| """bytecode_helper - support tools for testing correct bytecode generation""" |
| |
| import unittest |
| import dis |
| import io |
| |
| _UNSPECIFIED = object() |
| |
| class BytecodeTestCase(unittest.TestCase): |
| """Custom assertion methods for inspecting bytecode.""" |
| |
| def get_disassembly_as_string(self, co): |
| s = io.StringIO() |
| dis.dis(co, file=s) |
| return s.getvalue() |
| |
| def assertInBytecode(self, x, opname, argval=_UNSPECIFIED): |
| """Returns instr if op is found, otherwise throws AssertionError""" |
| for instr in dis.get_instructions(x): |
| if instr.opname == opname: |
| if argval is _UNSPECIFIED or instr.argval == argval: |
| return instr |
| disassembly = self.get_disassembly_as_string(x) |
| if argval is _UNSPECIFIED: |
| msg = '%s not found in bytecode:\n%s' % (opname, disassembly) |
| else: |
| msg = '(%s,%r) not found in bytecode:\n%s' |
| msg = msg % (opname, argval, disassembly) |
| self.fail(msg) |
| |
| def assertNotInBytecode(self, x, opname, argval=_UNSPECIFIED): |
| """Throws AssertionError if op is found""" |
| for instr in dis.get_instructions(x): |
| if instr.opname == opname: |
| disassembly = self.get_disassembly_as_string(x) |
| if argval is _UNSPECIFIED: |
| msg = '%s occurs in bytecode:\n%s' % (opname, disassembly) |
| elif instr.argval == argval: |
| msg = '(%s,%r) occurs in bytecode:\n%s' |
| msg = msg % (opname, argval, disassembly) |
| self.fail(msg) |