Fix extern "C" prototype generation

[facchinm]

Adds extern "C" as function modifier
Probably needs some testing for regressions (although the unit test are all passing)
Fixes #126
@igrr
arduino-builder-pr128.zip

[igrr]

Thanks! Is there a way to get an OS X binary of arduino-builder for this pull request, or should I build from source?

[facchinm]

I'm adding the build for all OS right now 😄

[leodesigner]

Hi,
The extern declaration like this is still not working:

extern "C" { 
  void test() {}
}

sketch_oct06a:12: error: previous declaration of 'void test()' with 'C++' linkage
   void test() {}
      ^
sketch_oct06a:12: error: conflicts with new declaration with 'C' linkage
   void test() {}
             ^
exit status 1
previous declaration of 'void test()' with 'C++' linkage

It used to work before in arduino version before 1.6.9

[facchinm]

Hi @leodesigner , the declaration spanning 2 lines is triggering the bug (again). I'm reopening the relevant bug. Thanks for reporting