def query(self, atom):
"""Query a relation on the compiled theory"""
self.compiler.substitutes_constants_in_array(atom.args)
if atom.table not in self.compiler.typed_tables:
raise base.Z3NotWellFormed(
"Unknown relation {}".format(atom.table))
atom.types = self.compiler.typed_tables[atom.table]
if len(atom.types) != len(atom.args):
raise base.Z3NotWellFormed(
"Arity of predicate inconsistency in {}".format(atom))
for i in moves.xrange(len(atom.types)):
atom.args[i].type = atom.types[i]
ast_vars = list(OrderedDict.fromkeys([
arg for arg in atom.args if isinstance(arg, ast.Variable)
]))
vars = {}
self.compiler.project = None
query = self.compile_atom(vars, atom, {})
if vars != {}:
compiled_vars = [vars[ast_var.full_id()] for ast_var in ast_vars]
query = z3.Exists(compiled_vars, query)
self.context.query(query)
types = [self.datasource.types[ast_var.type] for ast_var in ast_vars]
variables = [ast_var.id for ast_var in ast_vars]
raw_answer = self.context.get_answer()
logging.getLogger().debug("Raw answer:\n%s", raw_answer)
answer = z3r.z3_to_array(raw_answer, types)
return variables, answer
def extract_equal(eq):
"""Transform equals in a triple: var index, value, mask"""
if isinstance(eq.children()[0], z3.BitVecNumRef):
rhs = eq.children()[0]
lhs = eq.children()[1]
else:
rhs = eq.children()[1]
lhs = eq.children()[0]
if z3.is_var(lhs):
return ResultItem(
var=z3.get_var_index(lhs),
value=rhs,
mask=None)
else:
kind = lhs.decl().kind()
if kind == z3.Z3_OP_EXTRACT:
[high, low] = lhs.params()
sort = lhs.children()[0].sort()
val = rhs.as_long() << low
mask = (1 << (high + 1)) - (1 << low)
return ResultItem(
var=z3.get_var_index(lhs.children()[0]),
value=z3.BitVecVal(val, sort),
mask=z3.BitVecVal(mask, sort))
else:
raise base.Z3NotWellFormed(
"Bad lhs for equal {}".format(eq))
def flatten(self, atom, fields):
"""Replace named arguments with positional args.
Knowing the columns in use for extensible tables, column names are
replaced by positions as regular tables.
"""
dict_arg = {}
def new_var():
"""Create a new var with unique name"""
self.var_count += 1
return ast.Variable("::{}".format(self.var_count))
for (label, arg) in zip(atom.labels, atom.args):
if label in dict_arg:
raise base.Z3NotWellFormed(
"Duplicate label '{}' in atom {}".format(label, atom))
dict_arg[label] = arg
atom.args = [
dict_arg[label] if label in dict_arg else new_var()
for label in fields
]
# Hide labels for pretty printing.
atom.labels = None
def extract_and(item, types):
"""Extract a row"""
kind = item.decl().kind()
if kind == z3.Z3_OP_AND:
return split_cubes(item.children(), types)
elif kind == z3.Z3_OP_EQ or kind == z3.Z3_OP_NOT:
return split_cubes([item], types)
else:
raise base.Z3NotWellFormed(
"Bad result {}: {}".format(item, kind))
def get_field_from_cache(field):
"""Get a field compilation functions for csv access"""
type_name, _ = accessor.fields[field]
type_field = self.types[type_name]
try:
pos = index.index(field)
except ValueError:
raise base.Z3NotWellFormed(
"Field {} was not saved for table {}".format(
field, table_name))
return (type_field.to_z3,
lambda row: type_field.unmarshall(row[pos]),
type_field.marshall)
def find_base_relations(self):
"""Extracts base relations of the theory"""
aux_counter = 0
new_rules = []
for rule in self.rules:
if self.datasource.is_extensible(rule.head):
raise base.Z3NotWellFormed(
"No base predicate allowed in head: " + rule.head.table)
for i, atom in enumerate(rule.body):
if not self.datasource.is_extensible(atom):
continue
fields = self.extensible_tables.setdefault(atom.table, [])
if atom.labels is None:
raise base.Z3NotWellFormed(
"No labels for extensible atom {}".format(atom))
for label in atom.labels:
if label not in fields:
fields.append(label)
if atom.negated:
new_table = "_negated_%d" % aux_counter
aux_counter += 1
new_atom = ast.Atom(new_table, atom.args, negated=True)
var_row = [
ast.Variable("V%d" % i) for i in range(len(atom.args))
]
atom_head = ast.Atom(new_table, var_row)
atom_body = ast.Atom(atom.table,
var_row,
labels=atom.labels)
new_rule = ast.Rule(atom_head, [atom_body])
new_rules.append(new_rule)
rule.body[i] = new_atom
self.rules.extend(new_rules)
for fields in self.extensible_tables.values():
fields.sort()
for rule in self.rules:
for atom in rule.body:
if self.datasource.is_extensible(atom):
self.flatten(atom, self.extensible_tables[atom.table])
def substitutes_constants_in_array(self, args):
"""Substitute constants in arguments arrays"""
for i in moves.range(len(args)):
oarg = args[i]
if isinstance(oarg, ast.Constant):
arg = self.constants.get(args[i].name, None)
if arg is None:
raise base.Z3NotWellFormed("Unknown constant: {}".format(
args[i].name))
args[i] = copy.deepcopy(arg)
elif isinstance(args[i], ast.Operation):
nb_vars = operations.OPERATIONS[args[i].operation].ty_vars
args[i].var_types = [None] * nb_vars
self.substitutes_constants_in_array(args[i].args)
def z3_to_array(expr, types):
"""Compiles back a Z3 result to a matrix of values"""
kind = expr.decl().kind()
if kind == z3.Z3_OP_OR:
return [extract_and(item, types) for item in expr.children()]
elif kind == z3.Z3_OP_AND:
return [split_cubes(expr.children(), types)]
elif kind == z3.Z3_OP_EQ or kind == z3.Z3_OP_NOT:
return [split_cubes([expr], types)]
elif kind == z3.Z3_OP_FALSE:
return False
elif kind == z3.Z3_OP_TRUE:
return True
else:
raise base.Z3NotWellFormed("Bad result {}: {}".format(expr, kind))
def compile_expr(self, variables, expr, env):
"""Compile an expression to Z3"""
if isinstance(expr, (ast.NumConstant, ast.StringConstant,
ast.BoolConstant, ast.IpConstant)):
return self.datasource.types[expr.type].to_z3(expr.val)
elif isinstance(expr, ast.Variable):
full_id = expr.full_id()
if full_id in env:
return env[full_id]
if full_id in variables:
return variables[full_id]
expr_type = self.datasource.types[expr.type].type()
var = z3.Const(expr.id, expr_type)
variables[full_id] = var
return var
elif isinstance(expr, ast.Operation):
operator = operations.OPERATIONS[expr.operation].z3
return operator(
*(self.compile_expr(variables, arg, env) for arg in expr.args))
else:
raise base.Z3NotWellFormed(
"cannot proceed with {}".format(expr))
