def _num_minus(env, args):
op = env.curr_evaling[0] # XXX: to know the op
retval = obtype.Token('int')
retval.tacn = NewVar()
env.emit(tac.assign(retval.tacn, 0))
sll = 0
if len(args) != 0:
arg = args[0]
arg = env.eval_(arg)
if not arg.can_cast_to_type('int'):
sll = obtype.sizeof_byshift(arg.vt)
retval.vt = arg.vt
env.emit(tac.assign(retval.tacn, arg.tacn))
for arg in args[1:]:
arg = env.eval_(arg)
if not arg.can_cast_to_type('int'):
print 'WARNING: op %r -- argument must be number -- %r' % (
op, arg)
env.print_block()
if sll != 0:
tmp = NewVar()
env.emit(tac.binary(tmp, arg.tacn, '<<', sll))
else:
tmp = arg.tacn
env.emit(tac.binary(retval.tacn, retval.tacn, op.n, tmp))
return retval
def _nth(env, args):
sym, idx = args
sym = env.eval_(sym)
idx = env.eval_(idx)
if not sym.ptrp():
print 'WARNING: dereferencing a non-pointer %r' % sym
env.print_block()
# bound checking?
if not idx.can_cast_to_type('int'):
print 'WARNING: array index is not an integer %r' % idx
env.print_block()
retval = obtype.Token(sym.vt[:-1]) # dereferencing
retval.tacn = NewVar()
# sizeof retval, to facilitate idx
memsize = obtype.sizeof_byshift(retval.vt)
tmpoffset = NewVar()
env.emit(tac.binary(tmpoffset, idx.tacn, '<<', memsize))
env.emit(tac.binary(tmpoffset, tmpoffset, '+', sym.tacn))
env.emit(tac.load(retval.tacn, tmpoffset, 0))
return retval
def _set_nthbang(env, args):
sym, idx, val = map(env.eval_, args)
if not sym.ptrp():
print 'WARNING: dereferencing a non-pointer %r' % sym
env.print_block()
if not idx.can_cast_to_type('int'):
print 'WARNING: array index is not an integer %r' % idx
env.print_block()
if not sym.vt[:-1] == val.vt:
print 'WARNING: casting %r to %r at set-nth!' % (val.vt, sym.vt[:-1])
env.print_block()
memsize = obtype.sizeof_byshift(sym.vt[:-1])
if memsize != 0: # not zero: need to change
tmpoffset = NewVar()
env.emit(tac.binary(tmpoffset, idx.tacn, '<<', memsize))
env.emit(tac.binary(tmpoffset, tmpoffset, '+', sym.tacn))
env.emit(tac.store(tmpoffset, 0, val.tacn)) # *(p+c) = val
else: # zero: just do it
env.emit(tac.store(sym.tacn, 0, val.tacn))
return obtype.Token('void')
