def do_jump_next(src):
to_remove = True
while to_remove:
to_remove = []
for i in range(len(src)):
code = src[i]
if code[0] in ['if', 'ifnot']:
if code[2] == i+1:
to_remove.append(i)
elif code[0] == 'jmp':
if code[1] == i+1:
to_remove.append(i)
src = remove_lines(src, to_remove)
return src
def do_dead_code(src):
def merge(states):
return any(states)
def step(old_state,code,line_num):
return old_state
(state, state_out) = analyzer.analyze_forward(src, merge, step, True, False)
to_remove = []
for i in range(len(src)):
if not state[i]:
to_remove.append(i)
continue
code = src[i]
if analyzer.must_take(code):
src[i] = code = ('jmp', code[2])
if analyzer.must_not_take(code):
to_remove.append(i)
continue
return remove_lines(src, to_remove)
def do_unused_variable(src, final_usage):
states, states_out = analyzer.analyze_backward(src, merge, step, final_usage)
to_remove = []
for i in range(len(src)):
code = src[i]
if code[0] in BINARY_OPERATORS:
if code[1][1] not in states[i]:
to_remove.append(i)
elif code[0] in UNARY_OPERATORS:
if code[1][1] not in states[i]:
to_remove.append(i)
elif code[0] == 'call':
if code[1] is not None and code[1][1] not in states[i]:
code = list(code)
code[1] = None
src[i] = tuple(code)
elif code[0] not in ['jmp','if','ifnot']:
raise Exception("Unhandled op: " + code[0])
return remove_lines(src, to_remove)
def do_unused_variable(src, final_usage):
states, states_out = analyzer.analyze_backward(src, merge, step,
final_usage)
to_remove = []
for i in range(len(src)):
code = src[i]
if code[0] in BINARY_OPERATORS:
if code[1][1] not in states[i]:
to_remove.append(i)
elif code[0] in UNARY_OPERATORS:
if code[1][1] not in states[i]:
to_remove.append(i)
elif code[0] == 'call':
if code[1] is not None and code[1][1] not in states[i]:
code = list(code)
code[1] = None
src[i] = tuple(code)
elif code[0] not in ['jmp', 'if', 'ifnot']:
raise Exception("Unhandled op: " + code[0])
return remove_lines(src, to_remove)
def do_dead_code(src):
def merge(states):
return any(states)
def step(old_state, code, line_num):
return old_state
(state, state_out) = analyzer.analyze_forward(src, merge, step, True,
False)
to_remove = []
for i in range(len(src)):
if not state[i]:
to_remove.append(i)
continue
code = src[i]
if analyzer.must_take(code):
src[i] = code = ('jmp', code[2])
if analyzer.must_not_take(code):
to_remove.append(i)
continue
return remove_lines(src, to_remove)