Пример #1
0
    def extend_ts(ts, modifier):

        affect_init = False

        if ts.ftrans is None:
            return (ts, [])

        new_ftrans = {}

        vars = []

        for (assign, cond_assign_list) in ts.ftrans.items():
            fv = get_free_variables(assign)
            assert len(fv) == 1
            var = fv.pop()
            is_next = TS.has_next(var)

            refvar = TS.get_ref_var(var)
            nomvar = Symbol(NOMIN % refvar.symbol_name(), var.symbol_type())
            fvar = Symbol(FAULT % refvar.symbol_name(), BOOL)

            vars.append(nomvar)
            vars.append(fvar)

            repldic = dict([(refvar.symbol_name(), nomvar.symbol_name()), \
                            (TS.get_prime(refvar).symbol_name(), TS.get_prime(nomvar).symbol_name())])

            # Remapping nominal behavior to new variable
            new_ftrans[substitute(assign,
                                  repldic)] = [(substitute(c[0], repldic),
                                                substitute(c[1], repldic))
                                               for c in cond_assign_list]

            # Definition of the nominal behavior
            new_ftrans[refvar] = [(Not(fvar), nomvar)]

            # Application of the faulty behavior
            new_ftrans[refvar].append(
                (fvar, modifier.get_behavior(nomvar, refvar)))

            ts.trans = And(ts.trans, Implies(fvar, TS.get_prime(fvar)))

            if affect_init:
                ts.init = substitute(ts.init, repldic)
            else:
                ts.init = And(ts.init, Not(fvar))

        # add the vars to the transition system
        for var in vars:
            ts.add_var(var)

        ts.ftrans = new_ftrans

        return (ts, vars)
Пример #2
0
    def MemAcc(self, left, right):
        primed = False
        if TS.is_prime(left):
            primed = True
            left = TS.get_ref_var(left)

        timed_symbol = lambda v: v if not primed else TS.get_prime(v)
            
        memname = left.symbol_name()
        allsymbols = list(get_env().formula_manager.get_all_symbols())
        memsymbols = [(v.symbol_name(), timed_symbol(v)) for v in allsymbols \
                      if (not TS.is_prime(v)) and (not TS.is_timed(v)) and (v.symbol_name()[:len(memname)] == memname) \
                      and v.symbol_name() != memname]
        memsymbols.sort()
        memsize = len(memsymbols)

        if memsize < 1:
            Logger.error("Memory \"%s\" has size 1"%(memname))
        
        if right.is_int_constant():
            location = right.constant_value()
            if location > memsize-1:
                Logger.error("Out of bound access for memory \"%s\", size %d"%(memname, memsize))
            return memsymbols[location][1]
        else:
            if not (right.is_symbol() and right.symbol_type().is_bv_type()):
                Logger.error("Symbolic memory access requires Bitvector indexing")
            width_idx = right.symbol_type().width
            width_mem = min(memsize, width_idx)
            return mem_access(right, [m[1] for m in memsymbols], width_idx)
Пример #3
0
    def compile_sts(self, name, params):
        ts = TS()
        parsize = params[0]
        size = None

        if type(parsize) == str:
            sparser = StringParser()
            parsize = sparser.parse_formula(parsize)

        if parsize.is_constant():
            size = parsize.constant_value()

        if get_type(parsize).is_bv_type():
            size = get_type(parsize).width

        if size is None:
            Logger.error("Undefined size for symbol \"%s\"" % (params[0]))

        value = Symbol("%s.value" % name, BVType(size))
        ts.add_var(value)
        ts.trans = EqualsOrIff(value, TS.get_prime(value))

        return ts
Пример #4
0
    def parse_string(self, strinput):

        hts = HTS()
        ts = TS()

        nodemap = {}
        node_covered = set([])

        # list of tuples of var and cond_assign_list
        # cond_assign_list is tuples of (condition, value)
        # where everything is a pysmt FNode
        # for btor, the condition is always True
        ftrans = []

        initlist = []
        invarlist = []

        invar_props = []
        ltl_props = []

        prop_count = 0

        # clean string input, remove special characters from names
        for sc, rep in special_char_replacements.items():
            strinput = strinput.replace(sc, rep)

        def getnode(nid):
            node_covered.add(nid)
            if int(nid) < 0:
                return Ite(BV2B(nodemap[str(-int(nid))]), BV(0,1), BV(1,1))
            return nodemap[nid]

        def binary_op(bvop, bop, left, right):
            if (get_type(left) == BOOL) and (get_type(right) == BOOL):
                return bop(left, right)
            return bvop(B2BV(left), B2BV(right))

        def unary_op(bvop, bop, left):
            if (get_type(left) == BOOL):
                return bop(left)
            return bvop(left)

        for line in strinput.split(NL):
            linetok = line.split()
            if len(linetok) == 0:
                continue
            if linetok[0] == COM:
                continue

            (nid, ntype, *nids) = linetok

            if ntype == SORT:
                (stype, *attr) = nids
                if stype == BITVEC:
                    nodemap[nid] = BVType(int(attr[0]))
                    node_covered.add(nid)
                if stype == ARRAY:
                    nodemap[nid] = ArrayType(getnode(attr[0]), getnode(attr[1]))
                    node_covered.add(nid)

            if ntype == WRITE:
                nodemap[nid] = Store(*[getnode(n) for n in nids[1:4]])

            if ntype == READ:
                nodemap[nid] = Select(getnode(nids[1]), getnode(nids[2]))

            if ntype == ZERO:
                nodemap[nid] = BV(0, getnode(nids[0]).width)

            if ntype == ONE:
                nodemap[nid] = BV(1, getnode(nids[0]).width)

            if ntype == ONES:
                width = getnode(nids[0]).width
                nodemap[nid] = BV((2**width)-1, width)

            if ntype == REDOR:
                width = get_type(getnode(nids[1])).width
                zeros = BV(0, width)
                nodemap[nid] = BVNot(BVComp(getnode(nids[1]), zeros))

            if ntype == REDXOR:
                width = get_type(getnode(nids[1])).width
                nodemap[nid] = BV(0, width)
                zeros = BV(0, width)
                for yx_i in range(width):
                  tmp = BV(1 << yx_i, width)
                  tmp_2 = BVAnd(tmp, B2BV(getnode(nids[1])))
                  tmp_3 = BVZExt(B2BV(BVComp(tmp_2, zeros)), int(width - 1))
                  nodemap[nid] = BVAdd(tmp_3, nodemap[nid])
                nodemap[nid] = BVComp(BVAnd(BV(1, width), nodemap[nid]), BV(1, width))

