gh-124058: remove _PyCompile_IsNestedScope, roll it into _PyCompile_IsInteractive

[iritkatriel]

Fixes #124058.

• Issue: Remove _PyCompile_IsNestedScope roll it into _PyCompile_IsInteractive #124058

[JelleZijlstra]

jelle@m3mb-jelle cpython % ./python.exe         
Python 3.14.0a0 (heads/move_interactive:cebdf71c554, Sep 13 2024, 09:10:41) [Clang 15.0.0 (clang-1500.3.9.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 1; 2Assertion failed: (asdl_seq_LEN(stmts) == 1), function codegen_interactive, file codegen.c, line 748.
                                                                                                             zsh: abort      ./python.exe

This doesn't work correctly if there are multiple statements in one interactive.

[iritkatriel]

I don't get it:

>>> dis.dis(compile("1;2", "", "single"))
  0           RESUME                   0

  1           LOAD_CONST               0 (1)
              CALL_INTRINSIC_1         1 (INTRINSIC_PRINT)
              POP_TOP
              LOAD_CONST               1 (2)
              CALL_INTRINSIC_1         1 (INTRINSIC_PRINT)
              POP_TOP
              RETURN_CONST             2 (None)
>>> 1;2
2

how come the 1 is not printed?

[iritkatriel]

I don't get it:

>>> dis.dis(compile("1;2", "", "single"))
  0           RESUME                   0

  1           LOAD_CONST               0 (1)
              CALL_INTRINSIC_1         1 (INTRINSIC_PRINT)
              POP_TOP
              LOAD_CONST               1 (2)
              CALL_INTRINSIC_1         1 (INTRINSIC_PRINT)
              POP_TOP
              RETURN_CONST             2 (None)
>>> 1;2
2

how come the 1 is not printed?

This does print the 1:

>>> exec(compile("1;2", "", "single"))
1
2

so at the prompt we're doing something else.

[JelleZijlstra]

What do you think about renaming this to something like _PyCompile_IsInteractiveTopLevel for clarity?