from test.support.bytecode_helper import CodegenTestCase # Tests for the code-generation stage of the compiler. # Examine the un-optimized code generated from the AST. class IsolatedCodeGenTests(CodegenTestCase): def codegen_test(self, snippet, expected_insts): import ast a = ast.parse(snippet, "my_file.py", "exec"); insts = self.generate_code(a) self.assertInstructionsMatch(insts, expected_insts) def test_if_expression(self): snippet = "42 if True else 24" false_lbl = self.Label() expected = [ ('RESUME', 0, 0), ('LOAD_CONST', 0, 1), ('POP_JUMP_IF_FALSE', false_lbl := self.Label(), 1), ('LOAD_CONST', 1, 1), ('JUMP', exit_lbl := self.Label()), false_lbl, ('LOAD_CONST', 2, 1), exit_lbl, ('POP_TOP', None), ] self.codegen_test(snippet, expected) def test_for_loop(self): snippet = "for x in l:\n\tprint(x)" false_lbl = self.Label() expected = [ ('RESUME', 0, 0), ('LOAD_NAME', 0, 1), ('GET_ITER', None, 1), loop_lbl := self.Label(), ('FOR_ITER', exit_lbl := self.Label(), 1), ('STORE_NAME', 1, 1), ('PUSH_NULL', None, 2), ('LOAD_NAME', 2, 2), ('LOAD_NAME', 1, 2), ('CALL', 1, 2), ('POP_TOP', None), ('JUMP', loop_lbl), exit_lbl, ('END_FOR', None), ] self.codegen_test(snippet, expected)