def to_smt_expr_under_op (expr, env, solv):
if expr.kind == 'Op':
vals = [to_smt_expr (v, env, solv) for v in expr.vals]
return syntax.Expr ('Op', expr.typ, name = expr.name,
vals = vals)
else:
return to_smt_expr (expr, env, solv)
def get_var (k): head = rep.p.loop_id (i) if i != head: k += 1 restrs2 = restrs + ((head, vc_num (k)), ) (pc, env) = rep.get_node_pc_env ((i, restrs2)) return (to_smt_expr (pc, env, rep.solv), to_smt_expr (v_i, env, rep.solv))
def trace_mem(rep,
tag,
m,
verbose=False,
simplify=True,
symbs=True,
resolve_addrs=False):
p = rep.p
ns = walk_model(rep, tag, m)
trace = []
for (n, vc) in ns:
if (n, vc) not in rep.arc_pc_envs:
# this n_vc has a pre-state, but has not been emitted.
# no point trying to evaluate its expressions, the
# solve won't have seen them yet.
continue
n_nm = rep.node_count_name((n, vc))
node = p.nodes[n]
if node.kind == 'Call':
exprs = list(node.args)
elif node.kind == 'Basic':
exprs = [expr for (_, expr) in node.upds]
elif node.kind == 'Cond':
exprs = [node.cond]
env = rep.node_pc_envs[(tag, n, vc)][1]
accs = list(
set([acc for expr in exprs for acc in expr.get_mem_accesses()]))
for (kind, addr, v, mem) in accs:
addr_s = solver.smt_expr(addr, env, rep.solv)
v_s = solver.smt_expr(v, env, rep.solv)
addr = eval_str(addr, env, rep.solv, m)
v = eval_str(v, env, rep.solv, m)
m_nm = m_var_name(mem)
print '%s: %s @ <%s> -- %s -- %s' % (kind, m_nm, addr, v, n_nm)
if simplify:
addr_s = simplify_sexp(addr_s, rep, m)
v_s = simplify_sexp(v_s, rep, m)
if verbose:
print '\t %s -- %s' % (addr_s, v_s)
if symbs:
addr_n = str_to_num(addr)
(hit_symbs, secs) = find_symbol(addr_n, output=False)
ss = hit_symbs + secs
if ss:
print '\t [%s]' % ', '.join(ss)
if resolve_addrs:
accs = [(kind, solver.to_smt_expr(addr, env, rep.solv),
solver.to_smt_expr(v, env, rep.solv), mem)
for (kind, addr, v, mem) in accs]
trace.extend([(kind, addr, v, mem, n, vc)
for (kind, addr, v, mem) in accs])
if node.kind == 'Call':
msg = '<function call to %s at %s>' % (node.fname, n_nm)
print msg
trace.append(msg)
return trace
def trace_mem(rep, tag, m, verbose=False, simplify=True, symbs=True, resolve_addrs=False):
p = rep.p
ns = walk_model(rep, tag, m)
trace = []
for (n, vc) in ns:
if (n, vc) not in rep.arc_pc_envs:
