wasm/jit backend fixes, blackhole and frame-state repairs, and 3.14 interpreter surface parity

[youknowone]

74 commits, rebased onto main (8c878513ef, #878).

jit / blackhole / frame state

• Blackhole: drop the abort frame-state rollback that replayed executed effects; seed the miframe from every register and resume past a frame-forcing residual that ran user bytecode; end the deadframe root scope before the forward run.
• Walk declines: a jitcode register read that finds an unwritten slot, a code object past the jitcode label-id ceiling, the LOAD_GLOBAL cell fold when the namespace operand is null.
• Frames: force and write back the frame's locals for locals()/vars(); force the frame before f_locals reads its fastlocals; defer the escape-flush undo restore to the walk-end epilogue; exempt the FOR_ITER loop-variable store from the in-flight body-effect guard.
• Roots and barriers: root the deadframe exit values across handle_fail and blackhole resume; size the typed-array tids from the block they describe and barrier the blackhole ref stores; write-barrier the flat-pycall callee locals array; re-gray black stack roots before the major cycle freezes survivors.
• Cross-loop close is attempted once per recording walk instead of on every crossing of the same header (reached_loop_header answers a cancelled close with cancel_count += 1 and, with max_unroll_loops at its default 0, SwitchToBlackhole(ABORT_BAD_LOOP), so upstream re-attempts at most once per tracing pass).
• pypyjit.set_param; wide binop immediates materialize through the scratch register; GUARD_NOT_INVALIDATED's branch routes through the long-branch pattern; setarrayitem_vable_r for the BUILD_LIST push.

wasm backend

• Intern trace reference constants into a per-loop GcTable; root the deadframe exit-value copies; register the collect_full GC hook and the user-del action; give the launcher a stderr channel, an exit status and the script path; raise MAX_STACK_SIZE off wasm32 and clamp the length to the OS stack.

interpreter surface (3.14)

• Builtin call convention: bind arguments through the clinic two-branch arity check; word arity, keyword and receiver/module errors by the C calling convention.
• Descriptors: bind a method_descriptor to a builtin_function_or_method; __rpow__'s third (modulus) argument; publish __objclass__/__name__ as member descriptors; type's own docstring; type.__prepare__; object.__subclasshook__ as a classmethod; exception __str__/__repr__ descriptors, slot deletion and SystemExit init.
• Iteration: separate iterator types for str/bytes/bytearray/memoryview and for array; name the class, not the instance layout, in iteration errors.
• Errors and messages: structured renderer for uncaught exceptions with repeated-frame collapse; one ZeroDivisionError message for every zero divisor; source length in "too many values to unpack" only for an exact tuple or list; MRO blocked-base and store-miss wording; add_note argument-clinic wording.
• Sorting: port rpython/rlib/listsort.py TimSort, sort through the list strategy and reinstall the items in one bulk init.
• Also: recursion budget spent per frame activation; independent locals() snapshot for optimized frames; dir() resolves its frame the way locals() does; _abc_register structural-match marker; _imp.init_frozen; posix chown/lchown, pathconf_names, bytes-path directory names; _operator registration; bytes.translate(table, /, delete); str.islower/isupper skip uncased letters; TabError on mixed tabs and spaces; math/descroperation numeric-tower parity.

verification (macOS)

• pyre/check.py --backend dynasm,wasm on this tip, after re-extracting LLBC for pyre-object / pyre-interpreter / pyre-module / pyre-jit:
  • wasm 341/341 passed.
  • dynasm 343 passed, 1 failed: synth/const_arg_call_resume trips the perf gate. Its exec is stable at 0.19s across runs and rebases while the ratio floats 37.8x / 38.8x / 39.0x / 44.8x — the movement is entirely in the pypy denominator, which the harness rounds to 0.005–0.01s. A/B of the base and branch pyre-dynasm binaries earlier in this work measured the same user time, so this is the denominator-collapse class, not a behaviour change.
  • synth/str_search_index_bounds — red before this rebase and resolved now that main advanced; the MergePoint vable-identity fix is in the new base.
• pyre/extra_tests/run.py --dynasm-only — 235/241. The six failures are pre-existing: three deliberate declines (builtin_list, builtin_tuple, builtin_slice), pickle_pypy_module (fails on CPython 3.14 too), and two open epics (stdlib_sys frame→function link, stdlib_sqlite _sqlite3 port).
• cargo test -p pyre-interpreter --features dynasm --lib 430 passed; cargo test -p pyre-jit-trace --lib 300 passed; cargo fmt --all --check clean.

Known gap in the history: commit 728db88e17 does not compile standalone — getindex_repeat is still private in typedef.rs at that point while descroperation.rs already calls it through baseobjspace; the next commit moves and promotes it. The tip is fine; only git bisect is affected.

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Added Python 3.14-compatible iterator identities and expanded built-in API behavior.
  • Added improved WebAssembly script-path handling, stderr capture, and exit-code reporting.
  • Added support for additional filesystem, sorting, exception, and stream operations.

• Bug Fixes

  • Improved garbage-collection safety during JIT and WebAssembly execution.
  • Corrected recursion tracking, sequence operations, argument validation, and exception formatting.
  • Prevented failures from unreachable branches and oversized generated code.

• Tests

  • Expanded coverage for built-ins, iterators, descriptors, WebAssembly execution, and JIT edge cases.