• bitwise (70/70) Apr 21 2015 Hello!
• Dan Olson (10/13) Apr 21 2015 Hi, I think both examples need libstdc++ added when you link
• bitwise (42/55) Apr 22 2015 Awesome, Thanks!

bitwise <bitwise.pvt gmail.com> writes:

Hello!

I am trying to interface to C++, and getting linker errors. Below are my 3  
source files and 2 build scripts with their associated errors. Can anyone  
see what I'm doing wrong?


/////////////////  test.cpp
#include <stdio.h>

class Test {
public:
	virtual void Foo(){
		printf("Foobar\n");
	}
};

Test* CreateTest() {
	return new Test;
}

void DestroyTest(Test *test) {
	delete test;
}

/////////////////  Test.d
module TestMod;

extern(C++) {
	interface Test {
		void Foo();
	}

	Test CreateTest();
	void DestroyTest(Test test);
}

/////////////////  main.d
module main;
import TestMod;

void main(string[] args)
{
	Test test = CreateTest();
	test.Foo();
	DestroyTest(test);
	test = null;
}

/////////////////  script1.sh
clang++ test.cpp -olibTest.o -c -emit-llvm
ar rcs libTest.a libTest.o
ldc2 main.d Test.d libTest.a -ofTest

Error:
Undefined symbols for architecture x86_64:
   "___Z10CreateTestv", referenced from:
       __Dmain in main.o
   "___Z11DestroyTestP4Test", referenced from:
       __Dmain in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see  
invocation)
Error: /usr/bin/gcc failed with status: 1


/////////////////  script2.sh
g++ test.cpp -olibTest.o -c
ar rcs libTest.a libTest.o
dmd main.d Test.d libTest.a -ofTest

Error:
Undefined symbols for architecture x86_64:
   "vtable for __cxxabiv1::__class_type_info", referenced from:
       typeinfo for Test in libTest.a(libTest.o)
   NOTE: a missing vtable usually means the first non-inline virtual member  
function has no definition.
   "operator delete(void*)", referenced from:
       DestroyTest(Test*) in libTest.a(libTest.o)
   "operator new(unsigned long)", referenced from:
       CreateTest() in libTest.a(libTest.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see  
invocation)
--- errorlevel 1

 

Dan Olson <zans.is.for.cans yahoo.com> writes:

bitwise <bitwise.pvt gmail.com> writes:
 I am trying to interface to C++, and getting linker errors. Below are
 my 3 source files and 2 build scripts with their associated
 errors. Can anyone see what I'm doing wrong?

Hi, I think both examples need libstdc++ added when you link
(-L-lstdc++).  That should resolve the missing C++ operators.

For script1.sh with ldc2 I see an extra underscore in C++ mangled names.
You must be on OS X.  ldc was just fixed in merge-2.067 branch to remove
an extra underscore on OS X.  If you want to experiment, you can build
https://github.com/ldc-developers/ldc/tree/merge-2.067 and check it out.
There are still a few tests to reolve, but it works pretty well for me.
--
Dan

bitwise <bitwise.pvt gmail.com> writes:

On Wed, 22 Apr 2015 02:14:40 -0400, Dan Olson <zans.is.for.cans yahoo.com>  
wrote:

 bitwise <bitwise.pvt gmail.com> writes:
 I am trying to interface to C++, and getting linker errors. Below are
 my 3 source files and 2 build scripts with their associated
 errors. Can anyone see what I'm doing wrong?

 Hi, I think both examples need libstdc++ added when you link
 (-L-lstdc++).  That should resolve the missing C++ operators.

 For script1.sh with ldc2 I see an extra underscore in C++ mangled names.
 You must be on OS X.  ldc was just fixed in merge-2.067 branch to remove
 an extra underscore on OS X.  If you want to experiment, you can build
 https://github.com/ldc-developers/ldc/tree/merge-2.067 and check it out.
 There are still a few tests to reolve, but it works pretty well for me.
 --
 Dan

Awesome, Thanks!

I am now getting the expected error from clang/LDC, and the GCC/DMD build  
is working. I'll probably switch to LDC at some point, but I just need to  
get up and running right now.

My updated(objective-C++) and working code:

///////////////// test.mm
#include <stdio.h>
#import <Foundation/Foundation.h>

 interface XYZPerson : NSObject
- (void)sayHello;
 end

 implementation XYZPerson
- (void)sayHello {
     printf("Hello, World!\n");
}
 end

class Test {
public:
	virtual void Foo(){
		XYZPerson *person = [[XYZPerson alloc] init];
		[person sayHello];
		[person release];
	}
};

Test* CreateTest() {
	return new Test;
}

void DestroyTest(Test *test) {
	delete test;
}

/////////////////  Test.d
same

/////////////////  main.d
same

///////////////// script2.sh
g++ test.mm -olibTest.o -c -stdlib=libc++
ar rcs libTest.a libTest.o
dmd main.d Test.d libTest.a -ofTest -L/usr/lib/libc++.dylib -L-framework  
-LFoundation
./Test