check for newline at the end of source files

scripts/fix_style.py

@@ -52,10 +52,29 @@ def find_clang_format(version):
 clang_format_bin = find_clang_format(10)
 
 def reformat(filenames):
+	for filename in filenames:
+		with open(filename, 'r+b') as f:
+			try:
+				f.seek(-1, os.SEEK_END)
+				if f.read(1) != b'\n':
+					f.write(b'\n')
+			except OSError:
+				f.seek(0)
 	subprocess.check_call([clang_format_bin, "-i"] + filenames)
 
 def warn(filenames):
-	return subprocess.call([clang_format_bin, "-Werror", "--dry-run"] + filenames)
+	clang = subprocess.call([clang_format_bin, "-Werror", "--dry-run"] + filenames)
+	newline = 0
+	for filename in filenames:
+		with open(filename, 'rb') as f:
+			try:
+				f.seek(-1, os.SEEK_END)
+				if f.read(1) != b'\n':
+					print(filename + ": error: missing newline at EOF", file=sys.stderr)
+					newline = 1
+			except OSError:
+				f.seek(0)
+	return clang or newline
 
 def main():
 	p = argparse.ArgumentParser(description="Check and fix style of changed files")