sby/sbysrc/sby_engine_smtbmc.py

#
# SymbiYosys (sby) -- Front-end for Yosys-based formal verification flows
#
# Copyright (C) 2016  Claire Xenia Wolf <claire@yosyshq.com>
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#

import re, os, getopt, click, glob
from sby_core import SbyProc
from sby_sim import sim_witness_trace

def run(mode, task, engine_idx, engine):
    smtbmc_opts = []
    nomem_opt = False
    presat_opt = True
    unroll_opt = None
    syn_opt = False
    stbv_opt = False
    stdt_opt = False
    dumpsmt2 = False
    progress = False
    basecase_only = False
    induction_only = False
    keep_going = False
    random_seed = None
    task.precise_prop_status = True

    opts, args = getopt.getopt(engine[1:], "", ["nomem", "syn", "stbv", "stdt", "presat",
            "nopresat", "unroll", "nounroll", "dumpsmt2", "progress", "basecase", "induction", "keep-going", "seed="])

    for o, a in opts:
        if o == "--nomem":
            nomem_opt = True
        elif o == "--syn":
            syn_opt = True
        elif o == "--stbv":
            stbv_opt = True
        elif o == "--stdt":
            stdt_opt = True
        elif o == "--presat":
            presat_opt = True
        elif o == "--nopresat":
            presat_opt = False
        elif o == "--unroll":
            unroll_opt = True
        elif o == "--nounroll":
            unroll_opt = False
        elif o == "--dumpsmt2":
            dumpsmt2 = True
        elif o == "--progress":
            progress = True
        elif o == "--basecase":
            if induction_only:
                task.error("smtbmc options --basecase and --induction are exclusive.")
            basecase_only = True
        elif o == "--induction":
            if basecase_only:
                task.error("smtbmc options --basecase and --induction are exclusive.")
            induction_only = True
        elif o == "--keep-going":
            keep_going = True
        elif o == "--seed":
            random_seed = a
        else:
            task.error(f"Invalid smtbmc options {o}.")

    xtra_opts = False
    for i, a in enumerate(args):
        if i == 0 and a == "z3" and unroll_opt is None:
                unroll_opt = False
        if a == "--":
            xtra_opts = True
            continue
        if xtra_opts:
            smtbmc_opts.append(a)
        else:
            smtbmc_opts += ["-s" if i == 0 else "-S", a]

    if presat_opt:
        smtbmc_opts += ["--presat"]

    if unroll_opt is None or unroll_opt:
        smtbmc_opts += ["--unroll"]

    if task.opt_smtc is not None:
        smtbmc_opts += ["--smtc", f"src/{task.opt_smtc}"]

    if task.opt_tbtop is not None:
         smtbmc_opts += ["--vlogtb-top", task.opt_tbtop]

    model_name = "smt2"
    if syn_opt: model_name += "_syn"
    if nomem_opt: model_name += "_nomem"
    if stbv_opt: model_name += "_stbv"
    if stdt_opt: model_name += "_stdt"

    if mode == "prove":
        if not induction_only:
            run("prove_basecase", task, engine_idx, engine)
        if not basecase_only:
            run("prove_induction", task, engine_idx, engine)
        return

    procname = f"engine_{engine_idx}"
    trace_prefix = f"engine_{engine_idx}/trace"
    logfile_prefix = f"{task.workdir}/engine_{engine_idx}/logfile"

    if mode == "prove_basecase":
        procname += ".basecase"
        logfile_prefix += "_basecase"

    if mode == "prove_induction":
        procname += ".induction"
        trace_prefix += "_induct"
        logfile_prefix += "_induction"
        smtbmc_opts.append("-i")

    if mode == "cover":
        smtbmc_opts.append("-c")
        trace_prefix += "%"

    if keep_going and mode != "prove_induction":
        smtbmc_opts.append("--keep-going")
        if mode != "cover":
            trace_prefix += "%"

