Resync IDA Local Types

README.md

Resync Local Types in IDA

Sometimes there's some inconsistency between local types and structs view.

Typically, you can see the type in the "Structures" view are zero-lengthed, which should normally be the same size as local type's one.

When this happens, you'll not be able to rename the structure fields in HexRay Decompiler's view, and both hotkey N and right-clicking the item won't show the rename popup.

After reverse engineering the hexx64.dll, I found that IDA tries to do the following things:

if (vd->item->get_memptr()) { /* Add the rename handler */ }

and in get_memptr(), it's doing:

const char *name = expr->x->type.get_type_name()
struc_t *struc = get_struc(get_struc_id(name))
member_t *member  = get_member(struc, expr->m)

After debugging, it seems that name and struc can be retrieved, but member are not. Replaying the operations in IDAPython also fails.

I thought it's because that IDA didn't import the type correctly last time, so I wrote the script above to fix it.

resync_local_types.py

def is_autosync(name, tif):
    return idaapi.get_ordinal_from_idb_type(name, tif.get_decltype().to_bytes(1, 'little')) != -1

for ord in range(1, idaapi.get_ordinal_qty(None)):
    t = idaapi.tinfo_t()
    t.get_numbered_type(None, ord)
    typename = t.get_type_name()
    #print('Processing struct %d: %s' % (ord, typename))
    if typename.startswith('#'):
        continue
    
    autosync = is_autosync(typename, t)
    print('Processing struct %d: %s%s' % (ord, typename, ' (autosync) ' if autosync else ''))
    idaapi.import_type(None, -1, typename, idaapi.IMPTYPE_OVERRIDE)
    if autosync:
        continue
    struc = idaapi.get_struc(idaapi.get_struc_id(typename))
    if not struc:
        continue
    struc.ordinal = -1
    idaapi.save_struc(struc, False)