Replace cflow_function.json with a database

[lks9]

This should be more stable and more performant than the current way. Needs some work in instrumenter.py and retrace.py. There is a nice tutorial on databases with python here: https://vegibit.com/how-to-use-a-database-in-python/

The easiest option would be a sqlite database (which is also just a file). Then we need to have some argument/paramater for the instrumenter and retrace if you want to specify an alternate location for the database file.

Requires:

8

[ducorduck]

i can't continue with the #3 because of the dependency so i'll try to do this. how should we structure the database? Is just 1 table for the hex_list enough?

[lks9]

Sorry for keeping quiet so long. Yes one table with num, file, line, name should be enough to start.

1) The num should be a unique key. 2) We also need to lookup the num from file + line + name. But for that we don't need a separate table. 3) (optional) In the json there is also pre_file plus offset. This can be a useful info for manual look-up. Since one num can have multiple pre_files, this should be saved to a separete table with num, pre_file, offset. In that table, the combination pre_file plus offset would be unique.

[ducorduck]

i don't quite get why one num can have multiple pre_file? And also should i normalize it to 3NF?

[lks9]

If you compile

foo.c (including somelib.h) bar.c (including somelib.h)

and somelib.h contains some function definition, say

static inline int h(void) {
    return 0;
}

then you get the h function both in the pre-processed foo.i and in bar.i with different offsets. However, the file would still correspond to somelib.h with line inside somelib.h. And the num should be for both function copies in foo.i and bar.i the same.

3NF normalization: I think the result should be 2 tables if the optional part with num, pre_file and offset is takes a separate table.

[lks9]

Thank you very much, it got already merged!

I made two change suggestions in the pull request. So I leave this issue open until they are dealed with.