Re: Exec function D from C++

[Sean Campbell via Digitalmars-d-learn]

On Sunday, 21 June 2015 at 13:12:03 UTC, MGW wrote:

Linux 32, dmd 2.067.0

I want to connect and execute function D from main() C++.

---- d1.d ----
import core.stdc.stdio;

extern (C++) void d1() {
    printf("printf - exec d1()");
}

---- main_c1.cpp ----
#include <stdio.h>

void d1(void);

int main(void) {
    d1();
    return 0;
}

---- compile ----
dmd -c d1.d
gcc main_c1.cpp d1.o libphobos2.a -lpthread -o main_c1
./main_c1  --->  This option works correctly!

If I try to cause the functions connected to GC in the D function, there is an error.

---- d1.d ----
import import std.stdio;

extern (C++) void d1() {
    writeln("writeln - exec d1()");
}

---- compile ----
dmd -c d1.d
gcc main_c1.cpp d1.o libphobos2.a -lpthread -o main_c1
./main_c1  --->  Error:

'./main_c1' terminated by signal SIGSEGV (Address boundary error)

Examples from dmd2/html/d/dll-linux.html don't work if instead of printf() to use writeln(). I think that a problem in initialization of Phobos.

actually its that druntime hasn't been initialized just add:
import core.runtime;
import std.stdio;

extern(C++) void d1() {
     writeln("writeln - exec d1()");
}

extern(C++) void d_initialize() {
     Runtime.initialize();
}
extern(C++) void d_terminate()
{
     Runtime.terminate();
}

and the C++
#include <stdio.h>

void d1(void);
void d_initialize(void);
void d_terminate(void);

int main(void) {
    d_initialize();
    d1();
    d_terminate();
    return 0;
}