gh-122188: Move magic number to its own file (#122243)

* gh-122188: Move magic number to its own file

* Add versionadded directive

* Do work in C

* Integrate launcher.c

* Make _pyc_magic_number private

* Remove metadata

* Move sys.implementation -> _imp

* Modernize comment

* Move _RAW_MAGIC_NUMBER to the C side as well

* _pyc_magic_number -> pyc_magic_number

* Remove unused import

* Update docs

* Apply suggestions from code review

Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>

* Fix typo in tests

---------

Co-authored-by: Eric Snow <ericsnowcurrently@gmail.com>
This commit is contained in:
Michael Droettboom 2024-07-30 15:31:05 -04:00 committed by GitHub
parent 2b163aa9e7
commit af0a00f022
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7 changed files with 307 additions and 295 deletions

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@ -221,280 +221,7 @@ def _write_atomic(path, data, mode=0o666):
_code_type = type(_write_atomic.__code__)
# Finder/loader utility code ###############################################
# Magic word to reject .pyc files generated by other Python versions.
# It should change for each incompatible change to the bytecode.
#
# The value of CR and LF is incorporated so if you ever read or write
# a .pyc file in text mode the magic number will be wrong; also, the
# Apple MPW compiler swaps their values, botching string constants.
#
# There were a variety of old schemes for setting the magic number.
# The current working scheme is to increment the previous value by
# 10.
#
# Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic
# number also includes a new "magic tag", i.e. a human readable string used
# to represent the magic number in __pycache__ directories. When you change
# the magic number, you must also set a new unique magic tag. Generally this
# can be named after the Python major version of the magic number bump, but
# it can really be anything, as long as it's different than anything else
# that's come before. The tags are included in the following table, starting
# with Python 3.2a0.
#
# Known values:
# Python 1.5: 20121
# Python 1.5.1: 20121
# Python 1.5.2: 20121
# Python 1.6: 50428
# Python 2.0: 50823
# Python 2.0.1: 50823
# Python 2.1: 60202
# Python 2.1.1: 60202
# Python 2.1.2: 60202
# Python 2.2: 60717
# Python 2.3a0: 62011
# Python 2.3a0: 62021
# Python 2.3a0: 62011 (!)
# Python 2.4a0: 62041
# Python 2.4a3: 62051
# Python 2.4b1: 62061
# Python 2.5a0: 62071
# Python 2.5a0: 62081 (ast-branch)
# Python 2.5a0: 62091 (with)
# Python 2.5a0: 62092 (changed WITH_CLEANUP opcode)
# Python 2.5b3: 62101 (fix wrong code: for x, in ...)
# Python 2.5b3: 62111 (fix wrong code: x += yield)
# Python 2.5c1: 62121 (fix wrong lnotab with for loops and
# storing constants that should have been removed)
# Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)
# Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)
# Python 2.6a1: 62161 (WITH_CLEANUP optimization)
# Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND)
# Python 2.7a0: 62181 (optimize conditional branches:
# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)
