1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
#!/usr/bin/env python
"""Compiles C into assembly for the practicum processor (PP2)
Copyright (C) 2011-2014 Peter Wu <lekensteyn@gmail.com>
Licensed under the MIT license <http://opensource.org/licenses/MIT>.
"""
__author__ = "Peter Wu"
__copyright__ = "Copyright (C) 2011-2014 Peter Wu"
__credits__ = ["Peter Wu"]
__license__ = "MIT"
__version__ = "1.0"
__maintainer__ = "Peter Wu"
__email__ = "lekensteyn@gmail.com"
import re
class Asm(object):
id_re = "[a-zA-Z_][0-9a-zA-Z_]*"
re_identifier = re.compile("^" + id_re + "$")
re_label = re.compile("^\s*" + id_re + "\s*:")
# these instructions accept a label name
operators_branch = ("BEQ", "BNE", "BCS", "BCC", "BLS", "BHI", "BVC", "BVS",
"BPL", "BMI", "BLT", "BGE", "BLE", "BGT", "BRA", "BRS")
# these instructions are weird.
operators_unary = ("JMP", "JSR", "CLRI", "SETI", "PSEM", "VSEM")
# these instructions accept a register (arg 1) and addressing mode (arg 2)
operators_binary = ("LOAD", "ADD", "SUB", "CMP", "MULS", "MULL", "CHCK",
"DIV", "MOD", "DVMD", "AND", "OR", "XOR", "STOR")
# these operators accept a register
operators_misc_reg = ("PUSH", "PULL")
# these instructions accept no args
operators_misc_noreg = ("RTS", "RTE")
operators_misc = operators_misc_reg + operators_misc_noreg
# all available operators
operators_all = operators_branch + operators_unary + operators_binary
operators_all += operators_misc
def __init__(self):
self.level = 0
def is_identifier(self, text):
return self.re_identifier.match(text) is not None
def format_line(self, line, label="", indent_size=-1):
"""Returns an indented line optionally prefixed with label"""
if indent_size < 0:
indent_size = 8 + self.level * 4
if label:
indent_size -= len(label) + 2
if indent_size >= 0:
label += ": "
else:
label += ":"
# strip the previous label and indentation
line = self.re_label.sub("", line).rstrip("")
# whitespace is generated if indent_size > 0
indent = indent_size * " "
return indent + label + line
def binary_op(self, binop, reg, operand, label=""):
# output format: BBBB RR OO...
return self.format_line("{:<4} {:<2} {}".format(binop, reg, operand), label)
def unary_op(self, unop, operand, label=""):
# output format: UUUU OO...
return self.format_line("{:<4} {}".format(unop, operand), label)
def branch_op(self, brop, branch_label, label=""):
# output format: BBB LL...
return self.format_line("{:<4} {}".format(brop, branch_label), label)
def push(self, register, label=""):
return self.format_line("PUSH " + register, label)
def pull(self, register, label=""):
return self.format_line("PULL " + register, label)
def insert_label(self, instruction, label):
new_instruction = instruction.lstrip(" ")
indent_size = len(instruction) - len(new_instruction)
return self.format_line(new_instruction, label, indent_size)
def has_label(self, line):
"""Returns True if a line appears to contain a label, False otherwise"""
return self.get_label(line) != ""
def get_label(self, line):
"""Returns the label if any"""
label = self.re_label.match(line)
if label is None:
return ""
return label[0].strip(": ")
def noop(self, label, register="R0"):
"""Returns a labelled no operation operator
Note that the Zero, Negative and oVerflow flags are modified
"""
return self.binary_op("LOAD", register, register, label) + " ; NOOP"
|
