Files
RustPython/scripts/compare_bytecode.py
Jeong, YunWon ad5a55c1e3 Bytecode parity: align borrow optimization with CFG traversal (#7773)
* Align CFG cleanup bytecode with CPython

* Bytecode parity: fblock unwind, fstring join, folding, scope

- compile.rs: unwind_fblock_stack returns whether a finally ran so
  return-statement emission can adjust location handling; restructure
  try/except/finally cleanup to preserve or drop boundary NOPs based on
  whether the body falls through; rework f-string lowering with
  count/join helpers; remove the per-collection-type heuristic for
  AST-level folding and defer to flowgraph passes; add several folding
  helpers and a ComprehensionLoopControl enum.
- ir.rs: re-run unary/binop folding around tuple folding, add
  reorder_conditional_scope_exit_and_jump_back_blocks and several block
  classification helpers, add MAX_STR_SIZE, change is_exit_without_lineno
  to take the block list.
- symboltable.rs: in analyze_cells, remove names owned as cells in
  function-like scopes from the parent's free set; mark lambda scope
  type explicitly.

* Refine CFG scope-exit backedge ordering
2026-05-05 14:04:12 +09:00

674 lines
22 KiB
Python

#!/usr/bin/env python3
"""Compare bytecode between CPython and RustPython.
Compiles all Python files under Lib/ with both interpreters and reports
differences in the generated bytecode instructions.
Usage:
python scripts/compare_bytecode.py
python scripts/compare_bytecode.py --detail
python scripts/compare_bytecode.py --filter "asyncio/*.py"
python scripts/compare_bytecode.py --summary-json report.json
"""
import argparse
import fnmatch
import json
import os
import random
import subprocess
import sys
import tempfile
from collections import defaultdict
SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
PROJECT_ROOT = os.path.dirname(SCRIPT_DIR)
DIS_DUMP = os.path.join(SCRIPT_DIR, "dis_dump.py")
DEFAULT_REPORT = os.path.join(PROJECT_ROOT, "compare_bytecode.report")
DUMP_TIMEOUT = 600
def find_rustpython():
"""Locate the RustPython binary, allowing release builds only."""
if "RUSTPYTHON" in os.environ:
path = os.environ["RUSTPYTHON"]
normalized = os.path.normpath(path)
debug_fragment = os.path.join("target", "debug", "rustpython")
if normalized.endswith(debug_fragment):
raise ValueError(
"RUSTPYTHON must point to a release binary, not target/debug/rustpython"
)
return path
path = os.path.join(PROJECT_ROOT, "target", "release", "rustpython")
if os.path.isfile(path) and os.access(path, os.X_OK):
return path
return None
def collect_targets(lib_dir, pattern=None):
"""Collect Python files to compare, relative to lib_dir."""
targets = []
for root, dirs, files in os.walk(lib_dir):
dirs[:] = sorted(
d for d in dirs if d != "__pycache__" and not d.startswith(".")
)
for fname in sorted(files):
if not fname.endswith(".py"):
continue
fpath = os.path.join(root, fname)
relpath = os.path.relpath(fpath, lib_dir)
if pattern and not fnmatch.fnmatch(relpath, pattern):
continue
targets.append((relpath, fpath))
return targets
def _start_one(interpreter, targets, base_dir):
"""Start a single dis_dump.py subprocess."""
