IDA Pro - Applying function signatures

Question

I have three files:

1. ELF executable,
2. ELF dynamically linked library (.so),
3. C headers file (.h) with function signatures and related structures for that library.

#1 imports a number of functions from #2.

Is there a way for me to leverage #3 to automatically apply signatures from #3 to:

1. Imports in #1 in one instance of IDA?
2. Exports in #2 in another instance of IDA?

Answer 1

There are several functions in the SDK, in typeinf.hpp or ida_typeinf.py that could be of use here, with the python API being much easier to use.

• parse_decls - for converting a header file to a til_t type library.
  • this function seems to skip plain function declarations.
  • but does store typedefs by name.
• parse_decl - for converting a single declaration to a tinfo_t object.
  • this does work for function declarations, but loses the function name.
• get_named_type - for looking up a type in the til_t.
• apply_type - for applying a type to a function.

So you could either parse the name from the function declaration yourself, and then use parse_decl to parse each declaration seperately.

Or you could add typedef to the start of each declaration, so ida will store all your declarations, by name in a type libary.

Answer 2

Try using File -> Load File -> Parse C Header File (Ctrl+F9). You might need to tweak some things in the header file.