            if ntype == REDAND:
                width = get_type(getnode(nids[1])).width
                ones = BV((2**width)-1, width)
                nodemap[nid] = BVComp(getnode(nids[1]), ones)

            if ntype == CONSTD:
                width = getnode(nids[0]).width
                nodemap[nid] = BV(int(nids[1]), width)

            if ntype == CONST:
                width = getnode(nids[0]).width
                nodemap[nid] = BV(bin_to_dec(nids[1]), width)

            if ntype == STATE:
                if len(nids) > 1:
                    nodemap[nid] = Symbol(nids[1], getnode(nids[0]))
                else:
                    nodemap[nid] = Symbol((SN%nid), getnode(nids[0]))
                ts.add_state_var(nodemap[nid])

            if ntype == INPUT:
                if len(nids) > 1:
                    nodemap[nid] = Symbol(nids[1], getnode(nids[0]))
                else:
                    nodemap[nid] = Symbol((SN%nid), getnode(nids[0]))
                ts.add_input_var(nodemap[nid])

            if ntype == OUTPUT:
                # unfortunately we need to create an extra symbol just to have the output name
                # we could be smarter about this, but then this parser can't be greedy
                original_symbol = getnode(nids[0])
                output_symbol = Symbol(nids[1], original_symbol.get_type())
                nodemap[nid] = EqualsOrIff(output_symbol, original_symbol)
                invarlist.append(nodemap[nid])
                node_covered.add(nid)
                ts.add_output_var(output_symbol)

            if ntype == AND:
                nodemap[nid] = binary_op(BVAnd, And, getnode(nids[1]), getnode(nids[2]))

            if ntype == CONCAT:
                nodemap[nid] = BVConcat(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == XOR:
                nodemap[nid] = binary_op(BVXor, Xor, getnode(nids[1]), getnode(nids[2]))

            if ntype == XNOR:
                nodemap[nid] = BVNot(binary_op(BVXor, Xor, getnode(nids[1]), getnode(nids[2])))

            if ntype == NAND:
                bvop = lambda x,y: BVNot(BVAnd(x, y))
                bop = lambda x,y: Not(And(x, y))
                nodemap[nid] = binary_op(bvop, bop, getnode(nids[1]), getnode(nids[2]))

            if ntype == IMPLIES:
                nodemap[nid] = BVOr(BVNot(getnode(nids[1])), getnode(nids[2]))

            if ntype == NOT:
                nodemap[nid] = unary_op(BVNot, Not, getnode(nids[1]))

            if ntype == NEG:
                nodemap[nid] = unary_op(BVNeg, Not, getnode(nids[1]))

            if ntype == UEXT:
                nodemap[nid] = BVZExt(B2BV(getnode(nids[1])), int(nids[2]))

            if ntype == SEXT:
                nodemap[nid] = BVSExt(B2BV(getnode(nids[1])), int(nids[2]))

            if ntype == OR:
                nodemap[nid] = binary_op(BVOr, Or, getnode(nids[1]), getnode(nids[2]))

            if ntype == ADD:
                nodemap[nid] = BVAdd(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SUB:
                nodemap[nid] = BVSub(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == UGT:
                nodemap[nid] = BVUGT(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == UGTE:
                nodemap[nid] = BVUGE(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == ULT:
                nodemap[nid] = BVULT(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == ULTE:
                nodemap[nid] = BVULE(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SGT:
                nodemap[nid] = BVSGT(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SGTE:
                nodemap[nid] = BVSGE(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SLT:
                nodemap[nid] = BVSLT(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SLTE:
                nodemap[nid] = BVSLE(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == EQ:
                nodemap[nid] = BVComp(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == NEQ:
                nodemap[nid] = BVNot(BVComp(getnode(nids[1]), getnode(nids[2])))

            if ntype == MUL:
                nodemap[nid] = BVMul(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SLICE:
                nodemap[nid] = BVExtract(B2BV(getnode(nids[1])), int(nids[3]), int(nids[2]))

            if ntype == SLL:
                nodemap[nid] = BVLShl(getnode(nids[1]), getnode(nids[2]))

            if ntype == SRA:
                nodemap[nid] = BVAShr(getnode(nids[1]), getnode(nids[2]))

            if ntype == SRL:
                nodemap[nid] = BVLShr(getnode(nids[1]), getnode(nids[2]))

            if ntype == ITE:
                if (get_type(getnode(nids[2])) == BOOL) or (get_type(getnode(nids[3])) == BOOL):
                    nodemap[nid] = Ite(BV2B(getnode(nids[1])), B2BV(getnode(nids[2])), B2BV(getnode(nids[3])))
                else:
                    nodemap[nid] = Ite(BV2B(getnode(nids[1])), getnode(nids[2]), getnode(nids[3]))

            if ntype == NEXT:
                if (get_type(getnode(nids[1])) == BOOL) or (get_type(getnode(nids[2])) == BOOL):
                    lval = TS.get_prime(getnode(nids[1]))
                    rval = BV2B(getnode(nids[2]))
                else:
                    lval = TS.get_prime(getnode(nids[1]))
                    rval = getnode(nids[2])

                nodemap[nid] = EqualsOrIff(lval, rval)

                ftrans.append(
                     (lval,
                     [(TRUE(), rval)])
                )

            if ntype == INIT:
                if (get_type(getnode(nids[1])) == BOOL) or (get_type(getnode(nids[2])) == BOOL):
                    nodemap[nid] = EqualsOrIff(BV2B(getnode(nids[1])), BV2B(getnode(nids[2])))
                else:
                    nodemap[nid] = EqualsOrIff(getnode(nids[1]), getnode(nids[2]))
                initlist.append(getnode(nid))

            if ntype == CONSTRAINT:
                nodemap[nid] = BV2B(getnode(nids[0]))
                invarlist.append(getnode(nid))

            if ntype == BAD:
                nodemap[nid] = getnode(nids[0])

                if ASSERTINFO in line:
                    filename_lineno = os.path.basename(nids[3])
                    assert_name = 'embedded_assertion_%s'%filename_lineno
                    description = "Embedded assertion at line {1} in {0}".format(*filename_lineno.split(COLON_REP))
                else:
                    assert_name = 'embedded_assertion_%i'%prop_count
                    description = 'Embedded assertion number %i'%prop_count
                    prop_count += 1

