Support for BTOR witness to Yosys witness conversion

1 files changed, 131 insertions, 0 deletions

diff --git a/backends/smt2/witness.py b/backends/smt2/witness.py
index a1e65569d..14cf61fd7 100644
--- a/backends/smt2/witness.py
+++ b/backends/smt2/witness.py
@@ -110,6 +110,10 @@ class AigerMap:
     def __init__(self, mapfile):
         data = json.load(mapfile)
 
+        version = data.get("version") if isinstance(data, dict) else {}
+        if version != "Yosys Witness Aiger map":
+            raise click.ClickException(f"{mapfile.name}: unexpected file format version {version!r}")
+
         self.latch_count = data["latch_count"]
         self.input_count = data["input_count"]
 
@@ -250,5 +254,132 @@ def yw2aiw(input, mapfile, output):
 
     click.echo(f"Converted {len(inyw)} time steps.")
 
+class BtorMap:
+    def __init__(self, mapfile):
+        self.data = data = json.load(mapfile)
+
+        version = data.get("version") if isinstance(data, dict) else {}
+        if version != "Yosys Witness BTOR map":
+            raise click.ClickException(f"{mapfile.name}: unexpected file format version {version!r}")
+
+        self.sigmap = WitnessSigMap()
+
+        for mode in ("states", "inputs"):
+            for btor_signal_def in data[mode]:
+                if btor_signal_def is None:
+                    continue
+                if isinstance(btor_signal_def, dict):
+                    btor_signal_def["path"] = tuple(btor_signal_def["path"])
+                else:
+                    for chunk in btor_signal_def:
+                        chunk["path"] = tuple(chunk["path"])
+
+
+@cli.command(help="""
+Convert a BTOR witness trace into a Yosys witness trace.
+
+This requires a Yosys witness BTOR map file as generated by 'write_btor -ywmap'.
+""")
+@click.argument("input", type=click.File("r"))
+@click.argument("mapfile", type=click.File("r"))
+@click.argument("output", type=click.File("w"))
+def wit2yw(input, mapfile, output):
+    input_name = input.name
+    click.echo(f"Converting BTOR witness trace {input_name!r} to Yosys witness trace {output.name!r}...")
+    click.echo(f"Using Yosys witness BTOR map file {mapfile.name!r}")
+    btor_map = BtorMap(mapfile)
+
+    input = filter(None, (line.split(';', 1)[0].strip() for line in input))
+
+    sat = next(input, None)
+    if sat != "sat":
+        raise click.ClickException(f"{input_name}: not a BTOR witness file")
+
+    props = next(input, None)
+
+    t = -1
+
+    line = next(input, None)
+
+    frames = []
+    bits = {}
+
+    while line and not line.startswith('.'):
+        current_t = int(line[1:].strip())
+        if line[0] == '#':
+            mode = "states"
+        elif line[0] == '@':
+            mode = "inputs"
+        else:
+            raise click.ClickException(f"{input_name}: unexpected data in BTOR witness file")
+
+        if current_t > t:
+            t = current_t
+            values = WitnessValues()
+            frames.append(values)
+
+        line = next(input, None)
+        while line and line[0] not in "#@.":
+            if current_t > 0 and mode == "states":
+                line = next(input, None)
+                continue
+            tokens = line.split()
+            line = next(input, None)
+
+            btor_sig = btor_map.data[mode][int(tokens[0])]
+
+            if btor_sig is None:
+                continue
+
+            if isinstance(btor_sig, dict):
+                addr = tokens[1]
+                if not addr.startswith('[') or not addr.endswith(']'):
+                    raise click.ClickException(f"{input_name}: expected address in BTOR witness file")
+                addr = int(addr[1:-1], 2)
+
+                if addr < 0 or addr >= btor_sig["size"]:
+                    raise click.ClickException(f"{input_name}: out of bounds address in BTOR witness file")
+
+                btor_sig = [{
+                    "path": (*btor_sig["path"], f"\\[{addr}]"),
+                    "width": btor_sig["width"],
+                    "offset": 0,
+                }]
+
+                signal_value = iter(reversed(tokens[2]))
+            else:
+                signal_value = iter(reversed(tokens[1]))
+
+            for chunk in btor_sig:
+                offset = chunk["offset"]
+                path = chunk["path"]
+                for i in range(offset, offset + chunk["width"]):
+                    key = (path, i)
+                    bits[key] = mode == "inputs"
+                    values[key] = next(signal_value)
+
+            if next(signal_value, None) is not None:
+                raise click.ClickException(f"{input_name}: excess bits in BTOR witness file")
+
+
+    if line is None:
+        raise click.ClickException(f"{input_name}: unexpected end of BTOR witness file")
+    if line.strip() != '.':
+        raise click.ClickException(f"{input_name}: unexpected data in BTOR witness file")
+    if next(input, None) is not None:
+        raise click.ClickException(f"{input_name}: unexpected trailing data in BTOR witness file")
+
+    outyw = WriteWitness(output, 'yosys-witness wit2yw')
+
+    outyw.signals = coalesce_signals((), bits)
+    for clock in btor_map.data["clocks"]:
+        outyw.add_clock(clock["path"], clock["offset"], clock["edge"])
+
+    for values in frames:
+        outyw.step(values)
+
+    outyw.end_trace()
+    click.echo(f"Converted {outyw.t} time steps.")
+
 if __name__ == "__main__":
     cli()