asm.py

# python3 asm.py 'nop'

import os
import subprocess
import sys
import struct

def assemble(code, verbose=False):
	if not code:
		return b''
	with open('asm.tmp1.s', 'w') as f:
		f.write(code.replace(';', '\n'))
	if subprocess.call(['clang', '-c', 'asm.tmp1.s', '-march=armv8.5-a+sha3+fp16fml']):
		exit(1)

	for line in subprocess.check_output(['objdump', '-d', 'asm.tmp1.o', '--wide']).decode('utf-8').split('\n')[7:-1]:
		a, b = line.split('\t', 1)
		print('ibuf[o++] = 0x%08x; // %s' % (struct.unpack('<I', bytes.fromhex(a.split(': ')[1].replace(' ', '')))[0], b.replace('\t', ' ').strip()))
	
	txt = subprocess.check_output(['otool', '-t', 'asm.tmp1.o']).decode('ascii')
	u32s = []
	for line in txt.strip().split('\n')[2:]:
		for u32 in line.split()[1:]:
			u32s.append(struct.pack('<I', int(u32, 16)))
	os.unlink('asm.tmp1.s')
	os.unlink('asm.tmp1.o')
	return b''.join(u32s)

assemble('\n'.join(sys.argv[1:]))

I guess XCode 13.3 slightly changed the format of objdump?
As of 13.3 I find I have to change line 16 to extract elements [6:-1]; the code as shown right now with [7:-1] returns nothing, just an empty line.