Shared library in D on Linux

[Jacob Carlborg]

On 2012-04-08 10:45, "Timo Westkämper" <timo.westkamper at gmail.com>" wrote:
> 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?

This is what I can think of for now:

* Proper initialization of TLS data
* Setting up exception handling tables
* Setting up module info

-- 
/Jacob Carlborg