Is there a way to change a type definition using API?

[saruman9]

I have a type definition for example:

>>> old_t = [t for t in bv.types if "std::__cxx11::string" == '::'.join(t[0].name)][0]
>>> old_t
('std::__cxx11::string', <type: immutable:NamedTypeReferenceClass 'typedef std::__cxx11::string'>)

Yes, it's a cycle type (typedef std::__cxx11::string std::__cxx11::string;), but it's a example. I don't use get_type_by_name method, because it's don't work for C++ types.

I tried to change the type definition:

>>> t = [t for t in bv.types if "std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >" == '::'.join(t[0].name)][0]
>>> t
('std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >', <type: immutable:StructureTypeClass 'class'>)
>>> new_t = NamedTypeReferenceType.create_from_type("std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >", type = t[1])
>>> new_t
<type: immutable:NamedTypeReferenceClass 'class std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >'>
>>> bv.define_type(old_t[1].type_id, "std::__cxx11::string", new_t)
'std::__cxx11::string'

But nothing happens. If I will undefine std::__cxx11::string using UI, than Binary Ninja will crash (segmentation fault).

How I can change a type definition using API?

[fuzyll]

Here's the documentation for that: https://docs.binary.ninja/guide/type.html#type-modification

But, you should never get a crash from undefining a type. I'm going to turn this into an issue to track that crash.

[saruman9]

I have already tried to modify the type definition using mutable_copy, but I don't know how I can modify typedef, because neither NamedTypeReferenceBuilder nor TypeBuilder has the needed methods.

[fuzyll]

Yep, you're right - we're missing those in the API and will need to expose them. Thanks for pointing it out! The issue is #3014 and we'll track progress in there. Sorry for the issue.

EDIT: Re-marking this as answered because it will be the right answer once we fix the issue.