                # Following problem format (name, description, strformula)
                invar_props.append((assert_name, description, Not(BV2B(getnode(nid)))))

            if nid not in nodemap:
                Logger.error("Unknown node type \"%s\""%ntype)

            # get wirename if it exists
            if ntype not in {STATE, INPUT, OUTPUT, BAD}:
                # check for wirename, if it's an integer, then it's a node ref
                try:
                    a = int(nids[-1])
                except:
                    try:
                        wire = Symbol(str(nids[-1]), getnode(nids[0]))
                        invarlist.append(EqualsOrIff(wire, B2BV(nodemap[nid])))
                        ts.add_var(wire)
                    except:
                        pass

        if Logger.level(1):
            name = lambda x: str(nodemap[x]) if nodemap[x].is_symbol() else x
            uncovered = [name(x) for x in nodemap if x not in node_covered]
            uncovered.sort()
            if len(uncovered) > 0:
                Logger.warning("Unlinked nodes \"%s\""%",".join(uncovered))

        if not self.symbolic_init:
            init = simplify(And(initlist))
        else:
            init = TRUE()

        invar = simplify(And(invarlist))

        # instead of trans, we're using the ftrans format -- see below
        ts.set_behavior(init, TRUE(), invar)

        # add ftrans
        for var, cond_assign_list in ftrans:
            ts.add_func_trans(var, cond_assign_list)

        hts.add_ts(ts)

        return (hts, invar_props, ltl_props)
Пример #5
0
    def parse_string(self, strinput):

        hts = HTS()
        ts = TS()

        nodemap = {}
        node_covered = set([])

        # list of tuples of var and cond_assign_list
        # cond_assign_list is tuples of (condition, value)
        # where everything is a pysmt FNode
        # for btor, the condition is always True
        ftrans = []

        initlist = []
        invarlist = []

        invar_props = []
        ltl_props = []

        prop_count = 0

        # clean string input, remove special characters from names
        for sc, rep in special_char_replacements.items():
            strinput = strinput.replace(sc, rep)

        def getnode(nid):
            node_covered.add(nid)
            if int(nid) < 0:
                return Ite(BV2B(nodemap[str(-int(nid))]), BV(0, 1), BV(1, 1))
            return nodemap[nid]

        def binary_op(bvop, bop, left, right):
            if (get_type(left) == BOOL) and (get_type(right) == BOOL):
                return bop(left, right)
            return bvop(B2BV(left), B2BV(right))

        def unary_op(bvop, bop, left):
            if (get_type(left) == BOOL):
                return bop(left)
            return bvop(left)

        for line in strinput.split(NL):
            linetok = line.split()
            if len(linetok) == 0:
                continue
            if linetok[0] == COM:
                continue

            (nid, ntype, *nids) = linetok

            if ntype == SORT:
                (stype, *attr) = nids
                if stype == BITVEC:
                    nodemap[nid] = BVType(int(attr[0]))
                    node_covered.add(nid)
                if stype == ARRAY:
                    nodemap[nid] = ArrayType(getnode(attr[0]),
                                             getnode(attr[1]))
                    node_covered.add(nid)

            if ntype == WRITE:
                nodemap[nid] = Store(*[getnode(n) for n in nids[1:4]])

            if ntype == READ:
                nodemap[nid] = Select(getnode(nids[1]), getnode(nids[2]))

            if ntype == ZERO:
                nodemap[nid] = BV(0, getnode(nids[0]).width)

            if ntype == ONE:
                nodemap[nid] = BV(1, getnode(nids[0]).width)

            if ntype == ONES:
                width = getnode(nids[0]).width
                nodemap[nid] = BV((2**width) - 1, width)

            if ntype == REDOR:
                width = get_type(getnode(nids[1])).width
                zeros = BV(0, width)
                nodemap[nid] = BVNot(BVComp(getnode(nids[1]), zeros))

            if ntype == REDAND:
                width = get_type(getnode(nids[1])).width
                ones = BV((2**width) - 1, width)
                nodemap[nid] = BVComp(getnode(nids[1]), ones)

            if ntype == CONSTD:
                width = getnode(nids[0]).width
                nodemap[nid] = BV(int(nids[1]), width)

            if ntype == CONST:
                width = getnode(nids[0]).width
                try:
                    nodemap[nid] = BV(bin_to_dec(nids[1]), width)
                except ValueError:
                    if not all([i == 'x' or i == 'z' for i in nids[1]]):
                        raise RuntimeError(
                            "If not a valid number, only support "
                            "all don't cares or high-impedance but got {}".
                            format(nids[1]))
                    # create a fresh variable for this non-deterministic constant
                    nodemap[nid] = Symbol('const_' + nids[1], BVType(width))
                    ts.add_state_var(nodemap[nid])
                    Logger.warning(
                        "Creating a fresh symbol for unsupported X/Z constant %s"
                        % nids[1])

            if ntype == STATE:
                if len(nids) > 1:
                    nodemap[nid] = Symbol(nids[1], getnode(nids[0]))
                else:
                    nodemap[nid] = Symbol((SN % nid), getnode(nids[0]))
                ts.add_state_var(nodemap[nid])

            if ntype == INPUT:
                if len(nids) > 1:
                    nodemap[nid] = Symbol(nids[1], getnode(nids[0]))
                else:
                    nodemap[nid] = Symbol((SN % nid), getnode(nids[0]))
                ts.add_input_var(nodemap[nid])

            if ntype == OUTPUT:
                # unfortunately we need to create an extra symbol just to have the output name
                # we could be smarter about this, but then this parser can't be greedy
                original_symbol = B2BV(getnode(nids[0]))
                output_symbol = Symbol(nids[1], original_symbol.get_type())
                nodemap[nid] = EqualsOrIff(output_symbol, original_symbol)
                invarlist.append(nodemap[nid])
                node_covered.add(nid)
                ts.add_output_var(output_symbol)

            if ntype == AND:
                nodemap[nid] = binary_op(BVAnd, And, getnode(nids[1]),
                                         getnode(nids[2]))