# this n_vc has a pre-state, but has not been emitted.
# no point trying to evaluate its expressions, the
# solve won't have seen them yet.
continue
n_nm = rep.node_count_name((n, vc))
node = p.nodes[n]
if node.kind == "Call":
msg = "<function call to %s at %s>" % (node.fname, n_nm)
print msg
trace.append(msg)
if node.kind == "Basic":
exprs = [expr for (_, expr) in node.upds]
elif node.kind == "Cond":
exprs = [node.cond]
else:
continue
env = rep.node_pc_envs[(tag, n, vc)][1]
accs = list(set([acc for expr in exprs for acc in expr.get_mem_accesses()]))
for (kind, addr, v, mem) in accs:
addr_s = solver.smt_expr(addr, env, rep.solv)
v_s = solver.smt_expr(v, env, rep.solv)
addr = eval_str(addr, env, rep.solv, m)
v = eval_str(v, env, rep.solv, m)
m_nm = m_var_name(mem)
print "%s: %s @ <%s> -- %s -- %s" % (kind, m_nm, addr, v, n_nm)
if simplify:
addr_s = simplify_sexp(addr_s, rep, m)
v_s = simplify_sexp(v_s, rep, m)
if verbose:
print "\t %s -- %s" % (addr_s, v_s)
if symbs:
(hit_symbs, secs) = find_symbol(addr, output=False)
ss = hit_symbs + secs
if ss:
print "\t [%s]" % ", ".join(ss)
if resolve_addrs:
accs = [
(kind, solver.to_smt_expr(addr, env, rep.solv), solver.to_smt_expr(v, env, rep.solv), mem)
for (kind, addr, v, mem) in accs
]
trace.extend([(kind, addr, v, mem, n, vc) for (kind, addr, v, mem) in accs])
return trace
def eval_str(expr, env, solv, m):
expr = solver.to_smt_expr(expr, env, solv)
v = search.eval_model_expr(m, solv, expr)
if v.typ == syntax.boolT:
assert v in [syntax.true_term, syntax.false_term]
return v.name
elif v.typ.kind == "Word":
return solver.smt_num(v.val, v.typ.num)
else:
assert not "type printable", v
def eval_str(expr, env, solv, m):
expr = solver.to_smt_expr(expr, env, solv)
v = search.eval_model_expr(m, solv, expr)
if v.typ == syntax.boolT:
assert v in [syntax.true_term, syntax.false_term]
return v.name
elif v.typ.kind == 'Word':
return solver.smt_num_t(v.val, v.typ)
else:
assert not 'type printable', v
def find_case_split (p, head, restrs, hyps, tags = None):
# are there multiple paths to the loop head 'head' and can we
# restrict to one of them?
preds = set ()
frontier = list (set ([n2 for n in p.loop_body (head)
for n2 in p.preds[n] if p.loop_id (n2) != head]))
while frontier:
n2 = frontier.pop ()
if n2 in preds:
continue
preds.add (n2)
frontier.extend (p.preds[n2])
divs = [n2 for n2 in preds if len (set ([n3
for n3 in p.nodes[n2].get_conts ()
if n3 in preds or n3 == head])) > 1
if n2 not in p.loop_data]
trace ('find_case_split: possible divs %s.' % divs)
rep = mk_graph_slice (p)
err_restrs = restr_others (p, restrs, 2)
if tags:
l_tag, r_tag = tags
else:
l_tag, r_tag = p.pairing.tags
hvis_restrs = tuple ([(head, rep_graph.vc_num (0))]) + restrs
lhyps = hyps + [rep_graph.pc_false_hyp ((('Err', err_restrs), r_tag)),
rep_graph.pc_true_hyp (((head, hvis_restrs),
p.node_tags[head][0]))]
# for this to be a usable case split, both paths must be possible
for div in divs:
dhyps = lhyps + [rep_graph.pc_true_hyp (((div, restrs),
p.node_tags[div][0]))]
assert p.nodes[div].kind == 'Cond'
(_, env) = rep.get_node_pc_env ((div, restrs))
c = to_smt_expr (p.nodes[div].cond, env, rep.solv)
if (rep.test_hyp_whyps (c, dhyps)
or rep.test_hyp_whyps (mk_not (c), dhyps)):
continue
trace ("attempting case split at %d" % div)
sides = [n for n in p.nodes[div].get_conts ()
if n not in p.loop_data