# Python 2.7a0 62191 (introduce SETUP_WITH)
# Python 2.7a0 62201 (introduce BUILD_SET)
# Python 2.7a0 62211 (introduce MAP_ADD and SET_ADD)
# Python 3000: 3000
# 3010 (removed UNARY_CONVERT)
# 3020 (added BUILD_SET)
# 3030 (added keyword-only parameters)
# 3040 (added signature annotations)
# 3050 (print becomes a function)
# 3060 (PEP 3115 metaclass syntax)
# 3061 (string literals become unicode)
# 3071 (PEP 3109 raise changes)
# 3081 (PEP 3137 make __file__ and __name__ unicode)
# 3091 (kill str8 interning)
# 3101 (merge from 2.6a0, see 62151)
# 3103 (__file__ points to source file)
# Python 3.0a4: 3111 (WITH_CLEANUP optimization).
# Python 3.0b1: 3131 (lexical exception stacking, including POP_EXCEPT
#3021)
# Python 3.1a1: 3141 (optimize list, set and dict comprehensions:
# change LIST_APPEND and SET_ADD, add MAP_ADD #2183)
# Python 3.1a1: 3151 (optimize conditional branches:
# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE
#4715)
# Python 3.2a1: 3160 (add SETUP_WITH #6101)
# tag: cpython-32
# Python 3.2a2: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR #9225)
# tag: cpython-32
# Python 3.2a3 3180 (add DELETE_DEREF #4617)
# Python 3.3a1 3190 (__class__ super closure changed)
# Python 3.3a1 3200 (PEP 3155 __qualname__ added #13448)
# Python 3.3a1 3210 (added size modulo 2**32 to the pyc header #13645)
# Python 3.3a2 3220 (changed PEP 380 implementation #14230)
# Python 3.3a4 3230 (revert changes to implicit __class__ closure #14857)
# Python 3.4a1 3250 (evaluate positional default arguments before
# keyword-only defaults #16967)
# Python 3.4a1 3260 (add LOAD_CLASSDEREF; allow locals of class to override
# free vars #17853)
# Python 3.4a1 3270 (various tweaks to the __class__ closure #12370)
# Python 3.4a1 3280 (remove implicit class argument)
# Python 3.4a4 3290 (changes to __qualname__ computation #19301)
# Python 3.4a4 3300 (more changes to __qualname__ computation #19301)
# Python 3.4rc2 3310 (alter __qualname__ computation #20625)
# Python 3.5a1 3320 (PEP 465: Matrix multiplication operator #21176)
# Python 3.5b1 3330 (PEP 448: Additional Unpacking Generalizations #2292)
# Python 3.5b2 3340 (fix dictionary display evaluation order #11205)
# Python 3.5b3 3350 (add GET_YIELD_FROM_ITER opcode #24400)
# Python 3.5.2 3351 (fix BUILD_MAP_UNPACK_WITH_CALL opcode #27286)
# Python 3.6a0 3360 (add FORMAT_VALUE opcode #25483)
# Python 3.6a1 3361 (lineno delta of code.co_lnotab becomes signed #26107)
# Python 3.6a2 3370 (16 bit wordcode #26647)
# Python 3.6a2 3371 (add BUILD_CONST_KEY_MAP opcode #27140)
# Python 3.6a2 3372 (MAKE_FUNCTION simplification, remove MAKE_CLOSURE
# #27095)
# Python 3.6b1 3373 (add BUILD_STRING opcode #27078)
# Python 3.6b1 3375 (add SETUP_ANNOTATIONS and STORE_ANNOTATION opcodes
# #27985)
# Python 3.6b1 3376 (simplify CALL_FUNCTIONs & BUILD_MAP_UNPACK_WITH_CALL
#27213)