            if ntype == CONCAT:
                nodemap[nid] = BVConcat(B2BV(getnode(nids[1])),
                                        B2BV(getnode(nids[2])))

            if ntype == XOR:
                nodemap[nid] = binary_op(BVXor, Xor, getnode(nids[1]),
                                         getnode(nids[2]))

            if ntype == XNOR:
                nodemap[nid] = BVNot(
                    binary_op(BVXor, Xor, getnode(nids[1]), getnode(nids[2])))

            if ntype == NAND:
                bvop = lambda x, y: BVNot(BVAnd(x, y))
                bop = lambda x, y: Not(And(x, y))
                nodemap[nid] = binary_op(bvop, bop, getnode(nids[1]),
                                         getnode(nids[2]))

            if ntype == IMPLIES:
                nodemap[nid] = BVOr(BVNot(getnode(nids[1])), getnode(nids[2]))

            if ntype == NOT:
                nodemap[nid] = unary_op(BVNot, Not, getnode(nids[1]))

            if ntype == NEG:
                nodemap[nid] = unary_op(BVNeg, Not, getnode(nids[1]))

            if ntype == UEXT:
                nodemap[nid] = BVZExt(B2BV(getnode(nids[1])), int(nids[2]))

            if ntype == SEXT:
                nodemap[nid] = BVSExt(B2BV(getnode(nids[1])), int(nids[2]))

            if ntype == OR:
                nodemap[nid] = binary_op(BVOr, Or, getnode(nids[1]),
                                         getnode(nids[2]))

            if ntype == ADD:
                nodemap[nid] = BVAdd(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == SUB:
                nodemap[nid] = BVSub(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == UGT:
                nodemap[nid] = BVUGT(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == UGTE:
                nodemap[nid] = BVUGE(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == ULT:
                nodemap[nid] = BVULT(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == ULTE:
                nodemap[nid] = BVULE(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == SGT:
                nodemap[nid] = BVSGT(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == SGTE:
                nodemap[nid] = BVSGE(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == SLT:
                nodemap[nid] = BVSLT(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == SLTE:
                nodemap[nid] = BVSLE(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == EQ:
                nodemap[nid] = BVComp(B2BV(getnode(nids[1])),
                                      B2BV(getnode(nids[2])))

            if ntype == NEQ:
                nodemap[nid] = BVNot(BVComp(getnode(nids[1]),
                                            getnode(nids[2])))

            if ntype == MUL:
                nodemap[nid] = BVMul(B2BV(getnode(nids[1])),
                                     B2BV(getnode(nids[2])))

            if ntype == SLICE:
                nodemap[nid] = BVExtract(B2BV(getnode(nids[1])), int(nids[3]),
                                         int(nids[2]))

            if ntype == SLL:
                nodemap[nid] = BVLShl(getnode(nids[1]), getnode(nids[2]))

            if ntype == SRA:
                nodemap[nid] = BVAShr(getnode(nids[1]), getnode(nids[2]))

            if ntype == SRL:
                nodemap[nid] = BVLShr(getnode(nids[1]), getnode(nids[2]))

            if ntype == ITE:
                if (get_type(getnode(nids[2])) == BOOL) or (get_type(
                        getnode(nids[3])) == BOOL):
                    nodemap[nid] = Ite(BV2B(getnode(nids[1])),
                                       B2BV(getnode(nids[2])),
                                       B2BV(getnode(nids[3])))
                else:
                    nodemap[nid] = Ite(BV2B(getnode(nids[1])),
                                       getnode(nids[2]), getnode(nids[3]))

            if ntype == NEXT:
                if (get_type(getnode(nids[1])) == BOOL) or (get_type(
                        getnode(nids[2])) == BOOL):
                    lval = TS.get_prime(getnode(nids[1]))
                    rval = B2BV(getnode(nids[2]))
                else:
                    lval = TS.get_prime(getnode(nids[1]))
                    rval = getnode(nids[2])

                nodemap[nid] = EqualsOrIff(lval, rval)

                ftrans.append((lval, [(TRUE(), rval)]))

            if ntype == INIT:
                if (get_type(getnode(nids[1])) == BOOL) or (get_type(
                        getnode(nids[2])) == BOOL):
                    nodemap[nid] = EqualsOrIff(BV2B(getnode(nids[1])),
                                               BV2B(getnode(nids[2])))
                elif get_type(getnode(nids[1])).is_array_type():
                    _type = get_type(getnode(nids[1]))
                    nodemap[nid] = EqualsOrIff(
                        getnode(nids[1]),
                        Array(_type.index_type, default=getnode(nids[2])))
                else:
                    nodemap[nid] = EqualsOrIff(getnode(nids[1]),
                                               getnode(nids[2]))
                initlist.append(getnode(nid))

            if ntype == CONSTRAINT:
                nodemap[nid] = BV2B(getnode(nids[0]))
                invarlist.append(getnode(nid))

            if ntype == BAD:
                nodemap[nid] = getnode(nids[0])

                if len(nids) > 1:
                    assert_name = nids[1]
                    description = "Embedded assertion: {}".format(assert_name)
                else:
                    assert_name = 'embedded_assertion_%i' % prop_count
                    description = 'Embedded assertion number %i' % prop_count
                    prop_count += 1

                # Following problem format (name, description, strformula)
                invar_props.append(
                    (assert_name, description, Not(BV2B(getnode(nid)))))

            if nid not in nodemap:
                Logger.error("Unknown node type \"%s\"" % ntype)

            # get wirename if it exists
            if ntype not in {STATE, INPUT, OUTPUT, BAD}:
                # disregard comments at the end of the line
                try:
                    symbol_idx = nids.index(';')
                    symbol_idx -= 1  # the symbol should be before the comment
                except:
                    # the symbol is just the end
                    symbol_idx = -1

                # check for wirename, if it's an integer, then it's a node ref
                try:
                    a = int(nids[symbol_idx])
                except:
                    try:
                        name = str(nids[symbol_idx])
                        # use the exact name, unless it has already been used
                        wire = Symbol(name, getnode(nids[0]))
                        if wire in ts.vars:
                            wire = FreshSymbol(getnode(nids[0]),
                                               template=name + "%d")
                        invarlist.append(EqualsOrIff(wire, B2BV(nodemap[nid])))
                        ts.add_var(wire)
                    except:
                        pass

        if Logger.level(1):
            name = lambda x: str(nodemap[x]) if nodemap[x].is_symbol() else x
            uncovered = [name(x) for x in nodemap if x not in node_covered]
            uncovered.sort()
            if len(uncovered) > 0:
                Logger.warning("Unlinked nodes \"%s\"" % ",".join(uncovered))

        if not self.symbolic_init:
            init = simplify(And(initlist))
        else:
            init = TRUE()

        invar = simplify(And(invarlist))

