Summary

This example shows how to create an import hook that mutates a bytecode object.

Confused math

This demonstrates what happens if we swap the meaning of the BINARY_ADD and BINARY_MULTIPLY bytecodes.

> python -m ideas -a confused_math_bc
Ideas Console version 0.0.34. [Python version: 3.10.2]

>>> x = 3
>>> y = 7
>>> x + y
21
>>> x * y
10
>>> # Python does simple mathematical operations *before*
>>> # generating bytecode
>>> z = 3 + 4
>>> z
7

Yes, it is a silly example. However, I cannot come up with anything possibly useful to demonstrate the value of changing bytecode. Feel free to submit a better example.

API for confused_math_bc

confused_math_bc.py

Import hook that performs bytecode changes, swapping BINARY_ADD and BINARY_MULTIPLY.

Note: If code contains something like a + b, or a * b, where a and b are integer literals (e.g. 2 + 4), the operations are done prior to the creation of a code object and thus are not captured by this transformation.

ideas.examples.confused_math_bc.add_hook(**_kwargs)

Creates and automatically adds the import hook in sys.meta_path

ideas.examples.confused_math_bc.create_new_co(code_object)

Recursively creates new code objects from old ones, swapping BINARY_ADD and BINARY_MULTIPLY.

ideas.examples.confused_math_bc.swap_add_mul(bytecode)

Interchange BINARY_ADD and BINARY_MULTIPLY

ideas.examples.confused_math_bc.transform_bytecode(code_object, **_kwargs)

Transforms the code object into a new code object