# Python 3.6b1 3377 (set __class__ cell from type.__new__ #23722)
# Python 3.6b2 3378 (add BUILD_TUPLE_UNPACK_WITH_CALL #28257)
# Python 3.6rc1 3379 (more thorough __class__ validation #23722)
# Python 3.7a1 3390 (add LOAD_METHOD and CALL_METHOD opcodes #26110)
# Python 3.7a2 3391 (update GET_AITER #31709)
# Python 3.7a4 3392 (PEP 552: Deterministic pycs #31650)
# Python 3.7b1 3393 (remove STORE_ANNOTATION opcode #32550)
# Python 3.7b5 3394 (restored docstring as the first stmt in the body;
# this might affected the first line number #32911)
# Python 3.8a1 3400 (move frame block handling to compiler #17611)
# Python 3.8a1 3401 (add END_ASYNC_FOR #33041)
# Python 3.8a1 3410 (PEP570 Python Positional-Only Parameters #36540)
# Python 3.8b2 3411 (Reverse evaluation order of key: value in dict
# comprehensions #35224)
# Python 3.8b2 3412 (Swap the position of positional args and positional
# only args in ast.arguments #37593)
# Python 3.8b4 3413 (Fix "break" and "continue" in "finally" #37830)
# Python 3.9a0 3420 (add LOAD_ASSERTION_ERROR #34880)
# Python 3.9a0 3421 (simplified bytecode for with blocks #32949)
# Python 3.9a0 3422 (remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY, POP_FINALLY bytecodes #33387)
# Python 3.9a2 3423 (add IS_OP, CONTAINS_OP and JUMP_IF_NOT_EXC_MATCH bytecodes #39156)
# Python 3.9a2 3424 (simplify bytecodes for *value unpacking)
# Python 3.9a2 3425 (simplify bytecodes for **value unpacking)
# Python 3.10a1 3430 (Make 'annotations' future by default)
# Python 3.10a1 3431 (New line number table format -- PEP 626)
# Python 3.10a2 3432 (Function annotation for MAKE_FUNCTION is changed from dict to tuple bpo-42202)
# Python 3.10a2 3433 (RERAISE restores f_lasti if oparg != 0)
# Python 3.10a6 3434 (PEP 634: Structural Pattern Matching)
# Python 3.10a7 3435 Use instruction offsets (as opposed to byte offsets).
# Python 3.10b1 3436 (Add GEN_START bytecode #43683)
# Python 3.10b1 3437 (Undo making 'annotations' future by default - We like to dance among core devs!)
# Python 3.10b1 3438 Safer line number table handling.
# Python 3.10b1 3439 (Add ROT_N)
# Python 3.11a1 3450 Use exception table for unwinding ("zero cost" exception handling)
# Python 3.11a1 3451 (Add CALL_METHOD_KW)
# Python 3.11a1 3452 (drop nlocals from marshaled code objects)
# Python 3.11a1 3453 (add co_fastlocalnames and co_fastlocalkinds)
# Python 3.11a1 3454 (compute cell offsets relative to locals bpo-43693)
# Python 3.11a1 3455 (add MAKE_CELL bpo-43693)
# Python 3.11a1 3456 (interleave cell args bpo-43693)
# Python 3.11a1 3457 (Change localsplus to a bytes object bpo-43693)
# Python 3.11a1 3458 (imported objects now don't use LOAD_METHOD/CALL_METHOD)
# Python 3.11a1 3459 (PEP 657: add end line numbers and column offsets for instructions)
# Python 3.11a1 3460 (Add co_qualname field to PyCodeObject bpo-44530)
# Python 3.11a1 3461 (JUMP_ABSOLUTE must jump backwards)
# Python 3.11a2 3462 (bpo-44511: remove COPY_DICT_WITHOUT_KEYS, change
# MATCH_CLASS and MATCH_KEYS, and add COPY)
# Python 3.11a3 3463 (bpo-45711: JUMP_IF_NOT_EXC_MATCH no longer pops the
# active exception)
# Python 3.11a3 3464 (bpo-45636: Merge numeric BINARY_*/INPLACE_* into
# BINARY_OP)
# Python 3.11a3 3465 (Add COPY_FREE_VARS opcode)
# Python 3.11a4 3466 (bpo-45292: PEP-654 except*)
# Python 3.11a4 3467 (Change CALL_xxx opcodes)
# Python 3.11a4 3468 (Add SEND opcode)
# Python 3.11a4 3469 (bpo-45711: remove type, traceback from exc_info)
# Python 3.11a4 3470 (bpo-46221: PREP_RERAISE_STAR no longer pushes lasti)
# Python 3.11a4 3471 (bpo-46202: remove pop POP_EXCEPT_AND_RERAISE)
# Python 3.11a4 3472 (bpo-46009: replace GEN_START with POP_TOP)
# Python 3.11a4 3473 (Add