[swift-dev] Proof-of-concept port of Swift for Android

[Joe Groff]

> On Dec 11, 2015, at 7:13 AM, Douglas Gregor via swift-dev <swift-dev at swift.org> wrote:
> 
> 
>> On Dec 11, 2015, at 4:33 AM, Geordie Jay via swift-dev <swift-dev at swift.org> wrote:
>> 
>> Hi, maybe one of the Apple devs can help out with this quick Q:
>> 
>> To interface with the JNI, we’d presumably need to call swift functions from our compiled swift binaries from C (or directly from Java, the result being the same). Is there a way to demangle certain symbols in the output binary to this effect, or is there another / a better way to access Swift functions from C?
> 
> Others can probably give a more detailed response, but...
> 
> There’s a Swift demangler in Swift’s “Basic” library (lib/Basic/Demangle.cpp), along with a standalone tool (swift-demangle) you can experiment with. The information in the mangled name should be complete enough to call, but you’ll need to match Swift’s calling convention.
> 
> If it’s just a specific set of Swift functions you want to call from C, you can use the @_silgen_name attribute to override the mangled name, and/or make them @convention(c) to use the C calling convention.

@_silgen_name isn't the right answer here, since the convention will be wrong, and it won't interact properly with Clang imports and exports. Like Slava said, you want something like the '@_cdecl' attribute he proposed and I half-implemented.

-Joe