bpo-40334: PEP 617 implementation: New PEG parser for CPython (GH-19503)

Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

1 files changed, 140 insertions, 0 deletions

diff --git a/Tools/peg_generator/scripts/benchmark.py b/Tools/peg_generator/scripts/benchmark.py
new file mode 100644
index 00000000000..bc751156e89
--- /dev/null
+++ b/Tools/peg_generator/scripts/benchmark.py
@@ -0,0 +1,140 @@
+#!/usr/bin/env python3.9
+
+import argparse
+import ast
+import sys
+import os
+import resource
+from time import time
+
+import memory_profiler
+
+sys.path.insert(0, os.getcwd())
+from peg_extension import parse
+from pegen.build import build_parser_and_generator
+from scripts.test_parse_directory import parse_directory
+
+argparser = argparse.ArgumentParser(
+    prog="benchmark", description="Reproduce the various pegen benchmarks"
+)
+argparser.add_argument(
+    "--parser",
+    action="store",
+    choices=["pegen", "cpython"],
+    default="pegen",
+    help="Which parser to benchmark (default is pegen)",
+)
+argparser.add_argument(
+    "--target",
+    action="store",
+    choices=["xxl", "stdlib"],
+    default="xxl",
+    help="Which target to use for the benchmark (default is xxl.py)",
+)
+
+subcommands = argparser.add_subparsers(title="Benchmarks", dest="subcommand")
+command_compile = subcommands.add_parser(
+    "compile", help="Benchmark parsing and compiling to bytecode"
+)
+command_parse = subcommands.add_parser("parse", help="Benchmark parsing and generating an ast.AST")
+command_check = subcommands.add_parser(
+    "check", help="Benchmark parsing and throwing the tree away"
+)
+
+
+def benchmark(func):
+    def wrapper(*args):
+        times = list()
+        for _ in range(3):
+            start = time()
+            result = func(*args)
+            end = time()
+            times.append(end - start)
+        memory = memory_profiler.memory_usage((func, args))
+        print(f"{func.__name__}")
+        print(f"\tTime: {sum(times)/3:.3f} seconds on an average of 3 runs")
+        print(f"\tMemory: {max(memory)} MiB on an average of 3 runs")
+        return result
+
+    return wrapper
+
+
+@benchmark
+def time_compile(source, parser):
+    if parser == "cpython":
+        return compile(source, os.path.join("data", "xxl.py"), "exec")
+    else:
+        return parse.parse_string(source, mode=2)
+
+
+@benchmark
+def time_parse(source, parser):
+    if parser == "cpython":
+        return ast.parse(source, os.path.join("data", "xxl.py"), "exec")
+    else:
+        return parse.parse_string(source, mode=1)
+
+
+@benchmark
+def time_check(source):
+    return parse.parse_string(source, mode=0)
+
+
+def run_benchmark_xxl(subcommand, parser, source):
+    if subcommand == "compile":
+        time_compile(source, parser)
+    elif subcommand == "parse":
+        time_parse(source, parser)
+    elif subcommand == "check":
+        time_check(source)
+
+
+def run_benchmark_stdlib(subcommand, parser):
+    modes = {"compile": 2, "parse": 1, "check": 0}
+    extension = None
+    if parser == "pegen":
+        extension = build_parser_and_generator(
+            "../../Grammar/python.gram",
+            "peg_extension/parse.c",
+            compile_extension=True,
+            skip_actions=False,
+        )
+    for _ in range(3):
+        parse_directory(
+            "../../Lib",
+            "../../Grammar/python.gram",
+            verbose=False,
+            excluded_files=[
+                "*/bad*",
+                "*/lib2to3/tests/data/*",
+            ],
+            skip_actions=False,
+            tree_arg=0,
+            short=True,
+            extension=extension,
+            mode=modes[subcommand],
+            parser=parser,
+        )
+
+
+def main():
+    args = argparser.parse_args()
+    subcommand = args.subcommand
+    parser = args.parser
+    target = args.target
+
+    if subcommand is None:
+        argparser.error("A benchmark to run is required")
+    if subcommand == "check" and parser == "cpython":
+        argparser.error("Cannot use check target with the CPython parser")
+
+    if target == "xxl":
+        with open(os.path.join("data", "xxl.py"), "r") as f:
+            source = f.read()
+            run_benchmark_xxl(subcommand, parser, source)
+    elif target == "stdlib":
+        run_benchmark_stdlib(subcommand, parser)
+
+
+if __name__ == "__main__":
+    main()