Xamarin.Mac And C++
I am trying using C++ library (.a) in Visual Studio for Mac (a.k.a. Xamarin) I've found online some info on linking native libraries in Xamarin (https://developer.xamarin.com/guides/ios/advanced_topics/native_interop/) but it seems outdated since Visual Studio for Mac is out.
I uploaded both project to https://github.com/dawmster/XamarinAndCpp
Contents
- MyCppLib - XCode project producing libMyCppLib.a
- XamarinMacApp - Visual Studio For Mac solution
- libMyCppLib.a - that is a product of MyCppLib, XamarinMacApp references it.
What is ok
MyCppLib compiles fine and produces libMyCppLib.a
I intended to export only two C functions (my_C_Function, my_second_C_Function - MyCppLib.cpp) but I am unable to strip other sybols - which seems to be root of the problem
extern "C" {
int my_C_Function();
int my_second_C_Function();
}
In XamarinMacApp libMyCppLib.a is referenced (added to solution). And my_C_Function is called in AppDelegate.cs as follows:
using System.Runtime.InteropServices;
namespace XamarinMacApp
{
[Register("AppDelegate")]
public class AppDelegate : NSApplicationDelegate {
public AppDelegate(){}
[DllImport("__Internal")]
static extern int my_C_Function();
public override void DidFinishLaunching(NSNotification notification)
{
int myretval = my_C_Function();
}
public override void WillTerminate(NSNotification notification)
{
// Insert code here to tear down your application
}
}
}
What's not ok
XamarinMacApp - does not compile with following error :
Notice that C functions ( my_C_Function, my_second_C_Function is not listed in error below).
It seems only C++ Standard Library cannot be linked.
Full Visual Studio Mac compiler log.
Undefined symbols for architecture x86_64:
"std::__1::locale::use_facet(std::__1::locale::id&) const", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::ios_base::getloc() const", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(unsigned long, char)", referenced from:
l007 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()", referenced from:
l007 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::put(char)", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::flush()", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::sentry(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)", referenced from:
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::~sentry()", referenced from:
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::cout", referenced from:
l002 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::ctype<char>::id", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::locale::~locale()", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::ios_base::__set_badbit_and_consider_rethrow()", referenced from:
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::__1::ios_base::clear(unsigned int)", referenced from:
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"std::terminate()", referenced from:
l008 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"operator delete(void*)", referenced from:
l001 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"operator new(unsigned long)", referenced from:
l001 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"___cxa_begin_catch", referenced from:
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l008 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"___cxa_end_catch", referenced from:
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
"___gxx_personality_v0", referenced from:
l004 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l005 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
l007 in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
Dwarf Exception Unwind Info (__eh_frame) in libMyCppLib.a(libMyCppLib.a-x86_64-master.o)
ld: symbol(s) not found for architecture x86_64
clang : error : linker command failed with exit code 1 (use -v to see invocation)
MMP : error MM5109: Native linking failed with error code 1. Check build log for details.
Done building target "_CompileToNative" in project "XamarinMacApp.csproj" -- FAILED.
Done building project "XamarinMacApp.csproj" -- FAILED.
Any ideas how to move forward?
