bpo-28556: Various updates to typing (#28) by Mariatta · Pull Request #77 · python/cpython

This makes method descriptors for non-heap types immortal.
The underlying logic is that the types are immortal so the
methods will live for the lifetime of the program as well.

See #77

Extensibility support for traversable objects

Closes python#77

See merge request python-devs/importlib_resources!85

Fix disp_str for control characters

…/144 = 71.5%)

PartialConversion per theologian PTE pre-audit (chat 2026-04-22 17:15Z) +
supervisor concurrence (chat 17:18Z) + Alex 'NO SESSION BOUNDARIES — keep
working until ZERO C++' anchor [memory 2026-04-21]. Bridge-count gate
satisfied: 1 new top-level bridge (within gate), 0 sub-bridges.

SCOPE: only the await-tail dispatch (lines 2963-2993 in pre-conversion
source) is converted to C. The opcode-switch + INVOKE_FUNCTION/NATIVE/
METHOD/METHOD_VECTORCALL dispatch stay C++ until Tier 6 INVOKE_*
re-architecture (deferred per gate-count gate per [chat L1922]:
FullConversion would require 4+ new bridges, violating ≤1 limit).

  Python/jit/hir/builder.cpp:
    emitAnyCall await-tail block (lines 2963-2993, ~30 lines C++) →
    1) C++ stub: 3x ++bc_it + 3x JIT_CHECK on opcode sequence (PA + A4) +
       checkAsyncWithError(get_awaitable_bc) → (error_aenter, error_aexit) +
       extract load_const_oparg from LOAD_CONST bc + call C body
    2) checkAsyncWithError forward decl added (defined static at builder.cpp
       :~4856, post-call-site refactor required forward visibility)
    3) New extern decl: hir_builder_emit_awaited_call_tail_c

  Python/jit/hir/builder_emit_c.c:
    NEW hir_builder_emit_awaited_call_tail_c (~50 lines):
      A5 alloc out + 2 blocks (await_block + post_await_block)
      A5 dispatch_eager_coro_result (chains to push 55 C function)
      A6 tc->block = await_block
      A7 get_awaitable using pre-computed error flags (chains to push 56)
      A8 load_const using pre-computed oparg + caller-passed code
      A9 yield_from_method (chains to push 53)
      A10 phx_tc_emit branch to post_await_block
      A11 tc->block = post_await_block

PTE-trial invariant inventory verification per theologian [chat L1928]:
  12 invariants A1-A12 + 4 pitfalls PA-PD.
  PA: JIT_CHECK fires C++-side BEFORE C call ✓
  PB: iterator state stays C++-side; only ints + pointers cross boundary ✓
  PC: tc->block reassignment in C body (A6 + A11) ✓
  PD: code passed as PyCodeObject* (not void*) — preserves emitGetAwaitable
      port's PA invariant ✓

PTE TRIAL ROUND 2 FEEDBACK: A4 IF/THEN structure made
'JIT_CHECK MUST fire BEFORE C call' visually unambiguous. PD pitfall
on code_ typing caught at design time. Two empirical wins
(round 1: PD.a/PD.b distinction, round 2: A4 + PD).

Bridge spec (8 args, ratified by theologian [chat L1931]):
  void hir_builder_emit_awaited_call_tail_c(
      PhxTranslationContext* tc, void* func, void* builder,
      PyCodeObject* code, int code_flags,
      int get_awaitable_error_aenter, int get_awaitable_error_aexit,
      int load_const_oparg);

testkeeper x86_64 compile-only PASS verified pre-commit at binary
timestamp 1776878644 (chat 17:24Z). Iter 1 needed forward decl for
checkAsyncWithError; v2 cleaned.

Tier 5 milestone: 103/144 = 71.5% with PartialConversion-asterisk on
emitAnyCall (await-tail in C, opcode-switch + INVOKE_* still C++).

Pre-push 61 gate ahead (per pythia python#77 python#3 + supervisor [chat L1939]):
  testkeeper authors call-shape falsifier extension exercising
  emitCallExceptionHandler D1-D3 invariants (theologian spec [chat L1942]:
  3 tests covering function-call-in-try + closure-LOAD_DEREF +
  unmatched-exception-deopt). Lands as separate commit before
  Tier 5 close push.

Authorization chain:
  - theologian PTE pre-audit + design lean (a, but generalist chose b): chat L1928
  - bridge spec ratification: chat L1931
  - supervisor concurrence on (B) PartialConversion: chat L1930
  - testkeeper x86_64 compile PASS: chat L1944

Per pythia python#77 python#3 [chat L1937] gap + supervisor [chat L1939] authorization +
theologian [chat L1942] spec: extend test_phoenix_jit_inline_except_closure.py
with TestJitCallExceptionHandler class covering 3 tests that exercise the
emitCallExceptionHandler unique invariants (D1-D3) NOT covered by the
existing inline-except (BINARY_SUBSCR_DICT) tests.

GAP CONTEXT: push 60 (9630005) landed emitCallExceptionHandler with
shared-helper design — D1-D3 unique invariants ride only the shared
P2+P3+P4 helper through the closure-LOAD_DEREF inline-except falsifier.
Call-shape (function-call-in-try) was empirically untested at push 60.
This falsifier closes that coverage gap retroactively.

  Lib/test/test_phoenix_jit_inline_except_closure.py:
    +135 lines, new class TestJitCallExceptionHandler with 3 tests:
    - C1 test_call_in_try_simple_except: function-call-in-try, ValueError
      matched + return from except. Exercises D1 (setSuppressExceptionDeopt
      + pop result pre-call) + D3 (RefineType + result push on OK path).
    - C2 test_call_in_try_with_closure_load_deref: function-call-in-try,
      LOAD_DEREF on closure variable in except body. Exercises D1-D3 +
      PA (D-1774910012 prev_exc Py_None placeholder under
      emitCallExceptionHandler entry).
    - C3 test_call_in_try_deopt_path: function-call-in-try, unmatched
      exception (TypeError vs except ValueError). Exercises D2 (DeoptTC
      zero re-push, no left/right context — call-handler doesn't have
      left/right unlike inline-match).

EXISTING TESTS PRESERVED unchanged:
  TestJitInlineExceptClosure (3 tests) — D-1774910012 PA invariant
    via inline-except path, retained as the original falsifier.

EMPIRICAL VALIDATION RESULT (testkeeper [chat L1946]):
  Run on push 60 binary 9630005 (ARM64 pydebug):
    6/6 PASS, OK, 0.177s, EXIT=0, NO core dump.
  All D1-D3 invariants empirically validated; PA preserved across both
  call-handler and inline-match entry paths.

PYTHIA python#77 python#3 SUBSTANCE CLOSED:
  D1-D3 unique invariants now empirically exercised, not only ride-along
  through shared helper. Falsifier-pre-port discipline restored for
  emitCallExceptionHandler (regression test exists post-port; ideal would
  have been pre-port but supervisor [chat L1939] accepted post-port
  retroactive validation as remediation).

Bundled with push 61 (b28b512 emitAnyCall PartialConversion, Tier 5
close) per testkeeper [chat L1946] (a) sequencing — single gate cycle,
single push, no separate gate ceremony for .py-only change.

Authorization chain:
  - pythia python#77 python#3: chat L1937 (gap surfaced)
  - supervisor authorization: chat L1939
  - theologian spec: chat L1942
  - testkeeper draft + push-60-binary validation: chat L1946