Exemplo n.º 1
0
def ident_conds(fname, idents):
    rolling = syntax.true_term
    conds = []
    for ident in idents.get(fname, [syntax.true_term]):
        conds.append((ident, syntax.mk_and(rolling, ident)))
        rolling = syntax.mk_and(rolling, syntax.mk_not(ident))
    return conds
Exemplo n.º 2
0
def ident_conds (fname, idents):
	rolling = syntax.true_term
	conds = []
	for ident in idents.get (fname, [syntax.true_term]):
		conds.append ((ident, syntax.mk_and (rolling, ident)))
		rolling = syntax.mk_and (rolling, syntax.mk_not (ident))
	return conds
Exemplo n.º 3
0
def ident_callables (fname, callees, idents):
	from solver import to_smt_expr, smt_expr
	from syntax import mk_not, mk_and, true_term

	auto_callables = dict ([((ident, f, true_term), True)
		for ident in idents.get (fname, [true_term])
		for f in callees if f not in idents])

	if not [f for f in callees if f in idents]:
		return auto_callables

	fun = functions[fname]
	p = fun.as_problem (problem.Problem, name = 'Target')
	check_ns = [(n, ident, cond) for n in p.nodes
		if p.nodes[n].kind == 'Call'
		if p.nodes[n].fname in idents
		for (ident, cond) in ident_conds (p.nodes[n].fname, idents)]

	p.do_analysis ()
	assert check_ns

	rep = rep_graph.mk_graph_slice (p, fast = True)
	err_hyp = rep_graph.pc_false_hyp ((default_n_vc (p, 'Err'), 'Target'))

	callables = auto_callables
	nhyps = mk_not_callable_hyps (p)

	for (ident, cond) in ident_conds (fname, idents):
		renames = p.entry_exit_renames (tags = ['Target'])
		cond = syntax.rename_expr (cond, renames['Target_IN'])
		entry = p.get_entry ('Target')
		e_vis = ((entry, ()), 'Target')
		hyps = [err_hyp, rep_graph.eq_hyp ((cond, e_vis),
				(true_term, e_vis))]

		for (n, ident2, cond2) in check_ns:
			k = (ident, p.nodes[n].fname, ident2)
			(inp_env, _, _) = rep.get_func (default_n_vc (p, n))
			pc = rep.get_pc (default_n_vc (p, n))
			cond2 = to_smt_expr (cond2, inp_env, rep.solv)
			if rep.test_hyp_whyps (mk_not (mk_and (pc, cond2)),
					hyps + nhyps):
				callables[k] = False
			else:
				callables[k] = True
	return callables
Exemplo n.º 4
0
def ident_callables(fname, callees, idents):
    from solver import to_smt_expr, smt_expr
    from syntax import mk_not, mk_and, true_term

    auto_callables = dict([((ident, f, true_term), True)
                           for ident in idents.get(fname, [true_term])
                           for f in callees if f not in idents])

    if not [f for f in callees if f in idents]:
        return auto_callables

    fun = functions[fname]
    p = fun.as_problem(problem.Problem, name='Target')
    check_ns = [(n, ident, cond) for n in p.nodes if p.nodes[n].kind == 'Call'
                if p.nodes[n].fname in idents
                for (ident, cond) in ident_conds(p.nodes[n].fname, idents)]

    p.do_analysis()
    assert check_ns

    rep = rep_graph.mk_graph_slice(p, fast=True)
    err_hyp = rep_graph.pc_false_hyp((default_n_vc(p, 'Err'), 'Target'))

    callables = auto_callables
    nhyps = mk_not_callable_hyps(p)

    for (ident, cond) in ident_conds(fname, idents):
        renames = p.entry_exit_renames(tags=['Target'])
        cond = syntax.rename_expr(cond, renames['Target_IN'])
        entry = p.get_entry('Target')
        e_vis = ((entry, ()), 'Target')
        hyps = [err_hyp, rep_graph.eq_hyp((cond, e_vis), (true_term, e_vis))]

