IDA decompiler comments

# Author Robert Michel - Posted on March 22, 2019
# source:  https://github.com/GDATAAdvancedAnalytics/IDA-Python/blob/master/Trickbot/stringDecryption.py#L104
# article: https://cyber.wtf/2019/03/22/using-ida-python-to-analyze-trickbot/

def setCommentToDecompilation(address, comment):
    #Works in IDA 6.9 (worked fine in IDA 7.5 - dz)
    #see https://www.hex-rays.com/products/decompiler/manual/sdk/hexrays_8hpp_source.shtml used structures, const and functions
    cfunc = idaapi.decompile(address)
    
    #get the line of the decompilation for this address
    eamap = cfunc.get_eamap()
    decompObjAddr = eamap[address][0].ea

    #get a ctree location object to place a comment there
    tl = idaapi.treeloc_t()
    tl.ea = decompObjAddr
    
    commentSet = False
    #since the public documentation on IDAs APIs is crap and I don't know any other way, we have to brute force the item preciser
    #we do this by setting the comments with different idaapi.ITP_* types until our comment does not create an orphaned comment
    for itp in range(idaapi.ITP_SEMI, idaapi.ITP_COLON):
        tl.itp = itp    
        cfunc.set_user_cmt(tl, comment)
        cfunc.save_user_cmts()
        #apparently you have to cast cfunc to a string, to make it update itself
        unused = cfunc.__str__()
        if not cfunc.has_orphan_cmts():
            commentSet = True
            cfunc.save_user_cmts()
            break
        cfunc.del_orphan_cmts()

    if not commentSet:
        print("[ERROR] Please set "%s" to line %s manually" % (comment, hex(int(address))))