    if dumpsmt2:
        smtbmc_opts += ["--dump-smt2", trace_prefix.replace("%", "") + ".smt2"]

    if not progress:
        smtbmc_opts.append("--noprogress")

    if task.opt_skip is not None:
        t_opt = "{}:{}".format(task.opt_skip, task.opt_depth)
    else:
        t_opt = "{}".format(task.opt_depth)

    smtbmc_vcd = task.opt_vcd and not task.opt_vcd_sim

    smtbmc_append = 0
    sim_append = 0

    log = task.log_prefix(f"engine_{engine_idx}")

    if task.opt_append_assume:
        smtbmc_append = task.opt_append
    elif smtbmc_vcd:
        if not task.opt_append_assume:
            log("For VCDs generated by smtbmc the option 'append_assume off' is ignored")
        smtbmc_append = task.opt_append
    else:
        sim_append = task.opt_append

    trace_ext = 'fst' if task.opt_fst else 'vcd'

    random_seed = f"--info \"(set-option :random-seed {random_seed})\"" if random_seed else ""
    dump_flags = f"--dump-vcd {trace_prefix}.vcd " if smtbmc_vcd else ""
    dump_flags += f"--dump-yw {trace_prefix}.yw --dump-vlogtb {trace_prefix}_tb.v --dump-smtc {trace_prefix}.smtc"
    proc = SbyProc(
        task,
        procname,
        task.model(model_name),
        f"""cd {task.workdir}; {task.exe_paths["smtbmc"]} {" ".join(smtbmc_opts)} -t {t_opt} {random_seed} --append {smtbmc_append} {dump_flags} model/design_{model_name}.smt2""",
        logfile=open(logfile_prefix + ".txt", "w"),
        logstderr=(not progress)
    )

    if mode == "prove_basecase":
        task.basecase_procs.append(proc)

    if mode == "prove_induction":
        task.induction_procs.append(proc)

    proc_status = None
    last_prop = []
    pending_sim = None
    current_step = None
    procs_running = 1

    def output_callback(line):
        nonlocal proc_status
        nonlocal last_prop
        nonlocal pending_sim
        nonlocal current_step
        nonlocal procs_running

        if pending_sim:
            sim_proc = sim_witness_trace(procname, task, engine_idx, pending_sim, append=sim_append, inductive=mode == "prove_induction")
            sim_proc.register_exit_callback(simple_exit_callback)
            procs_running += 1
            pending_sim = None

        smt2_trans = {'\\':'/', '|':'/'}

        def parse_mod_path(path_string):
            # Match a path with . as delimiter, allowing escaped tokens in
            # verilog `\name ` format
            return [m[1] or m[0] for m in re.findall(r"(\\([^ ]*) |[^\.]+)(?:\.|$)", path_string)]

        match = re.match(r"^## [0-9: ]+ .* in step ([0-9]+)\.\.", line)
        if match:
            current_step = int(match[1])
            return line

        match = re.match(r"^## [0-9: ]+ Status: FAILED", line)
        if match:
            proc_status = "FAIL"
            return line.replace("FAILED", "failed")

        match = re.match(r"^## [0-9: ]+ Status: PASSED", line)
        if match:
            proc_status = "PASS"
            return line.replace("PASSED", "passed")

        match = re.match(r"^## [0-9: ]+ Status: PREUNSAT", line)
        if match:
            proc_status = "ERROR"
            return line

        match = re.match(r"^## [0-9: ]+ Unexpected response from solver:", line)
        if match:
            proc_status = "ERROR"
            return line

        match = re.match(r"^## [0-9: ]+ Assert failed in ([^:]+): (\S+)(?: \((\S+)\))?", line)
        if match:
            path = parse_mod_path(match[1])
            cell_name = match[3] or match[2]
            prop = task.design.hierarchy.find_property(path, cell_name, trans_dict=smt2_trans)
            prop.status = "FAIL"
            task.status_db.set_task_property_status(prop, data=dict(source="smtbmc", engine=f"engine_{engine_idx}"))
            last_prop.append(prop)
            return line

