I'm trying to learn how Kotlin Native works with this tutorial from JetBrains: https://kotlinlang.org/docs/tutorials/native/interop-with-c.html
But these tutorials are only fro macOS and Linux. Sometimes i use a windows computer and i want to know how it works there.
How can i add the libcurl library in windows and how can i add it to the libcurl.def file?
It isn't explained anywhere.
You need to install MSYS2, then in MSYS2 console install libcurl:
$ pacman -S mingw-w64-x86_64-curl
See https://github.com/JetBrains/kotlin-native/pull/1499
A more detailed step-by-step explanation on how to use dynamically built libcurl (aka DLL) with Kotlin/Native.
https://jonnyzzz.com/blog/2018/10/29/kn-libcurl-windows/
I do not think it is covered somewhere right now. The idea is still the same, and you should be able to make it work. The first step is to download and build libcurl locally from https://curl.haxx.se/libcurl/. There are instructions and documentation on how to build it. I do recommend to pick the Windows own implementation for SSL.
Once you are done with building you will have both the includes and the library. Note, on Windows, you will always have a static library. Even if you build curl as a dynamic library (DLL), you will have a generated static library that you use for linking. DLL is easier to build and use. A true static library is better because you will have no dependencies in your Kotlin/Native program binary. At that point, the tutorial instructions should work.
For Windows, if you need only basic HTTP communication, you can also try WinINet API which is a part of Windows and so no dependency is necessary. No hassle with the libcurl library.
See my example of how to use WinInet API with Kotlin MPP: https://github.com/localazy/kotlin-mpp-wininet
For macOS and Linux, instead of going through the hassle with libcurl manually, just use ktor clients: https://ktor.io/clients/index.html
I'm studying Kotlin too and it took many hours until I realize how to handle def file, includes and static library.
I made an example of how to use static library (curl with gzip and SSL support compiled with mingw) on kotlin-native. This way you dont need to dll files to be supplied with your app
https://github.com/carlosrafp/Libcurl-Kotlin-Native-standalone
On libcurl.def file you can see:
headers = curl/curl.h // path to curl header
libraryPaths = src/nativeInterop/cinterop // path to your static library
staticLibraries = libcurl.a // the static library
linkerOpts.mingw = -lws2_32 -lwldap32 // linking dependences
I based on the nice post of jonnyzzz:
https://jonnyzzz.com/blog/2018/10/29/kn-libcurl-windows/
Related
It's said that library authors should ship their library with a config-file instead of a plain find-module.
Basically config-file are to be installed with the associated library on the system and can be used transparently by the user, whereas find-module is written by the user by his own when he finds out that the library hasn't any config-file.
But, what if I'm sure that my library will never be installed?
I'm doing embedded system development and it doesn't make much sense to install my static libraries on the system.
Different modules are organized as static libraries and handled by each project with git submodules.
Is there any way I can use config-files even in this scenario? Or, as library author, I should write a example of vanilla Find-module and say to client code "Take and copy this to your CMAKE_MODULE_PATH"?
Or maybe just tell the client code cmake to call add_subdirectory?
I have a npapi plugin(bundle) for chrome, which use C++ and objective-c. now it needs to be build by google native client.
I wonder that can nacl support objective-c? how to compile o-c file by MakeFile
And if possible, how to build nacl plugin in Xcode? I tried, but i found that the libraries of nacl are " archive with no architecture specification".(use lipo -info *.a)
I hope someone to help me, thanks a lot!!!
If you use Objective-C without any of its usual libraries then you should be able to use the PNaCl toolchain (which is based on LLVM) to have it parse Objective-C. I'm not aware of projects that have done this, so you should definitely let folks on the mailing list know if you get something working (do keep the questions on SO, though!).
It sounds like your application won't be running on the open web (where only architecture-independent PNaCl can run, not NaCl), so you could either use the PNaCl toolchain to create a .pexe, or you could use the same toolchain to create a .nexe for each architecture you target. The documentation I linked to helps with both approaches, but note that using the PNaCl toolchain to create a .nexe is currently being improved. You can therefore follow the instructions on the bug tracker, or try out nacl-clang when it's released (or build it yourself if you're brave).
I have compiled shared libraries dynamically linked against libstdc++.so using GLIBCXX_3.4.11. I want to send my code to someone whose stdc++ library is only of version 3.4.10. Rather than ask him to update his library version (this is a software customer, so I can't assume they'll be willing or able to change system files) I would like to ship the appropriate version of libstdc++.so, placed in a lib folder with the directory location of my code. How do I get my own code to use the appropriate (later) version? I find that /etc/ld.so.conf includes the directory /lib64, where an offending older version of libstdc++.so resides. Setting LD_LIBRARY_PATH does not override this. This seems to deviate from the advertised behavior. Any idea why this is happening? How do I complete my rather simple task?
Thanks.
I understand that this question is old, but I found it while trying to sort out my own linking trouble which was similar. You will have to build your program against a version of libstdc++ which is compatible with your colleague's version of the library. The easiest solution, of course, is to link against his version of the library so he doesn't need to make special tweaks on his side to link your library.
To do this, you will want to install a version of GCC which can build binary compatible libraries so you can actually link against his version of libstdc++. GLIBCXX_3.4.11 is from gcc-4.4 and later, so you will need gcc-4.3. Build your program using this and you should be in good shape.
You can consult the following page for a list of library ABI compatabilities:
http://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html
You could also build an rpm/deb which requires the version of libstdc++ you already have and if it's not available, refuse to install. This gives you a bit of an interface which gives him a promise that if his system is setup with the correct dependencies, he can use your library. In that sense, it's like a loose SLA for your library in what you do and don't support.
Hope that helps!
How can I know, whether an external library can be compiled to work on a different platform? the library for instance is tesseract-ocr
And if it possible, how do I do this?? (Basically I would like to create a Qt application that uses this library)
To find out, try building the library yourself. At the moment your question is quite broad. Post new questions when you have something more specific to ask.
If building the library fails, it is most probably due to some unsupported dependencies that you need to port first yourself.
Porting to Maemo is probably straightforward as it is a Debian-based environment and supports all the build tools such as autotools.
Symbian doesn't have autotools. Perhaps the fastest way to get started there is to first configure and build the library on e.g. cygwin and then generate the required bld.inf and .mmp files to build it on Symbian.
You can link your Qt application to regular C/C++ libraries. Just include the necessary header files in your code and link to the library using LIBS += -lfoo in your .pro file.
I am writing an Apache module for my internship. I am using C for this (I am not acquainted with Perl or Python that much).
I need to use an HTML Parser to solve the problem for which I am writing this module. I am considering libxml2 for this purpose.
I am confused how should I link the library in my module ? Should I link the library while compiling the module OR Should I use the LoadFile directive in the configuration file to load the library.
My main concern is that while I am developing this on Ubuntu, but I don't know what will be the OS running on the deployment server. So I want its deployment, complications free and successful.
EDIT: #Grim: thanks for replying :)
I compiled the module with the following commands:
apxs -I /usr/include/libxml2/ -c mod_xmltest.c
sudo apxs -n xmltest_module -i mod_xmltest.la
I believe this does not link the libraries in the module, I was getting "Unresolved Symbols" error when starting the server, so I used the LoadFile directive to load libxml2 library. It seems to work.
Do you think there can be any issues this way? I think this makes my module more portable, as on the deployment server the admin can explicitly specify the location of the libxml2 library.
You should link the library while compiling your module.
There are of course the usual portability issues (at least then it comes to a non-posix OS). In this case some of them are solved by apxc. It's impossible to say which complications that might occur, but nothing of what you describe should cause any.