61 lines
1.8 KiB
Python
61 lines
1.8 KiB
Python
|
#!/usr/bin/env python3
|
||
|
|
|
||
|
|
"""
|
||
|
|
Generates the ARM64 Assembly for an executable that performs the given
|
||
|
|
calculation and exits with that number as the exit code. It currently
|
||
|
|
only allows for multiplication and addition. You can check the output
|
||
|
|
modulo 256 using `echo $?`. The only defined variables are the letters
|
||
|
|
a-z, where they represent their 1-based index into the alphabet.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import string
|
||
|
|
import sys, os; sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))) # just becuase this is in a subdirectory
|
||
|
|
from ppp_lexer import *
|
||
|
|
from ppp_parser import *
|
||
|
|
|
||
|
|
_program, file_path = sys.argv
|
||
|
|
|
||
|
|
lexer = Lexer.from_file(file_path)
|
||
|
|
expr = parse_expression(lexer)
|
||
|
|
lexer.assert_token(EofToken())
|
||
|
|
|
||
|
|
def get_index(char: str) -> int:
|
||
|
|
"""
|
||
|
|
Assuming char is [a-z]
|
||
|
|
"""
|
||
|
|
return ord(char)-96
|
||
|
|
|
||
|
|
def get_stack_address(index: int) -> int:
|
||
|
|
return 112-index*4
|
||
|
|
|
||
|
|
def to_asm(expr: Expression, *, taken: int=0):
|
||
|
|
"""
|
||
|
|
Generates the assembly using registers w0, w1, w2, ... as a stack.
|
||
|
|
|
||
|
|
`taken` is how many registers are already taken by previous elements 'on the stack'
|
||
|
|
"""
|
||
|
|
if isinstance(expr, Variable):
|
||
|
|
assert expr.name in string.ascii_lowercase
|
||
|
|
address = get_stack_address(get_index(expr.name))
|
||
|
|
print(f"\tldr w{taken}, [sp, {address}] // {expr.name}")
|
||
|
|
else:
|
||
|
|
match expr:
|
||
|
|
case Addition(): word = 'add'
|
||
|
|
case Multiplication(): word = 'mul'
|
||
|
|
case _: assert False, f"Unimplemented: {expr}"
|
||
|
|
to_asm(expr.lhs, taken=taken)
|
||
|
|
to_asm(expr.rhs, taken=taken+1)
|
||
|
|
|
||
|
|
print(f"\t{word} w{taken}, w{taken}, w{taken+1} // {expr.represent()}")
|
||
|
|
|
||
|
|
print(".global main")
|
||
|
|
print(".align 2")
|
||
|
|
print()
|
||
|
|
print("main:")
|
||
|
|
print("\tsub sp, sp, #112") # to fit 26*4=104 bytes. It seems that the sp should only be offset by 16 bytes at a time.
|
||
|
|
for i in range(1,27):
|
||
|
|
print(f"\tmov w0, {i}")
|
||
|
|
print(f"\tstr w0, [sp, {get_stack_address(i)}]")
|
||
|
|
to_asm(expr)
|
||
|
|
print("\tadd sp, sp, 112")
|
||
|
|
print("\tret")
|