env = os.environ.copy()
if interpreter != sys.executable:
env["RUSTPYTHONPATH"] = base_dir
files_file = None
output_file = None
try:
files_file = tempfile.NamedTemporaryFile(
mode="w",
encoding="utf-8",
delete=False,
prefix="compare-bytecode-files-",
)
output_file = tempfile.NamedTemporaryFile(
mode="w",
encoding="utf-8",
delete=False,
prefix="compare-bytecode-output-",
)
for _, path in targets:
files_file.write(path)
files_file.write("\n")
files_file.close()
output_file.close()
cmd = [
interpreter,
DIS_DUMP,
"--base-dir",
base_dir,
"--files-from",
files_file.name,
"--output",
output_file.name,
"--progress",
"10",
]
proc = subprocess.Popen(
cmd,
stdout=subprocess.PIPE,
stderr=None, # inherit stderr so progress dots appear on terminal
env=env,
cwd=PROJECT_ROOT,
)
return {
"proc": proc,
"files_file": files_file.name,
"output_file": output_file.name,
"targets": targets,
"interpreter": interpreter,
"base_dir": base_dir,
}
except Exception:
for handle in (files_file, output_file):
if handle is None:
continue
try:
handle.close()
finally:
if os.path.exists(handle.name):
os.unlink(handle.name)
raise
def _load_dump_output(output_file):
try:
with open(output_file, encoding="utf-8") as f:
content = f.read().strip()
except OSError as e:
print(" Failed to read dump output: %s" % e, file=sys.stderr)
return None
if not content:
return {}
try:
return json.loads(content)
except json.JSONDecodeError as e:
print(" JSON parse error: %s" % e, file=sys.stderr)
return None
def _run_sync_dump(interpreter, targets, base_dir, timeout=DUMP_TIMEOUT):
job = _start_one(interpreter, targets, base_dir)
proc = job["proc"]
stdout = b""
timed_out = False
try:
stdout = proc.communicate(timeout=timeout)[0]
except subprocess.TimeoutExpired:
proc.kill()
proc.communicate()
print(f" Timeout ({timeout}s)", file=sys.stderr)
timed_out = True
try:
data = _load_dump_output(job["output_file"])
finally:
for path in (job["files_file"], job["output_file"]):
if os.path.exists(path):
os.unlink(path)
if timed_out:
return {}
if proc.returncode != 0:
print(" Warning: exited with code %d" % proc.returncode, file=sys.stderr)
stray = stdout.decode(errors="replace").strip()
if stray:
print(" Warning: unexpected stdout from dump helper", file=sys.stderr)
return data
def _rerun_missing_targets(interpreter, targets, base_dir):
recovered = {}
failed = []
empty = []
for target in targets:
relpath = target[0]
data = _run_sync_dump(interpreter, [target], base_dir)
if data is None:
failed.append(relpath)
recovered[relpath] = {
"status": "error",
"error": "dump helper failed while rerunning target",
}
elif data:
recovered.update(data)
else:
empty.append(relpath)
recovered[relpath] = {
"status": "error",
"error": "dump helper produced no data while rerunning target",
}
if failed:
print(
" Warning: rerun failed for %d file(s): %s"
% (len(failed), ", ".join(failed[:5])),
file=sys.stderr,
)
if empty:
print(
" Warning: rerun produced no data for %d file(s): %s"
% (len(empty), ", ".join(empty[:5])),
file=sys.stderr,
)
return recovered
def _finish_one(job, timeout=DUMP_TIMEOUT):
"""Wait for a single dis_dump.py process and return parsed JSON."""
proc = job["proc"]
expected = {relpath for relpath, _ in job["targets"]}
stdout = b""
try:
stdout = proc.communicate(timeout=timeout)[0]
except subprocess.TimeoutExpired:
proc.kill()
proc.communicate()
print(
f" Timeout ({timeout}s), retrying {len(job['targets'])} file(s) serially",
file=sys.stderr,
)
data = None
else:
data = _load_dump_output(job["output_file"])
finally:
for path in (job["files_file"], job["output_file"]):
if os.path.exists(path):
os.unlink(path)
if proc.returncode != 0:
print(" Warning: exited with code %d" % proc.returncode, file=sys.stderr)
stray = stdout.decode(errors="replace").strip()
if stray:
print(" Warning: unexpected stdout from dump helper", file=sys.stderr)
if data is None:
return _rerun_missing_targets(
job["interpreter"], job["targets"], job["base_dir"]
)
missing = [
target
for target in job["targets"]
if target[0] not in data and target[0] in expected
]
if missing:
print(
" Re-running %d missing file(s) serially" % len(missing),
file=sys.stderr,
)
data.update(
_rerun_missing_targets(job["interpreter"], missing, job["base_dir"])
)
return data
def start_dump(interpreter, targets, base_dir, num_workers=1):
"""Start dis_dump.py under the given interpreter, split across workers."""
