376 lines
14 KiB
Python
376 lines
14 KiB
Python
#!/usr/bin/env python3
|
|
|
|
"""The Ichor VM.interpreterementation.
|
|
|
|
The whole point of Shoggoth is that program executions are checkpointable and restartable. This requires that rather than
|
|
using a traditional recursive interpreter which is difficult to snapshot, interpretation in shoggoth occur within a
|
|
context (a virtual machine) which DOES have an easily introspected and serialized representation.
|
|
|
|
"""
|
|
|
|
|
|
from dataclasses import dataclass
|
|
from functools import (
|
|
singledispatch,
|
|
update_wrapper,
|
|
)
|
|
from typing import Optional
|
|
|
|
from ichor import isa
|
|
from ichor.state import (
|
|
Closure,
|
|
FunctionRef,
|
|
Identifier,
|
|
Module,
|
|
Stackframe,
|
|
TypeRef,
|
|
Variant,
|
|
VariantRef,
|
|
)
|
|
|
|
|
|
@dataclass
|
|
class InterpreterState(object):
|
|
module: Module
|
|
stackframe: Stackframe
|
|
clock: int = 0
|
|
|
|
|
|
class InterpreterError(Exception):
|
|
"""An error raised by the interpreter when something goes awry."""
|
|
|
|
def __init__(self, state: InterpreterState, message: str, cause: Optional[Exception] = None):
|
|
super().__init__(message, cause)
|
|
self.state = state
|
|
|
|
|
|
class InterpreterReturn(Exception):
|
|
def __init__(self, val):
|
|
super().__init__()
|
|
self.val = val
|
|
|
|
|
|
class InterpreterRestart(Exception):
|
|
def __init__(self, state: InterpreterState):
|
|
super().__init__()
|
|
self.state = state
|
|
|
|
|
|
def handledispatch(func):
|
|
dispatcher = singledispatch(func)
|
|
def wrapper(self, state, opcode):
|
|
assert isinstance(state, InterpreterState)
|
|
assert isinstance(opcode, isa.Opcode)
|
|
return dispatcher.dispatch(opcode.__class__)(self, state, opcode)
|
|
wrapper.register = dispatcher.register
|
|
update_wrapper(wrapper, func)
|
|
return wrapper
|
|
|
|
|
|
class Interpreter(object):
|
|
"""A shit .interpretere instruction pointer based interpreter."""
|
|
def __init__(self, bootstrap_module: Module):
|
|
self.bootstrap = bootstrap_module
|
|
|
|
def pre_instr(self, state: InterpreterState, opcode: isa.Opcode) -> InterpreterState:
|
|
return state
|
|
|
|
def post_instr(self, state: InterpreterState, opcode: isa.Opcode) -> InterpreterState:
|
|
return state
|
|
|
|
def step(self, state: InterpreterState, opcode: isa.Opcode) -> InterpreterState:
|
|
return self.handle_opcode(state, opcode)
|
|
|
|
def handle_unknown(self, state: InterpreterState, opcode: isa.Opcode) -> InterpreterState:
|
|
raise InterpreterError(state, "Unsupported operation: {opcode}")
|
|
|
|
def handle_fault(self, state, opcode, message, cause=None) -> InterpreterState:
|
|
raise InterpreterError(state, message, cause)
|
|
|
|
@handledispatch
|
|
def handle_opcode(self, state: InterpreterState, opcode: isa.Opcode) -> InterpreterState:
|
|
return self.handle_unknown(state, opcode)
|
|
|
|
@handle_opcode.register(isa.IDENTIFIERC)
|
|
def _handle_identifierc(self, state: InterpreterState, opcode: isa.IDENTIFIERC) -> InterpreterState:
|
|
name = opcode.val
|
|
if not (name in state.module.functions
|
|
or name in state.module.types
|
|
or any(name in t.constructors for t in state.module.types.values())):
|
|
return self.handle_fault(state, opcode, "IDENTIFIERC references unknown entity")
|
|
|
|
state.stackframe.push(Identifier(name))
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.TYPEREF)
|
|
def _handle_typeref(self, state, opcode) -> InterpreterState:
|
|
id = state.stackframe.pop()
|
|
if not isinstance(id, Identifier):
|
|
return self.handle_fault(state, opcode, "TYPEREF consumes an identifier")
|
|
|
|
if not id.name in state.module.types:
|
|
return self.handle_fault(state, opcode, "TYPEREF must be given a valid type identifier")
|
|
|
|
state.stackframe.push(TypeRef(id.name))
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.ARMREF)
|
|
def _handle_armref(self, state, opcode) -> InterpreterState:
|
|
id: Identifier = state.stackframe.pop()
|
|
if not isinstance(id, Identifier):
|
|
return self.handle_fault(state, opcode, "VARIANTREF consumes an identifier and a typeref")
|
|
|
|
t: TypeRef = state.stackframe.pop()
|
|
if not isinstance(t, TypeRef):
|
|
return self.handle_fault(state, opcode, "VARIANTREF consumes an identifier and a typeref")
|
|
|
|
type = state.module.types[t.name]
|
|
if id.name not in type.constructors:
|
|
return self.handle_fault(state, opcode, f"VARIANTREF given {id.name!r} which does not name a constructor within {type!r}")
|
|
|
|
state.stackframe.push(VariantRef(t, id.name))
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.ARM)
|
|
def _handle_arm(self, state: InterpreterState, opcode: isa.ARM) -> InterpreterState:
|
|
armref: VariantRef = state.stackframe.pop()
|
|
if not isinstance(armref, VariantRef):
|
|
return self.handle_fault(state, opcode, "VARIANT must be given a valid constructor reference")
|
|
|
|
ctor = state.module.types[armref.type.name].constructors[armref.arm]
|
|
if opcode.nargs != len(ctor):
|
|
return self.handle_fault(state, opcode, "VARIANT given n-args inconsistent with the type constructor")
|
|
|
|
if opcode.nargs > len(state.stackframe):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