        match = re.match(r"^## [0-9: ]+ Reached cover statement in step \d+ at ([^:]+): (\S+)(?: \((\S+)\))?", line)
        if match:
            path = parse_mod_path(match[1])
            cell_name = match[3] or match[2]
            prop = task.design.hierarchy.find_property(path, cell_name, trans_dict=smt2_trans)
            prop.status = "PASS"
            task.status_db.set_task_property_status(prop, data=dict(source="smtbmc", engine=f"engine_{engine_idx}"))
            last_prop.append(prop)
            return line

        if smtbmc_vcd and not task.opt_fst:
            match = re.match(r"^## [0-9: ]+ Writing trace to VCD file: (\S+)", line)
            if match:
                tracefile = match[1]
                trace = os.path.basename(tracefile)[:-4]
                engine_case = mode.split('_')[1] if '_' in mode else None
                task.summary.add_event(engine_idx=engine_idx, trace=trace, path=tracefile, engine_case=engine_case)

            if match and last_prop:
                for p in last_prop:
                    task.summary.add_event(
                        engine_idx=engine_idx, trace=trace,
                        type=p.celltype, hdlname=p.hdlname, src=p.location, step=current_step)
                    p.tracefiles.append(tracefile)
                last_prop = []
                return line
        else:
            match = re.match(r"^## [0-9: ]+ Writing trace to Yosys witness file: (\S+)", line)
            if match:
                tracefile = match[1]
                pending_sim = tracefile

        match = re.match(r"^## [0-9: ]+ Unreached cover statement at ([^:]+): (\S+)(?: \((\S+)\))?", line)
        if match:
            path = parse_mod_path(match[1])
            cell_name = match[3] or match[2]
            prop = task.design.hierarchy.find_property(path, cell_name, trans_dict=smt2_trans)
            prop.status = "FAIL"
            task.status_db.set_task_property_status(prop, data=dict(source="smtbmc", engine=f"engine_{engine_idx}"))

        return line

    def simple_exit_callback(retcode):
        nonlocal procs_running
        procs_running -= 1
        if not procs_running:
            last_exit_callback()

    def exit_callback(retcode):
        if proc_status is None:
            task.error(f"engine_{engine_idx}: Engine terminated without status.")
        simple_exit_callback(retcode)

    def last_exit_callback():
        if mode == "bmc" or mode == "cover":
            task.update_status(proc_status)
            if proc_status == "FAIL" and mode == "bmc" and keep_going:
                task.pass_unknown_asserts(dict(source="smtbmc", keep_going=True, engine=f"engine_{engine_idx}"))
            proc_status_lower = proc_status.lower() if proc_status == "PASS" else proc_status
            task.summary.set_engine_status(engine_idx, proc_status_lower)
            if not keep_going:
                task.terminate()

        elif mode in ["prove_basecase", "prove_induction"]:
            proc_status_lower = proc_status.lower() if proc_status == "PASS" else proc_status
            task.summary.set_engine_status(engine_idx, proc_status_lower, mode.split("_")[1])

            if mode == "prove_basecase":
                for proc in task.basecase_procs:
                    proc.terminate()

                if proc_status == "PASS":
                    task.basecase_pass = True

                else:
                    task.update_status(proc_status)
                    task.terminate()

            elif mode == "prove_induction":
                for proc in task.induction_procs:
                    proc.terminate()

                if proc_status == "PASS":
                    task.induction_pass = True

            else:
                assert False

            if task.basecase_pass and task.induction_pass:
                task.update_status("PASS")
                task.summary.append("successful proof by k-induction.")
                if not keep_going:
                    task.terminate()

        else:
            assert False

    proc.output_callback = output_callback
    proc.register_exit_callback(exit_callback)