René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Track remaining test_inspect bytecode parity gaps","articleBody":"Summary\n\nThis tracks the bytecode parity gaps that still remain after the CFG, slice-folding, constant-ordering, annotation/type-alias, and heavy-function parity fixes.\n\nCurrent status\n\nThe previous tracked files now match CPython bytecode with the release RustPython binary:\n\n- `Lib/test/test_buffer.py`: match\n- `Lib/test/test_tarfile.py`: match\n- `Lib/test/test_codecs.py`: match\n- `Lib/doctest.py`: match\n\nThe only remaining tracked file that still differs is:\n\n- `Lib/test/test_inspect/test_inspect.py`\n\nCurrent `scripts/compare_bytecode.py --filter 'test/test_inspect/test_inspect.py' --detail` result\n\n```text\ntest/test_inspect/test_inspect.py:\n  \u003cmodule\u003e/TestRetrievingSourceCode/TestRetrievingSourceCode.test_getsource_on_class_without_firstlineno/TestRetrievingSourceCode.test_getsource_on_class_without_firstlineno.\u003clocals\u003e.C: 1 difference(s)\n    [  7] CPython:     ['STORE_DEREF', '__firstlineno__']\n          RustPython:  ['STORE_NAME', '__firstlineno__']\n\n  \u003cmodule\u003e/TestGetClosureVars/TestGetClosureVars.test_nonlocal_vars/TestGetClosureVars.test_nonlocal_vars.\u003clocals\u003e.\u003clambda\u003e/TestGetClosureVars.test_nonlocal_vars.\u003clocals\u003e.\u003clambda\u003e.\u003clocals\u003e.\u003clambda\u003e: 1 difference(s)\n    extra in CPython\n\n  \u003cmodule\u003e/TestGetClosureVars/TestGetClosureVars.test_nonlocal_vars/TestGetClosureVars.test_nonlocal_vars.\u003clocals\u003e.\u003clambda\u003e/TestGetClosureVars.test_nonlocal_vars.\u003clocals\u003e.\u003clambda\u003e.\u003clambda\u003e: 1 difference(s)\n    extra in RustPython\n```\n\nRemaining root causes\n\n- Class-body `__firstlineno__` store does not follow CPython name resolution in the nonlocal case.\n  - CPython 3.14 `Python/codegen.c` emits `__firstlineno__` through `codegen_nameop(..., Store)` in `codegen_class_body`.\n  - RustPython currently emits `STORE_NAME __firstlineno__` directly in `compile_class_body`, so a class body with `nonlocal __firstlineno__` does not become `STORE_DEREF`.\n- Nested lambda code-object naming/order still differs in `TestGetClosureVars.test_nonlocal_vars`.\n  - One nested lambda code object appears as extra in CPython and the corresponding one appears extra in RustPython.\n\nPolicy\n\nDo not paper over these diffs with file-specific hacks in `Lib/`. Fix them through shared compiler structure, preferably by following CPython 3.14 compiler behavior.\n\nDone when\n\n`Lib/test/test_inspect/test_inspect.py` reports `match` in `scripts/compare_bytecode.py` with the release RustPython binary, and the two representative diffs above are gone.\n","author":{"url":"https://github.com/youknowone","@type":"Person","name":"youknowone"},"datePublished":"2026-04-20T15:28:14.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/29/RustPython/issues/29"}