ref host_func_index,
} => {
if *finished {
return Err(ResumableError::AlreadyStarted);
}
*finished = true;
Ok(externals.invoke_index(*host_func_index, args.as_ref().into())?)
}
}
}
pub fn resume_execution<'externals, E: Externals + 'externals>(
&mut self,
return_val: Option<RuntimeValue>,
externals: &'externals mut E,
) -> Result<Option<RuntimeValue>, ResumableError> {
use crate::TrapKind;
if return_val.map(|v| v.value_type()) != self.resumable_value_type() {
return Err(ResumableError::Trap(Trap::new(
TrapKind::UnexpectedSignature,
)));
}
match &mut self.kind {
FuncInvocationKind::Internal(interpreter) => {
if interpreter.state().is_resumable() {
Ok(interpreter.resume_execution(return_val, externals)?)
} else {
Err(ResumableError::AlreadyStarted)
}
}
FuncInvocationKind::Host { .. } => Err(ResumableError::NotResumable),
}
}
}
#[derive(Clone, Debug)]
pub struct FuncBody {
pub locals: Vec<Local>,
pub code: isa::Instructions,
}