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-rw-r--r--backends/smt2/example.v11
-rw-r--r--backends/smt2/example.ys3
-rw-r--r--backends/smt2/smtbmc.py110
-rw-r--r--backends/smt2/smtio.py285
4 files changed, 409 insertions, 0 deletions
diff --git a/backends/smt2/example.v b/backends/smt2/example.v
new file mode 100644
index 000000000..b195266eb
--- /dev/null
+++ b/backends/smt2/example.v
@@ -0,0 +1,11 @@
+module main(input clk);
+ reg [3:0] counter = 0;
+ always @(posedge clk) begin
+ if (counter == 10)
+ counter <= 0;
+ else
+ counter <= counter + 1;
+ end
+ assert property (counter != 15);
+ // assert property (counter <= 10);
+endmodule
diff --git a/backends/smt2/example.ys b/backends/smt2/example.ys
new file mode 100644
index 000000000..6fccb344f
--- /dev/null
+++ b/backends/smt2/example.ys
@@ -0,0 +1,3 @@
+read_verilog -formal example.v
+hierarchy; proc; opt; memory -nordff -nomap; opt -fast
+write_smt2 -bv -mem -wires example.smt2
diff --git a/backends/smt2/smtbmc.py b/backends/smt2/smtbmc.py
new file mode 100644
index 000000000..283d12319
--- /dev/null
+++ b/backends/smt2/smtbmc.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+
+import os, sys, getopt, re
+from smtio import smtio, smtopts, mkvcd
+
+steps = 20
+vcdfile = None
+tempind = False
+topmod = "main"
+so = smtopts()
+
+def usage():
+ print("""
+python3 smtbmc.py [options] <yosys_smt2_output>
+
+ -t <steps>
+ default: 20
+
+ -c <vcd_filename>
+ write counter-example to this VCD file
+
+ -i
+ instead of BMC run temporal induction
+
+ -m <module_name>
+ name of the top module, default: main
+""" + so.helpmsg())
+ sys.exit(1)
+
+try:
+ opts, args = getopt.getopt(sys.argv[1:], so.optstr + "t:c:im:")
+except:
+ usage()
+
+for o, a in opts:
+ if o == "-t":
+ steps = int(a)
+ elif o == "-c":
+ vcdfile = a
+ elif o == "-i":
+ tempind = True
+ print("FIXME: temporal induction not yet implemented!")
+ assert False
+ elif so.handle(o, a):
+ pass
+ else:
+ usage()
+
+if len(args) != 1:
+ usage()
+
+smt = smtio(opts=so)
+
+print("Solver: %s" % so.solver)
+smt.setup("QF_AUFBV")
+
+debug_nets = set()
+debug_nets_re = re.compile(r"^; yosys-smt2-(input|output|register|wire) (\S+) (\d+)")
+
+with open(args[0], "r") as f:
+ for line in f:
+ match = debug_nets_re.match(line)
+ if match:
+ debug_nets.add(match.group(2))
+ smt.write(line)
+
+def write_vcd_model():
+ print("%s Writing model to VCD file." % smt.timestamp())
+
+ vcd = mkvcd(open(vcdfile, "w"))
+ for netname in sorted(debug_nets):
+ width = len(smt.get_net_bin("main", netname, "s0"))
+ vcd.add_net(netname, width)
+
+ for i in range(step+1):
+ vcd.set_time(i)
+ for netname in debug_nets:
+ vcd.set_net(netname, smt.get_net_bin("main", netname, "s%d" % i))
+
+ vcd.set_time(step+1)
+
+for step in range(steps):
+ smt.write("(declare-fun s%d () %s_s)" % (step, topmod))
+ smt.write("(assert (%s_u s0))" % (topmod))
+
+ if step == 0:
+ smt.write("(assert (%s_i s0))" % (topmod))
+
+ else:
+ smt.write("(assert (%s_t s%d s%d))" % (topmod, step-1, step))
+
+ print("%s Checking sequence of length %d.." % (smt.timestamp(), step))
+ smt.write("(push 1)")
+
+ smt.write("(assert (not (%s_a s%d)))" % (topmod, step))
+
+ if smt.check_sat() == "sat":
+ print("%s BMC failed!" % smt.timestamp())
+ if vcdfile is not None:
+ write_vcd_model()
+ break
+
+ else: # unsat
+ smt.write("(pop 1)")
+ smt.write("(assert (%s_a s%d))" % (topmod, step))
+
+print("%s Done." % smt.timestamp())
+smt.write("(exit)")
