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| author | Mark Shannon <mark@hotpy.org> | 2021-05-07 14:19:19 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-05-07 14:19:19 (GMT) |
| commit | adcd2205565f91c6719f4141ab4e1da6d7086126 (patch) | |
| tree | 0953b285944eccde57b05b8f3c7e30fb501a3d64 /Lib/importlib | |
| parent | b32c8e97951db46484ba3b646b988bcdc4062199 (diff) | |
| download | cpython-adcd2205565f91c6719f4141ab4e1da6d7086126.zip cpython-adcd2205565f91c6719f4141ab4e1da6d7086126.tar.gz cpython-adcd2205565f91c6719f4141ab4e1da6d7086126.tar.bz2 | |
bpo-40222: "Zero cost" exception handling (GH-25729)
"Zero cost" exception handling.
* Uses a lookup table to determine how to handle exceptions.
* Removes SETUP_FINALLY and POP_TOP block instructions, eliminating (most of) the runtime overhead of try statements.
* Reduces the size of the frame object by about 60%.
Diffstat (limited to 'Lib/importlib')
| -rw-r--r-- | Lib/importlib/_bootstrap_external.py | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py index 9a73c7b..469610a 100644 --- a/Lib/importlib/_bootstrap_external.py +++ b/Lib/importlib/_bootstrap_external.py @@ -352,6 +352,7 @@ _code_type = type(_write_atomic.__code__) # 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) # # MAGIC must change whenever the bytecode emitted by the compiler may no @@ -361,7 +362,7 @@ _code_type = type(_write_atomic.__code__) # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array # in PC/launcher.c must also be updated. -MAGIC_NUMBER = (3439).to_bytes(2, 'little') + b'\r\n' +MAGIC_NUMBER = (3450).to_bytes(2, 'little') + b'\r\n' _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c _PYCACHE = '__pycache__' |