T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Cranelift: Introduce support for return_call in the interpreter (#5697)

Browse Source 
Co-authored-by: Jamey Sharp <jsharp@fastly.com>
This commit is contained in:
Nick Fitzgerald
2023-02-03 15:53:54 -08:00
committed by GitHub
parent 72c8513411
commit e18d4cb711
3 changed files with 154 additions and 70 deletions
Download Patch File Download Diff File Expand all files Collapse all files

151
cranelift/interpreter/src/step.rs
View File

@@ -34,6 +34,15 @@ fn validate_signature_params(sig: &[AbiParam], args: &[impl Value]) -> bool {
})
}
// Helper for summing a sequence of values.
fn sum<V: Value>(head: V, tail: SmallVec<[V; 1]>) -> ValueResult<i128> {
let mut acc = head;
for t in tail {
acc = Value::add(acc, t)?;
}
acc.into_int()
}
/// Interpret a single Cranelift instruction. Note that program traps and interpreter errors are
/// distinct: a program trap results in `Ok(Flow::Trap(...))` whereas an interpretation error (e.g.
/// the types of two values are incompatible) results in `Err(...)`.
@@ -267,14 +276,75 @@ where
}
};
// Helper for summing a sequence of values.
fn sum<V: Value>(head: V, tail: SmallVec<[V; 1]>) -> ValueResult<i128> {
let mut acc = head;
for t in tail {
acc = Value::add(acc, t)?;
// Perform a call operation.
//
// The returned `ControlFlow` variant is determined by the given function
// argument, which should make either a `ControlFlow::Call` or a
// `ControlFlow::ReturnCall`.
let do_call = |make_ctrl_flow: fn(&'a Function, SmallVec<[V; 1]>) -> ControlFlow<'a, V>|
-> Result<ControlFlow<'a, V>, StepError> {
let func_ref = if let InstructionData::Call { func_ref, .. } = inst {
func_ref
} else {
unreachable!()
};
let curr_func = state.get_current_function();
let ext_data = curr_func
.dfg
.ext_funcs
.get(func_ref)
.ok_or(StepError::UnknownFunction(func_ref))?;
let signature = if let Some(sig) = curr_func.dfg.signatures.get(ext_data.signature) {
sig
} else {
return Ok(ControlFlow::Trap(CraneliftTrap::User(
TrapCode::BadSignature,
)));
};
let args = args()?;
// Check the types of the arguments. This is usually done by the verifier, but nothing
// guarantees that the user has ran that.
let args_match = validate_signature_params(&signature.params[..], &args[..]);
if !args_match {
return Ok(ControlFlow::Trap(CraneliftTrap::User(
TrapCode::BadSignature,
)));
}
acc.into_int()
}
Ok(match ext_data.name {
// These functions should be registered in the regular function store
ExternalName::User(_) | ExternalName::TestCase(_) => {
let function = state
.get_function(func_ref)
.ok_or(StepError::UnknownFunction(func_ref))?;
make_ctrl_flow(function, args)
}
ExternalName::LibCall(libcall) => {
debug_assert_ne!(inst.opcode(), Opcode::ReturnCall, "Cannot tail call to libcalls");
let libcall_handler = state.get_libcall_handler();
// We don't transfer control to a libcall, we just execute it and return the results
let res = libcall_handler(libcall, args);
let res = match res {
Err(trap) => return Ok(ControlFlow::Trap(CraneliftTrap::User(trap))),
Ok(rets) => rets,
};
// Check that what the handler returned is what we expect.
if validate_signature_params(&signature.returns[..], &res[..]) {
ControlFlow::Assign(res)
} else {
ControlFlow::Trap(CraneliftTrap::User(TrapCode::BadSignature))
}
}
ExternalName::KnownSymbol(_) => unimplemented!(),
})
};
// Interpret a Cranelift instruction.
Ok(match inst.opcode() {
@@ -328,70 +398,9 @@ where
Opcode::Trapnz => trap_when(arg(0)?.into_bool()?, CraneliftTrap::User(trap_code())),
Opcode::ResumableTrapnz => trap_when(arg(0)?.into_bool()?, CraneliftTrap::Resumable),
Opcode::Return => ControlFlow::Return(args()?),
Opcode::Call => {
let func_ref = if let InstructionData::Call { func_ref, .. } = inst {
func_ref
} else {
unreachable!()
};
let curr_func = state.get_current_function();
let ext_data = curr_func
.dfg
.ext_funcs
.get(func_ref)
.ok_or(StepError::UnknownFunction(func_ref))?;
let signature = if let Some(sig) = curr_func.dfg.signatures.get(ext_data.signature) {
sig
} else {
return Ok(ControlFlow::Trap(CraneliftTrap::User(
TrapCode::BadSignature,
)));
};
let args = args()?;
// Check the types of the arguments. This is usually done by the verifier, but nothing
// guarantees that the user has ran that.
let args_match = validate_signature_params(&signature.params[..], &args[..]);
if !args_match {
return Ok(ControlFlow::Trap(CraneliftTrap::User(
TrapCode::BadSignature,
)));
}
match ext_data.name {
// These functions should be registered in the regular function store
ExternalName::User(_) | ExternalName::TestCase(_) => {
let function = state
.get_function(func_ref)
.ok_or(StepError::UnknownFunction(func_ref))?;
ControlFlow::Call(function, args)
}
ExternalName::LibCall(libcall) => {
let libcall_handler = state.get_libcall_handler();
// We don't transfer control to a libcall, we just execute it and return the results
let res = libcall_handler(libcall, args);
let res = match res {
Err(trap) => return Ok(ControlFlow::Trap(CraneliftTrap::User(trap))),
Ok(rets) => rets,
};
// Check that what the handler returned is what we expect.
if validate_signature_params(&signature.returns[..], &res[..]) {
ControlFlow::Assign(res)
} else {
ControlFlow::Trap(CraneliftTrap::User(TrapCode::BadSignature))
}
}
ExternalName::KnownSymbol(_) => unimplemented!(),
}
}
Opcode::Call => do_call(ControlFlow::Call)?,
Opcode::CallIndirect => unimplemented!("CallIndirect"),
Opcode::ReturnCall => unimplemented!("ReturnCall"),
Opcode::ReturnCall => do_call(ControlFlow::ReturnCall)?,
Opcode::ReturnCallIndirect => unimplemented!("ReturnCallIndirect"),
Opcode::FuncAddr => unimplemented!("FuncAddr"),
Opcode::Load
@@ -1288,6 +1297,8 @@ pub enum ControlFlow<'a, V> {
ContinueAt(Block, SmallVec<[V; 1]>),
/// Indicates a call the given [Function] with the supplied arguments.
Call(&'a Function, SmallVec<[V; 1]>),
/// Indicates a tail call to the given [Function] with the supplied arguments.
ReturnCall(&'a Function, SmallVec<[V; 1]>),
/// Return from the current function with the given parameters, e.g.: `return [v1, v2]`.
Return(SmallVec<[V; 1]>),
/// Stop with a program-generated trap; note that these are distinct from errors that may occur