+smt.wait()
+
diff --git a/backends/smt2/smtio.py b/backends/smt2/smtio.py
new file mode 100644
index 000000000..774984f2d
--- /dev/null
+++ b/backends/smt2/smtio.py
@@ -0,0 +1,285 @@
+#!/usr/bin/env python3
+
+import sys
+import subprocess
+from select import select
+from time import time
+
+class smtio:
+ def __init__(self, solver=None, debug_print=None, debug_file=None, timeinfo=None, opts=None):
+ if opts is not None:
+ self.solver = opts.solver
+ self.debug_print = opts.debug_print
+ self.debug_file = opts.debug_file
+ self.timeinfo = opts.timeinfo
+
+ else:
+ self.solver = "z3"
+ self.debug_print = False
+ self.debug_file = None
+ self.timeinfo = True
+
+ if solver is not None:
+ self.solver = solver
+
+ if debug_print is not None:
+ self.debug_print = debug_print
+
+ if debug_file is not None:
+ self.debug_file = debug_file
+
+ if timeinfo is not None:
+ self.timeinfo = timeinfo
+
+ if self.solver == "yices":
+ popen_vargs = ['yices-smt2', '--incremental']
+
+ if self.solver == "z3":
+ popen_vargs = ['z3', '-smt2', '-in']
+
+ if self.solver == "cvc4":
+ popen_vargs = ['cvc4', '--incremental', '--lang', 'smt2']
+
+ if self.solver == "mathsat":
+ popen_vargs = ['mathsat']
+
+ self.p = subprocess.Popen(popen_vargs, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+ self.start_time = time()
+
+ def setup(self, logic="ALL", info=None):
+ self.write("(set-logic %s)" % logic)
+ if info is not None:
+ self.write("(set-info :source |%s|)" % info)
+ self.write("(set-info :smt-lib-version 2.5)")
+ self.write("(set-info :category \"industrial\")")
+
+ def timestamp(self):
+ secs = int(time() - self.start_time)
+ return "+ %6d %3d:%02d:%02d " % (secs, secs // (60*60), (secs // 60) % 60, secs % 60)
+
+ def write(self, stmt):
+ stmt = stmt.strip()
+ if self.debug_print:
+ print("> %s" % stmt)
+ if self.debug_file:
+ print(stmt, file=self.debug_file)
+ self.debug_file.flush()
+ self.p.stdin.write(bytes(stmt + "\n", "ascii"))
+ self.p.stdin.flush()
+
+ def read(self):
+ stmt = []
+ count_brackets = 0
+
+ while True:
+ line = self.p.stdout.readline().decode("ascii").strip()
+ count_brackets += line.count("(")
+ count_brackets -= line.count(")")
+ stmt.append(line)
+ if self.debug_print:
+ print("< %s" % line)
+ if count_brackets == 0:
+ break
+ if not self.p.poll():
+ print("SMT Solver terminated unexpectedly: %s" % "".join(stmt))
+ sys.exit(1)
+
+ stmt = "".join(stmt)
+ if stmt.startswith("(error"):
+ print("SMT Solver Error: %s" % stmt, file=sys.stderr)
+ sys.exit(1)
+
+ return stmt
+
+ def check_sat(self):
+ if self.debug_print:
+ print("> (check-sat)")
+ if self.debug_file:
+ print("; running check-sat..", file=self.debug_file)
+ self.debug_file.flush()
+
+ self.p.stdin.write(bytes("(check-sat)\n", "ascii"))
+ self.p.stdin.flush()
+
+ if self.timeinfo:
+ i = 0
+ s = "/-\|"
+
+ count = 0
+ num_bs = 0
+ while select([self.p.stdout], [], [], 0.1) == ([], [], []):
+ count += 1
+
+ if count < 25:
+ continue
+
+ if count % 10 == 0 or count == 25:
+ secs = count // 10
+
+ if secs < 60:
+ m = "(%d seconds)" % secs
+ elif secs < 60*60:
+ m = "(%d seconds -- %d:%02d)" % (secs, secs // 60, secs % 60)
+ else:
+ m = "(%d seconds -- %d:%02d:%02d)" % (secs, secs // (60*60), (secs // 60) % 60, secs % 60)
+
+ print("%s %s %c" % ("\b \b" * num_bs, m, s[i]), end="", file=sys.stderr)
+ num_bs = len(m) + 3
+
+ else:
+ print("\b" + s[i], end="", file=sys.stderr)
+
+ sys.stderr.flush()
+ i = (i + 1) % len(s)