if p.preds[n] == [div]]
if not sides:
trace ("skipping case split, no notable succ")
n = sides[0]
return ('CaseSplit', (n, p.node_tags[n][0]))
trace ('find_case_split: no case splits possible')
return (None, ())
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
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
def find_unknown_recursion (p, group, idents, tag, assns, extra_unfolds): from syntax import mk_not, mk_and, foldr1 rep = rep_graph.mk_graph_slice (p, fast = True) for n in p.nodes: if p.nodes[n].kind != 'Call': continue if p.node_tags[n][0] != tag: continue fname = p.nodes[n].fname if fname in extra_unfolds: return n if fname not in group: continue (inp_env, _, _) = rep.get_func (default_n_vc (p, n)) pc = rep.get_pc (default_n_vc (p, n)) new = foldr1 (mk_and, [pc] + [syntax.mk_not ( solver.to_smt_expr (ident, inp_env, rep.solv)) for ident in idents.get (fname, [])]) if rep.test_hyp_whyps (mk_not (new), assns): continue return n return None
def find_unknown_recursion(p, group, idents, tag, assns, extra_unfolds):
from syntax import mk_not, mk_and, foldr1
rep = rep_graph.mk_graph_slice(p, fast=True)
for n in p.nodes:
if p.nodes[n].kind != 'Call':
continue
if p.node_tags[n][0] != tag:
continue
fname = p.nodes[n].fname
if fname in extra_unfolds:
return n
if fname not in group:
continue
(inp_env, _, _) = rep.get_func(default_n_vc(p, n))
pc = rep.get_pc(default_n_vc(p, n))
new = foldr1(mk_and, [pc] + [
syntax.mk_not(solver.to_smt_expr(ident, inp_env, rep.solv))
for ident in idents.get(fname, [])
])
if rep.test_hyp_whyps(mk_not(new), assns):
continue
return n
return None
def add_recursion_ident(f, group, idents, extra_unfolds):
from syntax import mk_eq, mk_implies, mk_var
p = problem.Problem(None, name='Recursion Test')
chain = []
tag = 'fun0'
p.add_entry_function(functions[f], tag)
p.do_analysis()
assns = []
recursion_last_assns[0] = assns
while True:
res = find_unknown_recursion(p, group, idents, tag, assns,
extra_unfolds)
if res == None:
break
if p.nodes[res].fname not in group:
problem.inline_at_point(p, res)
continue
fname = p.nodes[res].fname
chain.append(fname)
tag = 'fun%d' % len(chain)
(args, _, entry) = p.add_entry_function(functions[fname], tag)
p.do_analysis()
assns += function_link_assns(p, res, tag)
if chain == []:
return None
recursion_trace.append(' created fun chain %s' % chain)
word_args = [(i, mk_var(s, typ)) for (i, (s, typ)) in enumerate(args)
if typ.kind == 'Word']
rep = rep_graph.mk_graph_slice(p, fast=True)
(_, env) = rep.get_node_pc_env((entry, ()))
m = {}
res = rep.test_hyp_whyps(syntax.false_term, assns, model=m)
assert m
if find_unknown_recursion(p, group, idents, tag, [], []) == None:
idents.setdefault(fname, [])
idents[fname].append(syntax.true_term)
recursion_trace.append(' found final ident for %s' % fname)
return syntax.true_term
assert word_args
recursion_trace.append(' scanning for ident for %s' % fname)
for (i, arg) in word_args:
(nm, typ) = functions[fname].inputs[i]
arg_smt = solver.to_smt_expr(arg, env, rep.solv)
val = search.eval_model_expr(m, rep.solv, arg_smt)
if not rep.test_hyp_whyps(mk_eq(arg_smt, val), assns):
recursion_trace.append(' discarded %s = 0x%x, not stable' %
(nm, val.val))
continue
entry_vis = ((entry, ()), tag)
ass = rep_graph.eq_hyp((arg, entry_vis), (val, entry_vis))
res = find_unknown_recursion(p, group, idents, tag, assns + [ass], [])
