Improving ipsw class-dump

[rgoldberg]

Is there any way for ipsw class-dump to generate headers that have more-precise argument & return types?

Does your own code extract & decompile headers from the DSC, or does ipsw use libraries or tools? (I assume the latter, because "why reinvent the wheel?"). If the latter, what libraries and/or tools does ipsw use so I can look into configuring them?

The main issues I've seen so far are:

1. It would be nice to replace id types with more specific types.
   • Is it not possible to get extract specific types than id?
   • Or is it possible, but just not yet implemented?
2. It seems like BOOL would be nicer than _Bool since the former is supposedly from Objective-C, while the latter is from C99 (maybe there's a reason to prefer _Bool in some or all circumstances, but I don't know, as I', programming in Swift, not in Objetive-C, C, or C++)

e.g.:

ipsw class-dump /System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_arm64e --headers CommerceKit --output /tmp/CommerceKit

Outputs CKSoftwareMap.h with:

+ (id)sharedSoftwareMap;

While a file generated with the obsolete class-dump tool on macOS 10.14.4 (I think) has the following (the file might have been manually modified, though, since I only have it from a repo, I don't exactly know if it was ever edited before being committed by someone else years ago):

+ (instancetype)sharedSoftwareMap;

Thanks.

[blacktop]

it is all pure Go written by myself. the older class-dump was also written by scratch but in objc I think, but the metadata is limited in what Apple actually includes, so for example the only info that apple encodes for the return value IS literally id or void * essentially so there's no way to know what it is, sometimes you can guess that it's returning an instant of the class but those heuristics are all brittle and not a good solution if accuracy is needed

[rgoldberg]

@blacktop

It looks like parameter/argument types are also just id in the headers, so I assume they are also just id in the binaries, too (you only mentioned return types, but I assume you also meant to include parameter/argument types, too).

I'll try to get in touch with the person who generated the headers I have to find out if they manually modified them, or if class-dump was somehow able to determine the types.

Thanks for all the info, and for ipsw.