1  
       2  from test.support.bytecode_helper import CodegenTestCase
       3  
       4  # Tests for the code-generation stage of the compiler.
       5  # Examine the un-optimized code generated from the AST.
       6  
       7  class ESC[4;38;5;81mIsolatedCodeGenTests(ESC[4;38;5;149mCodegenTestCase):
       8  
       9      def codegen_test(self, snippet, expected_insts):
      10          import ast
      11          a = ast.parse(snippet, "my_file.py", "exec");
      12          insts = self.generate_code(a)
      13          self.assertInstructionsMatch(insts, expected_insts)
      14  
      15      def test_if_expression(self):
      16          snippet = "42 if True else 24"
      17          false_lbl = self.Label()
      18          expected = [
      19              ('RESUME', 0, 0),
      20              ('LOAD_CONST', 0, 1),
      21              ('POP_JUMP_IF_FALSE', false_lbl := self.Label(), 1),
      22              ('LOAD_CONST', 1, 1),
      23              ('JUMP', exit_lbl := self.Label()),
      24              false_lbl,
      25              ('LOAD_CONST', 2, 1),
      26              exit_lbl,
      27              ('POP_TOP', None),
      28              ('LOAD_CONST', 3),
      29              ('RETURN_VALUE', None),
      30          ]
      31          self.codegen_test(snippet, expected)
      32  
      33      def test_for_loop(self):
      34          snippet = "for x in l:\n\tprint(x)"
      35          false_lbl = self.Label()
      36          expected = [
      37              ('RESUME', 0, 0),
      38              ('LOAD_NAME', 0, 1),
      39              ('GET_ITER', None, 1),
      40              loop_lbl := self.Label(),
      41              ('FOR_ITER', exit_lbl := self.Label(), 1),
      42              ('STORE_NAME', 1, 1),
      43              ('PUSH_NULL', None, 2),
      44              ('LOAD_NAME', 2, 2),
      45              ('LOAD_NAME', 1, 2),
      46              ('CALL', 1, 2),
      47              ('POP_TOP', None),
      48              ('JUMP', loop_lbl),
      49              exit_lbl,
      50              ('END_FOR', None),
      51              ('LOAD_CONST', 0),
      52              ('RETURN_VALUE', None),
      53          ]
      54          self.codegen_test(snippet, expected)