diff options
Diffstat (limited to 'Lib/importlib/_bootstrap.py')
| -rw-r--r-- | Lib/importlib/_bootstrap.py | 187 |
1 files changed, 93 insertions, 94 deletions
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index 9a48c16..d80c2c0 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -299,101 +299,100 @@ def _call_with_frames_removed(f, *args, **kwds): # 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. - -The magic numbers must be spaced apart at least 2 values, as the --U interpeter flag will cause MAGIC+1 being used. They have been -odd numbers for some time now. - -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 3.0a5: 3131 (lexical exception stacking, including POP_EXCEPT) - Python 3.1a0: 3141 (optimize list, set and dict comprehensions: - change LIST_APPEND and SET_ADD, add MAP_ADD) - Python 3.1a0: 3151 (optimize conditional branches: - introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) - Python 3.2a0: 3160 (add SETUP_WITH) - tag: cpython-32 - Python 3.2a1: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR) - tag: cpython-32 - Python 3.2a2 3180 (add DELETE_DEREF) - Python 3.3a0 3190 __class__ super closure changed - Python 3.3a0 3200 (__qualname__ added) - 3210 (added size modulo 2**32 to the pyc header) - Python 3.3a1 3220 (changed PEP 380 implementation) - Python 3.3a4 3230 (revert changes to implicit __class__ closure) - Python 3.4a1 3250 (evaluate positional default arguments before - keyword-only defaults) - -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). +# 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. +# +# The magic numbers must be spaced apart at least 2 values, as the +# -U interpeter flag will cause MAGIC+1 being used. They have been +# odd numbers for some time now. +# +# 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 3.0a5: 3131 (lexical exception stacking, including POP_EXCEPT) +# Python 3.1a0: 3141 (optimize list, set and dict comprehensions: +# change LIST_APPEND and SET_ADD, add MAP_ADD) +# Python 3.1a0: 3151 (optimize conditional branches: +# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) +# Python 3.2a0: 3160 (add SETUP_WITH) +# tag: cpython-32 +# Python 3.2a1: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR) +# tag: cpython-32 +# Python 3.2a2 3180 (add DELETE_DEREF) +# Python 3.3a0 3190 __class__ super closure changed +# Python 3.3a0 3200 (__qualname__ added) +# 3210 (added size modulo 2**32 to the pyc header) +# Python 3.3a1 3220 (changed PEP 380 implementation) +# Python 3.3a4 3230 (revert changes to implicit __class__ closure) +# Python 3.4a1 3250 (evaluate positional default arguments before +# keyword-only defaults) +# +# 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). -""" _MAGIC_BYTES = (3250).to_bytes(2, 'little') + b'\r\n' _RAW_MAGIC_NUMBER = int.from_bytes(_MAGIC_BYTES, 'little') |