Is Kotlin/Native essentially Kotlin's JNI API? Will it be used only for C interoperability or does it have constructs to write pure native code with Kotlin? Do native operations bear the same overhead as JNI calls?
Kotlin/Native is compiled to pure native code and runs without a JVM. There is no extra overhead for function calls in Kotlin/Native.
Kotlin native uses a LLVM (Low Level Virtual machine) to compile to native binaries.
It is independent of JVM. It doesn't need or use JVM.
You can't use Java System Libraries that haven't been implemented in native or Kotlin.
It also runs on IOS and pretty much everywhere a compiled C and C++ or Objective C binaries can run.
You can call C and Objective C libraries from Kotlin.
However Kotlin Native as of Novemeber 2017 can't build Shared libraries.
Source: https://github.com/JetBrains/kotlin-native/blob/master/FAQ.md
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We build and deploy a dynamic framework targeting iOS that contains Objective-c code. It consumes a "core" (our terminology) static library that contains C/C++ code. But we only consume it through the C interfaces. We do not have any Objective-C++ that we use to consume any of the internal C++ interfaces, and none of the C++ API is exposed through headers. It's all straight Objective-C in our framework consuming and linking in a static library through pure C headers and a C interface.
We are wondering if it is safe to consume the "core" static library if we build it with an older version of Xcode (LLVM). And if so, is it safe even for major version differences of compiler or minor only?
thanks
So I'm having the following problem:
I have an MEMS board that runs on FreeRTOS and includes gyro, accelerometer and magnetometer.
I cannot change any existing code (All in C).
Now I have a basic motion detection library written in C++ and I extended this library with some functions (All in C++).
I thought I can just use a C++ compiler and compile everything but I'm getting hundreds of errors.
I found some solution how to use C functions inside C++ but I don't know how to use C++ functions (or libraries) inside C.
Is there a feasible way? Can I somehow wrap all my C++ code in an easy way?
I'm using Keil uvision to compile the code for my embedded system in case that is important.
There are a few differences between C and C++ that may make a compiler stumble over some of the code. See for example the wikipedia page on this topic.
I'd suggest that you split your project into two projects, one being the RTOS and application in C, the other being the motion detection library. Then you have to write a C wrapper around your C++ library API. Here's a good SO post on writing a C wrapper for C++ code.
Then you would have to link your RTOS + application project to your library, which you compiled in your other uVision project.
I require zlib library for the development of Windows Store app.
Has anyone converted Win32 zlib project to WinRT yet?
Can anyone please describe the steps to convert the existing win32 static lib project to winRT?
Visual C++ is already a supported language for WinRT development, if you wan't to use zlib, just compile it together with your solution. There is nothing that is preventing you from reusing standard ISO C and C++ libraries from within the WinRT, if you are using the C++ language, you might have to expose certain aspects of your library as WinRT Components but only if you need to interface with facilities like XAML or other WinRT languages but that should be a walk in the park. Not something which is tremendously difficult to do.
The whole point of supporting C++ in the WinRT is to allow an existing ecosystem of largely native applications to be ported to the Windows Store. zlib is not an exception. Non-standard ISO C and C++ such as sockets are not supported but there you have alternatives that you can plug-in to, just check that the library you're using has some kind of portability support.
WinRT is very limited with regards to C library functions which are present. What this means is that virtually all cross-platform C libraries are (AFAIK, I'm not a WinRT dev) unusable for that target.
For the case of zlib, there is an alternative: see this question
EDIT: to clarify what I'm saying above, I dug up a list of all CRT functions that are absent for WinRT, which you can find here. As long as zlib or any other C library does not depend on these function calls, you should be able to use the WinRT tools to build that C library. I even found a project file for zlib on winrt by the Ogre team here, not sure how useful it is to you.
You could take a look into this WinRT (Un)Zip component. Its used in production code already.
See the unit tests inside on how to use the component. It compiles on all WinRT architectures including ARM. It has no custom asm for ARM though.
Is there a C++ "port" of .NET library, in the sense that the library class and methods correspond? At least some of them? Like System.Xml, System.Net?
You can have a mixed code solution whic contains pure c++ code and c++ cli code. Assuming of course that you are interested only in windows os.
I have a C++ dll file that uses a lot of other c++ librarys (IPP, Opencv +++) that I need to load into matlab. How can I do this?
I have tried loadlibrary and mex. The load library does not work.
The mex finds the linux things (platform independent library) and tries to include them. And that does not work.
Does anyone have any good ideas?
loadlibrary should work. I use it all the time to call functions from dlls written in C++ with C wrappers.
What errors are you getting when you try to use loadlibrary?
Make sure that the exported functions of the dll are C functions, not C++ functions. If not, then write C wrappers.
More info on exactly what you are doing when using loadlibrary would be helpful.
As mentioned by others, you should first wrap your C++ library as a C library - mathworks used to advise not to use C++ code directly in mex (dlopening C++ core directly is complicated), maybe it is still true.
Your description is quite unclear, too: what do you mean by "mex finds the linux thing", but that does not work. Saying that it does not work is not helpful: the exact commands and error message are.
You could go for the Java approach (since Matlab runs on a JRE and can access Java objects/methods -- just be aware that the Matlab JRE is not as up-to-date as the latest JRE, the one I'm running uses Java 1.5) and use JNA to access your DLL.
Or, if you wrote the top-level DLL, you could go for the COM/ActiveX approach.
I've had good success architecting the interface to my C++ functions as COM/ActiveX libraries -- you don't have to bother with that .h stuff.
See the External Interfaces guide on COM clients, particularly the part about managing/converting data.
It would be extra work to add the COM/ActiveX layer, but would make your library more portable within the Windows world and probably more easily used in MATLAB.
If you have a lot of function calls to your DLL, the COM/ActiveX approach might be faster (not sure), but otherwise I think the JNA approach would be easier.