if num_workers <= 1 or len(targets) <= num_workers:
return [_start_one(interpreter, targets, base_dir)]
chunks = [[] for _ in range(num_workers)]
for i, t in enumerate(targets):
chunks[i % num_workers].append(t)
return [_start_one(interpreter, chunk, base_dir) for chunk in chunks if chunk]
def finish_dump(procs):
"""Wait for all dis_dump.py processes and merge results."""
merged = {}
for job in procs:
merged.update(_finish_one(job))
return merged
def compare_insts(cp_insts, rp_insts):
"""Compare two instruction lists. Returns list of (index, cp, rp) diffs."""
diffs = []
for i in range(max(len(cp_insts), len(rp_insts))):
cp = cp_insts[i] if i < len(cp_insts) else None
rp = rp_insts[i] if i < len(rp_insts) else None
if cp != rp:
diffs.append((i, cp, rp))
return diffs
def compare_code(cp_code, rp_code, path=""):
"""Recursively compare code objects. Returns [(code_path, diffs)]."""
results = []
name = cp_code["name"]
full = (path + "/" + name) if path else name
diffs = compare_insts(cp_code.get("insts", []), rp_code.get("insts", []))
if diffs:
results.append((full, diffs))
cp_ch = cp_code.get("children", [])
rp_ch = rp_code.get("children", [])
cp_by_name = defaultdict(list)
rp_by_name = defaultdict(list)
for c in cp_ch:
cp_by_name[c["name"]].append(c)
for c in rp_ch:
rp_by_name[c["name"]].append(c)
all_names = list(dict.fromkeys(c["name"] for c in cp_ch))
for c in rp_ch:
if c["name"] not in cp_by_name:
all_names.append(c["name"])
for name in all_names:
cp_list = cp_by_name.get(name, [])
rp_list = rp_by_name.get(name, [])
for i in range(max(len(cp_list), len(rp_list))):
if i < len(cp_list) and i < len(rp_list):
results.extend(compare_code(cp_list[i], rp_list[i], full))
elif i < len(cp_list):
results.append((full + "/" + name, [(-1, "extra in CPython", None)]))
else:
results.append((full + "/" + name, [(-1, None, "extra in RustPython")]))
return results
def compare_code_summary(cp_code, rp_code):
"""Recursively compare code objects and return summary counts."""
diff_code_objects = 0
diff_instructions = compare_insts_count(
cp_code.get("insts", []), rp_code.get("insts", [])
)
if diff_instructions:
diff_code_objects += 1
cp_ch = cp_code.get("children", [])
rp_ch = rp_code.get("children", [])
cp_by_name = defaultdict(list)
rp_by_name = defaultdict(list)
for child in cp_ch:
cp_by_name[child["name"]].append(child)
for child in rp_ch:
rp_by_name[child["name"]].append(child)
all_names = list(dict.fromkeys(child["name"] for child in cp_ch))
for child in rp_ch:
if child["name"] not in cp_by_name:
all_names.append(child["name"])
for name in all_names:
cp_list = cp_by_name.get(name, [])
rp_list = rp_by_name.get(name, [])
for i in range(max(len(cp_list), len(rp_list))):
if i < len(cp_list) and i < len(rp_list):
child_objects, child_insts = compare_code_summary(
cp_list[i], rp_list[i]
)
diff_code_objects += child_objects
diff_instructions += child_insts
else:
diff_code_objects += 1
diff_instructions += 1
return diff_code_objects, diff_instructions
def compare_insts_count(cp_insts, rp_insts):
"""Count mismatched instruction slots without storing the full diff."""
