What is the feature you'd like to have?
Support for IL rewriting to remove Objective-C reference counting calls such as objc_retain / objc_release / objc_autorelease was implemented in #7440 and released in Binary Ninja 5.2. The initial implementation has a couple of limitations:
- It is only enabled for arm64 / arm64e.
- It does not support removing functions that use a custom calling convention, such as
objc_retain_x1 and friends that take their only argument in a specific register.
Addressing both of these requires more sophisticated IL rewriting in order to ensure that the argument to the function call being removed still ends up being available for the return value. For arm64 the first argument and result register are the same so we get away with replacing the call itself with a nop. This will need to be replaced by an explicit assignment of the first argument, whatever its location may be, to the result register.
Support for x86_64 also requires matching a wider range of LLIL patterns.
What is the feature you'd like to have?
Support for IL rewriting to remove Objective-C reference counting calls such as
objc_retain/objc_release/objc_autoreleasewas implemented in #7440 and released in Binary Ninja 5.2. The initial implementation has a couple of limitations:objc_retain_x1and friends that take their only argument in a specific register.Addressing both of these requires more sophisticated IL rewriting in order to ensure that the argument to the function call being removed still ends up being available for the return value. For arm64 the first argument and result register are the same so we get away with replacing the call itself with a nop. This will need to be replaced by an explicit assignment of the first argument, whatever its location may be, to the result register.
Support for x86_64 also requires matching a wider range of LLIL patterns.