# FIXME: Where does type variable to type binding occur?
|
|
# Certainly needs to be AT LEAST here, where we also need to be doing some typechecking
|
|
v = Variant(armref.type.name, armref.arm, tuple(state.stackframe[:opcode.nargs]))
|
|
state.stackframe.drop(opcode.nargs)
|
|
state.stackframe.push(v)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.ATEST)
|
|
def _handle_atest(self, state: InterpreterState, opcode: isa.ATEST) -> InterpreterState:
|
|
armref: VariantRef = state.stackframe.pop()
|
|
if not isinstance(armref, VariantRef):
|
|
return self.handle_fault(state, opcode, "VTEST must be given a variant reference")
|
|
|
|
inst: Variant = state.stackframe.pop()
|
|
if not isinstance(inst, Variant):
|
|
return self.handle_fault(state, opcode, "VTEST must be given an instance of a variant")
|
|
|
|
if inst.type == armref.type.name and inst.variant == armref.arm:
|
|
state.stackframe.goto(opcode.target)
|
|
else:
|
|
state.stackframe._ip += 1
|
|
|
|
return state
|
|
|
|
@handle_opcode.register(isa.GOTO)
|
|
def _handle_goto(self, state, opcode: isa.GOTO) -> InterpreterState:
|
|
if (opcode.target < 0):
|
|
return self.handle_fault(state, opcode, "Illegal branch target")
|
|
state.stackframe.goto(opcode.target)
|
|
return state
|
|
|
|
@handle_opcode.register(isa.DUP)
|
|
def _handle_dupe(self, state, opcode: isa.DUP) -> InterpreterState:
|
|
if (opcode.nargs > len(state.stackframe)):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
state.stackframe.dup(opcode.nargs)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.ROT)
|
|
def _handle_rot(self, state, opcode: isa.DUP) -> InterpreterState:
|
|
if (opcode.nargs > len(state.stackframe)):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
state.stackframe.rot(opcode.nargs)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.DROP)
|
|
def _handle_drop(self, state, opcode: isa.DROP) -> InterpreterState:
|
|
if (opcode.nargs > len(state.stackframe)):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
state.stackframe.drop(opcode.nargs)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.SLOT)
|
|
def _handle_slot(self, state, opcode: isa.SLOT) -> InterpreterState:
|
|
if (opcode.target < 0):
|
|
return self.handle_fault(state, opcode, "SLOT must have a positive reference")
|
|
|
|
if (opcode.target > len(state.stackframe) - 1):
|
|
return self.handle_fault(state, opcode, "SLOT reference out of range")
|
|
|
|
state.stackframe.slot(opcode.target)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.FUNREF)
|
|
def _handle_funref(self, state, opcode) -> InterpreterState:
|
|
id = state.stackframe.pop()
|
|
if not isinstance(id, Identifier):
|
|
return self.handle_fault(state, opcode, "FUNREF consumes an IDENTIFIER")
|
|
try:
|
|
# FIXME: Verify this statically
|
|
state.stackframe.push(FunctionRef.parse(id.name))
|
|
except:
|
|
return self.handle_fault(state, opcode, "Invalid function ref")
|
|
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.CALLF)
|
|
def _handle_callf(self, state, opcode: isa.CALLF) -> InterpreterState:
|
|
sig = state.stackframe.pop()
|
|
if not isinstance(sig, FunctionRef):
|
|
return self.handle_fault(state, opcode, "CALLF requires a funref at top of stack")
|
|
|
|
fun = state.module.functions[sig.name]
|
|
if opcode.nargs != len(fun.arguments):
|
|
return self.handle_fault(state, opcode, "CALLF target violation; argument count missmatch")
|
|
|
|
if opcode.nargs > len(state.stackframe):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
try:
|
|
ip = state.module.labels[fun.signature]
|
|
state.stackframe = state.stackframe.call(fun, ip)
|
|
except KeyError:
|
|
return self.handle_fault(state, opcode, "Unknown FUNREF target")
|
|
|
|
return state
|
|
|
|
@handle_opcode.register(isa.RETURN)
|
|
def _handle_return(self, state, opcode: isa.RETURN) -> InterpreterState:
|
|
n = 1 # FIXME: clean this up
|
|
if (n > len(state.stackframe)):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
if state.stackframe.depth == 0:
|
|
raise InterpreterReturn(state.stackframe[:n])
|
|
|
|
if (len(state.stackframe._fun.returns) != n):
|
|
return self.handle_fault(state, opcode, "Signature violation")
|
|
|
|
state.stackframe = state.stackframe.ret(n)
|
|
return state
|
|
|
|
@handle_opcode.register(isa.CLOSUREF)
|
|
def _handle_closuref(self, state: InterpreterState, opcode: isa.CLOSUREF) -> InterpreterState:
|
|
n = opcode.nargs
|
|
|
|
sig = state.stackframe.pop()
|
|
if not isinstance(sig, FunctionRef):
|
|
return self.handle_fault(state, opcode, "CLOSUREF requires a funref at top of stack")
|
|
|
|
fun = state.module.functions[sig.name]
|
|
if not n <= len(fun.arguments):
|
|
return self.handle_fault(state, opcode, "CLOSUREF target violation; too many parameters provided")
|
|
|
|
if n > len(state.stackframe):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
c = Closure(
|
|
sig,
|
|
state.stackframe[:n]
|
|
)
|
|
state.stackframe.drop(n)
|
|
state.stackframe.push(c)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.CLOSUREC)
|
|
def _handle_closurec(self, state, opcode: isa.CLOSUREC) -> InterpreterState:
|
|
n = opcode.nargs
|
|
|
|
c = state.stackframe.pop()
|
|
if not isinstance(c, Closure):
|
|
return self.handle_fault(state, opcode, "CLOSUREC requires a closure at top of stack")
|
|
|
|
fun = state.module.functions[c.funref.name]
|
|
if n + len(c.frag) > len(fun.arguments):
|
|
return self.handle_fault(state, opcode, "CLOSUREC target violation; too many parameters provided")
|
|
|
|
if n > len(state.stackframe):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
c = Closure(
|
|
c.funref,
|
|
state.stackframe[:n] + c.frag
|
|
)
|
|
state.stackframe.drop(n)
|
|
state.stackframe.push(c)
|
|
state.stackframe._ip += 1
|
|
return state
|
|
|
|
@handle_opcode.register(isa.CALLC)
|
|
def _handle_callc(self, state, opcode: isa.CALLC) -> InterpreterState:
|
|
n = opcode.nargs
|
|
c = state.stackframe.pop()
|
|
if not isinstance(c, Closure):
|
|
return self.handle_fault(state, opcode, "CALLC requires a closure at top of stack")
|
|
fun = state.module.functions[c.funref.name]
|
|
if n + len(c.frag) != len(fun.arguments):
|
|
return self.handle_fault(state, opcode, "CALLC target vionation; argument count missmatch")
|
|
if n > len(state.stackframe):
|
|
return self.handle_fault(state, opcode, "Stack size violation")
|
|
|
|
# Push the closure's stack fragment
|
|
state.stackframe._stack = c.frag + state.stackframe._stack
|
|
|
|
# Perform a "normal" funref call
|
|
try:
|
|
ip = state.module.labels[fun.signature]
|
|
except KeyError:
|
|
return self.handle_fault(state, opcode, "Unknown target")
|
|
|
|
state.stackframe = state.stackframe.call(fun, ip)
|
|
return state
|
|
|
|
@handle_opcode.register(isa.BREAK)
|
|
def _handle_break(self, state, _) -> InterpreterState:
|
|
raise InterpreterReturn(state.stackframe._stack)
|
|
|
|
def run(self, opcodes, stack=[]):
|
|
"""Directly interpret some opcodes in the configured environment."""
|
|
|
|
_mod = self.bootstrap.copy()
|
|
_main = _mod.define_function(";<main>;;", opcodes)
|
|
_main_fun = _mod.functions[_main]
|
|
_main_ip = _mod.labels[_main]
|
|
|
|
state = InterpreterState(
|
|
_mod, Stackframe(_main_fun, _main_ip, stack)
|
|
)
|
|
|
|
while True:
|
|
try:
|
|
opcode = state.module.codepage[state.stackframe._ip]
|
|
self.pre_instr(state, opcode)
|
|
state = self.handle_opcode(state, opcode)
|
|
self.post_instr(state, opcode)
|
|
state.clock += 1
|
|
|
|
# FIXME: This case analysis isn't super obvious.
|
|
except InterpreterReturn as r:
|
|
return r.val
|
|
|
|
except InterpreterRestart as r:
|
|
state = r.state
|
|
continue
|
|
|
|
except Exception as e:
|
|
raise e
|