diff_count = 0
for i in range(max(len(cp_insts), len(rp_insts))):
cp = cp_insts[i] if i < len(cp_insts) else None
rp = rp_insts[i] if i < len(rp_insts) else None
if cp != rp:
diff_count += 1
return diff_count
def main():
parser = argparse.ArgumentParser(description="Compare CPython/RustPython bytecode")
parser.add_argument(
"--detail", action="store_true", help="Show per-file instruction differences"
)
parser.add_argument("--filter", default=None, help="Glob pattern to filter files")
parser.add_argument(
"--max-diffs",
type=int,
default=5,
help="Max diffs shown per code object (default: 5)",
)
parser.add_argument(
"--summary-json", default=None, help="Write summary as JSON to file"
)
parser.add_argument(
"--sample",
type=int,
default=None,
help="Compare a random sample of N matching files",
)
parser.add_argument(
"--seed",
type=int,
default=None,
help="Random seed used with --sample",
)
parser.add_argument(
"--list-limit",
type=int,
default=10,
help="Max differing files to print in non-detail mode (default: 10)",
)
parser.add_argument(
"--lib-dir",
default=os.path.join(PROJECT_ROOT, "Lib"),
help="Library directory to compare",
)
parser.add_argument(
"-j",
"--jobs",
type=int,
default=None,
help="Number of parallel workers per interpreter (default: cpu_count)",
)
parser.add_argument(
"-o",
"--output",
default=DEFAULT_REPORT,
help="Report output file (default: compare_bytecode.report)",
)
args = parser.parse_args()
try:
rp_bin = find_rustpython()
except ValueError as exc:
print("Error: %s" % exc, file=sys.stderr)
sys.exit(1)
if not rp_bin:
print("Error: RustPython binary not found.", file=sys.stderr)
print(" Build with: cargo build --release", file=sys.stderr)
print(" Or set RUSTPYTHON=/path/to/binary", file=sys.stderr)
sys.exit(1)
if not os.path.isfile(DIS_DUMP):
print("Error: disassembler helper not found: %s" % DIS_DUMP, file=sys.stderr)
print(
" Expected scripts/dis_dump.py from origin/bytecode-parity",
file=sys.stderr,
)
sys.exit(1)
targets = collect_targets(args.lib_dir, args.filter)
sample_seed = None
if args.sample is not None:
if args.sample < 1:
print("Error: --sample must be >= 1", file=sys.stderr)
sys.exit(1)
sample_seed = (
args.seed
if args.seed is not None
else random.SystemRandom().randrange(2**32)
)
rng = random.Random(sample_seed)
sample_size = min(args.sample, len(targets))
targets = sorted(rng.sample(targets, sample_size), key=lambda item: item[0])
if not targets:
print("Error: no Python files matched", file=sys.stderr)
sys.exit(1)
report_path = args.output
log = lambda *a, **kw: print(*a, file=sys.stderr, **kw)
log("Report: %s" % os.path.relpath(report_path, PROJECT_ROOT))
log("Targets: %d file(s)" % len(targets))
num_workers = args.jobs if args.jobs else os.cpu_count() or 4
log("Workers: %d per interpreter" % num_workers)
sys.stderr.write("Dumping bytecode ")
sys.stderr.flush()
cp_procs = start_dump(sys.executable, targets, args.lib_dir, num_workers)
rp_procs = start_dump(rp_bin, targets, args.lib_dir, num_workers)
cp_data = finish_dump(cp_procs)
rp_data = finish_dump(rp_procs)
sys.stderr.write("\n")
if not cp_data:
log("Error: CPython dump produced no data")
sys.exit(1)
# Phase 2: Compare
all_files = sorted(set(cp_data) | set(rp_data))
match = 0
differ = 0
cp_err = 0
rp_err = 0
both_err = 0
rp_miss = 0
diff_files = []
rp_error_files = []
diff_summaries = []
need_detailed_diffs = args.detail
for fp in all_files:
cp = cp_data.get(fp)
rp = rp_data.get(fp)
if rp is None:
rp_miss += 1
continue
cp_ok = cp and cp.get("status") == "ok"
rp_ok = rp and rp.get("status") == "ok"
if not cp_ok and not rp_ok:
both_err += 1
elif not cp_ok:
cp_err += 1
elif not rp_ok:
rp_err += 1
rp_error_files.append((fp, rp.get("error", "?")))
