def invoke_interface_method(this_reg, m, args_asm):
'''Invokes an interface method m off this_reg using the SIT'''
from code_gen.manager import CodeGenManager
offset = CodeGenManager.get_sit_offset(m)
n_params = len(m.params)
pop_asm = ['pop ebx ; Pop param to garbage' for x in range(m.c_num_params)]
return [
'; Invoke interface method: {0}'.format(m.name),
check_null('eax'),
'push eax ; Push "this" as the first param',
args_asm,
'mov dword eax, [esp + 4*{0}] ; Get to "this"'.format(n_params),
'mov dword eax, [eax] ; Get to CIT for T[]',
'mov eax, [eax] ; Get to SIT for T[]',
'mov eax, [eax + {0}] ; Get the method loc in the SIT'.format(offset),
'call eax ; Call the method',
pop_asm,
]