        # instead of trans, we're using the ftrans format -- see below
        ts.set_behavior(init, TRUE(), invar)

        # add ftrans
        for var, cond_assign_list in ftrans:
            ts.add_func_trans(var, cond_assign_list)

        hts.add_ts(ts)

        return (hts, invar_props, ltl_props)
Пример #6
0
    def parse_string(self, strinput):

        hts = HTS()
        ts = TS()

        nodemap = {}
        node_covered = set([])

        translist = []
        initlist = []
        invarlist = []

        invar_props = []
        ltl_props = []

        def getnode(nid):
            node_covered.add(nid)
            if int(nid) < 0:
                return Ite(BV2B(nodemap[str(-int(nid))]), BV(0,1), BV(1,1))
            return nodemap[nid]

        def binary_op(bvop, bop, left, right):
            if (get_type(left) == BOOL) and (get_type(right) == BOOL):
                return bop(left, right)
            return bvop(B2BV(left), B2BV(right))

        def unary_op(bvop, bop, left):
            if (get_type(left) == BOOL):
                return bop(left)
            return bvop(left)

        for line in strinput.split(NL):
            linetok = line.split()
            if len(linetok) == 0:
                continue
            if linetok[0] == COM:
                continue

            (nid, ntype, *nids) = linetok

            if ntype == SORT:
                (stype, *attr) = nids
                if stype == BITVEC:
                    nodemap[nid] = BVType(int(attr[0]))
                    node_covered.add(nid)
                if stype == ARRAY:
                    nodemap[nid] = ArrayType(getnode(attr[0]), getnode(attr[1]))
                    node_covered.add(nid)

            if ntype == WRITE:
                nodemap[nid] = Store(*[getnode(n) for n in nids[1:4]])

            if ntype == READ:
                nodemap[nid] = Select(getnode(nids[1]), getnode(nids[2]))

            if ntype == ZERO:
                nodemap[nid] = BV(0, getnode(nids[0]).width)

            if ntype == ONE:
                nodemap[nid] = BV(1, getnode(nids[0]).width)

            if ntype == ONES:
                width = getnode(nids[0]).width
                nodemap[nid] = BV((2**width)-1, width)

            if ntype == REDOR:
                width = get_type(getnode(nids[1])).width
                zeros = BV(0, width)
                nodemap[nid] = BVNot(BVComp(getnode(nids[1]), zeros))

            if ntype == REDAND:
                width = get_type(getnode(nids[1])).width
                ones = BV((2**width)-1, width)
                nodemap[nid] = BVComp(getnode(nids[1]), ones)

            if ntype == CONSTD:
                width = getnode(nids[0]).width
                nodemap[nid] = BV(int(nids[1]), width)

            if ntype == CONST:
                width = getnode(nids[0]).width
                nodemap[nid] = BV(bin_to_dec(nids[1]), width)

            if ntype == STATE:
                if len(nids) > 1:
                    nodemap[nid] = Symbol(nids[1], getnode(nids[0]))
                else:
                    nodemap[nid] = Symbol((SN%nid), getnode(nids[0]))
                ts.add_state_var(nodemap[nid])

            if ntype == INPUT:
                if len(nids) > 1:
                    nodemap[nid] = Symbol(nids[1], getnode(nids[0]))
                else:
                    nodemap[nid] = Symbol((SN%nid), getnode(nids[0]))
                ts.add_input_var(nodemap[nid])

            if ntype == OUTPUT:
                if len(nids) > 2:
                    symbol = Symbol(nids[2], getnode(nids[0]))
                else:
                    symbol = Symbol((SN%nid), getnode(nids[0]))

                nodemap[nid] = EqualsOrIff(symbol, B2BV(getnode(nids[1])))
                invarlist.append(nodemap[nid])
                node_covered.add(nid)
                ts.add_output_var(symbol)

            if ntype == AND:
                nodemap[nid] = binary_op(BVAnd, And, getnode(nids[1]), getnode(nids[2]))

            if ntype == CONCAT:
                nodemap[nid] = BVConcat(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == XOR:
                nodemap[nid] = binary_op(BVXor, Xor, getnode(nids[1]), getnode(nids[2]))

            if ntype == NAND:
                bvop = lambda x,y: BVNot(BVAnd(x, y))
                bop = lambda x,y: Not(And(x, y))
                nodemap[nid] = binary_op(bvop, bop, getnode(nids[1]), getnode(nids[2]))

            if ntype == IMPLIES:
                nodemap[nid] = BVOr(BVNot(getnode(nids[1])), getnode(nids[2]))

            if ntype == NOT:
                nodemap[nid] = unary_op(BVNot, Not, getnode(nids[1]))

            if ntype == UEXT:
                nodemap[nid] = BVZExt(B2BV(getnode(nids[1])), int(nids[2]))

            if ntype == OR:
                nodemap[nid] = binary_op(BVOr, Or, getnode(nids[1]), getnode(nids[2]))

            if ntype == ADD:
                nodemap[nid] = BVAdd(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SUB:
                nodemap[nid] = BVSub(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == UGT:
                nodemap[nid] = BVUGT(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == UGTE:
                nodemap[nid] = BVUGE(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == ULT:
                nodemap[nid] = BVULT(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == ULTE:
                nodemap[nid] = BVULE(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == EQ:
                nodemap[nid] = BVComp(getnode(nids[1]), getnode(nids[2]))

            if ntype == NE:
                nodemap[nid] = BVNot(BVComp(getnode(nids[1]), getnode(nids[2])))

            if ntype == MUL:
                nodemap[nid] = BVMul(B2BV(getnode(nids[1])), B2BV(getnode(nids[2])))

            if ntype == SLICE:
                nodemap[nid] = BVExtract(B2BV(getnode(nids[1])), int(nids[3]), int(nids[2]))

            if ntype == SLL:
                nodemap[nid] = BVLShl(getnode(nids[1]), getnode(nids[2]))