else:
if need_detailed_diffs:
code_diffs = compare_code(cp["code"], rp["code"])
if code_diffs:
differ += 1
diff_files.append((fp, code_diffs))
else:
match += 1
else:
diff_code_objects, diff_instructions = compare_code_summary(
cp["code"], rp["code"]
)
if diff_code_objects:
differ += 1
diff_summaries.append(
{
"path": fp,
"diff_code_objects": diff_code_objects,
"diff_instructions": diff_instructions,
}
)
else:
match += 1
total = match + differ + cp_err + rp_err + both_err + rp_miss
def pct(n):
return "%.1f%%" % (100.0 * n / total) if total else "0%"
# Phase 3: Write report to file
with open(report_path, "w") as out:
p = lambda *a: print(*a, file=out)
p("CPython: %s (%s)" % (sys.executable, sys.version.split()[0]))
p("RustPython: %s" % rp_bin)
p("Lib: %s" % args.lib_dir)
if sample_seed is not None:
p("Sample: %s file(s), seed=%s" % (len(targets), sample_seed))
p()
p("=" * 60)
p(" Bytecode Comparison Report")
p("=" * 60)
p()
p(" Total files: %6d" % total)
p(" Match: %6d (%s)" % (match, pct(match)))
p(" Differ: %6d (%s)" % (differ, pct(differ)))
p(" RustPython error: %6d (%s)" % (rp_err, pct(rp_err)))
p(" CPython error: %6d (%s)" % (cp_err, pct(cp_err)))
p(" Both error: %6d (%s)" % (both_err, pct(both_err)))
if rp_miss:
p(" RustPython missing: %6d (%s)" % (rp_miss, pct(rp_miss)))
p()
if args.detail:
if rp_error_files:
p("-" * 60)
p(" RustPython Compile Errors")
p("-" * 60)
for fp, err in rp_error_files[:50]:
p(" %s: %s" % (fp, err))
if len(rp_error_files) > 50:
p(" ... and %d more" % (len(rp_error_files) - 50))
p()
if diff_files:
p("-" * 60)
p(" Bytecode Differences")
p("-" * 60)
for fp, code_diffs in diff_files:
p()
p(" %s:" % fp)
for code_path, diffs in code_diffs:
shown = min(len(diffs), args.max_diffs)
p(" %s: %d difference(s)" % (code_path, len(diffs)))
for idx, cp_inst, rp_inst in diffs[:shown]:
if idx == -1:
p(" %s" % (cp_inst or rp_inst))
else:
p(" [%3d] CPython: %s" % (idx, cp_inst))
p(" RustPython: %s" % rp_inst)
if len(diffs) > shown:
p(" ... and %d more" % (len(diffs) - shown))
p()
else:
list_limit = 0 if args.summary_json else max(args.list_limit, 0)
if diff_summaries and list_limit:
shown = min(list_limit, len(diff_summaries))
total = len(diff_summaries)
p(f"Top differing files ({shown} shown of {total}):")
top = sorted(
diff_summaries,
key=lambda item: (
item["diff_instructions"],
item["diff_code_objects"],
item["path"],
),
reverse=True,
)[:list_limit]
for item in top:
p(
" %s (%d code objects, %d instruction diffs)"
% (
item["path"],
item["diff_code_objects"],
item["diff_instructions"],
)
)
p()
p("Use --detail to see specific instruction differences.")
p()
# Summary JSON output
if args.summary_json:
summary = {
"total": total,
"sample": args.sample,
"sample_seed": sample_seed,
"match": match,
"differ": differ,
"rp_error": rp_err,
"cp_error": cp_err,
"both_error": both_err,
"rp_missing": rp_miss,
"match_pct": round(100.0 * match / total, 2) if total else 0,
"diff_files": [fp for fp, _ in diff_files]
if need_detailed_diffs
else [item["path"] for item in diff_summaries],
"top_diff_files": sorted(
diff_summaries,
key=lambda item: (
item["diff_instructions"],
item["diff_code_objects"],
item["path"],
),
reverse=True,
)[: min(20, len(diff_summaries))],
"rp_error_files": [fp for fp, _ in rp_error_files],
}
with open(args.summary_json, "w") as f:
json.dump(summary, f, indent=2)
log("Summary JSON: %s" % args.summary_json)
log("Done: %d match, %d differ, %d errors" % (match, differ, rp_err))
sys.exit(0 if differ == 0 and rp_err == 0 else 1)
if __name__ == "__main__":
main()