Using struct_layout for introspection

[yairlenga]

I came across this plugin, while looking for way to implement introspection like functionality for large code. Found it very elegant/compact. Interested to know if there is any activity here/follow-up project. In particular, trying to see if possible to implement this in such a way that the generated output will be embedded into the code. Something like

struct foo_bar { ... } *p;

const char *my_desc = structureof(*p) // or structureof(struct foo_bar)
print_struct (my_desc, p) ;

Which will automatically include members.

Ideally, the generate string will be easily decoded in "C" program, leading to easy implementation of print_struct_struct, read_struct, .... Thinking forward, this can be used to implement ORM - automatically read from SQL select and populate data structure, and the other way around. For RDB, document DB's. ...

[Jongy]

Hi @yairlenga !
I did not continue developing this project, what you see in this GitHub repository is all that I have on it.

About your question - the generated output can't be embedded into the code (as in, the "C code") because it runs in a relatively late stage, where there's no more "code".

The output can be embedded into the binary GCC is building, and then it can be used for reflection purposes like you suggest.
This plugin processes types defined by GCC and outputs information about them to a file. Instead, it could emit the information into the compilation unit, as binary code or as variables, accessible to the program. For example, per defined struct you could emit a static const structure which defines the declared struct type, it can contain its name & array of fields. Your program could then access that object in runtime and read the fields / offsets etc. I worked on another GCC plugin, actually, which not only processes GCC events in read-only but also emits some events back so they end up in the compiled binary. It could provide you some examples.

[yairlenga]

Seems like the path that worth exploring. Is the asset plugin running before or after the structure layout logic. Is it possible for it to create code with static data, that will be filled later (in the structure_layout) ?