        for (n, ident2, cond2) in check_ns:
            k = (ident, p.nodes[n].fname, ident2)
            (inp_env, _, _) = rep.get_func(default_n_vc(p, n))
            pc = rep.get_pc(default_n_vc(p, n))
            cond2 = to_smt_expr(cond2, inp_env, rep.solv)
            if rep.test_hyp_whyps(mk_not(mk_and(pc, cond2)), hyps + nhyps):
                callables[k] = False
            else:
                callables[k] = True
    return callables
Exemplo n.º 5
0
def loop_no_match_unroll (rep, restrs, hyps, split, other_tag, unroll):
	p = rep.p
	assert p.node_tags[split][0] != other_tag
	restr = ((split, vc_num (unroll)), )
	restrs2 = restr_others (p, restr + restrs, 2)
	loop_cond = rep.get_pc ((split, restr + restrs))
	ret_cond = rep.get_pc (('Ret', restrs2), tag = other_tag)
	# loop should be reachable
	if rep.test_hyp_whyps (mk_not (loop_cond), hyps):
		trace ('Loop weak at %d (unroll count %d).' %
			(split, unroll))
		return True
	# reaching the loop should imply reaching a loop on the other side
	hyp = mk_not (mk_and (loop_cond, ret_cond))
	if not rep.test_hyp_whyps (hyp, hyps):
		trace ('Loop independent at %d (unroll count %d).' %
			(split, unroll))
		return True
	return False
Exemplo n.º 6
0
	def emit_node (self, n):
		(pc, env) = self.get_node_pc_env (n, request = False)
		tag = self.p.node_tags[n[0]][0]
		app_eqs = self.apply_known_eqs_tm (n, tag)
		# node = logic.simplify_node_elementary (self.p.nodes[n[0]])
		# whether to ignore unreachable Cond arcs seems to be a huge
		# dilemma. if we ignore them, some reachable sites become
		# unreachable and we can't interpret all hyps
		# if we don't ignore them, the variable set disagrees with
		# var_deps and so the abstracted loop pc/env may not be
		# sufficient and we get EnvMiss again. I don't really know
		# what to do about this corner case.
		node = self.p.nodes[n[0]]
		env = dict (env)

		if node.kind == 'Call':
			self.try_inline (n[0], pc, env)

		if pc == false_term:
			return [(c, false_term, {}) for c in node.get_conts()]
		elif node.kind == 'Cond' and node.left == node.right:
			return [(node.left, pc, env)]
		elif node.kind == 'Cond' and node.cond == true_term:
			return [(node.left, pc, env),
				(node.right, false_term, env)]
		elif node.kind == 'Basic':
			upds = []
			for (lv, v) in node.upds:
				if v.kind == 'Var':
					upds.append ((lv, env[(v.name, v.typ)]))
				else:
					name = self.local_name (lv[0], n)
					v = app_eqs (v)
					vname = self.add_local_def (n,
						('Var', lv), name, v, env)
					upds.append ((lv, vname))
			for (lv, v) in upds:
				env[lv] = v
			return [(node.cont, pc, env)]
		elif node.kind == 'Cond':
			name = self.cond_name (n)
			cond = self.p.fresh_var (name, boolT)
			env[(cond.name, boolT)] = self.add_local_def (n,
				'Cond', name, app_eqs (node.cond), env)
			lpc = mk_and (cond, pc)
			rpc = mk_and (mk_not (cond), pc)
			return [(node.left, lpc, env), (node.right, rpc, env)]
		elif node.kind == 'Call':
			nm = self.success_name (node.fname, n)
			success = self.solv.add_var (nm, boolT)
			success = mk_smt_expr (success, boolT)
			fun = functions[node.fname]
			ins = dict ([((x, typ), smt_expr (app_eqs (arg), env, self.solv))
				for ((x, typ), arg) in azip (fun.inputs, node.args)])
			mem_name = None
			for (x, typ) in reversed (fun.inputs):
				if typ == builtinTs['Mem']:
					mem_name = (node.fname, ins[(x, typ)])
			outs = {}
			for ((x, typ), (y, typ2)) in azip (node.rets, fun.outputs):
				assert typ2 == typ
				if self.fast_const_ret (n[0], x, typ):
					outs[(y, typ2)] = env [(x, typ)]
					continue
				name = self.local_name (x, n)
				env[(x, typ)] = self.solv.add_var_restr (name,
					typ, mem_name = mem_name)
				outs[(y, typ2)] = env[(x, typ)]
			for ((x, typ), (y, _)) in azip (node.rets, fun.outputs):
				z = self.var_rep_request ((x, typ),
					'Call', n, env)
				if z != None:
					env[(x, typ)] = z
					outs[(y, typ)] = z
			self.add_func (node.fname, ins, outs, success, n)
			return [(node.cont, pc, env)]
		else:
			assert not 'node kind understood'