            if ntype == SRA:
                nodemap[nid] = BVAShr(getnode(nids[1]), getnode(nids[2]))

            if ntype == SRL:
                nodemap[nid] = BVLShr(getnode(nids[1]), getnode(nids[2]))

            if ntype == ITE:
                if (get_type(getnode(nids[2])) == BOOL) or (get_type(getnode(nids[3])) == BOOL):
                    nodemap[nid] = Ite(BV2B(getnode(nids[1])), BV2B(getnode(nids[2])), BV2B(getnode(nids[3])))
                else:
                    nodemap[nid] = Ite(BV2B(getnode(nids[1])), getnode(nids[2]), getnode(nids[3]))

            if ntype == NEXT:
                if (get_type(getnode(nids[1])) == BOOL) or (get_type(getnode(nids[2])) == BOOL):
                    nodemap[nid] = EqualsOrIff(BV2B(TS.get_prime(getnode(nids[1]))), BV2B(getnode(nids[2])))
                else:
                    nodemap[nid] = EqualsOrIff(TS.get_prime(getnode(nids[1])), getnode(nids[2]))
                translist.append(getnode(nid))

            if ntype == INIT:
                if (get_type(getnode(nids[1])) == BOOL) or (get_type(getnode(nids[2])) == BOOL):
                    nodemap[nid] = EqualsOrIff(BV2B(getnode(nids[1])), BV2B(getnode(nids[2])))
                else:
                    nodemap[nid] = EqualsOrIff(getnode(nids[1]), getnode(nids[2]))
                initlist.append(getnode(nid))

            if ntype == CONSTRAINT:
                nodemap[nid] = BV2B(getnode(nids[0]))
                invarlist.append(getnode(nid))

            if ntype == BAD:
                nodemap[nid] = getnode(nids[0])
                invar_props.append(Not(BV2B(getnode(nid))))

            if nid not in nodemap:
                Logger.error("Unknown node type \"%s\""%ntype)

        if Logger.level(1):
            name = lambda x: str(nodemap[x]) if nodemap[x].is_symbol() else x
            uncovered = [name(x) for x in nodemap if x not in node_covered]
            uncovered.sort()
            if len(uncovered) > 0:
                Logger.warning("Unlinked nodes \"%s\""%",".join(uncovered))

        if not self.symbolic_init:
            init = simplify(And(initlist))
        else:
            init = TRUE()
        trans = simplify(And(translist))
        invar = simplify(And(invarlist))

        ts.set_behavior(init, trans, invar)
        hts.add_ts(ts)

        return (hts, invar_props, ltl_props)
Пример #7
0
    def Reg(in_, clk, clr, rst, arst, out, initval, clk_posedge, arst_posedge):
        # INIT: out = initval

        # do_arst = Ite(arst_posedge, (!arst & arst'), (arst & !arst'))
        # do_clk = Ite(clk_posedge, (!clk & clk'), (clk & !clk'))
        # inr = Ite(clr, 0, Ite(rst, initval, in))

        # if Modules.functional
        # TRANS: out' = Ite(do_clk, Ite(clr, 0, Ite(rst, initval, in)), Ite(rst, initval, in))
        # INVAR: True
        # trans gives priority to clr signal over rst

        # else
        # act_trans = (out' = inr)
        # pas_trans = (out' = out)
        # TRANS: (!do_arst -> ((do_clk -> act_trans) & (!do_clk -> pas_trans))) & (do_arst -> (out' = initval))
        # INVAR: True
        # trans gives priority to clr signal over rst

        vars_ = [in_, clk, clr, rst, arst, out]
        comment = "Reg (in, clk, clr, rst, arst, out) = (%s, %s, %s, %s, %s, %s)" % (
            tuple([str(x) for x in vars_]))
        Logger.log(comment, 3)

        init = TRUE()
        trans = TRUE()
        invar = TRUE()

        initvar = None
        basename = SEP.join(out.symbol_name().split(
            SEP)[:-1]) if SEP in out.symbol_name() else out.symbol_name()
        initname = basename + SEP + INIT

        if initval is not None and not Modules.symbolic_init:
            if out.symbol_type() == BOOL:
                binitval = FALSE() if initval == 0 else TRUE()
            else:
                binitval = BV(initval, out.symbol_type().width)

            initvar = binitval
        else:
            if out.symbol_type() == BOOL:
                initvar = Symbol(initname, BOOL)
            else:
                initvar = Symbol(initname, BVType(out.symbol_type().width))

            trans = And(trans, EqualsOrIff(initvar, TS.get_prime(initvar)))
            vars_.append(initvar)

        init = And(init, EqualsOrIff(out, initvar))

        if arst_posedge is not None:
            arst_posedge0 = False if arst_posedge else True
            arst_posedge1 = True if arst_posedge else False
        else:
            arst_posedge0 = False
            arst_posedge1 = True

        if clk_posedge is not None:
            clk_posedge0 = False if clk_posedge else True
            clk_posedge1 = True if clk_posedge else False
        else:
            clk_posedge0 = False
            clk_posedge1 = True

        if clr is not None:
            if clr.symbol_type() == BOOL:
                clr0 = Not(clr)
                clr1 = clr
            else:
                clr0 = EqualsOrIff(clr, BV(0, 1))
                clr1 = EqualsOrIff(clr, BV(1, 1))
        else:
            clr0 = TRUE()
            clr1 = FALSE()

        if rst is not None:
            if rst.symbol_type() == BOOL:
                rst0 = Not(rst)
                rst1 = rst
            else:
                rst0 = EqualsOrIff(rst, BV(0, 1))
                rst1 = EqualsOrIff(rst, BV(1, 1))
        else:
            rst0 = TRUE()
            rst1 = FALSE()

        if arst is not None:
            if arst.symbol_type() == BOOL:
                arst0 = Not(arst)
                arst1 = arst
            else:
                arst0 = EqualsOrIff(arst, BV(0, 1))
                arst1 = EqualsOrIff(arst, BV(1, 1))
        else:
            arst0 = TRUE()
            arst1 = FALSE()

        if clk.symbol_type() == BOOL:
            clk0 = Not(clk)
            clk1 = clk
        else:
            clk0 = EqualsOrIff(clk, BV(0, 1))
            clk1 = EqualsOrIff(clk, BV(1, 1))

