On Saturday, 14 March 2020 at 20:53:45 UTC, Abby wrote:
I would like to export some functions from my bettec dll for
dotnet core application in windows.
Right now I have compiled dll using dmd v2.091.0-dirty simply
by ´dub build´
this is the function I have
extern(C) char* test_echo(const(char)* line, size_t len, ref
size_t resLen)
{
enum format = "{\"message\": \"%s\"}\n";
auto response = cast(char*)malloc(format.length + len);
resLen = sprintf(response, format, line);
return response;
}
and this is my dotnet core equivalent
[DllImport(DllName, CallingConvention =
CallingConvention.StdCall)]
static extern IntPtr
test_echo([MarshalAs(UnmanagedType.LPStr)]string line, ulong
len, out ulong resLen);
This works for me in linux but does not in windows, any idea
what I'm doing wrong?
For one thing, you're defining it with stdcall in dotnet, but
cdecl in the code. You should change the convention on the dotnet
side to CallingConvention.Cdecl. Or, if you really want to use
stdcall, use extern(System) in D -- the equivalent of
extern(Windows) on Windows and extern(C) everywhere else.
Also, I would expect you'd have to use export [1] on the D side
for the symbol to be loadable from the dll:
extern(C) export char* test_echo(...) { ... }
This should be the equivalent of __declspec(dllexport) for C and
C++ on Windows.
[1] https://dlang.org/spec/attribute.html#visibility_attributes
(Item #7)
