Method check_jump_targets

Lib/test/test_peepholer.py:54–69

(self, code)

class TestTranforms(BytecodeTestCase):

    def check_jump_targets(self, code):
        instructions = list(dis.get_instructions(code))
        targets = {instr.offset: instr for instr in instructions}
        for instr in instructions:
            if 'JUMP_' not in instr.opname:
                continue
            tgt = targets[instr.argval]
            # jump to unconditional jump
            if tgt.opname in ('JUMP_BACKWARD', 'JUMP_FORWARD'):
                self.fail(f'{instr.opname} at {instr.offset} '
                          f'jumps to {tgt.opname} at {tgt.offset}')
            # unconditional jump to RETURN_VALUE
            if (instr.opname in ('JUMP_BACKWARD', 'JUMP_FORWARD') and
                tgt.opname == 'RETURN_VALUE'):
                self.fail(f'{instr.opname} at {instr.offset} '
                          f'jumps to {tgt.opname} at {tgt.offset}')

    def check_lnotab(self, code):
        "Check that the lnotab byte offsets are sensible."