        if Modules.abstract_clock:
            do_clk = TRUE()
        else:
            do_clk = And(TS.to_next(clk1), clk0) if clk_posedge1 else And(
                TS.to_next(clk0), clk1)

        if out.symbol_type() == BOOL:
            out0 = FALSE()
        else:
            out0 = BV(0, out.symbol_type().width)

        inr = Ite(clr1, out0, Ite(rst1, initvar, in_))
        do_arst = And(TS.to_next(arst1), arst0) if arst_posedge1 else And(
            TS.to_next(arst0), arst1)
        ndo_arst = Not(do_arst)
        ndo_clk = Not(do_clk)
        act_trans = EqualsOrIff(inr, TS.get_prime(out))
        pas_trans = EqualsOrIff(out, TS.get_prime(out))

        if Modules.functional:
            f_outr = Ite(rst1, initvar, out)
            f_inr = Ite(rst1, initvar, in_)
            f_clr_rst = Ite(clr1, out0, f_inr)
            trans = And(
                trans,
                EqualsOrIff(TS.get_prime(out), Ite(do_clk, f_clr_rst, f_outr)))
        else:
            trans = And(trans, And(Implies(ndo_arst, And(Implies(do_clk, act_trans), Implies(ndo_clk, pas_trans))), \
                                   Implies(do_arst, EqualsOrIff(TS.get_prime(out), initvar))))

        trans = simplify(trans)
        ts = TS(comment)
        ts.vars, ts.state_vars = set([v for v in vars_
                                      if v is not None]), set([out])
        ts.set_behavior(init, trans, invar)
        return ts
Пример #8
0
    def parse_file(self, file_path, config, flags=None):
        # coreir needs a string representing the path
        strfile = str(file_path)

        self.config = config
        self.__reset_structures()

        Logger.msg("Reading CoreIR system... ", 1)
        top_module = self.context.load_from_file(strfile)

        if config.run_coreir_passes:
            self.run_passes()

        Modules.abstract_clock = self.config.abstract_clock
        Modules.symbolic_init = self.config.symbolic_init

        top_def = top_module.definition
        interface = list(top_module.type.items())
        modules = {}
        sym_map = {}

        not_defined_mods = []

        hts = HTS(top_module.name)
        invar_props = []
        ltl_props = []

        Logger.msg("Starting encoding... ", 1)

        count = 0

        def extract_value(x, modname, inst_intr, inst_conf, inst_mod):
            if x in inst_intr:
                return self.BVVar(modname + x, inst_intr[x].size)

            if x in inst_conf:
                xval = inst_conf[x].value
                if type(xval) == bool:
                    xval = 1 if xval else 0
                else:
                    if type(xval) != int:
                        try:
                            xval = xval.as_uint()
                        except:
                            xval = None
                return xval

            if inst_mod.generated:
                inst_args = inst_mod.generator_args
                if x in inst_args:
                    return inst_args[x].value

            return None

        if Logger.level(1):
            timer = Logger.start_timer("IntConvertion", False)
            en_tprinting = False

        if Logger.level(2):
            ttimer = Logger.start_timer("Convertion", False)

        td_instances = top_def.instances
        top_def_instances = [(inst.selectpath, inst.config, inst.module)
                             for inst in td_instances]
        # sorting keeps the behavior deterministic
        top_def_instances.sort()

        totalinst = len(top_def_instances)

        for inst in top_def_instances:
            if Logger.level(1):
                count += 1
                if count % 300 == 0:
                    dtime = Logger.get_timer(timer, False)
                    if dtime > 2:
                        en_tprinting = True
                    if en_tprinting:
                        Logger.inline(
                            "%s" % status_bar(
                                (float(count) / float(totalinst))), 1)
                        timer = Logger.start_timer("IntConvertion", False)

                    if Logger.level(2):
                        Logger.get_timer(timer, False)

            ts = None

            (inst_name, inst_conf, inst_mod) = inst
            inst_type = inst_mod.name
            inst_intr = dict(inst_mod.type.items())
            modname = (SEP.join(inst_name)) + SEP

            values_dic = {}

            for x in self.attrnames:
                values_dic[x] = extract_value(x, modname, inst_intr, inst_conf,
                                              inst_mod)

            def args(ports_list):
                return [values_dic[x] for x in ports_list]

            sym = self.__mod_to_sym(inst_type, args)
            if sym is not None:
                sym_map[sym[0].symbol_name()] = (sym[0], sym[1])
                continue

            ts = self.__mod_to_impl(inst_type, args)

            if ts is not None:

                if flags is not None:
                    if CoreIRModelFlags.NO_INIT in flags:
                        ts.init = TRUE()

                    if CoreIRModelFlags.FC_LEMMAS in flags:
                        for v in ts.vars:
                            v_name = v.symbol_name()
                            if (CR in v_name) or (RCR in v_name):
                                cons_v_name = v_name[:len(
                                    CR)] if CR in v_name else v_name[:len(RCR)]
                                cons_v = Symbol(cons_v_name, v.symbol_type())
                                lemma = EqualsOrIff(
                                    cons_v,
                                    BV(values_dic[self.VALUE],
                                       cons_v.symbol_type().width))
                                hts.add_lemma(lemma)

                        for v in ts.state_vars:
                            lemma = EqualsOrIff(
                                v,
                                BV(values_dic[self.INIT],
                                   v.symbol_type().width))
                            hts.add_lemma(lemma)

                hts.add_ts(ts)
            else:
                if inst_type not in not_defined_mods:
                    intface = ", ".join([
                        "%s" % (v) for v in values_dic
                        if values_dic[v] is not None
                    ])
                    Logger.error(
                        "Module type \"%s\" with interface \"%s\" is not defined"
                        % (inst_type, intface))
                    not_defined_mods.append(inst_type)

        Logger.clear_inline(1)

