• xoxo (39/39) May 21 Hello, I am loading a library built with dmd on linux, but when I
• kinke (7/8) May 21 This is the problem - you're casting the address to an
• xoxo (2/11) May 26 Thanks, it now works, I didn't know we could set it that way

xoxo <xororwr gmail.com> writes:

Hello, I am loading a library built with dmd on linux, but when I 
call other functions, the arguments order is reversed

I understand calling convention from C/D is different, but 
shouldn't the compiler handle that automatically? if not, then 
that sounds like a bug?



```sh
LD_LIBRARY_PATH="."

dmd -of=mylib.so -shared -betterC -fPIC -version=DLL app.d
dmd -of=app -betterC -fPIC app.d && ./app
```

```D
import core.stdc.stdio;
import core.sys.posix.dlfcn;

extern(C) void main()
{
     // load library and symbols
     auto lib = dlopen("mylib.so", RTLD_NOW | RTLD_DEEPBIND);
     auto fn_test = cast(void function(int, int)) dlsym(lib, 
"test");

     assert(lib);
     assert(fn_test);

     int a = 1;
     int b = 2;

     tick(a,b); // prints 1 2  ✅

     // call the loaded symbol, it'll then call `tick`
     fn_test(a,b); // prints 2 1 ❌
}

void tick(int a, int b)
{
     printf("%d %d\n", a, b);
}

version (DLL)
extern(C) export
void test(int a, int b)
{
     tick(a, b);
}
```

Thanks

kinke <noone nowhere.com> writes:

On Wednesday, 21 May 2025 at 08:09:23 UTC, xoxo wrote:
 auto fn_test = cast(void function(int, int)) dlsym(lib, "test");

This is the problem - you're casting the address to an 
`extern(D)` function pointer. Use something like this:
```
alias Fn = extern(C) void function(int, int);
auto fn_test = cast(Fn) dlsym(lib, "test");
```

xoxo <xororwr gmail.com> writes:

On Wednesday, 21 May 2025 at 10:43:17 UTC, kinke wrote:
 On Wednesday, 21 May 2025 at 08:09:23 UTC, xoxo wrote:
 auto fn_test = cast(void function(int, int)) dlsym(lib, 
 "test");

 This is the problem - you're casting the address to an 
 `extern(D)` function pointer. Use something like this:
 ```
 alias Fn = extern(C) void function(int, int);
 auto fn_test = cast(Fn) dlsym(lib, "test");
 ```

Thanks, it now works, I didn't know we could set it that way