+
+ if num_bs != 0:
+ print("\b \b" * num_bs, end="", file=sys.stderr)
+ sys.stderr.flush()
+
+ result = self.read()
+ if self.debug_file:
+ print("(set-info :status %s)" % result, file=self.debug_file)
+ print("(check-sat)", file=self.debug_file)
+ self.debug_file.flush()
+ return result
+
+ def parse(self, stmt):
+ def worker(stmt):
+ if stmt[0] == '(':
+ expr = []
+ cursor = 1
+ while stmt[cursor] != ')':
+ el, le = worker(stmt[cursor:])
+ expr.append(el)
+ cursor += le
+ return expr, cursor+1
+
+ if stmt[0] == '|':
+ expr = "|"
+ cursor = 1
+ while stmt[cursor] != '|':
+ expr += stmt[cursor]
+ cursor += 1
+ expr += "|"
+ return expr, cursor+1
+
+ if stmt[0] in [" ", "\t", "\r", "\n"]:
+ el, le = worker(stmt[1:])
+ return el, le+1
+
+ expr = ""
+ cursor = 0
+ while stmt[cursor] not in ["(", ")", "|", " ", "\t", "\r", "\n"]:
+ expr += stmt[cursor]
+ cursor += 1
+ return expr, cursor
+ return worker(stmt)[0]
+
+ def bv2hex(self, v):
+ if v == "true": return "1"
+ if v == "false": return "0"
+ h = ""
+ while len(v) > 2:
+ d = 0
+ if len(v) > 0 and v[-1] == "1": d += 1
+ if len(v) > 1 and v[-2] == "1": d += 2
+ if len(v) > 2 and v[-3] == "1": d += 4
+ if len(v) > 3 and v[-4] == "1": d += 8
+ h = hex(d)[2:] + h
+ if len(v) < 4: break
+ v = v[:-4]
+ return h
+
+ def bv2bin(self, v):
+ if v == "true": return "1"
+ if v == "false": return "0"
+ return v[2:]
+
+ def get(self, expr):
+ self.write("(get-value (%s))" % (expr))
+ return self.parse(self.read())[0][1]
+
+ def get_net(self, mod_name, net_name, state_name):
+ return self.get("(|%s_n %s| %s)" % (mod_name, net_name, state_name))
+
+ def get_net_bool(self, mod_name, net_name, state_name):
+ v = self.get_net(mod_name, net_name, state_name)
+ assert v in ["true", "false"]
+ return 1 if v == "true" else 0
+
+ def get_net_hex(self, mod_name, net_name, state_name):
+ return self.bv2hex(self.get_net(mod_name, net_name, state_name))
+
+ def get_net_bin(self, mod_name, net_name, state_name):
+ return self.bv2bin(self.get_net(mod_name, net_name, state_name))
+
+ def wait(self):
+ self.p.wait()
+
+
+class smtopts:
+ def __init__(self):
+ self.optstr = "s:d:vp"
+ self.solver = "z3"
+ self.debug_print = False
+ self.debug_file = None
+ self.timeinfo = True
+
+ def handle(self, o, a):
+ if o == "-s":
+ self.solver = a
+ elif o == "-v":
+ self.debug_print = True
+ elif o == "-p":
+ self.timeinfo = True
+ elif o == "-d":
+ self.debug_file = open(a, "w")
+ else:
+ return False
+ return True
+
+ def helpmsg(self):
+ return """
+ -s <solver>
+ set SMT solver: z3, cvc4, yices, mathsat
+ default: z3
+
+ -v
+ enable debug output
+
+ -p
+ disable timer display during solving
+
+ -d <filename>
+ write smt2 statements to file
+"""
+
+
+class mkvcd:
+ def __init__(self, f):
+ self.f = f
+ self.t = -1
+ self.nets = dict()
+
+ def add_net(self, name, width):
+ assert self.t == -1
+ key = "n%d" % len(self.nets)
+ self.nets[name] = (key, width)
+
+ def set_net(self, name, bits):
+ assert name in self.nets
+ assert self.t >= 0
+ print("b%s %s" % (bits, self.nets[name][0]), file=self.f)
+
+ def set_time(self, t):
+ assert t >= self.t
+ if t != self.t:
+ if self.t == -1:
+ for name in sorted(self.nets):
+ key, width = self.nets[name]
+ print("$var wire %d %s %s $end" % (width, key, name), file=self.f)
+ print("$enddefinitions $end", file=self.f)
+ self.t = t
+ assert self.t >= 0
+ print("#%d" % self.t, file=self.f)
+
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