saladdais / python-goto Goto Github PK

Right now python-goto is segfaulting on Python 3.9 and above when trying to jump out of a block.

From https://docs.python.org/3.11/whatsnew/3.11.html#cpython-bytecode-changes:

Replaced JUMP_IF_NOT_EXC_MATCH by CHECK_EXC_MATCH which performs the check but does not jump.

Replaced JUMP_IF_NOT_EG_MATCH by CHECK_EG_MATCH which performs the check but does not jump.

Replaced JUMP_ABSOLUTE by the relative JUMP_BACKWARD.

Added JUMP_BACKWARD_NO_INTERRUPT, which is used in certain loops where it is undesirable to handle interrupts.

Replaced POP_JUMP_IF_TRUE and POP_JUMP_IF_FALSE by the relative POP_JUMP_FORWARD_IF_TRUE, POP_JUMP_BACKWARD_IF_TRUE, POP_JUMP_FORWARD_IF_FALSE and POP_JUMP_BACKWARD_IF_FALSE.

Added POP_JUMP_FORWARD_IF_NOT_NONE, POP_JUMP_BACKWARD_IF_NOT_NONE, POP_JUMP_FORWARD_IF_NONE and POP_JUMP_BACKWARD_IF_NONE opcodes to speed up conditional jumps.

Looks like the most important change is that absolute jumps no longer exist, and we have to use separate forward / backward relative jump types now. Will need separate codegen paths for 3.11+.

Have some code to handle relative jumps, but https://bugs.python.org/issue26647 will make things more complicated since we need to change the bytecode parser and serializer. May make sense to drop Python 2.7 support and look for newer parts of dis that can do this dumping / parsing for us without requiring direct use of struct to manipulate a buffer of bytecode...