POP_JUMP_IF_NOT_NONE/POP_JUMP_IF_NONE opcodes)
# Python 3.11a4 3474 (Add RESUME opcode)
# Python 3.11a5 3475 (Add RETURN_GENERATOR opcode)
# Python 3.11a5 3476 (Add ASYNC_GEN_WRAP opcode)
# Python 3.11a5 3477 (Replace DUP_TOP/DUP_TOP_TWO with COPY and
# ROT_TWO/ROT_THREE/ROT_FOUR/ROT_N with SWAP)
# Python 3.11a5 3478 (New CALL opcodes)
# Python 3.11a5 3479 (Add PUSH_NULL opcode)
# Python 3.11a5 3480 (New CALL opcodes, second iteration)
# Python 3.11a5 3481 (Use inline cache for BINARY_OP)
# Python 3.11a5 3482 (Use inline caching for UNPACK_SEQUENCE and LOAD_GLOBAL)
# Python 3.11a5 3483 (Use inline caching for COMPARE_OP and BINARY_SUBSCR)
# Python 3.11a5 3484 (Use inline caching for LOAD_ATTR, LOAD_METHOD, and
# STORE_ATTR)
# Python 3.11a5 3485 (Add an oparg to GET_AWAITABLE)
# Python 3.11a6 3486 (Use inline caching for PRECALL and CALL)
# Python 3.11a6 3487 (Remove the adaptive "oparg counter" mechanism)
# Python 3.11a6 3488 (LOAD_GLOBAL can push additional NULL)
# Python 3.11a6 3489 (Add JUMP_BACKWARD, remove JUMP_ABSOLUTE)
# Python 3.11a6 3490 (remove JUMP_IF_NOT_EXC_MATCH, add CHECK_EXC_MATCH)
# Python 3.11a6 3491 (remove JUMP_IF_NOT_EG_MATCH, add CHECK_EG_MATCH,
# add JUMP_BACKWARD_NO_INTERRUPT, make JUMP_NO_INTERRUPT virtual)
# Python 3.11a7 3492 (make POP_JUMP_IF_NONE/NOT_NONE/TRUE/FALSE relative)
# Python 3.11a7 3493 (Make JUMP_IF_TRUE_OR_POP/JUMP_IF_FALSE_OR_POP relative)
# Python 3.11a7 3494 (New location info table)
# Python 3.11b4 3495 (Set line number of module's RESUME instr to 0 per PEP 626)
# Python 3.12a1 3500 (Remove PRECALL opcode)
# Python 3.12a1 3501 (YIELD_VALUE oparg == stack_depth)
# Python 3.12a1 3502 (LOAD_FAST_CHECK, no NULL-check in LOAD_FAST)
# Python 3.12a1 3503 (Shrink LOAD_METHOD cache)
# Python 3.12a1 3504 (Merge LOAD_METHOD back into LOAD_ATTR)
# Python 3.12a1 3505 (Specialization/Cache for FOR_ITER)
# Python 3.12a1 3506 (Add BINARY_SLICE and STORE_SLICE instructions)
# Python 3.12a1 3507 (Set lineno of module's RESUME to 0)
# Python 3.12a1 3508 (Add CLEANUP_THROW)
# Python 3.12a1 3509 (Conditional jumps only jump forward)
# Python 3.12a2 3510 (FOR_ITER leaves iterator on the stack)
# Python 3.12a2 3511 (Add STOPITERATION_ERROR instruction)
# Python 3.12a2 3512 (Remove all unused consts from code objects)
# Python 3.12a4 3513 (Add CALL_INTRINSIC_1 instruction, removed STOPITERATION_ERROR, PRINT_EXPR, IMPORT_STAR)
# Python 3.12a4 3514 (Remove ASYNC_GEN_WRAP, LIST_TO_TUPLE, and UNARY_POSITIVE)
# Python 3.12a5 3515 (Embed jump mask in COMPARE_OP oparg)
# Python 3.12a5 3516 (Add COMPARE_AND_BRANCH instruction)
# Python 3.12a5 3517 (Change YIELD_VALUE oparg to exception block depth)
# Python 3.12a6 3518 (Add RETURN_CONST instruction)
# Python 3.12a6 3519 (Modify SEND instruction)
# Python 3.12a6 3520 (Remove PREP_RERAISE_STAR, add CALL_INTRINSIC_2)
# Python 3.12a7 3521 (Shrink the LOAD_GLOBAL caches)
# Python 3.12a7 3522 (Removed JUMP_IF_FALSE_OR_POP/JUMP_IF_TRUE_OR_POP)
# Python 3.12a7 3523 (Convert COMPARE_AND_BRANCH back to COMPARE_OP)
# Python 3.12a7 3524 (Shrink the BINARY_SUBSCR caches)
# Python 3.12b1 3525 (Shrink the CALL caches)
# Python 3.12b1 3526 (Add instrumentation support)
# Python 3.12b1 3527 (Add LOAD_SUPER_ATTR)
# Python 3.12b1 3528 (Add