Creating __shifted pointers

[vient]

This is a question rather than an issue.

Like in #33, question is about new functionality added in IDA 7.2, shifted pointers. While they resemble CONTAINING_RECORD macro which you use(?) in core/negative_offsets.py, Hex-Rays claims that shifted pointers are more powerful. I thought you might be interested in this feature.

I also want to note some quirks of shifted pointers: when you use them as seen in example and you take some other int from structure, Hex-Rays would likely show it as myptr[42], not expected ADJ(myptr)->some_other_int. I tried some tweaks to pointer type like _UNKNOWN *__shifted(mystruct,20) myptr; but failed to get consistent use of ADJ with complex structures with lots of members of different types. Maybe you will be more successful.

[igogo-x86]

Actually I didn't work a lot with negative offsets, is it really that much of improvement? What the difference I see is that __shifted is the same as CONTAINING_RECORD but shorter and with offset rather than filed name. Implementing this doesn't not requires much changing in my code by the way and I could do it. But I think CONTAINING_RECORD gives more information and that information is not that useless.