python generator for capi interface stubs

[schachmat]

Heyho,

here is a python script for automatic implementation of the cef capi interface as listed in the TODO section of README.md. Some remarks:

• works not with the old cef version you are using, but with current one (2272)
• the pycparser fake includes have to be copied (I can also add them to the pullreq, if you want)
• mkdir cef/stubs has to be run
• my version of refcounting is implemented in cef/base.[ch] If you find errors, let me know
• script has to be called with one argument (e.g. the supplied gen.c file) and then iterates through all structs in this compilation unit after preprocessing. The main_linux.c could also be used as argument, then only the used structs from include/capi/ are generated to cef/stubs/
• To change the code of a stub, just copy it to cef/, change it there and built with your new version instead of the stub.
• Note: automatically release()-ing the refcounts on parameters supplied to functions is not implemented yet, but maybe soon to come.

I wrote this mainly because I want to use the C api from cef and documentation seems rare. The http://code.google.com/p/chromiumembedded/wiki/UsingTheCAPI page could also be updated with this refcounting example, if it indeed is implemented correctly (works so far for me).

--schachmat

[cztomczak]

Thanks schachmat. Will test it at the earliest opportunity.

Did you test it on Windows? I don't think pthread.h is available on Windows.

I think that the generator should also automate creation of the gen.c file.

[schachmat]

I did not test it on windows, since I have no windows machine and also have no idea how to do thread locking with windows.

So I propose that implement_interface.py takes one arg which is the path to the include/capi folder, automatically generates the gen.c file which includes all headers from the capi.

For the automatic release()-ing of refcounts, I think a first pass through the struct visitor should work: In the first pass I remember all struct names, which start with a cef_base_t*, in the second pass when generating the function stubs, I check every argument to a function if it has a pointer to one remembered struct as type and if yes, I add a RDEC(argument_name) call before the return.

[schachmat]

I updated my branch to automatically generate the gen.c file as you requested.

[cztomczak]

Updated to CEF branch 3029 and created Issue #5.