[Feature] - FSBV - Foreign struct by value for callbacks

[theangelperalta]

Implement foreign structure by value for callbacks using libffi 's Closure API. An issue raised by: #285

Launchpad Details: #LP1828643 - Ekaterina Vaartis - 2019-05-10T23:43:44.225888+00:00

[zacque0]

Hi, I'm new to both CFFI and GitHub.

How can I help with this PR? Because I need this functionality to work. Currently, my use-case is writing a CFFI library with libclang.so, which has something like:

typedef struct {
  enum CXCursorKind kind;
  int xdata;
  const void *data[3];
} CXCursor;

typedef enum CXChildVisitResult (*CXCursorVisitor)(CXCursor cursor,
                                                   CXCursor parent,
                                                   CXClientData client_data);

CINDEX_LINKAGE unsigned clang_visitChildren(CXCursor parent,
                                            CXCursorVisitor visitor,
                                            CXClientData client_data);

As you can see, invoking clang_visitChildren requires a callback passing struct by value.

[theangelperalta]

@zacque0, I don't believe this PR needs anymore work (yet I open it while ago, 6 months ago). However, I have yet to receive feedback from any of the maintainers.

[theangelperalta]

Hey everyone, can I get some feedback on this PR? cc: @stassats, @sionescu, @attila-lendvai?

[attila-lendvai]

sorry, but i'm not active in CL nowadays, so it would be quite some effort for me to test/review this.

[theangelperalta]

sorry, but i'm not active in CL nowadays, so it would be quite some effort for me to test/review this.

@attila-lendvai, thanks for the quick response and honesty. It seems like @luismbo is the main maintainer of the project. I'll have to wait for feedback from him.