How to mass set data type in scalar search in Ghidra?

Question

In Ghidra, I have an ARM9 binary that in many places stores hard-coded pointers to the same struct at the same location in RAM.

022308c8 a0 9f 23 02     undefined4 02239FA0h
...
02233290 a0 9f 23 02     undefined4 02239FA0h
...
02233838 a0 9f 23 02     undefined4 02239FA0h

I can easily find all/most references to that struct by doing a scalar search (Search > For Scalars...) and I would like to change the data type of all of those matches to be my_struct*.

In some cases there are too many pointers to the same RAM location to manually change the data type of each within a reasonable amount of time (ex. 1200+ pointers).

Is there any way to have Ghidra automate changing the data types of all of those matching hard-coded pointers?

Answer 1

You can automate that by using createData and getDataTypes methods from Ghidra API.

Something like that should do the trick:

ptr_type = getDataTypes("my_struct*")[0] 
# getDataTypes returns an array so we pick the first one

for addr in range(0x022308c8,02233838,4):
    createData(toAddr(addr), ptr_type)

It will work if there's nothing defined for those bytes already. If there are you need to clear that with clearListing.