        # sorting keeps the behavior deterministic
        interface.sort()

        for var in interface:
            varname = SELF + SEP + var[0]
            bvvar = self.BVVar(varname, var[1].size)
            if (var[1].is_input()):
                hts.add_input_var(bvvar)
            else:
                hts.add_output_var(bvvar)

            if var[1].kind == NAMED and var[1].name == COREIR_CLK:
                self.clock_list.add(bvvar)
                if self.config.abstract_clock:
                    self.abstract_clock_list.add(
                        (bvvar, (BV(0, var[1].size), BV(1, var[1].size))))
                else:
                    # add state variable that stores the previous clock value
                    # This is IMPORTANT for model checking soundness, but
                    #    it isn't obvious that this is necessary
                    #
                    # imagine we have an explicit clock encoding (not abstract_clock), e.g.
                    #   next(state_var) = (!clk & next(clk)) ? <state_update> : <old value>
                    # and if we're trying to prove something using k-induction, there's a "loop free"
                    #   constraint that the state and output variables don't repeat (reach the same
                    #   state twice) in the trace
                    #   but on a negedge clock, there can be scenarios where no state or outputs
                    #   can be updated and we'll get a trivial unsat which will be interpreted as
                    #   a converged proof -- uh oh
                    #
                    # adding this state element just ensures that the loop free constraint won't
                    #   be violated trivially
                    # e.g. on a neg-edge clock, this new state element will have changed

                    # make it hidden (won't be printed)
                    # HIDDEN_VAR is a prefix that printers check for
                    trailing_clock_var = self.BVVar(
                        "{}{}__prev".format(HIDDEN_VAR, varname), var[1].size)

                    ts = TS()
                    ts.add_state_var(trailing_clock_var)
                    # the initial state for this trailing variable is unconstrained
                    ts.set_behavior(
                        TRUE(),
                        EqualsOrIff(TS.get_prime(trailing_clock_var), bvvar),
                        TRUE())

                    hts.add_ts(ts)

        varmap = dict([(s.symbol_name(), s) for s in hts.vars])

        def split_paths(path):
            ret = []
            for el in path:
                ret += el.split(CSEP)

            return ret

        def dict_select(dic, el):
            return dic[el] if el in dic else None

        eq_conns = []
        eq_vars = set([])

        td_connections = top_def.connections
        top_def_connections = [
            ((conn.first.selectpath, conn.second.selectpath)
             if conn.first.selectpath < conn.second.selectpath else
             (conn.second.selectpath, conn.first.selectpath), conn)
            for conn in td_connections
        ]
        # sorting keeps the behavior deterministic
        top_def_connections.sort()

        for conn in top_def_connections:

            first_selectpath = split_paths(conn[0][0])
            second_selectpath = split_paths(conn[0][1])

            first = SEP.join(first_selectpath)
            second = SEP.join(second_selectpath)

            firstvar = None
            secondvar = None

            if is_number(first_selectpath[-1]):
                firstname = SEP.join(first_selectpath[:-1])
            else:
                firstname = SEP.join(first_selectpath)

            if is_number(second_selectpath[-1]):
                secondname = SEP.join(second_selectpath[:-1])
            else:
                secondname = SEP.join(second_selectpath)

            first = (dict_select(varmap, self.remap_or2an(firstname)), None)
            second = (dict_select(varmap, self.remap_or2an(secondname)), None)

            firstvar = first[0]
            secondvar = second[0]

            if (firstvar is None) and (self.remap_or2an(firstname) in sym_map):
                firstvar = sym_map[self.remap_or2an(firstname)][1]

            if (secondvar is None) and (self.remap_or2an(secondname)
                                        in sym_map):
                secondvar = sym_map[self.remap_or2an(secondname)][1]

            if (firstvar is None) and (secondvar is not None):
                Logger.error("Symbol \"%s\" is not defined" % firstname)
                first = (Symbol(self.remap_or2an(firstname),
                                secondvar.symbol_type()), None)
            else:
                if firstvar.is_constant():
                    sel = int(first_selectpath[-1]) if (is_number(
                        first_selectpath[-1])) else None
                    first = (firstvar, sel)
                else:
                    if (is_number(first_selectpath[-1])) and (
                            firstvar.symbol_type() !=
                            BOOL) and (firstvar.symbol_type().width > 1):
                        sel = int(first_selectpath[-1])
                        first = (firstvar, sel)

            if (firstvar is not None) and (secondvar is None):
                Logger.error("Symbol \"%s\" is not defined" % secondname)
                second = (Symbol(self.remap_or2an(secondname),
                                 firstvar.symbol_type()), None)
            else:
                if secondvar.is_constant():
                    sel = int(second_selectpath[-1]) if (is_number(
                        second_selectpath[-1])) else None
                    second = (secondvar, sel)
                else:
                    if (is_number(second_selectpath[-1])) and (
                            secondvar.symbol_type() !=
                            BOOL) and (secondvar.symbol_type().width > 1):
                        sel = int(second_selectpath[-1])
                        second = (secondvar, sel)

            assert ((firstvar is not None) and (secondvar is not None))

            eq_conns.append((first, second))

            if firstvar.is_symbol():
                eq_vars.add(firstvar)
            if secondvar.is_symbol():
                eq_vars.add(secondvar)

        conns_len = len(eq_conns)

        if self.pack_connections:
            eq_conns = self.__pack_connections(eq_conns)

        if len(eq_conns) < conns_len:
            Logger.log("Packed %d connections" % (conns_len - len(eq_conns)),
                       1)

        eq_formula = TRUE()

        for eq_conn in eq_conns:

            (fst, snd) = eq_conn

            if fst[1] is None:
                first = fst[0]
            else:
                if len(fst) > 2:
                    first = BVExtract(fst[0], fst[1], fst[2])
                else:
                    first = BVExtract(fst[0], fst[1], fst[1])

            if snd[1] is None:
                second = snd[0]
            else:
                if len(snd) > 2:
                    second = BVExtract(snd[0], snd[1], snd[2])
                else:
                    second = BVExtract(snd[0], snd[1], snd[1])

            if (first.get_type() != BOOL) and (second.get_type() == BOOL):
                second = Ite(second, BV(1, 1), BV(0, 1))

            if (first.get_type() == BOOL) and (second.get_type() != BOOL):
                first = Ite(first, BV(1, 1), BV(0, 1))

            eq_formula = And(eq_formula, EqualsOrIff(first, second))

            Logger.log(str(EqualsOrIff(first, second)), 3)

        ts = TS("Connections")
        ts.invar = eq_formula
        ts.vars = eq_vars

        hts.add_ts(ts)

        if self.enc_map is not None:
            del (self.enc_map)

        if Logger.level(2):
            Logger.get_timer(ttimer)

        # check that clocks were detected if there's any state
        if hts.state_vars:
            assert self.clock_list, "Expecting clocks if there are state variables"

        return (hts, invar_props, ltl_props)