Files
2025-12-11 01:09:28 +01:00

176 lines
4.9 KiB
Python

import syntax
from vistram.tram import *
label_counter = 0
def new_label():
global label_counter
label_counter += 1
return Label(text=f"L{label_counter}")
# Rules E1, E2
def elab_def(decls, rho, nl):
r = dict(rho)
for d in decls:
r = d.elab(r, nl)
return r
# Rule K6
class CONST(syntax.CONST):
def code(self, rho, nl):
return [const(self.value)]
# Rule K3
class ID(syntax.ID):
def code(self, rho, nl):
k, nl_def = rho[self.name]
return [load(k, nl - nl_def)]
# Rule K7
class AOP(syntax.AOP):
def code(self, rho, nl):
c1 = self.arg1.code(rho, nl)
c2 = self.arg2.code(rho, nl)
match self.operator:
case "+":
return c1 + c2 + [add()]
case "-":
return c1 + c2 + [sub()]
case "*":
return c1 + c2 + [mul()]
case "/":
return c1 + c2 + [div()]
case _:
raise Exception(f"Unknown AOP operator.")
# Rule K5
class COMP(syntax.COMP):
def code(self, rho, nl):
c1 = self.arg1.code(rho, nl)
c2 = self.arg2.code(rho, nl)
match self.operator:
case "<":
return c1 + c2 + [lt()]
case ">":
return c1 + c2 + [gt()]
case "<=":
# leq is not implemented in vistra.tram
return LOP("||", COMP("<", self.arg1, self.arg2), EQOP("==", self.arg1, self.arg2)).code(rho, nl)
case ">=":
# geq is not implemented in vistra.tram
return LOP("||", COMP(">", self.arg1, self.arg2), EQOP("==", self.arg1, self.arg2)).code(rho, nl)
case _:
raise ValueError(f"Unknown COMP operator.")
# Rule K5
class EQOP(syntax.EQOP):
def code(self, rho, nl):
c1 = self.arg1.code(rho, nl)
c2 = self.arg2.code(rho, nl)
match self.operator:
case "==":
return c1 + c2 + [eq()]
case "!=":
return c1 + c2 + [neq()]
case _:
raise ValueError(f"Unknown EQOP operator.")
# see lecture code generation AND/OR
class LOP(syntax.LOP):
def code(self, rho, nl):
c1 = self.arg1.code(rho, nl)
c2 = self.arg2.code(rho, nl)
l1 = new_label()
l2 = new_label()
match self.operator:
case "&&":
return c1 + [ifzero(l1)] + [const(1)] + c2 + [mul()] + [goto(l2)] + [nop(l1)] + [const(0)] + [nop(l2)]
case "||":
return c1 + [ifzero(l1)] + [const(1)] + [goto(l2)] + [nop(l1)] + c2 + [nop(l2)]
case _:
raise ValueError("Unknown LOP operator.")
# Rule K4
class ASSIGN(syntax.ASSIGN):
def code(self, rho, nl):
c = self.expr.code(rho, nl)
k, nl_def = rho[self.var.name]
dif = nl - nl_def
return c + [store(k, dif), load(k, dif)]
# Rule K9
class SEQ(syntax.SEQ):
def code(self, rho, nl):
c1 = self.exp1.code(rho, nl)
c2 = self.exp2.code(rho, nl)
return c1 + [pop()] + c2
# Rule K10
class IF(syntax.IF):
def code(self, rho, nl):
l1 = new_label()
l2 = new_label()
c1 = self.cond.code(rho, nl)
c2 = self.exp1.code(rho, nl)
c3 = self.exp2.code(rho, nl)
return c1 + [ifzero(l1)] + c2 + [goto(l2)] + [nop(assigned_label=l1)] + c3 + [nop(assigned_label=l2)]
# Rule K11
class WHILE(syntax.WHILE):
def code(self, rho, nl):
l1 = new_label()
l2 = new_label()
l3 = new_label()
l4 = new_label()
c1 = self.cond.code(rho, nl)
c2 = self.body.code(rho, nl)
return c1 + [ifzero(l3), goto(l4)] + [nop(l1)] + c1 + [ifzero(l2), pop()] + [nop(l4)] + c2 + [goto(l1)] + [nop(l3), const(None), nop(l2)]
# Rule K2
class LET(syntax.LET):
def code(self, rho, nl):
l = new_label()
# Normalize to list
decls = self.decl if isinstance(self.decl, list) else [self.decl]
shared_rho = elab_def(decls, rho, nl)
ds = []
for d in decls:
ds += d.code(shared_rho, nl)
es = self.body.code(shared_rho, nl)
return [goto(l)] + ds + [nop(assigned_label=l)] + es
# Rule K13
class DECL(syntax.DECL):
def elab(self, rho, nl):
nested_rho = dict(rho)
nested_rho[self.f_name] = (new_label(), nl)
return nested_rho
def code(self, rho, nl):
l, _ = rho[self.f_name]
nested_rho = dict(rho)
for i, p in enumerate(self.params):
nested_rho[p] = (i, nl + 1)
c = self.body.code(nested_rho, nl + 1)
return [nop(assigned_label=l)] + c + [ireturn()]
# Rule K12
class CALL(syntax.CALL):
def code(self, rho, nl):
c = []
for a in self.arg:
c += a.code(rho, nl)
l, nl_def = rho[self.f_name]
return c + [invoke(len(self.arg), l, nl - nl_def)]