Is there a way to rename the undefined1, undefined2, undefined4, undefined8 types?

[mrexodia]

Is there a way to rename these types?

I'd like them to be called uint8_t, uint16_t etc (or even IDA-style BYTE, WORD, DWORD).

[dev747368]

No, you can't rename built-in types. You can create an alias / typedef of them with whatever name you want.

[mrexodia]

In that case, is there perhaps a way to make the decompiler automatically use my typedefs per default?

And thanks a lot for the quick answer!

[dev747368]

generally, the decompiler will use the data types that have been assigned in the listing, either the function parameters or the type of a static variable.

[emteere]

The undefined datatypes are used to note an access of a size without knowing the real type, or the existence of a parameter without locking in the type. They are really placeholder types. The decompiler is free to propagate a type and replace the undefined with a good type for all undefined types. In addition, undefined types defined in memory can be replaced with a more specific type by algorithms.

If the decompiler were to use uint8_t, that could be incorrect as the type might be signed. It all depends on the access. The decompiler will try to replace the type with a correct type based on the access or use. Absent any other type information than a size, especially when accessing through an unknown pointer type, the decompiler will display undefined. If the pointer points to a structure or class, the decompiler is more likely to use uint, char, byte, etc... as the type for local variables and parameters.

There is a setting to disable type casts, which could help improve default display if you don't specify types for parameters which you could try as well.

[mrexodia]

Thanks for the detailed explanation!