LOAD_SUPER_ATTR_METHOD specialization)
# Python 3.12b1 3529 (Inline list/dict/set comprehensions)
# Python 3.12b1 3530 (Shrink the LOAD_SUPER_ATTR caches)
# Python 3.12b1 3531 (Add PEP 695 changes)
# Python 3.13a1 3550 (Plugin optimizer support)
# Python 3.13a1 3551 (Compact superinstructions)
# Python 3.13a1 3552 (Remove LOAD_FAST__LOAD_CONST and LOAD_CONST__LOAD_FAST)
# Python 3.13a1 3553 (Add SET_FUNCTION_ATTRIBUTE)
# Python 3.13a1 3554 (more efficient bytecodes for f-strings)
# Python 3.13a1 3555 (generate specialized opcodes metadata from bytecodes.c)
# Python 3.13a1 3556 (Convert LOAD_CLOSURE to a pseudo-op)
# Python 3.13a1 3557 (Make the conversion to boolean in jumps explicit)
# Python 3.13a1 3558 (Reorder the stack items for CALL)
# Python 3.13a1 3559 (Generate opcode IDs from bytecodes.c)
# Python 3.13a1 3560 (Add RESUME_CHECK instruction)
# Python 3.13a1 3561 (Add cache entry to branch instructions)
# Python 3.13a1 3562 (Assign opcode IDs for internal ops in separate range)
# Python 3.13a1 3563 (Add CALL_KW and remove KW_NAMES)
# Python 3.13a1 3564 (Removed oparg from YIELD_VALUE, changed oparg values of RESUME)
# Python 3.13a1 3565 (Oparg of YIELD_VALUE indicates whether it is in a yield-from)
# Python 3.13a1 3566 (Emit JUMP_NO_INTERRUPT instead of JUMP for non-loop no-lineno cases)
# Python 3.13a1 3567 (Reimplement line number propagation by the compiler)
# Python 3.13a1 3568 (Change semantics of END_FOR)
# Python 3.13a5 3569 (Specialize CONTAINS_OP)
# Python 3.13a6 3570 (Add __firstlineno__ class attribute)
# Python 3.14a1 3600 (Add LOAD_COMMON_CONSTANT)
# Python 3.14a1 3601 (Fix miscompilation of private names in generic classes)
# Python 3.14a1 3602 (Add LOAD_SPECIAL. Remove BEFORE_WITH and BEFORE_ASYNC_WITH)
# Python 3.14a1 3603 (Remove BUILD_CONST_KEY_MAP)
# Python 3.15 will start with 3650
# Please don't copy-paste the same pre-release tag for new entries above!!!
# You should always use the *upcoming* tag. For example, if 3.12a6 came out
# a week ago, I should put "Python 3.12a7" next to my new magic number.
# MAGIC must change whenever the bytecode emitted by the compiler may no
# longer be understood by older implementations of the eval loop (usually
# due to the addition of new opcodes).
#
# Starting with Python 3.11, Python 3.n starts with magic number 2900+50n.
#
# Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
# in PC/launcher.c must also be updated.
MAGIC_NUMBER = (3603).to_bytes(2, 'little') + b'\r\n'
_RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c
MAGIC_NUMBER = (_imp.pyc_magic_number).to_bytes(2, 'little') + b'\r\n'
_PYCACHE = '__pycache__'
_OPT = 'opt-'
@ -1133,7 +860,7 @@ class SourceLoader(_LoaderBasics):
_imp.check_hash_based_pycs == 'always')):
source_bytes = self.get_data(source_path)
source_hash = _imp.source_hash(
_RAW_MAGIC_NUMBER,
_imp.pyc_magic_number_token,
source_bytes,
)
_validate_hash_pyc(data, source_hash, fullname,
@ -1162,7 +889,7 @@ class SourceLoader(_LoaderBasics):
source_mtime is not None):
if hash_based:
if source_hash is None:
source_hash = _imp.source_hash(_RAW_MAGIC_NUMBER,
source_hash = _imp.source_hash(_imp.pyc_magic_number_token,
source_bytes)
data = _code_to_hash_pyc(code_object, source_hash, check_source)
else: