+def find_python_files(base: Path) -> List[Path]:
+ files = []
+ for entry in base.iterdir():
+ if entry.is_file() and entry.suffix == ".py":
+ files.append(entry)
+ elif entry.is_dir():
+ files.extend(find_python_files(entry))
+
+ return files
+
+
+USE_MYPYC = False
+# To compile with mypyc, a mypyc checkout must be present on the PYTHONPATH
+if len(sys.argv) > 1 and sys.argv[1] == "--use-mypyc":
+ sys.argv.pop(1)
+ USE_MYPYC = True
+if os.getenv("BLACK_USE_MYPYC", None) == "1":
+ USE_MYPYC = True
+
+if USE_MYPYC:
+ from mypyc.build import mypycify
+
+ src = CURRENT_DIR / "src"
+ # TIP: filepaths are normalized to use forward slashes and are relative to ./src/
+ # before being checked against.
+ blocklist = [
+ # Not performance sensitive, so save bytes + compilation time:
+ "blib2to3/__init__.py",
+ "blib2to3/pgen2/__init__.py",
+ "black/output.py",
+ "black/concurrency.py",
+ "black/files.py",
+ "black/report.py",
+ # Breaks the test suite when compiled (and is also useless):
+ "black/debug.py",
+ # Compiled modules can't be run directly and that's a problem here:
+ "black/__main__.py",
+ ]
+ discovered = []
+ # black-primer and blackd have no good reason to be compiled.
+ discovered.extend(find_python_files(src / "black"))
+ discovered.extend(find_python_files(src / "blib2to3"))
+ mypyc_targets = [
+ str(p) for p in discovered if p.relative_to(src).as_posix() not in blocklist
+ ]
+
+ opt_level = os.getenv("MYPYC_OPT_LEVEL", "3")
+ ext_modules = mypycify(mypyc_targets, opt_level=opt_level, verbose=True)
+else:
+ ext_modules = []
+