Shared library in D on Linux

[Timo Westkämper]

I am still testing which setup gives me reliable shared D 
libraries which can be used from C.

Here is my latest test:
* test.d:
import std.stdio;
extern (C) {
  void hiD() {
    writeln("hi from D lib");
  }
}

* main.c
#include <stdio.h>
#include <dlfcn.h>
#include <stdlib.h>
void main() {
    void (*hiD)(void);
    void* handle = dlopen("./libtest.so", RTLD_LAZY);
    if (handle == NULL) {
        printf("%s\n", dlerror());
        exit(1);
    }   
    hiD = dlsym(handle, "hiD");
    if (hiD != NULL) {
        hiD();
    } else {
        printf("hiD is null\n");
    }
    dlclose(handle);
}

* Makefile
#!/bin/bash
test:
        #gdc-4.6 -g -c test.d -fPIC -o test.o
        #gdc-4.6 -shared -o libtest.so -fPIC test.o -lc -nostartfiles
        dmd -g -c test.d -fPIC
        ld -shared -o libtest.so test.o -lrt -lphobos2 -lpthread
        gcc -g main.c -ldl -lpthread
        ./a.out
clean:
        rm -rf *.so *.o *.out

With this setup I get

  ./libtest.so: undefined symbol: _deh_beg

With a fake main method added I get

  make: *** [test] Segmentation fault

This is what I get from gdb

  Program received signal SIGSEGV, Segmentation fault.
  0xb7fd1ed3 in std.stdio.__T7writelnTAyaZ.writeln() 
(_param_0=...) at   /usr/include/d/dmd/phobos/std/stdio.d:1550
  1550      enforce(fprintf(.stdout.p.handle, "%.*s\n",

Event with the following startup hooks

extern(C) {

  void gc_init();
  void gc_term();

  void _init() {
    gc_init();
  }

  void _fini() {
    gc_term();
  }

}

I get the same error. I am using dmd 2.058 on Ubuntu 11.10 (32 
bit)

With gdc I get different errors, but it seems even more difficult 
to get it working.

Does anyone know what is missing to get proper shared library 
support working on Linux?