On 2012-09-28 01:21, Rob T wrote:
For me to get C or C++ to run a D function, I had to do the following:
// ====================
// C/C++ library source
// ====================
// sample D function from library
void foo(int i, int j, int k);
// D runtime initialization & shutdown
void init();
void done();
void bar()
{
foo(6, 7, 8);
}
int main(int argc, char **argv)
{
init();
bar();
done();
return 0;
}
// ================
// D library source
// ================
import std.stdio;
static import core.runtime;
// sample D function for test
extern (C++) // int foo(int i, int j, int k)
void foo(int i, int j, int k)
{
writefln("i = %s", i);
writefln("j = %s", j);
writefln("k = %s", k);
int t = i + j + k;
writefln("Total = %s", t);
}
// Had to initialize and shutdown D system from C/C++.
extern (C++) export void init() { // to be called once after loading
shared lib
core.runtime.Runtime.initialize();
}
extern (C++) export void done() { // to be called before unloading
shared lib
core.runtime.Runtime.terminate();
}
// I had to include main even though this is a library.
int main()
{
return 0;
}
That is not sufficient to have everything work. It might be ok if you
limit yourself to a C subset of D. On some platforms, calling
Runtime.initialize, will miss initializing some parts.
The implementation of the runtime initialization contains a lot of code
duplication and some functions/branches are missing functionality. Example:
https://github.com/D-Programming-Language/druntime/blob/master/src/rt/dmain2.d#L346
The C main function handles the runtime initialization for a regular
statically linked executable. If you initialize the runtime via
"rt_init", which is called by "Runtime.initialize", it will miss to
initialize some parts on some platforms. The C main function should
really call "rt_init" to remove the code duplication.
Also see this post why everything will not properly work:
http://forum.dlang.org/thread/k3vfm9$1tq$1...@digitalmars.com?page=3#post-k4219f:24uft:241:40digitalmars.com
--
/Jacob Carlborg