if res:
fname2 = p.nodes[res].fname
recursion_trace.append(
' discarded %s, allows recursion to %s' % (nm, fname2))
continue
eq = syntax.mk_eq(mk_var(nm, typ), val)
idents.setdefault(fname, [])
idents[fname].append(eq)
recursion_trace.append(' found ident for %s: %s' % (fname, eq))
return eq
assert not "identifying assertion found"
def add_recursion_ident (f, group, idents, extra_unfolds):
from syntax import mk_eq, mk_implies, mk_var
p = problem.Problem (None, name = 'Recursion Test')
chain = []
tag = 'fun0'
p.add_entry_function (functions[f], tag)
p.do_analysis ()
assns = []
recursion_last_assns[0] = assns
while True:
res = find_unknown_recursion (p, group, idents, tag, assns,
extra_unfolds)
if res == None:
break
if p.nodes[res].fname not in group:
problem.inline_at_point (p, res)
continue
fname = p.nodes[res].fname
chain.append (fname)
tag = 'fun%d' % len (chain)
(args, _, entry) = p.add_entry_function (functions[fname], tag)
p.do_analysis ()
assns += function_link_assns (p, res, tag)
if chain == []:
return None
recursion_trace.append (' created fun chain %s' % chain)
word_args = [(i, mk_var (s, typ))
for (i, (s, typ)) in enumerate (args)
if typ.kind == 'Word']
rep = rep_graph.mk_graph_slice (p, fast = True)
(_, env) = rep.get_node_pc_env ((entry, ()))
m = {}
res = rep.test_hyp_whyps (syntax.false_term, assns, model = m)
assert m
if find_unknown_recursion (p, group, idents, tag, [], []) == None:
idents.setdefault (fname, [])
idents[fname].append (syntax.true_term)
recursion_trace.append (' found final ident for %s' % fname)
return syntax.true_term
assert word_args
recursion_trace.append (' scanning for ident for %s' % fname)
for (i, arg) in word_args:
(nm, typ) = functions[fname].inputs[i]
arg_smt = solver.to_smt_expr (arg, env, rep.solv)
val = search.eval_model_expr (m, rep.solv, arg_smt)
if not rep.test_hyp_whyps (mk_eq (arg_smt, val), assns):
recursion_trace.append (' discarded %s = 0x%x, not stable' % (nm, val.val))
continue
entry_vis = ((entry, ()), tag)
ass = rep_graph.eq_hyp ((arg, entry_vis), (val, entry_vis))
res = find_unknown_recursion (p, group, idents, tag,
assns + [ass], [])
if res:
fname2 = p.nodes[res].fname
recursion_trace.append (' discarded %s, allows recursion to %s' % (nm, fname2))
continue
eq = syntax.mk_eq (mk_var (nm, typ), val)
idents.setdefault (fname, [])
idents[fname].append (eq)
recursion_trace.append (' found ident for %s: %s' % (fname, eq))
return eq
assert not "identifying assertion found"
return self.get_loop_pc_env (split, vcount)
pc_envs = [pc_env for n_prev in self.p.preds[n]
if self.p.node_tags[n_prev][0] == tag
for pc_env in self.get_arc_pc_envs (n_prev,
(n, vcount))]
pc_envs = [pc_env for pc_env in pc_envs if pc_env]
if pc_envs == []:
return None
if n == 'Err':
# we'll never care about variable values here
# and there are sometimes a LOT of arcs to Err
# so we save a lot of merge effort
pc_envs = [(to_smt_expr (pc, env, self.solv), {})
for (pc, env) in pc_envs]
(pc, env, large) = merge_envs_pcs (pc_envs, self.solv)
if large or len (smt_expr (pc, env, self.solv)) > 80:
name = self.path_cond_name ((n, vcount), tag)
name = self.solv.add_def (name, pc, env)
pc = mk_smt_expr (name, boolT)
for (nm, typ) in env:
if len (env[(nm, typ)]) > 80:
env[(nm, typ)] = self.contract (nm, (n, vcount),
env[(nm, typ)], typ)
return (pc, env)
